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  • Author or Editor: C.H. Zhang x
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Abstract  

The thermal degradation of cotton cellulose treated with chemical mixtures containing P and N was studied by thermal analysis, infrared spectroscopy, Char yield and limiting-oxygen-index (LOI). Our experiments demonstrated the following facts. The temperatures and activation energies of pyrolysis were lower for cotton cellulose treated with flame retardants than those for untreated samples and the values of Char yield and LOI were greater for treated cotton than those for untreated one.

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Thinopyrum ponticum (2n = 10x = 70) has donated rust resistance genes to protect wheat from this fungal disease. In the present study, the line ES-7, derived from the progeny of the crosses between common wheat cultivar Abbondanza and Triticum aestivumTh. ponticum partial amphiploid line Xiaoyan784, was characterized by cytological, fluorescence in situ hybridization (FISH), genomic in situ hybridization (GISH) and EST-STS marker techniques. Cytological observations revealed that the configuration of ES-7 was 2n = 42 = 21 II. GISH and FISH results showed that ES-7 had two St chromosomes and lacked 5A chromosomes compared to common wheat. The 4A chromosome of ES-7 had small alterations from common wheat. Two EST-SSR markers BE482522 and BG262826, specific to Th. ponticum and tetraploid Pseudoroegneria spicata (2n = 4x = 28), locate on the homoeologous group 5 chromosomes of wheat, could amplify polymorphic bands in ES-7. It was suggested that the introduced St chromosomes belonged to homoeologous group 5, that is, ES-7 was a 5St (5A) disomic substitution line. Furthermore, ES-7 showed highly resistance to mixed stripe rust races of CYR32 and CYR33 in adult stages, which was possibly inherited from Th. ponticum. Thus, ES-7 can be used for wheat stripe rust resistance breeding program.

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Hydrogen sulfide (H2S) has been recently found to be a gaseous signaling molecule in plants. In this work, we studied the role of H2S in alleviating salinity stress during wheat grain germination (Triticum aestivum L. Yangmai 158). Pretreatment with NaHS, a H2S donor, during wheat grain imbibition, could significantly attenuate the inhibitory effect of salinity stress on wheat germination. NaHS-pretreated grain showed higher amylase and esterase activities than water control. NaHS pretreatment differentially stimulated the activities of catalase (CAT), guaiacol peroxidase (POD) and ascorbate peroxidase (APX), decreased the level of malondialdehyde (MDA) and reduced NaCl-induced changes in plasma membrane integrity in the radicle tips of seedlings compared with water control. We conclude that H2S plays an important role in protecting wheat grain from oxidative damage induced by salinity stress.

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Abstract  

The stability constants for tracer concentrations of Co(II) complexes with the red earth fulvic acid were determined at pH 3.8–6.8 and ionic strength 0.0010–1.0 mol/l by using the cation exchange equilibrium method and the radiotracer60Co. The effects of ionic strength and pH on the stability constants of 1∶1 Co(II) complexes were investigated, and it was found that the stability constants of complexes of humic substances do not vary with ionic strength and pH in a manner similar to that of simple complexes.

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Abstract  

By substututing99Mo for the Mo in the reconstituted MoFe protein, the nuclear quadrupole interactions (NQI) of99Mo have been measured using the perturbed angular correlations (PAC). Two well-defined electric quadrupole interaction parameters have been observed. The configuration of the M-Center of the MoFe protein is identified by the quadrupole couplign constant Q1(412(9)MHz) and the asymmetry parameter 1(0.49(5)). Other parameters, VQ2(1939(13)MHz) and 1(0.90(1)), may correspond to a deformation M—Center of MoFe protein.

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Molecularly imprinted polymers (MIPs) were synthesized by imprinting a new template—S(-)-1,1′-binaphthalene-2,2′-diamine (S-DABN) and applied as chiral stationary phases for chiral separation of DABN racemates by high-performance liquid chromatography (HPLC). The influence of some key factors on the chiral recognition ability of MIPs, such as the type of functional monomers and porogen and the molar ratio of template to monomer, was systematically investigated. The chromatographic conditions, such as mobile phase composition, sample loading, and flow rate, were also measured. The chiral separation for DABN racemates under the optimum chromatographic conditions by using MIP chiral stationary phase (CSP) of P3, prepared with the S-DABN/MAA ratio = 1/4 and used acetonitrile (2 mL) and chloroform (4 mL) as porogen, showed the highest separation factor (2.14). Frontal analysis was used to evaluate affinity to the target molecule of MIPs. The binding sites (B t) of MIPs and dissociation constant (K d) were estimated as 4.56 μmol g−1 and 1.40 mmol L−1, respectively. In comparison with the previous studies, this approach had the advantages, such as the higher separation factor, easy preparation, and cost-effectiveness, it not only has the value for research but also has a potential in industrial application.

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Abstract  

The stability constants for tracer concentrations of Co(II) complexes with both the red earth humic and fulvic acids were determined at pH 5.9 and ionic strength 0.010 mol/l by using theArdakani-Stevenson cation exchange equilibrium method and the radiotracer60Co. It was found that the 1:1 complexes of Co(II) with the red earth humic and fulvic acids were formed and that the average values of logβ (stability constant) of humic and fulvic acid complexes were 5.76±0.19 and 4.42±0.03, respectively.

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Wheat glutenins containing high and low molecular weight glutenin subunits (HMW-GS and LMW-GS) are the major determinants of wheat gluten quality. In this study, the recently developed reversed-phase ultra-performance liquid chromatography (RP-UPLC) was used to study the synthesis and accumulation patterns of glutenins during grain development of four Chinese bread wheat cultivars with different gluten quality. Developing grains were collected based on thermal times from 150 °Cd to 750 °Cd at 100 °Cd intervals, and the content of glutenin subunits and their accumulation patterns were determined by RP-UPLC as well as sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The results showed that HMW-GS and LMW-GS synthesis were initiated currently at 250 °Cd and they displayed a gradually upregulated expression. All the HMW-GS can be detected at 250 °Cd, earlier than LMW-GS. Different glutenin subunits and genotypes showed clear accumulation diversity during grain development. Particularly, 1Dx5 + 1Dy10 in the cultivar Gaocheng 8901 and Zhongyou 9507 with superior dough properties were accumulated faster at early stages than 1Dx2 + 1Dy12 in Jingdong 8 and Zhengmai 9023 with poor dough quality, suggesting that faster accumulation rate of glutenin proteins at the early stages of grain development may contribute to the formation of superior gluten structure and dough quality.

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Abstract  

The heat capacities of 2-benzoylpyridine were measured with an automated adiabatic calorimeter over the temperature range from 80 to 340 K. The melting point, molar enthalpy, Δfus H m, and entropy, Δfus S m, of fusion of this compound were determined to be 316.49±0.04 K, 20.91±0.03 kJ mol–1 and 66.07±0.05 J mol–1 K–1, respectively. The purity of the compound was calculated to be 99.60 mol% by using the fractional melting technique. The thermodynamic functions (H TH 298.15) and (S TS 298.15) were calculated based on the heat capacity measurements in the temperature range of 80–340 K with an interval of 5 K. The thermal properties of the compound were further investigated by differential scanning calorimetry (DSC). From the DSC curve, the temperature corresponding to the maximum evaporation rate, the molar enthalpy and entropy of evaporation were determined to be 556.3±0.1 K, 51.3±0.2 kJ mol–1 and 92.2±0.4 J K–1 mol–1, respectively, under the experimental conditions.

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