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   332篇
  免费   14篇
  国内免费   35篇
耳鼻咽喉   2篇
儿科学   12篇
基础医学   22篇
口腔科学   16篇
临床医学   51篇
内科学   58篇
皮肤病学   6篇
神经病学   12篇
特种医学   97篇
外科学   20篇
综合类   24篇
预防医学   10篇
眼科学   3篇
药学   17篇
肿瘤学   31篇
  2023年   4篇
  2021年   4篇
  2019年   2篇
  2018年   3篇
  2017年   3篇
  2015年   1篇
  2014年   5篇
  2013年   3篇
  2012年   8篇
  2011年   8篇
  2010年   5篇
  2009年   7篇
  2008年   10篇
  2007年   20篇
  2006年   11篇
  2005年   25篇
  2004年   5篇
  2003年   4篇
  2002年   3篇
  2001年   8篇
  2000年   4篇
  1999年   11篇
  1998年   16篇
  1997年   18篇
  1996年   24篇
  1995年   13篇
  1994年   12篇
  1993年   24篇
  1992年   2篇
  1991年   5篇
  1990年   5篇
  1989年   11篇
  1988年   14篇
  1987年   10篇
  1986年   5篇
  1985年   6篇
  1984年   12篇
  1983年   8篇
  1982年   7篇
  1981年   8篇
  1980年   3篇
  1979年   3篇
  1978年   4篇
  1977年   4篇
  1976年   3篇
  1975年   3篇
  1973年   3篇
  1962年   1篇
  1946年   1篇
  1939年   1篇
排序方式: 共有381条查询结果,搜索用时 31 毫秒
61.
HLA and granulocyte-specific antibodies have been implicated in the production of transfusion-related acute lung injury (TRALI). Reported here is a case that suggests that the patient's preexisting condition may play an important role in determining whether TRALI develops upon transfusion of blood products containing anti-white cell (WBC) antibodies. A 29-year-old woman with thrombotic thrombocytopenic purpura (TTP) underwent an uneventful 1.5-volume plasma exchange, which was followed by the transfusion of 2 red cell (RBC) units. At the end of the second RBC transfusion, the patient developed clinical signs and symptoms of noncardiogenic pulmonary edema. Serologic studies demonstrated that the serum from the second RBC donor had no HLA antibodies but did have a granulocyte-specific antibody (anti-NB2) that caused the agglutination of the recipient's granulocytes, which were NB2 positive. Serum from the donor of the first RBC unit and serum from the donors of units used in the exchange had no HLA or granulocyte-specific antibodies that reacted with the recipient's WBCs. Because the donor implicated in this reaction had a history of 21 blood donations, none of which had been associated with a transfusion reaction, we suggest that the patient's preexisting condition played a significant role in this episode of TRALI, owing to the granulocyte-specific antibody.  相似文献   
62.
Disruption of the breast cancer susceptibility gene BRCA2 is associated with increased risk of developing breast and ovarian cancer. Over 1800 sequence changes in BRCA2 have been reported, although for many the pathogenicity is unclear. Classifying these changes remains a challenge, as they may disrupt regulatory sequences as well as the primary protein coding sequence. Sequence changes located in the splice site consensus sequences often disrupt splicing, however sequence changes located within exons are also able to alter splicing patterns. Unfortunately, the presence of these exonic splicing enhancers (ESEs) and the functional effect of variants within ESEs it is currently difficult to predict. We have previously developed a method of predicting which sequence changes within exons are likely to affect splicing, using BRCA1 as an example. In this paper, we have predicted ESEs in BRCA2 using the web-based tool ESEfinder and incorporated the same series of filters (increased threshold, 125 nt limit and evolutionary conservation of the motif) in order to identify predicted ESEs that are more likely to be functional. Initially 1114 ESEs were predicted for BRCA2, however after all the filters were included, this figure was reduced to 31, 3% of the original number of predicted ESEs. Reported unclassified sequence variants in BRCA2 were found to colocalise to 55% (17/31) of these conserved ESEs, while polymorphisms colocalised to 0 of the conserved ESEs. In summary, we have identified a subset of unclassified sequence variants in BRCA2 that may adversely affect splicing and thereby contribute to BRCA2 disruption.  相似文献   
63.
64.
65.
ObjectiveTo combine isoniazid (INH) and rifampicin (RIF) in a single media to detect and evaluate multi-drug resistant Mycobacterium tuberculosis (MDR-TB) strains using clinical specimens by direct and indirect drug susceptibility testing (DST).MethodsDrug susceptibility testing for INH and RIF using individual and combined drug media was performed by minimum inhibitory concentration (MIC) method on direct clinical specimens.ResultsThe combined drug media showed complete concordance with individual drug media in the detection of MDR-TB by direct DST method and 89% efficiency with indirect DST method. Susceptibility results were available by 3 weeks after the receipt of clinical specimen using direct DST on combined drug media.ConclusionsCombined drug media can be used as a fast track method in large scale studies warranting detection of MDR-TB.  相似文献   
66.
67.
68.
OBJECTIVES: To compare the relative amounts of elastase (primary polymorphonuclear leucocyte granule constituent) and lactoferrin (secondary PMN granule constituent) in the gingival crevicular fluid (GCF) of healthy, gingivitis and periodontitis sites.
DESIGN: This cross-sectional study looked at the two GCF constituents in three categories of disease status within the same subject.
MATERIALS AND METHODS: Patients with chronic adult periodontitis were screened and those exhibiting all three types of sites ie periodontally healthy, gingivitis and periodontitis sites were recruited (n = 10) and had GCF collected from the three sites. Lactoferrin and elastase were measured in eluates of GCF by enzyme-linked immunosorbent assay.
RESULTS: The absolute amount of lactoferrin measured in ng per 30 s samples was significantly lower in healthy and gingivitis sites as compared to periodontitis sites however this difference failed to reach significance when the concentration of lactoferrin in GCF was used as the analytical unit. No significant differences were found for elastase levels at any sites when expressed as either absolute amounts or concentrations. Secondary granule release, as evidenced by lactoferrin levels, occurs during cell migration and the process is independent of primary granule release, which is thought to correlate with PMN activation. The relationship between granule constituents in the samples showed significant differences, the highest lactoferrinlelastase ratio being at periodontitis sites (P < 0.001).
CONCLUSIONS These findings imply a change in the relative amounts of elastase and lactoferrin released at different disease level sites, with an almost 10-fold increase in the proportion of lactoferrin to elastase in periodontitis sites over healthy and gingivitis sites. This variation in the release by PMNs of primary and secondary granule constituents may indicate alterations in PMN function in different disease environments.  相似文献   
69.
70.
Interleukin-5 is at 5q31 and is deleted in the 5q- syndrome   总被引:3,自引:0,他引:3  
Human interleukin-5 (IL-5) is a selective eosinophilopoietic and eosinophil-activating growth hormone. By in situ hybridization this gene is mapped to chromosome 5q23.3 to 5q32. It is shown to be deleted in two patients with the 5q-syndrome and in one patient previously diagnosed with myelodysplasia whose condition had progressed to acute myeloblastic leukemia. The clustering of other genes involved in hematopoiesis (IL-3, granulocyte-macrophage colony-stimulating factor, feline sarcoma viral oncogene homolog, colony-stimulating factor 1) to the same region as IL-5 suggests a nonrandom localization and raises interesting questions concerning the evolution and regulation of these genes.  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