Tao� Zhang

Supported metal nanostructures are the most widely used type of heterogeneous catalyst in industrial processes. The size of metal particles is a key factor in determining the performance of such catalysts. In particular, because low-coordinated metal atoms often function as the catalytically active sites, the specific activity per metal atom usually increases with decreasing size of the metal particles. However, the surface free energy of metals increases significantly with decreasing particle size, promoting aggregation of small clusters. Using an appropriate support material that strongly interacts with the metal species prevents this aggregation, creating stable, finely dispersed metal clusters with a high catalytic activity, an approach industry has used for a long time. Nevertheless, practical supported metal catalysts are inhomogeneous and usually consist of a mixture of sizes from nanoparticles to subnanometer clusters. Such heterogeneity not only reduces the metal atom efficiency but also frequently leads to undesired side reactions. It also makes it extremely difficult, if not impossible, to uniquely identify and control the active sites of interest.The ultimate small-size limit for metal particles is the single-atom catalyst (SAC), which contains isolated metal atoms singly dispersed on supports. SACs maximize the efficiency of metal atom use, which is particularly important for supported noble metal catalysts. Moreover, with well-defined and uniform single-atom dispersion, SACs offer great potential for achieving high activity and selectivity.In this Account, we highlight recent advances in preparation, characterization, and catalytic performance of SACs, with a focus on single atoms anchored to metal oxides, metal surfaces, and graphene. We discuss experimental and theoretical studies for a variety of reactions, including oxidation, water gas shift, and hydrogenation. We describe advances in understanding the spatial arrangements and electronic properties of single atoms, as well as their interactions with the support. Single metal atoms on support surfaces provide a unique opportunity to tune active sites and optimize the activity, selectivity, and stability of heterogeneous catalysts, offering the potential for applications in a variety of industrial chemical reactions.

Fog is an emergent architecture for computing, storage, control, and networking that distributes these services closer to end users along the cloud-to-things continuum. It covers both mobile and wireline scenarios, traverses across hardware and software, resides on network edge but also over access networks and among end users, and includes both data plane and control plane. As an architecture, it supports a growing variety of applications, including those in the Internet of Things (IoT), fifth-generation (5G) wireless systems, and embedded artificial intelligence (AI). This survey paper summarizes the opportunities and challenges of fog, focusing primarily in the networking context of IoT.

A major yet unresolved quest in decoding the human genome is the identification of the regulatory sequences that control the spatial and temporal expression of genes. Distant-acting transcriptional enhancers are particularly challenging to uncover because they are scattered among the vast non-coding portion of the genome. Evolutionary sequence constraint can facilitate the discovery of enhancers, but fails to predict when and where they are active in vivo. Here we present the results of chromatin immunoprecipitation with the enhancer-associated protein p300 followed by massively parallel sequencing, and map several thousand in vivo binding sites of p300 in mouse embryonic forebrain, midbrain and limb tissue. We tested 86 of these sequences in a transgenic mouse assay, which in nearly all cases demonstrated reproducible enhancer activity in the tissues that were predicted by p300 binding. Our results indicate that in vivo mapping of p300 binding is a highly accurate means for identifying enhancers and their associated activities, and suggest that such data sets will be useful to study the role of tissue-specific enhancers in human biology and disease on a genome-wide scale.

Abstract Broadening the optical absorption of organic photovoltaic (OPV) materials by enhancing the intramolecular push-pull effect is a general and effective method to improve the power conversion efficiencies of OPV cells. However, in terms of the electron acceptors, the most common molecular design strategy of halogenation usually results in down-shifted molecular energy levels, thereby leading to decreased open-circuit voltages in the devices. Herein, we report a chlorinated non-fullerene acceptor, which exhibits an extended optical absorption and meanwhile displays a higher voltage than its fluorinated counterpart in the devices. This unexpected phenomenon can be ascribed to the reduced non-radiative energy loss (0.206 eV). Due to the simultaneously improved short-circuit current density and open-circuit voltage, a high efficiency of 16.5% is achieved. This study demonstrates that finely tuning the OPV materials to reduce the bandgap-voltage offset has great potential for boosting the efficiency.

Coiled-coil sequences in proteins consist of heptad repeats containing two characteristic hydrophobic positions. The role of these buried hydrophobic residues in determining the structures of coiled coils was investigated by studying mutants of the GCN4 leucine zipper. When sets of buried residues were altered, two-, three-, and four-helix structures were formed. The x-ray crystal structure of the tetramer revealed a parallel, four-stranded coiled coil. In the tetramer conformation, the local packing geometry of the two hydrophobic positions in the heptad repeat is reversed relative to that in the dimer. These studies demonstrate that conserved, buried residues in the GCN4 leucine zipper direct dimer formation. In contrast to proposals that the pattern of hydrophobic and polar amino acids in a protein sequence is sufficient to determine three-dimensional structure, the shapes of buried side chains in coiled coils are essential determinants of the global fold.

ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTLight-Driven Heterogeneous Reduction of Carbon Dioxide: Photocatalysts and PhotoelectrodesJames L. White†, Maor F. Baruch†, James E. Pander III†, Yuan Hu†, Ivy C. Fortmeyer†, James Eujin Park†, Tao Zhang†, Kuo Liao†, Jing Gu‡, Yong Yan‡, Travis W. Shaw†, Esta Abelev†, and Andrew B. Bocarsly*†View Author Information† Department of Chemistry, Princeton University , Princeton, New Jersey 08544, United States ‡ Chemical and Materials Science Center, National Renewable Energy Laboratory , Golden, Colorado 80401, United States *(A.B.B.) E-mail: [email protected]Cite this: Chem. Rev. 2015, 115, 23, 12888–12935Publication Date (Web):October 7, 2015Publication History Received23 June 2015Published online7 October 2015Published inissue 9 December 2015https://doi.org/10.1021/acs.chemrev.5b00370Copyright © 2015 American Chemical SocietyRequest reuse permissionsArticle Views37195Altmetric-Citations1282LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (7 MB) Get e-AlertscloseSUBJECTS:Catalysts,Electrodes,Oxides,Redox reactions,Semiconductors Get e-Alerts

<h2>Summary</h2> An outbreak of coronavirus disease 2019 (COVID-19) caused by the 2019 novel coronavirus (SARS-CoV-2) began in the city of Wuhan in China and has widely spread worldwide. Currently, it is vital to explore potential intermediate hosts of SARS-CoV-2 to control COVID-19 spread. Therefore, we reinvestigated published data from pangolin lung samples from which SARS-CoV-like CoVs were detected by Liu et al. [1]. We found genomic and evolutionary evidence of the occurrence of a SARS-CoV-2-like CoV (named Pangolin-CoV) in dead Malayan pangolins. Pangolin-CoV is 91.02% and 90.55% identical to SARS-CoV-2 and BatCoV RaTG13, respectively, at the whole-genome level. Aside from RaTG13, Pangolin-CoV is the most closely related CoV to SARS-CoV-2. The S1 protein of Pangolin-CoV is much more closely related to SARS-CoV-2 than to RaTG13. Five key amino acid residues involved in the interaction with human ACE2 are completely consistent between Pangolin-CoV and SARS-CoV-2, but four amino acid mutations are present in RaTG13. Both Pangolin-CoV and RaTG13 lost the putative furin recognition sequence motif at S1/S2 cleavage site that can be observed in the SARS-CoV-2. Conclusively, this study suggests that pangolin species are a natural reservoir of SARS-CoV-2-like CoVs.

The Fenton-like process presents one of the most promising strategies to generate reactive oxygen-containing radicals to deal with the ever-growing environmental pollution. However, developing improved catalysts with adequate activity and stability is still a long-term goal for practical application. Herein, we demonstrate single cobalt atoms anchored on porous N-doped graphene with dual reaction sites as highly reactive and stable Fenton-like catalysts for efficient catalytic oxidation of recalcitrant organics via activation of peroxymonosulfate (PMS). Our experiments and density functional theory (DFT) calculations show that the CoN4 site with a single Co atom serves as the active site with optimal binding energy for PMS activation, while the adjacent pyrrolic N site adsorbs organic molecules. The dual reaction sites greatly reduce the migration distance of the active singlet oxygen produced from PMS activation and thus improve the Fenton-like catalytic performance.

The ability to derive a whole-genome map of transcription-factor binding sites (TFBS) is crucial for elucidating gene regulatory networks. Herein, we describe a robust approach that couples chromatin immunoprecipitation (ChIP) with the paired-end ditag (PET) sequencing strategy for unbiased and precise global localization of TFBS. We have applied this strategy to map p53 targets in the human genome. From a saturated sampling of over half a million PET sequences, we characterized 65,572 unique p53 ChIP DNA fragments and established overlapping PET clusters as a readout to define p53 binding loci with remarkable specificity. Based on this information, we refined the consensus p53 binding motif, identified at least 542 binding loci with high confidence, discovered 98 previously unidentified p53 target genes that were implicated in novel aspects of p53 functions, and showed their clinical relevance to p53-dependent tumorigenesis in primary cancer samples.

A simple, nonhazardous, efficient and low energy-consuming process is desirable to generate powerful radicals from peroxymonosulfate (PMS) for recalcitrant pollutant removal. In this work, the production of radical species from PMS induced by a magnetic CuFe(2)O(4) spinel was studied. Iopromide, a recalcitrant model pollutant, was used to investigate the efficiency of this process. CuFe(2)O(4) showed higher activity and 30 times lower Cu(2+) leaching (1.5 μg L(-1) per 100 mg L(-1)) than a well-crystallized CuO at the same dosage. CuFe(2)O(4) maintained its activity and crystallinity during repeated batch experiments. In comparison, the activity of CuO declined significantly, which was ascribed to the deterioration in its degree of crystallinity. The efficiency of the PMS/CuFe(2)O(4) was highest at neutral pH and decreased at acidic and alkaline pHs. Sulfate radical was the primary radical species responsible for the iopromide degradation. On the basis of the stoichiometry of oxalate degradation in the PMS/CuFe(2)O(4), the radical production yield from PMS was determined to be near 1 mol/mol. The PMS decomposition involved an inner-sphere complexation with the oxide's surface Cu(II) sites. In situ characterization of the oxide surface with ATR-FTIR and Raman during the PMS decomposition suggested that surface Cu(II)-Cu(III)-Cu(II) redox cycle was responsible for the efficient sulfate radical generation from PMS.

Abstract Although the concept that cancers originate from stem cells (SC) is becoming scientifically accepted, mechanisms by which SC contribute to tumor initiation and progression are largely unknown. For colorectal cancer (CRC), investigation of this problem has been hindered by a paucity of specific markers for identification and isolation of SC from normal and malignant colon. Accordingly, aldehyde dehydrogenase 1 (ALDH1) was investigated as a possible marker for identifying colonic SC and for tracking them during cancer progression. Immunostaining showed that ALDH1+ cells are sparse and limited to the normal crypt bottom, where SCs reside. During progression from normal epithelium to mutant (APC) epithelium to adenoma, ALDH1+ cells increased in number and became distributed farther up the crypt. CD133+ and CD44+ cells, which are more numerous and broadly distributed in normal crypts, showed similar changes during tumorigenesis. Flow cytometric isolation of cancer cells based on enzymatic activity of ALDH (Aldefluor assay) and implantation of these cells in nonobese diabetic–severe combined immunodeficient mice (a) generated xenograft tumors (Aldefluor− cells did not), (b) generated them after implanting as few as 25 cells, and (c) generated them dose dependently. Further isolation of cancer cells using a second marker (CD44+ or CD133+ serially) only modestly increased enrichment based on tumor-initiating ability. Thus, ALDH1 seems to be a specific marker for identifying, isolating, and tracking human colonic SC during CRC development. These findings also support our original hypothesis, derived previously from mathematical modeling of crypt dynamics, that progressive colonic SC overpopulation occurs during colon tumorigenesis and drives CRC development. [Cancer Res 2009;69(8):3382–9]

Selective catalytic hydrogenation has wide applications in both petrochemical and fine chemical industries, however, it remains challenging when two or multiple functional groups coexist in the substrate. To tackle this challenge, the “active site isolation” strategy has been proved effective, and various approaches to the site isolation have been developed. In this review, we have summarized these approaches, including adsorption/grafting of N/S-containing organic molecules on the metal surface, partial covering of active metal surface by metal oxides either via doping or through strong metal–support interaction, confinement of active metal nanoparticles in micro- or mesopores of the supports, formation of bimetallic alloys or intermetallics or core@shell structures with a relatively inert metal (IB and IIB) or nonmetal element (B, C, S, etc.), and construction of single-atom catalysts on reducible oxides or inert metals. Both advantages and disadvantages of each approach toward the site isolation have been discussed for three types of chemoselective hydrogenation reactions, including alkynes/dienes to monoenes, α,β-unsaturated aldehydes/ketones to the unsaturated alcohols, and substituted nitroarenes to the corresponding anilines. The key factors affecting the catalytic activity/selectivity, in particular, the geometric and electronic structure of the active sites, are discussed with the aim to extract fundamental principles for the development of efficient and selective catalysts in hydrogenation as well as other transformations.

The catalytic hydrogenation of nitroarenes is an environmentally benign technology for the production of anilines, which are key intermediates for manufacturing agrochemicals, pharmaceuticals and dyes. Most of the precious metal catalysts, however, suffer from low chemoselectivity when one or more reducible groups are present in a nitroarene molecule. Herein we report FeOx-supported platinum single-atom and pseudo-single-atom structures as highly active, chemoselective and reusable catalysts for hydrogenation of a variety of substituted nitroarenes. For hydrogenation of 3-nitrostyrene, the catalyst yields a TOF of ~1,500 h−1, 20-fold higher than the best result reported in literature, and a selectivity to 3-aminostyrene close to 99%, the best ever achieved over platinum group metals. The superior performance can be attributed to the presence of positively charged platinum centres and the absence of Pt–Pt metallic bonding, both of which favour the preferential adsorption of nitro groups. Reduction of nitroarenes in the presence of other reducible groups is challenging, as is simultaneously achieving high selectivity and activity. Here, the authors report supported single-atom and pseudo-single-atom platinum catalysts with excellent activity and high degrees of chemoselectivity.

Processing-in-memory (PIM) is a promising solution to address the "memory wall" challenges for future computer systems. Prior proposed PIM architectures put additional computation logic in or near memory. The emerging metal-oxide resistive random access memory (ReRAM) has showed its potential to be used for main memory. Moreover, with its crossbar array structure, ReRAM can perform matrix-vector multiplication efficiently, and has been widely studied to accelerate neural network (NN) applications. In this work, we propose a novel PIM architecture, called PRIME, to accelerate NN applications in ReRAM based main memory. In PRIME, a portion of ReRAM crossbar arrays can be configured as accelerators for NN applications or as normal memory for a larger memory space. We provide microarchitecture and circuit designs to enable the morphable functions with an insignificant area overhead. We also design a software/hardware interface for software developers to implement various NNs on PRIME. Benefiting from both the PIM architecture and the efficiency of using ReRAM for NN computation, PRIME distinguishes itself from prior work on NN acceleration, with significant performance improvement and energy saving. Our experimental results show that, compared with a state-of-the-art neural processing unit design, PRIME improves the performance by ~2360× and the energy consumption by ~895×, across the evaluated machine learning benchmarks.

Amorphous Zr–Al–Ni alloys exhibiting a wide temperature region of supercooled liquid state and a high reduced glass transition temperature (Tg⁄Tm) were formed over a composition range from 0 to 37 at% Al and 3 to 67%Ni by melt spinning. The temperature span ΔTx(=Tx−Tg) between Tg and crystallization temperature (Tx) reaches as large as 77 K for Zr60Al15Ni25. The Tg⁄Tm is also as high as 0.64 in the vicinity of Zr60Al20Ni20 and their Zr–Al–Ni alloys are concluded to have a large glass-forming capacity. The Tx and hardness (Hv) increase with increasing Al and Ni contents in the range from 660 to 860 K and 400 to 720, respectively, and the tensile strength also has a similar compositional dependence in the range of 1335 to 1720 MPa. The compositional effect on Tx and Hv was presumed to originate from the variation of the atomic configuration which reflects the equilibrium compounds, because of the similarity in the compositional dependence among Tx, Hv and the melting temperature of the compounds. The high thermal stability of the supercooled liquid in the vicinity of Zr3Al1Ni1 seems to result from optimum bonding and packing states of the constituent atoms in the limited alloy.

Molecular sieving membranes with sufficient and uniform nanochannels that break the permeability-selectivity trade-off are desirable for energy-efficient gas separation, and the arising two-dimensional (2D) materials provide new routes for membrane development. However, for 2D lamellar membranes, disordered interlayer nanochannels for mass transport are usually formed between randomly stacked neighboring nanosheets, which is obstructive for highly efficient separation. Therefore, manufacturing lamellar membranes with highly ordered nanochannel structures for fast and precise molecular sieving is still challenging. Here, we report on lamellar stacked MXene membranes with aligned and regular subnanometer channels, taking advantage of the abundant surface-terminating groups on the MXene nanosheets, which exhibit excellent gas separation performance with H2 permeability >2200 Barrer and H2/CO2 selectivity >160, superior to the state-of-the-art membranes. The results of molecular dynamics simulations quantitatively support the experiments, confirming the subnanometer interlayer spacing between the neighboring MXene nanosheets as molecular sieving channels for gas separation.

High specific activity and cost effectiveness of single-atom catalysts hold practical value for water gas shift (WGS) reaction toward hydrogen energy. We reported the preparation and characterization of Ir single atoms supported on FeOx (Ir1/FeOx) catalysts, the activity of which is 1 order of magnitude higher than its cluster or nanoparticle counterparts and is even higher than those of the most active Au- or Pt-based catalysts. Extensive studies reveal that the single atoms accounted for ∼70% of the total activity of catalysts containing single atoms, subnano clusters, and nanoparticles, thus serving as the most important active sites. The Ir single atoms seem to greatly enhance the reducibility of the FeOx support and generation of oxygen vacancies, leading to the excellent performance of the Ir1/FeOx single-atom catalyst. The results have broad implications on designing supported metal catalysts with better performance and lower cost.

Amorphous alloys exhibiting a wide supercooled liquid region above 100 K were found to form in a compositional range from 0 to 3%Co, 0 to 15%Ni and 10 to 23%Cu in Zr65Al7.5Cu2.5(Co1−x−yNixCuy)25 system by melt spinning. The temperature span ΔTx(=Tx−Tg) between glass transition temperature (Tg) and crystallization temperature (Tx) reaches as large as 127 K for Zr65Al7.5Ni10Cu17.5. The Tg and hardness (Hv) increase from 622 to 685 K and 426 to 502 with increasing Co content while the Tx decreases from 749 to 690 K, resulting in the decrease of ΔTx from 127 to 30 K with increasing Co content. The compositional effect on Tg, Tx, ΔTx and Hv indicates that there is no close relation between the magnitude of the attractive bonding force and the stability of the supercooled liquid. The high stability of the supercooled liquid against the nucleation and growth of a crystalline phase in the limited composition range seems to result from a highly dense random packing structure consisting of atoms with an optimum atomic size ratio and a large negative enthalpy of mixing.

Amorphous alloys exhibiting a wide supercooled liquid region and a high reduced glass transition temperature (Tg⁄Tm) were found to be formed over a compositional range from 3 to 83 at% La and 0 to 60%Ni in Al–La–Ni system by melt spinning. The temperature span ΔTx(=Tx−Tg) between Tg and crystallization temperature (Tx) reaches as large as 69 K for Al25La55Ni20. The Tg⁄Tm is also as high as 0.68 for Al25La55Ni20 and the Al–La–Ni alloys are concluded to have a high glass-forming ability. The Tx and hardness (Hv) increase with increasing Al and Ni contents in the range from 425 K to 750 K and 170 to 520 and the tensile strength also has a similar compositional dependence in the range of 515 to 795 MPa. The compositional effect on Tx and Hv was presumed to originate from the variation of the atomic configuration which reflects the compounds of La3(Al, Ni), La(Al, Ni) and La(Al, Ni)2. The high stability of the supercooled liquid in the vicinity of the stoichiometric composition Al1La2Ni1 against the transformation of crystalline phases, i.e., large ΔTx and high Tg⁄Tm, seems to result from an optimum bonding state of the constituent atoms for the stoichiometric alloy.

We report a new search of weakly interacting massive particles (WIMPs) using the combined low background data sets in 2016 and 2017 from the PandaX-II experiment in China. The latest data set contains a new exposure of 77.1 live day, with the background reduced to a level of 0.8$\times10^{-3}$ evt/kg/day, improved by a factor of 2.5 in comparison to the previous run in 2016. No excess events were found above the expected background. With a total exposure of 5.4$\times10^4$ kg day, the most stringent upper limit on spin-independent WIMP-nucleon cross section was set for a WIMP with mass larger than 100 GeV/c$^2$, with the lowest exclusion at 8.6$\times10^{-47}$ cm$^2$ at 40 GeV/c$^2$.

Nickel saves dimes: The expense of using precious-metal catalysts is avoided in the high-yielding conversion of cellulose to ethylene glycol (see picture; AC=activated carbon). This process occurs in up to 29 % yield over a tungsten carbide catalyst, and in up to 61 % yield when the catalyst is promoted with a small amount of nickel. An attractive feature of this reaction is the low yields of other polyols with respect to ethylene glycol. Cellulose, the most abundant source of biomass, is currently regarded as a promising alternative for fossil fuels as it cannot be digested by human beings and thus its use, unlike corn and starch, will not impose a negative impact on food supplies.1, 2 One of the most attractive routes for the reaction of cellulose utilization is its direct conversion into useful organic compounds.3 A recent example of the catalytic conversion of cellulose has been demonstrated by Fukuoka and Dhepe, who utilized Pt/Al2O3 as an effective catalyst to convert cellulose into sugar alcohols4 (Scheme 1, Route A). The product sugar alcohols can be used as chemicals in their own right or as new starting materials for the production of fuels, as demonstrated by Dumesic and co-workers.5, 6 Recently, Luo et al. have studied this process further.7 In their work, the reaction was conducted at elevated temperatures so that water could generate H+ ions to catalyze the hydrolysis reactions. The subsequent hydrogenation reaction was catalyzed by Ru/C. An increased sugar alcohol yield was obtained, which was attributed to the higher reaction temperatures and the well-known high efficiency of Ru/C in the hydrogenation reaction.8. Catalytic conversion of cellulose into polyols. A disadvantage of the above two studies is the use of precious-metal catalysts. The amount of precious metals needed for the degradation of cellulose was relatively high, 4–10 mg per gram of cellulose. This is too expensive for the conversion of large quantities of cellulose, even though the solid catalyst could be reused. Therefore, it is highly desirable to develop a less expensive but efficient catalyst to replace precious-metal catalysts in this cellulose degradation process. The carbides of Groups 4–6 metals show catalytic performances similar to those of platinum-group metals in a variety of reactions involving hydrogen.9–13 In our previous work,14–16 tungsten and molybdenum carbides were found to exhibit excellent performances in the catalytic decomposition of hydrazine, which were comparable with those of expensive iridium catalysts. Tungsten carbides have been used as electrocatalysts because of their platinum-like catalytic behavior, stability in acidic solutions, and resistance to CO poisoning.17, 18 However, to the best of our knowledge, there have been no attempts so far to utilize metal carbides as catalysts for cellulose conversion. Herein we report the first observation that carbon-supported tungsten carbide (W2C/AC; AC=activated carbon) can effectively catalyze cellulose conversion into polyols (Scheme 1, Route B). More interestingly, when the catalyst is promoted with a small amount of nickel, the yield of polyols, especially ethylene glycol (EG) and sorbitol, can be significantly increased. These Ni-W2C/AC catalysts showed a remarkably higher selectivity for EG formation than Pt/Al2O34 and Ru/C.7 After 30 minutes at 518 K and 6 MPa H2, the cellulose could be completely converted into polyols and the yield of EG was as high as 61 wt % with a 2 % Ni-30 % W2C/AC-973 catalyst. This value is the highest yield reported to date. Currently in the petrochemical industry, EG is mainly produced from ethylene via the intermediate ethylene oxide. The global production of EG in 2007 is estimated to be 17.8 million tonnes, an increase of 5.4 % from 2006.19 In view of the increasing demand for EG for the manufacture of polyester fibers and resins in the plastics industry and as an antifreeze in the automotive industry, its direct production from cellulose will create a new method for reducing dependence on petroleum. W2C/AC and nickel-promoted W2C/AC catalysts were prepared by a carbothermal hydrogen reduction (CHR) method following our previous report14 and the method of Liang et al.20 Characterization of the samples showed that the addition of nickel brought about remarkable changes in the evolution of the W2C phase as well as the particle size distribution. The XRD patterns of samples prepared at different CHR temperatures show that the phase composition was critically dependent on the CHR temperature (Figure 1). In the absence of nickel, well-crystallized and phase-pure W2C was formed only at 1073 K, above which temperature a fraction of W2C was further carburized to WC (Figure 1 a). In contrast, with the addition of nickel, the phase-pure W2C was already formed at 973 K; increasing the CHR temperature to 1073 K increased the intensity of diffraction peaks of W2C, which implies the formation of larger W2C particles (Figure 1 b). Evidently, the presence of nickel lowered the W2C formation temperature by approximately 100 K, possibly arising from nickel-promoted H2 dissociation and thereby the reduction of the tungsten precursor.20 Transmission electron microscopy (TEM; Figure S1 in the Supporting Information) and CO chemisorption (Figure S2 in the Supporting Information) also confirmed the presence of nickel-induced agglomeration of W2C particles. This could be explained by the nickel-promoted methanation of the carbon support (Figure S3 in the Supporting Information). XRD patterns of 30 % W2C/AC (a) and 2 % Ni-30 % W2C/AC (b) prepared at different carbothermal hydrogen reduction temperatures. The conversion of cellulose into polyols was conducted in an aqueous medium, in a similar fashion to procedures reported previously.4, 7 The optimization of the reaction conditions (temperature, pressure, and reaction time) over tungsten carbide catalysts showed that the maximum yield of EG was obtained at 518 K, 6 MPa H2, and with a reaction time of 30 minutes (Figure S4 in the Supporting Information). Accordingly, all the catalysts were evaluated under these conditions. The degree of cellulose conversion and yields of the major products are listed in Table 1. The product distribution from the degradation of cellulose is very complex. In addition to the compounds listed in Table 1, which include EG, sorbitol, mannitol, erythritol, and 1,2-propylene glycol, two unknown products with a molecular weight of 164 and 132 Da were also detected by HPLC–ESI-MS. The carbon balance based on total organic carbon (TOC) analysis of the liquid product showed that a small amount of gas-phase products were also produced.21 However, EG was the dominant component of the polyol products (a typical analysis spectrum is shown in Figure S5 in the Supporting Information). The three W2C/AC catalysts, which were prepared at 1073 K but had different tungsten loadings, led to a nearly 100 % cellulose conversion; the main product was EG and its yield increased from 23.7 % to 29.0 % when the tungsten content was increased from 15 % to 60 % (Table 1, entries 1–3). When the catalyst was prepared at a lower temperature (e.g., 973 K and 1023 K) where the major phase was metallic tungsten rather than W2C, the yield of the polyols was negligible, which indicated that the W2C was the active phase for the formation of polyols. On the other hand, when the W2C/AC was prepared at a higher temperature, the yield of EG was decreased slightly (Table 1, entry 4). According to the XRD results, treatment of the catalyst precursor with H2 at 1073 K produced phase-pure W2C while a mixture of W2C and WC was yielded at 1123 K. Therefore, the lower yield of EG obtained over 30 % W2C/AC-1123 can be explained by the formation of a small amount of WC phase, which in turn lowered the activity for cellulose degradation. Entry Catalyst[a] Conversion [%][b] Yield [%][c] ethylene glycol sorbitol mannitol erythritol 1,2-propylene glycol 1 15 % W2C/AC-1073 97 23.7 0.7 0.9 0.6 5.1 2 30 % W2C/AC-1073 98 27.4 1.1 1.0 0.6 5.5 3 60 % W2C/AC-1073 99 29.0 1.4 1.2 0.7 6.0 4 30 % W2C/AC-1123 97 25.4 0.9 0.9 0.5 4.9 5 30 % WCx/Al2O3-1123 95 3.4 0.8 0.8 0.1 1.1 6 30 % W2C/AC-1073-2[d] 98 23.6 0.6 0.6 0.6 2.8 7 30 % W2C/AC-1073-3[e] 98 22.5 0.6 0.6 0.6 2.8 8 0.5 % Ni-30 %W2C/AC-973 95 39.4 5.6 2.3 2.6 5.8 9 1 % Ni-30 %W2C/AC-973 98 52.1 3.2 2.1 2.2 7.7 10 2 % Ni-30 %W2C/AC-973 100 61.0 3.9 1.9 2.3 7.6 11 3 % Ni-30 %W2C/AC-973 95 49.8 4.7 1.5 2.6 4.3 12 1 % Ni-30 %W2C/AC-1073 90 36.1 10.4 2.6 2.5 4.3 13 3 % Ni-30 %W2C/AC-1073 86 33.8 11.3 2.8 2.5 4.5 14 3 % Ni-30 %W2C/AC-973-2[f] 95 46.6 2.3 2.3 1.3 6.7 15 3 % Ni-30 %W2C/AC-973-3[g] 95 42.7 2.3 2.3 1.3 6.7 16 30 % W2C/AC-1073[h] 40 11.1 2.4 0.9 0.7 5.1 17 2.5 % Pt/Al2O3 98 14.2 9.5 6.0 1.7 9.3 18 2.5 % Pt/Al2O3[i] 46 9.6 26.3 8.9 1.5 0.9 19 2.5 % Pt/AC 66 8.2 3.2 1.5 1.0 5.9 20 2 % Ni/AC 68 5.2 3.1 1.6 0.7 4.3 21 3 % Ni/AC 69 5.8 3.8 1.2 0.7 4.2 When alumina, rather than activated carbon, was used as the support for W2C, the yield of EG was significantly lowered to 3.4 % (Table 1, entry 5). Fehling's test indicated the appearance of a large fraction of unidentified unsaturated products. These unsaturated products are assumed to result from the insufficient hydrogenation capability of the WCx/Al2O3 catalyst. This result strongly suggests that the nature of the support significantly influences the catalytic performance of the tungsten carbide. In our previous work on hydrazine decomposition,14 alumina-supported tungsten carbides were also found to have an activity inferior to those supported on activated carbon. This difference has been attributed to the different active phase formed on these two supports: W2C was formed on activated carbon whereas WC was formed on alumina; the metaphase W2C was found to have a higher intrinsic activity than the thermally stable WC. One outstanding feature of the W2C/AC catalysts in the catalytic conversion of cellulose is the surprisingly high selectivity for EG formation. The yield of EG obtained over the W2C/AC catalyst is almost twice as large as that obtained over Pt/Al2O3 (Table 1, entry 17). With the Pt/Al2O3 catalyst, the main product was sugar alcohols (9.5 % of sorbitol and 6.0 % of mannitol). When the reaction was carried out at a lower temperature (463 K), the EG yield over Pt/Al2O3 was further decreased to 9.6 %, and was accompanied with a sharp increase in the yield of sugar alcohols (26.3 % of sorbitol and 8.9 % of mannitol, Table 1, entry 18). Such yields of sugar alcohols are consistent with those reported by Fukuoka and Dhepe,4 although they did not report any production of EG. However, even under such milder conditions, our W2C/AC catalyst could still produce a relatively high yield of EG (11.1 %) with a very low yield of sugar alcohols (3.3 %, Table 1, entry 16). It is known that EG and other low molecular weight polyols originate predominantly from the hydrogenolysis of glucose, while the sugar alcohols result from the hydrogenation of glucose (Scheme 1). The high selectivity of the W2C/AC catalyst in the production of EG suggests that the hydrogenolysis of glucose prevails over its hydrogenation. The reverse case occurred with the Pt/Al2O3 catalysts because the Pt surface can dissociate H2 more easily than tungsten carbides. It can thus be concluded that tungsten carbides can be considered as a more efficient and low-cost catalyst to replace the precious metal catalyst for the production of valuable polyols in the degradation of cellulose. To further improve the yield of EG and sugar alcohols, we added a small amount of nickel to the above tungsten carbide catalysts. The idea is based on two considerations: 1) nickel is a well-known active catalyst for the hydrogenation of glucose to sorbitol;22 and 2) nickel could promote the formation of tungsten carbides as indicated in Figure 1, which suggests the possibility of synergy by combining nickel and W2C in catalytic reactions. Our results show that use of nickel-promoted W2C/AC catalysts led to a higher yield of EG and sugar alcohols compared to unpromoted catalysts (Table 1). The presence of even a very small amount of nickel (0.5 wt %) in W2C/AC resulted in a substantial increase in the yield of EG from 27.4 to 39.4 % (Table 1, entry 8). When 2 wt % of nickel was added, EG and sugar alcohols were obtained in yields of 61 % and 5.8 %, respectively (Table 1, entry 10). A further increase of the nickel loading resulted in a decrease of the EG yield (Table 1, entry 11). In addition, a different CHR temperature gave rise to a different catalytic performance of the nickel-promoted W2C catalysts. Use of catalysts prepared at 1073 K resulted in a lower yield of EG and a higher yield of sorbitol (Table 1, entries 12 and 13) than those prepared at 973 K. According to the XRD and TEM characterization described above, a large nickel content and a higher CHR temperature would induce a significant sintering of W2C particles, which in turn lowered its activity for cellulose degradation. As a reference, we also performed the reaction over Ni/AC catalysts, and found that they exhibited poor activity and selectivity for EG (Table 1, entries 20 and 21). Clearly, there is a synergetic effect between nickel and W2C in the reactions involving cellulose degradation, and this synergy was maximized at a nominal nickel loading of 2 wt % and CHR temperature of 973 K. Catalyst recycling is always important in metal-catalyzed liquid-phase reactions. Therefore, we recycled unpromoted and nickel-promoted W2C/AC catalysts over three runs. Table 1 shows that both the unpromoted (entries 6 and 7) and nickel-promoted (entries 14 and 15) W2C/AC catalysts exhibited good reusability, as indicated by only slight losses in the EG yield over the three repeated runs. Inductively coupled plasma (ICP) analysis of the liquid product shows that leaching of either nickel or tungsten is negligible. However, our results suggest that the slight oxidation of the W2C phase by the reaction medium (Figure S6 in the Supporting Information) may be responsible for the slight reduction of the yield of EG during recycling.21 In summary, our results have demonstrated that tungsten carbide can replace precious metals to catalyze the degradation of cellulose in an environmentally friendly way. A remarkable advantage of the tungsten carbide over platinum and ruthenium catalysts is the high yield of EG relative to other polyols. More importantly, with the promotion of a small amount of nickel, the yield of EG was significantly increased to 61 % by a synergistic effect between nickel and W2C. This is the first report that EG can be directly produced from cellulose in such a high yield. In view of the importance of EG in the petrochemical industry, this approach may open a new avenue for the production of valuable chemicals from renewable resources. In addition, the substitution of noble-metal catalysts with less expensive carbides in a variety of biomass conversion reactions will be of importance because of the limited resources and high prices of precious metals. Unpromoted and nickel-promoted tungsten carbides were prepared by the carbothermal hydrogen reduction (CHR) method; detailed synthesis procedures as well as the characterization methods are provided in the Supporting Information. The catalytic conversion of cellulose (Merck, microcrystalline) was carried out in a stainless-steel autoclave (Parr Instrument Company, 100 mL) typically at a H2 pressure of 6 MPa (measured at room temperature) and at 518 K for 30 min. For each reaction, cellulose (0.5 g), catalyst (0.15 g), and water (50 mL) were put into the reactor, and stirred at rate of 1000 r min−1. After the reaction, the liquid-phase products were analyzed by HPLC and ESI-MS. Cellulose conversions were determined by the change of cellulose weight before and after the reaction. The yield of polyols was calculated from the equation: yield (%)=(weight of polyol in the products)/(weight of cellulose put into the reactor) ×100 %. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by 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.

Autophagy is an important intracellular catabolic mechanism that mediates the degradation of cytoplasmic proteins and organelles. We report a potent small molecule inhibitor of autophagy named "spautin-1" for specific and potent autophagy inhibitor-1. Spautin-1 promotes the degradation of Vps34 PI3 kinase complexes by inhibiting two ubiquitin-specific peptidases, USP10 and USP13, that target the Beclin1 subunit of Vps34 complexes. Beclin1 is a tumor suppressor and frequently monoallelically lost in human cancers. Interestingly, Beclin1 also controls the protein stabilities of USP10 and USP13 by regulating their deubiquitinating activities. Since USP10 mediates the deubiquitination of p53, regulating deubiquitination activity of USP10 and USP13 by Beclin1 provides a mechanism for Beclin1 to control the levels of p53. Our study provides a molecular mechanism involving protein deubiquitination that connects two important tumor suppressors, p53 and Beclin1, and a potent small molecule inhibitor of autophagy as a possible lead compound for developing anticancer drugs.

Chickpea protein hydrolysate (CPH) was fractionated by gel filtration on Sephadex G-25. The antioxidant and free radical-scavenging activities of four CPH fractions (Fra.I, Fra.II, Fra.III, and Fra.IV) were measured using reducing power, inhibition of linoleic acid autoxidation, and 1,1-diphenyl-2- pycrylhydrazyl (DPPH)/superoxide/hydroxyl radical-scavenging assay. The antioxidant activity of Fra.IV (81.13%) was closer to that of α-tocopherol (83.66%) but lower than that of BHT (99.71%) in the linoleic acid oxidation system. Amino acid analyses showed that Fra.IV with the strongest antioxidant activity also had the highest total hydrophobic amino acids content (38.94% THAA) and hydrophobicity (125.62 kcal/mol amino acid residue) compared with the other three fractions. The molecular weight distribution of Fra.IV was found to vary from 200 to 3000 Da.

Peroxydisulfate (PDS) is an appealing oxidant for contaminated groundwater and toxic industrial wastewaters.Activation of PDS is necessary for application because of its low reactivity.Present activation processes always sulfate radicals as actual oxidants which unselectively oxidize organics and halide anions reducing oxidation capacity of PDS and producing toxic halogenated products.Here we report that copper oxide (CuO) can efficiently activate PDS under mild conditions without producing sulfate radicals.The PDS/CuO coupled process is most efficient at neutral pH for decomposing a model compound, 2,4-dichlorophenol (2,4-DCP).In a continuous-flow reaction with an empty-bed contact time of 0.55 min, over 90% 2,4-DCP (initially 20 µM) and 90% of adsorbable organic chlorine (AOCl) can be removed at the PDS/2,4-DCP molar ratio of 1 and 4, respectively.Based on kinetic study and surface characterization, PDS is proposed to be first activated by CuO through outer-sphere interaction, the rate-limiting step, followed by a rapid reaction with 2,4-DCP present in the solution.In the presence of ubiquitous chloride ions in groundwaters/industrial wastewater, the PDS/CuO oxidation shows significant advantages over sulfate radical oxidation by achieving much higher 2,4-DCP degradation capacity and avoiding the formation of highly chlorinated degradation products.This work provides a new way of PDS activation for contaminant removal.

The human gut is known to be a reservoir of a wide variety of microbes, including viruses. Many RNA viruses are known to be associated with gastroenteritis; however, the enteric RNA viral community present in healthy humans has not been described. Here, we present a comparative metagenomic analysis of the RNA viruses found in three fecal samples from two healthy human individuals. For this study, uncultured viruses were concentrated by tangential flow filtration, and viral RNA was extracted and cloned into shotgun viral cDNA libraries for sequencing analysis. The vast majority of the 36,769 viral sequences obtained were similar to plant pathogenic RNA viruses. The most abundant fecal virus in this study was pepper mild mottle virus (PMMV), which was found in high concentrations--up to 10(9) virions per gram of dry weight fecal matter. PMMV was also detected in 12 (66.7%) of 18 fecal samples collected from healthy individuals on two continents, indicating that this plant virus is prevalent in the human population. A number of pepper-based foods tested positive for PMMV, suggesting dietary origins for this virus. Intriguingly, the fecal PMMV was infectious to host plants, suggesting that humans might act as a vehicle for the dissemination of certain plant viruses.

The ever-increasing amount of anthropogenic carbon dioxide (CO₂) emissions has resulted in great environmental impacts, the heterogeneous catalysis of CO₂ hydrogenation to methanol is of great significance.

The mechanical properties of epoxy reinforced by carbon nanotubes, graphene, nanosilica and nanoclays are reviewed and the effects of nanoparticles loading on enhancing the toughness, stiffness and strength are summarised.

New amorphous alloys exhibiting a wide supercooled liquid region before crystallization were found to form by melt spinning in wide composition ranges of LaAlM, MgYM and ZrAlM (M = Ni or Cu) systems consisting of the constituent elements with significantly different atomic sizes. The temperature span between glass transition temperature, Tg, and crystallization temperature, Tx, ΔTx ( = Tx − Tg) is > 50 K in the compositional ranges around La2AlM, Mg6Ln3M and Zr3AlM and the largest ΔTx reaches 126 K. The critical cooling rate for the glass formation, Rc, is as low as 87–115 K/s and Tg/Tm is > 0.6 in the composition range where ΔTx > 50 K. There is a clear tendency for Rc to decrease with an increase of ΔTx and Tg/Tm. The crystallization of the alloys with large ΔTx occurs through the simultaneous precipitation of several compounds. Based on these results, it is presumed that the large glass-forming ability for these alloys is due to a combined effect of the difficulty of long-range atomic redistribution required for the precipitation of the compounds, the rapid increase of viscosity with decreasing temperature and the large liquidus-solidus interfacial energy which originates from the optimally bonding and packing states resulting from large negative heat of mixing and large atomic size ratios.

Single-atom metal catalysts offer a promising way to utilize precious noble metal elements more effectively, provided that they are catalytically active and sufficiently stable. Herein, we report a synthetic strategy for Pt single-atom catalysts with outstanding stability in several reactions under demanding conditions. The Pt atoms are firmly anchored in the internal surface of mesoporous Al2O3, likely stabilized by coordinatively unsaturated pentahedral Al3+ centres. The catalyst keeps its structural integrity and excellent performance for the selective hydrogenation of 1,3-butadiene after exposure to a reductive atmosphere at 200 °C for 24 h. Compared to commercial Pt nanoparticle catalyst on Al2O3 and control samples, this system exhibits significantly enhanced stability and performance for n-hexane hydro-reforming at 550 °C for 48 h, although agglomeration of Pt single-atoms into clusters is observed after reaction. In CO oxidation, the Pt single-atom identity was fully maintained after 60 cycles between 100 and 400 °C over a one-month period.

Geophysical Research LettersVolume 38, Issue 6 ClimateFree Access Was there a basis for anticipating the 2010 Russian heat wave? Randall Dole, Randall Dole Physical Sciences Division, Earth System Research Laboratory, NOAA, Boulder, Colorado, USASearch for more papers by this authorMartin Hoerling, Martin Hoerling [email protected] Physical Sciences Division, Earth System Research Laboratory, NOAA, Boulder, Colorado, USASearch for more papers by this authorJudith Perlwitz, Judith Perlwitz Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, Colorado, USASearch for more papers by this authorJon Eischeid, Jon Eischeid Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, Colorado, USASearch for more papers by this authorPhilip Pegion, Philip Pegion Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, Colorado, USASearch for more papers by this authorTao Zhang, Tao Zhang Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, Colorado, USASearch for more papers by this authorXiao-Wei Quan, Xiao-Wei Quan Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, Colorado, USASearch for more papers by this authorTaiyi Xu, Taiyi Xu Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, Colorado, USASearch for more papers by this authorDonald Murray, Donald Murray Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, Colorado, USASearch for more papers by this author Randall Dole, Randall Dole Physical Sciences Division, Earth System Research Laboratory, NOAA, Boulder, Colorado, USASearch for more papers by this authorMartin Hoerling, Martin Hoerling [email protected] Physical Sciences Division, Earth System Research Laboratory, NOAA, Boulder, Colorado, USASearch for more papers by this authorJudith Perlwitz, Judith Perlwitz Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, Colorado, USASearch for more papers by this authorJon Eischeid, Jon Eischeid Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, Colorado, USASearch for more papers by this authorPhilip Pegion, Philip Pegion Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, Colorado, USASearch for more papers by this authorTao Zhang, Tao Zhang Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, Colorado, USASearch for more papers by this authorXiao-Wei Quan, Xiao-Wei Quan Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, Colorado, USASearch for more papers by this authorTaiyi Xu, Taiyi Xu Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, Colorado, USASearch for more papers by this authorDonald Murray, Donald Murray Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, Colorado, USASearch for more papers by this author First published: 19 March 2011 https://doi.org/10.1029/2010GL046582Citations: 469AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Abstract [1] The 2010 summer heat wave in western Russia was extraordinary, with the region experiencing the warmest July since at least 1880 and numerous locations setting all-time maximum temperature records. This study explores whether early warning could have been provided through knowledge of natural and human-caused climate forcings. Model simulations and observational data are used to determine the impact of observed sea surface temperatures (SSTs), sea ice conditions and greenhouse gas concentrations. Analysis of forced model simulations indicates that neither human influences nor other slowly evolving ocean boundary conditions contributed substantially to the magnitude of this heat wave. They also provide evidence that such an intense event could be produced through natural variability alone. Analysis of observations indicate that this heat wave was mainly due to internal atmospheric dynamical processes that produced and maintained a strong and long-lived blocking event, and that similar atmospheric patterns have occurred with prior heat waves in this region. We conclude that the intense 2010 Russian heat wave was mainly due to natural internal atmospheric variability. Slowly varying boundary conditions that could have provided predictability and the potential for early warning did not appear to play an appreciable role in this event. 1. Introduction [2] Questions of vital societal interest are whether the 2010 Russian heat wave might have been anticipated, and to what extent human-caused greenhouse gas emissions played a role. Exceptional heat and poor air quality due to wildfires led to large increases in deaths in Moscow and elsewhere in western Russia, despite international efforts to improve public health responses to heat waves [World Health Organization, 2009]. Russia's extreme heat commenced in July nearly coincident with the peak temperatures in the annual cycle, thereby exacerbating human and environmental impacts. During July, when daily temperatures (Figure 1, top) were consistently near or above record levels, the heat wave spanned western Russia, the Republic of Belarus, the Ukraine, and the Baltic nations (see Figure S1 in Text S1 of the auxiliary material). Despite record warm globally-averaged surface temperatures over the first six months of 2010 [National Climatic Data Center, 2010], Moscow experienced an unusually cold winter and a relatively mild but variable spring, providing no hint of the record heat yet to come (Figure 1, top). Figure 1Open in figure viewerPowerPoint (top) Daily Moscow temperature record from November 1 2009 to October 31 2010, with daily departures computed with respect to the climatological seasonal cycle. Data are from the Global Summary of the Day produced by National Climatic Data Center. (middle) Observed time series of western Russia July temperature anomalies for the period 1880 to 2010 indicated as positive (red) and negative (blue) temperature anomalies relative to the base period from 1880 to 2009. Numbers indicate the years of the ten most extreme positive anomalies. The red asterisk indicates year 2010. The light and dark shaded areas represents the envelopes of positive and negative monthly mean temperature extremes based on 22 CMIP3 model simulations for normalized and non-normalized anomaly time series respectively. (bottom) Map of observed July temperature trend [oC/130yrs] for July 1880–2009. Box shows the area used to define “western Russia” surface temperatures. [3] For the 2003 western European heat wave, human influences are estimated to have at least doubled the risk for such an extreme event [Stott et al., 2004]. Other boundary forcings also contributed to the 2003 European heat wave, including anomalous sea surface temperatures (SSTs) [Feudale and Shukla, 2010]. The goal of this study is to identify the primary causes of the Russian heat wave and to assess to what extent it might have been anticipated from prior knowledge of natural and human forcings and observed regional climate trends. 2. Data and Model Experiments [4] The National Oceanic and Atmospheric Administration (NOAA) Land/Sea Merged analyses [Smith and Reynolds, 2005] are the primary surface temperature data used in this study. Results derived from this data set are compared with those obtained from three other observational temperature data sets (see Table S1 and references for these data sets in the auxiliary material). In the following analyses, western Russia temperatures are defined as area-averages over the region 50oN–60oN and 35oE to 55oE, the region of highest heat wave intensity and approximately centered over Moscow. [5] Model simulations were performed to determine the potential for anticipating the Russian heat wave. First, the potential influence of increasing greenhouse gas concentrations, aerosols, and other natural external forcings on western Russian temperatures was assessed from simulations of 22 CMIP3 models [Meehl et al., 2007]. These models are forced by specified monthly variations in greenhouse gases and tropospheric sulphate aerosols for 1880–1999, and with the IPCC Special Emissions Scenario (SRES) A1B thereafter. About half of the models also include changes in solar radiance and the effects of volcanic eruptions for the period 1880–1999. Model time series of western Russia temperatures were normalized relative to the observed mean standard deviation for July from 1880 to 2009 so that the magnitude of interannual variability in all models was comparable with observed variability. Second, possible effects of specific boundary conditions observed during July 2010 were evaluated. For this purpose, 50-member ensemble simulations were performed for each of two atmospheric general circulation models, the GFDL AM2.1 [Delworth et al., 2006] and the middle atmosphere configuration of ECHAM5 (MAECHAM5) [Roeckner et al., 2003], using observed global SST, sea ice and atmospheric carbon dioxide concentrations for July 2010. Responses to 2010 forcings were determined through comparisons with two parallel 50-member control simulations that used 1971–2000 mean climatological forcings. Third, predictions generated in June 2010 with NOAA's climate forecast system model [Saha et al., 2006] were examined to assess the potential role of atmospheric, land, and ocean initial conditions in this event. These predictions were initialized with atmospheric, land, and ocean conditions in early (1–4) and late (27–30) June 2010. 3. Results [6] The July surface temperatures for the region impacted by the 2010 Russian heat wave shows no significant warming trend over the prior 130-year period from 1880 to 2009 (Figures 1, middle and 1, bottom). A linear trend calculation yields a total temperature change over the 130 years of −0.1oC (with a range of 0 to −0.4oC over the four data sets, see Tables S1 and S2 of the auxiliary material for comparison). Similarly, no significant difference exists between July temperatures over western Russia averaged for the last 65 years (1945–2009) versus the prior 65 years (1880–1944) (Table S2). There is also no clear indication of a trend toward increasing warm extremes. The prior 10 warmest Julys are distributed across the entire period and exhibit only modest clustering earlier in this decade, in the 1980s and in the 1930s (Figure 1, middle). This behavior differs substantially from globally averaged annual temperatures, for which eleven of the last twelve years ending in 2006 rank among the twelve warmest years in the instrumental record since 1850 [Intergovernmental Panel on Climate Change, 2007]. The absence of prior July warming also differs from antecedent conditions for the 2003 western European heat wave, where a strong regional warming trend was detected over the twentieth century (see long-term trend map in Figure 1, bottom), a significant fraction of which has been attributed to anthropogenic forcing [Fischer and Schär, 2010]. [7] With no significant long-term trend in western Russia July surface temperatures detected over the period 1880–2009, mean regional temperature changes are thus very unlikely to have contributed substantially to the magnitude of the 2010 Russian heat wave. Another possibility is that long-term trends in variability may have increased the likelihood of an extreme heat wave. To assess this possibility, standard deviations of July surface temperatures were calculated for the two 65-yr periods before and after 1945. The results (Table S2) indicate slightly higher variability in the later period, but this increase is not statistically significant based on a standard F-test. Western Russia temperature extremes simulated in the 22 CMIP3 models (grey shaded area in Figure 1, middle) also do not display discernible trends during 1880–2009. The temporal distribution of extreme heat waves in the model data normalized to correspond with observed variability shows two events of similar magnitude to the heat wave intensity of about +5°C departure observed during 1880–2009, with one event in the earlier half of the 20th Century (light gray shading in Figure 1, middle). For model runs that are not normalized, the frequency of >5oC extreme events occurring before 1945 is even greater and comparable in frequency to that seen in more recent decades (dark gray shading in Figure 1, middle). In summary, the analysis of the observed 1880–2009 time series shows that no statistically significant long-term change is detected in either the mean or variability of western Russia July temperatures, implying that for this region an anthropogenic climate change signal has yet to emerge above the natural background variability. This is in contrast to regions such as western Europe, but similar to other regions like the central United States, consistent with strong regional (and seasonal) differences in climate trends that are yet to be fully understood. [8] The nature of this heat wave and its origins were intimately tied to the upper-level atmospheric flow. The 500 hPa July flow (Figure 2, top) was characterized by a classic “omega” blocking pattern [Dole and Gordon, 1983]. The highest July 2010 surface temperature anomalies (Figure 2, middle top) occurred near the center of the block, where northward displaced subtropical air, descending air motions and reduced cloudiness all contributed to abnormally warm surface temperatures. Severe drought occurred with the Russian heat wave, making it likely that land surface feedbacks amplified this heat wave's intensity, as has been observed in prior severe droughts [Atlas et al., 1993; Fischer et al., 2007]. To the east of the heat wave region, anomalously cool temperatures occurred in conjunction with an upper level trough and southward transport of polar air. Figure 2Open in figure viewerPowerPoint Observed climate conditions for July 2010 and for the 10 warmest western Russia July temperatures since 1880. (top) NCEP/NCAR Reanalysis 500 hPa height (contour, contour interval: 100 m), anomalies (shading), and wind vector anomalies (arrows, m s−1) for July 2010. Anomalies are relative to the 1948–2009 climatology. (middle top) Observed surface air temperature anomalies for July 2010 (base period is 1880–2009) from the NOAA merged land air and sea surface temperature data set. (middle bottom and bottom) As in Figures 2 (top) and 2 (middle top) but for composite of the ten warmest July monthly means over western Russia during the period 1880–2009. The Twentieth Century Reanalysis are the data source of 500 hPa heights [Compo et al., 2011]. [9] Russia is climatologically disposed toward blocking events during summer [Tyrlis and Hoskins, 2007], and many of its prior July heat waves were associated with blocks. Consistent with this, a composite analysis of the average temperature anomalies and 500 hPa heights associated with the ten largest prior heat waves in this region since 1880 shows patterns similar to 2010 (cf. Figures 2, top and 2, middle top and Figures 2, middle bottom and 2, bottom), although features are weaker as expected from such a composite analysis. The distance between centers of the temperature anomalies is comparable to the scale for stationary upper-air Rossby waves [Held, 1983], consistent with the role of atmospheric dynamical processes in accounting for the persistence of this pattern. [10] We have diagnosed additional model simulations forced by observed boundary conditions for this period to assess whether those may have produced a forced response consistent with the blocking pattern and associated heat wave. These boundary conditions reflect a mixture of both natural and human influences on the climate system. The observed global SSTs include positive anomalies in the Indo-west Pacific Ocean and tropical Atlantic and developing La Niña conditions in the east Pacific (see Figure S1). The observed Arctic sea ice extent in July 2010 was the second lowest in the satellite record [National Snow and Ice Data Center, 2010]. Figure 3 shows the model response based on the AM2.1 model. The ensemble-mean responses of the atmospheric circulation (Figure 3, top) and surface temperatures (Figure 3, middle top) are far weaker and their patterns are inconsistent with the observed blocking and heat wave (cf. Figure 2). A similar conclusion is drawn from the MAECHAM5 simulation whose response to July 2010 forcing is also very weak (Figure S2 of the auxiliary material). These findings suggest that the blocking and heat wave were not primarily a forced response to specific boundary conditions during 2010. Figure 3Open in figure viewerPowerPoint July 2010 climate conditions simulated with GFDL AM2.1. (top) The 50 member ensemble mean of 500 hPa height (contour, contour interval: 100 m), anomalies (shading), and wind vector anomalies (arrows). (middle top) Ensemble-mean surface temperature anomalies. (middle bottom and bottom) As in Figures 3 (top) and 3 (middle top), but for a single model run selected from the ensemble. [11] Nor are there indications that blocking would increase in response to increasing greenhouse gases. Results using very high-resolution climate models suggest that the number of Euro-Atlantic blocking events will decrease by the latter half of the 21st century [Matsueda et al., 2009; M. Matsueda and T. N. Palmer, personal communication, 2010]. The horizontal resolution of climate models is an important consideration in simulating blocking accurately. Although the ensemble-mean AM2.1 and MAECHAM5 responses bear no resemblance to the observed event, both models are capable of producing blocking over this area. For example, individual members within each model ensemble show flow patterns (Figures 3, middle bottom and S2, middle bottom) and temperature anomalies (Figures 3, bottom and S2, bottom) that are qualitatively similar to observations. However, these patterns reflect internal atmospheric variability within the models rather than a systematic response to boundary forcing, and thus are not evidence of a predictable signal. With only 50 ensemble members in these simulations, a meaningful assessment of changes in the tails of the distributions is not possible. [12] A third suite of model runs has also been considered which differs from the prior sets in that it is initialized with observed ocean-atmosphere-land conditions of 2010 in NOAA's operational coupled Climate Forecast System (CFS). Comparing predictions of July blocking in models initialized in early June versus in late June further clarifies the roles of boundary forcing and initial conditions and also addresses the potential for early warning capabilities. When initialized in early June 2010, the predictions show no evidence for a change in the probability of prolonged daily blocking during July 2010 over western Russia compared to the July hindcasts that were initialized in each June during 1981–2008. The model predictions do, however, show approximately a doubling of the average duration of daily blocking during July for runs begun in late June 2010, by which time blocking was already present in atmospheric initial conditions (see Figure S3 of the auxiliary material). This increase coincides with a shift of the probability density function of western Russian temperature anomalies towards warmer values by about +1.5oC. These results are consistent with the interpretation that the Russian heat wave was primarily caused by internal atmospheric dynamical processes rather than observed ocean or sea ice states or greenhouse gas concentrations. 4. Concluding Remarks [13] Our analysis points to a primarily natural cause for the Russian heat wave. This event appears to be mainly due to internal atmospheric dynamical processes that produced and maintained an intense and long-lived blocking event. Results from prior studies suggest that it is likely that the intensity of the heat wave was further increased by regional land surface feedbacks. The absence of long-term trends in regional mean temperatures and variability together with the model results indicate that it is very unlikely that warming attributable to increasing greenhouse gas concentrations contributed substantially to the magnitude of this heat wave. Nevertheless, there is evidence that such warming has contributed to observed heat waves in other regions, and is very likely to produce more frequent and extreme heat waves later this century [Intergovernmental Panel on Climate Change, 2007]. To assess this possibility for the region of western Russia, we have used the same IPCC model simulations to estimate the probability of exceeding various July temperature thresholds over the period 1880–2100 (Figure 4). The results suggest that we may be on the cusp of a period in which the probability of such events increases rapidly, due primarily to the influence of projected increases in greenhouse gas concentrations. Uncertainty in timing is nonetheless evident (Figure 4, inset), due in part to different model sensitivities to greenhouse gas forcing. Understanding the physical processes producing heat waves will be important for improving regional projections, and may also provide an improved capability for predicting some extreme events. However, as in the case of the 2010 Russian heat wave, events will also occur that are not readily anticipated from knowledge of either prior climate trends or specific climate forcings, and for which advance warning may thus be limited. Figure 4Open in figure viewerPowerPoint Simulated frequency of occurrence of western Russia temperature extremes for 30-year overlapping periods. Shown are time series for exceedance values of 3, 4, 5 and 6oC. Values are calculated based on 22 CMIP3 model ensemble. Insert shows the time series for the number of models in [%] that simulate at least a 10% probability of occurrence of a heat wave with specific temperature exceedance values. Acknowledgments [14] The study is supported in part by the NOAA Climate Program Office. The CFS forecast data were provided by Wanqui Wang of NOAA's Climate Prediction Center. The comments provided by William Neff and Klaus Wolter are gratefully acknowledged. [15] The authors thank two anonymous reviewers for their thoughtful comments. Supporting Information Auxiliary material for this article contains a comparison between different temperature data sets, a map of observed temperature anomalies for July 2010, supporting modeling results, and related references. Auxiliary material files may require downloading to a local drive depending on platform, browser, configuration, and size. To open auxiliary materials in a browser, click on the label. To download, Right-click and select “Save Target As…” (PC) or CTRL-click and select “Download Link to Disk” (Mac). Additional file information is provided in the readme.txt. Filename Description grl27860-sup-0001-readme.txtplain text document, 1.4 KB readme.txt grl27860-sup-0002-txts01.pdfPDF document, 1.7 MB Text S1. Temperature statistics for western Russia based on four temperature data sets and map of observed global temperature anomalies for July 2010, July 2010 climate conditions simulated with MAECHAM5, July blocking statistics in the NOAA Climate Forecast System and Reanalysis and References for temperature data sets and additional diagnostics. 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. References Atlas, R., N. Wolfson, and J. Terry (1993), The effects of SST and soil moisture anomalies on GLA model simulations of the 1988 US summer drought, J. Clim., 6, 2034– 2048, doi:10.1175/1520-0442(1993)006<2034:TEOSAS>2.0.CO;2. Compo, G. P., et al. (2011), The twentieth century reanalysis project, Q. J. R. Meteorol. Soc., 137, 1– 28, doi:10.1002/qj.776. Delworth, T. L., et al. (2006), GFDL's CM2 global coupled climate models. Part I: Formulation and simulation characteristics, J. Clim., 19, 643– 674, doi:10.1175/JCLI3629.1. Dole, R. M., and N. D. Gordon (1983), Persistent anomalies of the extra-tropical Northern Hemisphere wintertime circulation: Geographical distribution and regional persistence characteristics, Mon. Weather Rev., 111, 1567– 1586, doi:10.1175/1520-0493(1983)111<1567:PAOTEN>2.0.CO;2. Feudale, L., and J. Shukla (2010), Influence of sea surface temperature on the European heat wave of 2003 summer. Part II: A modeling study, Clim. Dyn., doi:10.1007/s00382-010-0789-z. Fischer, E. M., and C. Schär (2010), Consistent geographical patterns of changes in high-impact European heatwaves, Nat. Geosci., 3, 398– 403, doi:10.1038/ngeo866. Fischer, E. M., S. I. Seneviratne, D. Lüthi, and C. Schär (2007), Contribution of land-atmosphere coupling to recent European summer heat waves, Geophys. Res. Lett., 34, L06707, doi:10.1029/2006GL029068. Held, I. M. (1983), Stationary and quasi-stationary eddies in the extratropical troposphere, in Large-Scale Dynamical Processes in the Atmosphere, edited by B. Hoskins, and R. Pearce, pp. 127– 168, Academic, London. Intergovernmental Panel on Climate Change (2007), Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, edited by S. Solomon et al., Cambridge Univ. Press, Cambridge, U. K. Matsueda, M., R. Mizuta, and S. Kusunoki (2009), Future change in wintertime atmospheric blocking simulated using a 20-km-mesh atmospheric global circulation model, J. Geophys. Res., 114, D12114, doi:10.1029/2009JD011919. Meehl, G., et al. (2007), The WCRP CMIP3 multimodel dataset: A new era in climate change research, Bull. Am. Meteorol. Soc., 88, 1383– 1394, doi:10.1175/BAMS-88-9-1383. National Climatic Data Center (2010), State of the climate: Global analysis for June 2010, NOAA, Asheville, N. C. (Available at http://www.ncdc.noaa.gov/sotc/?report=global&year=2010&month=6). National Snow and Ice Data Center (2010), Arctic sea ice news and analysis, Boulder, Colo. (Available at http://nsidc.org/arcticseaicenews/2010/080410.html). Roeckner, E., et al. (2003), The atmospheric general circulation model ECHAM5. Part I. Model description, Rep. 349, 127 pp., Max-Planck-Inst. für Meteorol., Hamburg, Germany. Saha, S., et al. (2006), The NCEP Climate Forecast System, J. Clim., 19, 3483– 3517, doi:10.1175/JCLI3812.1. Smith, T. M., and R. W. Reynolds (2005), A global merged land air and sea surface temperature reconstruction based on historical observations (1880–1997), J. Clim., 18, 2021– 2036, doi:10.1175/JCLI3362.1. Stott, P. A., D. A. Stone, and M. R. Allen (2004), Human contribution to the European heat wave of 2003, Nature, 432, 610– 614, doi:10.1038/nature03089. Tyrlis, E., and B. J. Hoskins (2007), Aspects of a Northern Hemisphere atmospheric blocking climatology, J. Atmos. Sci., 65, doi:10.1175/2007JAS2337.1. World Health Organization (2009), Improving public health responses to extreme weather/heat waves-EuroHEAT, technical summary, edited by B. Menne, and F. Matthies, 60 pp., WHO Reg. Off. for Eur., Copenhagen. (Available at http://www.euro.who.int/__data/assets/pdf_file/0010/95914/E92474.pdf). Citing Literature Volume38, Issue6March 2011 This article also appears in:Atmospheric Linkages Between the Arctic and the Mid-Latitudes FiguresReferencesRelatedInformation

Co-N-C catalysts are promising candidates for substituting platinum in electrocatalysis and organic transformations. The heterogeneity of the Co species resulting from high-temperature pyrolysis, however, encumbers the structural identification of active sites. Herein, we report a self-supporting Co-N-C catalyst wherein cobalt is dispersed exclusively as single atoms. By using sub-Ångström-resolution HAADF-STEM in combination with XAFS and DFT calculation, the exact structure of the Co-N-C is identified to be CoN4C8-1-2O2, where the Co center atom is coordinated with four pyridinic N atoms in the graphitic layer, while two oxygen molecules are weakly adsorbed on Co atoms in perpendicular to the Co-N4 plane. This single-atom dispersed Co-N-C catalyst presents excellent performance for the chemoselective hydrogenation of nitroarenes to produce azo compounds under mild reaction conditions.

Deep neural networks (DNNs) have recently achieved great success in many visual recognition tasks. However, existing deep neural network models are computationally expensive and memory intensive, hindering their deployment in devices with low memory resources or in applications with strict latency requirements. Therefore, a natural thought is to perform model compression and acceleration in deep networks without significantly decreasing the model performance. During the past five years, tremendous progress has been made in this area. In this paper, we review the recent techniques for compacting and accelerating DNN models. In general, these techniques are divided into four categories: parameter pruning and quantization, low-rank factorization, transferred/compact convolutional filters, and knowledge distillation. Methods of parameter pruning and quantization are described first, after that the other techniques are introduced. For each category, we also provide insightful analysis about the performance, related applications, advantages, and drawbacks. Then we go through some very recent successful methods, for example, dynamic capacity networks and stochastic depths networks. After that, we survey the evaluation matrices, the main datasets used for evaluating the model performance, and recent benchmark efforts. Finally, we conclude this paper, discuss remaining the challenges and possible directions for future work.

In recent years, machine learning techniques have been widely used to solve many problems for fault diagnosis. However, in many real-world fault diagnosis applications, the distribution of the source domain data (on which the model is trained) is different from the distribution of the target domain data (where the learned model is actually deployed), which leads to performance degradation. In this paper, we introduce domain adaptation, which can find the solution to this problem by adapting the classifier or the regression model trained in a source domain for use in a different but related target domain. In particular, we proposed a novel deep neural network model with domain adaptation for fault diagnosis. Two main contributions are concluded by comparing to the previous works: first, the proposed model can utilize domain adaptation meanwhile strengthening the representative information of the original data, so that a high classification accuracy in the target domain can be achieved, and second, we proposed several strategies to explore the optimal hyperparameters of the model. Experimental results, on several real-world datasets, demonstrate the effectiveness and the reliability of both the proposed model and the exploring strategies for the parameters.

Semihydrogenation of acetylene in an ethylene-rich stream is an industrially important process. Conventional supported monometallic Pd catalysts offer high acetylene conversion, but they suffer from very low selectivity to ethylene due to overhydrogenation and the formation of carbonaceous deposits. Herein, a series of Ag alloyed Pd single-atom catalysts, possessing only ppm levels of Pd, supported on silica gel were prepared by a simple incipient wetness coimpregnation method and applied to the selective hydrogenation of acetylene in an ethylene-rich stream under conditions close to the front-end employed by industry. High acetylene conversion and simultaneous selectivity to ethylene was attained over a wide temperature window, surpassing an analogous Au alloyed Pd single-atom system we previously reported. Restructuring of AgPd nanoparticles and electron transfer from Ag to Pd were evidenced by in situ FTIR and in situ XPS as a function of increasing reduction temperature. Microcalorimetry and XANES measurements support both geometric and electronic synergetic effects between the alloyed Pd and Ag. Kinetic studies provide valuable insight into the nature of the active sites within these AgPd/SiO2 catalysts, and hence, they provide evidence for the key factors underpinning the excellent performance of these bimetallic catalysts toward the selective hydrogenation of acetylene under ethylene-rich conditions while minimizing precious metal usage.

Abstract The sluggish kinetics of Oxygen Reduction Reaction (ORR) at the cathode in proton exchange membrane fuel cells or metal-air batteries requires highly effective and stable electrocatalysts to boost the reaction. The low abundance and high price of Pt-based electrocatalysts hamper the widespread application of proton exchange membrane fuel cells and metal-air batteries. As promising alternatives, metal-free carbon materials, especially upon doping heteroatoms or creating defects demonstrated excellent ORR activity, which is as efficient as or even superior to commercial platinum on carbon. Significant progress on the development of advanced carbon materials as highly stable and durable catalysts has been achieved, but the catalytic mechanisms of these materials still remain undistinguished. In present review, we summarized the up-to-date progress in the studies of carbon materials, and emphasized on the combination of experiment and theory to clarify the underlying mechanisms of these materials. At last, we proposed the perspectives on the proper strategies of elucidating the mechanisms of carbon materials as electrocatalysts towards ORR.

In 2017, global CO2 emissions from burning fossil fuels reached 33 gigatons, twice the natural rate at which CO2 is absorbed back into land and ocean sinks. Harnessing solar radiation holds the answer to reducing our dependence on fossil fuels. It is the most abundant energy resource and could meet humans' future energy needs. The efficient conversion of solar radiation into stable, energy-dense liquid energy carriers that can use existing or adapt global supply chains for storage, shipping, and distribution is the key to large-scale deployment of solar energy at gigaton levels.Liquid sunshine is the vision of combining the sun's energy with carbon dioxide and water to produce green liquid fuels. CO2 released on using these fuels is recycled back into the environment, thus maintaining an ecologically balanced cycle. Multi-source and multi-purpose alcohols are optimal candidate fuels. Methanol and ethanol are actionable first targets with gigaton production potential.

Metal atoms dispersed on the oxide supports constitute a large category of single-atom catalysts. In this review, oxide supported single-atom catalysts are discussed about their synthetic procedures, characterizations, and reaction mechanism in thermocatalysis, such as water–gas shift reaction, selective oxidation/hydrogenation, and coupling reactions. Some typical oxide materials, including ferric oxide, cerium oxide, titanium dioxide, aluminum oxide, and so on, are intentionally mentioned for the unique roles as supports in anchoring metal atoms and taking part in the catalytic reactions. The interactions between metal atoms and oxide supports are summarized to give a picture on how to stabilize the atomic metal centers, and rationally tune the geometric structures and electronic states of single atoms. Furthermore, several directions in fabricating single-atom catalysts with improved performance are proposed on the basis of state-of-the-art understanding in metal-oxide interactions.

Background and Purpose To compare clinical outcomes and toxicities of two-dimensional conventional radiation therapy (2D-CRT) and intensity modulated radiation therapy (IMRT) for the treatment of nasopharyngeal carcinoma (NPC). Materials and methods Between July 2003 and October 2008, 616 patients with non-metastatic stage I to IVb NPC were prospectively randomized to receive 2D-CRT (n = 310; mean age, 44.8 ± 13.6 years) or IMRT (n = 306; mean age, 46.7 ± 12.5 years). Clinical outcomes and acute and late toxicities were determined and compared. Results The 2 groups were comparable with respect to all parameters of demographics and disease characteristics (all, p > 0.05). Median follow-up was 42 months (range, 1–83 months). The 5-year actuarial local control rate was 90.5% in the IMRT group and 84.7% in the 2D-CRT group. The local control rates were 91% for stage T3 and 81.5% for stage T4 disease in the IMRT group and 80% and 62.2% in the 2D-CRT group, respectively. The 5-year actuarial nodal relapse-free survival (NRFS) rate was 92.4% in the IMRT and 92.9% in the 2D-CRT group (p > 0.05). The NRFS was 93.9% for N2 disease in the IMRT group and 91.4% in the 2D-CRT group (p = 0.02). The 5-year overall survival (OS) rate was 79.6% for the IMRT group and 67.1% for the 2D-CRT group (p = 0.001). When stratified for stage, a significant difference was only noted for stage III disease. In terms of radiation-induced toxicities, patients in IMRT group had significantly lower radiation-induced toxicities than those in 2D-CRT group. Conclusion IMRT provides improved local-recurrence free survival, especially in late-stage NPC patients and is associated with a lower incidence of toxicities.

Abstract The land area surrounding the Mediterranean Sea has experienced 10 of the 12 driest winters since 1902 in just the last 20 years. A change in wintertime Mediterranean precipitation toward drier conditions has likely occurred over 1902–2010 whose magnitude cannot be reconciled with internal variability alone. Anthropogenic greenhouse gas and aerosol forcing are key attributable factors for this increased drying, though the external signal explains only half of the drying magnitude. Furthermore, sea surface temperature (SST) forcing during 1902–2010 likely played an important role in the observed Mediterranean drying, and the externally forced drying signal likely also occurs through an SST change signal. The observed wintertime Mediterranean drying over the last century can be understood in a simple framework of the region’s sensitivity to a uniform global ocean warming and to modest changes in the ocean’s zonal and meridional SST gradients. Climate models subjected to a uniform +0.5°C warming of the world oceans induce eastern Mediterranean drying but fail to generate the observed widespread Mediterranean drying pattern. For a +0.5°C SST warming confined to tropical latitudes only, a dry signal spanning the entire Mediterranean region occurs. The simulated Mediterranean drying intensifies further when the Indian Ocean is warmed +0.5°C more than the remaining tropical oceans, an enhanced drying signal attributable to a distinctive atmospheric circulation response resembling the positive phase of the North Atlantic Oscillation. The extent to which these mechanisms and the region’s overall drying since 1902 reflect similar mechanisms operating in association with external radiative forcing are discussed.

Porous carbon monoliths with defined multilength scale pore structures, a nitrogen-containing framework, and high mechanical strength were synthesized through a self-assembly of poly(benzoxazine-co-resol) and a carbonization process. Importantly, this synthesis can be easily scaled up to prepare carbon monoliths with identical pore structures. By controlling the reaction conditions, porous carbon monoliths exhibit fully interconnected macroporosity and mesoporosity with cubic Im3m symmetry and can withstand a press pressure of up to 15.6 MPa. The use of amines in the synthesis results in a nitrogen-containing framework of the carbon monolith, as evidenced by the cross-polarization magic-angle-spinning NMR characterization. With such designed structures, the carbon monoliths show outstanding CO2 capture and separation capacities, high selectivity, and facile regeneration at room temperature. At ∼1 bar, the equilibrium capacities of the monoliths are in the range of 3.3–4.9 mmol g–1 at 0 °C and of 2.6–3.3 mmol g–1 at 25 °C, while the dynamic capacities are in the range of 2.7–4.1 wt % at 25 °C using 14% (v/v) CO2 in N2. The carbon monoliths exhibit high selectivity for the capture of CO2 over N2 from a CO2/N2 mixture, with a separation factor ranging from 13 to 28. Meanwhile, they undergo a facile CO2 release in an argon stream at 25 °C, indicating a good regeneration capacity.

The existence of cancer stem cells (CSCs) in breast cancer has profound implications for cancer prevention. In this study, we evaluated sulforaphane, a natural compound derived from broccoli/broccoli sprouts, for its efficacy to inhibit breast CSCs and its potential mechanism.Aldefluor assay and mammosphere formation assay were used to evaluate the effect of sulforaphane on breast CSCs in vitro. A nonobese diabetic/severe combined immunodeficient xenograft model was used to determine whether sulforaphane could target breast CSCs in vivo, as assessed by Aldefluor assay, and tumor growth upon cell reimplantation in secondary mice. The potential mechanism was investigated using Western blotting analysis and beta-catenin reporter assay.Sulforaphane (1-5 micromol/L) decreased aldehyde dehydrogenase-positive cell population by 65% to 80% in human breast cancer cells (P < 0.01) and reduced the size and number of primary mammospheres by 8- to 125-fold and 45% to 75% (P < 0.01), respectively. Daily injection with 50 mg/kg sulforaphane for 2 weeks reduced aldehyde dehydrogenase-positive cells by >50% in nonobese diabetic/severe combined immunodeficient xenograft tumors (P = 0.003). Sulforaphane eliminated breast CSCs in vivo, thereby abrogating tumor growth after the reimplantation of primary tumor cells into the secondary mice (P < 0.01). Western blotting analysis and beta-catenin reporter assay showed that sulforaphane downregulated the Wnt/beta-catenin self-renewal pathway.Sulforaphane inhibits breast CSCs and downregulates the Wnt/beta-catenin self-renewal pathway. These findings support the use of sulforaphane for the chemoprevention of breast cancer stem cells and warrant further clinical evaluation.

Surface-supported isolated atoms in single-atom catalysts (SACs) are usually stabilized by diverse defects. The fabrication of high-metal-loading and thermally stable SACs remains a formidable challenge due to the difficulty of creating high densities of underpinning stable defects. Here we report that isolated Pt atoms can be stabilized through a strong covalent metal-support interaction (CMSI) that is not associated with support defects, yielding a high-loading and thermally stable SAC by trapping either the already deposited Pt atoms or the PtO2 units vaporized from nanoparticles during high-temperature calcination. Experimental and computational modeling studies reveal that iron oxide reducibility is crucial to anchor isolated Pt atoms. The resulting high concentrations of single atoms enable specific activities far exceeding those of conventional nanoparticle catalysts. This non defect-stabilization strategy can be extended to non-reducible supports by simply doping with iron oxide, thus paving a new way for constructing high-loading SACs for diverse industrially important catalytic reactions.

Development of cancer has been linked to chronic inflammation, particularly via interleukin-23 (IL-23) and IL-17 signaling pathways. However, the cellular source of IL-17 and underlying mechanisms by which IL-17-producing cells promote human colorectal cancer (CRC) remain poorly defined. Here, we demonstrate that innate γδT (γδT17) cells are the major cellular source of IL-17 in human CRC. Microbial products elicited by tumorous epithelial barrier disruption correlated with inflammatory dendritic cell (inf-DC) accumulation and γδT17 polarization in human tumors. Activated inf-DCs induced γδT17 cells to secrete IL-8, tumor necrosis factor alpha, and GM-CSF with a concomitant accumulation of immunosuppressive PMN-MDSCs in the tumor. Importantly, γδT17 cell infiltration positively correlated with tumor stages and other clinicopathological features. Our study uncovers an inf-DC-γδT17-PMN-MDSC regulatory axis in human CRC that correlates MDSC-meditated immunosuppression with tumor-elicited inflammation. These findings suggest that γδT17 cells might be key players in human CRC progression and have the potential for treatment or prognosis prediction.

A lot of attention has been paid to Li–O2 batteries in recent years, due to the huge potential specific energy and energy density, and they are extensively studied around the world. Much advance has been achieved, however, the fundamental understanding is still insufficient and challenges remain. Here, we provide a specific perspective on the development of non-aqueous Li–O2 batteries excluding those with aqueous, ionic liquid, hybrid, and solid-state electrolytes, because non-aqueous Li–O2 batteries possess a relatively simple configuration and the research on non-aqueous Li–O2 batteries is the most active of all Li–O2 batteries. The discussion will be focused on non-aqueous electrolytes, cathode catalysts, and anodes, and corresponding perspectives are provided at the end.

<h2>Summary</h2> The electrochemical oxygen reduction reaction in acidic media offers an attractive route for direct hydrogen peroxide (H₂O₂) generation and on-site applications. Unfortunately there is still a lack of cost-effective electrocatalysts with high catalytic performance. Here, we theoretically designed and experimentally demonstrated that a cobalt single-atom catalyst (Co SAC) anchored in nitrogen-doped graphene, with optimized adsorption energy of the *OOH intermediate, exhibited a high H₂O₂ production rate, which even slightly outperformed the state-of-the-art noble-metal-based electrocatalysts. The kinetic current of H₂O₂ production over Co SAC could reach 1 <mml:math><mml:mrow><mml:mrow><mml:mrow>mA</mml:mrow><mml:mo>/</mml:mo><mml:mrow><mml:mrow>cm</mml:mrow><mml:mrow>disk</mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:mrow></mml:mrow></mml:mrow></mml:math> at 0.6 V versus reversible hydrogen electrode in 0.1 M HClO₄ with H₂O₂ faraday efficiency > 90%, and these performance measures could be sustained for 10 h without decay. Further kinetic analysis and <i>operando</i> X-ray absorption study combined with density functional theory (DFT) calculation demonstrated that the nitrogen-coordinated single Co atom was the active site and the reaction was rate-limited by the first electron transfer step.

The worldwide incidence of bone disorders and conditions has been increasing. Bone is a nanomaterials composed of organic (mainly collagen) and inorganic (mainly nano-hydroxyapatite) components, with a hierarchical structure ranging from nanoscale to macroscale. In consideration of the serious limitation in traditional therapies, nanomaterials provide some new strategy in bone regeneration. Nanostructured scaffolds provide a closer structural support approximation to native bone architecture for the cells and regulate cell proliferation, differentiation, and migration, which results in the formation of functional tissues. In this article, we focused on reviewing the classification and design of nanostructured materials and nanocarrier materials for bone regeneration, their cell interaction properties, and their application in bone tissue engineering and regeneration. Furthermore, some new challenges about the future research on the application of nanomaterials for bone regeneration are described in the conclusion and perspectives part.

Using a chromatin immunoprecipitation-paired end diTag cloning and sequencing strategy, we mapped estrogen receptor α (ERα) binding sites in MCF-7 breast cancer cells. We identified 1,234 high confidence binding clusters of which 94% are projected to be bona fide ERα binding regions. Only 5% of the mapped estrogen receptor binding sites are located within 5 kb upstream of the transcriptional start sites of adjacent genes, regions containing the proximal promoters, whereas vast majority of the sites are mapped to intronic or distal locations (>5 kb from 5′ and 3′ ends of adjacent transcript), suggesting transcriptional regulatory mechanisms over significant physical distances. Of all the identified sites, 71% harbored putative full estrogen response elements (EREs), 25% bore ERE half sites, and only 4% had no recognizable ERE sequences. Genes in the vicinity of ERα binding sites were enriched for regulation by estradiol in MCF-7 cells, and their expression profiles in patient samples segregate ERα-positive from ERα-negative breast tumors. The expression dynamics of the genes adjacent to ERα binding sites suggest a direct induction of gene expression through binding to ERE-like sequences, whereas transcriptional repression by ERα appears to be through indirect mechanisms. Our analysis also indicates a number of candidate transcription factor binding sites adjacent to occupied EREs at frequencies much greater than by chance, including the previously reported FOXA1 sites, and demonstrate the potential involvement of one such putative adjacent factor, Sp1, in the global regulation of ERα target genes. Unexpectedly, we found that only 22%–24% of the bona fide human ERα binding sites were overlapping conserved regions in whole genome vertebrate alignments, which suggest limited conservation of functional binding sites. Taken together, this genome-scale analysis suggests complex but definable rules governing ERα binding and gene regulation.

We study the weak antilocalization (WAL) effect in topological insulator Bi(2)Te(3) thin films at low temperatures. The two-dimensional WAL effect associated with surface carriers is revealed in the tilted magnetic field dependence of magnetoconductance. Our data demonstrate that the observed WAL is robust against deposition of nonmagnetic Au impurities on the surface of the thin films, but it is quenched by the deposition of magnetic Fe impurities which destroy the π Berry phase of the topological surface states. The magnetoconductance data of a 5 nm Bi(2)Te(3) film suggests that a crossover from symplectic to unitary classes is observed with the deposition of Fe impurities.

With diminishing fossil resources and increasing concerns about environmental issues, searching for alternative fuels has gained interest in recent years. Cellulose, as the most abundant nonfood biomass on earth, is a promising renewable feedstock for production of fuels and chemicals. In principle, the ample hydroxyl groups in the structure of cellulose make it an ideal feedstock for the production of industrially important polyols such as ethylene glycol (EG), according to the atom economy rule. However, effectively depolymerizing cellulose under mild conditions presents a challenge, due to the intra- and intermolecular hydrogen bonding network. In addition, control of product selectivity is complicated by the thermal instabilities of cellulose-derived sugars. A one-pot catalytic process that combines hydrolysis of cellulose and hydrogenation/hydrogenolysis of cellulose-derived sugars proves to be an efficient way toward the selective production of polyols from cellulose. In this Account, we describe our efforts toward the one-pot catalytic conversion of cellulose to EG, a typical petroleum-dependent bulk chemical widely applied in the polyester industry whose annual consumption reaches about 20 million metric tons. This reaction opens a novel route for the sustainable production of bulk chemicals from biomass and will greatly decrease the dependence on petroleum resources and the associated CO₂ emission. It has attracted much attention from both industrial and academic societies since we first described the reaction in 2008. The mechanism involves a cascade reaction. First, acid catalyzes the hydrolysis of cellulose to water-soluble oligosaccharides and glucose (R1). Then, oligosaccharides and glucose undergo C-C bond cleavage to form glycolaldehyde with catalysis of tungsten species (R2). Finally, hydrogenation of glycolaldehyde by a transition metal catalyst produces the end product EG (R3). Due to the instabilities of glycolaldehyde and cellulose-derived sugars, the reaction rates should be r₁ << r₂ << r₃ in order to achieve a high yield of EG. Tuning the molar ratio of tungsten to transition metal and changing the reaction temperature successfully optimizes this reaction. No matter what tungsten compounds are used in the beginning reaction, tungsten bronze (HxWO₃) is always formed. It is then partially dissolved in hot water and acts as the active species to homogeneously catalyze C-C bond cleavage of cellulose-derived sugars. Upon cooling and exposure to air, the dissolved HxWO₃ is transformed to insoluble tungsten acid and precipitated from the solution to facilitate the separation and recovery of the catalyst. On the basis of this temperature-dependent phase-transfer behavior, we have developed a highly active, selective, and reusable catalyst composed of tungsten acid and Ru/C. Our work has unearthed new understanding of this reaction, including how different catalysts perform and the underlying mechanism. It has also guided researchers to the rational design of catalysts for other reactions involved in cellulose conversion.

Abstract Dry reforming of methane (DRM) is an attractive route to utilize CO 2 as a chemical feedstock with which to convert CH 4 into valuable syngas and simultaneously mitigate both greenhouse gases. Ni-based DRM catalysts are promising due to their high activity and low cost, but suffer from poor stability due to coke formation which has hindered their commercialization. Herein, we report that atomically dispersed Ni single atoms, stabilized by interaction with Ce-doped hydroxyapatite, are highly active and coke-resistant catalytic sites for DRM. Experimental and computational studies reveal that isolated Ni atoms are intrinsically coke-resistant due to their unique ability to only activate the first C-H bond in CH 4 , thus avoiding methane deep decomposition into carbon. This discovery offers new opportunities to develop large-scale DRM processes using earth abundant catalysts.

<h2>Summary</h2><h3>Background</h3> The cause of severe acute respiratory syndrome (SARS) has been identified as a new coronavirus. Whole genome sequence analysis of various isolates might provide an indication of potential strain differences of this new virus. Moreover, mutation analysis will help to develop effective vaccines. <h3>Methods</h3> We sequenced the entire SARS viral genome of cultured isolates from the index case (SIN2500) presenting in Singapore, from three primary contacts (SIN2774, SIN2748, and SIN2677), and one secondary contact (SIN2679). These sequences were compared with the isolates from Canada (TOR2), Hong Kong (CUHK-W1 and HKU39849), Hanoi (URBANI), Guangzhou (GZ01), and Beijing (BJ01, BJ02, BJ03, BJ04). <h3>Findings</h3> We identified 129 sequence variations among the 14 isolates, with 16 recurrent variant sequences. Common variant sequences at four loci define two distinct genotypes of the SARS virus. One genotype was linked with infections originating in Hotel M in Hong Kong, the second contained isolates from Hong Kong, Guangzhou, and Beijing with no association with Hotel M (p<0.0001). Moreover, other common sequence variants further distinguished the geographical origins of the isolates, especially between Singapore and Beijing. <h3>Interpretation</h3> Despite the recent onset of the SARS epidemic, genetic signatures are emerging that partition the worldwide SARS viral isolates into groups on the basis of contact source history and geography. These signatures can be used to trace sources of infection. In addition, a common variant associated with a non-conservative aminoacid change in the S1 region of the spike protein, suggests that immunological pressures might be starting to influence the evolution of the SARS virus in human populations. Published online May 9, 2003 http://image.thelancet.com/extras/03art4454web.pdf

Accurate control of tissue-specific gene expression plays a pivotal role in heart development, but few cardiac transcriptional enhancers have thus far been identified. Extreme noncoding-sequence conservation has successfully predicted enhancers that are active in many tissues but has failed to identify substantial numbers of heart-specific enhancers. Here, we used ChIP-Seq with the enhancer-associated protein p300 from mouse embryonic day 11.5 heart tissue to identify over 3,000 candidate heart enhancers genome wide. Compared to enhancers active in other tissues we studied at this time point, most candidate heart enhancers were less deeply conserved in vertebrate evolution. Nevertheless, transgenic mouse assays of 130 candidate regions revealed that most function reproducibly as enhancers active in the heart, irrespective of their degree of evolutionary constraint. These results provide evidence for a large population of poorly conserved heart enhancers and suggest that the evolutionary conservation of embryonic enhancers can vary depending on tissue type.

This paper investigates the predictability of economic policy uncertainty (EPU) to stock market volatility. Our in-sample evidence suggests that higher EPU leads to significant increases in market volatility. Out-of-sample findings show that incorporating EPU as an additional predictive variable into the existing volatility prediction models significantly improves forecasting ability of these models. The improvement is robust to the model specifications.

Abstract Homogeneous catalysts generally possess superior catalytic performance compared to heterogeneous catalysts. However, the issue of catalyst separation and recycling severely limits their use in practical applications. Single‐atom catalysts have the advantages of both homogeneous catalysts, such as “isolated sites”, and heterogeneous catalysts, such as stability and reusability, and thus would be a promising alternative to traditional homogeneous catalysts. In the hydroformylation of olefins, single‐atom Rh catalysts supported on ZnO nanowires demonstrate similar efficiency (TON≈40000) compared to that of homogeneous Wilkinson's catalyst (TON≈19000). HAADF‐STEM and infrared CO chemisorption experiments identified isolated Rh atoms on the support. XPS and XANES spectra indicate that the electronic state of Rh is almost metallic. The catalysts are about one or two orders of magnitude more active than most reported heterogeneous catalysts and can be reused four times without an obvious decline in activity.

Plant pathogenic fungi represent the largest group of disease-causing agents on crop plants, and are a constant and major threat to agriculture worldwide. Recent studies have shown that engineered production of RNA interference (RNAi)-inducing dsRNA in host plants can trigger specific fungal gene silencing and confer resistance to fungal pathogens1-7. Although these findings illustrate efficient uptake of host RNAi triggers by pathogenic fungi, it is unknown whether or not such an uptake mechanism has been evolved for a natural biological function in fungus-host interactions. Here, we show that in response to infection with Verticillium dahliae (a vascular fungal pathogen responsible for devastating wilt diseases in many crops) cotton plants increase production of microRNA 166 (miR166) and miR159 and export both to the fungal hyphae for specific silencing. We found that two V. dahliae genes encoding a Ca2+-dependent cysteine protease (Clp-1) and an isotrichodermin C-15 hydroxylase (HiC-15), and targeted by miR166 and miR159, respectively, are both essential for fungal virulence. Notably, V. dahliae strains expressing either Clp-1 or HiC-15 rendered resistant to the respective miRNA exhibited drastically enhanced virulence in cotton plants. Together, our findings identify a novel defence strategy of host plants by exporting specific miRNAs to induce cross-kingdom gene silencing in pathogenic fungi and confer disease resistance.

Plasmonic sensors are extremely promising candidates for label-free single-molecule analysis but require exquisite control over the physical arrangement of metallic nanostructures. Here we employ self-assembly based on the DNA origami technique for accurate positioning of individual gold nanoparticles. Our innovative design leads to strong plasmonic coupling between two 40 nm gold nanoparticles reproducibly held with gaps of 3.3 ± 1 nm. This is confirmed through far field scattering measurements on individual dimers which reveal a significant red shift in the plasmonic resonance peaks, consistent with the high dielectric environment due to the surrounding DNA. We use surface-enhanced Raman scattering (SERS) to demonstrate local field enhancements of several orders of magnitude through detection of a small number of dye molecules as well as short single-stranded DNA oligonucleotides. This demonstrates that DNA origami is a powerful tool for the high-yield creation of SERS-active nanoparticle assemblies with reliable sub-5 nm gap sizes.

Preferential oxidation of CO (PROX) in H2-rich stream is critical to the production of clean H2 for the H2-based fuel cells, which provide clean and efficient energy conversion. Development of highly active and selective PROX catalysts is highly desirable but proved to be extremely challenging. Here we report that CeO2-supported Au single atoms (Au1/CeO2) are highly active, selective, and extremely stable for PROX at the PEMFC working temperature (∼80 °C) with >99.5% CO conversion over a wide temperature window, 70–120 °C (or 50–100 °C, depending on the Au loading). The high CO conversion realized at high temperatures is attributed to the unique property of single-atom catalysts that is unable to dissociatively adsorb H2 and thus has a low reactivity toward H2 oxidation. This strategy is proven in general and can be extended to other oxide-supported Au atoms (e.g., Au1/FeOx), which may open a new window for the efficient catalysis of the PROX reaction.

An easy and versatile approach to construct DNA hydrogels is reported. The DNA building blocks, a Y-scaffold and a linker, can self-assemble into DNA hydrogels by the hybridization of their “sticky ends”. It is shown that the DNA hydrogels undergo a sol-gel transition upon heat or enzymatic treatment, and these responsiveness can be adjusted by tailoring the sequence of the building blocks. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by 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.

Preferential oxidation of CO (PROX) is an important reaction for removing small amounts of CO to a parts-per-million level from the hydrogen-rich stream, which will be ultimately supplied as a fuel to polymer–electrolyte membrane fuel cells. The key to the application of PROX is to develop a highly active and selective catalyst that operates well in a wide temperature window (e.g., 80–180 °C) and has good resistance to CO2 and steam. In the past decades, various catalyst formulations have been developed, among which platinum group metal catalysts, including Pt, Ru, and Ir—in particular, those modified with promoters such as alkali metals and reducible metal oxides—have received a great deal of attention for their significantly improved catalytic activities in the low-temperature range. In this minireview, the recent advances of the platinum group metal catalysts for the PROX reaction are summarized, including performances of unpromoted and promoted catalysts, reaction mechanisms, and kinetics. In addition, the important roles of hydroxyl groups in the PROX reaction are also discussed.

Supported metal catalysts play a central role in the modern chemical industry but often exhibit poor on-stream stability. The strong metal–support interaction (SMSI) offers a route to control the structural properties of supported metals and, hence, their reactivity and stability. Conventional wisdom holds that supported Au cannot manifest a classical SMSI, which is characterized by reversible metal encapsulation by the support upon high-temperature redox treatments. We demonstrate a classical SMSI for Au/TiO2, evidenced by suppression of CO adsorption, electron transfer from TiO2 to Au nanoparticles, and gold encapsulation by a TiOx overlayer following high-temperature reduction (reversed by subsequent oxidation), akin to that observed for titania-supported platinum group metals. In the SMSI state, Au/TiO2 exhibits markedly improved stability toward CO oxidation. The SMSI extends to Au supported over other reducible oxides (Fe3O4 and CeO2) and other group IB metals (Cu and Ag) over titania. This discovery highlights the general nature of the classical SMSI and unlocks the development of thermochemically stable IB metal catalysts.

Background Patients with advanced or metastatic oesophageal squamous cell carcinoma have poor prognosis and few treatment options after first-line therapy. We aimed to assess efficacy and safety of the anti-PD-1 antibody camrelizumab versus investigator's choice of chemotherapy in previously treated patients. Methods ESCORT is a randomised, open-label, phase 3 study of patients aged 18 to 75 years with a histological or cytological diagnosis of advanced or metastatic oesophageal squamous cell carcinoma done at 43 hospitals in China. Eligible patients had an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, and had progressed on, or were intolerant to, first-line standard therapy. Patients were randomly assigned (1:1) to camrelizumab (200 mg every 2 weeks) or chemotherapy with docetaxel (75 mg/m2 every 3 weeks) or irinotecan (180 mg/m2 every 2 weeks), all given intravenously. Central randomisation was done using the Randomization and Trial Supply Management system with block size randomly generated as four or six and stratified by disease and ECOG performance status. The primary endpoint was overall survival, assessed in randomised patients who had received at least one dose of treatment. Safety was assessed in all treated patients. The trial is registered with ClinicalTrials.gov, NCT03099382, and is closed to new participants. Findings From May 10, 2017, to July 24, 2018, 457 (75%) of 607 screened patients were randomly assigned to treatment, of whom 228 received camrelizumab treatment and 220 received chemotherapy. As of data cutoff on May 6, 2019, with a median follow-up time of 8·3 months (IQR 4·1–12·8) in the camrelizumab group and 6·2 months (3·6–10·1) in the chemotherapy group, median overall survival was 8·3 months (95% CI 6·8–9·7) in the camrelizumab group and 6·2 months (5·7–6·9) in the chemotherapy group (hazard ratio 0·71 [95% CI 0·57–0·87]; two-sided p=0·0010). The most common treatment-related adverse events of grade 3 or worse were anaemia (camrelizumab vs chemotherapy: six [3%] vs 11 [5%]), abnormal hepatic function (four [2%] vs one [<1%]), and diarrhoea (three [1%] vs nine [4%]). Serious treatment-related adverse events occurred in 37 (16%) of 228 patients in the camrelizumab group, and in 32 (15%) of 220 patients in the chemotherapy group. Ten treatment-related deaths occurred, seven (3%) in the camrelizumab group (three deaths from unknown causes, one enterocolitis, one hepatic function abnormal, one pneumonitis, and one myocarditis) and three (1%) in the chemotherapy group (two deaths from unknown causes, and one gastrointestinal haemorrhage). Interpretation Second-line camrelizumab significantly improved overall survival in patients with advanced or metastatic oesophageal squamous cell carcinoma compared with chemotherapy, with a manageable safety profile. It might represent a potential option of standard second-line treatment for patients with oesophageal squamous cell carcinoma in China. Funding Jiangsu Hengrui Medicine.

New bulk amorphous alloys exhibiting a wide supercooled liquid region before crystallization were found in Fe–(Co,Ni)–(Zr,Nb,Ta)–(Mo,W)–B systems. The Tg is as high as about 870 K and the supercooled liquid region reaches 88 K. The high thermal stability of the supercooled liquid enabled the production of bulk amorphous alloys with diameters up to 6 mm. These bulk amorphous alloys exhibit a high compressive strength of 3800 MPa, high Vickers hardness of 1360, and high corrosion resistance. Besides, the amorphous alloys exhibit a high magnetic-flux density of 0.74–0.96 T, low coercivity of 1.1–3.2 A/m, high permeability exceeding 1.2×104 at 1 kHz, and low magnetostriction of about 12×10−6.

Electrolyte degradation, Li dendrite formation and parasitic reactions with H₂O and CO₂ are all directly correlated to reversibility and cycleability of Li-air batteries when operated in ambient air. Here we replace easily decomposable liquid electrolytes with a solid Li-ion conductor, which acts as both a catholyte and a Li protector. Meanwhile, the conventional solid air cathodes are replaced with a gel cathode, which contacts directly with the solid catholyte to form a closed and sustainable gel/solid interface. The proposed Li-air cell has sustained repeated cycling in ambient air for 100 cycles (~78 days), with discharge capacity of 2,000 mAh g(-1). The recharging is based largely on the reversible reactions of Li₂CO₃ product, originating from the initial discharge product of Li₂O₂ instead of electrolyte degradation. Our results demonstrate that a reversible long-life Li-air battery is attainable by coordinated approaches towards the focal issues of electrolytes and Li metal.

The strong metal-support interaction (SMSI) is of great importance for supported catalysts in heterogeneous catalysis. We report the first example of SMSI between Au nanoparticles (NPs) and hydroxyapatite (HAP), a nonoxide. The reversible encapsulation of Au NPs by HAP support, electron transfer, and changes in CO adsorption are identical to the classic SMSI except that the SMSI of Au/HAP occurred under oxidative condition; the opposite condition for the classical SMSI. The SMSI of Au/HAP not only enhanced the sintering resistance of Au NPs upon calcination but also improved their selectivity and reusability in liquid-phase reaction. It was found that the SMSI between Au and HAP is general and could be extended to other phosphate-supported Au systems such as Au/LaPO4. This new discovery may open a new way to design and develop highly stable supported Au catalysts with controllable activity and selectivity.

Intermetallic alloying of one active metal to another inert metal provides not only the improved dispersion of active centers but also a unique and homogeneous ensemble of active sites, thus offering new opportunities in a variety of reactions. Herein, we report that PdZn intermetallic nanostructure with Pd–Zn–Pd ensembles are both highly active and selective for the semihydrogenation of acetylene to ethylene, which is usually inaccessible due to the sequential hydrogenation to ethane. Microcalorimetric measurements and density functional theory calculations demonstrate that the appropriate spatial arrangement of Pd sites in the Pd–Zn–Pd ensembles of the PdZn alloy leads to the moderate σ-bonding mode for acetylene with two neighboring Pd sites while the weak π-bonding pattern of ethylene adsorption on the single Pd site, which facilitates the chemisorption toward acetylene and promotes the desorption of ethylene from the catalyst surface. As a result, it leads to the kinetic favor of the selective conversion of acetylene to ethylene.

Background: The role of long noncoding RNA (lncRNA) highly up-regulated in liver cancer (HULC) in hepatocarcinogenesis mediated by hepatitis B virus X protein (HBx) remains unclear.Results: Up-regulation of HULC by HBx promotes hepatoma cell proliferation via down-regulating p18.Conclusion: HULC contributes to HBx-related hepatocarcinogenesis through suppressing p18.Significance: The finding provides insight into the roles of lncRNAs in HBx-associated hepatocarcinogenesis. Background: The role of long noncoding RNA (lncRNA) highly up-regulated in liver cancer (HULC) in hepatocarcinogenesis mediated by hepatitis B virus X protein (HBx) remains unclear. Results: Up-regulation of HULC by HBx promotes hepatoma cell proliferation via down-regulating p18. Conclusion: HULC contributes to HBx-related hepatocarcinogenesis through suppressing p18. Significance: The finding provides insight into the roles of lncRNAs in HBx-associated hepatocarcinogenesis.

Abstract Pancreatic cancer is an aggressive disease with multiple biochemical and genetic alterations. Thus, a single agent to hit one molecular target may not be sufficient to treat this disease. The purpose of this study is to identify a novel Hsp90 inhibitor to disrupt protein-protein interactions of Hsp90 and its cochaperones for down-regulating many oncogenes simultaneously against pancreatic cancer cells. Here, we reported that celastrol disrupted Hsp90-Cdc37 interaction in the superchaperone complex to exhibit antitumor activity in vitro and in vivo. Molecular docking and molecular dynamic simulations showed that celastrol blocked the critical interaction of Glu33 (Hsp90) and Arg167 (Cdc37). Immunoprecipitation confirmed that celastrol (10 μmol/L) disrupted the Hsp90-Cdc37 interaction in the pancreatic cancer cell line Panc-1. In contrast to classic Hsp90 inhibitor (geldanamycin), celastrol (0.1-100 μmol/L) did not interfere with ATP binding to Hsp90. However, celastrol (1-5 μmol/L) induced Hsp90 client protein degradation (Cdk4 and Akt) by 70% to 80% and increased Hsp70 expression by 12-fold. Celastrol induced apoptosis in vitro and significantly inhibited tumor growth in Panc-1 xenografts. Moreover, celastrol (3 mg/kg) effectively suppressed tumor metastasis by more than 80% in RIP1-Tag2 transgenic mouse model with pancreatic islet cell carcinogenesis. The data suggest that celastrol is a novel Hsp90 inhibitor to disrupt Hsp90-Cdc37 interaction against pancreatic cancer cells. [Mol Cancer Ther 2008;7(1):162–70]

A low pressure casting of a La55Al25Ni20 melt into a copper mold was found to bring about an amorphous bulk in cylindrical or sheet form. The maximum diameter of the amorphous cylinder and the maximum thickness of the amorphous sheet with a width of 5.0 mm were about 3.0 and 2.3 mm, respectively. In comparison with the thermal properties of a melt-spun amorphous La55Al25Ni20 ribbon, the amorphous bulks had a higher onset temperature and a smaller heat evolution of irreversible structural relaxation, but there was no distinct difference in glass transition and crystallization behavior. Thus, the amorphous phase produced by casting had a more relaxed atomic configuration as compared with that for the melt-spun ribbon, but there was no difference in the specific heat curves during reheating for both of the samples heated up to the supercooled liquid region. This is believed to be the first evidence that amorphization takes place by casting into a copper mold. The amorphization allows us to reconfirm an extremely large glass-forming capacity of the La–Al–Ni amorphous alloy as previously found by the present authors.

This work investigated the relationship between the property of the surface hydroxyl groups of hydroxylated synthetic α-FeOOH and their catalytic activity in promoting hydroxyl radical (OH) generation from aqueous ozone. Nitrobenzene was used as an ozone-resistant probe to quantify OH generation. ATR-FTIR analysis reveals that sulfate and phosphate suppressed the catalytic activity of α-FeOOH through substituting its surface hydroxyl groups, which implies that the catalyst surface hydroxyl groups were active sites for promoting OH generation. Compared with other synthetic oxo-hydroxides such as β-FeOOH, γ-FeOOH and γ-AlOOH, α-FeOOH achieved a highest Rc value (i.e., 1.11 × 10−7, molar concentration ratio of OH to O3) in catalytic ozonation. No correlation could be established between the surface hydroxyl density and the OH-promoting activity of the oxo-hydroxides. In contrast, their catalytic activity was found to be reversely related to the IR stretching frequencies of surface hydroxyl groups. The results indicate that not all surface hydroxyl groups of the oxo-hydroxides possessed the same high catalytic activity, but the weak surface MeO–H bonds were favorable sites for promoting OH generation from aqueous ozone. The surface hydroxyl–ozone interaction was thus proposed for the catalyzed OH generation, which can explain why neutral surface hydroxyl species of α-FeOOH was more active than protonated or deprotonated species.

Processing-in-memory (PIM) is a promising solution to address the "memory wall" challenges for future computer systems. Prior proposed PIM architectures put additional computation logic in or near memory. The emerging metal-oxide resistive random access memory (ReRAM) has showed its potential to be used for main memory. Moreover, with its crossbar array structure, ReRAM can perform matrix-vector multiplication efficiently, and has been widely studied to accelerate neural network (NN) applications. In this work, we propose a novel PIM architecture, called PRIME, to accelerate NN applications in ReRAM based main memory. In PRIME, a portion of ReRAM crossbar arrays can be configured as accelerators for NN applications or as normal memory for a larger memory space. We provide microarchitecture and circuit designs to enable the morphable functions with an insignificant area overhead. We also design a software/hardware interface for software developers to implement various NNs on PRIME. Benefiting from both the PIM architecture and the efficiency of using ReRAM for NN computation, PRIME distinguishes itself from prior work on NN acceleration, with significant performance improvement and energy saving. Our experimental results show that, compared with a state-of-the-art neural processing unit design, PRIME improves the performance by ~2360x and the energy consumption by ~895x, across the evaluated machine learning benchmarks.

Abstract Owing to their earth abundance, high atom utilization, and excellent activity, single iron atoms dispersed on nitrogen‐doped carbons (Fe‐N‐C) have emerged as appealing alternatives to noble‐metal platinum (Pt) for catalyzing the oxygen reduction reaction (ORR). However, the ORR activity of current Fe‐N‐C is seriously limited by the low density and inferior exposure of active Fe‐N x species. Here, a novel zinc‐mediated template synthesis strategy is demonstrated for constructing densely exposed Fe‐N x moieties on hierarchically porous carbon (SA‐Fe‐NHPC). During the thermal treatment of 2,6‐diaminopyridine/ZnFe/SiO 2 complex, the zinc prevents the formation of iron carbide nanoparticles and the SiO 2 template promotes the generation of hierarchically pores for substantially improving the accessibility of Fe‐N x moieties after subsequent leaching. As a result, the SA‐Fe‐NHPC electrocatalysts exhibit an unprecedentedly high ORR activity with a half‐wave potential ( E 1/2 ) of 0.93 V in a 0.1 m KOH aqueous solution, which outperforms those for Pt/C catalyst and state‐of‐the‐art noble metal‐free electrocatalysts. As the air electrode in zinc–air batteries, the SA‐Fe‐NHPC demonstrates a large peak power density of 266.4 mW cm −2 and superior long‐term stability. Therefore, the developed zinc‐mediated template synthesis strategy for boosting the density and accessibility of Fe‐N x species paves a new avenue toward high‐performance ORR electrocatalysts.

Designing effective electrocatalysts for the carbon dioxide reduction reaction (CO2 RR) is an appealing approach to tackling the challenges posed by rising CO2 levels and realizing a closed carbon cycle. However, fundamental understanding of the complicated CO2 RR mechanism in CO2 electrocatalysis is still lacking because model systems are limited. We have designed a model nickel single-atom catalyst (Ni SAC) with a uniform structure and well-defined Ni-N4 moiety on a conductive carbon support with which to explore the electrochemical CO2 RR. Operando X-ray absorption near-edge structure spectroscopy, Raman spectroscopy, and near-ambient X-ray photoelectron spectroscopy, revealed that Ni+ in the Ni SAC was highly active for CO2 activation, and functioned as an authentic catalytically active site for the CO2 RR. Furthermore, through combination with a kinetics study, the rate-determining step of the CO2 RR was determined to be *CO2- +H+ →*COOH. This study tackles the four challenges faced by the CO2 RR; namely, activity, selectivity, stability, and dynamics.

Strong metal-support interaction (SMSI) has gained great attention in the field of heterogeneous catalysis. However, whether single-atom catalysts can exhibit SMSI remains unknown. Here, we demonstrate that SMSI can occur on TiO2 -supported Pt single atoms but at a much higher reduction temperature than that for Pt nanoparticles (NPs). Pt single atoms involved in SMSI are not covered by the TiO2 support nor do they sink into its subsurface. The suppression of CO adsorption on Pt single atoms stems from coordination saturation (18-electron rule) rather than the physical coverage of Pt atoms by the support. Based on the new finding it is revealed that single atoms are the true active sites in the hydrogenation of 3-nitrostyrene, while Pt NPs barely contribute to the activity since the NP sites are selectively encapsulated. The findings in this work provide a new approach to study the active sites by tuning SMSI.

Si has been regarded as a promising anode material for Li-ion batteries. However, its dramatic volume change during cycling poses formidable challenges to building stable electrodes. Since Si microparticles (SiMPs) can easily cause the pulverization and loss of electronic contact, many previous works were focused on porous-structured, nanostructured, or hierarchically structured silicon materials to improve the cycle stability. However, their low-cost and mass production is mostly difficult or even impossible. Herein, a water-soluble polymer binder, poly(acrylic acid)-poly(2-hydroxyethyl acrylate-co-dopamine methacrylate), is designed and synthesized. It shows better wettability to liquid electrolyte than poly(acrylic acid). Moreover, its multiple network structure with rigid-soft chains and bonds, and special self-healing capability in situ formed during the electrode preparation, not only provides enough mechanical support but also buffers the strain caused by the volume change of SiMPs. Thus, the cycle stability and rate performance are remarkably improved under high reversible capacity or electrode loading.

Ever present hurdles for the discovery of new drugs for cancer therapy have necessitated the development of the alternative strategy of drug repurposing, the development of old drugs for new therapeutic purposes. This strategy with a cost-effective way offers a rare opportunity for the treatment of human neoplastic disease, facilitating rapid clinical translation. With an increased understanding of the hallmarks of cancer and the development of various data-driven approaches, drug repurposing further promotes the holistic productivity of drug discovery and reasonably focuses on target-defined antineoplastic compounds. The "treasure trove" of non-oncology drugs should not be ignored since they could target not only known but also hitherto unknown vulnerabilities of cancer. Indeed, different from targeted drugs, these old generic drugs, usually used in a multi-target strategy may bring benefit to patients. In this review, aiming to demonstrate the full potential of drug repurposing, we present various promising repurposed non-oncology drugs for clinical cancer management and classify these candidates into their proposed administration for either mono- or drug combination therapy. We also summarize approaches used for drug repurposing and discuss the main barriers to its uptake.

Quercetin, a dietary antioxidant present in fruits and vegetables, is a promising cancer chemopreventive agent that inhibits tumor promotion by inducing cell cycle arrest and promoting apoptotic cell death. In this study, we examined the biological activities of quercetin against gastric cancer. Our studies demonstrated that exposure of gastric cancer cells AGS and MKN28 to quercetin resulted in pronounced pro-apoptotic effect through activating the mitochondria pathway. Meanwhile, treatment with quercetin induced appearance of autophagic vacuoles, formation of acidic vesicular organelles (AVOs), conversion of LC3-I to LC3-II, recruitment of LC3-II to the autophagosomes as well as activation of autophagy genes, suggesting that quercetin initiates the autophagic progression in gastric cancer cells. Furthermore, either administration of autophagic inhibitor chloroquine or selective ablation of atg5 or beclin 1 using small interfering RNA (siRNA) could augment quercetin-induced apoptotic cell death, suggesting that autophagy plays a protective role against quercetin-induced apoptosis. Moreover, functional studies revealed that quercetin activated autophagy by modulation of Akt-mTOR signaling and hypoxia-induced factor 1α (HIF-1α) signaling. Finally, a xenograft model provided additional evidence for occurrence of quercetin-induced apoptosis and autophagy in vivo. Together, our studies provided new insights regarding the biological and anti-proliferative activities of quercetin against gastric cancer, and may contribute to rational utility and pharmacological study of quercetin in future anti-cancer research.

Abstract Heterogeneous single-atom catalyst (SAC) opens a unique entry to establishing structure–performance relationship at the molecular level similar to that in homogeneous catalysis. The challenge lies in manipulating the coordination chemistry of single atoms without changing single-atom dispersion. Here, we develop an efficient synthetic method for SACs by using ethanediamine to chelate Pt cations and then removing the ethanediamine by a rapid thermal treatment (RTT) in inert atmosphere. The coordination chemistry of Pt single atoms on a Fe 2 O 3 support is finely tuned by merely adjusting the RTT temperature. With the decrease in Pt-O coordination number, the oxidation state of Pt decreases, and consequently the hydrogenation activity increases to a record level without loss of chemoselectivity. The tunability of the local coordination chemistry, oxidation states of the metal, and the catalytic performance of single atoms reveals the unique role of SACs as a bridge between heterogeneous and homogeneous catalysis.

Au–Cu Alloy nanoparticles with sizes of ∼3 nm were prepared in the confined space of SBA-15 and showed much better performance than monometallic particles in catalyzing CO oxidation even with the rich presence of H2.

Tungsten-based bimetallic catalysts (W–M(8,9,10); where M(8,9,10) is Ni, Pd, Pt, Ir, Ru, or Rh) are found to be highly active and selective for the formation of ethylene glycol from cellulose. The cooperation between CC cracking reactions over metallic tungsten and the hydrogenation of unsaturated intermediates over the transition metals M(8,9,10) results in a particularly high selectivity towards ethylene glycol, up to 75 %. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by 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.

The separation of oily wastewater, including immiscible oil/water mixtures and emulsified oil/water mixtures, is a worldwide challenge because of the large amount of oily wastewater produced in many industrial processes and daily life. For the treatment of oily wastewater, membrane technology is considered the most efficient method because of its high separation efficiency and relatively simple operational process. Due to highly specific surface areas, interconnected nanoscale pore structures, controllable pore size, the potential of surface texture, and ease of chemical modification, fiber-based membranes with superwetting have become promising versatile platforms for the separation of oil/water mixtures and emulsions. Such fiber-based membranes can be categorized based on type of fiber membrane substrate and the surface wettability. Here, the theory and design of various superwetting states for selective oil/water separation including superhydrophobicity/superoleophilicity, superhydrophilicity/underwater superoleophobicity, Janus wettability, and smart wettability are discussed. Two types of fiber-based membrane substrate including inorganic fibers (e.g. metal mesh, carbon nanotube, and inorganic oxide fibers) and organic fibers (e.g. fabrics fiber and nonwoven fibers) are summarized. The unique advantages of each type fibers have been highlighted, with emphasis on the membrane wetting properties, membrane fouling and representative works. Moreover, the detail progress of fiber-based membrane for separation of both immiscible oil/water mixtures and emulsified ones were introduced. Finally, the challenges and future research directions of fiber-based membrane were briefly discussed.

Circular dichroism spectra of naturally occurring molecules and also of synthetic chiral arrangements of plasmonic particles often exhibit characteristic bisignate shapes. Such spectra consist of peaks next to dips (or vice versa) and result from the superposition of signals originating from many individual chiral objects oriented randomly in solution. Here we show that by first aligning and then toggling the orientation of DNA-origami-scaffolded nanoparticle helices attached to a substrate, we are able to reversibly switch the optical response between two distinct circular dichroism spectra corresponding to either perpendicular or parallel helix orientation with respect to the light beam. The observed directional circular dichroism of our switchable plasmonic material is in good agreement with predictions based on dipole approximation theory. Such dynamic metamaterials introduce functionality into soft matter-based optical devices and may enable novel data storage schemes or signal modulators.

The water stability of the fast lithium ion conducting glass–ceramic electrolyte, Li1+x+yAlxTi2−xSiyP3−yO12 (LATP), has been examined in distilled water, and aqueous solutions of LiNO3, LiCl, LiOH, and HCl. This glass–ceramics are stable in aqueous LiNO3 and aqueous LiCl, and unstable in aqueous 0.1 M HCl and 1 M LiOH. In distilled water, the electrical conductivity slightly increases as a function of immersion time in water. The Li–Al/Li3−xPO4−yNy/LATP/aqueous 1 M LiCl/Pt cell, where lithium phosphors oxynitrides Li3−xPO4−yNy (LiPON) are used to protect the direct reaction of Li and LATP, shows a stable open circuit voltage (OCV) of 3.64 V at 25 °C, and no cell resistance change for 1 week. Lithium phosphors oxynitride is effectively used as a protective layer to suppress the reaction between the LATP and Li metal. The water-stable Li/LiPON/LATP system can be used in Li/air secondary batteries with the air electrode containing water.

Background Immunotherapy combined with chemotherapy has been shown to be efficacious as treatment for advanced non-squamous non-small-cell lung cancer (NSCLC) without targetable genetic aberrations; however, there is scarce evidence of the effectiveness of the combinations in the Asian population. We evaluated camrelizumab plus chemotherapy against non-squamous NSCLC in China. Methods We did a randomised, open-label, multicentre, phase 3 trial (CameL) in 52 hospitals in China for patients with non-squamous NSCLC without EGFR and ALK alteration. Eligible patients were aged 18–70 years and had no previous systemic chemotherapy, Eastern Cooperative Oncology Group performance status of 0 or 1, and at least one measurable lesion per Response Evaluation Criteria in Solid Tumors (version 1.1). Patients were randomly assigned (1:1) to receive 4–6 cycles of carboplatin (area under curve 5 mg/mL per min) plus pemetrexed (500 mg/m2) with or without camrelizumab (200 mg) every 3 weeks, followed by maintenance therapy with camrelizumab plus pemetrexed or pemetrexed alone. Medication was administered intravenously on day 1 of each 3-week treatment cycle. Randomisation was done using a centralised interactive web-response system with the block size randomly generated as four or six and stratified by sex and smoking history. The two primary endpoints were progression-free survival per blinded independent central review, in all patients and in patients who were PD-L1 positive. Primary analysis was done in the full analysis set that included all randomly assigned patients who received at least one dose of the study treatment. Herein, due to the primary endpoint being met at the interim analysis, we reported the findings of prespecified interim analysis, which only included confirmatory statistical testing for progression-free survival in all patients. Safety was assessed in the as-treated population. This study is registered with ClinicalTrials.gov, NCT03134872 (follow-up is ongoing). Findings Between May 12, 2017, and June 6, 2018, of the 419 patients who were randomly assigned, seven did not receive assigned treatment and 412 received either camrelizumab plus chemotherapy (n=205) or chemotherapy alone (n=207). At interim analysis, median follow-up duration was 11·9 months (IQR 9·0–14·9). Progression-free survival in this interim analysis was significantly prolonged with camrelizumab plus chemotherapy than with chemotherapy alone (median 11·3 months [95% CI 9·6–15·4] vs 8·3 months [6·0–9·7]; hazard ratio 0·60 [0·45–0·79]; one-sided p=0·0001). Most common grade 3 or worse treatment-related adverse events were decreased neutrophil count (78 [38%] patients in the camrelizumab plus chemotherapy group vs 63 [30%] patients in the chemotherapy alone group), decreased white blood cell count (40 [20%] vs 30 [14%]), anaemia (38 [19%] vs 23 [11%]), and decreased platelet count (34 [17%] vs 24 [12%]). Serious treatment-related adverse events occurred in 74 (36%) patients in the camrelizumab plus chemotherapy group and 27 (13%) patients in the chemotherapy alone group. Interpretation The primary endpoint was met at the interim analysis, showing a statistically significant and clinically meaningful improvement in progression-free survival with camrelizumab plus carboplatin and pemetrexed versus chemotherapy alone in all patients, supporting camrelizumab plus carboplatin and pemetrexed as a first-line treatment option for Chinese patients with advanced non-squamous NSCLC without EGFR and ALK alterations. The trial is being continued to collect long-term outcomes in all patients and carry out confirmatory statistical testing for progression-free survival in the PD-L1–positive population. Funding Jiangsu Hengrui Medicine.

Monoliths of aromatic sulfur mediated mesoporous carbon were fabricated via an aqueous self-assembly strategy and the species of sulfide, sulfoxide, and sulfone on the surface can be tuned rationally. The resultant S-doped mesoporous carbon exhibited superior performance as supercapacitor electrodes. The controllable modulation of sulfur species provided a possibility to clearly understand the role sulfur playing and allowed mechanistic insight into material requirements for high performance capacitors.

Enzyme-free signal amplification has enabled sensitive in vitro detection of biomolecules such as proteins and nucleic acids. However, monitoring targets of interest in live cells via enzyme-free amplification is still challenging, especially for analytes with low concentrations. To the best of our knowledge, this paper reports the first attempt to perform mRNA imaging inside live cells, using a nonenzymatic hairpin DNA cascade reaction for high signal gain, termed a hairpin DNA cascade amplifier (HDCA). In conventional nucleic acid probes, such as linear hybridization probes, mRNA target signaling occurs in an equivalent reaction ratio (1:1), whereas, in HDCA, one mRNA target is able to yield multiple signal outputs (1:m), thus achieving the goal of signal amplification for low-expression mRNA targets. Moreover, the recycled mRNA target in the HDCA serves as a catalyst for the assembly of multiple DNA duplexes, generating the fluorescent signal of reduced MnSOD mRNA expression, thus indicating amplified intracellular imaging. This programmable cascade reaction presents a simple and modular amplification mechanism for intracellular biomarkers of interest, providing a significant boost to the search for clues leading to the accurate identification and effective treatment of cancers.

To investigate the prevalence and associated factors of kidney stones among adults in China.A nationwide cross-sectional survey was conducted among individuals aged ≥18 years across China, from May 2013 to July 2014. Participants underwent urinary tract ultrasonographic examinations, completed pre-designed and standardised questionnaires, and provided blood and urine samples for analysis. Kidney stones were defined as particles of ≥4 mm. Prevalence was defined as the proportion of participants with kidney stones and binary logistic regression was used to estimate the associated factors.A total of 12 570 individuals (45.2% men) with a mean (sd, range) age of 48.8 (15.3, 18-96) years were selected and invited to participate in the study. In all, 9310 (40.7% men) participants completed the investigation, with a response rate of 74.1%. The prevalence of kidney stones was 6.4% [95% confidence interval (CI) 5.9, 6.9], and the age- and sex-adjusted prevalence was 5.8% (95% CI 5.3, 6.3; 6.5% in men and 5.1% in women). Binary logistic regression analysis showed that male gender, rural residency, age, family history of urinary stones, concurrent diabetes mellitus and hyperuricaemia, increased consumption of meat, and excessive sweating were all statistically significantly associated with a greater risk of kidney stones. By contrast, consumption of more tea, legumes, and fermented vinegar was statistically significantly associated with a lesser risk of kidney stone formation.Kidney stones are common among Chinese adults, with about one in 17 adults affected currently. Some Chinese dietary habits may lower the risk of kidney stone formation.

Ventricular assist devices (VADs) have already helped many patients with heart failure but have the potential to assist more patients if current problems with blood damage (hemolysis, platelet activation, thrombosis and emboli, and destruction of the von Willebrand factor (vWf)) can be eliminated. A step towards this goal is better understanding of the relationships between shear stress, exposure time, and blood damage and, from there, the development of numerical models for the different types of blood damage to enable the design of improved VADs. In this study, computational fluid dynamics (CFD) was used to calculate the hemodynamics in three clinical VADs and two investigational VADs and the shear stress, residence time, and hemolysis were investigated. A new scalar transport model for hemolysis was developed. The results were compared with in vitro measurements of the pressure head in each VAD and the hemolysis index in two VADs. A comparative analysis of the blood damage related fluid dynamic parameters and hemolysis index was performed among the VADs. Compared to the centrifugal VADs, the axial VADs had: higher mean scalar shear stress (sss); a wider range of sss, with larger maxima and larger percentage volumes at both low and high sss; and longer residence times at very high sss. The hemolysis predictions were in agreement with the experiments and showed that the axial VADs had a higher hemolysis index. The increased hemolysis in axial VADs compared to centrifugal VADs is a direct result of their higher shear stresses and longer residence times. Since platelet activation and destruction of the vWf also require high shear stresses, the flow conditions inside axial VADs are likely to result in more of these types of blood damage compared with centrifugal VADs.

(Current Biology 30, 1346–1351.e1–e2; April 6, 2020) In the originally published paper, the legends for Figures S1 and S2 were inadvertently swapped. This error has now been corrected online. The authors apologize for the error and any confusion that may have resulted. Probable Pangolin Origin of SARS-CoV-2 Associated with the COVID-19 OutbreakZhang et al.Current BiologyMarch 19, 2020In BriefThe emerging SARS-coronavirus 2 (SARS-CoV-2) poses tremendous threat to human health. Zhang, Wu et al. show that like bats, pangolin species are a natural reservoir of SARS-CoV-2-like CoVs. This finding might help to find the intermediate host of SARS-CoV-2 for blocking a global coronavirus pandemic. Full-Text PDF Open Access

Emulsion templating presently extends far beyond the original hydrophobic porous polymers that were synthesized within surfactant-stabilized water-in-oil high internal phase emulsions (HIPEs) by using free radical polymerization. This Perspective presents the extraordinary versatility of emulsion templating that has emerged with the growing numbers of HIPE systems, HIPE stabilization strategies, monomers, polymerization chemistries, multicomponent materials, and surface functionalities. Emulsion templating now goes far beyond “porous polymers” by encompassing the encapsulation of aqueous solutions, ionic melts, and organic liquids as well as by encompassing porous carbons and porous inorganics. Herein, we present comprehensive pictures of the state-of-the-art, of the prospective large-scale and niche applications, of the advantages and challenges for industrial scale-up, and of the crucial directions that should be pursued in future work. We demonstrate that it is emulsion templating’s considerable and versatile parameter space that offers opportunities for pioneering work, breakthrough innovations, scientific/engineering achievements, and industrial adoption.

Methane adsorption in shale is a gas–liquid–solid interaction rather than a gas–solid interaction by considering the initial water saturation in actual condition. As an important constituent of inorganic matter, clay minerals may affect gas-in-place of shale systems. Generally, Clay minerals are strongly hydrophilic with a water film bound on its surface, significantly reducing gas sorption capacity, which will lead to overestimate gas-in-place (GIP) of shale gas reservoir. In this work, we analyze the interactions between methane, water film and clay, and results reveal that: methane adsorption on clay (dry) is a typical gas–solid interaction; however, methane adsorption on clay bound water film should belong to gas–liquid interaction. Furthermore, a unified model is established to describe gas-water-clay interactions, in which, gas–solid Langmuir equation and gas–liquid Gibbs equation are integrated by water coverage coefficient. Meanwhile, a mathematical model is presented to quantify thickness of water films by considering surface force interactions between liquid film and clay. Our results show that, the water film thickness in shale clay pores mainly depends on relative humidity and pore size. Under a certain humidity condition (such as 0.98), the water saturation distribute in different sized pores mainly as: (i) capillary water in the small pores (< 6 nm); (ii) water film in the larger pores. Thus, considering the water distribution characteristics, the effect of moisture on methane adsorption capacity is mainly for two aspects: (i) small pores (< 6 nm) blocked by water are invalid for methane adsorption, (ii) large pores bounded by water film change interaction characteristics for methane adsorption (from gas–solid interaction to the gas–liquid interaction). The overall effect could reduce the adsorption capacity by 80%–90%.

Abstract Lithium metal anodes hold great promise to enable high-energy battery systems. However, lithium dendrites at the interface between anode and separator pose risks of short circuits and fire, impeding the safe application. In contrast to conventional approaches of suppressing dendrites, here we show a deposition-regulating strategy by electrically passivating the top of a porous nickel scaffold and chemically activating the bottom of the scaffold to form conductivity/lithiophilicity gradients, whereby lithium is guided to deposit preferentially at the bottom of the anode, safely away from the separator. The resulting lithium anodes significantly reduce the probability of dendrite-induced short circuits. Crucially, excellent properties are also demonstrated at extremely high capacity (up to 40 mAh cm −2 ), high current density, and/or low temperatures (down to −15 °C), which readily induce dendrite shorts in particular. This facile and viable deposition-regulating strategy provides an approach to preferentially deposit lithium in safer positions, enabling a promising anode for next-generation lithium batteries.

Abstract The green synthesis of fine chemicals calls for a new generation of efficient and robust catalysts. Single-atom catalysts (SACs), in which all metal species are atomically dispersed on a solid support, and which often consist of well-defined mononuclear active sites, are expected to bridge homogeneous and heterogeneous catalysts for liquid-phase organic transformations. This review summarizes major advances in the SAC-catalysed green synthesis of fine chemicals in the past several years, with a focus on the catalytic activity, selectivity and reusability of SACs in various organic reactions. The relationship between catalytic performance and the active site structure is discussed in terms of the valence state, coordination environment and anchoring chemistry of single atoms to the support, in an effort to guide the rational design of SACs in this special area, which has traditionally been dominated by homogeneous catalysis. Finally, the challenges remaining in this research area are discussed and possible future research directions are proposed.

In concern of resource sustainability and environmental friendliness, organic electrode materials for rechargeable batteries have attracted increasing attentions in recent years. However, for many researchers, the primary impression on organic cathode materials is the poor cycling stability and low energy density, mainly due to the unfavorable dissolution and low redox potential, respectively. Herein, a novel polymer cathode material, namely poly(benzoquinonyl sulfide) (PBQS) is reported, for either rechargeable Li or Na battery. Remarkably, PBQS shows a high energy density of 734 W h kg –1 (2.67 V × 275 mA h g –1 ) in Li battery, or 557 W h kg –1 (2.08 V × 268 mA h g –1 ) in Na battery, which exceeds those of most inorganic Li or Na intercalation cathodes. Moreover, PBQS also demonstrates excellent long‐term cycling stability (1000 cycles, 86%) and superior rate capability (5000 mA g –1 , 72%) in Li battery. Besides the exciting battery performance, investigations on the structure–property relationship between benzoquinone (BQ) and PBQS, and electrochemical behavior difference between Li–PBQS battery and Na–PBQS battery, also provide significant insights into developing better Li‐organic and Na‐organic batteries beyond conventional Li‐ion batteries.

Sludge is an inevitable by product of sewage treatment, and it includes pathogens, heavy metals, organic pollutants and other toxic substances. The components of sludge are complex and variable with extracellular polymeric substances (EPS) being one. EPS are highly hydrophilic and compressible, and make sludge dewatering difficult. Therefore, the development of efficient sludge-dewatering technology is an important means of mitigating rapid sludge growth. At present, the main methods used for sludge deep-dewatering technology are chemical preconditioning with high-pressure filtration and electrical mechanical dewatering. The selection of chemical preconditioning directly determines the final efficiency of the sludge-dewatering process. In this paper, we conduct a comprehensive review of the problems related to sludge dewatering and systematically summarise the impact of different chemical conditioning technologies on the efficiency of sludge dewatering. Furthermore, the characteristics of different enhanced dewatering technologies are evaluated and analysed for their adaptability and final disposal methods. We believe that this review can clarify the chemical conditioner mechanism to improve sludge dewatering, provide reference debugging information for the sludge-dewatering process and promote the development of efficient and environmentally friendly sludge-dewatering technology.