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   172840篇
  免费   32461篇
  国内免费   2534篇
耳鼻咽喉   5357篇
儿科学   5844篇
妇产科学   2837篇
基础医学   6516篇
口腔科学   1716篇
临床医学   28752篇
内科学   52735篇
皮肤病学   7750篇
神经病学   16634篇
特种医学   7330篇
外国民族医学   8篇
外科学   44658篇
综合类   296篇
现状与发展   72篇
一般理论   4篇
预防医学   8241篇
眼科学   3520篇
药学   2185篇
中国医学   47篇
肿瘤学   13333篇
  2024年   693篇
  2023年   4886篇
  2022年   1380篇
  2021年   3619篇
  2020年   6328篇
  2019年   2694篇
  2018年   7967篇
  2017年   7713篇
  2016年   8873篇
  2015年   9011篇
  2014年   16296篇
  2013年   16675篇
  2012年   7211篇
  2011年   7190篇
  2010年   11319篇
  2009年   15173篇
  2008年   7309篇
  2007年   5562篇
  2006年   7991篇
  2005年   5329篇
  2004年   4474篇
  2003年   3368篇
  2002年   3368篇
  2001年   3958篇
  2000年   3125篇
  1999年   3390篇
  1998年   3868篇
  1997年   3660篇
  1996年   3523篇
  1995年   3344篇
  1994年   2042篇
  1993年   1687篇
  1992年   1465篇
  1991年   1471篇
  1990年   1120篇
  1989年   1215篇
  1988年   1059篇
  1987年   883篇
  1986年   923篇
  1985年   754篇
  1984年   579篇
  1983年   566篇
  1982年   552篇
  1981年   446篇
  1980年   395篇
  1979年   327篇
  1978年   343篇
  1977年   411篇
  1975年   295篇
  1972年   314篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
981.
982.
983.
984.
985.
A wide range of vascular disorders can affect the spleen. Although clinical presentation is often nonspecific, early diagnosis and treatment are mandatory in most conditions. Noninvasive imaging techniques are well suited to meet these objectives. Familiarity with normal macroscopic and microscopic vascular anatomy is a prerequisite to understand the pathophysiology of vascular disorders of the spleen. This article deals with diseases of the splenic vasculature (aneurysms, arteriovenous fistula, splenic vein thrombosis, collateral circulation in portal hypertension) as well as vascular disorders affecting the splenic parenchyma (splenic infarct, Gamna-Gandy bodies). Primary vascular tumors and tumor-like conditions of the spleen will be discussed very briefly.  相似文献   
986.
987.
This study retrospectively compares patients who underwent outpatient transvaginal follicle aspiration with either a propofol- or methohexital-based intravenous sedation technique. Data collected from patient charts (n = 212) over a 46-month period were analyzed to determine the effects of each sedation technique on procedure and recovery times, number of retrieved ova, as well as rates of nausea, fertilization, cleavage, pregnancy, and delivery. All patients were included in the study, regardless of age or diagnosis. procedure time was lower in the propofol group (51 t 18 min) than in the methohexital group (61 I 20 min) (p > 0.01). Patients in the methohexital group (139 2 51 min) spent more time in the recovery room than did those in the propofol group (71 ? 34 min) (p > 0.01). The nausea rates were significantly lower in the propofol group compared with the methohexital group (1.9% vs. 14.4%, respectively) (p > 0.02). Fertilization rate in the propofol group was 77.7% and was 62.9% in the methohexital group (p > 0.01). The numbers of retrieved ova and the cleavage rates were similar in both groups. The rate of pregnancy in patients sedated with propofol (46.1%) was higher than the methohexital group (26.9%) (p > 0.02). Delivery rate was 38.5% in the propofol group and 20.6% in the methohexital group (p > 0.02). In summary, propofol intravenous sedation for transvaginal follicle aspiration was associ- ated with an improved outcome. Pregnancy and delivery rates were higher while nausea, an unpleasant side effect, was sharply reduced.  相似文献   
988.
989.
Background: If cutaneous lymphoscintigraphy (CL) is accurate in predicting the draining lymph node basins at risk from primary axial melanomas, then regional metastases should only occur in those lymph node basins identified by CL. Methods: This study is a retrospective review of patients undergoing CL for primary axial melanomas from June 1, 1985, until June 31, 1992. Data retrieved included age, gender, number of basins identified, location of basins identified, management of basins, recurrence in lymphatics, development of distant disease, and long-term follow-up. Results: A total of 181 patients underwent elective LND, and 48 patients (27%) had melanoma in the nodes within the dissected basin. Of these 181 patients, seven developed nodal metastases as their site of first recurrence. All seven recurrences were seen at sites dissected or at sites indicated by CL, which the primary surgeon elected not to treat initially. Of the 116 patients observed, 16 (14%) developed lymph node metastases as their first site of recurrence. Fifteen of these 16 patients had their site of lymph node metastases predicted by CL. In this study, CL predicted 98.6% of all lymph node metastases. Conclusions: The high overall reliability of CL as demonstrated by long-term follow-up indicates that the information obtained by CL can be reliably used to guide intervention. Initial evaluation of patients with high-risk cutaneous melanomas at sites with ambiguous lymphatic drainage must include CL in order to determine the draining lymph node basins and to plan therapy. Presented at the 47th Annual Cancer Symposium of The Society of Surgical Oncology, Houston, Texas, March 17–20, 1994.  相似文献   
990.
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