全文获取类型
收费全文 | 655篇 |
免费 | 40篇 |
国内免费 | 2篇 |
出版年
2023年 | 10篇 |
2022年 | 11篇 |
2021年 | 17篇 |
2020年 | 10篇 |
2019年 | 10篇 |
2018年 | 14篇 |
2017年 | 8篇 |
2016年 | 23篇 |
2015年 | 28篇 |
2014年 | 27篇 |
2013年 | 41篇 |
2012年 | 48篇 |
2011年 | 74篇 |
2010年 | 49篇 |
2009年 | 32篇 |
2008年 | 50篇 |
2007年 | 53篇 |
2006年 | 33篇 |
2005年 | 37篇 |
2004年 | 40篇 |
2003年 | 15篇 |
2002年 | 20篇 |
2001年 | 6篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1998年 | 4篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 6篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1981年 | 2篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有697条查询结果,搜索用时 31 毫秒
91.
92.
93.
94.
95.
Ioannis Kyriakidis Eleni Vasileiou Sofia Karastrati Athanasios Tragiannidis Nikolaos Gompakis Maria Hatzistilianou 《中国病毒学》2016,31(6):517-520
正Dear Editor,Hypersensitivity to mosquito bites(HMB)is primarily seen in children and adolescents in Asia and Central America.HMB may be related to the reactivation of Epstein-Barr virus(EBV)in infected natural killer(NK)cells and is directly associated with chronic active EBV infection(CAEBV)and NK/T-cell leukemia/lymphoma. 相似文献
96.
The purpose of this study was to examine whether prediction of antagonist moment (M(flx)) of the hamstrings using clinically applicable models depends on the muscles examined. Nine healthy males performed maximal isometric knee extension and flexion contractions at 0 degrees , 45 degrees and 90 degrees angles. Calibration knee flexion efforts were also performed at different levels of intensity. The resulting electromyographic (EMG) - moment curves were fitted using polynomial equations which were then used to estimate M(flx) from the antagonist EMG. Analysis of variance designs showed that the M(flx) predicted using the biceps femoris EMG was not significantly different compared with those predicted using the semitendinosus EMG data (p>0.05). Further, prediction of M(flx) using the EMG of both muscles or a combination of EMGs and architectural properties reduced estimation error but did not provide significantly different predicted values compared with the simpler single-muscle EMG - moment models (p<0.05). It appears that M(flx) prediction using the present EMG - moment model is not muscle specific. Prediction using models which combine EMG data and anatomic parameters of the hamstring muscle components yielded more accurate estimates and therefore their use to examine co-contraction levels is recommended. 相似文献
97.
Matrix metalloproteinase inhibitors as anticancer agents 总被引:1,自引:0,他引:1
Konstantinopoulos PA Karamouzis MV Papatsoris AG Papavassiliou AG 《The international journal of biochemistry & cell biology》2008,40(6-7):1156-1168
The important role of matrix metalloproteinases (MMPs) in the process of carcinogenesis is well established. However, despite very promising activity in a plethora of preclinical models, MMP inhibitors (MMPIs) failed to demonstrate a statistically significant survival advantage in advanced stage clinical trials in most human malignancies. Herein, we review the implication of MMPs in carcinogenesis, outline the pharmacology and current status of various MMPIs as anticancer agents and discuss the etiologies for the discrepancy between their preclinical and clinical evaluation. Finally, strategies for effective incorporation of MMPIs in current anticancer therapies are proposed. 相似文献
98.
Runx2: of bone and stretch 总被引:4,自引:0,他引:4
Ziros PG Basdra EK Papavassiliou AG 《The international journal of biochemistry & cell biology》2008,40(9):1659-1663
99.
The scale of analysis determines the spatial pattern of woody species diversity in the Mediterranean environment 总被引:1,自引:0,他引:1
Athanasios S. Kallimanis John M. Halley Despina Vokou Stefanos P. Sgardelis 《Plant Ecology》2008,196(1):143-151
We examine the spatial pattern of woody species diversity at different scales, in two sites of Mt. Holomontas in northern
Greece, which falls within the transitional zone between temperate forests and Mediterranean-type ecosystems. We investigate
how diversity is distributed in space and whether the perceived pattern changes with the scale of observation. We use two
different metrics of diversity: species richness and species turnover. Our main finding is that the spatial pattern of diversity
changes with the scale of observation or analysis. For a given scale, the pattern of species richness (alpha diversity) is
negatively correlated with the pattern of species turnover (beta diversity). Species-rich areas have more species in common
with their neighbors than species-poor areas. The between-scale disparity of the spatial pattern of diversity may be a general
feature of ecological systems. For this to be validated, studies with different groups of species in different biomes and
in different biogeographical areas are required; our study contributes to this direction providing evidence that this holds
true for woody species in Mediterranean communities. Finally, we discuss how these findings might affect important issues
in theoretical and applied ecology, such as identifying the environmental factors driving biodiversity. 相似文献
100.
The effect of hypericin photoactivation on mitochondria of human prostate carcinoma cells was studied using a range of mitochondrial inhibitors. Oligomycin significantly enhanced hypericin phototoxicity while atractyloside and antymicin A conferred a significant protection. Use of myxothiazol did not affect cell survival following hypericin photoactivation. These results signify a protective role for F(1)F(0)-ATP synthase running in reverse mode, and a significant photodamage at the quinone-reducing site of mitochondrial complex III. In light of these results, we performed molecular modeling of hypericin binding to complex III. This revealed three binding sites, two of which coincided with the quinol-oxidizing and quinone-reducing centers. Using submitochondrial particles we examined hypericin as a possible substrate of complex III and compared this to its natural substrate, ubiquinone-10. Our results demonstrate uniquely that hypericin is an efficient substrate for complex III, and this activity is inhibited by myxothiazol and antimycin A. We further demonstrated that hypericin photosensitization completely inactivated complex III with ubiquinone as substrate. The ability to enhance HYP potency by inhibition of F(1)F(0)-ATP synthase or depress HYP efficacy by inhibition at the Qi site of complex III provides a potential to increase the therapeutic index of HYP and amplify its PDT action in tumor cells. 相似文献