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Abstract  

Investigations of trace elements in the atmosphere require the application of highly sensitive multielement analytical methods and methods allowing sampling of contrasting element speciations. Instrumental neutron activation analysis was used to determine 30 element concentrations in samples under investigation. The results of investigating properties of aerosol samples on filters and some aspects of the study of atmospheric trace-element vapor-gas and submicron aerosol phases are presented. A method for investigating the vapor-gas and submicron aerosol phases of atmospheric trace elements by sorption on collectors with neutron activation analysis of exposed collectors is offered.

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Lanzou Alkaline Stretched Noodles (LASN) was a traditional staple food in northwest China for nearly 90 years. LASN specialty wheat breeding has become an important target since 1990s. In order to discover the LASN specialty wheat quality requirement for allelic variations at Glu-3 of northwest China spring wheats. Two northwest China spring wheat cultivars and 39 elite F6 breeding lines were adopted to determine the low-molecular-weight glutenin subunits (LMW-GS) composition by one step one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) basing on the protocol of Singh et al. (1991). The results showed that Glu-A3d and Glu-B3g were correlated to high protein content, high volume of SDS-sediment and super dough strength (W). While Glu-A3a was bad to dry gluten content and SDS-sediment as well as dough properties such as dough strength (W) and dough tenacity (P). Moreover, Glu-B3j has not significant influence on flour quality, but it has the negative effect on dough strength (W) and dough extensibility (L). As for LASN quality, Glu-A3d and Glu-B3g were beneficial alleles and Glu-A3a was unbeneficial alleles for LASN quality.

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Abstract  

Poly(AN—co—St) (PAS) and poly(AN—St—MMA)(PASM) were synthetized by emulsion polymerisation. The glass transition temperatures (T g) of the copolymers and the relationship between T g and the components of the copolymers were investigated by differential scanning calorimetry. The results show that T g for the AN—St bipolymers has apeak value in the range 115–118°C at a content of 50 mass% St. When methyl methacrylate was added, the T g of the terpolymer was decreased by about 2–6°C.The thermostability and the activation energy E of degradation were determined by thermogravimetric analysis.

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Molecular markers are important tools that have been used to identify the short arm of rye chromosome 1R (1RS) which contains many useful genes introgressed into wheat background. Wheat expressed sequence tag (EST) sequences are valuable for developing molecular markers since ESTs are derived from gene transcripts and more likely to be conserved between wheat and its relative species. In the present study, 35 sequence-tagged site (STS) primers were designed based on EST sequences distributed on homology group 1 chromosomes of Triticum aestivum and used to screen specific markers for chromosome 1RS of Secale cereale . Two primer pairs different from the early studies, STS WE3 , which amplified a 1680-bp and a 1750-bp fragment, and STS WE126 , which produced a 850-bp fragment from rye genome, were proved to be specific to chromosome 1RS since the corresponding fragments were only amplified from 1R chromosome addition line and wheat-rye lines with chromosome 1RS, but not from wheat-rye 2R-7R chromosome addition lines and the other lines lacking chromosome 1RS. Eleven wheat-rye lines derived from ‘Xiaoyan 6’ and ‘German White’ were used to test the presence of specific markers for 1RS. The specific fragments of 1RS were amplified in 4 wheat-rye lines, but not in the other lines. The testing results using EST-STS markers of 1RS were consistent with those obtained from fluorescence in situ hybridization (FISH), suggesting that these markers specific to 1RS could be used in marker-assisted selection (MAS) for incorporating 1RS into wheat cultivars in breeding.

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Two new y-type HMW-GSs in Ae. tauschii , 1Dy12.1* t and 1Dy12.2 t with the mobility order of 1Dy12.2 t > 1Dy12.1* t > 1Dy12.1 t >1Dy12, were identified by both SDS-PAGE and MALDI-TOF-MS. Molecular cloning and sequencing showed that the genes encoding subunits 1Dy12.1* t and 1Dy12.2 t had identical nucleotide acid sequences with 1,947 bp encoding a mature protein of 627 residues. Their deduced molecular weights were 67,347.6 Da, satisfactorily corresponding to that of 1Dy12.2 t subunit determined by MALDI-TOF-MS (67,015.7 Da), but was significantly smaller than that of the the 1Dy12.1* t subunit (68,577.1 Da). Both subunits showed high similarities to 1Dy10, suggesting that they could have a positive effect on bread-making quality. Interestingly, the expressed protein of the cloned ORF from accessions TD87 and TD130 in E. coli co-migrated with subunit 1Dy12.2 t , but moved slightly faster than 1Dy12.1* t on SDS-PAGE. The expressed protein in transgenic tobacco seeds, however, had the same mobility as the 1Dy12.1* t subunit, as confirmed by both SDS-PAGE and Western blotting. Although direct evidence of phosphoprotein could not be obtained by specific staining method, certain types of post-translational modifications (PTMs) of the 1Dy12.1* t subunit could not be excluded. We believe PTMs might be responsible for the molecular weight difference between the subunits 1Dy12.1* t and 1Dy12.2 t .

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