设计了一种具有铲形终端微带馈电椭圆缝隙及枝节调节和接地板阶梯凹槽的超宽带（UWB）天线。利用仿真软件HFSS分析了铲形半椭圆、椭圆缝隙及枝节、半圆切槽、接地板与辐射体间隙、接地板三角形切角和阶梯凹槽等结构对天线性能的影响,对...设计了一种具有铲形终端微带馈电椭圆缝隙及枝节调节和接地板阶梯凹槽的超宽带（UWB）天线。利用仿真软件HFSS分析了铲形半椭圆、椭圆缝隙及枝节、半圆切槽、接地板与辐射体间隙、接地板三角形切角和阶梯凹槽等结构对天线性能的影响,对天线结构参数进行了优化。实测天线的阻抗带宽为2.8~12.0 GHz,在3.1~10.6GHz范围内基本呈全向性,并且具有较稳定的增益,约为2.5~4.6 d Bi。该天线可广泛用于无线通信领域。展开更多
AIM To investigated the relationships between HER2, c-Jun N-terminal kinase(JNK) and protein kinase B(AKT) with respect to metastatic potential of HER2-positive gastric cancer(GC) cells.METHODS Immunohistochemistry wa...AIM To investigated the relationships between HER2, c-Jun N-terminal kinase(JNK) and protein kinase B(AKT) with respect to metastatic potential of HER2-positive gastric cancer(GC) cells.METHODS Immunohistochemistry was performed on tissue array slides containing 423 human GC specimens. Using HER2-positve GC cell lines SNU-216 and NCI-N87, HER2 expression was silenced by RNA interference, and the activations of JNK and AKT were suppressed by SP600125 and LY294002, respectively. Transwell assay, Western blot, semi-quantitative reverse transcriptionpolymerase chain reaction and immunofluorescence staining were used in cell culture experiments. RESULTS In GC specimens, HER2, JNK, and AKT activations were positively correlated with each other. In vitro analysis revealed a positive regulatory feedback loop between HER2 and JNK in GC cell lines and the role of JNK as a downstream effector of AKT in the HER2/AKT signaling pathway. JNK inhibition suppressed migratory capacity through reversing EMT and dual inhibition of JNK and AKT induced a more profound effect on cancer cell motility.CONCLUSION HER2, JNK and AKT in human GC specimens are positively associated with each other. JNK and AKT, downstream effectors of HER2, co-operatively contribute to the metastatic potential of HER2-positive GC cells. Thus, targeting of these two molecules in combination with HER2 downregulation may be a good approach to combat HER2-positive GC.展开更多
The terminal velocity has been widely used in extensive fields, but the complexity of drag coefficient expression leads to the calculation of terminal velocity in transitional flow （1 〈 Re ≤ 1000） with much more d...The terminal velocity has been widely used in extensive fields, but the complexity of drag coefficient expression leads to the calculation of terminal velocity in transitional flow （1 〈 Re ≤ 1000） with much more difficulty than those in laminar flow （Re ≤ 1） and turbulent flow （Re ≥ 1000）. This paper summarized and compared 24 drag coefficient correlations, and developed an expression for calculating the terminal velocity in transitional flow, and also analyzed the effects of particle density and size, fluid density and viscosity on terminal velocity. The results show that 19 of 24 previously published correlations for drag coefficient have good prediction performance and can be used for calculating the terminal velocity in the entire transitional flow with higher accuracy. Adapting two dimensionless parameters （w＊, d＊）, a proposed explicit correlation, w＊=-25.68654 × exp （-d＊/77.02069）＋ 24.89826, is attained in transitional flow with good performance, which is helpful in calculating the terminal velocity.展开更多
文摘设计了一种具有铲形终端微带馈电椭圆缝隙及枝节调节和接地板阶梯凹槽的超宽带（UWB）天线。利用仿真软件HFSS分析了铲形半椭圆、椭圆缝隙及枝节、半圆切槽、接地板与辐射体间隙、接地板三角形切角和阶梯凹槽等结构对天线性能的影响,对天线结构参数进行了优化。实测天线的阻抗带宽为2.8~12.0 GHz,在3.1~10.6GHz范围内基本呈全向性,并且具有较稳定的增益,约为2.5~4.6 d Bi。该天线可广泛用于无线通信领域。
基金Supported by SNUH Research Fund,Grant NO 04-2016-0220the Education and Research Encouragement Fund of Seoul National University Hospital(2015)
文摘AIM To investigated the relationships between HER2, c-Jun N-terminal kinase(JNK) and protein kinase B(AKT) with respect to metastatic potential of HER2-positive gastric cancer(GC) cells.METHODS Immunohistochemistry was performed on tissue array slides containing 423 human GC specimens. Using HER2-positve GC cell lines SNU-216 and NCI-N87, HER2 expression was silenced by RNA interference, and the activations of JNK and AKT were suppressed by SP600125 and LY294002, respectively. Transwell assay, Western blot, semi-quantitative reverse transcriptionpolymerase chain reaction and immunofluorescence staining were used in cell culture experiments. RESULTS In GC specimens, HER2, JNK, and AKT activations were positively correlated with each other. In vitro analysis revealed a positive regulatory feedback loop between HER2 and JNK in GC cell lines and the role of JNK as a downstream effector of AKT in the HER2/AKT signaling pathway. JNK inhibition suppressed migratory capacity through reversing EMT and dual inhibition of JNK and AKT induced a more profound effect on cancer cell motility.CONCLUSION HER2, JNK and AKT in human GC specimens are positively associated with each other. JNK and AKT, downstream effectors of HER2, co-operatively contribute to the metastatic potential of HER2-positive GC cells. Thus, targeting of these two molecules in combination with HER2 downregulation may be a good approach to combat HER2-positive GC.
文摘The terminal velocity has been widely used in extensive fields, but the complexity of drag coefficient expression leads to the calculation of terminal velocity in transitional flow （1 〈 Re ≤ 1000） with much more difficulty than those in laminar flow （Re ≤ 1） and turbulent flow （Re ≥ 1000）. This paper summarized and compared 24 drag coefficient correlations, and developed an expression for calculating the terminal velocity in transitional flow, and also analyzed the effects of particle density and size, fluid density and viscosity on terminal velocity. The results show that 19 of 24 previously published correlations for drag coefficient have good prediction performance and can be used for calculating the terminal velocity in the entire transitional flow with higher accuracy. Adapting two dimensionless parameters （w＊, d＊）, a proposed explicit correlation, w＊=-25.68654 × exp （-d＊/77.02069）＋ 24.89826, is attained in transitional flow with good performance, which is helpful in calculating the terminal velocity.
