Exposure to polycyclic aromatic hydrocarbons, arsenic and environmental tobacco smoke, nutrient intake, and oxidative stress in Japanese preschool children

The association between oxidative stress and exposure to environmental chemicals was assessed in a group of Japanese preschool children. The concentrations of 8-hydroxy-2′-deoxyguanosine (8-OHdG), 1-hydroxypyrene (1-OHP), inorganic arsenic (iAs) and monomethylarsonic acid (MMA), and cotinine in spot urine samples, collected from 134 children (3-6 yrs) from a kindergarten in Kanagawa, Japan, were measured as biomarkers of oxidative stress or exposure to environmental chemicals. For 76 subjects of the 134, intakes of anti-oxidant nutrients (vitamins A, C, and E, manganese, copper, zinc and selenium (Se)) were estimated from a food consumption survey carried out 2-4 weeks after urine sampling and by urine analysis (Se). The median (min-max) creatinine-corrected concentrations of urinary biomarkers were 4.45 (1.98-12.3), 0.127 (0.04-2.41), 4.78 (1.18-12.7), and 0.62 (< 0.6-19.0) μg/g cre for 8-OHdG, 1-OHP, iAs + MMA, and cotinine, respectively. Multiple regression analysis was carried out using 8-OHdG concentration as a dependent variable and urinary biomarkers of exposure and Se intake, intakes of vitamins and biological attributes of the subjects as independent variables. To explain 8-OHdG concentrations, intake of vitamin A and age were significant variables with negative coefficients, while 1-OHP concentration had a positive coefficient. These results indicated that oxidative stress of children is affected by chemical exposure at environmental levels, by nutrient intake and by physiological factors in a complex manner. On the other hand, unstable statistical results due to sub-grouping of subject, based on the availability of food consumption data, were found: the present results should further be validated by future studies with suitable research design.     

Metallo-supramolecular Polymers: Versatile DNA Binding and Their Cytotoxicity

Metallo-supramolecular polymers (RuL1, RuL2, RuL3, FeL3, and FeL4) prepared by complexation of bis(terpyridine) derivatives with Ru²⁺ or Fe²⁺ ions with octahedral coordination structures showed high binding ability to several DNAs (calf thymus DNA, herring sperm DNA, [poly(dA-dT)]₂, and [poly(dG-dC)]₂), which were revealed by UV–Vis absorption titration experiments. The electrostatic interactions between the metal cations of the polymers and phosphate anions of DNA led to formation of conjugate structure. The binding constant observed reached 3.7 × 10⁷ M^?1, which is the highest among values reported for metal complexes to date. Based on a long strand structure of the polymer, groove binding is most possible binding mode. Cell viability experiments showed that RuL3 and FeL3 displayed highly statistical significance (**p<0.01) to human non small cell lung cancer cell lines (NCI-H460).     

Growth and microstructures of sputtered ferroelectric PbTiO3 thin films

Abstract

PbTiO₃ thin films, 5–200 nm in thickness, were epitaxially growth on miscut (001) SrTiO₃ substrates by planar magnetron sputtering for understanding of film growth mechanism and their ferroelectricity. The surface of the miscut substrates with miscut angle of 1.7 degree contains periodic step lines and terraces; the step height is 0.4 nm and terrace width is 14 nm. The surface structures of PbTiO₃ films comprised periodic striped patterns which was reflected in the initial surface of the substrate. It was found that under a stoichiometric film composition the film growth was governed by Frank-van der Merwe type and resultant epitaxial films showed extremely smooth surface. Deposition on a miscut substrate under a stoichiometric condition is essential to making the uniform ferroelectric thin films.     

Improving Functional Properties of Soy Protein Hydrolysate by Conjugation with Curdlan

ABSTRACT:  Soy protein hydrolysate was conjugated with curdlan through the naturally occurring Maillard reaction to extend its application in food processing. The gel-forming and emulsifying properties of soy protein hydrolysates were significantly improved ( P < 0.05) by conjugation with curdlan. The soy protein hydrolysate–curdlan conjugate (SPHCC)–soy protein isolate (SPI) mixed gel had a much thicker network than the soy protein hydrolysate and SPI mixed gel judged from scanning electron microscopic images. The improvement of gelling properties of soy protein hydrolysate by curdlan-conjugate was attributed to both the decrease in the repulsive forces among soy protein hydrolysates and the increase in the solubility. The covalent binding of soy protein hydrolysates and curdlan also showed a profound effect on the antioxidative activity of the soy protein hydrolysates. The higher antioxidative activity of SPHCC was related to the peptide reductants produced from the Maillard reaction and the higher emulsifying property of SPHCC. The conjugates of soy protein hydrolysate and curdlan can be used as a functional food additive having excellent gel-forming, emulsifying properties and antioxidative activity.     

Water retention in sandy substrates modified by cross-linked polymeric microgels and their complexes with a linear cationic polymer

New synthetic soil conditioners for anti-erosion protection of soils in the form of microgel copolymers of N-isopropylacrylamide and acrylic acid (PAA#) and their interpolyelectrolyte complexes (IPEC#) with different surface charges are tested for optimization of water retention and porous structure in two samples of soil substrates. Water retention curves (WRCs) are used as a fundamental thermodynamic indicator of water holding capacity in soil substrates treated by new polymeric materials. Soil-hydrological constants, as well as specific surface parameters and pore distribution curves are calculated from the WRCs using the van Genuhten model and the Voronin method in the author's modification. PAA# and anionic IPEC# with high swelling degree at a dose of 1% (by weight) increase field water capacity, available soil water range and specific surface area by 5–6 times for quartz sand, along with reorganizing its structure towards micropore dominance. For loamy sand, the same treatment was less effective with a twofold increase in field moisture capacity, double or triple increase of specific surface area, and an almost constant range of available soil water due to the strong increase of wilting point parameter. Weakly swelling linear polyacrylic acid and cationic IPEC# did not significantly affect properties of both mineral substrates.     

Preparation of pure and fully dense lanthanum nickelates Lan+1NinO3n+1 (n = 2, 3, ∞) by post-sintering oxidation process

Lanthanum nickelates with Ruddlesden-Popper structure (La₂NiO₄, La₃Ni₂O₇, and La₄Ni₃O₁₀) and perovskite structure (LaNiO₃) have attracted considerable attention due to their potential applications such as solid oxide fuel cells. Currently, the ionic and electronic conduction properties of La₃Ni₂O₇, La₄Ni₃O₁₀, and LaNiO₃ are not fully understood because it is quite difficult to prepare their dense bodies required for the characterization. The difficulty arises from their narrow thermodynamic stable temperature and oxygen partial pressure ranges. In this study, we successfully obtained dense bodies of single-phase La₃Ni₂O₇, La₄Ni₃O₁₀, and LaNiO₃ via a post-sintering oxidation process. First, dense pellets composed of fine-grain precursors La₂NiO₄ and NiO (~0.5 μm) were prepared by nitrate freeze-drying technique and low-temperature sintering at 1150°C-1225°C. Then they were converted into almost single-phase La₃Ni₂O₇, La₄Ni₃O₁₀, and LaNiO₃ by high-temperature oxidation. La₃Ni₂O₇ and La₄Ni₃O₁₀ were obtained under an oxygen partial pressure of 1 bar at 1275°C and 1200°C-1250°C, respectively, while LaNiO₃ was obtained under of 392 bar at 1250°C using hot isostatic pressing. The relative densities of the pellets exceeded 90%. With regard to their phase stability, decomposition was not detected at 600°C-1100°C in air for at least 100 hour despite their thermodynamic instability.     

Many Exciplex Systems Exhibit Organic Long‐Persistent Luminescence

Organic long‐persistent luminescence (OLPL) is a long‐lasting luminescence from a photogenerated intermediated state, such as a charge separated state. Here, it is shown that many exciplex systems exhibit OLPL and that emission pathways of OLPL can be controlled by the relationship among local excited states and charge‐transfer excited states of materials.     

Effect of NO 2 on Particle Formation in SO 2 /H 2 O/Air Mixtures by Ion-Induced and Homogeneous Nucleation

Effects of NO 2 on particle formation in SO 2 /H 2 O/Air mixtures by f -ray irradiation as a source of hydroxyl radicals are investigated to evaluate the contribution of homogeneous and ion-induced nucleation in the nanometer-sized aerosol particle generation. The total particle number concentration, the charged-particle fraction, and the electrical mobility distribution of particles and hydrated and solvated ions generated in NO 2 /SO 2 /H 2 O/Air mixtures were measured at NO 2 levels of 0-1.98 ppm, SO 2 levels of 0-3.87 ppm, and H 2 O levels of 6480-9889 ppm. Total particle number concen2 tration first tends to increase with increasing NO 2 concentration up to a certain NO 2 level and then decreases for NO 2 concentrations beyond this point. The charged-particle fraction, indicative of particle formation by ion-induced nucleation, tends to decrease with increasing NO 2 concentration, reaching a minimum value. The peak intensity of the electrical mobility distribution for particles significantly exceeded that in the absence of NO 2 at a relatively low concentration of NO 2 . The intensity decreased with increasing NO 2 concentration and fell below that in the absence of NO 2 . The results indicate that 2 opposing mechanisms that enhance and suppress the particle formation work simultaneously in NO 2 /SO 2 /H 2 O/Air mixtures, and the dominant mechanism depends on the NO 2 concentration.     

Non-firing ceramics: Activation of silica powder surface by a planetary ball milling

“Non-firing” ceramics have recently attracted much attention in recent years because many functional materials can be achieved by this method without the aid of sintering process. Amorphous silica powder was mechanically treated by a planetary ball mill system, by which the surface of powders was activated and simultaneously particle size reduced extensively. Surface of powders with different milling conditions was investigated by scanning electron microscopy (SEM) and nitrogen adsorption isotherm. The surface activity of raw and treated silica powders was measured based on the water adsorbed volume on the powder surface. Results showed that the powder surface was activated, and the silica powders were pulverized as an effect of ball milling. At milling times as short as 15?min, the powder was rubbed against balls, and the friction between particle/ball breaks the bonds of functional groups like SiOSi on the surface of particles. For longer milling times, powders were pulverized and more new active surfaces were formed.