电流镜输出误差主要由3个不同失配源造成:漏源电压(V_(DS)),阈值电压(V_(th)),跨导系数(β)。其中,第一项V_(DS)失配通常是由有限输出阻抗引起的确定性误差,该误差可以通过使用级联结构以及增益提升技术避免,后两项V_(th)和β失配是由...电流镜输出误差主要由3个不同失配源造成:漏源电压(V_(DS)),阈值电压(V_(th)),跨导系数(β)。其中,第一项V_(DS)失配通常是由有限输出阻抗引起的确定性误差,该误差可以通过使用级联结构以及增益提升技术避免,后两项V_(th)和β失配是由工艺引起的随机性误差。为解决电流镜因工艺失配现象导致的电压电流(Voltage to Current)转换电路精度、线性度较差的问题,提出了一种动态元件匹配(Dynamic Element Match,DEM)以及修调技术(TRIM)相结合的电流镜校准方法,该方法使用TRIM技术将待校准输出电流镜支路和基准电流镜支路之间的误差电流,通过电容与MOS管转换成校准电流后反馈流入待校准输出电流镜支路完成校准,并通过DEM技术切换多条待校准输出电流镜支路完成校准的同时使输出误差平均化。本文采用SMIC 0.18μm BCD工艺对所提出的V-I转换电路进行了电路设计,仿真结果表明,V-I转换电路的输出电流的失配误差从0.12%下降到了0.03%,有效位数ENOB达到了11.2 bit,总谐波失真THD为−72.6 dB。展开更多
Background:Nonalcoholic fatty liver disease(NAFLD)is one of the most common chronic liver diseases globally.Hepatic stellate cells(HSCs)are the major effector cells of liver fibrosis.HSCs contain abundant lipid drople...Background:Nonalcoholic fatty liver disease(NAFLD)is one of the most common chronic liver diseases globally.Hepatic stellate cells(HSCs)are the major effector cells of liver fibrosis.HSCs contain abundant lipid droplets(LDs)in their cytoplasm during quiescence.Perilipin 5(PLIN 5)is a LD surface-associated protein that plays a crucial role in lipid homeostasis.However,little is known about the role of PLIN 5 in HSC activation.Methods:PLIN 5 was overexpressed in HSCs of Sprague–Dawley rats by lentivirus transfection.At the same time,PLIN 5 gene knockout mice were constructed and fed with a high-fat diet(HFD)for 20 weeks to study the role of PLIN 5 in NAFLD.The corresponding reagent kits were used to measure TG,GSH,Caspase 3 activity,ATP level,and mitochondrial DNA copy number.Metabolomic analysis of mice liver tissue metabolism was performed based on UPLC-MS/MS.AMPK,mitochondrial function,cell proliferation,and apoptosis-related genes and proteins were detected by western blotting and qPCR.Results:Overexpression of PLIN 5 in activated HSCs led to a decrease in ATP levels in mitochondria,inhibition of cell proliferation,and a significant increase in cell apoptosis through AMPK activation.In addition,compared with the HFD-fed C57BL/6J mice,PLIN 5 knockout mice fed with HFD showed reduced liver fat deposition,decreased LD abundance and size,and reduced liver fibrosis.Conclusion:These findings highlight the unique regulatory role of PLIN 5 in HSCs and the role of PLIN 5 in the fibrosis process of NAFLD.展开更多
On the basis of computational fluid dynamics,the flow field characteristics of multi-trophic artificial reefs,including the flow field distribution features of a single reef under three different velocities and the ef...On the basis of computational fluid dynamics,the flow field characteristics of multi-trophic artificial reefs,including the flow field distribution features of a single reef under three different velocities and the effect of spacing between reefs on flow scale and the flow state,were analyzed.Results indicate upwelling,slow flow,and eddy around a single reef.Maximum velocity,height,and volume of upwelling in front of a single reef were positively correlated with inflow velocity.The length and volume of slow flow increased with the increase in inflow velocity.Eddies were present both inside and backward,and vorticity was positively correlated with inflow velocity.Space between reefs had a minor influence on the maximum velocity and height of upwelling.With the increase in space from 0.5 L to 1.5 L(L is the reef lehgth),the length of slow flow in the front and back of the combined reefs increased slightly.When the space was 2.0 L,the length of the slow flow decreased.In four different spaces,eddies were present inside and at the back of each reef.The maximum vorticity was negatively correlated with space from 0.5 L to 1.5 L,but under 2.0 L space,the maximum vorticity was close to the vorticity of a single reef under the same inflow velocity.展开更多
文摘电流镜输出误差主要由3个不同失配源造成:漏源电压(V_(DS)),阈值电压(V_(th)),跨导系数(β)。其中,第一项V_(DS)失配通常是由有限输出阻抗引起的确定性误差,该误差可以通过使用级联结构以及增益提升技术避免,后两项V_(th)和β失配是由工艺引起的随机性误差。为解决电流镜因工艺失配现象导致的电压电流(Voltage to Current)转换电路精度、线性度较差的问题,提出了一种动态元件匹配(Dynamic Element Match,DEM)以及修调技术(TRIM)相结合的电流镜校准方法,该方法使用TRIM技术将待校准输出电流镜支路和基准电流镜支路之间的误差电流,通过电容与MOS管转换成校准电流后反馈流入待校准输出电流镜支路完成校准,并通过DEM技术切换多条待校准输出电流镜支路完成校准的同时使输出误差平均化。本文采用SMIC 0.18μm BCD工艺对所提出的V-I转换电路进行了电路设计,仿真结果表明,V-I转换电路的输出电流的失配误差从0.12%下降到了0.03%,有效位数ENOB达到了11.2 bit,总谐波失真THD为−72.6 dB。
基金Discipline Key Special ProjectGrant/Award Number:XKZDQY202001+7 种基金Henan Provincial Key R&D and Promotion Special ProjectGrant/Award Number:212102310033Henan Provincial Medical Science and Technology Tackling ProgramGrant/Award Number:LHGJ20220557Key R&D Program of ChinaGrant/Award Number:2020YFC2006100,2020YFC2009000 and 2020YFC2009006National Natural Science Foundation of ChinaGrant/Award Number:31471330 and 81870408。
文摘Background:Nonalcoholic fatty liver disease(NAFLD)is one of the most common chronic liver diseases globally.Hepatic stellate cells(HSCs)are the major effector cells of liver fibrosis.HSCs contain abundant lipid droplets(LDs)in their cytoplasm during quiescence.Perilipin 5(PLIN 5)is a LD surface-associated protein that plays a crucial role in lipid homeostasis.However,little is known about the role of PLIN 5 in HSC activation.Methods:PLIN 5 was overexpressed in HSCs of Sprague–Dawley rats by lentivirus transfection.At the same time,PLIN 5 gene knockout mice were constructed and fed with a high-fat diet(HFD)for 20 weeks to study the role of PLIN 5 in NAFLD.The corresponding reagent kits were used to measure TG,GSH,Caspase 3 activity,ATP level,and mitochondrial DNA copy number.Metabolomic analysis of mice liver tissue metabolism was performed based on UPLC-MS/MS.AMPK,mitochondrial function,cell proliferation,and apoptosis-related genes and proteins were detected by western blotting and qPCR.Results:Overexpression of PLIN 5 in activated HSCs led to a decrease in ATP levels in mitochondria,inhibition of cell proliferation,and a significant increase in cell apoptosis through AMPK activation.In addition,compared with the HFD-fed C57BL/6J mice,PLIN 5 knockout mice fed with HFD showed reduced liver fat deposition,decreased LD abundance and size,and reduced liver fibrosis.Conclusion:These findings highlight the unique regulatory role of PLIN 5 in HSCs and the role of PLIN 5 in the fibrosis process of NAFLD.
基金supported by the National Natural Science Foundation of China(No.32002442)the National Key R&D Program(No.2019YFD0902101).
文摘On the basis of computational fluid dynamics,the flow field characteristics of multi-trophic artificial reefs,including the flow field distribution features of a single reef under three different velocities and the effect of spacing between reefs on flow scale and the flow state,were analyzed.Results indicate upwelling,slow flow,and eddy around a single reef.Maximum velocity,height,and volume of upwelling in front of a single reef were positively correlated with inflow velocity.The length and volume of slow flow increased with the increase in inflow velocity.Eddies were present both inside and backward,and vorticity was positively correlated with inflow velocity.Space between reefs had a minor influence on the maximum velocity and height of upwelling.With the increase in space from 0.5 L to 1.5 L(L is the reef lehgth),the length of slow flow in the front and back of the combined reefs increased slightly.When the space was 2.0 L,the length of the slow flow decreased.In four different spaces,eddies were present inside and at the back of each reef.The maximum vorticity was negatively correlated with space from 0.5 L to 1.5 L,but under 2.0 L space,the maximum vorticity was close to the vorticity of a single reef under the same inflow velocity.
