全文获取类型
收费全文 | 709篇 |
免费 | 57篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 44篇 |
妇产科学 | 6篇 |
基础医学 | 84篇 |
口腔科学 | 15篇 |
临床医学 | 74篇 |
内科学 | 133篇 |
皮肤病学 | 16篇 |
神经病学 | 13篇 |
特种医学 | 120篇 |
外科学 | 51篇 |
综合类 | 107篇 |
预防医学 | 56篇 |
眼科学 | 3篇 |
药学 | 25篇 |
中国医学 | 1篇 |
肿瘤学 | 29篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 7篇 |
2020年 | 4篇 |
2019年 | 8篇 |
2018年 | 4篇 |
2017年 | 10篇 |
2016年 | 11篇 |
2015年 | 19篇 |
2014年 | 26篇 |
2013年 | 16篇 |
2012年 | 29篇 |
2011年 | 15篇 |
2010年 | 34篇 |
2009年 | 40篇 |
2008年 | 35篇 |
2007年 | 24篇 |
2006年 | 17篇 |
2005年 | 11篇 |
2004年 | 9篇 |
2003年 | 12篇 |
2002年 | 13篇 |
2001年 | 18篇 |
2000年 | 8篇 |
1999年 | 18篇 |
1998年 | 47篇 |
1997年 | 42篇 |
1996年 | 32篇 |
1995年 | 22篇 |
1994年 | 27篇 |
1993年 | 22篇 |
1992年 | 8篇 |
1991年 | 16篇 |
1990年 | 11篇 |
1989年 | 14篇 |
1988年 | 15篇 |
1987年 | 26篇 |
1986年 | 11篇 |
1985年 | 20篇 |
1984年 | 6篇 |
1983年 | 10篇 |
1982年 | 14篇 |
1981年 | 6篇 |
1980年 | 7篇 |
1979年 | 2篇 |
1978年 | 9篇 |
1977年 | 5篇 |
1976年 | 8篇 |
1975年 | 5篇 |
1967年 | 1篇 |
排序方式: 共有781条查询结果,搜索用时 15 毫秒
1.
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
2.
Coronary artery bypass grafts: visualization with MR imaging 总被引:1,自引:0,他引:1
3.
4.
5.
J F Cockburn C A Eynon N Virji J E Jackson 《AJR. American journal of roentgenology》1992,159(1):121-124
During a 9-month period, 69 Hickman catheters were successfully inserted by using angiographic techniques in 59 patients with hematologic disorders. A pneumothorax, which did not require drainage, developed in one patient. No other significant complications occurred at the time of insertion. Eighteen catheters were removed electively, 15 are still in situ, six were removed for thrombosis, and five were accidentally removed. Infection precipitated removal in six subjects. Ten patients died with the catheter in place. Five catheters were removed in patients with refractory septicemia of unknown origin. One catheter burst during an injection and had to be removed. Three patients were lost to follow-up. There were 3.24 infectious episodes per 1000 days of catheterization, more than twice the rate found in some other series. The results of this study are compatible with the growing body of evidence in favor of the angiographic insertion of Hickman catheters. The apparently high rate of infection is ascribed to factors other than insertion in the angiography suite, including the high proportion of bone marrow transplantation patients. 相似文献
6.
7.
Competitive control of the self-renewing T cell repertoire 总被引:1,自引:0,他引:1
We develop a mathematical model for the self-renewing part of the T cell
repertoire. Assuming that self-renewing T cells have to be stimulated by
immunogenic MHC-peptide complexes presented on the surfaces of
antigen-presenting cells, we derive a model of T cell growth in which
competition for MHC-peptide complexes limits T cell clone sizes and
regulates the total number of self-renewing T cells in the animal. We show
that for a sufficient diversity and/or degree of cross-reactivity, the
total T cell number hardly depends upon the diversity of the T cell
repertoire or the diversity of the set of presented peptides. Conversely,
for repertoires of lower diversity and/or cross-reactivity, steady-state
total T cell numbers may be limited by the diversity of the T cells. This
provides a possible explanation for the limited repertoire expansion in
some, but not all, mouse T cell re-constitution experiments. We suggest
that the competitive interactions described by our model underlie the
normal T cells numbers observed in transgenic mice, germ-free mice and
various knockout mice.
相似文献
8.
Role of anti-pilus antibodies in host defense against gonococcal infection studied with monoclonal anti-pilus antibodies. 总被引:6,自引:0,他引:6 下载免费PDF全文
Several monoclonal antibodies directed against gonococcal pili have been used to investigate the potential contribution of anti-pilus antibodies to host defense against gonococcal infection. Included were two antibodies (SM1 and SM2) which reacted with conserved determinants present on pili from all strains tested and others which exhibited antigenic specificity. Immunoblotting experiments revealed that antibodies SM1 and SM2 recognize epitopes on two different peptides derived by CNBr cleavage of alpha-pili from Neisseria gonorrhoeae P9-2. All antibodies used were capable of activating complement, as shown by their ability to bind Clq, and one type-specific antibody was effective in complement-mediated bactericidal killing. Antibodies directed against at least some pilus epitopes may therefore contribute to bactericidal activity during the course of natural infection. The opsonic effect of type-specific antibodies was demonstrated by their ability to stimulate luminol-dependent chemiluminescence of human polymorphonuclear leukocytes and promote phagocytic killing of variant P9-2. Phagocytic killing in the presence of each monoclonal antibody paralleled the increase in chemiluminescence, suggesting that for this variant killing was an inevitable consequence of the interaction of polymorphonuclear leukocytes with gonococci opsonized with anti-pilus antibodies. Antibody-mediated chemiluminescence of polymorphonuclear leukocytes was enhanced in the presence of human complement, and a weak opsonic effect was detected with one of the cross-reacting antibodies (SM1) when this system was used. Although cross-reacting antibody SM1 and type-specific antibody SM13 showed considerable differences in biological properties, they were of the same isotype and bound to native pili on intact gonococci in similar numbers and with similar avidity. 相似文献
9.
Survey of CAG/CTG repeats in human cDNAs representing new genes: candidates for inherited neurological disorders 总被引:3,自引:2,他引:3
Neri C; Albanese V; Lebre AS; Holbert S; Saada C; Bougueleret L; Meier-Ewert S; Le Gall I; Millasseau P; Bui H; Giudicelli C; Massart C; Guillou S; Gervy P; Poullier E; Rigault P; Weissenbach J; Lennon G; Chumakov I; Dausset J; Lehrach H; Cohen D; Cann HM 《Human molecular genetics》1996,5(7):1001-1009
10.