剪切稠化流体是一种典型的非牛顿流体,研究气泡在其中的运动特性对优化设备结构、提高反应效率具有重要意义。文中采用流体体积(VOF)法,通过改变Gallilei数(Ga)、E tv s数(Eo)与流变指数(n),对牛顿流体(n=1)及剪切稠化流体(n>1)内气...剪切稠化流体是一种典型的非牛顿流体,研究气泡在其中的运动特性对优化设备结构、提高反应效率具有重要意义。文中采用流体体积(VOF)法,通过改变Gallilei数(Ga)、E tv s数(Eo)与流变指数(n),对牛顿流体(n=1)及剪切稠化流体(n>1)内气泡的形状、尾涡、终端速度和气泡周围液相黏度分布的变化进行了深入的数值研究。结果表明:气泡变形程度和尾涡尺寸随着Ga数或Eo数的增大而增加;剪切稠化效应会阻碍尾涡的形成,减小气泡的尾涡尺寸;气泡周围剪切速率的差异会导致气泡上方及尾部产生高黏度区域,该高黏度区域会随剪切稠化效应的增加而增大;气泡终端速度随Ga数的增大或流变指数n,Eo数的减小而增大。展开更多
Chile is a very important country that forms part of the Andean metallogenic belts. The Atacama and Domeyko fault systems in northern Chile control the tectonic- magmatic activities that migrate eastward and the types...Chile is a very important country that forms part of the Andean metallogenic belts. The Atacama and Domeyko fault systems in northern Chile control the tectonic- magmatic activities that migrate eastward and the types of mineral resources. In this paper, we processed and interpreted aeromagnetic data from northern Chile using reduction to pole, upward field continuation, the second derivative calculation in the vertical direction, inclination angle calculation, and analytical signal amplitude analysis. We revealed the locations and planar distribution characteristics of the regional deep faults along the NNE and NS directions. Furthermore, we observed that the major reasons for the formation of the tectonic-magmatic rocks belts were the nearly parallel deep faults distributed from west to east and multiple magmatic activities along these faults. We ascertained the locations of volcanic mechanisms and the relationships between them using these regional deep faults. We deduced the spatial distributions of the basic-intermediate, basic, and acidic igneous rocks, intrusive rocks, and sedimentary sequences. We showed the linear positive magnetic anomalies and magnetic anomaly gradient zones by slowly varying the background, negative magnetic anomaly field, which indicated the presence of strong magmatic activities in these regional deep faults; it also revealed the favorable areas of copper and polymetallic mineralization. This study provides some basic information for further research on the geology, structural characteristics, and mineral resource prospecting in northern Chile.展开更多
Background Treatment of ischemic heart disease remains an important challenge, though there have been enormous progresses in cardiovascular therapeutics. This study was conducted to evaluate whether Tongxinluo （TXL）...Background Treatment of ischemic heart disease remains an important challenge, though there have been enormous progresses in cardiovascular therapeutics. This study was conducted to evaluate whether Tongxinluo （TXL） treatment around the transplantation of mesenchymal stem cells （MSCs） can improve survival and subsequent activities of implanted cells in swine hearts with acute myocardial infarction （AMI） and reperfusion. Methods Twenty-eight Chinese mini-pigs were divided into four groups including a control group （n=7）; group 2, administration of low-close TXL alone from the 3rd day prior to AMI to the 4th day post transplantation （n=-7）; group 3, MSCs alone （n=-7） and group 4, TXL ＋ MSCs （n=7）. AMI models were made by occlusion of the left anterior descending coronary artery for 90 minutes. Autologous bone marrow-MSCs （3×10^7 cells/animal） were then injected into the post-infarct myocardium immediately after AMI and reperfusion. The survival and differentiation of implanted cells in vivo were detected by immunofluorescent analysis. The data of cardiac function were obtained at baseline （1 week after transplantation） and endpoint （6 weeks after transplantation） by single photon emission computed tomography （SPECT） and magnetic resonance imaging （MRI）. Apoptosis was detected by TUNEL assay and the oxidative stress level was investigated in the post-infarct myocardium at endpoint. Results At endpoint, there was less fibrosis and inflammatory cell infiltration with more surviving myocardium in group 4 than in the control group. In group 4 the survival and differentiation of implanted MSCs were significantly improved more than that seen in group 3 alone （P〈0.0001）; the capillary density was also significantly greater than in the control group, group 2 or 3 both in the infarcted zone （P〈0.0001） and the peri-infarct zone （P〈0.0001）. MRI showed that parameters at baseline were not significantly different between the 4 groups. At endpoint, regional wall thickening and the left ventricular ejection fraction were increased while the left ventricular mass index, dyskinetic segments and infarcted size were decreased only in group 4 compared with control group （P〈0.0001）. SPECT showed that the area of perfusion defect was significantly decreased at endpoint only in group 4 compared with control group （P〈0.0001）. TUNEL assay indicated that TXL administration significantly decreased cell apoptosis in peri-infarct myocardium in groups 2 and 4. Furthermore, superoxide dismutase （SOD） significantly increased and malondialdehyde （MDA） decreased in groups 2 and 4 by the administration of TXL. Conclusions Our study demonstrates the following： （1） immediate intramyocardial injection of MSCs after AMI and reperfusion resulted in limited survival and differentiation potential of implanted cells in vivo, thus being incapable of beneficially affecting post-hearts; （2） TXL-facilitation resulted in a significant survival and differentiation potential of implanted cells in vivo via inhibition of apoptosis and oxidative stress, accompanied by significant benefits in cardiac function.展开更多
文摘剪切稠化流体是一种典型的非牛顿流体,研究气泡在其中的运动特性对优化设备结构、提高反应效率具有重要意义。文中采用流体体积(VOF)法,通过改变Gallilei数(Ga)、E tv s数(Eo)与流变指数(n),对牛顿流体(n=1)及剪切稠化流体(n>1)内气泡的形状、尾涡、终端速度和气泡周围液相黏度分布的变化进行了深入的数值研究。结果表明:气泡变形程度和尾涡尺寸随着Ga数或Eo数的增大而增加;剪切稠化效应会阻碍尾涡的形成,减小气泡的尾涡尺寸;气泡周围剪切速率的差异会导致气泡上方及尾部产生高黏度区域,该高黏度区域会随剪切稠化效应的增加而增大;气泡终端速度随Ga数的增大或流变指数n,Eo数的减小而增大。
基金supported by the National Science Foundation of China(No.41404070)China Geological Survey(No.DD20160102-02)
文摘Chile is a very important country that forms part of the Andean metallogenic belts. The Atacama and Domeyko fault systems in northern Chile control the tectonic- magmatic activities that migrate eastward and the types of mineral resources. In this paper, we processed and interpreted aeromagnetic data from northern Chile using reduction to pole, upward field continuation, the second derivative calculation in the vertical direction, inclination angle calculation, and analytical signal amplitude analysis. We revealed the locations and planar distribution characteristics of the regional deep faults along the NNE and NS directions. Furthermore, we observed that the major reasons for the formation of the tectonic-magmatic rocks belts were the nearly parallel deep faults distributed from west to east and multiple magmatic activities along these faults. We ascertained the locations of volcanic mechanisms and the relationships between them using these regional deep faults. We deduced the spatial distributions of the basic-intermediate, basic, and acidic igneous rocks, intrusive rocks, and sedimentary sequences. We showed the linear positive magnetic anomalies and magnetic anomaly gradient zones by slowly varying the background, negative magnetic anomaly field, which indicated the presence of strong magmatic activities in these regional deep faults; it also revealed the favorable areas of copper and polymetallic mineralization. This study provides some basic information for further research on the geology, structural characteristics, and mineral resource prospecting in northern Chile.
基金This work was supported by the grants from the National Basic Research Program(973 Program)Ministry of Science and Technology,China(No.2005CB523303)
文摘Background Treatment of ischemic heart disease remains an important challenge, though there have been enormous progresses in cardiovascular therapeutics. This study was conducted to evaluate whether Tongxinluo （TXL） treatment around the transplantation of mesenchymal stem cells （MSCs） can improve survival and subsequent activities of implanted cells in swine hearts with acute myocardial infarction （AMI） and reperfusion. Methods Twenty-eight Chinese mini-pigs were divided into four groups including a control group （n=7）; group 2, administration of low-close TXL alone from the 3rd day prior to AMI to the 4th day post transplantation （n=-7）; group 3, MSCs alone （n=-7） and group 4, TXL ＋ MSCs （n=7）. AMI models were made by occlusion of the left anterior descending coronary artery for 90 minutes. Autologous bone marrow-MSCs （3×10^7 cells/animal） were then injected into the post-infarct myocardium immediately after AMI and reperfusion. The survival and differentiation of implanted cells in vivo were detected by immunofluorescent analysis. The data of cardiac function were obtained at baseline （1 week after transplantation） and endpoint （6 weeks after transplantation） by single photon emission computed tomography （SPECT） and magnetic resonance imaging （MRI）. Apoptosis was detected by TUNEL assay and the oxidative stress level was investigated in the post-infarct myocardium at endpoint. Results At endpoint, there was less fibrosis and inflammatory cell infiltration with more surviving myocardium in group 4 than in the control group. In group 4 the survival and differentiation of implanted MSCs were significantly improved more than that seen in group 3 alone （P〈0.0001）; the capillary density was also significantly greater than in the control group, group 2 or 3 both in the infarcted zone （P〈0.0001） and the peri-infarct zone （P〈0.0001）. MRI showed that parameters at baseline were not significantly different between the 4 groups. At endpoint, regional wall thickening and the left ventricular ejection fraction were increased while the left ventricular mass index, dyskinetic segments and infarcted size were decreased only in group 4 compared with control group （P〈0.0001）. SPECT showed that the area of perfusion defect was significantly decreased at endpoint only in group 4 compared with control group （P〈0.0001）. TUNEL assay indicated that TXL administration significantly decreased cell apoptosis in peri-infarct myocardium in groups 2 and 4. Furthermore, superoxide dismutase （SOD） significantly increased and malondialdehyde （MDA） decreased in groups 2 and 4 by the administration of TXL. Conclusions Our study demonstrates the following： （1） immediate intramyocardial injection of MSCs after AMI and reperfusion resulted in limited survival and differentiation potential of implanted cells in vivo, thus being incapable of beneficially affecting post-hearts; （2） TXL-facilitation resulted in a significant survival and differentiation potential of implanted cells in vivo via inhibition of apoptosis and oxidative stress, accompanied by significant benefits in cardiac function.
