• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1237-1238
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• 2006

When the coil with alternating current approaches to the conductor the eddy current flows in conductor. Eddy current is concentrated on the conductor surface and decrescent because of skin effet.. In this paper investigated eddy current characteristic that is happened in conductor. Analyzed characteristic using electromagnetic field finite element analysis program that is commercialized to analyze value of eddy current and penetration depth. Analyzed creation value of eddy current and penetration depth in conductor that change operation frequency and the material of conductor, coil outside diameter, inside diameter, position, type of conductor from analyzed eddy current characteristic. The results. using distribution of eddy current and penetration depth data is that will help to forecast ECT(Eddy Current Testing), Eddy current application and use field, eddy current loss.

• Bulletin of the Korean Chemical Society
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• v.32 no.3
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• pp.956-960
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• 2011

The objective of this investigation was to develop nanostructured lipid carriers (NLCs) of tacrolimus by the hot homogenization technique by sonication. NLCs are commonly prepared by emulsification and lyophilization. The feasibility of fabricating tacrolimus-loaded NLCs was successfully demonstrated in this study. The developed NLCs were characterized in terms of their particle size, zeta potential, entrapment efficiency (EE) of tacrolimus, and morphology. Studies were conducted to evaluate the effectiveness of the NLCs in improving the penetration rate through hairless mouse skin. Tacrolimus-loaded NLCs were found to have an average size of $123.4{\pm}0.3\;nm$, a zeta potential of $-24.3{\pm}6.2\;mV$, and an EE of 50%. In vitro penetration tests revealed that the tacrolimus-loaded NLCs have a penetration rate that is 1.64 times that of the commercial tacrolimus ointment, Protopic$^{(R)}$.

• Archives of Pharmacal Research
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• v.19 no.2
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• pp.95-99
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• 1996

Four N-adamantyl n-alkanamides were prepared by amide condensation reaction between amantadine and n-alkanoic acid. Their enhancing activity on the penetration of ibuprofen through rabbit skin from petrolatum ointment was evaluated in in-vivo experiment. The experiments showed that the compounds have a strong transdermal penetration-enhancing activity, and their activities were comparable with that of Azone. The measurements of the fluorescence polarization of DP[-i-labelled DPPC liposomes showed that these compounds considerablly decreased the phase transition temperature of the liposomes. The mechanism of the transdermal penetration-enhancing activity of the compounds was ascribed to the reduction of the resistance to drug flux of the stratum corneum lipid layers due to the loose packing of the layers when the bulk head group of the enhancers inserts into the layers.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1697-1698
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• 2006

When the coil with alternating current approaches to the conductor the eddy current flows in conductor. Eddy current is concentrated on the conductor surface and decrescent because of skin effect. In this paper investigated eddy current characteristic that is happened in conductor. Analyzed characteristic using electromagnetic field finite element analysis program that is commercialized to analyze value of eddy current and penetration depth. Analyzed creation value of eddy current and penetration depth in conductor that change operation frequency and the material of conductor, coil outside diameter, inside diameter, position, type of conductor from analyzed eddy current characteristic. The results, using distribution of eddy current and penetration depth data is that will help to forecast ECT(Eddy Current Testing), Eddy current application and use field, eddy current loss.

• Korean Chemical Engineering Research
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• v.58 no.1
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• pp.21-28
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• 2020

The stem extract from Pyrus serotina var has natural antioxidant ability, but the extraction method does not result in a soluble compound in cosmetic formulations. This study investigated the cosmetic efficacy of the Pyrus serotina var stem extract and its epidermis permeation ability when combined with polymer micelles and a cell penetrating peptide. The total concentration of polyphenol compounds was determined to be 103.1644 ± 1.38 mg/g in the ethanol extract and 78.97 ± 1.45 mg/g in the hydrothermal extract. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging effects were 55.94 ± 0.22% in the ethanol extract at 1,000 mg/L. Superoxide dismutase (SOD) activity rates were 104.05 ± 3.28% in the ethanol extract at 62.5 mg/L. The elastase inhibition rate was 67.21 ± 2.72% in the ethanol extract at 1,000 mg/L. An antimicrobial effect was observed in the Propionibacterium acnes strain. In the epidermal permeability experiment, it was confirmed that formulation of the polymer micelle containing the Pyrus serotina var stem extract and cell penetrating peptide (R6, hexa-D-arginine) showed small particle size and much better skin permeability. The cumulative amount of total Pyrus serotina var stem extract that penetrated to the skin over time increased over 24 hours in three formulations. The three formulations showed 51.61 ㎍/㎠ (Formulation 0), 75.97 ㎍/㎠ (Formulation 1) and 95.23 ㎍/㎠ (Formulation 2) skin penetration, respectively. Therefore, it was confirmed that the ethanol extracts of Pyrus serotina var stem showed good cosmetic efficacy and excellent epidermis permeation ability when combined with a polymer micelle and cell penetrating peptide. Thus, this extract has the potential to be used as a safe and natural cosmetic material in the future.

• Journal of Pharmaceutical Investigation
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• v.24 no.4
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• pp.281-287
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• 1994

The effects of oleic acid, propylene glycol and 5% (w/w) oleic acid in propylene glycol on the electrical properties of hairless mouse skin were studied and the results were compared. The complex electrical impedance was measured as a function of frequency, and resistance and capacitance were determined from the Nyquist plot. Immediately after the treatment with oleic acid, resistance was 145% of the pretreatment value. However it decreased with time and, after 20 hours, it was about 25% of its pretreatment value. Capacitance increased; immediately after the treatment, it was about 125% of pretreatment value and it seemed to increase slowly with time. When the skin was treated with propylene glycol, resistance decreased about 5O% and capacitance increased about 65%. Similar results were observed when the skin was treated with 5% (w/w) oleic acid in propylene glycol, except that the magnitude of resistance drop was much larger. Oleic acid acted synergistically with propylene glycol. Together with the flux data in the literature, the results obtained in this work indicate that electrical resistance is closely related to the permeability of drug molecules through the skin. The results are discussed in terms of the mechanism of action of these penetration enhancers. Overall, this work provided further mechanistic insight into the role of SC lipids in skin resistance and capacitance.

• Horticultural Science & Technology
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• v.32 no.4
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• pp.440-447
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• 2014

For this analysis, canopies of slender-spindle 'Hongro'/M9 apple trees were divided into 4 positions: upper, lower, exterior, and interior parts. The photosynthetic rate was highest in the external part of the upper canopy of the tree, where it was 4.5 times higher than in the internal part of the lower canopy. This difference was closely associated with differences in light penetration based on canopy position. Analysis of leaf growth characteristics showed that the leaves situated in the internal part of the canopy were larger and thinner than those in the external part of the canopy. The difference in leaf thickness was mainly due to thickness of the primary layer of palisade tissues (68.5 and $110.3{\mu}m$ for internal and external leaves, respectively). Fruit weight and quality were closely related to the extent of light penetration. Fruit weight, soluble solid content, and red skin color were higher in the fruits from the external part of the canopy. Thus, fruit maturity was delayed in the internal part of canopy. The fruit skin and wax layer were thicker in fruits from the internal canopy than in those from the external canopy. Therefore, our results indicate a need for improved light penetration in internal parts of the canopy and for split harvesting depending on maturity at different canopy positions.

• Archives of Pharmacal Research
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• v.24 no.6
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• pp.578-583
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• 2001

To investigate the feasibility of developing a new tenoxicam plaster, the effects of vehicles and penetration enhancers on the in vitro permeation of tenoxicam from a pressure-sensititre adhesive (PSA) matrices across the dorsal hairless mouse skin were studied. Vehicles employed in this study were propylene glycol (PC)-oleyl alcohol (OAI), PG-oleic acid (OA), and diethylene glycol monoethyl ether (DCMI)-propylene glycol monolaurate (PCML) cosolvents with/without fatty acids. In this studys amines such as triethanolamine (TEA) and tromethamine (TM) were additionally used as a solubilized. Among PSAs used, $Duro-Tak^{\circledR}$87-2510 showed much higher release rate than either $Duro-Tak^{\circledR}$ 87-2100 or $Duro-Tak^{\circledR}$87-2196. The relatively high flux rate was obtained with the formulation of DCMI-PCML (40:60, v/v) with 3% OA and 5% TM, and the flux increased as a function of the dose;the initial flux up to 12 h was $4.98{\pm}1.38{\;}{\mu\textrm{g}}/{\textrm{cm}^2}/h$ at the tenoxicam dose of $50{\;} mg/70{\;}{\textrm{cm}^2}$. This flux was much higher than that of a commercial piroxicam patch ($Trast^{\circledR}$) ($1.24{\pm}0.73{\;}{\mu\textrm{g}}/$\textrm{cm}^2/hr$) with almost only one-third that of the commercial patch. Therefore, these observations indicated that these composition of tenoxicam plaster may be practically applicable.

• Journal of the Korean Applied Science and Technology
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• v.36 no.3
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• pp.685-699
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• 2019

Antioxidant, antibacterial, and skin penetration tests were conducted to investigate the skin absorption of Pyrus serotina var leaf extracts using polymer micelles and their applicability to cosmetic ingredients. Total polyphenol content was found to be $118.83{\pm}9.39mg/g$ in Pyrus serotina var leaf ethanol extract and $106.89{\pm}4.45mg/g$ in Pyrus serotina var leaf hydrothermal extract. The DPPH radical scavenging activity was found to be the highest radical scavenging activity of $74.39{\pm}7.48%$ of the Pyrus serotina var leaf ethanol extract at the concentration of 500 mg/L. The SOD-like activity was $91.62{\pm}0.43%$, the highest value at the concentration of 1,000 mg/L in the hydrothermal extract. After the experiment, antioxidation, wrinkle improvement and whitening activity were confirmed, and the Pyrus serotina var leaf extract was highly likely to be realized as antioxidant and antibacterial material. In the skin penetration experiment with the Pyrus serotina var leaf ethanol extract, the permeation amount of total accumulated tannic acid was found to be Formulation 2 ($55.45{\mu}g/cm^2$), Formulation 1 ($46.43{\mu}g/cm^2$), Formulation 0 ($34.36{\mu}g/cm^2$). In the liposome's skin penetration experiment containing pear leaf hydrothemal extract, the total amount of accumulated tannic acid permeation was found to be Formulation 5 ($75.01{\mu}g/cm^2$), Formulation 4 ($64.01{\mu}g/cm^2$) and Formulation 3 ($36.60{\mu}g/cm^2$). Through this study, we confirmed the possibility of antioxidant and wrinkle effects of Pyrus serotina var leaf extract. In addition, as a result of skin penetration through the production of polymer micelles and liposome containing Pyrus serotina var leaf extract, It will be more usable in cosmetic industry.

• Journal of the Korean Applied Science and Technology
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• v.30 no.2
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• pp.215-224
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• 2013

Recently, many cosmetic researchers have been focused on the development of high functional cosmetics including anti-wrinkle and whitening. In these studies, they couldn't afford to pay a deep attention to stable encapsulations for unstable materials and efficient drug deliveries for them. Particularly, in order to show a degree of instant effects as cosmetics, they can't also ignore moisturizing effect enough to satisfy customers just after applying and its maintenance by improving the function of skin barrier as well as above two effects. Therefore, skin analogue systems have attracted considerable attention in the view of structural and compositional similarity to intercellular membrane in stratum corneum. And, some models for skin analogue composition were developed to improve the function of skin barrier, stably encapsulate unstable materials such as retinol, vitamin B, C, E, etc., and control their skin penetration in order to show good effects as cosmetics. In this study, we suggest the new skin analogue model having the compositional similarity as well as conventional structural ones. Our skin analogue membrane(SAM) is mainly composed of ceramide/ cholesterol/phosphatidylcholin/fatty acids and its structural defects are compensated by including cholesterol amphiphile and controlling the ratio of ceramide/cholesterol. It was possible to confirm the formation of skin analogue membrane having highly-densed multilamella structure and compare them according to the change of each ratio with a polarized microscope, X-ray diffraction. More detaily, we observed their structures with a electron microscope(TEM). Finally, we dispersed them in excess of continuous water phase, observed the formation of maltese-cross liquid crystalline and measured the efficiency of drug deliveries and moisturizing effects.