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   1408124篇
  免费   115862篇
  国内免费   3331篇
耳鼻咽喉   18361篇
儿科学   46591篇
妇产科学   41058篇
基础医学   200772篇
口腔科学   37695篇
临床医学   125923篇
内科学   284039篇
皮肤病学   33355篇
神经病学   116926篇
特种医学   53876篇
外国民族医学   464篇
外科学   210674篇
综合类   32787篇
现状与发展   3篇
一般理论   488篇
预防医学   109883篇
眼科学   31451篇
药学   98513篇
  1篇
中国医学   3347篇
肿瘤学   81110篇
  2021年   10860篇
  2019年   11672篇
  2018年   16588篇
  2017年   12686篇
  2016年   14289篇
  2015年   16031篇
  2014年   22596篇
  2013年   33452篇
  2012年   45432篇
  2011年   47997篇
  2010年   28191篇
  2009年   27082篇
  2008年   44355篇
  2007年   46874篇
  2006年   47451篇
  2005年   45890篇
  2004年   43789篇
  2003年   41734篇
  2002年   40231篇
  2001年   73047篇
  2000年   74577篇
  1999年   61599篇
  1998年   17003篇
  1997年   15446篇
  1996年   15601篇
  1995年   14804篇
  1994年   13405篇
  1993年   12588篇
  1992年   45861篇
  1991年   43502篇
  1990年   41512篇
  1989年   39578篇
  1988年   36195篇
  1987年   35369篇
  1986年   32875篇
  1985年   31286篇
  1984年   23841篇
  1983年   20041篇
  1982年   12217篇
  1981年   10787篇
  1979年   20715篇
  1978年   14589篇
  1977年   12103篇
  1976年   11365篇
  1975年   11629篇
  1974年   13997篇
  1973年   13538篇
  1972年   12635篇
  1971年   11474篇
  1970年   10903篇
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
131.
While therapeutic approaches for psoriasis are widely available, preventive regimens are lacking. We aimed to determine whether improvements in epidermal function could prevent psoriasis relapse. Two self‐controlled cohort studies were designed, enrolling two cohorts of patients with psoriasis (n = 30 and n = 60) to be treated topically with an in‐house‐prepared emollient or ATOPALM® cream applied twice daily to one forearm for 20 and 30 days, respectively, while the same sites on the contralateral arm served as the untreated control. Epidermal function on both arms was assessed prior to and at the end of the trials. Delayed relapse on the treated arm was seen in 54.5% and 71% of patients in the first and second cohort, respectively. The time of psoriatic relapse correlated with the extent of abnormalities in baseline epidermal function. These results suggest that improvements in epidermal function with topical emollients can prevent/attenuate the development of psoriasis.  相似文献   
132.
133.
134.
135.
First described in 1955 in New Jersey, epizootic haemorrhagic disease (EHD) causes a severe clinical disease in wild and domestic ruminants worldwide. Epizootic haemorrhagic disease outbreaks occur in deer populations each year from summer to late autumn. The etiological agent is EHD virus (EHDV) which is a double‐stranded segmented icosahedral RNA virus. EHD virus utilizes point mutations and reassortment strategies to maintain viral fitness during infection. In 2018, EHDV serotype 2 was predominantly detected in deer in Illinois. Whole genome sequencing was conducted for two 2018 EHDV2 isolates (IL41747 and IL42218) and the sequence analyses indicated that IL42218 was a reassortant between different serotypes whereas IL41747 was a genetically stable strain. Our data suggest that multiple strains contribute to outbreaks each year.  相似文献   
136.
137.
138.
139.
140.

Background Context

Low back pain (LBP) is a common complaint in clinical practice of multifactorial origin. Although obesity has been thought to contribute to LBP primarily by altering the distribution of mechanical loads on the spine, the additional contribution of obesity-related conditions such as diabetes mellitus (DM) to LBP has not been thoroughly examined.

Purpose

To determine if there is a relationship between DM and LBP that is independent of body mass index (BMI) in a large cohort of adult survey participants.

Study Design

Retrospective analysis of prospectively collected National Health and Nutrition Examination Survey (NHANES) data to characterize associations between LBP, DM, and BMI in adults subdivided into 6 subpopulations: normal weight (BMI 18.5–25), overweight (BMI 25–30), and obese (BMI >30) diabetics and nondiabetics. Diabetes was defined with glycohemoglobin A1c (HbA1c) 6.5%.

Patient Sample

11,756 participants from NHANES cohort.

Outcome Measures

Percentage of LBP reported.

Methods

LBP reported in the 1999-2004 miscellaneous pain NHANES questionnaire was the dependent variable examined. Covariates included HbA1c, BMI, age, and family income ratio to poverty as continuous variables as well as race, gender, and smoking as binary variables. Individuals were further subdivided by weight class and diabetes status. Regression and graphical analyses were performed on the study population as a whole and also on subpopulations.

Results

Increasing HbA1c did not increase the odds of reporting LBP in the full cohort. However, multivariate logistic regression of the 6 subpopulations revealed that the odds of LBP significantly increased with increasing HbA1c levels in normal weight diabetics. No other subpopulations reported significant relationships between LBP and HbA1c. LBP was also significantly associated with BMI for normal weight diabetics and also for obese subjects regardless of their DM status.

Conclusions

LBP is significantly related to DM status, but this relationship is complex and may interact with BMI. These results support the concept that LBP may be improved in normal weight diabetic subjects with improved glycemic control and weight loss, and that all obese LBP subjects may benefit from improved weight loss alone.  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