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31.
IntroductionMagnesium alloys are called green-engineeringmaterial with great development potential becauseof its low density, high specific strength and stiff-ness, superior damping capacity, good electromag-netic shielding characteristics and good machinabil-ity[1]. However, the number of commercially avail-able magnesium alloys is still limited especially forapplication at elevated temperatures. The applica-tions of most common magnesium alloys such asAZ91 and AM60 with outstanding mechani… 相似文献
32.
采用病因模拟法建立小儿厌食症动物模型。方法 用鱼松、奶粉、黄豆粉、白糖、鸡蛋等市售食品按比例配制特制饲料喂养幼龄大鼠建立动物模型 ,观察对大鼠摄食量、体重及下丘脑和血浆八肽胆囊收缩素 ( CCK- 8)浓度的影响 ,同时对特制饲料与常规鼠饲料的主要营养成分进行对比。结果 模型大鼠日摄食量明显低于对照组 ,体重增长缓慢 ,下丘脑和血浆八肽胆囊收缩素水平显著升高。特制饲料多种矿物质及多种维生素含量低下。结论 该模型符合小儿厌食症的自然病因和主要临床表现 ,状态稳定 ,基本成功 相似文献
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目的 探讨炎前因子在过敏性紫癜免疫病理损伤中的作用。方法 采用双抗体夹心ELISA法和硝酸还原酶化学比色法分别检测过敏性紫癜 (SHP)患儿血清肿瘤坏死因子α(TNFα)、白细胞介素 6(IL 6)、白细胞介素 8(IL 8)和一氧化氮 (NO)的浓度。结果 SHP急性期血清 4种炎前因子水平明显高于正常对照组 (P <0 .0 5 )。肾型中活动性肾脏病和 (或 )肾功能不全组较其他组血清IL 6明显升高 (P <0 .0 1 )。恢复期TNF α、IL 8仍高于正常对照组 (P <0 .0 5 )。急性期 4种炎前因子间呈正相关关系。结论 血清 4种炎前因子水平与SHP的发生、发展有关。 相似文献
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目的 探讨白介素 (IL) 6、8、1 0在小儿肾脏病发病机制中的作用、相互关系及与细胞免疫的关系。方法 采用双抗体夹心ELISA法检测 65例肾小球疾病患儿血清IL 6、8、1 0水平 ,McAb A E法检测 54例患儿T细胞亚群。结果 各型肾小球疾病患儿血清IL 6水平降低 ,IL 8、1 0水平升高 ,CD4+细胞及CD4+/CD8+比值均降低 ,IL 1 0水平与CD4+细胞呈负相关 ,血清IL 6、8、1 0分别与尿蛋白定量无相关性。结论 在小儿肾脏病中 ,①血清IL 6水平降低 ,可能是继发性改变 ;②血清IL 8、1 0水平升高 ,参与了肾小球疾病的发生 ;③CD4+细胞、CD4+/CD8+比值降低 ,是肾小球疾病发病的主要原因 ;④血清IL 1 0水平升高 ,与CD4+细胞呈负相关 ,抑制细胞免疫 ,导致免疫功能紊乱。 相似文献
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A study of the response of chlorophyll-a biomass to a winter upwelling event off Western Iberia using SeaWiFS and in situ data 总被引:2,自引:0,他引:2
Observations of a winter upwelling event off Western Iberia shelf/slope in the area of influence of the Western Iberia Buoyant Plume (WIBP) were conducted in February 2000. Spatial patterns and time evolution of the chlorophyll-a (chl-a) biomass are analysed, based on in situ and satellite data. SeaWiFS-derived chl-a concentration L2 products were used to track the chlorophyll front and estimate its westward migration velocity (maximum up to 29 km day−1), as well as to characterize the frontal system and its evolution. A method associating the type of spectral signature of a pixel to the fraction of chlorophyll probed by SeaWiFS enabled the estimation of the chl-a biomass within error intervals. High chlorophyll concentrations (for wintertime) were observed over the shelf and slope, up to large distances to the coast. Due to the WIBP, a shallow Ekman layer developed, being nearly coincident with the stratified upper meters. The transport comprised westward advection and stretching of the plume, with little entrainment with the offshore deep mixed layer waters. The relative enlargement of the total area of the Inside-Front Zone (IFZ) during the upwelling event was roughly accompanied by the maintenance of the average biomass per unit of area, considering the water column up to depths of interest. This suggests that there was a net increase of chl-a biomass inside the water column associated with the IFZ, roughly proportional to the increase in the IFZ area. Retention of phytoplankton in the shallow stratified nutrient-rich waters of the WIBP was a key factor for this increase in chl-a biomass. 相似文献
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Objective To investigate the association between psychological stress and oxidative damage in TNM stage Ⅲ patients with poorly differentiated gastric adenecarcinoma (GA). Methods One hundred and six patients with newly diagnosed poorly differentiated GA were assessed using the Hamilton Depression Rating Scale (HAMD), Zung Self-rating Depression Scale (SDS), Zung Self-rating Anxiety Scale (SAS), Symptom Checklist 90 (SCL-90), activities of daily living (ADL) and other multiple-item qnestionnaires. Oxidative-stress-related parameters in serum and the expression of DNA repair genes were monitored during a pretreatment period. Results The patients were divided into depression and nondepression groups (Groups A and B, respectively) based on a HAMD score cutoff of 20. The mean SDS, SAS, SCL-90, ADL and passive coping scores were higher in Group A, whereas social support and quality of life were lower. Serum total antioxidant capacity, eatalase, superoxide dismutuse concentrations and anti-superoxide anion capacity (A-ASC) were significantly decreased in Group A, whereas serum malondialdehyde (MDA) and 8-hydroxy-deoxyguanosine (8-OHdG) levels were significantly increased. Pearson correlation analysis revealed that depression was pesitively correlated with MDA, SAS, SCL-90 and ADL, but negatively correlated with A-ASC. Furthermore, real-time PCR revealed that the expression levels of hOGG1 and APEX1 were increased in Group A. Conclusion Psychological stress might be related to impaired antioxidant system in patients with GA, and it presents the first evidence of the involvement of oxidative DNA damage in the pathogenesis of depression. 相似文献
39.
新一代8000车级超巴拿马汽车滚装船是可到访日本关键港口的最大汽车滚装船,具有少压载水、多装车量满载出港的优点。目前全球仅有英雄系列和新视野系列这2型8000车级超巴拿马汽车滚装船。从主尺度、总布置、航速与EEDI、支柱和跳板/坡道配置等主要方面阐述了这2型船,并比较了各自的优点。最后,指出了可针对航运公司的运营理念进一步优化开发8000车级超巴拿马汽车滚装船。 相似文献
40.
探讨细胞因子在 Graves′病发病中的作用。方法 利用高敏感固相增敏免疫分析方法 ( EASIA)测定了 36例 Graves′病伴甲亢患者 ,1 9例未治亚急性甲状腺炎和 2 8例正常人血清 IL- 6、IL- 8水平。结果 GD患者血清 IL- 6、IL- 8浓度高于正常人水平 ( P1<0 .0 5,P2 <0 .0 5)。 IL- 6升高的 GD患者占 2 2 .2 2 % ( 8/36)。 IL - 6水平与 IL- 8不相关 ( P >0 .0 5)。 IL - 6水平与 TGA、MCA和 TRAb不相关 ,与 T3 也不相关。此外 1 9例未治亚急性甲状腺炎 ( SAT)患者血清 IL - 6水平也高于正常人 ( P <0 .0 5)。结论 在 GD患者发病中存在 IL - 6、IL - 8系统的参与 相似文献