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   9049篇
  免费   621篇
  国内免费   112篇
耳鼻咽喉   105篇
儿科学   318篇
妇产科学   301篇
基础医学   970篇
口腔科学   173篇
临床医学   942篇
内科学   1874篇
皮肤病学   229篇
神经病学   852篇
特种医学   384篇
外科学   1445篇
综合类   285篇
一般理论   3篇
预防医学   428篇
眼科学   134篇
药学   682篇
  1篇
中国医学   69篇
肿瘤学   587篇
  2023年   40篇
  2022年   27篇
  2021年   163篇
  2020年   105篇
  2019年   188篇
  2018年   231篇
  2017年   173篇
  2016年   190篇
  2015年   257篇
  2014年   319篇
  2013年   455篇
  2012年   581篇
  2011年   639篇
  2010年   401篇
  2009年   386篇
  2008年   543篇
  2007年   538篇
  2006年   538篇
  2005年   473篇
  2004年   460篇
  2003年   334篇
  2002年   317篇
  2001年   284篇
  2000年   226篇
  1999年   223篇
  1998年   89篇
  1997年   83篇
  1996年   87篇
  1995年   57篇
  1994年   66篇
  1993年   65篇
  1992年   109篇
  1991年   109篇
  1990年   110篇
  1989年   120篇
  1988年   99篇
  1987年   86篇
  1986年   79篇
  1985年   74篇
  1984年   59篇
  1983年   42篇
  1982年   33篇
  1981年   34篇
  1980年   32篇
  1979年   42篇
  1978年   29篇
  1977年   29篇
  1976年   31篇
  1975年   25篇
  1974年   24篇
排序方式: 共有9782条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
Background:Traditional Chinese medicine (TCM) tongue diagnosis plays an important role in differentiation of symptoms because the tongue reflects the physiological and pathological condition of the body. The automatic tongue diagnosis system (ATDS), which noninvasively captures tongue images, can provide objective and reliable diagnostic information. Chronic kidney disease (CKD) currently is an important global public health problem and contributor to morbidity and mortality from non-communicable diseases. Thus, it is interesting to analyze and probe the relationship between tongue examination and CKD.Methods:This protocol is a cross-sectional, case-controlled observational study investigating the usefulness of the ATDS in clinical practice by examining its efficacy as a diagnostic tool for CKD. Volunteers over 20 years old with and without CKD will be enrolled. Tongue images will be captured and the patients divided into 2 groups: CKD group and healthy group. Nine primary tongue features will be extracted and analyzed, including tongue shape, tongue color, tooth mark, tongue fissure, fur color, fur thickness, saliva, ecchymosis, and red dots.Result:The results of this study will systematically evaluate tongue manifestations of patients and examine its efficacy as an early detection and diagnosis of CKD.Discussion:The aim of this protocol is to investigate discriminating tongue features to distinguish between CKD and normal people, and establish differentiating index to facilitate the noninvasive detection of CKD.Trial registries:ClinicalTrials.gov; Identifier: NCT04708743.  相似文献   
5.
6.
Purpose: To systematically review the evidence about whether activity training on the ground is effective on activity or participation in children with cerebral palsy. Methods: Randomized controlled trials (RCTs) were searched in databases using relevant keywords. RCTs were included with children (≤18 years) with cerebral palsy who received activity training on the ground only or activity training on the ground combined with another type of physiotherapy. Outcome measures classified as measures of activity or participation according to the International Classification of Functioning, Disability, and Health were analyzed. Results: Nine RCTs (257 participants) were included in this review. Individual studies resulted in conflicting results when activity training on the ground was compared to no intervention. Based on meta-analysis, activity training on the ground was not more effective than no intervention (standardized mean difference [SMD]: 0.18; confidence interval [CI]: ?1.49 to 1.86) or other therapies (SMD: ?0.09; CI: ?0.86 to 0.69) (I2 > 75%) on improving activity or participation. Results from a single study demonstrated that activity training on the ground combined with other physiotherapy intervention was not more effective than no intervention (SMD: ?0.18 CI: ?0.89 to 0.54). Conclusions: The available evidence shows little effect of activity training on the ground on activity or participation in children with cerebral palsy, suggesting that rigorous trials with larger samples and larger “dosage” of activity training on the ground are needed in the future.  相似文献   
7.
Purpose: Significance of intracardiac echogenic focus (ICEF) in the fetal heart remains controversial. We aimed to investigate whether the location of ICEF is associated with fetal cardiac structure defects (CSDs) in low-risk pregnant women.

Materials and Methods: A retrospective cohort study was conducted. Singleton pregnancies with normal values of triple fetal serum markers were included. 758 of 9782 fetuses with ICEF were reviewed for involvement of three ICEF locations (left, right, and bilateral ventricles (BVs)) in CSDs. χ2 or Fisher’s exact test was performed for statistical analysis.

Results: ICEF prevalence was 7.7% and its location was most frequently in the left ventricle (LV) (84.8%), followed by the BV (11.6%) and the right ventricle (RV) (3.6%). No statistically significant difference was found between the ICEF location and maternal age (χ2?=?3.92, p-value?=?.1409). There were cardiac defects with an isolated echogenic focus in 24 of 758 fetuses (3.2%). Significant difference for CSDs was observed among groups of RV, LV, and BV (p-fisher?=?.0146).

Conclusions: Significantly more CSDs cases were identified in fetuses with ICEF in RV. Further investigation is warranted to examine the histological characteristics of fetal echogenic focus in the RV.  相似文献   
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