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1.
目的 设计气 液交界式浴槽,并用于探讨海马脑片H2O2损伤的机制.方法 气 液交界式浴槽包括内室和外室.内室的主要结构为嵌入体,用于放置海马脑片.外室的主要作用是为海马脑片提供足够的氧气.另外用生化、形态学、电生理的方法来验证浴槽的可行性.最后观察H2O2对海马脑片群峰电位的影响.结果 浴槽能够长时间(1～8h)的维持海马脑片活性.H2O2能够浓度依赖性损伤海马脑片,同时NMDA受体阻断剂氯胺酮对H2O2诱导的海马脑片损伤具有明显的保护作用.结论 浴槽可以适用于生化和形态学以及电生理等研究,并发现海马脑片H2O2损伤至少部分是通过NMDA受体发挥作用的. 相似文献
2.
目的探讨小肠缺血再灌注后不同时限小肠黏膜中增殖细胞核抗原(PCNA)的动态变化。方法选用健康雄性SD大鼠,建立小肠缺血再灌注损伤模型。每组大鼠根据缺血再灌注后不同时限,分为对照组、缺血再灌注后0min,30min,1h,2h,6h,12h,24h,48h,72h共10组(每组6只)。在缺血再灌注后不同时间点,采用HE染色观察小肠黏膜组织学形态,TUNEL染色、免疫组织化学方法检测PCNA的表达。结果①大鼠小肠历经热缺血40min后,再灌注0～72h大致经历了潜伏期、急性期、交错期、恢复期4个阶段的形态变化。缺血再灌注后,出现明显的细胞凋亡及组织学病理改变,开始于潜伏期,加重于急性期。②与对照组相比,PCNA在缺血再灌注组表达增强(P0.05)。结论①小肠在短时间缺血后,再灌注可出现明显的细胞凋亡及组织学病理改变。大多数小肠黏膜细胞经历短暂的凋亡前期反应后则进入恢复阶段,最终结果是小肠黏膜结构和功能的修复。②PCNA参与了小肠缺血再灌注损伤的病理生理过程,可作为动态监测机体缺血再灌注损伤中细胞凋亡与增殖的有效指标。 相似文献
3.
目的:研究JAK2/STAT3通路在加味丹参饮预处理中对大鼠心肌细胞再灌注损伤的调控作用,从信号转导水平探讨加味丹参饮对梗死大鼠心肌的保护机制。方法:1.取各组大鼠各三只以Evans-bule,TTC双染色法染色心肌,测定心肌梗死面积。2.石蜡包埋,切片,在光镜行细胞心态学观察。3.取各组大鼠各三只Western blot测定各组心肌细胞JAK2、STAT3蛋白的表达。最后应用SPSS 17.0 for Windows统计软件将实验结果进行统计学处理。多组比较采用单因素方差分析,p0.05认为有统计学意义。结果:1.I/R组ST段向上抬高约0.75(心电图背景的一竖格记为1)。加味丹参饮预处理组,ST抬高为0.50,下降了约33.3%。2.JDD组比I/R组梗死面积减少11%。3.加味丹参饮预处理组病理改变较I/R轻。4.I/R组的灰度值低于其他4组,有显著差异(p0.05)。JDD组JAK2、STAT3表达与I/R组比较,有明显的差异(P0.05),JDD+AG490组,JDD+RPM组的STAT3灰度值明显低于IPC组,有显著性差异(P0.05)。JDD+RPM组的JAK2灰度值低于其他组,有显著性差异(P0.05)。结论:在心肌梗死再灌注后存在缺血再灌注损伤,加味丹参饮预处理能有效对抗这种损伤,减轻心肌缺血再灌注损伤,降低心电图抬高的ST段,改变心肌细胞的病理形态学,其机制与JAK/STAT转导通路的干预有关,在JAK2/STAT3通路中,JAK2对STAT3有调控作用,而stat3对JAK2的表达同样有反馈作用。他们共同在缺血再灌注损伤中起到保护缺血心肌的作用。加味丹参饮预处理通过激活JAK/STAT转导通路,参与心肌细胞凋亡的保护。 相似文献
4.
目的:观察卵巢摘除对缺血再灌注大鼠脑组织BDNF表达的影响以及中医学益肾方剂左归丸的干预作用,探索中医学"肾脑相关"理论的物质基础。方法:采用卵巢摘除法建立雌激素缺失模型;线栓法建立大鼠大脑中动脉阻塞(MCAO)模型;免疫组织化学法检测BDNF表达。结果:脑缺血再灌注后BDNF表达增加。卵巢摘除可下调BDNF表达。左归丸干预后BDNF表达上调。结论:脑缺血再灌注后BDNF表达增加可能是机体的一种保护性反应。性激素剥夺可下调缺血后大鼠脑组织BDNF表达,左归丸干预可使BDNF表达上调。提示补肾中药左归丸可能有类雌激素样作用,并有可能通过上调BDNF表达促进缺血后脑损伤的恢复。 相似文献
5.
目的探讨阿托伐他汀钙对大鼠脑缺血再灌后脑组织中NF-kBp56及蛋白表达的影响。方法采用大脑中动脉线栓法制备局灶性脑缺血再灌注模型,参考onga的5分制法在大鼠麻醉清醒后进行评分。应用原位杂交和免疫化法检测NF-kBp56mRNA及蛋白表达。结果大鼠及缺血再灌注后缺血组织中NF-kBp56mRNA和蛋白表达增加（P＜0.01）.24h达高峰。给予阿托伐他汀钙干预后能减少缺血脑组织中NF-kBp56mRNA和蛋白表达（P＜0.05）,降低神经功能缺损评分（P＜0.05）。结论 阿托伐他汀钙能抑制大鼠及缺血再灌注后脑组织中NF-kBp56mRNA及蛋白表达。减轻缺血再灌损伤。 相似文献
6.
[目的]研究促红细胞生成素对全脑缺血再灌注大鼠缺氧诱导因子1α和凋亡相关蛋白存活素的调节,探讨其抗凋亡的可能机制。[方法]将成年雄性SD大鼠75只按随机数字表法分为全脑缺血组（n=35）和全脑缺血EPO干预组（n=35）,然后按再灌注时间不同又分为6h、12h、24h、48h、72h、5d和7d七个亚组。采用改良的Pu刘lsineli 4-VO法制作全脑缺血大鼠模型。应用TUNEL染色检测再灌注后不同时间点海马CA1区的神经元凋亡水平,免疫组织化学方法检测再灌注后不同时间点海马CA1区缺氧诱导因子1α和存活素表达水平的变化。[结果]全脑缺血EPO干预组24h至7d亚组TUNEL阳性神经元计数分别为1.50±0.73、3.14±0.88、5.78±1.03、7.78±1.79、10.34±1.82.与全脑缺血组相应时间点亚组相比明显减少,差异均有统计学意义（P〈0.05）。全脑缺血EPO干预组48h至5d亚组HIF-1α表达阳性细胞计数分别为11.26±0.02、20.28±2.03、3.33±0.04,与全脑缺血组相应时间点亚组相比明显减少,差异均有统计学意义（P〈0.05）.全脑缺血EPO干预组24h至5d亚组survivin蛋白表达阳性细胞计数分别为12.21±1.04、16.34±4.02、24.33±3.03、30.52±5.04,与全脑缺血组相应时间点亚组相比明显增高,差异均有统计学意义（P〈0.05）。[结论]在全脑缺血急性期,EPO抑制HIF-1α的表达而使存活素表达升高,具有一定的神经保护作用. 相似文献
7.
目的:应用肝硬化模型研究大鼠肝脏功能、血氨水平变化,并通过脑皮质厚度改变来探讨氨在慢性肝性脑病时脑组织病理改变发生中的作用。方法:应用四氯化碳制备肝硬化动物模型,检测肝硬化组与正常对照组血氨、肝功能水平;应用计算机扫描技术对16只肝硬化模型的大鼠和9只正常大鼠的大脑皮层的厚度进行了计算,用统计学方法比较二者之间的差异。结果:30只大鼠进行肝硬化动物模型制备,14只死亡;16只存活大鼠肝组织经HE染色在普通光镜下观察100%发生有硬化;肝硬化动物模型肝功改变明显,血氨增高155.74±12.70;肝硬化动物模型的血氨(231.80±24.17μmmol/L)明显高于正常大鼠(49.25±8.88μmmol/L)。在肝硬化动物模型中,大脑皮质的厚度(215.03±14.94μm)比正常大鼠大脑皮质明显变薄(248.35±19.82μm),p<0.01。结论:氨可能诱发肝硬化大鼠脑发生形态变化,进一步肯定了氨在肝硬化肝性脑病发生中的作用以及其作用机制。 相似文献
8.
一氧化氮合酶抑制剂对大鼠缺氧缺血性脑损伤神经元凋亡的影响 总被引：1，自引：0，他引：1
目的研究神经元凋亡在大鼠缺氧缺血性脑损伤（HIBD）中的地位及作用。并探讨选择性一氧化氮合酶抑制剂-7-硝基-吲唑（7-NI）对大鼠HIBD时神经元凋亡的影响。方法24h时用HE染色、TUNEL法、透射电镜观察和检测神经元凋亡并评估7-NI对神经元凋亡的影响。结果HIBD后24h在海马、皮质等处检测到神经元凋亡。7-NI使海马及皮质部位的神经元凋亡数显著降低。结论神经元凋亡参与了HIBD后神经元迟发性死亡。7NI有显著的抗HIBD后神经元凋亡的作用。 相似文献
9.
《黑龙江科技信息》2017,(32)
目的:观察模型组中家兔胆管缺血再灌注损伤中Toll样受体4(TLR4)的表达,探讨TLR4的激活与胆管缺血再灌注损伤之间的相关性。方法:建立家兔胆管缺血再灌注模型,假手术组仅解剖肝门部,不进行缺血及再灌注,模型组各组缺血时间均为1h,再灌注时间点分别为0、6、12、18、24h,在各时间点取缺血肝脏组织,光镜及电镜观察胆管损伤情况,检测静脉血中总胆红素(TBIL)、谷氨酰转肽酶(GGT)、碱性磷酸酶(AKP)指标的变化,免疫组化分析TLR4在胆管上皮细胞上的表达,进行统计学分析。结果:模型组在不同再灌注时间点,胆管上皮细胞内可见有TLR4表达,阳性细胞数分别为假手术组(9 2)个,缺血再灌注0、6、12、18、24 h组为(27 8)、(51 2)、(99 8)、(35 5)、(17 3)个,模型组各组与假手术组比较,差异有统计学意义(P0.05);TBIL、GGT、AKP指标随再灌注时间延长而逐渐升高,12h达高峰[分别为TBIL:(5.95 1.81)μmol/L;GGT:(95.86 16.80)IU/L;AKP:(3.27 0.61)IU/L]后逐渐下降,模型组较假手术组变化明显,差异均有统计学意义(P0.05)。结论:TLR4的激活参与了家兔胆管缺血再灌注损伤的过程;承受1 h以内的缺血再灌注损伤后的肝细胞、胆管上皮以细胞肿胀、线粒体肿胀等可逆性损伤为主;TBIL、GGT、AKP可作为监测胆管缺血再灌注损伤的指标。 相似文献
10.
目的在开放式压力控制培养系统作用下体外培养大鼠视网膜神经细胞（retinal neurons,RNs）,观察米诺环素对其活性及凋亡的影响．并进—步探讨其对受损RNs保护的可能机制．方法采用出生0-3d的Sprague Dawlev（SD）大鼠视网膜神经细胞体外混合培养。制备RNs加压培养模型．通过细胞形态学观察,四唑盐（MTT）比色法测定细胞活力,吖啶橙／溴化乙锭（AO／EB）染色法检测细胞的凋亡率来观察米诺环素对上述损伤细胞的保护及治疗作用．以及应用免疫细胞化学染色法。观察诱导型一氧化氮台酶（iNOS}和半胱天冬酶-3,（caspase-3）表达的改变、结果 加压培养后,在倒置显微镜下RNs与对照组相比形态改变较咀.细胞活力降低,大量细胞发生凋亡（占53.93％）.而米诺环素治疗组（20μmol／L）细胞则形态改善．活力显著增高：凋亡数目减少（占17．29％）．差异具有显著性（P〈0.0051）。免疫细胞化学染色法示米诺环素治疗组细胞内NOS和caspase-3表达较加压损伤组减少。结论 一定剂量的米潜环素在体外可有效抑制蓝力。引起的大鼠视网膜神经细胞损伤及凋亡。抑制NOS和capase-3的表达可能是其潜在作用机制。 相似文献
11.
Marjorie Armstrong-Stassen Margaret Landstrom Ramona Lumpkin 《The Information Society》1998,14(2):153-164
This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors. 相似文献
12.
A joint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology his co-workers from Norway US Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells suggesting that China's projected climate warming could decrease the pest's numbers. The study was published in Proceedings of the National Academy of Sciences on September .…… 《中国科学院院刊(英文版)》2008,22(1):6-7
Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007. 相似文献
13.
Caroline Haythornthwaite 《The Information Society》2001,17(3):211-226
A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction. 相似文献
14.
A research group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol-a chemical found in the skins of red grapes in red wine-can improve the sensitivity of mice to the hormone insulin according to a report in the October issue of Cell Metabolism.…… 《中国科学院院刊(英文版)》2008,22(1):14-15
Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said. 相似文献
15.
Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies. 相似文献
16.
Puay Tang 《The Information Society》1998,14(1):19-31
The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means. 相似文献
17.
Milton Mueller 《The Information Society》2001,17(3):151-163
Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP. 相似文献
18.
Prof. Raymond C.K. Chen a neuropsychologist with the CAS Institute of Psychology has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.…… 《中国科学院院刊(英文版)》2008,22(1):15-15
Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology. 相似文献
19.
Active biological molecules functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery disease diagnosis therapy new nanodevice construction.…… 《中国科学院院刊(英文版)》2008,22(1):22-22
Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction. 相似文献
20.
《中国科学院院刊(英文版)》2014,(3)
<正>In Xishuangbanna,one of China’s most biodiverse regions,landscape has changed dramatically during the past three decades due to the conversion of tropical rainforest to rubber plantations.In steep areas,terraces are often constructed before planting rubber trees,which causes two important changes in the soil:the destabilization of soil in the bench terraces and the increased vulnerability of unvegetated riser faces to erosion.Few studies have documented the nature and intensity of erosion on bench terraces.Prof.LIU Wenjie and his colleagues from the Xishuangbanna Tropical Botanical Garden(XTBG)conducted a study in Menglun County(21°5′39″N,101°15′55″E),Xishuangbanna to evaluate the influence 相似文献