目的聚类中国≥45岁中老年人多重慢性病模式的流行情况,并探讨多重慢性病模式与日常生活能力(activity of daily living,ADL)和工具性日常生活能力(instrumental activity of daily living,IADL)残疾的关联性。方法基于2018年中国健康...目的聚类中国≥45岁中老年人多重慢性病模式的流行情况,并探讨多重慢性病模式与日常生活能力(activity of daily living,ADL)和工具性日常生活能力(instrumental activity of daily living,IADL)残疾的关联性。方法基于2018年中国健康与养老追踪调查(China Health and Retirement Longitudinal Study,CHARLS)数据库,以19745名≥45岁中老年人为研究对象,采用双向聚类法(two⁃way clustering framework,TCF)识别非随机多重慢性疾病模式后进行人群聚类,并采用logistic回归分析模型分析多重慢性病模式与ADL和IADL残疾的相互关系。结果中国中老年人多重慢性病患者例数为10941,占55.4%,可聚类为心脑血管-代谢模式、呼吸系统-内脏模式和消化-关节-精神模式,根据多重慢性病模式的关联强度将人群划分为5个多重慢性病关联组。其中,高度关联心脑血管-代谢模式和消化-关节-精神模式人群的ADL和IADL残疾负担最重(OR=4.696,95%CI:4.196~5.255,P<0.001;OR=3.155,95%CI:2.840~3.504,P<0.001),高度关联心脑血管-代谢模式合并中度关联呼吸系统-内脏模式的人群罹患ADL和IADL残疾的风险次之(OR=2.821,95%CI:2.210~3.602,P<0.001;OR=2.662,95%CI:2.120~3.342,P<0.001)。结论中国中老年人群中高度关联心脑血管-代谢模式发生ADL和IADL残疾的风险最高。展开更多
The roughness increase on horizontal axis wind turbine(HAWT) blade surface,especially on the leading edge,can lead to an aerodynamic performance degradation of blade and power output loss of HAWT,so roughness sensitiv...The roughness increase on horizontal axis wind turbine(HAWT) blade surface,especially on the leading edge,can lead to an aerodynamic performance degradation of blade and power output loss of HAWT,so roughness sensitivity is an important factor for the HAWT blade design.However,there is no criterion for evaluating roughness sensitivity of blade currently.In this paper,the performance influences of airfoil aerodynamic parameters were analyzed by the blade element momentum(BEM) method and 1.5 MW wind turbine blade.It showed that airfoil lift coefficient was the key parameter to the power output and axial thrust of HAWT.Moreover,the evaluation indicators of roughness sensitivity for the different spanwise airfoils of the pitch-regulated HAWT blade were proposed.Those respectively were the lift-to-drag ratio and lift coefficient without feedback system,the maximum lift-to-drag ratio and design lift coefficient with feedback system for the airfoils at outboard section of blade,and lift coefficient without feedback,maximum lift coefficient with feedback for the airfoils at other sections under the pitch-fixed and variable-speed operation.It is not necessary to consider the roughness when HWAT can be regulated to the rated power output by the pitch-regulated and invariable-speed operation.展开更多
This paper presents the effect of wind tunnel sidewalls on the wind turbine airfoils with experimental and numerical methods.The test is carried out in a low-speed wind tunnel at Re=2.62×10^(5).Pressures acting o...This paper presents the effect of wind tunnel sidewalls on the wind turbine airfoils with experimental and numerical methods.The test is carried out in a low-speed wind tunnel at Re=2.62×10^(5).Pressures acting on the airfoil surface are measured by a multiport pressure device.And,the oil flow visualization technique is used to investigate the flow field characteristics of the airfoil surface.Then,a numerical simulation was conducted with the measurement results.As a result,it is clarified the flow structures on the airfoil surface depend strongly on the angles of attack and the sidewalls.At small angles of attack,the three-dimensional separation caused by the interaction between the sidewall boundary layer and the airfoil boundary layer is very small,and only appears near the junction of the airfoil model and the sidewall.This corner separation becomes large with the increase of the angle of attack.At the middle part of the testing model,the boundary layer flow evolves into three-dimensional separation,i.e.,stall cell,when the separation develops to an appreciate extent.The stall phenomenon will further spread from the center line to sidewalls with the increase of the angle of attack;and then,its development will be limited by the sidewall boundary layer separation.Comparably,the simulation shows that the sidewall make the pressure coefficient Cpdecrease,and proper boundary condition can maintain two-dimensional flow at large angles of attack by eliminating the influence of corner vortices.展开更多
Soluble adenylyl cyclase (sAC) plays a critical role in male fertility in mammals by regulating sperm hyperactivation. We aimed to study the mechanism of sAC in this phenomenon and to explore potential target sites fo...Soluble adenylyl cyclase (sAC) plays a critical role in male fertility in mammals by regulating sperm hyperactivation. We aimed to study the mechanism of sAC in this phenomenon and to explore potential target sites for male contraception. In this study, in vivo electroporation and rete testis microinjection-mediated short hairpin (sh)RNA plasmids were adopted to silence sAC gene expression in male rats. The results showed that high transfection efficiency (shRNA717, 49.0% and shRNA4205, 65.0%) was achieved by shRNA plasmids injected directly into the rete testis. When the sAC was downregulated, the cyclic adenosine mono-phosphate (cAMP) content and protein phosphorylation level of spermatozoa both declined with a significantly lower hyperactivation rate compared with negative controls. The highest transfection efficiency occurred at 15 d and was obviously time dependent. Bioinformatic and experimental results showed that sAC and tmAC both belong to the AC family and might have analogous functions. ShRNA717 and shRNA4205 were the best targets for the sAC gene, suggesting that they could be candidates for male contraception. Thus, it appears feasible to achieve male contraception by silencing the expression of sAC, affecting sperm hyper-activation via a cAMP-mediated signaling pathway.展开更多
文摘目的聚类中国≥45岁中老年人多重慢性病模式的流行情况,并探讨多重慢性病模式与日常生活能力(activity of daily living,ADL)和工具性日常生活能力(instrumental activity of daily living,IADL)残疾的关联性。方法基于2018年中国健康与养老追踪调查(China Health and Retirement Longitudinal Study,CHARLS)数据库,以19745名≥45岁中老年人为研究对象,采用双向聚类法(two⁃way clustering framework,TCF)识别非随机多重慢性疾病模式后进行人群聚类,并采用logistic回归分析模型分析多重慢性病模式与ADL和IADL残疾的相互关系。结果中国中老年人多重慢性病患者例数为10941,占55.4%,可聚类为心脑血管-代谢模式、呼吸系统-内脏模式和消化-关节-精神模式,根据多重慢性病模式的关联强度将人群划分为5个多重慢性病关联组。其中,高度关联心脑血管-代谢模式和消化-关节-精神模式人群的ADL和IADL残疾负担最重(OR=4.696,95%CI:4.196~5.255,P<0.001;OR=3.155,95%CI:2.840~3.504,P<0.001),高度关联心脑血管-代谢模式合并中度关联呼吸系统-内脏模式的人群罹患ADL和IADL残疾的风险次之(OR=2.821,95%CI:2.210~3.602,P<0.001;OR=2.662,95%CI:2.120~3.342,P<0.001)。结论中国中老年人群中高度关联心脑血管-代谢模式发生ADL和IADL残疾的风险最高。
基金supported by the National Natural Science Foundation of China (Grant Nos. 50976117 and 50836006)
文摘The roughness increase on horizontal axis wind turbine(HAWT) blade surface,especially on the leading edge,can lead to an aerodynamic performance degradation of blade and power output loss of HAWT,so roughness sensitivity is an important factor for the HAWT blade design.However,there is no criterion for evaluating roughness sensitivity of blade currently.In this paper,the performance influences of airfoil aerodynamic parameters were analyzed by the blade element momentum(BEM) method and 1.5 MW wind turbine blade.It showed that airfoil lift coefficient was the key parameter to the power output and axial thrust of HAWT.Moreover,the evaluation indicators of roughness sensitivity for the different spanwise airfoils of the pitch-regulated HAWT blade were proposed.Those respectively were the lift-to-drag ratio and lift coefficient without feedback system,the maximum lift-to-drag ratio and design lift coefficient with feedback system for the airfoils at outboard section of blade,and lift coefficient without feedback,maximum lift coefficient with feedback for the airfoils at other sections under the pitch-fixed and variable-speed operation.It is not necessary to consider the roughness when HWAT can be regulated to the rated power output by the pitch-regulated and invariable-speed operation.
基金funded by the National Natural Science Foundation of China(No.51776204)。
文摘This paper presents the effect of wind tunnel sidewalls on the wind turbine airfoils with experimental and numerical methods.The test is carried out in a low-speed wind tunnel at Re=2.62×10^(5).Pressures acting on the airfoil surface are measured by a multiport pressure device.And,the oil flow visualization technique is used to investigate the flow field characteristics of the airfoil surface.Then,a numerical simulation was conducted with the measurement results.As a result,it is clarified the flow structures on the airfoil surface depend strongly on the angles of attack and the sidewalls.At small angles of attack,the three-dimensional separation caused by the interaction between the sidewall boundary layer and the airfoil boundary layer is very small,and only appears near the junction of the airfoil model and the sidewall.This corner separation becomes large with the increase of the angle of attack.At the middle part of the testing model,the boundary layer flow evolves into three-dimensional separation,i.e.,stall cell,when the separation develops to an appreciate extent.The stall phenomenon will further spread from the center line to sidewalls with the increase of the angle of attack;and then,its development will be limited by the sidewall boundary layer separation.Comparably,the simulation shows that the sidewall make the pressure coefficient Cpdecrease,and proper boundary condition can maintain two-dimensional flow at large angles of attack by eliminating the influence of corner vortices.
基金supported by the National Natural Science Foundation of China (30471243)National Supporting Projects for Science and Techniques (2011BAD28B02, 2012BAD12B10)Provincial Project for Agricultural Techniques (SX2011-189, SXGC[2012]394)
文摘Soluble adenylyl cyclase (sAC) plays a critical role in male fertility in mammals by regulating sperm hyperactivation. We aimed to study the mechanism of sAC in this phenomenon and to explore potential target sites for male contraception. In this study, in vivo electroporation and rete testis microinjection-mediated short hairpin (sh)RNA plasmids were adopted to silence sAC gene expression in male rats. The results showed that high transfection efficiency (shRNA717, 49.0% and shRNA4205, 65.0%) was achieved by shRNA plasmids injected directly into the rete testis. When the sAC was downregulated, the cyclic adenosine mono-phosphate (cAMP) content and protein phosphorylation level of spermatozoa both declined with a significantly lower hyperactivation rate compared with negative controls. The highest transfection efficiency occurred at 15 d and was obviously time dependent. Bioinformatic and experimental results showed that sAC and tmAC both belong to the AC family and might have analogous functions. ShRNA717 and shRNA4205 were the best targets for the sAC gene, suggesting that they could be candidates for male contraception. Thus, it appears feasible to achieve male contraception by silencing the expression of sAC, affecting sperm hyper-activation via a cAMP-mediated signaling pathway.
