首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1478篇
  免费   0篇
  国内免费   1篇
化学工业   2篇
金属工艺   1篇
机械仪表   1篇
能源动力   2篇
轻工业   1篇
石油天然气   1篇
无线电   1篇
一般工业技术   2篇
冶金工业   1466篇
自动化技术   2篇
  2013年   2篇
  2011年   1篇
  2009年   1篇
  2007年   1篇
  2006年   1篇
  2005年   1篇
  2003年   4篇
  1999年   40篇
  1998年   427篇
  1997年   246篇
  1996年   158篇
  1995年   90篇
  1994年   81篇
  1993年   102篇
  1992年   6篇
  1991年   23篇
  1990年   18篇
  1989年   19篇
  1988年   27篇
  1987年   20篇
  1986年   16篇
  1985年   9篇
  1983年   4篇
  1982年   3篇
  1981年   12篇
  1980年   19篇
  1979年   1篇
  1978年   3篇
  1977年   43篇
  1976年   91篇
  1975年   6篇
  1973年   1篇
  1969年   1篇
  1955年   2篇
排序方式: 共有1479条查询结果,搜索用时 15 毫秒
91.
Plasma cystinylaminopeptidase (CAP) activity and 24 h urinary excretion of oestrogens were measured simultaneously in 102 pathological pregnancies. The correlation between the two chemical assays is weak (p = 0,13, to 0,47). Plasma CAP levels were significantly (p less than 0,01) lowered in cases of fetal death; but urinary oestrogen assays were within the normal limits (p greater than 0,1) in this group. Each assay suggested an equal number of correct or incorrect prognoses. Their association resulted in 9 correct prognoses in 12 pregnancies with unfavourable outcome, but led to 12 unduly bad prognoses in a group of 40 normal births. The association of the two assays allows a more adequate diagnosis of high-risk pregnancies, but has the disadvantage of offering an unduly bad prognosis in a greater number of normal cases.  相似文献   
92.
93.
94.
95.
In this work we tried to perform a dynamic analysis of coronary vascular response to histamine, using a simple mathematical analysis as a first step in the better understanding of complex histamine effects on coronary blood vessels of the isolated guinea pig heart. So, we defined more parameters, such as: I and delta I to quantify the intensity of coronary perfusion pressure (CPP) change, T and dt to quantify the time CPP change occurs and D to characterize the intensity and duration of CPP change, i.e. to quantify the dynamics of this change.  相似文献   
96.
97.
A previous study has shown that lipophilic prodrugs can be delivered efficiently to normal lung endothelium by incorporation into liposomes covalently conjugated to monoclonal antibody (mAb) 34A against the lung endothelial anticoagulant protein thrombomodulin. In the present study, the potential use of these lung-targeted immunoliposomes (34A-liposomes) for delivery of a lipophilic prodrug, 3',5'-O-dipalmitoyl-5-fluoro-2'-deoxyuridine (dpFUdR), to the tumor-bearing lung was examined using BALB/c mice bearing experimental lung metastasis induced by i.v. injection of EMT-6 mouse mammary tumor cells. Immunohistochemical examination of the tumor-bearing lung showed specificity of mAb 34A to lung endothelium. Tumor cells appeared to localize just outside of the normal blood vessels and were within a small diffusion distance from the mAb 34A-binding sites. 111In-labeled 34A-liposomes containing monosialoganglioside (GM1) were prepared that included [3H]-dpFUdR at 3.0 mol% in the lipid mixture. In vitro cell binding studies further demonstrated that 34A-liposomes bound specifically to normal mouse lung cells that expressed thrombomodulin but not to EMT-6 cells. Biodistribution study showed efficient and immunospecific accumulation of [3H]-dpFUdR incorporated into 34A-liposomes in the lung at a level parallel with that of 111In-labeled 34A-liposomes, indicating that the drug is delivered to the target organ in intact liposomes. Liposomal dpFUdR appeared to be metabolized in the lung to the parent drug FUdR at a rate slower than in the liver and spleen. Furthermore, treatment of lung-metastasis-bearing mice with dpFUdR incorporated into 34A-liposomes on days 1 and 3 after tumor cell injection resulted in a significant increase in the median survival time of treated mice as compared with control mice (%T/C value, 165%). dpFUdR either dispersed in emulsion or incorporated into antibody-free liposomes was ineffective in prolonging the survival of mice. These results indicate the potential effectiveness of organ-specific immunoliposomes containing a lipophilic prodrug for the targeted therapy of metastatic tumors.  相似文献   
98.
99.
100.
The -514T allele of hepatic lipase is associated with increased high density lipoprotein-cholesterol levels in men, but not in women. This observation suggests that the -514C to T polymorphism may diminish the response of hepatic lipase to androgens. To test this hypothesis, five -514T and five -514C homozygous men were treated with the anabolic steroid stanozolol for 6 days. The mean increase in hepatic lipase activity was similar in the two groups (45+/-10 vs. 51+/-10 mmol x hr(-1) x l(-1), P = 0.5). To evaluate the association between the -514 polymorphism and hepatic lipase activity at different physiological androgen concentrations, hepatic lipase genotypes and activities were measured in 44 men and 40 premenopausal women. The effect of the -514T allele on hepatic lipase activity was significant and quantitatively similar in both sexes. These data indicate that the -514 polymorphism does not influence the response of hepatic lipase activity to androgens, and that the effects of this polymorphism on hepatic lipase activity are independent of androgen action.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号