全文获取类型
收费全文 | 49779篇 |
免费 | 3233篇 |
国内免费 | 937篇 |
专业分类
耳鼻咽喉 | 414篇 |
儿科学 | 1252篇 |
妇产科学 | 1289篇 |
基础医学 | 5479篇 |
口腔科学 | 909篇 |
临床医学 | 4266篇 |
内科学 | 11958篇 |
皮肤病学 | 715篇 |
神经病学 | 4657篇 |
特种医学 | 1969篇 |
外国民族医学 | 2篇 |
外科学 | 6725篇 |
综合类 | 2090篇 |
现状与发展 | 1篇 |
一般理论 | 1篇 |
预防医学 | 2511篇 |
眼科学 | 631篇 |
药学 | 4066篇 |
8篇 | |
中国医学 | 967篇 |
肿瘤学 | 4039篇 |
出版年
2023年 | 461篇 |
2022年 | 1139篇 |
2021年 | 1794篇 |
2020年 | 1121篇 |
2019年 | 1200篇 |
2018年 | 1392篇 |
2017年 | 1107篇 |
2016年 | 1192篇 |
2015年 | 1493篇 |
2014年 | 1982篇 |
2013年 | 2406篇 |
2012年 | 3203篇 |
2011年 | 3210篇 |
2010年 | 1893篇 |
2009年 | 1764篇 |
2008年 | 2685篇 |
2007年 | 2726篇 |
2006年 | 2545篇 |
2005年 | 2416篇 |
2004年 | 2174篇 |
2003年 | 1895篇 |
2002年 | 1673篇 |
2001年 | 1433篇 |
2000年 | 1353篇 |
1999年 | 1258篇 |
1998年 | 477篇 |
1997年 | 356篇 |
1996年 | 371篇 |
1995年 | 290篇 |
1994年 | 262篇 |
1993年 | 224篇 |
1992年 | 675篇 |
1991年 | 575篇 |
1990年 | 544篇 |
1989年 | 553篇 |
1988年 | 465篇 |
1987年 | 422篇 |
1986年 | 404篇 |
1985年 | 326篇 |
1984年 | 269篇 |
1983年 | 213篇 |
1982年 | 119篇 |
1979年 | 214篇 |
1978年 | 131篇 |
1977年 | 110篇 |
1974年 | 123篇 |
1973年 | 126篇 |
1972年 | 124篇 |
1971年 | 112篇 |
1969年 | 103篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
Alessia Scarselli Silvia Di Cesare Claudia Capponi Simona Cascioli Maria L. Romiti Gigliola Di Matteo Alessandra Simonetti Paolo Palma Andrea Finocchi Barbarella Lucarelli Rita M. Pinto Ippolita Rana Giuseppe Palumbo Maurizio Caniglia Paolo Rossi Rita Carsetti Caterina Cancrini Alessandro Aiuti 《Journal of clinical immunology》2015,35(4):373-383
13.
Anastasiia Panfilova Sarah E. Shelton Cristina Caresio Ruud J.G. van Sloun Filippo Molinari Hessel Wijkstra Paul A. Dayton Massimo Mischi 《Ultrasound in medicine & biology》2019,45(2):539-548
Dynamic contrast-enhanced ultrasound (DCE-US) has been proposed as a powerful tool for cancer diagnosis by estimation of perfusion and dispersion parameters reflecting angiogenic vascular changes. This work was aimed at identifying which vascular features are reflected by the estimated perfusion and dispersion parameters through comparison with acoustic angiography (AA). AA is a high-resolution technique that allows quantification of vascular morphology. Three-dimensional AA and 2-D DCE-US bolus acquisitions were used to monitor the growth of fibrosarcoma tumors in nine rats. AA-derived vascular properties were analyzed along with DCE-US perfusion and dispersion to investigate the differences between tumor and control and their evolution in time. AA-derived microvascular density and DCE-US perfusion exhibited good agreement, confirmed by their spatial distributions. No vascular feature was correlated with dispersion. Yet, dispersion provided better cancer classification than perfusion. We therefore hypothesize that dispersion characterizes vessels that are smaller than those visible with AA. 相似文献
14.
15.
16.
17.
A. Cattapan K. Browne D.M. Halperin A. Di Castri P. Fullsack J. Graham J.M. Langley B.A. Taylor S.A. McNeil S.A. Halperin 《Vaccine》2019,37(2):289-295
Introduction/Hypothesis
Recruitment of participants into phase 1 vaccine clinical trials can be challenging since these vaccines have not been used in humans and there is no perceived benefit to the participant. Occasionally, as was the case with a phase 1 clinical trial of an Ebola vaccine in Halifax, Canada, during the 2014–2016 West African Ebola virus outbreak, recruitment is less difficult. In this study, we explored the motivations of participants in two phase 1 vaccine trials that were concurrently enrolling at the same centre and compared the motivations of participants in a high-profile phase 1 Ebola vaccine trial to those in a less high-profile phase 1 adjuvanted seasonal influenza vaccine study.Methods
An online survey which included participants’ prior experience with clinical trials, motivations to participate (including financial incentives), and demographic information was developed to examine the motivations of healthy participants in two phase 1 clinical vaccine trials conducted at the Canadian Center for Vaccinology in Halifax, Nova Scotia. Participants were invited via email to complete the online survey. Readability and clarity were assessed through pilot testing.Results
A total of 49 (55.7%) of 88 participants of the two studies completed the survey (22 [55%] of 40 participants from the Ebola vaccine study and 27 [56.3%] of 48 from the adjuvanted influenza vaccine study). Motivations that were most frequently ranked among participants' top three in both trials were (1) wanting to contribute to the health of others, (2) wanting to participate in something important, (3) wanting to contribute to the advancement of science, and (4) wanting to receive an incentive such as money or a tablet.Conclusions/Recommendations
Although media attention and financial compensation were more often cited by Ebola vaccine trial participants as a reason to participate, both altruistic and self-interested factors were important motivations for participants in their decision to participate in a phase 1 vaccine clinical trial. 相似文献18.
19.
Jae Eun Choi Tyler Werbel Zhenping Wang Chia Chi Wu Tony L. Yaksh Anna Di Nardo 《Journal of dermatological science》2019,93(1):58-64
Background
Rosacea is a chronic inflammatory skin condition whose etiology has been linked to mast cells and the antimicrobial peptide cathelicidin LL-37. Individuals with refractory disease have demonstrated clinical benefit with periodic injections of onabotulinum toxin, but the mechanism of action is unknown.Objectives
To investigate the molecular mechanism by which botulinum toxin improves rosacea lesions.Methods
Primary human and murine mast cells were pretreated with onabotulinum toxin A or B or control. Mast cell degranulation was evaluated by β-hexosaminidase activity. Expression of botulinum toxin receptor Sv2 was measured by qPCR. The presence of SNAP-25 and VAMP2 was established by immunofluorescence. In vivo rosacea model was established by intradermally injecting LL-37 with or without onabotulinum toxin A pretreatment. Mast cell degranulation was assessed in vivo by histologic counts. Rosacea biomarkers were analyzed by qPCR of mouse skin sections.Results
Onabotulinum toxin A and B inhibited compound 48/80-induced degranulation of both human and murine mast cells. Expression of Sv2 was established in mouse mast cells. Onabotulinum toxin A and B increased cleaved SNAP-25 and decreased VAMP2 staining in mast cells respectively. In mice, injection of onabotulinum toxin A significantly reduced LL-37-induced skin erythema, mast cell degranulation, and mRNA expression of rosacea biomarkers.Conclusions
These findings suggest that onabotulinum toxin reduces rosacea-associated skin inflammation by directly inhibiting mast cell degranulation. Periodic applications of onabotulinum toxin may be an effective therapy for refractory rosacea and deserves further study. 相似文献20.