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   1265篇
  免费   80篇
  国内免费   11篇
耳鼻咽喉   17篇
儿科学   98篇
妇产科学   14篇
基础医学   148篇
口腔科学   29篇
临床医学   145篇
内科学   267篇
皮肤病学   19篇
神经病学   55篇
特种医学   307篇
外科学   69篇
综合类   15篇
预防医学   50篇
眼科学   7篇
药学   39篇
肿瘤学   77篇
  2023年   2篇
  2021年   13篇
  2020年   7篇
  2019年   10篇
  2018年   19篇
  2017年   11篇
  2016年   10篇
  2015年   25篇
  2014年   21篇
  2013年   27篇
  2012年   23篇
  2011年   25篇
  2010年   35篇
  2009年   36篇
  2008年   24篇
  2007年   46篇
  2006年   39篇
  2005年   29篇
  2004年   31篇
  2003年   13篇
  2002年   11篇
  2001年   11篇
  2000年   17篇
  1999年   25篇
  1998年   97篇
  1997年   69篇
  1996年   77篇
  1995年   52篇
  1994年   56篇
  1993年   61篇
  1992年   16篇
  1991年   12篇
  1990年   21篇
  1989年   42篇
  1988年   31篇
  1987年   42篇
  1986年   24篇
  1985年   36篇
  1984年   26篇
  1983年   18篇
  1982年   22篇
  1981年   23篇
  1980年   29篇
  1979年   8篇
  1978年   18篇
  1977年   21篇
  1976年   20篇
  1975年   14篇
  1969年   2篇
  1930年   1篇
排序方式: 共有1356条查询结果,搜索用时 15 毫秒
41.
42.
Bridging bronchus: a rare airway anomaly   总被引:1,自引:0,他引:1  
  相似文献   
43.
44.
The aim of this study was to determine the inter‐rater reliability between one expert‐nurse and four clinical‐nurses who were asked to clinically assess infection of chronic wounds by using the World Union of Wound Healing Societies (WUWHS) criteria. A quasi‐experimental design was used to collect the data. In comparison to phase 1 in which ‘open questions’ were asked, in phase 2 a pre‐printed form (checklist) was introduced. In both phases, 55 chronic wounds were clinically assessed. For each WUWHS criterion the inter‐rater reliability of signs and symptoms was expressed by Cohens Kappa (κ). A substantial agreement (κ ≥ 0·6) was considered as adequate. In both phases pocketing (p < 0·02), and erythema (p < 0·004) scored statistically significant results. Phase 2 showed higher inter‐rater agreements compared with phase 1 (three substantial agreements (easily bleeding/friable granulation tissue, delayed healing, increasing exudate), an almost perfect‐ and a perfect agreement for malodour and pain, respectively. According to the results it can be concluded that the clinical assessment of infection of chronic wounds may be better supported by a pre‐printed form than making use of an ‘open questions’ form. To provide this with a higher level of evidence, there is need for more well conducted studies.  相似文献   
45.
Lucas  KG; Small  TN; Heller  G; Dupont  B; O'Reilly  RJ 《Blood》1996,87(6):2594-2603
Epstein-Barr virus-induced lymphoproliferative disease (EBV-LPD) is a potentially lethal complication during the first 6 months after allogeneic bone marrow transplantation (BMT). To determine whether deficiencies of EBV-specific cellular immunity contribute to EBV-LPD susceptibility and distinguish patients at risk, we performed limiting dilution analysis to quantify anti-EBV cytotoxic T-lymphocyte precursor (CTLp) frequencies in 26 recipients of unmodified or T-cell-depleted (TCD) grafts from EBV-seropositive donors. At 3 months post-BMT (n = 26), only five patients had EBV CTLp frequencies in the range of seropositive normal controls, irrespective of the type of transplant administered. By 6 months post-BMT, 9 of 13 patients tested had EBV CTLp frequencies within the normal range. The time period in which these patients had deficient cellular immunity to EBV corresponds to the period in which we have observed EBV-LPD in most prior patients. One patient with a low EBV CTLp frequency at 4 months post-BMT developed an EBV-LPD. Within 2 weeks of receiving an infusion of donor peripheral blood mononuclear cells (PBMC) providing less than 1,200 EBV- specific cytotoxic T-cell precursors, populations of EBV-specific CTL in the circulation were restored to levels detected in normal seropositive adults. Concurrently, the patient achieved a regression of the EBV-LPD, which has been sustained without further therapy. These studies indicate that recipients of both unmodified and TCD marrow grafts have profound deficiencies of EBV-specific T cell-mediated immunity early posttransplant, and that the period of risk for EBV-LPD closely corresponds to this interval of severe deficiency. Treatment of one patient with EBV-LPD with marrow donor-derived PBMC induced a rapid expansion of EBV-specific cytotoxic T-cell populations that occurred contemporaneously with the clinical regression of disease.  相似文献   
46.
Patients who have undergone allogeneic bone marrow transplantation (allo-BMT) are susceptible to a variety of opportunistic infectious complications in the months to years after engraftment. Impaired in vitro T-cell functions have been documented in these patients, and these T-cell dysfunctions contribute to the prolonged immune deficiency after allo-BMT. In the present study, we examined the expression of CD26 as well as the reconstitution of CD26-mediated T-cell costimulation via the CD3 and CD2 pathways at various times in patients aged greater than 18 years after CD6-positive, T-cell depleted allo- BMT. We found that the percentage of CD26- and CD3-positive cells, as well as the levels of expression of both antigens, was lower than in normal controls during the first 4 months after CD6-depleted allo-BMT. Subsequently, the amount of lymphocytes expressing CD3 and CD26 and the quantitative surface expression of CD3 and CD26 were not significantly different in patients and normal controls. Functional studies showed that CD26-mediated T-cell proliferation via the CD3 pathway was considerably improved and almost reached normal levels by 1 year, whereas recovery of CD26-mediated T-cell proliferation via the CD2 pathway was delayed for at least 2 years after CD6-depleted allo-BMT. As CD26 involvement in the regulation of human thymocyte activation is restricted preferentially to the CD3 pathway--unlike its involvement with both CD3 and CD2 pathways of peripheral T cells--our results suggest that the different effects of CD26-mediated costimulation via the CD3 and CD2 pathways after CD6-depleted allo-BMT may be a reflection of peripheral T-cell immaturity in those individuals, similar to that seen in mature medullary thymocytes or cord T lymphocytes.  相似文献   
47.
48.
49.
50.
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