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   50843篇
  免费   3569篇
  国内免费   104篇
耳鼻咽喉   403篇
儿科学   1927篇
妇产科学   1801篇
基础医学   6111篇
口腔科学   601篇
临床医学   8851篇
内科学   9140篇
皮肤病学   765篇
神经病学   4562篇
特种医学   885篇
外国民族医学   33篇
外科学   4514篇
综合类   635篇
一般理论   80篇
预防医学   7066篇
眼科学   548篇
药学   2907篇
  1篇
中国医学   88篇
肿瘤学   3598篇
  2023年   282篇
  2022年   205篇
  2021年   978篇
  2020年   663篇
  2019年   1077篇
  2018年   1228篇
  2017年   843篇
  2016年   964篇
  2015年   1049篇
  2014年   1449篇
  2013年   2417篇
  2012年   3443篇
  2011年   3689篇
  2010年   1967篇
  2009年   1847篇
  2008年   3253篇
  2007年   3714篇
  2006年   3568篇
  2005年   3479篇
  2004年   3360篇
  2003年   3191篇
  2002年   3007篇
  2001年   407篇
  2000年   311篇
  1999年   426篇
  1998年   659篇
  1997年   519篇
  1996年   453篇
  1995年   375篇
  1994年   369篇
  1993年   371篇
  1992年   271篇
  1991年   254篇
  1990年   244篇
  1989年   208篇
  1988年   218篇
  1987年   228篇
  1986年   185篇
  1985年   211篇
  1984年   229篇
  1983年   233篇
  1982年   279篇
  1981年   249篇
  1980年   195篇
  1979年   154篇
  1978年   140篇
  1977年   147篇
  1976年   115篇
  1974年   105篇
  1973年   116篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
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   
3.
4.
5.
6.
7.
8.
9.
PurposeTo examine what proportion of caregivers, if given a choice, would choose medical versus surgical treatment of appendicitis and what factors would be important in their decision.MethodsA survey was devised and given to the caregivers of children presenting to the pediatrician for a routine visit in community and academic pediatric clinics. The survey presented a summary of outcomes after medical (non-operative) and surgical treatment of uncomplicated appendicitis. Participants were then asked to choose medical versus surgical treatment if their child were to develop appendicitis. They were also asked to rate the importance of certain factors in their decision ? 1 being “not important” and 5 being “very important”.ResultsFour hundred surveys were distributed with an 86.2% (345/400) response rate. Six percent (21/342) of respondents reported a history of appendicitis and 49.4% (168/340) reported having known someone who had appendicitis. The majority of respondents, 85.3% (284/333), were mothers. A minority of respondents, 41.7% (95% CI: 36.7, 47.0), chose medical treatment over surgery for appendicitis. There was no statistical difference in the proportion of mothers (41.6%) versus fathers who chose medical treatment (41.3%). Caregivers who chose medical treatment were more likely to rate time in hospital (p = .008) and time out of school (p = 05) as important in decision making when compared with those who chose surgery. Those who chose surgical treatment were more likely to rate risk of recurrent appendicitis (p < .001) as important to decision making. In the multivariate analysis, those who rated time in hospital as very important had more than twice the odds of choosing medical therapy (OR 2.20, p = 0.02) when compared with those who rated it as less important. Not knowing someone who has had appendicitis was significantly associated with choosing medical therapy when compared with those who do know someone who has had appendicitis, OR 2.3, p = .002. Rating pain as very important was also significantly associated with choosing medical therapy, when compared to those rating pain 1–3, OR 3.38, p = .03.ConclusionsIn this survey of caregivers of children presenting for routine care, 41.7% would choose medical, or non-operative, therapy for their children with acute appendicitis. The risk of recurrence, time in hospital, and time out of school, pain, and knowing someone who has had appendicitis were all important factors that families may consider when making a decision. These data may be useful for surgeons counseling patients on which treatment to pursue.  相似文献   
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