Zhipeng Li

Ferroptosis is a form of regulated cell death that is caused by the iron-dependent peroxidation of lipids1,2. The glutathione-dependent lipid hydroperoxidase glutathione peroxidase 4 (GPX4) prevents ferroptosis by converting lipid hydroperoxides into non-toxic lipid alcohols3,4. Ferroptosis has previously been implicated in the cell death that underlies several degenerative conditions2, and induction of ferroptosis by the inhibition of GPX4 has emerged as a therapeutic strategy to trigger cancer cell death5. However, sensitivity to GPX4 inhibitors varies greatly across cancer cell lines6, which suggests that additional factors govern resistance to ferroptosis. Here, using a synthetic lethal CRISPR-Cas9 screen, we identify ferroptosis suppressor protein 1 (FSP1) (previously known as apoptosis-inducing factor mitochondrial 2 (AIFM2)) as a potent ferroptosis-resistance factor. Our data indicate that myristoylation recruits FSP1 to the plasma membrane where it functions as an oxidoreductase that reduces coenzyme Q10 (CoQ) (also known as ubiquinone-10), which acts as a lipophilic radical-trapping antioxidant that halts the propagation of lipid peroxides. We further find that FSP1 expression positively correlates with ferroptosis resistance across hundreds of cancer cell lines, and that FSP1 mediates resistance to ferroptosis in lung cancer cells in culture and in mouse tumour xenografts. Thus, our data identify FSP1 as a key component of a non-mitochondrial CoQ antioxidant system that acts in parallel to the canonical glutathione-based GPX4 pathway. These findings define a ferroptosis suppression pathway and indicate that pharmacological inhibition of FSP1 may provide an effective strategy to sensitize cancer cells to ferroptosis-inducing chemotherapeutic agents.

<h2>Abstract</h2> A substantial body of literature has provided evidence for the role of gut microbiota in metabolic diseases including type 2 diabetes. However, reports vary regarding the association of particular taxonomic groups with disease. In this systematic review, we focused on the potential role of different bacterial taxa affecting diabetes. We have summarized evidence from 42 human studies reporting microbial associations with disease, and have identified supporting preclinical studies or clinical trials using treatments with probiotics. Among the commonly reported findings, the genera of <i>Bifidobacterium, Bacteroides, Faecalibacterium, Akkermansia and Roseburia</i> were negatively associated with T2D, while the genera of <i>Ruminococcus, Fusobacterium,</i> and <i>Blautia</i> were positively associated with T2D. We also discussed potential molecular mechanisms of microbiota effects in the onset and progression of T2D.

A novel high excited state energy transfer pathway to overcome the phonon quenching effect in rare-earth (RE) oxide upconversion (UC) materials is reported. In Er(Tm)-Yb oxide systems, an extraordinary enhancement of UC luminescence efficiency with four orders of magnitude is realized by Mo co-doping. The RE oxides with significant UC efficiency are successfully utilized for temperature sensing and in vivo imaging.

We describe the development of novel and biocompatible core/shell (α-NaYbF4:Tm3+)/CaF2 nanoparticles that exhibit highly efficient NIRin–NIRout upconversion (UC) for high contrast and deep bioimaging. When excited at ∼980 nm, these nanoparticles emit photoluminescence (PL) peaked at ∼800 nm. The quantum yield of this UC PL under low power density excitation (∼0.3 W/cm2) is 0.6 ± 0.1%. This high UC PL efficiency is realized by suppressing surface quenching effects via heteroepitaxial growth of a biocompatible CaF2 shell, which results in a 35-fold increase in the intensity of UC PL from the core. Small-animal whole-body UC PL imaging with exceptional contrast (signal-to-background ratio of 310) is shown using BALB/c mice intravenously injected with aqueously dispersed nanoparticles (700 pmol/kg). High-contrast UC PL imaging of deep tissues is also demonstrated, using a nanoparticle-loaded synthetic fibrous mesh wrapped around rat femoral bone and a cuvette with nanoparticle aqueous dispersion covered with a 3.2 cm thick animal tissue (pork).

Abstract Highly efficient non‐noble metal electrocatalysts are vital for metal–air batteries and fuel cells. Herein, a noble‐metal–free single‐atom Fe‐N x ‐C electrocatalyst is synthesized by incorporating Fe‐Phen complexes into the nanocages in situ during the growth of ZIF‐8, followed by pyrolysis at 900 °C under inert atmosphere. Fe‐Phen species provide both Fe 2+ and the organic ligand (Phen) simultaneously, which play significant roles in preparing single‐atom catalysts. The obtained Fe‐N x ‐C exhibits a half‐wave potential of 0.91 V for the oxygen reduction reaction, higher than that of commercial Pt/C (0.82 V). As a cathode catalyst for primary zinc–air batteries (ZABs), the battery shows excellent electrochemical performances in terms of the high open‐circuit voltage (OCV) of 1.51 V and a high power density of 96.4 mW cm −2 . The rechargeable ZAB with Fe‐N x ‐C catalyst and the alkaline electrolyte shows a remarkable cycling performance for 300 h with an initial round‐trip efficiency of 59.6%. Furthermore, the rechargeable all‐solid‐state ZABs with the Fe‐N x ‐C catalyst show high OCV of 1.49 V, long cycle life for 120 h, and foldability. The single‐atom Fe‐N x ‐C electrocatalyst may function as a promising catalyst for various metal–air batteries and fuel cells.

The molecular understanding of autophagy has originated almost exclusively from yeast genetic studies. Little is known about essential autophagy components specific to higher eukaryotes. Here we perform genetic screens in C. elegans and identify four metazoan-specific autophagy genes, named epg-2, -3, -4, and -5. Genetic analysis reveals that epg-2, -3, -4, and -5 define discrete genetic steps of the autophagy pathway. epg-2 encodes a coiled-coil protein that functions in specific autophagic cargo recognition. Mammalian homologs of EPG-3/VMP1, EPG-4/EI24, and EPG-5/mEPG5 are essential for starvation-induced autophagy. VMP1 regulates autophagosome formation by controlling the duration of omegasomes. EI24 and mEPG5 are required for formation of degradative autolysosomes. This study establishes C. elegans as a multicellular genetic model to delineate the autophagy pathway and provides mechanistic insights into the metazoan-specific autophagic process.

Abstract Surface‐enhanced Raman scattering (SERS) is a new optical spectroscopic analysis technique with potential for highly sensitive detection of molecules. Recently, many efforts have been made to find SERS substrates with high sensitivity and reproducibility. In this Research News article, we provide a focused review on the synthesis of monodispersed silver particles with a novel, highly roughened, “flower‐like” morphology by reducing silver nitrate with ascorbic acid in aqueous solutions. The nanometer‐scale surface roughness of the particles can provide several hot spots on a single particle, which significantly increases SERS enhancement. The incident polarization‐dependent SERS of individual particles is also studied. Although the different “hot spots” on a single particle can have a strong polarization dependency, the total Raman signals from an individual particle usually have no obvious polarization dependency. Moreover, these flower‐like silver particles can be measured by SERS with high enhancement several times, which indicates the high stability of the hot spots. Hence, the flower‐like silver particles here can serve as highly sensitive and reproducible SERS substrates.

Using polarization dependent scattering spectroscopy, we investigate plasmon propagation on branched silver nanowires. By controlling the polarization of the incident laser light, the wire plasmons can be routed into different wire branches and result in light emission from the corresponding wire ends. This routing behavior is found to be strongly dependent on the wavelength of light. Thus for certain incident polarizations, light of different wavelength will be routed into different branches. The branched nanowire can thus serve as a controllable router and multiplexer in integrated plasmonic circuits.

We show that the local electric field distribution of propagating plasmons along silver nanowires can be imaged by coating the nanowires with a layer of quantum dots, held off the surface of the nanowire by a nanoscale dielectric spacer layer. In simple networks of silver nanowires with two optical inputs, control of the optical polarization and phase of the input fields directs the guided waves to a specific nanowire output. The QD-luminescent images of these structures reveal that a complete family of phase-dependent, interferometric logic functions can be performed on these simple networks. These results show the potential for plasmonic waveguides to support compact interferometric logic operations.

Phylogeny and characteristics of ruminants Ruminants are a diverse group of mammals that includes families containing well-known taxa such as deer, cows, and goats. However, their evolutionary relationships have been contentious, as have the origins of their distinctive digestive systems and headgear, including antlers and horns (see the Perspective by Ker and Yang). To understand the relationships among ruminants, L. Chen et al. sequenced 44 species representing 6 families and performed a phylogenetic analysis. From this analysis, they were able to resolve the phylogeny of many genera and document incomplete lineage sorting among major clades. Interestingly, they found evidence for large population reductions among many taxa starting at approximately 100,000 years ago, coinciding with the migration of humans out of Africa. Examining the bony appendages on the head—the so-called headgear—Wang et al. describe specific evolutionary changes in the ruminants and identify selection on cancer-related genes that may function in antler development in deer. Finally, Lin et al. take a close look at the reindeer genome and identify the genetic basis of adaptations that allow reindeer to survive in the harsh conditions of the Arctic. Science , this issue p. eaav6202 , p. eaav6335 , p. eaav6312 ; see also p. 1130

Abstract 2D materials are of particular interest in light‐to‐heat conversion, yet challenges remain in developing a facile method to suppress their light reflection. Herein, inspired by the black scales of Bitis rhinoceros , a generalized approach via sequential thermal actuations to construct biomimetic 2D‐material nanocoatings, including Ti 3 C 2 T x MXene, reduced graphene oxide (rGO), and molybdenum disulfide (MoS 2 ) is designed. The hierarchical MXene nanocoatings result in broadband light absorption (up to 93.2%), theoretically validated by optical modeling and simulations, and realize improved light‐to‐heat performance (equilibrium temperature of 65.4 °C under one‐sun illumination). With efficient light‐to‐heat conversion, the bioinspired MXene nanocoatings are next incorporated into solar steam‐generation devices and stretchable solar/electric dual‐heaters. The MXene steam‐generation devices require much lower solar‐thermal material loading (0.32 mg cm −2 ) and still guarantee high steam‐generation performance (1.33 kg m −2 h −1 ) compared with other state‐of‐the‐art devices. Additionally, the mechanically deformed MXene structures enable the fabrication of stretchable and wearable heaters dual‐powered by sunlight and electricity, which are reversibly stretched and heated above 100 °C. This simple fabrication process with effective utilization of active materials promises its practical application value for multiple solar–thermal technologies.

Two-dimensional layered transition metal dichalcogenides (TMDs) show intriguing potential for optoelectronic devices due to their exotic electronic and optical properties. Only a few efforts have been dedicated to large-area growth of TMDs. Practical applications will require improving the efficiency and reducing the cost of production, through (1) new growth methods to produce large size TMD monolayer with less-stringent conditions, and (2) nondestructive transfer techniques that enable multiple reuse of growth substrate. In this work, we report to employ atmospheric pressure chemical vapor deposition (APCVD) for the synthesis of large size (>100 μm) single crystals of atomically thin tungsten disulfide (WS2), a member of TMD family, on sapphire substrate. More importantly, we demonstrate a polystyrene (PS) mediated delamination process via capillary force in water which reduces the etching time in base solution and imposes only minor damage to the sapphire substrate. The transferred WS2 flakes are of excellent continuity and exhibit comparable electron mobility after several growth cycles on the reused sapphire substrate. Interestingly, the photoluminescence emission from WS2 grown on the recycled sapphire is much higher than that on fresh sapphire, possibly due to p-type doping of monolayer WS2 flakes by a thin layer of water intercalated at the atomic steps of the recycled sapphire substrate. The growth and transfer techniques described here are expected to be applicable to other atomically thin TMD materials.

One of the research hotspots in solar energy conversion is developing photocatalysts for visible-light-driven H2 production. In this study, a ternary CdS@Au/MXene composite was elaborately constructed by a facile in situ self-assembly strategy, where the ultrathin Ti3–xC2Ty nanosheets with characteristic Ti vacancies were employed as a support for core–shell structured CdS@Au nanojunctions. In the presence of 1.0 wt % MXene, merely 0.1 wt % Au helped the composites achieve a high H2-production rate of 5371 μmol·g–1·h–1 under visible-light irradiation, more than 26.6 times higher than that of bare CdS. Such an enhancement was predominantly attributed to the “dual Schottky barriers” formed at the interface of CdS@Au/MXene, which was evidenced by systematic characterizations including X-ray photoelectron spectroscopy and Kelvin probe measurements, in conjunction with density functional theory (DFT) calculations. This work not only highlights the significant role of MXene in reducing the dosage of noble metal cocatalysts for photocatalysis, but also opens avenues to fabricate more MXene-based composites for solar energy conversion and beyond.

A copper‐stabilized sulfur‐microporous carbon ( MC‐Cu‐S) composite is synthesized by uniformly dispersing 10% highly electronically conductive Cu nanoparticles into microporous carbon (MC), followed by wet‐impregnating S. In the MC‐Cu‐S composite, the MC host that physically confines S/polysulfides provides free space to accommodate volumetric expansion of S during lithiation, while the Cu nanoparticles that are anchored in the MC further chemically interact with S/polysulfides through bonding between Cu and S/polysulfides. The Cu loading allows the S content to increase from 30 to 50% in the carbon‐S cathode material without scarifying the electrochemical performance in a low‐cost carbonate electrolyte. At a current density of 100 mA g ‐1 , the MC‐Cu‐S cathode shows that Coulumbic efficiency is close to 100% and capacity maintains more than 600 mAh g ‐1 with progressive cycling up to more than 500 cycles. In addition, the Cu nano‐inclusins also enhance the electronic conductivity of the MC‐Cu‐S composite, remarkably increasing the rate capabilities. Even the current density increases 10.0 A g ‐1 , the MC‐Cu‐S cathode can still deliver a capacity of 200 mAh g ‐1 . This strategy of stabilization of S with small amount of metal nanoparticles anchored in MC provides an effective approach to improve the cycling stability, Coulumbic efficiency, and S loading for Li–S batteries.

Nanowires supporting propagating surface plasmons can function as nanowaveguides to realize the light guiding with field confinement beyond the diffraction limit, providing fundamental building blocks for nanophotonic integrated circuits. This review covers the recent developments of plasmon waveguiding in nanowires, mainly including plasmon waveguiding in metal nanowires, coupling of nanowire plasmons and emitters, hybrid nanowire waveguides and plasmonic gain, and nanowire photonic devices. We first introduce the main techniques for fabricating metal nanowires, the plasmon modes in metal nanowires and the excitation/detection methods. We then discuss the fundamental properties of plasmon propagation and emission, including zigzag, chiral and spin-dependent propagation, mode conversion, loss and propagation length, group velocity, terminal emission, and leaky radiation. Then the interactions between nanowires and emitters are reviewed, especially the coupling of single nanowires and single quantum emitters. Finally, we briefly introduce the hybrid nanowire waveguide composed of a semiconductor nanowire and a metal film with an intervening thin insulator and highlight a few nanophotonic devices based on plasmonic nanowire networks or plasmonic-photonic hybrid nanowire structures.

Abstract Dielectric ceramic capacitors, with the advantages of high power density, fast charge-discharge capability, excellent fatigue endurance, and good high temperature stability, have been acknowledged to be promising candidates for solid-state pulse power systems. This review investigates the energy storage performances of linear dielectric, relaxor ferroelectric, and antiferroelectric from the viewpoint of chemical modification, macro/microstructural design, and electrical property optimization. Research progress of ceramic bulks and films for Pb-based and/or Pb-free systems is summarized. Finally, we propose the perspectives on the development of energy storage ceramics for pulse power capacitors in the future.

Strong Coulomb interactions in single-layer transition metal dichalcogenides (TMDs) result in the emergence of strongly bound excitons, trions, and biexcitons. These excitonic complexes possess the valley degree of freedom, which can be exploited for quantum optoelectronics. However, in contrast to the good understanding of the exciton and trion properties, the binding energy of the biexciton remains elusive, with theoretical calculations and experimental studies reporting discrepant results. In this work, we resolve the conflict by employing low-temperature photoluminescence spectroscopy to identify the biexciton state in BN-encapsulated single-layer WSe2. The biexciton state only exists in charge-neutral WSe2, which is realized through the control of efficient electrostatic gating. In the lightly electron-doped WSe2, one free electron binds to a biexciton and forms the trion-exciton complex. Improved understanding of the biexciton and trion-exciton complexes paves the way for exploiting the many-body physics in TMDs for novel optoelectronics applications.

Here, we sucessfully demonstrate the continuous functionalization of grain boundaries (GBs) in CH3NH3PbI3 (MAPbI3) organic-inorganic halide perovskite (OIHP) thin films with a triblock copolymer that contains rationally selected hydrophilic-hydrophobic-hydrophilic symmetric blocks. The addition of the triblock copolymer into the precursor solution assists in perovskite solution crystallization, resulting in ultrasmooth thin films with GB regions that are continuously functionalized. Tuning of the thickness of the functionalized GBs is realized, leading to MAPbI3 OIHP thin films with simultaneously enhanced optoelectronic properties and environmental (thermal, moisture, and light) stability. The resulting perovskite solar cells show high stabilized efficiency of 19.4%, most of which is retained (92%) upon 480-hr 1-sun illumination. This approach is generic in nature, and it can be extended to a wide range of OIHPs and beyond.

The strong electron interactions in the minibands formed in moiré superlattices of van der Waals materials, such as twisted graphene and transition metal dichalcogenides, make such systems a fascinating platform with which to study strongly correlated states1–19. In most systems, the correlated states appear when the moiré lattice is filled by an integer number of electrons per moiré unit cell. Recently, correlated states at fractional fillings of 1/3 and 2/3 holes per moiré unit cell have been reported in the WS2/WSe2 hetero-bilayer, hinting at the long-range nature of the electron interaction16. Here we observe a series of correlated insulating states at fractional fillings of the moiré minibands on both electron- and hole-doped sides in angle-aligned WS2/WSe2 hetero-bilayers, with certain states persisting at temperatures up to 120 K. Simulations reveal that these insulating states correspond to ordering of electrons in the moiré lattice with a periodicity much larger than the moiré unit cell, indicating a surprisingly strong and long-range interaction beyond the nearest neighbours. Twisted bilayers of WS2 and WSe2 have correlated states that correspond to real-space ordering of the electrons on a length scale much longer than the moiré pattern.

Osteoblast cell adhesion is the initial step of early osseointegration responding to bone material implants. Enhancing the osteoblastic cell adhesion has become one of the prime aims when optimizing the surface properties of bone biomaterials. The traditional strategy focuses in improving the physical attachment of osteoblastic cells onto the surfaces of biomaterials. However, instead of a simple cell physical attachment, the osteoblastic cell adhesion has been revealed to be a sophisticated system. Despite the well-documented effect of bone biomaterial surface modifications on adhesion, few studies have focused on the underlying molecular mechanisms. Physicochemical signals from biomaterials can be transduced into intracellular signaling network and further initiate the early response cascade towards the implants, which includes cell survival, migration, proliferation, and differentiation. Adhesion is vital in determining the early osseointegration between host bone tissue and implanted bone biomaterials via regulating involving signaling pathways. Therefore, the modulation of early adhesion behavior should not simply target in physical attachment, but emphasize in the manipulation of downstream signaling pathways, to regulate early osseointegration. This review firstly summarized the basic biological principles of osteoblastic cell adhesion process and the activated downstream cell signaling pathways. The effects of different biomaterial physicochemical properties on osteoblastic cell adhesion were then reviewed. This review provided up-to-date research outcomes in the adhesion behavior of osteoblastic cells on bone biomaterials with different physicochemical properties. The strategy is optimised from traditionally focusing in physical cell adhesion to the proposed strategy that manipulating cell adhesion and the downstream signaling network for the enhancement of early osseointegration.

Metal sulfides are intensively studied as one of the most predominant materials for supercapacitors owing to such unique advantages as low-cost, low electronegativity and high electrochemical activity, and the appropriate architecture of hybrid metal sulfides is believed to be very effective for fully utilizing their material merits and breaking through their limits of the low-rate capability and inferior cycling stability in supercapacitor applications. Herein, a high-performance supercapacitor based on carbon-coated MoS2/NiCo2S4 urchin-like hollow hybrid microspheres (MoS2/NiCo2S4@C HMSs) is prepared by a facile self-template method. And the high specific capacity of 250 mAh g−1 at 2 A g−1 and ultra-high rate capability of 91.1% at 40 A g−1 achieved with the resultant MoS2/NiCo2S4@C HMSs due to their hierarchical hollow hybrid structure and the protection from the coated carbon thin layer. With the MoS2/NiCo2S4@C HMSs as the positive electrode and active carbon as the negative electrode, asymmetric supercapacitors (ASCs) have been assembled, which exhibit a high energy density of 53.01 Wh kg−1 at the power density of 4.20 kW kg−1, an energy density of 36.46 Wh kg−1 even at the ultra-high power density of 73.75 kW kg−1, and excellent cycling stability of 90.1% after 10 000 cycles of charge–discharge tests at the current density of 10 A g−1.

Precise and reliable wind-speed prediction is vital for wind-farm operational planning. However, wind speed series usually have complex features, such as non-linearity and volatility, which makes the wind energy forecasting highly difficult. Aimed at this challenge, this paper proposes a forecasting architecture based on a new hybrid decomposition technique (HDT) and an improved flower-pollination algorithm (FPA)-back propagation (BP) neural network prediction algorithm. The proposed HDT combines the complete ensemble empirical mode decomposition adaptive noise (CEEMDAN) and the empirical wavelet transform (EWT), which is unique, since the EWT is specifically employed to further decompose the high frequency intrinsic mode functions (IMFs) generated by CEEMDAN to reduce prediction complexity. And then an improved BPNN with the flower-pollination algorithm is applied to forecast all of the decomposed IMFs and modes. To investigate the forecasting ability of the proposed model, the wind speed data collected from two different wind farms in Shandong, China were used for multi-step ahead forecasting. The experimental results show that the proposed model performs remarkably better than all of the other considered models in one-step to five-step wind speed forecasting, which indicates that the proposed model is highly suitable for non-stationary multi-step wind speed forecasting.

The intrusion detection based on deep learning method has been widely attempted for representation learning. However, in various deep learning models for intrusion detection, there is rarely convolutional neural networks (CNN) model. In this work, we propose a image conversion method of NSL-KDD data. Convolutional neural networks automatically learn the features of graphic NSL-KDD transformation via the proposed graphic conversion technique. We evaluate the performance of the image conversion method by binary class classification experiments with NSL-KDD Test $$^+$$ and Test $$^{-21}$$ . Different structures of CNN are testified for comparison. On the two NSL-KDD test datasets, CNN performed better than most standard classifier although the CNN did not improve state of the art completely. Results show that the CNN model is sensitive to image conversion of attack data and our proposed method can be used for intrusion detection.

The studies of perovskite film in the perovskite solar cells (PSCs) mainly focus on their crystallization and growth, but the reactions that happen in the precursor solutions are still not very clear, which is leading to the bad reproducibility for high-efficient devices. We demonstrated that, in the methylammonium- and formamidinium-mixed organic cation perovskite solution, the methylamine molecule could be first generated from the deprotonation of methylammonium iodide, and then condensate with formamidinium iodide to form N-methyl formamidinium iodide and N, N′-dimethyl formamidinium iodide. The triethyl borate was carried out as a stabilizer to restrain the deprotonation of methylammonium iodide in the precursor solutions, resulting in the elimination of the impurity phase in perovskite films. We think that the introduction of stabilizer in the perovskite precursor solution will become a common strategy for mixed-organic-cation PSCs in the future to improve the reproducibility and efficiency.

Abstract An easy and scalable methylamine (MA) gas healing method was realized for inorganic cesium‐based perovskite (CsPbX 3 ) layers by incorporating a certain amount of MAX (X=I or Br) initiators into the raw film. It was found that the excess MAX accelerated the absorption of the MA gas into the CsPbX 3 film and quickly turned it into a liquid intermediate phase. Through the healing process, a highly uniform and highly crystalline CsPbX 3 film with enhanced photovoltaic performance was obtained. Moreover, the chemical interactions between a series of halides and MA gas molecules were studied, and the results could offer guidance in further optimizations of the healing strategy.

Phylogeny and characteristics of ruminants Ruminants are a diverse group of mammals that includes families containing well-known taxa such as deer, cows, and goats. However, their evolutionary relationships have been contentious, as have the origins of their distinctive digestive systems and headgear, including antlers and horns (see the Perspective by Ker and Yang). To understand the relationships among ruminants, L. Chen et al. sequenced 44 species representing 6 families and performed a phylogenetic analysis. From this analysis, they were able to resolve the phylogeny of many genera and document incomplete lineage sorting among major clades. Interestingly, they found evidence for large population reductions among many taxa starting at approximately 100,000 years ago, coinciding with the migration of humans out of Africa. Examining the bony appendages on the head—the so-called headgear—Wang et al. describe specific evolutionary changes in the ruminants and identify selection on cancer-related genes that may function in antler development in deer. Finally, Lin et al. take a close look at the reindeer genome and identify the genetic basis of adaptations that allow reindeer to survive in the harsh conditions of the Arctic. Science , this issue p. eaav6202 , p. eaav6335 , p. eaav6312 ; see also p. 1130

Inorganic CsPbI3 is promising to enhance the thermal stability of perovskite solar cells. The dimethylamine iodide (DMAI) derived method is currently the most efficient way to achieve high efficiency, but the effect of DMAI has not been fully explained. Herein, the chemical composition and phase evolution of the mixed DMAI/CsPbI3 layer during thermal treatment has been studied. The results demonstrate that, with the common DMAI/CsI/PbI2 recipe in DMSO solvent, a mixed perovskite DMA0.15Cs0.85PbI3 is first formed through a solid reaction between DMAPbI3 and Cs4PbI6. Further thermal treatment will transform the mixed perovskite phase directly to γ-CsPbI3 and then spontaneously convert to δ-CsPbI3. It has been also demonstrated that the DMA0.15Cs0.85PbI3 phase is thermodynamically stable and shows a bandgap of 1.67 eV, which is narrower than 1.73 eV of γ-CsPbI3. The device efficiency of the mixed DMA0.15Cs0.85PbI3 perovskite is therefore highly improved in comparison with the pure inorganic γ-CsPbI3 perovskite.

Abstract Background Gastrointestinal tract (GIT) microbiomes in ruminants play major roles in host health and thus animal production. However, we lack an integrated understanding of microbial community structure and function as prior studies are predominantly biased towards the rumen. In this study, we used shotgun metagenomics to profile the microbiota of 370 samples that represent 10 GIT regions of seven ruminant species. Results Our analyses reconstructed a GIT microbial reference catalog with &gt; 154 million nonredundant genes and identified 8745 uncultured candidate species from over 10,000 metagenome-assembled genomes. The integrated gene catalog across the GIT regions demonstrates spatial associations between the microbiome and physiological adaptations, and 8745 newly characterized genomes substantially expand the genomic landscape of ruminant microbiota, particularly those from the lower gut. This substantially expands the previously known set of endogenous microbial diversity and the taxonomic classification rate of the GIT microbiome. These candidate species encode hundreds of enzymes and novel biosynthetic gene clusters that improve our understanding concerning methane production and feed efficiency in ruminants. Overall, this study expands the characterization of the ruminant GIT microbiota at unprecedented spatial resolution and offers clues for improving ruminant livestock production in the future. Conclusions Having access to a comprehensive gene catalog and collections of microbial genomes provides the ability to perform efficiently genome-based analysis to achieve a detailed classification of GIT microbial composition and function. Our study will bring unprecedented power in future association studies to investigate the impact of the GIT microbiota in ruminant health and production.

Redox processes mediated by biochar(BC) enhanced the transformation of Cr(VI), which is largely dependent on the presence of PFRs as electron donors. Natural or artificial dopants in BC's could regulate inherent carbon configuration and PFRs. Until recently, the modulation of PFRs and transformation of Cr(VI) in BC by nonmetal-heterocyclic dopants was barely studied. In this study, changes in PFRs introduced by various nitrogen-dopants within BC are presented and the capacity for Cr(VI) transformation without light was investigated. It was found N-dopants were effectively embedded in carbon lattices through activated-Maillard reaction thus altering their charge and PFRs. Transformation of Cr(VI) in N doped biochar relied on mediated direct reduction by surface modulatory PFRs. The kinetic rate of transformation of Cr(VI) was increased 1.4-5 fold in N-BCs compared to nondoped BCs. Theortical calculation suggested a deficiency in surface electrons induced Lewis acid-base bonding which could acted as a bridge for electron transfer. Results of PCA and orbital energy indicated a colinear relationship between PFRs and pyrrolic N, as well as its dual-mode transformation of Cr(VI). This study provides an improved understanding of how N-doped BC contributes to the evolution of PFRs and their corresponding impacts on the transformation of Cr(VI) in environments.

Emerging soft exoskeletons pose urgent needs for high-performance strain sensors with tunable linear working windows to achieve a high-precision control loop. Still, the state-of-the-art strain sensors require further advances to simultaneously satisfy multiple sensing parameters, including high sensitivity, reliable linearity, and tunable strain ranges. Besides, a wireless sensing system is highly desired to enable facile monitoring of soft exoskeleton in real time, but is rarely investigated. Herein, wireless Ti3C2Tx MXene strain sensing systems were fabricated by developing hierarchical morphologies on piezoresistive layers and incorporating regulatory resistors into circuit designs as well as integrating the sensing circuit with near-field communication (NFC) technology. The wireless MXene sensor system can simultaneously achieve an ultrahigh sensitivity (gauge factor ≥ 14,000) and reliable linearity (R2 ≈ 0.99) within multiple user-designated high-strain working windows (130% to ≥900%). Additionally, the wireless sensing system can collectively monitor the multisegment exoskeleton actuations through a single database channel, largely reducing the data processing loading. We finally integrate the wireless, battery-free MXene e-skin with various soft exoskeletons to monitor the complex actuations that assist hand/leg rehabilitation.

Abstract Western diet (WD) is one of the major culprits of metabolic disease including type 2 diabetes (T2D) with gut microbiota playing an important role in modulating effects of the diet. Herein, we use a data-driven approach (Transkingdom Network analysis) to model host-microbiome interactions under WD to infer which members of microbiota contribute to the altered host metabolism. Interrogation of this network pointed to taxa with potential beneficial or harmful effects on host’s metabolism. We then validate the functional role of the predicted bacteria in regulating metabolism and show that they act via different host pathways. Our gene expression and electron microscopy studies show that two species from Lactobacillus genus act upon mitochondria in the liver leading to the improvement of lipid metabolism. Metabolomics analyses revealed that reduced glutathione may mediate these effects. Our study identifies potential probiotic strains for T2D and provides important insights into mechanisms of their action.

The germline mutation rate determines the pace of genome evolution and is an evolving parameter itself1. However, little is known about what determines its evolution, as most studies of mutation rates have focused on single species with different methodologies2. Here we quantify germline mutation rates across vertebrates by sequencing and comparing the high-coverage genomes of 151 parent-offspring trios from 68 species of mammals, fishes, birds and reptiles. We show that the per-generation mutation rate varies among species by a factor of 40, with mutation rates being higher for males than for females in mammals and birds, but not in reptiles and fishes. The generation time, age at maturity and species-level fecundity are the key life-history traits affecting this variation among species. Furthermore, species with higher long-term effective population sizes tend to have lower mutation rates per generation, providing support for the drift barrier hypothesis3. The exceptionally high yearly mutation rates of domesticated animals, which have been continually selected on fecundity traits including shorter generation times, further support the importance of generation time in the evolution of mutation rates. Overall, our comparative analysis of pedigree-based mutation rates provides ecological insights on the mutation rate evolution in vertebrates.

<h2>Summary</h2> The open-circuit voltage (<i>V</i>_OC) of cesium-based perovskite solar cells (Cs-PSCs) is severely limited by carrier recombination both in bulk and at the interface of the perovskite layer, which mainly roots in its elevated fabrication temperature. Enhancing the quality of perovskite film and optimizing the device structure are effective strategies to improve the performance of Cs-PSCs. Here, the <i>V</i>_OC is markedly promoted by constructing CsPbI₃/Cs_1-xDMA_xPbI₃ bulk heterojunction (BHJ) structure, which was spontaneously formed by a precisely controlled spatially selective phase transition method. The perovskite BHJ structure not only facilitates the charge separation and collection process by enhancing the built-in potential but also obviously reduces the carrier recombination loss. Importantly, a maximum <i>V</i>_OC of 1.23 V was obtained as the <i>V</i>_OC deficit was 0.45 V, and the champion power conversion efficiency (PCE) reached 20.32% (certified PCE of 19.66%). Our finding indicates that junction engineering will be a new strategy for efficient perovskite devices.

Abstract Lead-free bulk ceramics for advanced pulsed power capacitors show relatively low recoverable energy storage density ( W rec ) especially at low electric field condition. To address this challenge, we propose an A-site defect engineering to optimize the electric polarization behavior by disrupting the orderly arrangement of A-site ions, in which $${\rm{B}}{{\rm{a}}_{0.105}}{\rm{N}}{{\rm{a}}_{0.325}}{\rm{S}}{{\rm{r}}_{0.245 - 1.5x}}{_{0.5x}}{\rm{B}}{{\rm{i}}_{0.325 + x}}{\rm{Ti}}{{\rm{O}}_3}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mtext>Ba</mml:mtext> <mml:mrow> <mml:mn>0.105</mml:mn> </mml:mrow> </mml:msub> <mml:msub> <mml:mtext>Na</mml:mtext> <mml:mrow> <mml:mn>0.325</mml:mn> </mml:mrow> </mml:msub> <mml:msub> <mml:mtext>Sr</mml:mtext> <mml:mrow> <mml:mn>0.245</mml:mn> <mml:mo>−</mml:mo> <mml:mn>1.5</mml:mn> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> <mml:msub> <mml:mo>□</mml:mo> <mml:mrow> <mml:mn>0.5</mml:mn> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> <mml:msub> <mml:mtext>Bi</mml:mtext> <mml:mrow> <mml:mn>0.325</mml:mn> <mml:mo>+</mml:mo> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> <mml:msub> <mml:mtext>TiO</mml:mtext> <mml:mn>3</mml:mn> </mml:msub> </mml:math> ( $${\rm{BN}}{{\rm{S}}_{0.245 - 1.5x}}{_{0.5x}}{{\rm{B}}_{0.325 + x}}{\rm{T}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mtext>BNS</mml:mtext> <mml:mrow> <mml:mn>0.245</mml:mn> <mml:mo>−</mml:mo> <mml:mn>1.5</mml:mn> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> <mml:msub> <mml:mo>□</mml:mo> <mml:mrow> <mml:mn>0.5</mml:mn> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> <mml:msub> <mml:mtext>B</mml:mtext> <mml:mrow> <mml:mn>0.325</mml:mn> <mml:mo>+</mml:mo> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> <mml:mtext>T</mml:mtext> </mml:math> , x = 0, 0.02, 0.04, 0.06, and 0.08) lead-free ceramics are selected as the representative. The $${\rm{BN}}{{\rm{S}}_{0.245 - 1.5x}}{_{0.5x}}{{\rm{B}}_{0.325 + x}}{\rm{T}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mtext>BNS</mml:mtext> <mml:mrow> <mml:mn>0.245</mml:mn> <mml:mo>−</mml:mo> <mml:mn>1.5</mml:mn> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> <mml:msub> <mml:mo>□</mml:mo> <mml:mrow> <mml:mn>0.5</mml:mn> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> <mml:msub> <mml:mtext>B</mml:mtext> <mml:mrow> <mml:mn>0.325</mml:mn> <mml:mo>+</mml:mo> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> <mml:mtext>T</mml:mtext> </mml:math> ceramics are prepared by using pressureless solid-state sintering and achieve large W rec (1.8 J/cm 3 ) at a low electric field (@110 kV/cm) when x = 0.06. The value of 1.8 J/cm 3 is super high as compared to all other W rec in lead-free bulk ceramics under a relatively low electric field (&lt; 160 kV/cm). Furthermore, a high dielectric constant of 2930 within 15% fluctuation in a wide temperature range of 40–350 °C is also obtained in $${\rm{BN}}{{\rm{S}}_{0.245 - 1.5x}}{_{0.5x}}{{\rm{B}}_{0.325 + x}}{\rm{T}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mtext>BNS</mml:mtext> <mml:mrow> <mml:mn>0.245</mml:mn> <mml:mo>−</mml:mo> <mml:mn>1.5</mml:mn> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> <mml:msub> <mml:mo>□</mml:mo> <mml:mrow> <mml:mn>0.5</mml:mn> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> <mml:msub> <mml:mtext>B</mml:mtext> <mml:mrow> <mml:mn>0.325</mml:mn> <mml:mo>+</mml:mo> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> <mml:mtext>T</mml:mtext> </mml:math> ( x = 0.06) ceramics. The excellent performances can be attributed to the A-site defect engineering, which can reduce remnant polarization ( P r ) and improve the thermal evolution of polar nanoregions (PNRs). This work confirms that the $${\rm{BN}}{{\rm{S}}_{0.245 - 1.5x}}{_{0.5x}}{{\rm{B}}_{0.325 + x}}{\rm{T}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mtext>BNS</mml:mtext> <mml:mrow> <mml:mn>0.245</mml:mn> <mml:mo>−</mml:mo> <mml:mn>1.5</mml:mn> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> <mml:msub> <mml:mo>□</mml:mo> <mml:mrow> <mml:mn>0.5</mml:mn> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> <mml:msub> <mml:mtext>B</mml:mtext> <mml:mrow> <mml:mn>0.325</mml:mn> <mml:mo>+</mml:mo> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> <mml:mtext>T</mml:mtext> </mml:math> ( x = 0.06) ceramics are desirable for advanced pulsed power capacitors, and will push the development of a series of Bi 0.5 Na 0.5 TiO 3 (BNT)-based ceramics with high W rec and high-temperature stability.

Abstract Cephalopod skin, which is capable of dynamic optical camouflage, environmental perceptions, and herd communication, has long been a source of bio‐inspiration for developing soft robots with incredible optoelectronic functions. Yet, challenges still exist in designing a stretchable and compliant robotic skin with high‐level functional integration for soft robots with infinite degrees of freedom. Herein, an emerging 2D material, Ti 3 C 2 T x MXene, and an interfacial engineering strategy are adopted to fabricate the soft robotic skin with cephalopod skin‐inspired multifunctionality. By harnessing interfacial instability, the MXene robotic skin with reconfigurable microtextures demonstrates tunable infrared emission (0.30–0.80), enabling dynamic thermal camouflage for soft robots. Benefiting from the intrinsic Seebeck effect, crack propagation behaviors as well as high electrical conductivity, the MXene robotic skins are tightly integrated with thermal/strain sensation capabilities and can serve as a deformable antenna for wireless communication. Without additional electronics installed, the soft robots wearing the conformal MXene skins perform adaptive thermal camouflage based on the thermoelectric feedback in response to environmental temperature changes. With built‐in strain sensing and wireless communication capabilities, the soft robot can record its locomotion routes and wirelessly transmit the key information to the following soft robot to keep both in disguise under thermographic cameras.

It has been well-reported that using steel tubes to confine recycled aggregate concrete (RAC) is an effective solution to strengthen the imperfection of RAC, namely RAC-filled steel tubes (RAC-FST). Yet to date available design codes applicable to the axial compressive behavior of RAC-FST stub columns are still limited, and very scarce studies have concentrated on investigating the structural safety. This paper presents a full-scope reliability-based design analysis for the load-carrying capacity of circular RAC-FST stub columns under axial compression. First, the performances of several code-based models were evaluated in terms of model uncertainty based on a reliable experimental database that comprises 94 circular RAC-FST stub columns, respectively. Then, the statistical characteristics for characteristic compressive strength of RAC were specially identified, and other uncertainties associated with steel strength, geometrical configurations, and loads were taken from available publications. Subsequently, the reliability of circular RAC-FST stub columns designed using existing design factors in current normal concrete filled steel tubes (CFST) codes was investigated in conjunction with Monte Carlo simulation (MCS) technique. Results indicated that in order to achieve the reasonable design of circular RAC-FST stub columns, existing design factors need to be calibrated. Accordingly, a combined partial factor directly reducing the whole resistance of composite cross-section was proposed, and the corresponding recommendations were provided based on the target reliability index-oriented calibration process.

Abstract The unavoidable iodine loss in the perovskite layer is closely related to carrier non‐radiative and device degradation. During the post‐annealing process, the fragile PbI bond is easy to break, leading to the formation of iodine vacancies and inducing stress‐driven structure collapse. Herein, a PbI 6 octahedra stabilization strategy via building robust grain boundary modification networks is developed. The introduction of conjugated structure into amides can significantly enhance their anchoring ability with PbI units, while the π–π stacking effect of benzamide enables a passivation network with polymer‐like effect. This is well evidenced by the excellent properties in eliminated iodine loss and stabilized perovskite lattice. Therefore, benzamide modification not only transform the perovskite films from n‐type to p‐type by suppressing the iodine vacancy‐doping effect, but also reduces defect density, ultimately bringing the perovskite layer longer carrier diffusion length and better charge injection efficiency. Finally, the benzamide modified devices realize both high power conversion efficiency of 24.78% and excellent operating stability. Of particular note, the module efficiency with 14 cm 2 active area is over 21%.

Ferroptosis is a regulated form of cell death associated with the iron-dependent accumulation of phospholipid hydroperoxides. Inducing ferroptosis is a promising approach to treat therapy-resistant cancer. Ferroptosis suppressor protein 1 (FSP1) promotes ferroptosis resistance in cancer by generating the antioxidant form of coenzyme Q10 (CoQ). Despite the important role of FSP1, few molecular tools exist that target the CoQ-FSP1 pathway. Through a series of chemical screens, we identify several structurally diverse FSP1 inhibitors. The most potent of these compounds, ferroptosis sensitizer 1 (FSEN1), is an uncompetitive inhibitor that acts selectively through on-target inhibition of FSP1 to sensitize cancer cells to ferroptosis. Furthermore, a synthetic lethality screen reveals that FSEN1 synergizes with endoperoxide-containing ferroptosis inducers, including dihydroartemisinin, to trigger ferroptosis. These results provide new tools that catalyze the exploration of FSP1 as a therapeutic target and highlight the value of combinatorial therapeutic regimes targeting FSP1 and additional ferroptosis defense pathways.

The spontaneously formed uncoordinated Pb2+ defects usually make the perovskite films demonstrate strong n-type with relatively lower carrier diffusion length and serious non-radiative recombination energy loss. In this work, we adopt different polymerization strategies to construct three-dimensional passivation frameworks in the perovskite layer. Thanks to the strong C≡N⋅⋅⋅Pb coordination bonding and the penetrating passivation structure, the defect state density is obviously reduced, accompanied by a significant increase in the carrier diffusion length. Additionally, the reduction of iodine vacancies also changed the Fermi level of the perovskite layer from strong n-type to weak n-type, which substantially promotes the energy level alignment and carrier injection efficiency. As a result, the optimized device achieved an efficiency exceeded 24 % (the certified efficiency is 24.16 %) with a high open-circuit voltage of 1.194 V, and the corresponding module achieved an efficiency of 21.55 %.

High-performance perovskite solar cells have demonstrated commercial viability, but still face the risk of contamination from lead leakage and long-term stability problems caused by defects. Here, an organic small molecule (octafluoro-1,6-hexanediol diacrylate) is introduced into the perovskite film to form a polymer through in situ thermal crosslinking, of which the carbonyl group anchors the uncoordinated Pb2+ of perovskite and reduces the leakage of lead, along with the -CF2 - hydrophobic group protecting the Pb2+ from water invasion. Additionally, the polymer passivates varieties of Pb-related and I-related defects through coordination and hydrogen bonding interactions, regulating the crystallization of perovskite film with reduced trap density, releasing lattice strain, and promoting carrier transport and extraction. The optimal efficiencies of polymer-incorporated devices are 24.76 % (0.09 cm2 ) and 20.66 % (14 cm2 ). More importantly, the storage stability, thermal stability, and operational stability have been significantly improved.

The iodine loss in the perovskite layer is currently-one of the major limit for further boosting power conversion efficiency (PCE) and long-term stability of perovskite solar cells (PSCs). Iodine-poor interface dominates the generation of some deep level defects and the phase collapse in the perovskite layer. So how to adequately immobilize the iodine and passivate the existing undercoordinated lead cations is a critical challenge. Herein, the interaction between the bifunctional amide group and the perovskite layer was systematically investigated. The Malonamide (MAM) with bis(amide) group in structure can selectively hold iodine in place or interact with undercoordinated lead cations through adjusting the molecular conformation, resulting in more ideal I/Pb ratio, highly suppressed ion migration, harmonized surface potential and reduced defect density. Eventually, a significantly improved efficiency of 24.13% was demonstrated with the MAM-treating devices, and the device kept 96% of its initial efficiency after 900 h under continuous illumination.

Intrahepatic cholangiocarcinoma (iCCA) is a highly aggressive cancer that is challenging to diagnose at an early stage. Despite recent advances in combination chemotherapy, drug resistance limits the therapeutic value of this regimen. iCCA reportedly harbors high HMGA1 expression and pathway alterations, especially hyperactivation of the CCND1/CDK4/CDK6 and PI3K signaling pathway. In this study, we explored the potential of targeting CDK4/6 and PI3K inhibition to treat iCCA.The significance of HMGA1 in iCCA was investigated with in vitro/vivo experiments. Western blot, qPCR, dual-luciferase reporter and immunofluorescence assays were performed to examine the mechanism of HMGA1 induced CCND1 expression. CCK-8, western blot, transwell, 3D sphere formation and colony formation assays were conducted to predict the potential role of CDK4/6 inhibitors PI3K/mTOR inhibitors in iCCA treatment. Xenograft mouse models were also used to determine the efficacy of combination treatment strategies related to HMGA1 in iCCA.HMGA1 promoted the proliferation, epithelial-mesenchymaltransition (EMT), metastasis and stemness of iCCA. In vitro studies showed that HMGA1 induced CCND1 expression via promoting CCND1 transcription and activating the PI3K signaling pathway. Palbociclib(CDK4/6 inhibitor) could suppress iCCA proliferation, migration and invasion, especially during the first 3 days. Although there was more stable attenuation of growth in the HIBEpic model, we observed substantial outgrowth in each hepatobiliary cancer cell model. PF-04691502(PI3K/mTOR inhibitor) exhibited similar effects to palbociclib. Compared with monotherapy, the combination retained effective inhibition for iCCA through the more potent and steady inhibition of CCND1, CDK4/6 and PI3K pathway. Furthermore, more significant inhibition of the common downstream signaling pathways is observed with the combination compared to monotherapy.Our study reveals the potential therapeutic role of dual inhibition of CDK4/6 and PI3K/mTOR pathways in iCCA, and proposes a new paradigm for the clinical treatment of iCCA.

Abstract Introducing sodium as anode to develop sodium metal batteries (SMBs) is a promising approach for improving the energy density of sodium‐ion batteries. However, fatal problems, such as uncontrollable sodium dendrite growth, unstable solid electrolyte interphase (SEI) in low‐cost carbonate‐based electrolytes, and serious safety issues, greatly impede the practical applications. Here, a multifunctionalized separator is rationally designed, by coating PP separator (&lt;25 µm) with a solid‐state NASICON‐type fast ionic conductor layer (NZSP@PP) to replace the widely used thick glass fiber separator (&gt;200 µm) and successfully solves all of the above problems, and for the first time creats high performance SMBs by using Na 3 V 2 (PO 4 ) 3 (NVP) cathodes in pouch cell. The Na||NVP full cells can stably cycle over 1200 times with capacity retention of 80% at a high rate of 10 C and deliver a specific capacity of 80 mAh g −1 even at high rate of 30 C, indicating extraordinary fast‐charging characters. The full SMBs can also stably cycle 200 times with a retention of 96.4% under high NVP loading of 10.7 mg cm −2 . Most importantly, the SMB pouch cell can also deliver a long‐life cycles as well as high‐temperature battery performance, which guarantees the safety of SMBs in practical application.

Soft hydrogels are excellent candidate materials for repairing various tissue defects, yet the mechanical strength, anti-swelling properties, and biocompatibility of many soft hydrogels need to be improved. Herein, inspired by the nanostructure of collagen fibrils, we developed a strategy toward achieving a soft but tough, anti-swelling nanofibrillar hydrogel by combining the self-assembly and chemical crosslinking of nanoparticles. Specifically, the collagen fibril-like injectable hydrogel was subtly designed and fabricated by self-assembling methylacrylyl hydroxypropyl chitosan (HM) with laponite (LAP) to form nanoparticles, followed by the inter-nanoparticle bonding through photo-crosslinking. The assembly mechanism of nanoparticles was elucidated by both experimental and simulation techniques. Due to the unique structure of the crosslinked nanoparticles, the nanocomposite hydrogels exhibited low stiffness (G'< 2 kPa), high compressive strength (709 kPa), and anti-swelling (swelling ratio of 1.07 in PBS) properties. Additionally, by harnessing the photo-crosslinking ability of the nanoparticles, the nanocomposite hydrogels were processed as microgels, which can be three-dimensionally (3D) printed into complex shapes. Furthermore, we demonstrated that these nanocomposite hydrogels are highly biocompatible, biodegradability, and can effectively promote fibroblast migration and accelerate blood vessel formation during wound healing. This work presents a promising approach to develop biomimetic, nanofibrillar soft hydrogels for regenerative medicine applications.

We use optical tweezers to move single silver nanoparticles into near-field contact with immobilized particles, forming isolated surface-enhanced Raman spectroscopy (SERS) active Ag particle dimers. The surface-averaged SERS intensity increases by a factor ∼20 upon dimerization. Electrodynamics calculations indicate that the final approach between the particles is due to “optical binding”. The described methodology may facilitate controlled single molecule SERS analysis.

The interaction of light with metal nanoparticles leads to novel phenomena mediated by surface plasmon excitations. In this article we use single molecules to characterize the interaction of surface plasmons with light, and show that such interaction can strongly modulate the polarization of the emitted light. The simplest nanostructures that enable such polarization modulation are asymmetric silver nanocrystal trimers, where individual Raman scattering molecules are located in the gap between two of the nanoparticles. The third particle breaks the dipolar symmetry of the two-particle junction, generating a wavelength-dependent polarization pattern. Indeed, the scattered light becomes elliptically polarized and its intensity pattern is rotated in the presence of the third particle. We use a combination of spectroscopic observations on single molecules, scanning electron microscope imaging, and generalized Mie theory calculations to provide a full picture of the effect of particles on the polarization of the emitted light. Furthermore, our theoretical analysis allows us to show that the observed phenomenon is very sensitive to the size of the trimer particles and their relative position, suggesting future means for precise control of light polarization on the nanoscale.

How autophagy, an evolutionarily conserved intracellular catabolic system for bulk degradation, selectively degrades protein aggregates is poorly understood. Here, we show that several maternally derived germ P granule components are selectively eliminated by autophagy in somatic cells during C. elegans embryogenesis. The activity of sepa-1 is required for the degradation of these P granule components and for their accumulation into aggregates, termed PGL granules, in autophagy mutants. SEPA-1 forms protein aggregates and is also a preferential target of autophagy. SEPA-1 directly binds to the P granule component PGL-3 and also to the autophagy protein LGG-1/Atg8. SEPA-1 aggregates consistently colocalize with PGL granules and with LGG-1 puncta. Thus, SEPA-1 functions as a bridging molecule in mediating the specific recognition and degradation of P granule components by autophagy. Our study reveals a mechanism for preferential degradation of protein aggregates by autophagy and emphasizes the physiological significance of selective autophagy during animal development.

Upconversion nanoparticles (UCNPs) can convert tissue-penetrable nearinfrared light into UV emission, making them promising as transducers for photoactivation in biology. However, the choice of the UV emitting UCNPs is limited and their NIR-to-UV efficiency is low. G. Han and co-workers have addressed this issue by developing a family of CaF2-coated UCNPs with tunable UV enhancement. As reported on page 3213, such design outperforms known optimal UCNPs and in situ realtime live-cell photoactivation is recorded for the first time with such nanoparticles. This result is a potential game changer in photoactivation in living systems and a new tool for other biophotonic applications.

Nanowire plasmons can be launched by illumination at one terminus of the nanowire and emission can be detected at the other end of the wire. Using polarization dependent dark-field scattering spectroscopy, we measure how the polarization of the emitted light depends on the polarization of the incident light. We observe that the shape of the nanowire termination plays an important role in determining this polarization change. Depending on termination shape, a nanowire can serve as either a polarization-maintaining waveguide, or as a polarization-rotating, nanoscale half-wave plate. The understanding of how plasmonic waveguiding influence the polarization of the guided light is important for optimizing the structure of integrated plasmonic devices.

This paper presents an information-fusion-based approach to the estimation of urban traffic states. The approach can fuse online data from underground loop detectors and global positioning system (GPS)-equipped probe vehicles to more accurately and completely obtain traffic state estimation than using either of them alone. In this approach, three parts of the algorithms are developed for fusion computing and the data processing of loop detectors and GPS probe vehicles. First, a fusion algorithm, which integrates the federated Kalman filter and evidence theory (ET), is proposed to prepare a robust, credible, and extensible fusion platform for the fusion of multisensor data. After that, a novel algorithm based on the traffic wave theory is employed to estimate the link mean speed using single-loop detectors buried at the end of links. With the GPS data, a series of technologies are combined with the geographic information systems for transportation (GIS-T) map to compute another link mean speed. These two speeds are taken as the inputs of the proposed fusion platform. Finally, tests on the accuracy, conflict resistance, robustness, and operation speed by real-world traffic data illustrate that the proposed approach can well be used in urban traffic applications on a large scale.

Thin metallic nanowires are highly promising candidates for plasmonic waveguides in photonic and electronic devices. We have observed that light from the end of a silver nanowire, following excitation of plasmons at the other end of the wire, is emitted in a cone of angles peaking at nominally 45-60 degrees from the nanowire axis, with virtually no light emitted along the direction of the nanowire. This surprising characteristic can be explained in a simple picture invoking Fabry-Perot resonances of the forward- and back-propagating plasmons on the nanowire. This strongly angular-dependent emission is a critical property that must be considered when designing coupled nanowire-based photonic devices and systems.

We investigate the light emission from dipolar emitters located within nanoparticle antennas. It is found that the enormous emission enhancement can reach nearly a million fold. For multinanoparticle antennas, the polarization of the emissions strongly depends on the geometry of the antennas, the emitted wavelengths, and the dielectric functions of surrounding media. It is shown that a polarization nanorotator, which modulates the emission polarization on the nanometer scale, can be readily realized by varying either the geometry or surrounding media of nanoparticle antennas.

The autophagic digestion of lipid droplets (LDs) through lipophagy is an essential process by which most cells catabolize lipids as an energy source. However, the cellular machinery used for the envelopment of LDs during autophagy is poorly understood. We report a novel function for a small Rab guanosine triphosphatase (GTPase) in the recruitment of adaptors required for the engulfment of LDs by the growing autophagosome. In hepatocytes stimulated to undergo autophagy, Rab10 activity is amplified significantly, concomitant with its increased recruitment to nascent autophagic membranes at the LD surface. Disruption of Rab10 function by small interfering RNA knockdown or expression of a GTPase-defective variant leads to LD accumulation. Finally, Rab10 activation during autophagy is essential for LC3 recruitment to the autophagosome and stimulates its increased association with the adaptor protein EHBP1 (EH domain binding protein 1) and the membrane-deforming adenosine triphosphatase EHD2 (EH domain containing 2) that, together, are essential in driving the activated "engulfment" of LDs during lipophagy in hepatocytes.

Carrier-free pure nanodrugs (PNDs) that are composed entirely of pharmaceutically active molecules are regarded as promising candidates to be the next generation of drug formulations and are mainly formulated from supramolecular self-assembly of drug molecules. It benefits from the efficient use of drug compounds with poor aqueous solubility and takes advantage of nanoscale drug delivery systems. Here, a type of all-in-one nanoparticle consisting of multiple drugs with enhanced synergistic antiproliferation efficiency against drug-resistant cancer cells has been created. To nanoparticulate the anticancer drugs, 10-hydroxycamptothecin (HCPT) and doxorubicin (DOX) were chosen as a typical model. The resulting HD nanoparticles (HD NPs) were formulated by a “green” and convenient self-assembling method, and the water-solubility of 10-hydroxycamptothecin (HCPT) was improved 50-fold after nanosizing by coassembly with DOX. The formation process was studied by observing the morphological changes at various reaction times and molar ratios of DOX to HCPT. Molecular dynamics (MD) simulations showed that DOX molecules tend to assemble around HCPT molecules through intermolecular forces. With the advantage of nanosizing, HD NPs could improve the intracellular drug retention of DOX to as much as 2-fold in drug-resistant cancer cells (MCF-7R). As a dual-drug-loaded nanoformulation, HD NPs effectively enhanced drug cytotoxicity to drug-resistant cancer cells. The combination of HCPT and DOX exhibited a synergistic effect as the nanosized HD NPs improved drug retention in drug-resistant cancer cells against P-gp efflux in MCF-7R cells. Furthermore, colony forming assays were applied to evaluate long-term inhibition of cancer cell proliferation, and these assays confirmed the greatly improved cytotoxicity of HD NPs in drug-resistant cells compared to free drugs.

Defect engineering on transition metal dichalcogenides has been regarded as an effective method to improve electrochemical properties in terms of generating active sites and enhancing the intrinsic conductivity. This study reports a new high-performance electrochemical supercapacitor made of reduced CoNi2S4 (r-CoNi2S4) nanosheets, which are synthesized via a facile moderate-reduction process. The sulfur-deficient r-CoNi2S4 nanosheets exhibit significantly enhanced conductivity which is induced by abundant sulfur vacancies formed in the reduction reaction. Compared with the pristine CoNi2S4 nanosheets, the r-CoNi2S4 nanosheets are characterized with a higher specific capacity (1117C g−1 at current density of 2 A g−1) as well as excellent rate capability and stable cycling performance. First-principle analysis confirms that the sulfur vacancies originating from the reduction lead to improve hybridization between the Ni and Co d states and the S p states close to the fermi level, and consequently enhance conductivity with the CoNi2S4 nanostructure. Moreover, an ultrahigh energy density of 55.4 Wh kg−1 at the power density of 8 kW kg−1 is obtained in an asymmetric supercapacitor configuration, and 80% capacitance of the supercapacitor remains even after 10000 cycles.

Rational design of efficient bifunctional oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) electrocatalysts are critical for rechargeable Li–O2 batteries. Here, we report inverse spinel Co[Co,Fe]O4/nitrogen-doped graphene (NG) composite used as a promising catalyst for rechargeable Li–O2 batteries. The cells with Co[Co,Fe]O4/NG catalyst exhibit high initial capacity, remarkable cyclability, and good rate capability. Moreover, the overpotential of the Li–O2 batteries is reduced significantly. The improved ORR/OER performances are attributed to the good property of Co[Co,Fe]O4 with an inverse spinel structure toward ORR and the improved electronic conductivity of N-doped graphene. The density functional theory (DFT) calculation shows the rate limitation step for ORR on the inverse spinel surface is the growth of the Li2O2 cluster while the rate limitation step for the OER pathway is the oxidation of Li2O2. The inverse spinel surface in Co[Co,Fe]O4/NG is more active than that of the normal spinel phases for the Li–O2 battery reactions. This work not only provides a promising bifunctional catalyst for practical metal air batteries but also offers a general strategy to rationally design catalysts for various applications.

Abstract: The high aqueous solubility, poor permeability, and absorption of berberine (BBR) result in its low plasma level after oral administration, which greatly limits its clinical application. BBR solid lipid nanoparticles (SLNs) were prepared to achieve improved bioavailability and prolonged effect. Developed SLNs showed homogeneous spherical shapes, small size (76.8 nm), zeta potential (7.87 mV), encapsulation efficiency (58%), and drug loading (4.2%). The power of X-ray diffraction combined with 1 H nuclear magnetic resonance spectroscopy was employed to analyze chemical functional groups and the microstructure of BBR-SLNs, and indicated that the drug was wrapped in a lipid carrier. Single dose (50 mg/kg) oral pharmacokinetic studies in rats showed significant improvement ( P <0.05) in the peak plasma concentration, area under the curve, and variance of mean residence time of BBR-SLNs when compared to BBR alone ( P <0.05), suggesting improved bioavailability. Furthermore, oral administration of both BBR and BBR-SLNs significantly suppressed body weight gain, fasting blood glucose levels, and homeostasis assessment of insulin resistance, and ameliorated impaired glucose tolerance and insulin tolerance in db/db diabetic mice. BBR-SLNs at high dose (100 mg/kg) showed more potent effects when compared to an equivalent dose of BBR. Morphologic analysis demonstrated that BBR-SLNs potentially promoted islet function and protected the islet from regeneration. In conclusion, our study demonstrates that by entrapping BBR into SLNs the absorption of BBR and its anti-diabetic action were effectively enhanced. Keywords: berberine, solid lipid nanoparticles, pharmacokinetic, hypoglycemic effect

The objective of this work is to develop KH550-treated basalt fiber (KBF) reinforced polylactide (PLA) composite as a potential 3D-printed feedstock. Herein, physical (thermal, mechanical, and rheological) properties and the feasibility of PLA/KBF for 3D printing are investigated. KBF is found to be oriented-dispersed along the printing direction in printed specimen, in contrast with randomly-distributed KBF in casting counterparts. Mechanical tests, rheological behavior and microstructure observation of PLA/KBF filaments are performed to compare with carbon fiber (CF) reinforced counterparts with the same fiber weight fraction. The results suggest that PLA/KBF exhibit comparable tensile properties and superior flexural properties to those of PLA/CF control, which can be attributed to high complex viscosity of PLA/CF affecting the interlayer adhesion. Furthermore, the printing feasibility of PLA/KBF filaments are evaluated. With increasing fiber length and weight fraction of KBF, low infill and micro-defects are shown in CT scans, which explain the deterioration in mechanical performance. The present work proves PLA/KBF as a mechanical-improved and low-cost feedstock for 3D printing applications in complex design and variable sizes.

SERS-active silver hierarchical assemblies are synthesized in solution by the assistance of small acid molecules. We here demonstrate the acid-directed self-assembly of metal nanoparticles (MNPs) into large systems with complex structures, without the application of any polymer surfactant or capping agent. It is verified that small acid molecules (citric acid, mandelic acid, etc.) incorporated into conventional solution chemistry can direct the assembly of MNPs into well-defined hierarchical structures. The constructed assembled structures with highly roughened surfaces can be highly sensitive SERS platforms, and the fabricated core–shell Ag wires show especially high SERS sensitivity toward the analyte melamine. The prepared Ag particles with hierarchical structures show no evident polarization-dependent SERS behavior, and this isotropic feature may be an advantage for highly sensitive SERS tags, since no certain incident polarization is required for molecule detection. We believe the subsequent addition of acid to induce formation of self-assembled structures can be a general synthetic platform to fabricate metal structures with complex morphologies.

In this study, we present a broadband nano-photodetector based on single-layer graphene (SLG)-carbon nanotube thin film (CNTF) Schottky junction. It was found that the as-fabricated device exhibited obvious sensitivity to a wide range of illumination, with peak sensitivity at 600 and 920 nm. In addition, the SLG-CNTF device had a fast response speed (τr = 68 μs, τf = 78 μs) and good reproducibility in a wide range of switching frequencies (50-5400 Hz). The on-off ratio, responsivity, and detectivity of the device were estimated to be 1 × 102, 209 mAW-1 and 4.87 × 1010 cm Hz1/2 W-1, respectively. What is more, other device parameters including linear performance θ and linear dynamic range (LDR) were calculated to be 0.99 and 58.8 dB, respectively, which were relatively better than other carbon nanotube based devices. The totality of the above study signifies that the present SLG-CNTF Schottky junction broadband nano-photodetector may have promising application in future nano-optoelectronic devices and systems.

Tungsten-based monolayer transition metal dichalcogenides host a long-lived "dark" exciton, an electron-hole pair in a spin-triplet configuration. The long lifetime and unique spin properties of the dark exciton provide exciting opportunities to explore light-matter interactions beyond electric dipole transitions. Here we demonstrate that the coupling of the dark exciton and an optically silent chiral phonon enables the intrinsic photoluminescence of the dark-exciton replica in monolayer WSe2. Gate and magnetic-field dependent PL measurements unveil a circularly-polarized replica peak located below the dark exciton by 21.6 meV, equal to E″ phonon energy from Se vibrations. First-principles calculations show that the exciton-phonon interaction selectively couples the spin-forbidden dark exciton to the intravalley spin-allowed bright exciton, permitting the simultaneous emission of a chiral phonon and a circularly-polarized photon. Our discovery and understanding of the phonon replica reveals a chirality dictated emission channel of the phonons and photons, unveiling a new route of manipulating valley-spin.

Abstract Effective passivation and stabilization of both the inside and interface of a perovskite layer are crucial for perovskite solar cells (PSCs), in terms of efficiency, reproducibility, and stability. Here, the first formamidinium lead iodide (δ‐FAPbI 3 ) polymorph passivated and stabilized MAPbI 3 PSCs are reported. This novel MAPbI 3 /δ‐FAPbI 3 structure is realized via treating a mixed organic cation MA x FA 1‐ x PbI 3 perovskite film with methylamine (MA) gas. In addition to the morphology healing, MA gas can also induce the formation of δ‐FAPbI 3 phase within the perovskite film. The in situ formed 1D δ‐FAPbI 3 polymorph behaves like an organic scaffold that can passivate the trap state, tunnel contact, and restrict organic‐cation diffusion. As a result, the device efficiency is easily boosted to 21%. Furthermore, the stability of the MAPbI 3 /δ‐FAPbI 3 film is also obviously improved. This δ‐FAPbI 3 phase passivation strategy opens up a new direction of perovskite structure modification for further improving stability without sacrificing efficiency.

The fluorescence of tetraphenylethylene (TPE), an archetypal luminogen, is induced by restriction of intramolecular rotation (RIR). TPE was grafted with palmitic acid (PA) onto a hydrophilic peptide to yield a cell membrane tracker named TR4. TR4 was incorporated into liposomes, where it showed significant RIR characteristics. When cells were incubated with TR4, cytoplasmic membranes were specifically labeled. TR4 shows excellent photostability and low cytotoxicity.

Abstract (Ba 0.3 Sr 0.7 ) x (Bi 0.5 Na 0.5 ) 1- x TiO 3 (BS x BNT, x = 0.3–V0.8) ceramics were prepared to investigate their structure, dielectric and ferroelectric properties. BSxBNT ceramics possess pure perovskite structure accompanied from a tetragonal symmetry to pseudo-cubic one with the increase of x value, being confirmed by X-ray diffraction (XRD) and Raman results. The T m corresponding to a temperature in the vicinity of maximum dielectric constant gradually decreases from 110 °C ( x = 0.3) to -45 °C ( x = 0.8), across T m = 36 °C ( x = 0.5) with a maximum dielectric constant (ɛ r = 5920 @1 kHz) around room temperature. The saturated polarization P s gradually while the remnant polarization Pr sharply decreases with the increase of x value, making the P - E hysteresis loop of BS x BNT ceramics goes slim. A maximum difference between P s and P r ( P s - P r ) is obtained for BS x BNT ceramics with x = 0.5, at which a high recoverable energy density ( W rec = 1.04 J/cm 3 ) is achieved under an applied electric field of 100 kV/cm with an efficiency of η = 77%. Meanwhile, the varied temperature P - E loops, fatigue measurements, and electric breakdown characteristics for the sample with x = 0.5 indicate that it is promising for pulsed power energy storage capacitor candidate materials.

Polyunsaturated fatty acids (PUFAs) have been widely applied in the food and medical industry. In this study, malonyl-CoA: ACP transacylase (MAT) was overexpressed through homologous recombination to improve PUFA production in Schizochytrium. The results showed that the lipid and PUFA concentration were increased by 10.1 and 24.5% with MAT overexpression, respectively. Metabolomics analysis revealed that the intracellular tricarboxylic acid cycle was weakened and glucose absorption was accelerated in the engineered strain. In the mevalonate pathway, intracellular carotene content was decreased, and the carbon flux was then redirected toward PUFA synthesis. Furthermore, a glucose fed-batch fermentation was finally performed with the engineered Schizochytrium. The total lipid yield was further increased to 110.5 g/L, 39.6% higher than the wild strain. Docosahexaenoic acid and eicosapentaenoic acid yield were enhanced to 47.39 g/L and 1.65 g/L with an increase of 81.5 and 172.5%, respectively. This study provided an effective metabolic engineering strategy for industrial PUFA production.

Polysaccharides are an important class of materials that are often exploited in the fields of food, agriculture, biomedical engineering and wastewater treatment owing to their unique and tunable properties. In this work, we utilize an inexpensive and sustainable extracellular polysaccharide salecan (EPS), which is produced by bacterium Agrobacterium sp. ZX09, as a hydrogel matrix, poly(3-sulfopropyl methacrylate potassium salt) (PSM) as side chains to fabricate EPS-grafted-PSM adsorbents through a simple one-pot approach. Scanning electron microscope, X-ray diffraction, Fourier transformed infrared spectroscopy, rheometry and thermogravimetry were conducted to characterize the physicochemical properties of resultant adsorbents. We noticed that EPS not only served as the host chains of network to adjust the water uptake ability of adsorbents, but also endued them with tunable polarity. Further, the adsorption behaviors of developed adsorbents to copper ions (Cu2+) were explored: these gels present high absorption ability for Cu2+ through a chemical adsorption process which well described by Freundlich isotherm and pseudo-second-order kinetic models. In summary, the approach exhibited in this work opens a new avenue to design polysaccharide-based materials for Cu2+ adsorption.

In this study, the anaerobic co-digestion of food waste (FW) and sewage sludge (SS) was investigated for the production of hydrogen and volatile fatty acids (VFAs). The results showed that the anaerobic co-digestion of these materials enhanced the hydrogen content by 62.4% (v/v), 29.89% higher than that obtained by FW digestion alone, and the total VFA production reached at 281.84 mg/g volatile solid (VS), a 8.38% increase. This enhancement was primarily resulted from improvements in the multi-substrate characteristics, which were obtained by supplying a higher soluble chemical oxygen demand (23.78-32.14 g/L) and suitable a pH (6.12-6.51), decreasing total ammonia nitrogen by 18.67% and ensuring a proper carbon/nitrogen ratio (15.01-23.01). Furthermore, maximal hydrogen (62.39 mL/g VS) and total VFA production potential (294.63 mg/g VS) were estimated using response surface methodology optimization, which yielded FW percentages of 85.17% and 79.87%, respectively. Based on a pyrosequencing analysis, the dominant bacteria associated with VFA and hydrogen production were promoted under optimized condition, including members of genera Veillonella and Clostridium and the orders Bacteroidales and Lactobacillales.

The rational design of efficient and durable oxygen evolution reaction (OER) is important for energy conversion and storage devices. Here, we develop a two-step calcination method to prepare cobalt nanoparticles uniformly dispersed on perovskite oxide nanofibers and to tune oxygen vacancies in perovskite LaMn0.75Co0.25O3-δ nanofibers. The obtained product shows enhanced activity toward OER. In particular, the oxygen deficient LMCO-2 catalyst prepared by a two-step calcination shows excellent OER performance that is 27.5 times that of the LMO catalyst and is comparable to that of the commercial RuO2 catalyst. It also demonstates good stability because of its novel structure, abundant oxygen vacancies, and larger number of metal ions with a high oxidation state. As an air electrode for a flexible zinc-air battery, the cell with the LMCO-2 catalyst delivers a higher power density of 35 mW cm-2 and excellent cycling stability for 70 h. Moreover, the cell exhibits excellent flexibility under different bending conditions.

Designing versatile adsorption materials with high efficiency, excellent reversibility, and economic production is vital for treating wastewater but remains challenging. Here, a new polysaccharide (salecan) based superabsorbent was developed by graft copolymerization of acrylamide and sodium vinylsulfonate onto the salecan and used to remove lead ions (Pb2+) from water. Effects of salecan content, adsorbent amount, contact time, adsorbate concentration, and pH on the extent of Pb2+ adsorption were studied. The optimized absorbent (containing 9 mL of 2% salecan polysaccharide) exhibited an optimal adsorption performance in Pb2+ removal (172.8 mg/g). Noticeably, the adsorptive behavior of gel matched well with the Freundlich isotherm and pseudo-second-order kinetic model. In addition, our product presented no apparent loss in Pb2+ adsorption after 6 cycles. Overall, this work not only provided a new strategy to construct highly efficient and low-cost adsorbent but also demonstrated its potential application for heavy metal removal.

Wastewater primary sedimentation sludge was prepared into fermentation liquid as denitrification carbon source, and the main components of fermentation liquid was short-chain volatile fatty acids. Meanwhile, the acetic acid and propionic acid respectively accounted for about 29.36% and 26.56% in short-chain volatile fatty acids. The performance of fermentation liquid, methanol, acetic acid, propionic acid and glucose used as sole carbon source were compared. It was found that the denitrification rate with fermentation liquid as carbon source was 0.17mgNO3(-)-N/mg mixed liquor suspended solid d, faster than that with methanol, acetic acid, and propionic acid as sole carbon source, and lower than that with glucose as sole carbon source. For the fermentation liquid as carbon source, the transient accumulation of nitrite was insignificantly under different initial total nitrogen concentration. Therefore, the use of fermentation liquid for nitrogen removal could improve denitrification rate, and reduce nitrite accumulation in denitrification process.

A method is developed to synthesize surface‐enhanced Raman scattering (SERS) materials capable of single‐molecule detection, integrated with a microfluidic system. Using a focused laser, silver nanoparticle aggregates as SERS monitors are fabricated in a microfluidic channel through photochemical reduction. After washing out the monitor, the aggregates are irradiated again by the same laser. This key step leads to full reduction of the residual reactants, which generates numerous small silver nanoparticles on the former nanoaggregates. Consequently, the enhancement ability of the SERS monitor is greatly boosted due to the emergence of new “hot spots.” At the same time, the influence of the notorious “memory effect” in microfluidics is substantially suppressed due to the depletion of surface residues. Taking these advantages, two‐step photoreduced SERS materials are able to detect different types of molecules with the concentration down to 10 −13 m . Based on a well‐accepted bianalyte approach, it is proved that the detection limit reaches the single‐molecule level. From a practical point of view, the detection reproducibility at different probing concentrations is also investigated. It is found that the effective single‐molecule SERS measurements can be raised up to ≈50%. This microfluidic SERS with high reproducibility and ultrasensitivity will find promising applications in on‐chip single‐molecule spectroscopy.

The lubricant additives could be added into vegetable oil to improve the tribological. Two lubricant additives (GO-D and GO-T) were synthesized and characterized by the reaction between the carboxyl of graphene oxide (GO) and 1-dodecanethiol and tert-dodecyl mercaptan, respectively. The dispersion stability and tribological properties of GO-D and GO-T in rapeseed oil were investigated. The results show that the dispersion stability and tribological properties of GO-D in rapeseed oil are superior to that of GO-T, and both of them are better than that of GO. In addition, the surface morphology and chemical analysis of steel ball show that GO-D and GO-T sheets form absorption and tribochemical film on the rubbing surface.

Molybdenum dioxide (MoO2) nanoparticles with the size of 200 nm in diameter were synthesized by a facile hydrothermal method. The nanoparticles were directly functionalized as supercapacitors (SCs) electrodes and photocatalysts. The electrochemical studies showed that the SCs demonstrated high capacitance of 621 F g−1, which was 3 times larger than previous reports. Furthermore, they exhibited good cyclic performance with 90% capacity retention after 1000 cycles at a current density of 1 A g−1. The photocatalytic activities were evaluated by the degradation of methylene blue (MB) and rhodamine B (RhB), respectively, and the nanoparticles demonstrated preferred selectivity on the degradation of RhB (70%) than that of MB (30%).

PM2.5 pollution in Beijing has attracted extensive attention in recent years, but research on the detailed spatiotemporal characteristics of PM2.5 is critically lacking for effective pollution control. In our study, hourly PM2.5 concentration data of 35 fixed monitoring sites in Beijing were collected continuously from October 2012 to September 2013, for exploring the diurnal and seasonal characteristics of PM2.5 at traffic, urban, and background environments. Spatial trend and regional contribution of PM2.5 under different pollution levels were also investigated. Results show that the average PM2.5 concentration of all the 35 sites (including 5 traffic sites) was 88.6 μg/m3. Although PM2.5 varied largely with the site location and seasons, a clear spatial trend could be observed with the PM2.5 concentration decreasing linearly from south to north, with a gradient of −0.46 μg/m3/km for average days, −0.83 μg/m3/km for heavily–severely polluted days, −0.52 μg/m3/km at lightly–moderately polluted days, and −0.26 μg/m3/km for excellent–good days. PM2.5 at traffic sites was varied, but was generally over 10% higher than at the nearby urban assessment sites.

A novel electrocatalyst based on nitrogen-doped carbon nanocapsules containing metallic cobalt nanoparticle (Co–N–C) tetragonal microstructures was firstly synthesized.

Alginates (nickel alginate, NiA; copper alginate, CuA; zinc alginate, ZnA) and 3-aminopropyltriethoxysilane (APTES) were alternately deposited on a magnesium hydroxide (MH) surface by the spray-drying-assisted layer-by-layer assembly technique, fabricating some efficient and environmentally benign flame retardants (M–FR, including Ni–FR, Cu–FR, and Zn–FR). The morphology, chemical compositions, and structures of M–FR were investigated. With 50 wt % loading, compared with EVA28+MH, the peak heat release rate, smoke production rate, and CO production rate of EVA28+Ni–FR decreased by 50.78%, 61.76%, and 66.67%, respectively. The metals or metal oxide nanoparticles arising from alginates could catalyze the pyrolysis intermediates of EVA into graphene and amorphous carbon, which could bind the inorganic compounds (the decomposition products of MH and APTES) together and form some more protective barriers. For each M–FR, the flame retardant and smoke suppression efficiency were different, which were caused by the diverse carbonization and graphitization behaviors of three alginates. ZnA generated some ZnO aggregations and could not catalyze the graphitization of intermediates. For CuA, the catalytic graphitization was limited by the tightly binding graphene layer. As for NiA, the configuration of the Ni atom could not provide strong binding of Ni substrate and carbon. The liquid-like Ni nanoparticles could restructure and get out from firm graphene shells, so the catalytic graphitization of NiA was efficient and sustainable. This work displayed the catalytic graphitization mechanism of alginates while exploring a simple and novel strategy for fabricating efficient green flame retardants.

Salecan polysaccharide produced by Agrobacterium sp. ZX09 is an attractive biopolymer to construct hydrogel scaffolds for cell culture. However, some limitations such as poor mechanical performance, complicated fabrication process and slow gelation times still exist in the biomedical applications of microbial-based salecan polysaccharide hydrogels. Here, a series of polysaccharide hydrogels composed of salecan and agarose with adjustable structural properties are designed. The resultant hybrid salecan/agarose hydrogels exhibit controllable physical and chemical properties including thermal stability, water uptake, mechanical strength and microarchitecture, which can be readily realized with minimum change of the polysaccharide content. Furthermore, cytotoxicity assays reveal that the designed composite hydrogels are non-toxic. More importantly, these hydrogels support cell survival, proliferation, and migration. Together, this work opens up a new avenue to build polysaccharide hydrogel platforms for tissue engineering.

Hydrogels have emerged as fascinating material for various applications in the chemical, biomedical, and energy fields. Generally, their poor self-healing performance, mechanical properties, and bioactivity limit the application of hydrogels in bioelectronics. Herein, a self-healable, injectable, stretchable, self-adhesive, biocompatible, and conductive poly(N-vinylpyrrolidone)/gallic acid (PVP/GA) composite hydrogel was fabricated via hydrogen bonding between the tertiary amide groups in PVP and hydroxyl groups in GA. The PVP/GA composite hydrogel possesses excellent self-healing properties after damage. The composite hydrogel is highly stretchable and can adhere to human skin to detect physiological activity signals precisely according to the resistance signals. The composite hydrogel has good biocompatibility with living organisms. It is envisioned that multifunctional PVP/GA composite hydrogels can be applied to the electronic skins, wearable biosensors, and body movements monitoring equipment.

To compare the accuracy of an original and two newly designed CAD/CAM scan bodies used in digital impressions with one another as well as conventional implant impressions.A reference model containing four implants was fabricated. Digital impressions were taken using an intraoral scanner with different scan bodies: original scan bodies for Group I (DO), CAD/CAM scan bodies without extensional structure for Group II (DC), and CAD/CAM scan bodies with extensional structure for Group III (DCE). For Group IV, conventional splinted open-tray impressions (CI) were taken. The reference model and conventional stone casts were digitalized with a laboratory reference scanner. The Standard Tessellation Language datasets were imported into an inspection software for trueness and precision assessment. Statistical analysis was performed with a Kruskal-Wallis test and Dunn-Bonferroni test. The level of significance was set at α = .05.The median of trueness was 35.85, 38.50, 28.45, and 25.55 μm for Group I, II, III, and IV, respectively. CI was more accurate than DO (p = .015) and DC (p = .002). The median of precision was 48.40, 48.90, 27.30, and 19.00 for Group I, II, III, and IV, respectively. CI was more accurate than DO (p < .001), DC (p < .001), and DCE (p = .007). DCE was more accurate than DC (p < .001) and DO (p < .001).The design of the extensional structure could significantly improve scanning accuracy. Conventional splinted open-tray impressions were more accurate than digital impressions for full-arch implant rehabilitation.

Inversion symmetry breaking and 3-fold rotation symmetry grant the valley degree of freedom to the robust exciton in monolayer transition-metal dichalcogenides, which can be exploited for valleytronics applications. However, the short lifetime of the exciton significantly constrains the possible applications. In contrast, the dark exciton could be long-lived but does not necessarily possess the valley degree of freedom. In this work, we report the identification of the momentum-dark, intervalley exciton in monolayer WSe2 through low-temperature magneto-photoluminescence spectra. Interestingly, the intervalley exciton is brightened through the emission of a chiral phonon at the corners of the Brillouin zone (K point), and the pseudoangular momentum of the phonon is transferred to the emitted photon to preserve the valley information. The chiral phonon energy is determined to be ∼23 meV, based on the experimentally extracted exchange interaction (∼7 meV), in excellent agreement with the theoretical expectation of 24.6 meV. The long-lived intervalley exciton with valley degree of freedom adds an exciting quasiparticle for valleytronics, and the coupling between the chiral phonon and intervalley exciton furnishes a venue for valley spin manipulation.

Both Ganoderma lucidum (GL) and G. sinense (GS) are used as Lingzhi in China. Their functions are assumed to mainly derive from triterpenes and polysaccharides; however, the two species have very different triterpenes profiles, if this was the case, then the bioactivity of these two species should differ. Instead, could the polysaccharides be similar, contributing to the shared therapeutic basis? In this study, two main polysaccharide fractions from different batches of GL and GS were systematically compared by a series of chemical and biological experiments. The results showed that the polysaccharides from two species shared the same structural features in terms of mono-/oligo-saccharide profiles, molecular size, sugar linkages, and IR/NMR spectra. In addition, these polysaccharides showed similar tumor-suppressive activity in mice. Further study on RAW264.7 cells indicated that these polysaccharides exhibited similar inducing effects to macrophages, as evaluated in the phagocytosis function, NO/cytokines production, inhibition against the viability and migration of cancer cells. Mechanistic investigation revealed the identical activation via TLR-4 related MAPK/NF-κB signaling pathway and gut-microbiota modulatory effects. In summary, GL and GS polysaccharides presented similar chemical features, antitumor/immunomodulating activities and mechanism; this establishes polysaccharides as the active principles and supports the official use of both species as Lingzhi.

Transition metal dichalcogenides (TMDCs) heterostructure with a type II alignment hosts unique interlayer excitons with the possibility of spin-triplet and spin-singlet states. However, the associated spectroscopy signatures remain elusive, strongly hindering the understanding of the Moire potential modulation of the interlayer exciton. In this work, we unambiguously identify the spin-singlet and spin-triplet interlayer excitons in the WSe2/MoSe2 hetero-bilayer with a 60-degree twist angle through the gate- and magnetic field-dependent photoluminescence spectroscopy. Both the singlet and triplet interlayer excitons show giant valley-Zeeman splitting between the K and K' valleys, a result of the large Lande g-factor of the singlet interlayer exciton and triplet interlayer exciton, which are experimentally determined to be ~ 10.7 and ~ 15.2, respectively, in good agreement with theoretical expectation. The PL from the singlet and triplet interlayer excitons show opposite helicities, determined by the atomic registry. Helicity-resolved photoluminescence excitation (PLE) spectroscopy study shows that both singlet and triplet interlayer excitons are highly valley-polarized at the resonant excitation, with the valley polarization of the singlet interlayer exciton approaches unity at ~ 20 K. The highly valley-polarized singlet and triplet interlayer excitons with giant valley-Zeeman splitting inspire future applications in spintronics and valleytronics.

A wireless sensor based on bioresponsive DNA hydrogel provides smartphone-based detection of wound infection.

Poly(3,4 ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is perhaps the most successful polymer material for thermoelectric (TE) applications. So far, treatments by high-boiling solvents, acid or base, or mixing with the carbon nanotube (CNT) are the main ways to improve its TE performance. Herein, we report the synergistically boosting TE properties of PEDOT:PSS/single-walled CNT (SWCNT) composites by the ionic liquid (IL). The composites are prepared by physically mixing the SWCNT dispersion containing the IL with PEDOT:PSS solution and subsequent vacuum filtration. The IL additive has two major functions, that is, inducing the phase separation of PEDOT:PSS and a linear quinoid conformation of PEDOT and promoting the SWCNT dispersion. The maximum power factor at room temperature reaches 182.7 ± 9.2 μW m–1 K–2 (the corresponding electrical conductivity and Seebeck coefficient are 1602.6 ± 103.0 S cm–1 and 33.4 ± 0.4 μV K–1, respectively) for the free-standing flexible film of the PEDOT:PSS/SWCNT composites with the IL, which is much higher than those of the pristine PEDOT:PSS, the IL-free PEDOT:PSS/SWCNT, and the SWCNT films. The high TE performance of composites can be ascribed to synergistic roles of the ion-exchange effect and promotion of SWCNT dispersion by the IL. This work demonstrates the dual roles for the IL in regulating each component of the PEDOT:PSS/SWCNT composite that synergistically boosts the TE performance.

Periodontitis is one of the most common dental diseases. Compared with healthy periodontal tissues, the immune microenvironment plays the key role in periodontitis by allowing the invasion of pathogens. It is possible that modulating the immune microenvironment can supplement traditional treatments and may even promote periodontal regeneration by using stem cells, bacteria, etc. New anti-inflammatory therapies can enhance the generation of a viable local immune microenvironment and promote cell homing and tissue formation, thereby achieving higher levels of immune regulation and tissue repair. We screened recent studies to summarize the advances of the immunomodulatory treatments for periodontitis in the aspects of drug therapy, microbial therapy, stem cell therapy, gene therapy and other therapies. In addition, we included the changes of immune cells and cytokines in the immune microenvironment of periodontitis in the section of drug therapy so as to make it clearer how the treatments took effects accordingly. In the future, more research needs to be done to improve immunotherapy methods and understand the risks and long-term efficacy of these methods in periodontitis.

A slim <italic>P</italic>–<italic>E</italic> loop with delayed early polarization saturation is more beneficial for enhancing energy storage performance.

The differences in physiological and immunological parameters and pathological damage to organ tissues exposed to chronic heat stress provide the basis for evaluating heat resistance of different chicken breeds (white recessive rock [WRR] and The Lingshan [LS]). Ninety broilers of each breed were divided equally into a chronic heat stress group and a no heat stress group. The effects of chronic heat stress on the physiological and immunological parameters of broilers were analyzed using flow cytometry, ELISA, RT-qPCR, etc. Under heat stress conditions: (1) H and H/L values were significantly increased (P < 0.01) in the 2 breeds, and were higher in the WRR broilers than in the LS broilers at a late stage (P < 0.05). Although the corticosterone levels were also significantly increased (P < 0.01) in both breeds, they were lower in the 49 d WRR broilers than in the LS broilers (P < 0.01). The number of leukocytes were significantly increased in the 49 d WRR broilers (P < 0.01), whereas the number of CD3+, CD8+ cells, and erythrocytes were significantly reduced (P < 0.05). A significantly (P < 0.01) lower number of CD3+, CD4+ T-lymphocytes, and CD4+/CD8+ were present in WRR compared to that in the LS broilers. (2) The HSP70 transcript was significantly increased in the WRR broilers (P < 0.01), and was higher than the level in the LS broilers. The expression level of HSP70 protein was significantly (P < 0.05) increased in WRR broilers. (3) The WRR broilers developed cardiac and leg muscle inflammatory cellular hyperplasia and local inflammatory lesions, as well as cerebral meningitis and inflammatory hyperplasia of the brain tissue. The LS broilers developed mild cerebral inflammatory hyperplasia and mild inflammatory cellular proliferation in the leg muscle. In conclusion, under heat stress conditions, the relative physiological and immunological parameters were worse in the WRR broilers than in the LS broilers. The WRR broilers showed poor heat tolerance as evidenced from the expression of HSP70 and the extent of histopathological damages.

Abstract Interface engineering is of great concern in photovoltaic devices. For the solution‐processed perovskite solar cells, the modification of the bottom surface of the perovskite layer is a challenge due to solvent incompatibility. Herein, a Cl‐containing tin‐based electron transport layer; SnO x ‐Cl, is designed to realize an in situ, spontaneous ion‐exchange reaction at the interface of SnO x ‐Cl/MAPbI 3 . The interfacial ion rearrangement not only effectively passivates the physical contact defects, but, at the same time, the diffusion of Cl ions in the perovskite film also causes longitudinal grain growth and further reduces the grain boundary density. As a result, an efficiency of 20.32% is achieved with an extremely high open‐circuit voltage of 1.19 V. This versatile design of the underlying carrier transport layer provides a new way to improve the performance of perovskite solar cells and other optoelectronic devices.

In solution-processed organic-inorganic halide perovskite films, halide-anion related defects including halide vacancies and interstitial defects can easily form at the surfaces and grain boundaries. The uncoordinated lead cations produce defect levels within the band gap, and the excess iodides disturb the interfacial carrier transport. Thus these defects lead to severe nonradiative recombination, hysteresis, and large energy loss in the device. Herein, polyacrylonitrile (PAN) was introduced to passivate the uncoordinated lead cations in the perovskite films. The coordinating ability of cyano group was found to be stronger than that of the normally used carbonyl groups, and the strong coordination could reduce the I/Pb ratio at the film surface. With the PAN perovskite film, the device efficiency improved from 21.58 % to 23.71 % and the open-circuit voltage from 1.12 V to 1.23 V, the ion migration activation energy increased, and operational stability improved.

While advances in microfluidics have enabled rapid and highly integrated detection of nucleic acid targets, the detection sensitivity is still unsatisfactory in the current POC (point-of-care) detection systems, especially for low abundance samples. In this study, a chip that integrates rapid nucleic acid extraction based on IFAST (immiscible phase filtration assisted by surface tension) and digital isothermal detection was developed to achieve highly sensitive POC detection within 60 min. Based on the interface theory, the factors influencing the interface stability of the IFAST process were studied, and the IFAST nucleic acid extraction conditions were optimized to increase the nucleic acid extraction recovery rate to 75%. Spiral mixing channel and flow-focusing droplet generation structure were designed to achieve the mixing and sample partitioning by applying negative pressure. A portable microdroplet fluorescence detection device was developed based on smartphone imaging. Validation tests were carried out for quantification of low-abundance cfDNA and detection of mutations.

Abstract In the recent decade, polymer thermoelectric (TE) composite has witnessed explosive achievements to address energy generation and utilization. Besides the significant progress in enhancement of TE performance, the high mechanical property has received increasing attention, being important for practical applications in complex environments. However, the mechanical performance has always been improved at the sacrifice of TE performance, and vice versa, which poses a great challenge. Here, ionic liquid (IL)‐assisted fabrication of flexible films of polymer TE composites with simultaneously high TE and mechanical performances based on poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), polyvinyl alcohol (PVA), and single‐walled carbon nanotubes (SWCNTs) are reported. The resultant composite shows a high TE performance with a power factor of 106.1 ± 8.2 µW m −1 K −2 at room temperature, and strong mechanical robustness with a tensile modulus of 4.2 ± 0.5 GPa and fracture strength of 136.5 ± 10.6 MPa. It is the most mechanically robust TE composite known with such a high power factor in the available literature. The present study provides a promising way to help address the longstanding and intractable issue of inferior mechanical performance of TE composites without compromising TE performance.

BackgroundCholangiocarcinoma (CCA), consisting of intrahepatic (IHCCA), perihilar (PHCCA), and distal (DCCA) CCA, is a type of highly aggressive malignancy with a very dismal prognosis. Potential biomarkers and drug targets of CCA are urgently needed. As a new member of the Annexin (ANXA) family, the role of ANXA10 in the progression and prognosis of CCA is unknown.MethodsPotential PHCCA biomarkers were screened by transcriptome sequencing of 5 pairs of PHCCA and adjacent tissues. The clinical significance of ANXA10 was evaluated by analyzing its correlation with clinicopathological variables, and the prognostic value of ANXA10 was evaluated with univariate and multivariate analyses. The function of ANXA10 in the epithelial-mesenchymal transition (EMT), proliferation, invasion and metastasis was detected with in vitro and in vivo experiments. Moreover, we screened the key molecule in ANXA10-induced CCA progression by mRNA sequencing and evaluated the correlation between PLA2G4A and ANXA10. The effect of PLA2G4A downstream signaling, including Cyclooxygenase 2, Prostaglandin E2(PGE2) and Signal transducer and activator of transcription 3(STAT3), on EMT and metastasis was further detected with in vitro and in vivo experiments.FindingsANXA10 expression was upregulated in PHCCA and DCCA but not in IHCCA. High ANXA10 expression was significantly associated with poor tumor differentiation and prognosis. ANXA10 promoted the proliferation, migration and invasion of the PHCCA cells. PLA2G4A expression was regulated by ANXA10 and high PLA2G4A predicted poor prognosis in PHCCA and DCCA. ANXA10 facilitated EMT and promoted metastasis by upregulating PLA2G4A expression, thus increasing PGE2 levels and activating STAT3.InterpretationANXA10 was an independent prognostic biomarker of PHCCA and DCCA but not IHCCA. ANXA10 promoted the progression of PHCCA and facilitated metastasis by promoting the EMT process via the PLA2G4A/PGE2/STAT3 pathway. ANXA10, PLA2G4A and their downstream molecules, such as COX2 and PGE2, may be promising drug targets of PHCCA and DCCA.

Abstract Skutterudite CoP 3 holds a unique structural formation that exhibits much better electronic properties for obtaining high energy density supercapacitors. Herein, novel skutterudite Ni–CoP 3 nanosheets are constructed by etching and coprecipitating at room temperature and subsequent low‐temperature phosphorization reaction. Benefiting from the enhanced electrical conductivity and more electroactive sites brought about by adjusting the electronic structure with Ni incorporating the Ni–CoP 3 electrode with a battery‐type demonstrates an ultrahigh specific capacity of 0.7 mA h cm −2 and exceptional cycling stability. The asymmetric supercapacitor (ASC) device fabricated by employing Ni–CoP 3 and activated carbon (AC) as positive and negative electrodes, resepectively, exhibits a remarkable high energy density of 89.6 Wh kg −1 at 796 W kg −1 and excellent stability of 93% after 10 000 cycles, due to the skutterudite structure. The skutterudite Ni–CoP 3 shows a great potential to be an excellent next‐generation electrode candidate for supercapacitors and other energy storage devices.

Laser-assisted grinding (LAG) is a promising method for cost-effective machining of hard and brittle materials. Knowledge of material removal mechanism and attainable surface integrity are crucial to the development of this new technique. This paper focusing on the application of LAG to Reaction Bonded (RB)-SiC ceramics investigate the material removal mechanism, grinding force ratio and specific grinding energy as well as workpiece surface temperature and surface integrity, together with those of the conventional grinding for comparison. Response surface method and genetic algorithm were used to optimize the machining parameters, achieving minimum surface roughness and subsurface damage, maximum material removal rate. The experiments results revealed that the structural changes and hardness decrease enhanced the probability of plastic removal in LAG, therefore obtained better surface integrity. The error of 3-D finite element simulation model that developed to predict the temperature gradient produced by the laser radiation is found to be within 2.7%–15.8%.

Spin-forbidden intravalley dark exciton in tungsten-based transition metal dichalcogenides (TMDCs), owing to its unique spin texture and long lifetime, has attracted intense research interest.Here, we show that we can control the dark exciton electrostatically by dressing it with one free electron or free hole, forming the dark trions.The existence of the dark trions is suggested by the unique magneto-photoluminescence spectroscopy pattern of the boron nitride (BN) encapsulated monolayer WSe2 device at low temperature.The unambiguous evidence of the dark trions is further obtained by directly resolving the radiation pattern of the dark trions through back focal plane imaging.The dark trions possess binding energy of ~ 15 meV, and they inherit the long lifetime and large g-factor from the dark exciton.Interestingly, under the out-of-plane magnetic field, dressing the dark exciton with one free electron or hole results in distinctively different valley polarization of the emitted photon, a result of the different intervalley scattering mechanism for the electron and hole.Finally, the lifetime of the positive dark trion can be further tuned from ~ 50 ps to ~ 215 ps by controlling the gate voltage.The gate tunable dark trions ushers in new opportunities for excitonic optoelectronics and valleytronics.

Temporally harmonized elimination of damaged or unnecessary organelles and cells is a prerequisite of health. Under Type 2 inflammatory conditions, human airway epithelial cells (HAECs) generate proferroptotic hydroperoxy-arachidonoyl-phosphatidylethanolamines (HpETE-PEs) as proximate death signals. Production of 15-HpETE-PE depends on activation of 15-lipoxygenase-1 (15LO1) in complex with PE-binding protein-1 (PEBP1). We hypothesized that cellular membrane damage induced by these proferroptotic phospholipids triggers compensatory prosurvival pathways, and in particular autophagic pathways, to prevent cell elimination through programmed death. We discovered that PEBP1 is pivotal to driving dynamic interactions with both proferroptotic 15LO1 and the autophagic protein microtubule-associated light chain-3 (LC3). Further, the 15LO1-PEBP1-generated ferroptotic phospholipid, 15-HpETE-PE, promoted LC3-I lipidation to stimulate autophagy. This concurrent activation of autophagy protects cells from ferroptotic death and release of mitochondrial DNA. Similar findings are observed in Type 2 Hi asthma, where high levels of both 15LO1-PEBP1 and LC3-II are seen in HAECs, in association with low bronchoalveolar lavage fluid mitochondrial DNA and more severe disease. The concomitant activation of ferroptosis and autophagy by 15LO1-PEBP1 complexes and their hydroperoxy-phospholipids reveals a pathobiologic pathway relevant to asthma and amenable to therapeutic targeting.