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   2376245篇
  免费   194685篇
  国内免费   4209篇
耳鼻咽喉   34287篇
儿科学   72793篇
妇产科学   62936篇
基础医学   335069篇
口腔科学   67531篇
临床医学   215631篇
内科学   468790篇
皮肤病学   47977篇
神经病学   200885篇
特种医学   95992篇
外国民族医学   886篇
外科学   360630篇
综合类   56225篇
现状与发展   1篇
一般理论   977篇
预防医学   190660篇
眼科学   55476篇
药学   177569篇
  5篇
中国医学   4368篇
肿瘤学   126451篇
  2018年   24236篇
  2016年   20606篇
  2015年   23316篇
  2014年   33566篇
  2013年   50863篇
  2012年   68809篇
  2011年   72343篇
  2010年   42509篇
  2009年   40914篇
  2008年   68814篇
  2007年   73169篇
  2006年   74060篇
  2005年   72085篇
  2004年   69391篇
  2003年   67070篇
  2002年   66313篇
  2001年   112486篇
  2000年   116554篇
  1999年   98363篇
  1998年   27865篇
  1997年   25530篇
  1996年   25463篇
  1995年   24616篇
  1994年   23173篇
  1993年   21562篇
  1992年   79401篇
  1991年   76411篇
  1990年   73589篇
  1989年   70848篇
  1988年   65853篇
  1987年   64805篇
  1986年   61340篇
  1985年   58408篇
  1984年   44227篇
  1983年   37663篇
  1982年   22895篇
  1981年   20335篇
  1980年   19037篇
  1979年   41308篇
  1978年   28991篇
  1977年   24351篇
  1976年   22836篇
  1975年   23970篇
  1974年   29645篇
  1973年   28048篇
  1972年   26230篇
  1971年   24155篇
  1970年   22754篇
  1969年   21094篇
  1968年   19142篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
Red cell exchange (RCE) is a common procedure in adults with sickle cell disease (SCD). Implantable dual lumen Vortex (DLV) ports can be used for RCE in patients with poor peripheral venous access. We performed a retrospective cohort study of RCE procedures performed in adults with SCD. The main objective of the study was to compare the inlet speed, duration of procedures and rate of complications performed through DLV ports to those performed through temporary central venous and peripheral catheters. Twenty‐nine adults with SCD underwent a total of 318 RCE procedures. Twenty adults had DLV ports placed and 218 procedures were performed using DLV ports. Mean length of follow‐up after DLV port placement was 397 ± 263 days. Six DLV ports were removed due to infection and 1 for malfunction after a mean of 171 ± 120 days. Compared to temporary central venous and peripheral catheters, DLV port procedures had a greater rate of procedural complications, a longer duration, and a lower inlet speed (all P < 0.01). When accounting for the maximum allowable inlet speed to avoid citrate toxicity, 40% of DLV port procedures were greater than 10% below maximum speed, compared to 7 and 14% of procedures performed through temporary central venous and peripheral catheters (P < 0.0001). In conclusion, DLV ports can be used for RCE in adults with SCD, albeit with more procedural complications and longer duration. The smaller internal diameter and longer catheter of DLV ports compared to temporary central venous catheters likely accounts for the differences noted. J. Clin. Apheresis 30:353–358, 2015. © 2015 Wiley Periodicals, Inc.  相似文献   
52.
53.
54.
55.
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   
56.
57.
58.
59.
60.
To evaluate the changes in alveolar contour after guided bone regeneration (GBR) with two different combinations of biomaterials in dehiscence defects arou  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