• YAKHAK HOEJI
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• v.41 no.6
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• pp.730-736
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• 1997

Distribution of radioactivity in the skin tissues, subcutaneous tissues, blood and body organs was examined following topical application of $^{125}I-rhEGF$(0.4 ${\mu}Ci$), in the form of a Pluronic F-127 gel, on the normal and damaged (burned and stripped) skins of SD male rats. The radioactivity in the skin tissues and subcutaneous tissues was 3-5 times higher for the damaged skins than for the normal skin. But pretreatment of the skin with rhEGF (1${\mu}g$)) twice at 24 hr dose intervals affected the distribution of the radioactivity yielding the order of burned skin> stripped skin=normal skin. The decrease for the stripped skin by the pretreatment might be related either to the pathophysiological change of the skin or to the down regulation of the EGF receptor. Liver showed the highest radioactivity in amount following single and multiple administration of the drug to the normal and damaged skins. But,in concentration, the kidney and stomach showed higher value than the liver which is consistent with that kidney is a major eliminating organ of EGF and that EGF exerts its pharmacological effect specifically for the stomach.

• Steel and Composite Structures
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• v.34 no.2
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• pp.299-308
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• 2020

This study aims to carry out the experimental and numerical investigation on the flexural behavior of sandwich honeycomb composite (SHC) beams reinforced with novel triaxially woven fabric composite skins. Different stacking sequences of the carbon fiber reinforcement polymer (CFRP) laminate; i.e., 0°-direction of TW (TW0), 0°-direction of UD (UD0), and 90°-direction of UD (UD90) were studied, from which the flexural behavior of SHC beam behaviors reinforced with TW0/UD0 or TW0/UD90 novel laminated skins were compared with those reinforced with UD0/90 conventional laminated skins under four-point loading. Generally, TW0/UD0 SHC beams displayed the same flexural stiffness as UD0/90 SHC beams in terms of load-deflection relationships. In contrast, TW0/UD90 SHC beams showed a 70% lower efficiency than those of UD0/90 SHC. Hence, the TW0/UD0 laminate arrangement is more effective with a mass reduction of 39% compared with UD0/90 for SHC beams, although their stiffness and shear strength are practically identical.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.26 no.1
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• pp.17-40
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• 2000

Cytotoxicity assays using artificial skins have been proposed as in vitro alternatives to minimize animal ocular and dermal irritation testing. Accordingly, the responses of artificial skins to the well-characterized chemical irritants toluene, glutaraldehyde, and sodium lauryl sulfate (SLS), and the nonirritant polyethylene glycol were studied. The evaluation of the irritating and non-irritating test chemicals was also compared with the responses observed in human dermal fibroblasts and human epidermal keratinocytes grown in a monolayer culture. The responses monitored included an MTT mitochondrial functionality assay. In order to better understand the local mechanisms involved in skin damage and repair, the production of several mitogenic proinflammatory mediators, interleukin-l$\alpha$, 12-HETE, and 15-HETE, was also investigated. Dose-dependent increases in the levels of かIn and the HETEs were observed in the underlying medium of the skin systems exposed to the two skin irritants, glutaraldehyde and SLS. The results of the present study show that both human artificial skins can be used as efficient in vitro testing models for the evaluation of skin toxicity and for screening contact skin irritancy.

• Structural Engineering and Mechanics
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• v.12 no.2
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• pp.169-188
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• 2001

This note presents the main results of an experimental investigation into the mechanical behaviour of a composite sandwich conceived as a lightweight material for naval engineering applications. The sandwich structure is formed by a three-dimensional glass fibre/polymer matrix fabric with transverse piles interconnecting the skins; the core is filled with a polymer matrix/glass microspheres syntactic foam; additional Glass Fibre Reinforced Plastics extra-skins are laminated on the external facings of the filled fabric. The main features of the experimental tests on syntactic foam, skins and sandwich panels are presented and discussed, with focus on both in-plane and out-of-plane responses. This work is part of a broader research investigation aimed at a complete characterisation, both experimental and numerical, of the complex mechanical behaviour of this composite sandwich.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.440-442
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• 2002

The electrical characteristics of biologically active points (BAPs) compared with those of the surrounding human skins are studied. And we confirm that BAPs have lower resistance and higher capacitance than the surrounding skins do. We also find that BAPs have higher characteristic frequency than surrounding skins and the impedance spectra of BAPs sometimes have two semicircles on the complex impedance plane. We propose the skin impedance model that is proper to the BAPs and this circuit describes our experimental results sufficiently well.

• Structural Monitoring and Maintenance
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• v.4 no.2
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• pp.133-151
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• 2017

The paper describes the results of an experimental and numerical investigation into the structural and damage response of sandwich composites to low-velocity impact. Sandwich panels consisting of laminated composite skins with three different layups bonded to a PVC foam core were subjected to impact at various energy levels corresponding to barely visible impact damage (BVID) in the impacted skins. Damage assessment analyses were performed on the impacted panels to characterise the extent and the nature of the major failure mechanisms occurring in the skins. The data collected during the experimental analyses were finally used to assess the predictive capabilities of an FE tool recently developed by the authors for detailed simulation of impact damage in composite sandwich panels. Good agreement was observed between experimental results and model predictions in terms of structural response to impact, global extent of damage and typical features of individual damage mechanisms.

• YAKHAK HOEJI
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• v.41 no.6
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• pp.737-748
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• 1997

Distribution of rhEGF in the skin, plasma and several organ tissues following topical application of $^{125}I-rhEGF$ (0.4${\mu}$Ci) solution in 25% Pluronic F-127 on 154$mm^2$ normal and damaged (burned and stripped) skins of hairless mice was examined. The radioactivity in the stripped skin tissues increased as a function of time, and was 10-20 times higher than that in the normal and burned skins. The fractions of intact drug in the skin tissues were 40-60% for the normal and burned skins, and 60-80% for the stripped skin. It indicates that the stratum corneum layer behaves as a barrier for the dermal penetration of the drug. The radioactivity in the plasma was much higher for the stripped skin than for the normal and burned skins. However, the concentration of intact drug in the stripped skin was comparable to those in the normal and burned skins indicating most severe degradation (or metabolism) of the drug in the stripped skin. As a result, the fraction of intact drug in the plasma was lowest for the stripped skin (<10%). Body organ distribution of the drug was much higher for the stripped skin. The concentration in the stomach. Both in total radioactivity and intact drug, showed more than 10-times higher value than in the other organs (liver, kidney and spleen). The fraction of intact drug in each organ tissue was below 10-20%. And generally lowest for the stripped skin. The lowest fraction of the drug for the stripped skin could not be explained by the activity of the aminopeptidases in the skin since it was lower for the stripped skin than for the normal skin. Thereover, the fraction of intact drug appears to be determined by the balance between dermal uptake and systemic elimination of the drug, for example. The mechanism of dermal uptake of rhEGF was examined by topical applying 200${\mu}$l of 25% Pluronic F-127 solution containing 0.4 ${\mu}$Ci of $^{125}I-rhEGF$ and 0.14${\mu}$Ci of $^{14}C$-inulin (a marker of passive diffusion). The radioactivity of $^{125}I-rhEGF$ at each sampling time point (0.5, 1, 2, 4 and 8hr) was correlated (p<0.05) with the corresponding radioactivity of $^{14}C$-inulin. It appears to indicate the rhEGF may be uptaken into the skins mainly by the passive diffusion. This hypothesis was supported by the constant specific binding of EGF to the skin homogenates regardless of the skin models. Receptor mediated endocytosis (RME) appears to contribute negligibly, if any, to the overall uptake process.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.205-208
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• 2006

We report the recent progress and future prospects of flexible, large-area sensors and actuator using organic thin-film transistors (TFTs). In particular, we describe printing technologies to manufacture electronic artificial skins (e-skins) for robots, sheet image scanners suitable for mobile applications, and Braille sheet display with plastic actuator arrays. We also present recent progress of reliability and stability issues.

• Applied Microscopy
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• v.38 no.1
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• pp.35-41
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• 2008

Onions are commonly available and easily processed, and since their skins are thrown away they could be very useful materials from the viewpoint of environmental preservation. This study aimed to process onion skins into the state of powder and look into the optimum condition for hair dyeing by decoloring virgin hair four times and observing the hair dyeing quality and its mechanical and morphologic changes by the different condition of onion skins in duration, temperature, density, pH, and mordant treatment. The observations of hair surface through scanning microscopy showed the formation of cuticle layer, though in a little blown-up state in the case of the hair dyed with onion skin application, when compared with bleaching hair with the completely dissolved cuticle layer. According to the above findings of experiments, the dyeing quality of the hair dyes with onion skin application was excellent, the dyeing was also feasible without mordants, and the use of Fe as the mordant increased dyeing exhaustion more, which would make it an effective hair dye. These results of the experiments indicate that the natural pigment extracted from onion skins can be actually used for hair dyeing from the viewpoints of the dyeing quality and the skin treatment.

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.547-559
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• 1994

To effectively utilize fish skin wastes from marine manufactory, the optimal extraction conditions to prepare gelatin from fish skins of Alaska pollack, cod and yellowfin sole were investigated. In addition, the physical properties of the fish skin gelatins prepared under the optimal extraction conditions were compared with the commercial animal skin gelatin. The conditions for extraction of gelatins from fish skins were as follows ; The skins were limed with 1.0~1.5%(w/v) calcium hydroxide solution. The fish skin gelatins were extracted with 6~7 volumes of water(pH 6.0~7.0) for 5hrs at $40{\sim}50^{\circ}C$, and the yield of Alaska pollack skin gelatin extracted under the above conditions was higher than those of cod and yellowfin sole skins. The heavy metal contents, jelly strength and electric conductivities of fish skin gelatins were lower than those of a commercial gelatin(bovine skin), but the viscosity and isoelectric point were higher. The amount of amino acid in fish skin, such as gelatin, glutamic acid, serine, threonine, methionine and cysteine, were higher than those in pig and ox skin. However, the contents of hydroxyproline and proline were lower.