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   3677篇
  免费   318篇
  国内免费   109篇
耳鼻咽喉   9篇
儿科学   151篇
妇产科学   61篇
基础医学   471篇
口腔科学   77篇
临床医学   524篇
内科学   701篇
皮肤病学   89篇
神经病学   209篇
特种医学   232篇
外科学   436篇
综合类   189篇
预防医学   327篇
眼科学   81篇
药学   422篇
中国医学   4篇
肿瘤学   121篇
  2021年   39篇
  2020年   32篇
  2018年   45篇
  2017年   42篇
  2016年   45篇
  2015年   45篇
  2014年   67篇
  2013年   134篇
  2012年   122篇
  2011年   123篇
  2010年   94篇
  2009年   85篇
  2008年   121篇
  2007年   167篇
  2006年   108篇
  2005年   120篇
  2004年   101篇
  2003年   102篇
  2002年   99篇
  2001年   96篇
  2000年   102篇
  1999年   106篇
  1998年   54篇
  1997年   67篇
  1996年   62篇
  1995年   67篇
  1994年   57篇
  1993年   51篇
  1992年   98篇
  1991年   80篇
  1990年   88篇
  1989年   102篇
  1988年   83篇
  1987年   91篇
  1986年   82篇
  1985年   94篇
  1984年   67篇
  1983年   52篇
  1982年   40篇
  1981年   43篇
  1979年   50篇
  1978年   46篇
  1977年   45篇
  1976年   42篇
  1975年   34篇
  1974年   46篇
  1973年   47篇
  1972年   37篇
  1971年   45篇
  1970年   40篇
排序方式: 共有4104条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
5.
SUMMARY: The effect of mild acute tubular injury on the progression of tubulointerstitial fibrosis was studied in pair-fed uninephrectomized male Wistar rats with established adriamycin nephrosis ( n = 34). Rats were stratified into three groups according to endogenous creatinine clearance (CrCl), proteinuria (Upr) and body weight (BW): (i) group 1 (Fe, n = 12) received a single intraperitoneal injection of ferric nitrilotriacetate (5 mg Fe/kg BW); (ii) group 2 (G, n = 10) three daily subcutaneous injections of gentamicin (60 mg/kg BW) and; (iii) group 3 (C, n = 12) saline injections. Serial CrCl (day 2, day 5, weeks 2, 4, 6 and 8) and renal histology (week 8) were examined following administration of nephrotoxin. CrCl was reduced on d2 (Fe: 0.78 ± 0.23 mL/min; mean ± SD) and day 5 (G: 0.91 ± 0.36 mL/min) as compared with C (1.22 ± 0.12 mL/min; P <0.05). There was no change in the serum creatinine and functional recovery occurred by d5 (Fe) and week 2 (G). Upr decreased transiently in G at week 2 (G: 482 ± 208 mg/day vs C: 716 ± 233; P = 0.05) despite similar food intake, baseline Upr and CrCl. At week 8, CrCl in Fe (0.84 ± 0.40 mL/min) was similar to C (0.84 ± 0.58 mL/min), whereas in G it remained stable (1.27 ± 0.39 mL/min; P <0.05). By morphometric analysis, mean relative interstitial volume (RIV) and glomerulosclerosis (GS) in Fe (RIV: 28.5 ± 13.4%; GS: 10.3 ± 12.3%) was no different to C (RIV: 24.5 ± 12.5%; GS: 20.9 ± 20.0%), whereas both parameters were reduced in G (RIV: 14.1 ± 8.1%; GS: 4.0 ± 4.8%; P <0.05). Mild gentamicin nephrotoxicity therefore reduced the progression of adriamycin nephrosis. the mechanism of this finding is unclear, but it may relate to altered glomerular and tubular cell handling of protein.  相似文献   
6.
Study Objective . To compare digoxin tablets and liquid-filled capsules with respect to excretion of the drug and its metabolites in urine and feces at steady state. Design . A randomized, crossover trial, each period lasting 3 weeks, with no washout period. Setting . A university hospital. Patients . Six patients, five of whom were elderly, with histories of gastrointestinal disorders, such as hypochlorhydria, intestinal bacterial overgrowth, and inflammatory bowel disease. Interventions . The patients received digoxin once/day in either tablet or capsule form for 3 weeks, and then were switched to the other formulation. Total urinary and fecal excretion from the last 3 days of each regimen were analyzed for the drug and metabolites. Measurements and Main Results . No statistically significant differences were found between tablets and capsules in recovery of digoxin or its metabolites in urine or feces (p=0.05). One subject had a 4-fold increase in urinary drug excretion and 50% decrease in fecal excretion after taking the capsules compared with tablets. Intersubject variability in extent and type of metabolite excretion was greater than intrasubject variability. Conclusions . Fecal analyses may be an accurate way to classify patients as formers of digoxin reduction products.  相似文献   
7.
Glucose metabolism in injured tissue: a longitudinal study   总被引:1,自引:0,他引:1  
Injured tissue is characterized by increased glucose uptake and increased lactate production as compared to normal tissue. These metabolic changes have been attributed to the presence of inflammatory cells in injured tissues. To correlate these metabolic changes with changes in the inflammatory cell population at various times after injury, we studied the lambda-carrageenan hindlimb wound model in anesthetized rats. Perfusion studies demonstrated that at 3 and 5 days after injury glucose uptake was increased in injured hindlimbs, compared with hindlimbs from pair-fed control animals. At 3, 5, and 10 days after injury, lactate production from glucose was increased in injured hindlimbs, compared with hindlimbs from pair-fed control animals. These metabolic changes were not related to differences in body weight or food intake. There was no difference in glucose oxidation or in oxygen consumption in injured hindlimbs, compared with hindlimbs from pair-fed control animals. The increased glucose uptake and increased lactate production from glucose was coincident with the presence of inflammatory cells--predominantly macrophages--at the site of injury. It is suggested that the glucose metabolism in injured tissue reflects the metabolism of the inflammatory cells at the site of injury.  相似文献   
8.
OBJECTIVES: This study evaluated the association between quality of life and non-insulin-dependent diabetes mellitus (NIDDM) status, and whether this association differs between Hispanics and non-Hispanic Whites. METHODS: Between 1986 and 1989, cross-sectional data on perceived quality of life (PQOL) were collected from 223 persons with NIDDM and 753 non-diabetic subjects. RESULTS: After adjustment, persons with NIDDM rated their PQOL significantly lower than did control subjects. The relationship of diabetes and PQOL did not differ by ethnicity. The number of complications of diabetes was not associated with lower PQOL scores. CONCLUSIONS: Control and treatment strategies should reflect an understanding of the impact that diabetes has on social functioning, leisure activities, and physical and mental health.  相似文献   
9.
10.
本文通过将无环鸟苷(acyclovir,简称ACV)2’位羟基分别与月桂酰氯或棕榈酰氯进行酯化反应,制得亲脂性前体药物无环鸟苷月桂酸酯和无环鸟苷棕榈酸酯(分别简称为C12-ACV和C16-ACV),使脂质体包封率从ACV的29.9%提高到C12-ACV的95.6%和C16-ACV的97.1%;漏泄实验表明在4℃透析60h后,一半以上的ACV从脂质体中漏泄,而C12-ACV和C16-ACV的滞留率分别为70%和80%;体外抗疱疹病毒的试验中,在最低试验浓度0.044μmol/L时,ACV不显示抗病毒活性,而C16-ACV脂质体抑制细胞病变率达75%,说明前体药物通过与脂质体脂膜的结合增加了药物的进入细胞能力,从而提高了ACV的抗病毒能力。  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