Catabolic fate of dietary trilinoleoylglycerol hydroperoxides in rat gastrointestines

To elucidate whether dietary lipid peroxides are absorbed in the body, the catabolic fate of trilinoleoylglycerol hydroperoxides (TL-OOH), in the gastrointestines of rats was examined. Oxidized trilinoleoylglycerol with a peroxide value of 1000 meq/kg, 0.5 or 20 mg, was dosed intragastrically to rat together with 59.5 or 40 mg unoxidized trilinoleoylglycerol, respectively. The fate of TL-OOH in gastric and intestinal lumina was determined by high-performance liquid chromatography periodically until 240 min after treatment. At low dose, TL-OOH was soon broken down to linoleic acid hydroperoxides (LA-OOH) and hydroxyls, probably through gastric lipases, whereas at high dose, TL-OOH was retained in the stomach. In both cases, TL-OOH did not reach the intestines, though the unoxidized lipids moved to the intestines. When LA-OOH was given intragastrically, the lipids decomposed in the stomach, and linoleic acid hydroxyls, hexanal, 9-oxononanoic acid, and two novel compounds were detected 30 min after treatment. The novel compounds were identified to be epoxyketones, 11-oxo-12,13-epoxy-9- and 11-oxo-9,10-epoxy-12-octadecenoic acids. Thus, dietary TL-OOH was broken down in the stomach releasing, LA-OOH which decomposed further, and did not reach the intestines.     

Dynamic moduli for short fiber-CR composites

The dynamic moduli, E′ and E″, and tan δ for nylon–CR and PET–CR composites with unidirectional short fibers were studied as a function of temperature by using a Rheovibron. The temperature dependence of tan δ showed two dispersion peaks for nylon–CR composite. The peak at ?28°C corresponded to the main dispersion of CR and the peak at 100°C to the α-dispersion of nylon 6. For a PET-CR composite, in addition to the individual dispersion of CR and PET, a small and broad peak was observed at about 90°C. The angular dependence of E′ indicated that the short fibers assumed good orientation. The storage modulus for the composites was given by the parallel model as E′ = V_f′E_f + V_mE′_m., where E′_c, E′_f and E′_m were the storage modulus for the composite, fiber, and matrix and V_f and V_m were the volume fraction of fiber and matrix, respectively. In the transverse direction of fiber, the peak values of tan δ at ?28°C were given by the following equation; tan δ_c = tan δ_m ? δV_f, where tan δ_c and tan δ_m are the loss tangent for the composite and matrix, respectively, and α is coefficient depending on fiber type. The results indicated that a region with strong interaction was formed between fibers and CR matrix.     

DNA‐Templated Synthesis of Perylenediimide Stacks Utilizing Abasic Sites as Binding Pockets and Reactive Sites

DNA is considered to be a promising biomolecule as a template and scaffold for arranging and organizing functional molecules on the nanoscale. The construction and evaluation of DNAs containing multiple functional molecules that are useful for optoelectronic devices and sensors has been studied. In this paper we report the efficient incorporation of perylenediimide (PDI) units into DNA by using abasic sites both as binding sites and as reactive sites and the construction of PDI stacks within the DNA structure, accomplished through the preorganization of the PDI units in the hydrophobic pocket within the DNA. Our approach could become a valuable method for construction of DNA/chromophore hybrid structures potentially useful for the design of DNA‐based devices and biosensors.     

Effects of growth temperature on the fatty acid composition of the free-living nematodeCaenorhabditis elegans

The effects of growth temperature on the fatty acid compositions of the phosphatidylcholine (PC), phosphatidylethanolamine (PE), and total lipid (TL) fractions of the free-living nematodeCaenorhabditis elegans were investigated. A reduction in growth temperature from 25 to 15°C caused the proportions of eicosapentaenoic acid (20∶5n-3) to increase from 23.6 to 32.5% in the PC, from 7.4 to 10.8% in the PE, and from 12.9 to 19.9% in the TL fractions. Conversely, the levels of dihomo-γ-linolenic acid (20∶3n-6) and arachidonic acid (20∶4n-6) in these phospholipid fractions and the TL fraction both decreased with decreasing growth temperature. Analysis of the positional distribution of fatty acids in the PC fraction revealed that the change in the composition of C₂₀ polyunsaturated fatty acid was obvious in positionsn-2. Lowering the growth temperature induced an increase in the level of the diacyl subclass of PE from 58% at 25°C to 71% at 15°C, with a concomitant decrease in the levels of the alkylacyl and alkenylacyl subclass of PE ofC. elegans. These changes observed in the phospholipids ofC. elegans might be one mechanism for adaptation to low temperature. Lipids 31, 1173–1178 (1996).     

Glucosamine Extends the Lifespan of Caenorhabditis elegans via Autophagy Induction

Glucosamine (GlcN) is commonly used as a dietary supplement to promote cartilage health in humans. We previously reported that GlcN could induce autophagy in cultured mammalian cells. Autophagy is known to be involved in the prevention of various diseases and aging. Here, we showed that GlcN extended the lifespan of the nematode Caenorhabditis elegans by inducing autophagy. Autophagy induction by GlcN was demonstrated by western blotting for LGG-1 (an ortholog of mammalian LC3) and by detecting autophagosomal dots in seam cells by fluorescence microscopy. Lifespan assays revealed that GlcN-induced lifespan extension was achieved with at least 5 mM GlcN. A maximum lifespan extension of approximately 30 % was achieved with 20 mM GlcN (p<0.0001). GlcN-induced lifespan extension was not dependent on the longevity genes daf-16 and sir-2.1 but dependent on the autophagy-essential gene atg-18. Therefore, we suggest that oral administration of GlcN could help delay the aging process via autophagy induction.     

Effect of matrix's type on the dynamic properties for short fiber-elastomer composite

The dynamic moduli, E′ and E″, and tan δ for PET–CR, PET–EPDM, and PET–UR composites with unidirectional short fibers were studied as a function of temperature by using a Rheovibron. The temperature dependence of tan δ showed three peaks for PET–elastomer composites. The peaks at the low temperature corresponded to the main dispersion of the respective matrixes and the peak at about 140°C to the α-dispersion of PET fiber. A small and broad peak observed at a temperature between 60 and 120°C may be caused by the relaxation of the interface region between fibers and matrix. The longitudinal storage modulus for the composite E was given by the parallel model as \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm E'}_\parallel = V_f \cdot E'_f + V_m \cdot E'_m $\end{document}, where E and E are the storage moduli for fiber and matrix and V_f and V_m are the volume fraction of fiber and matrix, respectively. In the transverse direction of fibers, the composite modulus E was expressed by the logarithmic law of mixing as follows: \documentclass{article}\pagestyle{empty}\begin{document}$ \log E'_ \bot = V_f \cdot \log E'_f + V_m \cdot \log E'_m $\end{document}. The peak values of tan δ from the main dispersion of the respective matrixes were given by the equation, (tan δ_⊥max)_c/(tan δ_max)_m 1 ? β · V_f, where (tan δ_⊥max)_c and (tan δ_max)_m are the maximum values of the loss tangent for the composite and matrix, respectively, and β is coefficient depending on matrix's type. The β value of PET–CR composite is the largest one among those of the composites.     

Chain‐length Distribution Profiles of Amylopectin Isolated from Endosperm Starch of Waxy and Low‐amylose Bread Wheat (Triticum aestivum L.) Lines with Common Genetic Background

Large A‐type endosperm starch granules were isolated from near‐isogenic waxy and non‐waxy lines and low‐amylose mutant lines of bread wheat with a common genetic background. The amylose contents of A‐type starch ranged from 2.6% to 23.6%. Amylopectin was isolated by concanavalin A (Con A) precipitation from the isolated starch. The λ_max (range: 532‐538 nm) and blue values at 680 nm (range: 0.026‐0.037) of the iodine‐amylopectin complex were not significantly different among the isolated amylopectins, indicating that amylopectins from non‐waxy and low‐amylose lines did not contain such long chains as amylose or extra‐long chains of amylopectin affecting iodine complex properties. Chain‐length distribution profiles measured by both high‐performance size‐exclusion chromatography (HPSEC) and high‐performance anion‐exchange chromatography (HPAEC) showed that the amylopectin structures of these lines were indistinguishable from each other. Extra‐long chains were not detected in the amylopectins by HPSEC measurement. The side‐chains measured by HPAEC were classified into four groups according to their degree of polymerization (DP), and the proportion of each group were in the following ranges: DP 6‐12, 26.5‐27.5%; DP 13‐24, 43.6‐44.1%; DP 25‐36, 13.6‐14.2%, and DP 37‐60, 11.0‐11.7%. The alleles on the Wx‐D1 locus, i.e., Wx‐D1a, Wx‐D1d, Wx‐D1f, and Wx‐D1g, responsible for granule‐bound starch synthase (GBSS I) biosynthesis had no influence on the properties of iodine‐amylopectin complex and the chain‐length distribution profiles of amylopectin.     

Production of eicosapentaenoic acid by a recombinant marine cyanobacterium, Synechococcus sp.

The eicosapentaenoic acid (EPA) synthesis gene cluster from an EPA-producing bacterium, Shewanella sp. SCRC-2738, was cloned into a broad-host range vector, pJRD215, and then introduced into a marine cyanobacterium, Synechococcus sp. NKBG15041c, by conjugation. The transconjugant cyanobacteria produced 3.7±0.2% (2.24±0.13 mg/L) EPA (n-3) and 2.5 ±0.2% (1.49±0.06 mg/L) eicosatetraenoic acid (n-3) of the total fatty acids when the cells were cultured at 23°C at a light intensity of 1,000–1,500 Lux. The EPA and eico-satetraenoic acid contents of the cells were increased to 4.6±0.6% (3.86±1.11 mg/L) and 4.7±0.3% (3.86±0.82 mg/L), and 7.5±0.3% (1.76±0.10 mg/L) and 5.1±0.2% (1.19±0.06 mg/L) when they were cultured at low temperature (18°C) and at lower light intensity (40 Lux), respectively.     

Ns-kriging based microstructural optimization applied to minimizing stochastic variation of homogenized elasticity of fiber reinforced composites

This paper describes an approximate microstructural optimization using the ns-kriging (noise-resistant smoothed kriging) method for minimizing the maximum stochastic variation of homogenized elastic properties of a composite material caused by microscopic uncertainties of component materials. Since evaluation of a stochastic characteristic of a homogenized material property such as expectation or variance will involve a high computational cost and its results include inaccuracy in using the Monte Carlo simulation, an approximation-based optimization technique is useful for solving the optimization problem considering the multiscale stochastic problem. Especially, the ns-kriging will work well in case of using inaccurate data for an unknown objective function. In order to investigate applicability and effectiveness of the proposed ns-kriging based approach to the optimization problem, it is applied to the cross-sectional shape optimization of fiber in a unidirectional FRP. From the numerical results, validity and effectiveness of the proposed approach are confirmed.     

Synthesis of the Orthorhombic Phase of ZrO2

Single-phase orthorhombic ZrO₂ was prepared by quenching from high temperature and high pressure. The lattice parameters are a₀=0.5042, b₀=0.5092, and c₀=0.5257 nm; the calculated density is 6.09 Mg·m⁻³. This phase is metastable under atmospheric pressure and reverts to the monoclinic phase either on heating above 300°C or when it is ground in a mortar.