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主要阐述空调水系统利用平衡阀调节系统阻力,保持系统水力稳定;利用软启动器实施水泵的平滑软启动;压差旁通阀的作用及选型安装;系统管道热膨胀等问题。  相似文献   
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项红军  赵佐庆  李纪鹏  张志培 《医学争鸣》2002,23(21):1974-1977
目的:研究大鼠小肠缺血再灌注后后血中一氧化氮(NO),超氧化物歧化酶(SOD)的浓度变化以及肺组织中Bax,Bcl-2的表达,探讨小肠缺血再灌注后对肺组织的损伤,方法:建立小肠缺血再灌注模型,分对照 ,再灌注后0,30min,1,2h,1,3,7d共8组,于各时点检测血中Bax,Bcl-2的表达情况。结果:大鼠小肠缺血再灌注后NO浓度0min明显升高,2h时降低,随后升高,7d时达高峰,SOD浓度0min明显下降,2h 时升高,随后下降,7d时达最低,Bax,Bcl-2免疫阳性细胞主要位于肺组织中血管内皮细胞和肺泡上皮细胞,再灌注0min,Bax,Bcl-2阳性细胞率增多,30min时Bax,Bcl-2阳性细胞率均升高分别为17.1%和78.1%,Bcl-2表达高于Bax,两者差别显著(P<0.01),2h时降低,其后升高,7d时阳性细胞率达高峰分别为94.1%和83.4%,Bax表达明显高于Bcl-2,两者差异显著(P<0.01)。结论:大鼠小肠缺血再灌注后可引起血中NO,SOD的浓度变化和Bax及Bcl-2阳性细胞在肺组织中的表达改变并可能引起肺组织细胞凋亡和损伤。  相似文献   
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组织多肽特异性抗原在原发性肝癌中的临床应用   总被引:2,自引:0,他引:2  
OBJECTIVE: To evaluate the clinical value of serum tissue polypeptide specific antigen (TPS) for primary hepatic cancer in comparison with alpha-fetoprotein (AFP). METHODS: TPS and AFP were measured by enzyme-linked immunosorbent assay (ELISA) in 85 patients with primary hepatic cancer, 19 with metastatic hepatic cancer, 35 with liver cirrhosis, 22 with chronic hepatitis and 50 healthy control subjects. RESULTS: Serum AFP levels were elevated in patients with hepatocellular carcinoma in comparison with that in cholangiocarcinoma patients (P=0.037), but the difference was not significant (P=0.737). Serum TPS levels were significantly correlated with the tumor size (P=0.001), but not with the number of the tumors, portal invasion, extrahepatic metastasis, clinical stage or histological differentiation (P>0.05). A significant correlation was observed between AFP level and tumor size (P=0.028), portal invasion(P=0.005), and histological differentiation (P=0.000). CONCLUSION: TPS alone offers no more clues than AFP for the diagnosis of primary hepatic cancer, though it can be helpful for the diagnosis of cholangiocarcinoma. It has only limited clinical utility as a marker for primary hepatic cancer.  相似文献   
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Background: Preconditioning the brain with relatively safe drugs seems to be a viable option to reduce ischemic brain injury. The authors and others have shown that the volatile anesthetic isoflurane can precondition the brain against ischemia. Here, the authors determine whether isoflurane preconditioning improves long-term neurologic outcome after brain ischemia.

Methods: Six-day-old rats were exposed to 1.5% isoflurane for 30 min at 24 h before the brain hypoxia-ischemia that was induced by left common carotid arterial ligation and then exposure to 8% oxygen for 2 h. The neuropathology, motor coordination, and learning and memory functions were assayed 1 month after the brain ischemia. Western analysis was performed to quantify the expression of the heat shock protein 70, Bcl-2, and survivin 24 h after isoflurane exposure.

Results: The mortality was 45% after brain hypoxia-ischemia. Isoflurane preconditioning did not affect this mortality. However, isoflurane preconditioning attenuated ischemia-induced loss of neurons and brain tissues, such as cerebral cortex and hippocampus in the survivors. Isoflurane also improved the motor coordination of rats at 1 month after ischemia. The learning and memory functions as measured by performance of Y-maze and social recognition tasks in the survivors were not affected by the brain hypoxia-ischemia or isoflurane preconditioning. The expression of Bcl-2, a well-known antiapoptotic protein, in the hippocampus is increased after isoflurane exposure. This increase was reduced by the inhibitors of inducible nitric oxide synthase. Inducible nitric oxide synthase inhibition also abolished isoflurane preconditioning-induced neuroprotection.  相似文献   

7.
BACKGROUND: Personality traits are associated with substance dependence (SD); genetic factors may influence both. Strong associations between ADH4 variation and SD have been reported. We aimed to investigate the relationship between ADH4 variation and personality traits in the present study. METHODS: We assessed dimensions of the five-factor model of personality in 243 subjects with SD (175 European Americans [EAs] and 68 African Americans [AAs]) and 296 healthy control subjects (256 EAs and 40 AAs). We also genotyped 7 ADH4 markers (spanning the locus) and 38 unlinked ancestry-informative markers in these subjects. The relationships between the diplotypes, alleles, and genotypes at ADH4 and personality traits were examined using multivariate analysis of covariance (MANCOVA), controlling for potential confounders. RESULTS: Generally, SD patients, older individuals, and male subjects scored higher on neuroticism and lower on other personality factors. Personality factors were associated with the diplotypes. The allele A or genotype A/A of single nucleotide polymorphism (SNP)6 (rs1800759 at the gene promoter) was significantly associated with agreeableness scores. There were associations between extraversion and SNP1 (hcv2033010 at the 3' end) and SNP2 (rs1042364 in exon 9) in subjects with higher conscientiousness scores. CONCLUSIONS: The personality traits of agreeableness and extraversion are related to ADH4 polymorphism. Among the ADH4 markers that appear to predispose to certain personality traits, the functional variant rs1800759 (SNP6) in the promoter region is most important. We conclude that personality traits and SD have a partially overlapping genetic basis.  相似文献   
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目的对弱视儿童不同部位所记录的视觉诱发电位(VEP)进行比较研究。方法分析52只弱视眼常规视觉刺激时于O1、O2、Oz三点记录的VEP,并以66只健康眼的VEP作比较。结果弱视眼三个点VEP的异常率:Oz一个点23%,O1、O2两点为75%,Oz、O1和O2三个点为81%。与正常眼比较,弱视眼此三点VEP的潜伏期均显著延长,Oz点波幅显著降低,O1、O2点波幅则无显著差异。弱视眼的VEPO1和O2点潜伏期较其Oz点显著延长,波幅亦显著降低。结论对VEP的评价,必须考虑到有无弱视和记录部位这两个因素。  相似文献   
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观察按摩内关和合谷穴对上有底荧光血管造影中恶心和呕吐的影响。眼底荧光血管造影中发生恶心和呕吐的60例患者随机分为治疗组和对照组。治疗组按摩一侧或双侧内关穴和合谷穴;对照组未进行治疗,在发生恶心患者中,治疗组30例中发生哎者2例;对照组发生呕吐者9例,两组的发生率有显著差异  相似文献   
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BACKGROUND: Dendritic cell is the most major antigen presenting cell of organism. It is proved in recent studies that human umbilical cord blood mononuclear cells induced and cultured in vitro by recombinant human granulocyte-macrophage colony stimulating factor (rhG-MCSF) and recombinant human interleukin-4(rhIL-4) can generate a great many dendritic cells and promote the lethal effect of T cells on human neuroblastoma, but it is unclear that whether the lethal effect is associated with the most proper concentration of dendritic cells. OBJECTIVE: To investigate the lethal effect of human umbilical cord blood mononuclear cells induced in vitro by cytokines differentiating into dendritic cells on human neuroblastoma, and its best concentration range. DESIGN: Open experiment. SETTING: Department of Pediatrics, the Medical School Hospital of Qingdao University. MATERIALS: The study was carried out in the Shandong Provincial Key Laboratory (Laboratory for the Department of Pediatrics of the Medical School Hospital of Qingdao University) during September 2005 to May 2006. Human umbilical cord blood samples were taken from the healthy newborn infants of full-term normal delivery during October to November 2005 in the Medical School Hospital of Qingdao University, and were voluntarily donated by the puerperas. Main instruments: type 3111 CO2 incubator (Forma Scientific, USA), type 550 ELISA Reader (Bio-Rad, USA). Main reagents: neuroblastoma cell line SK-N-SH (Shanghai Institute of Life Science, Chinese Academy of Sciences), RPMI-1640 culture fluid and fetal bovine serum (Hyclone), rhIL-4 (Promega, USA), rhG-MCSF (Harbin Pharmaceutic Group Bioengineering Co.Ltd), rat anti-human CD1a monoclonal antibody and FITC-labeled rabbit anti-rat IgG (Xiehe Stem cell Gene Engineering Co.Ltd). METHODS: ① Human umbilical cord blood mononuclear cells obtained with attachment methods differentiated into human umbilical cord blood dendritic cells, presenting typical morphology of dendritic cells after in vitro induction by rhG-MCSF and rhIL-4. ② Different concentrations of dendritic cells[ dendritic cells: neuroblastoma cells=20∶1,50∶1,100∶1(2×108 L-1,5×108 L-1,1×109 L-1)], 1×109 L-1 T cells and 1×107 L-1 neuroblastoma cells were added in the experimental group. 1×109 L-1 T cells and 1×107 L-1 neuroblastoma cells were added in the control group. ③ Main surface marker CD1a molecules of dendritic cells were detected with indirect immunofluorescence, and the percent rate of dendritic cells was counted with ultraviolet light and expressed as the expression rate of CD1a+ cells. ④ Single effector cells and target cells were respectively set in the experimental group and control group to obtain the lethal effect. The lethal effect of dendritic cells on neuroblastoma cells was indirectly evaluated by detecting cellular survival with MTT assay. The lethal effect(%)=(1-A experimental well-A effector cell well/A target cell well)×100%.⑤The experimental data were presented as Mean ±SD, and paired t test was used. MAIN OUTCOME MEASURES: ① Morphological characters of dendritic cells in the process of induction and differentiation. ②CD1a+ cellular expression rate. ③Lethal effect of dendritic cells on neuroblastoma cells. RESULTS: ①Morphological characters of dendritic cells in the process of induction and differentiation: On the 15th day after human umbilical cord blood mononuclear cells were induced by rhG-MCSF and rhIL-4, typical morphology of dendritic cells could be seen under an inverted microscope. ②Expression rate of CD1a+ cells was (43.12±5.83)%. ③Lethal effect of dendritic cells on neuroblastoma cells: Lethal effect of dendritic cells stimulated T cells in each experimental group ( dendritic cells: neuroblastoma cells=100∶1,50∶1,20∶1 respectively) on neuroblastoma cells was significantly higher than that in control group[(31.00 ±4.41)%,(30.92±5.27)%,(33.57±5.35)%,(26.23±5.20)%, t=3.51,2.98,4.24, P < 0.01); But the lethal effect of dendritic cells on neuroblastoma was significantly lower when their ratio was 100∶1 and 50∶1 in comparison with 20:1 (t=2.01,2.36, P < 0.05), and no significant difference in lethal effect existed between the ratio at 100∶1 and 50∶1(t=0.06,P > 0.05). CONCLUSION: Dendritic cells differentiated from human umbilical cord blood mononuclear cells after in vitro induction of cytokines can promote the lethal effect of T cells on neuroblastoma cells. The lethal effect is associated with the concentration of dendritic cells within some range.  相似文献   
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