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All-inorganic metal halides perovskites (CsPbX3, X = Br or Cl) show strong excitonic and spin-orbital coupling effects, underpinning spin-selective excitonic transitions and therefore exhibiting great promise for spintronics and quantum-optics applications. Here we report spin-dependent optical nonlinearities in CsPbX3 single crystals by using ultrafast pump-probe spectroscopy. Many-body interactions between spin-polarized excitons act like a pseudo-magnetic field and thus lift the degeneracy of spin states resulting in a photoinduced circular dichroism. Such spontaneous spin splitting between “spin-up” and “spin-down” excitons can be several tens of milli-electron volts under intense excitations. The exciton spin relaxation time is ~20 picoseconds at very low pump fluence, the longest reported in the metal halides perovskites family at room temperature. The dominant spin-flip mechanism is attributed to the electron-hole exchange interactions. Our results provide essential understandings towards realizing practical spintronics applications of perovskite semiconductors., Strong excitonic effects and spin-orbit coupling in all-inorganic halide perovskite is promising for spintronic application, yet the spin-dependent phenomenon is not well understood. Here, the authors reveal that many-body interactions between spin-polarized excitons act like pseudo-magnetic field, lifting the degeneracy and resulting in circular dichroism.

The COVID-19 pandemic has killed more than 1 000 000 people within nine months in 2020. The world is changed as the cities were locked down, the traffic reduced, and people forced to work from home and keep social distance. These controlling measures also resulted in drastic reduction of the emission of many air pollutants, providing researchers an unprecedented large-scale natural experiment in examining how the air quality would respond to a strong forcing. In this panel discussion held on 22 September 2020, five experts gathered to discuss their observations and analyses, as well as the current understanding and misconception about airborne transmission. This Forum article is dedicated to Prof. Martin Williams of the Imperial College London, who intended to join the panel discussion but passed away one day before it. Guy Brasseur Professor of Max Planck Institute for Meteorology, Germany Junji Cao Professor of Institute of Earth Environment, Chinese Academy of Sciences, China Aijun Ding Dean and Professor of School of Atmospheric Sciences, Nanjing University, China Lidia Morawska Professor of Queensland University of Technology, Australia Tong Zhu (Chair) Dean and Professor of College of Environmental Sciences and Engineering, Peking University, China

Synthetic biology aims to redesign and reconstruct living systems for understanding life or for useful real-world applications. In the past two decades, scientists have been able to use engineered living systems to produce many kinds of products from bioplastics to drugs, to construct a minimal bacterium with a fully synthetic genome and to store huge amount of information within a cell. And in 2020, when the COVID-19 pandemic swept across the world, the synthetic biology community became one of the major forces to develop effective diagnostic approaches as well as the drugs and vaccines, to rapidly cope with this great challenge with the state-of-the-art technologies in their hands. In this panel discussion held on 3rd August 2020, eleven pioneering synthetic biologists from six countries across four continents gathered to discuss the development trend, challenges and biosafety issues concerning synthetic biology. George Church Professor of Genetics at Harvard Medical School and Professor of Health Sciences and Technology at Harvard and MIT, USA Paul Freemont Professor of Structural Biology in the Department of Infectious Disease at Imperial College and a member of the Science Advisory Board of Tierra Biosciences, UK Akihiko Kondo Professor in School of Science, Technology and Innovation, and Department of Chemical Science and Engineering at Kobe University, Japan Christina Smolke Professor of Bioengineering and of Chemical Engineering at Stanford University and CEO of Antheia Inc., USA Xian-En Zhang Professor at the Institute of Biophysics, Chinese Academy of Sciences, China Chenli Liu (Chair) Professor and Director of Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, China Jim Collins Termeer Professor of Medical Engineering & Science and Professor of Biological Engineering at MIT, USA Jay Keasling Professor of Chemical Engineering and Bioengineering at the University of California, Berkeley, USA Sang Yup Lee Dean of KAIST Institutes and Distinguished Professor in the Department of Chemical and Biomolecular Engineering at Korea Advanced Institute of Science and Technology (KAIST), South Korea Claudia Vickers Director of the Future Science Platform in Synthetic Biology at Commonwealth Science and Industry Research Organization (CSIRO), Australia Guoping Zhao Professor at the Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, China

In order to generate images for a given category, existing deep generative models generally rely on abundant training images. However, extensive data acquisition is expensive and fast learning ability from limited data is necessarily required in real-world applications. Also, these existing methods are not well-suited for fast adaptation to a new category. Few-shot image generation, aiming to generate images from only a few images for a new category, has attracted some research interest. In this paper, we propose a Fusing-and-Filling Generative Adversarial Network (F2GAN) to generate realistic and diverse images for a new category with only a few images. In our F2GAN, a fusion generator is designed to fuse the high-level features of conditional images with random interpolation coefficients, and then fills in attended low-level details with non-local attention module to produce a new image. Moreover, our discriminator can ensure the diversity of generated images by a mode seeking loss and an interpolation regression loss. Extensive experiments on five datasets demonstrate the effectiveness of our proposed method for few-shot image generation., This paper is accepted by ACM Multimedia 2020

van der Waals two-dimensional layered heterostructures have recently emerged as a platform, where the interlayer couplings give rise to interesting physics and multifunctionalities in optoelectronics. Such couplings can be rationally controlled by dielectric, separation, and stacking angles, which affect the overall charge or energy-transfer processes, and emergent potential landscape for twistronics. Herein, we report the efficient Förster resonance energy transfer (FRET) in WS

Hepatoprotectant is critical for the treatment of liver disease. This study first reported the application of a liver chip in the hepatoprotective effect assessment. We first established a biomimetic sinusoid-on-a-chip by laminating four types of hepatic cell lines (HepG2, HUVEC, LX-2, and U937 cells) in a single microchannel with the help of laminar flow in the microchannel and some micro-fences. This chip was straightforward to fabricate and operate and was able to be long-term cultured. It also demonstrated better hepatic activity (cell viability, albumin synthesis, urea secretion, and cytochrome P450 enzyme activities) over the traditional planar cell culture model. Then, we loaded three hepatoprotectants (tiopronin, bifendatatum, and glycyrrhizinate) into the chip followed by the addition of acetaminophen as a toxin. We successfully observed the hepatoprotective effect of these hepatoprotectants in the chip, and we also found that bifendatatum predominantly reduced alanine transaminase secretion, tiopronin predominantly reduced lactate dehydrogenase secretion, and glycyrrhizinate predominantly reduced aspartate transaminase secretion, which revealed the different mechanisms of these hepatoprotectants and provided a clue for following molecular biological study of the protecting mechanism.

The year of 2020 has been overshadowed by the COVID-19 pandemic. Medical workers throughout China have played critical roles in battling severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) and saving lives. The whole of society has now fully realized the significance of medical workers and many began to think about medical education in China: How can we further improve medical education for the next generation of clinicians, medical scientists, nurses, public-health workers and administrators related to medical care, so that they are well prepared to meet societal needs for medical care in the ever-changing world? In this panel discussion, medical-education experts from several prominent medical schools in China gathered to discuss the reform and future development of China's medical education. Xiang Chen President of Xiangya School of Medicine, Vice President of Central South University, Changsha, China Baorong Chi Professor of Norman Bethune Health Science Center of Jilin University, Changchun, China Yiqun Hu Vice Chancellor of Shanghai Jiao Tong University School of Medicine, Shanghai, China Yang Ke Professor of Peking University Health Science Center, former Vice President of Peking University, Beijing, China Ming Kuang Vice President of Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China Mengfeng Li President of Southern Medical University, Guangzhou, China Hongbing Shen President of Nanjing Medical University, Nanjing, China Xuehong Wan Professor of West China Medical Center, Vice President of Graduate School of Sichuan University, Chengdu, China Hong Yan President of Xi’an Jiaotong University Health Science Center, Vice President of Xi’an Jiaotong University, Xi’an, China Guoqiang Chen (Chair) Chancellor of Shanghai Jiao Tong University School of Medicine, Vice President of Shanghai Jiao Tong University, Shanghai, China

The natural resistance of rapid growth Mycobacterium (RGM) against multiple antibiotics renders the treatment of caused infections less successful and time consuming. Therefore, new effective agents are urgently needed. The aim of this study was to evaluate the in vitro susceptibility of 115 isolates, constituting different RGM species, against four oxazolidinones i.e. delpazolid, sutezolid, tedizolid and linezolid. Additionally, 32 reference strains of different RGM species were also tested. The four oxazolidinones exhibited potent in vitro activity against the recruited RGM reference strains, 24 out of 32 RGM species had MICs ≤ 8 μg/mL against all four oxazolidinones whereas tedizolid and delpazolid generally presented lower MICs than linezolid or sutezolid. Tedizolid showed the strongest activity against clinical isolates of M. abscessus with MIC50=1μg/mL and MIC90=2μg/mL. MIC values for tedizolid were usually 4- to 8-fold less than the MICs of linezolid for M. abscessus subsp. abscessus. The MIC distributions of sutezolid and linezolid were similar, while delpazolid showed 2-fold lower MIC as compared with linezolid. Linezolid was not active against most of the tested M. fortuitum isolates, 22 out of the 25 M. fortuitum were resistant against linezolid. However, delpazolid exhibited better antimicrobial activity against these isolates with 4-fold lower MIC values, in contrast with linezolid. In addition, the protein alignment of RplC and RplD and structure based analysis showed that there may be no correlation between oxazolidinones resistance and mutations in rplC, rplD and 23 srRNAgenes in tested RGM. This study showed tedizolid harbors the strongest inhibitory activity against M. abscessus in vitro, while delpazolid presented the best activity against M. fortuitum, which provided important insights on the potential clinical application of oxazolidinones to treat RGM infections.

Parasitic characteristics, mutations and resistance of influenza A virus make it difficult for current influenza antiviral drugs to maintain long-term effectiveness. Currently, to design non-adamantane compounds targeting the S31N mutant of M2 proton channel is a promising direction for the development of novel anti-influenza drugs. In our previous research, a pinanamine-based antiviral M090 was discovered to target hemagglutinin instead of M2, with its structure being highly similar to reported M2-S31N inhibitors. Herein, a series of pinane oxime derivatives were designed from scratch and evaluated for anti-influenza activity and their cytotoxicity in vitro. Utilizing a combination of structure-activity relationship analysis, electrophysiological assay and molecular docking, the most potent compound 11h, as a M2-S31N blocker, exhibited excellent activity with EC50 value at the low micromolar level against both H3N2 and H1N1. No significant toxicity of 11h was observed. In addition, compound 11h was located tightly in the pore of the drug-binding site with the thiophene moiety facing down toward the C-terminus, and did not adopt a similar position and orientation as the reference inhibitor.

This study aimed to investigate the effects of conjugated linoleic acid (CLA) on intestinal epithelial barrier function and explore the underlying mechanisms. IPEC-J2 cells and mice were treated with different CLA isomers. The intestinal epithelial barrier function determined by transepithelial electrical resistance (TEER), the expression of tight junction proteins, and the involvement of G-protein coupled receptor 120 (GPR120), intracellular calcium ([Ca2+]i) and myosin light chain kinase (MLCK) were assessed. In vitro, c9, t11-CLA, but not t10, c12-CLA isomer, impaired epithelial barrier function in IPEC-J2 by downregulating the expression of tight junction proteins. Meanwhile, c9, t11-CLA isomer enhanced GPR120 expression, while knockdown of GPR120 eliminated the impaired epithelial barrier function induced by c9, t11-CLA isomer. In addition, c9, t11-CLA isomer increased [Ca2+]i and activated the MLCK signaling pathway in a GPR120-dependent manner. However, chelation of [Ca2+]i reversed c9, t11-CLA isomer-induced MLCK activation and the epithelial barrier function impairment of IPEC-J2. Furthermore, inhibition of MLCK totally abolished the impairment of epithelial barrier function induced by c9, t11-CLA. In vivo, dietary supplementation of c9, t11-CLA rather than t10, c12-CLA isomer decreased the expression of intestinal tight junction proteins and GPR120, increased intestinal permeability, and activated the MLCK signaling pathway in mice. Taken together, our findings showed that c9, t11-CLA, but not t10, c12-CLA isomer, impaired intestinal epithelial barrier function in IPEC-J2 cells and mice through activation of GPR120-[Ca2+]i and the MLCK signaling pathway. These data provided new insight into the regulation of the intestinal epithelial barrier by different CLA isomers and more references for CLA application in humans and animals.

Approximate nearest neighbor (ANN) searching is a fundamental problem in computer science with numerous applications in (e.g.,) machine learning and data mining. Recent studies show that graph-based ANN methods often outperform other types of ANN algorithms. For typical graph-based methods, the searching algorithm is executed iteratively and the execution dependency prohibits GPU adaptations. In this paper, we present a novel framework that decouples the searching on graph algorithm into 3 stages, in order to parallel the performance-crucial distance computation. Furthermore, to obtain better parallelism on GPU, we propose novel ANN-specific optimization methods that eliminate dynamic GPU memory allocations and trade computations for less GPU memory consumption. The proposed system is empirically compared against HNSW–the state-of-the-art ANN method on CPU–and Faiss–the popular GPU-accelerated ANN platform–on 6 datasets. The results confirm the effectiveness: SONG has around 50-180x speedup compared with single-thread HNSW, while it substantially outperforms Faiss.

Recently, embryo muscle development, which is crucial for postnatal skeletal muscle growth, has been investigated widely. Nutrients in ovo were suggested to be critical in embryo muscle development since the chick growth mostly relies on nutrients in eggs at the early developmental stage. Phytosterol esters (PE), which are derived from the reactions between phytosterols and fatty acids, were demonstrated to have important effects on lipid and cholesterol metabolism regulation. In order to reveal the effect of maternal lipid metabolism on the deposition of nutrients in eggs and the development of embryonic muscles, broiler hens were fed with a diet supplemented with 5% PE or control diet. Lipid deposition in eggs and growth of the hatched chicks were studied. We found that PE increased bile acid (BA) deposition in the eggs and serum of hens (p=0.02 and p

Photodynamic therapy (PDT) is a non-invasive and innovative therapeutic approach which has been increasingly applied in clinical cancer therapy. As the central element of PDT, the development of novel photosensitizers (PSs) with longer absorption wavelength, proper lipophilic/hydrophilic profiles, target tissue selectivity, and higher photo-/lowest dark-cytotoxicity is a challenging task. Previously, we designed and synthesized a series of novel long-wavelength chlorin e6 (Ce6)-based PSs via introducing aromatic groups to the vinyl of Ce6 skeleton. The new formed compounds with π-extension system exhibited improved photodynamic effects and spectral characteristics. Among these π-conjugated chlorin PSs, (E)-32-(4-methoxyphenyl)-chlorin e6, named A15, was expected to be a potent antitumor candidate as a PDT agent due to its good photobiological properties. Herein, in this work, we evaluated the effectiveness of A15 in cancer PDT. In vitro, a novel rare earth probe, ATTA-Eu3+ was applied to detect the singlet oxygen (1O2) production of A15 in solution and human hepatoma HepG2 cells, respectively. Moreover, A15 exhibited strong phototoxicity and weak dark cytotoxity to HepG2 cells. In H22 tumor bearing mice, A15 showed excellent tumor accumulation ability via i.v. administration and induced tumor regression, followed by laser treatment. These results indicated that A15 is a potential novel π-extension chlorin-type PS for PDT applications.

Oleanolic acid (OA) and its semi-synthetic derivatives have been reported to have a wide range of biological activities. The introduction of electrophilic Michael acceptor group can increase the reactivity of OA to cellular targets and thus improve the anti-tumor activity. In this work, a series of novel α,β-unsaturated carbonyl derivatives of OA were designed and synthesized. Their in vitro cytotoxic activity against MCF-7, HepG2 and HeLa cells were tested. Most derivatives exhibited improved cell growth inhibitory activity, especially for 3d with an IC50 of 0.77 μM in MCF-7 cells. Moreover, 3d inhibited the migration of MCF-7 and HeLa cells at the concentration of 4 μM. Flow cytometric analysis revealed that 3d induced cell apoptosis and S phase arrest in a concentration-dependent manner. Western blotting experiment demonstrated that 3d inhibited the phosphorylation of AKT and mTOR. These results suggest that this series of OA derivatives bearing exocyclic methylene ketone pharmacophore are promising anticancer agents as potential PI3K/AKT/mTOR pathway inhibitors.

Some long non-coding RNAs (lncRNAs) have been suggested to play critical roles in Parkinson's disease (PD) pathogenesis, including nuclear enriched abundant transcript 1 (NEAT1). The purpose of this study was to further elucidate the molecular mechanism of NEAT1 in PD.The expression levels of NEAT1, miR-212-5p and RAB3A-interacting protein (RAB3IP) were determined by quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability and apoptosis were evaluated by Cell Counting Kit-8 (CCK-8) assay and flow cytometry analysis, respectively. Western blot analysis was applied to detect the protein expression of IL-1β, TNF-α and RAB3IP. The LDH activity, ROS generation and SOD activity were measured by Lactate LDH activity assay kit, ROS assay kit, and SOD activity assay kit, respectively. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were performed to verify the relationship between miR-212-5p and NEAT1 or mRNA of RAB3IP. 1-methyl-4-phenylpyridinium ion (MPPNEAT1 and RAB3IP were upregulated while miR-212-5p was downregulated in SK-N-SH cells treated with MPPNEAT1 knockdown suppressed MPP

van der Waals two-dimensional layered heterostructures have recently emerged as a platform, where the interlayer couplings give rise to interesting physics and multifunctionalities in optoelectronics. Such couplings can be rationally controlled by dielectric, separation, and stacking angles, which affect the overall charge or energy-transfer processes, and emergent potential landscape for twistronics. Herein, we report the efficient Förster resonance energy transfer (FRET) in WS2/hBN/MoSe2 heterostructure, probed by both steady-state and time-resolved optical spectroscopy. We clarified the evolution behavior of the electron-hole pairs and free electrons from the trions, that is, ∼59.9% of the electron-hole pairs could transfer into MoSe2 by FRET channels (∼38 ps) while the free electrons accumulate at the WS2/hBN interface to photogate MoSe2. This study presents a clear picture of the FRET process in two-dimensional transition-metal dichalcogenides' heterojunctions, which establishes the scientific foundation for developing the related heterojunction optoelectronic devices. Ministry of Education (MOE) National Research Foundation (NRF) Accepted version Q.X. gratefully acknowledges the Singapore Ministry of Education Tier3 Programme “Geometrical Quantum Materials” (MOE2018-T3-1-002), AcRF Tier2 grant (MOE2017-T2-1-040), and Tier1 grant (RG 194/17). Q.X. also acknowledges strong support from Singapore National Research Foundation Competitive Research Programme “Integrated On-chip Planar Coherent Light Sources” (NRF-CRP-21-2018-0007), and National Research Foundation-Agence Nationale de la Recherche (NRF-ANR) Grant (NRF2017-NRF-ANR005 2DCHIRAL). K.W. and T.T. acknowledge support from the Elemental Strategy Initiative conducted by the MEXT, Japan, Grant Number JPMXP0112101001, JSPS KAKENHI Grant Numbers JP20H00354 and the CREST(JPMJCR15F3), JST. Author Contributions: Q.X. supervised the research. Z. H. conceived the idea. Z.H. and X.L. prepared the heterostructures. P.H.M. and H.V.D. performed the numerical simulation. Z.H., X.L., and M.R.A. performed the micro-spectroscopy experiments. K.W. and T.T. provided the h-BN bulk crystals. Z.H., X.L., and Q.X. analyzed the data. Z.H. wrote the manuscript with input from all authors.

Additional file 1: Figure S1. TCM and Tnaive were analyzed for CD27 versus CD28 staining. a The percentage of four subsets divided by CD27 and CD28. Figure S2. CD8 + dT were treated with PMA/Ionomycin stimulation. a Percentage of intracellular granzyme B expression. b The gating of IFN-γin CD8 + Tcellson multiple patients. Figure S3. A Percentage of intracellular IL-4 expressionin CD103 + versus CD103-CD8 + T cells.

Corrosion effects on copper exposed in a humid atmosphere with formic acid (mimicking indoor corrosion) have been explored through successive increase in surface lateral resolution from macroscale (IRRAS, GIXRD) over microscale (LOM, SEM, IR microscopy) to nanoscale (Nano-FTIR, FIB/SEM/EDS). Initial more uniform growth of Cu2O is followed by more varying topography and thickness until local removal of Cu2O enables the aqueous adlayer to react with the copper substrate. Local formation of Cu(OH)(HCOO) and adjacent Cu2O provide microscopic and spectroscopic evidence of corrosion cells. Nano-FTIR shows that the density of Cu(OH)(HCOO) nuclei, but not their size, increases with exposure time.

Ensuring the safety of large curved-roof structures subjected to blizzards in cold regions remains challenging. This paper assesses the reliability of a large curved-roof structure considering the coupled effects of wind and snow. To this end, a two-way coupled simulation considering the interaction between snow particles and turbulent wind is first carried out using a computational fluid dynamics scheme and a spectral representation method based on the wavenumber-frequency joint power spectrum and stochastic harmonic function; thereby, the uneven snow distribution and stochastic wind field on a large curved roof are revealed. The probability density evolution method is then adopted to conduct a stochastic response and reliability analysis of the structure. The simulation results reveal that a credible uneven distribution of snow on the large curved roof can be obtained using the suggested snowdrift simulation scheme, and the refined spectral representation method can efficiently and accurately simulate the two-dimensional fluctuating wind field of the large curved-roof structure. It is shown that under stochastic wind, snow and self-weight loads for a 100-year return period, the large curved-roof structure has a higher risk of member yielding than of node deflection. Meanwhile, the axial stress acting on the structural member is far less than the maximum allowable stress and the structure is thus deemed to be sufficiently safe.

It has been more than 10 years since Satoshi Nakamoto published his famous paper entitled ‘Bitcoin: a peer-to-peer electronic cash system’, which set the foundation of blockchain technology. Accompanied by the price volatility of bitcoins from 2017 to 2018, blockchain has been a hot word on the internet, and particularly hot in China. Blockchain offers a distributed and secure system for data storage and value transactions. Its applications are springing up in multiple fields. The Chinese government is considering these trends with great caution. Initial coin offering has been banned in China since September 2017. By contrast, an official white paper on China's blockchain technology, which was released in May 2018, said that blockchain technology will be widely applied in the real economy of China within 3 years. In a recent panel discussion held by National Science Review, experts talked about related topics. Their opinions may provide a quick view of the future development of blockchain in China and abroad. Jing Chen Assistant Professor of Computer Science Department, Stony Brook University and Chief Scientist at Algorand LLC, USA Xiaotie Deng Professor of School of Electronics Engineering and Computer Science, Peking University, China Guohua Gan Vice President of Beijing Tai Cloud Technology Corp., China Xiaoyun Wang Professor of Institute of Advanced Study, Tsinghua University, China Zhiming Zheng Professor of School of Mathematics and Systems Science, Beihang University, China Lei Guo (Chair) Professor of Academy of Mathematics and Systems Science, Chinese Academy of Sciences, China

The 1D Ag3PO4 sensitized SrTiO3 nanowires are prepared by simple route of electrospinning-in situ deposition technique. The results of the thermogravimetry (TG), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive Spectrometer (EDS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV–Visible diffuse reflectance spectroscopy (UV–Vis) indicate that the Ag3PO4 nanoparticles has been deposited on the surface of the SrTiO3 nanowires successfully. Experimental results showed that compared with pure SrTiO3, the as-prepared 1D Ag3PO4 sensitized SrTiO3 nanowires exhibit obvious enhancement of photocatalytic performance and stability. Especially, the Ag3PO4/SrTiO3 (3AS sample) had a satisfactory photocatalytic activity for degrading methylene blue (MB) more than 98% under visible light irradiation. As to pure SrTiO3 and Ag3PO4, only 9.8% and 49% of MB was decomposed after 35 min irradiation respectively. Furthermore, the mechanism of the enhancing photocatalytic activity could be ascribed to the nano-heterojunction of the Ag3PO4/SrTiO3, the visible light response of the Ag3PO4, and the 1D structure of the nanowires.

Metal halide perovskite materials are an emerging class of solution-processable semiconductors with considerable potential for use in optoelectronic devices1–3. For example, light-emitting diodes (LEDs) based on these materials could see application in flat-panel displays and solid-state lighting, owing to their potential to be made at low cost via facile solution processing, and could provide tunable colours and narrow emission line widths at high photoluminescence quantum yields4–8. However, the highest reported external quantum efficiencies of green- and red-light-emitting perovskite LEDs are around 14 per cent7,9 and 12 per cent8, respectively—still well behind the performance of organic LEDs10–12 and inorganic quantum dot LEDs13. Here we describe visible-light-emitting perovskite LEDs that surpass the quantum efficiency milestone of 20 per cent. This achievement stems from a new strategy for managing the compositional distribution in the device—an approach that simultaneously provides high luminescence and balanced charge injection. Specifically, we mixed a presynthesized CsPbBr3 perovskite with a MABr additive (where MA is CH3NH3), the differing solubilities of which yield sequential crystallization into a CsPbBr3/MABr quasi-core/shell structure. The MABr shell passivates the nonradiative defects that would otherwise be present in CsPbBr3 crystals, boosting the photoluminescence quantum efficiency, while the MABr capping layer enables balanced charge injection. The resulting 20.3 per cent external quantum efficiency represents a substantial step towards the practical application of perovskite LEDs in lighting and display. A strategy for managing the compositional distribution in metal halide perovskite light-emitting diodes enables them to surpass 20% external quantum efficiency—a step towards their practical application in lighting and displays.

A novel magnetic silica gel adsorbent (Fe3O4-Si-COOH) was successfully prepared by introducing carboxyl group in situ to improve the performance for Pb(II), Zn(II), and Cd(II) adsorption. Infrared spectroscopy (IR), scanning electron microscope (SEM), transmission electron microscope (TEM), thermo-gravimetric analyzer (TGA), the Brunauer-Emmett-Teller (BET) surface area, X-ray diffraction (XRD), and vibrating sample magnetometer (VSM) characterizations suggested that Fe3O4-Si-COOH has been successfully prepared. The adsorption performance was evaluated by batch experiments with different initial concentrations, ionic strength, contact time, and pH. The adsorption kinetics data followed pseudo-second-order model and exhibited a three-stage intraparticle diffusion mode. Isothermal adsorption equilibrium data were best fitted by the Freundlich model and the adsorption capacity were 155, 110, and 93 mg/g (initial concentration 210 mg/L) for Pb(II), Zn(II), and Cd(II), respectively. The result of X-ray photoelectron spectroscopy (XPS) survey spectrum suggested that the main adsorption mechanism is that the H+ of carboxyl groups exchanged with heavy metal ions in the adsorption processes. In addition, the adsorbed Fe3O4-Si-COOH could be regenerated and the adsorption capacity of reused Fe3O4-Si-COOH could maintain 80.3% after five cycles. Hence, the Fe3O4-Si-COOH could be a kind of potential material for removing Pb(II), Zn(II), and Cd(II) from wastewater.

The 3D Z-scheme Ag3PO4/Ag/MoS2/TiO2 nano-heterojunction is synthesized via electrospinning-hydrothermal-chemical co-deposition method. Compared with the unmodified samples, the photocatalysis of the Ag3PO4/Ag/MoS2/TiO2 nano-heterojunction exhibits a remarkable enhancement by the degradation of methylene blue(MB) in sunlight. Further, the Z-scheme heterojunction is considered as the main reason for the enhancement.

The past two decades have seen increasing interests in open data. Many scientists believe that the original research data should be properly organized and opened to the public and researchers throughout the world, and, once the open-data strategies are put into practice, the entire scientific research enterprise could be transformed. Driven by the trend of data sharing many platforms and repositories have been established. Universities, funding agencies and academic journals are also taking an active role in facilitating data sharing. In this forum discussion organized by National Science Review and chaired by Jianhui Li, panelists from diverse backgrounds who have all participated in the development of open data gathered together and talked about the recent progress and future directions of open data. Chenzhou Cui Chief Information Officer of the National Astronomical Observatories, Chinese Academy of Sciences, Beijing, China Xiangdong Fang Professor at Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China Mark Musen Director of the Stanford Center for Biomedical Informatics Research, Stanford University, California, USA Lydia Pintscher Product manager of Wikidata, Wikimedia Deutschland, Berlin, Germany Beth Plale Director of Data to Insight Center, Professor of Informatics and Computing, Indiana University, Bloomington, USA Paul Uhlir Consultant, Information Policy and Management, New York, USA; Formerly Director of the Board on Research Data and Information, National Academy of Sciences, Washington, USA Jianhui Li (Chair) Professor at Computer Network Information Centre, Chinese Academy of Sciences, Beijing, China

In the foreseeable future, human beings will continue to live on this blue planet named Earth. Our planet has limited space, resources and environmental carrying capacity, yet the human population and quality of life will continue to rise. Economic development and environmental protection are often conflicting goals, and it is a great challenge for us to achieve both at the same time: to develop sustainably. Green chemistry—the aim of making the whole industrial chain of chemistry and chemical industry environmentally friendly—has contributed, and will further contribute, to the sustainable development of the chemical industry. Recently, NSR talked with Buxing Han—an academician of the Chinese Academy of Sciences and one of the leading scientists in this field. Han introduced the major scientific issues of green chemistry and talked about the challenges and future developments of this field.

The porous TiO2 nanotubes/Ag3PO4 heterojunction are synthesized via simple electrospining and chemical co-deposition method. The results of SEM, XRD, TEM and XPS imply that the Ag3PO4 nanoparticles have been introduced on to the surface of TiO2 nanotubes successfully. Compared with the unmodified samples, the photocatalytic activity of the as-prepared porous TiO2 nanotubes/Ag3PO4 heterojunction exhibit a remarkable enhancement by the degradation of methylene blue (MB) under the sunlight. Further, the Z-Scheme structure of the samples and the porous-tubular structure of the TiO2 are considered as the main reasons for the enhancement.

The dual function carbon quantum dots (C QDs) modified porous g-C3N4/TiO2 two dimension (2D) nano-heterojunctions are prepared by a simple route, through which the porous g-C3N4 nanosheets are prepared by thermal polycondensation, the TiO2 nanoparticles are introduced by hydrothermal method and the C QDs are introduced on the surface of the porous g-C3N4 and TiO2 by coupling successively. The results indicate that TiO2 and C QDs are well combined with the porous g-C3N4. The hydrogen production properties of those 2D nano-heterojunctions are investigated, which exhibit an obvious hydrogen production enhancement (nearly two orders of magnitude) compared with those of the unmodified samples. Through analysis, this enhancement of the photocatalystic hydrogen production is attributed to the dual function C QDs with high catalytic activity of H2O2 decomposition and unique up-conversion photoluminescence.

Smart phones, video, computer games, social platforms and mobile payments have dramatically changed our daily lives in the past 10 years. Behind the rise of the internet industry, fourth-generation (4G) network technology played an instrumental role. According to the plans of major communications companies and the global standardization organization 3GPP (3rd Generation Partnership Project), the next generation of wireless network technology (5G) will start to be commercially used before 2020. What will be the technological improvements in performance of 5G comparing with 4G? Would 5G be similarly transformative? In a recent interview with NSR, Huawei's Chief 5G scientist, Wen Tong, talked about these topics, as well as about the transformation of China's communications industry from a technology follower in the eras of 3G and 4G to one of the leading forces behind 5G.

When we talk about materials, we may have several images in our minds. We have functional materials with fine nanostructures and unique physical/chemical properties; we have structural materials such as metals and cement. However, we may sometimes ignore the construction pattern of materials. In fact, glass, iron, coal, cement, and many other materials that are common in our everyday life are particulate/granular materials. Recently, NSR talked to Aibing Yu, a professor of Monash University, Australia, and a scientist who has been working on particle systems for 30 years, about how to deepen our understanding of these particulate materials by computer simulation and modelling.

Doping of traditional semiconductors has enabled technological applications in modern electronics by tailoring their chemical, optical and electronic properties. However, substitutional doping in two-dimensional semiconductors is at a comparatively early stage, and the resultant effects are less explored. In this work, we report unusual effects of degenerate doping with Nb on structural, electronic and optical characteristics of MoS2 crystals. The doping readily induces a structural transformation from naturally occurring 2H stacking to 3R stacking. Electronically, a strong interaction of the Nb impurity states with the host valence bands drastically and nonlinearly modifies the electronic band structure with the valence band maximum of multilayer MoS2 at the Γ point pushed upward by hybridization with the Nb states. When thinned down to monolayers, in stark contrast, such significant nonlinear effect vanishes, instead resulting in strong and broadband photoluminescence via the formation of exciton complexes tightly bound to neutral acceptors.

The OER process would be a mainly factor for restricting overall water splitting, so the matching of HER/OER would be an important issue. Herein, the MnOx/CdS/Ti3+-SrTiO3 core–shell heterojunction is fabricated via a continuous hydrothermal-annealing-chemical-photodeposition method. Evaluated by the photocatalytic performance, the MnOx/CdS/Ti3+-SrTiO3 exhibits an enhanced HER performance of about ~ 10 folds than that of pure SrTiO3 nanosphere, and achieves a decent overall water splitting performance of about ~ 176.07(H2)/86.03(O2) μmol/g∙h, which can be mainly ascribed to the well matched HER/OER process and formation of heterojunction. There, the new potential induced by Ti3+/Ov can increase the solar efficiency and accelerate the photo-generated electrons diffusion, the Ti3+ ions can reduced water splitting activation barrier to enhance the H+ reduction, the MnOx with mixed chemical valance Mn3+/Mn4+ ions can activate the hole­related species and promote the H2O2 decomposition, and the core–shell CdS/Ti3+-SrTiO3 heterojunction with appropriate potential gradient can improve the charge carrier separation and transport. Additionally, the core–shell structure can inhibit the photocorrosion to maintain good photocatalytic stability.

Selaginellins are a type of rare natural products from the genus Selaginella with unusual alkynyl phenol skeletons and extensive biological activities. Previous structural simplification of these natural compounds afforded a series of diaryl acetylene derivatives with hypoxia-inducible factor 1 (HIF-1) inhibitory activity. In this study, we synthesized thirty compounds by stepwise optimization using methyl 3-(4-methoxylphenyl ethynyl)-[4′-methoxyl-1,1′-biphenyl]-2-carboxylate (1a) as a lead compound and evaluated their HIF-1 inhibitory activity by dual luciferase reporter assay. Among them, compound 9i displayed the most potent HIF-1 inhibitory activity (IC50 = 1.5 ± 0.03 μM) with relatively low cytotoxicity. Under hypoxia, compound 9i showed no effect on the accumulation of HIF-1α protein in western blot analysis, but could down-regulate the expression of VEGF mRNA, the downstream target gene of HIF-1 pathway. Cell-based activity assay demonstrated that compound 9i could inhibit the hypoxia-induced migration, invasion and proliferation of HeLa cells at the concentrations of 1 ~ 5 μM. In mouse breast cancer xenograft model, compound 9i exhibited obvious tumor growth inhibition and very low toxicity at a dose of 15 mg/kg. The results suggested that compound 9i would be a potential antitumor agent via HIF-1 pathway inhibition.

Photodynamic therapy (PDT) is a non-invasive treatment method for tumors by exciting photosensitizers (PS) upon light irradiation to generate cytotoxic reactive oxygen species (ROS). However, the low oxygen concentration near the tumor tissue limits the therapeutic effect of PDT. Herein, we synthesized six chlorin e6 derivatives containing NO-donors to enhance their antitumor activity by synergistic effect of ROS and NO. The results revealed that the new NO-donor containing photosensitizers (PS-NO) exhibited more potent photodynamic activity than chlorin e6, and the introduction of NO donor moieties to chlorin e6 increased the level of NO and ROS in cells. The addition of Ferrostatin-1, a ferroptosis inhibitor, markedly reduced the photodynamic activity of PS-NO as well as the level of NO and ROS in cells. Mechanism studies further showed that PS-NO could reduce intracellular GSH level, inhibit GPX4 activity and promote malondialdehyde (MDA) accumulation upon light irradiation, which suggested the ferroptosis mechanism underlying the PDT effect of PS-NO.

The corrosion inhibition of self-assembled octadecylphosphonic acid (ODPA) layers on non-oxidized and pre-oxidized copper and Langmuir-Blodgett deposited ODPA layers on pre-oxidized copper was investigated under a simulated indoor atmospheric corrosion environment containing 80% RH and 100 ppb formic acid. The corrosion process was monitored in-situ with infrared absorption/reflection spectroscopy, and the corrosion products were further characterised by grazing incidence X-ray diffraction. Nano-FTIR microscopy was used to reveal the nature, size, and distribution of the corrosion products on the nanoscale. The combination of pre-formed cuprite and ODPA layers, both with only some nanometres thickness, provided an excellent protection under this environment. Data availability The raw/processed data required to reproduce these findings cannot be shared at this time as the data also forms part of an ongoing study.

Hydrogen evolution reaction/Oxygen evolution reaction (HER/OER) synergy would be the most important issue for overall water splitting. The Pt-free 1T/2H-MoS2/CdS/MnOx hollow core–shell nanocomposites are fabricated via a continuous hydrothermal–chemical method; therefore, the OER co-catalysts MnOx and CdS shell are deposited on the surface of SiO2 nanosphere templates continuously via hydrothermal–chemical method. Subsequently, the SiO2 templates are etched via chemical method and the 2H-MoS2/CdS hollow core–shell heterojunction and 1T-MoS2 HER co-catalyst are introduced via one-step hydrothermal method. Evaluated by photocatalytic performance, the 1T/2H-MoS2/CdS/MnOx exhibits an enhanced HER performance of about ~50 folds than that of single CdS hollow nanosphere, and achieves a decent overall water splitting performance of about ~1668.00(H2)/824.61(O2) μmol/g∙h, which can be mainly ascribed to the well HER/OER synergy and formation of hollow core–shell structure. Therefore, the 1T-MoS2 with quick electron transport and decent solid/liquid interface can promote the photogenerated electron diffusing, the MnOx with mixed Mn3+/Mn4+ ions can activate the hole-related species for OH− oxidation and promote H2O2 decomposition, the 2H–MoS2/CdS heterojunction can separate the charge carrier and meet the potential to achieve overall water splitting. Additionally, the 1T/2H-MoS2 with decent lattice matching can improve the charge carrier transport, the 1T-MoS2 with sufficient specific surface areas can increase active sites and the hollow core–shell structure can increase solar efficiency which is also beneficial for enhancing the overall water splitting performance and stability.

The dynamic simulation of the continuous catalytic reforming process is of great significance to the performance prediction and optimization of the entire process. In this study, a 34-lumped mechanism model described by differential algebra was established based on the actual process conditions of the continuous catalytic reforming process in China, and an efficient dynamic simulation solution method based on simultaneous equations was proposed. First, a 34-lumped differential–algebraic mechanism model was established based on the basic principles of reforming kinetics, thermodynamics, material balance, and energy balance. Secondly, in order to solve and simulate the mechanism model composed of 144 differential equations and several algebraic equations, the method of finite-element collocation is used to discretize the differential equations and convert them into large-scale, nonlinear programming problems, and the interior point algorithm is used to estimate its parameters and verify the model. In addition, in order to avoid the problem of too long derivative solution time and too large memory in the solution process, methods such as sparse derivative and Broyden–Fletcher–Goldfarb–Shanno (BFGS) with limited storage are used to solve the problem. Finally, on the basis of model verification, dynamic simulation and sensitivity analysis of the whole process are carried out by modifying different input parameters. The results show that the mechanism model and solution method presented in this paper can quickly and accurately simulate the continuous catalytic reforming process dynamically.

The rising prevalence of obesity and being overweight is a worldwide health concern. Food reward dysregulation is the basic factor for the development of obesity. Dopamine (DA) neurons in the ventral tegmental area (VTA) play a vital role in food reward. Toll-like receptor 4 (TLR4) is a transmembrane pattern recognition receptor that can be activated by saturated fatty acids. Here, we show that the deletion of TLR4 specifically in DA neurons increases body weight, increases food intake, and decreases food reward. Conditional deletion of TLR4 also decreased the activity of DA neurons while suppressing the expression of tyrosine hydroxylase (TH) in the VTA, which regulates the concentration of DA in the nucleus accumbens (NAc) to affect food reward. Meanwhile, AAV-Cre-GFP mediated VTA-specific TLR4-deficient mice recapitulates food reward of DAT-TLR4-KO mice. Food reward could be rescued by re-expressing TLR4 in VTA DA neurons. Moreover, effects of intra-VTA infusion of lauric acid (a saturated fatty acid with 12 carbon) on food reward were abolished in mice lacking TLR4 in DA neurons. Our study demonstrates the critical role of TLR4 signaling in regulating the activity of VTA DA neurons and the normal function of the mesolimbic DA system that may contribute to food reward.

Video game streaming (VGS) has attracted hundreds of millions of viewers all over the world to not only watch but also participate in a variety of VGS activities, such as interacting with streamers and other co-viewers, gift-giving, and social sharing of the viewing experience. The success of the VGS paradigm depends on the active participation of the viewers, since it creates economic, hedonic, and social values. This study applied a mixed-methods approach to explore the critical environmental stimuli evoking viewers’ cognitive and emotional state and empirically tested a research model examining viewers’ participation. Using qualitative interviews, three environmental stimuli were identified (i.e., broadcaster appeal, medium appeal, and perceived co-viewer involvement), which were adopted in the quantitative research model. The research findings suggested that environmental stimuli were positively related to both cognitive and emotional organisms, namely cognitive involvement and arousal, which in turn impacted viewers’ participation.

The Institute of High Energy Physics (IHEP), Chinese Academy of Sciences (CAS), is China's biggest laboratory for basic sciences. IHEP aims to understand the universe at the most fundamental level—from the smallest subatomic particles to the large-scale structure of the cosmos. As well as theoretical and experimental research into particle and astroparticle physics, IHEP has a broad range of research in related fields from accelerator technologies to nuclear analysis techniques. The Institute also provides beam facilities for researchers in other fields of sciences.

The Z-Scheme Ag3PO4/Ag/g-C3N4 nanosheets composites are synthesised via simple annealing and anion-exchange precipitation method. The obtained samples are characterized by SEM, XRD, TEM, XPS, UV–Vis and PL, which imply that the Z-Scheme Ag3PO4/Ag/g-C3N4 structure has been prepared successfully. The photocatalytic activity of the as-prepared Ag3PO4/Ag/g-C3N4 nanosheets composites displays a remarkable enhancement after the Ag3PO4/Ag nanoparticles being introduced by the hydrogen production under visible light. Further, the Z-Scheme structure of the sample and the lamellar structure of the C3N4 are considered as the main reasons for the enhancement.