Antioxidative activities of some peptides isolated from hydrolyzed potato protein extract

Three peptides (5A, 5C and 6C), purified from potato protein hydrolysate fractions, possessed antioxidative activities. Isolation and purification were carried out using gel permeation chromatography and successive reverse-phase HPLC. These three peptide fractions were sequenced and identified as Phe-Gly-Glu-Arg, Phe-Asp-Arg-Arg and Phe-Gly-Glu-Arg-Arg, respectively. The fractions 5A, 5C and 6C inhibited linoleic acid oxidation by 55.3%, 58.5% and 61.7% using β-carotene decolorization assay system, while the inhibition ratio was 32.1%, 93.0% and 93.4% in the ferric thiocyanate assay system, respectively. The peptide fractions 5A, 5C and 6C also repressed lipid oxidation by 24.2%, 14.7% and 26.4% in the erythrocyte membrane ghost assay system, respectively. Oral administration of 100 mg/kg of body weight of the chemically synthesized peptides, 5A, 5C and 6C to rats (male Wistar) 30 min prior to ethanol injection reduced ethanol-induced gastric mucosal damage by 67.9%, 57.0% and 60.3%, respectively. Conclusively, these peptides have shown real potent antioxidative activities and could further be investigated for potential use as food additives.     

Effects of CdS buffer layers on photoluminescence properties of Cu(In,Ga)Se2 solar cells

Photoluminescence (PL) have been studied on Cu(In,Ga)Se₂ (CIGS) thin films, CdS/CIGS and CIGS solar cells, to clarify the carrier recombination process. The chemical-bath deposition (CBD) of the CdS buffer layer on the CIGS thin film leads to (i) the enhancement of near-band-edge PL intensity by a factor of 2–3, (ii) change in energy of the defect-related PL and (iii) the slight change in the decay time. They are related not only to the minimization of the surface recombination but also to the modification of native defects at the Cu-poor surface of CIGS by the occupation of Cd atom at the Cu site. A donor–acceptor pair PL at low-temperature and temperature-dependent PL have been studied. They are discussed in terms of the impurity and defect levels created in the CIGS film during the CBD-CdS process.     

Ruthenium (II) complexes with π expanded ligand having phenylene–ethynylene moiety as sensitizers for dye-sensitized solar cells

Ruthenium(II) complexes by introducing phenylene–ethynylene subunit into a tpy (tpy=2,2′:6′,2″-terpyridine) ligand were newly synthesized, and their photophysical and photochemical properties were characterized. The molar extinction coefficients of these dyes were larger than that of black dye. The photovoltaic performances of the solar cells based on these synthesizing dyes were investigated under AM 1.5 irradiation (100 mW cm^?2). The conversion efficiencies of 1a and 1b were 5.7% and 2.4%, respectively.     

Near-IR sensitization of nanocrystalline TiO2 with a new ruthenium complex having a 2,6-bis(4-carboxyquinolin-2-yl)pyridine ligand

A new ruthenium(II)–polypyridine complex (1) having a 2,6-bis(4-carboxyquinolin-2-yl)pyridine ligand was synthesized as a sensitizer for dye-sensitized solar cells (DSCs). This complex exhibited remarkable light-harvesting properties in the near-IR region. DSCs sensitized with 1 showed a 35% incident photon-to-current conversion efficiency (IPCE) at 900 nm.     

Analogy Between Mechanical and Dielectric Strength Distributions for BaTiO3 Ceramics

Mechanical and dielectric strengths were measured for BaTiO₃, ceramics at room temperature. The results were evaluated in terms of Weibull statistics, and a clear analogy between the mechanical and dielectric strength distributions was found.     

Sequence distribution of cis-1,4- and trans-1,4-units in polyisoprenes

The ¹³C n.m.r. spectra of chicle polyisoprene and cis-trans isomerized 1, 4-polyisoprenes were studied. The splittings of signals were observed in the C₁, C₂, and C₄ carbon signals of the isomerized polyisoprenes. The newly appearing signals were assigned to the carbon atoms in cis-trans linkages. The fractions of the diad sequences (trans-trans, trans-cis, cis-trans, and cis-cis) were determined by using the four signals of C₁ carbon. It was found that the cis-1, 4- and trans-1, 4-units were randomly distributed in the isomerized polyisoprenes and it was confirmed that the chicle polyisoprene was a mixture of cis-1, 4- and trans-1, 4-polyisoprenes.     

Polymerization of macromers

Summary The possibility of group transfer polymerization of methyl methacrylate-terminated polystyrene macromer (MA-PSt) was explored by using 1-methoxy-1-(trimethylsiloxy)-2-methyl-1-propene and tris(dimethylamino)sulfonium difluorotrimethylsilicate as initiator and catalyst, respectively. The results obtained at the polymerization temperature of 0°C were undesirable. However, the oligomerization at -78°C gave almost quantitatively oligo(MA-PSt) of which the degree of polymerization was in good agreement with the mole ratio of macromer to initiator. The GPC curve of oligo(MA-PSt) was sharp and symmetrical. In addition, it was shown by the copolymerization with methyl methacrylate that the polymerizability of the macromer was markedly enhanced in the presence of methyl methacrylate comonomer.     

Morphology and breaking of latex particle deposits at a cylindrical collector in a microfluidic chamber

We report an analysis for the morphology and breaking behavior of deposits of spherical latex particles (1 and 3.6 μm in diameter) at a cylindrical collector in a microfluidic channel fabricated by soft-lithography. In-situ observation of particle deposition over a large range of flow rate conditions evidence the relationship between deposit morphology and mode of particle transport toward the collector. For low Pe?clet number (Pe), particle deposits are nearly uniform all over the collector surface except at the rear where particles do not attach. Upon increase of Pe, deposits gradually adopt a columnar morphology at the collector stagnation point. These results are qualitatively consistent with previously reported Monte Carlo simulations of deposits formation in stagnation point flow systems. However, these simulations fail to quantitatively predict the observed deposition at the rear of the collector for sufficiently high flow rate. Additional deposit breaking experiments together with numerical evaluations of particle flux around the collector suggest that such "anomalous" deposition at large Pe is significantly governed by concomitant detachment of deposited particles at the stagnation point and the presence of recirculation flow at the collector rear. Finally, kinetics of deposition are discussed in connection with particle size-dependence of deposit breaking features.