全文获取类型
收费全文 | 10069篇 |
免费 | 940篇 |
国内免费 | 477篇 |
出版年
2024年 | 14篇 |
2023年 | 226篇 |
2022年 | 317篇 |
2021年 | 606篇 |
2020年 | 618篇 |
2019年 | 757篇 |
2018年 | 635篇 |
2017年 | 370篇 |
2016年 | 335篇 |
2015年 | 548篇 |
2014年 | 888篇 |
2013年 | 860篇 |
2012年 | 588篇 |
2011年 | 689篇 |
2010年 | 528篇 |
2009年 | 564篇 |
2008年 | 514篇 |
2007年 | 493篇 |
2006年 | 375篇 |
2005年 | 317篇 |
2004年 | 248篇 |
2003年 | 180篇 |
2002年 | 156篇 |
2001年 | 86篇 |
2000年 | 54篇 |
1999年 | 45篇 |
1998年 | 55篇 |
1997年 | 40篇 |
1996年 | 50篇 |
1995年 | 34篇 |
1994年 | 32篇 |
1993年 | 28篇 |
1992年 | 41篇 |
1991年 | 29篇 |
1990年 | 18篇 |
1989年 | 11篇 |
1988年 | 15篇 |
1987年 | 17篇 |
1986年 | 13篇 |
1985年 | 10篇 |
1984年 | 14篇 |
1983年 | 14篇 |
1982年 | 14篇 |
1981年 | 11篇 |
1980年 | 7篇 |
1978年 | 5篇 |
1976年 | 2篇 |
1974年 | 4篇 |
1971年 | 2篇 |
1970年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
181.
182.
Sheng-Ping Huang Chun-Hsiang Huang Jia-Fwu Shyu Herng-Sheng Lee Shyi-Gen Chen James Yi-Hsin Chan Shih-Ming Huang 《Journal of biomedical science》2013,20(1):51
Background
Wound healing is a complex biologic process that involves the integration of inflammation, mitosis, angiogenesis, synthesis, and remodeling of the extracellular matrix. However, some wounds fail to heal properly and become chronic. Although some simulated chronic wound models have been established, an efficient approach to treat chronic wounds in animal models has not been determined. The aim of this study was to develop a modified rat model simulating the chronic wounds caused by clinical radiation ulcers and examine the treatment of chronic wounds with adipose-derived stem cells.Results
Sprague–Dawley rats were irradiated with an electron beam, and wounds were created. The rats received treatment with adipose-derived stem cells (ASCs), and a wound-healing assay was performed. The wound sizes after ASC treatment for 3 weeks were significantly smaller compared with the control condition (p < 0.01). Histological observations of the wound edge and immunoblot analysis of the re-epithelialization region both indicated that the treatment with ASCs was associated with the development of new blood vessels. Cell-tracking experiments showed that ASCs were colocalized with endothelial cell markers in ulcerated tissues.Conclusions
We established a modified rat model of radiation-induced wounds and demonstrated that ASCs accelerate wound-healing. 相似文献183.
Joo-Hyun Kim Eun-Hyang Lee Hye-jeong Park Eui-Kyun Park Tae-Geon Kwon Hong-In Shin Je-Yoel Cho 《Molecules and cells》2013,35(6):543-549
Adult human dental pulp stem cells (hDPSCs) are a unique population of precursor cells those are isolated from postnatal dental pulp and have the ability to differentiate into a variety of cell types utilized for the formation of a reparative dentin-like complex. Using LC-MS/MS proteomics approaches, we identified the proteins secreted from the differentiating hDPSCs in mineralization media. Lysyl oxidase-like 2 (LOXL2) was identified as a protein that was down-regulated in the hDPSCs that differentiate into odontoblast-like cells. The role of LOXL2 has not been studied in dental pulp stem cells. LOXL2 mRNA levels were reduced in differentiating hDPSCs, whereas the levels of other LOX family members including LOX, LOXL1, LOXL3, and LOXL4, are increased. The protein expression and secretion levels of LOXL2 were also decreased during odontogenic differentiation. Recombinant LOXL2 protein treatment to hDPSCs resulted in a dose-dependent decrease in the early differentiation and the mineralization accompanying with the lower levels of odontogenic markers such as DSPP, DMP-1 and ALP. These results suggest that LOXL2 has a negative effect on the differentiation of hDPSCs and blocking LOXL2 can promote the hDPSC differentiation to odontoblasts. 相似文献
184.
M. Reimeringer N. Nuño C. Desmarais-Trépanier M. Lavigne P.A. Vendittoli 《Computer methods in biomechanics and biomedical engineering》2013,16(11):1221-1231
One of the crucial factors for short- and long-term clinical success of total hip arthroplasty cementless implants is primary stability. Indeed, motion at the bone–implant interface above 40 μm leads to partial bone ingrowth, while motion exceeding 150 μm completely inhibits bone ingrowth. The aim of this study was to investigate the effect of two cementless femoral stem designs with different lengths on the primary stability. A finite element model of a composite Sawbones® fourth generation, implanted with five lengths of the straight prosthesis design and four lengths of the curved prosthesis design, was loaded with hip joint and abductor forces representing two physiological activities: fast walking and stair climbing. We found that reducing the straight stem length from 146 to 54 mm increased the average micromotion from 17 to 52 μm during fast walking, while the peak value increased from 42 to 104 μm. With the curved stem, reducing length from 105 to 54 mm increased the average micromotion from 10 to 29 μm, while the peak value increased from 37 to 101 μm. Similar findings are obtained for stair climbing for both stems. Although the present study showed that femoral stem length as well as stem design directly influences its primary stability, for the two femoral stems tested, length could be reduced substantially without compromising the primary stability. With the aim of minimising surgical invasiveness, newer femoral stem design and currently well performing stems might be used with a reduced length without compromising primary stability and hence, long-term survivorship. 相似文献
185.
Insu Jeon Ji-Yong Bae Jin-Hong Park Taek-Rim Yoon Mitsugu Todo Masaaki Mawatari 《Computer methods in biomechanics and biomedical engineering》2013,16(1):103-112
To investigate the biomechanical effect of collars, finite element analyses are carried out through two hip joints that are implanted using collared and collarless stems, respectively, and an intact hip joint model. For the analyses, the sacrum, coxal bone, and the cancellous and cortical bones of a femur are modelled using finite elements based on X-ray computed tomographic images taken from a 27-year-old woman. From the results, it is found that a collar with perfect calcar contact prevents stem subsidence and decreases the proximal–lateral gap and the lateral stem tilting. Therefore, it can impart reasonable biomechanical stability for total hip arthroplasty. However, its low load transmission ability and increased stem tilting effect due to the imperfect contact between the collar and the calcar are found to be serious problems that need to be solved. Results of clinical follow-up are presented for supporting the computational results. 相似文献
186.
C-K Yang C-C Feng J-F Lo J-W Chen V. V Padma C-H Lai 《Biotechnic & histochemistry》2013,88(8):632-639
Mesenchymal stem cells are an attractive source of multipotent cells in part because they are easy to obtain. Several E3 ligases regulate the stability and functions of various factors in different adult stem cells through the ubiquitylation pathway. We investigated the C-terminus of Hsc70-interacting protein (CHIP) E3 ligase that regulates pluripotency of human Wharton’s jelly mesenchymal stem cells (hWJMSC). We found that CHIP increases protein kinase B (Akt) phosphorylation by decreased expression of phosphatase and tensin homolog (PTEN), which suggests improvement of the survival pathway by CHIP over-expression. We also found that increased CHIP expression induced Sox2 and NANOG, which can promote stem cell self-renewal and prevent oxidative stress-induced senescence of hWJMSC by decreased p21. We found that CHIP could be used to enhance the multiple functions of hWJMSC. 相似文献
187.
188.
189.
190.