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   778篇
  免费   92篇
  国内免费   16篇
耳鼻咽喉   2篇
儿科学   42篇
妇产科学   16篇
基础医学   125篇
口腔科学   8篇
临床医学   81篇
内科学   187篇
皮肤病学   23篇
神经病学   13篇
特种医学   229篇
外科学   42篇
综合类   40篇
预防医学   39篇
眼科学   4篇
药学   12篇
中国医学   1篇
肿瘤学   22篇
  2022年   2篇
  2021年   9篇
  2020年   7篇
  2019年   2篇
  2018年   10篇
  2017年   5篇
  2016年   11篇
  2015年   9篇
  2014年   6篇
  2013年   13篇
  2012年   8篇
  2011年   15篇
  2010年   23篇
  2009年   29篇
  2008年   18篇
  2007年   19篇
  2006年   21篇
  2005年   24篇
  2004年   14篇
  2003年   32篇
  2002年   16篇
  2001年   5篇
  2000年   13篇
  1999年   22篇
  1998年   52篇
  1997年   49篇
  1996年   39篇
  1995年   24篇
  1994年   43篇
  1993年   29篇
  1992年   15篇
  1991年   17篇
  1990年   24篇
  1989年   33篇
  1988年   27篇
  1987年   25篇
  1986年   31篇
  1985年   24篇
  1984年   18篇
  1983年   14篇
  1982年   13篇
  1981年   25篇
  1980年   6篇
  1979年   5篇
  1978年   9篇
  1977年   10篇
  1976年   11篇
  1975年   10篇
排序方式: 共有886条查询结果,搜索用时 15 毫秒
91.
A 3 year old Turkish girl is described who was suffering from major histocompatibility complex (MHC) class II deficiency syndrome, which is characterised by the lack of expression of HLA class II antigens on mononuclear cells. The presence of HLA class II genes was demonstrable at the DNA level. Combined immunodeficiency was indicated by hypogammaglobulinaemia and the absence of delayed type hypersensitivity on skin testing. Further, she was unable to produce specific antibodies towards foreign antigens and suffered from recurrent pulmonary, gastrointestinal, and septic infections from the third month of life. The clinical course was complicated by a Coombs test positive haemolytic anaemia due to the production of autoantibodies against the rhesus "e' antigen, a non-glycosylated protein antigen. Haemolysis could be controlled by oral steroid treatment. This case is of interest as it shows that despite the absence of HLA class II antigens and combined immunodeficiency autoimmune reactions with production of specific autoantibodies directed to protein antigens are possible.  相似文献   
92.
Miliary blastomycosis and HIV infection.   总被引:1,自引:0,他引:1       下载免费PDF全文
  相似文献   
93.

Background  

In the Philippines, traditional mass dog vaccination campaigns have only achieved limited and transient success in dog rabies control, mainly because a large segment of the dog population is not accessible for traditional parenteral vaccination. Oral vaccination of dogs has been suggested as a supplementary method to increase the overall vaccination coverage of the dog populations involved. For this purpose, it is necessary to identify a suitable bait that is readily accepted by local dogs and that can be prepared without high costs.  相似文献   
94.
Extraction of staphylococcal abscesses by the Folch procedure revealed that all of the staphylocidal activity was present in the lipid fraction. Further separation of the lipids indicated that the bactericidal activity resided in the free fatty acid pool. Lipids similarly extracted from mesenteric or epididymal fat tissue, either before of after activation, did not possess comparable activity. Myristic, palmitic, palmitoleic, linoleic, and oleic acids, as well as lysolecithin, also failed to exhibit the properties of the fatty acid fraction obtained from abscess homogenates. These findings suggest the staphylocidal fatty acid is not a common host lipid.  相似文献   
95.
Immunoglobulin (Ig) was demonstrated in paraffin sections of 12 trephine bone marrow biopsies by means of the unlabelled antibody peroxidase-antiperoxidase (PAP) method. The Ig-containing cells, which were counted with the Reichert-Jung (Kontron) MOP-AMO3 user-controlled image-analyser, were found to constitute approximately 4·2% of all the nucleated cells in the marrow, a figure significantly higher than those reported by previous workers.  相似文献   
96.
Epidemiologic, animal, and in vitro models suggest an important role for interferon (IFN)-gamma in the clearance of Chlamydia trachomatis infection. IFN-gamma in the supernatants of in vitro-stimulated peripheral blood mononuclear cells (PBMC) from 22 human immunodeficiency virus type 1 (HIV-1)-infected and 73 uninfected women at high risk for C. trachomatis acute pelvic inflammatory disease (PID) was studied. PBMC were stimulated with C. trachomatis purified major outer membrane protein (MOMP) and whole elementary bodies (EBs) from the 4 predominant serovars (E, F, K, and L2) that circulate in Nairobi. PBMC IFN-gamma secretion after stimulation with C. trachomatis EBs was significantly decreased in HIV-1-infected women. Among HIV-1-infected women, CD4 T cell depletion was associated with lower IFN-gamma secretion from PBMC stimulated with either C. trachomatis MOMP or EB antigen. Decreased antigen-specific IFN-gamma production may enhance the susceptibility of HIV-1-infected women to C. trachomatis PID.  相似文献   
97.
We developed a murine model of systemic infection with Chlamydia trachomatis biovar lymphogranuloma venereum (LGV). The pathological features of this infection resemble those of human LGV infection since both are characterized by granuloma formation. Mice developed resistance to reinfection with LGV, and this resistance was based on cellular immune mechanisms since it was transferable with immune spleen cells but not with immune serum. Resistance required viable organisms for induction. We compared LGV biovar infection with trachoma biovar infection. Trachoma biovar produced similar but less marked microbiological and pathological features. Cross-immunity was less apparent between serovars from trachoma and LGV biovars than it was between serovars within the same biovar. This model of systemic C. trachomatis infection will be useful in exploring virulence features of LGV.  相似文献   
98.
In this study, the psychological functioning of patients with chronic post-traumatic headache (PTH), chronic combination headache and chronic low back pain without headache, whose time of onset was similar, and a matched group of controls was investigated. The Symptom Checklist 90-Revised (SCL-90-R), State-Trait Anger Expression Inventory (STAXI), State-Trait Anxiety Inventory, Form Y (STAI-Y), and Beck Depression Inventory (BDI) were used to assess the degree of psychopathology. A MANOVA test indicated highly significant differences between groups. In general, the pain groups fell along a continuum with PTH subjects demonstrating the highest elevations, back pain subjects demonstrating the next highest elevations, and combination subjects demonstrating fewer elevations. A cluster analysis indicated that findings were best classified into four clusters, but no one pain diagnosis predominated in any cluster. Eighty-nine percent of controls were assigned to clusters 1 or 2, which revealed essentially normal scores on all tests. It is suggested that while chronic pain patients demonstrate more psychopathology than non-pain controls, a variety of coping styles exists within each pain group independent of diagnostic categorization.  相似文献   
99.
Up to 70% of cases of pelvic inflammatory disease do not have a known cause. We recruited 115 women who had presented to a clinic for sexually transmitted diseases in Nairobi, Kenya with pelvic pain that had persisted for 14 days or less, to look for an association between Mycoplasma genitalium and endometritis. With PCR, we detected M genitalium in the cervix, endometrium, or both in nine (16%) of 58 women with histologically confirmed endometritis and in one (2%) of 57 women without endometritis (p=0.02). Our results suggest that infection with M genitalium is strongly associated with acute endometritis in this population.  相似文献   
100.
囊性纤维化相关性糖尿病(CFRD)是囊性纤维化(CF)的并发症,主要由胰岛素分泌不足引起,在青少年和成人中的发病率分别为20%和40%~50%。本指南由美国糖尿病协会(ADA)、囊性纤维瘤基金会(CFF)和儿童内分泌学会共同发布,包括CFRD的筛查、诊断和治疗。  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