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   9619篇
  免费   789篇
  国内免费   46篇
耳鼻咽喉   107篇
儿科学   449篇
妇产科学   200篇
基础医学   1012篇
口腔科学   439篇
临床医学   962篇
内科学   1854篇
皮肤病学   115篇
神经病学   779篇
特种医学   629篇
外国民族医学   1篇
外科学   1200篇
综合类   195篇
一般理论   9篇
预防医学   910篇
眼科学   283篇
药学   657篇
  1篇
中国医学   22篇
肿瘤学   630篇
  2022年   55篇
  2021年   88篇
  2020年   83篇
  2019年   104篇
  2018年   124篇
  2017年   108篇
  2016年   117篇
  2015年   136篇
  2014年   155篇
  2013年   263篇
  2012年   301篇
  2011年   372篇
  2010年   247篇
  2009年   270篇
  2008年   361篇
  2007年   457篇
  2006年   432篇
  2005年   410篇
  2004年   401篇
  2003年   352篇
  2002年   352篇
  2001年   328篇
  2000年   330篇
  1999年   285篇
  1998年   190篇
  1997年   203篇
  1996年   188篇
  1995年   149篇
  1994年   164篇
  1993年   180篇
  1992年   272篇
  1991年   257篇
  1990年   229篇
  1989年   226篇
  1988年   225篇
  1987年   195篇
  1986年   197篇
  1985年   180篇
  1984年   132篇
  1983年   134篇
  1982年   95篇
  1981年   90篇
  1980年   68篇
  1979年   91篇
  1978年   81篇
  1977年   70篇
  1976年   74篇
  1974年   59篇
  1973年   79篇
  1971年   59篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Male genital oedema can be defined as swelling or the appearance of swelling of the scrotum and/or the penile shaft and prepuce. Despite the various causes of genital oedema reported in the published work, a concise approach to the evaluation and management has not been sufficiently addressed.  相似文献   
42.
BACKGROUND: Chronic inflammation is associated with processes that contribute to the onset or progression of cancer. This study examined the relationships between circulating levels of the inflammatory markers interleukin-6 (IL-6), C-reactive protein (CRP), and tumor necrosis factor-alpha (TNF-alpha) and total as well as site-specific cancer incidence. METHODS: Study subjects (n = 2,438) were older adults (ages 70-79 years) participating in the Health Aging and Body Composition study, who did not report a previous cancer diagnosis (except for nonmelanoma skin cancer) at baseline. Incident cancer events (n = 296) were ascertained during an average follow-up of 5.5 years. Inflammatory markers were measured in stored baseline fasting blood samples. RESULTS: The adjusted hazard ratios (95% confidence intervals) for incident cancer associated with a 1-unit increase on the natural log-scale were 1.13 (0.94-1.37), 1.25 (1.09-1.43), and 1.28 (0.96-1.70) for IL-6, CRP, and TNF-alpha, respectively. Markers were more strongly associated with cancer death: hazard ratios were 1.63 (1.19-2.23) for IL-6, 1.64 (1.20-2.24) for CRP, and 1.82 (1.14-2.92) for TNF-alpha. Although precision was low for site-specific analyses, our results suggest that all three markers were associated with lung cancer, that IL-6 and CRP were associated with colorectal cancer, and that CRP was associated with breast cancer. Prostate cancer was not associated with any of these markers. CONCLUSIONS: These findings suggest that (a) the associations between IL-6, CRP, and TNF-alpha and the risk of cancer may be site specific and (b) increased levels of inflammatory markers are more strongly associated with the risk of cancer death than cancer incidence.  相似文献   
43.
OBJECTIVE: Issues concerning the training and certification of surgical specialists have taken on great significance in the last decade. A realistic computer-assisted, tissue-based simulator developed for use in the training of cardiac surgical residents in the conduct of a variety of cardiac surgical procedures in a low-volume cardiothoracic surgery unit of a typical developing country is described. The simulator can also be used to demonstrate the function of technology specific to cardiac surgical procedures in a way that previously has only been possible via the conduct of a procedure on a live animal or human being. METHODS: A porcine heart in a novel simulated operating theatre environment with real-time simulated haemodynamic monitoring and coronary blood flow, in arrested and beating-heart modes, is used as a training tool for surgical residents. RESULTS: Standard and beating-heart coronary arterial bypass, aortic valve replacement, aortic homograft replacement and pulmonary autograft procedures can be simulated with high degrees of realism and with the superimposition of adverse clinical scenarios requiring valid decision making and clinical judgments to be made by the trainees. CONCLUSIONS: The cardiac surgical simulation preparation described here would appear to be able to contribute positively to the training of residents in low-volume centres, as well as having the potential for application in other settings as a training tool or clinical skills assessment or accreditation device. Collaboration with larger centres is recommended in order to accurately assess the utility of this preparation as an adjunctive cardiothoracic surgical training aid.  相似文献   
44.
BACKGROUND: Inflammatory bowel disease is associated with increased mucosal release of eicosanoids. Among these, thromboxane A2 has been proposed as a possible inflammatory mediator; its suppression may be a useful therapeutic option. METHODS: Using a tissue incubation technique, we compared release of immunoreactive thromboxane B2 by colonic biopsies from patients with ulcerative colitis, Crohn's disease and controls, and assessed the inhibitory effect of picotamide, a thromboxane synthesis inhibitor-receptor antagonist, which has been widely used in Italy for management of ischaemic heart and cerebrovascular disease. RESULTS: Increased amounts of thromboxane B2 were released from biopsies from patients with active ulcerative colitis (median 238 pg/20 min/mg wet weight (interquartile range 147- 325), n = 12) and active Crohn's disease (252 (174-450), 6) compared with those from patients with quiescent ulcerative colitis (95 (61- 140), 12) or Crohn's disease (105 (57-201), 13), or controls (136 (64- 206), 8). Incubation with picotamide at concentrations between 100 microM and 1 mM reduced thromboxane B2 release (IC50 890 microM). CONCLUSION: Since increased thromboxane A2 production may have pathogenetic importance, thromboxane synthesis inhibitor-receptor antagonists such as picotamide merit therapeutic trial in the management of inflammatory bowel disease.  相似文献   
45.
46.
The ureteral access set was used 43 times during an 18-month period between 1984 and 1985. Stones lodged throughout the ureter and in the renal pelvis were extracted with a success rate of 51 per cent. Of the upper tract strictures 92 per cent were dilated successfully. Filling defects were diagnosed in 88 per cent of the cases. Foreign bodies were retrieved, Double-J stents were placed and biopsies were successful in each case. Ureteral perforation in 28 per cent of the cases was caused by the dilator in 8 of 12 (19 per cent over-all). The technique and short-term results are discussed. Long-term followup data are not yet available.  相似文献   
47.
Resection of a Wilms' tumor that extends into the vena cava or right atrium results in excellent survival when combined with adjuvant therapy. Preoperative identification of the presence of intravascular tumor thrombus and the level of vascular involvement is essential. It facilitates safe surgical resection, with cardiopulmonary bypass immediately available for retrohepatic and atrial tumors. Six patients with intracaval or intracardiac tumor thrombus were treated over a 5-year period with no perioperative deaths. Preoperative chemotherapy was useful in two patients with extensive tumors and pulmonary metastases. Our results using an integrated management plan suggest that an aggressive surgical approach is justified for this extensive variant of Wilms' tumor.  相似文献   
48.
Recognition of thalidomide defects.   总被引:4,自引:0,他引:4       下载免费PDF全文
  相似文献   
49.
A 12-year-old girl is described who developed rectal bleeding 5 months after being diagnosed as having a Coombs-positive hemolytic anemia. Colonoscopy showed that the rectal bleeding was due to ulcerative proctitis. This is the first case report of Coombs-positive hemolytic anemia preceding the onset of ulcerative proctitis in a child.  相似文献   
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