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   500569篇
  免费   32107篇
  国内免费   1140篇
耳鼻咽喉   6447篇
儿科学   15596篇
妇产科学   14292篇
基础医学   71385篇
口腔科学   11897篇
临床医学   43711篇
内科学   99229篇
皮肤病学   9025篇
神经病学   40815篇
特种医学   18324篇
外国民族医学   56篇
外科学   78661篇
综合类   11036篇
现状与发展   3篇
一般理论   449篇
预防医学   38638篇
眼科学   11189篇
药学   34910篇
  1篇
中国医学   1141篇
肿瘤学   27011篇
  2021年   5536篇
  2020年   3401篇
  2019年   5526篇
  2018年   7454篇
  2017年   5770篇
  2016年   6358篇
  2015年   7391篇
  2014年   10461篇
  2013年   15768篇
  2012年   21742篇
  2011年   23380篇
  2010年   13946篇
  2009年   12632篇
  2008年   21903篇
  2007年   23542篇
  2006年   22894篇
  2005年   23028篇
  2004年   22142篇
  2003年   20774篇
  2002年   19925篇
  2001年   15155篇
  2000年   15072篇
  1999年   13417篇
  1998年   5776篇
  1997年   5168篇
  1996年   4787篇
  1995年   4436篇
  1994年   4058篇
  1993年   3820篇
  1992年   9493篇
  1991年   9568篇
  1990年   9291篇
  1989年   9009篇
  1988年   8300篇
  1987年   8072篇
  1986年   7696篇
  1985年   7569篇
  1984年   6204篇
  1983年   5546篇
  1982年   4228篇
  1981年   3652篇
  1980年   3526篇
  1979年   5221篇
  1978年   4157篇
  1977年   3644篇
  1976年   3313篇
  1975年   3506篇
  1974年   4006篇
  1973年   3942篇
  1972年   3540篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
Recently, we demonstrated that spaghetti caused significantly lower glycaemic response than rice and potato in insulin-dependent diabetic (IDDM) subjects and that this difference was also present when spaghetti and potato were taken as part of a mixed meal. We have now compared the blood glucose and insulin responses to 50 g of carbohydrate in the form of white bread, potato and white spaghetti in 6 non-insulin-dependent diabetic (NIDDM) patients. The blood glucose response after white spaghetti observed over a 3-h period was only 60 +/- 10 per cent (P less than 0.02) of that seen in response to potato (395 +/- 116 mmol/l x 180 min vs 641 +/- 108 mmol/l x 180 min) and 47 +/- 9 per cent (P less than 0.01) of that seen in response to white bread (395 +/- 116 mmol/l x 180 min vs 805 +/- 93 mmol/l x 180 min). Insulin responses showed an identical pattern reflecting the glycaemic responses. To see if the difference in the glucose responses in NIDDM patients is preserved if these carbohydrate-rich foods are taken as part of a mixed meal we looked at the blood glucose and insulin responses to 50 g of carbohydrate in the form of potato and white spaghetti when ingested together with bolognese sauce (167 g) in 7 NIDDM patients.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
53.
The writers examine the course of Greek ophthalmology from the Hellenistic period to the foundation of the first universities (19th century). In particular, the study refers to Galen, Antyllus, the Byzantine doctors Oribasius, Aetius of Ameda, Paul of Aegina, Alexander of Tralles, Nonnus Theophanes, Theophilus Protospatharius, Michael Psellos, Meletius Monachus, Nemesius bishop of Emeses and John Actuarius. The practice of empirical ophthalmology during the Ottoman domination of Greece is also examined, as is the earliest available evidence of modern Greek ophthalmological knowledge, deriving from the Ionian Islands.  相似文献   
54.
Sixty-three mallards were fed one of ten poly(methyl methacrylate) based synthetic grit formulations containing varying concentrations of a proposed wildlife contraceptive (nicarbazin), plasticizer (acetyl tributylcitrate) and/or cross-linking agent (1,4-butanediol diacrylate). Release characteristics of the contraceptive agent were monitored for the purpose of developing a contraceptive formulation for control of pest waterfowl in urban settings. The addition of plasticizer increased the erosion rate (t(1/2)=0.97-2.85 days), cross-linking the polymer matrix slightly decreased the erosion rate (t(1/2)=4.45-5.05 days) and increasing the concentration of the contraceptive agent increased the erosion rate (t(1/2)=3.3 and 9.9 days at 60% and 7.5% active ingredient, respectively). The larger and smaller grit pieces had longer half lives at 11.0 and 11.6 days, respectively while the mid sized grit had a half life of 4.95 days. Control grit had a half life of 12.7 days based on weight loss. Analysis of blood and feces for monitoring release from the grit and approximate indirect plasma levels of the active ingredient proved feasible.  相似文献   
55.
The in vitro activities of povidone iodine, potassium peroxymonosulfate, and dimethyldidecylammonium chloride were investigated against 379 nosocomial isolates of Staphylococcus aureus and Pseudomonas aeruginosa responsible for surgical wound infections in patients operated on between July 1995 and June 2001. Overall, the isolates were inhibited by the antiseptics at concentrations below those used routinely. In spite of increasing resistance to the various antibiotics used to treat surgical wound infections, no significant variation in the susceptibility to antiseptics was demonstrated during this 6-year study. Electronic Publication  相似文献   
56.
OBJECTIVE AND DESIGN: Bacterial products as well as the host airway inflammatory responses contribute to the pathogenesis of Pseudomonas infections. We sought to determine if Pseudomonas elastase (PE) induces mitogen-activated protein (MAP) kinase activity in association with interleukin-8 (IL-8) production by alveolar epithelial cells. METHODS: We utilized Western blot analysis to detect phosphorylation of signaling intermediates and ELISA was used to measure IL-8 production. RESULTS: We found that PE induces phosphorylation of the extracellular signal-regulated (ERK1/2) proteins of the MAPK pathway in A549 epithelial cells. Similar results were obtained using primary cultures of rabbit alveolar type II epithelial cells. PE also enhanced IL-8 production, which was abolished in the presence of the ERK activation inhibitor U0126. CONCLUSIONS: We conclude that PE activates the ERK1/2 arm of the MAPK pathway and that activation of this pathway results in enhanced IL-8 production. The results demonstrate that PE may augment pulmonary inflammation via cellular signaling that regulates expression of IL-8.  相似文献   
57.
58.
59.
Formulae for the calculation of the count of microorganisms isolated from natural bacterial biocenoses of a child's body have been derived. The authors suggest a variant of simplified drip method for the computation of microorganism colonies in solid media. The described method helps cut down the nutrient media consumption at least 3-fold and is time-saving.  相似文献   
60.
The aqueous, organic, and volatile oil extracts of leaves of Eugenia uniflora Linn. Family Myrtaceae were investigated for antibacterial properties using agar dilution techniques. The aqueous extract was the most active against the organisms compared to the organic and volatile oil extracts. The extracts were found to inhibit Gram positive Staphylococcus aureus and Bacillus subtilis and Gram negative Escherichia coli and Shigella dysentcriae. Pseudomonas aeruginosa, Klebsiella pneumoniac, and Salmonella typhi were not inhibited.  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