全文获取类型
收费全文 | 274篇 |
免费 | 13篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 6篇 |
2020年 | 6篇 |
2019年 | 5篇 |
2018年 | 7篇 |
2017年 | 3篇 |
2016年 | 8篇 |
2015年 | 14篇 |
2014年 | 17篇 |
2013年 | 20篇 |
2012年 | 21篇 |
2011年 | 23篇 |
2010年 | 16篇 |
2009年 | 10篇 |
2008年 | 14篇 |
2007年 | 7篇 |
2006年 | 12篇 |
2005年 | 18篇 |
2004年 | 15篇 |
2003年 | 9篇 |
2002年 | 9篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1995年 | 2篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1986年 | 5篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1979年 | 1篇 |
1971年 | 2篇 |
排序方式: 共有287条查询结果,搜索用时 374 毫秒
281.
Stanescu Sinziana Belanger-Quintana Amaya Fernandez-Felix Borja Manuel Ruiz-Sala Pedro del Valle Mercedes Garcia Fernando Arrieta Francisco Martinez-Pardo Mercedes 《Amino acids》2022,54(5):777-786
Amino Acids - Propionic acidemia is an inborn error of metabolism caused by a deficiency in the mitochondrial enzyme propionyl-CoA carboxylase that converts the propionyl CoA to methyl malonyl CoA.... 相似文献
282.
Beatriz Pías Silvia Matesanz Amaya Herrero Teresa E. Gimeno Adrián Escudero Fernando Valladares 《Oikos》2010,119(9):1435-1444
Plant populations are subjected to changes in their natural environment as a result of the incidence of simultaneous global change drivers. Despite the fact that these changes can largely affect early fitness components, information on the effects of simultaneous drivers of global change on offspring traits and performance is particularly scant. We analyzed the combined effect of three global change drivers of critical importance in Mediterranean ecosystems (habitat fragmentation, reductions in habitat quality and water availability) on germination and seedling performance of the gypsophile shrub Centaurea hyssopifolia. Seedlings from 39 mother plants from eight different environments (resulting from the combination of the three global change drivers) were sown and grown in a common garden. First, germination percentage, seedling size and seedling survival were monitored. Secondly, seedling performance and ecophysiological traits were measured under well and low‐watered conditions. Fragmentation showed the largest negative effect on germination and offspring performance. Seedlings of mothers from small fragments germinated more slowly, showed lower survival, died faster, and showed lower photosynthetic rates under well‐watered conditions compared to seedlings of mother plants from large populations. Seedlings of different maternal origins did not differ in their response to water stress or in their ability to survive to drought. Ninety‐five percent of the seedlings survived until soil water content was as low as 3%. Our study shows that global change can have not only immediate impacts on plant populations but also transgenerational effects, and highlights the importance of studies involving multiple drivers and a more integral understanding of global change. 相似文献
283.
284.
M Takiguchi T Matsubasa Y Amaya M Mori 《BioEssays : news and reviews in molecular, cellular and developmental biology》1989,10(5):163-166
The functions and expression pattern of urea cycle enzymes have undergone considerable changes during the course of evolution. Sequence analyses shows that urea cycle enzymes from mammals are homologous to microbial enzymes of the arginine-metabolic pathway. Recently, an unexpected relationship was found between argininosuccinate lyase (EC 4.3.2.1), the fourth enzyme of the cycle, and delta-crystallin, a lens structural protein of birds and reptiles. 相似文献
285.
286.
287.
E de Teresa A Vera J Ortigosa L A Pulpon A P Arus M de Artaza 《BMJ (Clinical research ed.)》1979,2(6200):1260-1261
To assess the effects of oral contraceptives on anticoagulant treatment the prothrombin times of 12 patients were measured while they were taking both drugs simultaneously and while they were taking only anticoagulants. The mean prothrombin time ratio was significantly higher when patients were taking both drugs than when they were taking only anticoagulants and their doses of anticoagulant were significantly lower. During both periods most of the prothrombin values remained in the therapeutic range. These findings suggest that, contrary to the common belief that oral contraceptives diminish the effects of anticoagulants, contraceptives in fact potentiate the action of the anticoagulants. 相似文献