Multi-walled carbon nanotube-reinforced copper nanocomposite coating fabricated by low-pressure cold spray process

Multi-walled carbon nanotube (MWCNT)-reinforced copper (Cu) nanocomposite coatings were successfully deposited on aluminum (Al) substrate by a cold spraying process at a low pressure. The microstructure and the Raman spectrum of the low-pressure-cold-sprayed MWCNT–Cu nanocomposite coating showed that the MWCNTs maintained their tube structure in the Cu matrix, even though structural damage to the MWCNTs increased slightly. MWCNT–Cu nanocomposite-coated Al exhibits higher thermal diffusivity than pure-Cu-coated Al with a comparable hardness. The higher thermal diffusivity of the MWCNT–Cu coating could be explained by the dispersion of MWCNTs within the clean and closed CNT/Cu interfaces, which were achieved with the aid of compressive stress during the cold spraying.     

New type of phenolic resin: Curing reaction of phenol‐novolac based benzoxazine with bisoxazoline or epoxy resin using latent curing agent and the properties of the cured resin

In this study, we aimed to reduce the cure time, and to lower the cure temperature of the benzoxazine compound. Therefore, curing reaction of benzoxazine with bisoxazoline or epoxy resin using the latent curing agent and the properties of the cured resins were investigated. The cure behavior of benzoxazine with bisoxazoline or epoxy resin using the latent curing agent was monitored by differential scanning calorimetry and measurements for storage modulus (G′). The properties of the cured resin were estimated by mechanical properties, electrical insulation, water resistance, heat resistance, and flame resistance. As a result, it was confirmed that by using the latent curing agent, cure time of benzoxazine and bisoxazoline or epoxy resin was reduced, and cure temperature was lowered. And it was found that the curing reaction using phenol‐novolac based benzoxazine (Na) as the benzoxazine compound could proceed more rapidly than that using bisphenol‐A based benzoxazine (Ba) as the benzoxazine compound. However, the cured resins from Ba and bisoxazoline or epoxy resin using the latent curing agent showed good heat resistance, flame resistance, and mechanical properties compared with those from Na and bisoxazoline or epoxy resin using the latent curing agent. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Potato and soy peptides alter caecal fermentation and reduce serum non‐HDL cholesterol in rats fed cholesterol

We examined the effect of potato peptides (PPC) in rats fed a cholesterol‐enriched diet, in comparison with two cholesterol‐enriched diets containing soy peptides (SPC) or casein (CNC), and a cholesterol‐free diet containing casein (CN) for 4 weeks. The serum non‐high‐density lipoprotein (HDL) cholesterol level was lower in the PPC‐ (–18.39%) and SPC‐fed (–32.76%) groups (p <0.05) than in the CNC‐fed group at the end of the feeding period. The low‐density lipoprotein receptor mRNA level in the PPC‐fed group, and cholesterol 7α‐hydroxylase and scavenger receptor class B type 1 mRNA levels in the SPC‐fed group, were higher (p <0.05) than in the CN‐ and CNC‐fed groups. Faecal neutral sterol and caecal short‐chain fatty acid concentrations in the PPC‐ and SPC‐fed groups were higher (p <0.05) than in the CN‐ and CNC‐fed groups. The faecal total acidic sterol concentration was higher in the SPC‐fed group than in the CN‐ and PPC‐fed groups. Caecal anaerobe and Bifidobacterium populations were higher (p <0.05) in the PPC‐ and SPC‐fed groups than in the CN‐fed group. This study suggests that potato peptides, as soy peptides, alter caecal fermentation and steroid absorption and reduce the serum non‐HDL cholesterol level in rats fed cholesterol.     

Stabilization of flavylium dye by incorporation into the pore of protonated zeolites

Flavylium dye, a model compound of natural anthocyanin, has a defect that its color stability is very poor. We have complexed the flavylium dye with protonated zeolites and succeeded to enhance both the thermal and chemical stability of the dye. The aqueous dispersion of the flavylium/zeolite complex maintains its color even at 353 K or at pH 9, under which conditions the aqueous solution of the flavylium loses its color immediately. The stability is enhanced when the dye is incorporated into the pore of the zeolites, and a large stabilization effect is obtained by a tight adsorption with a narrow pore, as long as the dye is incorporated into the pore. Because of its enhanced color stability, the flavylium dye incorporated in the zeolite pore can be a candidate for an environmentally friendly coloring material.     

Effects of Age and Mating on Female Sex Attractant Pheromone Levels in the Sorghum Plant Bug, <Emphasis Type=Italic>Stenotus rubrovittatus</Emphasis> (Matsumura)

Previous work has shown that male sorghum plant bugs, Stenotus rubrovittatus (Matsumura) (Heteroptera: Miridae), are more attracted to young virgin females than to old virgin females and are not attracted to mated females. Therefore, we examined the effects of age and mating status on female sex pheromone levels. The pheromone components, hexyl butyrate, (E)-hex-2-en-1-yl butyrate, and (E)-4-oxohex-2-enal, were collected from females in two different ways. First, the compounds were extracted from whole bodies of each female and quantified by gas chromatography-mass spectrometry (GC-MS). Pheromone levels extracted from virgin female bodies decreased with age. In females that had just mated, pheromone levels did not differ from those of virgin females, and pheromone levels in mated females remained relatively constant up to 15 d after mating. This absence of change in pheromone levels extracted from whole bodies of mated females is not congruent with previous reports of lack of male attraction to these females. In a second method for pheromone recovery (adsorption on a PDMS-coated stir bar), GC-MS analysis showed that mated females released lower amounts of pheromone components compared to those emitted by virgin females of the same age (4 d). As was the case with whole body extracts, young virgin females (3 d) released higher amounts of pheromone components than did old virgin females (8 d). The results suggest that male response in S. rubrovittatus is dictated more by the quantities of pheromone components released into the volatile headspace by females than by the quantities present in the body.     

Contribution of Invariant Natural Killer T Cells to the Clearance of Pseudomonas aeruginosa from Skin Wounds

Chronic infections are considered one of the most severe problems in skin wounds, and bacteria are present in over 90% of chronic wounds. Pseudomonas aeruginosa is frequently isolated from chronic wounds and is thought to be a cause of delayed wound healing. Invariant natural killer T (iNKT) cells, unique lymphocytes with a potent regulatory ability in various inflammatory responses, accelerate the wound healing process. In the present study, we investigated the contribution of iNKT cells in the host defense against P. aeruginosa inoculation at the wound sites. We analyzed the re-epithelialization, bacterial load, accumulation of leukocytes, and production of cytokines and antimicrobial peptides. In iNKT cell–deficient (Jα18KO) mice, re-epithelialization was significantly decreased, and the number of live colonies was significantly increased, when compared with those in wild-type (WT) mice on day 7. IL-17A, and IL-22 production was significantly lower in Jα18KO mice than in WT mice on day 5. Furthermore, the administration of α-galactosylceramide (α-GalCer), a specific activator of iNKT cells, led to enhanced host protection, as shown by reduced bacterial load, and to increased production of IL-22, IL-23, and S100A9 compared that of with WT mice. These results suggest that iNKT cells promote P. aeruginosa clearance during skin wound healing.     

The Effects of Insulin on Immortalized Rat Schwann Cells,IFRS1

Schwann cells play an important role in peripheral nerve function, and their dysfunction has been implicated in the pathogenesis of diabetic neuropathy and other demyelinating diseases. The physiological functions of insulin in Schwann cells remain unclear and therefore define the aim of this study. By using immortalized adult Fischer rat Schwann cells (IFRS1), we investigated the mechanism of the stimulating effects of insulin on the cell proliferation and expression of myelin proteins (myelin protein zero (MPZ) and myelin basic protein (MBP). The application of insulin to IFRS1 cells increased the proliferative activity and induced phosphorylation of Akt and ERK, but not P38-MAPK. The proliferative potential of insulin-stimulated IFRS1 was significantly suppressed by the addition of LY294002, a PI3 kinase inhibitor. The insulin-stimulated increase in MPZ expression was significantly suppressed by the addition of PD98059, a MEK inhibitor. Furthermore, insulin-increased MBP expression was significantly suppressed by the addition of LY294002. These findings suggest that both PI3-K/Akt and ERK/MEK pathways are involved in insulin-induced cell growth and upregulation of MPZ and MBP in IFRS1 Schwann cells.     

Significance of the detection of staphylococcal enterotoxin A gene in low fat milk which caused a serious outbreak of food poisoning

In June 2000, there was a large-scale outbreak of food poisoning after consumption of Snow Brand low fat milk. In the evening of a day the incident made public, some cartons of low fat milk were brought to our laboratory for examination. Next day, we detected only staphylococcal enterotoxin (SE) A gene among SE (A-E) genes by PCR in left-over milk samples or samples from the same lots that patients had consumed. We presumed that the outbreak was caused by the intake of SEA. We subsequently confirmed the presence of SEA in these samples. To investigate the existence of SE (A-E) genes in milk, we examined 100 samples of commercial low fat milk and milk by PCR, but none of the genes was detected. We estimated the detection limit of SEA gene in low fat milk by PCR. Four strains of SEA-producing Staphylococcus aureus cultures were serially diluted in low fat milk. The SEA gene was detected at levels of 5.5 x 10(2) to 1.6 x 10(4) cfu/mL of S. aureus. These amounts of S. aureus are higher than the values in raw milk reported previously. Therefore we consider that SE genes in low fat milk should usually be undetectable by our PCR. This study shows that quick detection of SE genes by PCR is very helpful to analyze outbreaks, especially if no significant bacterium can be cultured.     

Simple determination of residual anticoccidial drugs (diclazuril and nicarbazin) in chicken tissues by HPLC

A simple and rapid determination of anticoccidial drug residues, diclazuril (DCZ) and nicarbazin (NCZ), in chicken tissues has been developed. DCZ and NCZ were extracted with acetonitrile from chicken liver, muscle, and fat. The extract was rinsed with n-hexane saturated with acetonitrile and then evaporated. The residue was dissolved in 1.4 mL of acetonitrile-methanol (1:1), then 1.0 mL of n-hexane saturated with acetonitrile-methanol (1:1) was added, and the mixture was partitioned by the addition of 0.6 mL of water. DCZ and NCZ in the aqueous layers were determined by HPLC on an Xterra RP-18 column with acetonitrile-0.5% ammonium acetate containing 0.01 mol/L tetra-n-butylammonium hydrogen sulfate (43:57) as the mobile phase. The mean recoveries (n = 5) of DCZ and NCZ spiked in chicken tissues at the maximum residue levels were 92.0-95.6% (CV 2.4-3.0%) and 87.3-89.4% (CV 1.7-2.8%), respectively. The detection limits of DCZ and NCZ were 0.01 and 0.004 microgram/g, respectively.     

Acute illness induces the release of aversive odor cues from adult, but not prepubertal, male rats and suppresses social investigation by conspecifics.

The present study examined odorant communication during acute illness provoked by injection of lipopolysaccharide (LPS; 100 μg/kg) and how these effects vary between prepubertal and adult conspecifics. Exposure to odor of LPS-treated adult male rats produced increased avoidance in both sexes of adults and prepubertal male partners. This response was not found when they were exposed to odor of LPS-treated prepubertal males. Even a 2.5-fold higher load of LPS in prepubertal males failed to produce aversive odor cues, suggesting that the difference in the odor is not a simple issue of dose/body volume. Both estradiol benzoate (20 μg/kg) and testosterone propionate (500 μg/kg), but not dihydrotestosterone (500 μg/kg) pretreatment in prepubertal males administered LPS restored the expression of aversive odor. These hormone treatments per se did not influence odor properties of prepubertal males, indicating that estrogen receptors may play a key regulatory role in the expression of aversive odor in LPS-treated prepubertal rats. These data suggest that the expression of sickness-related odor emerges through puberty, and likely involves a complex interaction between inflammation and sex steroids across development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)