• 치과방사선
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• 제17권1호
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• pp.7-20
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• 1987

The author studied the acute reaction of cobalt-60 irradiation to buccal mucosa in rats and difference of the effects of single versus fractionated exposure. 195 Sprague Dowley strain rats, weighing about 120gm, were used in this experiment. 3 rats served as controls and the remaining 192 rats were divided into six groups of 32 rats each. Experimental group Ⅰ, Ⅱ, Ⅲ were received a single dose of 15Gy, 16.5Gy, 18Gy and group Ⅳ, Ⅴ, Ⅵ were received two equal sized fractionated dose of 9Gy, 9.75Gy, 10.5Gy at 4 hour intervals, respectively. The experimental groups were irradiated with cobalt-60 teletherapy unit, Picker model 4M 60 (Field size, 12x5 cm, SSD, 50㎝, Dose rate, 222cGy/min, Depth, 1㎝). The animals were sacrificed at 1, 2, 3, 6, 12 hours, 1, 3, 7 days after irradiation and the changes of the irradiated buccal mucosa were observed by electron and light microscopy. The results were as follows: 1. A single exposure was more damaging than fractionated exposure, and as the radiation dose increased, the changes of cell organelles became faster, but the healing of radiation-induced damage in fractionated exposure was faster than in single exposure. 2. The radiation-induced changes of the basal cells were the most prominent in 18Gy-single exposure group, and the least in 18Gy-fractionated exposure group. 3. Electron-microscopically, there appeared nuclear changes, swelling of mitochondria and rough endoplasmic reticulum, decrease of free ribosome, presence of vesicles, widening of intercellular space, and loss of basal lamina. The early remarkable changes were partly loss of nuclear membrane and swelling of mitochondria. 4. Light-microscopically, derangement and pyknosis of basal cells, hydropic changes of spinous cells, enlargement of granular cells, indistinctness of basement membrane, and proliferation of epithelium were observed.

• Journal of Microbiology and Biotechnology
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• 제18권2호
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• pp.270-282
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• 2008

The yeast Saccharomyces cerevisiae has defense mechanisms identical to higher eukaryotes. It offers the potential for genome-wide experimental approaches owing to its smaller genome size and the availability of the complete sequence. It therefore represents an ideal eukaryotic model for studying cellular redox control and oxidative stress responses. S. cerevisiae Yap1 is a well-known transcription factor that is required for $H_2O_2$-dependent stress responses. Yap1 is involved in various signaling pathways in an oxidative stress response. The Gpx3 (Orp1/PHGpx3) protein is one of the factors related to these signaling pathways. It plays the role of a transducer that transfers the hydroperoxide signal to Yap1. In this study, using extensive proteomic and bioinformatics analyses, the function of the Gpx3 protein in an adaptive response against oxidative stress was investigated in wild-type, gpx3-deletion mutant, and gpx3-deletion mutant overexpressing Gpx3 protein strains. We identified 30 proteins that are related to the Gpx3-dependent oxidative stress responses and 17 proteins that are changed in a Gpx3-dependent manner regardless of oxidative stress. As expected, $H_2O_2$-responsive Gpx3-dependent proteins include a number of antioxidants related with cell rescue and defense. In addition, they contain a variety of proteins related to energy and carbohydrate metabolism, transcription, and protein fate. Based upon the experimental results, it is suggested that Gpx3-dependent stress adaptive response includes the regulation of genes related to the capacity to detoxify oxidants and repair oxidative stress-induced damages affected by Yap1 as well as metabolism and protein fate independent from Yap1.

• 한국콘텐츠학회논문지
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• 제10권10호
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• pp.120-127
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• 2010

디지털 카메라 및 카메라폰의 보급으로 언제 어디서나 디지털 사진을 찍고 즐기는 시대가 되었다. 이렇게 생활 속에서 생성되는 디지털 사진 콘텐츠의 양은 증가하고 있는데 그것을 감상하는 방법은 초기에는 휴대폰을 통해 보거나 PC를 통해 보는 것이 고작이었다. 휴대폰의 작은 화면이나 책상 앞의 PC모니터를 통해 보는 사진은 사진이라는 매체의 감상 행태와 어울리지 않았고, 그에 따라 사진감상 용도에 최적화된 디지털 액자라는 새로운 제품의 시장이 열리게 되었다. 지금까지 몇 년 간 여러 제조사에서 다양한 디지털액자 제품이 출시되고 있는데 시장에서 판매되는 대부분의 디지털액자들이 그 형태적 특성으로 인해 비슷한 인터랙션 방식을 갖고 있고, 그러한 인터랙션 방식이 사진액자라는 제품에 대해 사용자들이 갖고 있는 직관적 멘탈모델을 충족시켜주지 못하고 있다. 이에 본 연구는 사용자의 사용 행태와 제품이 놓이는 공간적 환경에 따라 한층 우수한 사용성과 감성적 만족을 제공할 수 있는 디지털액자의 인터랙션 방식을 제안하고자 한다.

• 한국정보통신학회논문지
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• 제20권3호
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• pp.621-629
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• 2016

본 논문은 소아 및 성인의 중이염을 자동 판별할 수 있는 알고리즘을 제안한다. 제안 방법은 중이염 영상과 정상 영상 데이터베이스에서 HoG(histogram of oriented gradient) 기술자를 사용하여 특징을 추출한 다음 SVM(support vector machine) 분류기를 통하여 추출된 특징들을 학습시킨다. 여기서 SVM 입력 벡터의 추출을 위하여 입력영상은 영상크기를 사전에 정의된 일정크기의 영상으로 변환되고 변환된 영상을 16개의 블록과 4개의 셀로 분할하며 9개의 빈을 가진 HoG를 사용한다. 결과적으로 입력 영상에서 576개의 특징을 추출하고 이를 SVM의 학습과 분류에 사용된다. 입력 영상이 학습된 특징들의 모델을 기반으로 SVM 분류기를 통하여 중이염 여부가 판별된다. 실험 결과 제안한 방법은 정확도 90% 이상의 판별 성능을 나타내었다.

• Journal of Microbiology and Biotechnology
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• 제29권11호
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• pp.1830-1840
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• 2019

Loliolide is one of the most ubiquitous monoterpenoid compounds found in algae, and its potential therapeutic effect on various dermatological conditions via agent-induced biological functions, including anti-oxidative and anti-apoptotic properties, was demonstrated. Here, we investigated the effects of loliolide on hair growth in dermal papilla (DP) cells, the main components regulating hair growth and loss conditions. For this purpose, we used a three-dimensional (3D) DP spheroid model that mimics the in vivo hair follicle system. Biochemical assays showed that low doses of loliolide increased the viability and size of 3D DP spheroids in a dose-dependent manner. This result correlated with increases in expression levels of hair growth-related autocrine factors including VEGF, IGF-1, and KGF. Immunoblotting and luciferase-reporter assays further revealed that loliolide induced AKT phosphorylation, and this effect led to stabilization of β-catenin, which plays a crucial role in the hair-inductive properties of DP cells. Further experiments showed that loliolide increased the expression levels of the DP signature genes, ALP, BMP2, VCAN, and HEY1. Furthermore, conditioned media from loliolide-treated DP spheroids significantly enhanced proliferation and the expression of hair growth regulatory genes in keratinocytes. These results suggested that loliolide could function in the hair growth inductivity of DP cells via the AKT/β-catenin signaling pathway.

• 한국추진공학회지
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• 제20권5호
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• pp.60-69
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• 2016

본 연구에서는 케로신-공기 혼합물 데토네이션 계산과 다물질 해석을 기반으로 데토네이션 하중에 의한 얇은 금속관의 열탄소성 거동에 대한 수치계산을 수행하였다. 데토네이션 하중은 케로신-공기 혼합물의 데토네이션을 활용하여 모델링하였으며, 검증을 위해 해석 결과를 C-J 조건과 실험적 셀 직경을 통해 비교 검증하였다. 또한 금속의 탄성/소성 거동을 확인하기 위하여, 소성 거동은 구리의 Taylor impact 문제로, 탄성 거동은 베를리움 평판 떨림 문제를 활용하였다. 온도에 의한 관의 탄소성 거동 변화를 확인하기 위하여 동일한 데토네이션 하중 하에서 초기 온도가 다른 관의 거동을 확인하고 이론식과의 비교를 통해 열연화 효과가 고려되어야 함을 확인하였다.

• 대한의생명과학회지
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• 제23권3호
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• pp.261-271
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• 2017

It has been suggested that ginseng is beneficial for ameliorating the aging males' symptoms, such as weight gain, fatigue, erectile dysfunction, and depression, in elderly men with testosterone deficiency. We thus investigated the effects of Korean red ginseng (Panax ginseng C.A. Meyer; Araliaceae) on obesity in a mouse model of testosterone deficiency (castrated C57BL/6J mice). The effects of ginseng extract (GE) and/or testosterone on obesity and adipogenesis in high-fat diet (HFD)-fed castrated C57BL/6J mice and 3T3-L1 adipocytes were examined using in vivo and in vitro approaches. After feeding mice a HFD for 8 weeks, we found that mice also receiving GE and/or testosterone showed decreased body weight, adipose tissue mass, adipocyte size, and hepatic lipid accumulation compared with untreated HFD-fed mice. Expression of adipogenic genes ($PPAR{\gamma}$, $C/EBP{\alpha}$, and aP2) was decreased by GE and/or testosterone in adipose tissues. Consistent with the in vivo data, lipid accumulation and the mRNA expression of adipogenesis genes in 3T3-L1 adipocytes were decreased by GE, ginsenosides, and testosterone. The inhibitory effects of GE (or ginsenosides) were comparable to those of testosterone, and the effects of co-treatment with GE (or ginsenosides) and testosterone were greater than those of testosterone alone in vivo and in vitro. Our results indicate that ginseng may be able to potentiate the inhibitory effects of testosterone on obesity and adipogenesis in HFD-fed castrated mice, providing possible therapeutic implications in men with testosterone deficiency.

• Spatial Information Research
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• 제10권2호
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• pp.301-316
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• 2002

강우나 물의 유출에 의한 토양침식은 농업 생산성을 떨어뜨리고 목초지를 손상시키며, 물의 흐름을 방해하는 등의 각종 환경적인 문제를 야기시키고 있다. 또한 침식된 토사의 하천유입으로 저수지나 댐의 유효저수량이 감소되는 문제가 발생하고 있다. GIS를 연계하여 유역의 토양침식량을 추정하기 위해 수정범용토양손실공식(RUSLE)을 주로 활용하고 있으나, 실측자료와의 비교가 어려워 계산된 토양침식량을 정량적으로 평가하는 것은 큰 의미가 없다 본 연구에서는 RUSLE 모형으로 계산한 토양침식량의 정량적인 추정을 위해 보성강 유역의 비퇴사량 실측자료를 이용하였다. RUSLE 모형으로 계산한 비유사량과 비퇴사량 실측자료로부터 계산한 비유사량과의 비교 검토를 통해 RUSLE 계산에 적합한 해상도를 결정한 결과, 150m의 셀크기가 가장 적절한 것으로 평가되었다.

• 대한전자공학회논문지SD
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• 제46권12호
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• pp.66-72
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• 2009

본 논문에서는 H.264/AVC에서 사용되는 엔트로피 부호화 방법 중 하나인 CABAC를 위한 효율적인 이진 산술 부호화기를 제안한다. 기존의 이진 산술 부호화 알고리즘은 연산의 복잡도와 각 단계간의 데이터 의존도가 매우 높기 때문에 빠른 연산이 어렵다. 따라서 연산 과정의 복잡도와 데이터 의존도를 줄이기 위하여 재정규화 과정을 효율적으로 처리할 수 있는 2단 파이프라인 구조를 사용한다. 하드웨어 면적을 줄이기 위해서 문맥 모델 갱신기는 transIdxMPS 표를 간단한 식으로 표현하고, transIdxLPS 표와 rangeTabLPS 표를 함께 구현한다. 산술 연산기는 입력 값의 발생 확률에 따라 일반 모드, 우회 모드, 종결 모드로 나누어 설계하여 각 모드마다 최대 속도로 동작할 수 있게 한다. 제안하는 이진 산술 부호화기는 0.18um 표준 셀 라이브러리에서 7282 게이트의 면적을 사용하며 입력 심벌 당 소요되는 사이클 수는 약 1을 갖는다.

• Journal of Ginseng Research
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• 제34권4호
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• pp.327-335
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• 2010

We reported previously that the administration of Korean red ginseng water extract (KRG-WE) protected the guinea pig testis against damage induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (a potent endocrine disruptor). We also found that crude saponin from ginseng was the active ingredient responsible for this protection. Here, we examined the biological role of KRG-WE in an animal model of age-induced dysfunction of spermatogenesis. Twenty-four male Sprague-Dawley (six 2-month-old and eighteen 12-month-old) rats were used. The young and old control groups received only vehicle. The ginseng saponin (GS)- and KRG-WE-treated groups received GS (40 mg/kg body weight/day) and KRG-WE (200 mg/kg body weight/day), respectively, for 4 months. The number of cells, Sertoli cell index, Johnsen's score, and sex hormone levels decreased significantly with age. However, the administration of KRG-WE and GS markedly improved the number of germ cells, seminiferous tubular size, and Johnsen's score in the old rats. Ginseng produced a distinct testicular histological improvement in old rats. KRG-WE and GS elevated testosterone levels, while attenuating the aberrant increase in follicle stimulating hormone and luteinizing hormone levels. Sperm kinematics evaluated by a computer-assisted sperm analyzer demonstrated improvement in the percentage of motile sperm, progressive sperm motility, and curvilinear velocity associated with sperm quality, supporting the beneficial role of red ginseng in senile spermatogenesis. Overall, the total water extract had a more potent effect than the corresponding saponin fraction. In conclusion, Korean red ginseng rejuvenated age-induced testicular dysfunction. Additionally, the total water extract was more potent than the corresponding saponin fraction.