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   6227篇
  免费   312篇
  国内免费   64篇
耳鼻咽喉   53篇
儿科学   95篇
妇产科学   18篇
基础医学   802篇
口腔科学   195篇
临床医学   330篇
内科学   1652篇
皮肤病学   160篇
神经病学   289篇
特种医学   253篇
外科学   1067篇
综合类   34篇
预防医学   252篇
眼科学   83篇
药学   429篇
中国医学   38篇
肿瘤学   853篇
  2023年   33篇
  2022年   28篇
  2021年   141篇
  2020年   75篇
  2019年   107篇
  2018年   109篇
  2017年   125篇
  2016年   155篇
  2015年   150篇
  2014年   188篇
  2013年   248篇
  2012年   397篇
  2011年   409篇
  2010年   241篇
  2009年   221篇
  2008年   373篇
  2007年   436篇
  2006年   439篇
  2005年   471篇
  2004年   430篇
  2003年   418篇
  2002年   407篇
  2001年   71篇
  2000年   55篇
  1999年   101篇
  1998年   98篇
  1997年   76篇
  1996年   92篇
  1995年   56篇
  1994年   38篇
  1993年   48篇
  1992年   40篇
  1991年   30篇
  1990年   34篇
  1989年   45篇
  1988年   32篇
  1987年   26篇
  1986年   17篇
  1985年   17篇
  1984年   25篇
  1983年   11篇
  1982年   12篇
  1981年   9篇
  1980年   6篇
  1979年   13篇
  1978年   7篇
  1977年   6篇
  1976年   6篇
  1975年   7篇
  1967年   4篇
排序方式: 共有6603条查询结果,搜索用时 31 毫秒
91.
92.
Analysis of psoriatic parakeratotic cells is helpful for understanding the pathogenesis of psoriasis. Methylation analysis can be performed on psoriatic scales, but it is unclear whether genes can be silenced by DNA methylation in psoriatic stratum corneum. The present study was conducted to detect genes silenced in psoriatic stratum corneum. Methylation array analysis with 485 577 probes, quantitative real‐time methylation‐specific PCR (RT‐MSP) and bisulphite sequencing were performed for 30 psoriatic scale samples, 6 fully developed psoriatic skin samples and 12 normal skin samples. Immunohistochemical staining of HOXA5 was performed for 29 psoriatic epidermal samples and 13 normal epidermal samples. The genome‐wide methylation array detected two CpG sites within CpG islands (CGIs) located in promoter regions of HOXA5 and LIAS that had methylation levels of >0.6 in at least one of the three psoriatic scale samples and of <0.2 in all three normal skin tissue samples (methylation rate range, 0.0‐1.0). RT‐MSP for HOXA5CGI, in which the primers were successfully developed, revealed that the average methylation level of 27 psoriasis scales (60.2%) is significantly higher than that of 9 normal skin samples (34.6%) (P=.013). Immunohistochemical staining revealed that HOXA5 protein was not expressed in the stratum corneum of fully developed psoriatic epidermis, but the protein was expressed in the stratum corneum of incompletely developed epidermis and normal epidermis. In conclusion, HOXA5 can be silenced in the stratum corneum of psoriasis. The silenced gene was identified by non‐invasive methylation analysis of psoriatic scales.  相似文献   
93.
94.
ObjectivesEating alone is associated with an increased risk of depression symptoms. This association may be confounded by poor social networks. The present study aimed to determine the role of poor social networks in the association of eating alone with depression symptoms, focusing on cohabitation status.MethodsSeven hundred and ten community-dwelling older adults were categorized according to their eating style and social network size, evaluated using an abbreviated version of the Lubben Social Network Scale, with poor social network size (defined as the lowest quartile). Living arrangements and depression symptoms, detected using the Zung Self-Rating Depression Scale, were also assessed.ResultsA mixed-design two-way analysis of covariance (eating style and social network size factors) for the depression scale score, adjusted by covariates, yielded significant effects of social network size and eating style without interaction. Greater depression scores were observed in eating alone and poor social network size. Analysis of participants living with others showed the same results. However, among older adults living alone, only a significant main effect of social network size was observed; poor social network size resulted in greater depression scores irrespective of eating style.ConclusionsPoor social network size, and not eating alone, was associated with greater depression symptoms among older adults living alone, whereas both factors may increase depression symptoms among older adults living with others. Poor social network size may show a stronger influence on depression than eating alone in older adults living alone; thus, social network size is an important health indicator.Key words: eating alone, social network, living alone, depression, older adults  相似文献   
95.
96.
97.
98.
99.
100.
Activated platelets form platelet–leukocyte aggregates in the circulation in inflammatory diseases. We investigated whether activated platelets in inflamed skin tissues are phagocytized and removed by neutrophils. To investigate the kinetics of platelets and neutrophils, we immunohistochemically examined the spatiotemporal distribution of them in a murine model of 2,4,6-trinitro-1-chlorobenzene (TNCB)-induced dermatitis by using confocal and structured illumination microscopy. Four hours after elicitation, aggregates of CD41-positive platelets were adhered to CD31-positive endothelial cells within the vessels, and CD62P and PF4, markers of activated platelets, were expressed on platelet aggregates. At 8 hour post-elicitation, fragmented CD41-positive platelets were located both inside and outside vessels. Twenty-four hours after elicitation, the number of Ly-6G-positive neutrophils ingesting fragmented CD41-positive platelets outside vessels was increased, and CD62P and PF4 expression on the phagocytosed platelets was no longer observed. Disc-shaped CD41-positive platelets were not found outside vessels at any time during the experiment. Our data revealed that aggregates of activated platelets inside vessels were ingested and removed by neutrophils in the early stage of TNCB-induced dermatitis, suggesting that the process of removal of activated platelets by neutrophils may play an important role not only in the early phase of skin inflammation but also in other types of acute inflammation.  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