Search Results

You are looking at 21 - 24 of 24 items for

  • Author or Editor: G. J. Yang x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract  

Positron annihilation lifetime (PAL) experiments are performed in polycarbonate (PC) exposed to CO2 and He gases as a function of time and pressure. In PC/CO2 systems, hole size and fraction reduced from PAL data increase as a function of CO2 pressure and exposure time. Significant hysteresis in positron lifetime data is observed during CO2 abasorption/desorption. In PC/He systems, no variation is observed. Hole size distribution in the CO2-exposed polymers is found to be significantly broader than in unexposed samples. The high sensitivity of PAL results to CO2 exposure of PC is thought to relate to the microstructural changes in the polymer matrix, such as penetrant plasticization, gas hydrostatic pressure effect, and molecular filling and creation of holes.

Restricted access
Acta Alimentaria
Authors:
C.Y. Zhou
,
Q.W. Cheng
,
T. Chen
,
L.L. Meng
,
T.G. Sun
,
B. Hu
,
J. Yang
, and
D.Y. Zhang

Abstract

To study the feasibility of evaluating the quality characteristics of banana based on the browning area. The texture characteristics, total soluble solids (TSS), ascorbic acid, malondialdehyde (MDA) concentrations, relative conductivity, polyphenol oxidase, peroxidase, and phenylalanine ammonia-lyase (PAL) activities in banana peels were detected during storage. A linear model was made by principal component analysis and multiple linear regression between the banana browning area and characteristic indices. The results showed that the changes in the physiological characteristics of bananas were significantly different during different storage periods. The main factors that affected the banana browning area were relative conductivity, PAL, TSS, and MDA, indicating that lipid peroxidation, respiration, and metabolism of phenylpropanoids had significant influence on the banana browning area during storage. Thus, it is feasible to predict banana quality based on changes in browning area, which could be a rapid and non-destructive detection of banana quality during storage.

Restricted access

Abstract

This study aimed to explore the inhibitory effect and mechanism of the total alkaloids of Dendrobium officinale Kimura et Migo (DENA) against cholesterol esterase (CE). DENA was characterised by SEM, 1H NMR, and X-ray diffraction (XRD). The inhibitory effect and mechanism of DENA against CE were investigated through fluorescence chromatography, circular dichroism, and molecular docking. DENA inhibited CE activity (IC50 = 1.08 ± 0.09 mg mL−1), characterised by a non-competitive inhibition mechanism. Furthermore, DENA induced a fluorescence quenching in CE, causing a blue shift in the λmax. This coincided with a transition in the secondary structure of CE from a layered to a helical structure by circular dichroism, indicating a significant reduction in its stability. Moreover, molecular docking confirmed that DENA binds to amino acid residues in the enzyme through hydrogen bonds and hydrophobic interactions, leading to structural changes and reduced enzyme activity. These results suggest DENA has the potential to lower blood lipid levels by inhibiting CE activity.

Restricted access

Aegilops sharonensis (Sharon goatgrass) is a valuable source of novel high molecular weight glutenin subunits, resistance to wheat rust, powdery mildew, and insect pests. In this study, we successfully hybridized Ae. sharonensis as the pollen parent to common wheat and obtained backcross derivatives. F1 intergeneric hybrids were verified using morphological observation and cytological and molecular analyses. The phenotypes of the hybrid plants were intermediate between Ae. sharonensis and common wheat. Observations of mitosis in root tip cells and meiosis in pollen mother cells revealed that the F1 hybrids possessed 28 chromosomes. Chromosome pairing at metaphase I of the pollen mother cells in the F1 hybrid plants was low, and the meiotic configuration was 25.94 I + 1.03 II (rod). Two pairs of primers were screened out from 150 simple sequence repeat markers, and primer WMC634 was used to identified the presence of the genome of Ae. sharonensis. Sequencing results showed that the F1 hybrids contained the Ssh genome of Ae. sharonensis. The sodium dodecyl sulfate polyacrylamide gel electrophoresis profile showed that the alien high molecular weight glutenin subunits of Ae. sharonensis were transferred into the F1 and backcross derivatives. The new wheat-Ae. sharonensis derivatives that we have produced will be valuable for increasing resistance to various diseases of wheat and for improving the quality of bread wheat.

Restricted access