全文获取类型
收费全文 | 655篇 |
免费 | 48篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 28篇 |
妇产科学 | 13篇 |
基础医学 | 61篇 |
口腔科学 | 50篇 |
临床医学 | 168篇 |
内科学 | 80篇 |
皮肤病学 | 8篇 |
神经病学 | 76篇 |
特种医学 | 21篇 |
外科学 | 72篇 |
预防医学 | 37篇 |
眼科学 | 19篇 |
药学 | 47篇 |
中国医学 | 1篇 |
肿瘤学 | 28篇 |
出版年
2023年 | 4篇 |
2022年 | 7篇 |
2021年 | 11篇 |
2020年 | 9篇 |
2019年 | 12篇 |
2018年 | 17篇 |
2017年 | 12篇 |
2016年 | 26篇 |
2015年 | 20篇 |
2014年 | 24篇 |
2013年 | 34篇 |
2012年 | 38篇 |
2011年 | 55篇 |
2010年 | 24篇 |
2009年 | 24篇 |
2008年 | 39篇 |
2007年 | 49篇 |
2006年 | 51篇 |
2005年 | 41篇 |
2004年 | 43篇 |
2003年 | 40篇 |
2002年 | 29篇 |
2001年 | 12篇 |
2000年 | 11篇 |
1999年 | 15篇 |
1998年 | 6篇 |
1997年 | 9篇 |
1996年 | 2篇 |
1995年 | 8篇 |
1994年 | 2篇 |
1992年 | 9篇 |
1991年 | 9篇 |
1990年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1979年 | 1篇 |
排序方式: 共有711条查询结果,搜索用时 0 毫秒
111.
Pancreatic adenocarcinoma is the fifth leading cause of cancer death with a 5-year survival rate of less than 5%. Although the role of a few known oncogenes and tumor suppressor genes in the development of pancreatic cancer is fairly well established, it is obvious that the majority of genetic changes responsible for the initiation and progression of this disease are still unknown. In this review, the authors will discuss the results from various genome-wide screening efforts, from traditional chromosome analyses to modern DNA microarray studies, which have provided an enormous amount of information on genetic alterations in pancreatic adenocarcinoma. Exciting findings have emerged from these studies, highlighting multiple potential chromosomal regions that may harbor novel cancer genes involved in the molecular pathogenesis of this lethal disorder. These findings complete the picture of pancreatic adenocarcinoma as a genetically highly complex and heterogeneous tumor type with an ongoing instability process. In addition, the precisely localized copy number changes offer a valuable starting point for further studies required to identify the genes involved and to characterize their potential functional role in the development and progression of pancreatic adenocarcinoma. 相似文献
112.
Skottman H Strömberg AM Matilainen E Inzunza J Hovatta O Lahesmaa R 《Stem cells (Dayton, Ohio)》2006,24(1):151-167
Understanding the interaction between human embryonic stem cells (hESCs) and their microenvironment is crucial for the propagation and the differentiation of hESCs for therapeutic applications. hESCs maintain their characteristics both in serum-containing and serum-replacement (SR) media. In this study, the effects of the serum-containing and SR culture media on the gene expression profiles of hESCs were examined. Although the expression of many known embryonic stem cell markers was similar in cells cultured in either media, surprisingly, 1,417 genes were found to be differentially expressed when hESCs cultured in serum-containing medium were compared with those cultured in SR medium. Several genes upregulated in cells cultured in SR medium suggested increased metabolism and proliferation rates in this medium, providing a possible explanation for the increased growth rate of nondifferentiated cells observed in SR culture conditions compared with that in serum medium. Several genes characteristic for cells with differentiated phenotype were expressed in cells cultured in serum-containing medium. Our data clearly indicate that the manipulation of hESC culture conditions causes phenotypic changes of the cells that were reflected also at the level of gene expression. Such changes may have fundamental importance for hESCs, and gene expression changes should be monitored as a part of cell culture optimization aiming at a clinical use of hESCs for cell transplantation. 相似文献
113.
114.
In this case report, even a moderate dose of dexmedetomidine, a very selective alpha(2)-adrenergic agent, resulted in a rapid response to alcohol withdrawal delirium after the standard treatment. Psychiatrists should be aware of this relatively new drug that provides advantages over clonidine, heavy sedation and secondary restraints. Dexmedetomidine should be further evaluated in the treatment of specific forms of aggressive behavior and complicated withdrawal states. 相似文献
115.
Amitriptyline effectively relieves neuropathic pain following treatment of breast cancer. However, adverse effects are a major problem. Venlafaxine has no anticholinergic effects and could have a better compliance. The aim of the study was to evaluate the effectiveness of venlafaxine in neuropathic pain. The study was a randomized, double-blind, crossover comparison of venlafaxine and inactive placebo. The study lasted 10 weeks. The number of tablets (18.75 mg) taken daily was increased by one at a 1 week interval. Pain intensity and pain relief were registered daily by a diary and by a questionnaire and a computer program (Painscreen) on each visit. Adverse effects were evaluated with the diaries and a 10-item list on each visit. Also, anxiety and depression were measured on each visit. Venous blood samples were collected before the treatment and at 4 weeks for the determination of the serum levels of venlafaxine and its three metabolites. Thirteen patients were analysed. The average daily pain intensity as reported in the diary (primary outcome) was not significantly reduced by venlafaxine compared with placebo. However, the average pain relief (diary) and the maximum pain intensity (retrospective assessment by the computer program) were significantly lower with venlafaxine compared with placebo. Anxiety and depression were not affected. Adverse effects did not show significant differences between treatments. The two poor responders had low venlafaxine concentrations whereas the two slow hydroxylizers had high venlafaxine concentrations and excellent pain relief. Thus, higher doses could be used in order to improve pain relief. 相似文献
116.
Intense cytoplasmic ezrin immunoreactivity predicts poor survival in colorectal cancer 总被引:1,自引:0,他引:1
Elzagheid A Korkeila E Bendardaf R Buhmeida A Heikkilä S Vaheri A Syrjänen K Pyrhönen S Carpén O 《Human pathology》2008,39(12):1737-1743
Ezrin is a membrane-cytoskeleton anchor, which, in experimental models, regulates tumor cell invasion and metastatic ability. We carried out immunohistochemical analysis of ezrin in 74 advanced colorectal cancer patients and correlated it to clinicopathologic variables and disease outcome. In contrast to the predominantly membraneous immunoreactivity of normal colorectal epithelium, ezrin expression in the colorectal cells was typically cytoplasmic. Altogether, 16.2% (12/74) of the tumors showed negative/weak ezrin staining, 35.1% (26/74) had moderate staining, and 48.6% (36/74) had intense staining. The expression was more intense in colon than in rectal carcinomas (P = .003). Increased ezrin expression was associated with adverse outcome, that is, shorter disease-specific survival; 48.3 months and 36.6 months for negative-weak versus intense expression (P = .041) as well as shorter survival with metastases at 36 months (P = .030); the metastases36 rates in ezrinneg/weak, ezrinmoderate, ezrinintense are 58.3%, 25.0%, and 18.4%, respectively. In univariate survival analysis, dichotomized (negative/weak versus moderate/strong) ezrin expression significantly predicted both the 5-year disease specific survival (P = .035) and 5-year metastases (P = .018) but lost this predictive power in multivariate (Cox) analysis. High ezrin expression was also related to high E-cadherin (cytoplasmic) expression, DNA aneuploidy, and high thymidylate synthase expression (P = .046, P = .042, P = .046, respectively). These results suggest that ezrin may play a role in colorectal cancer progression and that ezrin expression might provide clinically valuable information in predicting the biological behavior of colorectal cancer. 相似文献
117.
118.
119.
120.
AbstractIn the field of alcohol, drug, tobacco, and gambling studies, empirical research on the barriers and facilitators for public prevention policies has been scarce. Public policy studies show that the implementers of different organizational positions impact on policy implementation. In this paper, the barriers and facilitators for the implementation of an integrated national policy for addiction prevention, as seen from the positions of managers, prevention specialists, and frontline workers, are analyzed on the basis of qualitative interview data. The results indicate that the managers were structurally oriented in their thinking and emphasized local structures as facilitators. All the groups saw prevention as underfunded and undervalued. The specialists were most focused on the official structures and regarded the functioning of the structures as a key facilitator. The frontline workers underlined that their position was a facilitator in itself, offering a unique viewpoint to the localities and to the lives of their clients. A key finding is also the normalcy of gambling that both the specialist and frontline workers regarded as a major barrier. The results show that studying the policy implementation context is important: it makes it possible to understand social and cultural factors that can function as barriers or facilitators. 相似文献