排序方式: 共有76条查询结果,搜索用时 31 毫秒
51.
Stanley CK Cheung Li-zhong Liu Lin-lin Lan Qiao-quan Liu Samuel SM Sun Juliana CN Chan Peter CY Tong 《BMC biotechnology》2011,11(1):37
Background
Human insulin-like growth factor-I (hIGF-I) is a growth factor which is highly resemble to insulin. It is essential for cell proliferation and has been proposed for treatment of various endocrine-associated diseases including growth hormone insensitivity syndrome and diabetes mellitus. In the present study, an efficient plant expression system was developed to produce biologically active recombinant hIGF-I (rhIGF-I) in transgenic rice grains. 相似文献52.
AE Clarke S Bernatsky KH Costenbader MB Urowitz DD Gladman PR Fortin M Petri S Manzi DA Isenberg A Rahman D Wallace C Gordon C Peschken MA Dooley EM Ginzler C Aranow SM Edworthy O Nived S Jacobsen G Ruiz-Irastorza E Yelin SG Barr L Criswell G Sturfelt L Dreyer I Blanco L Gottesman CH Feldman R Ramsey-Goldman 《Arthritis research & therapy》2012,14(Z3):A16
53.
Jayne E Rattray Marc Strous Huub JM Op den Camp Stefan Schouten Mike SM Jetten Jaap S Sinninghe Damsté 《Biology direct》2009,4(1):8-16
Background
The fatty acids of anaerobic ammonium oxidizing (anammox) bacteria contain linearly concatenated cyclobutane moieties, so far unique to biology. These moieties are under high ring strain and are synthesised by a presently unknown biosynthetic pathway. 相似文献54.
Background
Analysis of heart rate variation (HRV) has become a popular noninvasive tool for assessing the activities of the autonomic nervous system (ANS). HRV analysis is based on the concept that fast fluctuations may specifically reflect changes of sympathetic and vagal activity. It shows that the structure generating the signal is not simply linear, but also involves nonlinear contributions. These signals are essentially non-stationary; may contain indicators of current disease, or even warnings about impending diseases. The indicators may be present at all times or may occur at random in the time scale. However, to study and pinpoint abnormalities in voluminous data collected over several hours is strenuous and time consuming. 相似文献55.
A genomic library of Bacillus coagulans strain 81-11 was screened in Escherichia coli JM83 for lipolytic activity by using tributyrin agar plates. A 2.4 kb DNA fragment was subcloned from a lipolytic-positive clone and completely sequenced. Nucleotide sequence analysis predicted a 723 bp open reading frame (ORF), designated estC1, encoding a protein of 240 amino acids with an estimated molecular mass of 27 528 Da and a pI of 9.15. The deduced amino acid sequence of the estC1 gene exhibited significant amino acid sequence identity with carboxylesterases from thermophilic Geobacillus spp. and sequence analysis showed that the protein contains the signature G-X-S-X-G included in most esterases and lipases. Enzyme assays using p-nitrophenyl (p-NP) esters with different acyl chain lengths as the substrate confirmed the esterase activity. EstC1 exhibited a marked preference for esters of short-chain fatty acids, yielding the highest activity with p-NP butyrate. Maximum activity was found at pH 8 and 50°C, although the enzyme displayed stability at temperatures up to 60°C. 相似文献
56.
Evolution of transposable elements: an IS10 insertion increases fitness in Escherichia coli 总被引:3,自引:0,他引:3
Strains of Escherichia coli carrying Tn10, a transposon consisting of two
IS10 insertion sequences flanking a segment encoding for a
tetracycline-resistance determinant, gain a competitive advantage in
chemostat cultures. All Tn10-bearing strains that increase in frequency
during competition have a new IS10 insertion that is found in the same
location in the genome of those strains. We mapped, by a gradient of
transmission, the position of the new IS10 insertion. We examined 11
isolates whose IS10 insertion was deleted by recombinational crossing-
over, and in all cases the competitive fitness of the isolates was
decreased. These results show that the IS10-generated insertion increases
fitness in chemostat cultures. We named the insertion fit::IS10 and suggest
that transposable elements may speed the rate of evolution by promoting
nonhomologous recombination between preexisting variations within a genome
and thereby generating adaptive variation.
相似文献
57.
Members of the ZFY and ZNF6 gene families have been cloned from species
representing different taxa and different modes of sex determination.
Comparisons of these genes show the ZFY-like and ZNF6 sequences to be
strongly conserved across marsupials, birds, and lepidosaurians. Sequence
analyzed by neighbor-joining indicated that both gene families are
monophyletic with a high bootstrap value. Pairing of sequences from males
and females of nonmammalian species showed there to be no significant
difference between male and female sequences from a single species,
consistent with autosomal locations. The molecular distances between murine
Zfy-1, Zfy-2, and other ZFY-like sequences suggested that Zfy genes have
undergone a period of rapid evolutionary change not seen in human ZFY.
相似文献
58.
59.
60.