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   30446篇
  免费   3007篇
  国内免费   2157篇
耳鼻咽喉   237篇
儿科学   456篇
妇产科学   362篇
基础医学   3464篇
口腔科学   569篇
临床医学   4121篇
内科学   4676篇
皮肤病学   363篇
神经病学   1458篇
特种医学   1399篇
外国民族医学   12篇
外科学   3519篇
综合类   4892篇
现状与发展   36篇
一般理论   3篇
预防医学   1929篇
眼科学   695篇
药学   3159篇
  27篇
中国医学   1587篇
肿瘤学   2646篇
  2024年   94篇
  2023年   563篇
  2022年   963篇
  2021年   1377篇
  2020年   1068篇
  2019年   954篇
  2018年   1011篇
  2017年   962篇
  2016年   976篇
  2015年   1368篇
  2014年   1683篇
  2013年   1527篇
  2012年   1972篇
  2011年   2366篇
  2010年   1571篇
  2009年   1246篇
  2008年   1529篇
  2007年   1622篇
  2006年   1532篇
  2005年   1493篇
  2004年   1139篇
  2003年   1155篇
  2002年   1032篇
  2001年   871篇
  2000年   807篇
  1999年   770篇
  1998年   468篇
  1997年   550篇
  1996年   372篇
  1995年   330篇
  1994年   261篇
  1993年   223篇
  1992年   235篇
  1991年   219篇
  1990年   191篇
  1989年   186篇
  1988年   153篇
  1987年   148篇
  1986年   119篇
  1985年   87篇
  1984年   54篇
  1983年   31篇
  1982年   24篇
  1981年   27篇
  1980年   37篇
  1979年   46篇
  1978年   27篇
  1976年   25篇
  1975年   28篇
  1974年   23篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Gold nanoparticles (Au NPs) hold great promise in food, industrial and biomedical applications due to their unique physicochemical properties. However, influences of the gastrointestinal tract (GIT), a likely route for Au NPs administration, on the physicochemical properties of Au NPs has been rarely evaluated. Here, we investigated the influence of GIT fluids on the physicochemical properties of Au NPs (5, 50, and 100?nm) and their implications on intestinal epithelial permeability in vitro. Au NPs aggregated in fasted gastric fluids and generated hydroxyl radicals in the presence of H2O2. Cell studies showed that GIT fluids incubation of Au NPs affected the cellular uptake of Au NPs but did not induce cytotoxicity or disturb the intestinal epithelial permeability.  相似文献   
3.
4.
The value of adding simeprevir (SMV) vs placebo (PBO) to peginterferon and ribavirin (PR) for treatment of chronic hepatitis C virus infection was examined using patient‐reported outcomes (PROs); further, concordance of PROs with virology endpoints and adverse events (AEs) was explored. Patients (= 768 SMV/PR,= 393 PBO/PR) rated fatigue (FSS), depressive symptoms (CES‐D) and functional impairment (WPAI: Hepatitis C Productivity, Daily Activity and Absenteeism) at baseline and throughout treatment in three randomised, double‐blind trials comparing the addition of SMV or PBO during initial 12 weeks of PR. PR was administered for 48 weeks (PBO group) and 24/48 weeks (SMV group) using a response‐guided therapy (RGT) approach. Mean PRO scores (except Absenteeism) worsened from baseline to Week 4 to the same extent in both groups but reverted after Week 24 for SMV/PR and only after Week 48 for PBO/PR. Accordingly, there was a significantly lower area under the curve (baseline–Week 60, AUC60) and fewer weeks with clinically important worsening of scores in the SMV/PR group at any time point. Incidences of patients with fatigue and anaemia AEs were similar in both groups, but FSS scores showed that clinically important increases in fatigue lasted a mean of 6.9 weeks longer with PBO/PR (P < 0.001). PRO score subgroup analysis indicated better outcomes for patients who met the criteria for RGT or achieved sustained virological response 12 weeks post‐treatment (SVR12); differences in mean PRO scores associated with fibrosis level were only observed with PBO/PR. Greater efficacy of SMV/PR enabled reduced treatment duration and reduced time with PR‐related AEs without adding to AE severity.  相似文献   
5.
6.
7.
8.
9.
10.

Aim

Leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) is an immune inhibitory receptor which is expressed within most types of hematopoietic cells and negatively regulates immune responses. Recently, we found LAIR-1 expression to be present within tumors of nonhematopoietic lineages. However, the roles of LAIR-1 in hepatocellular carcinoma (HCC) have yet to be examined. The purpose of this study was to investigate the expression of LAIR-1 in HCC tissue and assess its clinical significance at this site.

Materials and methods

Expression levels of LAIR-1 within HCC samples collected from 90 patients and compared with that of slides of normal liver tissue collected from 9 non-HCC patients were measured by immunohistochemistry using tissue microarrays. A semiquantitative score was assigned, as was based on staining intensity and percent of positive cells and a Spearman Rank correlation test was used to assess any potential significant correlations between LAIR-1 expression and clinicopathological factors. Overall survival analysis was performed using the Kaplan-Meier and Log Rank statistical test.

Results

LAIR-1 expression was detected in cancer tissue and adjacent tumor tissue, but not in normal liver tissue. The percent of LAIR-1-positive expression in cancer tissue of HCC samples was 97.78% (88/90) while that in adjacent tumor tissue was 96.67% (87/90). Significantly greater expression levels of LAIR-1 were obtained from cancer tissue (Mean?±?SD?=?5.722?±?2.145) than that in adjacent tumor tissue (4.141?±?1.486). In addition, LAIR-1 expression was found to be significantly correlated with pathological grade of HCC, T stage, and age. Expression levels of LAIR-1 were related with worse overall survival rates of HCC patients, especially in HCC patients with hepatic cirrhosis.

Conclusion

Results of this study show that LAIR-1 is expressed in HCC tissues and that high levels of LAIR-1 expression are associated with the poor cancer differentiation. In addition, overexpression of LAIR-1 was significantly associated with worse overall survival in the patients with HCC. These data suggest that LAIR-1 may be an independent predictor for clinical outcomes in patients with HCC.  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