810 research outputs found
PPARγ激动剂罗格列酮对大鼠心肌缺血-再灌注心律失常的影响
【目的】探讨PPARγ激动剂对大鼠心肌缺血-再灌注心律失常的影响及相关机制。【方法】将雄性SD大鼠60只随机分成假手术(Sham)组、缺血再灌注(I/R)组、缺血再灌注+罗格列酮(I/R+Ros)组、缺血再灌注+罗格列酮+缓激肽B2受体拮抗剂HOE140(I/R+Ros+HOE140)组,每组15只。麻醉大鼠后,结扎大鼠冠状动脉前降支根部30min,再灌注40min,观察缺血再灌注前后心律失常发生情况,检测肌组织丙二醛(MDA)、超氧化物歧化酶(SOD)、总一氧化氮合酶(tNOS)、还原型一氧化氮合酶(eNOS)、诱导型一氧化氮合酶(iNOS)和一氧化氮(N0)水平。【结果】罗格列酮预处理组的大鼠恶性室性心律失常的发生时间(13min),持续时间(14.37s),室性早搏的发生次数(47次)和心律失常评分等指标均得到改善(P〈0.05);提前应用Hoe140可部分或全部阻断缺血一再灌注时罗格列酮的抗心律失常作用(P〈0.05);I/R+Ros组与I/R组相比心肌组织eNOS、NO、和SOD活性水平明显提高,而iNOS活性和MDA水平显著下降(P〈0.051;HOE140可阻断此作用(P〈0.05)。【结论】PPARγ激动剂罗格列酮有抗大鼠心肌缺血再灌注心律失常作用,这可能是通过缓激肽-一氧化氮途径实现的
Different roles of the left inferior prefrontal cortex in visual Chinese word recognition
目的利用事件相关功能磁共振成像(functionalMRI)技术比较中文双字真词与假词的认知加工的脑机制。方法14名大学生在MR扫描过程中执行词汇判断任务,用视觉方式随机呈现120个双字词,其中真、假词各60个。结果真、假词的判断激活了相似的包括双侧额下回,颞中回,梭状回和舌回,双侧缘上回,丘脑等区域。其中,左侧额下回(BA4
Comparative study on the adhesive capabilities of sodium alginate and guar gum as bone adhesives
目的比较研究海藻酸钠和瓜儿胶作为骨骼黏合材料的黏合性能。方法通过测定两种胶体的动力黏度、固化时间和对钙离子的作用,探讨相应的黏合性能。结果瓜儿胶的黏度较高,能适应多种形式的补钙剂,但其固化性能还有待改进;海藻酸钠固化性能优越,能在瞬间完成固化,但其黏度比瓜儿胶低,只能适应非离子钙型的补钙剂。结论海藻酸钠和瓜儿胶都是较有潜力的天然骨骼黏合剂。
【英文摘要】 Objective To comparatively investigate the adhesive capabilities of sodium alginate and guar gum as bone adhesives.Methods The adhesive capabilities were analysed and discussed by measuring their kinetic viscosities,solidification time and the reaction with calcium ions.Results Guar gum had higher kinetic viscosity and could fit to the supply of both ion calcium and non-ion calcium for the bone cure,but its capability of solidification need to be improved.Sodium alginate had higher solubility and its solidi...卫生部科学研究基金-福建省卫生教育联合攻关计划项目(No.WKJ2005-2-018
Rat glioma C6 cell apoptosis induced by UV radiation via p38-MAPK
目的 :探讨 p38MAPK在紫外线损伤刺激细胞中的特异性信号转导作用 .方法 :流式细胞仪检测紫外线照射 30min后 1,2及 4h的C6细胞周期变化和是否有凋亡发生 ;应用免疫细胞化学技术观察紫外线刺激前后 p38MAPK在C6细胞中的表达强度和分布特征 .结果 :细胞周期结果显示 1,2和 4h后G1期细胞数分数各增多 0 .12 ,0 .2 1和 0 .19,而S期细胞数分数减少 0 .10 ,0 .14和 0 .15 ;各组的凋亡率分别是12 % ,4 9%和 34% ;未受刺激的细胞中 ,p38MAPK在胞质和胞核表达较弱 ;紫外线损伤作用 2h后 ,细胞核区的染色强度即明显增强 ,而胞质区域的染色强度相对降低 .结论 :C6细胞受紫外线损伤后可通过 p38MAPK通路发生凋亡.
【英文摘要】 AIM: To study the signal transduction of p38 mitogen activated protein kinase in rat glioma C6 cells after the stimulation of UV radiation. METHODS: Flow cytometry was applied to measure the fraction number changes in the cell cycle phase and to detect whether UV could induce apoptosis of C6 cells. The level and distribution of p38MAPK expression was examined by immunocytochemical method both before and after the UV radiation. RESULTS: Flow cytometry indicated that the numbers of G1 phase fraction of 1,...高等学校骨干教师计划资助 ;; 留学归国人员科研启动基金([1 999] 747号
A STUDY ON NANO-HYDROXYAPATITE-CHITOSAN SCAFFOLD FOR BONE TISSUE ENGINEERING
作者单位: 1 中国医学科学院中国协和医科大学生物医学工程研究所天津市生物医学材料重点实验室( 天津, 300192 ) ; 2 厦门大学生物医学工
程研究中心厦门大学医学院厦门市生物医学工程技术研究中心
通讯作者: 张其清, 教授, 博士导师, 研究方向: 组织引导再生, E-mail: zhangqiq@ xmu . edu. cn[中文文摘]目的以一种简单、有效的方法制备多孔的纳米羟基磷灰石(nano hydroxyapatite,nano-HA)-壳聚糖(chitosan,CS)复合支架,并评价其理化性能及与细胞相容性。方法采用原位复合-冷冻干燥方法,制备多孔nano-HA-CS支架。通过扫描电镜、透射电镜、X线衍射和傅立叶红外光谱分析支架的微观形貌及材料的组成。分离初生Wistar大鼠的成骨细胞,取传代培养第3代细胞分别与nano-HA-CS支架和纯CS支架共培养2、4、6、8h,各时间点各取4个样品,测定细胞在支架上的黏附率,并通过组织化学染色、扫描电镜观察细胞形态。结果nano-HA-CS复合支架具有多孔结构,孔径为100~500μm,大多数孔径为400~500μm。具有很高的孔隙率,随CS和HA含量的增加,孔隙率明显降低,密度升高。扫描电镜和透射电镜观察显示合成的HA晶体,晶粒大小为纳米级,在支架孔壁上均匀、连续分布如“铺路石”样。X线衍射和红外光谱分析表明合成的HA是含CO32-弱结晶纳米晶体。细胞相容性实验显示,成骨细胞在支架上黏附、增殖,并分泌纤维状细胞外基质;在复合支架上的黏附率明显高于纯CS支架。结论采用原位复合与冷冻干燥法结合制备的nano-HA-CS复合支架具有良好的理化性质和细胞相容性,有望应用于组织工程骨的构建。[英文文摘] Objective To fabricate a nano-hydroxyapatite-chitosan (nano-HA-CS) scaffold with high porosity by a simple and effective technique and to evaluate the physical and chemical properties and the cytocompatibility of the composite scaffold. Methods The three-dimensional nano-HA-CS scaffolds with high porosity were prepared by the in situ hybridization-freeze-drying method. The microscopic morphology and components of the composite scaffolds were analyzed by the scanning electron microscopy (SEM), the transmission electron microscopy(TEM), the X-ray diffraction(XRD)examination, and the Fourier transformed infrared spectroscopy(FTIR). The calvarial osteoblasts were isolated from the neonatal Wistar rats. The serial subcultured cells (3rd passage) were respectively seeded onto the nano-HA-CS scaffold and the CS scaffold, and then were co-cultured for 2, 4, 6 and 8 hours. At each time point, four specimens from each matrix were taken to determine the cell-adhesion rate. The cell morphology was observed by the histological staining and SEM. Results The macroporous nano-HA-CS scaffolds had a feature of high porosity with a pore diameter from 100 to 500 μm (mostly 400-500 μm). The scaffolds had a high interval porosity; however, the interval porosity was obviously decreased and the scaffold density was increased with an increase in the contents of CS and HA. The SEM and TEM results showed that the nano-sized HA was synthesized and was distributed on the pore walls homogeneously and continuously. The XRD and FTIR results showed that the HA crystals were carbonate-substituded and not well-crystallized. The cytocompatibility test showed that the seeded osteoblasts could adhere the scaffolds, proliferating and producing the extracellular matrix on the scaffolds. The adherence rate for the nano-HA-CS scaffolds was obviously higher than that for the pure CS scaffolds. Conclusion The nano-HA-CS scaffolds fabricated by the in situ hybridization-freeze-drying method have a good physical and chemical properties and a good cytocompatibility; therefore, this kind of scaffolds may be successfully used in the bone tissue engineering.天津市科技攻关项目资助项目(05YFGZGX03800
原位心脏移植(7例报告)
【目的】总结7例心脏移植经验,探讨心脏移植的近远期疗效。【方法】1998年10月至2005年4月施行7例原位心脏移植,7例均为心肌病,其中5例为扩张型,2例为限制型,手术方法采用标准法4例、双腔静脉法3例,供心平均冷缺血时间为(167.4±22.1)min,术后定期行心内膜活检,使用四联免疫抑制剂。【结果】第1例存活5d,死于低心排及主动脉内球囊反搏(IABP)的并发症,第4例存活18月,死于中一重度的急、慢性并存的排斥反应,余5例至今存活,至今存活时间分别为6年9个月、5年6个月、1年7个月、10个月、3个月。【结论】心脏移植是治疗终末期心脏病的有效手段,处理好术后并发症,密切监测和处理排斥反应,能取得良好的近远期疗效,长期生存病例需特别注意慢性排斥反应的发生
Mechanism and kinetics of cellobiose hydrogenation catalyzed by Ru/CNT
联系人及第一作者: 谭雪松( 1985- ),男, 硕士, 助理研究员。[中文文摘]引言化石资源的日益枯竭,使得人们对从可再生生物质资源合成化学品和燃料的研究给予了广泛关注[1-2]。木质纤维素是地球上分布最广、产量最多的生物质资源之一。纤维素由葡萄糖通过β-1,4糖苷键连接而成,其分子的刚性结构和高度结晶性使其成为最难转化的多糖[3]。目前通过高温气化或热解转化纤维素为合成气等燃料的工艺过程已经建立[4]。但在温和条件下通过平台分子继而生成油品或化学品的过程还有待开发。山梨醇是纤维素转化中有价值的平台分子之一,可以在较温和条件下通过水汽重整和费托合成等方法合成烷烃燃油和化学品[5-6]。因而,对纤维素催化加氢制备山梨醇的研究将有助于纤维素的有效利用。Fukuoka等[7]报道了在水相体系下,铂/氧化铝催化剂催化纤维素加氢制备山梨醇的反应,在190℃反应24h,山梨醇的收率为25%。Liu等[8]利用高温水形成的独特酸性质,以钌/活性炭为催化剂,245℃反应得到山梨醇,收率为30%。Deng等[9]利用碳纳米管优异的氢吸脱附与溢流性质,以Ru/CNT为催化剂,在185℃反应24h,山梨醇收率达到36%。虽然在催化纤维素加氢制山梨醇的研究方面已取得一定成果,但山梨醇收率不高(<40%),高效催化体系
依旧缺乏, 开展相关基础研究仍十分必要。纤维二
糖是纤维素的次级结构单元, 由两个葡萄糖通过
β-1,4糖苷键连接而成。由于纤维二糖结构与纤维
素类似, 且易于溶解, 故可用于研究纤维素转化的
模型分子[ 10-11] 。
本研究考察了以Ru/ CNT 为催化剂, 水相条
件下催化纤维二糖加氢制备山梨醇的反应。推导了
纤维二糖转化反应机理, 建立了纤维二糖催化加氢
反应的动力学模型, 可为纤维素的催化加氢研究提
供指导。[英文文摘]The production of chemicals or fuels from renewable biomass resources especially cellulose has attracted much attention because of the worldwide demand for less dependence on fossil resources.However,the direct utilization of cellulose is still a challenge because of its robust crystalline structure.Herein,the hydrogenation of cellobiose,a typical cellulose,over carbon nanotube supported ruthenium catalyst (Ru/CNT) was reported.The mechanism of cellobiose conversion was proposed and the kinetic equation was obtained. Based on the kinetic experiments carried out in the range 120- 185℃ under 5. 0 MPa H2 , the reaction rate constants and activation energies of each reaction step in cellobiose
hydrogenation were obtained with MATLAB, in which the activation energy for hydroly sis and
hydrogenolysis of cellobio se was est imated as 147.1 kJ·mol- 1 and 71.2 kJ·mol- 1, respectively. The
obtained kinetic model and some general rules on the catalyt ic hydrog enation of cellobio se may provide impo rtant data for eff icient ut ilization of cellulose.国家自然科学基金项目(20625310, 20773099,20873110
Promotion of glioma C6 cells proliferation by overexpressed RGS16
目的 探讨 G蛋白调节子 16 (RGS16 )对大鼠胶质瘤C6细胞的生物学特性的影响 .方法 利用脂质体介导法将RGS16基因导入 C6细胞中 ,在倒置显微镜下观察细胞形态变化和贴壁情况 ;3H- Td R法检测 C6细胞在转染不同梯度p CMV5 - RGS16和 p CMV 5质粒后的增殖情况 ;免疫细胞化学法检测转染前后 RGS16蛋白的表达情况 ;流式细胞仪检测转染 p CMV5 - RGS16和 p CMV5质粒 36 h后细胞周期变化和细胞是否有凋亡发生 .结果 转染 p CMV5 - RGS16质粒 2 4 h后 30 %细胞贴壁性降低 ,突起收缩 ,细胞变圆 ;RGS16蛋白表达阳性 ;3H- Td R法检测显示 C6细胞增殖速度与转染p CMV5 - RGS16的量呈正相关 ;细胞周期结果显示 G1期细胞百分数减少 10 % ,而 S期细胞百分数增多 14 % ;未发现RGS16与凋亡有直接关系 .结论 RGS16可能促进 C6细胞的增殖 .
【英文摘要】 s: AIM To study the effect of RGS16 on the biological characteristics of glioma C6 cells. METHODS pCMV5 RGS16 was transfected into C6 cells by lipofectin. The morphological and adhesive changes of the cells were observed under an inverted microscope. Proliferation of C6 cells was measured by 3H thymidine ( 3H TdR) assay after gradient transfections of pCMV5 RGS16 and pCMV5. Expression of RGS16 was examined by immunocytochemical method both before and after the transfection. Flow cytometry ...高等学校骨干教师计划资
Regulation of Cell Cycle of Glioma C6 Cells by Regulator of G Protein Signaling 16
目的 探讨G蛋白调节子 16(RGS16)对胶质瘤C6细胞周期的影响。方法 利用脂质体介导法将RGS16基因导入C6细胞中 ,在倒置显微镜下观察细胞形态变化和贴壁生长情况 ;免疫细胞化学法检测转染前后RGS16蛋白的表达情况 ;流式细胞仪检测转染pCMV 5 RGS16和 pCMV 5质粒后每隔 12h后的细胞周期变化。 结果 转染pCMV 5 RGS16质粒 2 4h后 3 0 .0 %细胞贴壁性降低 ,突起收缩 ,细胞变圆 ,72h之后细胞又恢复正常 ;RGS16蛋白的表达呈时相性 ,3 6h时表达率最高 (阳性率为13 .0 % ) ,72h表达终止 ;C6细胞的各期细胞比例变化与RGS16蛋白表达对应 ,在 3 6h时G1期比例从转染前的 70 .5 %降低到60 .2 % ,S期比例从 2 0 .9%增加到 3 4.9% ;在 48h时G1期增加到 76.2 % ,S期减少到 11.4% ;72h各期恢复到正常比例。对照组细胞转染前后形态变化不明显 ,RGS16蛋白表达阴性 ,细胞周期变化不明显。结论 RGS16能促进C6细胞周期的运行
【英文摘要】 Objective To study the effect of regulator of G protein signaling 16(RGS16) on the cell cycle of glioma C6 cell.Methods pCMV5 RGS16 was transfected into C6 cells by lipofectin.The morphological and adhesive changes of the cells were observed under an inverted microscope.Expression of RGS16 was examined by immunocytochemical method both before and after the transfection.Flow Cytometry was adopted to measure the fraction number changes of the cell cycle phase every 12 h.Results 24 hours after the transfec..
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