全文获取类型
收费全文 | 37612篇 |
免费 | 16411篇 |
国内免费 | 11篇 |
出版年
2023年 | 54篇 |
2022年 | 106篇 |
2021年 | 597篇 |
2020年 | 2292篇 |
2019年 | 3876篇 |
2018年 | 4079篇 |
2017年 | 4318篇 |
2016年 | 4494篇 |
2015年 | 4610篇 |
2014年 | 4396篇 |
2013年 | 4872篇 |
2012年 | 2873篇 |
2011年 | 2567篇 |
2010年 | 3676篇 |
2009年 | 2298篇 |
2008年 | 1543篇 |
2007年 | 1002篇 |
2006年 | 933篇 |
2005年 | 914篇 |
2004年 | 909篇 |
2003年 | 756篇 |
2002年 | 635篇 |
2001年 | 557篇 |
2000年 | 475篇 |
1999年 | 263篇 |
1998年 | 113篇 |
1997年 | 85篇 |
1996年 | 58篇 |
1995年 | 63篇 |
1994年 | 51篇 |
1993年 | 38篇 |
1992年 | 94篇 |
1991年 | 61篇 |
1990年 | 46篇 |
1989年 | 52篇 |
1988年 | 29篇 |
1987年 | 28篇 |
1986年 | 24篇 |
1985年 | 23篇 |
1984年 | 13篇 |
1983年 | 15篇 |
1982年 | 13篇 |
1981年 | 14篇 |
1980年 | 13篇 |
1979年 | 11篇 |
1978年 | 15篇 |
1975年 | 14篇 |
1974年 | 12篇 |
1971年 | 6篇 |
1970年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Hyuck Choi Byung-Chul Jeong Sung-Woong Hur Jung-Woo Kim Keun-Bae Lee Jeong-Tae Koh 《PloS one》2015,10(10)
Craniofacial bone defects are observed in a variety of clinical situations, and their reconstructions require coordinated coupling between angiogenesis and osteogenesis. In this study, we explored the effects of cartilage oligomeric matrix protein-angiopoietin 1 (COMP-Ang1), a synthetic and soluble variant of angiopoietin 1, on bone morphogenetic protein 2 (BMP2)-induced cranial bone regeneration, and recruitment and osteogenic differentiation of perivascular pericytes. A critical-size calvarial defect was created in the C57BL/6 mouse and COMP-Ang1 and/or BMP2 proteins were delivered into the defects with absorbable collagen sponges. After 3 weeks, bone regeneration was evaluated using micro-computed tomography and histologic examination. Pericyte recruitment into the defects was examined using immunofluorescence staining with anti-NG2 and anti-CD31 antibodies. In vitro recruitment and osteoblastic differentiation of pericyte cells were assessed with Boyden chamber assay, staining of calcified nodules, RT-PCR and Western blot analyses. Combined administration of COMP-Ang1 and BMP2 synergistically enhanced bone repair along with the increased population of CD31 (an endothelial cell marker) and NG2 (a specific marker of pericyte) positive cells. In vitro cultures of pericytes consistently showed that pericyte infiltration into the membrane pore of Boyden chamber was more enhanced by the combination treatment. In addition, the combination further increased the osteoblast-specific gene expression, including bone sialoprotein (BSP), osteocalcin (OCN) and osterix (OSX), phosphorylation of Smad/1/5/8, and mineralized nodule formation. COMP-Ang1 can enhance BMP2-induced cranial bone regeneration with increased pericyte recruitment. Combined delivery of the proteins might be a therapeutic strategy to repair cranial bone damage. 相似文献
3.
4.
Detection and genotyping of group A rotaviruses isolated from sewage samples in Monastir,Tunisia between April 2007 and April 2010 下载免费PDF全文
5.
6.
7.
8.
9.