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Protective effect of L-arginine preconditioning on ischemia and reperfusion injury associated with rat small bowel transplantation

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World Journal of Gastroenterology 2005年第19期11卷 2994-2997页

作者： bincao NingLi YongWang Jie-ShouLi DepartmentofSurgery NanjingUniversityMedicalSchoolTheFirstAffiliatedHospitalofNanjingMedicalUniversityNanjing210029JiangsuProvinceChina DepartmentofSurgery NanjingUniversityMedicalSchoolNanjing210002JiangsuProvinceChina

AIM: To investigate the protective effect and possible mechanism of L-arginine preconditioning on ischemia and reperfusion injury associated with small bowel transplantation (SBT).METHODS: Male inbred Wistar rats weighting between 180 and 250 g were used as donors and recipients in thestudy. Heterotopic rat SBT was performed according to the techniques of Li and Wu. During the experiment, intestinal grafts were preserved in 4 ℃ Ringer's solution for 8 h before being transplanted. Animals were divided into three groups. In group 1, donors received intravenous L-arginine (50 mg/kg, 1 mL) injection 90 min before graft harvesting. However, donors in control group were given normal saline (NS) instead. In group 3, six rats were used as sham-operated control. Specimens were taken from intestinal grafts 15 min after reperfusion. Histological grading, tissue malondialdehyde (MDA) and myeloperoxidase (MPO) levels were assessed. The graft survival of each group was monitored daily until 14 d after transplantation. RESULTS: Levels of MDA and MPO in intestine of shamoperated rats were 2.0±0.22 mmol/g and 0.66±0.105 U/g. Eight hours of cold preservation followed by 15 min of reperfusion resulted in significant increases in tissue MDA and MPO levels. Pretreatment with L-arginine before graft harvesting resulted in lower enhancement of tissue levels of MDA and MPO and the differences were significant (4.71±1.02 mmol/g vs8.02±3.49 mmol/g, 1.03±0.095 U/g vs 1.53±0.068 U/g, P＜0.05). Besides, animals in L-arginine pretreated group had better histological structures and higher 2-wk graft survival rates comparing with that in NS treated group (3.3±0.52 vs6±0.1, 0/6 vs6/6, P＜0.05or 0.01).CONCLUSION: L-arginine preconditioning attenuates ischemia and reperfusion injury in the rat SBT model,which was due to antioxidant activities partially.

关键词： L-arginine Small bowel transplantation

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Involvement of extracellular signal-regulated kinase/mitogenactivated protein kinase pathway in multidrug resistance induced by HBx in hepatoma cell line

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World Journal of Gastroenterology 2004年第23期10卷 3522-3527页

作者： JianGuan Xiao-PingChen HongZhu Shun-FengLuo bincao LeiDing HepaticSurgeryCenter TongjiHospitalTongjiMedicalCollegeHuazhongUniversityofScienceandTechnologyWuhan430030HubeiProvinceChina

AIM: To investigate the molecular mechanism of the influence of HBx protein on multidrug resistance associated genes: multidrug resistance 1 (MDR-1), multidrug related protein (MRP-1), lung resistance related protein (LRP) in hepatoma cells and the potential role of extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) pathway in this ***: A cell model stably expressing the HBx protein was established by liposome-mediated transfection of HBx gene into HepG2 cell line. The expression of multidrug resistance associated genes and proteins was detected by RT-PCR and Western blot. AnnexinV-FITC/PI assay was used to confirm the multidrug resistance (MDR) phenotype of transfected cells by fluorescence cytometry (FACS). The ERK/MAPK pathway activation was measured by Western blot through comparing the ratio of phosphorylation of ERK/MAPK to total ERK/MAPK protein. After treated with the ERK/MAPK pathway inhibitor U0126, the HBx-expressing cells were harvested. Then RT-PCR, Western blot and FACS were used to analyze the alterations in the expression of multidrug resistance associated genes and the MDR phenotype after ***: Compared with the control group, the transfected cells showed a higher expression of MDR associated genes and proteins. Marked elevations in MDR-1 (64.3%), MRP-1 (87.5%) and LRP (90.8%) were observed in the transfected cells (P<0.05). RT-PCR revealed that the over-expression of MDR associated proteins was due to amplification of such genes (MDR1 2.9 fold, MRP1 1.67 fold, LRP1.95 fold).Furthermore, we found that the ERK/MAPK activity was remarkably high in the HBx-expressing cells. The activation of ERK/MAPK, as measured by the ratio of phosphorylated ERK bands normalized to the total ERK bands, was increased by 2.3-fold in HBx-transfected cells compared with cells transfected with the empty vector. After treated with the ERK/MAPK pathway inhibitor, the level of MDR associated genes and proteins in the tr

关键词：细胞外信号控制激酶有丝分裂蛋白质药剂抵抗力诱导作用 HBx 肝细胞癌癌细胞系统

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电子封装用硅铝合金镀金黑点分析

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电镀与涂饰 2023年第1期42卷 42-45页

作者：田阳杨洋唐勇刚吕滨草李枘高天乐成都四威高科技产业园有限公司四川成都611731

针对某硅铝合金微波组件表面镀金黑点问题,采用扫描电镜、能谱和金相显微镜分析了缺陷区域基材和镀层的微观形貌与元素组成。其原因是前处理后基材中弥散分布的硅颗粒脱落,附着于表面而难于除净,在电镀Au后才脱落,留下了坑洞。通过调整... 详细信息

针对某硅铝合金微波组件表面镀金黑点问题,采用扫描电镜、能谱和金相显微镜分析了缺陷区域基材和镀层的微观形貌与元素组成。其原因是前处理后基材中弥散分布的硅颗粒脱落,附着于表面而难于除净,在电镀Au后才脱落,留下了坑洞。通过调整粗化液组分和缩短粗化时间,延长超声清洗时间,问题得到解决。

关键词：电子封装微波组件硅铝合金电镀金黑点硅颗粒故障排除

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电子封装硅铝合金条纹分析及改进

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有色金属加工 2023年第1期52卷 44-47,52页

作者：田阳杨洋罗伟吕滨草唐勇刚成都四威高科技产业园有限公司四川成都611730

对微波T/R组件硅铝腔体出现的连续带状条纹现象,采用拉伸强度测试、金相、扫描电子显微镜及能谱对材料力学性能、微观组织等进行了分析试验。结果表明,条纹区域微观组织是由初晶硅相、α-Al相及部分杂质相聚集形成的细晶区,硅相平均尺... 详细信息

对微波T/R组件硅铝腔体出现的连续带状条纹现象,采用拉伸强度测试、金相、扫描电子显微镜及能谱对材料力学性能、微观组织等进行了分析试验。结果表明,条纹区域微观组织是由初晶硅相、α-Al相及部分杂质相聚集形成的细晶区,硅相平均尺寸较正常区域小。进一步分析了条纹产生的原因是,喷射沉积过程中因沉积盘导热率低使部分组织重新熔化,杂质相随液相扩散,形核质点增多,硅相在冷却过程中受其影响被细化形成带状的细晶区。根据原因制定了控制措施,通过改进沉积盘材质及结构以提高喷射沉积过程的散热效率,经验证措施有效。

关键词：硅铝合金电子封装条纹喷射沉积

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