全文获取类型
收费全文 | 6310篇 |
免费 | 268篇 |
国内免费 | 64篇 |
专业分类
耳鼻咽喉 | 183篇 |
儿科学 | 343篇 |
妇产科学 | 230篇 |
基础医学 | 451篇 |
口腔科学 | 295篇 |
临床医学 | 627篇 |
内科学 | 1499篇 |
皮肤病学 | 97篇 |
神经病学 | 329篇 |
特种医学 | 339篇 |
外科学 | 1215篇 |
综合类 | 203篇 |
预防医学 | 158篇 |
眼科学 | 235篇 |
药学 | 224篇 |
中国医学 | 6篇 |
肿瘤学 | 208篇 |
出版年
2024年 | 5篇 |
2023年 | 57篇 |
2022年 | 77篇 |
2021年 | 119篇 |
2020年 | 89篇 |
2019年 | 135篇 |
2018年 | 141篇 |
2017年 | 133篇 |
2016年 | 155篇 |
2015年 | 209篇 |
2014年 | 229篇 |
2013年 | 297篇 |
2012年 | 424篇 |
2011年 | 386篇 |
2010年 | 259篇 |
2009年 | 234篇 |
2008年 | 492篇 |
2007年 | 525篇 |
2006年 | 503篇 |
2005年 | 442篇 |
2004年 | 352篇 |
2003年 | 295篇 |
2002年 | 231篇 |
2001年 | 133篇 |
2000年 | 115篇 |
1999年 | 118篇 |
1998年 | 76篇 |
1997年 | 65篇 |
1996年 | 50篇 |
1995年 | 28篇 |
1994年 | 35篇 |
1993年 | 32篇 |
1992年 | 16篇 |
1991年 | 23篇 |
1990年 | 13篇 |
1989年 | 12篇 |
1988年 | 15篇 |
1987年 | 28篇 |
1986年 | 8篇 |
1985年 | 12篇 |
1984年 | 5篇 |
1983年 | 7篇 |
1982年 | 14篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1978年 | 8篇 |
1977年 | 5篇 |
1976年 | 8篇 |
1975年 | 6篇 |
1971年 | 3篇 |
排序方式: 共有6642条查询结果,搜索用时 15 毫秒
1.
2.
3.
Targeting in a cellular level is still one of the major challenges in biomedical treatments. However, new synthetic and analytical techniques now allow the development of precisely prepared macromolecules. Thus, glycopolymer chains are reported to be prepared with controlled length, monomer sequences, as well as chain‐folded structures. A high level of complexity in synthetic macromolecules also allows increased selectivity in targeting, which is a key factor in biomedical applications. 相似文献
4.
Akira Sawaki Nobumasa Mizuno Kuniyuki Takahashi Tsuneya Nakamura Masahiro Tajika Hiroki Kawai Toshifumi Isaka Hiroshi Imaoka Yasuyuki Okamoto Masatoshi Aoki Hiroyuki Inoue Ahmed AS Salem Yasushi Yatabe Kenji Yamao 《Digestive endoscopy》2006,18(1):40-44
Background: Gastrointestinal stromal tumors (GIST) are one of the most common mesenchymal tumors of the gastrointestinal tract. GIST are defined by positive immunohistochemical staining for KIT or CD34 and thus are generally diagnosed after surgery. Because small GIST are rarely diagnosed before surgery, the clinical course of these small tumors is not clear. The aim of the present study was to follow changes in size and configuration of small GIST that were pathologically confirmed using endoscopic ultrasonography‐guided fine‐needle aspiration biopsy (EUS‐FNAB). Methods: Between July 1997 and December 2003, 16 tumors in 16 patients (10 men and 6 women) with an immunohistochemical diagnosis of GIST were regularly followed in our hospital. The median patient age when EUS‐FNAB was performed was 62 years (range 26–82 years) and the median follow‐up period was 4.9 years (range 0.5–9.6 years). Results: Fourteen tumors showed no remarkable changes in size and shape during follow up compared with the initial diagnosis. Two tumors enlarged: one tumor approximately doubled its diameter in 8 years and the other tumor increased from 1.8 cm at diagnosis to up to 10 cm after only 2 years. Doubling time of the latter tumor was calculated as 3.1 months. Conclusions: We conclude that EUS‐FNAB might be a good modality for final diagnosis of GIST without surgery, and that GIST without rapid growth on follow up can be endoscopically followed. 相似文献
5.
Coronary artery bypass grafts: visualization with MR imaging 总被引:1,自引:0,他引:1
6.
7.
Formulation and in Vitro-in Vivo Evaluation of Sustained-Release Lithium Carbonate Tablets 总被引:1,自引:0,他引:1
Çiftçi Kadriye Çapan Yilmaz Öztürk Orhan Hincal A. Atilla 《Pharmaceutical research》1990,7(4):359-363
The release of lithium carbonate incorporated into polymethylmethacrylate, poly vinyl chloride, hy-drogenated vegetable oil, and carbomer matrix tablets was studied in vitro. The formulation containing 10% carbomer showed a sustained-release profile comparable to that of a standard, commercially available, sustained-release preparation containing 400 mg lithium carbonate embedded in a composite material. In vivo the newly formulated and standard sustained-release lithium carbonate tablets were compared to an oral solution and conventional lithium carbonate tablets in 12 healthy subjects. These crossover studies showed that the sustained-release tablets produced a flatter serum concentration curve than the oral solution and conventional tablet, without loss of total bioavailability. 相似文献
8.
9.
10.