全文获取类型
收费全文 | 34254篇 |
免费 | 2378篇 |
国内免费 | 214篇 |
专业分类
耳鼻咽喉 | 473篇 |
儿科学 | 581篇 |
妇产科学 | 590篇 |
基础医学 | 4628篇 |
口腔科学 | 913篇 |
临床医学 | 3228篇 |
内科学 | 7489篇 |
皮肤病学 | 757篇 |
神经病学 | 2525篇 |
特种医学 | 1502篇 |
外科学 | 4776篇 |
综合类 | 902篇 |
现状与发展 | 1篇 |
一般理论 | 27篇 |
预防医学 | 2275篇 |
眼科学 | 965篇 |
药学 | 2488篇 |
中国医学 | 182篇 |
肿瘤学 | 2544篇 |
出版年
2023年 | 323篇 |
2022年 | 675篇 |
2021年 | 1225篇 |
2020年 | 657篇 |
2019年 | 924篇 |
2018年 | 1093篇 |
2017年 | 787篇 |
2016年 | 923篇 |
2015年 | 1168篇 |
2014年 | 1489篇 |
2013年 | 1698篇 |
2012年 | 2696篇 |
2011年 | 2612篇 |
2010年 | 1471篇 |
2009年 | 1345篇 |
2008年 | 1989篇 |
2007年 | 2025篇 |
2006年 | 1954篇 |
2005年 | 1942篇 |
2004年 | 1661篇 |
2003年 | 1385篇 |
2002年 | 1203篇 |
2001年 | 648篇 |
2000年 | 605篇 |
1999年 | 517篇 |
1998年 | 285篇 |
1997年 | 223篇 |
1996年 | 172篇 |
1995年 | 179篇 |
1994年 | 151篇 |
1993年 | 132篇 |
1992年 | 207篇 |
1991年 | 208篇 |
1990年 | 183篇 |
1989年 | 175篇 |
1988年 | 165篇 |
1987年 | 187篇 |
1986年 | 161篇 |
1985年 | 136篇 |
1984年 | 125篇 |
1983年 | 116篇 |
1982年 | 88篇 |
1981年 | 55篇 |
1980年 | 62篇 |
1979年 | 91篇 |
1977年 | 63篇 |
1976年 | 51篇 |
1974年 | 51篇 |
1970年 | 51篇 |
1969年 | 51篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
Marcelo Miranda MD Claudia Castiglioni MD Beat M. Frey MD Martin Hergersberg PhD Adrian Danek MD Hans H. Jung MD 《Movement disorders》2007,22(9):1358-1361
The X‐linked McLeod neuroacanthocytosis syndrome strongly resembles Huntington's disease and has been reported in various countries world‐wide. Herein, we report two Chilean brothers with predominant psychiatric features at disease onset including schizophrenia‐like psychosis and obsessive compulsive disorder. Molecular genetic analysis revealed a small deletion in the XK gene (938‐942delCTCTA), which has been already described in a North American patient of Anglo‐Saxon descent and a Japanese family, presenting with seizures, muscle atrophy or chorea yet absence of psychiatric features. These findings argue against a founder effect and indicate a profound phenotypic variability associated with the 938‐942delCTCTA deletion. Our report supports the inclusion of McLeod syndrome in the differential diagnosis of Huntington's disease as well as acute psychosis in male subjects. © 2007 Movement Disorder Society 相似文献
72.
Do commonly used oral antihypertensives alter fetal or neonatal heart rate characteristics? A systematic review. 总被引:1,自引:0,他引:1
E J Waterman L A Magee K I Lim A Skoll D Rurak P von Dadelszen 《Hypertension in pregnancy》2004,23(2):155-169
OBJECTIVE: To examine fetal (FHR) and neonatal heart rate patterns following use of common oral antihypertensives in pregnancy. METHODS: A systematic review of randomized controlled trials (RCTs), observational studies (N >/= 6 women), and animal studies. Data were abstracted (two reviewers) to determine relative risk (RR) (or risk difference (RD) for low event rates) and 95% CI. RESULTS: Eighteen RCTs (1858 women), one controlled observational study (N = 22), and seven case series (N = 117) were reviewed. Most hypertension was pregnancy-induced (N = 14 studies). The FHR was assessed by cardiotocogram (CTG) (N = 17 studies (visual interpretation); 1 study (computerized CTG), or umbilical artery velocimetry (N = 4). Four studies examined neonatal heart rate. In placebo-controlled RCTs (N = 192 women), adverse FHR effects did not differ between groups [9/101 (drugs) vs. 7/91 (placebo); RD 0.02, 95% CI (- 0.06, 0.11); chi2 = 1.02]. In six drug vs. drug RCTs (295 women), adverse FHR effects did not differ between groups [29/144 (methyldopa) vs. 42/151 (other drugs); RR 0.72, 95% CI (0.49, 1.07); chi2 = 0.69]. In one labetalol vs. placebo trial, neonatal bradycardia did not differ between groups [4/70 (labetalol) vs. 4/74 (placebo); OR 1.06, 95% CI (0.26, 4.39)], while in three drug vs. drug RCTs, neonatal bradycardia was not observed (0/24 vs. 0/26). CONCLUSIONS: Available data are inadequate to conclude whether oral methyldopa, labetalol, nifedipine, or hydralazine adversely affect fetal or neonatal heart rate and pattern. Until definitive data are available, FHR changes cannot be reliably attributed to drug effect, but may be due to progression of the underlying maternal or placental disease. 相似文献
73.
Werner Adrian 《Clinical & experimental optometry》2003,86(3):179-182
Background: Field studies of the duration of fixation during daytime driving find that it is about 0.2 seconds on average. Thus, the time available to read traffic signs is often limited. There are other circumstances where time to read alphanumeric messages is limited. Data relating time of observation are needed for purposes of ergonomic design as the data available in the literature are limited and uncertain. Method: Visual acuity was measured using Landolt rings in negative contrast, which were presented on a computer screen with a background luminance of 32 cd/m2 for durations that varied between two and 0.02 seconds at three different contrasts. Resulte: Visual acuity depends on the log of the light dose reduced by a factor that may be related to absorption of the light by the eye media. For young observers, it was found that: VA = 0.57 (log C t) + 1.705, where C is the contrast and is expressed as δL/L, where δL is the difference between target and background luminances in cd/m2 and t is the observation time in seconds. Conclusion: This formula or the functions fitted to the data obtained can be used to calculate the increase in target size needed to allow for short observation times. 相似文献
74.
Following the discovery of X-rays in 1895 by Wilhelm Röntgen the value to the military surgeon of the new technique was soon realised. The localisation of retained bullets by radiography avoided inappropriate exploration of the wound. The X-rays were first used on casualties from the Abyssinian War of 1896 and the developing radiological technology was progressively applied to military surgery. In addition the needs of warfare stimulated the development of all aspects of radiology. 相似文献
75.
76.
Paul S Ramphal Daniel N Coore Michael P Craven Neil F Forbes Somara M Newman Adrian A Coye Sherard G Little Brian C Silvera 《European journal of cardio-thoracic surgery》2005,27(5):910-916
OBJECTIVE: Issues concerning the training and certification of surgical specialists have taken on great significance in the last decade. A realistic computer-assisted, tissue-based simulator developed for use in the training of cardiac surgical residents in the conduct of a variety of cardiac surgical procedures in a low-volume cardiothoracic surgery unit of a typical developing country is described. The simulator can also be used to demonstrate the function of technology specific to cardiac surgical procedures in a way that previously has only been possible via the conduct of a procedure on a live animal or human being. METHODS: A porcine heart in a novel simulated operating theatre environment with real-time simulated haemodynamic monitoring and coronary blood flow, in arrested and beating-heart modes, is used as a training tool for surgical residents. RESULTS: Standard and beating-heart coronary arterial bypass, aortic valve replacement, aortic homograft replacement and pulmonary autograft procedures can be simulated with high degrees of realism and with the superimposition of adverse clinical scenarios requiring valid decision making and clinical judgments to be made by the trainees. CONCLUSIONS: The cardiac surgical simulation preparation described here would appear to be able to contribute positively to the training of residents in low-volume centres, as well as having the potential for application in other settings as a training tool or clinical skills assessment or accreditation device. Collaboration with larger centres is recommended in order to accurately assess the utility of this preparation as an adjunctive cardiothoracic surgical training aid. 相似文献
77.
78.
Adrian Fogarty 《British medical journal》2003,326(7403):1396-1397
79.
80.