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   1489篇
  免费   83篇
  国内免费   4篇
耳鼻咽喉   9篇
儿科学   118篇
妇产科学   50篇
基础医学   232篇
口腔科学   34篇
临床医学   120篇
内科学   290篇
皮肤病学   83篇
神经病学   90篇
特种医学   28篇
外科学   98篇
综合类   15篇
预防医学   122篇
眼科学   68篇
药学   115篇
中国医学   19篇
肿瘤学   85篇
  2024年   1篇
  2023年   20篇
  2022年   27篇
  2021年   55篇
  2020年   38篇
  2019年   53篇
  2018年   72篇
  2017年   46篇
  2016年   57篇
  2015年   59篇
  2014年   94篇
  2013年   102篇
  2012年   159篇
  2011年   139篇
  2010年   70篇
  2009年   58篇
  2008年   105篇
  2007年   55篇
  2006年   72篇
  2005年   69篇
  2004年   59篇
  2003年   57篇
  2002年   38篇
  2001年   6篇
  2000年   5篇
  1999年   3篇
  1998年   5篇
  1997年   7篇
  1996年   9篇
  1995年   5篇
  1994年   7篇
  1993年   5篇
  1992年   2篇
  1991年   4篇
  1990年   2篇
  1989年   5篇
  1986年   1篇
  1983年   1篇
  1977年   1篇
  1976年   2篇
  1975年   1篇
排序方式: 共有1576条查询结果,搜索用时 46 毫秒
991.
Individual characteristics of pathophysiology and course of depressive episodes are at present not considered in diagnostics. There are no biological markers available that can assist in categorizing subtypes of depression and detecting molecular variances related to disease-causing mechanisms between depressed patients. Identification of such differences is important to create patient subgroups, which will benefit from medications that specifically target the pathophysiology underlying their clinical condition. To detect characteristic biological markers for major depression, we analyzed the cerebrospinal fluid (CSF) proteome of depressed vs control persons, using two-dimensional polyacrylamide gel electrophoresis and time-of-flight (TOF) mass spectrometry peptide profiling. Proteins of interest were identified by matrix-assisted laser desorption ionization TOF mass spectrometry (MALDI-TOF-MS). Validation of protein markers was performed by immunoblotting. We found 11 proteins and 144 peptide features that differed significantly between CSF from depressed patients and controls. In addition, we detected differences in the phosphorylation pattern of several CSF proteins. A subset of the differentially expressed proteins implicated in brain metabolism or central nervous system disease was validated by immunoblotting. The identified proteins are involved in neuroprotection and neuronal development, sleep regulation, and amyloid plaque deposition in the aging brain. This is one of the first hypothesis-free studies that identify characteristic protein expression differences in CSF of depressed patients. Proteomic approaches represent a powerful tool for the identification of disease markers for subgroups of patients with major depression.  相似文献   
992.
The concept of irreversibility of cirrhosis has been challenged in the recent past with literature in this regard, albeit still scarce, now being accumulated across all age groups, etiologies, and geographical regions. This small series of nine pediatric cases elegantly recapitulates the concept of regression of hepatic fibrosis/cirrhosis and paves way for further detailed studies to enable development of therapeutic anti-fibrotic modalities in future.  相似文献   
993.
We developed a food frequency questionnaire (FFQ) designed to measure the dietary practices of adult Nepalese. The present study examined the validity and reproducibility of the FFQ. To evaluate the reproducibility of the FFQ, 116 subjects completed two 115-item FFQ across a four-month interval. Six 24-h dietary recalls were collected (1 each month) to assess the validity of the FFQ. Seven major food groups and 23 subgroups were clustered from the FFQ based on macronutrient composition. Spearman correlation coefficients evaluating reproducibility for all food groups were greater than 0.5, with the exceptions of oil. The correlations varied from 0.41 (oil) to 0.81 (vegetables). All crude spearman coefficients for validity were greater than 0.5 except for dairy products, pizzas/pastas and sausage/burgers. The FFQ was found to be reliable and valid for ranking the intake of food groups for Nepalese dietary intake.  相似文献   
994.
995.
996.
997.
998.
Cyclooxygenase (COX)-2 inhibition by nonsteroidal anti-inflammatory drugs is a useful approach for cancer prevention but has several side effects. A novel approach combining these chemopreventive agents at low doses with dietary elements has been suggested to augment their effects and reduce side effects. Dietary fats, particularly, n-3 polyunsaturated fatty acids (PUFA) also exert cancer chemopreventive effect mediated through COX-2 inhibition. Therefore, the present study was designed to investigate the effect of combined dosage of celecoxib and n-3 PUFA-rich fish oil in experimental mammary carcinogenesis. Female Wistar rats were distributed into control and DMBA-treated groups. The groups were further subdivided based on pretreatment with celecoxib and/or fish oil. The animals were maintained for 90 days before sacrifice. To analyze the role of redox signaling, the two mediators, reactive oxygen species and calcium, and their effects on c-myc expression were evaluated. The chemopreventive effect was assessed by measurement of cell proliferation, apoptosis, and p53 in isolated mammary epithelial cells. Increased redox signaling with enhanced c-myc, p53 expression, and augmented apoptotic and proliferative rate were observed in carcinogen-treated animals. Pretreatment of carcinogen-treated animals with celecoxib and/or fish oil altered redox signaling with reduced c-myc, p53 expression, apoptosis, and proliferation. However, a combination dosage of celecoxib and fish oil had a better chemopreventive effect. The results suggest that a combination of celecoxib and fish oil is more effective in the chemoprevention of experimental mammary carcinogenesis, and this effect can be attributed to the modification of redox signaling.  相似文献   
999.
1000.
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