A General Strategy for Ordered Carrier Transport of Quasi‑2D and 3D Perovskite Films for Giant Self‑Powered Photoresponse and Ultrahigh Stability

Organic–inorganic hybrid perovskite materials have been focusing more attention in the field of self-powered photodetectors due to their superb photoelectric properties.However,a universal growth approach is required and challenging to realize vertically oriented growth and grain boundary fusion of 2D and 3D perovskite grains to promote ordered carrier transport,which determines superior photoresponse and high stability.Herein,a general thermal-pressed(TP)strategy is designed to solve the above issues,achieving uniaxial orientation and single-grain penetration along the film thickness direction.It constructs the efficient channel for ordered carrier transport between two electrodes.Combining of the improved crystal quality and lower trap-state density,the quasi-2D and 3D perovskite-based self-powered photodetector devices(with/without hole transport layer)all exhibit giant and stable photoresponse in a wide spectrum range and specific wavelength laser.For the MAPbI_(3)-based self-powered photodetectors,the largest R_(λ) value is as high as 0.57 A W^(−1)at 760 nm,which is larger than most reported results.Meanwhile,under laser illumination(532 nm),the FPEA_(2)MA_(4)Pb_(5)I_(16)-based device exhibits a high responsivity(0.4 A W^(−1)) value,which is one of the best results in 2DRP self-powered photodetectors.In addition,fast response,ultralow detection limit,and markedly improved humidity,optical and heat stabilities are clearly demonstrated for these TP-based devices.

Subcellular Distribution and Chemical Forms of Cadmium in the Medicine Food Homology Plant Platycodon grandiflorum(Jacq.)A.DC.

Although Platycodon grandiflorum(Jacq.)A.DC.is a renowned medicine food homology plant,reports of excessive cadmium(Cd)levels are common,which affects its safety for clinical use and food consumption.To enable its Cd levels to be regulated or reduced,it is necessary to first elucidate the mechanism of Cd uptake and accumulation in the plant,in addition to its detoxification mechanisms.This present study used inductively couple plasma-mass-spectrometry to analyze the subcellular distribution and chemical forms of Cd in different tissues of P.grandiflorum.The experimental results showed that Cd was mainly accumulated in the roots[predominantly in the cell wall(50.96%-61.42%)],and it was found primarily in hypomobile and hypotoxic forms.The proportion of Cd in the soluble fraction increased after Cd exposure,and the proportion of insoluble phosphate Cd and oxalate Cd increased in roots and leaves,with a higher increase in oxalate Cd.Therefore,it is likely that root retention mechanisms,cell wall deposition,vacuole sequestration,and the formation of low mobility and low toxicity forms are tolerance strategies for Cd detoxification used by P.grandiflorum.The results of this study provide a theoretical grounding for the study of Cd accumulation and detoxification mechanisms in P.grandiflorum,and they can be used as a reference for developing Cd limits and standards for other medicine food homology plants.

温度-应力耦合条件下聚四氟乙烯的压缩蠕变行为与寿命预测

利用自行设计搭建的人工加速老化实验装置,研究了聚四氟乙烯(PTFE)在温度-应力耦合作用下的压缩蠕变行为。结果表明,随温度或应力上升,平衡压缩应变呈增加趋势,该过程以物理老化为主,并伴随晶区分子链螺旋程度降低和片层滑移。以典型实验条件下聚四氟乙烯的非线性蠕变数据为依据,通过构建合适的位移因子,建立了符合广义蠕变柔度曲线的寿命预测模型。进一步选择应变量作为失效判据,合理预测了不同温度条件下材料的压缩蠕变寿命。通过与实验结果比对,证实该模型对聚四氟乙烯寿命预测准确可靠,且对于有类似蠕变行为的高分子材料寿命预测具有一定的普适性和指导性。

Deletion of the waaf gene affects O antigen synthesis and pathogenicity in Vibrio parahaemolyticus from shellfish

Vibrio parahaemolyticus is the main cause of foodborne gastroenteritis,which is widely distributed in shellfish and other seafood.Most V.parahaemolyticus are nonpathogenic,and only a few types,such as serotype O3:K6,are pathogenic,which is also the most prevalent strain in Asia.However,the relationship between this serotype and pathogenicity has yet to be established.The waaf gene is located in the O antigen synthesis gene cluster.Thus,we constructed a waaf gene deletion mutant(i.e.,Δwaaf)of wild-type(WT)which isolated from shellfish serotype O3:K6 via chitin-mediated transformation technology.We then constructed theΔwaaf complementary strain(i.e.,C-△waaf)via the Escherichia coli S17λpir strain by conjugation.The basic physiological characteristics,adhesion to Caco2 cells,and pathogenicity of the WT,△waaf,and C-△waaf strains were compared.Growth curves showed no remarkable differences between the WT andΔwaaf strains.However,theΔwaaf strain non-reactive to O3 antisera and other 12 O-group antisera of V.parahaemolyticus.Moreover,the number of flgella and extracellular polysaccharides decreased,the adhesion decreased,and the pathogenicity weakened.These characteristics of the C-△waaf strain were similar to those of the WT strain These results indicated that the waaf gene is vital to the serotype in V.parahaemolyticus,and changes in O antigen could affect the pathogenicity of this bacterium.This study will be helpful to understand the pathogenic mechanism of V.parahaemolyticus.

Introduction to the Special Issue on Computer Modelling of Transmission, Spread, Control and Diagnosis of COVID-19

The 2019–20 coronavirus pandemic is an ongoing pandemic of coronavirus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).It was declared to be a Public Health Emergency of International Concern and recognized as a pandemic by the World Health Organization.The outbreak of COVID-19 has rapidly spread to most countries in the world.This special issue started at 21 April 2020,when there were more than 2.5 million confirmed cases and 174,336 deaths around the world.After 10 months,this special issue closes at 23 February 2021,the two figures increase to 112.2 million confirmed cases and 2.48 million death tolls,respectively.

Hydrochloric Acid-Promoted Synthesis of cBN via Hydrothermal Route

Single phase crystalline cubic boron nitride （cBN） with high yield was prepared by hydrothermal route at low temperature, using hydrochloric acid （HCI） as the promoter. The promotion effect of HCI on the synthesis of cBN is briefly discussed.

MoS2-intercalated carbon hetero-layers bonded on graphene as electrode materials for enhanced sodium/potassium ion storage

MoS2 is considered as an ideal electrode material in the field of energy storage due to high theoretical specific capacity and unique layered structure.However,limited interlayer distance and poor intrinsic electrical conductivity restrict its potential realworld application.Herein,an alternately intercalated structure of MoS2 monolayer and N-doped porous carbon(NC)layer is grown on reduced graphene oxide(rGO)via a chemical intercalated strategy.The expanded interlayer distance of MoS2(0.96 nm),enlarged by the intercalation of N-doped porous carbon layers,can enhance ion diffusion mobility,provide additional reactive sites for ion storage and maintain the stability of electrode structure.In addition,the hierarchical structures between rGO substrate and intercalated N-doped carbon layers construct a three-dimensional(3D)conductive network,which can significantly improve the electrical conductivity and the structural stability.As a result,the rGO-supported MoS2/NC electrode exhibits an ultrahigh reversible capacity and remarkable long cycling stability for sodium-ion batteries(SIBs)and potassium-ion(PIBs).Meanwhile,the as-obtained MoS2/NC@rGO electrode also delivers a superior cycle performance of 250 mAh·g−1 after 160 cycles at 0.5 A·g−1 when employed as an anode for sodium-ion full cells.

The cGAS-STING signaling in cardiovascular and metabolic diseases: Future novel target option for pharmacotherapy

The cyclic GMP-AMP synthase(cGAS)-stimulator of interferon genes(STING) signaling exert essential regulatory function in microbial-and onco-immunology through the induction of cytokines, primarily type I interferons. Recently, the aberrant and deranged signaling of the cGAS-STING axis is closely implicated in multiple sterile inflammatory diseases, including heart failure,myocardial infarction, cardiac hypertrophy, nonalcoholic fatty liver diseases, aortic aneurysm and dissection, obesity, etc. This is because of the massive loads of damage-associated molecular patterns(mitochondrial DNA, DNA in extracellular vesicles) liberated from recurrent injury to metabolic cellular organelles and tissues, which are sensed by the pathway. Also, the cGAS-STING pathway crosstalk with essential intracellular homeostasis processes like apoptosis, autophagy, and regulate cellular metabolism.Targeting derailed STING signaling has become necessary for chronic inflammatory diseases. Meanwhile, excessive type I interferons signaling impact on cardiovascular and metabolic health remain entirely elusive. In this review, we summarize the intimate connection between the cGAS-STING pathway and cardiovascular and metabolic disorders. We also discuss some potential small molecule inhibitors for the pathway. This review provides insight to stimulate interest in and support future research into understanding this signaling axis in cardiovascular and metabolic tissues and diseases.

Porous-hollow nanorods constructed from alternate intercalation of carbon and MoS2 monolayers for lithium and sodium storage

Weak ion diffusion and electron transport due to limited interlayer spacing and poor electrical conductivity have been identified as critical roadbacks for fast and abundant energy storage of both MoS2-based lithium ion batteries (LIBs) and sodium ion batteries (SIBs). In this work, MoS2 porous-hollow nanorods (MoS2/m-C800) have been designed and synthesized via an annealing-followed chemistry-intercalated strategy to solve the two issues. They are uniformly assembled from ultrathin MoS2 nanosheets, deviated to the rod-axis direction, with expanded interlayer spacing due to alternate intercalation of N-doped carbon monolayers between the adjacent MoS2 monolayers. Electrochemical studies of the MoS2/m-C800 sample, as an anode of LIBs, demonstrate that the superstructure can deliver a reversible discharge capacity of 1,170 mAh·g^-1 after 100 cycles at 0.2 A·g^-1 and maintain a reversible capacity of 951 mAh·g^-1 at 1.25 A·g^-1 after 350 cycles. While for SIBs, the superstructure also delivers a reversible discharge capacity of 350 mAh·g^-1 at 0.5 A-g-1 after 500 cycles and exhibits superior rate capacity of 238 mAh·g^-1 at 15 A·g^-1 .The excellent electrochemical performance is closely related with the hierarchical superstructures, including expanded interlayer spacing, alternate intercalation of carbon monolayers and mesoporous feature, which effectively reduce ion diffusion barrier, shorten ion diffusion paths and improve electrical conductivity.

Preparation and Photocatalytic Properties of g-C_3N_4 /TiO_2 Hybrid Composite

g-C3N4/TiO2 composite were prepared by hydrolysis of Ti（OC4Hn9） 4 and the precursors of g-C3N4 at room temperature and annealing in nitrogen atmosphere.X-ray diffraction results revealed that all the products were anatase structure.The chemical nature of O,N of the g-C 3N4/TiO2 were identified by X-ray photoelectron spectroscopy,presenting N-Ti-O and N-Ti-N doping status of the composite.The g-C3N4 /TiO2 composite showed better photocatalytic activity for the UV and visible-light degradation of Rhodamine B.

Assembly of flower-like VS_(2)/N-doped porous carbon with expanded(001)plane on rGO for superior Na-ion and K-ion storage

VS2 with natural layered structure and metallic conductivity is a prospective candidate for sodium-ion batteries(SIBs)and potassium-ion batteries(PIBs).However,due to large radius of Na+and K+,the limited interlayer spacing(0.57 nm)of VS2 generally determines high ion diffusion barrier and large volume variation,resulting in unsatisfactory electrochemical performance of SIBs and PIBs.In this work,flower-like VS_(2)/N-doped carbon(VS_(2)/N-C)with expanded(001)plane is grown on reduced graphene oxide(rGO)via a solvothermal and subsequently carbonization strategy.In the VS_(2)/N-C@rGO nanohybrids,the ultrathin VS2"petals"are alternately intercalated by the N-doped porous carbon monolayers to achieve an expanded interlayer spacing(1.02 nm),which can effectively reduce ions diffusion barrier,expose abundant active sites for Na+/K+intercalation,and tolerate large volume variation.The N-C and rGO carbonous materials can significantly promote the electrical conductivity and structural stability.Benefited from the synergistic effect,the VS2/N-C@rGO electrode exhibits large reversible capacity(Na+:407 mAh·g^(-1) at 1 A·g^(-1);K^(+):334 mAh·g^(-1) at 0.2 A·g^(-1)),high rate capacity(Na+:273 mAh·g^(-1) at 8 A·g^(-1);K+:186 mAh·g^(-1) at 5 A·g^(-1)),and remarkable cycling stability(Na+:316 mAh·g^(-1) at 2 A·g^(-1) after 1,400 cycles;K^(+):216 mAh·g^(-1) at 1 A·g^(-1) after 500 cycles).

Antibody upstream sequence diversity and its biological implications revealed by repertoire sequencing

The sequence upstream of the antibody variable region(antibody upstream sequence[AUS])consists of a 5′untranslated region(5′UTR)and a preceding leader region.The sequence variations in AUS affect antibody engineering and PCR based antibody quantification and may also be implicated in mRNA transcription and translation.However,the diversity of AUSs remains elusive.Using 5′rapid amplification of cDNA ends and high-throughput antibody repertoire sequencing technique,we acquired full-length AUSs for human,rhesus macaque,cynomolgus macaque,mouse,and rat.We designed a bioinformatics pipeline and identified 3307 unique AUSs,corresponding to 3026 and 1457 unique sequences for 5′UTR and leader region,respectively.Comparative analysis indicated that 928(63.69%)leader sequences are novel relative to those recorded in the international ImMunoGeneTics information system.Evolutionarily,leader sequences are more conserved than 5′UTR and seem to coevolve with their downstream V genes.Besides,single-nucleotide polymorphisms are position dependent for leader regions and may contribute to the functional reversal of the downstream V genes.Finally,the AUGs in AUSs were found to have little impact on gene expression.Taken together,our findings can facilitate primer design for capturing antibodies efficiently and provide a valuable resource for antibody engineering and molecule-level antibody studies.

Proteome landscape and spatial map of mouse primordial germ cells

Primordial germ cells(PGCs)are precursors of both male and female gametes as fundamental materials for organism development.The transcriptome,methylome,and chromatin accessibility profiles of PGCs in both mice and humans have been recently reported.However,little is known about the characteristics of PGCs at the protein levels,which directly exert cellular functions.Here,we construct landscapes of both proteome and 3D spatial distribution of mouse PGCs at E11.5,E13.5 and E16.5 days,the three critical developmental windows for PGCs'sex differentiation,female meiosis initiation and male mitotic arrest.In each developmental stage of PGCs,nearly 2,000–3,000 proteins are identified,among which specific functional pathways such as oxidative phosphorylation,DNA damage repair,and meiotic cell cycle are involved for different events during PGCs development.Interestingly,by 3D modeling we find that PGCs spatially cluster into around 1,300 nests in genital ridge at E11.5 and the nest number is not increased by the exponential proliferation of PGCs.Comparative analysis of our proteomic data with published transcriptomic data does not show a close correlation,meaning that the practically executive factors are beyond the transcriptome.Thus,our work offers a valuable resource for the systematic investigations of PGC development at protein level and spatial map.

Water-soluble boron carbon oxynitride dots with excellent solid-state fluorescence and ultralong room-temperature phosphorescence

Developing metal-free and long lifetime room-temperature phosphorescence(RTP)materials has received tremendous interest due to their numerous potential applications,of which stable triplet-excited state is the core challenge.Here,boron carbon oxynitride(BCNO)dots,emitting stable blue fluorescence and green RTP,are reported for the first time.The obtained BCNO dots exhibit an unexpected ultralong RTP lifetime of 1.57 s,lasting over 8 s to naked eyes.The effective doping of carbon and oxygen elements in boron nitride(BN)actually provides a small energy gap between singlet and triplet states,facilitating the intersystem crossing(ISC)and populating of triplet excitons.The formation of compact cores via crystallization and effective inter-/intra-dot hydrogen bonds further stabilizes the excited triplet states and reduces quenching of RTP by oxygen at room temperature.Based on the water-soluble feature of BCNO dots,a novel advanced security ink is developed toward anti-counterfeiting tag and confidential information encryption.This study extends BCNO dots to rarely exploited phosphorescence fields and also provides a facile strategy to prepare ultralong lifetime metal-free RTP materials.