The microstructures and mechanical properties of Ti–47 at%Ni–3 at%Fe shape memory alloy wire under the condition of severe cold-drawing at room temperature and different postdeformation annealing processes were inte...The microstructures and mechanical properties of Ti–47 at%Ni–3 at%Fe shape memory alloy wire under the condition of severe cold-drawing at room temperature and different postdeformation annealing processes were intensively investigated using transmission electron microscope(TEM),X-ray diffraction(XRD),Vickers microhardness tester and electron tensile tester.It is indicated that the structure of the alloy evolves into a predominant amorphous structure with a trace of nanocrystalline B2 phase after the cold-drawing of 76%areal reduction.Postdeformation annealing process exerted significant influence on the microstructure and mechanical properties.Crystallization occurs when the cold-drawn wire was annealed at 300℃ for 30 min.The ultimate tensile strength and ductility as well as the superelasticity of the wire are improved significantly by cold-drawing plus postdeformation annealing.展开更多
Coronaviruses are single-stranded,positive-sense RNA enveloped viruses that have posed a significant threat to human health over the past few decades,particularly severe acute respiratory syndrome coronavirus(SARS-CoV...Coronaviruses are single-stranded,positive-sense RNA enveloped viruses that have posed a significant threat to human health over the past few decades,particularly severe acute respiratory syndrome coronavirus(SARS-CoV),Middle East respiratory syndrome coronavirus(MERS-CoV),and SARS-CoV-2.These viruses have caused widespread infections and fatalities,with profound impacts on global economies,social life,and public health systems.Due to their broad host range in natural settings and the consequent high potential for zoonotic spillover events,a thorough investigation of the common viral mechanisms and the identification of druggable targets for pan-coronavirus antiviral development are of utmost importance.展开更多
Deformation twins and stacking faults were observed in nanostructure A1-Mg alloys subjected to high pressure torsion. These observations are surprising because deformation twinnings have never been observed in their c...Deformation twins and stacking faults were observed in nanostructure A1-Mg alloys subjected to high pressure torsion. These observations are surprising because deformation twinnings have never been observed in their coarse-grained counterparts under normal conditions. Experimental evidences are introduced on non-equilibrium grain boundaries, deformation twinnings and partial dislocation emissions from grain boundaries. Some of these features can be explained by the results reported from molecular-dynamics simulations of pure FCC metals. Special emphasis is laid on the recent observations of high density hexagonal and rhombic shaped nanostructures with an average size of 3 nm in the A1-Mg alloys processed by high pressure torsion. A possible formation process of these nanostructures is proposed based on molecular-dynamics simulations.展开更多
The recent emergence and rapid global spread of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) pose an unprecedented medical and socioeconomic crisis, and the disease caused by it, Coronavirus disease...The recent emergence and rapid global spread of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) pose an unprecedented medical and socioeconomic crisis, and the disease caused by it, Coronavirus disease 2019(COVID-19),was declared a pandemic by the World Health Organization(WHO) on March 11, 2020. Chinese scientists and physicians rapidly identified the causative pathogen, which turned out to be a novel betacoronavirus with high sequence similarities to bat and pangolin coronaviruses. The scientific community has ignited tremendous efforts to unravel the biological underpinning of SARS-CoV-2, which constitutes the foundation for therapy and vaccine development strategies. Here, we summarize the current state of knowledge on the genome, structure, receptor, and origin of SARS-CoV-2.展开更多
SARS-CoV-2 has become a global pandemic threatening human health and safety.It is urgent to find effective therapeutic agents and targets with the continuous emergence of novel mutant strains.The knowledge of the mole...SARS-CoV-2 has become a global pandemic threatening human health and safety.It is urgent to find effective therapeutic agents and targets with the continuous emergence of novel mutant strains.The knowledge of the molecular basis and pathogenesis of SARS-CoV-2 in host cells requires to be understood comprehensively.The unknown structure and function of nsp2 have hindered our understanding of its role in SARS-CoV-2 infection.Here,we report the crystal structure of the N-terminal of SARS-CoV-2 nsp2 to a high resolution of 1.96?.This novel structure contains three zinc fingers,belonging to the C2 H2,C4,and C2 HC types,respectively.Structure analysis suggests that nsp2 may be involved in binding nucleic acids and regulating intracellular signaling pathways.The binding to single or double-stranded nucleic acids was mainly through the large positively charged region on the surface of nsp2,and K111,K112,K113 were key residues.Our findings lay the foundation for a better understanding of the relationship between structure and function for nsp2.It is helpful to make full use of nsp2 as further research and development of antiviral targets and drug design.展开更多
This paper focuses on how aging can affect performance of safety-related structures in nuclear power plant (NPP). Knowledge and assessment of impacts of aging on structures are essential to plant life extension analys...This paper focuses on how aging can affect performance of safety-related structures in nuclear power plant (NPP). Knowledge and assessment of impacts of aging on structures are essential to plant life extension analysis,especially performance to severe loadings such as loss-of-coolant-accidents or major seismic events. Plant life extension issues are of keen interest in countries (like the United States) which have a large,aging fleet of NPPs. This paper addresses the overlap and relationship of structure aging to severe loading performance,with particular emphasis on containment structures.展开更多
BACKGROUND Depression,anxiety,and insomnia were found out that were significant relevance to the mental health impact of the coronavirus disease 2019(COVID-19)lock-down.AIM To examine the interrelationships among perc...BACKGROUND Depression,anxiety,and insomnia were found out that were significant relevance to the mental health impact of the coronavirus disease 2019(COVID-19)lock-down.AIM To examine the interrelationships among perceived severity,anxiety,depression,insomnia,and sense of security in Chinese community residents during the COVID-19 lockdown period.METHODS Participants were selected using simple random sampling from four large gated communities in Chengdu,China.All participants were invited to complete a survey that included the Perceived Severity Questionnaire,Security Question-naire,Patient Health Questionnaire-9,Generalized Anxiety Disorder 7-item,and Insomnia Severity Index-7.In total,568 valid questionnaires were gathered.Co-rrelation analysis and structural equation models were used to explore the rela-RESULTS The observed prevalence rates of anxiety,depression,and insomnia among residents during lockdown were 27.5%,17.6%,and 16.0%,respectively.Correlation analysis showed that both perceived severity and sense of security were positively correlated with anxiety,depression,and insomnia[Pearson’s r was perceived severity and anxiety r=0.44(P<0.01);with depression r=0.48(P<0.01);with insomnia r=0.43(P<0.01);security with anxiety r=-0.65(P<0.01);with depression r=-0.65(P<0.01);with insomnia r=-0.53(P<0.01)].Structural equation modeling and bootstrap tests revealed that sense of security acted as a significant mediator in the relationship between perceived severity and emotional and sleep disorders(anxiety,depression,and insomnia).CONCLUSION This study demonstrates that sense of security is a significant predictor of emotional and sleep disorders(namely,depression,anxiety,and insomnia)among residents during the COVID-19 lockdown,with sense of security acting as a mediating factor.These findings suggest that mental health interventions for Chinese community residents during lockdowns may benefit from developing community-based educational programs to reduce perceived severity and ensuring the stable supply of essential resources and promoting social support networks to enhance the sense of security.展开更多
Apparently balanced chromosomal structural rearrangements are known to cause male infertility and account for approximately 1%of azoospermia or severe oligospermia.However,the underlying mechanisms of pathogenesis and...Apparently balanced chromosomal structural rearrangements are known to cause male infertility and account for approximately 1%of azoospermia or severe oligospermia.However,the underlying mechanisms of pathogenesis and etiologies are still largely unknown.Herein,we investigated apparently balanced interchromosomal structural rearrangements in six cases with azoospermia/severe oligospermia to comprehensively identify and delineate cryptic structural rearrangements and the related copy number variants.In addition,high read-depth genome sequencing(GS)(30-fold)was performed to investigate point mutations causative of male infertility.Mate-pair GS(4-fold)revealed additional structural rearrangements and/or copy number changes in 5 of 6 cases and detected a total of 48 rearrangements.Overall,the breakpoints caused truncations of 30 RefSeq genes,five of which were associated with spermatogenesis.Furthermore,the breakpoints disrupted 43 topological-associated domains.Direct disruptions or potential dysregulations of genes,which play potential roles in male germ cell development,apoptosis,and spermatogenesis,were found in all cases(n=6).In addition,high read-depth GS detected dual molecular findings in case MI6,involving a complex rearrangement and two point mutations in the gene DNAH1.Overall,our study provided the molecular characteristics of apparently balanced interchromosomal structural rearrangements in patients with male infertility.We demonstrated the complexity of chromosomal structural rearrangements,potential gene disruptions/dysregulation and single-gene mutations could be the contributing mechanisms underlie male infertility.展开更多
基金supported by the National Natural Science Foundation of China (No. 50921003)Industry, Education and Research Projects of the China Aviation Industrial (No.cxy2012BH04)
文摘The microstructures and mechanical properties of Ti–47 at%Ni–3 at%Fe shape memory alloy wire under the condition of severe cold-drawing at room temperature and different postdeformation annealing processes were intensively investigated using transmission electron microscope(TEM),X-ray diffraction(XRD),Vickers microhardness tester and electron tensile tester.It is indicated that the structure of the alloy evolves into a predominant amorphous structure with a trace of nanocrystalline B2 phase after the cold-drawing of 76%areal reduction.Postdeformation annealing process exerted significant influence on the microstructure and mechanical properties.Crystallization occurs when the cold-drawn wire was annealed at 300℃ for 30 min.The ultimate tensile strength and ductility as well as the superelasticity of the wire are improved significantly by cold-drawing plus postdeformation annealing.
基金supported by the Key Research and Development Program,Ministry of Science and Technology of the People’s Republic of China(Nos.2023YFC2606500,2023YFE0206500).
文摘Coronaviruses are single-stranded,positive-sense RNA enveloped viruses that have posed a significant threat to human health over the past few decades,particularly severe acute respiratory syndrome coronavirus(SARS-CoV),Middle East respiratory syndrome coronavirus(MERS-CoV),and SARS-CoV-2.These viruses have caused widespread infections and fatalities,with profound impacts on global economies,social life,and public health systems.Due to their broad host range in natural settings and the consequent high potential for zoonotic spillover events,a thorough investigation of the common viral mechanisms and the identification of druggable targets for pan-coronavirus antiviral development are of utmost importance.
基金Project(50971087) supported by the National Natural Science Foundation of ChinaProject supported by the Research Council of Norway under the Strategic University Program on Light Metals Technology Projects(67692, 71594) supported by the Hungarian National Science Foundation
文摘Deformation twins and stacking faults were observed in nanostructure A1-Mg alloys subjected to high pressure torsion. These observations are surprising because deformation twinnings have never been observed in their coarse-grained counterparts under normal conditions. Experimental evidences are introduced on non-equilibrium grain boundaries, deformation twinnings and partial dislocation emissions from grain boundaries. Some of these features can be explained by the results reported from molecular-dynamics simulations of pure FCC metals. Special emphasis is laid on the recent observations of high density hexagonal and rhombic shaped nanostructures with an average size of 3 nm in the A1-Mg alloys processed by high pressure torsion. A possible formation process of these nanostructures is proposed based on molecular-dynamics simulations.
基金supported by the Fundamental Research Funds for the Central Universities (2020kfyXGYJ028)the National Natural Science Foundation of China (81861138044 and 91742114)+1 种基金the National Science and Technology Major Project (2017ZX10202203)the Medical Faculty of the University of Duisburg-Essen and Stiftung Universitaetsmedizin, University Hospital Essen, Germany。
文摘The recent emergence and rapid global spread of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) pose an unprecedented medical and socioeconomic crisis, and the disease caused by it, Coronavirus disease 2019(COVID-19),was declared a pandemic by the World Health Organization(WHO) on March 11, 2020. Chinese scientists and physicians rapidly identified the causative pathogen, which turned out to be a novel betacoronavirus with high sequence similarities to bat and pangolin coronaviruses. The scientific community has ignited tremendous efforts to unravel the biological underpinning of SARS-CoV-2, which constitutes the foundation for therapy and vaccine development strategies. Here, we summarize the current state of knowledge on the genome, structure, receptor, and origin of SARS-CoV-2.
基金supported financially by National Key Research and Development Program of China(2018YFE0113100)National Natural Science Foundation of China(31872713)。
文摘SARS-CoV-2 has become a global pandemic threatening human health and safety.It is urgent to find effective therapeutic agents and targets with the continuous emergence of novel mutant strains.The knowledge of the molecular basis and pathogenesis of SARS-CoV-2 in host cells requires to be understood comprehensively.The unknown structure and function of nsp2 have hindered our understanding of its role in SARS-CoV-2 infection.Here,we report the crystal structure of the N-terminal of SARS-CoV-2 nsp2 to a high resolution of 1.96?.This novel structure contains three zinc fingers,belonging to the C2 H2,C4,and C2 HC types,respectively.Structure analysis suggests that nsp2 may be involved in binding nucleic acids and regulating intracellular signaling pathways.The binding to single or double-stranded nucleic acids was mainly through the large positively charged region on the surface of nsp2,and K111,K112,K113 were key residues.Our findings lay the foundation for a better understanding of the relationship between structure and function for nsp2.It is helpful to make full use of nsp2 as further research and development of antiviral targets and drug design.
文摘This paper focuses on how aging can affect performance of safety-related structures in nuclear power plant (NPP). Knowledge and assessment of impacts of aging on structures are essential to plant life extension analysis,especially performance to severe loadings such as loss-of-coolant-accidents or major seismic events. Plant life extension issues are of keen interest in countries (like the United States) which have a large,aging fleet of NPPs. This paper addresses the overlap and relationship of structure aging to severe loading performance,with particular emphasis on containment structures.
基金Supported by Young Talent Project of Air Force Medical Center,No.2022YXQN008and Rapid Response Project of Air Force Medical University,No.2023KXKT041.
文摘BACKGROUND Depression,anxiety,and insomnia were found out that were significant relevance to the mental health impact of the coronavirus disease 2019(COVID-19)lock-down.AIM To examine the interrelationships among perceived severity,anxiety,depression,insomnia,and sense of security in Chinese community residents during the COVID-19 lockdown period.METHODS Participants were selected using simple random sampling from four large gated communities in Chengdu,China.All participants were invited to complete a survey that included the Perceived Severity Questionnaire,Security Question-naire,Patient Health Questionnaire-9,Generalized Anxiety Disorder 7-item,and Insomnia Severity Index-7.In total,568 valid questionnaires were gathered.Co-rrelation analysis and structural equation models were used to explore the rela-RESULTS The observed prevalence rates of anxiety,depression,and insomnia among residents during lockdown were 27.5%,17.6%,and 16.0%,respectively.Correlation analysis showed that both perceived severity and sense of security were positively correlated with anxiety,depression,and insomnia[Pearson’s r was perceived severity and anxiety r=0.44(P<0.01);with depression r=0.48(P<0.01);with insomnia r=0.43(P<0.01);security with anxiety r=-0.65(P<0.01);with depression r=-0.65(P<0.01);with insomnia r=-0.53(P<0.01)].Structural equation modeling and bootstrap tests revealed that sense of security acted as a significant mediator in the relationship between perceived severity and emotional and sleep disorders(anxiety,depression,and insomnia).CONCLUSION This study demonstrates that sense of security is a significant predictor of emotional and sleep disorders(namely,depression,anxiety,and insomnia)among residents during the COVID-19 lockdown,with sense of security acting as a mediating factor.These findings suggest that mental health interventions for Chinese community residents during lockdowns may benefit from developing community-based educational programs to reduce perceived severity and ensuring the stable supply of essential resources and promoting social support networks to enhance the sense of security.
基金supported by the National Natural Science Foundation of China(No.31801042)the Health and Medical Research Fund(No.04152666 and No.07180576)General Research Fund(No.14115418),and Direct Grant(No.2020.052).
文摘Apparently balanced chromosomal structural rearrangements are known to cause male infertility and account for approximately 1%of azoospermia or severe oligospermia.However,the underlying mechanisms of pathogenesis and etiologies are still largely unknown.Herein,we investigated apparently balanced interchromosomal structural rearrangements in six cases with azoospermia/severe oligospermia to comprehensively identify and delineate cryptic structural rearrangements and the related copy number variants.In addition,high read-depth genome sequencing(GS)(30-fold)was performed to investigate point mutations causative of male infertility.Mate-pair GS(4-fold)revealed additional structural rearrangements and/or copy number changes in 5 of 6 cases and detected a total of 48 rearrangements.Overall,the breakpoints caused truncations of 30 RefSeq genes,five of which were associated with spermatogenesis.Furthermore,the breakpoints disrupted 43 topological-associated domains.Direct disruptions or potential dysregulations of genes,which play potential roles in male germ cell development,apoptosis,and spermatogenesis,were found in all cases(n=6).In addition,high read-depth GS detected dual molecular findings in case MI6,involving a complex rearrangement and two point mutations in the gene DNAH1.Overall,our study provided the molecular characteristics of apparently balanced interchromosomal structural rearrangements in patients with male infertility.We demonstrated the complexity of chromosomal structural rearrangements,potential gene disruptions/dysregulation and single-gene mutations could be the contributing mechanisms underlie male infertility.
