脑小血管病(cerebral small vessel disease,CSVD)是老年人最常见的脑血管疾病,也是引起认知功能障碍的最常见原因之一。目前对CSVD的治疗有很大的局限性。CSVD的病理机制、临床表现和影像学表现的异质性,以及对本病缺乏共识,均可影响...脑小血管病(cerebral small vessel disease,CSVD)是老年人最常见的脑血管疾病,也是引起认知功能障碍的最常见原因之一。目前对CSVD的治疗有很大的局限性。CSVD的病理机制、临床表现和影像学表现的异质性,以及对本病缺乏共识,均可影响相关药物临床试验的进展。为了给CSVD的治疗提供可靠的依据,并为今后的临床实践增加特异性药物的选择,国家神经系统疾病临床医学研究中心和中国卒中学会脑小血管病分会联合起草本共识。期望规范CSVD相关临床试验来评价药物的疗效和安全性,为CSVD的治疗提供可靠的证据支持。展开更多
增龄相关性脑小血管病谱系(spectrumofage-relatedcerebralsmallvesseldiseases,ArCSVDS)是指随着年龄的增长,脑小动脉、微动脉、毛细血管、微静脉、小静脉出现老化的一组脑小血管病(cerebral small vessel disease,CSVD),包括深穿支动...增龄相关性脑小血管病谱系(spectrumofage-relatedcerebralsmallvesseldiseases,ArCSVDS)是指随着年龄的增长,脑小动脉、微动脉、毛细血管、微静脉、小静脉出现老化的一组脑小血管病(cerebral small vessel disease,CSVD),包括深穿支动脉病(deep perforating arteriopathy,DPA)和β淀粉样蛋白(β-amyloid,Aβ)有关的脑淀粉样血管病(cerebralamyloidangiopathy,CAA)。以往的研究往往将这两种疾病视为独立的实体,然而最近的研究发现,无论从年龄、高血压等相似的脑血管病危险因素,还是从潜在的相互作用角度出发,DPA与CAA是一组ArCSVDS疾病,血脑屏障(blood brainbarrier,BBB)破坏、内皮细胞损伤、血管周围Aβ是连接DPA与CAA的共同发病机制,而且有30%~68%的患者两者可以重叠发病。展开更多
电线积冰是电网正常运行中最大的气象灾害之一,而冻雨是造成电线积冰事故的主要灾害性天气。利用耦合了中尺度天气研究和预报(weather research and forecasting,WRF)模式的美国空军气象局(Air Force Weather Agency,AWFA)冻雨预报系统...电线积冰是电网正常运行中最大的气象灾害之一,而冻雨是造成电线积冰事故的主要灾害性天气。利用耦合了中尺度天气研究和预报(weather research and forecasting,WRF)模式的美国空军气象局(Air Force Weather Agency,AWFA)冻雨预报系统,对发生在中国南方的3次冻雨事件进行预报,通过威胁指数(threat scores,TS)评分对AWFA系统在中国地区的冻雨预报能力进行了评估,并根据其输出的冻雨参数,用覆冰增长模型对三次冻雨过程中,电线积冰厚度进行了模拟。结果表明:冻雨事件的发生必须同时满足逆温层、空中高液态含水量和地温低于0℃这三个气象条件;AFWA冻雨预报系统对中国冻雨也有一定的预报能力,但预测范围较实际观测的区域偏大,三次冻雨事件预报TS评分在0.30~0.63,平均为0.45;模拟电线积冰厚度的范围与观测的冻雨密集区相当吻合,对明显的冻雨过程有较好的预报能力且能够获得电线积冰厚度的精细化分布。研究结果对中国南方冻雨预报、电线积冰预报有重大的参考价值,并为电网的防灾减灾提供了坚实的理论支撑。展开更多
冻雨是一种对交通、电网以及人民生活带来严重影响的小概率灾害性天气。通过对2018年1月25日—26日中国南方大面积冻雨的天气形势、云微物理量变化的分析,探讨了本次大范围冻雨天气形成的气象条件,进而利用耦合了改进Ramer参数化方案的...冻雨是一种对交通、电网以及人民生活带来严重影响的小概率灾害性天气。通过对2018年1月25日—26日中国南方大面积冻雨的天气形势、云微物理量变化的分析,探讨了本次大范围冻雨天气形成的气象条件,进而利用耦合了改进Ramer参数化方案的天气预报模式(weather research and forecasting model,WRF),对本次冻雨过程进行预报并评估了其预报能力,得到了如下结论:①冷干与暖湿气流在贵州-湖南-江西一带形成来回摆动的高空切变线,出现逆温层,地面温度小于0℃,天气形势有利于冰冻天气出现。②冻雨形成必须同时满足三个气象条件:一定厚度的暖层、较高的液水含量和地面温度低于0℃。在一次完整的冻雨过程中,气象要素并不能总是满足上述三个条件,因而一次冻雨过程并不一定是连续的,期间往往夹杂着降雨或降雪事件的出现。③耦合改进Ramer参数化方案的WRF模式对冻雨有很好的预报能力,平均威胁分数(threat score,TS)评分达到了0.52。该研究对冻雨预报有较大的参考价值,并为交通、电网的防灾减灾提供了坚实的理论支撑。展开更多
通过对2018年3月15—16日河南省发生的一次春季大风的天气学分析,探讨了大风极值中心出现在豫北地区的原因。在此基础上,利用耦合了阵风估算(wind gust estimate,WGE)方法的天气研究和预报(weather research and forecasting,WRF)模式...通过对2018年3月15—16日河南省发生的一次春季大风的天气学分析,探讨了大风极值中心出现在豫北地区的原因。在此基础上,利用耦合了阵风估算(wind gust estimate,WGE)方法的天气研究和预报(weather research and forecasting,WRF)模式模拟了研究区风场的空间特征,评估了WRF和WRF-WGE对本次大风天气的模拟效果。结果表明:冷锋过境河南时正值白天,冷锋前后温度差很大,冷锋移速快是河南大风风速高于其他地区的主要原因,豫北地区因叠加了地形的“狭管效应”成为此次春季大风的核心区。WRF模式和WRF-WGE均对大风有一定的模拟能力,能够模拟出大风的时间、空间分布特征,但WRF模拟的最大风速值远低于观测值,而WRF-WGE模拟的最大风速值与观测更为匹配,其优势主要在于预报大于10 m/s以上的大风,表明WGE方法在中国大陆系统性大风的预报中有一定的适用性。展开更多
云贵高原的冻雨是中国南方冬季最严重的气象灾害。利用天气研究和预报模式(weather research and forecasting model, WRF),对云贵高原大地形进行了敏感性实验,模拟了不同地形高度对大气环流、云微物理参量及冻雨分布的影响,结果显示:...云贵高原的冻雨是中国南方冬季最严重的气象灾害。利用天气研究和预报模式(weather research and forecasting model, WRF),对云贵高原大地形进行了敏感性实验,模拟了不同地形高度对大气环流、云微物理参量及冻雨分布的影响,结果显示:随着云贵高原大地形的抬升,准静止锋的锋线一直维持在24°N附近,但锋面越来越陡,表明高原大地形是形成云贵准静止锋的主要因素,准静止锋长时间滞留在贵州中东部和湖南西部,是该区冻雨高发的原因。随着高原的抬升,从全境的云滴碰并增长逐渐在高原东部出现冰晶融化过程,高原主体上的冻雨以过冷暖雨机制为主,而低海拔的东部地区以融化机制为主。随着高原抬升,高空逆温层及冻雨区均从贵州西北向贵州中部及东部地区移动,逆温层的存在及其冷-暖-冷的垂直结构是冻雨形成非常重要的因子。当云贵高原降至原地形的一半时,冻雨量最大,其后随着高原抬升,冻雨量开始减少。该研究有助于更深入了解云贵高原大地形对冻雨形成、范围和强度的影响机制。展开更多
The amorphous TbFeCo films covered with the protective AIN films have been prepared by the rf magnetron sputtering system.It is found that the protective AIN films not only protect rare earth elements from oxidation a...The amorphous TbFeCo films covered with the protective AIN films have been prepared by the rf magnetron sputtering system.It is found that the protective AIN films not only protect rare earth elements from oxidation and enhance magneto-optical Kerr effect but also affect the magnetic properties of the rare earth-transition metal films.The coercivity Hc and perpendicular magnetic anisotropy energy constants K'U1 and KU2 of the films are changed with the thickness of the protective AIN films.It can be explained according to the stress mechanism and the model of single ion anisotropy.展开更多
Background High levels of nitric oxide （NO） produced by inducible NO synthase （iNOS） have been associated with atherosclerosis processes. Naoxintong is a traditional Chinese medicine for treatment of cerebrovascul...Background High levels of nitric oxide （NO） produced by inducible NO synthase （iNOS） have been associated with atherosclerosis processes. Naoxintong is a traditional Chinese medicine for treatment of cerebrovascular and cardiovascular disease. The aim of the present study was to detect and quantify changes of iNOS mRNA and NO levels in the vessel wall after the administration of Naoxintong in an atherosclerotic rabbit model. Methods Forty New Zealand white rabbits were randomly divided into five groups （n=8）. Rabbits were fed a standard diet （group A）, an atherogenic diet consisting of 79% standard feed＋l% cholesterol＋5% lard＋15% egg yolk powder （group B）, an atherogenic diet with Naoxintong 0.25 mg.kg^-l.d^-1 （group C）, an atherogenic diet with Naoxintong 0.5 mg.kg^-l.d^-1 （group D）, or atherogenic diet with Naoxintong 1.0mg.kg^-l.d^-1 （group E） for 12 weeks. Results Supplemented administration of Naoxintong led to a down-regulation of cholesterol （CHOL） （P 〈0.001） and low-density lipoprotein （LDL） （P 〈0.001）. The trend became more notable as the dose of Naoxintong increased; group C vs. group B （CHOL, P=0.568; LDL-cholesterol （LDL-C）, P=0.119）, group D vs. group B （CHOL, P=0.264; LDL-C, P=0.027）, group E vs. group B （CHOL, P=0.028; LDL-C, P=0.002）. Atherosclerotic lesions in aorta were reduced in Naoxintong groups （groups C, D, E） compared to group B. Group B had higher iNOS mRNA （P=0.001） and NO level （P 〈0.001） than group A. Compared with the atherogenic diet fed-rabbits, Naoxintong supplements decreased the expression of iNOS mRNA （P 〈0.001） and the NO level （P 〈0.001） in the vessel wall. Groups given a higher Naoxintong dose exhibited greater benefits, iNOS mRNA and NO levels seemed to be reduced in group C, although the difference did not quite reach statistical significance （iNOS mRNA, P=0.130; NO, P=0.038）. iNOS mRNA and NO levels significantly decreased in group D （iNOS mRNA, P=0.019; NO, P=0.018） and group E （iNOS mRNA, P=0.004; NO, P 〈0.001）. Conclusion Naoxintong has beneficial effects on atherosclerosis treatment by reducing expression of iNOS mRNA and the NO level in the vessel wall.展开更多
Background Despite the large scale technical innovations that have been made,a number of patients with neuromyelitis optica （NMO） are lacking NMO-IgG in both serum and cerebrospinal fluid.Longitudinally extensive sp...Background Despite the large scale technical innovations that have been made,a number of patients with neuromyelitis optica （NMO） are lacking NMO-IgG in both serum and cerebrospinal fluid.Longitudinally extensive spinal cord （LESC） lesions and linear lesions are associated with NMO.However,differences of spinal cord magnetic resonance imaging （MRI） features,including LESC lesions and linear lesions,between NMO-IgG positive and negative patients still remain unknown.The aim of the present study was to analyze the relationship between NMO-IgG status and spinal cord MRI features in NMO patients,particularly concerned about LESC lesions and linear lesions.Methods Clinical data and spinal cord MRI of 52 NMO patients were retrospectively analyzed.Eight patients were NMO-IgG negative in both serum and cerebrospinal fluid,while 44 were NMO-IgG positive.Quantitative data between the two cohorts were compared by the Student＇s t test or Mann-Whitney U test,the chi-square test or Fisher＇s exact test was used to evaluate qualitative data.Results NMO-IgG negative patients had a higher sex ratio （male/female） （P=0.014）.On axial MRI,lesions in the NMO-IgG negative group were mostly located in the peripheral cord （50%）,and central lesions （55%） were more common in the NMO-IgG positive group （P=-0.051）.LESC lesions were common in both cohorts.None of linear lesions was found in NMO-IgG negative patients,while the NMO-IgG positive cohort had significantly more linear lesions （48%）（P=0.016）.Conclusions Patients with NMO-IgG negativity may have different spinal cord lesion features compared to NMO-IgG positive patients.Diagnosis of NMO cannot be excluded even when NMO-IgG negativity and non-specific spinal lesions occur.展开更多
文摘脑小血管病(cerebral small vessel disease,CSVD)是老年人最常见的脑血管疾病,也是引起认知功能障碍的最常见原因之一。目前对CSVD的治疗有很大的局限性。CSVD的病理机制、临床表现和影像学表现的异质性,以及对本病缺乏共识,均可影响相关药物临床试验的进展。为了给CSVD的治疗提供可靠的依据,并为今后的临床实践增加特异性药物的选择,国家神经系统疾病临床医学研究中心和中国卒中学会脑小血管病分会联合起草本共识。期望规范CSVD相关临床试验来评价药物的疗效和安全性,为CSVD的治疗提供可靠的证据支持。
文摘随着全球预期寿命的延长,增龄相关性脑小血管病(cerebral small vessel disease,CSVD)患病率不断增加。最近研究显示,深穿支动脉病(deep perforating arteriopathy,DPA)和脑淀粉样血管病(cerebral amyloid angiopathy,CAA)均属于增龄相关性脑小血管病谱系(spectrum of age-related cerebral small vessel diseases)疾病,两者存在重叠性,且相互作用。增龄相关性CSVD治疗包括特异性及非特异性治疗。非特异性治疗包括控制血管危险因素、抗血小板治疗及静脉溶栓等。特异性治疗方面,最近研究提示抗炎治疗对增龄相关性CSVD或许有效;而针对CAA相关性炎症,已显示其对类固醇和(或)环磷酰胺有良好的反应。随着对增龄相关性CSVD发病机制的进一步了解,未来可能会出现更多特异性的治疗方法。
文摘电线积冰是电网正常运行中最大的气象灾害之一,而冻雨是造成电线积冰事故的主要灾害性天气。利用耦合了中尺度天气研究和预报(weather research and forecasting,WRF)模式的美国空军气象局(Air Force Weather Agency,AWFA)冻雨预报系统,对发生在中国南方的3次冻雨事件进行预报,通过威胁指数(threat scores,TS)评分对AWFA系统在中国地区的冻雨预报能力进行了评估,并根据其输出的冻雨参数,用覆冰增长模型对三次冻雨过程中,电线积冰厚度进行了模拟。结果表明:冻雨事件的发生必须同时满足逆温层、空中高液态含水量和地温低于0℃这三个气象条件;AFWA冻雨预报系统对中国冻雨也有一定的预报能力,但预测范围较实际观测的区域偏大,三次冻雨事件预报TS评分在0.30~0.63,平均为0.45;模拟电线积冰厚度的范围与观测的冻雨密集区相当吻合,对明显的冻雨过程有较好的预报能力且能够获得电线积冰厚度的精细化分布。研究结果对中国南方冻雨预报、电线积冰预报有重大的参考价值,并为电网的防灾减灾提供了坚实的理论支撑。
文摘冻雨是一种对交通、电网以及人民生活带来严重影响的小概率灾害性天气。通过对2018年1月25日—26日中国南方大面积冻雨的天气形势、云微物理量变化的分析,探讨了本次大范围冻雨天气形成的气象条件,进而利用耦合了改进Ramer参数化方案的天气预报模式(weather research and forecasting model,WRF),对本次冻雨过程进行预报并评估了其预报能力,得到了如下结论:①冷干与暖湿气流在贵州-湖南-江西一带形成来回摆动的高空切变线,出现逆温层,地面温度小于0℃,天气形势有利于冰冻天气出现。②冻雨形成必须同时满足三个气象条件:一定厚度的暖层、较高的液水含量和地面温度低于0℃。在一次完整的冻雨过程中,气象要素并不能总是满足上述三个条件,因而一次冻雨过程并不一定是连续的,期间往往夹杂着降雨或降雪事件的出现。③耦合改进Ramer参数化方案的WRF模式对冻雨有很好的预报能力,平均威胁分数(threat score,TS)评分达到了0.52。该研究对冻雨预报有较大的参考价值,并为交通、电网的防灾减灾提供了坚实的理论支撑。
文摘通过对2018年3月15—16日河南省发生的一次春季大风的天气学分析,探讨了大风极值中心出现在豫北地区的原因。在此基础上,利用耦合了阵风估算(wind gust estimate,WGE)方法的天气研究和预报(weather research and forecasting,WRF)模式模拟了研究区风场的空间特征,评估了WRF和WRF-WGE对本次大风天气的模拟效果。结果表明:冷锋过境河南时正值白天,冷锋前后温度差很大,冷锋移速快是河南大风风速高于其他地区的主要原因,豫北地区因叠加了地形的“狭管效应”成为此次春季大风的核心区。WRF模式和WRF-WGE均对大风有一定的模拟能力,能够模拟出大风的时间、空间分布特征,但WRF模拟的最大风速值远低于观测值,而WRF-WGE模拟的最大风速值与观测更为匹配,其优势主要在于预报大于10 m/s以上的大风,表明WGE方法在中国大陆系统性大风的预报中有一定的适用性。
文摘云贵高原的冻雨是中国南方冬季最严重的气象灾害。利用天气研究和预报模式(weather research and forecasting model, WRF),对云贵高原大地形进行了敏感性实验,模拟了不同地形高度对大气环流、云微物理参量及冻雨分布的影响,结果显示:随着云贵高原大地形的抬升,准静止锋的锋线一直维持在24°N附近,但锋面越来越陡,表明高原大地形是形成云贵准静止锋的主要因素,准静止锋长时间滞留在贵州中东部和湖南西部,是该区冻雨高发的原因。随着高原的抬升,从全境的云滴碰并增长逐渐在高原东部出现冰晶融化过程,高原主体上的冻雨以过冷暖雨机制为主,而低海拔的东部地区以融化机制为主。随着高原抬升,高空逆温层及冻雨区均从贵州西北向贵州中部及东部地区移动,逆温层的存在及其冷-暖-冷的垂直结构是冻雨形成非常重要的因子。当云贵高原降至原地形的一半时,冻雨量最大,其后随着高原抬升,冻雨量开始减少。该研究有助于更深入了解云贵高原大地形对冻雨形成、范围和强度的影响机制。
文摘The amorphous TbFeCo films covered with the protective AIN films have been prepared by the rf magnetron sputtering system.It is found that the protective AIN films not only protect rare earth elements from oxidation and enhance magneto-optical Kerr effect but also affect the magnetic properties of the rare earth-transition metal films.The coercivity Hc and perpendicular magnetic anisotropy energy constants K'U1 and KU2 of the films are changed with the thickness of the protective AIN films.It can be explained according to the stress mechanism and the model of single ion anisotropy.
文摘Background High levels of nitric oxide （NO） produced by inducible NO synthase （iNOS） have been associated with atherosclerosis processes. Naoxintong is a traditional Chinese medicine for treatment of cerebrovascular and cardiovascular disease. The aim of the present study was to detect and quantify changes of iNOS mRNA and NO levels in the vessel wall after the administration of Naoxintong in an atherosclerotic rabbit model. Methods Forty New Zealand white rabbits were randomly divided into five groups （n=8）. Rabbits were fed a standard diet （group A）, an atherogenic diet consisting of 79% standard feed＋l% cholesterol＋5% lard＋15% egg yolk powder （group B）, an atherogenic diet with Naoxintong 0.25 mg.kg^-l.d^-1 （group C）, an atherogenic diet with Naoxintong 0.5 mg.kg^-l.d^-1 （group D）, or atherogenic diet with Naoxintong 1.0mg.kg^-l.d^-1 （group E） for 12 weeks. Results Supplemented administration of Naoxintong led to a down-regulation of cholesterol （CHOL） （P 〈0.001） and low-density lipoprotein （LDL） （P 〈0.001）. The trend became more notable as the dose of Naoxintong increased; group C vs. group B （CHOL, P=0.568; LDL-cholesterol （LDL-C）, P=0.119）, group D vs. group B （CHOL, P=0.264; LDL-C, P=0.027）, group E vs. group B （CHOL, P=0.028; LDL-C, P=0.002）. Atherosclerotic lesions in aorta were reduced in Naoxintong groups （groups C, D, E） compared to group B. Group B had higher iNOS mRNA （P=0.001） and NO level （P 〈0.001） than group A. Compared with the atherogenic diet fed-rabbits, Naoxintong supplements decreased the expression of iNOS mRNA （P 〈0.001） and the NO level （P 〈0.001） in the vessel wall. Groups given a higher Naoxintong dose exhibited greater benefits, iNOS mRNA and NO levels seemed to be reduced in group C, although the difference did not quite reach statistical significance （iNOS mRNA, P=0.130; NO, P=0.038）. iNOS mRNA and NO levels significantly decreased in group D （iNOS mRNA, P=0.019; NO, P=0.018） and group E （iNOS mRNA, P=0.004; NO, P 〈0.001）. Conclusion Naoxintong has beneficial effects on atherosclerosis treatment by reducing expression of iNOS mRNA and the NO level in the vessel wall.
文摘Background Despite the large scale technical innovations that have been made,a number of patients with neuromyelitis optica （NMO） are lacking NMO-IgG in both serum and cerebrospinal fluid.Longitudinally extensive spinal cord （LESC） lesions and linear lesions are associated with NMO.However,differences of spinal cord magnetic resonance imaging （MRI） features,including LESC lesions and linear lesions,between NMO-IgG positive and negative patients still remain unknown.The aim of the present study was to analyze the relationship between NMO-IgG status and spinal cord MRI features in NMO patients,particularly concerned about LESC lesions and linear lesions.Methods Clinical data and spinal cord MRI of 52 NMO patients were retrospectively analyzed.Eight patients were NMO-IgG negative in both serum and cerebrospinal fluid,while 44 were NMO-IgG positive.Quantitative data between the two cohorts were compared by the Student＇s t test or Mann-Whitney U test,the chi-square test or Fisher＇s exact test was used to evaluate qualitative data.Results NMO-IgG negative patients had a higher sex ratio （male/female） （P=0.014）.On axial MRI,lesions in the NMO-IgG negative group were mostly located in the peripheral cord （50%）,and central lesions （55%） were more common in the NMO-IgG positive group （P=-0.051）.LESC lesions were common in both cohorts.None of linear lesions was found in NMO-IgG negative patients,while the NMO-IgG positive cohort had significantly more linear lesions （48%）（P=0.016）.Conclusions Patients with NMO-IgG negativity may have different spinal cord lesion features compared to NMO-IgG positive patients.Diagnosis of NMO cannot be excluded even when NMO-IgG negativity and non-specific spinal lesions occur.
