全文获取类型
收费全文 | 65篇 |
免费 | 3篇 |
出版年
2021年 | 1篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 4篇 |
2012年 | 2篇 |
2011年 | 5篇 |
2010年 | 4篇 |
2009年 | 2篇 |
2008年 | 2篇 |
2007年 | 6篇 |
2006年 | 5篇 |
2005年 | 2篇 |
2004年 | 3篇 |
2003年 | 1篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1985年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1966年 | 1篇 |
1926年 | 1篇 |
排序方式: 共有68条查询结果,搜索用时 109 毫秒
51.
Carmen Lai Hugo M Horlings Marc J van de Vijver Eric H van Beers Petra M Nederlof Lodewyk FA Wessels Marcel JT Reinders 《BMC bioinformatics》2007,8(1):422
Background
Array comparative genome hybridization (aCGH) provides information about genomic aberrations. Alterations in the DNA copy number may cause the cell to malfunction, leading to cancer. Therefore, the identification of DNA amplifications or deletions across tumors may reveal key genes involved in cancer and improve our understanding of the underlying biological processes associated with the disease. 相似文献52.
53.
Herman MJ Sontrop Perry D Moerland René van den Ham Marcel JT Reinders Wim FJ Verhaegh 《BMC bioinformatics》2009,10(1):389-22
Background
Large discrepancies in signature composition and outcome concordance have been observed between different microarray breast cancer expression profiling studies. This is often ascribed to differences in array platform as well as biological variability. We conjecture that other reasons for the observed discrepancies are the measurement error associated with each feature and the choice of preprocessing method. Microarray data are known to be subject to technical variation and the confidence intervals around individual point estimates of expression levels can be wide. Furthermore, the estimated expression values also vary depending on the selected preprocessing scheme. In microarray breast cancer classification studies, however, these two forms of feature variability are almost always ignored and hence their exact role is unclear. 相似文献54.
To understand why cross-species infection of prion disease often results in inefficient transmission and reduced protein conversion, most research has focused on defining the effect of variations in PrP primary structures, including sequence compatibility of substrate and seed. By contrast, little research has been aimed at investigating structural differences between different variants of PrPC and secondary structural requirements for efficient conversion. This is despite a clear role for molecular chaperones in formation of prions in non-mammalian systems, indicating the importance of secondary/tertiary structure during the conversion process. Recent data from our laboratory on the cellular location of disease-specific prion cofactors supports the critical role of specific secondary structural motifs and the stability of these motifs in determining the efficiency of disease-specific prion protein conversion. In this paper we summarize our recent results and build on the hypothesis previously suggested by Wuthrich and colleagues, that stability of certain regions of the prion protein is crucial for protein conversion to abnormal isoforms in vivo. It is suggested that one role for molecular cofactors in the conversion process is to stabilize PrPC structure in a form that is amenable for conversion to PrPSc.Key words: cofactor, structure, cell-free conversion assay, fibrillization, stability, loop region 相似文献
55.
Rat liver microsomes were used to measure the rates of chain elongation and desaturation of acids in the linoleate, oleate and palmitoleate biosynthetic pathways. These studies were designed to determine whether there is a relationship between rates of conversion and the types of unsaturated fatty acids found in rat liver lipids. In some cases rates of conversion correlate well with the types of unsaturated fatty acid found inrat liver lipids. In other cases, rates of conversion must be correlated with other controls such as competitive interactions, retroconversion, and specificities for incorporating given acids into lipids in order to explain the unsaturated fatty acid composition of rat liver lipids. The roles and interrelationships of these various metabolic processes are discussed relative to the control of polyunsaturated fatty acid biosynthesis. 相似文献
56.
57.
Schwaiger FW; Weyers E; Buitkamp J; Ede AJ; Crawford A; Epplen JT 《Molecular biology and evolution》1994,11(2):239-249
Exon 2 sequences of an expressed MHC-DRB locus from sheep were examined for
polymorphisms in both the antigen-binding regions and the adjacent intronic
mixed simple tandem repeat. Twenty-one novel exon 2 Ovar-DRB alleles were
identified. Short nucleotide motifs are extensively shared between certain
exon 2 regions of Ovar-DRB alleles. The simple repeat variations, the
number of different amino acids at usually polymorphic sites, and the
number of silent substitutions were reduced in the intraspecies analyses of
sheep DRB sequences, compared with those of cattle and goats. It was
paradoxical that the abundance of different sheep alleles was similar to
that of cattle and goats. This paradox may be explained by postulating a
relatively small number of "ancient" alleles, with the present-day Ovar-DRB
alleles being generated by reciprocal exchange of nucleotide motifs. At the
antigen-binding sites, new combinations of amino acids were maintained in
Ovar-DRB alleles by strong positive selection. In sheep--and less
pronounced in goats and cattle--the DRB alleles can be divided into two
groups. In one group, silent substitutions are increased when compared with
the other. This suggests separate evolutionary pathways for certain groups
of DRB alleles within a species. The simple repetitive sequences are also
discussed with respect to the evolution of DRB alleles.
相似文献
58.
Analysis of the rates of overall chain elongation and condensation of malonyl-CoA with palmitoyl-CoA and stearoyl-CoA as primers demonstrated that for each primer, the rate of the overall metabolic process was similar to the initial condensation. The specific activity for condensation with palmitoyl-CoA was eleven times greater than for stearoyl-CoA. The specific activities of both the beta-hydroxyacyl-CoA dehydrase and 2-trans-enoyl-CoA reductase reactions were much higher than for either condensation or chain elongation, although these rates were somewhat greater with the intermediates required in chain elongating palmitoyl-CoA than for stearoyl-CoA. Both substrates were incorporated into phospholipids at low rates and there was a time-dependent hydrolytic cleavage of the acyl-CoA primers which was partially prevented by bovine serum albumin. These findings demonstrate that there was no selective removal of either primer which could result in specific substrate depletion and an apparent reduction in the rate of condensation. These combined results firmly establish the rate-limiting nature and high degree of substrate specificity exhibited during the initial condensation step in fatty acid elongation. 相似文献
59.
60.
Valerie Crowell Olivier JT Briët Diggory Hardy Nakul Chitnis Nicolas Maire Aurelio Di Pasquale Thomas A Smith 《Malaria journal》2013,12(1):1-14