全文获取类型
收费全文 | 126490篇 |
免费 | 31831篇 |
国内免费 | 1197篇 |
学科分类
医药卫生 | 159518篇 |
出版年
2023年 | 5247篇 |
2022年 | 1366篇 |
2021年 | 3860篇 |
2020年 | 6052篇 |
2019年 | 2949篇 |
2018年 | 8042篇 |
2017年 | 8110篇 |
2016年 | 8732篇 |
2015年 | 8986篇 |
2014年 | 11701篇 |
2013年 | 13658篇 |
2012年 | 6066篇 |
2011年 | 6087篇 |
2010年 | 8125篇 |
2009年 | 10044篇 |
2008年 | 5203篇 |
2007年 | 4113篇 |
2006年 | 4939篇 |
2005年 | 3359篇 |
2004年 | 2559篇 |
2003年 | 2165篇 |
2002年 | 1954篇 |
2001年 | 2536篇 |
2000年 | 1837篇 |
1999年 | 2210篇 |
1998年 | 2249篇 |
1997年 | 1985篇 |
1996年 | 2032篇 |
1995年 | 1787篇 |
1994年 | 1184篇 |
1993年 | 998篇 |
1992年 | 1068篇 |
1991年 | 912篇 |
1990年 | 793篇 |
1989年 | 756篇 |
1988年 | 717篇 |
1987年 | 517篇 |
1986年 | 540篇 |
1985年 | 448篇 |
1984年 | 366篇 |
1983年 | 394篇 |
1982年 | 306篇 |
1981年 | 254篇 |
1980年 | 174篇 |
1979年 | 206篇 |
1978年 | 195篇 |
1977年 | 179篇 |
1976年 | 145篇 |
1974年 | 148篇 |
1970年 | 136篇 |
排序方式: 共有10000条查询结果,搜索用时 16 毫秒
91.
92.
Talita da Silva Mendes de Farias Ariclécio Cunha de Oliveira Sandra Andreotti Fernanda Gaspar do Amaral Patrícia Chimin André Ricardo Alves de Proença Francisco Leonardo Torres Leal Rogério Antonio Laurato Sertié Amanda Baron Campana Andressa Bolsoni Lopes Arnaldo Henrique de Souza José Cipolla‐Neto Fabio Bessa Lima 《Journal of pineal research》2015,58(3):251-261
Melatonin, the main hormone produced by the pineal gland, is secreted in a circadian manner (24‐hr period), and its oscillation influences several circadian biological rhythms, such as the regulation of clock genes expression (chronobiotic effect) and the modulation of several endocrine functions in peripheral tissues. Assuming that the circadian synchronization of clock genes can play a role in the regulation of energy metabolism and it is influenced by melatonin, our study was designed to assess possible alterations as a consequence of melatonin absence on the circadian expression of clock genes in the epididymal adipose tissue of male Wistar rats and the possible metabolic repercussions to this tissue. Our data show that pinealectomy indeed has impacts on molecular events: it abolishes the daily pattern of the expression of Clock, Per2, and Cry1 clock genes and Pparγ expression, significantly increases the amplitude of daily expression of Rev‐erbα, and affects the pattern of and impairs adipokine production, leading to a decrease in leptin levels. However, regarding some metabolic aspects of adipocyte functions, such as its ability to synthesize triacylglycerols from glucose along 24 hr, was not compromised by pinealectomy, although the daily profile of the lipogenic enzymes expression (ATP‐citrate lyase, malic enzyme, fatty acid synthase, and glucose‐6‐phosphate dehydrogenase) was abolished in pinealectomized animals. 相似文献
93.
94.
95.
96.
97.
Diego Dias da Silva Ana Helena da Rosa Paz Ciro Paz Portinho Elizabeth Obino Cirne Lima Lúcia Maria Kliemann Marcus Vinicius Martins Collares 《Acta cirúrgica brasileira / Sociedade Brasileira para Desenvolvimento Pesquisa em Cirurgia》2020,35(12)
Purpose:This study assessed the regeneration potential of mesenchymal stem cells (MSC) from adipose tissue associated with platelet-rich plasma (PRP) in bone regeneration.Methods:Thirty Wistar rats (Rattus norvegicus albinos) were divided into five groups (according to the grafting material and time to euthanasia): (1) autograft - 14 days (control), (2) autograft - 28 days (control), (3) MSC + PRP - 14 days, (4) MSC + PRP + papaverine - 14 days and (5) MSC + PRP + papaverine - 28 days. After euthanasia, the graft was removed and histological slides were prepared. They were assessed by a blinded pathologist using a previously published histological scale as parameter.Results:There was some degree of neoformed bone trabeculae (NBT) in 93.3% of the samples, as well as osteoblastic activity (OA). The autograft groups (14 and 28 days) had higher levels in the formation of bone trabeculae. Nonparametric data were analyzed using the Wilcoxon-Mann-Whitney test and proved not to be statistically significant at p < 0.05.Conclusions:Experimental parietal bone reconstruction, combining MSC, PRP and papaverine presented regeneration in all groups with no significant difference among them.Key words: Bone Regeneration, Platelet-Rich Plasma, Tissue Engineering, Rats 相似文献
98.
99.
Yolanda Carrascal PhD Gregorio Laguna PhD Miriam Blanco MD Bárbara Segura MD Iciar Martínez-Almeida MD 《Journal of cardiac surgery》2020,35(2):457-459
Gray platelet syndrome (GPS) is a rare (<1/1 000 000) and inherited platelet function disorder characterized by macrothrombocytopenia, α-granule deficiency, and hemorrhages. Bleeding intensity does not correlate with platelet count nor with functional test results. We hereby describe the perioperative bleeding prevention and management of a patient with GPS requiring multiple redo cardiac surgeries. 相似文献
100.
Femoral access‐related complications during percutaneous transcatheter aortic valve implantation comparing single versus double Prostar XL device closure 下载免费PDF全文