全文获取类型
收费全文 | 124157篇 |
免费 | 7573篇 |
国内免费 | 978篇 |
专业分类
耳鼻咽喉 | 1491篇 |
儿科学 | 3365篇 |
妇产科学 | 2763篇 |
基础医学 | 16360篇 |
口腔科学 | 3599篇 |
临床医学 | 10134篇 |
内科学 | 28558篇 |
皮肤病学 | 2347篇 |
神经病学 | 11835篇 |
特种医学 | 4872篇 |
外国民族医学 | 23篇 |
外科学 | 17956篇 |
综合类 | 1724篇 |
一般理论 | 53篇 |
预防医学 | 6718篇 |
眼科学 | 1988篇 |
药学 | 9288篇 |
3篇 | |
中国医学 | 582篇 |
肿瘤学 | 9049篇 |
出版年
2023年 | 712篇 |
2022年 | 1554篇 |
2021年 | 2842篇 |
2020年 | 1774篇 |
2019年 | 2492篇 |
2018年 | 3074篇 |
2017年 | 2376篇 |
2016年 | 2559篇 |
2015年 | 2882篇 |
2014年 | 3751篇 |
2013年 | 5202篇 |
2012年 | 7286篇 |
2011年 | 7394篇 |
2010年 | 4603篇 |
2009年 | 4085篇 |
2008年 | 6329篇 |
2007年 | 6642篇 |
2006年 | 6232篇 |
2005年 | 5849篇 |
2004年 | 6009篇 |
2003年 | 5738篇 |
2002年 | 5581篇 |
2001年 | 3918篇 |
2000年 | 3849篇 |
1999年 | 3162篇 |
1998年 | 1336篇 |
1997年 | 1065篇 |
1996年 | 948篇 |
1995年 | 907篇 |
1994年 | 794篇 |
1993年 | 761篇 |
1992年 | 1870篇 |
1991年 | 1830篇 |
1990年 | 1558篇 |
1989年 | 1480篇 |
1988年 | 1384篇 |
1987年 | 1229篇 |
1986年 | 1206篇 |
1985年 | 1087篇 |
1984年 | 804篇 |
1983年 | 725篇 |
1982年 | 484篇 |
1981年 | 409篇 |
1979年 | 601篇 |
1978年 | 443篇 |
1975年 | 442篇 |
1974年 | 495篇 |
1973年 | 486篇 |
1972年 | 444篇 |
1971年 | 406篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.
A I D'hulst K R Bracke T Maes J L De Bleecker R A Pauwels G F Joos G G Brusselle 《The European respiratory journal》2006,28(1):102-112
Chronic obstructive pulmonary disease (COPD) is characterised by a local pulmonary inflammatory response to respiratory pollutants and by systemic inflammation. Tumour necrosis factor (TNF)-alpha has been implicated in systemic effects of COPD and operates by binding the p55 (R1) and p75 (R2) TNF-alpha receptors. To investigate the contribution of each TNF-alpha receptor in the pathogenesis of COPD, the present study examined the effects of chronic air or cigarette smoke (CS) exposure in TNF-alpha R1 knockout (KO) mice, TNF-alpha R2 KO mice and wild type (WT) mice. CS was found to significantly increase the protein levels of soluble TNF-alpha R1 (by four-fold) and TNF-alpha R2 (by 10-fold) in the bronchoalveolar lavage of WT mice. After 3 months, CS induced a prominent pulmonary inflammatory cell influx in WT and TNF-alpha R1 KO mice. In TNF-alpha R2 KO mice, CS-induced pulmonary inflammation was clearly attenuated. After 6 months, no emphysema was observed in CS-exposed TNF-alpha R2 KO mice in contrast to WT and TNF-alpha R1 KO mice. CS-exposed WT and TNF-alpha R1 KO mice failed to gain weight, whereas the body mass of TNF-alpha R2 KO mice was not affected. These current findings suggest that both tumour necrosis factor-alpha receptors contribute to the pathogenesis of chronic obstructive pulmonary disease, but tumour necrosis factor-alpha receptor-2 is the most active receptor in the development of inflammation, emphysema and systemic weight loss in this murine model of chronic obstructive pulmonary disease. 相似文献
5.
S Chinn S H Downs J M Anto M W Gerbase B Leynaert R de Marco C Janson D Jarvis N Künzli J Sunyer C Svanes E Zemp U Ackermann-Liebrich P Burney 《The European respiratory journal》2006,28(4):763-771
The incidence of asthma has been reported to be associated with obesity. An alternative analysis, of net change in prevalence, does not require exclusion of those with asthma at baseline. Follow-up data were obtained from 9,552 participants in the European Community Respiratory Health Survey and the Swiss cohort Study on Air Pollution and Lung Disease in Adults. Incidence of asthma was analysed by proportional hazards regression, and net changes in symptoms and asthma status by generalised estimating equations, by obesity group. Incidence and net change in ever having had asthma were greater in females than in males, and in participants who remained obese compared with those who were never obese (hazard ratio 2.00, 95% confidence interval 1.25-3.20; excess net change 2.8%, 0.4-5.3% per 10 yrs). The effect of being obese on net change in diagnosed asthma was greater in females than in males, but for net change in wheeze without a cold it was greater in males. The present results are consistent with asthma being more frequently diagnosed in females, especially obese females. These findings may help to explain the reports of a stronger association between asthma and obesity in females than in males. 相似文献
6.
7.
Cyanoacrylate-based glues have been reported as producing dermatitis and bronchial asthma. The paper describes the case of a patient occupationally exposed to Loctite 406, who developed irritation of the skin and mucosae of the face and late bronchial asthma. Preventive measures for subjects exposed to cyanoacrylic instant glues are discussed. 相似文献
8.
The response of single detergent treated bovine retinal pigment epithelial cells in culture to ATP was measured with an image analyser. The most pronounced contraction was produced by 1.0 mM ATP with most change taking place in the first 10 min. At 1 h the area had decreased by about 33%, perimeter 22% and maximum length 25%. By way of comparison rabbit skin fibroblasts had a decreased area of approximately 40%, perimeter 25% and maximum length 22%. Bovine aortic smooth muscle cells on the other hand decreased in area by 55%, perimeter 40% and maximum length 36%. It is hoped that this assay may be used to evaluate drugs which could counteract contractile events in proliferative vitreoretinopathy. 相似文献
9.
10.
4-Aminopyridine affects synaptosomal protein phosphorylation in rat hippocampal slices 总被引:2,自引:0,他引:2
Rat brain hippocampal slices were incubated with or without the convulsant 4-aminopyridine (4-AP). From these slices a crude mitochondrial/synaptosomal membrane fraction was prepared and analyzed for endogenous protein phosphorylation. 4-AP (10(-5) M) stimulated the phosphorylation of a 50 kDa protein by 86%. The phosphorylation of this 50 kDa protein is Ca2+/calmodulin-dependent and we suggest that this protein is the lower molecular weight subunit of Ca2+/calmodulin-dependent protein kinase II (CaMK II). 相似文献