全文获取类型
收费全文 | 1435篇 |
免费 | 93篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 47篇 |
妇产科学 | 19篇 |
基础医学 | 213篇 |
口腔科学 | 8篇 |
临床医学 | 131篇 |
内科学 | 344篇 |
皮肤病学 | 13篇 |
神经病学 | 103篇 |
特种医学 | 20篇 |
外科学 | 178篇 |
综合类 | 23篇 |
一般理论 | 2篇 |
预防医学 | 112篇 |
眼科学 | 57篇 |
药学 | 83篇 |
中国医学 | 22篇 |
肿瘤学 | 161篇 |
出版年
2023年 | 17篇 |
2022年 | 15篇 |
2021年 | 42篇 |
2020年 | 22篇 |
2019年 | 32篇 |
2018年 | 54篇 |
2017年 | 23篇 |
2016年 | 24篇 |
2015年 | 40篇 |
2014年 | 32篇 |
2013年 | 75篇 |
2012年 | 96篇 |
2011年 | 80篇 |
2010年 | 56篇 |
2009年 | 45篇 |
2008年 | 79篇 |
2007年 | 96篇 |
2006年 | 84篇 |
2005年 | 73篇 |
2004年 | 71篇 |
2003年 | 52篇 |
2002年 | 34篇 |
2001年 | 51篇 |
2000年 | 50篇 |
1999年 | 39篇 |
1998年 | 11篇 |
1997年 | 9篇 |
1996年 | 17篇 |
1995年 | 11篇 |
1994年 | 13篇 |
1993年 | 11篇 |
1992年 | 16篇 |
1991年 | 27篇 |
1990年 | 13篇 |
1989年 | 23篇 |
1988年 | 18篇 |
1987年 | 12篇 |
1986年 | 10篇 |
1985年 | 14篇 |
1984年 | 3篇 |
1983年 | 6篇 |
1982年 | 6篇 |
1981年 | 10篇 |
1980年 | 7篇 |
1978年 | 7篇 |
1977年 | 4篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1968年 | 1篇 |
1967年 | 2篇 |
排序方式: 共有1539条查询结果,搜索用时 437 毫秒
61.
62.
Zixin Wang Joseph T. F. Lau Mary Ip Shara P. Y. Ho Phoenix K. H. Mo Carl Latkin Yee Ling Ma Yoona Kim 《AIDS and behavior》2018,22(1):190-201
We developed an innovative home-based HIV self-testing (HIVST) service that included mailing of a free HIVST kit, and providing online real-time instructions and pre-test/post-test counseling (HIVST-OIC). The present parallel-group and non-blinded randomized controlled trial was conducted to evaluate the efficacy of promoting HIVST-OIC in increasing HIV testing rate among 430 men who have sex with men (MSM), with access to online live-chat applications in Hong Kong. At month 6, as compared to the control group, the intervention group reported significantly higher prevalence of HIV testing of any type (89.8 vs. 50.7%; relative risk (RR): 1.77; p < 0.001). Among those who have taken up any HIV testing in the last six months, significant between-group difference was found in multiple male sex partnerships (34.2 vs. 47.7%, RR: 0.72; p = 0.021). HIVST-OIC has a strong potential in increasing prevalence of HIV testing and reducing sexual risk behaviors. Implementation research is warranted. 相似文献
63.
64.
Stephen Ip AbdulRazaq AH Sokoro Lisa Kaita Claudia Ruiz Elaine McIntyre Harminder Singh 《Journal canadien de gastroenterologie》2014,28(9):489-494
BACKGROUND:
The fecal occult blood test (FOBT), widely used as a colorectal cancer screening tool, continues to be used in hospitalized patients. However, the utility of this test for hospitalized patients is unclear.OBJECTIVE:
To assess FOBT use in a large urban regional health authority.METHODS:
Reports of all FOBTs performed between April 1, 2011 and March 30, 2012 from two academic and four community hospitals in Winnipeg (Manitoba) were extracted. Of 650 hospitalizations with a positive FOBT result and 1254 with a negative FOBT result, random samples of 230 and 97 charts, respectively, were reviewed. Information including demographics, admission diagnos(es), indication(s) for ordering the FOBT and clinical management was extracted.RESULTS:
Thirty-four percent (650 of 1904) of hospitalizations with an FOBT had a positive FOBT result. Family medicine physicians ordered approximately one-half of the reviewed FOBTs. The most common indication for ordering an FOBT was anemia. Of those with a positive FOBT, 66% did not undergo further gastrointestinal investigations. Of those with a positive FOBT and overt gastrointestinal bleeding and/or melena who underwent endoscopy, 60% had their endoscopy performed before the FOBT result being reported while 38% underwent their endoscopy ≥3 days after the stool sample was collected. There were minimal differences in clinical practices between academic and community hospitals.CONCLUSIONS:
The present study suggests that FOBT results in hospitalized patients may have little beneficial impact on clinical management. Hospital laboratories may be better served in directing resources to other tests. 相似文献65.
Differential Regulation of Lipid Metabolism Genes in the Brain of Acetylcholinesterase Knockout Mice
Huang-Quan Lin Yan Wang Kam-Leung Chan Tsz-Ming Ip Chi-Cheong David Wan 《Journal of molecular neuroscience : MN》2014,53(3):397-408
Mice deficient in acetylcholinesterase (AChE; EC3.1.1.7) exhibited significant phenotypical and biochemical changes when compared with wild-type littermates. They showed a delay of growth in weight and size, immature external ears, and persistent body tremor, and they circled when walking. The molecular mechanisms underlying these changes have not been investigated yet. Here, we studied the profiles of both the messenger RNA (mRNA) and protein expression in the brain of AChE-deficient mice using mRNA microarray, quantitative PCR, and two-dimensional difference gel electrophoresis (2D DIGE) coupled to protein identification with matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry. Analysis of gene expression profile was conducted by DAVID (http://david.abcc.ncifcrf.gov) and Ingenuity Pathway Analysis (IPA, http://www.ingenuity.com). Previous results implicated that there is a close relationship between lipid metabolisms which were associated with central nervous system development. Here, we demonstrated that the mRNA expressions of brain specific fatty acid protein 7 (fabp-7) and phospholipase A2 group IV (pla2g4) were significantly downregulated in AChE-deficient mice. These results suggested that AChE may play a role in neurogenesis and neurodegeneration by specifically regulating lipid metabolism in the brain. 相似文献
66.
Adrian B Levine Jason Peng David Farnell Mitchell Nursey Yiping Wang Julia R Naso Hezhen Ren Hossein Farahani Colin Chen Derek Chiu Aline Talhouk Brandon Sheffield Maziar Riazy Philip P Ip Carlos Parra-Herran Anne Mills Naveena Singh Basile Tessier-Cloutier Taylor Salisbury Jonathan Lee Tim Salcudean Steven JM Jones David G Huntsman C Blake Gilks Stephen Yip Ali Bashashati 《The Journal of pathology》2020,252(2):178-188
Deep learning-based computer vision methods have recently made remarkable breakthroughs in the analysis and classification of cancer pathology images. However, there has been relatively little investigation of the utility of deep neural networks to synthesize medical images. In this study, we evaluated the efficacy of generative adversarial networks to synthesize high-resolution pathology images of 10 histological types of cancer, including five cancer types from The Cancer Genome Atlas and the five major histological subtypes of ovarian carcinoma. The quality of these images was assessed using a comprehensive survey of board-certified pathologists (n = 9) and pathology trainees (n = 6). Our results show that the real and synthetic images are classified by histotype with comparable accuracies and the synthetic images are visually indistinguishable from real images. Furthermore, we trained deep convolutional neural networks to diagnose the different cancer types and determined that the synthetic images perform as well as additional real images when used to supplement a small training set. These findings have important applications in proficiency testing of medical practitioners and quality assurance in clinical laboratories. Furthermore, training of computer-aided diagnostic systems can benefit from synthetic images where labeled datasets are limited (e.g. rare cancers). We have created a publicly available website where clinicians and researchers can attempt questions from the image survey ( http://gan.aimlab.ca/ ). © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. 相似文献
67.
Wong CK Cheung PF Ip WK Lam CW 《American journal of respiratory cell and molecular biology》2005,33(2):186-194
Interleukin (IL)-25, a novel Th2 cytokine, is capable of amplifying allergic inflammation. We investigated the modulation of nuclear factor (NF)-kappaB and mitogen-activated protein kinases (MAPK) pathways in IL-25-activated eosinophils, the principal effector cells of allergic inflammation, for the in vitro release of chemokines including monocyte chemoattractant protein-1 (MCP-1), IL-8, and macrophage inflammatory protein (MIP)-1alpha, and inflammatory cytokine IL-6. Gene expression of chemokines and IL-6 was evaluated by RT-PCR, and concentrations of chemokines and cytokine were measured by cytokine protein array, cytometric bead array, and enzyme-linked immunosorbent assay. NF-kappaB, c-Jun amino-terminal kinase (JNK), and p38 MAPK activities in eosinophils were assessed by electrophoretic mobility shift assay and Western blot. IL-25 was found to upregulate the gene expression of chemokines MCP-1, MIP-1alpha, and IL-8, and cytokine IL-6, in eosinophils, and to significantly increase the release of the above chemokines and IL-6 from eosinophils. IL-25 could also activate the JNK, p38 MAPK, and NF-kappaB activities of eosinophils, while inhibitor of IkappaB-alpha phosphorylation (BAY11-7082), JNK (SP600125), and p38 MAPK (SB203580) could suppress the release of IL-8, MIP-1alpha, MCP-1, and IL-6. Together, the above results showed that the induction of MCP-1, MIP-1alpha, IL-8, and IL-6 in IL-25-activated eosinophils are regulated by JNK, p38 MAPK, and NF-kappaB pathways. 相似文献
68.
The value of routine bronchial aspirate culture at fibreoptic bronchoscopy for the diagnosis of tuberculosis 总被引:5,自引:0,他引:5
We review the results of bronchial aspirate culture for mycobacteria sent routinely in a series of 1734 fibreoptic bronchoscopic procedures. The incidence of tuberculosis in the series was 8.3% (144 cases). Of these cases, a positive bronchial aspirate culture was obtained in 119 (82.6%) cases, and it was the exclusive means of diagnosis in 64 (44.4%). In 66% of these cases tuberculosis was not suspected at the time of bronchoscopy. Our results suggest that in an area with a high prevalence of tuberculosis, routine bronchial aspirate culture is a useful adjunct to diagnosis. 相似文献
69.
70.
The currently accepted guidelines of open surgical repair for acute type A aortic dissection include the resection of the primary entry tear, replacement of the ascending aorta and “hemi-arch” with an open distal anastomosis, and aortic valve resuspension and some form of obliteration of the aortic root false lumen. The principal aim is protection against aortic rupture, aortic regurgitation, and coronary ischemia and restoration of antegrade preferential true lumen perfusion. Proponents argue that this operation is tailored to be in the armamentarium of most cardiac surgeons and deliver the lowest early operative risk while leaving the infrequent long-term sequelae to be dealt with electively by experienced aortic centers. Although this may sound to be a compelling argument, the actual outcomes suggest that it falls significantly short of achieving its noble goals on both acute and chronic counts. This led us to develop a seemingly more radical paradigm, which aims to achieve total aortic healing in the acute phase. We describe a total aortic repair technique for acute type A aortic dissection consisting of “branch first” total arch repair, followed by thoracoabdominal stenting and balloon rupture of the septum. The total aortic repair technique ensures that the aortic valve, ascending aorta, and arch are surgically securely repaired, and provides complete decompression of the false lumen as well as internal support in the remainder of the aorta. This has provided excellent early results and will hopefully minimize future complications and interventions. 相似文献