Search results

1

Compositions of Al-Based Quasicrystals Interpreted by Cluster Formulae

100%

Chen H., Qiang J., Wang Y., Dong C.

|

vol. 126

|

issue 2

446-448

EN

It is known previously that bulk metallic glass compositions satisfy cluster formulae [cluster](glue atom)_{1, 3} of 24 valence electrons as deduced from our cluster-resonance model. In the present work, it is further shown that compositions of Al-based binary and ternary quasicrystals are also explained by 24-electron cluster formulae of the types [icosahedron](glue atom)_{0, 1}, where the icosahedral cluster is identified from a corresponding crystalline approximant according to dense atomic packing and cluster isolation criteria, and the glue atom site is either vacant for an icosahedral quasicrystal or equal to one for a decagonal quasicrystal. Ternary quasicrystals are formulated with the same formulae as their basic binary ones but the icosahedron shell sites are substituted by third elements. The 24-electron cluster formulae are then the chemical and electronic structural units of quasicrystals, mimicking the molecular formulae of chemical substances.

2

Positron Annilation Lifetime and Glass Transition Temperatures in CO_2 Sorption Polystyrene

100%

Jean Y., Chen H., Lee L., Yang J.

Acta Physica Polonica A

|

2008

|

vol. 113

|

issue 5

1385-1395

EN

Positron annihilation lifetime spectroscopy was used to measure the free-volume size and distributions as a function of temperature in polystyrene with and without 400 psi CO_2 sorption. The transition temperatures in the polystyrene with CO_2 sorption obtained from ortho-positronium lifetimes were found to depend on the thermal cycles and a meta-stable state showing a negative thermal expansion coefficient was observed between 53°C and 82°C during the first heating up experiment. The observed T_g in polystyrene with, and without CO_2 sorption after annealing from ortho-positronium lifetimes were found to be 86°C and 91°C, which are 5°C higher, and 10°C lower than from the differential scanning calorimetry data, respectively. The observed free-volume variations are discussed in terms of hole expansion, creation, free-volume relaxation, plasticization, and hole filling in amorphous polymers.

3

Mapping QTLs for root morphological traits in Brassica rapa L. based on AFLP and RAPD markers

88%

Lu G., Cao J., Yu X., Xiang X., Chen H.

Journal of Applied Genetics

|

2008

|

vol. 49

|

issue 1

23-31

EN

Root growth and thickening plays a key role in the final productivity and even the quality of storage roots in root crops. This study was conducted to identify and map quantitative trait loci (QTLs) affecting root morphological traits in Brassica rapa by using molecular markers. An F2 population was developed from a cross between Chinese cabbage (Brassica rapa ssp. chinensis) and turnip (B. rapa ssp. rapifera), which differed greatly in root characters. A genetic map covering 1837.1 cM, with 192 marker loci and 11 linkage groups, was constructed by using this F2 population. The F3 families derived from F2 plants were grown in the field and evaluated for taproot traits (thickness, length, and weight). QTL analysis via simple interval mapping detected 18 QTLs for the 3 root traits, including 7 QTLs for taproot thickness, 5 QTLs for taproot length, and 6 QTLs for taproot weight. Individually, the QTLs accounted for 8.4?27.4% of the phenotypic variation. The 2 major QTLs, qTRT4b for taproot thickness and qTRW4 for taproot weight, explained 27.4% and 24.8% of the total phenotypic variance, respectively. The QTLs for root traits, firstly detected in Brassica crops, may provide a basis for marker-assisted selection to improve productivity in root-crop breeding.

4

Novel SNP of the goat prolactin gene (PRL) associated with cashmere traits

76%

Lan X.-Y., Pan C.-Y., Chen H., Lei C.-Z., Li F.-Y., Zhang H.-Y., Ni Y.-S.

Journal of Applied Genetics

|

2009

|

vol. 50

|

issue 1

51-54

EN

Concentrations of the single-chain polypeptide hormone prolactin (PRL) are associated with wool or cashmere traits, and its seasonal changes may determine patterns of enzymatic activity and may affect cashmere fibre growth and moult. So, the PRL gene is a potential candidate gene for cashmere traits in marker-assisted selection (MAS). In this paper, we report a novel missense single-nucleotide polymorphism (SNP) within the goat PRL gene in 1367 individuals by PCR-SSCP (polymerase chain reaction with single-strand conformation polymorphism) analysis and DNA sequencing. The novel X76049:g.576C>A mutation is confirmed by Eco24I PCR-RFLP (restriction fragment length polymorphism) analysis and causes a missense codon (Pro176Thr). The frequencies of allele C varied from 0.79 to 0.93 in 9 analysed goat populations. C allele was correlated with higher fibre length (P = 0.014).

5

A novel single-nucleotide polymorphism of the visfatin gene and its associations with performance traits in the chicken

52%

Han R.-L., Lan X.-Y., Zhang L.-Z., Ren G., Jing Y.-J., Li M.-J., Zhang B., Zhao M., Guo Y.-K., Kang X.-T., Chen H.

|

vol. 51

|

issue 1

59-65

EN

Visfatin is a peptide that is predominantly expressed in visceral adipose tissue and is hypothesized to be related to obesity and insulin resistance. In this study, a novel silent single-nucleotide polymorphism (SNP) was found in exon 7 of the chicken visfatin gene (also known as PBEF1) by single-stranded conformation polymorphism (SSCP) and DNA sequencing. In total, 836 chickens forming an F2 resource population of Gushi chicken crossed with Anka broiler were genotyped by XbaI forced RFLP, and the associations of this polymorphism with chicken growth, carcass characteristics, and meat quality were analyzed. Significant associations were found between the polymorphism and 4-week body weight (BW4), 6-week body weight (BW6), 4-week body slanting length (BSL4), fat bandwidth (FBW), breast muscle water loss rate (BWLR) and breast muscle fiber density (BFD) (P < 0.05), as well as 4-week breastbone length (BBL4) (P < 0.01). These observations suggested that the polymorphism in exon7 of the visfatin gene had significant effects on the early growth traits of chicken.

6

Novel 12-bp deletion in the coding region of the bovine NPM1 gene affects growth traits

52%

Huang Y.-Z., Zhang E.-P., Chen H., Wang J., Li Z.-J., Huai Y.-T., Ma L., Lan X.-Y., Ren G., Lei C.-Z., Fang X.-T., Wang J.-Q.

|

vol. 51

|

issue 2

199-202

EN

The nucleophosmin 1 gene (NPM1) encodes a multifunctional nucleolar phosphoprotein that plays a crucial role in the control of various aspects of cell growth and homeostasis. In this study, the coding region of the NPM1 gene was screened in 1035 individuals of 4 Chinese cattle breeds by DNA sequencing and polyacrylamide gel electrophoresis. A novel 12-bp deletion mutation was identified in the coding region of the NPM1 gene. The PCR products of primer NPM1-P2 exhibited 3 genotypes and 2 alleles: 178 bp (denoted as W) and 166 bp (denoted as D). Genotype DD and allele D were predominant in the studied populations. Association analysis with growth traits in the Nanyang breed (N = 265) showed that the animals with genotype DD had significantly greater birth weight, body weight, body length, and heart girth than those with genotype WD (P < 0.01 or P < 0.05) at birth and after 6 months and 12 months, but not at 18 and 24 months of age. Results of this study suggest that the NPM1 gene is a candidate gene for growth traits in cattle.

Refine search results

Compositions of Al-Based Quasicrystals Interpreted by Cluster Formulae

Positron Annilation Lifetime and Glass Transition Temperatures in CO_2 Sorption Polystyrene

Mapping QTLs for root morphological traits in Brassica rapa L. based on AFLP and RAPD markers

Novel SNP of the goat prolactin gene (PRL) associated with cashmere traits

A novel single-nucleotide polymorphism of the visfatin gene and its associations with performance traits in the chicken

Novel 12-bp deletion in the coding region of the bovine NPM1 gene affects growth traits