目的:探究补骨膏对绝经后骨质疏松症(PMOP)大鼠的骨保护作用及其对骨保护素(OPG)-核因子κB受体激活蛋白(RANK)-核因子κB受体激活蛋白配体(RANKL)信号通路的调控作用。方法:将36只大鼠随机分为假手术组(9只)和手术组(27只),手术组采用...目的:探究补骨膏对绝经后骨质疏松症(PMOP)大鼠的骨保护作用及其对骨保护素(OPG)-核因子κB受体激活蛋白(RANK)-核因子κB受体激活蛋白配体(RANKL)信号通路的调控作用。方法:将36只大鼠随机分为假手术组(9只)和手术组(27只),手术组采用双侧卵巢切除建立PMOP大鼠模型。造模成功后,将24只PMOP大鼠随机分为模型组、戊酸雌二醇组、补骨膏低剂量组、补骨膏高剂量组,然后予相应药物灌胃8周。骨密度仪检测股骨近端骨密度;Micro-CT三维重建分析股骨微结构;苏木精-伊红(HE)染色观察股骨组织病理形态;酶联免疫吸附试验(ELISA)法检测血清中骨碱性磷酸酶(BALP)、骨钙素(BGP)、OPG水平,测定盒检测血清中磷、钙水平;蛋白质印迹法(Western blotting)检测股骨组织中OPG、RANK、RANKL蛋白表达水平;RT-qPCR法检测股骨组织肿瘤坏死因子-α(TNF-α)mRNA、干扰素-γ(IFN-γ)mRNA、精氨酸酶-1(Arg-1)mRNA、转化生长因子-β1(TGF-β1)mRNA、基质金属蛋白酶-9(MMP-9)mRNA、OPG mRNA、RANK mRNA、RANKL mRNA表达水平。结果:假手术组大鼠股骨结构连续完整,骨小梁数目较多,形态较厚,结构致密;模型组大鼠股骨近端骨密度明显降低;补骨膏低剂量组、补骨膏高剂量组和戊酸雌二醇组大鼠股骨近端骨小梁数量、骨组织形态结构均得到不同程度改善。模型组大鼠骨密度及血清中钙、BALP、BGP、OPG水平均低于假手术组(P<0.01),血清磷水平高于假手术组(P<0.01);补骨膏低剂量组、补骨膏高剂量组及戊酸雌二醇组大鼠骨密度及血清中钙、BALP、BGP、OPG水平均高于模型组(P<0.05或P<0.01),血清磷低于模型组(P<0.01)。模型组大鼠股骨组织OPG蛋白相对表达量低于假手术组(P<0.01),RANK、RANKL蛋白相对表达量均高于假手术组(P<0.01);补骨膏低剂量组、补骨膏高剂量组及戊酸雌二醇组大鼠股骨组织中OPG蛋白相对表达量高于模型组(P<0.05)或(P<0.01),RANK、RANKL蛋白相对表达量均低于模型组(P<0.01)。模型组大鼠股骨组织TNF-α mRNA、IFN-γ mRNA、MMP-9 m RNA、RANK m RNA、RANKL mRNA对表达量均高于假手术组(P<0.01),Arg-1 m RNA、TGF-β1 mRNA、OPG mRNA对表达量均低于假手术组(P<0.01);补骨膏高剂量组及戊酸雌二醇组大鼠股骨组织TNF-α mRNA、IFN-γ m RNA、MMP-9mRNA、RANK mRNA、RANKL mRNA相对表达量均低于模型组(P<0.01),Arg-1 mRNA、TGF-β1 mRNA、OPG m RNA相对表达量均高于模型组(P<0.01)。结论:补骨膏可能通过调控OPG-RANK-RANKL信号通路,抑制免疫炎症反应,调节骨基质胶原合成与降解,从而维持骨代谢平衡,改善PMOP大鼠骨密度及骨微结构病理损伤。展开更多
Purpose:Citation-based assessments of countries’research capabilities often misrepresent their ability to achieve breakthrough advancements.These assessments commonly classify Japan as a developing country,which cont...Purpose:Citation-based assessments of countries’research capabilities often misrepresent their ability to achieve breakthrough advancements.These assessments commonly classify Japan as a developing country,which contradicts its prominent scientific standing.The purpose of this study is to investigate the underlying causes of such inaccurate assessments and to propose methods for conducting more reliable evaluations.Design/methodology/approach:The study evaluates the effectiveness of top-percentile citation metrics as indicators of breakthrough research.Using case studies of selected countries and research topics,the study examines how deviations from lognormal citation distributions impact the accuracy of these percentile indicators.A similar analysis is conducted using university data from the Leiden Ranking to investigate citation distribution deviations at the institutional level.Findings:The study finds that inflated lower tails in citation distributions lead to undervaluation of research capabilities in advanced technological countries,as captured by some percentile indicators.Conversely,research-intensive universities exhibit the opposite trend:a reduced lower tail relative to the upper tail,which causes percentile indicators to overestimate their actual research capacity.Research limitations:The descriptions are mathematical facts that are self-evident.Practical implications:The ratios between the number of papers in the global top 10%and 1%by citation count to the total number of papers are commonly used to describe research performance.However,due to variations in citation patterns across countries and institutions with reference to the global pattern,these ratios can be misleading and lose their value as research indicators.Originality/value:Size-independent research performance indicators,obtained as the ratios between paper counts in top percentiles and the total numbers of publications,are widely used by public and private institutions.This study demonstrates that the use of these ratios for research evaluations and country rankings can be highly misleading.展开更多
Among natural disasters,flash floods are the most destructive events,causing signif-icant damage to the economy and posing a serious threat to human life and property.Comprehensive risk assessment of these sudden floo...Among natural disasters,flash floods are the most destructive events,causing signif-icant damage to the economy and posing a serious threat to human life and property.Comprehensive risk assessment of these sudden floods is a key strategy to mitigate their impact.Accurate analysis of flash flood hazards can greatly enhance prevention efforts and inform critical decision-making processes,ultimately improving our ability to protect communities from these fast-onset disasters.This study analyzed the driving forces of flash flood disaster-causing factors in Heilongjiang Province.Meanwhile,nine different categories of variables affecting the occurrence of flash floods were selected,and the degree of influence of each driving factor on flash floods was quantitatively analyzed,and the driving force analysis of the driving factors of flash floods in Hei-longjiang Province was carried out by using the geographic probe model.This paper employs an uncertainty approach,utilizing a statistical-based interval weight deter-mination technique for evaluation indices and a two-dimensional information-based interval number sorting method.These methodologies are combined to construct a comprehensive flash flood risk assessment model.On this basis,the model was implemented in six regions within China's Heilongjiang province to evaluate and prioritize flash flood risks.The resulting risk ranking for these areas was as follows:Bayan≻Shuangcheng≻Boli≻Suibin≻Hailun≻Yian.The findings demonstrate that the interval number-based evaluation method effectively handles uncertainty,providing a more reliable risk grading system.This approach,by leveraging modern scientific advances and risk quantification techniques,is crucial for improving disaster management and mitigating flash flood impacts.展开更多
This paper studies certain estimates for the lower bound of distance between unitary orbits of normal elements.We show that the distance between unitary orbits of normal elements of simple C^(*)-algebras of tracial ra...This paper studies certain estimates for the lower bound of distance between unitary orbits of normal elements.We show that the distance between unitary orbits of normal elements of simple C^(*)-algebras of tracial rank no more than k has a lower bound.Furthermore,if k≤1 and normal elements are commuting,then the lower bound will be better.Another result establishes a connection involving the spectrum distance operator Dc between a C^(*)-algebra of stable rank one C^(*)-algebra and its hereditary C^(*)-subalgebra.展开更多
In order to rank searching results according to the user preferences,a new personalized web pages ranking algorithm called PWPR（personalized web page ranking）with the idea of adjusting the ranking scores of web page...In order to rank searching results according to the user preferences,a new personalized web pages ranking algorithm called PWPR（personalized web page ranking）with the idea of adjusting the ranking scores of web pages in accordance with user preferences is proposed.PWPR assigns the initial weights based on user interests and creates the virtual links and hubs according to user interests.By measuring user click streams,PWPR incrementally reflects users’ favors for the personalized ranking.To improve the accuracy of ranking, PWPR also takes collaborative filtering into consideration when the query with similar is submitted by users who have similar user interests. Detailed simulation results and comparison with other algorithms prove that the proposed PWPR can adaptively provide personalized ranking and truly relevant information to user preferences.展开更多
随着基于位置社交网络(location-based social network,LBSN)的发展,兴趣点推荐成为满足用户个性化需求、减轻信息过载问题的重要手段.然而,已有的兴趣点推荐算法存在如下的问题:1)多数已有的兴趣点推荐算法简化用户签到频率数据,仅使...随着基于位置社交网络(location-based social network,LBSN)的发展,兴趣点推荐成为满足用户个性化需求、减轻信息过载问题的重要手段.然而,已有的兴趣点推荐算法存在如下的问题:1)多数已有的兴趣点推荐算法简化用户签到频率数据,仅使用二进制值来表示用户是否访问一个兴趣点;2)基于矩阵分解的兴趣点推荐算法把签到频率数据和传统推荐系统中的评分数据等同看待,使用高斯分布模型建模用户的签到行为;3)忽视用户签到数据的隐式反馈属性.为解决以上问题,提出一个基于Ranking的泊松矩阵分解兴趣点推荐算法.首先,根据LBSN中用户的签到行为特点,利用泊松分布模型替代高斯分布模型建模用户在兴趣点上签到行为;然后采用BPR(Bayesian personalized ranking)标准优化泊松矩阵分解的损失函数,拟合用户在兴趣点对上的偏序关系;最后,利用包含地域影响力的正则化因子约束泊松矩阵分解的过程.在真实数据集上的实验结果表明:基于Ranking的泊松矩阵分解兴趣点推荐算法的性能优于传统的兴趣点推荐算法.展开更多
文摘目的:探究补骨膏对绝经后骨质疏松症(PMOP)大鼠的骨保护作用及其对骨保护素(OPG)-核因子κB受体激活蛋白(RANK)-核因子κB受体激活蛋白配体(RANKL)信号通路的调控作用。方法:将36只大鼠随机分为假手术组(9只)和手术组(27只),手术组采用双侧卵巢切除建立PMOP大鼠模型。造模成功后,将24只PMOP大鼠随机分为模型组、戊酸雌二醇组、补骨膏低剂量组、补骨膏高剂量组,然后予相应药物灌胃8周。骨密度仪检测股骨近端骨密度;Micro-CT三维重建分析股骨微结构;苏木精-伊红(HE)染色观察股骨组织病理形态;酶联免疫吸附试验(ELISA)法检测血清中骨碱性磷酸酶(BALP)、骨钙素(BGP)、OPG水平,测定盒检测血清中磷、钙水平;蛋白质印迹法(Western blotting)检测股骨组织中OPG、RANK、RANKL蛋白表达水平;RT-qPCR法检测股骨组织肿瘤坏死因子-α(TNF-α)mRNA、干扰素-γ(IFN-γ)mRNA、精氨酸酶-1(Arg-1)mRNA、转化生长因子-β1(TGF-β1)mRNA、基质金属蛋白酶-9(MMP-9)mRNA、OPG mRNA、RANK mRNA、RANKL mRNA表达水平。结果:假手术组大鼠股骨结构连续完整,骨小梁数目较多,形态较厚,结构致密;模型组大鼠股骨近端骨密度明显降低;补骨膏低剂量组、补骨膏高剂量组和戊酸雌二醇组大鼠股骨近端骨小梁数量、骨组织形态结构均得到不同程度改善。模型组大鼠骨密度及血清中钙、BALP、BGP、OPG水平均低于假手术组(P<0.01),血清磷水平高于假手术组(P<0.01);补骨膏低剂量组、补骨膏高剂量组及戊酸雌二醇组大鼠骨密度及血清中钙、BALP、BGP、OPG水平均高于模型组(P<0.05或P<0.01),血清磷低于模型组(P<0.01)。模型组大鼠股骨组织OPG蛋白相对表达量低于假手术组(P<0.01),RANK、RANKL蛋白相对表达量均高于假手术组(P<0.01);补骨膏低剂量组、补骨膏高剂量组及戊酸雌二醇组大鼠股骨组织中OPG蛋白相对表达量高于模型组(P<0.05)或(P<0.01),RANK、RANKL蛋白相对表达量均低于模型组(P<0.01)。模型组大鼠股骨组织TNF-α mRNA、IFN-γ mRNA、MMP-9 m RNA、RANK m RNA、RANKL mRNA对表达量均高于假手术组(P<0.01),Arg-1 m RNA、TGF-β1 mRNA、OPG mRNA对表达量均低于假手术组(P<0.01);补骨膏高剂量组及戊酸雌二醇组大鼠股骨组织TNF-α mRNA、IFN-γ m RNA、MMP-9mRNA、RANK mRNA、RANKL mRNA相对表达量均低于模型组(P<0.01),Arg-1 mRNA、TGF-β1 mRNA、OPG m RNA相对表达量均高于模型组(P<0.01)。结论:补骨膏可能通过调控OPG-RANK-RANKL信号通路,抑制免疫炎症反应,调节骨基质胶原合成与降解,从而维持骨代谢平衡,改善PMOP大鼠骨密度及骨微结构病理损伤。
文摘Purpose:Citation-based assessments of countries’research capabilities often misrepresent their ability to achieve breakthrough advancements.These assessments commonly classify Japan as a developing country,which contradicts its prominent scientific standing.The purpose of this study is to investigate the underlying causes of such inaccurate assessments and to propose methods for conducting more reliable evaluations.Design/methodology/approach:The study evaluates the effectiveness of top-percentile citation metrics as indicators of breakthrough research.Using case studies of selected countries and research topics,the study examines how deviations from lognormal citation distributions impact the accuracy of these percentile indicators.A similar analysis is conducted using university data from the Leiden Ranking to investigate citation distribution deviations at the institutional level.Findings:The study finds that inflated lower tails in citation distributions lead to undervaluation of research capabilities in advanced technological countries,as captured by some percentile indicators.Conversely,research-intensive universities exhibit the opposite trend:a reduced lower tail relative to the upper tail,which causes percentile indicators to overestimate their actual research capacity.Research limitations:The descriptions are mathematical facts that are self-evident.Practical implications:The ratios between the number of papers in the global top 10%and 1%by citation count to the total number of papers are commonly used to describe research performance.However,due to variations in citation patterns across countries and institutions with reference to the global pattern,these ratios can be misleading and lose their value as research indicators.Originality/value:Size-independent research performance indicators,obtained as the ratios between paper counts in top percentiles and the total numbers of publications,are widely used by public and private institutions.This study demonstrates that the use of these ratios for research evaluations and country rankings can be highly misleading.
基金Basic Scientific Research Expense Project of IWHR-Extreme rainstorm development trends and prediction techniques,Grant/Award Number:JZ0145B142024National Natural Science Foundation of China,Grant/Award Number:42271095。
文摘Among natural disasters,flash floods are the most destructive events,causing signif-icant damage to the economy and posing a serious threat to human life and property.Comprehensive risk assessment of these sudden floods is a key strategy to mitigate their impact.Accurate analysis of flash flood hazards can greatly enhance prevention efforts and inform critical decision-making processes,ultimately improving our ability to protect communities from these fast-onset disasters.This study analyzed the driving forces of flash flood disaster-causing factors in Heilongjiang Province.Meanwhile,nine different categories of variables affecting the occurrence of flash floods were selected,and the degree of influence of each driving factor on flash floods was quantitatively analyzed,and the driving force analysis of the driving factors of flash floods in Hei-longjiang Province was carried out by using the geographic probe model.This paper employs an uncertainty approach,utilizing a statistical-based interval weight deter-mination technique for evaluation indices and a two-dimensional information-based interval number sorting method.These methodologies are combined to construct a comprehensive flash flood risk assessment model.On this basis,the model was implemented in six regions within China's Heilongjiang province to evaluate and prioritize flash flood risks.The resulting risk ranking for these areas was as follows:Bayan≻Shuangcheng≻Boli≻Suibin≻Hailun≻Yian.The findings demonstrate that the interval number-based evaluation method effectively handles uncertainty,providing a more reliable risk grading system.This approach,by leveraging modern scientific advances and risk quantification techniques,is crucial for improving disaster management and mitigating flash flood impacts.
基金Supported by Zhejiang Provincial Natural Science Foundation of China(No.ZCLQN25A0103)。
文摘This paper studies certain estimates for the lower bound of distance between unitary orbits of normal elements.We show that the distance between unitary orbits of normal elements of simple C^(*)-algebras of tracial rank no more than k has a lower bound.Furthermore,if k≤1 and normal elements are commuting,then the lower bound will be better.Another result establishes a connection involving the spectrum distance operator Dc between a C^(*)-algebra of stable rank one C^(*)-algebra and its hereditary C^(*)-subalgebra.
基金The Natural Science Foundation of South-Central University for Nationalities(No.YZZ07006)
文摘In order to rank searching results according to the user preferences,a new personalized web pages ranking algorithm called PWPR（personalized web page ranking）with the idea of adjusting the ranking scores of web pages in accordance with user preferences is proposed.PWPR assigns the initial weights based on user interests and creates the virtual links and hubs according to user interests.By measuring user click streams,PWPR incrementally reflects users’ favors for the personalized ranking.To improve the accuracy of ranking, PWPR also takes collaborative filtering into consideration when the query with similar is submitted by users who have similar user interests. Detailed simulation results and comparison with other algorithms prove that the proposed PWPR can adaptively provide personalized ranking and truly relevant information to user preferences.
文摘随着基于位置社交网络(location-based social network,LBSN)的发展,兴趣点推荐成为满足用户个性化需求、减轻信息过载问题的重要手段.然而,已有的兴趣点推荐算法存在如下的问题:1)多数已有的兴趣点推荐算法简化用户签到频率数据,仅使用二进制值来表示用户是否访问一个兴趣点;2)基于矩阵分解的兴趣点推荐算法把签到频率数据和传统推荐系统中的评分数据等同看待,使用高斯分布模型建模用户的签到行为;3)忽视用户签到数据的隐式反馈属性.为解决以上问题,提出一个基于Ranking的泊松矩阵分解兴趣点推荐算法.首先,根据LBSN中用户的签到行为特点,利用泊松分布模型替代高斯分布模型建模用户在兴趣点上签到行为;然后采用BPR(Bayesian personalized ranking)标准优化泊松矩阵分解的损失函数,拟合用户在兴趣点对上的偏序关系;最后,利用包含地域影响力的正则化因子约束泊松矩阵分解的过程.在真实数据集上的实验结果表明:基于Ranking的泊松矩阵分解兴趣点推荐算法的性能优于传统的兴趣点推荐算法.
