Antioxidant activity and inhibition of lipid peroxidation in germinating seeds of transgenic soybean expressing OsHGGT

Tocochromanols are potent lipid-soluble antioxidants and essential nutrients for human health. Genetic engineering techniques were used to develop soybeans with enhanced vitamin E levels, including tocotrienols, which are not found in soybean. The gene encoding rice homogentisate geranylgeranyl transferase (HGGT) was overexpressed in soybeans using seed-specific and constitutive promoters. The association between abundance of vitamin E isomers and antioxidant activity was investigated during seed germination. With the exception of β-tocotrienol, all vitamin E isomers were detected in germinating seeds expressing OsHGGT. The antioxidant properties of germinating seed extracts were determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radicals and lipid peroxidation (TBARS). Compared with intact wild-type seeds, transgenic seeds showed increases in radical scavenging of 5.4-17 and 23.2-35.3% in the DPPH and ABTS assays, respectively. Furthermore, the lipid peroxidation levels were 2.0-4.5-fold lower in germinating seeds from transgenic lines than in wild-type seeds. Therefore, it appears that the antioxidant potential of transgenic oil-producing plants such as soybean, sunflower, and corn may be enhanced by overexpressing OsHGGT during seed germination.     

Probing nanoscale ferroelectricity by ultraviolet Raman spectroscopy

We demonstrated that ultraviolet Raman spectroscopy is an effective technique to measure the transition temperature (Tc) in ferroelectric ultrathin films and superlattices. We showed that one-unit-cell-thick BaTiO3 layers in BaTiO3/SrTiO3 superlattices are not only ferroelectric (with Tc as high as 250 kelvin) but also polarize the quantum paraelectric SrTiO3 layers adjacent to them. Tc was tuned by approximately 500 kelvin by varying the thicknesses of the BaTiO3 and SrTiO3 layers, revealing the essential roles of electrical and mechanical boundary conditions for nanoscale ferroelectricity.     

Epitaxial and Smooth Films of a-Axis YBa2Cu3O7

YBa(2)Cu(3)O(7) films have been grown epitaxially on SrTiO(3) (100) and LaAlO(3) (100) substrates with nearly pure a-axis orientation and with transition temperature T(c) (R = 0) of 85 K. A unique feature of these films is their smooth surface. These smooth surfaces enable the growth of short-period superlattices with well-defined modulations. The films are untwinned and the grains grow with their c-axis along one of two perpendicular directions on the substrate ([100] or [010]). The fabrication of sandwich-type Josephson junctions with good characteristics may now be possible because unlike c-axis-oriented films, the superconducting coherence length of these smooth films is appreciably large perpendicular to their surfaces.     

Rapid pneumococcal evolution in response to clinical interventions

Epidemiological studies of the naturally transformable bacterial pathogen Streptococcus pneumoniae have previously been confounded by high rates of recombination. Sequencing 240 isolates of the PMEN1 (Spain(23F)-1) multidrug-resistant lineage enabled base substitutions to be distinguished from polymorphisms arising through horizontal sequence transfer. More than 700 recombinations were detected, with genes encoding major antigens frequently affected. Among these were 10 capsule-switching events, one of which accompanied a population shift as vaccine-escape serotype 19A isolates emerged in the USA after the introduction of the conjugate polysaccharide vaccine. The evolution of resistance to fluoroquinolones, rifampicin, and macrolides was observed to occur on multiple occasions. This study details how genomic plasticity within lineages of recombinogenic bacteria can permit adaptation to clinical interventions over remarkably short time scales.     

Echinochrome A Protects Mitochondrial Function in Cardiomyocytes against Cardiotoxic Drugs

Echinochrome A (Ech A) is a naphthoquinoid pigment from sea urchins that possesses antioxidant, antimicrobial, anti-inflammatory and chelating abilities. Although Ech A is the active substance in the ophthalmic and cardiac drug Histochrome^®, its underlying cardioprotective mechanisms are not well understood. In this study, we investigated the protective role of Ech A against toxic agents that induce death of rat cardiac myoblast H9c2 cells and isolated rat cardiomyocytes. We found that the cardiotoxic agents tert-Butyl hydroperoxide (tBHP, organic reactive oxygen species (ROS) inducer), sodium nitroprusside (SNP; anti-hypertension drug), and doxorubicin (anti-cancer drug) caused mitochondrial dysfunction such as increased ROS level and decreased mitochondrial membrane potential. Co-treatment with Ech A, however, prevented this decrease in membrane potential and increase in ROS level. Co-treatment of Ech A also reduced the effects of these cardiotoxic agents on mitochondrial oxidative phosphorylation and adenosine triphosphate level. These findings indicate the therapeutic potential of Ech A for reducing cardiotoxic agent-induced damage.     

Thermal conductivity and thermal expansion behavior of pseudo-unidirectional and 2-directional quasi-carbon fiber/phenolic composites

In the present paper, a variety of fiber reinforcements, for instance, stabilized OXI-PAN fibers, quasi-carbon fibers, commercial carbon fibers, and their woven fabric forms, have been utilized to fabricate pseudo-unidirectional (pseudo-UD) and 2-directional (2D) phenolic matrix composites using a compression molding method. Prior to fabricating quasi-carbon fiber/phenolic (QC/P) composites, stabilized OXI-PAN fibers and fabrics were heat-treated under low temperature carbonization processes to prepare quasi-carbon fibers and fabrics. The thermal conductivity and thermal expansion/contraction behavior of QC/P composites have been investigated and compared with those of carbon fiber/phenolic (C/P) and stabilized fiber/phenolic composites. Also, the chemical compositions of the fibers used have been characterized. The results suggest that use of proper quasi-carbonization process may control effectively not only the chemical compositions of resulting quasi-carbon fibers but also the thermal conductivity and thermal expansion behavior of quasi-carbon fibers/phenolic composites in the intermediate range between stabilized PAN fiber- and carbon fiber-reinforced phenolic composites.     

Effects of chrysophanol, parietin, and nepodin of Rumex crispus on barley and cucumber powdery mildews

Three substances that show antifungal activity against Blumeria graminis f. sp. hordei were isolated from roots of Rumex crispus and identified as chrysophanol, parietin, and nepodin. The substances were tested for plant disease control activity in vivo against six plant pathogenic fungi. All specifically reduced the development of barley powdery mildew. The concentrations required for 50% disease control were 4.7 μg/ml for chrysophanol, 0.48 μg/ml for parietin, and 20 μg/ml for nepodin. These agents showed both curative and protective activity against barley powdery mildew. Chrysophanol (100 μg/ml) and nepodin (400 μg/ml) were more effective than the fungicides fenarimol (30 μg/ml) and polyoxin B (100 μg/ml), under glasshouse conditions, against cucumber powdery mildew, which is caused by Podosphaera xanthii. Parietin (30 and 10 μg/ml) reduced the development of cucumber powdery mildew as efficiently as fenarimol (30 μg/ml) and more effectively than polyoxin B (100 μg/ml).     

Preparation of poly(vinyl alcohol)/silver-zeolite composite hydrogels by UV-irradiation

Poly(vinyl alcohol) (PVA)/Ag-zeolite nanocomposite hydrogels were prepared by UV irradiation using PVA solution mixed with Ag-zeolite nanoparticles. Physical properties and changes in morphology of the PVA/Ag-zeolite hydrogels were investigated. The PVA/Ag-zeolite hydrogels were prepared at a PVA concentration of 9 wt% with a UV irradiation distance of 15 cm, where gel fraction and swelling ratio were optimized. Hardness of the PVA/Ag-zeolite hydrogels decreased with increasing amounts of Ag-zeolite, reaching that of soft elastomer when the amount of Ag-zeolite was 5 % by weight. The PVA/Ag-zeolite hydrogels showed strong antimicrobial activities against Staphylococcus aureus and Klebsiella pneumoniae, inducing a reduction of bacteria of over 99.9 % at a Ag-zeolite content of 3 wt%.     

Mechanical properties of wool fiber in the stretch breaking process

Short wool fibers obtained by the stretch breaking process can be blended with cotton fibers and processed in a cotton spinning system, which has a high production rate. For the structural property of the wool fiber after stretch breaking, the diameter and length of the wool fiber were measured as a function of time. The diameter of the broken fibers was finer than the diameter of untreated fibers. The fiber diameter at the break point was the finest and was more irregular than the original fiber. The broken fiber showed mechanical properties of increased modulus, decreased breaking strain, and increased breaking strength.     

The effects of blend composition and blending time on the ester interchange reaction and tensile properties of PLA/LPCL/HPCL blends

PLA/LPCL/HPCL blends composed of poly(lactic acid) (PLA), low molecular weight poly(ε-caprolactone) (LPCL), and high molecular weight poly(ε-caprolactone) (HPCL) were prepared by melt blending for bioabsorbable filament sutures. The effects of blend composition and blending time on the ester interchange reaction by alcoholysis in the PLA/LPCL/HPCL blends were studied. Their thermal properties and the miscibility due to the ester interchange reaction were investigated by¹H-NMR, DSC, X-ray, and UTM analyses. The hydroxyl group contents of LPCL in the blends decreased by the ester interchange reaction due to alcoholysis. Thus, the copolymer was formed by the ester interchange reaction at 220 °C for 30–60 minutes. The thermal properties of PLA/LPCL/HPCL blends such as melting temperature and heat of fusion decreased with increasing ester interchange reaction levels. However, the miscibility among the three polymers was improved greatly by ester interchange reaction. Tensile strength and modulus of PLA/LPCL/HPCL blend fibers increased with increasing HPCL content, while the elongation at break of the blend fibers increased with increasing LPCL content.