The thermogenic curves of metabolism of the four strains of Escherichia coli pUC19cab/JM109, pUC19cab/XL-IBlue, JM109 and XL-IBlue were determined using the LKB-2277 BioActivity Monitor and the ampoule
method at 37�C. The pUC19cab/JM109 and pUC19cab/XL-IBlue are recombinant E. coli strains bearing the same foreign plasmid pUC19cab, which confers the ability to produce polyhydroxyalkanoates (PHAs). The
yield of PHAs of pUC19cab/XL-IBlue was higher than that of pUC19cab/JM109. XL-IBlue and JM109 were the host bacteria. The
heat flow of these strains was XL-Blue≈JM109>pUC19cab/JM109>pUC19cab/XL-IBlue. These results indicate an obvious interrelation
between the PHAs production and the heat flow rate of E. coli strains.
Authors:L. Li, X. Wang, J. Shen, L. Zhou, and T. Zhang
Adsorption microcalorimetry has been employed to study the interaction of ethylene with the reduced and oxidized Pt-Ag/SiO2catalysts with different Ag contents to elucidate the modified effect of Ag towards the hydrocarbon processing on platinum
catalysts. In addition, microcalorimetric adsorption of H2, O2, CO and FTIR of CO adsorption were conducted to investigate the influence of Ag on the surface structure of Pt catalyst.
It is found from the microcalorimetric results of H2and O2adsorption that the addition of Ag to Pt/SiO2leads to the enrichment of Ag on the catalyst surface which decreases the size of Pt surface ensembles of Pt-Ag/SiO2catalysts. The microcalorimetry and FTIR of CO adsorption indicates that there still exist sites for linear and bridged CO
adsorption on the surface of platinum catalysts simultaneously although Ag was incorporated into Pt/SiO2. The ethylene microcalorimetric results show that the decrease of ensemble size of Pt surface sites suppresses the formation
of dissociative species (ethylidyne) upon the chemisorption of C2H4on Pt-Ag/SiO2. The differential heat vs. uptake plots for C2H4adsorption on the oxygen-preadsorbed Pt/SiO2and Pt-Ag/SiO2catalysts suggest that the incorporation of Ag to Pt/SiO2could decrease the ability for the oxidation of C2H4.
Authors:L. Chen, W. Song, J. Lv, L. Wang, and C. Xie
Aluminum (Al) nanopowders with mean diameter of about 50 nm and passivated by alumina (Al2O3) coatings were prepared by an evaporation route: laser heating evaporation. Thermal properties of the nanopowders were investigated
by simultaneous thermogravimetric-differential thermal analysis (TG-DTA) in dry oxygen environment, using a series of heating
rates (5, 10, 20, 30, 50 and 90°C min−1) from room temperature to 1200°C. With the heating rates rise, the onset and peak temperatures of the oxidation rise, and
the conversion degree of Al to Al2O3 varies. However, the specific heat release keeps relatively invariant and has an average value of 18.1 kJ g−1. So the specific heat release is the intrinsic characteristic of Al nanopowders, which can represent the ability of energy
Authors:M. L. Zhang, M. L. Zhang, M. L. Zhang, A. Ren, A. Ren, A. Ren, D. Shao, D. Shao, D. Shao, X. Wang, X. Wang, and X. Wang
The sorption and desorption of radionuclide 90Sr2+were investigated on untreated calcareous soil and two treated soils to remove organic matter and calcium carbonate using
batch technique. The experiments were carried out at ambient condition, pH 7.8±0.1 and in the presence of 0.001M NaCl. Effects
of fulvic acid and ionic strength on the sorption of 90Sr2+on calcareous soil were also studied. It was found that the sorption isotherms are linear in the strontium concentration range
used herein, and the sorption of 90Sr2+on the calcareous soil can be described as a reversible sorption process and the sorption mechanism is mainly ion-exchange.
The sorption is dependent on ionic strength, and fulvic acid enhances the sorption of 90Sr2+on calcareous soil. Organic matter present in the calcareous soil is a significant trap of 90Sr2+and is responsible for the sorption.
Aegiolops kotschyi cytoplasmic male sterile system often results in part of haploid plants in wheat (Triticum aestivum L.). To elucidate the origin of haploid, 235 wheat microsatellite (SSR) primers were randomly selected and screened for polymorphism between haploid (2n = 3x = 21 ABD) and its parents, male-sterile line YM21 (2n = 6x = 42 AABBDD) and male fertile restorer YM2 (2n = 6x = 42 AABBDD). About 200 SSR markers yielded clear bands from denatured PAGE, of which 180 markers have identifiable amplification patterns, and 20 markers (around 8%) resulted in different amplification products between the haploid and the restorer, YM2. There were no SSR markers that were found to be distinguishable between the haploid and the male sterile line YM21. In addition, different distribution of HMW-GS between endosperm and seedlings from the same seeds further confirmed that the haploid genomes were inherited from the maternal parent. After haploidization, 1.7% and 0.91% of total sites were up- and down-regulated exceeding twofold in the shoot and the root of haploid, respectively, and most of the differentially expressed loci were up/down-regulated about twofold. Out of the sensitive loci in haploid, 94 loci in the shoot, 72 loci in the root can be classified into three functional subdivisions: biological process, cellular component and molecular function, respectively.
Authors:Y. Wang, L. Yin, G. Lv, Y. Xu, L. Xu, Y. Qi, L. Zheng, and J. Peng
In the present paper, a simple and reliable high-performance liquid chromatography-diode array detection (HPLC-DAD) method was developed both for quantitative determination and fingerprint analysis of Agrimonia pilosa Ledeb for quality control. Under the optimized HPLC conditions, seven bioactive compounds including rutin, quercetin-3-rhamnoside, luteoloside, tiliroside, apigenin, kaempferol, and agrimonolide were determined simultaneously. For fingerprint analysis, 11 common peaks were selected as the characteristic peaks to evaluate the similarities of 16 different samples collected from different origins in China. Besides, hierarchical cluster analysis (HCA) was also performed to evaluate the variation of the raw materials. This is the first report of using a simple method for quality control of A. pilosa Ledeb through multi-component determination and chromatographic fingerprint analysis to the best of our knowledge.
Authors:Q. Du, L. Zhang, H. Cui, K. Wang, L. Xiu, and L. Sheng
Cleavage of glucosinolates with myrosinase yields thioglycosidic compounds which have cancer chemoprevention activity. In this paper, glucosinolates in an extract (2.0 g) of broccoli seeds (Brassica oleracea var. italica) were separated by high-speed countercurrent chromatography (HSCCC) with the solvent system n-butanol-acetonitrile-10% ammonium sulfate solution 1:0.5:2.2 (v/v) to yield five glucosinolate compounds after desalting and decolorizing by MCI column chromatography. The five compounds, 7-methylsulfinylheptyl glucosinolate (22.4 mg), 4-pentenyl glucosinolate (33.6 mg), 3-butenyl glucosinolate (24.0 mg), 4-methylsulfinylbutyl glucosinolate (161.4 mg), and 3-methylsulfinylpropyl glucosinolate (29.6 mg), were identified by ESI-MS, 1H NMR and 13C NMR. The purity of the products was >98%, and 7-methylsulfinylheptyl glucosinolate was obtained from broccoli seeds for the first time.
Authors:C. Liu, S. Li, X. Wang, Z. Wang, H. Wang, R. Li, C. Xin, B. Li, L. Jiang, and C. Jia
The migration of 99Tc in unsaturated Chinese loess was investigated in-situ with a tracer method. Quartz containing 3H (HTO) and 99Tc (99TcO4-) was introduced into the bottom of an experimental pit which was then backfilled at the field test site. Then core soil samples were taken and cut vertically into 1 cm long slices. The slice samples were analyzed by liquid scintillation techniques in the laboratory. The results indicate that the migration pattern of 99Tc was quite similar to that of 3H and the vertical diffusion coefficients of 99Tc and 3H were calculated as (4.7±0.4).10-2 cm2/d and (7.8±0.4).10-2 cm2/d, respectively.
Authors:W. N. Zhou, J. Ouyang, Z. H. Wang, X. Y. Wang, Y. R. Suo, Z. Zhang, and H. L. Wang
Elsholtzia densa Benth. var. densa (Lamiaceae) is a famous medicinal herb which has been widely used for treatment of colds, headaches, pharyngitis, fever, diarrhea, digestion disorder, rheumatic arthritis, nephritises, and nyctalopia in China. In this study, fraction of the ethyl alcohol extract of E. densa (aerial part) by different polarity solvents indicated that the ethyl acetate soluble fraction exhibited a potent 1,1-diphenyl-2-picryhydrazyl (DPPH) radical scavenging activity with the IC50 value of 148.2 μg/mL. Under the target guidance of DPPH experiment, isoquercitrin, trachelogenin, ethyl caffeate, and arctigenin were separated with purities 95.98%, 92.98%, 96.07%, and 88.83%, respectively, by a dual-mode high-speed counter-current chromatography (HSCCC) method using n-hexane–ethyl acetate–methanol–water (4.5:5:3:4, v/v/v/v) as the solvent system. In order to evaluate the scientific basis, antioxidant activity of four isolated compounds was assessed by the radical scavenging effect on DPPH radical; isoquercitrin and ethyl caffeate showed stronger antioxidant activities with IC50 values of 9.4 μg/mL and 9.2 μg/mL, respectively, while trachelogenin and arctigenin showed weak antioxidant activities with IC50 values of >500 μg/mL and 72.8 μg/mL, respectively. Results of the present study indicated that the combinative method using DPPH antioxidant assay and dual-mode HSCCC could be widely applied for rapid screening and isolating of antioxidants from complex traditional Chinese medicine extract.
Authors:F. Cui, J. Li, A. Ding, C. Zhao, X. Li, D. Feng, X. Wang, L. Wang, and H. Wang
To comprehensively understand the genetic basis of plant height (PH), quantitative trait locus (QTL) analysis for internode lengths, internode component indices and plant height component index (PHCI) were firstly conducted in the present study. Two related F8:9 recombinant inbred line (RIL) populations comprising 485 and 229 lines were used. Two hundred and nine putative additive QTL for the eight traits were identified, 35 of which showed significance in at least three trials. Of these, at least 11 pairwise QTL were common to the two populations. PH components at the QTL level had different effects on PH, confirming our previous multivariate conditional analysis (Cui et al. 2011). Eleven major QTL that showed consistency in expression across environments should be of great value in the genetic improvement of PH in wheat. The results above will enhance the understanding of the genetic basis of PH in wheat.