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   3173336篇
  免费   223638篇
  国内免费   8429篇
耳鼻咽喉   43518篇
儿科学   100968篇
妇产科学   86535篇
基础医学   446419篇
口腔科学   89728篇
临床医学   288356篇
内科学   621664篇
皮肤病学   74506篇
神经病学   259595篇
特种医学   122412篇
外国民族医学   800篇
外科学   480005篇
综合类   63138篇
现状与发展   5篇
一般理论   1167篇
预防医学   238071篇
眼科学   71783篇
药学   234101篇
  10篇
中国医学   6602篇
肿瘤学   176020篇
  2019年   24414篇
  2018年   35051篇
  2017年   27044篇
  2016年   31342篇
  2015年   34993篇
  2014年   47938篇
  2013年   72022篇
  2012年   95625篇
  2011年   101299篇
  2010年   60758篇
  2009年   57939篇
  2008年   95391篇
  2007年   101171篇
  2006年   102834篇
  2005年   98681篇
  2004年   95129篇
  2003年   91783篇
  2002年   88920篇
  2001年   156419篇
  2000年   160711篇
  1999年   135312篇
  1998年   37834篇
  1997年   33390篇
  1996年   33581篇
  1995年   32413篇
  1994年   29775篇
  1993年   27891篇
  1992年   104604篇
  1991年   100470篇
  1990年   97471篇
  1989年   94196篇
  1988年   86229篇
  1987年   84544篇
  1986年   79234篇
  1985年   75723篇
  1984年   56104篇
  1983年   47508篇
  1982年   27514篇
  1981年   24471篇
  1979年   49598篇
  1978年   34551篇
  1977年   29590篇
  1976年   27074篇
  1975年   28966篇
  1974年   34398篇
  1973年   32597篇
  1972年   30552篇
  1971年   28467篇
  1970年   26523篇
  1969年   25404篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
191.
The normal function of the hypothalamic-pituitary-adrenal (HPA) axis, and resultant glucocorticoid (GC) secretion, is essential for human health. Disruption of GC regulation is associated with pathologic, psychological, and physiological disease states such as depression, post-traumatic stress disorder, hypertension, diabetes, and osteopenia, among others. As such, understanding the mechanisms by which HPA output is tightly regulated in its responses to environmental stressors and circadian cues has been an active area of investigation for decades. Over the last 20 years, however, advances in gene targeting and genome modification in rodent models have allowed the detailed dissection of roles for key molecular mediators and brain regions responsible for this control in vivo to emerge. Here, we summarize work done to elucidate the function of critical neuropeptide systems, GC-signaling targets, and inflammation-associated pathways in HPA axis regulation and behavior, and highlight areas for future investigation.  相似文献   
192.
193.
194.
195.
Objective:To study the effect of oral administration of dimethyl dimethoxy biphenyl dicarboxylate(DDB) on adjusting angiogeneic/inflammatory mediators and ameliorating the pathology of bones in rats with collagen-induced arthritis(CIA).Methods:Wistar rat model of CIA was set up using bovine collagen type Ⅱ.Fifty rats were divided into five groups randomly:normal,CIA model,DDB treatment,methotrexate(MTX) treatment,and combined DDB+MTX treatment.Ankle joints of rats were imaged with digital X-ray machine to show the destruction of joints.Fore and hind paw and knee joints were removed above the ankle joint then processed for haematoxylin and eosin staining.Plasma levels of vascular endothelial growth factor(VEGF),platelet derived growth factor,interleukin-8(IL-8),IL-4,tumor necrosis factor α(TNF-α),and cyclooxygenase-2(COX-2) were quantified by enzyme-linked immunosorbent assay.Nitric oxide levels were detected by Griess reagent.Results:Compared with the CIA model group,a remarkable reduction in various angiogenic(VEGF and IL-8) and inflammatory mediators(TNF-α,IL-4 and COX-2) after treatment with DDB either alone or combined with MTX(P0.05 or P0.01).Histopathological and X-ray findings were confirmatory to the observed DDB anti-arthritic effect.The DDB-treated group showed amelioration in signs of arthritis which appeared essentially similar to normal.Conclusion:Our data shed light on the therapeutic efficacy of DDB in experimental rheumatoid arthritis(RA) compared with a choice drug(MTX) and it may be offered as a second-line drug in the treatment of RA.  相似文献   
196.
197.
Traditionally, major complications and unanticipated admission/readmission rates were used to assess outcome after day surgery. However, in view of the relative absence of major complications the quality of recovery (QOR) should be considered one of the principal endpoints after day surgery. In our study, the level of QOR is defined by a combination of the Global Surgical Recovery (GSR) Index and the Quality of Life (QOL).The aim of this study was to analyze prevalence and predictors of QOR after day surgery on the fourth postoperative day.Elective patients scheduled for day surgery from November 2008 to April 2010 were enrolled in a prospective cohort study. Outcome parameters were measured by using questionnaire packages at 2 time points: 1 week preoperatively and 4 days postoperatively. Primary outcome parameter is the QOR and is defined as good if the GSR index >80% as well as the postoperative QOL is unchanged or improved as compared with baseline. QOR is defined as poor if both the GSR index ≤80% and if the postoperative QOL is decreased as compared with baseline. QOR is defined as intermediate in all other cases. Three logistic regression analyses were performed to determine predictors for poor QOR after day surgery.A total of 1118 patients were included. A good QOR was noted in 17.3% of patients, an intermediate QOR in 34.8%, and a poor QOR in 47.8% 4 days after day surgery. The best predictor for poor QOR after day surgery was type of surgery. Other predictors were younger age, work status, and longer duration of surgery. A history of previous surgery, expected pain (by the patient) and high long-term surgical fear were significant predictors of poor QOR in only 1 of 3 prediction models.The QOR at home 4 days after day surgery was poor in the majority of patients and showed a significant procedure-specific variation. Patients at risk for poor QOR can be identified during the preoperative period based on type of surgery, age, work status, and the duration of the surgery.  相似文献   
198.
199.
200.
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