AC flashover voltage (ACFOV) between insulation surfaces coated with surfactant and interrupted by an air gap depends on the surfactant. The surfactants used are alkyl-benzene sulfonate (Neogen T®), alkyl-trimethyl-ammonium chloride (Catiogen L®) , and polyoxyethylene-sorbitan monolaurate (Tween 20®). The insulating material is polymethylmethacrylate (PMMA). In the ac prebreakdown discharge, the luminescence at the positive phase is streamer-like and that at the negative phase is glow-like. The intensity of the positive streamer luminescence for the coatings increases in the order: Catiogen L, Tween 20, Neogen T. This ordering may be caused by two factors: polarity difference of ions in the surfactant, or mobility difference between the surfactant ion and its counter ion. When violent positive prebreakdown discharge is generated, ACFOV should be lower than that for weak discharge. For this reason, ACFOV of an air gap between insulation surfaces decreases in the order shown above. Non-coated specimens have almost the same ACFOV as Tween 20 coated ones.
Background Vitiligo is an acquired pigmentary disorder characterized by depigmented patches on the skin that majorly impact patients' quality of life. Although its etiology involves genetic and environmental factors, the role of microorganisms as environmental factors in vitiligo pathology remains under-researched. Objectives Our study explored the presence of characteristic bacterial and fungal flora in vitiligo-affected skin and investigated their potential roles in vitiligo pathogenesis. Methods We sequenced bacterial 16 S rRNA and the fungal ITS1 region from skin swabs collected at frequently affected sites, namely the forehead and back, of patients with vitiligo. We analyzed bacterial and fungal flora in lesional and non-lesional areas of patients with vitiligo compared with corresponding sites in age- and sex-matched healthy subjects. Results Our findings revealed elevated α-diversity in both bacterial and fungal flora within vitiligo lesions compared with healthy controls. Notably, bacterial flora exhibited a distinctive composition in patients with vitiligo, and the proportional representation of Enterococcus was inversely correlated with the degree of vitiligo progression. Gammaproteobacteria, Staphylococcus spp., and Corynebacterium spp. were more abundant in vitiligo patients, with notable Staphylococcus spp. prevalence during the stable phase on the forehead. Conversely, the proportion of Malassezia sympodialis was lower and that of Malassezia globosa was higher in the progressive phase on the back of vitiligo patients. Conclusion Our study identified some characteristic bacterial and fungal groups associated with vitiligo activity and prognosis, highlighting the potential roles of microorganisms in pathogenesis and offering insights into personalized disease-management approaches.
Abstract Non-invasive acquisition of mRNA data from the skin would be extremely useful for understanding skin physiology and diseases. Inspired by the holocrine process, in which the sebaceous glands secrete cell contents into the sebum, we focused on the possible presence of mRNAs in skin surface lipids (SSLs). We found that measurable human mRNAs exist in SSLs, where sebum protects them from degradation by RNases. The AmpliSeq transcriptome analysis was modified to measure SSL-RNAs, and our results revealed that SSL-RNAs predominantly contained mRNAs derived from sebaceous glands, epidermis, and hair follicles. Analysis of SSL-RNAs non-invasively collected from patients with atopic dermatitis revealed significantly increased expression of inflammation-related genes and decreased expression of terminal differentiation-related genes, consistent with the results of previous reports. Further, we found that lipid synthesis-related genes were downregulated in the sebaceous glands of patients with atopic dermatitis. These results indicate that the analysis of SSL-RNAs is promising to understand the pathophysiology of skin diseases.
Corona light in coaxial cylindrical electrodes is measured photoelectrically and photographically. Calculations are made in the space charge field. Calculated intensity of the light emission within the corona sheath decreases steeply as the distance from the surface of the central electrode increases. The logarithmic gradient near the central electrode and near the outer boundary of the sheath is larger than that in the intermediate portion. The thickness of the corona sheath is independent of applied voltage. The thickness is 0.62, 1.01, 1.57 and 2.00 mm for a central electrode 0.25, 0.5, 1.0 and 1.5 mm in radius, respectively. These values can be expressed as 1.56r00.65, where r0 is the radius of the central electrode in mm. The peak level of the measured brightness distribution curve is more than 103 times higher than the skirt level.
Abstract Objectives Hyaluronan ( HA ), an important constituent of extracellular matrix in the skin, has many biological activities such as hydration that contributes to firmness and bounciness of the skin. We have reported that reduction in HA in the papillary dermis and over‐expression of HYBID ( HY aluronan Binding protein Involved in hyaluronan Depolymerization, alias KIAA 1199 or CEMIP ), a key molecule for HA degradation in skin fibroblasts, are implicated in facial skin wrinkling in Japanese and Caucasian women. However, little or no information is available for substances which inhibit the HYBID ‐mediated HA degradation. Methods Inhibition of Sanguisorba officinalis root extract and ziyuglycoside I, one of the components of Sanguisorba officinalis root extract, to the HYBID ‐mediated HA degradation was assessed by size‐exclusion chromatography of HA depolymerized by stable transfectants of HYBID in HEK 293 cells ( HYBID / HEK 293 cells) or normal human skin fibroblasts (Detroit 551 cells and NHDF ‐Ad cells). The HYBID mRNA and protein expression was examined by quantitative real‐time PCR and immunoblotting in the skin fibroblasts treated with Sanguisorba officinalis root extract, and size distribution of newly produced HA was evaluated by preparing metabolically radiolabelled HA . A double‐blind, randomized and placebo‐controlled study was carried out in the 21 healthy Japanese women, who were topically treated with the formulation containing Sanguisorba officinalis root extract or the placebo on each side of the face including crow's foot area. Results Sanguisorba officinalis root extract, but not ziyuglycoside I, abolished HYBID ‐mediated HA degradation by HYBID / HEK 293 cells. Sanguisorba officinalis root extract also inhibited HYBID ‐mediated HA degradation in skin fibroblasts by down‐regulating HYBID mRNA and protein expression. Although control untreated skin fibroblasts produced polydispersed HA , the cells treated with Sanguisorba officinalis root extract produced only high‐molecular‐weight HA . Treatment with Sanguisorba officinalis root extract‐formulated lotion significantly improved skin elasticity, and reduced skin wrinkling scores at the outer eye corner compared with the placebo formulation. Conclusion Sanguisorba officinalis root extract showed an anti‐ HYBID ‐mediated HA degradation activity and anti‐wrinkle activity on human facial skin, which is accompanied by the improvement in elasticity. Our study provides the possibility of a new strategy to inhibit HYBID ‐mediated HA degradation for anti‐wrinkle care.
An insulation system for the 66 kV class high-T/sub c/ superconducting fault current limiter (FCL) coil has been developed. The breakdown characteristics were investigated for three kinds of model coils in 77 K liquid nitrogen and 65 K sub-cooled liquid nitrogen at atmospheric pressure. For the model coils, the breakdown tests at AC voltage and lightning impulse voltage in 77 K liquid nitrogen were carried out. The breakdown voltage in 65 K sub-cooled liquid nitrogen confirmed that the breakdown voltage is almost equivalent to 77 K liquid nitrogen. To verify this insulating capability, performance tests with lightning impulse voltage of positive and negative 350 kV were carried out in the 8-layer coil. A power lead that was insulated by ethylene propylene rubber (EPR) without filler was constructed based on the results of the R&D. The insulation systems of these power leads were evaluated for crack resistance and electrical insulation properties. No cracks occurred after seven trials of thermal cycling. The power leads withstood AC 140 kVrms for 1 min and the lightning impulse of positive and negative 350 kV three times each.
