全文获取类型
收费全文 | 2579篇 |
免费 | 186篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 20篇 |
儿科学 | 39篇 |
妇产科学 | 40篇 |
基础医学 | 438篇 |
口腔科学 | 25篇 |
临床医学 | 293篇 |
内科学 | 636篇 |
皮肤病学 | 62篇 |
神经病学 | 292篇 |
特种医学 | 37篇 |
外科学 | 191篇 |
综合类 | 5篇 |
一般理论 | 1篇 |
预防医学 | 256篇 |
眼科学 | 46篇 |
药学 | 218篇 |
中国医学 | 9篇 |
肿瘤学 | 174篇 |
出版年
2024年 | 5篇 |
2023年 | 30篇 |
2022年 | 87篇 |
2021年 | 115篇 |
2020年 | 80篇 |
2019年 | 92篇 |
2018年 | 84篇 |
2017年 | 79篇 |
2016年 | 68篇 |
2015年 | 79篇 |
2014年 | 132篇 |
2013年 | 131篇 |
2012年 | 200篇 |
2011年 | 217篇 |
2010年 | 87篇 |
2009年 | 108篇 |
2008年 | 131篇 |
2007年 | 154篇 |
2006年 | 129篇 |
2005年 | 128篇 |
2004年 | 117篇 |
2003年 | 132篇 |
2002年 | 119篇 |
2001年 | 13篇 |
2000年 | 14篇 |
1999年 | 13篇 |
1998年 | 23篇 |
1997年 | 18篇 |
1996年 | 9篇 |
1995年 | 16篇 |
1994年 | 11篇 |
1993年 | 10篇 |
1992年 | 8篇 |
1991年 | 12篇 |
1990年 | 10篇 |
1989年 | 6篇 |
1987年 | 12篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1982年 | 10篇 |
1981年 | 4篇 |
1980年 | 6篇 |
1979年 | 5篇 |
1974年 | 5篇 |
1969年 | 5篇 |
1967年 | 3篇 |
1966年 | 7篇 |
1963年 | 5篇 |
1957年 | 4篇 |
排序方式: 共有2782条查询结果,搜索用时 343 毫秒
1.
2.
3.
4.
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.
S. Stegemann F. Leveiller D. Franchi H. de Jong H. Lindn 《European journal of pharmaceutical sciences》2007,31(5):249-261
Drug absorption, sufficient and reproducible bioavailability and/or pharmacokinetic profile in humans are recognized today as one of the major challenges in oral delivery of new drug substances. The issue arose especially when drug discovery and medicinal chemistry moved from wet chemistry to combinatorial chemistry and high throughput screening in the mid-1990s. Taking into account the drug product development times of 8–12 years, the apparent R&D productivity gap as determined by the number of products in late stage clinical development today, is the result of the drug discovery and formulation development in the late 1990s, which were the early and enthusiastic times of the combinatorial chemistry and high throughput screening. In parallel to implementation of these new technologies, tremendous knowledge has been accumulated on biological factors like transporters, metabolizing enzymes and efflux systems as well as on the physicochemical characteristics of the drug substances like crystal structures and salt formation impacting oral bioavailability. Research tools and technologies have been, are and will be developed to assess the impact of these factors on drug absorption for the new chemical entities.
The conference focused specifically on the impact of compounds with poor solubility on analytical evaluation, prediction of oral absorption, substance selection, material and formulation strategies and development. The existing tools and technologies, their potential utilization throughout the drug development process and the directions for further research to overcome existing gaps and influence these drug characteristics were discussed in detail. 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.
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
10.
Weller A Leguisamo AC Towns L Ramboz S Bagiella E Hofer M Hen R Brunner D 《Developmental psychobiology》2003,42(2):194-205
The influence of the pre- and postweaning maternal environment on the offspring's phenotype was examined in 5-HT1A and 5-HT1B receptor knockout mice (KO1A and KO1B, respectively). We have previously shown that, when born to and raised by homozygous dams of the same genotype, adult KO1A are more anxious than wild-type (WT) mice, and adult KO1B are hyperactive and slightly less anxious than WT mice. We extend our studies here to the behavioral results of the offspring's own genotype, when the dam's genotype is constant, and the effects of the dam's genotype when the offspring's genotype is constant. In Experiments 1 and 2, KO1A-/- pups produced less ultrasonic vocalizations (USV) than controls in an isolation test on postnatal Day 7 when born to and reared by KO1A dams, either -/- or +/-. Heterozygous F1 pups reared by KO1A-/- dams produced more USV and were less anxious in the plus-maze at 2 to 3 months of age than F1 pups born to and reared by WT dams (Experiment 3). F1 pups reared by KO1B-/- dams produced less USV and were more anxious in the plus-maze than F1 pups reared by WT dams (Experiment 4). The results support a role for maternal effects that may comprise direct effects such as the dam's behavior and nutritional care of the pup, and possibly more complex indirect effects through the establishment of idiosyncratic dam-pup dyadic interactions. We recommend that breeding techniques that rely on same genotype (mutant-mutant or WT-WT) breeding pairs not be used to generate offspring when the focus of research is the study of gene function, but rather when familial effects need to be studied. 相似文献