The inflammasome is a multiprotein oligomer in the cell cytoplasm and is part of the innate immune system.It plays a crucial role in the pathological process of noise-induced hearing loss(NIHL).However,the mechanisms ...The inflammasome is a multiprotein oligomer in the cell cytoplasm and is part of the innate immune system.It plays a crucial role in the pathological process of noise-induced hearing loss(NIHL).However,the mechanisms of NLR family pyrin domain containing 3(NLRP3)inflammasome activation in NIHL have not been clearly demonstrated.In this study,miniature pigs were exposed to white noise at 120 dB(A)and auditory brainstem response measurements were used to measure their hearing function.Immunofluorescence staining,confocal laser scanning microscopy,western blot assay,and quantitative reverse transcription-polymerase chain reaction were used to analyze inflammasome-related protein distribution and expression.NLRP3,interleukin-1β,interleukin-18,and cleaved-caspase-1 were highly expressed in the cochlea after 120 dB(A)white noise exposure.Our findings suggest that NLRP3-inflammasomes in the cochlea may be activated after acoustic trauma,which may be an important mechanism of noise-induced hearing loss.展开更多
Clostridium difficile infection (CDI) was generally considered as a hospital-associated disease;however, recent community-acquired CDI has raised the concerns regarding the transmission of the pathogen through environ...Clostridium difficile infection (CDI) was generally considered as a hospital-associated disease;however, recent community-acquired CDI has raised the concerns regarding the transmission of the pathogen through environmental sources. Limited data are available regarding the presence of C. difficile in food and water. In this study, oysters (Crassostrea virginica) and the harvest water collected from the commercial harvesting areas along the Louisiana Gulf Coast as well as the influent and effluent of a municipal treatment plant in New Orleans, LA were analyzed for toxigenic C. difficile. The bacterium was isolated from 47.37% (9/19) of oysters and 37.5% (3/8) of harvest water samples. Toxigenic C. difficile were also detected in all the wastewater influent and effluent samples. All the isolates harbored the gene tcdB encoding the virulence factor toxin B. Further PCR-ribotyping showed that the C. difficile isolated from the oysters and harvest water differed from the wastewater isolates. However, similar ribotypes were found in oysters and the surrounding harvest water. We found that oysters growing in contaminated water could bioaccumulate toxigenic C. difficile and pose a health risks by serving as a vehicle for the transmission of the pathogen to humans.展开更多
Rhizoma Coptidis,a traditional Chinese herbal medicine,has been used for treating diabetes for thousands of years.However,the molecular basis for this action has not been elucidated.In the present study,the effects of...Rhizoma Coptidis,a traditional Chinese herbal medicine,has been used for treating diabetes for thousands of years.However,the molecular basis for this action has not been elucidated.In the present study,the effects of seven main alkaloids of Rhizoma Coptidis on glycometabolism were investigated and the related molecular mechanism of five active compounds on insulin resistant(IR)cell model was explored for the first time.Results showed that berberine,palmatine,epiberberine,columbamine and groenlandicine enhanced glucose consumption in the palmitic acid(PA)-induced IR-HepG2 cells,indicating that these compounds could improve IR.In addition,we found that among these active alkaloids,berberine,columbamine,epiberberine and groenlandicine could inhibit the activation of ERK and p38 pathway,while berberine,columbamine,palmatine and epiberberine could activate AMPK pathway.Moreover,palmatine and columbamine regulated the mRNA expression of GLUT2 to ameliorate IR via activating AMPK and inactivating p38 MAPK signal pathway.To sum up,berberine,columbamine,palmatine,epiberberine and groenlandicine might be the active reagents,which contribute to the glucose lowering effects of Rhizoma Coptidis.展开更多
Target detection is always an important application in hyperspectral image processing field. In this paper, a spectral-spatial target detection algorithm for hyperspectral data is proposed.The spatial feature and spec...Target detection is always an important application in hyperspectral image processing field. In this paper, a spectral-spatial target detection algorithm for hyperspectral data is proposed.The spatial feature and spectral feature were unified based on the data filed theory and extracted by weighted manifold embedding. The novelties of the proposed method lie in two aspects. One is the way in which the spatial features and spectral features were fused as a new feature based on the data field theory, and the other is that local information was introduced to describe the decision boundary and explore the discriminative features for target detection. The extracted features based on data field modeling and manifold embedding techniques were considered for a target detection task.Three standard hyperspectral datasets were considered in the analysis. The effectiveness of the proposed target detection algorithm based on data field theory was proved by the higher detection rates with lower False Alarm Rates(FARs) with respect to those achieved by conventional hyperspectral target detectors.展开更多
Nanocrystalline Hf B2 powders were successfully synthesized by molten salt synthesis technique at 1373 K using B and Hf O2 as precursors within KCl/Na Cl molten salts.The results showed that the as-synthesized powders...Nanocrystalline Hf B2 powders were successfully synthesized by molten salt synthesis technique at 1373 K using B and Hf O2 as precursors within KCl/Na Cl molten salts.The results showed that the as-synthesized powders exhibited an irregular polyhedral morphology with the average particle size of 155 nm and possessed a single-crystalline structure.From a fundamental aspect,we demonstrated the molten-salt assisted formation mechanism that the molten salts could accelerate the diffusion rate of the reactants and improve the chemical reaction rate of the reactants in the system to induce the synthesis of the high-purity nanocrystalline powders.Thermogravimetric analysis showed that the oxidation of the as-synthesized Hf B2 powders at 773–1073 K in air was the weight gain process and the corresponding oxidation behavior followed parabolic kinetics governed by the diffusion of oxygen in the oxide layer.展开更多
Tropical cyclones(TCs),including tropical depressions and different categories of typhoons,hurricanes,and cyclonic storms,mostly originate over the oceans in the absence of direct observations.Thus,detailed monitoring...Tropical cyclones(TCs),including tropical depressions and different categories of typhoons,hurricanes,and cyclonic storms,mostly originate over the oceans in the absence of direct observations.Thus,detailed monitoring and analysis of TCs has always been an unsolved problem.In the recent 20 years,great changes have taken place in domestic and foreign TC monitoring techniques,imposing a significant impact on TC operations and research.Some new technologies and products gradually emerge to support operations,with improved monitoring accuracy.In this paper,the progress on TC monitoring and analysis via meteorological satellites,radars,and airplanes in China and the world is reviewed,compared,and summarized,with special focuses on multisatellite fusion observations,in situ aircraft measurements,and some unconventional observation equipment such as rockets,saildrones,and underwater gliders.On this basis,the paper points out future directions for improving TC monitoring and analysis in aid of better TC forecast and early warning.展开更多
[目的]2016年以来,新疆阿克苏等地区出现了一种新的枣树病害,严重威胁当地及周边红枣产业。本研究旨在鉴定引起此次病害的病原,探究病原体的传播方式,为生物防治策略的开发提供研究基础。[方法]对发病植株进行小RNA测序以鉴定病原体;对...[目的]2016年以来,新疆阿克苏等地区出现了一种新的枣树病害,严重威胁当地及周边红枣产业。本研究旨在鉴定引起此次病害的病原,探究病原体的传播方式,为生物防治策略的开发提供研究基础。[方法]对发病植株进行小RNA测序以鉴定病原体;对新鉴定的病毒,通过RNAseq和反转录PCR获取病毒全序列;体外表达重组的病毒结构蛋白并制备特异性抗体,通过Western斑点杂交法在发病植株中确证病毒蛋白;收集发病区域的媒介昆虫,通过反转录PCR在昆虫体内检测病毒的基因组,鉴定可能的传毒介体。[结果]本研究鉴定一种新的欧洲山梣环斑病毒属病毒为新疆新发枣树病害可能的病原体,命名为中国枣树花叶伴随病毒(Chinese date mosaic-associated virus,CDMaV)。CDMaV是一种多分段单链RNA病毒,基因组由5条负义RNA组成;RNA1-RNA5大小分别为7160、2224、1230、1493、971 nt,每条基因组RNA的互补链包含一个开放阅读框,共编码5个蛋白,依次为依赖RNA的RNA聚合酶、包膜糖蛋白、核衣壳蛋白和两个未知功能蛋白。在枣树寄生虫枣瘿螨体内扩增到病毒序列,表明该病毒可能以枣瘿螨为介体在枣树间进行传播。[结论]本研究为新疆新发枣树病害鉴定了相关病原体CDMaV,完成CDMaV全基因组测序,并鉴定枣瘿螨为可能的传毒介体。鉴定病原体和传播介体是建立病害防治方法的必要基础。展开更多
High-entropy nanomaterials have been arousing considerable interest in recent years due to their huge composition space,unique microstructure,and adjustable properties.Previous studies focused mainly on high-entropy n...High-entropy nanomaterials have been arousing considerable interest in recent years due to their huge composition space,unique microstructure,and adjustable properties.Previous studies focused mainly on high-entropy nanoparticles,while other high-entropy nanomaterials were rarely reported.Herein,we reported a new class of high-entropy nanomaterials,namely(Tao2Nbo2Ti.2Wo.2Moo2)B2 high-entropy diboride(HEB-1)nanoflowers,for the first time.Formation possibility of HEB-1 was first theoretically analyzed from two aspects of lattice size difference and chemical reaction thermodynamics.We then successfully synthesized HEB-1 nanoflowers by a facile molten salt synthesis method at 1423 K.The as-synthesized HEB-1 nanoflowers showed an interesting chrysanthemum-like morphology assembled from numerous well-aligned nanorods with diameters of 20--30 nm and lengths of 100-200 nm.Meanwhile,these nanorods possessed a single-crystalline hexagonal structure of metal diborides and highly compositional uniformity from nanoscale to microscale.In addition,the formation of the as-synthesized HEB-I nanoflowers could be well interpreted by a classical surface-contolled crystal growth theory.This work not only enriches the categories of high-entropy nanomaterials but also opens up a new research field on high-entropy diboride nanomaterials.展开更多
High-entropy ceramics(HECs) are gaining significant interest due to their huge composition space, unique microstructure, and adjustable properties. Previously reported studies focus mainly on HECs with the multi-catio...High-entropy ceramics(HECs) are gaining significant interest due to their huge composition space, unique microstructure, and adjustable properties. Previously reported studies focus mainly on HECs with the multi-cationic structure, while HECs with more than one anion are rarely studied. Herein we reported a new class of HECs, namely highentropy alumino-silicides(Mo0.25Nb0.25Ta0.25V0.25)(Al0.5Si0.5)2(HEAS-1) with multi-cationic and-anionic structure. The formation possibility of HEAS-1 was first theoretically analyzed from the aspects of thermodynamics and lattice size difference based on the first-principles calculations and then the HEAS-1 were successfully synthesized by the solid-state reaction at 1573K. The as-synthesized HEAS-1 exhibited good single-crystal hexagonal structure of metal alumino-silicides and simultaneously possessed high compositional uniformity.This study not only enriches the categories of HECs but also will open up a new research field on HECs with multi-cationic and-anionic structure.展开更多
Plant endophytic bacteria colonize the internal tissues of plants and interact with plants closely.The past two decades have witnessed the increasing application of next-generation 16S r RNA gene sequencing in the inv...Plant endophytic bacteria colonize the internal tissues of plants and interact with plants closely.The past two decades have witnessed the increasing application of next-generation 16S r RNA gene sequencing in the investigation of bacterial communities.However,deciphering plant endo-bacterial communities by this method is difficult because of the co-amplification of massive plant organellar DNAs with bacterial 16S.Here,we designed polymerase chain reaction(PCR) primer sets,including799F/1107R,322F/796R,and 322F-Dr/796Rs(primer pair 322F/796R with a penultimate-base substitution in 322F),that can specifically amplify bacterial 16S from plant total DNAs.We computationally and experimentally evaluated the specificity,coverage,and accuracy of the newly designed primer sets.Both 799F/1107R and 322F-Dr/796Rs produced plant DNA-free 16S amplicon libraries or reduced plant DNA contamination to lower than 5% for the plant materials with extremely-low-abundance bacterial communities.The primer set 322F-A/796R was used through absolute quantitative PCR to quantitate the population size of rice leaf or root endo-bacteriome,which revealed 10^(6)–10^(7) and 10^(9)–10^(10) bacteria per gram fresh weight,respectively.These 16S primer sets and amplification methods enable the simple and inexpensive next-generation sequencing and quantification of plant endo-bacteriome,which will significantly advance studies on the plant-related microbiome.展开更多
Targeted genome modifications with the Cas9/gRNA system derived from the clustered regularly interspaced short palin- dromic repeat/CRISPR-associated (CRISPR/Cas) system have been successfully used in cultured human...Targeted genome modifications with the Cas9/gRNA system derived from the clustered regularly interspaced short palin- dromic repeat/CRISPR-associated (CRISPR/Cas) system have been successfully used in cultured human cells as well as in most model organisms, including zebrafish (Danio rerio), mouse, and fruit fly (Chang et al., 2013; Cong et al., 2013; Gratz et al., 2013; Hwang et al., 2013; Jao et al., 2013; Shen et al., 2013; Wei et al., 2013). Its application in zebrafish is particu- larly attractive due to the ease of handling this organism and the simple application of this method by direct injection of Cas9/ gRNA. However, the information about its specificity in this organism is very limited and needs further evaluation. In addition, it is conceivable that a Cas9 mRNA optimized for zebrafish codon preference could enhance its activity.展开更多
Mammals exhibit limited heart regeneration ability,which can lead to heart failure after myocardial infarction.In contrast,zebrafish exhibit remarkable cardiac regeneration capacity.Several cell types and signaling pa...Mammals exhibit limited heart regeneration ability,which can lead to heart failure after myocardial infarction.In contrast,zebrafish exhibit remarkable cardiac regeneration capacity.Several cell types and signaling pathways have been reported to participate in this process.However,a comprehensive analysis of how different cells and signals interact and coordinate to regulate cardiac regeneration is unavailable.We collected major cardiac cell types from zebrafish and performed high-precision single-cell transcriptome analyses during both development and post-injury regeneration.We revealed the cellular heterogeneity as well as the molecular progress of cardiomyocytes during these processes,and identified a subtype of atrial cardiomyocyte exhibiting a stem-like state which may transdifferentiate into ventricular cardiomyocytes during regeneration.Furthermore,we identified a regeneration-induced cell(RIC)population in the epicardium-derived cells(EPDC),and demonstrated Angiopoietin 4(Angpt4)as a specific regulator of heart regeneration.angpt4 expression is specifically and transiently activated in RIC,which initiates a signaling cascade from EPDC to endocardium through the Tie2-MAPK pathway,and further induces activation of cathepsin K in cardiomyocytes through RA signaling.Loss of angpt4 leads to defects in scar tissue resolution and cardiomyocyte proliferation,while overexpression of angpt4 accelerates regeneration.Furthermore,we found that ANGPT4 could enhance proliferation of neonatal rat cardiomyocytes,and promote cardiac repair in mice after myocardial infarction,indicating that the function of Angpt4 is conserved in mammals.Our study provides a mechanistic understanding of heart regeneration at single-cell precision,identifies Angpt4 as a key regulator of cardiomyocyte proliferation and regeneration,and offers a novel therapeutic target for improved recovery after human heart injuries.展开更多
A highly novel and direct synthesis of benzoxazinones was developed via Cp*Co(Ⅲ)-catalyzed C-H activation and[3+3]annulation between sulfoxonium ylides and dioxazolones.The reaction is conducted under base-free condi...A highly novel and direct synthesis of benzoxazinones was developed via Cp*Co(Ⅲ)-catalyzed C-H activation and[3+3]annulation between sulfoxonium ylides and dioxazolones.The reaction is conducted under base-free conditions and tolerates various functional groups.Starting from diverse readily available sulfoxonium ylides and dioxazolones,a variety of benzoxazinones could be synthesized in one step in 32%-75%yields.展开更多
The preparation and regeneration conditions of the identified catalyst X/Y/MgO/?-Al2O3 with high catalytic activity were studied and optimized. The biodiesel was prepared by transesterification of Jatropha curcas see...The preparation and regeneration conditions of the identified catalyst X/Y/MgO/?-Al2O3 with high catalytic activity were studied and optimized. The biodiesel was prepared by transesterification of Jatropha curcas seed oil produced in Guizhou with methanol at its reflux temoerature in the presence of X/Y/MgO/?-Al2O3 . The pilot plant tests were carried out in a 100 L reaction vessel. Both average yield and fatty acid methyl esters (FAME) content reached more than 96.50% under the optimum reaction conditions of the pilot plant tests designed with an oil/methanol molar ratio of 1 : 10, catalyst concentration of 1.00%, and reaction time of 3 h at reflux temperature. In addition, analysis shows that the quality of biodiesel meets the standard EN 14214.展开更多
基金supported by the National Key Research and Development Program of China, No.2020YFC2005200(to WWG and WJH)the National Nature Science Foundation of China, Nos.81770992(to NS and WJH), 81970897(to WWG)+1 种基金Health and Family Planning System Research Project of Shenzhen Municipality, No.SZXJ2018079(to YYY)Shenzhen Sanming Project, No.SZSM201612076(to YYY)
文摘The inflammasome is a multiprotein oligomer in the cell cytoplasm and is part of the innate immune system.It plays a crucial role in the pathological process of noise-induced hearing loss(NIHL).However,the mechanisms of NLR family pyrin domain containing 3(NLRP3)inflammasome activation in NIHL have not been clearly demonstrated.In this study,miniature pigs were exposed to white noise at 120 dB(A)and auditory brainstem response measurements were used to measure their hearing function.Immunofluorescence staining,confocal laser scanning microscopy,western blot assay,and quantitative reverse transcription-polymerase chain reaction were used to analyze inflammasome-related protein distribution and expression.NLRP3,interleukin-1β,interleukin-18,and cleaved-caspase-1 were highly expressed in the cochlea after 120 dB(A)white noise exposure.Our findings suggest that NLRP3-inflammasomes in the cochlea may be activated after acoustic trauma,which may be an important mechanism of noise-induced hearing loss.
文摘Clostridium difficile infection (CDI) was generally considered as a hospital-associated disease;however, recent community-acquired CDI has raised the concerns regarding the transmission of the pathogen through environmental sources. Limited data are available regarding the presence of C. difficile in food and water. In this study, oysters (Crassostrea virginica) and the harvest water collected from the commercial harvesting areas along the Louisiana Gulf Coast as well as the influent and effluent of a municipal treatment plant in New Orleans, LA were analyzed for toxigenic C. difficile. The bacterium was isolated from 47.37% (9/19) of oysters and 37.5% (3/8) of harvest water samples. Toxigenic C. difficile were also detected in all the wastewater influent and effluent samples. All the isolates harbored the gene tcdB encoding the virulence factor toxin B. Further PCR-ribotyping showed that the C. difficile isolated from the oysters and harvest water differed from the wastewater isolates. However, similar ribotypes were found in oysters and the surrounding harvest water. We found that oysters growing in contaminated water could bioaccumulate toxigenic C. difficile and pose a health risks by serving as a vehicle for the transmission of the pathogen to humans.
基金supported by Technology Major Project of China“Key New Drug Creation and Manufacturing Program”(No.2017ZX09301012-001)the National Natural Science Foundation of China(No.20972098,No.81703776 and No.81430095)the National Basic Research Program of China(No.2014CB560706).
文摘Rhizoma Coptidis,a traditional Chinese herbal medicine,has been used for treating diabetes for thousands of years.However,the molecular basis for this action has not been elucidated.In the present study,the effects of seven main alkaloids of Rhizoma Coptidis on glycometabolism were investigated and the related molecular mechanism of five active compounds on insulin resistant(IR)cell model was explored for the first time.Results showed that berberine,palmatine,epiberberine,columbamine and groenlandicine enhanced glucose consumption in the palmitic acid(PA)-induced IR-HepG2 cells,indicating that these compounds could improve IR.In addition,we found that among these active alkaloids,berberine,columbamine,epiberberine and groenlandicine could inhibit the activation of ERK and p38 pathway,while berberine,columbamine,palmatine and epiberberine could activate AMPK pathway.Moreover,palmatine and columbamine regulated the mRNA expression of GLUT2 to ameliorate IR via activating AMPK and inactivating p38 MAPK signal pathway.To sum up,berberine,columbamine,palmatine,epiberberine and groenlandicine might be the active reagents,which contribute to the glucose lowering effects of Rhizoma Coptidis.
文摘Target detection is always an important application in hyperspectral image processing field. In this paper, a spectral-spatial target detection algorithm for hyperspectral data is proposed.The spatial feature and spectral feature were unified based on the data filed theory and extracted by weighted manifold embedding. The novelties of the proposed method lie in two aspects. One is the way in which the spatial features and spectral features were fused as a new feature based on the data field theory, and the other is that local information was introduced to describe the decision boundary and explore the discriminative features for target detection. The extracted features based on data field modeling and manifold embedding techniques were considered for a target detection task.Three standard hyperspectral datasets were considered in the analysis. The effectiveness of the proposed target detection algorithm based on data field theory was proved by the higher detection rates with lower False Alarm Rates(FARs) with respect to those achieved by conventional hyperspectral target detectors.
基金financial support from the National Key R&D Program of China (No. 2017YFB0703200)National Natural Science Foundation of China (Nos. 51802100 and 51972116)+1 种基金Young Elite Scientists Sponsorship Program by CAST (No. 2017QNRC001)the fund of the State Key Laboratory of Solidification Processing in NWPU (No. SKLSP201820)
文摘Nanocrystalline Hf B2 powders were successfully synthesized by molten salt synthesis technique at 1373 K using B and Hf O2 as precursors within KCl/Na Cl molten salts.The results showed that the as-synthesized powders exhibited an irregular polyhedral morphology with the average particle size of 155 nm and possessed a single-crystalline structure.From a fundamental aspect,we demonstrated the molten-salt assisted formation mechanism that the molten salts could accelerate the diffusion rate of the reactants and improve the chemical reaction rate of the reactants in the system to induce the synthesis of the high-purity nanocrystalline powders.Thermogravimetric analysis showed that the oxidation of the as-synthesized Hf B2 powders at 773–1073 K in air was the weight gain process and the corresponding oxidation behavior followed parabolic kinetics governed by the diffusion of oxygen in the oxide layer.
基金Supported by the National Natural Science Foundation of China(41930972)。
文摘Tropical cyclones(TCs),including tropical depressions and different categories of typhoons,hurricanes,and cyclonic storms,mostly originate over the oceans in the absence of direct observations.Thus,detailed monitoring and analysis of TCs has always been an unsolved problem.In the recent 20 years,great changes have taken place in domestic and foreign TC monitoring techniques,imposing a significant impact on TC operations and research.Some new technologies and products gradually emerge to support operations,with improved monitoring accuracy.In this paper,the progress on TC monitoring and analysis via meteorological satellites,radars,and airplanes in China and the world is reviewed,compared,and summarized,with special focuses on multisatellite fusion observations,in situ aircraft measurements,and some unconventional observation equipment such as rockets,saildrones,and underwater gliders.On this basis,the paper points out future directions for improving TC monitoring and analysis in aid of better TC forecast and early warning.
文摘[目的]2016年以来,新疆阿克苏等地区出现了一种新的枣树病害,严重威胁当地及周边红枣产业。本研究旨在鉴定引起此次病害的病原,探究病原体的传播方式,为生物防治策略的开发提供研究基础。[方法]对发病植株进行小RNA测序以鉴定病原体;对新鉴定的病毒,通过RNAseq和反转录PCR获取病毒全序列;体外表达重组的病毒结构蛋白并制备特异性抗体,通过Western斑点杂交法在发病植株中确证病毒蛋白;收集发病区域的媒介昆虫,通过反转录PCR在昆虫体内检测病毒的基因组,鉴定可能的传毒介体。[结果]本研究鉴定一种新的欧洲山梣环斑病毒属病毒为新疆新发枣树病害可能的病原体,命名为中国枣树花叶伴随病毒(Chinese date mosaic-associated virus,CDMaV)。CDMaV是一种多分段单链RNA病毒,基因组由5条负义RNA组成;RNA1-RNA5大小分别为7160、2224、1230、1493、971 nt,每条基因组RNA的互补链包含一个开放阅读框,共编码5个蛋白,依次为依赖RNA的RNA聚合酶、包膜糖蛋白、核衣壳蛋白和两个未知功能蛋白。在枣树寄生虫枣瘿螨体内扩增到病毒序列,表明该病毒可能以枣瘿螨为介体在枣树间进行传播。[结论]本研究为新疆新发枣树病害鉴定了相关病原体CDMaV,完成CDMaV全基因组测序,并鉴定枣瘿螨为可能的传毒介体。鉴定病原体和传播介体是建立病害防治方法的必要基础。
基金We acknowledge financial support from the National Key R&D Program of China(No.2017YFB0703200)National Natural Science Foundation of China(Nos.51802100 and 51972116)+1 种基金Young Elite Scientists Sponsorship Program by CAST(No.2017QNRC001)Guangdong Basic and Applied Basic Research Foundation(No.2019A1515012145).
文摘High-entropy nanomaterials have been arousing considerable interest in recent years due to their huge composition space,unique microstructure,and adjustable properties.Previous studies focused mainly on high-entropy nanoparticles,while other high-entropy nanomaterials were rarely reported.Herein,we reported a new class of high-entropy nanomaterials,namely(Tao2Nbo2Ti.2Wo.2Moo2)B2 high-entropy diboride(HEB-1)nanoflowers,for the first time.Formation possibility of HEB-1 was first theoretically analyzed from two aspects of lattice size difference and chemical reaction thermodynamics.We then successfully synthesized HEB-1 nanoflowers by a facile molten salt synthesis method at 1423 K.The as-synthesized HEB-1 nanoflowers showed an interesting chrysanthemum-like morphology assembled from numerous well-aligned nanorods with diameters of 20--30 nm and lengths of 100-200 nm.Meanwhile,these nanorods possessed a single-crystalline hexagonal structure of metal diborides and highly compositional uniformity from nanoscale to microscale.In addition,the formation of the as-synthesized HEB-I nanoflowers could be well interpreted by a classical surface-contolled crystal growth theory.This work not only enriches the categories of high-entropy nanomaterials but also opens up a new research field on high-entropy diboride nanomaterials.
基金supported by the National Key Research and Development Program of China (2017YFB0703200)Young Elite Scientists Sponsorship Program by China Association for Science and Technology (2017QNRC001)the National Natural Science Foundation of China (51802100 and 51972116)
文摘High-entropy ceramics(HECs) are gaining significant interest due to their huge composition space, unique microstructure, and adjustable properties. Previously reported studies focus mainly on HECs with the multi-cationic structure, while HECs with more than one anion are rarely studied. Herein we reported a new class of HECs, namely highentropy alumino-silicides(Mo0.25Nb0.25Ta0.25V0.25)(Al0.5Si0.5)2(HEAS-1) with multi-cationic and-anionic structure. The formation possibility of HEAS-1 was first theoretically analyzed from the aspects of thermodynamics and lattice size difference based on the first-principles calculations and then the HEAS-1 were successfully synthesized by the solid-state reaction at 1573K. The as-synthesized HEAS-1 exhibited good single-crystal hexagonal structure of metal alumino-silicides and simultaneously possessed high compositional uniformity.This study not only enriches the categories of HECs but also will open up a new research field on HECs with multi-cationic and-anionic structure.
基金supported by the Major Program of the National Natural Science Foundation of China (32090013)the National Transgenic Major Project of China (2019ZX08010-004)the National Natural Science Foundation of China (31871932)。
文摘Plant endophytic bacteria colonize the internal tissues of plants and interact with plants closely.The past two decades have witnessed the increasing application of next-generation 16S r RNA gene sequencing in the investigation of bacterial communities.However,deciphering plant endo-bacterial communities by this method is difficult because of the co-amplification of massive plant organellar DNAs with bacterial 16S.Here,we designed polymerase chain reaction(PCR) primer sets,including799F/1107R,322F/796R,and 322F-Dr/796Rs(primer pair 322F/796R with a penultimate-base substitution in 322F),that can specifically amplify bacterial 16S from plant total DNAs.We computationally and experimentally evaluated the specificity,coverage,and accuracy of the newly designed primer sets.Both 799F/1107R and 322F-Dr/796Rs produced plant DNA-free 16S amplicon libraries or reduced plant DNA contamination to lower than 5% for the plant materials with extremely-low-abundance bacterial communities.The primer set 322F-A/796R was used through absolute quantitative PCR to quantitate the population size of rice leaf or root endo-bacteriome,which revealed 10^(6)–10^(7) and 10^(9)–10^(10) bacteria per gram fresh weight,respectively.These 16S primer sets and amplification methods enable the simple and inexpensive next-generation sequencing and quantification of plant endo-bacteriome,which will significantly advance studies on the plant-related microbiome.
基金partially supported by the National Natural Science Foundation of China (No. 31110103904)the National Program on Key Basic Research Project (973 Program) of the Ministry of Science and Technology of China (Nos. 2011CBA01000 and 2012CB945101)
文摘Targeted genome modifications with the Cas9/gRNA system derived from the clustered regularly interspaced short palin- dromic repeat/CRISPR-associated (CRISPR/Cas) system have been successfully used in cultured human cells as well as in most model organisms, including zebrafish (Danio rerio), mouse, and fruit fly (Chang et al., 2013; Cong et al., 2013; Gratz et al., 2013; Hwang et al., 2013; Jao et al., 2013; Shen et al., 2013; Wei et al., 2013). Its application in zebrafish is particu- larly attractive due to the ease of handling this organism and the simple application of this method by direct injection of Cas9/ gRNA. However, the information about its specificity in this organism is very limited and needs further evaluation. In addition, it is conceivable that a Cas9 mRNA optimized for zebrafish codon preference could enhance its activity.
基金the National Key Research and Development Program of China and the National Natural Science Foundation of China(NSFC)(Grant Nos.2018YFA0801001,32070824,31871458,2019YFA0802800,2016YFA0100500,31671500,81371264,31671177,and 2018YFA0800501).
文摘Mammals exhibit limited heart regeneration ability,which can lead to heart failure after myocardial infarction.In contrast,zebrafish exhibit remarkable cardiac regeneration capacity.Several cell types and signaling pathways have been reported to participate in this process.However,a comprehensive analysis of how different cells and signals interact and coordinate to regulate cardiac regeneration is unavailable.We collected major cardiac cell types from zebrafish and performed high-precision single-cell transcriptome analyses during both development and post-injury regeneration.We revealed the cellular heterogeneity as well as the molecular progress of cardiomyocytes during these processes,and identified a subtype of atrial cardiomyocyte exhibiting a stem-like state which may transdifferentiate into ventricular cardiomyocytes during regeneration.Furthermore,we identified a regeneration-induced cell(RIC)population in the epicardium-derived cells(EPDC),and demonstrated Angiopoietin 4(Angpt4)as a specific regulator of heart regeneration.angpt4 expression is specifically and transiently activated in RIC,which initiates a signaling cascade from EPDC to endocardium through the Tie2-MAPK pathway,and further induces activation of cathepsin K in cardiomyocytes through RA signaling.Loss of angpt4 leads to defects in scar tissue resolution and cardiomyocyte proliferation,while overexpression of angpt4 accelerates regeneration.Furthermore,we found that ANGPT4 could enhance proliferation of neonatal rat cardiomyocytes,and promote cardiac repair in mice after myocardial infarction,indicating that the function of Angpt4 is conserved in mammals.Our study provides a mechanistic understanding of heart regeneration at single-cell precision,identifies Angpt4 as a key regulator of cardiomyocyte proliferation and regeneration,and offers a novel therapeutic target for improved recovery after human heart injuries.
基金financial support from the Hunan Provincial Innovation Foundation for Postgraduate(No.CX20190267)Natural Science Foundation of Hunan Province(No.2020JJ4171)。
文摘A highly novel and direct synthesis of benzoxazinones was developed via Cp*Co(Ⅲ)-catalyzed C-H activation and[3+3]annulation between sulfoxonium ylides and dioxazolones.The reaction is conducted under base-free conditions and tolerates various functional groups.Starting from diverse readily available sulfoxonium ylides and dioxazolones,a variety of benzoxazinones could be synthesized in one step in 32%-75%yields.
基金supported by the Key Science and Technology Project of Guizhou(No.20076004).
文摘The preparation and regeneration conditions of the identified catalyst X/Y/MgO/?-Al2O3 with high catalytic activity were studied and optimized. The biodiesel was prepared by transesterification of Jatropha curcas seed oil produced in Guizhou with methanol at its reflux temoerature in the presence of X/Y/MgO/?-Al2O3 . The pilot plant tests were carried out in a 100 L reaction vessel. Both average yield and fatty acid methyl esters (FAME) content reached more than 96.50% under the optimum reaction conditions of the pilot plant tests designed with an oil/methanol molar ratio of 1 : 10, catalyst concentration of 1.00%, and reaction time of 3 h at reflux temperature. In addition, analysis shows that the quality of biodiesel meets the standard EN 14214.