首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   670篇
  免费   35篇
耳鼻咽喉   2篇
儿科学   35篇
妇产科学   10篇
基础医学   77篇
口腔科学   40篇
临床医学   125篇
内科学   72篇
皮肤病学   24篇
神经病学   63篇
特种医学   6篇
外科学   39篇
综合类   2篇
一般理论   4篇
预防医学   110篇
眼科学   12篇
药学   39篇
肿瘤学   45篇
  2024年   1篇
  2023年   1篇
  2022年   4篇
  2021年   6篇
  2020年   9篇
  2019年   12篇
  2018年   11篇
  2017年   17篇
  2016年   14篇
  2015年   11篇
  2014年   10篇
  2013年   48篇
  2012年   44篇
  2011年   26篇
  2010年   23篇
  2009年   30篇
  2008年   51篇
  2007年   45篇
  2006年   50篇
  2005年   67篇
  2004年   39篇
  2003年   38篇
  2002年   37篇
  2001年   8篇
  2000年   4篇
  1999年   5篇
  1998年   17篇
  1997年   14篇
  1996年   8篇
  1995年   7篇
  1994年   5篇
  1993年   3篇
  1992年   3篇
  1991年   2篇
  1989年   4篇
  1987年   2篇
  1986年   2篇
  1985年   3篇
  1984年   3篇
  1983年   3篇
  1982年   2篇
  1981年   6篇
  1980年   5篇
  1977年   3篇
  1974年   1篇
  1973年   1篇
排序方式: 共有705条查询结果,搜索用时 0 毫秒
701.
Up to now for Swine Workshop Cluster 2 (SWC2) the orthologous human CD molecule was unknown. By use of the SWC2-specific mAb b30c7 and a retroviral cDNA expression library derived from stimulated porcine peripheral blood mononuclear cells we could identify SWC2 as porcine CD27. Phenotypic analyses of lymphocytes isolated from blood and lymphatic organs revealed that mature T cells in thymus and T cells in the periphery with a na?ve phenotype were CD27(+). However, within CD8α(+) T helper and CD8α(+) γδ T cells also CD27(-) cells were present, indicating a down-regulation after antigen contact in vivo. B cells lacked CD27 expression, whereas NK cells expressed intermediate levels. Furthermore, plate-bound mAb b30c7 showed a costimulatory capacity on CD3-activated T cells for proliferation, IFN-γ and TNF-α production. Hence, our data indicate an important role of porcine CD27 for T-cell differentiation and activation as described for humans and mice.  相似文献   
702.

Objective

To explore contexts of experiences of physical activity perceived as beneficial or harmful for CFS patients.

Methods

A qualitative study with empirical data from two focus groups with purposive sampling. Mean age was 50, two of ten participants were male, and social demographics varied. Participants were invited to share stories of good as well as bad experiences concerning physical activity. Data were analysed with systematic text condensation.

Results

Participants were not averse to physical activity, but specific preconditions would determine how the activity was perceived. Physical activity was experienced as helpful and enjoyable, especially related to leisure activities where flexible and individual adaptation was feasible. Non-customized activity may precipitate set-backs giving patients the impression of losing control and being betrayed by their bodies. Strategies to review energy usage in daily life could adjust expectations, diminish stress load and assist in approaching a more appropriate priority and balance.

Conclusion

Self-management, body awareness and physical activity of choice combined with facilitation and advice from health care professionals is essential to achieve a positive outcome.

Practice implications

Exercise programmes should be adapted, paced, and self-managed in accordance with personal preferences and activity levels to be beneficial and empowering for CFS patients.  相似文献   
703.
Etiologic aspects of chronic urticaria   总被引:2,自引:0,他引:2  
Background Urticaria is a common disease that is always a challenge to the dermatologist due to its evasive etiology. Patients and methods One hundred and seven chronic urticaria patients were studied. Routine laboratory investigations were performed and Helicobacter pylori (H. pylori) immunoglobulin G (IgG) antibody determinations, autoimmune reactivity, infections, allergies, and hyperreactivities were investigated. Results Pathologic findings were seen in 92 patients. Concomitant diseases suggesting autoimmune reactivity were detected in nine patients and, in 16 patients, infections including maxillary sinusitis, streptococcal tonsillitis, and tooth infection were found. Elevated total IgE level was detected in 37 out of 75 patients and positive skin prick test results in 47 out of 91 patients. Fifty-five patients had a history of recent dyspeptic symptoms. A diagnosis of adult celiac disease was made in two patients and, additionally, IgA antigliadin antibodies were seen in four patients. H. pylori IgG antibodies were found in 40 out of 107 patients. Active gastritis was verified by esophagogastroduodenoscopy in 30 out of 32 patients with positive Helicobacter staining in 24 samples. An elevated IgE level was detected in 64% of H. pylori-positive and in 39% of H. pylori-negative patients. Conclusions In this study, several findings suggesting aberrant immunologic activation were detected in chronic urticaria patients. Inflammation in the gastrointestinal tract, e.g. caused by H. pylori infection, may have an important role in the etiology of chronic urticaria.  相似文献   
704.

Objective  

To examine associations between childhood psychopathology and family factors at age 8, and sense of coherence (SOC) at age 18.  相似文献   
705.
Capillary hemangioblastoma is a benign tumor, occurring sporadically or as a manifestation of von Hippel-Lindau (VHL) disease. Inactivation of the VHL gene at 3p25-26 has been demonstrated in all VHL-associated hemangioblastomas. However, the VHL gene has been found to be inactivated in only 20% to 50% of sporadic tumors. So far, no other gene has been reported to be involved in the development of hemangioblastomas. DNA losses at 6q are frequent alterations in hemangioblastomas, as shown by comparative genomic hybridization. We therefore analyzed 15 hemangioblastomas for loss of heterozygosity (LOH) on chromosome 3p and 6q to reveal the frequency of allelic losses and to determine minimal deleted areas. We detected LOH at 6q for one or more markers in 11 (73%) out of 15 cases (in 9 of 11 sporadic and in 2 of 4 VHL-associated tumors). The analyses revealed a minimal 3-megabase (Mb) deleted region at 6q23-24, where 9 of 11 (82%) informative cases showed LOH. LOH at 3p was seen in 14 out of 15 tumors. LOH occurred concurrently at 6q and 3p in 67% of cases. Our data strongly suggests that a tumor suppressor gene located at 6q23-24 is involved in tumorigenesis of hemangioblastomas, in addition to the VHL gene.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号