• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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• pp.820-829
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• 2003

One of the important function of skin is the protection from harmful environments. Many studies were carried out to keep the skin from wrinkling and pigmenting. Skin wrinkle and pigmentation could be caused' by the unusual disruption of connective tissue, the formation of free radicals and the radiation of ultraviolet. In this study, the extracts obtained from 23 different kinds of medicinal plants were examined whether they have inhibitory effect on tyrosinase and elastase as well as free radical scavenging effect. All the extracts examined were obtained by using 70% (v/v) ethanol at $60^{\circ}C$. It has been found that there were two medicinal plants which have positive effects matching with the purpose of this study. The extract of Ephedra sinica stapf shows an inhibitory effect on tyrosinase ($IC_{50}$ = 83.7~$\mu\textrm{g}$/ml), on elastase ($IC_{50}$ = $690{\mu}\textrm{g}$/ml), and also shows free radical scavenging effect ($IC_{50}$ = 29.6$\mu\textrm{g}$/ml). The extract of Betula platyphylla Var. shows an inhibitory effect on elastase ($IC_{50}$ = 498.1$\mu\textrm{g}$/ml), and free radical scavenging effect ($IC_{50}$ = 9$\mu\textrm{g}$/ ml). The aim of the study is to find the natural compounds which have function in skin-lightening, anti-wrinkling and anti-oxidation, with safe and active ingredients in cosmetic.

• Imaging Science in Dentistry
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• 제47권4호
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• pp.233-239
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• 2017

Purpose: This study was performed to quantify the repeat rate of imaging acquisitions based on different clinical examinations, and to assess the prevalence of error types in intraoral bitewing and periapical imaging using a digital complementary metal-oxide-semiconductor(CMOS) intraoral sensor. Materials and Methods: A total of 8,030 intraoral images were retrospectively collected from 3 groups of undergraduate clinical dental students. The type of examination, stage of the procedure, and reasons for repetition were analysed and recorded. The repeat rate was calculated as the total number of repeated images divided by the total number of examinations. The weighted Cohen's kappa for inter- and intra-observer agreement was used after calibration and prior to image analysis. Results: The overall repeat rate on intraoral periapical images was 34.4%. A total of 1,978 repeated periapical images were from endodontic assessment, which included working length estimation (WLE), trial gutta-percha (tGP), obturation, and removal of gutta-percha (rGP). In the endodontic imaging, the highest repeat rate was from WLE (51.9%) followed by tGP (48.5%), obturation (42.2%), and rGP (35.6%). In bitewing images, the repeat rate was 15.1% and poor angulation was identified as the most common cause of error. A substantial level of intra- and inter-observer agreement was achieved. Conclusion: The repeat rates in this study were relatively high, especially for certain clinical procedures, warranting training in optimization techniques and radiation protection. Repeat analysis should be performed from time to time to enhance quality assurance and hence deliver high-quality health services to patients

• 한국전자파학회논문지
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• 제28권12호
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• pp.954-963
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• 2017

본 연구에서는 공진형 무선전력전송시스템에 의해 발생되는 자기장과 전기장 강도 및 이에 의한 인체 내부 전자파 비흡수율(Specific Absorption Rate: SAR) 분포를 분석하였다. 연구에서 사용된 동작주파수는 ISM 대역에 해당하는 6.78 MHz이다. 실제 시스템을 제작하고, 시스템의 송신측에 공급되는 가용 전력을 1 W로 제한하여 전기장 및 자기장 분포를 측정하고, 동일한 규격으로 시뮬레이션한 결과와 비교하였다. 피부, 지방, 근육의 순으로 조직층이 구성된 단순인체모델을 이용하여, WPT 시스템으로부터의 거리에 따른 인체 내부의 유도 전류밀도와 SAR 분포를 구하였다. 측정과 시뮬레이션을 통해 얻어진 전자파 노출 정도를 ICNIRP(International Commission on Non-Ionizing Radiation Protection)의 국제 권고기준과 비교하여 분석하였다.

• Molecular & Cellular Toxicology
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• 제3권1호
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• pp.23-30
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• 2007

The effects of high energy short wave solar radiation on human skin have received much publicity as the major cause of accelerated skin ageing and of skin cancers. To meet public demand, the cosmetic industry has developed sun protection factor products, which contain a variety of so-called "UV filters", among others benzophenone (BP) and its metabolites are the widely used UV filters. UV filters are also used to prevent UV light from damaging scents and colors in a variety of cosmetics products and to protect of plastic products against light-induced degradation. There are many variants of BP in use. In this respect, to regulate and to evaluate the hazardous effect of BP-type UV filters will be important to environment and human health. The genotoxicity of 7 BP-type UV filters was evaluated in L5178Y $(tk^{+/-})$ mouse lymphoma cells in vitro. BP, benzhydrol, 4-hydroxybenzophenone 2-hydroxy-4-methoxybenzophenone and 2, 4-dihydroxybenzophenone did not induce significant mutation frequencies both in the presence and absence of metabolic activation system. 2, 2'-Dihydroxy-4-methoxybenzophenone appeared the positive results at the highest dose, i.e. 120.4 ${\mu}g/mL$ only in the absence of metabolic activation system. And also, 2, 3, 4-trihydroxybenzophenone revealed a significant increase of mutation frequencies in the range of 138.1-207.2 ${\mu}g/mL$ in the absence of metabolic activation system and 118.3-354.8 ${\mu}g/mL$ in the presence of metabolic activation system. Through the results of MLA with 7 BP-type UV filters in L5178Y cells in vitro, we may provide the important clues on the genotoxic potentials of these BP-type UV filters.

• Asian Pacific Journal of Cancer Prevention
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• 제16권15호
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• pp.6279-6284
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• 2015

Opisthorchis viverrini (OV)-induced cholangiocarcinoma (CCA) is an important cancer in the Great Mekong region, particularly in Thailand. Limitations of treatment options and the lack of an effective diagnostic tool for early detection of CCA are major concerns for the control of this type of cancer. The aim of the study was to investigate anti-CCA activity of the ethanolic extract of Atractylodes lancea (Thunb.) DC., and the applicability of positron emission tomography-computed tomography (PET-CT) as a tool for detection and monitoring the progression of CCA in Opisthorchis viverrini (OV)/dimethylnitrosamine (DMN)-induced CCA hamsters. Male Syrian hamsters were used for toxicity tests and anti-CCA activity evaluation. Development of CCA was induced by initial feeding of 50 metacercariae of OV, followed by drinking water containing 12.5 ppm of DMN in hamsters. The ethanolic extract of A. lancea (Thunb.) DC. was administered orally for 30 days. PET-CT was performed every 4 weeks after initiation of CCA using 18F-fluorodeoxyglucose ($^{18}F-FDG$). Results from the present study suggest that the ethanolic extract of A. lancea (Thunb.) DC. rhizome exhibited promising anti-CCA activity and safety profile in the OV/DMN-induced hamster model. To successfully apply PET-CT as a tool for early detection of tumor development and progression, modification of radiolabeling approach is required to improve its specificity for CCA cells.

• 한국콘텐츠학회논문지
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• 제13권1호
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• pp.287-293
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• 2013

민들레는 한방에서 산화방지, 위장 점막 보호 및 담즙 등에 탁월한 효과가 있다고 알려져 있다. 민들레 잎과 뿌리에서 추출한 물질을 SD Rat에 투여한 후 10Gy 방사선 조사 후에 생존율, 혈액변화, 소장조직변화 및 간 조직 변화를 관찰하였다. 관찰결과 민들레 추출물을 투여한 실험군에서 생존율이 4배 이상 높았으며 백혈구, 혈소판 등의 혈액변화에서도 뚜렷한 차이가 보였다. 또한 소장 조직 관찰결과 소장점막세포 소멸 억제 및 소장 점막근판 조직의 염증과 공포가 감소되었다. 따라서 민들레 추출물이 방사선 조사에 따른 혈액구성세포와 소장 조직 손상에 대한 방사선 방호효과를 확인하였다.

• 대한본초학회지
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• 제31권4호
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• pp.87-91
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• 2016

Objectives : In order to confirm whether extracts of different parts of Zostera marina (ZM), a marine flowering plant, can be used as cosmetic ingredients, this study evaluated their cytotoxicity and cytoprotective effects against ultraviolet B (UVB). Inflammatory responses induced by UV stimuli are also associated with the aging of the skin.Methods : We investigated the effects of ZM extracts on cells through the water soluble tetrazolium salt-1(WST-1) assay for cell viability. In order to investigate the anti-inflammatory effects, we evaluated the suppression of Cyclooxygenase-2 (COX-2) expression by ZM extracts in HaCaT cells with UVB-induced damages, and also evaluated the production of Prostaglandin E₂ (PGE₂) in RAW 264.7 cells with LPS-induced damages.Results : High cell viabilities above 90% were observed in all types of ZM extracts, except for whole ZM extract at 0.5 mg/ml; in keratinocytes with UVB-induced damages, the cell viabilities were above 80% when treated with all types of ZM extracts. We confirmed their anti-inflammatory effects by investigating the suppression of inflammatory mediators. In keratinocytes with UVB-induced damages, COX-2 expression decreased in the experimental group treated with ZM extract. Similarly, in RAW 264.7 cells where inflammation was induced with LPS, the biosynthesis of PGE₂ was inhibited.Conclusion : These results suggest that ethanol extracts from Zostera marina may have value as the potential anti-inflammatory medicinal plant. Also based on the abovementioned results, ZM extract protects skin cells from UV-induced damages, and thus can be used in topically applied products for skin protection.

• 한국콘텐츠학회논문지
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• 제15권6호
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• pp.283-289
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• 2015

현재 방사선치료는 치료효과를 높이기 위해 고에너지 광자선의 사용이 증가하고 있는 추세이다. 일반적으로 6~8 MeV 이상의 고에너지 광자선을 사용하는 경우에는, 광핵반응에 의한 광중성자가 발생됨으로써 방사선 방호의 측면에서 많은 문제를 야기 시킬 수 있다. 이에 본 연구는 MCNPX를 이용하여 방사선 치료실의 광중성자 선량분포를 분석하였다. 그 결과 10 MV와 12 MV 구간에서 급격한 흡수선량의 증가를 보였다. 이를 통해 10 MV를 시작으로 광중성자 플루언스의 급격한 증가가 흡수선량으로 연계됨을 알 수 있었다. 또한 산출된 흡수선량을 바탕으로 등가선량을 환산한 결과는 ICRP 103 권고안의 경우, 낮은 에너지 범위에서 인체의 흡수선량에 대한 2차 광자의 기여를 반영함으로써 ICRP 60 권고안에 비해 낮은 등가선량을 나타냈다.

• 방사성폐기물학회지
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• 제3권4호
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• pp.359-372
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• 2005

원자력발전소 사고시 방사성물질이 발전소외 지역으로 유출될 경우 주민을 안전하게 보호하기 위한 조치의 일환으로 주민소개가 고려된다. 소개시간 산정에 필요한 인자를 도출하고, 각각의 인자에 대해 원전 주변의 현장자료를 토대로 부지주변의 교통환경 여건을 반영하여 울진원전의 방사선비상계획구역 내의 주민전체를 소개시키는데 소요되는 시간을 예측하였다. 평상교통, 여름철 첨두교통, 그리고 겨울철 첨두교통에 대해 각각 주간 및 야간, 평상기상 및 악기상의 경우로 나누어 12가지의 주민소개 시나리오를 설정하였다. 비상계획구역 경계 남단과 북단에서 모든 소개차량(인구)이 비상계획구역을 벗어나는 데 걸리는 시간은 전체적으로는 $210\~315$분 정도로 예측되었다. 소개시간은 밤이 낮보다 약 45분 정도 더 소요되는 것으로 예측되었다.

• Journal of Applied Biological Chemistry
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• 제50권4호
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• pp.215-220
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• 2007

One of the important functions of skin is protection from harmful environments. Many studies have explored how to prevent skin from wrinkling and the occurrence of pigmentation changes. Skin wrinkling and pigmentation changes could be caused by unusual disruption of connective tissue, the formation of free radicals and ultraviolet radiation. In this study, extracts obtained from 254 different kinds of Jeju medicinal plants were screened for inhibitory effects on tyrosinase and elastase, and for free radical scavenging effects. Four herbs, Phormium tenax, Morus bombycis, Morus alba, and Cudrania tricuspidata, were potent inhibitors of tyrosinase ($IC_{50}$ values 4.62, 5.46, 8.17, and 64.17 ${\mu}g$/mL, respectively). Aleurites fordii [$IC_{50}$: 5.29 ${\mu}g$/mL, 1,1-diphenyl-2-picrylhydrazyl (DPPH)], Distylium racemosum ($IC_{50}$: 6.14 ${\mu}g$/mL), Acer palmatum ($IC_{50}$: 5.44 ${\mu}g$/mL), and Spiraea salicifolia ($IC_{50}$: 5.25 ${\mu}g$/mL) showed good antioxidative effects. Furthermore, Distylium racemosum ($IC_{50}$: 7.51 ${\mu}g$/mL), Diospyros kaki ($IC_{50}$: 15.1 ${\mu}g$/mL), Cornus macrophylla ($IC_{50}:$ 16.59 ${\mu}g$/mL), and Psidium guajava ($IC_{50}$: 40.25 ${\mu}g$/mL) exhibited potent inhibitory effects on elastase. These results suggest that medicinal plants possessing several biological activities may be potent inhibitors of the processes involved in pigmentation increases and aging. Further investigations will focus on in vivo assays and on the chemical identification of the major active components responsible for whitening and anti-aging activity in the screened efficacious extracts.