Although covalent organic frameworks(COFs)with highπ-conjugation have recently exhibited great prospects in perovskite solar cells(PSCs),their further application in PSCs is still hindered by face-to-face stacking an...Although covalent organic frameworks(COFs)with highπ-conjugation have recently exhibited great prospects in perovskite solar cells(PSCs),their further application in PSCs is still hindered by face-to-face stacking and aggregation issues.Herein,metal-organic framework(MOF-808)is selected as an ideal platform for the in situ homogeneous growth of a COF to construct a core-shell MOF@COF nanoparticle,which could effectively inhibit COF stacking and aggregation.The synergistic intrinsic mechanisms induced by the MOF@COF nanoparticles for reinforcing intrinsic stability and mitigating lead leakage in PSCs have been explored.The complementary utilization ofπ-conjugated skeletons and nanopores could optimize the crystallization of large-grained perovskite films and eliminate defects.The resulting PSCs achieve an impressive power conversion efficiency of 23.61%with superior open circuit voltage(1.20 V)and maintained approximately 90%of the original power conversion efficiency after 2000 h(30-50%RH and 25-30℃).Benefiting from the synergistic effects of the in situ chemical fixation and adsorption abilities of the MOF@COF nanoparticles,the amount of lead leakage from unpackaged PSCs soaked in water(<5 ppm)satisfies the laboratory assessment required for the Resource Conservation and Recovery Act Regulation.展开更多
The multifaceted switches are part of our everyday life from the macroscopic to the molecular world.A molecular switch operating in the solution and in the crystalline state is very different.In this review,we summari...The multifaceted switches are part of our everyday life from the macroscopic to the molecular world.A molecular switch operating in the solution and in the crystalline state is very different.In this review,we summarize the state-of-the-art of smart molecular crystal switches based on molecular martensites.These crystal switches respond to external stimuli and reversibly change between states,retaining their macroscopic integrity.The operation of the switches predominantly relies on temperature alterations or mechanical stress,with emerging methods based on photothermal effects,photoisomerization,and host-vip chemistry.The capability of changing the molecular orientation and interaction in smart molecular crystal switches offers opportunities in several applications,including actuators,reversibly shaping structural materials,optoelectronic and magnetic materials,as well as switchable porous materials.Smart molecular crystal switches have vast potential in modern scientific and technological progress.The ongoing research shapes a rich landscape for innovation and future scientific exploration across diverse disciplines.展开更多
Bone morphogenetic proteins (BMPs) are members of the TGF-β superfamily and have diverse functions during development and organogenesis. BMPs play a major role in skeletal development and bone formation, and disrupti...Bone morphogenetic proteins (BMPs) are members of the TGF-β superfamily and have diverse functions during development and organogenesis. BMPs play a major role in skeletal development and bone formation, and disruptions in BMP signaling cause a variety of skeletal and extraskeletal anomalies. Several knockout models have provided insight into the mechanisms responsible for these phenotypes. Proper bone formation requires the differentiation of osteoblasts from mesenchymal stem cell (MSC) precursors, a process mediated in part by BMP signaling. Multiple BMPs, including BMP2, BMP6, BMP7 and BMP9, promote osteoblastic differentiation of MSCs both in vitro and in vivo. BMP9 is one of the most osteogenic BMPs, yet it is a poorly characterized member of the BMP family. Several studies demonstrate that the mechanisms controlling BMP9-mediated osteogenesis differ from other osteogenic BMPs, but little is known about these specific mechanisms. Several pathways critical to BMP9-mediated osteogenesis are also important in the differentiation of other cell lineages, including adipocytes and chondrocytes. BMP9 has also demonstrated translational promise in spinal fusion and bone fracture repair. This review will summarize our current knowledge of BMP-mediated osteogenesis, with a focus on BMP9, by presenting recently completed work which may help us to further elucidate these pathways.展开更多
Liver cancer is one of the most threatening diseases in Chinese population. Just like in other tissues, tumor initiation and development in liver involve multiple steps of genetic and epigenetic alterations with sever...Liver cancer is one of the most threatening diseases in Chinese population. Just like in other tissues, tumor initiation and development in liver involve multiple steps of genetic and epigenetic alterations with several unknown details. However, unlike in other tissues, a tissue specific inducible Cre recombinase system that allows temporal and spatial deletion of a target DNA fragment is still not available for in vivo functional gene annotation in hepatocytes. In our pursuit to establish such a mouse model, we designed a dual inducible Cre transgene system and tested it in cultured cells. By combining a CCAAT/enhancer binding protein β （C/EBP β） promoter derived Tet-off expression system and the estrogen receptor （ER） mediated functional control, we show a desirable profile of both hepatocyte-specificity and regulability of the Cre expression in a series of critical assessments in the cell culture system, which provides confidence in continuation of our ongoing pursuit in mouse.展开更多
The semi-interpenetrating network anion exchange membranes(AEMs)based on quaternized polyvinyl alcohol(QPVA)and poly(-diallyldimethylammonium chloride)(PDDA)are synthesized.The chemical cross-linking structure is form...The semi-interpenetrating network anion exchange membranes(AEMs)based on quaternized polyvinyl alcohol(QPVA)and poly(-diallyldimethylammonium chloride)(PDDA)are synthesized.The chemical cross-linking structure is formed between hydroxyl groups of QPVA and aldehyde groups of glutaraldehyde(GA),which makes PDDA more stable embed in the QPVA matrix and also improves the mechanical properties and dimensional stability of AEMs.Due to the phase separation phenomenon of AEMs swelling in water,a microporous structure may be formed in the membrane,which reduces the transmission resistance of hydroxide ions and provides a larger space for the transfer of hydroxide ions,thus improving the conductivity.The ring structure of PDDA is introduced as a cationic group to transfer hydroxide ions,and shields the nucleophilic attack of the hydroxide ions through the steric hindrance effect,which improves alkaline stability.The hydroxide conductivity of semi-interpenetrating network membrane(QPVA/PDDA0.5-GA)is 36.5 mS cm^(-1) at 60℃.And the membrane of QPVA/PDDA0.5-GA exhibits excellent mechanical property with maximum tensile strength of 19.6 MPa.After immersing into hot 3 mol L^(-1) NaOH solutions at 60℃ for 300 h,the OHconductivity remains 78%of its initial value.The semi-interpenetrating network AEMs with microporous structure exhibit good ionic conductivity,mechanical strength and alkaline durability.展开更多
Magnesium hydride, with high specific capacity, favorable voltage profile and low voltage hysteresis properties, is regarded as a promising anode for lithium storage. However, the rapid fading of capacity caused by hu...Magnesium hydride, with high specific capacity, favorable voltage profile and low voltage hysteresis properties, is regarded as a promising anode for lithium storage. However, the rapid fading of capacity caused by huge volume change, low electron/ion conduction, and spontaneous agglomeration of active materials during cycling greatly limit its practical application in lithium-ion batteries. Herein, we report the synthesis of monodisperse MgH2 nanoparticles with an average particle size of <20 nm homogeneously anchored on Ti3C2 MXene sheets by bottom-up self-assembly strategy. The unique nanoarchitectures are able to efficiently enhance the lithium insertion/extraction kinetics, accelerate the electron/lithium ion transfer and buffer the strain of volume changes. More importantly, the formed F–Mg bounding between MgH2 and MXene could avoid the shedding of MgH2 nanoparticles to electrolyte during cycling, which significantly enhance the capacity, cyclability, and rate performance of magnesium hydride. Moreover, due to the high density of MXene and the synergistic effect between the MgH2 and MXene matrix, the MgH2/MXene composite with 60 wt% MgH2 delivers a superior volumetric capacity of 1092.9 mAh cm−3 at a current density of 2000 mA g^(−1) after 1000 cycles. These results highlight the great promising of MgH2/MXene composite for high performance lithium-ion batteries.展开更多
This paper reports a sustainable,water-assisted,solid-state method for synthesizing ammonium nickel molybdate（（NH4）HNi2（OH）2（MoO4）2,ANM）,a precursor for an unsupported hydrodesulfurization（HDS） catalyst.The ...This paper reports a sustainable,water-assisted,solid-state method for synthesizing ammonium nickel molybdate（（NH4）HNi2（OH）2（MoO4）2,ANM）,a precursor for an unsupported hydrodesulfurization（HDS） catalyst.The associated ANM formation mechanism is also discussed.The synthesis route consists of physical mixing of the raw materials,water-assisted grinding and heating.The formation mechanism involves replacement of a Mo atom by a Ni atom,generating the metastable intermediate（NH4）4（NiH6Mo6O（24））·5H2O.Heating of this intermediate at 120 ℃ removes the added water and produces ANM.Catalysts prepared by this method exhibit almost the same physicochemical properties and catalytic performance during the HDS of dibenzothiophene as materials made from ANM synthesized by a chemical precipitation procedure.Compared with traditional hydrothermal or chemical precipitation methods,this water-assisted,solid-state synthesis provides several significant advantages,including simplifying the synthetic procedure,reducing waste and energy costs and increasing product yields.These features will be highly important with regard to allowing the application of ANM in industrial-scale processes involving HDS reactions.This water-assisted,solid-state strategy can also be extended to the synthesis of isomorphous compounds such as ammonium cobalt（zinc and copper） molybdate.展开更多
Okra(Abelmoschus esculentus)is an important vegetable crop with high nutritional value.However,the mechanism underlying its high nutrient content remains poorly understood.Here,we present a chromosome-scale genome of ...Okra(Abelmoschus esculentus)is an important vegetable crop with high nutritional value.However,the mechanism underlying its high nutrient content remains poorly understood.Here,we present a chromosome-scale genome of okra with a size of 1.19 Gb.Comparative genomics analysis revealed the phylogenetic status of A.esculentus,as well as whole-genome duplication(WGD)events that have occurred widely across the Malvaceae species.We found that okra has experienced three additional WGDs compared with the diploid cotton Gossypium raimondii,resulting in a large chromosome number(2n=130).After three WGDs,okra has undergone extensive genomic deletions and retained substantial numbers of genes related to secondary metabolite biosynthesis and environmental adaptation,resulting in significant differences between okra and G.raimondii in the gene families related to cellulose synthesis.Combining transcriptomic and metabolomic analysis,we revealed the relationship between gene expression and metabolite content change across different okra developmental stages.Furthermore,the sinapic acid/S-lignin biosynthesis-related gene families have experienced remarkable expansion in okra,and the expression of key enzymes involved in the sinapic acid/S-lignin biosynthesis pathway vary greatly across developmental periods,which partially explains the differences in metabolite content across the different stages.Our study gains insights into the comprehensive evolutionary history of Malvaceae species and the genetic basis that underlies the nutrient content changes in okra,which will facilitate the functional study and genetic improvement of okra varieties.展开更多
[Objectives] To analyze the low melting point fat constituents in the black soybeans with green and yellow heart and their relative content,and compare the differences in the low melting point fat constituents between...[Objectives] To analyze the low melting point fat constituents in the black soybeans with green and yellow heart and their relative content,and compare the differences in the low melting point fat constituents between different kinds of black soybeans. [Methods] Using HS-SPME-GC-MS,the qualitative analysis was performed on the low melting point fat constituents of black soybeans; using peak area normalization method,the relative content of constituents was calculated. [Results]A total of 42 peaks were identified from the low melting point fat constituents of the black soybeans with yellow heart,and 18 kinds of chemical constituents were identified,accounting for 81.39% of total relative content of low melting point fat constituents; a total of 37 peaks were identified from the low melting point fat constituents of the black soybeans with green heart,and 15 kinds of chemical constituents were identified,accounting for 83.24% of total relative content of low melting point fat constituents. There were 9 kinds of common chemical constituents for the two kinds of black soybeans,and 5-allylguaiacol had the highest relative content,followed by hexanol. [Conclusions] There was no significant difference in the low melting point fat constituents between two kinds of black soybeans.展开更多
The solidified microstructure of a Ni-Cu-Si cast alloy has been investigated, and a kind of banding structure was observed. The results showed that, the banding structure was composed of coarser particles which were N...The solidified microstructure of a Ni-Cu-Si cast alloy has been investigated, and a kind of banding structure was observed. The results showed that, the banding structure was composed of coarser particles which were Ni3Si type of precipitates and similar to the fine particles precipitate uniformly distributed within matrix of Ni solid solution, in both crystal structure and composition. The formation of bandings was resulted from cast thermal stress and dislocation walls. It was found that the cracks propagated along these bandings in tensile test. The banding structure can be depressed by reducing the cast thermal stress, which can improve the tensile ductility.展开更多
Photonic-plasmonic hybrid microcavities,which possess a higher figure of merit Q/V(the ratio of quality factor to mode volume)than that of pure photonic microcavities or pure plasmonic nano-antennas,play key roles in ...Photonic-plasmonic hybrid microcavities,which possess a higher figure of merit Q/V(the ratio of quality factor to mode volume)than that of pure photonic microcavities or pure plasmonic nano-antennas,play key roles in enhancing light–matter interaction.In this review,we summarize the typical photonic-plasmonic hybrid microcavities,such as photonic crystal microcavities combined with plasmonic nano-antenna,whispering gallery mode microcavities combined with plasmonic nano-antenna,and Fabry–Perot microcavities with plasmonic nano-antenna.The physics and applications of each hybrid photonic-plasmonic system are illustrated.The recent developments of topological photonic crystal microcavities and topological hybrid nano-cavities are also introduced,which demonstrates that topological microcavities can provide a robust platform for the realization of nanophotonic devices.This review can bring comprehensive physical insights of the hybrid system,and reveal that the hybrid system is a good platform for realizing strong light–matter interaction.展开更多
[Objectives]The use of natural enemies of living insects and their derivatives can effectively avoid the problems of pesticide residues,pest resistance,biodiversity decline,control effect weakening and so on.[Methods]...[Objectives]The use of natural enemies of living insects and their derivatives can effectively avoid the problems of pesticide residues,pest resistance,biodiversity decline,control effect weakening and so on.[Methods]Parasites inject various parasitic factors into hosts to inhibit the development of hosts,adjust the immunity of hosts,interfere with the growth and development of hosts,and reduce the nutrition metabolism of hosts,so as to ensure the growth and development of the offspring.Host pests can escape or conquer the parasitism of parasitic wasps through immune defense system in order to reproduce their own offspring.[Results]Under intense and strong selection pressure,in order to effectively ensure the success rate of parasitism,the adaptive diversity of parasitism strategies of parasitic wasps is finally caused.In the process of evolution and under the pressure of directional selection,the innate immunity and acquired immunity gradually evolve.[Conclusions]In-depth research on parasitic factors of parasitic wasps and their interaction with crop pests immunity and development can not only improve theoretical understanding of insect immunity and development biology,pest biological control and other disciplines,but also be expected to enable the application of some components of parasitic factors to agriculture,medicine and pharmacy.Bactrocera dorsalis is a destructive fruit and vegetable pest.This paper summarized the venom protein of B.dorsalis parasitoids and the immune interaction with hosts,in order to provide theoretical basis for biological control of plant pests by using parasitic natural enemies.展开更多
The upgrading of diesel oil to produce ethylene rich cracking feedstock is an important and promising technical route to reduce the ratio of diesel to gasoline. In the present work, a hydrocracking catalyst suitable f...The upgrading of diesel oil to produce ethylene rich cracking feedstock is an important and promising technical route to reduce the ratio of diesel to gasoline. In the present work, a hydrocracking catalyst suitable for selective hydrocracking of straight run diesel oil to produce high-quality ethylene cracking feedstock at low cost was developed, by optimizing the composition of catalyst support materials, using amorphous silicon aluminum and aluminum oxide with high mesopore content as the main support, and modified Y zeolite with excellent aromatic ring opening selectivity as the acidic component. The catalyst has in-depth characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, N<sub>2</sub>-low temperature adsorption-desorption, NH<sub>3</sub>-temperature-programmed desorption, and IR techniques. And its catalytic cracking straight run diesel oil performance was evaluated. The results show that the prepared catalyst has high polycyclic aromatic hydrocarbon ring opening cracking selectivity. However, alkanes retained in diesel distillates can achieve the goal of producing more ethylene cracking feedstocks with low BMCI value under low and moderate pressure conditions. This work may shed significant technical insight for oil refining transformation.展开更多
Gualou Xiebai is a basic prescription for the treatment of angina pectoris in Synopsis of the Golden Chamber.This article is a summary of the theoretical research and clinical application of Gualou Xiebai,in hope to p...Gualou Xiebai is a basic prescription for the treatment of angina pectoris in Synopsis of the Golden Chamber.This article is a summary of the theoretical research and clinical application of Gualou Xiebai,in hope to promote the use of Gualou Xiebai in clinical practice.展开更多
Rheum officinale,a member of the Polygonaceae family,is an important medicinal plant that is widely used in traditional Chinese medicine.Here,we report a 7.68-Gb chromosome-scale assembly of R.officinale with a contig...Rheum officinale,a member of the Polygonaceae family,is an important medicinal plant that is widely used in traditional Chinese medicine.Here,we report a 7.68-Gb chromosome-scale assembly of R.officinale with a contig N50 of 3.47 Mb,which was clustered into 44 chromosomes across four homologous groups.Comparative genomics analysis revealed that transposable elements have made a significant contribution to its genome evolution,gene copy number variation,and gene regulation and expression,particularly of genes involved in metabolite biosynthesis,stress resistance,and root development.We placed the recent autotetraploidization of R.officinale at~0.58 mya and analyzed the genomic features of its homol-ogous chromosomes.Although no dominant monoploid genomes were observed at the overall expression level,numerous allele-differentially-expressed genes were identified,mainly with different transposable element insertions in their regulatory regions,suggesting that they functionally diverged after polyploidization.Combining genomics,transcriptomics,and metabolomics,we explored the contributions of gene family amplification and tetraploidization to the abundant anthraquinone production of R.officinale,as well as gene expression patterns and differences in anthraquinone content among tissues.Our report of-fers unprecedented genomic resources for fundamental research on the autopolyploid herb R.officinale and guidance for polyploid breeding of herbs.展开更多
With the advancement of modern science and technology, large scientific facilities are increasingly oriented toward demand and application, and can be used for basic research as well as serving multiple disciplines. D...With the advancement of modern science and technology, large scientific facilities are increasingly oriented toward demand and application, and can be used for basic research as well as serving multiple disciplines. Developing large scientific facilities and related analytical technologies enhances understanding of large scientific facilities and popularizes their application in research across multiple disciplines. The combination of light or neutron sources from large scientific facilities and advanced analytical technologies can be achieved for materials structure information, dynamics study of chemical reactions, high dissociation of biomolecules, 3D visualization of energy materials or biological samples, etc. We first introduce the progress of domestic large scientific facilities of synchrotron radiation(SR) and free electron lasers(FELs) with different wavelengths and neutron sources.We further discuss the comparison between Chinese and typical foreign facilities in X-ray radiation from X-ray tubes, synchrotrons, X-ray FELs, and neutron sources based on physical parameters of light and neutron sources. In addition, we focus on the technological progress and perspectives combined with advanced X-ray radiation and neutron sources of large scientific facilities in China, especially in the nanoscience fields of energy catalysis and biological science. We hope that this roadmap will provide references on technology and methods to experimental users, as well as prospects for future development of technologies based on large research infrastructure facilities. Comprehensive studies and guidelines for basic research to practical application in various disciplines can be made with the assistance of large scientific facilities.展开更多
Genes on the Y chromosome play important roles in male sex determination and development.The identification of Y-chromosome-specific genes not only provides a theoretical basis for the study of male reproductive devel...Genes on the Y chromosome play important roles in male sex determination and development.The identification of Y-chromosome-specific genes not only provides a theoretical basis for the study of male reproductive development,but also offers genetic control targets for agricultural pests.However,Y-chromosome genes are rarely characterized due to their high repeatability and high heterochromatinization,especially in the oriental fruit fly.In this study,1011 Y-chromosome-specific candidate sequences were screened from 2 to 4 h Bactrocera dorsalis embryo datasets with the chromosome quotient method,6 of which were identified as Y-chromosome-specific sequences by polymerase chain reaction,including typo-gyf,a 19126-bp DNA sequence containing a 575-amino acid open reading frame.Testicular deformation and a significant reduction in sperm number were observed after typo-gyf knockdown with RNA interference in embryos.After typo-gyf knockout with clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated protein 9 in the embryonic stage,the sex ratio of the emergent adults was unbalanced,with far more females than males.A genotype analysis of these females with the Y-chromosome gene MoY revealed no sex reversal.Typo-gyf knockout led to the death of XY individuals in the embryonic stage.We conclude that typo-gyf is an essential gene for male survival,and is also involved in testicular development and spermatogenesis.The identification of typo-gyf and its functional verification provide insight into the roles of Y-chromosome genes in male development.展开更多
基金supported by the National Natural Science Foundation of China(22072034,and 22001050)the China Postdoctoral Science Foundation(2022M710949,2020T130147,and 2020M681084)+2 种基金the Postdoctoral Foundation of Heilongjiang Province(LBH-Z22106,and LBH-Z19059)the Natural Science Foundation of Heilongjiang Youth Fund(YQ2021B002)Education Department of Heilongjiang Province(LJYXL2022-038).
文摘Although covalent organic frameworks(COFs)with highπ-conjugation have recently exhibited great prospects in perovskite solar cells(PSCs),their further application in PSCs is still hindered by face-to-face stacking and aggregation issues.Herein,metal-organic framework(MOF-808)is selected as an ideal platform for the in situ homogeneous growth of a COF to construct a core-shell MOF@COF nanoparticle,which could effectively inhibit COF stacking and aggregation.The synergistic intrinsic mechanisms induced by the MOF@COF nanoparticles for reinforcing intrinsic stability and mitigating lead leakage in PSCs have been explored.The complementary utilization ofπ-conjugated skeletons and nanopores could optimize the crystallization of large-grained perovskite films and eliminate defects.The resulting PSCs achieve an impressive power conversion efficiency of 23.61%with superior open circuit voltage(1.20 V)and maintained approximately 90%of the original power conversion efficiency after 2000 h(30-50%RH and 25-30℃).Benefiting from the synergistic effects of the in situ chemical fixation and adsorption abilities of the MOF@COF nanoparticles,the amount of lead leakage from unpackaged PSCs soaked in water(<5 ppm)satisfies the laboratory assessment required for the Resource Conservation and Recovery Act Regulation.
基金supported by the National Natural Science Foundation of China(51773077 and 52173164 H.Z)the Natural Science Foundation of Jilin Province(20230101038JC,H.Z)+1 种基金a fund from New York University Abu Dhabi(P.N)This material is based upon works supported by Tamkeen under NYUAD RRC Grant No.CG011.
文摘The multifaceted switches are part of our everyday life from the macroscopic to the molecular world.A molecular switch operating in the solution and in the crystalline state is very different.In this review,we summarize the state-of-the-art of smart molecular crystal switches based on molecular martensites.These crystal switches respond to external stimuli and reversibly change between states,retaining their macroscopic integrity.The operation of the switches predominantly relies on temperature alterations or mechanical stress,with emerging methods based on photothermal effects,photoisomerization,and host-vip chemistry.The capability of changing the molecular orientation and interaction in smart molecular crystal switches offers opportunities in several applications,including actuators,reversibly shaping structural materials,optoelectronic and magnetic materials,as well as switchable porous materials.Smart molecular crystal switches have vast potential in modern scientific and technological progress.The ongoing research shapes a rich landscape for innovation and future scientific exploration across diverse disciplines.
文摘Bone morphogenetic proteins (BMPs) are members of the TGF-β superfamily and have diverse functions during development and organogenesis. BMPs play a major role in skeletal development and bone formation, and disruptions in BMP signaling cause a variety of skeletal and extraskeletal anomalies. Several knockout models have provided insight into the mechanisms responsible for these phenotypes. Proper bone formation requires the differentiation of osteoblasts from mesenchymal stem cell (MSC) precursors, a process mediated in part by BMP signaling. Multiple BMPs, including BMP2, BMP6, BMP7 and BMP9, promote osteoblastic differentiation of MSCs both in vitro and in vivo. BMP9 is one of the most osteogenic BMPs, yet it is a poorly characterized member of the BMP family. Several studies demonstrate that the mechanisms controlling BMP9-mediated osteogenesis differ from other osteogenic BMPs, but little is known about these specific mechanisms. Several pathways critical to BMP9-mediated osteogenesis are also important in the differentiation of other cell lineages, including adipocytes and chondrocytes. BMP9 has also demonstrated translational promise in spinal fusion and bone fracture repair. This review will summarize our current knowledge of BMP-mediated osteogenesis, with a focus on BMP9, by presenting recently completed work which may help us to further elucidate these pathways.
基金supported by Shanghai Science Foundation grants,National Science Foundation of China(No.30570850 and 10574134)National Research Program for Basic Research of China(No.2004CB518804)+1 种基金National Research Program for High Technology(No.2006AA02Z-320 and 2006AA 02Z197)European 6th Program(LSHBCT-2005-019067).
文摘Liver cancer is one of the most threatening diseases in Chinese population. Just like in other tissues, tumor initiation and development in liver involve multiple steps of genetic and epigenetic alterations with several unknown details. However, unlike in other tissues, a tissue specific inducible Cre recombinase system that allows temporal and spatial deletion of a target DNA fragment is still not available for in vivo functional gene annotation in hepatocytes. In our pursuit to establish such a mouse model, we designed a dual inducible Cre transgene system and tested it in cultured cells. By combining a CCAAT/enhancer binding protein β （C/EBP β） promoter derived Tet-off expression system and the estrogen receptor （ER） mediated functional control, we show a desirable profile of both hepatocyte-specificity and regulability of the Cre expression in a series of critical assessments in the cell culture system, which provides confidence in continuation of our ongoing pursuit in mouse.
基金The authors gratefully acknowledge the financial support of this work by Natural Science Foundation of China(grant no.s 51673030,51603017 and 51803011)Jilin Provincial Science&Technology Department(grant no.s 20200801011GH,20180101209JC,20160520138JH,20160519020JH)+1 种基金Jilin Province Development and Reform Commission(Grant nos:2019C042-5)ChangBai Mountain Scholars Program of Jilin Province.
文摘The semi-interpenetrating network anion exchange membranes(AEMs)based on quaternized polyvinyl alcohol(QPVA)and poly(-diallyldimethylammonium chloride)(PDDA)are synthesized.The chemical cross-linking structure is formed between hydroxyl groups of QPVA and aldehyde groups of glutaraldehyde(GA),which makes PDDA more stable embed in the QPVA matrix and also improves the mechanical properties and dimensional stability of AEMs.Due to the phase separation phenomenon of AEMs swelling in water,a microporous structure may be formed in the membrane,which reduces the transmission resistance of hydroxide ions and provides a larger space for the transfer of hydroxide ions,thus improving the conductivity.The ring structure of PDDA is introduced as a cationic group to transfer hydroxide ions,and shields the nucleophilic attack of the hydroxide ions through the steric hindrance effect,which improves alkaline stability.The hydroxide conductivity of semi-interpenetrating network membrane(QPVA/PDDA0.5-GA)is 36.5 mS cm^(-1) at 60℃.And the membrane of QPVA/PDDA0.5-GA exhibits excellent mechanical property with maximum tensile strength of 19.6 MPa.After immersing into hot 3 mol L^(-1) NaOH solutions at 60℃ for 300 h,the OHconductivity remains 78%of its initial value.The semi-interpenetrating network AEMs with microporous structure exhibit good ionic conductivity,mechanical strength and alkaline durability.
基金This work was partially supported by the National Science Fund for Distinguished Young Scholars(51625102)the National Natural Science Foundation of China(51971065)+1 种基金the Innovation Program of Shanghai Municipal Education Commission(2019-01-07-00-07-E00028)the Open Fund of Jiangsu Key Laboratory of Electrochemical Energy Storage Technologies No.EEST2019-2.
文摘Magnesium hydride, with high specific capacity, favorable voltage profile and low voltage hysteresis properties, is regarded as a promising anode for lithium storage. However, the rapid fading of capacity caused by huge volume change, low electron/ion conduction, and spontaneous agglomeration of active materials during cycling greatly limit its practical application in lithium-ion batteries. Herein, we report the synthesis of monodisperse MgH2 nanoparticles with an average particle size of <20 nm homogeneously anchored on Ti3C2 MXene sheets by bottom-up self-assembly strategy. The unique nanoarchitectures are able to efficiently enhance the lithium insertion/extraction kinetics, accelerate the electron/lithium ion transfer and buffer the strain of volume changes. More importantly, the formed F–Mg bounding between MgH2 and MXene could avoid the shedding of MgH2 nanoparticles to electrolyte during cycling, which significantly enhance the capacity, cyclability, and rate performance of magnesium hydride. Moreover, due to the high density of MXene and the synergistic effect between the MgH2 and MXene matrix, the MgH2/MXene composite with 60 wt% MgH2 delivers a superior volumetric capacity of 1092.9 mAh cm−3 at a current density of 2000 mA g^(−1) after 1000 cycles. These results highlight the great promising of MgH2/MXene composite for high performance lithium-ion batteries.
基金supported by the National Natural Science Fundation of China(U1162203,21106185)the Fundamental Research Funds for the Central Universities(15CX02023A,15CX06051A)Financial support from Petro China Corporation Limited~~
文摘This paper reports a sustainable,water-assisted,solid-state method for synthesizing ammonium nickel molybdate（（NH4）HNi2（OH）2（MoO4）2,ANM）,a precursor for an unsupported hydrodesulfurization（HDS） catalyst.The associated ANM formation mechanism is also discussed.The synthesis route consists of physical mixing of the raw materials,water-assisted grinding and heating.The formation mechanism involves replacement of a Mo atom by a Ni atom,generating the metastable intermediate（NH4）4（NiH6Mo6O（24））·5H2O.Heating of this intermediate at 120 ℃ removes the added water and produces ANM.Catalysts prepared by this method exhibit almost the same physicochemical properties and catalytic performance during the HDS of dibenzothiophene as materials made from ANM synthesized by a chemical precipitation procedure.Compared with traditional hydrothermal or chemical precipitation methods,this water-assisted,solid-state synthesis provides several significant advantages,including simplifying the synthetic procedure,reducing waste and energy costs and increasing product yields.These features will be highly important with regard to allowing the application of ANM in industrial-scale processes involving HDS reactions.This water-assisted,solid-state strategy can also be extended to the synthesis of isomorphous compounds such as ammonium cobalt（zinc and copper） molybdate.
基金This work was supported by the Natural Science Foundation of Hebei Province(Grant No.C2021201048)the Interdisciplinary Research Program of Natural Science of Hebei University(Grant No.513201422004)。
文摘Okra(Abelmoschus esculentus)is an important vegetable crop with high nutritional value.However,the mechanism underlying its high nutrient content remains poorly understood.Here,we present a chromosome-scale genome of okra with a size of 1.19 Gb.Comparative genomics analysis revealed the phylogenetic status of A.esculentus,as well as whole-genome duplication(WGD)events that have occurred widely across the Malvaceae species.We found that okra has experienced three additional WGDs compared with the diploid cotton Gossypium raimondii,resulting in a large chromosome number(2n=130).After three WGDs,okra has undergone extensive genomic deletions and retained substantial numbers of genes related to secondary metabolite biosynthesis and environmental adaptation,resulting in significant differences between okra and G.raimondii in the gene families related to cellulose synthesis.Combining transcriptomic and metabolomic analysis,we revealed the relationship between gene expression and metabolite content change across different okra developmental stages.Furthermore,the sinapic acid/S-lignin biosynthesis-related gene families have experienced remarkable expansion in okra,and the expression of key enzymes involved in the sinapic acid/S-lignin biosynthesis pathway vary greatly across developmental periods,which partially explains the differences in metabolite content across the different stages.Our study gains insights into the comprehensive evolutionary history of Malvaceae species and the genetic basis that underlies the nutrient content changes in okra,which will facilitate the functional study and genetic improvement of okra varieties.
文摘[Objectives] To analyze the low melting point fat constituents in the black soybeans with green and yellow heart and their relative content,and compare the differences in the low melting point fat constituents between different kinds of black soybeans. [Methods] Using HS-SPME-GC-MS,the qualitative analysis was performed on the low melting point fat constituents of black soybeans; using peak area normalization method,the relative content of constituents was calculated. [Results]A total of 42 peaks were identified from the low melting point fat constituents of the black soybeans with yellow heart,and 18 kinds of chemical constituents were identified,accounting for 81.39% of total relative content of low melting point fat constituents; a total of 37 peaks were identified from the low melting point fat constituents of the black soybeans with green heart,and 15 kinds of chemical constituents were identified,accounting for 83.24% of total relative content of low melting point fat constituents. There were 9 kinds of common chemical constituents for the two kinds of black soybeans,and 5-allylguaiacol had the highest relative content,followed by hexanol. [Conclusions] There was no significant difference in the low melting point fat constituents between two kinds of black soybeans.
文摘The solidified microstructure of a Ni-Cu-Si cast alloy has been investigated, and a kind of banding structure was observed. The results showed that, the banding structure was composed of coarser particles which were Ni3Si type of precipitates and similar to the fine particles precipitate uniformly distributed within matrix of Ni solid solution, in both crystal structure and composition. The formation of bandings was resulted from cast thermal stress and dislocation walls. It was found that the cracks propagated along these bandings in tensile test. The banding structure can be depressed by reducing the cast thermal stress, which can improve the tensile ductility.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 91850117 and 11654003)Beijing Institute of Technology Research Fund Program for Young Scholars
文摘Photonic-plasmonic hybrid microcavities,which possess a higher figure of merit Q/V(the ratio of quality factor to mode volume)than that of pure photonic microcavities or pure plasmonic nano-antennas,play key roles in enhancing light–matter interaction.In this review,we summarize the typical photonic-plasmonic hybrid microcavities,such as photonic crystal microcavities combined with plasmonic nano-antenna,whispering gallery mode microcavities combined with plasmonic nano-antenna,and Fabry–Perot microcavities with plasmonic nano-antenna.The physics and applications of each hybrid photonic-plasmonic system are illustrated.The recent developments of topological photonic crystal microcavities and topological hybrid nano-cavities are also introduced,which demonstrates that topological microcavities can provide a robust platform for the realization of nanophotonic devices.This review can bring comprehensive physical insights of the hybrid system,and reveal that the hybrid system is a good platform for realizing strong light–matter interaction.
基金Supported by Fund of Guangxi Key Laboratory of Biology for Crop Diseases and Insect Pests (2020-ST-05)Science and Technology Major Project of Guangxi (GK AA17202017-2).
文摘[Objectives]The use of natural enemies of living insects and their derivatives can effectively avoid the problems of pesticide residues,pest resistance,biodiversity decline,control effect weakening and so on.[Methods]Parasites inject various parasitic factors into hosts to inhibit the development of hosts,adjust the immunity of hosts,interfere with the growth and development of hosts,and reduce the nutrition metabolism of hosts,so as to ensure the growth and development of the offspring.Host pests can escape or conquer the parasitism of parasitic wasps through immune defense system in order to reproduce their own offspring.[Results]Under intense and strong selection pressure,in order to effectively ensure the success rate of parasitism,the adaptive diversity of parasitism strategies of parasitic wasps is finally caused.In the process of evolution and under the pressure of directional selection,the innate immunity and acquired immunity gradually evolve.[Conclusions]In-depth research on parasitic factors of parasitic wasps and their interaction with crop pests immunity and development can not only improve theoretical understanding of insect immunity and development biology,pest biological control and other disciplines,but also be expected to enable the application of some components of parasitic factors to agriculture,medicine and pharmacy.Bactrocera dorsalis is a destructive fruit and vegetable pest.This paper summarized the venom protein of B.dorsalis parasitoids and the immune interaction with hosts,in order to provide theoretical basis for biological control of plant pests by using parasitic natural enemies.
文摘The upgrading of diesel oil to produce ethylene rich cracking feedstock is an important and promising technical route to reduce the ratio of diesel to gasoline. In the present work, a hydrocracking catalyst suitable for selective hydrocracking of straight run diesel oil to produce high-quality ethylene cracking feedstock at low cost was developed, by optimizing the composition of catalyst support materials, using amorphous silicon aluminum and aluminum oxide with high mesopore content as the main support, and modified Y zeolite with excellent aromatic ring opening selectivity as the acidic component. The catalyst has in-depth characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, N<sub>2</sub>-low temperature adsorption-desorption, NH<sub>3</sub>-temperature-programmed desorption, and IR techniques. And its catalytic cracking straight run diesel oil performance was evaluated. The results show that the prepared catalyst has high polycyclic aromatic hydrocarbon ring opening cracking selectivity. However, alkanes retained in diesel distillates can achieve the goal of producing more ethylene cracking feedstocks with low BMCI value under low and moderate pressure conditions. This work may shed significant technical insight for oil refining transformation.
文摘Gualou Xiebai is a basic prescription for the treatment of angina pectoris in Synopsis of the Golden Chamber.This article is a summary of the theoretical research and clinical application of Gualou Xiebai,in hope to promote the use of Gualou Xiebai in clinical practice.
基金supported by the Natural Science Foundation of Hebei Province (grant C2021201048)the National Natural Science Foundation of China (grant 32100500)the Young Elite Scientists Sponsorship Program by CAST grant YESS20210080.
文摘Rheum officinale,a member of the Polygonaceae family,is an important medicinal plant that is widely used in traditional Chinese medicine.Here,we report a 7.68-Gb chromosome-scale assembly of R.officinale with a contig N50 of 3.47 Mb,which was clustered into 44 chromosomes across four homologous groups.Comparative genomics analysis revealed that transposable elements have made a significant contribution to its genome evolution,gene copy number variation,and gene regulation and expression,particularly of genes involved in metabolite biosynthesis,stress resistance,and root development.We placed the recent autotetraploidization of R.officinale at~0.58 mya and analyzed the genomic features of its homol-ogous chromosomes.Although no dominant monoploid genomes were observed at the overall expression level,numerous allele-differentially-expressed genes were identified,mainly with different transposable element insertions in their regulatory regions,suggesting that they functionally diverged after polyploidization.Combining genomics,transcriptomics,and metabolomics,we explored the contributions of gene family amplification and tetraploidization to the abundant anthraquinone production of R.officinale,as well as gene expression patterns and differences in anthraquinone content among tissues.Our report of-fers unprecedented genomic resources for fundamental research on the autopolyploid herb R.officinale and guidance for polyploid breeding of herbs.
基金supported by the National Basic Research Program of China (2022YFA1603701, 2021YFA1200900)the institutionalized scientific research platform relies on Beijing Synchrotron Radiation Facility of Chinese Academy of Sciences,the Strategic Priority Research Program of Chinese Academy of Sciences (XDB36000000)+2 种基金the National Natural Science Foundation of China (22027810, 82341044,22388101 and 22307028)the CAMS Innovation Fund for Medical Sciences(CIFMS 2019-I2M-5-018)the New Cornerstone Science Foundation。
文摘With the advancement of modern science and technology, large scientific facilities are increasingly oriented toward demand and application, and can be used for basic research as well as serving multiple disciplines. Developing large scientific facilities and related analytical technologies enhances understanding of large scientific facilities and popularizes their application in research across multiple disciplines. The combination of light or neutron sources from large scientific facilities and advanced analytical technologies can be achieved for materials structure information, dynamics study of chemical reactions, high dissociation of biomolecules, 3D visualization of energy materials or biological samples, etc. We first introduce the progress of domestic large scientific facilities of synchrotron radiation(SR) and free electron lasers(FELs) with different wavelengths and neutron sources.We further discuss the comparison between Chinese and typical foreign facilities in X-ray radiation from X-ray tubes, synchrotrons, X-ray FELs, and neutron sources based on physical parameters of light and neutron sources. In addition, we focus on the technological progress and perspectives combined with advanced X-ray radiation and neutron sources of large scientific facilities in China, especially in the nanoscience fields of energy catalysis and biological science. We hope that this roadmap will provide references on technology and methods to experimental users, as well as prospects for future development of technologies based on large research infrastructure facilities. Comprehensive studies and guidelines for basic research to practical application in various disciplines can be made with the assistance of large scientific facilities.
基金supported by the National Natural Science Foundation of China(no.32220103009)the China Agriculture Research System of MOF and MARA(No.CARS-26)and Hubei Hongshan Laboratory.
文摘Genes on the Y chromosome play important roles in male sex determination and development.The identification of Y-chromosome-specific genes not only provides a theoretical basis for the study of male reproductive development,but also offers genetic control targets for agricultural pests.However,Y-chromosome genes are rarely characterized due to their high repeatability and high heterochromatinization,especially in the oriental fruit fly.In this study,1011 Y-chromosome-specific candidate sequences were screened from 2 to 4 h Bactrocera dorsalis embryo datasets with the chromosome quotient method,6 of which were identified as Y-chromosome-specific sequences by polymerase chain reaction,including typo-gyf,a 19126-bp DNA sequence containing a 575-amino acid open reading frame.Testicular deformation and a significant reduction in sperm number were observed after typo-gyf knockdown with RNA interference in embryos.After typo-gyf knockout with clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated protein 9 in the embryonic stage,the sex ratio of the emergent adults was unbalanced,with far more females than males.A genotype analysis of these females with the Y-chromosome gene MoY revealed no sex reversal.Typo-gyf knockout led to the death of XY individuals in the embryonic stage.We conclude that typo-gyf is an essential gene for male survival,and is also involved in testicular development and spermatogenesis.The identification of typo-gyf and its functional verification provide insight into the roles of Y-chromosome genes in male development.
