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   10124篇
  免费   450篇
  国内免费   132篇
耳鼻咽喉   76篇
儿科学   161篇
妇产科学   66篇
基础医学   1090篇
口腔科学   277篇
临床医学   620篇
内科学   2769篇
皮肤病学   146篇
神经病学   724篇
特种医学   417篇
外科学   2156篇
综合类   37篇
预防医学   221篇
眼科学   115篇
药学   573篇
中国医学   15篇
肿瘤学   1243篇
  2023年   77篇
  2022年   118篇
  2021年   282篇
  2020年   162篇
  2019年   179篇
  2018年   237篇
  2017年   189篇
  2016年   244篇
  2015年   255篇
  2014年   373篇
  2013年   447篇
  2012年   672篇
  2011年   720篇
  2010年   398篇
  2009年   347篇
  2008年   637篇
  2007年   670篇
  2006年   663篇
  2005年   719篇
  2004年   694篇
  2003年   643篇
  2002年   628篇
  2001年   110篇
  2000年   90篇
  1999年   134篇
  1998年   165篇
  1997年   124篇
  1996年   116篇
  1995年   86篇
  1994年   73篇
  1993年   75篇
  1992年   54篇
  1991年   48篇
  1990年   33篇
  1989年   40篇
  1988年   28篇
  1987年   20篇
  1986年   21篇
  1985年   17篇
  1984年   18篇
  1983年   17篇
  1982年   7篇
  1981年   11篇
  1980年   7篇
  1979年   7篇
  1978年   9篇
  1977年   5篇
  1976年   6篇
  1975年   8篇
  1973年   5篇
排序方式: 共有10000条查询结果,搜索用时 250 毫秒
101.
The effects of exercise on nutrient digestion and absorption in the intestinal tract are not well understood. A few studies have reported that exercise training increases the expression of molecules involved in carbohydrate digestion and absorption. Exercise was also shown to increase the blood concentration of glucagon-like peptide-2 (GLP-2), which regulates carbohydrate digestion and absorption in the small intestine. Therefore, we investigated the effects of exercise on the expression of molecules involved in intestinal digestion and absorption, including GLP-2. Six-week-old male mice were divided into a sedentary (SED) and low-intensity exercise (LEx) group. LEx mice were required to run on a treadmill (12.5 m/min, 1 h), whereas SED mice rested. All mice were euthanized 1 h after exercise or rest, and plasma, jejunum, ileum, and colon samples were collected, followed by analysis via IHC, EIA, and immunoblotting. The levels of plasma GLP-2 and the jejunum expression of the GLP-2 receptor, sucrase-isomaltase (SI), and glucose transporter 2 (GLUT2) were higher in LEx mice. Thus, we showed that acute low-intensity exercise affects the expression of molecules involved in intestinal carbohydrate digestion and absorption via GLP-2. Our results suggest that exercise might be beneficial for small intestine function in individuals with intestinal frailty.  相似文献   
102.
103.
Purpose

Intravesical bacillus Calmette–Guérin (BCG) is the standard of care for bladder carcinoma in situ (CIS). The response to BCG therapy against CIS is generally assessed by random bladder biopsy (RBB). In this study, we examined the necessity of routine RBB after BCG therapy.

Methods

We retrospectively identified 102 patients who were initially diagnosed with CIS with or without papillary tumor and received subsequent 6–8-week BCG therapy. Thereafter, all patients underwent voiding cytology analysis, cystoscopy, and RBB to evaluate the effects of BCG therapy. We evaluated the association between clinical parameters (voiding cytology and cystoscopy findings) and the final pathological results by RBB specimens.

Results

According to the pathological results of RBB, 30 (29%) patients had BCG-unresponsive disease (remaining urothelial carcinoma was confirmed pathologically) and 20 were diagnosed with CIS. Positive/suspicious voiding cytology and positive cystoscopy findings were well observed in patients who had BCG-unresponsive disease compared with their counterparts (p?=?0.116, and p?<?0.001, respectively). The sensitivity (Sen.), specificity (Spe.), positive predictive value (PPV), and negative predictive value (NPV) of voiding cytology were 50%, 68%, 39%, and 77%, respectively. The values for cystoscopy findings were as follows: Sen.: 87%, Spe.: 57%, PPV: 46%, and NPV: 91%. The values for their combination (having either of them) were as follows: Sen.: 100%, Spe.: 44%, PPV: 43%, and NPV: 100%.

Conclusion

RBB after BCG therapy for patients with negative voiding cytology and negative cystoscopy may be omitted because their risk of BCG-unresponsive disease is significantly low (NPV: 100%).

  相似文献   
104.
105.
BackgroundShoulder 36 (Sh-36) is an original quality of life measure for shoulder lesions with high reliability and validity; however, in some cases, especially in those with a Bankart lesion, we observed no improvement in Sh-36 during the postoperative follow-up. Sh-36 may be less effective for a certain shoulder lesion. This study aimed to compare the reliability, validity, and responsiveness of Sh-36 among different representative diagnoses of shoulder lesions.MethodsSh-36 and the Disability of the Arm, Shoulder and Hand (DASH) were measured in 192 patients with a Bankart lesion (Bankart group), rotator cuff tear (Cuff group), and SLAP lesion (SLAP group) who underwent arthroscopic surgery. Both measures were evaluated before surgery, and at 3, 6, 9, 12, 18, and 24 months postoperatively, and reliability, validity, and responsiveness of Sh-36 and the DASH were compared among the three groups.ResultsSignificant postoperative improvement was observed in the three groups (p < 0.0001) within 9 months. No marked improvement was observed after 9 months in the Bankart and SLAP groups due to the ceiling effect; however, most domains of Sh-36 increased continuously in the Cuff group during the whole follow-up period. Reliability and construct validity were sufficient in all the groups. The longitudinal validity was sufficient in most domains for the three groups; however, the standardized response mean in the Bankart group was lower than that in other two groups, indicating low responsiveness in this group because of the ceiling effect.ConclusionsSh-36 was a valid and reliable instrument in patients who have undergone arthroscopic shoulder surgery, especially for patient with a rotator cuff tear with high responsiveness. However, Sh-36 had lower standard response mean representing lower responsiveness in the Bankart group due to the ceiling effect and may not be ideal for longitudinal follow-up in patients with a Bankart lesion.  相似文献   
106.
107.
108.
109.
Estrogen receptors and their downstream targets in cancer   总被引:6,自引:0,他引:6  
  相似文献   
110.
Although excessive immune responses by Th17 cells, a helper T cell subset, are implicated in the pathogenesis of inflammatory bowel disease (IBD), the mechanism by which its localization in an inflamed colon is regulated remains unclear. Chemokines and their receptors are involved in the pathogenesis of IBD, however, the relative significance of each receptor on Th17 cells remains unknown. We generated C–C motif chemokine receptor 2 (CCR2) knockout (KO) and CCR6 KO mice in the syngeneic background using the CRISPR/Cas9 system and found that the phenotypes of experimental colitis worsened in both mutant mice. Surprisingly, the phenotype of colitis in CCR2/CCR6-double knockout (CCR2/6 DKO) mice was opposite to that of the single-deficient mice, with significantly milder experimental colitis (p < .05). The same was true for the symptoms in CCR6 KO mice, but not in wild type mice treated with a CCR2 inhibitor, propagermanium. Colonic CCR2+CCR6+ Th17 cells produced a potentially pathogenic cytokine GM-CSF whose levels in the gut were significantly reduced in CCR2/6 DKO mice (p < .05). These results suggest that GM-CSF-producing CCR2+CCR6+ Th17 cells are pathogenic and are attracted to the inflamed colon by either CCR2 or CCR6 gradient, which subsequently exacerbates experimental colitis in mice.  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