• Nuclear Engineering and Technology
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• v.31 no.5
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• pp.512-521
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• 1999

A feasibility study was performed to design an epithermal neutron beam for BNCT using the neutron of 2.45 MeV on the average produced from $^2H(d,n)^3$He reaction induced by plasma focus in the z-pinch instead of the conventional accelerator-based $^3H(d, n)^4$He neutron generator. Flux and spectrum were analyzed to use these neutrons as the neutron source for BNCT. Neutronic characteristics of several candidate materials in this neutron source were investigated Using MCNP Code, and $^7LiF$ ; 40%Al + 60%$AIF_3$, and Pb Were determined as moderator, filter, and reflector in an epithermal neutron beam design for BNCT, respectively. The skin-skull-brain ellipsoidal phantom, which consists of homogeneous regions of skin-, bone-, or brain-equivalent material, was used in order to assess the dosimetric effect in brain. An epithermal neutron beam design for BNCT was proposed by the repeated work with MCNP runs, and the dosimetric properties (AD, AR, ADDR, and Dose Components) calculated within the phantom showed that the neutron beam designed in this work is effective in tumor therapy. If the neutron source flux is high enough using the z-pinch plasma, BNCT using the neutron source produced from $^2H(d,n)^3$He reaction will be very feasible.

• Journal of Biomedical Engineering Research
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• v.43 no.5
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• pp.308-318
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• 2022

The purpose of this study is to evaluate the biomechanical properties of fractured adjacent soft tissue during closed reduction after forearm fracture using the finite element method. To accomplish this, a finite element (FE) model of the forearm including soft tissue was constructed, and the material properties reported in previous studies were implemented. Based on this, nine finite element models with different fracture types and fracture positions, which are the main parameters, were subjected to finite element analysis under the same load and boundary conditions. The load condition simulated the traction of increasing the fracture site spacing from 0.4 mm to 1.6 mm at intervals of 0.4 mm at the distal end of the radioulnar bone. Through the finite element analysis, the fracture type, fracture location, and displacement were compared and analyzed for the fracture site spacing of the fractured portion and the maximum equivalent stress of the soft tissues adjacent to the fracture(interosseous membrane, muscle, fat, and skin). The results of this study are as follows. The effect of the major parameters on the fracture site spacing of the fractured part is negligible. Also, from the displacement of 1.2 mm, the maximum equivalent stress of the interosseous membrane and muscle adjacent to the fractured bone exceeds the ultimate tensile strength of the material. In addition, it was confirmed that the maximum equivalent stresses of soft tissues(fat, skin) were different in size but similar in trend. As a result, this study was able to numerically confirm the damage to the adjacent soft tissue due to the fracture site spacing during closed reduction of forearm fracture.

• Journal of the Korean Applied Science and Technology
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• v.33 no.2
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• pp.361-373
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• 2016

This study tested the antioxidant activities and anti-aging effects of an extract of Orostachys japonicus, a herb used as a folk remedy for cancer for a long time. To assess the antioxidant activities of the Orostachys japonicus extract (OJE), the total polyphenol content was confirmed to have a high caffeic acid equivalent weight of 12 g by dry weight of 100g OJE and the total flavonoid content was confirmed that the quercetin equivalent of 1.7 g by dry weight of 100g OJE. DPPH free radical scavenging activity was confirmed a high scavenging activity of 79.7% at a concentration of 1%. To confirm the anti-aging effect of OJE, MMP-1 expression was decreased in $25{\mu}L/mL$ and $50{\mu}L/mL$ similar to control. In a clinical experiment, a group of subjects who used a cosmetic product containing OJE showed a significant increase in the amount of skin moisture from the forehead, left cheek, and chin. The experimental group showed a significant increase in the amount of skin sebum from the chin and maintaining pH balance of normal skin, As a result, the OJE demonstrates the efficacy of natural cosmetic material as antioxidant and anti-aging.

• Journal of Life Science
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• v.23 no.8
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• pp.1019-1024
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• 2013

The aims of this study were to determine antioxidation effect and neuroblastoma cell protection effect of donkey's bone and skin extracts (DBSE). DBSE was extracted by a pressure-cooker for 48 h and lyophilized. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was significantly increased with increased doses of DBSE and 40 mg/ml of DBSE showed 95.43% of the DPPH scavenging effect, which was equivalent to 1 mg/ml of vitamin C. The 2,2'-azino-bis (3-ethylbenzothiazoline-6- sulphonic acid) (ABTS) radical scavenging activity was also increased in a dose-dependent manner, and 20 mg/ml of DBSE showed 88.73% of the ABTS scavenging effect. The oxygen radical absorbance capacity (${\mu}M$ Trolox equivalent) of DBSE was significantly increased at a concentration of 10 mg/ml, which showed $132.53{\mu}M$ TE. The viability of oxidatively stressed brain cells induced by $500{\mu}M\;H_2O_2$ was protected by DBSE at concentrations greater than $50{\mu}M$. Cell viability after DBSE treatment at 50 and $100{\mu}g/ml$ was 53.78 and $54.34{\mu}M$ TE, respectively. There was no significant difference between both doses; however, 200 and $500{\mu}g/ml$ of DBSE showed 59.74 and 66.08% of cell viability, respectively indicating that DBSE protected SK-N-SH from oxidation stress. These results suggest that DBSE may have potential to be used as natural antioxidants in food industry, while in vivo evidence is necessary to support DBSE's in vitro-based antioxidative efficiency.

• Food Science of Animal Resources
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• v.40 no.2
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• pp.183-196
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• 2020

The protective effect of pig skin gelatin water extracts (PSW) and the low molecular weight hydrolysates of PSW generated via enzymatic hydrolysis with Flavourzyme® 1000L (LPSW) against scopolamine-induced impairment of cognitive function in mice was determined. Seventy male ICR mice weighing 20-25 g were randomly assigned to seven groups: Control (CON); scopolamine (SCO, 1 mg/kg B.W., intraperitoneally (i.p.); tetrahydroaminoacridine 10 [THA 10, tacrine; 10 mg/kg B.W. per oral (p.o.) with SCO (i.p.)]; PSW 10 (10 mg/kg B.W. (p.o.) with SCO (i.p.); PSW 40 (40 mg/kg B.W. (p.o.) with SCO (i.p.); LPSW 100 (100 mg/kg B.W. (p.o.) with SCO (i.p.); LPSW 400 (400 mg/kg B.W. (p.o.) with SCO (i.p.). All treatment groups, except CON, received scopolamine on the day of the experiment. The oxygen radical absorbance capacity of LPSW 400 at 1 mg/mL was 154.14 μM Trolox equivalent. Administration of PSW and LPSW for 15 weeks did not significantly affect on physical performance of mice. LPSW 400 significantly increased spontaneous alternation, reaching the level observed for THA and CON. The latency time of animals receiving LPSW 400 was higher than that of mice treated with SCO alone in the passive avoidance test, whereas it was shorter in the water maze test. LPSW 400 increased acetylcholine (ACh) content and decreased ACh esterase activity (p<0.05). LPSW 100 and LPSW 400 reduced monoamine oxidase-B activity. These results indicated that LPSW at 400 mg/kg B.W. is a potentially strong antioxidant and contains novel components for the functional food industry.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.1 s.49
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• pp.51-58
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• 2005

Alkyl ethoxy sulfate type surfactants, widely used in commercial cleansers, are easily adsorbed to skin to often cause skin irritation and inflammation if not thoroughly rinsed nut. In order to replace or complement existing surfactants, we screened the existing surfactants through protein denaturation method, cell cytotoxicity assay and human IL-1$\alpha$ assay, etc. Fourteen surfactants have been chosen from among too irritant anionic, cationic and/or zwitter-ionic ones and investigated for cell cytotoxicity in human fibroblast cell lines using monolayer culture with the thirteen commercially available cleansers for sensitive skin. From these results, we selected 5 surfactants and 2 commercial cleansers (names not shown), such as sodium laureth sulfate (anionic), sodium cocoyl isethionate (anionic), sodium lauroamphoacetate (zwitter-ionic), and cocamidopropyl betaine (zwitter-ionic), alkyl polyglycoside (non-ionic). 20 formulations were made out of 5 surfactants and five of them were chosen through a protein denaturation method (lower than 3 M sodium dodecyl sulfate solution ($13.2\%$)), cell cytotoxicity and human patch test. These five selected formulations containing preservatives were compared to two selected commercial cleansers by cell cytotoxicity and human IL-1$\alpha$ ELISA assay using dermal equivalent. Finally, we selected the best formulation. To this formulation, fructan ($3\%$ or $5\%$) or/and portulaca extract ($3\%$ or $5\%$) well known for its anti-inflammatory and moisturizing effects were added and investigated for cell cytotoxicity using dermal equivalent. In cytotoxicity assay using dermal equivalent, two formulations containing $5\%$ fructan and $3\%$ or $5\%$ portulaca extract were less toxic than the others. In cytotoxicity assay and human IL-1$\alpha$ ELISA using 3D culture, the selected formulation containing $5\%$ fructan and $5\%$ portulaca extract showed better efficiency than those of the others and 2 commercial cleansers. As a result, we could develop a low irritant and safe liquid cleanser.

• Journal of Radiation Protection and Research
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• v.23 no.1
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• pp.7-15
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• 1998

In order to evaluate the effectiveness of some decontamination agents against skin contamination of $^{60}Co$ and $^{137}Cs$, the experiments were carried out in this study. In the experiments, pig skin was used instead of human skin , $^{60}CoC1_2$ and $^{137}CsCl$ were used the liquid sources of skin contamination. To examine the effectiveness of decontamination agents, skin decontamination was tried using soup, EDTA, KAERICON which was developed for decontamination of radionulides on the surface of building structure, and new decontamination agents such as IOCON, TRICON, and CHARCON, which were developed in this study. The absorption of radionuclides through the skin was evaluated by the gamma-tay detection on the surface of sample skin after radionuclides were penetrated into the skin during 16 hour soiling time. The results of this absorption experiment indicated that 11.5% and 3.2% of initial amounts of $^{137}Cs$ and $^{60}Co$, respectively, were panerated into the skin. In the experiment to remove the residual radioactivity fixed on the skin, KAERICON showed the decontamination rates up to 52.1%(decontamination factor of 2.1) and IOCON showed the equivalent decontamination rate (decontamination factor 1.9) for $^{137}Cs$. However, IOCON and CHARCON showed the poor decontamination rates of less than 20%(decontamination factor of 1.2) for $^{60}Co$, and KAERICON showed the poor decontamination rate (decontamination factor 1.1) for $^{60}Co$. For TRICON, the decontamination factors were 1.6 to 1.8 for $^{137}Cs$, and 1.0 to 1.2 for $^{60}Co$, respectively.

• The Journal of Korean Society for Radiation Therapy
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• v.24 no.2
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• pp.189-196
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• 2012

Purpose: The sufficiency of skin dose and the reemergence of patient set-up position to the success of skin cancer radiation treatment is a very important element. But the conventional methods to increase the skin dose were used to vacuum cushion, bolus and water tank have several weak points. For this reason, we producted Foxtail Millet Vacuum Cushion and evaluated the efficiency of the Foxtail Millet Vacuum Cushion in skin cancer Radiation treatment. Materials and Methods: We measured absolute dose for 3 materials (Foxtail Millet Vacuum Cushion, bolus and solid water phantom) and compared each dose distribution. We irradiated 6 MV 100 MU photon radiation to every material of 1 cm, 2 cm, 3 cm thickness at three times. We measured absolute dose and compared dose distribution. Finally we inspected the CT simulation and radiation therapy planing using the Foxtail Millet Vacuum Cushion. Results: Absolute dose of Foxtail Millet Vacuum Cushion was similar to absolute dose of bolus and solid water phantom's result in each thickness. it Showed only the difference of 0.1~0.2% between each material. Also the same result in dose distribution comparison. About 97% of the dose distribution was within the margin of error in the prescribed ranges ($100{\pm}3%$), and achieved the enough skin dose (Gross Tumor Volume dose : $100{\pm}5%$) in radiation therapy planing. Conclusion: We evaluated important fact that Foxtail Millet Vacuum Cushion is no shortage of time to replace the soft tissue equivalent material and normal vacuum cushion at the low energy radiation transmittance. Foxtail Millet Vacuum Cushion can simultaneously achieve the enough skin dose in radiation therapy planing with maintaining normal vacuum cushion' function. Therefore as above We think that Foxtail Millet Vacuum Cushion is very useful in skin cancer radiation treatment.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.113-117
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• 2003

The recent development of methods for culturing hair follicles in vitro has proved an important tool to investigate many aspects of drug screening. Hair follicles develop as a result of epithelial-mesenchymal interactions between epidermal keratinocytes and dermal cells. We isolated some follicle cells using explantation and enzymatic digestion method from human scalp hair follicles. So we could culture some follicular cells, such as outer root sheath (ORS) cells, dermal papilla (DP) cells, dermal sheath (DS) cells, matrix cells and melanocytes. To induce hair morphogenesis in vitro the cells were 3-D cultured as skin structures. Moreover, to develop hair follicel organ culture model, we applied dermal equivalent (DE) to culturing hair follicles to expand hair growth period.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.5
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• pp.351-357
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• 2004

In this paper, we present an analytical method that provides fast and efficient evaluation of the conversion efficiency for switching power supplies. In the proposed method, the conduction losses are evaluated by calculating the effective values of the ideal current waveform first and incorporating them into an exact equivalent circuit model of the switching power supply that includes all the parasitic resistances of the circuit components. While the winding losses and core losses are accurately accounted for the magnetic components, the skin and proximity effects are assumed to be negligible in order to simplify the analysis. The validity and accuracy of the proposed method are verified with experiments on a prototype active-clamped forward converter with synchronous rectification. An excellent correlation between the experiments and theories are obtained for the input voltages of 36-75 V with 4-6 MOSFETs employed for the synchronous rectification.