全文获取类型
收费全文 | 1846954篇 |
免费 | 114831篇 |
国内免费 | 2420篇 |
专业分类
耳鼻咽喉 | 24552篇 |
儿科学 | 61867篇 |
妇产科学 | 50573篇 |
基础医学 | 271677篇 |
口腔科学 | 46884篇 |
临床医学 | 157267篇 |
内科学 | 351953篇 |
皮肤病学 | 36694篇 |
神经病学 | 141159篇 |
特种医学 | 73602篇 |
外国民族医学 | 410篇 |
外科学 | 284038篇 |
综合类 | 35129篇 |
现状与发展 | 2篇 |
一般理论 | 399篇 |
预防医学 | 140239篇 |
眼科学 | 41544篇 |
药学 | 137479篇 |
2篇 | |
中国医学 | 3979篇 |
肿瘤学 | 104756篇 |
出版年
2018年 | 36595篇 |
2017年 | 28105篇 |
2016年 | 31927篇 |
2015年 | 16633篇 |
2014年 | 22306篇 |
2013年 | 33356篇 |
2012年 | 52209篇 |
2011年 | 68994篇 |
2010年 | 46429篇 |
2009年 | 37587篇 |
2008年 | 65206篇 |
2007年 | 71369篇 |
2006年 | 52181篇 |
2005年 | 52374篇 |
2004年 | 51856篇 |
2003年 | 51356篇 |
2002年 | 48622篇 |
2001年 | 74708篇 |
2000年 | 76800篇 |
1999年 | 64719篇 |
1998年 | 18425篇 |
1997年 | 16265篇 |
1996年 | 16420篇 |
1995年 | 15493篇 |
1994年 | 14568篇 |
1992年 | 51606篇 |
1991年 | 52045篇 |
1990年 | 51661篇 |
1989年 | 50285篇 |
1988年 | 46790篇 |
1987年 | 45970篇 |
1986年 | 43597篇 |
1985年 | 41678篇 |
1984年 | 31061篇 |
1983年 | 26888篇 |
1982年 | 15584篇 |
1981年 | 13866篇 |
1979年 | 29578篇 |
1978年 | 20837篇 |
1977年 | 17780篇 |
1976年 | 17244篇 |
1975年 | 19353篇 |
1974年 | 22603篇 |
1973年 | 21771篇 |
1972年 | 20545篇 |
1971年 | 19293篇 |
1970年 | 18023篇 |
1969年 | 17162篇 |
1968年 | 16178篇 |
1967年 | 14331篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Pankaj Dabir Snehal Dabir B V Siva Prasad M V R Reddy 《Infection, genetics and evolution》2006,6(4):287-291
Molecular characterization of Wuchereria bancrofti is essential to develop suitable anti-filarial drugs and vaccines. We describe here isolation, sequence analysis and cloning of a partial cDNA of an enzyme superoxide dismutase from this parasite. The immunoscreening of a lambda zap W. bancrofti microfilarial (Mf) cDNA library with microfilaremic sera had resulted in the isolation of several seroreactive clones including, WbSOD. This clone contained a 309 bp insert and showed significant nucleotide and deduced amino acid sequence homologies to the superoxide dismutases of other nematode parasites. The antioxidant property of this enzyme may have important contribution in the defense mechanism of the parasite against host immune response. 相似文献
62.
L Laforest E Van Ganse G Devouassoux S Chretin L Osman G Bauguil Y Pacheco G Chamba 《The European respiratory journal》2006,27(1):42-50
French asthma patients may be supervised by general practitioners (GPs) and/or specialists. Therefore, this study examined asthma management in patients exclusively supervised by specialists (SPE), GPs, (GP) and both (GP+SPE group), and compared the findings. Asthma patients were consecutively recruited in 348 pharmacies. Each patient completed a questionnaire providing data on personal characteristics, asthma management, perception of disease and asthma supervision. Asthma control was measured using the Asthma Control Test. Questionnaires were linked to computerised records of medications which had been dispensed before inclusion in the study. From the 1,256 patients (mean age = 36.1 yrs, 54.3% females), 11.4, 36.6, and 52.0% were placed in the SPE, GP, and GP+SPE groups, respectively. During the previous 4 weeks, most patients in the SPE group were properly controlled (52.2 versus 26.4 and 21.5% in GP and GP+SPE groups, respectively). The SPE group made more use of fixed combinations of long-acting beta agonist and inhaled corticosteroid, while receiving less short-acting beta agonists, antitussives and antibiotics. Striking differences in symptoms and asthma management were observed according to the type of asthma supervision. The current results strongly support the need to improve the management of asthma in primary care, and the coordination of care between general practitioners and specialists. 相似文献
63.
64.
65.
66.
67.
68.
A Sharma H L Goh N Asokananthan A Bakker G A Stewart H W Mitchell 《The European respiratory journal》2006,27(1):20-28
Mucosal trypsin, a protease-activated receptor (PAR) stimulant, may have an endogenous bronchoprotective role on airway smooth muscle. To test this possibility the effects of lumenal trypsin on airway tone in segments of pig bronchus were tested. Bronchial segments from pigs were mounted in an organ chamber containing Kreb's solution. Contractions were assessed from isovolumetric lumen pressure induced by acetylcholine (ACh) or carbachol added to the adventitia. Trypsin, added to the airway lumen (300 microg x mL(-1)), had no immediate effect on smooth muscle tone but suppressed ACh-induced contractions after 60 min, for at least 3 h. Synthetic activating peptides (AP) for PAR1, PAR2 or PAR3 were without effect, but PAR4 AP caused rapid, weak suppression of contractions. Lumenal thrombin was without effect and did not prevent the effects of trypsin. Effects of trypsin were reduced by N(omega)-nitro-L-arginine methyl ester but not indomethacin. Trypsin, thrombin and PAR4 AP released prostaglandin E2. Adventitially, trypsin, thrombin and PAR4 AP (but not PAR2 AP) relaxed carbachol-toned airways after <3 min. The findings of this study show that trypsin causes delayed and persistent bronchoprotection by interacting with airway cells accessible from the lumen. The signalling mechanism may involve nitric oxide synthase but not prostanoids or protease-activated receptors. 相似文献
69.
M B?ttner J Christoffel G Rimoldi W Wuttke 《Experimental and clinical endocrinology & diabetes》2006,114(2):82-90
The lack of estrogen during menopause is associated with various symptoms including osteoporosis, cardiovascular diseases, and menopausal symptoms. For many years, conventional hormone replacement therapy has been successfully used to treat these conditions. However, in light of recent studies that draw attention to potential hazards of conventional HRT, various attempts were undertaken to search for alternatives of classical HRT. Phytoestrogens are supposed to ameliorate various discomforts associated with menopause. Resveratrol (RES) is present in red wine, grapes and peanuts and has been implicated in cardioprotection and prevention of adverse side effects observed after regular HRT. As the pituitary-thyroid axis is a target of estrogen action, we first assessed the effects of E2 administration on thyroid hormone stimulating hormone releasing hormone (TRH)-induced thyroid stimulating hormone (TSH) secretion from pituitary cell cultures in vitro. Our data reveal that E2 treatment augments the TRH-induced TSH secretion. We furthermore designed a long-term study of three months to assess the effects of subcutaneous and oral administration of 17beta-estradiol (E2), as well as the actions of RES on the pituitary-thyroid axis in ovariectomized (OVX) female rats. Our results demonstrate that serum levels of 1.0 and 8.1 microM RES lead to a significant increase in total serum triiodthyronine (T3) levels. OVX induces TSHbeta mRNA in the adenohypohysis and E2 treatment attenuates this effect. Treatment of rats with subcutaneous implants of E2 does not affect the pituitary-thyroid axis, whereas orally applied E2 benzoate (E2B) increases plasma TSH and total thyroxine (T4) in OVX rats. In all animals, we could not detect changes in thyroid morphology as assessed by hematoxylin-eosin (HE) and Perjod-Acid Schiff's (PAS) staining. 相似文献
70.