Min Wang

To characterize somatic alterations in colorectal carcinoma, we conducted a genome-scale analysis of 276 samples, analysing exome sequence, DNA copy number, promoter methylation and messenger RNA and microRNA expression. A subset of these samples (97) underwent low-depth-of-coverage whole-genome sequencing. In total, 16% of colorectal carcinomas were found to be hypermutated: three-quarters of these had the expected high microsatellite instability, usually with hypermethylation and MLH1 silencing, and one-quarter had somatic mismatch-repair gene and polymerase ε (POLE) mutations. Excluding the hypermutated cancers, colon and rectum cancers were found to have considerably similar patterns of genomic alteration. Twenty-four genes were significantly mutated, and in addition to the expected APC, TP53, SMAD4, PIK3CA and KRAS mutations, we found frequent mutations in ARID1A, SOX9 and FAM123B. Recurrent copy-number alterations include potentially drug-targetable amplifications of ERBB2 and newly discovered amplification of IGF2. Recurrent chromosomal translocations include the fusion of NAV2 and WNT pathway member TCF7L1. Integrative analyses suggest new markers for aggressive colorectal carcinoma and an important role for MYC-directed transcriptional activation and repression.

Structural variants are implicated in numerous diseases and make up the majority of varying nucleotides among human genomes. Here we describe an integrated set of eight structural variant classes comprising both balanced and unbalanced variants, which we constructed using short-read DNA sequencing data and statistically phased onto haplotype blocks in 26 human populations. Analysing this set, we identify numerous gene-intersecting structural variants exhibiting population stratification and describe naturally occurring homozygous gene knockouts that suggest the dispensability of a variety of human genes. We demonstrate that structural variants are enriched on haplotypes identified by genome-wide association studies and exhibit enrichment for expression quantitative trait loci. Additionally, we uncover appreciable levels of structural variant complexity at different scales, including genic loci subject to clusters of repeated rearrangement and complex structural variants with multiple breakpoints likely to have formed through individual mutational events. Our catalogue will enhance future studies into structural variant demography, functional impact and disease association. The Structural Variation Analysis Group of The 1000 Genomes Project reports an integrated structural variation map based on discovery and genotyping of eight major structural variation classes in 2,504 unrelated individuals from across 26 populations; structural variation is compared within and between populations and its functional impact is quantified. The Structural Variation Analysis Group of The 1000 Genomes Project reports an integrated structural variation map based on discovery and genotyping of eight major structural variation classes in genomes for 2,504 unrelated individuals from across 26 populations. They characterize structural variation within and between populations and quantify its functional effect. The authors further create a phased reference panel that will be valuable for population genetic and disease association studies.

Pancreatic cancer is a highly lethal malignancy with few effective therapies. We performed exome sequencing and copy number analysis to define genomic aberrations in a prospectively accrued clinical cohort (n = 142) of early (stage I and II) sporadic pancreatic ductal adenocarcinoma. Detailed analysis of 99 informative tumours identified substantial heterogeneity with 2,016 non-silent mutations and 1,628 copy-number variations. We define 16 significantly mutated genes, reaffirming known mutations (KRAS, TP53, CDKN2A, SMAD4, MLL3, TGFBR2, ARID1A and SF3B1), and uncover novel mutated genes including additional genes involved in chromatin modification (EPC1 and ARID2), DNA damage repair (ATM) and other mechanisms (ZIM2, MAP2K4, NALCN, SLC16A4 and MAGEA6). Integrative analysis with in vitro functional data and animal models provided supportive evidence for potential roles for these genetic aberrations in carcinogenesis. Pathway-based analysis of recurrently mutated genes recapitulated clustering in core signalling pathways in pancreatic ductal adenocarcinoma, and identified new mutated genes in each pathway. We also identified frequent and diverse somatic aberrations in genes described traditionally as embryonic regulators of axon guidance, particularly SLIT/ROBO signalling, which was also evident in murine Sleeping Beauty transposon-mediated somatic mutagenesis models of pancreatic cancer, providing further supportive evidence for the potential involvement of axon guidance genes in pancreatic carcinogenesis.

Liver cancer has the second highest worldwide cancer mortality rate and has limited therapeutic options. We analyzed 363 hepatocellular carcinoma (HCC) cases by whole-exome sequencing and DNA copy number analyses, and we analyzed 196 HCC cases by DNA methylation, RNA, miRNA, and proteomic expression also. DNA sequencing and mutation analysis identified significantly mutated genes, including LZTR1, EEF1A1, SF3B1, and SMARCA4. Significant alterations by mutation or downregulation by hypermethylation in genes likely to result in HCC metabolic reprogramming (ALB, APOB, and CPS1) were observed. Integrative molecular HCC subtyping incorporating unsupervised clustering of five data platforms identified three subtypes, one of which was associated with poorer prognosis in three HCC cohorts. Integrated analyses enabled development of a p53 target gene expression signature correlating with poor survival. Potential therapeutic targets for which inhibitors exist include WNT signaling, MDM4, MET, VEGFA, MCL1, IDH1, TERT, and immune checkpoint proteins CTLA-4, PD-1, and PD-L1.

Whole-exome sequencing is a diagnostic approach for the identification of molecular defects in patients with suspected genetic disorders.We developed technical, bioinformatic, interpretive, and validation pipelines for whole-exome sequencing in a certified clinical laboratory to identify sequence variants underlying disease phenotypes in patients.We present data on the first 250 probands for whom referring physicians ordered whole-exome sequencing. Patients presented with a range of phenotypes suggesting potential genetic causes. Approximately 80% were children with neurologic phenotypes. Insurance coverage was similar to that for established genetic tests. We identified 86 mutated alleles that were highly likely to be causative in 62 of the 250 patients, achieving a 25% molecular diagnostic rate (95% confidence interval, 20 to 31). Among the 62 patients, 33 had autosomal dominant disease, 16 had autosomal recessive disease, and 9 had X-linked disease. A total of 4 probands received two nonoverlapping molecular diagnoses, which potentially challenged the clinical diagnosis that had been made on the basis of history and physical examination. A total of 83% of the autosomal dominant mutant alleles and 40% of the X-linked mutant alleles occurred de novo. Recurrent clinical phenotypes occurred in patients with mutations that were highly likely to be causative in the same genes and in different genes responsible for genetically heterogeneous disorders.Whole-exome sequencing identified the underlying genetic defect in 25% of consecutive patients referred for evaluation of a possible genetic condition. (Funded by the National Human Genome Research Institute.).

<h3>Importance</h3> Clinical whole-exome sequencing is increasingly used for diagnostic evaluation of patients with suspected genetic disorders. <h3>Objective</h3> To perform clinical whole-exome sequencing and report (1) the rate of molecular diagnosis among phenotypic groups, (2) the spectrum of genetic alterations contributing to disease, and (3) the prevalence of medically actionable incidental findings such as<i>FBN1</i>mutations causing Marfan syndrome. <h3>Design, Setting, and Patients</h3> Observational study of 2000 consecutive patients with clinical whole-exome sequencing analyzed between June 2012 and August 2014. Whole-exome sequencing tests were performed at a clinical genetics laboratory in the United States. Results were reported by clinical molecular geneticists certified by the American Board of Medical Genetics and Genomics. Tests were ordered by the patient’s physician. The patients were primarily pediatric (1756 [88%]; mean age, 6 years; 888 females [44%], 1101 males [55%], and 11 fetuses [1% gender unknown]), demonstrating diverse clinical manifestations most often including nervous system dysfunction such as developmental delay. <h3>Main Outcomes and Measures</h3> Whole-exome sequencing diagnosis rate overall and by phenotypic category, mode of inheritance, spectrum of genetic events, and reporting of incidental findings. <h3>Results</h3> A molecular diagnosis was reported for 504 patients (25.2%) with 58% of the diagnostic mutations not previously reported. Molecular diagnosis rates for each phenotypic category were 143/526 (27.2%; 95% CI, 23.5%-31.2%) for the neurological group, 282/1147 (24.6%; 95% CI, 22.1%-27.2%) for the neurological plus other organ systems group, 30/83 (36.1%; 95% CI, 26.1%-47.5%) for the specific neurological group, and 49/244 (20.1%; 95% CI, 15.6%-25.8%) for the nonneurological group. The Mendelian disease patterns of the 527 molecular diagnoses included 280 (53.1%) autosomal dominant, 181 (34.3%) autosomal recessive (including 5 with uniparental disomy), 65 (12.3%) X-linked, and 1 (0.2%) mitochondrial. Of 504 patients with a molecular diagnosis, 23 (4.6%) had blended phenotypes resulting from 2 single gene defects. About 30% of the positive cases harbored mutations in disease genes reported since 2011. There were 95 medically actionable incidental findings in genes unrelated to the phenotype but with immediate implications for management in 92 patients (4.6%), including 59 patients (3%) with mutations in genes recommended for reporting by the American College of Medical Genetics and Genomics. <h3>Conclusions and Relevance</h3> Whole-exome sequencing provided a potential molecular diagnosis for 25% of a large cohort of patients referred for evaluation of suspected genetic conditions, including detection of rare genetic events and new mutations contributing to disease. The yield of whole-exome sequencing may offer advantages over traditional molecular diagnostic approaches in certain patients.

Agricultural production continues to be constrained by a number of biotic and abiotic factors that can reduce crop yield quantity and quality.Potassium (K) is an essential nutrient that affects most of the biochemical and physiological processes that influence plant growth and metabolism.It also contributes to the survival of plants exposed to various biotic and abiotic stresses.The following review focuses on the emerging role of K in defending against a number of biotic and abiotic stresses, including diseases, pests, drought, salinity, cold and frost and waterlogging.The availability of K and its effects on plant growth, anatomy, morphology and plant metabolism are discussed.The physiological and molecular mechanisms of K function in plant stress resistance are reviewed.This article also evaluates the potential for improving plant stress resistance by modifying K fertilizer inputs and highlights the future needs for research about the role of K in agriculture.

Abundantly expressed in fetal tissues and adult muscle, the developmentally regulated H19 long noncoding RNA (lncRNA) has been implicated in human genetic disorders and cancer. However, how H19 acts to regulate gene function has remained enigmatic, despite the recent implication of its encoded miR-675 in limiting placental growth. We noted that vertebrate H19 harbors both canonical and noncanonical binding sites for the let-7 family of microRNAs, which plays important roles in development, cancer, and metabolism. Using H19 knockdown and overexpression, combined with in vivo crosslinking and genome-wide transcriptome analysis, we demonstrate that H19 modulates let-7 availability by acting as a molecular sponge. The physiological significance of this interaction is highlighted in cultures in which H19 depletion causes precocious muscle differentiation, a phenotype recapitulated by let-7 overexpression. Our results reveal an unexpected mode of action of H19 and identify this lncRNA as an important regulator of the major let-7 family of microRNAs.

Many genomes have been sequenced to high-quality draft status using Sanger capillary electrophoresis and/or newer short-read sequence data and whole genome assembly techniques. However, even the best draft genomes contain gaps and other imperfections due to limitations in the input data and the techniques used to build draft assemblies. Sequencing biases, repetitive genomic features, genomic polymorphism, and other complicating factors all come together to make some regions difficult or impossible to assemble. Traditionally, draft genomes were upgraded to "phase 3 finished" status using time-consuming and expensive Sanger-based manual finishing processes. For more facile assembly and automated finishing of draft genomes, we present here an automated approach to finishing using long-reads from the Pacific Biosciences RS (PacBio) platform. Our algorithm and associated software tool, PBJelly, (publicly available at https://sourceforge.net/projects/pb-jelly/) automates the finishing process using long sequence reads in a reference-guided assembly process. PBJelly also provides "lift-over" co-ordinate tables to easily port existing annotations to the upgraded assembly. Using PBJelly and long PacBio reads, we upgraded the draft genome sequences of a simulated Drosophila melanogaster, the version 2 draft Drosophila pseudoobscura, an assembly of the Assemblathon 2.0 budgerigar dataset, and a preliminary assembly of the Sooty mangabey. With 24× mapped coverage of PacBio long-reads, we addressed 99% of gaps and were able to close 69% and improve 12% of all gaps in D. pseudoobscura. With 4× mapped coverage of PacBio long-reads we saw reads address 63% of gaps in our budgerigar assembly, of which 32% were closed and 63% improved. With 6.8× mapped coverage of mangabey PacBio long-reads we addressed 97% of gaps and closed 66% of addressed gaps and improved 19%. The accuracy of gap closure was validated by comparison to Sanger sequencing on gaps from the original D. pseudoobscura draft assembly and shown to be dependent on initial reference quality.

Understanding soybean (Glycine max) domestication and improvement at a genetic level is important to inform future efforts to further improve a crop that provides the world's main source of oilseed. We detect 230 selective sweeps and 162 selected copy number variants by analysis of 302 resequenced wild, landrace and improved soybean accessions at >11× depth. A genome-wide association study using these new sequences reveals associations between 10 selected regions and 9 domestication or improvement traits, and identifies 13 previously uncharacterized loci for agronomic traits including oil content, plant height and pubescence form. Combined with previous quantitative trait loci (QTL) information, we find that, of the 230 selected regions, 96 correlate with reported oil QTLs and 21 contain fatty acid biosynthesis genes. Moreover, we observe that some traits and loci are associated with geographical regions, which shows that soybean populations are structured geographically. This study provides resources for genomics-enabled improvements in soybean breeding.

A 3D N-doped graphene foam with a 6.8 at% nitrogen content is prepared by annealing a freeze-dried graphene oxide foam in ammonia. It is used as an anode in sodium ion batteries to deliver a high initial reversible capacity of 852.6 mA h g-1 at 1 C between 0.02 and 3 V with a long-term retention of 69.7% after 150 cycles. Over the past several decades, lithium ion batteries (LIBs) have been successfully used as the rechargeable energy source of choice in various portable and smart devices (e.g., personal computers, cell phones, cameras, MP3 players) because of their high energy density and long lifetime.1 A continuously growing demand for them in large-scale applications, such as electric vehicles (EVs) and hybrid electric vehicles (HEVs), raises great concerns about the high cost ($5000/ton for lithium) and limited terrestrial reservation of lithium.2 Therefore, sodium ion batteries (SIBs), based on the earth-abundant inexpensive sodium ($150/ton for sodium) from the alkaline family, have recently attracted increasing attention as a low-cost alternative to LIBs. So far, there are a few anode materials have been identified for SIBs while a large number of potential cathode materials, including NaCrO2, Na0.44MnO2, NaV6O15, NaNi1/3Mn1/3Fe1/3O2, Na2/3[MxMn1−x]O2, NaMF3 (M = Fe, Mn, V, and Ni), NaFePO4, Na2MPO4F, and Na3M2(PO4)3 (M = Fe, Mn, Co, and Ni), were developed.[2],3 Consequently, one of the major critical issues for the development of high-performance SIBs is to identify suitable anode materials. Being earth-abundant, cost-effective, eco-friendly, thermally stable, and electrically conductive, carbon nanomaterials are considered to be one of the most promising candidates among the limited number of various anode materials for SIBs, including Na2Ti3O7, NiCo2O4, TiO2, Sn, P/C, and Li4Ti5O12.2-4 Nevertheless, the commonly-used commercial graphite anode has been demonstrated to show a low reversible capacity in SIBs (Table S1, Supporting Information).5 On the other hand, a variety of other carbon based materials (Table S1, Supporting Information), such as hard carbon,6 carbon black,7 cellulose and polyparaphenylene,8 petroleum coke,9 carbon spheres,10 porous carbon,11 carbon fibers,12 carbon nanotubes,13 and graphene,14 were found to facilitate the insertion/extraction of sodium ions into/from the host structures of SIBs. Recent research results indicate that the improvement of the electrochemical performance of SIBs strongly depend on the morphology and pore size of carbon materials at anodes.6, 10-14 Furthermore, heteroatom doping (e.g., N, B, S, and P) of carbon nanomaterials, including graphene, has been demonstrated to significantly enhance the electrical conductivity and surface hydrophilicity of carbon-based electrodes to facilitate the charge transfer and electrode–electrolyte interactions.15 In this regard, N-doped carbon nanomaterials have been explored as the anode materials for LIBs and SIBs.16,[11],[11],[12],[12] Examples include LIBs based on anodes from N-doped (3.06 at% nitrogen) graphene (a reversible capacity of >1040 mAh g−1 at a current density of 50 mA g−1 in the voltage range of 0–2 V),[16] N-doped porous carbon nanofibers (a capacity of ≈152 mAh g−1 with 88.6% capacity retention after 200 cycles at 200 mA g−1 in the voltage range of 0–2 V),[11] and N-doped porous carbon sheets (a highly reversible capacity of 349.7 mAhg−1 with ≈50% capacity retention after 260 cycles at 50 mA g−1 in the voltage range of 0–3 V).[12] The performance of other SIBs based on carbon anodes is summarized in Table S1 (Supporting Information). As can be seen, the carbon-based anodes in SIBs still suffer from a much lower capacity and rate capability with respect to LIB counterparts. As mentioned above, the morphology and pore size of carbon anodes play important roles in regulating the Na+ transport and storage in SIBs.6, 10-14 The use of carbon nanomaterials with a well-defined 3D morphology and pore size, in conjunction with heteroatom-doping, could lead to ideal anodes for SIBs with high performance. However, the potential use of 3D nanocarbon anodes for SIBs has hardly been investigated, though various 3D carbon electrodes with excellent charge/ion transport and mechanical properties in all dimensions have found applications in solar cells,17 supercapacitors,18 fuel cells,19 and even LIBs.20 In the present study, we prepared 3D N-doped graphene foams (N-GF) (Product 6 in Figure S1, Supporting Information) with a high 6.8 at% nitrogen content (elemental analysis shown in Table S2, Supporting Information) by annealing the freeze-dried graphene oxide foams (GOF) (Product 3, Figure S1, Supporting Information) in ammonia,17 and used them as the anode for SIBs. The use of the GOF (Product 3, Figure S1, Supporting Information) as a precursor for the post-synthesis annealing in ammonia allowed for a low-cost, large-scale production of 3D N-GF.17 For comparison, we have also prepared reduced graphene (rG) (1 → 2), nitrogen-doped graphene (N-G) (1 → 4), and reduced graphene foams (rGF) (1 → 3 → 5) (Figure S1, Supporting Information, for experimental details). Figure 1a shows Raman spectra of the N-G, rGF, and N-GF, all of which revealed the pronounced D and G bands at around 1349 cm−1 and 1592 cm−1, respectively. The N-GF sample exhibited the highest peak intensity ratio of the D to G band (ID/IG = 0.99) as compared to the corresponding ratios for the N-G (ID/IG = 0.94) and rGF (ID/IG = 0.83) because of the structural distortion induced by N-doping and the edge defects associated with the 3D foam-like structure. Both the N-doping and edge defects could enhance the electrocatalytic activity of the N-GF electrode.17, 21 X-ray diffraction (XRD) profiles for N-G, rGF, and N-GF are shown in Figure 1b. As can be seen, a characteristic (002) peak for graphitic carbon appeared at 26.1°, 26.1°, and 26.0° for the N-G, rGF, and N-GF, corresponding to a layer-to-layer distance (d-spacing) of 0.341, 0.341, and 0.342 nm, respectively. Compared to a d-spacing of 0.336 nm for conventional graphite, the observed larger d-spacing for the N-G, rGF, and N-GF samples is important for the insertion/extraction of relatively large sodium ions.22 Figure 1c displays the X-ray photoelectron spectroscopic (XPS) survey spectra of the N-G, rGF, and N-GF, which show a pronounced XPS C1s peak at about 285 eV for all of the three samples, along with a much weaker O 1s peak at 534 eV (2.8 at% for N-G, 3.2 at% for rGF, and 2.7 at% for N-GF). Upon doping with nitrogen to produce the N-G (5.4 at%) and N-GF (5.9 at%), the N1s peak appeared at about 400 eV (Figure 1c). High-resolution XPS C1s spectra of the rGF, N-G, and N-GF are presented in Figures S2b–d (Supporting Information), respectively (Figure 1d). These C1s XPS peaks can be deconvoluted into a dominated component for sp2-C at 284.5 eV, along with other weaker bands associated with sp3-C at 285.4 eV, C–N at 285.2 eV, and C–O at 285.9 eV, respectively.23 As shown in Figure 1e and Figure S2f d), the high resolution XPS N1s spectra of the N-GF and N-G can be deconvoluted into two peaks at 398.2 and 400.6 eV corresponding to the pyridinic nitrogen and pyrrolic nitrogen, respectively.17, 24 To examine the morphology of the materials studied, we performed scanning electron microscopy (SEM) and transmission electron microscopy (TEM) imaging. SEM images of the rG (Figure S3a, Supporting Information) and N-G (Figure S3b, Supporting Information) show mainly the “plate-like” graphene. By contrast, all of the foam samples, including the GOF (Figure S3c, Supporting Information), rGF (Figure S3d, Supporting Information), and N-GF (Figure S3e, Supporting Information, Figure 2a,b), exhibit a foam-like surface structure consisting of “flake-like” graphene sheets. A comparison of the higher magnification SEM image of the rG (Figure S3a2, Supporting Information) with that of rGF (Figure S3d2, Supporting Information) indicates that the foam sample possesses a more loosely packed graphitic sheets. Similar morphology difference was observed between the N-G (Figure S3b2, Supporting Information) and N-GF (Figure S3e2, Supporting Information), which could lead to a higher sodium ion storage in the foam-like electrode during discharge/charge processes. Figure 2c,d and Figure S4 (Supporting Information) show the corresponding TEM images for the N-G, rGF, and N-GF. The low magnification TEM images in Figure S4a1–a3 (Supporting Information) show that the N-G, rGF, and N-GF were all composed of transparent thin films with some thicker ripples, indicating a single and/or few layered wrinkled graphene sheets. The corresponding high resolution TEM images in Figure S4b1–b3 (Supporting Information) show largely amorphous structures for the N-G, rGF, and N-GF, which are also indicated by the diffused rings seen in the associated selected area electron diffraction (SAED) patterns (Figure S4c1–c3, Supporting Information). It seems that the partial crystallization of the amorphous GO starting materials resulted in the formation of small crystalline domains (cf. Figure 1b) interdispersed in the amorphous matrix; the latter showed up dominantly in the TEM images. The partial crystallization of N-GF was further confirmed by HRTEM (Figure S4d, Supporting Information). As can be seen, an estimated lattice spacing of 0.347 nm (i.e., 1.04/3 nm) in the crystalline domain is consistent with the XRD results, both indicating that the lattice spacing of the N-GF is larger than that of conventional graphite, which is important for the insertion/extraction of relatively large sodium ions. Besides, the partially crystalline domains could enhance the charge transport and stabilize the foam-like amorphous carbon matrix during the discharge–charge process. The stable 3D matrix would provide additional sites for sodium storage without volume expansion, and hence enhanced storage capacity and cycling performance.[11],[12],14,[16],[16] Figure 3a reproduces the discharge/charge profiles for the N-G, rGF, and N-GF at 0.2 C in the voltage range of 0.02–3 V, which shows two apparent plateaus in the first discharge process for all of the three samples. Note that the second discharge plateau at around 0.1 V for the N-GF is longer as compared to those for the rGF and N-G within the first cycle, indicating a larger amount of sodium ions have inserted into the N-GF during the discharge process. This phenomenon was also confirmed by cyclic voltammetry (CV) measurements. As shown in Figure S5b,d,f (Supporting Information), a strong cathodic peak was observed for the N-G (C1), rGF (C3), and N-GF (C5) electrodes at around 0.7 V, corresponding to the first discharge plateaus in the first discharge curves shown in Figure 3a. These pronounced peaks were generated from the electrolyte decomposition, leading to the formation of the solid electrolyte interphase (SEI) films on the surfaces of the graphene electrodes. However, the intensity of the second cathodic peak of the N-GF electrode recorded at around 0.1 V (C6) was much higher than those recorded for the rGF (C4) and N-G (C2), which is consistent with the longer second discharge plateau seen in Figure 3a. The electrolyte decomposition for the SEI formation in our SIBs occurred at about 0.7 V, which is very close to the equivalent values for certain LIBs[16],[16] and SIBs based on N-doped carbon nanofibers.[11] In the subsequent discharge cycles, the cathodic peaks (C1, C3, and C5) for the N-G, rGF, and N-GF, respectively, disappeared (Figure S5b,d,f, Supporting Information) due to the presence of the dense SEI films formed during the first discharge cycle. During the charge process, however, the two anodic peaks (A5 and A6) at around 0.97 and 0.75 V for the N-GF became stronger during the subsequent cycles (Figure S5f, Supporting Information), whereas the relatively weak anodic peaks (A3 and A4) for the rGF (Figure S5d, Supporting Information) and (A1 and A2) for the N-G (Figure S5b, Supporting Information) further weakened to disappear in the following cycles. The presence of pronounced and highly overlapped anodic peaks could be attributed to the partial oxidation of Na-OX groups, which are generated from the interaction between sodium ions and oxygen containing functional groups during the discharge process. Therefore, the more highly reversible Na-OX redox reactions for N-GF than N-G and rGF indicate that the N-GF anode has a higher sodium ion insertion/extraction capability than the rGF and N-G in the SIBs. To test the rate and cycling performance, we charged and discharged SIB cells based on the N-G, rGF, and N-GF anodes for 50 cycles in the voltage range of 0.02–3 V from 0.2 to 10 C (Figure 3b, Supporting Information). As shown in Figure S6d (Supporting Information), the initial reversible capacities of the N-G and rGF are 717.4 and 836.2 mAh g−1 at 0.2 C, which are about 1.77 and 2.06 times that of the r-G (406.2 mAh g−1), respectively, and much higher than that of the GOF with 18.7 mAh g−1 (Figure S6b, Supporting Information). When the C rate was increased from 0.2 to 1 C, the N-G and rGF both still showed higher reversible capacity than that of the r-G (Figure S6d, Supporting Information). Thus, either the foam-like structure or N-doping could significantly improve the electrochemical performance. As expected, therefore, the N-GF exhibited much higher average charge capacities of 1057.1 (0.2 C), 943.5 (0.4 C), 815.2 (1 C), 467.1 (2 C), 244.7 (4 C), and 137.7 (10 C) mAh g−1 than those of 707.4 (0.2 C), 416.4 (0.4 C), 310.2 (1 C), 148.2 (2 C), 41.8 (4 C), and 10.3 (10 C) mAh g−1 for the N-G, and 809.4 (0.2 C), 423.3 (0.4 C), 348.7 (1 C), 178.3 (2 C), 51.0 (4 C), and 10.5 (10 C) mAh g−1 for the rGF (Figure 3b). As shown in Figure 3c, the charge capacity retention after 45 cycles at 10 C for N-GF (13%) was also higher than those for the NG (1.5%) and rGF (1.3%). Figure 3d shows the relatively long-term cycling performance for the N-G, rGF, and N-GF measured at 1 C in the voltage range of 0.02–3 V. As can be seen, the N-G, rGF, and N-GF exhibited the initial discharge/charge capacities of 1550.0/391.1, 1636.9/472.3, and 2000.5/852.6 mAh g−1 with an initial Coulombic efficiency of 25.6%, 28.8%, and 42.6%, respectively. The large capacity loss of the initial discharge/charge capacities is mainly attributed to the reductive decomposition of the electrolyte and the formation of a dense SEI film due to the large surface area, and irreversible reaction between sodium ions and the residual oxygen-containing functional group of the graphene.[10],[12],[12],[14] After 150 cycles, the N-G, rGF, and N-GF cells can deliver discharge/charge capacities of 161.1/160.1, 329.6/323.1, and 605.6/594.0 mAh g−1 with the initial capacity retention of 10.4%/40.9%, 20.1%/68.4%, and 30.3%/69.7%, respectively. In spite of the relatively low Coulombic efficiencies for the N-G, rGF, and N-GF in the first cycle, all electrodes exhibited a much higher average Coulombic efficiency of 97.9% for the N-G, 97.2% for the rGF, and 98.9% for the N-GF over 150 cycles. The higher discharge/charge capacities, capacity retention, and Coulombic efficiency observed for the N-GF than those of the N-G and rGF indicate, once again, that the N-GF anode has a better cycling performance with respect to the N-G and rGF electrodes. Moreover, as shown in Figure S7 (Supporting Information), the N-GF cell also exhibited a lower electrode polarization (≈65% capacity secured under 1.0 V over 150 cycles) than those of the N-G and rGF. To gain a better understanding of the observed superb electrochemical performance for the N-GF, nitrogen adsorption studies were performed. As shown in Figure 4a and Figure S8a1–d1 (Supporting Information), all adsorption isotherms for the rG, N-G, rGF, and N-GF show small hysteresis loops over the relative pressure range of 0.50–0.95. Insets in Figure 4a and Figure S8a2–d2 (Supporting Information) show the incremental pore size distributions calculated from the corresponding adsorption isotherms by using the density functional theory (DFT) method for slit-like pore geometry. These distributions indicate the presence of abundant mesopores (≈40 nm) in the samples. The BET specific surface areas for the rG, N-G, rGF, and N-GF samples are listed in Table S3 (Supporting Information), which shows the highest surface area of 357 m2 g−1 for the N-GF. The large surface area, together with the 3D mesoporous structure and N-doping-induced defects, makes the 3D N-GF favorable for the fast diffusion of the relatively large-sized sodium ions with a low ion-transport resistance and effective storage of sodium ions during discharge–charge processes.11, 16 Figure S9 (Supporting Information) shows the electrochemical impedance spectra (EIS) for the rG, N-G, rGF, and N-GF measured before cycling and after 3 cycles (Figure 4b). The Nyquist plot for each of the cells shows a semicircle with a large diameter at high frequencies before cycling. Upon cycling, the depressed two semicircles at high frequencies and medium frequencies suggest a new impedance formation and a decreased impedance after cycling due to the SEI formation and electrode/electrolyte activation. The kinetic parameters obtained from the equivalent circuit fitting are listed in Table S4 (Supporting Information). As can be seen in Table S4 (Supporting Information), the charge-transfer resistances (Rct) calculated by using the equivalent circuit model (Figure 4b) for all the samples are decreased after 3 discharge–charge cycles, attributable to the electrode–electrolyte activation in the initial cycles. Meanwhile, the Rct for all of the samples decreased in the same order before and after cycling, as exemplified by the order of rG (839.8 Ω), N-G (744.8 Ω), rGF (604.1 Ω), and N-GF (502.0 Ω) after 3 cycles, indicating the highest ionic conductivity for the N-GF. As shown in Figure 4c, our thermogravimetric analyses (TGA) and differential thermogravimetry (DTG) profiles further indicate that N-doping enhanced thermal stability of the N-GF and N-G, as exemplified by an increase in the decompression temperature from 564 °C for rGF to 584 °C for N-GF and 621 °C for N-G, probably due to the doping-induced reduction process.[16] The relatively low decomposition temperature for the N-GF (584 °C) with respect to that of the N-G (621 °C) suggests that the 3D graphene foam with a high surface area (Table S3, Supporting Information) in the N-GF sample is more susceptible to thermal decomposition. However, the “foam-like” 3D structure could act as a buffer to alleviate the volume expansion associated with excessive sodium intercalation, and hence improve the cycling life,[11],[12],[16],[16] leading to an overall high performance for the N-GF-based SIBs. Furthermore, as shown in Figure S10 (Supporting Information), the ex situ XRD of the N-GF electrode at different discharge voltages of 2.8 V (open circuit voltage), 0.9 V (SEI formation), 0.02 V (full discharge) indicated various degrees of sodiation in the graphene throughout the discharge process. In the charge process, there is no obvious XRD peak shift for the N-GF at 1.0 V with a complete amorphous feature at 3.0 V (full charge) without any distinct peaks, indicating a stable structure of the N-GF with an estimated volumetric capacity of 220 mAh cm−3 (Figure S11, Supporting Information). In summary, we have demonstrated, for the first time, that 3D N-GF can be used as anode to significantly improve the overall performance of SIBs. Specifically, we found that the 3D N-GF delivered an unusually high initial reversible capacity of 852.6 mAh g−1 at a current density of 1 C (1 C = 500 mA g−1) between 0.02 and 3 V. After 150 cycles, the N-GF could still maintain a charge capacity of 594 mAh g−1 with 69.7% retention of the initial charge capacity, significantly outperformed previously reported carbonaceous materials (Table S1, Supporting Information). The observed superb performance of the 3D N-GF anode in SIBs was attributed to synergistic effects associated with the 3D mesoporous structure with a well-defined porosity, large surface area, and enlarged lattice spacing between grapheme layers, coupled with the N-doping-induced defects, to facilitate the diffusion of the large-size sodium ions, enhance the storage of sodium ions, and minimize the effect of volume expansion during discharge–charge processes. This work clearly indicates that 3D carbon nanomaterials with well-defined structures and heteroatom-doping induced defects could be used as anode materials for the development of high-performance sodium ion batteries and other energy devices. The authors are grateful for financial support from AFOSR (Grant Nos. FA9550–12–1–0037 and FA-9550–12–1–0069), NSF (Grant Nos. NSF-CMMI-1000768, NSF-CMMI-1400274, and NSF-DMR-1106160), and Auto CRC 2020. The authors thank Dr. T. Silver for critical reading of the manuscript. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Glioblastomas (GBMs) are highly vascular and lethal brain tumors that display cellular hierarchies containing self-renewing tumorigenic glioma stem cells (GSCs). Because GSCs often reside in perivascular niches and may undergo mesenchymal differentiation, we interrogated GSC potential to generate vascular pericytes. Here, we show that GSCs give rise to pericytes to support vessel function and tumor growth. In vivo cell lineage tracing with constitutive and lineage-specific fluorescent reporters demonstrated that GSCs generate the majority of vascular pericytes. Selective elimination of GSC-derived pericytes disrupts the neovasculature and potently inhibits tumor growth. Analysis of human GBM specimens showed that most pericytes are derived from neoplastic cells. GSCs are recruited toward endothelial cells via the SDF-1/CXCR4 axis and are induced to become pericytes predominantly by transforming growth factor β. Thus, GSCs contribute to vascular pericytes that may actively remodel perivascular niches. Therapeutic targeting of GSC-derived pericytes may effectively block tumor progression and improve antiangiogenic therapy.

Abstract Multifunctional composite microspheres with spinel Fe 3 O 4 cores and anatase TiO 2 shells (Fe 3 O 4 @TiO 2 ) are synthesized by combining a solvothermal reaction and calcination process. The size, morphology, microstructure, phase purity, and magnetic properties are characterized by scanning electron microscopy, transmission electron microscopy (TEM), high‐resolution TEM, selected‐area electron diffraction, electron energy loss spectroscopy, powder X‐ray diffraction, and superconducting quantum interference device magnetometry. The results show that the as‐synthesized microspheres have a unique morphology, uniform size, good crystallinity, favorable superparamagnetism, and high magnetization. By varying the experimental conditions such as Fe 3 O 4 size and concentration, microspheres with different core sizes and shell thickneses can be readily synthesized. Furthermore, the microwave absorption properties of these microspheres are investigated in terms of complex permittivity and permeability. By integration of the chemical composition and unique structure, the Fe 3 O 4 @TiO 2 microspheres possess lower reflection loss and a wider absorption frequency range than pure Fe 3 O 4 . Moreover, the electromagnetic data demonstrate that Fe 3 O 4 @TiO 2 microspheres with thicker TiO 2 shells exhibit significantly enhanced microwave absorption properties compared to those with thinner TiO 2 shells, which may result from effective complementarities between dielectric loss and magnetic loss. All the results indicate that these Fe 3 O 4 @TiO 2 microspheres may be attractive candidate materials for microwave absorption applications.

We describe the landscape of somatic genomic alterations of 66 chromophobe renal cell carcinomas (ChRCCs) on the basis of multidimensional and comprehensive characterization, including mtDNA and whole-genome sequencing. The result is consistent that ChRCC originates from the distal nephron compared with other kidney cancers with more proximal origins. Combined mtDNA and gene expression analysis implicates changes in mitochondrial function as a component of the disease biology, while suggesting alternative roles for mtDNA mutations in cancers relying on oxidative phosphorylation. Genomic rearrangements lead to recurrent structural breakpoints within TERT promoter region, which correlates with highly elevated TERT expression and manifestation of kataegis, representing a mechanism of TERT upregulation in cancer distinct from previously observed amplifications and point mutations.

Significance The two pepper genomes together with 20 resequencing accessions, including 3 accessions that are classified as semiwild/wild, provide a better understanding of the evolution, domestication, and divergence of various pepper species and ultimately, will enhance future genetic improvement of this important worldwide crop.

A library of overlapping cDNAs obtained from Norwalk virus purified from stools of human volunteers (Jiang et al., 1990, Science 250, 1580-1583) was used to obtain the nucleotide sequence of the viral genome. The sequence has a total of 7642 nucleotides, excluding the 3' poly(A) tail, and has a base composition of 48% G + C. Three open reading frames (ORF) are predicted in the sequence. The longest ORF (ORF1, nucleotides (nt) 146 to 5359) is predicted to encode a polyprotein precursor to nonstructural proteins based on identification of sequences similar to the picornavirus 2C protein, 3C protease, and 3D RNA-dependent RNA polymerase. ORF2 (nt 5346 to 6935) is predicted to encode a polypeptide with a predicted molecular weight of 56,571 (56.6K, close to the expected size of the viral capsid protein), and it contains a short region of sequence similarity to the picornavirus structural protein VP3. A third potential ORF (nt 6938 to 7573) could encode a small polypeptide of 22.5K. The genomic organization found in Norwalk virus shares striking similarities with the genome of two caliciviruses, the feline calicivirus and the rabbit hemorrhagic disease virus. The morphology, size, polarity, and genomic organization of the Norwalk virus indicate it is a member of the Caliciviridae family.

The availability of low-cost, efficient, and durable catalysts for oxygen reduction reaction (ORR) is a prerequisite for commercialization of the fuel cell technology. Along with intensive research efforts of more than half a century in developing nonprecious metal catalysts (NPMCs) to replace the expensive and scarce platinum-based catalysts, a new class of carbon-based, low-cost, metal-free ORR catalysts was demonstrated to show superior ORR performance to commercial platinum catalysts, particularly in alkaline electrolytes. However, their large-scale practical application in more popular acidic polymer electrolyte membrane (PEM) fuel cells remained elusive because they are often found to be less effective in acidic electrolytes, and no attempt has been made for a single PEM cell test. We demonstrated that rationally designed, metal-free, nitrogen-doped carbon nanotubes and their graphene composites exhibited significantly better long-term operational stabilities and comparable gravimetric power densities with respect to the best NPMC in acidic PEM cells. This work represents a major breakthrough in removing the bottlenecks to translate low-cost, metal-free, carbon-based ORR catalysts to commercial reality, and opens avenues for clean energy generation from affordable and durable fuel cells.

Rationale: Chronic nonhealing diabetic wound therapy and complete skin regeneration remains a critical clinical challenge.The controlled release of bioactive factors from a multifunctional hydrogel was a promising strategy to repair chronic wounds.Methods: Herein, for the first time, we developed an injectable, self-healing and antibacterial polypeptide-based FHE hydrogel (F127/OHA-EPL) with stimuli-responsive adipose-derived mesenchymal stem cells exosomes (AMSCs-exo) release for synergistically enhancing chronic wound healing and complete skin regeneration.The materials characterization, antibacterial activity, stimulated cellular behavior and in vivo full-thickness diabetic wound healing ability of the hydrogels were performed and analyzed. Results:The FHE hydrogel possessed multifunctional properties including fast self-healing process, shear-thinning injectable ability, efficient antibacterial activity, and long term pH-responsive bioactive exosomes release behavior.In vitro, the FHE@exosomes (FHE@exo) hydrogel significantly promoted the proliferation, migration and tube formation ability of human umbilical vein endothelial cells (HUVECs).In vivo, the FHE@exo hydrogel significantly enhanced the healing efficiency of diabetic full-thickness cutaneous wounds, characterized with enhanced wound closure rates, fast angiogenesis, re-epithelization and collagen deposition within the wound site.Moreover, the FHE@exo hydrogel displayed better healing outcomes than those of exosomes or FHE hydrogel alone, suggesting that the sustained release of exosomes and FHE hydrogel can synergistically facilitate diabetic wound healing.Skin appendages and less scar tissue also appeared in FHE@exo hydrogel treated wounds, indicating its potent ability to achieve complete skin regeneration.Conclusion: This work offers a new approach for repairing chronic wounds completely through a multifunctional hydrogel with controlled exosomes release.

A series of nitrogen-containing polymer and carbon spheres were obtained by the sol–gel method. In particular, the nitrogen-rich carbon spheres were prepared by one-pot hydrothermal synthesis in the presence of resorcinol/formaldehyde as carbon precursors and ethylenediamine (EDA) as both a base catalyst and nitrogen precursor, followed by carbonization in nitrogen and activation with CO2. The introduction of EDA to the sol–gel system resulted in structurally bonded nitrogen-containing carbon spheres. The nitrogen doping level and the particle size can be tuned by varying the EDA amount in the reaction mixture. The maximum nitrogen doping level of 7.2 wt % in carbon spheres could be achieved without sacrificing the spherical morphology. The diameter of these carbon spheres (CS) can be tuned in the rage of 50–1200 nm by varying the EDA amount. N2 adsorption analysis showed that the aforementioned activated carbon spheres exhibited high surface area reaching up to1224 m2/g. Ultra high CO2 adsorption capacities, 4.1 and 6.2 mmol/g, corresponding to an equilibrium pressure of 1 bar, were measured on nitrogen-containing activated carbon spheres at 25 and 0 °C, respectively. Electrochemical measurements performed on these carbon spheres for double layer capacitors showed very high capacitance up to ∼388 F/g at 1.0 A/g, outstanding rate capability (60% capacitance retention at 100 A/g), and unprecedented cycling stability (∼98% capacitance retention even after 8000 cycles) in 1 M H2SO4 electrolyte solution.

Steel slag is the main waste product in the steelmaking process. Because of its chemical composition and technical properties, it can be reused as raw material in steel plants and can serve as a substitute for aggregates in civil engineering. In this paper, we reviewed steel slag treatment, recycling, and management in China. Although China’s annual slag production reached more than 100 million tons, its utilization rate is only 29.5%. As of 2016, more than 300 million tons of steel slag have not been used effectively. Large steel slag emissions are causing environmental problems for China. China’s steel slag utilization rate is low compared with that of industrial countries: the utilization rate is 98.4% in Japan, 87.0% in Europe, and 84.4% in the United States. Compared with other nations, China also has a gap in its usage of slag in road construction and agriculture. Although the Chinese government has been active in creating a legislative and institutional framework to realize effective steel slag treatment and recycling, these efforts are limited. Outdated treatment approaches is one of the reason for low utilization rate in China, most Chinese steel plants carry out the preliminary treatment (like family workshops) of steel slag, no one system can be used for all ferrous waste recovery, and 47% enterprises’ steel slag stability after treatment do not meet requirements of follow-up product. Road construction issues caused by high costs and policy limited, legal restrictions and lack of standard on agricultural applications are other two reasons for low utilization rate of steel slag. New policies are needed to improve utilization rates. We propose the concept of gradual utilization to promote the effective utilization of steel slag.

Deep neural networks have achieved remarkable performance in both image classification and object detection problems, at the cost of a large number of parameters and computational complexity. In this work, we show how to reduce the redundancy in these parameters using a sparse decomposition. Maximum sparsity is obtained by exploiting both inter-channel and intra-channel redundancy, with a fine-tuning step that minimize the recognition loss caused by maximizing sparsity. This procedure zeros out more than 90% of parameters, with a drop of accuracy that is less than 1% on the ILSVRC2012 dataset. We also propose an efficient sparse matrix multiplication algorithm on CPU for Sparse Convolutional Neural Networks (SCNN) models. Our CPU implementation demonstrates much higher efficiency than the off-the-shelf sparse matrix libraries, with a significant speedup realized over the original dense network. In addition, we apply the SCNN model to the object detection problem, in conjunction with a cascade model and sparse fully connected layers, to achieve significant speedups.

P-doped g-C₃N₄ has been successfully synthesized using hexachlorocyclotriphosphazene, a low cost and environmentally benign compound, as phosphorus source, and guanidiniumhydrochloride as g-C₃N₄ precursor, <italic>via</italic> a thermally induced copolymerization route.

One of the key enablers of future wireless communications is constituted by massive multiple-input multiple-output (MIMO) systems, which can improve the spectral efficiency by orders of magnitude. In existing massive MIMO systems, however, conventional phased arrays are used for beamforming. This method results in excessive power consumption and high hardware costs. Recently, reconfigurable intelligent surface (RIS) has been considered as one of the revolutionary technologies to enable energy-efficient and smart wireless communications, which is a two-dimensional structure with a large number of passive elements. In this paper, we develop a new type of high-gain yet low-cost RIS that bears 256 elements. The proposed RIS combines the functions of phase shift and radiation together on an electromagnetic surface, where positive intrinsic-negative (PIN) diodes are used to realize 2-bit phase shifting for beamforming. This radical design forms the basis for the world’s first wireless communication prototype using RIS having 256 two-bit elements. The prototype consists of modular hardware and flexible software that encompass the following: the hosts for parameter setting and data exchange, the universal software radio peripherals (USRPs) for baseband and radio frequency (RF) signal processing, as well as the RIS for signal transmission and reception. Our performance evaluation confirms the feasibility and efficiency of RISs in wireless communications. We show that, at 2.3 GHz, the proposed RIS can achieve a 21.7 dBi antenna gain. At the millimeter wave (mmWave) frequency, that is, 28.5 GHz, it attains a 19.1 dBi antenna gain. Furthermore, it has been shown that the RIS-based wireless communication prototype developed is capable of significantly reducing the power consumption.

SUMO-1 is an ubiquitin-related protein that is covalently conjugated to a diverse assortment of proteins. The consequences of SUMO-1 modification include the regulation of protein-protein interactions, protein-DNA interactions, and protein subcellular localization. At present, very little is understood about the specific mechanisms that govern the recognition of proteins as substrates for SUMO-1 modification. However, many of the proteins that are modified by SUMO-1 interact directly with the SUMO-1 conjugating enzyme, Ubc9. These interactions suggest that Ubc9 binding may play an important role in substrate recognition as well as in substrate modification. The SUMO-1 consensus sequence (SUMO-1-CS) is a motif of conserved residues surrounding the modified lysine residue of most SUMO-1 substrates. This motif conforms to the sequence “ΨKXE,” where Ψ is a large hydrophobic residue, K is the lysine to which SUMO-1 is conjugated, X is any amino acid, and E is glutamic acid. In this study, we demonstrate that the SUMO-1-CS is a major determinant of Ubc9 binding and SUMO-1 modification. Mutating residues in the SUMO-1-CS abolishes both Ubc9 binding and substrate modification. These findings have important implications for how SUMO-1 substrates are recognized and for how SUMO-1 is ultimately transferred to specific lysine residues on these substrates. SUMO-1 is an ubiquitin-related protein that is covalently conjugated to a diverse assortment of proteins. The consequences of SUMO-1 modification include the regulation of protein-protein interactions, protein-DNA interactions, and protein subcellular localization. At present, very little is understood about the specific mechanisms that govern the recognition of proteins as substrates for SUMO-1 modification. However, many of the proteins that are modified by SUMO-1 interact directly with the SUMO-1 conjugating enzyme, Ubc9. These interactions suggest that Ubc9 binding may play an important role in substrate recognition as well as in substrate modification. The SUMO-1 consensus sequence (SUMO-1-CS) is a motif of conserved residues surrounding the modified lysine residue of most SUMO-1 substrates. This motif conforms to the sequence “ΨKXE,” where Ψ is a large hydrophobic residue, K is the lysine to which SUMO-1 is conjugated, X is any amino acid, and E is glutamic acid. In this study, we demonstrate that the SUMO-1-CS is a major determinant of Ubc9 binding and SUMO-1 modification. Mutating residues in the SUMO-1-CS abolishes both Ubc9 binding and substrate modification. These findings have important implications for how SUMO-1 substrates are recognized and for how SUMO-1 is ultimately transferred to specific lysine residues on these substrates. small ubiquitin-like modifier-1 SUMO-1 consensus sequence SUMO-1 conjugating enzyme Ran GTPase activating protein 1 glutathione S-transferase polyacrylamide gel electrophoresis promyelocytic leukemia protein ubiquitin activating enzyme ubiquitin carrier protein ubiquitin-protein isopeptide ligase. SUMO-11 is a member of a family of ubiquitin-like proteins that are post-translationally conjugated to other proteins (1Melchior F. Annu. Rev. Cell Dev. Biol. 2000; 16: 591-626Crossref PubMed Scopus (656) Google Scholar). The specific effects of SUMO-1 modification appear to be substrate dependent, but they are clearly distinct from the effects of ubiquitination in mediating protein degradation. In a number of cases, SUMO-1 modification regulates the subcellular localization of specific substrates. For example, SUMO-1 modification targets RanGAP1 from the cytoplasm to the nuclear pore complex (2Mahajan R. Gerace L. Melchior F. J. Cell Biol. 1998; 140: 259-270Crossref PubMed Scopus (239) Google Scholar, 3Matunis M.J. Wu J. Blobel G. J. Cell Biol. 1998; 140: 499-509Crossref PubMed Scopus (381) Google Scholar) and PML from the nucleoplasm to PML nuclear bodies (4Muller S. Matunis M.J. Dejean A. EMBO J. 1998; 17: 61-70Crossref PubMed Scopus (581) Google Scholar). SUMO-1 modification of certain other substrates may play a role in antagonizing ubiquitin-mediated proteolysis. IκBα and MDM2, for example, are both modified by SUMO-1 on lysine residues that also function as sites for ubiquitination (5Desterro J.M. Rodriguez M.S. Hay R.T. Mol. Cell. 1998; 2: 233-239Abstract Full Text Full Text PDF PubMed Scopus (919) Google Scholar, 6Buschmann T. Fuchs S.Y. Lee C.G. Pan Z.Q. Ronai Z. Cell. 2000; 101: 753-762Abstract Full Text Full Text PDF PubMed Scopus (227) Google Scholar). SUMO-1 modification of these lysines has been proposed to stabilize the substrates by blocking ubiquitin modification. For a growing list of other substrates, the exact effects of SUMO-1 modification remain to be determined. A majority of these substrates, including p53 (7Muller S. Berger M. Lehembre F. Seeler J.S. Haupt Y. Dejean A. J. Biol. Chem. 2000; 275: 13321-13329Abstract Full Text Full Text PDF PubMed Scopus (350) Google Scholar, 8Gostissa M. Hengstermann A. Fogal V. Sandy P. Schwarz S.E. Scheffner M. Del Sal G. EMBO J. 1999; 18: 6462-6471Crossref PubMed Scopus (438) Google Scholar, 9Rodriguez M.S. Desterro J.M. Lain S. Midgley C.A. Lane D.P. Hay R.T. EMBO J. 1999; 18: 6455-6461Crossref PubMed Scopus (561) Google Scholar), c-Jun (7Muller S. Berger M. Lehembre F. Seeler J.S. Haupt Y. Dejean A. J. Biol. Chem. 2000; 275: 13321-13329Abstract Full Text Full Text PDF PubMed Scopus (350) Google Scholar), and topoisomerases I and II (10Mao Y. Desai S.D. Liu L.F. J. Biol. Chem. 2000; 275: 26066-26073Abstract Full Text Full Text PDF PubMed Scopus (123) Google Scholar, 11Mao Y. Sun M. Desai S.D. Liu L.F. Proc. Natl. Acad. Sci. U. S. A. 2000; 97: 4046-4051Crossref PubMed Scopus (181) Google Scholar) are nuclear proteins that function in regulating transcription or chromatin structure. Immunofluorescence analysis and cell fractionation studies further indicate that the majority of proteins modified by SUMO-1 are nuclear and that they correspond to only a small subfraction of all cellular proteins (12Matunis M.J. Coutavas E. Blobel G. J. Cell Biol. 1996; 135: 1457-1470Crossref PubMed Scopus (961) Google Scholar). The specific subfraction of proteins modified by SUMO-1 also varies throughout the cell cycle (13Li S.J. Hochstrasser M. Nature. 1999; 398: 246-251Crossref PubMed Scopus (608) Google Scholar), and possibly in response to cellular growth conditions, indicating that SUMO-1 modification and de-modification are dynamic processes. However, the precise mechanisms involved in substrate selection and in regulating the timing of modification or demodification are poorly defined. Many steps involved in SUMO-1 modification parallel those involved in ubiquitination. Like ubiquitin, SUMO-1 is synthesized as a precursor that is proteolytically processed to generate the mature, active polypeptide (13Li S.J. Hochstrasser M. Nature. 1999; 398: 246-251Crossref PubMed Scopus (608) Google Scholar, 14Johnson E.S. Schwienhorst I. Dohmen R.J. Blobel G. EMBO J. 1997; 16: 5509-5519Crossref PubMed Scopus (445) Google Scholar). Once processed, SUMO-1 is activated in an ATP-dependent reaction that creates a thioester intermediate between the active-site cysteine of the SUMO-1 activating enzyme (E1) and the carboxyl terminus of SUMO-1. The SUMO-1 E1 enzyme, a heterodimer consisting of Aos1 and Uba2, is structurally and functionally related to the ubiquitin E1 enzyme (14Johnson E.S. Schwienhorst I. Dohmen R.J. Blobel G. EMBO J. 1997; 16: 5509-5519Crossref PubMed Scopus (445) Google Scholar, 15Gong L. Li B. Millas S. Yeh E.T. FEBS Lett. 1999; 448: 185-189Crossref PubMed Scopus (132) Google Scholar, 16Okuma T. Honda R. Ichikawa G. Tsumagari N. Yasuda H. Biochem. Biophys. Res. Commun. 1999; 254: 693-698Crossref PubMed Scopus (184) Google Scholar). Following activation, SUMO-1 is transferred from the E1 enzyme to Ubc9, a protein similar in structure and function to ubiquitin E2 enzymes (17Gong L. Kamitani T. Fujise K. Caskey L.S. Yeh E.T. J. Biol. Chem. 1997; 272: 28198-28201Abstract Full Text Full Text PDF PubMed Scopus (169) Google Scholar, 18Saitoh H. Sparrow D.B. Shiomi T. Pu R.T. Nishimoto T. Mohun T.J. Dasso M. Curr. Biol. 1998; 8: 121-124Abstract Full Text Full Text PDF PubMed Scopus (162) Google Scholar, 19Lee G.W. Melchior F. Matunis M.J. Mahajan R. Tian Q. Anderson P. J. Biol. Chem. 1998; 273: 6503-6507Abstract Full Text Full Text PDF PubMed Scopus (121) Google Scholar, 20Desterro J.M. Thomson J. Hay R.T. FEBS Lett. 1997; 417: 297-300Crossref PubMed Scopus (304) Google Scholar, 21Johnson E.S. Blobel G. J. Biol. Chem. 1997; 272: 26799-26802Abstract Full Text Full Text PDF PubMed Scopus (411) Google Scholar). How SUMO-1 is subsequently transferred from Ubc9 to specific protein substrates is the most poorly defined step in the SUMO-1 conjugation pathway. Although SUMO-1 modification must be quite specific by virtue of the limited number of cellular proteins that are modified, there is very little, if any, homology among the currently known substrates. Probably all ubiquitination reactions involve E3 ligases, factors that mediate the transfer of ubiquitin from E2 enzymes to specific protein substrates (22Yamao F. J. Biochem. ( Tokyo ). 1999; 125: 223-229Crossref PubMed Scopus (41) Google Scholar, 23Hershko A. Ciechanover A. Annu. Rev. Biochem. 1998; 67: 425-479Crossref PubMed Scopus (6959) Google Scholar). In general, E3s function in substrate recognition and are responsible for the high degree of specificity that is characteristic of most ubiquitination reactions. Currently no E3-like factors have been identified for SUMO-1 conjugation, so how specific proteins are recognized as substrates for SUMO-1 conjugation remains unknown. Relative to ubiquitin-specific E2 enzymes, an unusual feature of Ubc9 is that it interacts directly with many SUMO-1 substrates (1Melchior F. Annu. Rev. Cell Dev. Biol. 2000; 16: 591-626Crossref PubMed Scopus (656) Google Scholar). These interactions suggest that Ubc9 may play a direct role in recognizing SUMO-1 substrates, as well as in modifying them. In this study, we demonstrate that Ubc9 binds to the SUMO-1 consensus sequence (SUMO-1-CS), a motif of conserved residues surrounding the modified lysine of many SUMO-1 substrates. We further demonstrate that the binding of Ubc9 to the SUMO-1-CS is essential for SUMO-1 modification. Expression vectors coding for wild-type mouse RanGAP1, CΔ23, NΔ419/PK, and NΔ502/PK were constructed as previously described (3Matunis M.J. Wu J. Blobel G. J. Cell Biol. 1998; 140: 499-509Crossref PubMed Scopus (381) Google Scholar). Site-directed mutagenesis was performed using the GeneEditor Mutatgenesis System (Promega Corp., Madison, WI) and mutations were verified by DNA sequencing. A cDNA coding for human Ubc9 was obtained from a fetal liver cDNA library using the polymerase chain reaction and cloned into the GST expression vector, pGEX-5X-1 (Amersham Pharmacia Biotech, Piscataway, NJ). The carboxyl-terminal domain of mouse RanGAP1 (NΔ419: amino acids 420–589) was similarly amplified from a cDNA clone by polymerase chain reaction and subcloned into pGEX-5X-1. In vitro transcription and translation of RanGAP1 and RanGAP1-pyruvate kinase fusion proteins were performed in rabbit reticulocyte lysate in the presence of [35S]methionine as described by the manufacturer (Promega Corp., Madison, WI). GST-NΔ419 and GST-Ubc9 fusion proteins were expressed in bacteria, purified by affinity chromatography on glutathione-Sepharose beads, and cleaved from the beads by Factor Xa as outlined by the manufacturer (Amersham Pharmacia Biotech). Gel filtration analysis of the carboxyl-terminal domain of RanGAP1 and Ubc9 was performed on a Amersham Pharmacia Biotech Superdex 75 chromatography column. The column was equilibrated and proteins were fractionated with buffer containing 110 mm potassium acetate, 2 mm magnesium acetate, 20 mm HEPES (pH 7.3), and 1 mm dithiothreitol. 20μ of each protein was loaded either individually or together following mixing and incubation for 30 min at room temperature. 0.5-ml fractions were collected, trichloroacetic acid precipitated, and analyzed by SDS-PAGE. GST-Ubc9, or GST alone, was bound to 20 μ l of glutathione-Sepharose beads (1 mg of protein/ml beads) in phosphate-buffered saline containing 1 mmdithiothreitol. Nonspecific protein-binding sites were blocked by incubation with 2% bovine serum albumin for 60 min at 4 °C. An equivalent amount (radioactive counts) of each in vitrotranslated protein was incubated with the beads in 100 μ l of binding buffer (20 mm Tris (pH 7.5), 150 mm NaCl, 0.1% Tween 20) for 30 min at room temperature. Beads were washed three times with binding buffer followed by elution of the bound proteins with SDS-PAGE sample buffer. Binding was analyzed by SDS-PAGE, or by quantifying counts in a liquid scintillation counter. The Ubc9 binding observed for each mutant protein relative to that of wild-type was determined from the ratio of GST-Ubc9 bound radioactive counts (following subtraction of counts bound to GST alone). Competition studies using SUMO-1 as a competitor were performed as described above except that translated proteins were incubated with immobilized Ubc9 in the presence of the indicated amounts of recombinant SUMO-1. Quantification of the relative amounts of modified and unmodified proteins bound to Ubc9 was determined by PhosphorImager analysis after separation of the proteins by SDS-PAGE. The carboxyl-terminal domain of RanGAP1 is modified by SUMO-1 at lysine residue 526 (3Matunis M.J. Wu J. Blobel G. J. Cell Biol. 1998; 140: 499-509Crossref PubMed Scopus (381) Google Scholar, 24Mahajan R. Delphin C. Guan T. Gerace L. Melchior F. Cell. 1997; 88: 97-107Abstract Full Text Full Text PDF PubMed Scopus (1010) Google Scholar). We have previously shown that modification at this site is dependent on a ∼120-amino acid domain of RanGAP1 extending from residue 470 to the carboxyl terminus (3Matunis M.J. Wu J. Blobel G. J. Cell Biol. 1998; 140: 499-509Crossref PubMed Scopus (381) Google Scholar) (summarized in Fig.1). The ability of this domain to specify SUMO-1 modification was demonstrated by in vitro translation in rabbit reticulocyte lysate, where SUMO-1 modification is mediated by endogenous Aos1/Uba2 and Ubc9 activities (3Matunis M.J. Wu J. Blobel G. J. Cell Biol. 1998; 140: 499-509Crossref PubMed Scopus (381) Google Scholar) (Fig.2, lanes 1 and7).Figure 2A 120-amino acid domain near the carboxyl terminus of RanGAP1 mediates Ubc9 binding. Wild-type RanGAP1 (lanes 1–3), the carboxyl-terminal deletion mutant CΔ23 (lanes 4–6), and the pyruvate kinase fusion proteins NΔ419/PK (lanes 7–9), and ND502/PK (lanes 10–12) were transcribed and translated in rabbit reticulocyte lysates in the presence of [35S]methionine and incubated with immobilized GST-Ubc9 or GST. Bound proteins were eluted with SDS sample buffer and analyzed by SDS-PAGE followed by autoradiography. The amount of protein loaded in “input” is equivalent to 40% the amount of protein assayed in each binding reaction. Molecular mass standards are indicated on the left and asterisksindicate SUMO-1-modified proteins. Unmodified RanGAP1 and pyruvate kinase fusion protein translation products all appear as triplets following separation by SDS-PAGE, possibly due to initiation of translation at internal start sites or to phosphorylation.View Large Image Figure ViewerDownload Hi-res image Download (PPT) A significant fraction of the proteins modified by SUMO-1 are known to interact directly with the SUMO-1 conjugating enzyme, Ubc9 (1Melchior F. Annu. Rev. Cell Dev. Biol. 2000; 16: 591-626Crossref PubMed Scopus (656) Google Scholar). Although RanGAP1 is one of the best characterized SUMO-1 substrates, its interactions with Ubc9 have not been analyzed previously. To investigate the functional relevance of Ubc9-substrate interactions, we assayed for the ability of Ubc9 to bind to RanGAP1 and also to the various mutant and heterologous proteins summarized in Fig. 1. GST-Ubc9 (or GST alone as a control) was immobilized on glutathione-Sepharose beads and incubated with 35S-labeled proteins produced by translation in rabbit reticulocyte lysate. Bound proteins were eluted with SDS sample buffer and analyzed by SDS-PAGE. Full-length RanGAP1 interacted specifically with Ubc9 (Fig. 2, lanes 1–3), as did NΔ419/PK (Fig. 2, lanes 7–9). Significantly, both of these proteins are also modified by SUMO-1. Notably, both unmodified and SUMO-1-modified RanGAP1 and NΔ419/PK interacted with Ubc9. In contrast, CΔ23 (Fig. 2, lanes 4–6) and NΔ502/PK (Fig.2, lanes 10–12) did not interact with Ubc9. As apparent inlanes 4 and 10, these same two proteins also failed to be modified by SUMO-1. These results indicate a correlation between the ability of these proteins to interact with Ubc9 and their ability to be modified by SUMO-1. The binding reactions described above were done in the presence of rabbit reticulocyte lysate, making it possible that the observed interaction between Ubc9 and RanGAP1 was indirect. To investigate whether Ubc9 and the carboxyl-terminal domain of RanGAP1 could form a complex in the absence of other factors, we analyzed the proteins by gel filtration chromatography either alone or together after mixing and incubating at room temperature. Bacterially expressed Ubc9 and NΔ419 were purified and individually fractionated by gel filtration chromatography on a Superdex 75 column (Amersham Pharmacia Biotech). Under these conditions, both proteins eluted as apparent monomers with calculated molecular masses of 20 kDa (Fig.3). When Ubc9 and NΔ419 were incubated together and subsequently fractionated on the same column they co-eluted as an apparent heterodimer with a calculated molecular mass of 40 kDa (Fig. 3). This result demonstrates that Ubc9 and the carboxyl-terminal domain of RanGAP1 interact directly to form a complex and that the complex is sufficiently stable to allow purification by gel filtration chromatography. This result also demonstrates that Ubc9 can bind to RanGAP1 prior to forming a thiol ester with SUMO-1. The precise lysine residues modified by SUMO-1 have been identified in approximately a dozen known substrates (1Melchior F. Annu. Rev. Cell Dev. Biol. 2000; 16: 591-626Crossref PubMed Scopus (656) Google Scholar). The majority of these modification sites conform to a consensus sequence that we refer to as the SUMO-1 consensus sequence, or SUMO-1-CS. The SUMO-1-CS is defined by four amino acids with the sequence “ΨKXE,” were Ψ is a large hydrophobic amino acid, K is the lysine residue modified by SUMO-1, X is any amino acid, and E is glutamic acid (Fig. 4). The conservation of residues surrounding the modified lysine suggests that they may be critical for substrate recognition and/or for the selection of the specific lysine residue for SUMO-1 modification. Nearly all of the substrates containing the SUMO-1-CS also interact with Ubc9, suggesting that the SUMO-1-CS may play a role in Ubc9 binding. To address this possibility, we mutated residues surrounding lysine 526 of RanGAP1, including the highly conserved residues conforming to the consensus sequence (Fig.5 A). Individual mutants were analyzed for their ability to be modified by SUMO-1 following translation in rabbit reticulocyte lysate and separation by SDS-PAGE (Fig. 5 B). Approximately one-third of the wild-type protein was converted to the SUMO-1-modified form when translated in rabbit reticulocyte lysate (Fig. 5 B, lane 1). As expected, mutating lysine 526 to arginine or alanine completely inhibited SUMO-1 modification (Fig. 5 B, lanes 5 and 6). Mutating histidine 521 to alanine had a noticeable, but less dramatic effect on SUMO-1 modification (Fig. 5 B, lane 2), whereas substituting alanine for lysine 530 had no effect on SUMO-1 modification (Fig.5 B, lane 8). Most notably, alanine substitutions of leucine residues 524 and 525 (Fig. 5 B, lanes 3 and 4), and glutamic acid 528 (Fig. 5 B, lane 7) completely inhibited SUMO-1 modification. These results demonstrate that conserved residues surrounding the SUMO-1 modification site are critical for efficient SUMO-1 modification.Figure 5Conserved residues of the SUMO-1-CS are essential for SUMO-1 modification. Mutations in the SUMO-1-CS were introduced into the RanGAP1 pyruvate kinase fusion protein NΔ419/PK. Wild-type and mutant proteins were assayed for their ability to be modified by SUMO-1 by transcription and translation in rabbit reticulocyte lysates. Reaction products were analyzed by SDS-PAGE followed by autoradiography. A, amino acid sequences surrounding the SUMO-1-CS of RanGAP1. B, SDS-PAGE analysis of modification assays for wild-type NΔ419/PK (lane 1) and various NΔ419/PK mutant proteins containing point mutations in and around the SUMO-1-CS (lanes 2–8). Protein molecular mass standards are indicated on the left and thebracket on the right indicates SUMO-1-modified proteins.View Large Image Figure ViewerDownload Hi-res image Download (PPT) As indicated above, we observed a correlation between the ability of proteins to interact with Ubc9 and their ability to be modified by SUMO-1. We therefore assayed for whether mutations of the conserved residues surrounding the SUMO-1 modification site of RanGAP1 affected Ubc9 binding. GST-Ubc9 was immobilized on glutathione beads and incubated with 35S-labeled proteins produced byin vitro translation. Bound proteins were eluted with SDS sample buffer and analyzed by SDS-PAGE, or by quantification using a scintillation counter. Four mutations were found to dramatically affect the interaction with Ubc9: leucine 524 to alanine (Fig.6, lanes 7–9), leucine 525 to alanine (Fig. 6, lanes 10–12), lysine 526 to alanine (Fig.6, lanes 13–15), and glutamic acid 528 to alanine (Fig. 6,lanes 19–21). Each of these mutations reduced the interaction with Ubc9 to less than 10% of that observed with the wild-type protein. Mutations of histidine 521 (Fig. 6, lanes 4–6) and lysine 530 (Fig. 6, lanes 22–24) to alanine had only modest affects on Ubc9 binding, reducing the interaction by ∼50 and 30%, respectively. Mutating the actual modification site, lysine 526, to arginine (Fig. 6, lanes 16–18) had no noticeable affect on Ubc9 binding, possibly due to the conservative nature of this amino acid substitution. These results again demonstrate a correlation between Ubc9 binding and SUMO-1 modification: proteins that retained their ability to interact with Ubc9 were modified by SUMO-1 (with the exception of K526R), whereas those that did not bind Ubc9 were not modified by SUMO-1. These results further demonstrate that conserved residues surrounding the SUMO-1 modification site are essential for Ubc9 binding. Despite the apparent role of the SUMO-1-CS (including the targeted lysine) in mediating Ubc9 binding, we observed that SUMO-1 modified RanGAP1 bound to Ubc9 as well as, and possibly better than, unmodified RanGAP1. To investigate whether SUMO-1 itself, after being conjugated to RanGAP1, could contribute to Ubc9 binding, we assayed for the binding of NΔ419/PK to Ubc9 in the presence of increasing concentrations of free SUMO-1. Surprisingly, we found that free SUMO-1 had a significant effect on the binding of SUMO-1-modified RanGAP1 to Ubc9, but had only a modest effect on the binding of unmodified RanGAP1 (Fig. 7). We observed an ∼60% reduction in the binding of SUMO-1-modified RanGAP1 when binding assays were performed in the presence of 3.25 mg/ml SUMO-1 (corresponding to an ∼15-fold excess over immobilized Ubc9) (Fig. 7,lanes 1 and 5). In the same assay, the binding of unmodified RanGAP1 was reduced by less than 20% (Fig. 7, lanes 1 and 5). These findings indicate that Ubc9 interacts with SUMO-1 modified RanGAP1 through SUMO-1, possibly independent of direct interactions with RanGAP1. SUMO-1 modification modulates protein functions by altering protein-protein interactions, protein-DNA interactions, protein subcellular localization, and possibly by directly altering protein activity. It is anticipated that SUMO-1 modification is highly regulated, with substrates being selectively recognized and modified in response to specific cellular signals. Several studies, for example, have demonstrated that SUMO-1-modified proteins vary with changes in the cell cycle (13Li S.J. Hochstrasser M. Nature. 1999; 398: 246-251Crossref PubMed Scopus (608) Google Scholar) and in response to cellular growth conditions (10Mao Y. Desai S.D. Liu L.F. J. Biol. Chem. 2000; 275: 26066-26073Abstract Full Text Full Text PDF PubMed Scopus (123) Google Scholar,25Saitoh H. Hinchey J. J. Biol. Chem. 2000; 275: 6252-6258Abstract Full Text Full Text PDF PubMed Scopus (694) Google Scholar). However, the mechanisms by which proteins are selectively recognized as substrates for SUMO-1 modification or de-modification and how such mechanisms might be regulated are not yet understood. We have begun to investigate how proteins are recognized as substrates for SUMO-1 modification and present evidence that direct interaction with the E2 enzyme, Ubc9, is an important part of this process. Using a domain derived from a well characterized SUMO-1 substrate, RanGAP1, we have demonstrated that SUMO-1 modification correlates with the ability to directly interact with Ubc9. This domain of RanGAP1 contains a consensus sequence, the SUMO-1-CS, which is found in nearly all known SUMO-1 substrates. The SUMO-1-CS contains the lysine residue to which SUMO-1 is covalently attached, and several highly conserved residues that flank this lysine. Although recognized by several other groups (26Duprez E. Saurin A.J. Desterro J.M. Lallemand-Breitenbach V. Howe K. Boddy M.N. Solomon E. de The H. Hay R.T. Freemont P.S. J. Cell Sci. 1999; 112: 381-393Crossref PubMed Google Scholar, 27Rodriguez M.S. Dargemont C. Hay R.T. J. Biol. Chem. 2000; 275: 12654-12659Abstract Full Text Full Text PDF Scopus (129) Google Scholar, 28Sternsdorf T. Jensen K. Reich B. Will H. J. Biol. Chem. 1999; 274: 12555-12566Abstract Full Text Full Text PDF PubMed Scopus (220) Google Scholar), the functional significance of the SUMO-1-CS was not previously characterized. To investigate its role in SUMO-1 modification, we made alanine substitutions of the conserved residues in the SUMO-1-CS. These mutations were found to inhibit both Ubc9 binding and SUMO-1 modification. These findings indicate that the SUMO-1-CS plays a direct role in mediating the binding of Ubc9 to SUMO-1 substrates and that this binding is essential for substrate modification. The actual lysine acceptor in the SUMO-1-CS of RanGAP1 is important for the interaction with Ubc9, as an alanine substitution at this position inhibits Ubc9 binding. In apparent contradiction to this finding, it was also observed that SUMO-1-modified RanGAP1 and free RanGAP1 interact equally well with Ubc9. Competition experiments using excess free SUMO-1, however, indicated that modified RanGAP1 likely interacts with Ubc9 through the SUMO-1 moiety. It remains to be determined whether the binding of modified RanGAP1 to Ubc9 is mediated solely through interactions with SUMO-1 or through a combination of interactions with RanGAP1 and SUMO-1. Previous studies have indicated that Ubc9 and free SUMO-1 can form direct, noncovalent interactions (29Liu Q. Jin C. Liao X. Shen Z. Chen D.J. Chen Y. J. Biol. Chem. 1999; 274: 16979-16987Abstract Full Text Full Text PDF PubMed Scopus (88) Google Scholar). It will be interesting to determine whether other SUMO-1-modified substrates interact similarly with Ubc9, or whether this interaction is specific for modified RanGAP1. In vivo, Ubc9 is concentrated at the nuclear envelope at sites that overlap with the localization of SUMO-1-modified RanGAP1 (19Lee G.W. Melchior F. Matunis M.J. Mahajan R. Tian Q. Anderson P. J. Biol. Chem. 1998; 273: 6503-6507Abstract Full Text Full Text PDF PubMed Scopus (121) Google Scholar). Although Ubc9 has been shown to interact with the nucleoporin Nup358 (18Saitoh H. Sparrow D.B. Shiomi T. Pu R.T. Nishimoto T. Mohun T.J. Dasso M. Curr. Biol. 1998; 8: 121-124Abstract Full Text Full Text PDF PubMed Scopus (162) Google Scholar), it remains to be determined whether this interaction is direct or mediated by SUMO-1-modified RanGAP1. In addition to demonstrating a role for the SUMO-1-CS in Ubc9 binding, we also found that ∼50 amino acids on either side of the consensus sequence were required for Ubc9 binding and SUMO-1 modification. Comparison of the amino acid sequence of this larger domain with other SUMO-1 substrates reveals no obvious homologies outside of the SUMO-1-CS. It therefore remains to be determined whether additional residues outside of the SUMO-1-CS are directly involved in Ubc9 binding, or whether they indirectly affect binding by influencing the proper folding and exposure of a smaller domain containing the SUMO-1-CS. Evidence that the precise position of the SUMO-1 CS within a protein can be an important determinant of its ability to function in SUMO-1 modification is provided by analysis of the heat shock transcription factor, HSF2. HSF2 contains three putative SUMO-1-CS motifs, but is modified at a lysine residue in only one of these motifs (45Goodson, M. L., Hong, Y., Rogers, R., Matunis, M. J., Park-Sarge, O.-K., and Sarge, K. D. (2001) J. Biol. Chem. 276, in press.Google Scholar). The precise position of the SUMO-1-CS within a protein is likely to determine its accessibility and, therefore, its potential to interact with Ubc9. The presence of a SUMO-1-CS in a protein is therefore not an absolute indicator of whether that protein will be a substrate for SUMO-1 modification. Further analysis of the amino acid residues surrounding the SUMO-1-CS and their contributions to Ubc9 binding will be needed to refine the definition of a SUMO-1 substrate. In this particular study, we examined the SUMO-1-CS of RanGAP1, but we propose that the SUMO-1-CS of other SUMO-1 substrates will function similarly to mediate Ubc9 binding and facilitate SUMO-1 modification. Ubc9-binding domains have been partially mapped in a large number of known and putative SUMO-1 substrates. Many of these domains contain SUMO-1-CS motifs, including the Ubc9-binding domains found in WT1 (30Wang Z.Y. Qiu Q.Q. Seufert W. Taguchi T. Testa J.R. Whitmore S.A. Callen D.F. Welsh D. Shenk T. Deuel T.F. J. Biol. Chem. 1996; 271: 24811-24816Abstract Full Text Full Text PDF PubMed Scopus (70) Google Scholar), TEL (31Chakrabarti S.R. Sood R. Ganguly S. 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Mattei M.G. de Murcia G. Niedergang C.P. Gene ( Amst .). 1997; 190: 287-296Crossref PubMed Scopus (32) Google Scholar). Other motifs in addition to the SUMO-1-CS may also mediate Ubc9 binding, however. Most notably, Ubc9 also interacts with the RING domain of PML (26Duprez E. Saurin A.J. Desterro J.M. Lallemand-Breitenbach V. Howe K. Boddy M.N. Solomon E. de The H. Hay R.T. Freemont P.S. J. Cell Sci. 1999; 112: 381-393Crossref PubMed Google Scholar). The functional significance of this interaction remains unclear as mutations that disrupt interactions between Ubc9 and the PML RING domain have very little effect on the SUMO-1 modification of PML (26Duprez E. Saurin A.J. Desterro J.M. Lallemand-Breitenbach V. Howe K. Boddy M.N. Solomon E. de The H. Hay R.T. Freemont P.S. J. Cell Sci. 1999; 112: 381-393Crossref PubMed Google Scholar,37Kamitani T. Kito K. Nguyen H.P. Wada H. Fukuda-Kamitani T. Yeh E.T. J. Biol. Chem. 1998; 273: 26675-26682Abstract Full Text Full Text PDF PubMed Scopus (275) Google Scholar). It has also recently been proposed that PEST sequences may play a role in regulating the interaction of Ubc9 with at least some SUMO-1 substrates (1Melchior F. Annu. Rev. Cell Dev. Biol. 2000; 16: 591-626Crossref PubMed Scopus (656) Google Scholar, 38Kim Y.H. Choi C.Y. Kim Y. Proc. Natl. Acad. Sci. U. S. A. 1999; 96: 12350-12355Crossref PubMed Scopus (143) Google Scholar). Although PEST sequences are best known for their involvement in ubiquitin-mediated proteolysis (39Rechsteiner M. Revis Biol. Celular. 1989; 20: 235-253PubMed Google Scholar), they are found in more than half of the known SUMO-1 substrates. The binding of Ubc9 to the SUMO-1-CS argues against a direct requirement for E3 ligases in SUMO-1 modification. However, it is possible that the modification of substrates with a SUMO-1-CS may be regulated or facilitated by the action of E3-like factors in vivo. Regardless of this consideration, a more detailed analysis of the direct interactions between Ubc9 and the SUMO-1-CS will provide important insights into the mechanisms involved in the ultimate transfer of SUMO-1 to specific substrates. Despite crystallographic studies of ubiquitin E2-E3 complexes (40Huang L. Kinnucan E. Wang G. Beaudenon S. Howley P.M. Huibregtse J.M. Pavletich N.P. Science. 1999; 286: 1321-1326Crossref PubMed Scopus (445) Google Scholar, 41Zheng N. Wang P. Jeffrey P.D. Pavletich N.P. Cell. 2000; 102: 533-539Abstract Full Text Full Text PDF PubMed Scopus (724) Google Scholar), the exact mechanism that underlies the transfer of ubiquitin from upstream factors to protein substrates remains poorly defined. Given the high degree of homology between Ubc9 and ubiquitin E2 enzymes, it is likely that the transfer of SUMO-1 to protein substrates will be very similar to the process of ubiquitination. Detailed characterization of the interactions between Ubc9 and the SUMO-1-CS should, therefore, provide important insights into the mechanisms of both ubiquitination and SUMO-1 modification. It will also be important to further characterize the role of amino acids surrounding the SUMO-1-CS, to determine whether they function indirectly to present an exposed consensus sequence, or whether they are also involved in significant interactions with Ubc9. We thank Janet Cronshaw, Richard Rogers, Maria Vassileva, and Cecile Pickart for comments and suggestions during the course of this work.

Nat. Biotechnol. 33, 408–414 (2015); published online 2 February 2015; corrected after print 4 February 2016 In the version of this article initially published, grant no. 91131005 from the National Natural Science Foundation of China was inadvertently omitted. The error has been corrected in the HTML and PDF versions of the article.

Our understanding of phylogenetic relationships among bony fishes has been transformed by analysis of a small number of genes, but uncertainty remains around critical nodes. Genome-scale inferences so far have sampled a limited number of taxa and genes. Here we leveraged 144 genomes and 159 transcriptomes to investigate fish evolution with an unparalleled scale of data: >0.5 Mb from 1,105 orthologous exon sequences from 303 species, representing 66 out of 72 ray-finned fish orders. We apply phylogenetic tests designed to trace the effect of whole-genome duplication events on gene trees and find paralogy-free loci using a bioinformatics approach. Genome-wide data support the structure of the fish phylogeny, and hypothesis-testing procedures appropriate for phylogenomic datasets using explicit gene genealogy interrogation settle some long-standing uncertainties, such as the branching order at the base of the teleosts and among early euteleosts, and the sister lineage to the acanthomorph and percomorph radiations. Comprehensive fossil calibrations date the origin of all major fish lineages before the end of the Cretaceous.

Metal–organic frameworks (MOF) derivative used as microwave absorber has been attracting extensive interest due to the diversity of host-guest coordination and unique structure at micro/nano-meters level. However, the accurate adjustment of metal-semiconductor interfaces construct remains a great challenge. Here, a novel hierarchical multi-interfacial [email protected]@ZnO microsphere with special Schottky contact structure was successfully fabricated after annealed the bimetallic Ni-Zn-MOF precursor. The unique yolk-shell microsphere was assembled together by the core-shell [email protected] micro-units and ZnO flakes. The uniformly dispersed ZnO flakes were anchored inside the hierarchical conductive carbon matrix. The yolk-shell [email protected]@ZnO materials displayed high-performance microwave absorption after the micro-nano structure and interfacial design were optimized. In particular, with a low mass additive amount of only 25%, the maximum reflection loss (RL) reached −55.8 dB at 2.5 mm, and the effective absorption bandwidth (RL ≤ −10 dB) covered as wide as 4.1 GHz. The excellent microwave absorption performance could be attributed to the polarized interfaces of Ni-C-ZnO, which contributes a metallic/semiconductor barrier. Thus, both magnetic-dielectric synergetic effect and interfacial polarization might lead to an evident absorption. This novel lightweight magnetic MOF-derived composites promise great potential in the practical microwave absorption fields.

Neuronal conversion from human fibroblasts can be induced by lineage-specific transcription factors; however, the introduction of ectopic genes limits the therapeutic applications of such induced neurons (iNs). Here, we report that human fibroblasts can be directly converted into neuronal cells by a chemical cocktail of seven small molecules, bypassing a neural progenitor stage. These human chemical-induced neuronal cells (hciNs) resembled hiPSC-derived neurons and human iNs (hiNs) with respect to morphology, gene expression profiles, and electrophysiological properties. This approach was further applied to generate hciNs from familial Alzheimer's disease patients. Taken together, our transgene-free and chemical-only approach for direct reprogramming of human fibroblasts into neurons provides an alternative strategy for modeling neurological diseases and for regenerative medicine.

Tissue engineering is promising in realizing successful treatments of human body tissue loss that current methods cannot treat well or achieve satisfactory clinical outcomes. In scaffold-based bone tissue engineering, a high performance scaffold underpins the success of a bone tissue engineering strategy and a major direction in the field is to produce bone tissue engineering scaffolds with desirable shape, structural, physical, chemical and biological features for enhanced biological performance and for regenerating complex bone tissues. Three-dimensional (3D) printing can produce customized scaffolds that are highly desirable for bone tissue engineering. The enormous interest in 3D printing and 3D printed objects by the science, engineering and medical communities has led to various developments of the 3D printing technology and wide investigations of 3D printed products in many industries, including biomedical engineering, over the past decade. It is now possible to create novel bone tissue engineering scaffolds with customized shape, architecture, favorable macro-micro structure, wettability, mechanical strength and cellular responses. This article provides a concise review of recent advances in the R & D of 3D printing of bone tissue engineering scaffolds. It also presents our philosophy and research in the designing and fabrication of bone tissue engineering scaffolds through 3D printing.

A series of noble metal diphosphides (IrP₂@NC, RhP₂@NC and Pd₅P₂@NC) have been designed and fabricated, and among which IrP₂@NC exhibits ultrahigh hydrogen evolution reaction performance.

The regulatory loop between long noncoding RNAs (lncRNAs) and microRNAs has a dynamic role in transcriptional and translational regulation, and is involved in cancer. However, the regulatory circuitry between lncRNAs and microRNAs in tumorigenesis remains elusive. Here we demonstrate that a nuclear lncRNA LINC00336 is upregulated in lung cancer and functions as an oncogene by acting as a competing endogenous RNA (ceRNAs). LINC00336 bound RNA-binding protein ELAVL1 (ELAV-like RNA-binding protein 1) using nucleotides 1901–2107 of LINC00336 and the RRM interaction domain and key amino acids (aa) of ELAVL1 (aa 101–213), inhibiting ferroptosis. Moreover, ELAVL1 increased LINC00336 expression by stabilizing its posttranscriptional level, whereas LSH (lymphoid-specific helicase) increased ELAVL1 expression through the p53 signaling pathway, further supporting the hypothesis that LSH promotes LINC00336 expression. Interestingly, LINC00336 served as an endogenous sponge of microRNA 6852 (MIR6852) to regulate the expression of cystathionine-β-synthase (CBS), a surrogate marker of ferroptosis. Finally, we found that MIR6852 inhibited cell growth by promoting ferroptosis. These data show that the network of lncRNA and ceRNA has an important role in tumorigenesis and ferroptosis.

Introducing O vacancies into the lattice of a semiconductor photocatalyst can alter its intrinsic electronic properties and band gap, thus enhancing the visible light absorption, promoting the separation/transfer of photogenerated charge carriers, and resultantly elevating the photocatalytic activity of oxide semiconductors. Moreover, O vacancies can help adsorb and activate CO2 on photocatalyst surfaces, which, however, are prone to being filled by O atoms during the photoreduction reaction. In this work, Cu was introduced to increase the O vacancy concentration in CeO2–x and promote the photocatalytic activity of CeO2–x. The sample Cu/CeO2–x-0.1 showed the highest photocatalytic activity with a CO yield of 8.25 μmol g–1 under 5 h irradiation, which is ∼26 times that on CeO2–x. According to the analysis of Raman and X-ray photoelectron spectroscopy (XPS) spectra, it has been evidenced that Cu introduction benefits the chemical stabilization of O vacancies in CeO2–x during photocatalytic CO2 reduction, which is responsible for the improved and sustained photocatalytic activity.

Abstract High energy density at high power density is still a challenge for the current Li‐ion capacitors (LICs) due to the mismatch of charge‐storage capacity and electrode kinetics between capacitor‐type cathode and battery‐type anode. In this work, B and N dual‐doped 3D porous carbon nanofibers are prepared through a facile method as both capacitor‐type cathode and battery‐type anode for LICs. The B and N dual doping has profound effect in tuning the porosity, functional groups, and electrical conductivity for the porous carbon nanofibers. With rational design, the developed B and N dual‐doped carbon nanofibers (BNC) exhibit greatly improved electrochemical performance as both cathode and anode for LICs, which greatly alleviates the mismatch between the two electrodes. For the first time, a 4.5 V “dual carbon” BNC//BNC LIC device is constructed and demonstrated, exhibiting outstanding energy density and power capability compared to previously reported LICs with other configurations. In specific, the present BNC//BNC LIC device can deliver a large energy density of 220 W h kg −1 and a high power density of 22.5 kW kg −1 (at 104 W h kg −1 ) with reasonably good cycling stability (≈81% retention after 5000 cycles).

Epithelial–mesenchymal transition (EMT) is associated with characteristics of breast cancer stem cells, including chemoresistance and radioresistance. However, it is unclear whether EMT itself or specific EMT regulators play causal roles in these properties. Here we identify an EMT-inducing transcription factor, zinc finger E-box binding homeobox 1 (ZEB1), as a regulator of radiosensitivity and DNA damage response. Radioresistant subpopulations of breast cancer cells derived from ionizing radiation exhibit hyperactivation of the kinase ATM and upregulation of ZEB1, and the latter promotes tumour cell radioresistance in vitro and in vivo. Mechanistically, ATM phosphorylates and stabilizes ZEB1 in response to DNA damage, ZEB1 in turn directly interacts with USP7 and enhances its ability to deubiquitylate and stabilize CHK1, thereby promoting homologous recombination-dependent DNA repair and resistance to radiation. These findings identify ZEB1 as an ATM substrate linking ATM to CHK1 and the mechanism underlying the association between EMT and radioresistance. Ma and colleagues show that when the EMT-associated transcription factor ZEB1 is stabilized by the ATM kinase, it interacts with the ubiquitin protease USP7 to counteract CHK1 degradation and promote DNA repair in breast cancer cells.

It has been shown that thioredoxin (Trx) in a reduced form binds to and inhibits apoptosis signal-regulating kinase 1 (ASK1). Apoptotic stimuli such as tumor necrosis factor (TNF) and reactive oxygen species (ROS) activate ASK1 in part by oxidizing Trx (forming intramolecular disulfide between C32 and C35) to release Trx from ASK1. In the present study, we examined if Trx affects ASK1 protein stability and whether the redox activity of Trx is critical in regulating ASK1 activity. First, we showed that overexpression of the wild-type Trx (Trx-WT) in endothelial cells induced ASK1 ubiquitination and degradation. Trx-induced ASK1 ubiquitination/degradation could be blocked by ASK1 activators TNF and TRAF2. We then tested the single-mutation of Trx at the catalytic site C32 or C35 (Trx-C32S or Trx-C35S) and the double-mutation (Trx-CS). The results showed that the single mutants (but not Trx-CS) retained the binding activity for ASK1 and the ability to induce ASK1 ubiquitination/degradation. Unlike Trx-WT, Trx-C32S and Trx-C35S mutants constitutively bind to ASK1 even in the presence of hydrogen peroxide in vitro and TNF in vivo. Finally, we showed that the single mutants (not Trx-WT) significantly (n=4 and P &lt;0.05) inhibited ASK1-induced JNK activation, caspase 3 activity, and apoptosis in TNF/ROS-resistant manner. Our data suggest that association of Trx with ASK1 through a single Cysteine (C32 or C35) is necessary and sufficient for Trx activity in inducing ASK1 ubiquitination/degradation leading to inhibition of ASK1-induced apoptosis.

Cas13a, a type VI-A CRISPR-Cas RNA-guided RNA ribonuclease, degrades invasive RNAs targeted by CRISPR RNA (crRNA) and has potential applications in RNA technology. To understand how Cas13a is activated to cleave RNA, we have determined the crystal structure of Leptotrichia buccalis (Lbu) Cas13a bound to crRNA and its target RNA, as well as the cryo-EM structure of the LbuCas13a-crRNA complex. The crRNA-target RNA duplex binds in a positively charged central channel of the nuclease (NUC) lobe, and Cas13a protein and crRNA undergo a significant conformational change upon target RNA binding. The guide-target RNA duplex formation triggers HEPN1 domain to move toward HEPN2 domain, activating the HEPN catalytic site of Cas13a protein, which subsequently cleaves both single-stranded target and collateral RNAs in a non-specific manner. These findings reveal how Cas13a of type VI CRISPR-Cas systems defend against RNA phages and set the stage for its development as a tool for RNA manipulation.

Diabetic wound healing and angiogenesis remain a worldwide challenge for both clinic and research. The use of adipose stromal cell derived exosomes delivered by bioactive dressing provides a potential strategy for repairing diabetic wounds with less scar formation and fast healing. In this study, we fabricated an injectable adhesive thermosensitive multifunctional polysaccharide-based dressing (FEP) with sustained pH-responsive exosome release for promoting angiogenesis and diabetic wound healing. The FEP dressing possessed multifunctional properties including efficient antibacterial activity/multidrug-resistant bacteria, fast hemostatic ability, self-healing behavior, and tissue-adhesive and good UV-shielding performance. FEP@exosomes (FEP@exo) can significantly enhance the proliferation, migration, and tube formation of endothelial cells in vitro. In vivo results from a diabetic full-thickness cutaneous wound model showed that FEP@exo dressing accelerated the wound healing by stimulating the angiogenesis process of the wound tissue. The enhanced cell proliferation, granulation tissue formation, collagen deposition, remodeling, and re-epithelialization probably lead to the fast healing with less scar tissue formation and skin appendage regeneration. This study showed that combining bioactive molecules into multifunctional dressing should have great potential in achieving satisfactory healing in diabetic and other vascular-impaired related wounds.

This report concerns the speech and language outcomes of young adults (N = 242) who participated in a 14-year, prospective, longitudinal study of a community sample of children with (n = 114) and without (n = 128) speech and/or language impairments. Participants were initially identified at age 5 and subsequently followed at ages 12 and 19. Direct assessments were conducted in multiple domains (communicative, cognitive, academic, behavioral, and psychiatric) at all three time periods. Major findings included (a) high rates of continued communication difficulties in those with a history of impairment; (b) considerable stability in language performance over time; (c) better long-term outcomes for those with initial speech impairments than for those with language impairments; and (d) more favorable prognoses for those with specific language impairments than for those with impairments secondary to sensory, structural, neurological, or cognitive deficits. These general conclusions held when either a liberal or a more stringent criterion for language impairment was employed. Some of these findings are consistent with those from earlier follow-up studies, which used less optimal methods. Thus, the present replication and extension of these findings with a sound methodology enables greater confidence in their use for prognostic, planning, and research purposes.

CO2 is highly stable and therefore extremely difficult to be reduced at room temperature. Herein, mesostructured CeO2/graphite carbon nitride (m-CeO2/g-C3N4) was designed and synthesized through a hard-template route. The heterogeneous nanocomposites showed greatly enhanced response to solar light, promoted charge carrier separation and transfer efficiency. Consequently, their CO2 photoreduction performance has been remarkably enhanced. Maximum CO and CH4 yields of 0.590 and 0.694 μmol, respectively, have been obtained from the CO2 reduction after one hour irradiation at room temperature on 50 mg nanocomposite photocatalyst. Different from common g-C3N4-based composites in which the additional component only plays a role of electron sink in electron–hole separation, a synergetic effect of mutual activations between the two components is proposed, which is featured with g-C3N4 activation due to significantly promoted separation of photo-generated carriers under Xenon lamp irradiation, and CeO2 activation via the reduction of Ce4+ to Ce3+ by the trapped electrons.

Obesity is common in patients with coronavirus disease 2019 (COVID-19). The effects of obesity on clinical outcomes of COVID-19 warrant systematical investigation.This study explores the effects of obesity with the risk of severe disease among patients with COVID-19.Body mass index (BMI) and degree of visceral adipose tissue (VAT) accumulation were used as indicators for obesity status. Publication databases including preprints were searched up to August 10, 2020. Clinical outcomes of severe COVID-19 included hospitalization, a requirement for treatment in an intensive care unit (ICU), invasive mechanical ventilation (IMV), and mortality. Risks for severe COVID-19 outcomes are presented as odds ratios (OR) and 95% confidence interval (95%CI) for cohort studies with BMI-defined obesity, and standardized mean difference (SMD) and 95%CI for controlled studies with VAT-defined excessive adiposity.A total of 45, 650 participants from 30 studies with BMI-defined obesity and 3 controlled studies with VAT-defined adiposity were included for assessing the risk of severe COVID-19. Univariate analyses showed significantly higher ORs of severe COVID-19 with higher BMI: 1.76 (95%: 1.21, 2.56, P = 0.003) for hospitalization, 1.67 (95%CI: 1.26, 2.21, P<0.001) for ICU admission, 2.19 (95%CI: 1.56, 3.07, P<0.001) for IMV requirement, and 1.37 (95%CI: 1.06, 1.75, P = 0.014) for death, giving an overall OR for severe COVID-19 of 1.67 (95%CI: 1.43, 1.96; P<0.001). Multivariate analyses revealed increased ORs of severe COVID-19 associated with higher BMI: 2.36 (95%CI: 1.37, 4.07, P = 0.002) for hospitalization, 2.32 (95%CI: 1.38, 3.90, P = 0.001) for requiring ICU admission, 2.63 (95%CI: 1.32, 5.25, P = 0.006) for IMV support, and 1.49 (95%CI: 1.20, 1.85, P<0.001) for mortality, giving an overall OR for severe COVID-19 of 2.09 (95%CI: 1.67, 2.62; P<0.001). Compared to non-severe COVID-19 patients, severe COVID-19 cases showed significantly higher VAT accumulation with a SMD of 0.49 for hospitalization (95% CI: 0.11, 0.87; P = 0.011), 0.57 (95% CI: 0.33, 0.81; P<0.001) for requiring ICU admission and 0.37 (95% CI: 0.03, 0.71; P = 0.035) for IMV support. The overall SMD for severe COVID-19 was 0.50 (95% CI: 0.33, 0.68; P<0.001).Obesity increases risk for hospitalization, ICU admission, IMV requirement and death among patients with COVID-19. Further, excessive visceral adiposity appears to be associated with severe COVID-19 outcomes. These findings emphasize the need for effective actions by individuals, the public and governments to increase awareness of the risks resulting from obesity and how these are heightened in the current global pandemic.

Described herein is a facile one-pot strategy to synthesize N-doped graphitic carbon-incorporated g-C3N4 by adding slight amount of citric acid into urea as the precursor during thermal polymerization. The obtained materials retained the original framework of g-C3N4 and show remarkably enhanced visible light harvesting and promoted photo-excited charge carrier separation and transfer. The high-resolution N 1s spectrum of XPS showed a graphitic N peak, which could be attributed to N-doped graphitic carbon. In addition to the common-recognized light harvesting enhancement and charge carrier recombination inhibition, the incorporation of N-doped graphitic carbon into the planar framework of g-C3N4 is suggested to result in extended and delocalized π-conjugated system of this copolymer, thus greatly elevating the photocatalytic performance for H2 evolution by water splitting under visible light. The H2 evolution rate on N-doped graphitic carbon-incorporated g-C3N4 reached 64 μmol h−1, which is almost 4.3 times the rate on pure g-C3N4. This approach may provide a promising route for rational design of high performance, cost-effective and metal-free photocatalysts.

Background Hepatocellular carcinoma (HCC) is prevalent worldwide and improvements in timely and effective diagnosis are needed. We assessed whether measurement of Dickkopf-1 (DKK1) in serum could improve diagnostic accuracy for HCC. Methods We analysed data for patients with HCC, chronic hepatitis B virus (HBV) infection, liver cirrhosis, and healthy controls, recruited from two Chinese centres between December, 2008, and July, 2009. A validation cohort matched for age and sex was recruited from another centre in China between February, 2009, and June, 2011. DKK1 was measured in serum by ELISA by independent researchers who had no access to patients' clinical information. We used receiver operating characteristics (ROC) to calculate diagnostic accuracy. Findings We assessed serum DKK1 in 831 participants: 424 with HCC, 98 with chronic HBV infection, 96 with cirrhosis, and 213 healthy controls. The validation cohort comprised 453 participants: 209 with HCC, 73 with chronic HBV infection, 72 with cirrhosis, and 99 healthy controls. Levels of DKK1 in serum were significantly higher in patients with HCC than in all controls. ROC curves showed the optimum diagnostic cutoff was 2·153 ng/mL (area under curve [AUC] 0·848 [95% CI 0·820–0·875], sensitivity 69·1%, and specificity 90·6% in the test cohort; 0·862 [0·825–0·899], 71·3%, and 87·2% in the validation cohort). Similar results were noted for early-stage HCC (0·865 [0·835–0·895], 70·9%, and 90·5% in the test cohort; 0·896 [0·846–0·947], 73·8%, and 87·2% in the validation cohort). Furthermore, DKK1 maintained diagnostic accuracy for patients with HCC who were α-fetoprotein (AFP) negative (0·841 [0·801–0·882], 70·4%, and 90·0% in the test cohort; 0·869 [0·815–0·923], 66·7%, and 87·2% in the validation cohort), including for patients with early-stage HCC (0·870 [0·829–0·911], 73·1%, and 90·0% in the test cohort; 0·893 [0·804–0·983], 72·2%, and 87·2% in the validation cohort), compared with all controls. Raised concentrations of DKK1 in serum could differentiate HCC from chronic HBV infection and cirrhosis (0·834 [0·798–0·871], 69·1%, and 84·7% in the test cohort; 0·873 [0·832–0·913], 71·3%, and 90·6% in the validation cohort). Moreover, measurement of DKK1 and AFP together improved diagnostic accuracy for HCC versus all controls compared with either test alone (0·889 [0·866–0·913], 73·3%, and 93·4% in the test cohort; 0·888 [0·856–0·920], 78·5%, and 87·2% in the validation cohort). Interpretation DKK1 could complement measurement of AFP in the diagnosis of HCC and improve identification of patients with AFP-negative HCC and distinguish HCC from non-malignant chronic liver diseases. Funding National Key Basic Research Programme of China, National Key Sci-Tech Special Projects of Infectious Diseases, National Natural Science Foundation of China, Research Fund for the Doctoral Programme of Higher Education of China.

Decreased expression of specific microRNAs (miRNAs) occurs in human tumors, which suggests a function for miRNAs in tumor suppression. Herein, levels of the miR-17-5p/miR-20a miRNA cluster were inversely correlated to cyclin D1 abundance in human breast tumors and cell lines. MiR-17/20 suppressed breast cancer cell proliferation and tumor colony formation by negatively regulating cyclin D1 translation via a conserved 3' untranslated region miRNA-binding site, thereby inhibiting serum-induced S phase entry. The cell cycle effect of miR-17/20 was abrogated by cyclin D1 siRNA and in cyclin D1-deficient breast cancer cells. Mammary epithelial cell-targeted cyclin D1 expression induced miR-17-5p and miR-20a expression in vivo, and cyclin D1 bound the miR-17/20 cluster promoter regulatory region. In summary, these studies identify a novel cyclin D1/miR-17/20 regulatory feedback loop through which cyclin D1 induces miR-17-5p/miR-20a. In turn, miR-17/20 limits the proliferative function of cyclin D1, thus linking expression of a specific miRNA cluster to the regulation of oncogenesis.

In humans the glutathione S-transferase (GST) genes encode four classes of proteins (GST) important in the detoxification of reactive electrophiles. Recently, a gene deletion polymorphism was discovered within the GST class theta locus that leads to a functional deficiency in GST theta activity within circulating red blood cells. In this study we have examined the ethnic distribution of this polymorphism using a polymerase chain reaction (PCR)-based genotyping method. Five different ethnic groups were studied: North American Caucasians, African-Americans, Mexican-Americans, Chinese and Koreans. The prevalence of the null genotype was highest among Chinese (64.4%), followed by Koreans (60.2%), African-Americans (21.8%) and Caucasians (20.4%), whereas the prevalence was lowest among Mexican-Americans (9.7%). Interestingly, the prevalence of the deleted genotype in Caucasians differed significantly when 257 individuals drawn from a nation wide organization were compared with 185 people from the New England area (23.7 versus 15.7%, P < 0.05, chi 2 test). These results indicate that there are major differences in the prevalence of this trait attributable to ethnicity and that ethnic origin even among Caucasians should be considered in studies of gene-environment interaction involving this polymorphism.

A strategy to covalently connect crystalline covalent organic frameworks (COFs) with semiconductors to create stable organic-inorganic Z-scheme heterojunctions for artificial photosynthesis is presented. A series of COF-semiconductor Z-scheme photocatalysts combining water-oxidation semiconductors (TiO2 , Bi2 WO6 , and α-Fe2 O3 ) with CO2 reduction COFs (COF-316/318) was synthesized and exhibited high photocatalytic CO2 -to-CO conversion efficiencies (up to 69.67 μmol g-1 h-1 ), with H2 O as the electron donor in the gas-solid CO2 reduction, without additional photosensitizers and sacrificial agents. This is the first report of covalently bonded COF/inorganic-semiconductor systems utilizing the Z-scheme applied for artificial photosynthesis. Experiments and calculations confirmed efficient semiconductor-to-COF electron transfer by covalent coupling, resulting in electron accumulation in the cyano/pyridine moieties of the COF for CO2 reduction and holes in the semiconductor for H2 O oxidation, thus mimicking natural photosynthesis.

This review summarizes recent advances relating to transition metal sulfide (TMS)-based bifunctional electrocatalysts, providing guidelines for the design and fabrication of TMS-based catalysts for practical application in water electrolysis.

Rapid land use change has taken place in many mega cities of China such as Beijing over the past two decades. In this paper, land use change dynamics were investigated by the combined use of satellite remote sensing, geographic information systems (GIS). The results indicated that there had been a notable and uneven urban growth and a major loss of cropland loss between 1986 and 2001. Most of the urban growth and loss of agriculture land occurred in inner and outer suburbs. Land use change was projected for the next 20 years using Markov chains and regression analyses. The further integration of remote sensing and GIS technologies with Markov model and regression model was found to be useful for describing, analyzing and predicting the process of land use change.

This paper addresses a decentralized leader-follower formation control problem for a group of fully actuated unmanned surface vehicles with prescribed performance and collision avoidance. The vehicles are subject to time-varying external disturbances, and the vehicle dynamics include both parametric uncertainties and uncertain nonlinear functions. The control objective is to make each vehicle follow its reference trajectory and avoid collision between each vehicle and its leader. We consider prescribed performance constraints, including transient and steady-state performance constraints, on formation tracking errors. In the kinematic design, we introduce the dynamic surface control technique to avoid the use of vehicle's acceleration. To compensate for the uncertainties and disturbances, we apply an adaptive control technique to estimate the uncertain parameters including the upper bounds of the disturbances and present neural network approximators to estimate uncertain nonlinear dynamics. Consequently, we design a decentralized adaptive formation controller that ensures uniformly ultimate boundedness of the closed-loop system with prescribed performance and avoids collision between each vehicle and its leader. Simulation results illustrate the effectiveness of the decentralized formation controller.

A modified high-performance liquid chromatography method of pre-column derivatization with 1-phenyl-3-methyl-5-pyrazolone (PMP) has been established for high resolution separation and high sensitivity determination of ten monosaccharides simultaneously, which frequently occur in algae polysaccharides. The effects of volume proportion of acetonitrile and pH value of mobile phase (0.1 M phosphate buffer–acetonitrile) on retention and separation of the monosaccharide derivatives were investigated with Eclipse XPB-C18 column screened out. The hydrolyzation condition of polysaccharides and derivatization procedure of hydrolysates were also optimized. The modified analysis method was used for the determination of monosaccharide compositions in five polysaccharide fractions isolated from Duanaliella salina. The results showed that PD1 and PD4a were acidic heteropolysaccharide mainly containing glucose and galactose respectively, and PD4a contained sulfated groups; PD2 and PD3 all were a glucan; while PD4b was a complex of polysaccharide linked with nucleic acids by covalent bonds.

Using covalent organic polymer pre­cursors, we have developed a new strategy for location control of N-dopant heteroatoms in the graphitic porous carbon, which otherwise is impossible to achieve with conventional N-doping techniques. The electrocatalytic activities of the N-doped holey graphene analogues are well correlated to the N-locations, showing possibility for tailoring the structure and property of N-doped carbon nanomaterials. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Muramyl dipeptide (MDP), a product of bacterial cell-wall peptidoglycan, activates innate immune cells by stimulating nucleotide-binding oligomerization domain containing 2 (NOD2) -dependent activation of the transcription factor NFkappaB and transcription of proinflammatory genes. A20 is a ubiquitin-modifying enzyme that restricts tumor necrosis factor (TNF) receptor and Toll-like receptor (TLR) -induced signals. We now show that MDP induces ubiquitylation of receptor- interacting protein 2 (RIP2) in primary macrophages. A20-deficient cells exhibit dramatically amplified responses to MDP, including increased RIP2 ubiquitylation, prolonged NFkappaB signaling, and increased production of proinflammatory cytokines. In addition, in vivo responses to MDP are exaggerated in A20-deficient mice and in chimeric mice bearing A20-deficient hematopoietic cells. These exaggerated responses occur independently of the TLR adaptors MyD88 and TRIF as well as TNF signals. These findings indicate that A20 directly restricts NOD2 induced signals in vitro and in vivo, and provide new insights into how these signals are physiologically restricted.

The construction of intramolecular donor–acceptor conjugated copolymers has been devised for years to enhance the mobility of charge carriers in an organic photovoltaic field; however, surprisingly, similar strategies have not been reported in polymeric photocatalytic systems for promoting the separation of charge carriers. Graphitic carbon nitride (g-C3N4) is an emerging polymeric visible-light photocatalyst with high stability but still low photocatalytic efficiency. Here, we prepared a series of g-C3N4-based intramolecular donor–acceptor copolymers (aromatics-incorporated g-C3N4) via nucleophilic substitution/addition reactions. The copolymer showed remarkably enhanced and stable visible-light photocatalytic hydrogen evolution performance. The intramolecular charge transfer transition is first proposed to explain the photocatalytic activity of g-C3N4-based photocatalysts under long-wavelength-light irradiation.

This study is an investigation of the contribution of morphological awareness in Chinese-English biliteracy acquisition. Comparable tasks in Chinese and English were administered to test children's skills in morphological awareness, phonological awareness, oral vocabulary, word reading, and reading comprehension. The results showed that after the effect of Chinese-based predictors had been accounted for, English morphological awareness of compound structure still contributed to variance in both character reading and reading comprehension in Chinese. This finding indicates a cross-language morphological transfer in acquisition of two distinct writing systems. The transfer from English L2 to Chinese L1 is due to the bilingual children's rapidly increasing English L2 skills in their primary school years.

Tumor-associated macrophages (TAMs) can influence ovarian cancer growth, migration, and metastasis, but the detailed mechanisms underlying ovarian cancer metastasis remain unclear. Here, we have shown a strong correlation between TAM-associated spheroids and the clinical pathology of ovarian cancer. Further, we have determined that TAMs promote spheroid formation and tumor growth at early stages of transcoelomic metastasis in an established mouse model for epithelial ovarian cancer. M2 macrophage–like TAMs were localized in the center of spheroids and secreted EGF, which upregulated αMβ2 integrin on TAMs and ICAM-1 on tumor cells to promote association between tumor cells and TAM. Moreover, EGF secreted by TAMs activated EGFR on tumor cells, which in turn upregulated VEGF/VEGFR signaling in surrounding tumor cells to support tumor cell proliferation and migration. Pharmacological blockade of EGFR or antibody neutralization of ICAM-1 in TAMs blunted spheroid formation and ovarian cancer progression in mouse models. These findings suggest that EGF secreted from TAMs plays a critical role in promoting early transcoelomic metastasis of ovarian cancer. As transcoelomic metastasis is also associated with many other cancers, such as pancreatic and colon cancers, our findings uncover a mechanism for TAM-mediated spheroid formation and provide a potential target for the treatment of ovarian cancer and other transcoelomic metastatic cancers.

<h3>Importance</h3> Difference in breast cancer survival by race is a recognized problem among Medicare beneficiaries. <h3>Objective</h3> To determine if racial disparity in breast cancer survival is primarily attributable to differences in presentation characteristics at diagnosis or subsequent treatment. <h3>Design, Setting, and Patients</h3> Comparison of 7375 black women 65 years and older diagnosed between 1991 to 2005 and 3 sets of 7375 matched white control patients selected from 99 898 white potential controls, using data for 16 US Surveillance, Epidemiology and End Results (SEER) sites in the SEER-Medicare database. All patients received follow-up through December 31, 2009, and the black case patients were matched to 3 white control populations on demographics (age, year of diagnosis, and SEER site), presentation (demographics variables plus patient comorbid conditions and tumor characteristics such as stage, size, grade, and estrogen receptor status), and treatment (presentation variables plus details of surgery, radiation therapy, and chemotherapy). <h3>Main Outcomes and Measures</h3> 5-Year survival. <h3>Results</h3> The absolute difference in 5-year survival (blacks, 55.9%; whites, 68.8%) was 12.9% (95% CI, 11.5%-14.5%;<i>P</i> &lt; .001) in the demographics match. This difference remained unchanged between 1991 and 2005. After matching on presentation characteristics, the absolute difference in 5-year survival was 4.4% (95% CI, 2.8%-5.8%;<i>P</i> &lt; .001) and was 3.6% (95% CI, 2.3%-4.9%;<i>P</i> &lt; .001) lower for blacks than for whites matched also on treatment. In the presentation match, fewer blacks received treatment (87.4% vs 91.8%;<i>P</i> &lt; .001), time from diagnosis to treatment was longer (29.2 vs 22.8 days;<i>P</i> &lt; .001), use of anthracyclines and taxols was lower (3.7% vs 5.0%;<i>P</i> &lt; .001), and breast-conserving surgery without other treatment was more frequent (8.2% vs 7.3%;<i>P</i> = .04). Nevertheless, differences in survival associated with treatment differences accounted for only 0.81% of the 12.9% survival difference. <h3>Conclusions and Relevance</h3> In the SEER-Medicare database, differences in breast cancer survival between black and white women did not substantially change among women diagnosed between 1991 and 2005. These differences in survival appear primarily related to presentation characteristics at diagnosis rather than treatment differences.

Abstract Therapeutic antibodies that target T-cell co-inhibitory molecules display potent antitumor effects in multiple types of cancer. LSECtin is a cell surface lectin of the DC-SIGN family expressed in dendritic cells that inhibits T-cell responses. LSECtin limits T-cell activity in infectious disease, but it has not been studied in cancer. Here we report the finding that LSECtin is expressed commonly in melanomas where it blunts tumor-specific T-cell responses. When expressed in B16 melanoma cells, LSECtin promoted tumor growth, whereas its blockade slowed tumor growth in either wild-type or LSECtin-deficient mice. The tumor-promoting effects of LSECtin were abrogated in Rag1−/− mice or in response to CD4+ or CD8+ T-cell depletion. Mechanistic investigations determined that LSECtin inhibited the proliferation of tumor-specific effector T cells by downregulating the cell cycle kinases CDK2, CDK4, and CDK6. Accordingly, as expressed in B16, tumor cells LSECtin inhibited tumor-specific T-cell responses relying upon proliferation in vitro and in vivo. Notably, LSECtin interacted with the co-regulatory molecule LAG-3, the blockade of which restored IFNγ secretion that was reduced by melanoma-derived expression of LSECtin. Together, our findings reveal that common expression of LSECtin in melanoma cells engenders a mechanism of immune escape, with implications for novel immunotherapeutic combination strategies. Cancer Res; 74(13); 3418–28. ©2014 AACR.

Photocatalytic hydrogen production from biomass is a promising alternative to water splitting thanks to the oxidation half-reaction being more facile and its ability to simultaneously produce solar fuels and value-added chemicals. Here, we demonstrate the coproduction of H2 and diesel fuel precursors from lignocellulose-derived methylfurans via acceptorless dehydrogenative C−C coupling, using a Ru-doped ZnIn2S4 catalyst and driven by visible light. With this chemistry, up to 1.04 g gcatalyst−1 h−1 of diesel fuel precursors (~41% of which are precursors of branched-chain alkanes) are produced with selectivity higher than 96%, together with 6.0 mmol gcatalyst−1 h−1 of H2. Subsequent hydrodeoxygenation reactions yield the desired diesel fuels comprising straight- and branched-chain alkanes. We suggest that Ru dopants, substituted in the position of indium ions in the ZnIn2S4 matrix, improve charge separation efficiency, thereby accelerating C−H activation for the coproduction of H2 and diesel fuel precursors. Biomass can be used to scavenge photogenerated holes in photocatalytic hydrogen production, but the oxidized molecules that form are not always useful products. Here, the authors use Ru-ZnIn2S4 to photocatalyse the dehydrogenative C−C coupling of lignocellulose-derived methylfurans, forming both hydrogen and diesel fuel precursors.

Abstact Background and Aim The gut microbiota plays a pivotal role in the intestinal diseases. Fecal microbiota transplantation ( FMT ) might be a rescue therapy for refractory inflammatory bowel disease. This study aimed to evaluate the safety, feasibility, and efficacy of FMT through mid‐gut for refractory C rohn's disease ( CD ). Methods We established standardized laboratory protocol and clinical work flow for FMT . Only refractory CD patients with H arvey– B radshaw I ndex ( HBI ) score ≥ 7 were enrolled for this study. All included patients were treated with single FMT through mid‐gut and assessed during follow‐up. Results Metagenomics analysis showed a high concordance between feces sample and purified fecal microbiota from same donors. Standardized fecal microbiota preparation and clinical flow significantly simplified the practical aspects of FMT . Totally, 30 patients were qualified for the present analysis. The rate of clinical improvement and remission based on clinical activity at the first month was 86.7% (26/30) and 76.7% (23/30), respectively, which was higher than other assessment points within 15‐month follow‐up. Patients' body weight increased after FMT , and the lipid profile improved as well. FMT also showed a fast and continuous significant effect in relieving the sustaining abdominal pain associated with sustaining CD . Conclusion This is a pilot study with the largest sample of patients with refractory CD who underwent single FMT . The results demonstrated that FMT through mid‐gut might be a safe, feasible, and efficient rescue therapy for refractory CD .

This paper studies neural learning control with predefined tracking error bound for a marine surface vessel whose accurate dynamics could not be obtained a priori. With the introduction of an error transformation function, the constrained tracking control of the original vessel is transformed into the stabilization of an unconstrained system. A filtered tracking error is introduced based on the error transformation, and radial basis function (RBF) neural networks (NNs) are employed to approximate unknown vessel dynamics. Subsequently, stable adaptive NN control is proposed to ensure ultimate boundedness of all the signals in the closed-loop system and to guarantee prescribed tracking performances. Under persistent excitation (PE) condition, the proposed adaptive NN control is shown to be capable of acquiring knowledge on the vessel dynamics and of storing the learned knowledge in memory. The stored knowledge is reused to develop neural learning control such that the improved control performance with faster tracking convergence rate and less computational burden could be achieved, while prescribed transient and steady-state tracking control performances are guaranteed. Simulation studies are performed to demonstrate the effectiveness of the proposed design techniques.

Presented is the first enantioselective copper-catalyzed 1,6-conjugate addition of bis(pinacolato)diboron to para-quinone methides. The reaction proceeds with excellent yields and good to excellent enantioselectivities, and provides an attractive approach to the construction of optically active gem-diarylmehtine boronic esters. Additionally, the subsequent conversion of the derived potassium trifluoroborates into triarylmethanes with highly enantiospecificity was realized.

C2c2, the effector of type VI CRISPR-Cas systems, has two RNase activities—one for cutting its RNA target and the other for processing the CRISPR RNA (crRNA). Here, we report the structures of Leptotrichia shahii C2c2 in its crRNA-free and crRNA-bound states. While C2c2 has a bilobed structure reminiscent of all other Class 2 effectors, it also exhibits different structural characteristics. It contains the REC lobe with a Helical-1 domain and the NUC lobe with two HEPN domains. The two RNase catalytic pockets responsible for cleaving pre-crRNA and target RNA are independently located on Helical-1 and HEPN domains, respectively. crRNA binding induces significant conformational changes that are likely to stabilize crRNA binding and facilitate target RNA recognition. These structures provide important insights into the molecular mechanism of dual RNase activities of C2c2 and establish a framework for its future engineering as a RNA editing tool.

Although silicon (Si) is not recognized as an essential element for general higher plants, it has beneficial effects on the growth and production of a wide range of plant species. Si is known to effectively mitigate various environmental stresses and enhance plant resistance against both fungal and bacterial pathogens; however, the underlying mechanisms are largely unknown. In this review, the effects of Si on plant-pathogen interactions are discussedanalyzed, mainly from on physical, biochemical, and molecular aspects. In most cases, the Si-induced biochemical/molecular resistance during plant-pathogen interactions were dominated as joint resistance, involving activating defense-related enzymes activates, stimulating antimicrobial compound production, regulating the complex network of signal pathways, and activating of the expression of defense-related genes. The most previous studies described an independent process, however, the whole plant resistances were rarely considered, especially the interaction of different process in higher plants. Si can act as a modulator influencing plant defense responses and interacting with key components of plant stress signaling systems leading to induced resistance. Priming of plant defense responses, alterations in phytohormone homeostasis, and networking by defense signaling components are all potential mechanisms involved in Si-triggered resistance responses. This review summarizes the roles of Si in plant-microbe interactions, evaluates the potential for improving plant resistance by modifying Si fertilizer inputs, and highlights future research concerning the role of Si in agriculture.

The first catalytic formal [5+4] cycloaddition to prepare nine-membered heterocycles is presented. Under palladium catalysis, the reaction of N-tosyl azadienes and substituted vinylethylene carbonates (VECs) proceeds smoothly to produce benzofuran-fused heterocycles in uniformly high efficiency. Highly diastereoselective functionalization of the nine-membered heterocycles through peripheral attack is also demonstrated.

Traditional skin tumor surgery and chronic bacterial-infection-induced wound healing/skin regeneration is still a challenge. The ideal strategy should eliminate the tumor, enhance wound healing/skin formation, and be anti-infection. Herein, we designed a multifunctional elastomeric poly(l-lactic acid)–poly(citrate siloxane)–curcumin@polydopamine hybrid nanofibrous scaffold (denoted as PPCP matrix) for tumor-infection therapy and infection-induced wound healing. The PPCP matrix showed intrinsically multifunctional properties including antioxidative, anti-inflammatory, photothermal, antibacterial, anticancer, and angiogenesis bioactivities. The polydopamine/curcumin presented an excellent near-infrared photothermal/cancer cell toxicity capacity, respectively, which supported PPCP for synergetic skin tumor therapy and antibacterial properties in vitro/in vivo. Additionally, the PPCP nanofibrous matrix significantly promotes the adhesion and proliferation of normal skin cells and accelerates the cutaneous wound healing in normal mice and bacterial-infected mice by enhancing the early angiogenesis. The PPCP nanofibrous matrix with multifunctional bioactivities provides a competitive strategy for skin tumor and bacterial-infection-induced wound healing.

Pericytes are positioned between brain capillary endothelial cells, astrocytes and neurons. They degenerate in multiple neurological disorders. However, their role in the pathogenesis of these disorders remains debatable. Here we generate an inducible pericyte-specific Cre line and cross pericyte-specific Cre mice with iDTR mice carrying Cre-dependent human diphtheria toxin receptor. After pericyte ablation with diphtheria toxin, mice showed acute blood–brain barrier breakdown, severe loss of blood flow, and a rapid neuron loss that was associated with loss of pericyte-derived pleiotrophin (PTN), a neurotrophic growth factor. Intracerebroventricular PTN infusions prevented neuron loss in pericyte-ablated mice despite persistent circulatory changes. Silencing of pericyte-derived Ptn rendered neurons vulnerable to ischemic and excitotoxic injury. Our data demonstrate a rapid neurodegeneration cascade that links pericyte loss to acute circulatory collapse and loss of PTN neurotrophic support. These findings may have implications for the pathogenesis and treatment of neurological disorders that are associated with pericyte loss and/or neurovascular dysfunction. Using pericyte-specific Cre and ablation mouse lines, the authors show that loss of brain pericytes leads to circulatory failure and reduced pleiotrophin causing rapid neuron loss. These findings link pericyte loss to a rapid neurodegeneration cascade.

A novel strategy is used to design large-scale polarized carbon-based dielectric composites with sufficient interaction to electromagnetic waves. Highly uniform polar zinc oxide arrays are vertically grown on a flexible conductive carbon cloth substrate (CC@ZnO) via an in situ orientation growth process. Anion regulation is found to be a key factor to the morphology of hierarchical ZnO arrays including single-rod, cluster and tetrapod-shaped. As a typical dielectric loss hybrid composite, the electromagnetic parameters of the CC@ZnO system and charge density distribution in polarized ZnO rods confirm that the 3D intertwined carbon cloth is used as a conductive network to provide ballistic electron transportation. Moreover, the defect-rich ZnO arrays are well in contact with the CC substrate, favoring interface polarization, multiscattering, as well as impedance matching. Surprisingly, the efficient absorption bandwidth of the CC@ZnO-1 composite can reach 10.6 GHz, covering all X and Ku bands. The oriented ZnO possesses oxygen vacancies and exposure to a large amount of intrinsic polar surfaces, encouraging the polarization behavior under microwave frequency. Optimized CC@ZnO materials exhibit fast electron transportation, strong microwave energy dissipation, and superior wide absorption. The results suggest that the CC@ZnO composites have promising potential as flexible, tuning, and broadband microwave absorbers.

VEGF is a potent vascular growth factor produced by podocytes in the developing and mature glomerulus. Specific deletion of VEGF from podocytes causes glomerular abnormalities including profound endothelial cell injury, suggesting that paracrine signaling is critical for maintaining the glomerular filtration barrier (GFB). However, it is not clear whether normal GFB function also requires autocrine VEGF signaling in podocytes. In this study, we sought to determine whether an autocrine VEGF-VEGFR-2 loop in podocytes contributes to the maintenance of the GFB in vivo. We found that induced, whole-body deletion of VEGFR-2 caused marked abnormalities in the kidney and also other tissues, including the heart and liver. By contrast, podocyte-specific deletion of the VEGFR-2 receptor had no effect on glomerular development or function even up to 6 months old. Unlike cell culture models, enhanced expression of VEGF by podocytes in vivo caused foot process fusion and alterations in slit diaphragm-associated proteins; however, inhibition of VEGFR-2 could not rescue this defect. Although VEGFR-2 was dispensable in the podocyte, glomerular endothelial cells depended on VEGFR-2 expression: postnatal deletion of the receptor resulted in global defects in the glomerular microvasculature. Taken together, our results provide strong evidence for dominant actions of a paracrine VEGF-VEGFR-2 signaling loop both in the developing and in the filtering glomerulus. VEGF produced by the podocyte regulates the structure and function of the adjacent endothelial cell.

Stature is affected by many polymorphisms of small effect in humans 1 . In contrast, variation in dogs, even within breeds, has been suggested to be largely due to variants in a small number of genes2,3. Here we use data from cattle to compare the genetic architecture of stature to those in humans and dogs. We conducted a meta-analysis for stature using 58,265 cattle from 17 populations with 25.4 million imputed whole-genome sequence variants. Results showed that the genetic architecture of stature in cattle is similar to that in humans, as the lead variants in 163 significantly associated genomic regions (P < 5 × 10−8) explained at most 13.8% of the phenotypic variance. Most of these variants were noncoding, including variants that were also expression quantitative trait loci (eQTLs) and in ChIP–seq peaks. There was significant overlap in loci for stature with humans and dogs, suggesting that a set of common genes regulates body size in mammals. Meta-analysis of data from 58,265 cattle shows that the genetic architecture underlying stature is similar to that in humans, where many genomic regions individually explain only a small amount of phenotypic variance.

Intrinsic electric-magnetic property and special nano-micro architecture of functional materials have a significant effect on its electromagnetic wave energy conversion, especially in the microwave absorption (MA) field. Herein, porous Ni1-xCox@Carbon composites derived from metal-organic framework (MOF) were successfully synthesized via solvothermal reaction and subsequent annealing treatments. Benefiting from the coordination, carbonized bimetallic Ni-Co-MOF maintained its initial skeleton and transformed into magnetic-carbon composites with tunable nano-micro structure. During the thermal decomposition, generated magnetic particles/clusters acted as a catalyst to promote the carbon sp2 arrangement, forming special core-shell architecture. Therefore, pure Ni@C microspheres displayed strong MA behaviors than other Ni1-xCox@Carbon composites. Surprisingly, magnetic-dielectric Ni@C composites possessed the strongest reflection loss value - 59.5 dB and the effective absorption frequency covered as wide as 4.7 GHz. Meanwhile, the MA capacity also can be boosted by adjusting the absorber content from 25% to 40%. Magnetic-dielectric synergy effect of MOF-derived Ni1-xCox@Carbon microspheres was confirmed by the off-axis electron holography technology making a thorough inquiry in the MA mechanism.

A cooperative Cu/Pd-catalyzed asymmetric three-component reaction of styrenes, B2(pin)2, and allyl carbonates was reported. This reaction, in the presence of chiral CuOAc/SOP and achiral Pd(dppf)Cl2 catalysts, occurs smoothly with high enantioselectivities (up to 97% ee) . The allylboration products, which contain alkene (or diene) unite and alkylboron group, are easily functionalized. The utility of this protocol was demonstrated through the synthesis of an antipsychotic drug, (-)-preclamol.

Direct chemical vapor deposition (CVD) growth of single-layer graphene on CVD-grown hexagonal boron nitride (h-BN) film can suggest a large-scale and high-quality graphene/h-BN film hybrid structure with a defect-free interface. This sequentially grown graphene/h-BN film shows better electronic properties than that of graphene/SiO2 or graphene transferred on h-BN film, and suggests a new promising template for graphene device fabrication.

Canonical functions of mitochondria include the regulation of cellular survival, orchestration of anabolic and metabolic pathways, as well as reactive oxygen species (ROS) signaling. Recent discoveries, nevertheless, have demonstrated that mitochondria are also critical elements to stimulate innate immune signaling cascade that is able to intensify the inflammation upon cytotoxic stimuli beyond microbial infection. Here we review the expanding research field of mitochondria and oxidative stress in innate immune system to highlight the new mechanistic insights and discuss the pathological relevance of mitochondrial dysregulation induced aberrant innate immune responses in a growing list of sterile inflammatory diseases.

A novel MnO2/g-C3N4 heterojunction composite was synthesized via a simple in-situ redox reaction between KMnO4 and MnSO4·H2O adsorbed on the surface of g-C3N4 for the first time. MnO2 featuring 2D δ-phase layered structure was intimately attached onto the surface of g-C3N4 layers via CO bonding. Notably, the synthesized MnO2/g-C3N4 photocatalyst showed substantially enhanced photocatalytic activity in the reduction of CO2 than pure g-C3N4 and MnO2. The highest CO production amount of 9.6 μmol g−1 has been obtained at an optimized loading amount of MnO2 under 1 h irradiation of a 300 W Xe lamp. The incorporation of narrow band gap MnO2 on the surface of g-C3N4 enhanced its light harvesting ability. And the solid hetero-interface between MnO2 and g-C3N4 together with their well matched band structure was favorable for the separation of photo-induced carriers, consequently enhanced its photocatalytic activity. This novel 2D-2D MnO2/g-C3N4 heterostructure is expected to have great potentials in CO2 photoreduction.

Vascular endothelial cells normally perform several key homeostatic functions such as keeping blood fluid, regulating blood flow, regulating macromolecule and fluid exchange with the tissues, preventing leukocyte activation, and aiding in immune surveillance for pathogens. Injury or cell death impairs or prevents conduct of these activities, resulting in dysfunction. Most endothelial cell death is apoptotic, involving activation of caspases, but nonapoptotic death responses also have been described. Stimuli that can cause endothelial injury or death include environmental stresses such as oxidative stress, endoplasmic reticulum stress, metabolic stress, and genotoxic stress, as well as pathways of injury mediated by the innate and adaptive immune systems. Pathways of immune-mediated death include those activated by death receptors as well as those activated by cytolytic granules and reactive oxygen species. The biochemical pathways activated by these injurious stimuli are described herein and will serve as a basis for future development of endothelial protective therapies.

Controlled growth of high-quality graphene is still the bottleneck of practical applications. The widely used chemical vapour deposition process generally suffers from an uncontrollable carbon precipitation effect that leads to inhomogeneous growth and strong correlation to the growth conditions. Here we report the rational design of a binary metal alloy that effectively suppresses the carbon precipitation process and activates a self-limited growth mechanism for homogeneous monolayer graphene. As demonstrated by an Ni–Mo alloy, the designed binary alloy contains an active catalyst component for carbon source decomposition and graphene growth and a black hole counterpart for trapping the dissolved carbons and forming stable metal carbides. This type of process engineering has been used to grow strictly single-layer graphene with 100% surface coverage and excellent tolerance to variations in growth conditions. With simplicity, scalability and a very large growth window, the presented approach may facilitate graphene research and industrial applications. Graphene may be used in nanoscale electronics and devices, but the ability to synthesise uniform graphene with well-controlled layer numbers is necessary for these applications. Using a Ni–Mo alloy, this study demonstrates single-layer graphene growth with 100% surface coverage and tolerance to variations in growth conditions.

A triple signal amplification strategy was designed for ultrasensitive immunosensing of cancer biomarker. This strategy was achieved using graphene to modify immunosensor surface for accelerating electron transfer, poly(styrene-co-acrylic acid) microbead (PSA) carried gold nanoparticles (AuNPs) as tracing tag to label signal antibody (Ab2) and AuNPs induced silver deposition for anodic stripping analysis. The immunosensor was constructed by covalently immobilizing capture antibody on chitosan/electrochemically reduced graphene oxide film modified glass carbon electrode. The in situ synthesis of AuNPs led to the loading of numerous AuNPs on PSA surface and convenient labeling of the tag to Ab2. With a sandwich-type immunoreaction, the AuNPs/PSA labeled Ab2 was captured on the surface of an immunosensor to further induce a silver deposition process. The electrochemical stripping signal of the deposited silver nanoparticles in KCl was used to monitor the immunoreaction. The triple signal amplification greatly enhanced the sensitivity for biomarker detection. The proposed method could detect carcinoembryonic antigen with a linear range of 0.5 pg mL–1 to 0.5 ng mL–1 and a detection limit down to 0.12 pg mL–1. The immunosensor exhibited good stability and acceptable reproducibility and accuracy, indicating potential applications in clinical diagnostics.

Type 2 diabetes mellitus (T2DM) is a common clinical chronic disease, while its pathogenesis is still inconclusive. Intestinal flora, the largest micro-ecological system in the human body, is involved in, meanwhile has a major impact on the body's material and energy metabolism. Recent studies have shown that in addition to obesity, genetics, and islet dysfunction, the disturbance of intestinal flora may partly give rise to diabetes. In this paper, we summarized the current research on the correlation between T2DM and intestinal flora, and concluded the pathological mechanisms of intestinal flora involved in T2DM. Moreover, the ideas and methods of prevention and treatment of T2DM based on intestinal flora were proposed, providing theoretical basis and literature reference for the treatment of T2DM and its complications based on the regulation of intestinal flora.

A single nucleotide polymorphism in the DAB2IP gene is associated with risk of aggressive prostate cancer (PCa), and loss of DAB2IP expression is frequently detected in metastatic PCa. However, the functional role of DAB2IP in PCa remains unknown. Here, we show that the loss of DAB2IP expression initiates epithelial-to-mesenchymal transition (EMT), which is visualized by repression of E-cadherin and up-regulation of vimentin in both human normal prostate epithelial and prostate carcinoma cells as well as in clinical prostate-cancer specimens. Conversely, restoring DAB2IP in metastatic PCa cells reversed EMT. In DAB2IP knockout mice, prostate epithelial cells exhibited elevated mesenchymal markers, which is characteristic of EMT. Using a human prostate xenograft-mouse model, we observed that knocking down endogenous DAB2IP in human carcinoma cells led to the development of multiple lymph node and distant organ metastases. Moreover, we showed that DAB2IP functions as a scaffold protein in regulating EMT by modulating nuclear beta-catenin/T-cell factor activity. These results show the mechanism of DAB2IP in EMT and suggest that assessment of DAB2IP may provide a prognostic biomarker and potential therapeutic target for PCa metastasis.

microRNAs are thought to regulate tumor progression and invasion via direct interaction with target genes within cells. Here the microRNA17/20 cluster is shown to govern cellular migration and invasion of nearby cells via heterotypic secreted signals. microRNA17/20 abundance is reduced in highly invasive breast cancer cell lines and node-positive breast cancer specimens. Cell-conditioned medium from microRNA17/20–overexpressing noninvasive breast cancer cell MCF7 was sufficient to inhibit MDA-MB-231 cell migration and invasion through inhibiting secretion of a subset of cytokines, and suppressing plasminogen activation via inhibition of the secreted plasminogen activators (cytokeratin 8 and α-enolase). microRNA17/20 directly repressed IL-8 by targeting its 3′ UTR, and inhibited cytokeratin 8 via the cell cycle control protein cyclin D1. At variance with prior studies, these results demonstrated a unique mechanism of how the altered microRNA17/20 expression regulates cellular secretion and tumor microenvironment to control migration and invasion of neighboring cells in breast cancer. These findings not only reveal an antiinvasive function of miR-17/20 in breast cancer, but also identify a heterotypic secreted signal that mediates the microRNA regulation of tumor metastasis.

<h2>Summary</h2> Bacteria acquire memory of viral invaders by incorporating invasive DNA sequence elements into the host CRISPR locus, generating a new spacer within the CRISPR array. We report on the structures of Cas1-Cas2-dual-forked DNA complexes in an effort toward understanding how the protospacer is sampled prior to insertion into the CRISPR locus. Our study reveals a protospacer DNA comprising a 23-bp duplex bracketed by tyrosine residues, together with anchored flanking 3′ overhang segments. The PAM-complementary sequence in the 3′ overhang is recognized by the Cas1a catalytic subunits in a base-specific manner, and subsequent cleavage at positions 5 nt from the duplex boundary generates a 33-nt DNA intermediate that is incorporated into the CRISPR array via a cut-and-paste mechanism. Upon protospacer binding, Cas1-Cas2 undergoes a significant conformational change, generating a flat surface conducive to proper protospacer recognition. Here, our study provides important structure-based mechanistic insights into PAM-dependent spacer acquisition.

Inspired by the fantastic and fast-growing wearable electronics such as Google Glass and Apple iWatch, matchable lightweight and weaveable energy storage systems are urgently demanded while remaining as a bottleneck in the whole technology. Fiber-shaped energy storage devices that can be woven into electronic textiles may represent a general and effective strategy to overcome the above difficulty. Here a coaxial fiber lithium-ion battery has been achieved by sequentially winding aligned carbon nanotube composite yarn cathode and anode onto a cotton fiber. Novel yarn structures are designed to enable a high performance with a linear energy density of 0.75 mWh cm–1. A wearable energy storage textile is also produced with an areal energy density of 4.5 mWh cm–2.

An approach for designing a wide-angle perfect absorber at infrared frequencies is proposed. The technique is based on a perfectly impedance-matched sheet (PIMS) formed by plasmonic nanostructure. It is shown that the effective impedance is more physical meaningful and beneficial than effective medium in describing the electromagnetic properties of metamaterial absorber. As a specific implementation of this technique, a wide-angle polarization-independent dual-band absorber is numerically demonstrated at frequencies of 100THz and 280THz with absorption close to 100% simultaneously. Circuit models are utilized to describe the impedance property of localized plasmon modes and the results show good agreement with that retrieved from reflection coefficient at normal incidence.

Although much progress has been made to develop high-performance lithium–sulfur batteries (LSBs), the reported physical or chemical routes to sulfur cathode materials are often multistep/complex and even involve environmentally hazardous reagents, and hence are infeasible for mass production. Here, we report a simple ball-milling technique to combine both the physical and chemical routes into a one-step process for low-cost, scalable, and eco-friendly production of graphene nanoplatelets (GnPs) edge-functionalized with sulfur (S-GnPs) as highly efficient LSB cathode materials of practical significance. LSBs based on the S-GnP cathode materials, produced by ball-milling 70 wt % sulfur and 30 wt % graphite, delivered a high initial reversible capacity of 1265.3 mAh g–1 at 0.1 C in the voltage range of 1.5–3.0 V with an excellent rate capability, followed by a high reversible capacity of 966.1 mAh g–1 at 2 C with a low capacity decay rate of 0.099% per cycle over 500 cycles, outperformed the current state-of-the-art cathode materials for LSBs. The observed excellent electrochemical performance can be attributed to a 3D “sandwich-like” structure of S-GnPs with an enhanced ionic conductivity and lithium insertion/extraction capacity during the discharge–charge process. Furthermore, a low-cost porous carbon paper pyrolyzed from common filter paper was inserted between the 0.7S-0.3GnP electrode and porous polypropylene film separator to reduce/eliminate the dissolution of physically adsorbed polysulfide into the electrolyte and subsequent cross-deposition on the anode, leading to further improved capacity and cycling stability.

Neural progenitor cells (NPCs) can be induced from somatic cells by defined factors. Here we report that NPCs can be generated from mouse embryonic fibroblasts by a chemical cocktail, namely VCR (V, VPA, an inhibitor of HDACs; C, CHIR99021, an inhibitor of GSK-3 kinases and R, Repsox, an inhibitor of TGF-β pathways), under a physiological hypoxic condition. These chemical-induced NPCs (ciNPCs) resemble mouse brain-derived NPCs regarding their proliferative and self-renewing abilities, gene expression profiles, and multipotency for different neuroectodermal lineages in vitro and in vivo. Further experiments reveal that alternative cocktails with inhibitors of histone deacetylation, glycogen synthase kinase, and TGF-β pathways show similar efficacies for ciNPC induction. Moreover, ciNPCs can also be induced from mouse tail-tip fibroblasts and human urinary cells with the same chemical cocktail VCR. Thus our study demonstrates that lineage-specific conversion of somatic cells to NPCs could be achieved by chemical cocktails without introducing exogenous factors.

As highlighted by recent articles [Phys. Rev. Lett. 105, 053901 (2010) and Science 331, 889-892 (2011)], the coherent control of narrowband perfect absorption in intrinsic silicon slab has attracted much attention. In this paper, we demonstrate that broadband coherent perfect absorber (CPA) can be achieved by heavily doping an ultrathin silicon film. Two distinct perfect absorption regimes are derived with extremely broad and moderately narrow bandwidth under symmetrical coherent illumination. The large enhancement of bandwidth may open up new avenues for broadband applications. Subsequently, interferometric method is used to control the absorption coherently with extremely large contrast between the maximum and minimum absorptance. Compared with the results in literatures, the thin film CPAs proposed here show much more flexibility in both operation frequency and bandwidth.

Photosensitive Al2O3-resin slurries with high solid loading, low viscosity used for stereolithography based additive manufacturing were prepared in this paper. The dispersion behavior and rheological behavior of the Al2O3-resin slurries were studied by rheology observation and sedimentation tests. The dispersant type, concentration and solid loading had significant effects on the rheological behavior and stability of the photosensitive Al2O3-resin slurries. A long term stability and homogeneity slurry was obtained when the dispersant and concentration were KOS110 and 5 wt%, respectively. The Al2O3 slurry prepared with a high solid loading up to 60 vol%, low viscosity of 15.4 Pa s at 200 s−1 was chosen for stereolithography based additive manufacturing.

Abstract The surgical procedure in skin‐tumor therapy usually results in cutaneous defects, and multidrug‐resistant bacterial infection could cause chronic wounds. Here, for the first time, an injectable self‐healing antibacterial bioactive polypeptide‐based hybrid nanosystem is developed for treating multidrug resistant infection, skin‐tumor therapy, and wound healing. The multifunctional hydrogel is successfully prepared through incorporating monodispersed polydopamine functionalized bioactive glass nanoparticles (BGN@PDA) into an antibacterial F127‐ε‐Poly‐L‐lysine hydrogel. The nanocomposites hydrogel displays excellent self‐healing and injectable ability, as well as robust antibacterial activity, especially against multidrug‐resistant bacteria in vitro and in vivo. The nanocomposites hydrogel also demonstrates outstanding photothermal performance with (near‐infrared laser irradiation) NIR irradiation, which could effectively kill the tumor cell (&gt;90%) and inhibit tumor growth (inhibition rate up to 94%) in a subcutaneous skin‐tumor model. In addition, the nanocomposites hydrogel effectively accelerates wound healing in vivo. These results suggest that the BGN‐based nanocomposite hydrogel is a promising candidate for skin‐tumor therapy, wound healing, and anti‐infection. This work may offer a facile strategy to prepare multifunctional bioactive hydrogels for simultaneous tumor therapy, tissue regeneration, and anti‐infection.

The Notch pathway plays an important role in both stem cell biology and cancer. Dysregulation of Notch signaling has been reported in several human tumor types. In this report, we describe the development of an antibody, OMP-59R5 (tarextumab), which blocks both Notch2 and Notch3 signaling.We utilized patient-derived xenograft tumors to evaluate antitumor effect of OMP-59R5. Immunohistochemistry, RNA microarray, real-time PCR, and in vivo serial transplantation assays were employed to investigate the mechanisms of action and pharmacodynamic readouts.We found that anti-Notch2/3, either as a single agent or in combination with chemotherapeutic agents was efficacious in a broad spectrum of epithelial tumors, including breast, lung, ovarian, and pancreatic cancers. Notably, the sensitivity of anti-Notch2/3 in combination with gemcitabine in pancreatic tumors was associated with higher levels of Notch3 gene expression. The antitumor effect of anti-Notch2/3 in combination with gemcitabine plus nab-paclitaxel was greater than the combination effect with gemcitabine alone. OMP-59R5 inhibits both human and mouse Notch2 and Notch3 function and its antitumor activity was characterized by a dual mechanism of action in both tumor and stromal/vascular cells in xenograft experiments. In tumor cells, anti-Notch2/3 inhibited expression of Notch target genes and reduced tumor-initiating cell frequency. In the tumor stroma, OMP-59R5 consistently inhibited the expression of Notch3, HeyL, and Rgs5, characteristic of affecting pericyte function in tumor vasculature.These findings indicate that blockade of Notch2/3 signaling with this cross-reactive antagonist antibody may be an effective strategy for treatment of a variety of tumor types.

Photocatalysis is a potentially promising approach to harvest aromatic compounds from lignin. However, the development of an active and selective solid photocatalyst is still challenging for lignin transformation under ambient conditions. We herein report a mild photocatalytic oxidative strategy for C–C bond cleavage of lignin β-O-4 and β-1 linkages using a mesoporous graphitic carbon nitride catalyst. Identifications by solid-state NMR techniques and density functional theory (DFT) calculations indicate that π–π stacking interactions are most likely present between the flexible carbon nitride surface and lignin model molecule. Besides, low charge recombination efficiency and high specific surface area (206.5 m2 g–1) of the catalyst also contribute to its high catalytic activity. Mechanistic investigations reveal that photogenerated holes, as the main active species, trigger the oxidation and C–C bond cleavage of lignin models. This study sheds light on the interaction between complex lignin structures and the catalyst surface and provides a new strategy of photocatalytic cleavage of lignin models with heterogeneous photocatalysts.

Microneedles are an efficient and minimally invasive approach to transdermal drug delivery and extraction of skin interstitial fluid. Compared to solid microneedles made of silicon, metals and ceramics, polymeric microneedles have attracted extensive attention due to their excellent biocompatibility, biodegradability and nontoxicity. They are easy to fabricate in large scale and can load drugs in high amounts. More importantly, polymers with different degradation profiles, swelling properties, and responses to biological/physical stimuli can be employed to fabricate polymeric microneedles with different mechanical properties and performance. This review provides a guideline for the selection of polymers and the corresponding fabrication methods for polymeric microneedles while summarizing their recent application in drug delivery and fluid extraction. It should be noted that although polymeric microneedles can achieve efficient transdermal delivery of drugs, their wide applications were limited by their unsatisfactory transdermal therapeutic efficiency. Delivery of nanomedicines that incorporate drugs into functional nanoparticles/capsules can address this problem and thus may be an interesting direction in the future.

Electrospun superhydrophobic organic/inorganic composite nanofibrous membranes exhibiting excellent direct contact membrane distillation (DCMD) performance were fabricated by a facile route combining the hydrophobization of silica nanoparticles (SiO2 NPs) and colloid electrospinning of the hydrophobic silica/poly(vinylidene fluoride) (PVDF) matrix. Benefiting from the utilization of SiO2 NPs with three different particle sizes, the electrospun nanofibrous membranes (ENMs) were endowed with three different delicate nanofiber morphologies and fiber diameter distribution, high porosity, and superhydrophobic property, which resulted in excellent waterproofing and breathability. Significantly, structural attributes analyses have indicated the major contributing role of fiber diameter distribution on determining the augment of permeate vapor flux through regulating mean flow pore size (MFP). Meanwhile, the extremely high liquid entry pressure of water (LEPw, 2.40 ± 0.10 bar), robust nanofiber morphology of PVDF immobilized SiO2 NPs, remarkable mechanical properties, thermal stability, and corrosion resistance endowed the as-prepared membranes with prominent desalination capability and stability for long-term MD process. The resultant choreographed PVDF/silica ENMs with optimized MFP presented an outstanding permeate vapor flux of 41.1 kg/(m(2)·h) and stable low permeate conductivity (∼2.45 μs/cm) (3.5 wt % NaCl salt feed; ΔT = 40 °C) over a DCMD test period of 24 h without membrane pores wetting detected. This result was better than those of typical commercial PVDF membranes and PVDF and modified PVDF ENMs reported so far, suggesting them as promising alternatives for MD applications.

The histone variants H3.3 and H2A.Z have recently emerged as two of the most important features in transcriptional regulation, the molecular mechanism of which still remains poorly understood. In this study, we investigated the regulation of H3.3 and H2A.Z on chromatin dynamics during transcriptional activation. Our in vitro biophysical and biochemical investigation showed that H2A.Z promoted chromatin compaction and repressed transcriptional activity. Surprisingly, with only four to five amino acid differences from the canonical H3, H3.3 greatly impaired higher-ordered chromatin folding and promoted gene activation, although it has no significant effect on the stability of mononucleosomes. We further demonstrated that H3.3 actively marks enhancers and determines the transcriptional potential of retinoid acid (RA)-regulated genes via creating an open chromatin signature that enables the binding of RAR/RXR. Additionally, the H3.3-dependent recruitment of H2A.Z on promoter regions resulted in compaction of chromatin to poise transcription, while RA induction results in the incorporation of H3.3 on promoter regions to activate transcription via counteracting H2A.Z-mediated chromatin compaction. Our results provide key insights into the mechanism of how histone variants H3.3 and H2A.Z function together to regulate gene transcription via the modulation of chromatin dynamics over the enhancer and promoter regions.

Obtaining high selectivity of aromatic monomers from renewable lignin has been extensively pursued but is still unsuccessful, hampered by the need to efficiently cleave C–O/C–C bonds and inhibit lignin proliferation reactions. Herein, we report a transfer hydrogenolysis protocol using a heterogeneous ZnIn2S4 catalyst driven by visible light. In this process, alcoholic groups (CαH–OH) of lignin act as hydrogen donors. Proliferation of phenolic products to dark substances is suppressed under visible light illumination at low temperature (below 50 °C); formation of a light and transparent reaction solution allows visible light to be absorbed by the catalyst. With this strategy, 71–91% yields of phenols in the conversion of lignin β-O-4 models and a 10% yield of p-hydroxyl acetophenone derivatives from organosolv lignin are achieved. Mechanistic studies reveal that CαH–OH groups of lignin β-O-4 linkage are initially dehydrogenated on ZnIn2S4 to form a “hydrogen pool”, and the adjacent Cβ–O bond is subsequently hydrogenolytically cleaved to two monomers by the “hydrogen pool”. Thus, the dehydrogenation and hydrogenolysis reaction are integrated in one-pot with lignin itself as a hydrogen donor. This study shows a promising way of supplying phenolic compounds by taking advantages of both renewable biomass feedstocks and photoenergy.

Abstract We report on fabrication of high-Q lithium niobate (LN) whispering-gallery-mode (WGM) microresonators suspended on silica pedestals by femtosecond laser direct writing followed by focused ion beam (FIB) milling. The micrometer-scale (diameter ~82 μm) LN resonator possesses a Q factor of ~2.5 × 10 5 around 1550 nm wavelength. The combination of femtosecond laser direct writing with FIB enables high-efficiency, high-precision nanofabrication of high-Q crystalline microresonators.

The peroxidase-like catalytic activity of gold nanoclusters (Au-NCs) is quite low around physiological pH, which greatly limits their biological applications. Herein, we found heparin can greatly accelerate the peroxidase-like activity of Au-NCs at neutral pH. The catalytic activity of Au-NCs toward the peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) oxidation by H2O2 was 25-fold increased in the presence of heparin at pH 7. The addition of heparin not only accelerated the initial catalytic rate of Au-NCs but also prevented the Au-NCs from catalyst deactivation. This allows the sensitive colorimetric detection of heparin at neutral pH. In the presence of heparinase, heparin was hydrolyzed into small fragments, weakening the enhancement effect of catalytic activity. On the basis of this phenomenon, the colorimetric determination of heparinase in the range from 0.1 to 3 μg·mL-1 was developed with a detection limit of 0.06 μg·mL-1. Finally, the detection of heparin and heparinase activity in diluted serum samples was also demonstrated.

Biomass is renewable and the most abundant carbon resource, and it shows great potential for sustainable production of chemicals in the future. With respect to limited fossil reserves, biomass conversion has aroused global attention. The use of biomass as a resource has developed rapidly in recent years, and various kinds of chemicals could be produced from biomass. Although biomass is annually renewable and abundant, it is important to process it in the most efficient way. Before rushing into biomass conversion, it is necessary to consider what chemicals are reasonably and economically produced from biomass. In this Review, we first analyzed the products from biomass based on the structural properties and economics. Taking into account the oxygen-rich character of the feedstock, it is a reasonable route to convert the biomass into valuable oxygen-containing fine chemicals, among which organic acids are one class of important and widely used fine chemicals. Then, we provided insights into the recent progress in the oxidative cleavage of biomass into organic acids and their derivatives, such as esters and anhydrides. The biomass resources cover the lignocellulose biomass, sugars, chitin, platform molecules, and fats. As biomass resources are generally polymers and the C–C bond is the backbone, the oxidative cleavage of C–C bond can break up the biomass to small molecules and introduce acid functionality at the same time. This Review particularly focuses on the generation of acids via a C–C bond-oxidative-cleavage process. Various methods, catalytic systems, and C–C bond-cleavage mechanisms are summarized. Finally, we conclude with mentioning the challenges in the oxidative conversion of biomass and the possible research direction in this area.

Abstract Compelling evidence has demonstrated the potential functions of circular RNAs (circRNAs) in breast cancer (BC) tumorigenesis. Nevertheless, the underlying mechanism by which circRNAs regulate BC progression is still unclear. The purpose of present research was to investigate the novel circRNA circRNF20 (hsa_circ_0087784) and its role in BC. CircRNA microarray sequencing revealed that circRNF20 was one of the upregulated transcripts in BC samples. Increased circRNF20 level predicted the poor clinical outcome in BC specimens. Functionally, circRNF20 promoted the proliferation and Warburg effect (aerobic glycolysis) of BC cells. Mechanistically, circRNF20 harbor miR-487a, acting as miRNA sponge, and then miR-487a targeted the 3’-UTR of hypoxia-inducible factor-1α (HIF-1α). Moreover, HIF-1α could bind with the promoter of hexokinase II (HK2) and promoted its transcription. In conclusion, this finding illustrates the vital roles of circRNF20 via the circRNF20/ miR-487a/HIF-1α/HK2 axis in breast cancer progress and Warburg effect, providing an interesting insight for the BC tumorigenesis.

Abstract Diabetic wound healing still faces great challenges due to the excessive inflammation, easy infection, and impaired angiogenesis in wound beds. The immunoregulation of macrophages polarization toward M2 phenotype that facilitates the transition from inflammation to proliferation phase has been proved to be an effective way to improve diabetic wound healing. Herein, an M2 phenotype‐enabled anti‐inflammatory, antioxidant, and antibacterial conductive hydrogel scaffolds (GDFE) for producing rapid angiogenesis and diabetic wound repair are reported. The GDFE scaffolds are fabricated facilely through the dynamic crosslinking between polypeptide and polydopamine and graphene oxide. The GDFE scaffolds possess thermosensitivity, self‐healing behavior, injectability, broad‐spectrum antibacterial activity, antioxidant and anti‐inflammatory ability, and electronic conductivity. GDFE effectively activates the polarization of macrophages toward M2 phenotype and significantly promotes the proliferation of dermal fibroblasts, the migration, and in vitro angiogenesis of endothelial cells through paracrine mechanisms. The in vivo results from a full‐thickness diabetic wound model demonstrate that GDFE can rapidly promote the diabetic wound repair and skin regeneration, through fast anti‐inflammation and angiogenesis and M2 macrophage polarization. This study provides highly efficient strategy for treating diabetic wound repair through designing the M2 polarization‐enabled anti‐inflammatory, antioxidant, and antibacterial bioactive materials.