全文获取类型
收费全文 | 1182篇 |
免费 | 64篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 68篇 |
妇产科学 | 33篇 |
基础医学 | 114篇 |
口腔科学 | 20篇 |
临床医学 | 103篇 |
内科学 | 208篇 |
皮肤病学 | 25篇 |
神经病学 | 112篇 |
特种医学 | 127篇 |
外国民族医学 | 1篇 |
外科学 | 121篇 |
综合类 | 108篇 |
预防医学 | 41篇 |
眼科学 | 6篇 |
药学 | 95篇 |
中国医学 | 1篇 |
肿瘤学 | 71篇 |
出版年
2022年 | 11篇 |
2021年 | 14篇 |
2020年 | 11篇 |
2019年 | 15篇 |
2018年 | 23篇 |
2017年 | 13篇 |
2016年 | 13篇 |
2015年 | 22篇 |
2014年 | 33篇 |
2013年 | 32篇 |
2012年 | 47篇 |
2011年 | 45篇 |
2010年 | 45篇 |
2009年 | 46篇 |
2008年 | 53篇 |
2007年 | 48篇 |
2006年 | 36篇 |
2005年 | 30篇 |
2004年 | 30篇 |
2003年 | 27篇 |
2002年 | 29篇 |
2001年 | 34篇 |
2000年 | 31篇 |
1999年 | 44篇 |
1998年 | 54篇 |
1997年 | 47篇 |
1996年 | 39篇 |
1995年 | 24篇 |
1994年 | 36篇 |
1993年 | 30篇 |
1992年 | 26篇 |
1991年 | 16篇 |
1990年 | 15篇 |
1989年 | 26篇 |
1988年 | 23篇 |
1987年 | 33篇 |
1986年 | 18篇 |
1985年 | 19篇 |
1984年 | 6篇 |
1983年 | 9篇 |
1982年 | 15篇 |
1981年 | 8篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1978年 | 11篇 |
1977年 | 8篇 |
1976年 | 11篇 |
1975年 | 9篇 |
1973年 | 7篇 |
1966年 | 5篇 |
排序方式: 共有1262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.
Developmental spectrum of the excitotoxic cascade induced by ibotenate: a model of hypoxic insults in fetuses and neonates 总被引:1,自引:0,他引:1
Ibotenate, a glutamatergic agonist, was used to study the spectrum of excitoxic disturbances at different ages of cerebral development. Cultures of whole mouse embryo were submitted to ibotenate at E8 for 20 h: during the phase of early premigratory differentiation; ibotenate did not induce any detectable histological lesion. During migration of supragranular neurons, newborn hamsters intracerebrally injected at P0 with ibotenate display neuronal migration disorders graded from nodular heterotopias to extensive laminar heterotopias mimicking some aspects of lissencephalic and double-cortex syndromes. After completion of neuronal layer V, P0 mice injected with ibotenate exhibit laminar neuronal depopulation of layer V-VIa mimicking human micro-gyria. At P5 in mouse, after completion of neuronal migration of the cortical plate, ibotenate induces neuronal loss in all cortical layers and the formation of porencephalic cysts. This study emphasizes the dramatic role played by glutamate in brain development, in the occurrence of neuronal migration disorders in the cortex. and in grey and white matter damage. 相似文献
6.
Serge Evrard Yves Bécouarn René Brunet Marianne Fonck Caroline Larrue Simone Mathoulin-Pélissier 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》2007,392(1):41-44
BACKGROUND AND AIMS: The aim of this work was to test the feasibility of using a bipolar low thermal acting system inducing collagenic sealing but not protein coagulation to secure hepatic parenchyma cutting. MATERIALS AND METHODS: Thirty consecutive hepatectomies were carried out using kellyclasy plus ligatures and clips (controls), while the following 50 hepatectomies used kellyclasy plus bipolar vessels sealer (BVS). Blood loss, duration of hepatic pedicle clamping, length of hospital stay, and complications were recorded. RESULTS: There was no statistically significant difference in blood loss and duration of clamping between controls and BVS. Specific complications (9/21 in the control group vs 1/49 for the BVS group, p<0.00045) and length of hospital stay (14 days in the control group vs 11 days in the BVS group, p<0.014) were statistically lower in BVS group than in the controls, mainly due to prevention of bile duct leakages. CONCLUSIONS: Our data suggest that BVS may be particularly efficient to achieve bilistasis leading to the highest level of safety in performing hepatectomies. Further studies are now needed to confirm its superiority on the classical biliary ducts occlusion techniques. 相似文献
7.
Ecological association between indoor radon concentration and childhood leukaemia incidence in France, 1990-1998. 总被引:1,自引:0,他引:1
A S Evrard D Hémon S Billon D Laurier E Jougla M Tirmarche J Clavel 《European journal of cancer prevention》2005,14(2):147-157
The objective of this study was to evaluate the ecological association between indoor radon concentration and acute leukaemia incidence among children under 15 years of age in the 348 geographical units (zones d'emploi, ZE) of France between 1990 and 1998. During that period, 4015 cases were registered by the French National Registry of Childhood Leukaemia and Lymphoma. Exposure assessment was based on a campaign of 13 240 measurements covering the whole country. The arithmetic mean radon concentration was 85 Bq/m (range, 15-387 Bq/m) and the geometric mean, 59 Bq/m (range: 13-228 Bq/m). A positive ecological association, on the borderline of statistical significance (P=0.053), was observed between indoor radon concentration and childhood leukaemia incidence. The association was highly significant for acute myeloid leukaemia (AML) (P=0.004) but not for acute lymphocytic leukaemia (ALL) (P=0.49). The standardized incidence ratio (SIR) increased by 7, 3 and 24% for all acute leukaemia, ALL and AML, respectively, when radon concentration increased by 100 Bq/m. In conclusion, the present ecological study supports the hypothesis of a moderate association between indoor radon concentration and childhood acute myeloid leukaemia. It is consistent with most previous ecological studies. Since the association is moderate, this result does not appear inconsistent with the five published case-control studies, most of which found no significant association. 相似文献
8.
Evaluation of a new enzyme-linked immunosorbent assay test for rotavirus antigen in faeces 总被引:6,自引:0,他引:6 下载免费PDF全文
A new commercial test for the diagnosis of rotavirus gastroenteritis was assessed. With some modifications it compared favourably with electron microscopy and immunofluorescence. 相似文献
9.
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
10.
Brites P Motley AM Gressens P Mooyer PA Ploegaert I Everts V Evrard P Carmeliet P Dewerchin M Schoonjans L Duran M Waterham HR Wanders RJ Baes M 《Human molecular genetics》2003,12(18):2255-2267
Rhizomelic chondrodysplasia punctata is a human autosomal recessive disorder characterized by skeletal, eye and brain abnormalities. The disorder is caused by mutations in the PEX7 gene, which encodes the receptor for a class of peroxisomal matrix enzymes. We describe the generation and characterization of a Pex7 mouse knockout (Pex7(-/-)). Pex7(-/-) mice are born severely hypotonic and have a growth impairment. Mortality in Pex7(-/-) mice is highest in the perinatal period although some Pex7(-/-) mice survived beyond 18 months. Biochemically Pex7(-/-) mice display the abnormalities related to a Pex7 deficiency, i.e. a severe depletion of plasmalogens, impaired alpha-oxidation of phytanic acid and impaired beta-oxidation of very-long-chain fatty acids. In the intermediate zone of the developing cerebral cortex Pex7(-/-) mice have an increase in neuronal density. In vivo neuronal birthdating revealed that Pex7(-/-) mice have a delay in neuronal migration. Analysis of bone ossification in newborn Pex7(-/-) mice revealed a defect in ossification of distal bone elements of the limbs as well as parts of the skull and vertebrae. These findings demonstrate that Pex7 knockout mice provide an important model to study the role of peroxisomal functioning in the pathogenesis of the human disorder. 相似文献