[ Objective] The paper presents the diumal changes of photosynthesis and transpiration of different alfalfa varieties and their relationship with the associated physiological and ecological factors during branching st...[ Objective] The paper presents the diumal changes of photosynthesis and transpiration of different alfalfa varieties and their relationship with the associated physiological and ecological factors during branching stage, so as to provide a basis for the development, utilization, and breed- ing of alfalfa. [ Method] Under natural conditions, the diurnal changes of net photosynthetic rate （Pn）, transpiration rate （Tr）, the relevant physio- logical factors including leaf temperature （TI）, stomatal conductance （Gs） and intemal COn concentration （Ci）, as well as the relevant physiologi- cal factors including photosynthetic available radiation （PAR）, CO2 concentration in field （Ca） and air temperature （Ta） were measured in four al- falfa varieties （Algonguin, WL323 HQ, WL414, and Millionaire）. The water use efficiency （WUE） and light use efficiency （LUE） were calculated, and the correlation among them was also analyzed. [Result] The Pn, Tr, PAR and Ta of the four varieties appeared to vary in a single-peak curve; the sequence of WUE was WL323 HQ ~ Algonguin ~ WL414 ~ Millionaire; there was no significant difference in LUE of the four alfalfa varieties; coef- ficient analysis showed that Pn was mainly affected by PAR, Gs, and Ci, while Tr by PAR and Ta. [ Conclusion] WL323 HQ is the variety with high Pn, high WUE and low Tr, and it has strong adaptability to drought. In four alfalfa varieties, PAR, Ta, Gs, and TI are the primary determining fac- tors while Ca and Ci the limiting factors of Tr; Gs is the primary determining factor while Ci the limiting factor of Pn.展开更多
目的:探讨不同病因所致的大血管闭塞性脑卒中患者在亚急性期磁敏感血管征(susceptibility vessel sign,SVS)的表现。方法:选择北京大学第一医院神经内科病房2017年12月—2019年8月收治的经磁共振血管成像、CT血管造影或数字减影血管造...目的:探讨不同病因所致的大血管闭塞性脑卒中患者在亚急性期磁敏感血管征(susceptibility vessel sign,SVS)的表现。方法:选择北京大学第一医院神经内科病房2017年12月—2019年8月收治的经磁共振血管成像、CT血管造影或数字减影血管造影证实存在颅内大血管闭塞,且在发病第3~14天接受磁敏感加权成像(susceptibility-weighted imaging,SWI)检查的卒中患者进行回顾性分析,对比心源性栓塞(cardioembolism,CE)和大动脉粥样硬化性卒中(large artery atherosclerosis,LAA)患者的SVS征出现情况。结果:共有51例患者进入分析,其中女19例、男32例,平均年龄(63.04±11.23)岁。两组患者在性别、高血压、糖尿病、冠心病、高脂血症、吸烟、入院美国国立卫生研究院卒中量表(National Institute of Health stroke scale,NIHSS)评分间差异均无统计学意义。与LAA组相比,CE组患者年龄更大,合并房颤的比例更高,差异有统计学意义(P<0.05)。共有30例患者表现为SVS征阳性,心源性栓塞组患者SVS征阳性率为30%,显著低于大动脉粥样硬化性卒中患者(65.9%),两组间差异有统计学意义(P=0.039)。在敏感度测试中仅纳入SWI检查时间在卒中后第7~14天的患者,两组间SVS征阳性率的差异仍有统计学意义(0 vs.72.7%,P=0.006)。以有无房颤分组,合并房颤的卒中患者SVS征阳性率为25%,显著低于无房颤的卒中患者(65.1%),两组间差异有统计学意义(P=0.043)。结论:大动脉闭塞性脑卒中发病的亚急性期,心源性栓塞患者的SVS征阳性率低于LAA亚型的卒中患者;SVS征在卒中不同亚型鉴别中的作用尚需要进一步大样本的病例研究来验证。展开更多
目的应用经颅多普勒超声(TCD)评价颈动脉支架成形术后脑血流动力学的超早期改变。方法回顾我院2017年1月~2019年3月收治的85例颈动脉支架成形术患者,其中12例因颞窗透声不佳排除,剩余73例行TCD监测,采用TCD检测术前、术后1 h、术后6 h...目的应用经颅多普勒超声(TCD)评价颈动脉支架成形术后脑血流动力学的超早期改变。方法回顾我院2017年1月~2019年3月收治的85例颈动脉支架成形术患者,其中12例因颞窗透声不佳排除,剩余73例行TCD监测,采用TCD检测术前、术后1 h、术后6 h患侧大脑中动脉(MCA)收缩期流速峰值(PSV)、搏动指数(PI)的变化情况。结果术前平均收缩压为(152.47±12.85)mmHg,术后1 h平均收缩压(127.86±16.48)mmHg(P<0.01),术后6 h平均收缩压(126.75±14.31)mmHg(P<0.01)。术前患侧MCA-PSV为(70.25±19.87)cm/s,术后1 h MCA-PSV为(84.81±17.88)cm/s(P<0.001),增幅为24.95%;术后6 h MCA-PVS为(83.58±17.26)cm/s(P<0.01),增幅为23.17%。术前患侧MCA-PI为(0.836±0.158),术后1 h MCA-PI为(0.933±0.178)(P<0.01),平均增幅为12.14%;术后6 h MCA-PI为(0.921±0.164)(P<0.01),平均增幅为10.88%。结论在颈动脉支架植入术后1 h、术后6 h术侧MCA-PSV、MCA-PI就明显增高,而术后1 h与术后6 h对比无明显差异。狭窄程度>90%者术后1 h MCA-PSV增幅明显升高,可能会增加脑高灌注综合征的发生风险。展开更多
文摘[ Objective] The paper presents the diumal changes of photosynthesis and transpiration of different alfalfa varieties and their relationship with the associated physiological and ecological factors during branching stage, so as to provide a basis for the development, utilization, and breed- ing of alfalfa. [ Method] Under natural conditions, the diurnal changes of net photosynthetic rate （Pn）, transpiration rate （Tr）, the relevant physio- logical factors including leaf temperature （TI）, stomatal conductance （Gs） and intemal COn concentration （Ci）, as well as the relevant physiologi- cal factors including photosynthetic available radiation （PAR）, CO2 concentration in field （Ca） and air temperature （Ta） were measured in four al- falfa varieties （Algonguin, WL323 HQ, WL414, and Millionaire）. The water use efficiency （WUE） and light use efficiency （LUE） were calculated, and the correlation among them was also analyzed. [Result] The Pn, Tr, PAR and Ta of the four varieties appeared to vary in a single-peak curve; the sequence of WUE was WL323 HQ ~ Algonguin ~ WL414 ~ Millionaire; there was no significant difference in LUE of the four alfalfa varieties; coef- ficient analysis showed that Pn was mainly affected by PAR, Gs, and Ci, while Tr by PAR and Ta. [ Conclusion] WL323 HQ is the variety with high Pn, high WUE and low Tr, and it has strong adaptability to drought. In four alfalfa varieties, PAR, Ta, Gs, and TI are the primary determining fac- tors while Ca and Ci the limiting factors of Tr; Gs is the primary determining factor while Ci the limiting factor of Pn.
文摘目的:探讨不同病因所致的大血管闭塞性脑卒中患者在亚急性期磁敏感血管征(susceptibility vessel sign,SVS)的表现。方法:选择北京大学第一医院神经内科病房2017年12月—2019年8月收治的经磁共振血管成像、CT血管造影或数字减影血管造影证实存在颅内大血管闭塞,且在发病第3~14天接受磁敏感加权成像(susceptibility-weighted imaging,SWI)检查的卒中患者进行回顾性分析,对比心源性栓塞(cardioembolism,CE)和大动脉粥样硬化性卒中(large artery atherosclerosis,LAA)患者的SVS征出现情况。结果:共有51例患者进入分析,其中女19例、男32例,平均年龄(63.04±11.23)岁。两组患者在性别、高血压、糖尿病、冠心病、高脂血症、吸烟、入院美国国立卫生研究院卒中量表(National Institute of Health stroke scale,NIHSS)评分间差异均无统计学意义。与LAA组相比,CE组患者年龄更大,合并房颤的比例更高,差异有统计学意义(P<0.05)。共有30例患者表现为SVS征阳性,心源性栓塞组患者SVS征阳性率为30%,显著低于大动脉粥样硬化性卒中患者(65.9%),两组间差异有统计学意义(P=0.039)。在敏感度测试中仅纳入SWI检查时间在卒中后第7~14天的患者,两组间SVS征阳性率的差异仍有统计学意义(0 vs.72.7%,P=0.006)。以有无房颤分组,合并房颤的卒中患者SVS征阳性率为25%,显著低于无房颤的卒中患者(65.1%),两组间差异有统计学意义(P=0.043)。结论:大动脉闭塞性脑卒中发病的亚急性期,心源性栓塞患者的SVS征阳性率低于LAA亚型的卒中患者;SVS征在卒中不同亚型鉴别中的作用尚需要进一步大样本的病例研究来验证。
文摘目的应用经颅多普勒超声(TCD)评价颈动脉支架成形术后脑血流动力学的超早期改变。方法回顾我院2017年1月~2019年3月收治的85例颈动脉支架成形术患者,其中12例因颞窗透声不佳排除,剩余73例行TCD监测,采用TCD检测术前、术后1 h、术后6 h患侧大脑中动脉(MCA)收缩期流速峰值(PSV)、搏动指数(PI)的变化情况。结果术前平均收缩压为(152.47±12.85)mmHg,术后1 h平均收缩压(127.86±16.48)mmHg(P<0.01),术后6 h平均收缩压(126.75±14.31)mmHg(P<0.01)。术前患侧MCA-PSV为(70.25±19.87)cm/s,术后1 h MCA-PSV为(84.81±17.88)cm/s(P<0.001),增幅为24.95%;术后6 h MCA-PVS为(83.58±17.26)cm/s(P<0.01),增幅为23.17%。术前患侧MCA-PI为(0.836±0.158),术后1 h MCA-PI为(0.933±0.178)(P<0.01),平均增幅为12.14%;术后6 h MCA-PI为(0.921±0.164)(P<0.01),平均增幅为10.88%。结论在颈动脉支架植入术后1 h、术后6 h术侧MCA-PSV、MCA-PI就明显增高,而术后1 h与术后6 h对比无明显差异。狭窄程度>90%者术后1 h MCA-PSV增幅明显升高,可能会增加脑高灌注综合征的发生风险。
