目的:构建条件性胰岛β细胞钙/钙调蛋白依赖性丝氨酸蛋白激酶(calcium/calmodulin-dependent serine protein kinase,CASK)基因敲除小鼠,为研究CASK基因在糖尿病发生中的机制提供动物模型。方法:将CASKloxp/-雌鼠与CASKloxp/Y雄鼠杂交,...目的:构建条件性胰岛β细胞钙/钙调蛋白依赖性丝氨酸蛋白激酶(calcium/calmodulin-dependent serine protein kinase,CASK)基因敲除小鼠,为研究CASK基因在糖尿病发生中的机制提供动物模型。方法:将CASKloxp/-雌鼠与CASKloxp/Y雄鼠杂交,获得基因型为CASKloxp/loxp雌鼠、CASKloxp/Y雄鼠;再让条件性胰岛β细胞特异性表达Cre重组酶雄鼠与CASKloxp/loxp雌鼠杂交获得CASKloxP/YMIP-Cre雄鼠和CASKloxP/-MIP-Cre雌鼠。CASKloxP/YMIP-Cre基因型小鼠即为本实验所需要构建的模型小鼠。小鼠生后1~2周剪尾,通过PCR鉴定小鼠基因型,4~5周龄时腹腔注射他莫昔芬诱导Cre重组酶表达后,利用实时荧光定量PCR、蛋白质印迹技术验证CASK基因敲除效果。结果:从引进这两种小鼠开始,繁殖10个月,共获得基因型为CASKloxP/YMIP-Cre的雄鼠28只,PCR结果证实小鼠基因型符合CASKloxP/YMIP-Cre。实时荧光定量PCR、蛋白质印迹结果显示CASKloxP/YMIP-Cre小鼠胰岛CASK表达量明显下降。结论:利用Cre/loxp系统,成功构建了条件性胰岛β细胞CASK基因敲除小鼠,为在动物水平研究CASK基因在糖尿病发病机制中的作用提供了研究平台。展开更多
Considering the problems in the discrimination of fracture penetration and the evaluation of fracturing performance in the stimulation of thin sand-mud interbedded reservoirs in the eighth member of Shihezi Formation ...Considering the problems in the discrimination of fracture penetration and the evaluation of fracturing performance in the stimulation of thin sand-mud interbedded reservoirs in the eighth member of Shihezi Formation of Permian(He-8 Member)in the Sulige gas field,a geomechanical model of thin sand-mud interbedded reservoirs considering interlayer heterogeneity was established.The experiment of hydraulic fracture penetration was performed to reveal the mechanism of initiation–extension–interaction–penetration of hydraulic fractures in the thin sand-mud interbedded reservoirs.The unconventional fracture model was used to clarify the vertical initiation and extension characteristics of fractures in thin interbedded reservoirs through numerical simulation.The fracture penetration discrimination criterion and the fracturing performance evaluation method were developed.The results show that the interlayer stress difference is the main geological factor that directly affects the fracture morphology during hydraulic fracturing.When the interlayer stress difference coefficient is less than 0.4 in the Sulige gas field,the fractures can penetrate the barrier and extend in the target sandstone layer.When the interlayer stress difference coefficient is not less than 0.4 and less than 0.45,the factures can penetrate the barrier but cannot extend in the target sandstone layers.When the interlayer stress difference coefficient is greater than 0.45,the fractures only extend in the perforated reservoir,but not penetrate the layers.Increasing the viscosity and pump rates of the fracturing fluid can compensate for the energy loss and break through the barrier limit.The injection of high viscosity(50–100 mPa·s)fracturing fluid at high pump rates(12–18 m~3/min)is conducive to fracture penetration in the thin sand-mud interbedded reservoirs in the Sulige gas field.展开更多
文摘目的:构建条件性胰岛β细胞钙/钙调蛋白依赖性丝氨酸蛋白激酶(calcium/calmodulin-dependent serine protein kinase,CASK)基因敲除小鼠,为研究CASK基因在糖尿病发生中的机制提供动物模型。方法:将CASKloxp/-雌鼠与CASKloxp/Y雄鼠杂交,获得基因型为CASKloxp/loxp雌鼠、CASKloxp/Y雄鼠;再让条件性胰岛β细胞特异性表达Cre重组酶雄鼠与CASKloxp/loxp雌鼠杂交获得CASKloxP/YMIP-Cre雄鼠和CASKloxP/-MIP-Cre雌鼠。CASKloxP/YMIP-Cre基因型小鼠即为本实验所需要构建的模型小鼠。小鼠生后1~2周剪尾,通过PCR鉴定小鼠基因型,4~5周龄时腹腔注射他莫昔芬诱导Cre重组酶表达后,利用实时荧光定量PCR、蛋白质印迹技术验证CASK基因敲除效果。结果:从引进这两种小鼠开始,繁殖10个月,共获得基因型为CASKloxP/YMIP-Cre的雄鼠28只,PCR结果证实小鼠基因型符合CASKloxP/YMIP-Cre。实时荧光定量PCR、蛋白质印迹结果显示CASKloxP/YMIP-Cre小鼠胰岛CASK表达量明显下降。结论:利用Cre/loxp系统,成功构建了条件性胰岛β细胞CASK基因敲除小鼠,为在动物水平研究CASK基因在糖尿病发病机制中的作用提供了研究平台。
基金Supported by the National Key Research and Development Program of China(2022YFE0129800)CNPC and China University of Petroleum(Beijing)Strategic Cooperation Science and Technology Special Project(ZLZX2020-02)。
文摘Considering the problems in the discrimination of fracture penetration and the evaluation of fracturing performance in the stimulation of thin sand-mud interbedded reservoirs in the eighth member of Shihezi Formation of Permian(He-8 Member)in the Sulige gas field,a geomechanical model of thin sand-mud interbedded reservoirs considering interlayer heterogeneity was established.The experiment of hydraulic fracture penetration was performed to reveal the mechanism of initiation–extension–interaction–penetration of hydraulic fractures in the thin sand-mud interbedded reservoirs.The unconventional fracture model was used to clarify the vertical initiation and extension characteristics of fractures in thin interbedded reservoirs through numerical simulation.The fracture penetration discrimination criterion and the fracturing performance evaluation method were developed.The results show that the interlayer stress difference is the main geological factor that directly affects the fracture morphology during hydraulic fracturing.When the interlayer stress difference coefficient is less than 0.4 in the Sulige gas field,the fractures can penetrate the barrier and extend in the target sandstone layer.When the interlayer stress difference coefficient is not less than 0.4 and less than 0.45,the factures can penetrate the barrier but cannot extend in the target sandstone layers.When the interlayer stress difference coefficient is greater than 0.45,the fractures only extend in the perforated reservoir,but not penetrate the layers.Increasing the viscosity and pump rates of the fracturing fluid can compensate for the energy loss and break through the barrier limit.The injection of high viscosity(50–100 mPa·s)fracturing fluid at high pump rates(12–18 m~3/min)is conducive to fracture penetration in the thin sand-mud interbedded reservoirs in the Sulige gas field.
