全文获取类型
收费全文 | 320篇 |
免费 | 19篇 |
出版年
2022年 | 5篇 |
2021年 | 8篇 |
2020年 | 5篇 |
2019年 | 1篇 |
2018年 | 6篇 |
2017年 | 8篇 |
2016年 | 10篇 |
2015年 | 13篇 |
2014年 | 20篇 |
2013年 | 30篇 |
2012年 | 35篇 |
2011年 | 31篇 |
2010年 | 11篇 |
2009年 | 15篇 |
2008年 | 15篇 |
2007年 | 13篇 |
2006年 | 18篇 |
2005年 | 19篇 |
2004年 | 16篇 |
2003年 | 9篇 |
2002年 | 8篇 |
2001年 | 5篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1988年 | 4篇 |
1985年 | 3篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有339条查询结果,搜索用时 156 毫秒
291.
Neurofilaments (NF) are the most abundant cytoskeletal component of large myelinated axons from adult central and peripheral nervous system. Here, we provide an overview of the complementary approaches, including biochemistry, cell biology and transgenic technology that were used to investigate the assembly, axonal transport and functions of NF in normal and pathological situations. Following their synthesis and assembly in the cell body, NFs are transported along the axon. This process is finely regulated via phosphorylation of the carboxy-terminal part of the two high-molecular-weight subunits of NF. The correct formation of an axonal network of NF is crucial for the establishment and maintenance of axonal calibre and consequently for the optimisation of conduction velocity. The frequent disorganisation of NF network observed in several neuropathologies support their contribution. However, despite the presence of NF mutations found in some patients, the exact relations between these mutations, the abnormal NF organisation and the pathological process remain a challenging field of investigation. 相似文献
292.
293.
Identification and Characterization of Leuconostoc fallax Strains Isolated from an Industrial Sauerkraut Fermentation 总被引:2,自引:0,他引:2 下载免费PDF全文
Rodolphe Barrangou Sung-Sik Yoon Frederick Breidt Jr. Henry P. Fleming Todd R. Klaenhammer 《Applied microbiology》2002,68(6):2877-2884
Lactic acid bacterial strains were isolated from brines sampled after 7 days of an industrial sauerkraut fermentation, and six strains were selected on the basis of susceptibility to bacteriophages. Bacterial growth in cabbage juice was monitored, and the fermentation end products were identified, quantified, and compared to those of Leuconostoc mesenteroides. Identification by biochemical fingerprinting, endonuclease digestion of the 16S-23S intergenic transcribed spacer region, and sequencing of variable regions V1 and V2 of the 16S rRNA gene indicated that the six selected sauerkraut isolates were Leuconostoc fallax strains. Random amplification of polymorphic DNA fingerprints indicated that the strains were distinct from one another. The growth and fermentation patterns of the L. fallax isolates were highly similar to those of L. mesenteroides. The final pH of cabbage juice fermentation was 3.6, and the main fermentation end products were lactic acid, acetic acid, and mannitol for both species. However, none of the L. fallax strains exhibited the malolactic reaction, which is characteristic of most L. mesenteroides strains. These results indicated that in addition to L. mesenteroides, a variety of L. fallax strains may be present in the heterofermentative stage of sauerkraut fermentation. The microbial ecology of sauerkraut fermentation appears to be more complex than previously indicated, and the prevalence and roles of L. fallax require further investigation. 相似文献
294.
A catalytic subunit of the sugar beet protein kinase CK2 is induced by salt stress and increases NaCl tolerance in Saccharomyces cerevisiae 总被引:3,自引:0,他引:3
Salinity is an important limiting factor in plant growth and development. We have cloned a catalytic subunit of the sugar beet protein kinase CK2 (BvCKA2) by functional expression in yeast of a NaCl-induced cDNA library. BvCKA2 was able to increase the yeast tolerance to NaCl and to functionally complement the cka1 cka2 yeast double mutant upon over-expression. Southern blot analysis indicated that, in sugar beet, the BCKA2 gene is a member of a multigene family. The mRNA levels of BvCKA2 were up-regulated in response to NaCl stress which suggests that protein kinase CK2 may be involved in the plant response to salt stress. 相似文献
295.
Rodolphe Meyer Enrico Benetto Elorri Igos Catherine Lavandier 《The International Journal of Life Cycle Assessment》2017,22(5):744-757
Purpose
Despite that different methods for the inclusion of transport noise in life cycle assessment (LCA) have been proposed, none of them has become consensual. Leveraging a case study on car tires, this paper aims at comparing two among these characterization approaches to identify strengths and weaknesses and to investigate the relative contribution of noise to human health (in disability-adjusted life years (DALYs)) as compared to other environmental stressors.Methods
The case study analyzed two tires showing different acoustical properties. The two methods applied are the one developed by Müller-Wenk and further improved by other authors and the recent one proposed by Cucurachi. These two methods were adapted to the case study, and a full LCA study of the car tires was carried out. Both uncertainty and sensitivity analyses were performed.Results and discussion
Both methods highlight the potential high contribution of noise damage to the DALYs generated by car tires, even considering parameters’ uncertainties. This study shows therefore the necessity to integrate noise impact in LCA in a broader way. Both methods present coherent results regarding the environmental performance differences between the two products. However, the absolute DALY scores differ by eight orders of magnitude, probably because Cucurachi’s methods overestimate the damages. The analysis of modeling choices and parameter uncertainties could not explain this difference.Conclusions
Noise impact on human health has to be included in LCA, and additional efforts should focus on the characterization modeling since there is not yet a consensual method for a systematic integration. The case study shows that the improvement of tire design can efficiently reduce noise impact on human health. Both methods have advantages and inconveniences. We think that it is possible to elaborate a method combining the strengths of both approaches. An incremental approach used on accurate localized and temporalized data processed with noise propagation software could provide characterization factors for a set of archetypes. This should be a good compromise for a method allowing systematic integration of noise impact in LCA.296.
Christelle?Hennequet-AntierEmail author Hélène?Chiapello Karine?Piot Séverine?Degrelle Isabelle?Hue Jean-Paul?Renard Fran?ois?Rodolphe Stéphane?Robin 《BMC bioinformatics》2005,6(1):150
Background
Analysis of variance is a powerful approach to identify differentially expressed genes in a complex experimental design for microarray and macroarray data. The advantage of the anova model is the possibility to evaluate multiple sources of variation in an experiment. 相似文献297.
Klaenhammer TR Barrangou R Buck BL Azcarate-Peril MA Altermann E 《FEMS microbiology reviews》2005,29(3):393-409
The lactic acid bacteria are a functionally related group of organisms known primarily for their bioprocessing roles in food and beverages. More recently, selected members of the lactic acid bacteria have been implicated in a number of probiotic roles that impact general health and well-being. Genomic analyses of multiple members of the lactic acid bacteria, at the genus, species, and strain level, have now elucidated many genetic features that direct their fermentative and probiotic roles. This information is providing an important platform for understanding core mechanisms that control and regulate bacterial growth, survival, signaling, and fermentative processes and, in some cases, potentially underlying probiotic activities within complex microbial and host ecosystems. 相似文献
298.
Yáñez AJ Bertinat R Spichiger C Carcamo JG de Los Angeles García M Concha II Nualart F Slebe JC 《Journal of cellular physiology》2005,205(1):19-24
Several reports have indicated the absence of gluconeogenic enzymes in pancreatic islet cells. In contrast, here we demonstrate that liver fructose-1,6-bisphosphatase (FBPase) is highly expressed both in human and rat pancreas. Interestingly, pancreatic FBPase is active and functional, and is inhibited by AMP and fructose-2,6-bisphosphate (Fru-2,6-P2). These results suggest that FBPase may participate as a component of a metabolic sensing mechanism present in the pancreas. Immunolocalization analysis showed that FBPase is expressed both in human and rat Langerhans islets, specifically in beta cells. In humans, FBPase was also located in the canaliculus and acinar cells. These results indicate that FBPase coupled with phosphofructokinase (PFK) plays a crucial role in the metabolism of pancreatic islet cells. The demonstration of gluconeogenic recycling of trioses as a new metabolic signaling pathway may contribute to our understanding of the differences between the insulin secretagogues trioses, fructose, and glucose in pancreas. 相似文献
299.
300.
Single and combined deletions of the NTAL/LAB and LAT adaptors minimally affect B-cell development and function 下载免费PDF全文