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大鼠坐骨神经再生过程的条件损伤效应
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作者 邹飞 佟振清 高天明 《中国应用生理学杂志》 CAS CSCD 1991年第4期332-335,共4页
在大鼠腓神经伸趾长肌标本上,用微电极记录小终板电位(MEPP)和静息膜电位(RMP),观察腓神经损伤后的再生过程和条件损伤效应。结果表明:损伤后1~10d突触前递质自发释放完全消失,RMP幅度变小。到14d才出现频率慢波幅变宽的MEPP,30d仍未... 在大鼠腓神经伸趾长肌标本上,用微电极记录小终板电位(MEPP)和静息膜电位(RMP),观察腓神经损伤后的再生过程和条件损伤效应。结果表明:损伤后1~10d突触前递质自发释放完全消失,RMP幅度变小。到14d才出现频率慢波幅变宽的MEPP,30d仍未恢复正常,其频率和时程分别为正常的60%和169%。而RMP幅度仅为正常的84%。条件损伤组在损伤后30d MEPP的频率、时程和RMP幅度分别为正常时的78%、120%和97%,均比损伤对照组恢复快。说明条件损伤在运动神经的再生过程中可促进自发MEPP的出现和RMP的恢复。 展开更多
关键词 神经再生 条件损伤 小终板电位
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条件损伤对运动神经再生和功能恢复的作用
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作者 邹飞 佟振清 高天明 《第一军医大学学报》 CSCD 1992年第3期235-238,共4页
以大鼠腓神经伸趾长肌为标本。用不同频率的直接刺激,间接刺激引起肌肉收缩的比值和肌肉对ACh敏感性测定为指标,观察条件损伤对运动神经再生的影响。结果显示:条件损伤组在损伤后15、20、30天时肌肉收缩功能恢复均较对照组快,且突触后AC... 以大鼠腓神经伸趾长肌为标本。用不同频率的直接刺激,间接刺激引起肌肉收缩的比值和肌肉对ACh敏感性测定为指标,观察条件损伤对运动神经再生的影响。结果显示:条件损伤组在损伤后15、20、30天时肌肉收缩功能恢复均较对照组快,且突触后ACh敏感性也较对照组恢复的快。说明条件损伤有促进运动神经再生作用。 展开更多
关键词 神经再生 条件损伤 肌肉 乙酰胆碱
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大鼠周围神经条件性损伤促进对侧神经再生
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作者 韩天宇 朱庆生 《中国组织工程研究与临床康复》 CAS CSCD 2001年第20期59-60,共2页
目的了解条件性损伤与神经再生的关系。方法50只雄性SD大鼠,按术式随机分成两组。A组:显露左侧坐骨神经,不损伤。B组:造成左侧坐骨神经挤压伤。于伤后5 d,两组均造成右侧坐骨神经挤压伤。分别于术后0、1、3、5、7 d行挤压反射试验... 目的了解条件性损伤与神经再生的关系。方法50只雄性SD大鼠,按术式随机分成两组。A组:显露左侧坐骨神经,不损伤。B组:造成左侧坐骨神经挤压伤。于伤后5 d,两组均造成右侧坐骨神经挤压伤。分别于术后0、1、3、5、7 d行挤压反射试验,检测神经轴突再生的距离及组织学观察。结果试验组的初期延迟1.05 d明显短于对照组的初期延迟1.70 d(P< 0.05)。结论大鼠坐骨神经条件性损伤通过缩短再生延迟,而促进神经再生。 展开更多
关键词 周围神经 条件损伤
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条件性损伤的时间与频次对神经根撕脱伤后脊髓前角运动神经元死亡及NOS表达的影响 被引量:1
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作者 韩曙 周丽华 +1 位作者 吴武田 姚志彬 《解剖学研究》 CAS 2000年第2期116-119,T008,共5页
目的 探索条件性损伤 (CL)的时间和频次对神经根撕脱 (TL)后脊髓前角运动神经元一氧化氮合酶 (NOS)表达及细胞死亡的影响。方法 成年SD雌性大鼠 116只 ,体重 2 0 0~ 30 0g ,以钳夹神经干为CL ,分为两个系列。时间系列 :在CL后 1d、3d... 目的 探索条件性损伤 (CL)的时间和频次对神经根撕脱 (TL)后脊髓前角运动神经元一氧化氮合酶 (NOS)表达及细胞死亡的影响。方法 成年SD雌性大鼠 116只 ,体重 2 0 0~ 30 0g ,以钳夹神经干为CL ,分为两个系列。时间系列 :在CL后 1d、3d、1w、2w后进行TL ,频次系列分别在 1w和 2w内行 1次、2次、6次钳夹 ,术后不同时间点处死动物 ,以单纯撕脱臂丛为对照 ,取C5~C8节段脊髓 ,行NADPH d组化染色 ,中性红复染。定量观察前角运动神经元NOS表达及神经元数目。结果 单纯撕脱组术后第 5d脊髓前角运动神经元开始表达NOS ,术后 3wNOS阳性神经元数达到高峰 ,随后逐渐下降并伴有神经元丢失。时间系列 :撕脱后 3d和 2w ,CL与TL间隔 1d组的NOS表达和神经元数目与对照组无显著性差异 ,但 3d、1w、2w组的NOS细胞数及神经元的丢失均较对照组明显 (P <0 0 5P <0 0 1) ,但在撕脱后 4w各CL时间的NOS表达和神经元存活均较对照组减少 (P <0 0 5 )。频次系列 :在 1w和 2w内增加CL次数可使NOS的表达水平和神经细胞的死亡数目有显著增加 ,在撕脱后 2w和 4w等较后的时间点更为明显 ;但在一定时间内 2次与 6次钳夹之间则无显著性差异。结论 条件性损伤与二次损伤之间的间隔影响撕脱后神经元NOS表达和神经元的死亡 。 展开更多
关键词 条件损伤 神经根撕脱 前角运动神经元 NADPH-D
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无损伤条件疲劳极限 被引量:2
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作者 师照峰 《机械强度》 CAS CSCD 北大核心 1991年第4期29-31,69,共4页
假设材料有无损伤条件疲劳极限 S_(nd),从而构造出双对数应力—寿命线性关系。以相关系数γ为目标函数进行优化拟合,得到22种常用国产金属材料的 S_(nd)砭 S—N 曲线;给出了国产钢材 S_(nd)的经验公式及在不同可靠度下 S_(nd)的估算方... 假设材料有无损伤条件疲劳极限 S_(nd),从而构造出双对数应力—寿命线性关系。以相关系数γ为目标函数进行优化拟合,得到22种常用国产金属材料的 S_(nd)砭 S—N 曲线;给出了国产钢材 S_(nd)的经验公式及在不同可靠度下 S_(nd)的估算方法。拟合所得 P—S—N 曲线比常规 P—S—N 曲线适用范围更广。 展开更多
关键词 损伤条件疲劳极限 P-S-N曲线 金属材料 疲劳试验
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大鼠坐骨神经损伤对背根节GDNF表达的影响 被引量:1
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作者 张文捷 李兵仓 《创伤外科杂志》 2002年第5期266-269,共4页
目的 应用免疫组化技术观察大鼠坐骨神经条件性损伤对相应背根节及坐骨神经胶质细胞源性神经营养因子 (glialcellline derivedneurotrophicfactor,GDNF)表达的影响 ,以探讨GDNF对损伤神经元的作用。方法  4 5只成年雌性Wistar大鼠随... 目的 应用免疫组化技术观察大鼠坐骨神经条件性损伤对相应背根节及坐骨神经胶质细胞源性神经营养因子 (glialcellline derivedneurotrophicfactor,GDNF)表达的影响 ,以探讨GDNF对损伤神经元的作用。方法  4 5只成年雌性Wistar大鼠随机分为 3组 :A组 (N =5 )正常对照组 ,B组 (N =2 0 )坐骨神经压榨伤组 ,C组 (N =2 0 )坐骨神经切断 /结扎组 ;B、C两组按存活期不同再各分为 4个亚组 ,每组 5例。大鼠分别于伤后 3天、2周、1个月、2个月处死 ,取材L5节段损伤侧背根节及损伤坐骨神经的远近节段 ,免疫组化染色观测GDNF表达。结果  (1)正常背根节细胞GDNF表达主要分布于小神经元 ,少数为大神经元。 (2 )坐骨神经损伤促使同侧背根节神经元GDNF表达显著增强 ,伤后 2周达到高峰 ;B组背根节细胞GDNF表达在伤后1个月时轻度下调 ,伤后 2个月恢复为对照组水平。C组背根节细胞GDNF表达保持高水平 ,并至观察后期 2个月。 (3)坐骨神经损伤同时诱导背根节卫星细胞及坐骨神经雪旺氏细胞GDNF表达显著增强 ,其中远端坐骨神经GDNF表达强于近端。B组这些细胞的阳性表达持续至伤后 2周 ,C组伤后 1个月时其表达仍显著。结论 GDNF是参与损伤初级感觉神经元反应的重要因子 ,并可能对正常及受损背根节细胞发挥营养作用。 展开更多
关键词 胶质细胞源性神经营养因子 条件损伤 背根节 坐骨神经
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混凝土各向异性损伤模型 被引量:1
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作者 熊健民 陈升平 《桥梁建设》 EI CSCD 北大核心 1997年第3期50-52,57,共4页
在能量等价假设的基础上建立了混凝土的各向异性损伤本构方程。损伤演变由损伤强化条件决定,当损伤强化达到临界值时,混凝土发生破坏。本模型能较好地描述混凝土的单侧受力性能。
关键词 各向异性损伤 损伤强化条件 混凝土 损伤演变
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p38信号通路在小鼠骨髓间充质干细胞体外分化肝细胞中的作用 被引量:2
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作者 杨超 董学君 《医学研究杂志》 2011年第1期85-88,共4页
目的探索p38信号转导通路在损伤肝脏条件培养液体外诱导小鼠骨髓间充质干细胞(mBMMSCs)向肝细胞分化中的作用。方法将四氯化碳(CC l4)注射的小鼠肝脏进行培养,收集到的上清液即为损伤肝脏条件培养液;密度梯度离心法分离获得小鼠骨髓来... 目的探索p38信号转导通路在损伤肝脏条件培养液体外诱导小鼠骨髓间充质干细胞(mBMMSCs)向肝细胞分化中的作用。方法将四氯化碳(CC l4)注射的小鼠肝脏进行培养,收集到的上清液即为损伤肝脏条件培养液;密度梯度离心法分离获得小鼠骨髓来源的骨髓间充质干细胞,采用反复贴壁筛选法纯化,培养并传代;将培养至第3~7代骨髓间充质干细胞分为3组:对照组、正常诱导组和抑制剂组,对照组用10%FBS的IMDM培养液培养,其余两组均加入损伤肝脏条件培养液,此外抑制剂组再加入p38信号转导通路抑制剂SB203580至终浓度10.5μmol/L。结果①正常组在诱导处理21天后,相差显微镜下观察,细胞形态由梭形、纤维样分化为多边形或上皮样,胞核清晰,并出现双核或多核;而抑制剂组在诱导处理21天后,细胞形态改变的比例明显减少;②p38信号通路抑制剂SB203580作用于抑制剂组中骨髓间充质干细胞7天后,肝细胞分化特异性指标AFP在诱导第7天时、ALB以及分泌尿素量在诱导第14天和第21天时,与正常诱导组相比,明显减少(P<0.05,n=5)。结论丝裂原激活蛋白酶p38的活化可能在损伤肝脏条件培养液诱导骨髓间充质干细胞分化为肝细胞过程中起重要作用。 展开更多
关键词 P38 骨髓间充质干细胞 肝细胞 细胞分化 肝脏损伤条件培养液
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对颅骨骨折机制中“颅骨整体变形”说之我见
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作者 郭迎利 焦建军 《河北北方学院学报(医学版)》 2006年第4期71-72,共2页
分析了颅骨整体变形的损伤机制,主要从导致颅骨骨折的作用物、作用方式、骨折的表现形式等阐述了对“颅骨整体变形”的不同见解,并对正规考试题的筛选提出不同看法。
关键词 颅骨整体变形 损伤条件 致伤机制 远离受力点 骨折 考试题
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Potential of acoustic emissions from three point bending tests as rock failure precursors 被引量:8
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作者 Agioutantis Z. Kaklis K. +3 位作者 Mavrigiannakis S. Verigakis M. Vallianatos F. Saltas V. 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2016年第1期155-160,共6页
Development of failure in brittle materials is associated with microcracks,which release energy in the form of elastic waves called acoustic emissions. This paper presents results from acoustic emission measurements o... Development of failure in brittle materials is associated with microcracks,which release energy in the form of elastic waves called acoustic emissions. This paper presents results from acoustic emission measurements obtained during three point bending tests on Nestos marble under laboratory conditions.Acoustic emission activity was monitored using piezoelectric acoustic emission sensors,and the potential for accurate prediction of rock damage based on acoustic emission data was investigated. Damage localization was determined based on acoustic emissions generated from the critically stressed region as scattered events at stresses below and close to the strength of the material. 展开更多
关键词 Acoustic emissionsThree point bending testIndirect tensile strengthCrack localizationNestos marble
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Mechanical and damage evolution properties of sandstone under triaxial compression 被引量:15
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作者 Zong Yijiang Han Lijun +1 位作者 Wei Jianjun Wen Shengyong 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2016年第4期601-607,共7页
To study the mechanical and damage evolution properties of sandstone under triaxial compression, we analyzed the stress strain curve characteristics, deformation and strength properties, and failure process and charac... To study the mechanical and damage evolution properties of sandstone under triaxial compression, we analyzed the stress strain curve characteristics, deformation and strength properties, and failure process and characteristics of sandstone samples under different stress states. The experimental results reveal that peak strength, residual strength, elasticity modulus and deformation modulus increase linearly with confining pressure, and failure models transform from fragile failure under low confining pressure to ductility failure under high confining pressure. Macroscopic failure forms of samples under uniaxial compression were split failure parallel to the axis of samples, while macroscopic failure forms under uniaxial compression were shear failure, the shear failure angle of which decreased linearly with confin- ing pressure. There were significant volume dilatation properties in the loading process of sandstone under different confining pressures, and we analyzed the damage evolution properties of samples based on acoustic emission damage and volumetric dilatation damage, and established damage constitutive model, realizing the real-time Quantitative evaluation of samnles damage state in loading process. 展开更多
关键词 Rock mechanics Mechanical properties Dilatation Damage evolution Failure characteristics
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Effects of different light conditions on repair of UV-B-induced damage in carpospores of Chondrus ocellatus Holm
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作者 鞠青 肖慧 +1 位作者 王悠 唐学玺 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第3期664-678,共15页
We evaluated the effects of ultraviolet-B (UV-B) radiation and different light conditions on the repair of UV-B-induced damage in carpospores of Chondrus ocellatus Holm (Rhodophyta) in laboratory experiments. Carp... We evaluated the effects of ultraviolet-B (UV-B) radiation and different light conditions on the repair of UV-B-induced damage in carpospores of Chondrus ocellatus Holm (Rhodophyta) in laboratory experiments. Carpospores were treated daily with different doses of UV-B radiation for 48 days, when vertical branches had formed in all treatments; after each daily treatment, the carpospores were subjected to photosynthetically active radiation (PAR), darkness, red light, or blue light during a 2-h repair stage. Carpospore diameters were measured every 4 days. We measured the growth and cellular contents of cyclobutane pyrimidine dimers (CPDs), chlorophyll a, phycoerythrin, and UV-B-absorbing mycosporine-like amino acids (MAAs) in carpospores on Day 48. Low doses of UV-B radiation (36 and 72 J/m2) accelerated the growth of C. ocellatus. However, as the amount of UV-B radiation increased, the growth rate decreased and morphological changes occurred. UV-B radiation significant damaged DNA and photosynthetic pigments and induced three kind of MAAs, palythine, asterina-330, and shinorine. PAR conditions were best for repairing UV-B-induced damage. Darkness promoted the activity of the DNA dark- repair mechanism. Red light enhanced phycoerythrin synthesis but inhibited light repair of DNA. Although blue light, increased the activity of DNA photolyase, greatly improving remediation efficiency, the growth and development of C. ocellatus earpospores were slower than in other light treatments. 展开更多
关键词 Chondrus ocellatus Holm UV-B radiation blue light red light REPAIR
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Wind-induced Damage in Two Regions of Argentina
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作者 Bruno Natalini Jorge Lassig +1 位作者 Mario Bruno Natalini Claudia Palese 《Journal of Civil Engineering and Architecture》 2012年第2期166-173,共8页
Information on wind-induced damage to civil structures in Argentina is scarce. In this paper, general trends regarding both meteorological conditions and patterns of damage when damage occurred in two regions of Argen... Information on wind-induced damage to civil structures in Argentina is scarce. In this paper, general trends regarding both meteorological conditions and patterns of damage when damage occurred in two regions of Argentina are presented. The regions under study were the north-east of Argentina (NEA) and the north-Patagonia. This research is based on a collection of data comprising field surveys conducted after the passage of destructive storms, NCEP/NCAR Reanalysis, a Global Data Assimilation System model and other secondary sources like emergency services, local press, local councils and the National Weather Service. It is shown that both regions have similar problems of vulnerability, even though they have different meteorological environments. Topics that must be addressed to reduce the vulnerability of civil structures have been identified. 展开更多
关键词 WIND DAMAGE BUILDINGS field survey reanalysis.
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关节镜下腓骨长肌腱保留残端重建前交叉韧带的效果
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作者 王雪臣 魏威 +1 位作者 王力兴 史福东 《中文科技期刊数据库(全文版)医药卫生》 2022年第5期22-25,共4页
在重建前交叉韧带(Anterior Cruciate Ligament,ACL)采取关节镜下腓骨长肌腱保留,分析其效果。方法:44例研究对象为唐山市人民医院骨三科2018年9月-2020年12月期间收治的44例关节镜下重建ACL治疗患者。分组方法为双盲法,其中参考组接受... 在重建前交叉韧带(Anterior Cruciate Ligament,ACL)采取关节镜下腓骨长肌腱保留,分析其效果。方法:44例研究对象为唐山市人民医院骨三科2018年9月-2020年12月期间收治的44例关节镜下重建ACL治疗患者。分组方法为双盲法,其中参考组接受清除残端后施行重建ACL(22例)。实验组则施行腓骨长肌腱保留残端ACL治疗(22例)。以膝关节韧带损伤条件特异性评分、膝关节主观症状评分、ACL强度评定(膝关节稳定度测试仪)指标以及本体感觉功能评价患者的治疗效果。 结果:治疗前膝关节韧带损伤条件特异性评分对比中,两组差异较小不符合统计学含义(P>0.05)。实验组治疗3个月、6个月、9个月以及12个月后,其膝关节韧带损伤条件特异性评分相比较参考组要高(P<0.05)。治疗前膝关节主观症状评分对比中,两组差异较小不符合统计学含义(P>0.05)。实验组治疗3个月、6个月、9个月以及12个月后,其膝关节主观症状评分相比较参考组要高(P<0.05)。两组治疗后3、6、9、12个月ACL强度评定指标对比分析,可见实验组较低(P<0.05)。两组治疗后3、6、9、12个月对比可见,实验组较高(P<0.05)。 结论:在重建ACL采取关节镜下腓骨长肌腱保留的效果确切,值得在临床上应用。 展开更多
关键词 关节镜 下腓骨长肌腱 保留残端 重建前交叉韧带 膝关节韧带损伤条件特异性评分 膝关节主观症状评分 前交叉韧带强度 本体感觉功能
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Protective effect of astrocyte-conditioned medium on neurons following hypoxia and mechanical injury 被引量:2
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作者 YAN Ji-wen TAN Tong-yan HUANG Qi-lin 《Chinese Journal of Traumatology》 CAS CSCD 2013年第1期3-9,共7页
Objective: To investigate the protective effect of mouse astrocyte-conditioned medium (ACM) on hypoxic and mechanically injured neurons by a cell model in vitro, and to explore the possible mechanism. Methods: Th... Objective: To investigate the protective effect of mouse astrocyte-conditioned medium (ACM) on hypoxic and mechanically injured neurons by a cell model in vitro, and to explore the possible mechanism. Methods: The model of hypoxic neuronal injury was caused by 3% 02 in three-gas incubator. Neurons were cultured with ordinary medium or 20% ACM respectively and randomly divided into hypoxic group (hypoxia for 4, 8, 24 h and marked as H4R0, H8R0, H24R0) and hypoxia reoxygenation group (H4R24, H8R24, H24R24). Mechanical injury model was developed by scratching neurons cultured in 20% ACM or ordinary medium to different degrees. Neu- rons in both medium were divided into normal control group, mild, moderate and severe injury groups. The 20% ACM was added 24 h before hypoxia/reoxygenation or mechanical injury. The morphology and survival of neurons were observed and counted by trypan blue staining. The concentration of NO, lactic dehydrogenase (LDH) and membrane ATPase activity were detected by corresponding kits. Results: It was showed that 20% ACM can obviously promote the survival rate of hypoxia/reoxygenated neurons and scratched neurons as well. The morphology and num- ber of neurons exposed to hypoxia or scratch injury showed great difference between groups with or without ACM treatment. Compared with control group, the concentration of NO and LDH was much lower in hypoxic/reoxygenated neurons treated with 20% ACM, and the ATPase activity was higher. For the mechanical injury model, neurons with moderate injury also revealed a lower NO and LDH concen- tration than the control group. All the differences were sta- tistically significant (P〈0.05). Conclusion: ACM can promote the survival and func- tional recovery of neurons following hypoxia or scratching to a certain degree. The mechanism may be associated with reducing the synthesis and release of NO and LDH as well as increasing the activity of membrane ATPase. 展开更多
关键词 Glial cell line-derived neurotrophic factor NEURONS Cell hypoxia
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Continuum damage mechanics for sintered powder metals
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作者 YUAN Huang MA SongYun ZHANG Long 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2015年第1期95-106,共12页
Sintered metals are characterized by the high porosity(8%)and voids/micro-cracks in microns.Inelastic behavior of the materials is coupled with micro-crack propagation and coalescence of open voids.In the present work... Sintered metals are characterized by the high porosity(8%)and voids/micro-cracks in microns.Inelastic behavior of the materials is coupled with micro-crack propagation and coalescence of open voids.In the present work the damage evolution of the sintered iron under multi-axial monotonic loading conditions was investigated experimentally and computationally.The tests indicated that damage of the sintered iron initiated already at a stress level much lower than the macroscopic yield stress.The damage process can be divided into the stress-dominated elastic damage and the plastic damage described by the plastic strain.Based on the uniaxial tensile tests an elastic-plastic continuum damage model was developed which predicts both elastic damage and plastic damage in the sintered iron under general multi-axial monotonic loading conditions.Computational predictions agree with experiments with different multi-axial loading paths.A phenomenological continuum damage model for the sintered metal is developed based on the experimental observations to predict the inelastic behavior and damage process to failure under multi-axial loading conditions.The proposed damage model is experimentally verified under different loading conditions. 展开更多
关键词 sintered metal porous material damage evolution multi-axial damage continuum damage model
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