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   98771篇
  免费   42676篇
  国内免费   133篇
耳鼻咽喉   1742篇
儿科学   4775篇
妇产科学   1005篇
基础医学   18690篇
口腔科学   6030篇
临床医学   14391篇
内科学   28142篇
皮肤病学   8026篇
神经病学   15364篇
特种医学   2675篇
外科学   15612篇
综合类   57篇
一般理论   31篇
预防医学   6379篇
眼科学   1706篇
药学   7010篇
  3篇
中国医学   1115篇
肿瘤学   8827篇
  2024年   91篇
  2023年   288篇
  2022年   635篇
  2021年   2417篇
  2020年   6394篇
  2019年   11445篇
  2018年   10838篇
  2017年   11904篇
  2016年   12688篇
  2015年   12600篇
  2014年   12751篇
  2013年   13485篇
  2012年   6065篇
  2011年   6082篇
  2010年   9932篇
  2009年   6111篇
  2008年   3545篇
  2007年   2347篇
  2006年   2248篇
  2005年   1905篇
  2004年   1740篇
  2003年   1581篇
  2002年   1553篇
  2001年   844篇
  2000年   736篇
  1999年   328篇
  1998年   145篇
  1997年   119篇
  1996年   102篇
  1995年   77篇
  1994年   71篇
  1993年   66篇
  1992年   60篇
  1991年   46篇
  1990年   35篇
  1989年   41篇
  1988年   25篇
  1987年   20篇
  1986年   27篇
  1985年   26篇
  1984年   27篇
  1983年   22篇
  1982年   20篇
  1981年   12篇
  1979年   8篇
  1978年   8篇
  1977年   6篇
  1975年   7篇
  1974年   6篇
  1971年   6篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
This study aimed to evaluate changes in sleep during the COVID‐19 outbreak, and used data‐driven approaches to identify distinct profiles of changes in sleep‐related behaviours. Demographic, behavioural and psychological factors associated with sleep changes were also investigated. An online population survey assessing sleep and mental health was distributed between 3 April and 24 June 2020. Retrospective questions were used to estimate temporal changes from before to during the outbreak. In 5,525 Canadian respondents (67.1% females, 16–95 years old: Mean ± SD = 55.6 ± 16.3 years), wake‐up times were significantly delayed relative to pre‐outbreak estimates (p < .001,  = 0.04). Occurrences of clinically meaningful sleep difficulties significantly increased from 36.0% before the outbreak to 50.5% during the outbreak (all p < .001, g ≥ 0.27). Three subgroups with distinct profiles of changes in sleep behaviours were identified: “Reduced Time in Bed”, “Delayed Sleep” and “Extended Time in Bed”. The “Reduced Time in Bed” and “Delayed Sleep” subgroups had more adverse sleep outcomes and psychological changes during the outbreak. The emergence of new sleep difficulties was independently associated with female sex, chronic illnesses, being employed, family responsibilities, earlier wake‐up times, higher stress levels, as well as heavier alcohol use and television exposure. The heterogeneity of sleep changes in response to the pandemic highlights the need for tailored interventions to address sleep problems.  相似文献   
3.

Introduction

When evaluating a quality-of-life questionnaire (QLQ), many validation studies do not correlate quality-of-life scores with objective measurements of complications associated with treatment.

Patients and Methods

We performed a cross-sectional observational study with 300 patients submitted to breast-conserving therapy. The patients answered the European Organization for Research and Treatment of Cancer (EORTC) QLQs C-30 and BR23, as well as the Brazilian Portuguese version of the Breast Cancer Treatment Outcome Scale (BCTOS) questionnaire. Retest, internal consistency, factorial analysis, convergent/divergent analysis, and Rasch evaluation were performed. All patients underwent physical evaluations to assess lymphedema, handgrip strength, shoulder range of motion, breast cosmesis, and breast pain, and these groups were compared on the basis of BCTOS scores. Receiver operating characteristic curve determined the predictive value of BCTOS scores associated with clinical practice.

Results

The internal consistencies of the BCTOS domains ranged from 0.785 to 0.895. Factor analysis grouped according to the original questionnaire. Convergent validation showed differences in the sexual functioning and sexual enjoyment domains of the EORTC BR23. Analysis of known groups found that in most domains, the scores were higher in patients with lymphedema, strength deficit, shoulder range-of-motion alteration, poor breast cosmesis, breast pain, and axillary lymphadenectomy. Using a cutoff of 1.26, lymphedema was associated with the edema domain; using a cutoff of 1.33, Late Effects Normal Tissue Task Force/Subjective, Objective, Management, Analytic pain was associated with the pain domain; and using a cutoff of 2.37, the cosmetic domain was associated with subjective cosmesis.

Conclusion

The association of objective measurements in a validation study of quality of life qualified the study and allowed us to develop better parameters for comparisons of results of breast-conserving therapy between populations.  相似文献   
4.
5.

Purpose

To study the use of functional capacity (FC) level and duration of aromatase inhibitor (AI) therapy with adiposity parameters in women with breast cancer.

Patients and Methods

FC was evaluated through the Health Assessment Questionnaire, which was assessed by classification and divided into 3 groups: G1 = mild to moderate difficulty, G2 = moderate to severe disability, and G3 = severe or very severe disability. Body mass, height, and waist circumference (WC) were measured, and body mass index (BMI) was calculated. Bioelectrical impedance analysis was used to calculate body fat (BF) and fat-free mass. The women were divided into 2 time groups (T1 and T2), which were determined by the median months of AI use (T1 ≤ 29.5 and T2 > 29.5 months).

Results

Impaired FC and adiposity parameters were significantly positively correlated. In addition, physical exercise was significantly lower in women assessed as G2 and G3 compared to those assessed as G1. The effect of FC on BMI, BF, and WC was also verified, as was the effect of the duration of AI receipt on BMI and BF. Women at T1 had significantly greater functional disability, BMI, and BF values. In addition, although not statistically significant, women in T1 who were assessed as G3 presented higher BMI, WC, and BF values than those in T2.

Conclusion

Adiposity above the recommended parameters and impaired FC were associated with the shortest time of receipt of adjuvant endocrine therapy with AI.  相似文献   
6.
Loxoprofen is an anti‐inflammatory drug that requires bioactivation into the trans‐OH metabolite to exert pharmacological activity. Evidence suggests that carbonyl reductase 1 (CBR1) is important during the bioactivation of loxoprofen. This study examined the impact of the functional single nucleotide polymorphism CBR1 rs9024 on the bioactivation of loxoprofen in a collection of human liver samples. The synthesis ratios of trans‐OH loxoprofen/cis‐OH loxoprofen were 33% higher in liver cytosols from donors homozygous for the CBR1 rs9024 G allele in comparison with the ratios in samples from donors with heterozygous GA genotypes. Complementary studies examined the impact of CBR1 rs9024 on the bioactivation of loxoprofen in lymphoblastoid cell lines. CBR1 rs9024 genotype status impacts the synthesis of the bioactive trans‐OH metabolite of loxoprofen in human liver.  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