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- Author or Editor: Y. Chen x
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Abstract
A method of efficiency calibration for the measurement of 88Kr and 138Xe by HPGe γ-spectrometer is proposed in the present paper. The question for the efficient calibration is, how to achieve homogeneous sources of 88Kr-88Rb and 138Xe-138Cs. The fission product gases were obtained by irradiating a precisely measured amount of U3O8 (90% 235U) filled in a quartz glass ampoule. Source cell was first filled up with stearic acid, and then the fission product gases were charged into it. Xenon and krypton are not adsorbed on stearic acid, therefore, homogeneous sources of 88Kr-88Rb and 138Xe-138Cs can be prepared. The results of the experiment demonstrate that the method is feasible and successful.
A field experiment was carried out to study the effect of K nutrition and genotypic variation on the dry matter (DM) accumulation, and the K concentration, accumulation, uptake and utilization efficiency in barley (Hordeum vulgare L.). Successive increases in potassium nutrition had a significant effect on the dry matter and K accumulation either in the total or in various plant parts of barley at the tillering, stem elongation, heading and maturity growth stages. K nutrition also led to significantly higher grain yield with each unit K application than without K application. The yield increase due to K application was mainly due to the improvement in spike development from tillers. Dry matter and K accumulation in various plant parts varied significantly between genotypes at the main growth stages. Among the various plant parts, the stem contained the highest K concentration, had the highest K accumulation at maturity and changed considerably with the K level, while other plant parts remained relatively unchanged. Among the eleven genotypes, genotype 98-6 had the highest grain yield and the K use efficiency of this genotype was 10.4 kg grain per kg K applied. It could thus be used as a breeding line to breed barley varieties for higher productivity under rainfed conditions with low available soil potassium.
This study aimed to investigate the effects of single local vibration (LV) with and without blood flow restriction (BFR) on muscle activity and hormonal responses. A total of 12 physically inactive males were exposed to 10 sets of intermittent LV (35–40 Hz) on unilateral mid-quadriceps in the supine lying position and LV + BFR (inflated to 140 mmHg) sessions in a repeated-measures randomized crossover design, with a 1-week interval separating the sessions. The results indicated that the electromyography values from the rectus femoris during LV + BFR were greater than those during LV (p < 0.05). LV + BFR caused a minor increase in the lactate (LA) response (p < 0.05); LV with or without BFR failed to elicit change in growth hormone (GH) and testosterone (T) levels (p > 0.05). Cortisol (C) levels were decreased postexercise in both the sessions (p < 0.05). In conclusion, BFR elicited higher increase in muscle activity and metabolic response, but it did not induce hormonal responses. The exposure of LV and LV + BFR may only have a relief effect as detected by the reduction in C levels, probably because the LV did not elicit sufficient stimulus to the muscles.
Lipopolysaccharide and b-1,3-glucan binding protein (LGBP) is a pattern recognition receptor that can recognize and bind LPS and b-1,3-glucan. LGBP has crucial roles in innate immune defense against Gram-negative bacteria and fungi. In this study, LGBP functions in Portunus trituberculatus innate immunity were analyzed. First, the mRNA expression of PtLGBP in hemocytes, hepatopancreas, and muscle toward three typical pathogen-associated molecular patterns (PAMPs) stimulations were examined using real-time PCR. Results show that the overall trend of relative expressions of the LGBP gene in three tissues is consistent, showing up-down trend. In each group, the highest expression of the LGBP gene was at 3 and 12 h post-injection. The LGBP gene is also expressed significantly higher in the hemocytes and hepatopancreas than in the muscle. The highest level of LGBP was in the lipopolysaccharides (LPS) and glucan-injected group, whereas the lowest level was in the PGN-injected group. Furthermore, bacterial agglutination assay with polyclonal antibody specifically for PtLGBP proved that the recombinant PtLGBP (designated as rPtLGBP) could exhibit obvious agglutination activity toward Gram-negative bacteria Escherichia coli, Vibrio parahaemolyticus, and V. alginolyticus; Gram-positive bacteria Bacillus subtilis; and fungi Saccharomyces cerevisiae. LGBP in Portunus trituberculatus possibly served as a multi-functional PRR. In addition, LGBP is not only involved in the immune response against Gram-negative and fungi, as manifested in other invertebrates, but also has a significant role in anti-Gram-positive bacteria infection.
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 .
The dwarf-male-sterile wheat is unique to China and has been improved by introducing good germplasm. In order to clear the subunits background of Dwarf-Male-Sterile wheat, sodium dodecyl sulphate polyacrylamide-gel electrophoresis (SDS-PAGE) was used to detect the high and low molecular weight glutenin subunits (HMW-GS and LMW-GS) compositions in BC1F1, F2 and F3 generations from Dwarf-Male-Sterile wheat. Twenty-five alleles and 49 HMW-GS compositions at the Glu-1 loci were detected in different generations. Null and subunit 1 were mainly existed at Glu-A1 , and 7 + 8 and 7 + 9 were primarily detected at Glu-B1 in different generations. Subunit combination 5 + 10 mainly appeared in BC1F1, while 2 + 12 major presented in F2 and F3 generations. HMW-GS compositions null, 7 + 8, 5 + 10 and null, 7 + 9, 5 + 10 showed higher frequencies than other banding patterns, followed by null, 14 + 15, 5 + 10 and null, 7 + 9, 2 + 12 combinations. In addition, some rare subunit combinations such as 14 + 15, 13 + 16, 17 + 18, 4 + 12, 2 + 10 and 5 + 12 were found in different generations. Eighteen alleles and 51 LMW-GS compositions at Glu-3 loci were found in different generations. Glu-A3 a and Glu-B3 d showed higher frequencies than others among three generations. There were mainly a, b, c alleles at Glu-D3 . Thirty, 31 and 14 different combinations were detected in BC1F1, F2 and F3 populations, respectively. There were some good combinations such as A3 d/ B3 h, A3 d/ B3 d/ D3 a, A3 b/ B3 b/ D3 a, A3 a/ B3 d/ D3 a for different quality characteristics. So some desirable subunit combinations could be selected from different generations and new cultivars with good quality under distinct subunits background should be bred from Dwarf-Male-Sterile wheat in future.
Abstract
High-performance liquid chromatography with a hydrophilic-interaction liquid chromatographic (HILIC) column has been successfully used to retain and separate the polar phosphonic herbicides glyphosate and glufosinate. Online electrospray tandem ion-trap mass spectrometric and DAD detection were used. The effects on the separation of mobile phase acetonitrile content, buffer concentration, and flow rate, and of column temperature, were investigated. With UV-visible detection at 195 nm, LOQ were <850 mg kg−1, showing the method is suitable for product quality control of these herbicides alone or in combination. Tandem mass spectrometric conditions were optimized for ion-trap detection. Quantification was by use of selected reaction monitoring transitions m/z 168 → 150 in negative-ion mode for glyphosate and m/z 182 → 136 in positive-ion mode for glufosinate. Limits of detection (LOD; S/N > 3) were 0.20 and 0.16 ng for glyphosate and glufosinate, respectively, and the respective limits of quantification (LOQ; S/N = 10) were 0.02 and 0.05 mg kg−1. Sample derivatization was not necessary to achieve low detection limits in residue analysis in this study. Recovery from watermelon, spinach, potato, tomato, radish-root, and water fortified with the herbicides ranged from 63.6 to 107.3% and relative standard deviations were <15.3%.
Abstract
New complexes of the non-natural amino acid (p-iodo-phenylalanine) with divalent cobalt and nickel ions have been synthesized. The composition of the complexes is [M(IC6H4CH2CHNH2COO)2]2.5H2O (M=Co, Ni) and the crystal structure belongs to orthorhombic system. Infrared spectra indicate the nature of bonding in the complex. The first stage in the thermal decomposition process of the complex shows the presence of crystal water. The thermal decomposition process of cobalt complex differs from that of nickel. The intermediate and final residues in the thermal decomposition process have been analyzed to check the pyrolysis reactions. Thermal analysis indicates that the iodine atom of the ligand may coordinate to the metal ion in the lattice.
Abstract
This study was performed under the joint TRMC/INER program for the determination of low level85Kr and133Xe concentrations in the environmental air samples. Based on cryogenic adsorption of krypton and xenon on charcoal followed by chromatographic separation from other gases, the85Kr and133Xe recovered from 200 liters of atmospheric air can be determined by either on-line gas flow proportional counter or liquid scintillation counting. The recovery yields of krypton and xenon examined by using85Kr and133Xe tracers were nearly 100%. The minimum detectable activity of85Kr and133Xe by gas flow proportional counting is about 7.40 Bq. The method is satisfactory for environmental monitoring applications under abnormal conditions of nuclear facilities. However, for lower level environmental85Kr and133Xe measurements, the liquid scintillation counting method can be applied due to their extremely low detection limits (i.e. 0.107 Bq and 0.093 Bq for85Kr and133Xe, respectively). Using this method, the measurable limits of concentrations are 0.535 Bq/m3 and 0.466 Bq/m3 for85Kr and133Xe, respectively.
Abstract
The 
—T and d/dT—T curves of the FeCuNbSiB amorphous alloy, which are the relationship between the total saturated magnetic moment per unit mass and temperature, are investigated by magnetic thermogravimetry analysis (TG(M)) technique. It is found that the crystallization process of the samples can be divided into five stages. The studies of samples annealed in temperature range of 480–610°C for 1h show that when the annealing temperature (T
a) is less than 540°C, the quantity of nanocrystalline 
-Fe(Si) phase increases evidently with T
a, and the Curie temperature (T
C) of residual amorphous phase also increases linearly with T
a, i.e. T
C=0.52T
a+91.7°C, with correlation coefficient 
=0.98. The variation of volume fraction of -Fe(Si) nanocrystalline phase or residual amorphous phase with T
a is measured by TG(M) technique.
