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   4469篇
  免费   380篇
  国内免费   15篇
耳鼻咽喉   21篇
儿科学   110篇
妇产科学   80篇
基础医学   679篇
口腔科学   98篇
临床医学   501篇
内科学   904篇
皮肤病学   90篇
神经病学   406篇
特种医学   166篇
外科学   493篇
综合类   51篇
一般理论   4篇
预防医学   406篇
眼科学   85篇
药学   385篇
中国医学   20篇
肿瘤学   365篇
  2023年   28篇
  2022年   63篇
  2021年   113篇
  2020年   64篇
  2019年   76篇
  2018年   102篇
  2017年   83篇
  2016年   103篇
  2015年   117篇
  2014年   151篇
  2013年   208篇
  2012年   259篇
  2011年   297篇
  2010年   197篇
  2009年   138篇
  2008年   256篇
  2007年   282篇
  2006年   247篇
  2005年   254篇
  2004年   211篇
  2003年   245篇
  2002年   191篇
  2001年   81篇
  2000年   89篇
  1999年   92篇
  1998年   46篇
  1997年   37篇
  1996年   29篇
  1995年   35篇
  1994年   29篇
  1993年   23篇
  1992年   59篇
  1991年   47篇
  1990年   37篇
  1989年   52篇
  1988年   58篇
  1987年   49篇
  1986年   41篇
  1985年   38篇
  1984年   40篇
  1983年   28篇
  1982年   21篇
  1981年   19篇
  1980年   16篇
  1979年   31篇
  1978年   18篇
  1977年   17篇
  1975年   13篇
  1974年   13篇
  1970年   14篇
排序方式: 共有4864条查询结果,搜索用时 13 毫秒
51.
Network analyses inform complex systems such as human brain connectivity, but this approach is seldom applied to gold-standard histopathology. Here, we use two complimentary computational approaches to model microscopic progression of the main subtypes of tauopathy versus TDP-43 proteinopathy in the human brain. Digital histopathology measures were obtained in up to 13 gray matter (GM) and adjacent white matter (WM) cortical brain regions sampled from 53 tauopathy and 66 TDP-43 proteinopathy autopsy patients. First, we constructed a weighted non-directed graph for each group, where nodes are defined as GM and WM regions sampled and edges in the graph are weighted using the group-level Pearson''s correlation coefficient for each pairwise node comparison. Additionally, we performed mediation analyses to test mediation effects of WM pathology between anterior frontotemporal and posterior parietal GM nodes. We find greater correlation (i.e., edges) between GM and WM node pairs in tauopathies compared with TDP-43 proteinopathies. Moreover, WM pathology strongly correlated with a graph metric of pathology spread (i.e., node-strength) in tauopathies (r = 0.60, p < 0.03) but not in TDP-43 proteinopathies (r = 0.03, p = 0.9). Finally, we found mediation effects for WM pathology on the association between anterior and posterior GM pathology in FTLD-Tau but not in FTLD-TDP. These data suggest distinct tau and TDP-43 proteinopathies may have divergent patterns of cellular propagation in GM and WM. More specifically, axonal spread may be more influential in FTLD-Tau progression. Network analyses of digital histopathological measurements can inform models of disease progression of cellular degeneration in the human brain.SIGNIFICANCE STATEMENT In this study, we uniquely perform two complimentary computational approaches to model and contrast microscopic disease progression between common frontotemporal lobar degeneration (FTLD) proteinopathy subtypes with similar clinical syndromes during life. Our models suggest white matter (WM) pathology influences cortical spread of disease in tauopathies that is less evident in TDP-43 proteinopathies. These data support the hypothesis that there are neuropathologic signatures of cellular degeneration within neurocognitive networks for specific protienopathies. These distinctive patterns of cellular pathology can guide future efforts to develop tissue-sensitive imaging and biological markers with diagnostic and prognostic utility for FTLD. Moreover, our novel computational approach can be used in future work to model various neurodegenerative disorders with mixed proteinopathy within the human brain connectome.  相似文献   
52.
53.
[This corrects the article on p. 115 in vol. 1, PMID: 22053307.].  相似文献   
54.
55.
In order to investigate the possible role of fiber in the etiology of acute appendicitis, 203 consecutive appendectomized children with histologically proved appendicitis and 1922 controls were studied by the diet history method. Statistics were performed by multivariate analysis of variance, discriminant analysis and χ2. Appendectomized children had statistically significant lower mean daily intake of fiber (17.4 g versus 20.4 g, P < 0.001) including all fiber fractions: cellulose, uronic acid, pentose, exose and lignin. No statistical difference was found for energy, protein, carbohydrate and fat intake. Discriminant analysis proved that only cellulose and exose are independently correlated to appendicitis and lower fiber intake is thought to be the cause in 70% of the cases. Recurrent abdominal pain, chronic constipation and positive family history of appendectomy were more frequent in appendectomized children (P < 0.001). This study gives evidence that low fiber intake could play an important role in the pathogenesis of appendicitis.  相似文献   
56.
57.
Thyroid alterations have been shown to occur following exposure to polybrominated diphenyl ether (PBDE) mixtures, possibly indicating that disruptions in thyroid hormone levels may underlie behavior deficits observed in animals following postnatal PBDE exposure. This study determined whether acute postnatal exposure to PBDE-47 would alter thyroid hormones. Mice were dosed with PBDE-47 on postnatal day 10, and serum collected either 1, 5, or 10 days after the dose. No effect was observed on thyroxine and triiodothyronine levels at any age examined. This suggests that the neurological abnormalities reported in mice exposed to PBDE-47 are not due to acute changes in circulating thyroid hormones at these observed periods.  相似文献   
58.
59.
60.
The combination of challenge and humor inherent in teasing creates an ambiguous situation that can either increase bonding or create tension in a relationship, depending on how the teasing is interpreted. Although it is well established that individuals with social anxiety interpret ambiguous social situations negatively, no research has examined how individuals with social anxiety react to and interpret teasing. Ninety undergraduate students with high (n = 56) and low (n = 34) levels of social anxiety read vignettes depicting teasing scenarios, and rated how they would feel and behave in the situations. Participants also completed a self-report measure of recalled childhood teasing. Compared to the low social anxiety group, participants in the high social anxiety group reported that they would experience more negative affect in response to the teasing scenarios, and interpreted the teasing scenarios as more malicious and mean-spirited. As well, participants in the high social anxiety group reported being more likely to change the behavior that was the focus of teasing (e.g., changing the way they dress if the focus of teasing was their outfits) compared to participants in the low social anxiety group. Recalled childhood teasing partially mediated group differences on negative affect and behavior change in response to the teasing scenarios. The present results are consistent with the information processing bias literature and have implications for the social functioning of individuals with high levels of social anxiety.  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