全文获取类型
收费全文 | 10731篇 |
免费 | 766篇 |
国内免费 | 51篇 |
专业分类
耳鼻咽喉 | 179篇 |
儿科学 | 367篇 |
妇产科学 | 218篇 |
基础医学 | 1398篇 |
口腔科学 | 167篇 |
临床医学 | 975篇 |
内科学 | 2172篇 |
皮肤病学 | 258篇 |
神经病学 | 1072篇 |
特种医学 | 536篇 |
外科学 | 1744篇 |
综合类 | 52篇 |
预防医学 | 720篇 |
眼科学 | 132篇 |
药学 | 787篇 |
中国医学 | 15篇 |
肿瘤学 | 756篇 |
出版年
2023年 | 120篇 |
2022年 | 141篇 |
2021年 | 241篇 |
2020年 | 206篇 |
2019年 | 260篇 |
2018年 | 317篇 |
2017年 | 295篇 |
2016年 | 272篇 |
2015年 | 311篇 |
2014年 | 394篇 |
2013年 | 524篇 |
2012年 | 714篇 |
2011年 | 762篇 |
2010年 | 376篇 |
2009年 | 357篇 |
2008年 | 583篇 |
2007年 | 624篇 |
2006年 | 644篇 |
2005年 | 555篇 |
2004年 | 525篇 |
2003年 | 495篇 |
2002年 | 447篇 |
2001年 | 126篇 |
2000年 | 146篇 |
1999年 | 155篇 |
1998年 | 100篇 |
1997年 | 86篇 |
1996年 | 90篇 |
1995年 | 91篇 |
1994年 | 72篇 |
1993年 | 71篇 |
1992年 | 86篇 |
1991年 | 96篇 |
1990年 | 94篇 |
1989年 | 76篇 |
1988年 | 77篇 |
1987年 | 101篇 |
1986年 | 103篇 |
1985年 | 82篇 |
1984年 | 67篇 |
1983年 | 77篇 |
1982年 | 37篇 |
1981年 | 47篇 |
1980年 | 34篇 |
1979年 | 57篇 |
1978年 | 40篇 |
1976年 | 34篇 |
1975年 | 37篇 |
1974年 | 31篇 |
1973年 | 31篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Larsen TB Nielsen JN Fredholm L Lund ED Brandslund I Munkholm P Hey H 《Pathophysiology of haemostasis and thrombosis》2002,32(2):92-96
Patients with inflammatory bowel disease (IBD) are susceptible to thromboembolic complications. Several mechanisms can be responsible, including abnormal regulation of coagulation activity, disturbances of fibrinolysis, inflammatory reactions and thrombocytosis. The aim of this study was to assess hemostatic alterations in these parameters during exacerbation of disease. We studied disease activity in 99 IBD patients receiving anti-inflammatory therapy, in relation to: procoagulant markers, i.e. prothrombin fragment F1 + 2 (F1 + 2), D-dimer and platelet count, anticoagulant markers, i.e. protein C, protein S and antithrombin, and a mediator of inflammation (IL-6). Coagulation activity and platelet count were increased during active disease in IBD patients compared with those in a state of remission. The IL-6 concentrations were positively correlated with disease activity and thrombocytosis in patients with ulcerative colitis, but no association with the anticoagulant capacity could be demonstrated except for a decrease in protein C during high disease activity. 相似文献
92.
CCR2+ and CCR5+ CD8+ T cells increase during viral infection and migrate to sites of infection 总被引:6,自引:0,他引:6
Chemokines and their receptors play a critical role in the selective recruitment of various leukocyte subsets. In this study, we correlated the expression of multiple chemokine and CC chemokine receptor (CCR) genes during the course of intracerebral (i.c.) infection with lymphocytic choriomeningitis virus (LCMV) and vesicular stomatitis virus (VSV), which are prototypic of a noncytopathic and a cytopathic virus, respectively. Infection of mice with either virus resulted in rapid activation and overlapping cerebral expression of a number of chemokine genes. Infection with VSV i.c. causes a rapidly lethal, T cell-independent encephalitis, and infection resulted in a dramatic early up-regulation of chemokine gene expression. Similar marked up-regulation of chemokine expression was not seen until late after LCMV infection and required the presence of activated T cells. Cerebral CCR gene expression was dominated by CCR1, CCR2 and CCR5. However, despite a stronger initial chemokine signal in VSV-infected mice, only LCMV-induced T cell-dependent inflammation was found to be associated with substantially increased expression of CCR genes. Virus-activated CD8+ T cells were found to express CCR2 and CCR5, whereas activated monocytes/macrophages expressed CCR1 in addition to CCR2 and CCR5. Together, these CCR profiles readily account for the CCR profile prominent during CD8+-dependent CNS inflammation. 相似文献
93.
94.
The effect of changes in carbon dioxide tension in arterial blood upon intracellular pH in brain tissue was studied in seven healthy volunteers, aged 22-45 years. The pH changes were monitored by use of 31P nuclear magnetic resonance spectroscopy, performed on a whole-body 1.5 Tesla Siemens imaging system. The measurements were carried out during hyperventilation and with the subject breathing atmospheric air containing 5 vol. % and 7 vol. % carbon dioxide. Intracellular pH increased significantly during 15 min of hyper-ventilation and decreased significantly during 18 min respiration of air containing 7 vol. % carbon dioxide. The intracellular buffer capacity was estimated. These results suggest that the ventilation response to carbon dioxide is correlated to changes in intracellular fluid pH. 相似文献
95.
IgE Anti-IgG Antibodies in Patients with Juvenile and Adult Rheumatoid Arthritis Including Felty's Syndrome 总被引:1,自引:0,他引:1
Anti-IgG; antihodies (anti-IgG) of the IgE class were studied in sera from patients with juvenile rheumatoid arthritis (JRA). rheumatoid arthritis (RA) and patients with Felty's syndrome (FS) by use of an indirect immunofluorescence technique. Forty-two percent of 26 patients with JRA had IgE anti-IgG in serum all in low titers. Positive reactions prevailed in patients with multiple joint involvement. Sixty-three percent of 30 patients with RA and 80% of 20 patients with FS had IgE anti-IgG, the titers found in FS patients being significantly higher. In JRA and FS patients the IgE anti-IgG titers were correlated to the titers of anti-IgG of the IgG class, and for FS patients also with the IgM and IgA classes of anti-IgG. In six of 10 patients with RA the synovial fluid samples from both knees contained IgE anti-IgG. In four of these patients the titers of IgE anti-IgG were higher than in the corresponding serum sample, pointing to a local production. After G-200 Sephadex chromatography IgE anti-IgG were demonstrated in the void volume indicating the presence of these autoantibodies in immune complexes. IgE anti-IgG may be involved in the pathogenesis of JRA and RA by eliciting Type I and III reactions. 相似文献
96.
97.
98.
99.
Fluorescence in situ hybridization with peptide nucleic acid probes for rapid identification of Candida albicans directly from blood culture bottles
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Rigby S Procop GW Haase G Wilson D Hall G Kurtzman C Oliveira K Von Oy S Hyldig-Nielsen JJ Coull J Stender H 《Journal of clinical microbiology》2002,40(6):2182-2186
A new fluorescence in situ hybridization (FISH) method that uses peptide nucleic acid (PNA) probes for identification of Candida albicans directly from positive-blood-culture bottles in which yeast was observed by Gram staining (herein referred to as yeast-positive blood culture bottles) is described. The test (the C. albicans PNA FISH method) is based on a fluorescein-labeled PNA probe that targets C. albicans 26S rRNA. The PNA probe is added to smears made directly from the contents of the blood culture bottle and hybridized for 90 min at 55 degrees C. Unhybridized PNA probe is removed by washing of the mixture (30 min), and the smears are examined by fluorescence microscopy. The specificity of the method was confirmed with 23 reference strains representing phylogenetically related yeast species and 148 clinical isolates covering the clinically most significant yeast species, including C. albicans (n = 72), C. dubliniensis (n = 58), C. glabrata (n = 5), C. krusei (n = 2), C. parapsilosis (n = 4), and C. tropicalis (n = 3). The performance of the C. albicans PNA FISH method as a diagnostic test was evaluated with 33 routine and 25 simulated yeast-positive blood culture bottles and showed 100% sensitivity and 100% specificity. It is concluded that this 2.5-h method for the definitive identification of C. albicans directly from yeast-positive blood culture bottles provides important information for optimal antifungal therapy and patient management. 相似文献
100.