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   22641篇
  免费   1662篇
  国内免费   47篇
耳鼻咽喉   205篇
儿科学   738篇
妇产科学   647篇
基础医学   2820篇
口腔科学   265篇
临床医学   3332篇
内科学   4174篇
皮肤病学   347篇
神经病学   2171篇
特种医学   446篇
外科学   2479篇
综合类   219篇
一般理论   49篇
预防医学   2918篇
眼科学   299篇
药学   1478篇
  1篇
中国医学   29篇
肿瘤学   1733篇
  2024年   30篇
  2023年   268篇
  2022年   391篇
  2021年   839篇
  2020年   537篇
  2019年   851篇
  2018年   900篇
  2017年   686篇
  2016年   667篇
  2015年   773篇
  2014年   1022篇
  2013年   1383篇
  2012年   2004篇
  2011年   1973篇
  2010年   1081篇
  2009年   877篇
  2008年   1529篇
  2007年   1550篇
  2006年   1365篇
  2005年   1360篇
  2004年   1187篇
  2003年   1024篇
  2002年   921篇
  2001年   126篇
  2000年   74篇
  1999年   107篇
  1998年   174篇
  1997年   141篇
  1996年   112篇
  1995年   67篇
  1994年   52篇
  1993年   59篇
  1992年   29篇
  1991年   30篇
  1990年   18篇
  1989年   13篇
  1988年   14篇
  1987年   14篇
  1986年   17篇
  1985年   18篇
  1984年   13篇
  1983年   10篇
  1982年   9篇
  1981年   8篇
  1980年   4篇
  1978年   3篇
  1977年   3篇
  1976年   4篇
  1974年   2篇
  1972年   3篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
The contribution of each monocular pathway to the timing of the binocular pattern visual evoked potential was assessed in situations where a significant interocular timing discrepancy was observed. Monocular and binocular pattern visual evoked potentials to 0.5° checks were recorded from normal subjects, normal subjects in whom one eye was blurred, patients with monocular amblyopia, and patients with resolved unilateral optic neuritis. Normal subjects showed facilitation, while suppression was evidenced in subjects with monocular blurring. In patients with amblyopia, the affected pathway had no effect on binocular pattern visual evoked potential latency, suggesting that the amblyopic eye was suppressed. In contrast, all patients with optic neuritis showed binocular averaging. Our results show that different forms of binocular interaction are evidenced in normal subjects, in amblyopia and in optic neuritis, and suggest that a comparative analysis of monocular and binocular pattern visual evoked potential peak times brings valuable information to the clinical evaluation that could be used to distinguish disease processes further.Abbreviation BPVEP binocular pattern visual evoked potential  相似文献   
52.
53.
Carcinoma of the papilla of Vater is classified as periampullary cancer representing 5% of all gastrointestinal tract malignancies. Early and accurate diagnosis is important for those patients with a tumor of the papilla, as the prognosis is more favorable than in other periampullary neoplasms. Endoscopically obtained biopsies from suspicious papillae can detect an early tumor, although even for skilled pathologists it is often difficult to differentiate carcinomas from noninvasive lesions on the basis of forceps biopsies. The purpose of this study was to assess the preoperative diagnostic accuracy of duodenoscopy appearance and biopsy in all cases with suspicion of tumor. Thirty patients with suspicion of carcinoma of the papilla of Vater and with final diagnosis established by pancreatoduodenectomy were included in this retrospective study. In each case, a comparison was made between endoscopic biopsy and duodenoscopic appearance. Duodenoscopic appearance sensitivity and accuracy for malignancy were 86% and 83%, respectively, whereas endoscopic biopsy sensitivity and accuracy were 65% and 67%, respectively. Although preoperative diagnosis of carcinoma of the papilla of Vater is useful for making therapeutic decisions, the diagnostic value of the endoscopic appearance was superior to endoscopic biopsy in this series. Presented at the 2003 American Hepato-Pancreato-Biliary Association Congress, Miami, Florida, February 27-March 3, 2003. Supported by FADA-CAPES/PROP 200J (M.L.D.).  相似文献   
54.
55.
Purpose: Using peripheral venous pressure (PVP) instead of central venous pressure (CVP) as a volume monitor decreases patient risks and costs, and is convenient. This study was undertaken to determine if PVP predicts CVP in pediatric patients. METHODS: With ethical approval and informed consent, 30 pediatric patients aged neonate to 12 yr requiring a central venous line were studied prospectively in a tertiary care teaching hospital. In the supine position, PVP and CVP were simultaneously transduced. Ninety-six paired recordings of CVP and PVP were made. Correlation and Bland-Altman analysis of agreement of end-expiratory measurements were performed. RESULTS: The mean (SD; range) CVP was 10.0 mmHg (6.0; -1.0 to 27.0); the mean PVP was 13.7 mmHg (6.3; 0.0 to 33.0); offset (bias) of PVP > CVP was 3.7 mmHg with SD 2.6. The 95% confidence intervals (CI) for the bias were 3.2 to 4.1 mmHg. In the Bland-Altman analysis, lower and upper limits of agreement (LOA; CI in parentheses) were -1.5 (-2.3 to -0.7) and 8.8 (8.1 to 9.6) mmHg. Eight of 96 points were outside the limits of agreement. The correlation of PVP on CVP was r = 0.92, P < 0.0001. For a subset of ten patients (20 simultaneous recordings) with iv catheters proximal to the hand, limits of agreement were better - offset: 3.8 mmHg (+/- 1.4); lower LOA: 1.2 mmHg (0.25 to 2.1); upper LOA: 6.6 mmHg (5.7 to 7.5). CONCLUSION: Peripheral venous pressure measured from an iv catheter in the hand predicts CVP poorly in pediatric patients.  相似文献   
56.
Male infertility is the result of a variety of highly treatable conditions. The critical step in treating male infertility is to evaluate properly every male partner of an infertile couple and to generate the proper treatment strategy. There are many medical and surgical options that can help most couples overcome male factor infertility. Male infertility can most easily be broken down into problems of sperm production (testicular dysfunction) and problems of sperm transport (obstruction). When applicable, medical therapies are used as an initial strategy to improve sperm production or as a preliminary therapy to boost production transiently in anticipation of a surgical sperm retrieval attempt. A range of surgical options is available to correct varicoceles, reconstruct the obstructed system, or retrieve sperm for assisted reproduction.  相似文献   
57.
58.
A rare case of anaplastic ameloblastic fibrosarcoma (AS) arising in an ameloblastic fibroma (AF) of the maxilla of a 48-year-old patient 10 years after the primary excision is presented. The recurrent tumor retained focal areas of AF but manifested heterogeneous malignant features ranging from low-grade spindle to highly pleomorphic sarcomas. Biomarker analysis showed alterations of the p53 and c-KIT genes restricted to the sarcomatous component. The biological implications of these findings in the future management of these tumors are discussed.  相似文献   
59.
重睑术   总被引:4,自引:1,他引:3  
重睑术是美国最流行的美容外科手术,每年的手术人数达500000-600000之多。洛杉矶Jules Stein眼科研究所的Baylis医师说,1年做10例的医师可以与1年做200例其他医师一样熟练。Baylis医师估计,人群的25%企望做重险术。  相似文献   
60.
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