Authors:X. Xia, R. Naumann d’Alnoncourt, and M. Muhler
Standard entropies of adsorption (Δs0) of CO on different materials (Cu catalysts, Au catalysts, ZnO and to TiO2) are obtained from static adsorption microcalorimetry, adsorption isobars and temperature-programmed desorption, based on
the thermodynamics of adsorption on energetically heterogeneous surfaces. Vibrational entropies of the surfaces svibα are normally between the rotational and the standard translational entropy of CO in gas phase, and decrease with increasing
adsorption energy, which agrees with the explanation of statistical thermodynamics. Δs0 reflects both the mobility of adsorbates and the specific adsorbate-adsorbent interaction. Limits for reasonable values of
the entropy of adsorption are proposed.
Authors:R. Naumann d’Alnoncourt, B. Graf, X. Xia, and M. Muhler
The back-titration of atomic oxygen chemisorbed on metallic copper using carbon monoxide is investigated by microcalorimetry.
Results from simulations based on a microkinetic model of the back-titration are used for processing of microcalorimetric
data. In addition, surface oxidation of copper by nitrous oxide is investigated by microcalorimetry. The results are compared
with results obtained by nitrous oxide reactive frontal chromatography and by static oxygen adsorption studied by microcalorimetry.
The heat of adsorption of nitrous oxide on copper amounts to 304 kJ mol−1, and the heat of adsorption of carbon monoxide on surfaceoxidized copper is in the range from 120 to 70 kJ mol−1.
Authors:Y. Yang, X. Chen, Z. He, M. Röder, and L. Xia
Genotypes with various
alleles perform different levels of pre-harvest sprouting (PHS) tolerance. In this study, 217 white-grained wheat cultivars, including 75 landraces, 39 historical cultivars, and 103 modern cultivars from five major regions of China, were examined to characterize the diversity of the Viviparous-1B (
) locus associated with PHS tolerance. Four
alleles were identified, three (
) of which were previously reported in Chinese wheat cultivars. A new allele,
, was identified in the PHS tolerant landrace Hongheshangtou. Sequence analysis showed that
had an insertion of a 4-bp fragment, two SNPs, and a deletion of an 83-bp fragment compared with the nucleotide sequence of
(AJ400713), all located in the third intron.
shared 97.80% similarity with the nucleotide sequence of AJ400713. The frequencies of
were 36.0%, 5.3%, and 57.3% in landraces; 23.1%, 7.7%, and 69.2% in historical cultivars; and 52.4%, 0%, and 47.6% in current cultivars, respectively.
Authors:N. Li, Z. Yu, L. Wang, Y. Zheng, J. Jia, Q. Wang, M. Zhu, X. Liu, X. Xia, and W. Li
The aim of this study was to investigate the effects of maternal lead exposure on the learning and memory ability and expression of tau protein phosphorylation (P-tau) and beta amyloid protein (Aβ) in hippocampus of mice offspring. Pb exposure initiated from beginning of gestation to weaning. Pb acetate administered in drinking solutions was dissolved in distilled deionized water at the concentrations of 0.1%, 0.5% and 1% groups. On the 21
of postnatal day, the learning and memory ability of the mouse pups was tested by Water Maze test and the Pb levels in blood and hippocampus of the offspring were also determined. The expression of P-tau and Aβ in hippocampus was measured by immunohistochemistry and Western blotting. The Pb levels in blood and hippocampus of all exposure groups were significantly higher than that of the control group (
< 0.05). In Water Maze test, the performances of 0.5% and 1% groups were worse than that of the control group (
< 0.05). The expression of P-tau and Aβ was increased in Pb exposed groups than that of the control group (
< 0.05). Tau hyper-phosphorylation and Aβ increase in the hippocampus of pups may contribute to the impairment of learning and memory associated with maternal Pb exposure.
Authors:Y. Shen, H. Yang, G. Xia, J. Wang, B. Cai, and X. Jia
Silica-gel column chromatography and preparative reversed-phase high-performance liquid chromatography (RP-HPLC) were sequentially employed for the isolation of two antioxidants including gallic acid and methyl gallate from Folium Toonea Sinensis. An RP-HPLC-UV method was then developed and validated to rapidly determine their content in this herb with ethyl gallate as internal standard. The quantitation was performed on an XBridge Shield RP18 column (150 mm × 4.6 mm, 5 μm) under 40°C. The mobile phase consisting of acetonitrile and 0.1% formic acid aqueous solution was driven at 1.0 mL min−1 under gradient elution, and 270 nm was selected to monitor the separation. To evaluate the fitness for purpose of the method and to investigate the difference in the content of analytes among different samples, the leaves collected from five production sites were analyzed. The newly established method is suitable for routine analysis of gallic acid and methyl gallate in the herb and, hence, can assist in its quality assessment. It was also found that not only the content of two antioxidants but also the ratio varied significantly among different geographical origins. In addition, three samples from Yantai, Zumadian, and Zhenjiang were distinguished as they have a much higher content ratio than the other two.
Authors:L. Liu, Z. He, W. Ma, J. Liu, X. Xia, and R. Peña
Glutenin subunit alleles at the
locus and their effects on dough properties, pan bread, and dry white Chinese noodle (DWCN) qualities were investigated using 106 winter and facultative wheat cultivars and advanced lines. Allele
(42.5%) was the most frequent glutenin subunit, followed by
occurred in only three and six cultivars, respectively. The effect of
was significant forDWCNquality, accounting for up to 16% of the variation, but there were no significant differences between individual
alleles on dough properties and qualities of DWCNand pan bread. Interaction effects
Glu-A1 × Glu-D3
Glu-B1 × Glu-D3
were significant for DWCN quality and loaf volume. More work is needed to understand the effects of
variation on the determination of dough properties and end-use quality.
Authors:L. Ma, P. Xiao, J. Cai, X. Li, Z. Ji, Y. Xia, C. Yang, and J. Bao
Uniformity in the height of main stem and tillers is a key factor affecting ideal plant type, a key component in super high-yielding rice breeding. An understanding of the genetic basis of the panicle layer uniformity may thus contribute to breeding varieties with good plant type and high yield. In the present study, a doubled haploid (DH) population, derived from a cross between
rice variety Zhai-Ye-Qing 8 (ZYQ8) and
rice variety Jing-Xi 17 (JX17) was used to analyze quantitative trait loci (QTL) for panicle layer uniformity related traits. Six, four and three QTL were detected for the highest panicle height (HPH), lowest panicle height (LPH) and panicle layer dis-uniformity (PLD), respectively. qHPH-1-1 and qPLD-1 were located at the same interval on chromosome 1. The JX17 allele(s) of these QTL increased HPH and PLD by 2.57 and 1.26 cm, respectively. Similarly, qPLD-7 and qHPH-7 were located at the same interval on chromosome 7, where the ZYQ8 allele(s) increased HPH and PLD by 3.74 and 1.96 cm, respectively. These four QTL were unfavourable for panicle layer uniformity improvement because a decrease of the PLD was accompanied by decrease of the plant height. qPLD-6 and qLPH-6-1 were located at the same interval on chromosome 6, however here the JX17 allele(s) increased LPH, but decreased PLD, suggesting that this QTL was favourable for improvement of panicle layer uniformity. The markers identified in this study are potential for marker assisted breeding for the improvement of the panicle layer uniformity and ideal plant type.
Authors:J.Q. Xu, L. Wang, B.L. Liu, T.F. Xia, D.C. Liu, X. Chang, T.W. Zhang, H.G. Zhang, and Y.H. Shen
As one of the world’s earliest domesticated crops, barley is a model species for the study of evolution and domestication. Domestication is an evolutionary process whereby a population adapts, through selection; to new environments created by human cultivation. We describe the genome-scanning of molecular diversity to assess the evolution of barley in the Tibetan Plateau. We used 667 Diversity Arrays Technology (DArT) markers to genotype 185 barley landraces and wild barley accessions from the Tibetan Plateau. Genetic diversity in wild barley was greater than in landraces at both genome and chromosome levels, except for chromosome 3H. Landraces and wild barley accessions were clearly differentiated genetically, but a limited degree of introgression was still evident. Significant differences in diversity between barley subspecies at the chromosome level were observed for genes known to be related to physiological and phenotypical traits, disease resistance, abiotic stress tolerance, malting quality and agronomic traits. Selection on the genome of six-rowed naked barley has shown clear multiple targets related to both its specific end-use and the extreme environment in Tibet. Our data provide a platform to identify the genes and genetic mechanisms that underlie phenotypic changes, and provide lists of candidate domestication genes for modified breeding strategies.