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   86001篇
  免费   5549篇
  国内免费   167篇
耳鼻咽喉   973篇
儿科学   2849篇
妇产科学   2292篇
基础医学   13243篇
口腔科学   2435篇
临床医学   7873篇
内科学   17383篇
皮肤病学   1658篇
神经病学   8711篇
特种医学   3161篇
外国民族医学   24篇
外科学   11385篇
综合类   347篇
现状与发展   1篇
一般理论   79篇
预防医学   7094篇
眼科学   1386篇
药学   4644篇
中国医学   83篇
肿瘤学   6096篇
  2023年   408篇
  2022年   730篇
  2021年   1298篇
  2020年   971篇
  2019年   1366篇
  2018年   1635篇
  2017年   1401篇
  2016年   1740篇
  2015年   1847篇
  2014年   2414篇
  2013年   3218篇
  2012年   4830篇
  2011年   4885篇
  2010年   2695篇
  2009年   2742篇
  2008年   4318篇
  2007年   4541篇
  2006年   4391篇
  2005年   4243篇
  2004年   3698篇
  2003年   3552篇
  2002年   3186篇
  2001年   2573篇
  2000年   2493篇
  1999年   2325篇
  1998年   1061篇
  1997年   903篇
  1996年   834篇
  1995年   705篇
  1994年   633篇
  1993年   627篇
  1992年   1523篇
  1991年   1510篇
  1990年   1456篇
  1989年   1291篇
  1988年   1228篇
  1987年   1103篇
  1986年   1095篇
  1985年   1030篇
  1984年   726篇
  1983年   599篇
  1982年   366篇
  1981年   352篇
  1979年   605篇
  1978年   368篇
  1977年   339篇
  1975年   359篇
  1974年   395篇
  1973年   368篇
  1972年   382篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
ObjectiveSpinal cord stimulation (SCS) is an effective treatment in failed back surgery syndrome (FBSS). We studied the effect of preimplantation opioid use on SCS outcome and the effect of SCS on opioid use during a two-year follow-up period.Materials and methodsThe study cohort included 211 consecutive FBSS patients who underwent an SCS trial from January 1997 to March 2014. Participants were divided into groups, which were as follows: 1) SCS trial only (n = 47), 2) successful SCS (implanted and in use throughout the two-year follow-up period, n = 131), and 3) unsuccessful SCS (implanted but later explanted or revised due to inadequate pain relief, n = 29). Patients who underwent explantation for other reasons (n = 4) were excluded. Opioid purchase data from January 1995 to March 2016 were retrieved from national registries.ResultsHigher preimplantation opioid doses associated with unsuccessful SCS (ROC: AUC = 0.66, p = 0.009), with 35 morphine milligram equivalents (MME)/day as the optimal cutoff value. All opioids were discontinued in 23% of patients with successful SCS, but in none of the patients with unsuccessful SCS (p = 0.004). Strong opioids were discontinued in 39% of patients with successful SCS, but in none of the patients with unsuccessful SCS (p = 0.04). Mean opioid dose escalated from 18 ± 4 MME/day to 36 ± 6 MME/day with successful SCS and from 22 ± 8 MME/day to 82 ± 21 MME/day with unsuccessful SCS (p < 0.001).ConclusionsHigher preimplantation opioid doses were associated with SCS failure, suggesting the need for opioid tapering before implantation. With continuous SCS therapy and no explantation or revision due to inadequate pain relief, 39% of FBSS patients discontinued strong opioids, and 23% discontinued all opioids. This indicates that SCS should be considered before detrimental dose escalation.  相似文献   
2.
Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Akteure der öffentlichen Gesundheit (Public Health) tragen wesentlich zu Gesundheitsschutz, -förderung und...  相似文献   
3.
4.
5.
6.
Prevalence of osteoporosis is more than 50% in older adults, yet current clinical methods for diagnosis that rely on areal bone mineral density (aBMD) fail to detect most individuals who have a fragility fracture. Bone fragility can manifest in different forms, and a “one-size-fits-all” approach to diagnosis and management of osteoporosis may not be suitable. High-resolution peripheral quantitative computed tomography (HR-pQCT) provides additive information by capturing information about volumetric density and microarchitecture, but interpretation is challenging because of the complex interactions between the numerous properties measured. In this study, we propose that there are common combinations of bone properties, referred to as phenotypes, that are predisposed to different levels of fracture risk. Using HR-pQCT data from a multinational cohort (n = 5873, 71% female) between 40 and 96 years of age, we employed fuzzy c-means clustering, an unsupervised machine-learning method, to identify phenotypes of bone microarchitecture. Three clusters were identified, and using partial correlation analysis of HR-pQCT parameters, we characterized the clusters as low density, low volume, and healthy bone phenotypes. Most males were associated with the healthy bone phenotype, whereas females were more often associated with the low volume or low density bone phenotypes. Each phenotype had a significantly different cumulative hazard of major osteoporotic fracture (MOF) and of any incident osteoporotic fracture (p < 0.05). After adjustment for covariates (cohort, sex, and age), the low density followed by the low volume phenotype had the highest association with MOF (hazard ratio = 2.96 and 2.35, respectively), and significant associations were maintained when additionally adjusted for femoral neck aBMD (hazard ratio = 1.69 and 1.90, respectively). Further, within each phenotype, different imaging biomarkers of fracture were identified. These findings suggest that osteoporotic fracture risk is associated with bone phenotypes that capture key features of bone deterioration that are not distinguishable by aBMD. © 2021 American Society for Bone and Mineral Research (ASBMR).  相似文献   
7.
8.
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