Background With the rapid growth of internet usage,adolescent cyberbullying has become a pressing issue.This study examines the longitudinal impact of leisure-time physical activity and peer relationships on cyberbull...Background With the rapid growth of internet usage,adolescent cyberbullying has become a pressing issue.This study examines the longitudinal impact of leisure-time physical activity and peer relationships on cyberbullying over a one-year period,drawing on the Stage-Environment Fit Theory and the Interpersonal Relationship Theory.Methods A three-wave longitudinal study was conducted over one year,involving 896 middle school students from five schools in Sichuan,Jiangsu,and Guangdong,China,selected to ensure regional diversity.Participants were recruited using stratified random sampling,and data were collected at four-month intervals.Leisure-time physical activity,peer relationships,and cyberbullying behaviors were assessed using validated scales.Data were analyzed using latent growth modeling(LGM)and structural equation modeling(SEM)to examine longitudinal effects and mediation relationships.Results(1)Leisure-time physical activity,peer relationships,and cyberbullying behaviors remained relatively stable over time.(2)Both leisure-time physical activity and peer relationships significantly reduced future cyberbullying incidents,with physical activity also enhancing subsequent peer relationships.(3)Peer relationships partially mediated the effect of leisure-time physical activity on cyberbullying,indicating that improved peer interactions contributed to a reduction in cyberbullying behaviors.Conclusion This study found that leisure-time sports activities and peer relationships are important factors affecting cyberbullying,and peer relationships play a partial mediating role in it.The results provide empirical support for understanding the formation mechanism and influencing factors of cyberbullying.展开更多
The interaction between supply chain relationships and corporate finance has become a focal issue in academic and practical circles,especially under the dual drivers of globalization and marketization.This paper syste...The interaction between supply chain relationships and corporate finance has become a focal issue in academic and practical circles,especially under the dual drivers of globalization and marketization.This paper systematically reviews existing research on this topic,covering theoretical foundations from perspectives such as agency theory,stakeholder theory,and co-opetition game theory,which explain the nature of customer-supplier relationships.It also combs through empirical studies from four core angles:competition-cooperation,signal transmission,spillover effects,and information transfer,summarizing findings on how supply chain relationships impact corporate investment,financing,operations,and performance,as well as existing controversies.The aim is to clarify the research context,identify theoretical and empirical gaps,and provide theoretical support and direction for deepening future research on supply chain and corporate finance.展开更多
Within the prefrontal-cingulate cortex,abnormalities in coupling between neuronal networks can disturb the emotion-cognition interactions,contributing to the development of mental disorders such as depression.Despite ...Within the prefrontal-cingulate cortex,abnormalities in coupling between neuronal networks can disturb the emotion-cognition interactions,contributing to the development of mental disorders such as depression.Despite this understanding,the neural circuit mechanisms underlying this phenomenon remain elusive.In this study,we present a biophysical computational model encompassing three crucial regions,including the dorsolateral prefrontal cortex,subgenual anterior cingulate cortex,and ventromedial prefrontal cortex.The objective is to investigate the role of coupling relationships within the prefrontal-cingulate cortex networks in balancing emotions and cognitive processes.The numerical results confirm that coupled weights play a crucial role in the balance of emotional cognitive networks.Furthermore,our model predicts the pathogenic mechanism of depression resulting from abnormalities in the subgenual cortex,and network functionality was restored through intervention in the dorsolateral prefrontal cortex.This study utilizes computational modeling techniques to provide an insight explanation for the diagnosis and treatment of depression.展开更多
BACKGROUND Hypertension is a chronic cardiovascular disease characterized by persistently elevated arterial blood pressure.It is not only a significant risk factor for cardio-vascular and cerebrovascular diseases(such...BACKGROUND Hypertension is a chronic cardiovascular disease characterized by persistently elevated arterial blood pressure.It is not only a significant risk factor for cardio-vascular and cerebrovascular diseases(such as myocardial infarction and stroke)but also closely related to multiple organ damages(such as kidney disease and retinopathy),imposing a heavy health and economic burden on individuals and society.AIM To investigate the expression differences and relationships of endothelin-1(ET-1),interleukin-6(IL-6),stem cell factor(SCF),and its receptor(c-kit)in hypertensive patients with or without depression.METHODS A retrospective analysis was conducted on the clinical data of 163 hypertensive patients admitted to our hospital from March 2022 to January 2024.Based on the presence of depression,patients were divided into Group A(n=77,with depre-ssion)and Group B(n=86,without depression).Serum levels of ET-1 and IL-6 were measured using radioimmunoassay,while serum levels of SCF and c-kit were measured using ELISA.The differences in ET-1,IL-6,SCF,and c-kit levels between Groups A and B were compared.Additionally,the differences in these biomarkers among patients with varying degrees of depression in Group A were analyzed.Pearson correlation analysis was used to examine the relationship between ET-1,IL-6,SCF,c-kit levels,and Hamilton depression rating scale(HAMD)scores.Multivariate logistic regression analysis was performed to identify factors influencing hypertension with depression.The diagnostic efficacy of individual and combined biomarkers was analyzed using receiver operating characteristic(ROC)curves.Comparative statistical analysis of the area under the curve(AUC)values was performed using DeLong’s test to assess the superiority of combined biomarker detection.RESULTS The levels of ET-1 and IL-6 in Group A were significantly higher than those in Group B,while the levels of SCF and c-kit were significantly lower in Group A compared to Group B(P<0.05).In the severe depression subgroup,ET-1 and IL-6 levels were higher than those in the mild-to-moderate depression subgroup,while SCF and c-kit levels were lower(P<0.05).Pearson correlation analysis showed that ET-1 and IL-6 levels were positively correlated with HAMD scores(r=0.442,0.463,P<0.05),while SCF and c-kit levels were negatively correlated with HAMD scores(r=-0.429,-0.394,P<0.05).Multivariate logistic regression analysis revealed that high ET-1,high IL-6,low SCF,and low c-kit were independent influencing factors for hypertension with depression(P<0.05).ROC analysis revealed AUCs of 0.746(ET-1),0.801(IL-6),0.732(SCF),0.779(c-kit),and 0.884(combination).The combined diagnosis demonstrated significantly higher AUC than individual markers(DeLong's test,P<0.01),with superior sensitivity(90.24%)and specificity(85.37%).CONCLUSION Compared to patients with hypertension alone,patients with hypertension and depression exhibited higher serum levels of ET-1 and IL-6 and lower levels of SCF and c-kit.High ET-1,high IL-6,low SCF,and low c-kit were inde-pendent influencing factors for hypertension with depression.The combination of ET-1,IL-6,SCF,and c-kit demonstrated significant diagnostic value for hypertension with depression.展开更多
The evidential reasoning(ER)rule framework has been widely applied in multi-attribute decision analysis and system assessment to manage uncertainty.However,traditional ER implementations rely on two critical limitatio...The evidential reasoning(ER)rule framework has been widely applied in multi-attribute decision analysis and system assessment to manage uncertainty.However,traditional ER implementations rely on two critical limitations:1)unrealistic assumptions of complete evidence independence,and 2)a lack of mechanisms to differentiate causal relationships from spurious correlations.Existing similarity-based approaches often misinterpret interdependent evidence,leading to unreliable decision outcomes.To address these gaps,this study proposes a causality-enhanced ER rule(CER-e)framework with three key methodological innovations:1)a multidimensional causal representation of evidence to capture dependency structures;2)probabilistic quantification of causal strength using transfer entropy,a model-free information-theoretic measure;3)systematic integration of causal parameters into the ER inference process while maintaining evidential objectivity.The PC algorithm is employed during causal discovery to eliminate spurious correlations,ensuring robust causal inference.Case studies in two types of domains—telecommunications network security assessment and structural risk evaluation—validate CER-e’s effectiveness in real-world scenarios.Under simulated incomplete information conditions,the framework demonstrates superior algorithmic robustness compared to traditional ER.Comparative analyses show that CER-e significantly improves both the interpretability of causal relationships and the reliability of assessment results,establishing a novel paradigm for integrating causal inference with evidential reasoning in complex system evaluation.展开更多
The physicochemical properties,structural characteristics,antioxidant,radioprotective and lipid-lowering activities,as well as the underlying structure-activity relationships of polysaccharides extracted from Nostoc f...The physicochemical properties,structural characteristics,antioxidant,radioprotective and lipid-lowering activities,as well as the underlying structure-activity relationships of polysaccharides extracted from Nostoc flagelliforme grown under normal(WL-EPS-1),salt stress(NaCl-EPS-1)and mixotrophic culture conditions(Glu-EPS-1)were studied.The results demonstrated that WL-EPS-1,NaCl-EPS-1 and Glu-EPS-1 were heteropolysaccharides comprising different proportions of monosaccharides and uronic acid,with different average molecular weights of 0.99×10^(3),1.09×10^(3)and 1.18×10^(3)kDa,respectively.Their intrinsic viscosity were significantly different,at 24.72,29.98,and 41.06 dL/g,respectively.The functional groups of polysaccharides were not greatly affected,but the chemical composition,triple-helix structure,chain length and surface morphology were significantly influenced by culture conditions.In vitro bioactivity assays showed that the antioxidant activity generally increased in the order of WL-EPS-1<NaCl-EPS-1<Glu-EPS-1,while NaCl-EPS-1 had the best radioprotective effect,and Glu-EPS-1 had the best lipid-lowering effect.In addition,the structure-activity relationship of the polysaccharides was analyzed by partial least squares,which revealed that the most important factors affecting the antioxidant,radioprotective and lipid-lowering activities of polysaccharides were viscosity and molecular weight.This study provides a strategy for obtaining high-bioactivity polysaccharides by appropriate regulation of culture conditions,as well as opening new directions for the molecular modification of polysaccharides.展开更多
The relationship between the neighborhood environment and well-being is attracting increasingly attention from researchers and policymakers,as the goal of development has shift from economy to well-being.However,exist...The relationship between the neighborhood environment and well-being is attracting increasingly attention from researchers and policymakers,as the goal of development has shift from economy to well-being.However,existing literature predominantly adopts the utilitarian approach,understanding well-being as people’s feelings about their lives and viewing the neighborhood environment as resources that benefit well-being.The Capability Approach,a novel approach that conceptualize well-being as the freedoms to do or to be and regard environment as conversion factors that influence well-being,can offer new lens by incorporating human development in-to these topics.This paper proposes an alternative theoretical framework:well-being is conceptualized and measured by capability;neighborhood environment affects well-being by providing spatial services,functioning as environmental conversion factors,and serving as social conversion factors.We conducted a case study of Changshu City located in eastern China,utilizing multiple resource data,applying explainable artificial intelligence(XAI),namely eXtreme Gradient Boosting(XGBoost)and SHapley Additive exPlana-tions(SHAP).Our findings highlight the significance of viewing the neighborhood environment as a set of conversion factors,as it provides more explanatory power than providing spatial services.Compared to conventional research based on linear relationship as-sumption,our results demonstrate that the effects of neighborhood environment on well-being are non-linear,characterized by threshold effects and interaction effects.These insights are crucial for informing urban planning and public policy.This research enriches our un-derstanding of well-being,neighborhood environment,and their relationship as well as provides empirical evidence for the core concept of conversion factors in the capability approach.展开更多
Titanium aluminide(TiAl)alloys,known for their light weight and high specific strength,hold promising potential for aerospace applications.Recent studies have focused on improving their properties through composite st...Titanium aluminide(TiAl)alloys,known for their light weight and high specific strength,hold promising potential for aerospace applications.Recent studies have focused on improving their properties through composite strengthening.An in situ synthesized Ti_(5)Si_(3)-reinforced TiAl composite with excellent performance was successfully fabricated via a dual-wire electron beam-directed energy deposition(EB-DED)process.The microstructure of the as-deposited Ti_(5)Si_(3)/TiAl composite consisted of primary Ti_(5)Si_(3)rods,eutectic Ti_(5)Si_(3)needles,and lamellar TiAl+Ti_(3)Al structures.The phase transformation during the EB-DED process was L→Ti_(5)Si_(3)+L→Ti_(5)Si_(3)+(α+Ti_(5)Si_(3))Eutectic→Ti_(5)Si_(3)+(Ti3Al+TiAl)Eutectoid.The expanded Blackburn orientation relationships among the ternary phases emerged from the eutectic reaction of L→α+Ti_(5)Si_(3)with an undercooling exceeding 136°C and the subsequent eutectoid reaction with ordering transformation and were expressed as<1120>TisAl//<10I0>Ti_(5)Si_(3)//<110]Ti_(3)Al and{0001}TiзA//{0001}Ti_(5)Si_(3)//{111}TiAl.The Ti_(5)Si_(3)phase had a greater hardness than did the lamellar structures and enhanced the mechanical properties of the matrix.The compressive yield strengths at room temperature and 750°C were 1221±51 and 1034±34 MPa,respectively,whereas the tensile yield strength was 347.4±12.7 MPa at 950°C,surpassing those of other TiAl alloys.The calculated strength with different strengthening mechanisms was 1056.4 MPa,and the greatest improvement in strength was attributed to the decreased interlamellar spacing.This work provides critical insight into the design of TiAl composites with superior mechanical properties and aids in understanding the microstructural evolution of as-deposited Ti_(5)Si_(3)/TiAl composites.展开更多
Thirty-three mutations and four different haplotypes were found when cytochrome b（Cytb） gene partial sequences of 12 gayals were analyzed. Together with sequences of Bos indicus, Bos taurus, Bos grunniens, and Bos g...Thirty-three mutations and four different haplotypes were found when cytochrome b（Cytb） gene partial sequences of 12 gayals were analyzed. Together with sequences of Bos indicus, Bos taurus, Bos grunniens, and Bos gaurus with Bubalus bubalis as the out group, the partial sequences of Cytb gene of gayals were aligned and base composition and nucleotide variation of Cytb gene were analyzed. The phylogenetic trees were constructed by the NJ method and the MP method respectively, both supporting almost the same topology. Gayal is an independent species of Bos from Bos indicus, Bos taurus, and Bos gaurus. The results also indicate that a great proportion of gayal bloodline was invaded by other species, and the protection of gayal is facing a formidable situation.展开更多
The internal transcribed spacer (ITS) regions of nuclear ribosomal DNA (including 5.8S rRNA) of 15 Rhododendron, species, representing most sections of the genus, one Ledum species and Cassiope fastigiata were sequenc...The internal transcribed spacer (ITS) regions of nuclear ribosomal DNA (including 5.8S rRNA) of 15 Rhododendron, species, representing most sections of the genus, one Ledum species and Cassiope fastigiata were sequenced. Together with the ITS sequences of 13 selected Rhododendron species and Bejaria racemosa downloaded from GenBank, we explored the infrageneric and sectional relationships of this important North Temperate genus by employing maximum-parsimony analysis using PAUP software. C. fastigiata and B. racemosa were designated as outgroups. The ITS-based tree inferred that: (1) Rhododendron was a well-supported monophyletic group, while subg. Therorhodion was basal to the rest of the genus; (2) Ledum was a member of Rhododendron, and its close relationship with the lepidote rhododendron was confirmed; (3) the lepidote rhododendron plus Ledum formed a strongly-supported monophyletic clade which was sister to the rest of the elepidote rhododendron; (4) the elepidote rhododendron formed a weakly-supported clade within which the monophyly of subg. Hynwrianthes and subg. Tsutsusi were strongly supported, while subg. Pentanthera and subg. Azaleastrum were polyphyletic; and (5) the monophyly of sect. Choniastnini, (subg. Azaleastrum) was strongly-supported, while subg. Tsutsusi could be sister to a weakly-supported clade composed of two sampled species of sect. Azaleastrum (subg. Azaleastrum) together with R. sentibarbatum, of subg. Mumeazalea.展开更多
近三年,以大语言模型(large language models,LLMs)为代表的人工智能技术和产业得到快速发展,实际应用也取得显著效果。为应对国家和行业发展的需求,国内许多高校纷纷设置人工智能学院、学科和专业,但与计算机学院、学科及专业的边界仍...近三年,以大语言模型(large language models,LLMs)为代表的人工智能技术和产业得到快速发展,实际应用也取得显著效果。为应对国家和行业发展的需求,国内许多高校纷纷设置人工智能学院、学科和专业,但与计算机学院、学科及专业的边界仍不够明晰。为此,本文描述了人工智能的含义、组成,并试图厘清与计算机学科及专业的关系,提出人工智能学院与计算机学院学科、专业发展的一些建议,期望为后续相关研究提供参考。展开更多
基金funded by the following projects:National Social Science Fund Project“The Empowerment Mechanism of Physical Exercise on Emotional Regulation in Adolescents”(23BTY116)Leshan Normal University 2024 Research Cultivation Project:“Research on the Trajectory Effect of Family Cumulative Risk and Home-based Activity of Adolescents”(KYPY2025-0014)+1 种基金Key Humanities and Social Sciences Cultivation Project of Leshan Normal University:“Research on the Sequence Difference of Knowledge and Behavior of Physical Activity among Adolescents and the Compensation Mechanism”and Sichuan Province College Students’Sports Association Annual Project“The Trajectory Effect of Family Cumulative Risk and Adolescents’Home Physical Activity”(23CDTXQ004).
文摘Background With the rapid growth of internet usage,adolescent cyberbullying has become a pressing issue.This study examines the longitudinal impact of leisure-time physical activity and peer relationships on cyberbullying over a one-year period,drawing on the Stage-Environment Fit Theory and the Interpersonal Relationship Theory.Methods A three-wave longitudinal study was conducted over one year,involving 896 middle school students from five schools in Sichuan,Jiangsu,and Guangdong,China,selected to ensure regional diversity.Participants were recruited using stratified random sampling,and data were collected at four-month intervals.Leisure-time physical activity,peer relationships,and cyberbullying behaviors were assessed using validated scales.Data were analyzed using latent growth modeling(LGM)and structural equation modeling(SEM)to examine longitudinal effects and mediation relationships.Results(1)Leisure-time physical activity,peer relationships,and cyberbullying behaviors remained relatively stable over time.(2)Both leisure-time physical activity and peer relationships significantly reduced future cyberbullying incidents,with physical activity also enhancing subsequent peer relationships.(3)Peer relationships partially mediated the effect of leisure-time physical activity on cyberbullying,indicating that improved peer interactions contributed to a reduction in cyberbullying behaviors.Conclusion This study found that leisure-time sports activities and peer relationships are important factors affecting cyberbullying,and peer relationships play a partial mediating role in it.The results provide empirical support for understanding the formation mechanism and influencing factors of cyberbullying.
文摘The interaction between supply chain relationships and corporate finance has become a focal issue in academic and practical circles,especially under the dual drivers of globalization and marketization.This paper systematically reviews existing research on this topic,covering theoretical foundations from perspectives such as agency theory,stakeholder theory,and co-opetition game theory,which explain the nature of customer-supplier relationships.It also combs through empirical studies from four core angles:competition-cooperation,signal transmission,spillover effects,and information transfer,summarizing findings on how supply chain relationships impact corporate investment,financing,operations,and performance,as well as existing controversies.The aim is to clarify the research context,identify theoretical and empirical gaps,and provide theoretical support and direction for deepening future research on supply chain and corporate finance.
基金supported by the Major Research Instrument Development Project of the National Natural Science Foundation of China(82327810)the Foundation of the President of Hebei University(XZJJ202202)the Hebei Province“333 talent project”(A202101058).
文摘Within the prefrontal-cingulate cortex,abnormalities in coupling between neuronal networks can disturb the emotion-cognition interactions,contributing to the development of mental disorders such as depression.Despite this understanding,the neural circuit mechanisms underlying this phenomenon remain elusive.In this study,we present a biophysical computational model encompassing three crucial regions,including the dorsolateral prefrontal cortex,subgenual anterior cingulate cortex,and ventromedial prefrontal cortex.The objective is to investigate the role of coupling relationships within the prefrontal-cingulate cortex networks in balancing emotions and cognitive processes.The numerical results confirm that coupled weights play a crucial role in the balance of emotional cognitive networks.Furthermore,our model predicts the pathogenic mechanism of depression resulting from abnormalities in the subgenual cortex,and network functionality was restored through intervention in the dorsolateral prefrontal cortex.This study utilizes computational modeling techniques to provide an insight explanation for the diagnosis and treatment of depression.
文摘BACKGROUND Hypertension is a chronic cardiovascular disease characterized by persistently elevated arterial blood pressure.It is not only a significant risk factor for cardio-vascular and cerebrovascular diseases(such as myocardial infarction and stroke)but also closely related to multiple organ damages(such as kidney disease and retinopathy),imposing a heavy health and economic burden on individuals and society.AIM To investigate the expression differences and relationships of endothelin-1(ET-1),interleukin-6(IL-6),stem cell factor(SCF),and its receptor(c-kit)in hypertensive patients with or without depression.METHODS A retrospective analysis was conducted on the clinical data of 163 hypertensive patients admitted to our hospital from March 2022 to January 2024.Based on the presence of depression,patients were divided into Group A(n=77,with depre-ssion)and Group B(n=86,without depression).Serum levels of ET-1 and IL-6 were measured using radioimmunoassay,while serum levels of SCF and c-kit were measured using ELISA.The differences in ET-1,IL-6,SCF,and c-kit levels between Groups A and B were compared.Additionally,the differences in these biomarkers among patients with varying degrees of depression in Group A were analyzed.Pearson correlation analysis was used to examine the relationship between ET-1,IL-6,SCF,c-kit levels,and Hamilton depression rating scale(HAMD)scores.Multivariate logistic regression analysis was performed to identify factors influencing hypertension with depression.The diagnostic efficacy of individual and combined biomarkers was analyzed using receiver operating characteristic(ROC)curves.Comparative statistical analysis of the area under the curve(AUC)values was performed using DeLong’s test to assess the superiority of combined biomarker detection.RESULTS The levels of ET-1 and IL-6 in Group A were significantly higher than those in Group B,while the levels of SCF and c-kit were significantly lower in Group A compared to Group B(P<0.05).In the severe depression subgroup,ET-1 and IL-6 levels were higher than those in the mild-to-moderate depression subgroup,while SCF and c-kit levels were lower(P<0.05).Pearson correlation analysis showed that ET-1 and IL-6 levels were positively correlated with HAMD scores(r=0.442,0.463,P<0.05),while SCF and c-kit levels were negatively correlated with HAMD scores(r=-0.429,-0.394,P<0.05).Multivariate logistic regression analysis revealed that high ET-1,high IL-6,low SCF,and low c-kit were independent influencing factors for hypertension with depression(P<0.05).ROC analysis revealed AUCs of 0.746(ET-1),0.801(IL-6),0.732(SCF),0.779(c-kit),and 0.884(combination).The combined diagnosis demonstrated significantly higher AUC than individual markers(DeLong's test,P<0.01),with superior sensitivity(90.24%)and specificity(85.37%).CONCLUSION Compared to patients with hypertension alone,patients with hypertension and depression exhibited higher serum levels of ET-1 and IL-6 and lower levels of SCF and c-kit.High ET-1,high IL-6,low SCF,and low c-kit were inde-pendent influencing factors for hypertension with depression.The combination of ET-1,IL-6,SCF,and c-kit demonstrated significant diagnostic value for hypertension with depression.
基金supported by the Natural Science Foundation of China(Nos.U22A2099,62273113,62203461,62203365)the Innovation Project of Guangxi Graduate Education under Grant YCBZ2023130by the Guangxi Higher Education Undergraduate Teaching Reform Project Key Project,grant number 2022JGZ130.
文摘The evidential reasoning(ER)rule framework has been widely applied in multi-attribute decision analysis and system assessment to manage uncertainty.However,traditional ER implementations rely on two critical limitations:1)unrealistic assumptions of complete evidence independence,and 2)a lack of mechanisms to differentiate causal relationships from spurious correlations.Existing similarity-based approaches often misinterpret interdependent evidence,leading to unreliable decision outcomes.To address these gaps,this study proposes a causality-enhanced ER rule(CER-e)framework with three key methodological innovations:1)a multidimensional causal representation of evidence to capture dependency structures;2)probabilistic quantification of causal strength using transfer entropy,a model-free information-theoretic measure;3)systematic integration of causal parameters into the ER inference process while maintaining evidential objectivity.The PC algorithm is employed during causal discovery to eliminate spurious correlations,ensuring robust causal inference.Case studies in two types of domains—telecommunications network security assessment and structural risk evaluation—validate CER-e’s effectiveness in real-world scenarios.Under simulated incomplete information conditions,the framework demonstrates superior algorithmic robustness compared to traditional ER.Comparative analyses show that CER-e significantly improves both the interpretability of causal relationships and the reliability of assessment results,establishing a novel paradigm for integrating causal inference with evidential reasoning in complex system evaluation.
基金support from the National Natural Science Foundation of China(32172191)the Tianjin Research Innovation Project for Postgraduate Students(2021YJSB211).
文摘The physicochemical properties,structural characteristics,antioxidant,radioprotective and lipid-lowering activities,as well as the underlying structure-activity relationships of polysaccharides extracted from Nostoc flagelliforme grown under normal(WL-EPS-1),salt stress(NaCl-EPS-1)and mixotrophic culture conditions(Glu-EPS-1)were studied.The results demonstrated that WL-EPS-1,NaCl-EPS-1 and Glu-EPS-1 were heteropolysaccharides comprising different proportions of monosaccharides and uronic acid,with different average molecular weights of 0.99×10^(3),1.09×10^(3)and 1.18×10^(3)kDa,respectively.Their intrinsic viscosity were significantly different,at 24.72,29.98,and 41.06 dL/g,respectively.The functional groups of polysaccharides were not greatly affected,but the chemical composition,triple-helix structure,chain length and surface morphology were significantly influenced by culture conditions.In vitro bioactivity assays showed that the antioxidant activity generally increased in the order of WL-EPS-1<NaCl-EPS-1<Glu-EPS-1,while NaCl-EPS-1 had the best radioprotective effect,and Glu-EPS-1 had the best lipid-lowering effect.In addition,the structure-activity relationship of the polysaccharides was analyzed by partial least squares,which revealed that the most important factors affecting the antioxidant,radioprotective and lipid-lowering activities of polysaccharides were viscosity and molecular weight.This study provides a strategy for obtaining high-bioactivity polysaccharides by appropriate regulation of culture conditions,as well as opening new directions for the molecular modification of polysaccharides.
基金Under the auspices of National Natural Science Foundation of China(No.42271230,42330510)。
文摘The relationship between the neighborhood environment and well-being is attracting increasingly attention from researchers and policymakers,as the goal of development has shift from economy to well-being.However,existing literature predominantly adopts the utilitarian approach,understanding well-being as people’s feelings about their lives and viewing the neighborhood environment as resources that benefit well-being.The Capability Approach,a novel approach that conceptualize well-being as the freedoms to do or to be and regard environment as conversion factors that influence well-being,can offer new lens by incorporating human development in-to these topics.This paper proposes an alternative theoretical framework:well-being is conceptualized and measured by capability;neighborhood environment affects well-being by providing spatial services,functioning as environmental conversion factors,and serving as social conversion factors.We conducted a case study of Changshu City located in eastern China,utilizing multiple resource data,applying explainable artificial intelligence(XAI),namely eXtreme Gradient Boosting(XGBoost)and SHapley Additive exPlana-tions(SHAP).Our findings highlight the significance of viewing the neighborhood environment as a set of conversion factors,as it provides more explanatory power than providing spatial services.Compared to conventional research based on linear relationship as-sumption,our results demonstrate that the effects of neighborhood environment on well-being are non-linear,characterized by threshold effects and interaction effects.These insights are crucial for informing urban planning and public policy.This research enriches our un-derstanding of well-being,neighborhood environment,and their relationship as well as provides empirical evidence for the core concept of conversion factors in the capability approach.
基金financially supported by the National Natural Science Foundation of China(No.52301050)the Young Elite Scientists Sponsorship Program by the China Association for Science and Technology(No.2022QNRC001)the China Postdoctoral Science Foundation(No.2023M741701).
文摘Titanium aluminide(TiAl)alloys,known for their light weight and high specific strength,hold promising potential for aerospace applications.Recent studies have focused on improving their properties through composite strengthening.An in situ synthesized Ti_(5)Si_(3)-reinforced TiAl composite with excellent performance was successfully fabricated via a dual-wire electron beam-directed energy deposition(EB-DED)process.The microstructure of the as-deposited Ti_(5)Si_(3)/TiAl composite consisted of primary Ti_(5)Si_(3)rods,eutectic Ti_(5)Si_(3)needles,and lamellar TiAl+Ti_(3)Al structures.The phase transformation during the EB-DED process was L→Ti_(5)Si_(3)+L→Ti_(5)Si_(3)+(α+Ti_(5)Si_(3))Eutectic→Ti_(5)Si_(3)+(Ti3Al+TiAl)Eutectoid.The expanded Blackburn orientation relationships among the ternary phases emerged from the eutectic reaction of L→α+Ti_(5)Si_(3)with an undercooling exceeding 136°C and the subsequent eutectoid reaction with ordering transformation and were expressed as<1120>TisAl//<10I0>Ti_(5)Si_(3)//<110]Ti_(3)Al and{0001}TiзA//{0001}Ti_(5)Si_(3)//{111}TiAl.The Ti_(5)Si_(3)phase had a greater hardness than did the lamellar structures and enhanced the mechanical properties of the matrix.The compressive yield strengths at room temperature and 750°C were 1221±51 and 1034±34 MPa,respectively,whereas the tensile yield strength was 347.4±12.7 MPa at 950°C,surpassing those of other TiAl alloys.The calculated strength with different strengthening mechanisms was 1056.4 MPa,and the greatest improvement in strength was attributed to the decreased interlamellar spacing.This work provides critical insight into the design of TiAl composites with superior mechanical properties and aids in understanding the microstructural evolution of as-deposited Ti_(5)Si_(3)/TiAl composites.
基金This work was supported by the National Natureal Sciences Foundation of China(No: 30571323).
文摘Thirty-three mutations and four different haplotypes were found when cytochrome b（Cytb） gene partial sequences of 12 gayals were analyzed. Together with sequences of Bos indicus, Bos taurus, Bos grunniens, and Bos gaurus with Bubalus bubalis as the out group, the partial sequences of Cytb gene of gayals were aligned and base composition and nucleotide variation of Cytb gene were analyzed. The phylogenetic trees were constructed by the NJ method and the MP method respectively, both supporting almost the same topology. Gayal is an independent species of Bos from Bos indicus, Bos taurus, and Bos gaurus. The results also indicate that a great proportion of gayal bloodline was invaded by other species, and the protection of gayal is facing a formidable situation.
文摘The internal transcribed spacer (ITS) regions of nuclear ribosomal DNA (including 5.8S rRNA) of 15 Rhododendron, species, representing most sections of the genus, one Ledum species and Cassiope fastigiata were sequenced. Together with the ITS sequences of 13 selected Rhododendron species and Bejaria racemosa downloaded from GenBank, we explored the infrageneric and sectional relationships of this important North Temperate genus by employing maximum-parsimony analysis using PAUP software. C. fastigiata and B. racemosa were designated as outgroups. The ITS-based tree inferred that: (1) Rhododendron was a well-supported monophyletic group, while subg. Therorhodion was basal to the rest of the genus; (2) Ledum was a member of Rhododendron, and its close relationship with the lepidote rhododendron was confirmed; (3) the lepidote rhododendron plus Ledum formed a strongly-supported monophyletic clade which was sister to the rest of the elepidote rhododendron; (4) the elepidote rhododendron formed a weakly-supported clade within which the monophyly of subg. Hynwrianthes and subg. Tsutsusi were strongly supported, while subg. Pentanthera and subg. Azaleastrum were polyphyletic; and (5) the monophyly of sect. Choniastnini, (subg. Azaleastrum) was strongly-supported, while subg. Tsutsusi could be sister to a weakly-supported clade composed of two sampled species of sect. Azaleastrum (subg. Azaleastrum) together with R. sentibarbatum, of subg. Mumeazalea.
文摘近三年,以大语言模型(large language models,LLMs)为代表的人工智能技术和产业得到快速发展,实际应用也取得显著效果。为应对国家和行业发展的需求,国内许多高校纷纷设置人工智能学院、学科和专业,但与计算机学院、学科及专业的边界仍不够明晰。为此,本文描述了人工智能的含义、组成,并试图厘清与计算机学科及专业的关系,提出人工智能学院与计算机学院学科、专业发展的一些建议,期望为后续相关研究提供参考。
