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   33912篇
  免费   3336篇
  国内免费   2309篇
耳鼻咽喉   240篇
儿科学   475篇
妇产科学   381篇
基础医学   3721篇
口腔科学   591篇
临床医学   4808篇
内科学   4926篇
皮肤病学   309篇
神经病学   1547篇
特种医学   1433篇
外国民族医学   13篇
外科学   3663篇
综合类   5782篇
现状与发展   7篇
一般理论   3篇
预防医学   2248篇
眼科学   727篇
药学   3699篇
  41篇
中国医学   1978篇
肿瘤学   2965篇
  2024年   123篇
  2023年   529篇
  2022年   1356篇
  2021年   1701篇
  2020年   1299篇
  2019年   1086篇
  2018年   1134篇
  2017年   1114篇
  2016年   1082篇
  2015年   1593篇
  2014年   1924篇
  2013年   1740篇
  2012年   2265篇
  2011年   2680篇
  2010年   1727篇
  2009年   1355篇
  2008年   1732篇
  2007年   1825篇
  2006年   1728篇
  2005年   1613篇
  2004年   1239篇
  2003年   1235篇
  2002年   1120篇
  2001年   932篇
  2000年   874篇
  1999年   823篇
  1998年   475篇
  1997年   529篇
  1996年   359篇
  1995年   313篇
  1994年   244篇
  1993年   195篇
  1992年   237篇
  1991年   214篇
  1990年   183篇
  1989年   166篇
  1988年   133篇
  1987年   137篇
  1986年   120篇
  1985年   78篇
  1984年   50篇
  1983年   28篇
  1982年   18篇
  1981年   19篇
  1980年   25篇
  1979年   45篇
  1978年   22篇
  1976年   12篇
  1975年   18篇
  1974年   20篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
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   
4.
5.
目的 了解某设备实验条件下不同位置脉冲X射线电离辐射水平,提出适当的防护建议。方法 采用热释光测量方法,分别在设备舱周围不同方向不同距离布放热释光剂量计,累积一定数量脉冲辐射后进行测量;采用电离室型X、γ剂量率仪(FJ-347A)实时测量工作状态下不同距离处电离辐射剂量率水平。依据《电离辐射防护与辐射源安全基本标准》(GB18871—2002)规定的职业照射人员和公众个人剂量限值提出不同工作位辐射防护建议。结果 热释光剂量计累计接收3 000个脉冲辐射,设备舱外壁0.01~8.98 mGy,顶部0.01~15.67 mGy,距外壁1~12 m之间0.01~2.18 mGy,工作位0 mGy。工作状态下,X射线剂量率仪测得距设备舱外侧壁1~20 m之间空气比释动能率范围0.26~16 mGy/h。结论 热释光剂量计、电离室型剂量率仪测量结果基本一致,说明两种方法均可用于脉冲X射线测量;工作状态下设备舱外近距离处辐射剂量率较高,可通过采取防护措施或者限制人员工作量以满足辐射防护要求。  相似文献   
6.
7.
8.
9.
刘冰  王红梅  余雨滋  黄浙学  潘永良 《全科护理》2021,19(19):2612-2615
总结广泛性焦虑症(generalized anxiety disorder,GAD)心理治疗方法,分析不同心理治疗的疗效及研究进展,为今后多角度、整合式运用各种心理疗法治疗GAD提供新思路.  相似文献   
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