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   13718篇
  免费   2872篇
  国内免费   131篇
耳鼻咽喉   467篇
儿科学   419篇
妇产科学   469篇
基础医学   785篇
口腔科学   200篇
临床医学   3362篇
内科学   2567篇
皮肤病学   409篇
神经病学   1086篇
特种医学   486篇
外科学   1825篇
综合类   501篇
现状与发展   2篇
一般理论   2篇
预防医学   2106篇
眼科学   197篇
药学   472篇
  1篇
中国医学   104篇
肿瘤学   1261篇
  2024年   83篇
  2023年   426篇
  2022年   136篇
  2021年   300篇
  2020年   530篇
  2019年   228篇
  2018年   634篇
  2017年   651篇
  2016年   712篇
  2015年   795篇
  2014年   816篇
  2013年   1197篇
  2012年   611篇
  2011年   581篇
  2010年   653篇
  2009年   753篇
  2008年   547篇
  2007年   526篇
  2006年   524篇
  2005年   445篇
  2004年   368篇
  2003年   335篇
  2002年   287篇
  2001年   337篇
  2000年   253篇
  1999年   286篇
  1998年   323篇
  1997年   340篇
  1996年   349篇
  1995年   298篇
  1994年   215篇
  1993年   162篇
  1992年   179篇
  1991年   213篇
  1990年   163篇
  1989年   162篇
  1988年   146篇
  1987年   125篇
  1986年   99篇
  1985年   105篇
  1984年   98篇
  1983年   79篇
  1982年   62篇
  1981年   76篇
  1980年   45篇
  1979年   52篇
  1978年   47篇
  1977年   40篇
  1973年   33篇
  1972年   46篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
Initial care of the trauma victim begins at the scene of the accident, where the "load and go" principle is applied. A systematic approach to management of the trauma victim improves patient outcome. After insertion of an airway and stabilization of the spine, hemorrhage is treated and volume is replaced. At this point, invasive techniques, such as chest tube insertion, peritoneal lavage and pericardiocentesis, may be therapeutic as well as diagnostic.  相似文献   
52.
Summary The effects of personality characteristics on social support and hence risk of depression are explored in a group of 150 largely working-class mothers, a subsample of 400 women who took part in a prospective study. This established that once those with depression at first interview were excluded, practically all of the onsets of depression in the follow-up year occurred among 150 women with a severe event or major difficulty — that is a provoking agent. It was also found that low self-esteem and lack of support from a core tie at the time of the crisis was associated with a considerably increased risk. In the subsample as a whole, measures of dependency and attitudinal constraints to support taken at first interview were not associated with risk of depression. But, it is argued, any enduring personality traits that play a role in the link between lack of support and depression would most likely be seen in a smaller group, namely those who had had early inadequate parenting. And the most promising lead concerning the role of personality characteristics did in fact emerge in relation to a small high risk group with such parenting. Most of them had low self-esteem, and they appeared to confide in inappropriate and unreliable sources of support at time of crisis.  相似文献   
53.
Improving the management of bladder cancer with fluorescence cystoscopy.   总被引:1,自引:0,他引:1  
Endoscopic visualization (cystoscopy) and transurethral resection are effective, well-tolerated diagnostic and treatment techniques for bladder cancer. However, it is widely recognized that cystoscopy can miss biologically important lesions, such as carcinoma in situ. Attempts to improve the effectiveness of cystoscopy are not new, but initial methods were impractical and had limited efficacy. Fluorescence cystoscopy became feasible with the discovery that intravesical administration of aminolevulinic acid (ALA) made bladder cancers fluoresce when exposed to blue light. More recently, the creation of a hexyl ester of ALA (HAL) made this technique practical, because HAL significantly shortens the amount of time needed for drug exposure prior to cystoscopy. Not surprisingly, studies have shown that fluorescence cystoscopy can reveal carcinoma in situ that is visually occult under conventional (white-light) cystoscopy. An unexpected finding was that fluorescence cystoscopy also enhanced the detection of papillary tumors. Studies with ALA have shown that resection of bladder cancer with fluorescence results in improved disease-free survival compared to conventional resection under white light. This report summarizes some of the recent studies of fluorescence cystoscopy in bladder cancer.  相似文献   
54.
V L Calder  Z S Zhao  Y Wang  K Barton    S L Lightman 《Immunology》1993,79(2):255-262
During the later stages of soluble-antigen (sAg)-induced experimental autoimmune uveoretinitis (EAU), an increase in the relative number of CD8+ lymphocytes has been observed at the site of inflammation in the retina. It has been suggested that these late-appearing CD8+ cells might down-regulate this acute disease process. To determine the role of the CD8+ cells in EAU, Lewis rats were depleted of CD8+ cells prior to and during disease and the enucleated eyes examined histologically. The spleen cells from CD8-depleted rats were also examined for their ability to respond to concanavalin A (Con A) and to allogeneic targets as determined by mixed lymphocyte reaction (MLR) and cytotoxicity assays. The results suggest that depleting CD8+ cells had no effect on the course of disease and that CD8+ cells do not play a crucial role in the immunoregulation of EAU.  相似文献   
55.
56.

Background  

Results of previous autopsy studies indicate that increased hepatic iron stores or hepatic iron overload is common in African Americans dying in hospitals, but there are no reports of hepatic iron content in other cohorts of African Americans.  相似文献   
57.
58.
Human T Lymphocyte Antigens as Defined by Monoclonal Antibodies   总被引:21,自引:0,他引:21  
  相似文献   
59.
The aim of the study was to investigate whether polymorphisms of macrophage migration inhibitory factor (MIF) determine susceptibility to or severity of inflammatory polyarthritis (IP). Genotypes for a single-nucleotide polymorphism (MIF-173*G/C) and a tetranucleotide (CATT)(n) repeat mapping to the promoter region of the MIF gene were compared between UK Caucasian IP cases (n=438) and controls (n=343). Both polymorphisms were also investigated for association with features of disease activity and severity at baseline and by 5 years. The MIF-173*C allele (OR 1.7, 95% CI 1.3-2.4, P=1.8 x 10(-4)) and the CATT(7) allele (OR 1.5, 95% CI 1.0-2.1, P=0.02) were found to be associated with increased susceptibility to IP. Furthermore, presence of the haplotype containing both associated polymorphisms was associated with a three-fold increase risk of developing IP. No association with disease severity or activity either at baseline or by 5 years was detected for either of the promoter polymorphisms studied. In conclusion, MIF is a susceptibility gene for the development of IP. The same alleles previously reported to be associated with susceptibility to juvenile idiopathic arthritis account for the increased risk. The promoter polymorphisms of MIF, investigated in this study, do not influence the severity of disease outcome by 5 years.  相似文献   
60.
As part of a U.S. multi-regional pilot study conducted by the six Centers for Radiological Physics, 12-mm-diameter by 0.4-mm-thick CaSO4:Dy Teflon-embedded discs were evaluated and used to measure patient entrance exposure on 60 "average" patients at 12 clinical centers. The discs were found to have adequate sensitivity, reproducibility and linearity up to 69.7 microC kg-1 (270 mR). The minimum measurable exposure was estimated as 0.4 microC kg-1 (1.5 mR). All responses were corrected for energy dependence, which varied +/- 20% from 1.7 to 6.5 mm Al half-value layer. Patient entrance exposure values ranged from 1.3 to 28 microC kg-1 (5 to 110 mR), with a median value of 5.2 microC kg-1 (20 mR). This value agreed with exposure measurements made on the chest radiography equipment using an ionization chamber and a phantom which simulated an "average" patient, and with published Nationwide Evaluation of X-Ray Trends (NEXT) data for the same period.  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