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   150篇
  免费   0篇
化学工业   3篇
机械仪表   1篇
能源动力   1篇
轻工业   1篇
石油天然气   1篇
一般工业技术   1篇
冶金工业   142篇
  2013年   2篇
  2007年   1篇
  2006年   1篇
  2003年   1篇
  1999年   4篇
  1998年   39篇
  1997年   25篇
  1996年   18篇
  1995年   9篇
  1994年   13篇
  1993年   7篇
  1992年   1篇
  1990年   1篇
  1989年   2篇
  1988年   3篇
  1987年   1篇
  1985年   3篇
  1983年   1篇
  1982年   2篇
  1981年   1篇
  1980年   1篇
  1977年   6篇
  1976年   8篇
排序方式: 共有150条查询结果,搜索用时 15 毫秒
111.
112.
OBJECTIVE: To evaluate the effect of chocolate cyst fluid on the proliferation of cultured human endometrioma cells and to assay the concentration of transforming growth factor-B1 in this fluid. DESIGN: Controlled in vitro study. SETTING: Department of Obstetrics and Gynecology, State University of New York Health Science Center. PATIENT(S): Five women with ovarian endometriomas. INTERVENTION(S): Endometrioma tissue and chocolate fluid from five different patients were entered in this study. MAIN OUTCOME MEASURE(S): Endometrioma cell proliferation in culture with and without chocolate cyst fluid. RESULT(S): Chocolate cyst fluid increased the proliferation of endometrioma cells compared with controls. Also, high concentrations of transforming growth factor-B1 were found in cysts' fluid. CONCLUSIONS: Chocolate cyst fluid has a growth-enhancing effect on endometrioma cells. One promoting growth factor is transforming growth factor-B1.  相似文献   
113.
We assessed mechanisms of acetylcholine- and bradykinin-induced relaxations in human omental resistance vessels. Ring segments (approximately 200 microns normalized ID) were dissected from omental biopsies obtained from women at laparotomy (nonpregnant) or at cesarean delivery (pregnant) and were studied under isometric conditions in a Mulvany-Halpern myograph. All arginine vasopressin-preconstricted vessels relaxed in a strictly endothelium-dependent manner to acetylcholine and bradykinin; maximal relaxations were not decreased by either NG-nitro-L-arginine or indomethacin. By contrast, bradykinin failed to relax vessels that had been preconstricted with potassium gluconate. In the combined presence of NG-nitro-L-arginine and indomethacin, addition of charybdotoxin, a selective antagonist of some calcium-sensitive potassium channels, did not inhibit maximal bradykinin-induced relaxation. By contrast, addition of 10 mmol/L tetraethylammonium chloride abolished relaxation in vessels from nonpregnant women but not in vessels from gravidas. We conclude that bradykinin relaxes these human resistance arteries in an endothelium-dependent but predominantly nitric oxide- and prostanoid-independent manner; relaxation likely depends on the action of an endothelium-derived hyperpolarizing vasodilator. Furthermore, in striking contrast to mechanistic insights from animal studies, human pregnancy appears to augment a mechanism of endothelium-dependent relaxation in these vessels that is insensitive to the inhibitors noted above. Whether a similar novel vasodilator mechanism in vivo contributes to the physiological vasodilation that characterizes human gestation or whether failure of such a mechanism might lead to preeclampsia remains the subject of future study.  相似文献   
114.
The isolation and characterization of rabbit and human cDNAs revealed a new low density lipoprotein receptor (LDLR)-related protein (LRP) designated as LRP5. Human LRP5 cDNA encodes a 1, 616-amino acid type I membrane-like protein with three ligand binding repeats in its extracellular region. LDLR-deficient cells transduced by recombinant adenovirus containing human LRP5 exhibited increased binding of apolipoprotein E (apoE)-enriched beta-migrating very low density lipoprotein. Northern blotting and in situ hybridization revealed a high level of LRP5 expression in hepatocytes and the adrenal gland cortex. In LDLR-deficient Watanabe heritable hyperlipidemic rabbits, LRP5 mRNA was increased in the liver and accumulated in cholesterol-laden foam cells of atherosclerotic lesions.  相似文献   
115.
116.
117.
The efficacy of sisomicin and gentamicin was compared in mouse protection studies against strains of Escherichia coli, Klebsiella sp., Enterobacter aerogenes, Serratia marcescens, Proteus mirabilis, and Pseudomonas aeruginosa. There was no significant difference in mortality of the mice in any of the protocol groups when five different dosages of sisomicin and gentamicin given by three separate schedules were compared for each bacterial inoculum in each antibiotic protocol. The mean protective dose values of sisomicin were at least one-half those of gentamicin for each protocol against Pseudomonas aeruginosa.  相似文献   
118.
119.
Using labelled streptavidin-biotin (LSAB) method, we examined the expression of nucleoside diphosphate kinase(NDPK), the product of metastasis suppressor gene nm23, in human lung cancer. Of 88 patients tested, 48 (54.5%) showed positive staining. The positive staining rate was higher in adenocarcinoma (28/42, 66.7%) than in squamous cell carcinoma (20/46, 43.5%; P < 0.05). Higher incidence of positive staining was also found in squamous cell carcinoma without hilar or mediastinal lymph node metastasis (16/27, 59.3%) than in that with hilar or mediastinal lymph node involvement (4/19, 21.1%; P < 0.05). NDPK/nm23 was equally expressed in adenocarcinoma irrespective of lymph node status. In both cell types of carcinoma, expression of NDPK/nm23 was not correlated with tumor cell differentiation, nor was it correlated with the P-TNM staging. Our results suggest that NDPK/nm23 may play different roles in the pathogenesis and metastasis of human pulmonary squamous cell carcinoma and adenocarcinoma. Its expression levels are inversely correlated with lymph node metastasis in squamous cell carcinoma.  相似文献   
120.
This study examines certain aspects of the interaction of acridines with DNA. A comparative study of the methods available for the determination of the association constants (Kap) for compounds which interact with DNA has been pursued. A new equation which permits the spectrophotomeric determination of Kap has been derived. This equation can be applied to compounds which upon interaction with a polymer exhibit discrete absorption changes. Application of this equation to substituted acridines and tetrahydroacridines yields some preliminary information on the effect of ring substituents on the interaction of acridines with DNA. Low levels of DNA/dye ratios have been used in the studies reported herein.  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