全文获取类型
收费全文 | 1173698篇 |
免费 | 62071篇 |
国内免费 | 1464篇 |
专业分类
耳鼻咽喉 | 15448篇 |
儿科学 | 30024篇 |
妇产科学 | 27362篇 |
基础医学 | 160805篇 |
口腔科学 | 32458篇 |
临床医学 | 103489篇 |
内科学 | 230090篇 |
皮肤病学 | 22344篇 |
神经病学 | 94768篇 |
特种医学 | 46339篇 |
外国民族医学 | 92篇 |
外科学 | 186390篇 |
综合类 | 20460篇 |
现状与发展 | 2篇 |
一般理论 | 402篇 |
预防医学 | 77481篇 |
眼科学 | 26678篇 |
药学 | 87235篇 |
40篇 | |
中国医学 | 2460篇 |
肿瘤学 | 72866篇 |
出版年
2021年 | 10692篇 |
2019年 | 10937篇 |
2018年 | 14502篇 |
2017年 | 11132篇 |
2016年 | 12490篇 |
2015年 | 14327篇 |
2014年 | 19872篇 |
2013年 | 27996篇 |
2012年 | 39948篇 |
2011年 | 41640篇 |
2010年 | 24244篇 |
2009年 | 22958篇 |
2008年 | 39310篇 |
2007年 | 41127篇 |
2006年 | 41555篇 |
2005年 | 40377篇 |
2004年 | 38673篇 |
2003年 | 36490篇 |
2002年 | 35495篇 |
2001年 | 56588篇 |
2000年 | 57932篇 |
1999年 | 48869篇 |
1998年 | 13362篇 |
1997年 | 11574篇 |
1996年 | 11420篇 |
1995年 | 10582篇 |
1994年 | 9713篇 |
1993年 | 9028篇 |
1992年 | 36416篇 |
1991年 | 34790篇 |
1990年 | 33483篇 |
1989年 | 32574篇 |
1988年 | 29646篇 |
1987年 | 28834篇 |
1986年 | 26897篇 |
1985年 | 25793篇 |
1984年 | 18681篇 |
1983年 | 15896篇 |
1982年 | 8786篇 |
1979年 | 16226篇 |
1978年 | 11092篇 |
1977年 | 9479篇 |
1976年 | 8285篇 |
1975年 | 8929篇 |
1974年 | 10757篇 |
1973年 | 10110篇 |
1972年 | 9527篇 |
1971年 | 8999篇 |
1970年 | 8530篇 |
1969年 | 7999篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
K Sasai H Iwai T Yoshizawa S Nishimoto Y Shibamoto Y Kitakabu N Oya M Takahashi M Abe 《International journal of radiation biology》1992,62(2):221-227
We have previously reported that KU-2285, a 2-nitroimidazole with a fluorinated N1-substituent (-CH2-CF2CONH(CH2)nOH, n = 2), was a promising hypoxic cell radiosensitizer. In this study the pharmacokinetics of KU-2285 and its related compounds (n = 3 and n = 4) were compared with those of etanidazole (a 2-nitroimidazole with an N1-substituent of -CH2CONH(CH2)nOH, n = 2) and its related compounds (n = 3 and n = 4) to assess the effects of incorporation of a CF2 group. The lipophilicity of the fluorinated compounds was higher than that of etanidazole, as measured by the octanol/water partition coefficient. As the number of CH2 groups increased, the lipophilicity of the compounds in both the KU-2285 and etanidazole series increased. The brain tissue levels of the fluorinated compounds were as low as those of the etanidazole derivatives, while the biological half-lives of the fluorinated compounds in peripheral nervous tissues were shorter than those of related non-fluorinated compounds. 相似文献
992.
993.
P Hanson P Schumacker T Debugne M Clerin 《American journal of physical medicine & rehabilitation / Association of Academic Physiatrists》1992,71(1):44-47
The relationship between somatic and autonomic neuropathy was assessed in the feet of 30 diabetic patients. Somatic small fiber function was evaluated by the thermal threshold test for cold (A delta fibers) and warmth (C fibers). Telethermography and transcutaneous oxygen tension were used to investigate the autonomic control of peripheral circulation. Autonomic neuropathy caused the opening of arteriovenous anastomosis, which was revealed through an elevation of the feet's temperature and a low transcutaneous oxygen tension. The association of the opening of the arteriovenous anastomosis and the perturbation of the thermal threshold test established a relationship between the dysfunction of the autonomic and the somatic fibers. 相似文献
994.
Three cases of proved peritoneal carcinomatosis were examined by magnetic resonance imaging (MRI). Air was used to distend the entire gastrointestinal tract via an antegrade method. The findings included seedings along the small intestine, transverse and sigmoid colon, stellate pattern in the mesentery, plaque-like and bulky tumor masses in the mesentery and greater omentum, and focal thickenings along the right subdiaphragmatic parietal peritoneum. Stenosis caused by tumor encasement at the duodenojejunal junction and ileocolic anastomosis were first detected by MRI and later confirmed by barium studies. Ascites was present in all cases. One case showed ascites located only along the left paracolic gutter. This report shows that MRI is also able to demonstrate peritoneal carcinomatosis by using air as a gastrointestinal contrast medium. 相似文献
995.
996.
997.
998.
A woman with severe cicatricial conjunctival changes secondary to allopurinol-induced Stevens-Johnson syndrome developed bilateral palpebral conjunctival cysts. Pathologic examination of these lesions revealed respiratory-like pseudostratified ciliated epithelium in the walls of several cysts of one eye. To our knowledge, this is the first report of this phenomenon. 相似文献
999.
S Kojima M Kanashiro T Sanai M Imanishi M Kawamura Y Kawano G Kimura M Kuramochi H Amemiya T Omae 《Nephron》1992,61(1):89-93
While serum magnesium (Mg) level is increased in patients with end-stage renal disease (ESRD), it is decreased in renal transplant recipients (TR) receiving ciclosporin. This study was performed to examine the cation metabolism of red blood cells (RBC) in these patients. Intracellular free Mg was measured with 31P-nuclear magnetic resonance spectrometry, and ouabain-sensitive sodium (Na) efflux rate (Eos) was measured from the increase in RBC-Na concentration when RBC were incubated in the presence of ouabain. The ouabain-sensitive Na efflux rate constant (ERCos) was obtained by dividing Eos by RBC-Na concentration. RBC free Mg and ERCos were significantly higher in the TR group than in the ESRD group. There was a significant correlation between RBC free Mg and ERCos (r = 0.474, p less than 0.01). These results support the views that the regulation mechanism for intracellular free Mg is different from that for extracellular Mg in patients with renal disease, and intracellular free Mg modulates Na pump activity of RBC. 相似文献
1000.
To evaluate the acute effects of anti-asthmatic drugs in vitro, we examined the modulation of various anti-asthmatic drugs in therapeutic concentrations on PAF-induced human eosinophil chemotaxis. Aminophylline (20 micrograms/ml) and Isoproterenol (10 nM) inhibited PAF (3 X 10(-8) M)-induced eosinophil chemotaxis nearly 30%, whereas no inhibitory effects were observed by Dexamethasone (0.1 microM), Tranilast, Ketotifen or Azelastine. Aminophylline (20 micrograms/ml) also inhibited LTB4 (3 X 10(-8) M)-induced eosinophil chemotaxis nearly 30%, whereas it did not inhibit chemotaxis induced by zymosan (5 mg/ml)-activated serum. These results indicate that anti-asthmatic drugs except for aminophylline and isoproterenol, when used acutely in therapeutic concentrations, have no striking inhibitory effects on PAF-induced eosinophil chemotaxis. These results further suggest the possibility that there are different mechanisms in eosinophil chemotaxis induced by PAF, LTB4 or by C5a. 相似文献