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- Author or Editor: B. Yu x
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Abstract
Conversion of economic microcrystalline cellulose (MCC) into high value-added prebiotic glucans, is not only stimulates utilisation of renewable lignocellulosic biomass, but also provides cheap prebiotics to reduce high incidence of obesity and metabolic syndrome. Herein, glucans (C0.25–C0.50–C1.00) from MCC were prepared by pre-impregnation with dilute sulphuric acid (0.25–0.50–1.00%) and ball-milling treatment for 1 h. NMR spectroscopy and gel-permeation chromatography of the glucan products showed a significant reduction in the degree of polymerisation (DP) and molecular weights (Mw). All prepared glucans improved gut stress evaluated by in vitro digestion and fermentation (young and aging mouse faecal inocula). C1.00 with lower DP and Mw showed better water solubility, earlier peak, and exhibited increased 1-diphenyl-2-picrylhydrazyl activity, higher ratios of Lactobacillus to Escherichia coli, and a higher level of short chain fatty acids better than C0.25 and C0.50 treatment (P < 0.05). Better prebiotic effects were observed in aging mice than in young mice. The highest ratio of Lactobacillus to E. coli was a 2.13-fold increase for aging mice compared to a 1.79-fold increase for young mice, relative to the initial value after C1.00 treatment. The study provides a novel pathway and a new resource for producing glucan.
Abstract
The characterization of different sized TiO2 (25 nm, 80 nm, and 155 nm) was carried out by transmission electron microscopy (TEM) and the micro-distributions of TiO2 in the olfactory bulb of mice after nasal inhalation were investigated by microbeam SRXRF mapping techniques. The results show that TiO2 particles can be translocated to the olfactory bulb through the olfactory nerve system after inhalation. The distributions of Fe, Cu, and Zn in the olfactory bulb were also studied.
Abstract
Recoil ions from alpha-particle emission can contaminate surface-barrier detection systems. This contamination results in increased measurement uncertainty, and may require the replacement of expensive detectors. Disposable thin Collodion films are easily prepared and effectively retard the recoil ions when either directly applied to the surface of alpha-sources or as catcher foils between the source and the detector. The thin films are particularly effective for relatively low-level sources, but can sustain structural damage when exposed to high levels of recoil ions (tens of thousands per second) over extended periods of time.
Abstract
The title goal was achieved using a DOWEX 50Wx8 cation exchange column saturated with La(OH)3 and ammonia solution as eluent. Hf, Ta and Lu were adsorbed on this column, whereas W remained in the solution. This chemical system may be used for fast on-line separations of element 106.
Abstract
An extended U/Pb-assembly was irradiated with an extracted beam of 2.52 GeV deuterons from the Nuclotron accelerator of the Laboratory of High Energies within the JINR in Dubna, Russia. The lay-out of this experiment and first results are reported. The Pb-target (diameter 8.4 cm, length 45.6 cm) is surrounded by a natU-blanket (206.4 kg) and used for transmutation studies of hermetically sealed radioactive samples of 129I, 237Np, 238Pu and 239Pu. Estimates of transmutation rates were obtained as result of measurements of gamma-activities of the samples. Information about the spatial and energy distribution of neutrons in the volume of the lead target and the uranium blanket was obtained with sets of activation threshold detectors (Al, Y and Au) and solid state nuclear track detectors (SSNTD). An electronic 3He neutron detector was tested on-line. A comparison of experimental data with theoretical model calculations using the MCNPX program was performed yielding satisfactory results.
