全文获取类型
收费全文 | 2885535篇 |
免费 | 217717篇 |
国内免费 | 5447篇 |
专业分类
耳鼻咽喉 | 38837篇 |
儿科学 | 95115篇 |
妇产科学 | 80063篇 |
基础医学 | 409473篇 |
口腔科学 | 85687篇 |
临床医学 | 258959篇 |
内科学 | 557559篇 |
皮肤病学 | 63680篇 |
神经病学 | 228636篇 |
特种医学 | 111995篇 |
外国民族医学 | 698篇 |
外科学 | 437201篇 |
综合类 | 70098篇 |
现状与发展 | 6篇 |
一般理论 | 1011篇 |
预防医学 | 220246篇 |
眼科学 | 68266篇 |
药学 | 214798篇 |
9篇 | |
中国医学 | 6372篇 |
肿瘤学 | 159990篇 |
出版年
2018年 | 30275篇 |
2017年 | 23313篇 |
2016年 | 25728篇 |
2015年 | 29459篇 |
2014年 | 40903篇 |
2013年 | 61087篇 |
2012年 | 83759篇 |
2011年 | 88273篇 |
2010年 | 52326篇 |
2009年 | 49207篇 |
2008年 | 83070篇 |
2007年 | 88058篇 |
2006年 | 88954篇 |
2005年 | 85689篇 |
2004年 | 83639篇 |
2003年 | 79856篇 |
2002年 | 77479篇 |
2001年 | 140819篇 |
2000年 | 144876篇 |
1999年 | 121273篇 |
1998年 | 32821篇 |
1997年 | 29225篇 |
1996年 | 29175篇 |
1995年 | 28161篇 |
1994年 | 26219篇 |
1993年 | 24397篇 |
1992年 | 96113篇 |
1991年 | 93368篇 |
1990年 | 90528篇 |
1989年 | 87322篇 |
1988年 | 80450篇 |
1987年 | 78873篇 |
1986年 | 74933篇 |
1985年 | 71945篇 |
1984年 | 53312篇 |
1983年 | 45792篇 |
1982年 | 26375篇 |
1981年 | 23599篇 |
1979年 | 49410篇 |
1978年 | 34075篇 |
1977年 | 28953篇 |
1976年 | 27178篇 |
1975年 | 28770篇 |
1974年 | 35094篇 |
1973年 | 33729篇 |
1972年 | 31168篇 |
1971年 | 29235篇 |
1970年 | 27042篇 |
1969年 | 25318篇 |
1968年 | 23329篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
In order to draw attention to this rather rare condition affecting all age groups, 4 cases of fibroepithelial polyps of the ureter are reported. Conservative surgery is mandatory after adequate preoperative work-up. The pathological findings, incidence and diagnostic and therapeutic modalities are discussed and some etiological factors proposed. 相似文献
993.
994.
995.
Association between PCBs and lower embryonic weight in black-crowned night herons in San Francisco Bay 总被引:3,自引:0,他引:3
D J Hoffman B A Rattner C M Bunck A Krynitsky H M Ohlendorf R W Lowe 《Journal of toxicology and environmental health》1986,19(3):383-391
Reproductive problems, including congenital malformations, reduced hatching success, and decreased survival of hatchlings, have been observed in colonial-nesting water birds at the San Francisco Bay National Wildlife Refuge (SFBNWR). Twenty-four black-crowned night heron (Nycticorax nycticorax) eggs were collected from SFBNWR in 1983. Twelve of these were collected from separate nests when late-stage embryos were pipping, and an additional egg was randomly collected from each nest for organochlorine analysis. Overt anomalies and skeletal defects were not apparent. Embryonic weights (with partially absorbed yolk sacs removed) were 15% lower (p less than 0.05) in SFBNWR embryos compared to control embryos from the Patuxent Wildlife Research Center (PWRC). Crown-rump length and femur length were shorter for SFBNWR embryos. The geometric mean polychlorinated biphenyl (PCB) concentration in SFBNWR eggs was 4.1 ppm wet weight, with a range of 0.8-52.0 ppm. A negative correlation (r = -0.61; p less than 0.05) existed between embryonic weight and log-transformed PCB residues in whole eggs collected from the same nest at SFBNWR, suggesting a possible impact of PCBs on embryonic growth. A correlation with embryonic weight did not occur for DDE [1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene] residues. Liver microsomal aryl hydrocarbon hydroxylase activity was neither significantly elevated nor correlated with PCB, DDE, or PCB plus DDE log-transformed residues. It is unknown whether the apparent association between PCBs and lower weight is persistent through hatching. 相似文献
996.
R A Weddell 《Scandinavian journal of rehabilitation medicine》1987,19(3):93-98
In view of the strong evidence supporting the hypothesis that high Expressed Emotion of a key relative contributes to relapse in psychiatric patients, methods used in Expressed Emotion research were applied in an investigation of psychiatric disorder in stroke patients receiving hospital based rehabilitation and support. Patient mood in 37 stroke patients was related to the critical attitude of a key relative. Patient depression may also have been associated with severity of dysphasia, but no link was found between patient mood and the other measures of cognitive or physical deficit used in this study. Psychiatric distress in the key relative had a rather different causal basis. Relatives' psychiatric disorders were associated with physical burden, cognitive deficit, and severity of dysphasia. This study suggests that, when the patient is dependent for self-care, rehabilitation-assisted recovery may alleviate relative distress more than patient distress. 相似文献
997.
998.
P A DeSimone C A Martin C B Bacdayan J S Macdonald F J Rizzo J Engelberg 《Hospital practice (Office ed.)》1986,21(1):158, 160, 165-158, 7 passim
999.
Alpha-adrenoreceptor reagents. 4. Resolution of some potent selective prejunctional alpha 2-adrenoreceptor antagonists 总被引:1,自引:0,他引:1
A P Welbourn C B Chapleo A C Lane P L Myers A G Roach C F Smith M R Stillings I F Tulloch 《Journal of medicinal chemistry》1986,29(10):2000-2003
The resolution of three 2-substituted derivatives of idazoxan is described. The enantiomers show large separations in activity in a variety of in vitro and in vivo tests, and the active isomers are all potent and selective antagonists at the alpha 2-adrenoreceptor. The significance of these results in relation to those published on the enantiomers of idazoxan and to those on optically active alpha 2-adrenoreceptor agonists is discussed. 相似文献
1000.
E B Nelson D R Abernethy D J Greenblatt B Ameer 《British journal of clinical pharmacology》1986,22(1):111-113
Disposition of paracetamol oral elixir was determined in two male patients after administration via feeding jejunostomy and compared with four male controls who received the same dose by mouth. Area under the plasma concentration-time curve, elimination half-life, and time to maximum concentration were similar in both groups after 650 mg paracetamol elixir. The absolute amounts and ratio of paracetamol glucuronide to sulphate, the major urinary metabolites after therapeutic paracetamol doses, were similar after jejunal administration as compared to oral administration. Paracetamol is absorbed and biotransformed in a similar manner after either jejunal or oral administration. Therefore, it may be administered effectively via jejunostomy tube in patients who require this route of administration. 相似文献