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   4899篇
  免费   219篇
  国内免费   22篇
耳鼻咽喉   221篇
儿科学   284篇
妇产科学   174篇
基础医学   399篇
口腔科学   277篇
临床医学   468篇
内科学   1004篇
皮肤病学   113篇
神经病学   356篇
特种医学   258篇
外科学   882篇
综合类   81篇
一般理论   1篇
预防医学   133篇
眼科学   142篇
药学   180篇
中国医学   11篇
肿瘤学   156篇
  2024年   6篇
  2023年   57篇
  2022年   64篇
  2021年   130篇
  2020年   101篇
  2019年   106篇
  2018年   138篇
  2017年   109篇
  2016年   163篇
  2015年   159篇
  2014年   191篇
  2013年   240篇
  2012年   341篇
  2011年   382篇
  2010年   196篇
  2009年   194篇
  2008年   378篇
  2007年   406篇
  2006年   408篇
  2005年   356篇
  2004年   265篇
  2003年   257篇
  2002年   203篇
  2001年   54篇
  2000年   56篇
  1999年   41篇
  1998年   17篇
  1997年   14篇
  1996年   17篇
  1995年   10篇
  1994年   8篇
  1993年   4篇
  1992年   14篇
  1991年   14篇
  1990年   15篇
  1989年   5篇
  1988年   3篇
  1987年   2篇
  1986年   4篇
  1984年   1篇
  1983年   1篇
  1982年   3篇
  1979年   1篇
  1977年   2篇
  1972年   1篇
  1969年   1篇
  1966年   2篇
排序方式: 共有5140条查询结果,搜索用时 11 毫秒
71.
Endothelium is the first physiological barrier between blood and tissues and can be injured by physical or chemical stress, particularly by the drugs used in the cancer therapy. Paclitaxel and doxorubicin are frequently used anticancer drugs and their cardiac side effects are well observed in clinical setting. Their side effects on the endothelium are still not clear enough. There are few investigations assessing the damages elicited by the combination use of chemotherapy agents in animal experimental models. The purpose of this study was to examine and compare the side effects of doxorubicin and paclitaxel on endothelium in vivo. The drugs were administered weekly to rats via intraperitoneal injections singly or in combinations. Lastly, aorta endothelium was examined. The most familiar parts of the aorta endothelium are the nucleus, free ribosomes, Weibel-Palada granules, plasmalemmal vesicles, and clear basement membrane. Examination of the endothelium and the related structures revealed some clear degenerative findings. Notably, administration of a paclitaxel and doxorubicin combinations caused the most dramatic change in ultrastructure, which may disrupt many functions of the endothelium.  相似文献   
72.
In this study, we report a large family cluster consisting of 29 genetically related patients hospitalized with coronavirus disease‐2019 (COVID‐19). We sought to determine the clinical characteristics relevant to the clinical course of COVID‐19 by comparing the family cluster to unrelated patients with SARS‐CoV‐2 infection so that the presence of potential determinants of disease severity, other than traditional risk factors previously reported, could be investigated. Twenty‐nine patient files were investigated in group 1 and group 2 was created with 52 consecutive patients with COVID‐19 having age and gender compatibility. The virus was detected for diagnosis. The clinical, laboratory and imaging features of all patients were retrospectively screened. Disease course was assessed using records regarding outcome from patient files retrospectively. Groups were compared with respect to baseline characteristics, disease severity on presentation, and disease course. There was no difference between the two groups in terms of comorbidity and smoking history. In terms of inhospital treatment, use differed not significantly between two groups. We found that all 29 patients in the group 1 had severe pneumonia, 18 patients had severe pneumonia. Hospitalization rates, length of hospital stay, and transferred to intensive care unit were found to be statistically significantly higher in the group 1. In the present study, COVID‐19 cases in the large family cluster were shown to have more severe disease and worse clinical course compared with consecutive patients with COVID‐19 presenting to the same time. We believe further studies into potential genetic mechanisms of host susceptibility to COVID‐19 should include such family clusters.  相似文献   
73.
74.
Annals of Nuclear Medicine - Pulmonary embolism is a severe source of mortality and morbidity in patients with severe and critical coronavirus disease 2019. It is not yet clear whether the tendency...  相似文献   
75.
Oral Radiology - The purpose of this study is to evaluate CBCT images of impacted mandibular canines in detail and to discuss implications for diagnosis and treatment. CBCT images of dental...  相似文献   
76.
Yaman  Deniz  Alpaslan  Cansu  Akca  Gülçin  Avcı  Emre 《Clinical oral investigations》2020,24(12):4455-4461
Objectives

The synovial membrane and fluid are involved in the pathogenesis of temporomandibular joint (TMJ) disorders. This study aims to assess the relationship between matrix metalloproteinase-2 (MMP-2), chemerin and prostaglandin (PGE2) levels in the synovial fluid (SF) and saliva of patients with TMJ disorder regarding their role in inflammation and the value of being a candidate for predictive biomarkers in the disease. Also, it is aimed to find out whether chemerin’s main function triggers the formation inflammatory cytokine markers in the associated area.

Materials and methods

Thirty-two samples of SF and saliva were obtained from patients with disc displacement without reduction with limited opening (DDWORwLO). Mann-Whitney-U test was used for the comparisons of the biomarker levels in SF and saliva. The correlation between chemerin and BMI (Body Mass Index) is analyzed by non-parametric Spearman’s rho correlation coefficient.

Results

For all of the three biomarkers, statistically significant differences were found between SF and saliva. An unexpectedly high level expression of chemerin was observed in SF. A statistically significant, positive correlation was observed between PGE2 -MMP-2, and chemerin-PGE2 in saliva, chemerin and MMP-2 in SF, respectively (p = 0.031, r = 0.382 / p = 0.039, r = 0.366 / p = 0.032, r = 0.379). A positive correlation was determined between saliva and SF levels of PGE2 (p = 0.016, r = 0.421).

Conclusions

Chemerin, MMP-2, and PGE2 can play a role as an inflammatory factor for the development of TMJ disorder.

Clinical relevance

The search for molecular markers in TMJ and the inhibition of the associated molecular signaling mechanism is important to reduce joint inflammation and cartilage degradation.

  相似文献   
77.
78.
79.
80.
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