全文获取类型
收费全文 | 181392篇 |
免费 | 13013篇 |
国内免费 | 4235篇 |
专业分类
耳鼻咽喉 | 1363篇 |
儿科学 | 2580篇 |
妇产科学 | 3060篇 |
基础医学 | 23744篇 |
口腔科学 | 3445篇 |
临床医学 | 12241篇 |
内科学 | 23328篇 |
皮肤病学 | 2217篇 |
神经病学 | 12145篇 |
特种医学 | 6450篇 |
外国民族医学 | 3篇 |
外科学 | 14770篇 |
综合类 | 24153篇 |
现状与发展 | 21篇 |
一般理论 | 8篇 |
预防医学 | 15022篇 |
眼科学 | 2306篇 |
药学 | 25835篇 |
53篇 | |
中国医学 | 12733篇 |
肿瘤学 | 13163篇 |
出版年
2024年 | 335篇 |
2023年 | 2219篇 |
2022年 | 4750篇 |
2021年 | 7531篇 |
2020年 | 6048篇 |
2019年 | 6148篇 |
2018年 | 6177篇 |
2017年 | 6765篇 |
2016年 | 6764篇 |
2015年 | 6304篇 |
2014年 | 7050篇 |
2013年 | 11078篇 |
2012年 | 8938篇 |
2011年 | 10867篇 |
2010年 | 6769篇 |
2009年 | 6899篇 |
2008年 | 8436篇 |
2007年 | 9469篇 |
2006年 | 8905篇 |
2005年 | 8276篇 |
2004年 | 7082篇 |
2003年 | 6356篇 |
2002年 | 5030篇 |
2001年 | 4525篇 |
2000年 | 3788篇 |
1999年 | 3242篇 |
1998年 | 2512篇 |
1997年 | 2621篇 |
1996年 | 2405篇 |
1995年 | 2089篇 |
1994年 | 2026篇 |
1993年 | 1712篇 |
1992年 | 1571篇 |
1991年 | 1470篇 |
1990年 | 1275篇 |
1989年 | 1042篇 |
1988年 | 997篇 |
1987年 | 907篇 |
1986年 | 843篇 |
1985年 | 1250篇 |
1984年 | 1019篇 |
1983年 | 752篇 |
1982年 | 794篇 |
1981年 | 656篇 |
1980年 | 636篇 |
1979年 | 502篇 |
1978年 | 321篇 |
1977年 | 275篇 |
1976年 | 259篇 |
1975年 | 197篇 |
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
11.
12.
13.
14.
Xiying Fan Glen A. Bjerke Kent Riemondy Li Wang Rui Yi 《Molecular carcinogenesis》2019,58(12):2241-2253
MicroRNAs (miRNAs) play important roles in prostate cancer development. However, it remains unclear how individual miRNAs contribute to the initiation and progression of prostate cancer. Here we show that a basal layer‐enriched miRNA is required for prostate tumorigenesis. We identify miR‐205 as the most highly expressed miRNA and enriched in the basal cells of the prostate. Although miR‐205 is not required for normal prostate development and homeostasis, genetic deletion of miR‐205 in a Pten null tumor model significantly compromises tumor progression and does not promote metastasis. In Pten null basal cells, loss of miR‐205 attenuates pAkt levels and promotes cellular senescence. Furthermore, although overexpression of miR‐205 in prostate cancer cells with luminal phenotypes inhibits cell growth in both human and mouse, miR‐205 has a minimal effect on the growth of a normal human prostate cell line. Taken together, we have provided genetic evidence for a requirement of miR‐205 in the progression of Pten null‐induced prostate cancer. 相似文献
15.
This study is focussed on micro-encapsulation of essential oils in polylactic acid (PLA) and a poly(methyl methacrylate) (PMMA) matrix as well as blends of the same. Microspheres were prepared by the solvent evaporation technique and characterised by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infra-red spectroscopy (FTIR). The encapsulation efficiencies and release profiles of the essential oils were studied by gas chromatography mass spectrometry (GC-MS) and head-space solid-phase microextraction GC-MS, respectively. Furthermore, the microspheres were tested for antibacterial activity against both Gram-negative and Gram-positive bacterial strains.
The results showed that the microspheres compositions (PLA/PMMA ratio) have significant effect on their characteristics. The process adopted for preparing the microspheres promoted formation of spherical particles at the sizes of 1.5–9.5?µm. The highest encapsulation efficiency of the prepared microspheres was observed in systems consisting of linalool (81.10?±?10.0?wt. % for PLA system and 76.0?±?3.3?wt. % for PMMA system). Confirmation was also made that the release rate of the microspheres was affected by the size of the same. 相似文献
16.
17.
目的总结近年来股骨转子间骨折在稳定性重建方面的概念演化与研究进展。方法查阅国内外相关文献并结合自身经验,从股骨转子间骨折的解剖特点、稳定型骨折与不稳定型骨折分类、稳定性复位与不稳定性复位、术中加压初始稳定与术后滑动二次稳定、内固定术后稳定性评估、早期下地站立负重等方面进行总结分析。结果股骨转子间骨折发生于股骨颈干骺端转换区,具有天然的内翻不稳定倾向。骨折复位质量是影响后续内固定物安放的最重要前提因素。判断骨折复位质量有对线和对位两方面,对线采用 Garden 指数;在对位方面,随着皮质对位理念(正性、中性、负性)的提出,特别强调前内侧皮质的相互砥住支撑(解剖、正性),是获得骨折稳定性复位的关键,而不再强调后内侧小转子骨块的作用。术后影像学的稳定性评分为早期下地站立负重提供了量化指标。但术中的前内侧皮质支撑复位,在术后头颈骨块滑动获得二次稳定的过程中,仍有皮质对位丢失现象,需研究其危险因素和防范措施。结论股骨转子间骨折在取得良好对线的基础上,只要获得了前内侧皮质的相互砥住和支撑,并用内固定器械维持住,就获得了术后稳定性。术后稳定性评分优良者,可以安全地早期下地负重、站立行走活动。 相似文献
18.
19.
20.
《Foot and Ankle Surgery》2020,26(2):193-197
BackgroundThe aim of this study was to compare the radiographic and functional results between fixation and non-fixation in the Cotton osteotomy for the treatment of adult acquired flatfoot.MethodsA retrospective, case-controlled study of consecutive stage IIB posterior tibial tendon dysfunction (PTTD) patients treated with the same bony reconstructive surgery including cotton osteotomy between 2013 and 2017. Meary’s angle, the medial arch sag angle (MASA), and medial cuneiform cobb angle (MCCA) were evaluated pre-operation, at first weight bearing after surgery, and 12 months post operation.ResultsForty feet were included in the study. The cotton osteotomy utilized screw fixation (n = 20) or non-fixation technique (n = 20). No significant differences between groups were found in pre-operative and follow-up radiographic parameters, union rate, and functional results.ConclusionThe non-fixation with press fit technique is a reliable procedure for Cotton osteotomy and as effective as screw fixation.Level of evidenceLevel III, case control study 相似文献