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   44763篇
  免费   4993篇
  国内免费   74篇
耳鼻咽喉   632篇
儿科学   1284篇
妇产科学   1259篇
基础医学   6920篇
口腔科学   1059篇
临床医学   6072篇
内科学   8261篇
皮肤病学   601篇
神经病学   3563篇
特种医学   1571篇
外国民族医学   1篇
外科学   6020篇
综合类   932篇
一般理论   29篇
预防医学   4577篇
眼科学   698篇
药学   3632篇
中国医学   58篇
肿瘤学   2661篇
  2021年   523篇
  2020年   406篇
  2019年   698篇
  2018年   802篇
  2017年   577篇
  2016年   718篇
  2015年   759篇
  2014年   1037篇
  2013年   1583篇
  2012年   2102篇
  2011年   2165篇
  2010年   1221篇
  2009年   1094篇
  2008年   1888篇
  2007年   1966篇
  2006年   1929篇
  2005年   1872篇
  2004年   1798篇
  2003年   1738篇
  2002年   1768篇
  2001年   1571篇
  2000年   1589篇
  1999年   1361篇
  1998年   591篇
  1997年   476篇
  1996年   416篇
  1995年   486篇
  1994年   455篇
  1993年   424篇
  1992年   1117篇
  1991年   1053篇
  1990年   1039篇
  1989年   949篇
  1988年   876篇
  1987年   898篇
  1986年   876篇
  1985年   893篇
  1984年   709篇
  1983年   604篇
  1982年   430篇
  1981年   351篇
  1980年   373篇
  1979年   579篇
  1978年   443篇
  1977年   365篇
  1976年   370篇
  1974年   379篇
  1973年   333篇
  1972年   338篇
  1971年   304篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
BackgroundAdjuvant chemotherapy, postoperative radiation (PORT), and prophylactic cranial irradiation (PCI) have been individually examined in limited-stage small cell lung cancer (SCLC). There is a paucity of data on the effectiveness of each adjuvant treatment modality when used in combination after surgical resection of SCLC.MethodsData were collected from 5 cancer centers on all patients with limited-stage SCLC who underwent surgical resection between 1986 and 2019. Univariate and multivariable models were conducted to identify predictors of long-term outcomes, focusing on freedom from recurrence and survival benefit of adjuvant chemotherapy, PORT, and PCI.ResultsA total of 164 patients were analyzed. Multivariable Cox regression analysis did not identify any adjuvant therapies to significantly influence recurrence in this cohort. Specifically, PORT was not associated with a significant influence on locoregional recurrence and PCI was not significantly associated with intracranial outcomes. Adjuvant chemotherapy improved survival in all stage I through III disease (hazard ratio, 0.49; 95% confidence interval, 0.29-0.81; P = .005) and even in pathologically node negative patients (hazard ratio, 0.49; 95% confidence interval, 0.27-0.91; P = .024). Although PCI was found to improve survival in univariate analysis, it was not significant in a multivariable model. PORT was not found to affect survival on either univariate or multivariable analysis.ConclusionsThis is among the largest multi-institutional studies on surgically resected limited-stage SCLC. Our results highlight survival benefit of adjuvant chemotherapy, but did not identify a statistically significant influence from mediastinal PORT or PCI in our cohort. Larger prospective studies are needed to determine the benefit of PORT or PCI in a surgically resected limited-stage SCLC population.  相似文献   
4.
5.
6.
BackgroundThe optimal timing of treatment of liver metastases from low-grade neuroendocrine tumors (LG-NELM) varies significantly due to numerous treatment modalities and the literature supporting various treatment(s). This study sought to create and validate a literature-based treatment algorithm for LG-NELM.MethodsA treatment algorithm to maximize overall survival (OS) was designed using peer-reviewed articles evaluating treatment of LG-NELM. This algorithm was retrospectively applied to patients treated for LG-NELM at our institution. Deviation was determined based on whether or not a patient received treatment consistent with that recommended by the algorithm. Patients who did and did not deviate from the algorithm were compared with respect to OS and number of treatments.ResultsApplying our algorithm to a 149-patient cohort, 57 (38%) deviated from recommended treatment. Deviation occurred in the form of alternative (28, 49%) versus additional procedures (29, 51%). Algorithm deviators underwent significantly more procedures than non-deviators (median 1 vs. 2, p < 0.001). Cox model indicated no difference in OS associated with algorithm deviation (HR 1.19, p = 0.58) when controlling for age and tumor characteristics.ConclusionThis literature-based algorithm helps standardize treatment protocols in patients with LG-NELM and can reduce cost and risk by minimizing unnecessary procedures. Prospective implementation and validation is required.  相似文献   
7.
8.
Concern has been raised regarding the use of simethicone, a de‐foaming agent, during endoscopic procedures. Following reports of simethicone residue in endoscope channels despite high level disinfection, an endoscope manufacturer recommended that it not be used due to concerns of biofilm formation and a possible increased risk of microorganism transmission. However, a detailed mucosal assessment is essential in performing high‐standard endoscopic procedures. This is impaired by bubbles within the gastrointestinal lumen. The Gastroenterological Society of Australia's Infection Control in Endoscopy Guidelines (ICEG) Committee conducted a literature search utilizing the MEDLINE database. Further references were sourced from published paper bibliographies. Following a review of the available evidence, and drawing on extensive clinical experience, the multidisciplinary ICEG committee considered the risks and benefits of simethicone use in formulating four recommendations. Published reports have documented residual liquid or crystalline simethicone in endoscope channels after high level disinfection. There are no data confirming that simethicone can be cleared from channels by brushing. Multiple series report benefits of simethicone use during gastroscopy and colonoscopy in improving mucosal assessment, adenoma detection rate, and reducing procedure time. There are no published reports of adverse events related specifically to the use of simethicone, delivered either orally or via any endoscope channel. An assessment of the risks and benefits supports the continued use of simethicone during endoscopic procedures. Strict adherence to instrument reprocessing protocols is essential.  相似文献   
9.
10.
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