全文获取类型
收费全文 | 23947篇 |
免费 | 682篇 |
国内免费 | 581篇 |
专业分类
耳鼻咽喉 | 620篇 |
儿科学 | 1294篇 |
妇产科学 | 452篇 |
基础医学 | 2167篇 |
口腔科学 | 735篇 |
临床医学 | 1515篇 |
内科学 | 5133篇 |
皮肤病学 | 385篇 |
神经病学 | 1555篇 |
特种医学 | 678篇 |
外科学 | 3674篇 |
综合类 | 1085篇 |
一般理论 | 10篇 |
预防医学 | 2475篇 |
眼科学 | 508篇 |
药学 | 1716篇 |
8篇 | |
中国医学 | 644篇 |
肿瘤学 | 556篇 |
出版年
2024年 | 44篇 |
2023年 | 152篇 |
2022年 | 202篇 |
2021年 | 265篇 |
2020年 | 235篇 |
2019年 | 242篇 |
2018年 | 270篇 |
2017年 | 158篇 |
2016年 | 217篇 |
2015年 | 194篇 |
2014年 | 294篇 |
2013年 | 217篇 |
2012年 | 2172篇 |
2011年 | 2447篇 |
2010年 | 663篇 |
2009年 | 435篇 |
2008年 | 1867篇 |
2007年 | 2097篇 |
2006年 | 1853篇 |
2005年 | 1975篇 |
2004年 | 1869篇 |
2003年 | 1796篇 |
2002年 | 1682篇 |
2001年 | 1118篇 |
2000年 | 1629篇 |
1999年 | 757篇 |
1998年 | 105篇 |
1997年 | 33篇 |
1996年 | 37篇 |
1995年 | 36篇 |
1994年 | 25篇 |
1993年 | 24篇 |
1992年 | 14篇 |
1991年 | 17篇 |
1990年 | 7篇 |
1989年 | 11篇 |
1988年 | 16篇 |
1987年 | 5篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1957年 | 1篇 |
1942年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
73.
74.
75.
Suárez-Pérez E Oliver-Vázquez M De Andino R Vega R Conde J García M Rosario R Vélez H 《Puerto Rico health sciences journal》1999,18(4):377-386
In order to plan the health services for the elderly population, it is necessary to quantify their health status and their functional capacity. In Puerto Rico, few epidemiological studies have been conducted regarding functional capacity and chronic diseases in the elderly population. One of the difficulties to undertake these studies is the high cost and risks to move this population for clinical exams, in addition to the methodology limitation of self-report in the elderly population. This study shows the use of logistic regression to estimate the prevalence of chronic diseases and functional capacity, when the observed data are not consisted with the planed sampling scheme. Four hundred and eighty-seven elderly persons (65 yr. and over) were interviewed in the municipalities of Canóvanas, Carolina, Loíza and Trujillo Alto in Puerto Rico, using a cross-sectional design. More than half of the elderly had visual problems (IC 95%: 54.8%, 63.8%), arthritis (IC 95%: 52.7%, 61.5%) and hypertension (IC 95%: 47.3%, 56.3%). In the case of hypertension, significant differences (p < 0.05) by sex were observed, where women reported a higher prevalence than men. One of the higher prevalences in the functional capacity status was with urine accidents. More than one-third of the population is estimated to have this problem (IC 95%: 34.7%, 43.4%). One-fourth of the population had limitations with going out for shopping (IC 95%: 23.9%, 31.9%) and using public and private transportation (IC 95%: 19.5%, 26.9%). We conclude that the applied methodology was consistent with the estimation presented in the literature and statistics from the Puerto Rico Health Department. However, it is necessary to continue assessing the design and analytical methodology, in order to undertake consistent and periodic evaluations of the elderly population. 相似文献
76.
PURPOSE: To present the results of PC IOLs transscleral fixation to the ciliary sulcus in six years follow-up. MATERIAL AND METHODS: 152 eyes in 3 groups: 15 eyes with primary fixations of PC IOLs, 92 eyes with secondary fixations of PC IOLs and 45 eyes with secondary fixations of PC IOLs combined with penetrating keratoplasty. RESULTS: Postoperative corrected visual acuity was 0.5 or better in 32.2% of cases, the most common complications in our material was CME (9.9%), lens tilt (4.6%) and increase of IOP (3.95%). CONCLUSION: Transscleral fixation of PC IOLs offers good visual outcome with relatively low rate of complications and is recommended in cases with inadequate posterior capsule support. 相似文献
77.
78.
Hummer G Garde S García AE Pohorille A Pratt LR 《Proceedings of the National Academy of Sciences of the United States of America》1996,93(17):8951-8955
A molecular model of poorly understood hydrophobic effects is heuristically developed using the methods of information theory. Because primitive hydrophobic effects can be tied to the probability of observing a molecular-sized cavity in the solvent, the probability distribution of the number of solvent centers in a cavity volume is modeled on the basis of the two moments available from the density and radial distribution of oxygen atoms in liquid water. The modeled distribution then yields the probability that no solvent centers are found in the cavity volume. This model is shown to account quantitatively for the central hydrophobic phenomena of cavity formation and association of inert gas solutes. The connection of information theory to statistical thermodynamics provides a basis for clarification of hydrophobic effects. The simplicity and flexibility of the approach suggest that it should permit applications to conformational equilibria of nonpolar solutes and hydrophobic residues in biopolymers. 相似文献
79.
80.
Brzozowski Z Sławiński J Janiec W Cegieła U Sliwiński L Sedlak I 《Acta poloniae pharmaceutica》1992,49(5-6):75-79
Preparation of some novel 6-chloro-3-carboxyalkylamino-7-methyl-1,1-dioxo-1,4,2-benzodithiazines (I-V) and its sodium salts (Ia, IVa) have been elaborated. Their chemical structures have been confirmed by elemental analysis, IR and 1H-NMR spectrometry. In preliminary pharmacological examination compounds I, Ia, IV and IVa exhibited low acute toxicity, moreover investigated compounds shown hypertensive and cholagogic activity (I, Ia) and also hypotensive (IV, IVa) or diuretic (Ia, IVa) activity, on the other hand above mentioned compounds didn't exhibit antiarrhythmic activity. Some relationships between the chemical structure and pharmacological activity of the investigated compounds have also been discussed. 相似文献