Cavitation of centrifugal blood pump is a serious problem accompany with the blocking failure of short inlet cannula. However, hardly any work has been seen in published literature on this complex cavitation phenomeno...Cavitation of centrifugal blood pump is a serious problem accompany with the blocking failure of short inlet cannula. However, hardly any work has been seen in published literature on this complex cavitation phenomenon caused by the coupling effect of inlet cannula blocking and pumps suction. Even for cavitation studies on ordinary centrifugal pumps, similar researches on this issue are rare. In this paper, the roles of throttling, rotation speed and fluid viscosity on bubble inception and intensity in a centrifugal blood pump are studied, on the basis of experimental observations. An adjustable throttle valve installed just upstream blood pump inlet is used to simulate the throttling effect of the narrowed inlet cannula. The rotation speed is adjusted from 2 600 r/rain to 3 200 r/min. Glycerin water solutions are used to investigate the influences of kinetic viscosity. Bubbles are recorded with a high-speed video camera. Direct observation shows that different from cavitation in industrial centrifugal pumps, gas nuclei appears at the nearby of vane leading edges while throttling is light, then moves upstream to the joint position of inlet pipe and pump with the closing of the valve. It＇s found that the critical inlet pressure, obtained when bubbles are first observed, decreases linearly with viscosity and the slope is independent with rotation speeds; the critical inlet pressure and the inlet extreme pressure which is obtained when the throttle valve is nearly closed, fall linearly with rotation speed respectively and the relative pressure between them is independent with rotation speed and fluid viscosity. This paper studies experimentally on cavitation in centrifugal blood pump that caused by the failure of assembled short inlet cannula, which mav beneficial the desima of centrifugal blood Dumo with inlet cannula.展开更多
The synchrotron RF team of High Intensity heavy-ion Accelerator Facility(HIAF)successfully developed the first low-frequency broadband,high gradient,fast response,oil-cooled magnetic alloy(MA)RF system in China.
基金supported by the National Natural Science Foundation of China(Grant No.51275461)the Zhejiang Provincial Natural Science Foundation of China(Grant No.Z1110189)
文摘Cavitation of centrifugal blood pump is a serious problem accompany with the blocking failure of short inlet cannula. However, hardly any work has been seen in published literature on this complex cavitation phenomenon caused by the coupling effect of inlet cannula blocking and pumps suction. Even for cavitation studies on ordinary centrifugal pumps, similar researches on this issue are rare. In this paper, the roles of throttling, rotation speed and fluid viscosity on bubble inception and intensity in a centrifugal blood pump are studied, on the basis of experimental observations. An adjustable throttle valve installed just upstream blood pump inlet is used to simulate the throttling effect of the narrowed inlet cannula. The rotation speed is adjusted from 2 600 r/rain to 3 200 r/min. Glycerin water solutions are used to investigate the influences of kinetic viscosity. Bubbles are recorded with a high-speed video camera. Direct observation shows that different from cavitation in industrial centrifugal pumps, gas nuclei appears at the nearby of vane leading edges while throttling is light, then moves upstream to the joint position of inlet pipe and pump with the closing of the valve. It＇s found that the critical inlet pressure, obtained when bubbles are first observed, decreases linearly with viscosity and the slope is independent with rotation speeds; the critical inlet pressure and the inlet extreme pressure which is obtained when the throttle valve is nearly closed, fall linearly with rotation speed respectively and the relative pressure between them is independent with rotation speed and fluid viscosity. This paper studies experimentally on cavitation in centrifugal blood pump that caused by the failure of assembled short inlet cannula, which mav beneficial the desima of centrifugal blood Dumo with inlet cannula.
文摘The synchrotron RF team of High Intensity heavy-ion Accelerator Facility(HIAF)successfully developed the first low-frequency broadband,high gradient,fast response,oil-cooled magnetic alloy(MA)RF system in China.
文摘目的:分析趋化因子受体8(C⁃C motif chemokine receptor 8,CCR8)在卵巢癌肿瘤浸润性调节性T细胞(regulatory T cell,Treg)中的表达,探讨CCR8对Treg分化的作用。方法:构建C57BL/6小鼠卵巢癌细胞ID8荷瘤模型;流式细胞术检测小鼠肿瘤组织、脾脏和外周血中Treg上CCR8的表达比例,CCR8^(+)Treg上免疫检查点相关蛋白程序性细胞死亡蛋白1(programmed cell death protein 1,PD⁃1)、细胞素性T淋巴细胞抗原4(cytotoxic T⁃lymphocyte antigen 4,CTLA⁃4)、可诱导的T细胞共刺激分子(inducible T cell costimulators,ICOS)、淋巴细胞激活基因3(lymphocyte activation gene 3,LAG⁃3)的表达;流式细胞术检测CCR8变构抑制剂AZ084加入前后对C57BL/6小鼠脾脏中初始CD4^(+)T细胞向Treg分化的影响。结果:卵巢癌荷瘤小鼠肿瘤中Treg上的CCR8表达相比脾脏、外周血的Treg显著增高;相比CCR8^(-)Treg,CCR8^(+)Treg上免疫检查点相关蛋白表达更高;AZ084有效抑制小鼠脾脏中初始CD4^(+)T细胞向Treg的分化。结论:CCR8^(+)Treg在肿瘤浸润性Treg中占主要比例,CCR8作为卵巢癌浸润性Treg的主要标志物,变构CCR8蛋白可以抑制Treg的分化。靶向消除CCR8^(+)Treg可为改善卵巢癌肿瘤微环境的免疫抑制状态提供新思路。
