全文获取类型
收费全文 | 2917篇 |
免费 | 204篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 46篇 |
妇产科学 | 118篇 |
基础医学 | 411篇 |
口腔科学 | 30篇 |
临床医学 | 336篇 |
内科学 | 686篇 |
皮肤病学 | 57篇 |
神经病学 | 368篇 |
特种医学 | 81篇 |
外科学 | 198篇 |
综合类 | 6篇 |
一般理论 | 1篇 |
预防医学 | 291篇 |
眼科学 | 47篇 |
药学 | 218篇 |
中国医学 | 9篇 |
肿瘤学 | 211篇 |
出版年
2024年 | 6篇 |
2023年 | 31篇 |
2022年 | 110篇 |
2021年 | 116篇 |
2020年 | 83篇 |
2019年 | 97篇 |
2018年 | 94篇 |
2017年 | 82篇 |
2016年 | 76篇 |
2015年 | 87篇 |
2014年 | 142篇 |
2013年 | 144篇 |
2012年 | 205篇 |
2011年 | 228篇 |
2010年 | 101篇 |
2009年 | 114篇 |
2008年 | 151篇 |
2007年 | 185篇 |
2006年 | 163篇 |
2005年 | 165篇 |
2004年 | 128篇 |
2003年 | 146篇 |
2002年 | 129篇 |
2001年 | 34篇 |
2000年 | 28篇 |
1999年 | 28篇 |
1998年 | 29篇 |
1997年 | 22篇 |
1996年 | 13篇 |
1995年 | 18篇 |
1994年 | 8篇 |
1993年 | 9篇 |
1992年 | 11篇 |
1991年 | 17篇 |
1990年 | 15篇 |
1989年 | 8篇 |
1988年 | 8篇 |
1987年 | 18篇 |
1986年 | 8篇 |
1985年 | 6篇 |
1984年 | 9篇 |
1983年 | 6篇 |
1982年 | 10篇 |
1981年 | 4篇 |
1980年 | 6篇 |
1979年 | 10篇 |
1976年 | 7篇 |
1974年 | 6篇 |
1971年 | 4篇 |
1966年 | 3篇 |
排序方式: 共有3137条查询结果,搜索用时 0 毫秒
1.
2.
M R Garcia N D Ryan H Rabinovitch P Ambrosini J Twomey S Iyengar H Novacenko B Nelson J Puig-Antich 《Journal of the American Academy of Child and Adolescent Psychiatry》1991,30(3):398-406
In an effort to evaluate whether differences exist in the hypothalamic-pituitary-thyroid axis of depressed children, a thyrotropin releasing hormone (TRH) stimulation test was administered to 55 prepubertal subjects who were divided into three groups matched for age and sex: a depressed group (endogenous N = 15, nonendogenous N = 15), a psychiatric nondepressed control group (N = 16), and a normal control group (N = 9). Each subject was tested at two dosages of TRH, 2 micrograms/kg and 7 micrograms/kg. Increasing age and female sex were positively correlated with a greater thyroid stimulating hormone (TSH) response. TSH response to TRH was examined with subjects reclassified by severe suicidal ideation, severe aggression, and parental history of alcoholism. Results of this study are contrasted with the adult psychiatric literature. 相似文献
3.
4.
E Cosmi P Litta A Andrisani L Di Lenardo G M Fadda G Ambrosini 《Ultrasound in obstetrics & gynecology》2005,25(4):415-416
5.
Cristina Tassorelli Francesca Mancini Laura Balloni Claudio Pacchetti Giorgio Sandrini Giuseppe Nappi Emilia Martignoni 《Movement disorders》2006,21(12):2240-2243
Currently, the best treatment option for idiopathic cervical dystonia (ICD) is injection of botulinum toxin (BTX) into the affected muscles, whereas rehabilitative approaches have given disappointing results. We evaluated whether the association of an ad hoc rehabilitative program may improve the clinical efficacy of BTX treatment in a single-center, cross-over, controlled study. Forty patients with ICD were randomly assigned to two different treatment groups: (1) BTX type A (BTX-A) plus a specific program of physical therapy (BTX-PT) or (2) BTX-A alone (BTX-0). Patients in the BTX-PT group showed a longer duration of the clinical benefit (118.8 vs. 99.1 days) and needed a lower dose of BTX at reinjection (284.5 vs. 325.5 units). In addition, they showed more marked reductions in their disability in activities of daily living (-9.7 vs. -4.85 points) and subjective pain (-13.35 vs. 6.95 points) scores. Association of BTX-A therapy with a specific program of physical therapy may improve ICD treatment outcome. 相似文献
6.
Female adult rats were trained for a two-way active avoidance task (4 h), and allowed free sleep (3 h). Control rats (C) were left in their home cages during the acquisition period. Dural electrodes and an intraventricular cannula, implanted one week in advance, were used for EEG recording during the period of sleep and for the injection of [3H]thymidine at the beginning of the training session, respectively. Rats were killed at the end of the sleep period, and the DNA-specific activity was determined in the main brain regions and in liver. Correlations among sleep, behavioral and biochemical variables were assessed using Spearman's nonparametric method. In learning rats (L), the number of avoidances was negatively correlated with SS-W variables, and positively correlated with SS-PS variables (episodes of synchronized sleep followed by wakefulness or paradoxical sleep, respectively) and with PS variables. An inverse pattern of correlations was shown by the number of escapes or freezings. No correlations occurred in rats unable to achieve the learning criterion (NL). In L rats, the specific activity of brain DNA was negatively correlated with SS-W variables and positively correlated with SS-PS variables, while essentially no correlation concerned PS variables. On the other hand, in NL rats, comparable correlations were positive with SS-W variables and negative with SS-PS and PS variables. Few and weak correlations occurred in C rats. The data support a role of SS in brain information processing, as postulated by the sequential hypothesis on the function of sleep. In addition, they suggest that the elimination of nonadaptive memory traces may require several SS-W episodes and a terminal SS-PS episode. During PS episodes, adaptive memory traces cleared of nonadaptive components may be copied in more suitable brain sites. 相似文献
7.
Support vector machines (SVMs) are a powerful technique developed in the last decade to effectively tackle classification and regression problems. In this paper we describe how support vector machines and artificial neural networks can be integrated in order to classify objects correctly. This technique has been successfully applied to the problem of determining the quality of tiles. Using an optical reader system, some features are automatically extracted, then a subset of the features is determined and the tiles are classified based on this subset. 相似文献
8.
9.
A. Urbano C. Babiloni P. Onorati F. Carducci A. Ambrosini L. Fattorini F. Babiloni 《The European journal of neuroscience》1998,10(2):765-770
We modelled the responses of human primary sensorimotor areas and supplementary motor area to simple, self-initiated unilateral and simultaneous bilateral middle finger movements using a novel high-resolution electroencephalography technology. The results support the view that these cortical motor areas are involved in parallel and present similar activity in the preparation, initiation, and execution of the contralateral and bilateral movements. Furthermore, the left primary sensorimotor area (dominant hemisphere) appears to be activated more than the right primary sensorimotor area during the preparation and performance of the ipsilateral movements. 相似文献
10.
Emilia Lachica Aurelio Luna Enrique Villanueva 《International journal of legal medicine》1989,103(2):111-119
Summary The diagnosis of myocardial infarction requires the use of a group of tests that are very efficient, quick and inexpensive. Another important consideration is the choice of myocardial sampling zones, especially in cases of differential diagnosis between a cardiac injury secondary to a trauma or violent asphyxia and others, secondary to myocardial infarction. The aim of this work was to choose, through discriminant analysis, the most useful zones of cardiac tissue for the quantification of free fatty acids and free carnitine and for the performance of the K/Na quotient, as biochemical parameters for the postmortem diagnosis of myocardial infarction. According to the discriminant analysis performed, seven zones of cardiac tissue are necessary to achieve a differential diagnosis among myocardial infarction, other natural deaths, and violent deaths with a 71.9% efficacy. Greater diagnostic efficacy was found (78.1%) for differentiating between natural deaths and violent deaths.
Offprint requests to: E. Lachica 相似文献