Development of Low-Shrink Epoxy Putty to Solve Appearance-Quality Defects of Carbon-Fiber-Reinforced Plastic Automotive Exterior Parts.

In this study, epoxy putties with novel compositions were developed for the filling of structural voids in carbon-fiber-reinforced plastics (CFRPs), which are used to fabricate automotive parts. Two constituent solutions-one consisting of epoxy resins and the other consisting of a hardener-were formulated, mixed, and then coated on CFRP surfaces, followed by curing. The surfaces were then evaluated to determine the shrinkage rates (calculated based on the liquid densities and cured mixtures), adhesion properties (determined by a peel test), and color differences (measured with a colorimeter) of the synthesized putties. The last two properties were compared with those of the commercially available putties to ascertain the thermal resistance of the developed putties. The results indicated that the synthesized epoxy putties were more strongly adhesive and exhibited less difference in color. Furthermore, after thermal impact, both the adhesive properties and color stabilities of the synthesized epoxy putties were found to be superior to those of the commercial putty.

Green tomato extract attenuates high-fat-diet-induced obesity through activation of the AMPK pathway in C57BL/6 mice.

Obesity is a risk factor for numerous metabolic disorders. Recently, natural compounds that may be beneficial for improving obesity have received increasing attention. In this study, we investigated whether red and green tomato extracts attenuate high-fat-diet-induced obesity in C57BL/6 mice. The mice were maintained on a normal diet (ND) or high-fat diet (HFD) for 4 weeks and then fed ND, HFD, HFD plus 2% red tomato extract (RTE) or HFD plus 2% green tomato extract (GTE) for 13 weeks. The weekly food intakes among the groups were not significantly different. Body weight of mice fed HFD plus GTE was significantly decreased to the level of mice fed ND, but the body weight was only slightly reduced in mice fed HFD plus RTE. Epididymal adipose tissue and liver weights were significantly decreased in mice fed HFD plus GTE compared to those in HFD. Serum total cholesterol and low-density lipoprotein cholesterol levels in mice fed GTE were modestly reduced, and liver total cholesterol level was strongly decreased in HFD plus GTE-fed mice compared to that in HFD-fed mice. Adenosine-monophosphate-activated protein kinase (AMPK) and acetyl-CoA carboxylase phosphorylation in liver from HFD plus GTE-fed mice was significantly elevated, and HMG-CoA reductase expression was also significantly decreased. GTE strongly decreased the expression of peroxisome proliferator-activated receptor gamma, CCAAT/enhancer-binding protein alpha and perilipin in the adipose tissue of mice fed HFD plus GTE. Our results indicate that the antiobesity effects of GTE may be associated with activation of the AMPK pathway.

Rhamnetin-induced suppression of clonal expansion during early stage of adipogenesis.

Adipocyte differentiation plays a pivotal role in the progression of obesity which is a major risk factor for several diseases such as diabetes, hypertension and coronary heart disease. In this study, the inhibitory effect of rhamnetin, a flavonoid compound, on adipogenesis in 3T3-L1 cells was investigated. Rhamnetin decreased the accumulation of lipid droplets, and inhibited the elevation of triglyceride content in the adipocytes (IC(50) = 17.3 µM). The expressions of PPARγ, C/EBPα, and perilipin, adipocyte differentiation markers, were significantly reduced by rhamnetin. Triglyceride biosynthesis and clonal expansion of adipocytes were completely inhibited during the early stage by rhamnetin. Additionally, rhamnetin significantly decreased the expression of C/EBPß, an early stage marker. Our results indicate that suppression of clonal expansion during the early stage of adipogenesis by rhamnetin may be associated with inhibition of the C/EBPß, C/EBPα, and PPARγ pathways.

Quantitative analysis of sphingomyelin by high-performance liquid chromatography after enzymatic hydrolysis.

Sphingomyelin is the most abundant sphingolipid in mammalian cells and is mostly present in the plasma membrane. A new analytical method using high-performance liquid chromatography (HPLC) was developed to quantify sphingomyelin in mouse plasma and tissues, 3T3-L1 cells, rat aortic smooth muscle cells, and HT-29 cells. Sphingomyelin and dihydrosphingomyelin, an internal standard, were separated by high-performance thin-layer chromatography and simultaneously hydrolyzed with sphingolipid ceramide N-deacylase and sphingomyelinase to release sphingosine and dihydrosphingosine, respectively. Sphingomyelin content was measured by HPLC following o-phthalaldehyde derivatization. Sphingomyelin concentrations in 3T3-L1 cells, rat aortic smooth muscle cells, and HT-29 cells were 60.10 ± 0.24, 62.69 ± 0.08, and 58.38 ± 0.37 pmol/µg protein, respectively, whereas those in brain, kidney, and liver of ICR mice were 55.60 ± 0.43, 43.75 ± 0.21, and 22.26 ± 0.14 pmol/µg protein. The sphingomyelin concentration in mouse plasma was 407.40 ± 0.31 µM. The limits of detection and quantification for sphingomyelin were 5 and 20 pmol, respectively, in the HPLC analysis with fluorescence detection. This sensitivity was sufficient for analyzing sphingomyelin in biological samples. In conclusion, this analytical method is a sensitive and specific technique for quantifying sphingomyelin and was successfully applied to diverse biological samples with excellent reproducibility.

Heterogeneity of skin surface oxygen level of wrist in relation to acupuncture point.

The distribution of partial oxygen pressure (pO(2)) is analyzed for the anterior aspect of the left wrist with an amperometric oxygen microsensor composed of a small planar Pt disk-sensing area (diameter = 25 µm). The pO(2) levels vary depending on the measurement location over the wrist skin, and they are systematically monitored in the analysis for both one-dimensional single line (along the wrist transverse crease) and two-dimensional square area of the wrist region. Relatively higher pO(2) values are observed at certain area in close proximity to the position of acupuncture points with statistical significance, indicating strong relationship between oxygen and acupuncture point. The used oxygen microsensor is sensitive enough to detect the pO(2) variation depending on the location. This study may provide information helpful to understand possible physiological roles of the acupuncture points.