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旋转不稳型骨盆骨折的诊治 被引量:7
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作者 马梦昆 陈鸿 《中国骨伤》 CAS 2000年第5期314-314,共1页
关键词 旋转不稳型 骨盆骨折 诊断 治疗
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国产药物洗脱支架在不稳定型心绞痛中的应用
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作者 唐欧杉 秦丰明 +3 位作者 成银宏 陈钟良 陈丽娜 周浩亮 《岭南心血管病杂志》 2007年第4期282-283,共2页
目的探讨国产西罗莫司(sirolimus,雷帕霉素)洗脱支架(FirebirdTM)在冠心病不稳定型心绞痛中应用的安全性和有效性。方法选择2004年10月~2006年1月68例不稳定型心绞痛予国产西罗莫司支架治疗。术后长期随访,观察术后6个月及12个月随访... 目的探讨国产西罗莫司(sirolimus,雷帕霉素)洗脱支架(FirebirdTM)在冠心病不稳定型心绞痛中应用的安全性和有效性。方法选择2004年10月~2006年1月68例不稳定型心绞痛予国产西罗莫司支架治疗。术后长期随访,观察术后6个月及12个月随访终点时的主要心脏不良事件(包括死亡、急性心肌梗死、靶血管再成形等)发生率、支架内再狭窄发生率。结果67例病人治疗获得成功,92处靶病变血管共置入97枚支架,1例靶血管介入治疗术中并发心肌梗死。术后平均随访(22±4)个月,6个月随访终点时非心源性死亡1例,支架内再狭窄1例,6个月主要心脏不良事件发生率2.9%。12个月随访终点时临床复发3例,其中1例为支架内再狭窄,再狭窄发生率1.5%。结论国产西罗莫司洗脱支架在不稳定型心绞痛中有较好的安全性和有效性,并可以明显降低再狭窄率。 展开更多
关键词 西罗莫司 药物支架 不稳型心绞痛
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肝素治疗老年人不稳定型心绞痛的探讨——附16例临床分析
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作者 曹素艳 赵莉 《医学研究杂志》 1993年第2期26-27,共2页
当今肝素用于急性心肌梗塞已非常广泛,而用于不稳定型心绞痛(UA)尤其是老年人UA的报道尚少。我院急诊科1992年3~11月用肝素治疗老年人UA16例,取得一定疗效。现报告如下。
关键词 不稳心绞痛 急性心肌梗塞 急诊科 临床分析 不稳型心绞痛 陈旧性心肌梗塞 心肌灌注 血流变学指标 抗凝血酶 常规组
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小剂量肝素钙治疗不稳定型心绞痛的疗效分析
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作者 胡桂才 唐世英 吕喜英 《医学理论与实践》 2001年第8期750-750,共1页
不稳定型心绞痛是一种介于稳定性心绞痛与急性心肌梗塞(AMI)之间的临床状态,病情较重,预后较差,若不及时有效的治疗,部分不稳定性心绞痛可发展为AMI.笔者在常规治疗的基础上,应用小剂量肝素钙皮下注射,治疗不稳定心绞痛42例收到满意疗效... 不稳定型心绞痛是一种介于稳定性心绞痛与急性心肌梗塞(AMI)之间的临床状态,病情较重,预后较差,若不及时有效的治疗,部分不稳定性心绞痛可发展为AMI.笔者在常规治疗的基础上,应用小剂量肝素钙皮下注射,治疗不稳定心绞痛42例收到满意疗效.总结如下. 1资料与方法 1.1一般资料按1979年WHO推荐的及1994年南京召开的有关UAP诊断治疗研讨会诊断标准诊断的UAP病人80例,均为我院住院病人,随机分为2组:治疗组42例(男30例,女12例),平均年龄58.1岁,其中初发劳力型心绞痛9例,恶化劳力型心绞痛18例,自发型心绞痛11例,心肌梗塞后心绞痛4例;常规治疗组(对照组)38例,(男28例,女10例),平均年龄57.9岁,其中初发劳力型心绞痛8例,恶化劳力型心绞痛16例,自发型心绞痛10例,心肌梗塞后心绞痛4例;两组临床资料无显著性差异,并具有可比性. 展开更多
关键词 肝素钙 治疗 不稳型心绞痛
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不稳定型心绞痛危险因素分析及其临床意义
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作者 保方 《医学检验与临床》 2012年第1期63-64,共2页
目的探讨TC、TG与CK-MB/CK比值联合检测在早期筛查不稳定型心绞痛中的临床意义。方法利用EX-EL软件和SPSS16.0统计软件对TC和TG检测值与CK-MB/CK比值之间的变化规律进行趋势及相关性分析。结果TC浓度组与CK-MB/CK比值组之间中度相关... 目的探讨TC、TG与CK-MB/CK比值联合检测在早期筛查不稳定型心绞痛中的临床意义。方法利用EX-EL软件和SPSS16.0统计软件对TC和TG检测值与CK-MB/CK比值之间的变化规律进行趋势及相关性分析。结果TC浓度组与CK-MB/CK比值组之间中度相关(P〈0.01),CK-MB/CK比值变化趋势随TC浓度的增高而增大;但TG浓度组与CK-MB/CK比值组之间没有明显的相关性(P〉0.01)。TG浓度变化与CK-MB/CK比值变化趋势随TG浓度的升高没有明显的改变。在高TG浓度情况(0.57mm01/L以上)时,CK-MB/CK比值变化趋势在高水平的12.05-17.08%之间。结论TC、TG与CK/CK-MB比值联合检测能够较全面的反映心肌损害情况,能较好的避免CK-MB/CK比值假阳性结果给临床诊断带来的困扰。可以用于不稳型心绞痛的早期诊断。 展开更多
关键词 不稳型心绞痛 急性心肌梗死 三酰甘油 胆固醇 肌酸肌酶 肌酸肌酶同工酶
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阿托伐他汀治疗不稳定型心绞痛的临床疗效研究
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作者 徐丹 李刚 《中国医药指南》 2015年第9期125-126,共2页
目的观察阿托伐他汀对不稳定型心绞痛的疗效。方法确诊的不稳型性心绞痛患者40例,随机分为治疗组和对照组,每组20例。两组常规治疗相同,治疗组患者加用阿托伐他汀,观察治疗4个月心绞痛患者的临床症状、记录12导联心电图ST段压低数值及... 目的观察阿托伐他汀对不稳定型心绞痛的疗效。方法确诊的不稳型性心绞痛患者40例,随机分为治疗组和对照组,每组20例。两组常规治疗相同,治疗组患者加用阿托伐他汀,观察治疗4个月心绞痛患者的临床症状、记录12导联心电图ST段压低数值及血脂的变化。结果治疗4个月阿托伐他汀组(治疗组)胆固醇、低密度脂蛋白胆固醇明显下降(P<0.05),心绞痛症状及心电图均明显改善(P<0.05)有显著性差异,明显减少了心脏事件发生。结论阿托伐他汀治疗不稳定型心绞痛疗效显著。 展开更多
关键词 阿托伐他汀 不稳型性心绞痛 心电图
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姿势不稳-步态困难型帕金森病患者血清甲状腺激素水平与认知功能障碍的关系 被引量:4
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作者 张琛 安军 +2 位作者 赵猛 郑国华 李伟 《山东医药》 CAS 2021年第27期61-63,共3页
目的探讨姿势不稳—步态困难型帕金森病(PIGD)患者血清甲状腺激素水平与认知功能障碍的关系。方法根据MoCA量表评分将76例PIGD患者分为认知功能障碍组44例和认知功能正常组32例,比较两组甲状腺激素水平,Logistic回归分析甲状腺激素水平... 目的探讨姿势不稳—步态困难型帕金森病(PIGD)患者血清甲状腺激素水平与认知功能障碍的关系。方法根据MoCA量表评分将76例PIGD患者分为认知功能障碍组44例和认知功能正常组32例,比较两组甲状腺激素水平,Logistic回归分析甲状腺激素水平与PIGD患者认知功能障碍的关系。结果与认知功能正常组比较,认知功能障碍组T3水平低,TSH水平高(P均<0.05);两组T4水平比较,P>0.05。TSH水平是PIGD患者发生认知功能障碍的独立危险因素(P<0.05)。结论血清TSH水平升高是PIGD患者发生认知功能障碍的危险因素。 展开更多
关键词 甲状腺激素 认知功能障碍 帕金森病 姿势不稳—步态困难帕金森病
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不稳定型心绞痛合并糖尿病患者经皮冠状动脉介入治疗后应对方式分析
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作者 罗曲博 张园园 丁苗苗 《四川解剖学杂志》 2022年第1期45-47,共3页
目的:分析不稳定型心绞痛合并糖尿病患者经皮冠状动脉介入治疗(PCI)后应对方式的影响因素.方法:选取2018年2月至2020年6月于本院接受PCI治疗的80例不稳定型心绞痛合并糖尿病患者作为研究对象.采用医学方式应对问卷(MCMQ)评估患者应对方... 目的:分析不稳定型心绞痛合并糖尿病患者经皮冠状动脉介入治疗(PCI)后应对方式的影响因素.方法:选取2018年2月至2020年6月于本院接受PCI治疗的80例不稳定型心绞痛合并糖尿病患者作为研究对象.采用医学方式应对问卷(MCMQ)评估患者应对方式.根据PCI后患者应对方式,分别纳入消极组(n=27)与积极组(n=53).统计所有患者临床资料,将可能的影响因素纳入分析,找出不稳定型心绞痛合并糖尿病患者PCI后应对方式的影响因素.结果:80例不稳定性心绞痛合并糖尿病患者消极应对27例(33.75%),积极应对53例(66.25%).消极应对组文化程度、医疗费用支付方式占比高于积极应对组,差异有统计学意义(P<0.05).经Logistic回归分析结果显示,文化程度为高中及以下、医疗费用支付方式为自费是不稳定性心绞痛合并糖尿病患者PCI后消极应对的影响因素(OR=3.042、4.235,P=0.023、0.004).结论:不稳定性心绞痛合并糖尿病患者PCI后消极应对受高中及以下文化程度、医疗费用支付方式因素的影响. 展开更多
关键词 心绞痛 不稳 糖尿病 经皮冠状动脉介入治疗 应对方式
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早期应用阿托伐他汀治疗不稳定性心绞痛 被引量:1
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作者 刘妍 《中国实用医药》 2009年第17期150-151,共2页
目的观察应用阿托伐他汀对不稳定型心绞痛的疗效。方法将80例住院确诊的不稳型性心绞痛患者随机分为治疗组41例,对照组39例,两组常规治疗相同,治疗组加服阿托伐他汀。结果治疗组能明显降低血清总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)... 目的观察应用阿托伐他汀对不稳定型心绞痛的疗效。方法将80例住院确诊的不稳型性心绞痛患者随机分为治疗组41例,对照组39例,两组常规治疗相同,治疗组加服阿托伐他汀。结果治疗组能明显降低血清总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)、三酰甘油(TG),明显减少心脏事件发生,减少再住院次数。结论早期应用阿托伐他汀治疗不稳型性心绞痛疗效显著。 展开更多
关键词 早期应用 阿托伐他汀 不稳型心绞痛
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洛文斯顿作业疗法认知评定量表在无痴呆型帕金森病患者中的应用价值 被引量:10
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作者 陈伟 李威 谢瑞满 《临床神经病学杂志》 CAS 北大核心 2010年第1期4-7,共4页
目的探讨洛文斯顿作业疗法认知评定量表(LOTCA)在无痴呆型帕金森病(PD)患者中的应用价值。方法采用简易精神状态检查(MMSE)量表及LOTCA对60例无痴呆型PD患者和50例对照者的认知功能进行检测,并对引起认知功能损害的相关因素进行分析。... 目的探讨洛文斯顿作业疗法认知评定量表(LOTCA)在无痴呆型帕金森病(PD)患者中的应用价值。方法采用简易精神状态检查(MMSE)量表及LOTCA对60例无痴呆型PD患者和50例对照者的认知功能进行检测,并对引起认知功能损害的相关因素进行分析。结果采用MMSE评分时,仅2例(3.3%)无痴呆型PD患者出现认知功能损害;采用LOTCA评分时,23例(38.3%)无痴呆型PD患者出现认知功能损害,主要累及视运动组织功能和思维运作能力。单因素分析显示:年龄、起病年龄、抑郁症、运动障碍的严重程度及类型与PD患者认知功能损害有关;多因素Logistic回归分析显示:年龄、抑郁、姿势不稳-步态异常(PIGD)型运动障碍是认知功能损害的危险因素。结论LOTCA量表适合无痴呆型PD患者认知功能的评定;老龄、抑郁状态及PIGD型运动功能障碍可能是影响无痴呆型PD患者的认知功能的危险因素。 展开更多
关键词 帕金森病 认知功能 洛文斯顿作业疗法认知评定量表 抑郁 姿势不稳-步态异常
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不同亚型帕金森病患者认知功能障碍临床特点的研究
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作者 孙晓敏 刘琦慧 +1 位作者 王磊 周丽 《当代医药论丛》 2022年第9期56-59,共4页
目的:研究不同亚型帕金森病患者认知功能障碍的临床特点。方法:选取潍坊市人民医院神经内科收治的100例帕金森病患者作为研究对象。按照世界运动障碍病学会新版帕金森病综合评价量表(MDS-UPDRS)将其帕金森病的类型分为震颤型(纳入TD组)... 目的:研究不同亚型帕金森病患者认知功能障碍的临床特点。方法:选取潍坊市人民医院神经内科收治的100例帕金森病患者作为研究对象。按照世界运动障碍病学会新版帕金森病综合评价量表(MDS-UPDRS)将其帕金森病的类型分为震颤型(纳入TD组)、姿势不稳/步态障碍型(纳入PIGD组)与中间型(纳入mixed组)。对三组患者的认知功能进行评估,总结不同亚型帕金森病患者认知功能障碍的临床特点。结果:PIGD组患者和mixed组患者蒙特利尔认知评估量表(MoCA)中的语言能力评分和延迟记忆力评分均低于TD组患者,P<0.05。PIGD组患者与mixed组患者的数字广度测验(DST)评分和月份倒背试验评分均低于TD组患者,P<0.05。mixed组患者的短期回忆测验评分低于其他两组患者,P<0.05。结论:不同亚型的帕金森病患者其认知功能受损的程度各不相同,TD型帕金森病患者的总体认知功能与分认知域的损害程度较PIGD型与中间型帕金森病患者轻。PIGD型与中间型帕金森病患者的总体认知功能中以语言功能和延迟记忆力下降最为明显,分认知域中以注意力与记忆力下降最为明显。 展开更多
关键词 帕金森病 认知功能障碍 震颤 姿势不稳/步态障碍 中间 总体认知功能 分认知域
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急性冠脉综合征患者血尿酸与全血黏度变化分析 被引量:4
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作者 杨友新 吴吕燕 陆承凤 《右江民族医学院学报》 2011年第1期31-32,共2页
目的探讨急性冠脉综合征(ACS)患者血尿酸与全血黏度(低切、中切、高切)的变化及临床意义。方法选择166例住院ACS患者为实验组[其中稳定型心绞痛(SA)72例,不稳定型心绞痛(UA)66例,急性心肌梗死(AMI)28例],同期健康体检者158例为对照组。... 目的探讨急性冠脉综合征(ACS)患者血尿酸与全血黏度(低切、中切、高切)的变化及临床意义。方法选择166例住院ACS患者为实验组[其中稳定型心绞痛(SA)72例,不稳定型心绞痛(UA)66例,急性心肌梗死(AMI)28例],同期健康体检者158例为对照组。分别测定两组的血尿酸与全血黏度指标。结果实验组的血尿酸与全血黏度由SA、UA到AMI依次升高,与对照组比较差异有显著性(P<0.05);实验组内全血黏度由SA、UA及AMI依次升高,差异有显著性(P<0.05),实验组内血尿酸由SA、UA及AMI依次升高,但差异无显著性(P>0.05)。结论血尿酸、全血黏度与ACS有密切关系,是ACS的危险因素。 展开更多
关键词 急性冠脉综合征 血尿酸 血液黏度 心绞痛 不稳型 心肌梗死
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比索洛尔联合辛伐他汀治疗老年不稳定型心绞痛患者的临床疗效 被引量:1
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作者 王宁宁 《中国药物经济学》 2015年第12期55-56,共2页
目的探讨比索洛尔联合辛伐他汀治疗老年不稳定型心绞痛(UA)患者的临床疗效。方法选取2013年8月至2014年10月朝阳市中心医院收治的52例老年UA患者作为研究对象,按随机数字表法将其分为对照组和观察组,各26例。对照组患者睡前口服辛伐他汀... 目的探讨比索洛尔联合辛伐他汀治疗老年不稳定型心绞痛(UA)患者的临床疗效。方法选取2013年8月至2014年10月朝阳市中心医院收治的52例老年UA患者作为研究对象,按随机数字表法将其分为对照组和观察组,各26例。对照组患者睡前口服辛伐他汀,观察组患者在对照组基础上给予比索洛尔,比较两组患者的临床疗效及不良反应发生情况。结果观察组患者的总有效率明显高于对照组,差异有统计学意义(P<0.05);观察组患者的不良反应发生率明显低于对照组,差异有统计学意义(P<0.05)。结论比索洛尔联合辛伐他汀治疗老年UA临床疗效明显,可明显改善患者的临床症状,且不良反应少,临床用药安全高。 展开更多
关键词 比索洛尔 辛伐他汀 老年 不稳型心绞痛
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Preliminary Studies on the Effect of Photoperiod and Temperature on Male Fertility of a Cytoplasmic Male Sterile Line in Wheat 被引量:2
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作者 王丰青 巍荷 +1 位作者 何觉民 何仪 《Agricultural Science & Technology》 CAS 2008年第2期85-89,共5页
[Objective] The study aimed to reveal the effect of photoperiod and temperature on male fertility of cytoplasmic male sterile line Vtai911289a in wheat and discuss the mechanism of male fertility alteration. [ Method ... [Objective] The study aimed to reveal the effect of photoperiod and temperature on male fertility of cytoplasmic male sterile line Vtai911289a in wheat and discuss the mechanism of male fertility alteration. [ Method ] The sowing-date tests and designed conditions were conducted during 2003 -2005. [ Result] Fertility of Vtai911289a, could alter under specific photoperiod and temperature conditions. Temperature is one of the main factors influencing male fertility of the male sterile lines. Vtai911289a, showed stable sterility under the condition of the mean of daily temperature at fertility sensitive stage lower than 19℃ and presented partial fertility when the mean of daily temperature at fertility sensitive stage lower than 20 - 22℃. Photoperiod to some extent affects the male fertility of Vtai911289a, long-day condition is helpful for the male fertility of the sterile line. [ Conclusion] The application of photoperiod temperature-sensitive cytoplasmic male sterile line in production has a higher safety than that of temperature sensitive sterile line. 展开更多
关键词 Temperature PHOTOPERIOD Cytoplasmic male sterile line Male fertility
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Stable ischemic heart disease in the older adults 被引量:5
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作者 Xuming DAI Jan Busby-Whitehead +1 位作者 Daniel E Forman Karen P Alexander 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2016年第2期109-114,共6页
1 Introduction Ischemic heart disease is caused by atherosclerotic and/or thrombotic obstruction of coronary arteries. Clinical spec- trum of ischemic heart disease expands from asymptomatic atherosclerosis of corona... 1 Introduction Ischemic heart disease is caused by atherosclerotic and/or thrombotic obstruction of coronary arteries. Clinical spec- trum of ischemic heart disease expands from asymptomatic atherosclerosis of coronary arteries to acute coronary syn- dromes (ACS) including unstable angina, acute myocardial infarction (non-ST elevation myocardial infarction and ST elevation myocardial infarction). Stable ischemic heart dis- ease (SIHD) refers to patients with known or suspected SIHD who have no recent or acute changes in their symp- tomatic status, suggesting no active thrombotic process is underway. 展开更多
关键词 AGING Coronary artery disease Older adults Risk assessment Stable ischemic heart disease
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Beneficial clinical effects of grape seed proanthocyanidin extract on the progression of carotid atherosclerotic plaques 被引量:4
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作者 Ai-Hong CAO Jian WANG +2 位作者 Hai-Qing GAO Ping ZHANG Jie QIU 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2015年第4期417-423,共7页
Background Atherosclerotic plaques indicate the occurrence of ischemia events and it is a difficult task for clinical physicians. Grape seed proanthocyanidin extract (GSPE) has been reported to exert an antiatheroge... Background Atherosclerotic plaques indicate the occurrence of ischemia events and it is a difficult task for clinical physicians. Grape seed proanthocyanidin extract (GSPE) has been reported to exert an antiatherogenic effect by inducing regression of atherosclerotic plaques in animal experimental studies. In this study, the antiatherogenic effect of GSPE has been investigated in clinical use. Methods Consecu- tive 287 patients diagnosed with asymptomatic carotid plaques or abnormal plaque free carotid intima-media thickness (CIMT) were ran- domly assigned to the GSPE group (n = 146) or control group (n = 141). The patients in the GSPE group received GSPE 200 mg per day orally, while patients in the control group were only enrolled in a lifestyle intervention program. Carotid ultrasound examination was per- formed at baseline and 6, 12, 24 months during follow-up. Mean maximum CIMT (MMCIMT), plaque score, echogenicity of plaques and ischemic vascular events were recorded. Results As anticipated, after treatment, GSPE resulted in significant reduction in MMCIMT pro- gression (4.2% decrease after six months, 4.9% decrease after 12 months and 5.8% decrease after 24 months) and plaque score (10.9% de- crease after six months, 24.1% decrease after 12 months and 33.1% decrease after 24 months) for the primary outcome, while MMCIMT and plaque score were stable and even increased with the time going on in control group. The number of plaques and unstable plaques also de- creased after treatment of GSPE. Furthermore, the carotid plaque can disappear after treatment with GSPE. The incidence rate for transitory ischemic attack (TIA), arterial revascularization procedure, and hospital readmission for unstable angina in GSPE group were statistically significant lower (P = 0.02, 0.08, 0.002, respectively) compared with the control group. Conclusions GSPE inhibited the progression of MMCIMT and reduced carotid plaque size in GSPE treated patients, and with extended treatment, the superior efficacy on MMCIMT and carotid plaque occurred. Furthermore, the GSPE group showed lower rates of clinical vascular events. 展开更多
关键词 ATHEROSCLEROSIS Carotid plaque Grape seed proanthocyanidin extract
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Experiments of Brittle-Plastic Transition and Instability Modes of Juyongguan Granite at Different Temperatures and Pressures 被引量:3
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作者 Zhou Yongsheng, Jiang Haikun and He ChangrongInstitute of Geology, Open Tectonophysics Laboratory, CSB, Beijing 100029, China 《Earthquake Research in China》 2003年第2期169-182,共14页
Three groups of experiments on brittle-plastic transition and instability modes of granite were performed in a triaxial vessel with solid pressure medium at high temperature and high pressure. The results of experimen... Three groups of experiments on brittle-plastic transition and instability modes of granite were performed in a triaxial vessel with solid pressure medium at high temperature and high pressure. The results of experiments show that brittle faulting is the major failure mode at temperature <300℃, but crystal-plastic deformation is dominate at temperature >800℃, and there is a transition with increasing temperature from semi-brittle faulting to cataclastic flow and semi-brittle flow at temperatures of 300~800℃. So, temperature is the most influential factor in brittle-plastic transition of granite and confining pressure is the second factor. The results also show that progressive failure of granite occurs at lower pressure or high temperature where there is crystal plasticity, and sudden instability occurs at room temperature and high pressure (>300MPa) or high temperature and great pressure(550℃600MPa ~650℃700MPa), and a broad regime of quasi-sudden instability exists between the T-P condition of progressive failure and sudden instability. So, instability modes of granite depend simultaneously on the pressure and temperature. 展开更多
关键词 Deformation and failure Instability modes Brittle-plastic transition High temperature and great pressure GRANITE
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Two Approaches of Substance Flow Analysis—An Inspiration from Fluid Mechanics 被引量:2
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作者 Lu Zhongwu 《Engineering Sciences》 EI 2008年第1期2-8,共7页
That flow is the common feature of substance flow and fluid flow is the viewpoint emphasized in the paper. Some notes on fluid mechanics, including the two approaches of fluid flow description, were given. The concept... That flow is the common feature of substance flow and fluid flow is the viewpoint emphasized in the paper. Some notes on fluid mechanics, including the two approaches of fluid flow description, were given. The concepts of the chain and the chain group of product life cycles, which are essential for understanding the specific features of substance flow, were advanced. Taking the specific feature of substance flow into consideration, on the analogy of the two approaches in fluid mechanics, two approaches of substance flow analysis, i.e. L method and E model, were formulated. Illustrative models of steady and unsteady substance flow were sketched by both methods, and comparison between them was made in general. 展开更多
关键词 Lagran gian and Eulerian approaches of fluid flow description the chain of product life cycles the chaingroup of product life cycles the L approach of substance flow analysis the E approach of substance flow analysis steady and unsteady substance flow
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Performance enhancement of IMC-PID controller design for stable and unstable second-order time delay processes 被引量:2
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作者 Munna KUMAR Durga PRASAD Ram Sharan SINGH 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第1期88-100,共13页
An IMC-PID controller was proposed for unstable second-order time delay system which shows the characteristics of inverse response(RHP zero). A plot of Ms versus λ was suggested to calculate the suitable tuning param... An IMC-PID controller was proposed for unstable second-order time delay system which shows the characteristics of inverse response(RHP zero). A plot of Ms versus λ was suggested to calculate the suitable tuning parameter λ, which provides a trade-off between performance and robustness. Six different forms of process models were selected from literature to show the applicability of the present method. Performance of controller was calculated by ITAE and total variation TV and compared with recently published tuning rules. Undesirable overshoot was removed by using a set-point weighting parameter. Robustness was tested by introducing a perturbation into the various model parameters and closed-loop results show that the designed controller is robust in the case of model uncertainty. The proposed method shows an overall better closed-loop response as compared to other recently reported methods. 展开更多
关键词 maximum sensitivity internal model control unstable process set-point weighting integral of time-weighted absolute error
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Analysis on optimal working fluid flowrate and unstable power generation for miniaturized ORC systems 被引量:1
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作者 刘克涛 朱家玲 +1 位作者 胡开永 吴秀杰 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第5期1224-1231,共8页
For efficient utilization of a limited geothermal resource in practical projects,the cycle parameters were comprehensively analyzed by combining with the heat transfer performance of the plate heat exchanger,with a va... For efficient utilization of a limited geothermal resource in practical projects,the cycle parameters were comprehensively analyzed by combining with the heat transfer performance of the plate heat exchanger,with a variation of flowrate of R245 fa.The influence of working fluid flowrate on a 500 W ORC system was investigated.Adjusting the working fluid flowrate to an optimal value results in the most efficient heat transfer and hence the optimal heat transfer parameters of the plate heat exchanger can be determined.Therefore,for the ORC systems,optimal working fluid flowrate should be controlled.Using different temperature hot water as the heat source,it is found that the optimal flowrate increases by 6-10 L/h with 5 ℃ increment of hot water inlet temperature.During experiment,lower degree of superheat of the working fluid at the outlet the plate heat exchanger may lead to unstable power generation.It is considered that the plate heat exchanger has a compact construction which makes its bulk so small that liquid mixture causes the unstable power generation.To avoid this phenomenon,the flow area of plate heat exchanger should be larger than the designed one.Alternatively,installing a small shell and tube heat exchanger between the outlet of plate heat exchanger and the inlet of expander can be another solution. 展开更多
关键词 organic Rankine cycle (ORC) plate heat exchanger optimal working fluid flowrate unstable power generation
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