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   4317篇
  免费   485篇
  国内免费   10篇
耳鼻咽喉   33篇
儿科学   113篇
妇产科学   89篇
基础医学   709篇
口腔科学   72篇
临床医学   486篇
内科学   713篇
皮肤病学   100篇
神经病学   293篇
特种医学   339篇
外科学   554篇
综合类   144篇
一般理论   3篇
预防医学   350篇
眼科学   130篇
药学   377篇
中国医学   5篇
肿瘤学   302篇
  2021年   64篇
  2020年   37篇
  2019年   68篇
  2018年   99篇
  2017年   65篇
  2016年   71篇
  2015年   89篇
  2014年   117篇
  2013年   152篇
  2012年   205篇
  2011年   213篇
  2010年   136篇
  2009年   126篇
  2008年   181篇
  2007年   195篇
  2006年   156篇
  2005年   152篇
  2004年   185篇
  2003年   159篇
  2002年   156篇
  2001年   152篇
  2000年   128篇
  1999年   124篇
  1998年   102篇
  1997年   54篇
  1996年   45篇
  1995年   54篇
  1994年   50篇
  1993年   46篇
  1992年   99篇
  1991年   91篇
  1990年   87篇
  1989年   81篇
  1988年   92篇
  1987年   92篇
  1986年   83篇
  1985年   56篇
  1984年   58篇
  1983年   55篇
  1982年   35篇
  1981年   32篇
  1979年   56篇
  1978年   43篇
  1977年   30篇
  1975年   35篇
  1973年   30篇
  1972年   51篇
  1971年   40篇
  1970年   29篇
  1969年   30篇
排序方式: 共有4812条查询结果,搜索用时 15 毫秒
181.
182.
183.
184.
185.
186.
187.

BACKGROUND.

In addition to the reporting of atypical glandular cells (AGC) and adenocarcinoma (ADCA), the 2001 Bethesda System requires the reporting of benign‐appearing endometrial cells in women aged >40 years (BAEMC). In this study, the authors evaluated the contribution of each of these reporting categories to the sensitivity and specificity of a liquid‐based Papanicolaou test for endometrial carcinoma or hyperplasia.

METHODS.

Over the 3‐year study period, in the setting of a large, multihospital health care system, the authors analyzed the results from liquid‐based Papanicolaou tests that were performed within the 6 months that preceded a histologic diagnosis of endometrial carcinoma or hyperplasia and that were reported according to the 2001 Bethesda System.

RESULTS.

Two hundred seventy‐two women had a histologic diagnosis of endometrial hyperplasia (n = 199) or malignancy (n = 73) within 6 months after a Papanicolaou test. In total, 188,594 Papanicolaou tests (91,385 from women aged >40 years) were interpreted during the study period and resulted in 3810 diagnoses of BAEMC, 326 diagnoses of AGC, and 30 diagnoses of ADCA. Only 28 of 73 women (38.4%) with endometrial carcinoma had cytologically AGC or ADCA reported on a previous Papanicolaou test. The reporting of BAEMC increased this sensitivity by only 5.5% (4 additional tests) but decreased the specificity of the Papanicolaou test for endometrial malignancy from 99.8% to 96%. For endometrial hyperplasias, the sensitivity of the Papanicolaou test was even lower (39 of 198 tests; 19.7%), but BAEMC represented the majority of endometrial‐type cells reported (36 of 39 tests).

CONCLUSIONS.

The reporting of BAEMC led to an only marginal increase in sensitivity that had to be weighed against the significant loss in specificity of the Papanicolaou test for endometrial neoplasia. Cancer (Cancer Cytopathol) 2007. © 2007 American Cancer Society.  相似文献   
188.

Background  

Non-islet cell tumor induced hypoglycemia (NICTH) is a very rare phenomenon, but even more so in gastrointestinal stromal tumors. It tends to present in large or metastatic tumors, and can appear at any time in the progression of the disease. We present herein a case of NICTH in a GIST tumor and report an exon 9 mutation associated to it.  相似文献   
189.
UDP-glucuronosyltransferases (UGTs) catalyze phase II biotransformation reactions in which lipophilic substrates are conjugated with glucuronic acid to increase water solubility and enhance excretion. Currently, little information regarding tissue- or gender-specific expression of mouse UGTs is available. Mice are increasingly popular models in biomedical research, and therefore, thorough characterization of murine drug metabolism is desired. The purpose of the present study was to determine both tissue- and gender-specific UGT gene expression profiles in mice. RNA from 14 tissues was isolated from male and female C57BL/6 mice and UGT expression was determined by the branched DNA signal amplification assay. UGTs highly expressed in mouse liver include Ugt1a1, Ugt1a5, Ugt1a6, Ugt1a9, Ugt2a3, Ugt2b1, Ugt2b5/37/38, Ugt2b34, Ugt2b35, and Ugt2b36. Several isoforms were expressed in the gastrointestinal (GI) tract, including Ugt1a6, Ugt1a7c, Ugt2a3, Ugt2b34, and Ugt2b35. In kidney, Ugt1a2, Ugt1a7c, Ugt2b5/37/38, Ugt2b35, and Ugt3a1/2 were expressed. UGT expression was also observed in other tissues: lung (Ugt1a6), brain (Ugt2b35), testis and ovary (Ugt1a6 and Ugt2b35), and nasal epithelia (Ugt2a1/2). Male-predominant expression was observed for Ugt2b1 in liver, Ugt2b5/37/38 in kidney, and Ugt1a6 in lung. Female-predominant expression was observed for Ugt1a1 and Ugt1a5 in liver, Ugt1a2 in kidney, Ugt2b35 in brain, and Ugt2a1/2 in nasal epithelia. UDP-glucose pyrophosphorylase was highly expressed in liver, kidney, and GI tract, whereas UDP-glucose dehydrogenase was highly expressed in the GI tract. In conclusion, marked differences in tissue- and gender-specific expression patterns of UGTs exist in mice, potentially influencing drug metabolism and pharmacokinetics.  相似文献   
190.
目的着重探讨45例缺血性肠病患者的病因、CT检查技术及其影像表现。资料与方法45例缺血性肠病均经螺旋CT扫描。26例经过手术证实,14例经过治疗痊愈,5例急性死亡。结果其中肠系膜动脉缺血24例,肝固有动脉缺血4例,肠系膜静脉缺血17例。结论严格掌握CT检查技术,根据CT影像表现并密切结合临床,对缺血性肠病患者可以作出确定诊断。  相似文献   
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