Preparation and optimisation of liposome‐in‐alginate beads containing oyster hydrolysate for sustained release

Oyster (Crassostrea gigas) hydrolysate shows antihypertensive effect in our previous study. Oral administration of oyster hydrolysate can loss bioactive peptides due to enzymatic degradation in vivo. To maximise its bioavailability, liposome‐in‐alginate (LA) beads were used to encapsulate the oyster hydrolysates to protect from degradation and obtain sustained release. The preparation conditions of the LA beads were optimised by response surface method using a model peptide of tyrosylalanine (YA). Their characterisation, swelling and release properties were investigated. The optimised conditions for the concentration of calcium chloride, sodium alginate and the amount of ethanol‐dissolved lecithin (EDL) were 0.5 m , 3% and 95.4 mg, respectively. The encapsulation efficiencies of YA and the oyster hydrolysate in the optimised condition were 74.9% and 84.3%, respectively. The release time of the oyster hydrolysate in the simulated gastrointestinal fluid was up to 16 h. The LA beads can be recommended to encapsulate oyster hydrolysate for bioavailability improvement.     

Wavelength conversion using rare earth doped oxides in polyolefin based nanocomposite films

Nanocomposites are a new class of polymeric materials which include organic or inorganic nano‐phase materials. These nanocomposite films can show interesting properties which have many applications for wavelength conversion and energy saving. In this paper, we present polyolefin based nanocomposite films prepared using wavelength‐converting red ‘phosphors’ such as Y₂O₃: Eu³⁺ and LiAl₅O₈:Fe³⁺ and blue ‘phosphor’ CaMgSi₂O₆: Eu²⁺. The durability of the polymer chain is unaffected by incorporation of inorganic nanoparticles as there is no direct interaction between them. The addition of surfactant in the nanocomposite film helps to improve the dispersion ability of the nanoparticles and increase the flexibility of the polymer film. Wavelength‐converting ‘nanophosphors’ incorporated in a polymer matrix help to increase the tensile strength of the film. The films show excellent wavelength conversion ability of UV light into the visible and near IR range. These nanocomposite films have great application in energy saving devices. Copyright © 2012 Society of Chemical Industry     

深基坑工程中交叉地下涵道拆除施工技术

由于涵道穿越站前广场下方,进入规划新建北广场地下广场基坑内.针对既有车站站前广场上开挖地面,拆除交叉地下涵道,通过围堰加钢板桩防止河道河水倒灌回流,应用OptumG2进行围堰可靠性模拟,确定围堰形式.钢板桩采用单元组打入法,提高打入精度和质量.使用翻转晾晒加水泥拌和的综合处理方法对涵道淤泥进行固化处理,对所处涵道进行拆除,保证深基坑桩基施工.     

Crack tip shielding and anti-shielding effects of parallel cracks for a superconductor slab under an electromagnetic force

In this letter, the shielding or anti-shielding effect is firstly applied to obtain the behavior of two parallel cracks in a two-dimensional type-II superconducting under electromagnetic force. Fracture analysis is performed by the finite element method and the magnetic behavior of superconductor is described by the critical state Bean model. The stress intensity factors at the crack tips can be obtained and discussed for decreasing field after zero-field cooling. The shielding or anti-shielding effect at the crack tips depend on the distance between two parallel cracks and the crack length. The results indicate that the shielding effects of the two parallel cracks increase when the distance between the two parallel cracks decreases. It can be also obtained that the superconductors with shorter cracks has more remarkable shielding effect than those with longer cracks.     

Investigation of the stereodefect distribution and conformational behavior of isotactic polypropylene polymerized with different Ziegler–Natta catalysts

Two isotactic polypropylene (iPP) samples (PP-A and PP-B) were obtained by utilizing two different heterogeneous Ziegler–Natta catalysts in a given polymerization system. The molecular structure and conformational behavior of the samples were studied. The results of determination of xylene soluble material (XS) and ¹³C NMR showed that the average isotacticity of the samples were nearly same. However, the results of high-resolution high-temperature ¹³C NMR (HRHT ¹³C NMR) and successive self-nucleation and annealing (SSA) fractionation revealed that the amount of high isotacticity of PP-B was lower than that of PP-A, and the amount of relative medium and low isotacticity of PP-B was higher than PP-A, indicating that the stereodefect distribution of PP-B was more uniform than PP-A. The calculation of average meso sequence length from SSA was found to be in good agreement with that calculated from the results of HRHT ¹³C NMR. Moreover, Fourier transformation infrared was utilized to study the influence of stereodefect distribution on the conformational behavior of iPP. The result suggested that the molecular conformation of the PP-B was more disordered than PP-A, the regularity of molecular structure for PP-B was lower than that of PP-A. The related action mechanism and the influences of which on crystallization behavior were discussed. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Texture development and deformation behavior of a statically recrystallized Mg-Al-Zn alloy sheet

A statically recrystallized Mg-3Al-1Zn alloy was fabricated by low temperature roll heating (140 °C) processes and subsequent annealing at 250 °C for 5 min. The fabricated sheet, with a grain size of 4.1 m, shows an improved planar anisotropy and higher elongations to failure at room temperature and 200 °C, compared with those of the sheet fabricated by conventional hot rolling processes, due to the weak basal texture along with the refined microstructure.     

Analytical performance of 3?m and 3?m +1 armchair graphene nanoribbons under uniaxial strain

The electronic band structure and carrier density of strained armchair graphene nanoribbons (AGNRs) with widths of n =3 m and n =3 m +1 were examined using tight-binding approximation. The current-voltage (I-V) model of uniaxial strained n =3 m AGNRs incorporating quantum confinement effects is also presented in this paper. The derivation originates from energy dispersion throughout the entire Brillouin zone of uniaxial strained AGNRs based on a tight-binding approximation. Our results reveal the modification of the energy bandgap, carrier density, and drain current upon strain. Unlike the two-dimensional graphene, whose bandgap remains near to zero even when a large strain is applied, the bandgap and carrier density of AGNRs are shown to be sensitive to the magnitude of uniaxial strain. Discrepancies between the classical calculation and quantum calculation were also measured. It has been found that as much as 19% of the drive current loss is due to the quantum confinement. These analytical models which agree well with the experimental and numerical results provide physical insights into the characterizations of uniaxial strained AGNRs.