• 한국수자원학회논문집
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• 제55권12호
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• pp.1125-1135
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• 2022

적설에 의한 피해는 자주 발생하지 않지만 발생하면 광범위한 지역에 피해를 준다. 적설에 의한 피해를 예방하기 위해서는 지역별로 피해를 유발하는 적설심을 미리 파악해 둘 필요가 있다. 하지만 관측하고 있는 적설심은 특정 관측지점으로 한정되어 피해를 유발하는 지역별 피해유발적설심을 파악하는데 어려움이 있다. 이를 극복하기 위한 일반적인 방법은 관측지점의 적설을 보간하여 공간적으로 확대하는 것이다. 하지만 이것은 매우 적은 자료를 가지고 고도 등 지형적인 특성이 다른 넓은 영역을 통계적으로 추론해야 하는 한계로 인해 지역에 대한 피해유발 피해유발적설심의 구명에 더 혼란을 주기도 한다. 이를 보완하기 위해서는 넓은 영역을 관측하는 위성영상을 활용할 수 있으며, 그 중에서도 합성개구레이더(Synthetic Aperture Radar; SAR)를 이용한 위상차분 간섭기법(DInSAR)을 활용할 수 있다. 위상간섭영상은 두 개의 다른 시기에 측정된 합성개구레이더 영상의 위상간섭을 이용한 것으로 일반적으로 미세한 지형의 변화를 추적할 때 사용되기도 한다. 본 연구에서는 유럽우주국(ESA)에서 운영하는 Sentinel-1B 위성의 dual polarimetric IW 모드 C-band SAR 데이터를 사용하여 DInSAR 분석을 수행하여 적설심의 공간분포를 추정하였다. 또한 정지궤도복합위성 천리안 2호(GK-2A)의 L2 적설심 추정 자료를 이용하여 비교하였다. 적용 결과, 적설예측의 정확도는 격자별로 계산할 경우, DInSAR 는 약 0.92%, GK-2A 는 약 0.71% 를 나타내 DInSAR의 적용성이 높게 나타났다. 즉, DInSAR 방법을 이용하여 계산된 적설심과 기상관측소에서 관측된 적설심을 공간보간하여 비교한 결과, 적설의 분석 결과 적설심을 과대추정하는 경우가 발생하기는 했으나, 적설심의 공간분포를 추정하는데 충분한 정보를 제공했으며, 이러한 방법으로 파악된 적설심의 공간분포는 실제 피해발생지역의 적설심을 보다 정확하게 추정하는데 기여할 수 있으며, 이것은 지역별 피해유발적설심을 파악하는데 도움이 될 것이다.

• 대한원격탐사학회지
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• 제34권3호
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• pp.451-463
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• 2018

본 연구는 서울지역에서 2015년 1월부터 12월까지 정지궤도 천리안 위성(Communication Ocean and Meteorological Satellite, COMS) 해양 탑재체(Geostationary Ocean Color Imager, GOCI)의 에어로졸광학두께(Aerosol Optical Depth, AOD)로부터 지상 초미세먼지(Particulate Matter; $PM_{2.5}$) 농도를 추정하기 위한 계절별 경험/통계모델을 개발했다. 행성경계층고도(Planetary Boundary Layer Height, PBLH) 그리고 에어로졸 수직 비율(Vertical Ratio of Aerosol, VRA)을 사용한 두 가지 수직보정방법과 흡습성장계수(Hygroscopic growth factor, f(RH))로부터의 습도보정방법이 각각의 경험적 모델에 적용된 결과 AOD에 대한 수직 보정과 $PM_{2.5}$에 대한 지표 습도보정이 모델 성능 향상에 중요한 역할을 했다. AOD-$PM_{2.5}$ 사이에 관련이 있다고 알려진 기상인자들(온도, 풍속, 시정)을 추가적으로 사용하여 다중 선형 회귀모델을 구성한 결과 경험모델에 비해 $R^2$값이 최대 0.25 증가했다. 본 연구에선 AOD-$PM_{2.5}$ 모델의 계절별, 월별, 시간별 특성을 분석하고 계절별로 구분하여 모델을 구성한 결과 고농도 사례에서 과소평가 되던 경향이 개선됨을 알 수 있고 관측된 $PM_{2.5}$와 추정된 $PM_{2.5}$의 월 및 시간변동성은 서로 경향성이 일치했다. 따라서 정지궤도 위성 AOD를 이용하여 지상 $PM_{2.5}$ 농도를 추정한 본 연구의 결과는 향후 발사 예정인 GK-2A와 GK-2B에 적용 가능할 것으로 기대된다.

• Nutrition Research and Practice
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• 제11권3호
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• pp.180-189
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• 2017

BACKGROUND/OBJECTIVES: Recent living condition improvements, changes in dietary habits, and reductions in physical activity are contributing to an increase in metabolic syndrome symptoms including diabetes and obesity. Through such societal developments, humankind is continuously exposed to metabolic diseases such as diabetes, and the number of the victims is increasing. This study investigated Cordyceps militaris water extract (CMW)-induced glucose uptake in HepG2 cells and the effect of CMW treatment on glucose metabolism. MATERIALS/METHODS: Colorimetric assay kits were used to determine the glucokinase (GK) and pyruvate dehydrogenase (PDH) activities, glucose uptake, and glycogen content. Either RT-PCR or western blot analysis was performed for quantitation of glucose transporter 2 (GLUT2), hepatocyte nuclear factor 1 alpha ($HNF-1{\alpha}$), phosphatidylinositol 3-kinase (PI3k), protein kinase B (Akt), phosphorylated AMP-activated protein kinase (pAMPK), phosphoenolpyruvate carboxykinase, GK, PDH, and glycogen synthase kinase 3 beta ($GSK-3{\beta}$) expression levels. The ${\alpha}-glucosidase$ inhibitory activities of acarbose and CMW were evaluated by absorbance measurement. RESULTS: CMW induced glucose uptake in HepG2 cells by increasing GLUT2 through $HNF-1{\alpha}$ expression stimulation. Glucose in the cells increased the CMW-induced phosphorylation of AMPK. In turn, glycolysis was stimulated, and glyconeogenesis was inhibited. Furthermore, by studying the mechanism of action of PI3k, Akt, and $GSK-3{\beta}$, and measuring glycogen content, the study confirmed that the glucose was stored in the liver as glycogen. Finally, CMW resulted in a higher level of ${\alpha}-glucosidase$ inhibitory activity than that from acarbose. CONCLUSION: CMW induced the uptake of glucose into HepG2 cells, as well, it induced metabolism of the absorbed glucose. It is concluded that CMW is a candidate or potential use in diabetes prevention and treatment.

• Mycobiology
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• 제30권1호
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• pp.31-36
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• 2002

Soil bacteria were screened for the ability to control cucumber anthracnose caused by Colletotrichum orbiculare through induced systemic resistance(ISR). Sixty-four bacterial strains having in vitro antifungal activity were used for selecting ISR-inducing strains in cucumber. Cucumber seeds(cv. Baeknokdadagi) were sown in potting mixtures incorporated with the soil bacteria, at a rate of ca. $10^8$ cells per gram of the mixture. Two week-old plants were then transplanted into the steam-sterilized soil. Three leaf-stage plants were inoculated with a conidial suspension($5{\times}10^5$ conidia/ml) of C. orbiculare. Diseased leaf area(%) and number of lesions per $cm^2$ leaf were evaluated on third leaves of the plants, $5{\sim}6$ days after inoculation. Among 64 strains tested, nine strains, GC-B19, GC-B35, GK-B18, MM-B22, PK-B14, RC-B41, RC-B64, RC-B65, and RC-B77 significantly(P=0.05) reduced anthracnose disease compared to the untreated control. In contrast, some bacterial strains promoted susceptibility of cucumber to the disease. From the repeated experiments using the nine bacterial strains, GC-B19, MM-B22, PK-B14, and RC-B65 significantly(P=0.05) reduced both diseased leaf area(%) and number of lesions per $cm^2$ leaf in at lease one experiment. These strains with control efficacy of $37{\sim}80%$ were determined to be effective ISR-inducing strains.

• 한국응용과학기술학회지
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• 제28권3호
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• pp.267-272
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• 2011

This study was carried to investigate the antidiabetic metabolism effect of water extract $Cordyceps$ $Militalis$(C.M.) in Streptozotocin(STZ) induced diabetic rats. Diabetes were induced by intravenous injection of STZ at a dose of 42mg/kg,b.w. dissolved in citrate buffer. The water extract of C.M. was orally administrated once a day for 7 days at a dose of 500mg/kg,b.w(body weight). or 1,000mg/kg.b.w. The content serum glucose was significantly decreased in C.M. treated group compared to the those of STZ-control group. The content of hepatic glycogen and activities of glucose-6-phosphate dehydrogenase(G-6-PDH), glucokinase(GK) were significantly increased, but activity of glucose-6-phoshatase(G-6-Pase) was significantly decreased in C.M. treated group compared to the those of STZ-control group. These results indicated that water extract of C.M. would have antidiabetic metabolism effect in STZ-induced diabetic rats.

• Biomolecules & Therapeutics
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• 제27권1호
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• pp.34-40
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• 2019

Transglutaminase 2 (TGase 2) plays a key role in p53 regulation, depleting p53 tumor suppressor through autophagy in renal cell carcinoma. We found that microtubule-associated protein 1A/1B-light chain 3 (LC3), a hallmark of autophagy, were tightly associated with the level of TGase 2 in cancer cells. TGase 2 overexpression increased LC3 levels, and TGase 2 knockdown decreased LC3 levels in cancer cells. Transcript abundance of LC3 was inversely correlated with level of wild type p53. TGase 2 knockdown using siRNA, or TGase 2 inhibition using GK921 significantly reduced autophagy through reduction of LC3 transcription, which was followed by restoration of p53 levels in cancer cells. TGase 2 overexpression promoted the autophagy process by LC3 induction, which was correlated with p53 depletion in cancer cells. Rapamycin-resistant cancer cells also showed higher expression of LC3 compared to the rapamycin-sensitive cancer cells, which was tightly correlated with TGase 2 levels. TGase 2 knockdown or TGase 2 inhibition sensitized rapamycin-resistant cancer cells to drug treatment. In summary, TGase 2 induces drug resistance by potentiating autophagy through LC3 induction via p53 regulation in cancer.

• Asian Pacific Journal of Cancer Prevention
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• 제17권6호
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• pp.2841-2846
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• 2016

Background: Tobacco use is the single most important preventable risk factor for cancer. Surveillance of tobacco-related cancers (TRC) is critical for monitoring trends and evaluating tobacco control programmes. We analysed the trends of TRC and evaluated the population-based cancer registry (PBCR) in Delhi for simplicity, comparability, validity, timeliness and representativeness. Materials and Methods: We interviewed key informants, observed registry processes and analysed the PBCR dataset for the period 1988-2009 using the 2009 TRC definition of the International Agency for Research on Cancer. We calculated the percentages of morphologically verified cancers, death certificate-only (DCO) cases, missing values of key variables and the time between cancer diagnosis and registration or publication for the year 2009. Results: The number of new cancer cases increased from 5,854 to 15,244 (160%) during 1988-2009. TRC constituted 58% of all cancers among men and 47% among women in 2009. The age-adjusted incidence rates of TRC per 100,000 population increased from 64.2 to 97.3 among men, and from 66.2 to 69.2 among women during 1988-2009. Data on all cancer cases presenting at all major government and private health facilities are actively collected by the PBCR staff using standard paper-based forms. Data abstraction and coding is conducted manually following ICD-10 classifications. Eighty per cent of cases were morphologically verified and 1% were identified by death certificate only. Less than 1% of key variables had missing values. The median time to registration and publishing was 13 and 32 months, respectively. Conclusions: The burden of TRC in Delhi is high and increasing. The Delhi PBCR is well organized and generates high-quality, representative data. However, data could be published earlier if paper-based data are replaced by electronic data abstraction.

• 한국항공우주학회지
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• 제47권12호
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• pp.890-896
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• 2019

지구 주위 궤도를 공전하는 위성체가 지구 지향 자세를 유지할 경우, 위성체에 장착된 태양전지판이 태양지향을 할 수 없기 때문에 태양전지판구동기를 장착하여 태양전지판이 태양을 지향하도록 운용한다. 이 때 태양 주변을 공전하는 지구 공전궤도의 이심율과 지구 자전축의 기욺으로 인해 태양전지판이 태양을 지향하는 위치가 계절에 따라 변경되어 균시차가 발생하는데 본 논문에서는 자세안정화 요구조건에 따라 두 개의 속도로 운용하는 태양전지판구동기 운용의 경우에 대해 균시차로 인한 태양지향 오차를 효과적으로 보상하는 운용 방안에 대해서 기술하고 실제적인 시뮬레이션을 통해 검증한 결과를 제시한다.

• 대한원격탐사학회지
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• 제39권6_2호
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• pp.1605-1613
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• 2023

해양 내의 다양한 물리적 변화는 수온과 염분의 지속적인 변동에 의해 결정된다. 수온과 더불어 넓은 영역의 염분 변화를 파악하기 위해서는 인공위성 자료에 의존할 수밖에 없다. 그럼에도 불구하고 염분을 관측하는 위성인 Soil Moisture Active Passive (SMAP)는 낮은 시·공간 해상도로 인해 연안 근처에서 빠르게 변화하는 해양환경을 관측하기에는 어렵다는 한계가 존재한다. 이러한 한계를 극복하기 위해 본 연구에서는 천리안 해양 관측 위성의 정지궤도 해색 센서인 Geostationary Ocean Color Imager-II (GOCI-II) 원격반사도 자료를 입력자료로 하여 고해상도 표층 염분을 산출하는 Multi-layer Perceptron Neural Network (MPNN) 기반의 알고리즘을 개발하였다. SMAP과 비교한 결과 coefficient of determination (R²)는 0.94, root mean square error (RMSE)는 0.58 psu 그리고 relative root mean square error (RRMSE)는 1.87%였으며, 공간적인 분포 또한 매우 유사한 결과를 나타냈다. R²의 공간 분포는 0.8 이상을 보여주었으며 RMSE는 전반적으로 1 psu 이하의 낮은 값을 보여주었다. 이어도 과학기지에서의 실측 염분값과도 비교하였지만 상대적으로 조금 낮은 결과를 보여주었다. 이에 대한 원인을 분석하였으며, 산출된 GOCI-II 기반 고해상도 염분 자료를 활용하여 2022년 11호 태풍 힌남노에 의한 하루 동안의 동중국해 표층 염분 변화를 표준편차로 계산하였다. 그 결과 SMAP에서 관측할 수 없는 시공간의 염분 변화를 고해상도의 GOCI-II 기반 염분 산출물을 통해 확인할 수 있었다. 따라서 본 연구를 통해 시간 단위로 변화하는 해양환경 모니터링에 큰 기여를 할 것으로 기대된다.

• Asian Pacific Journal of Cancer Prevention
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• 제17권7호
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• pp.3095-3099
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• 2016

Background: Cervical cancer is the most frequently diagnosed cancer among women in India. Understanding quality of life (QOL) in women undergoing chemo-radiotherapy for cervical cancer will help in introducing interventions for better care and outcomes in these women. This study assessed QOL before and after chemo-radiotherapy in cervical cancer patients. Materials and Methods: This follow-up study covered sixty-seven newly diagnosed women with advanced cervical cancer (stages 2b to 4b). Structured questionnaires (the European Organization for Research and Treatment of Cancer, EORTC QLQ-C30 and EORTC QLQ-CX24) were used to assess the change in QOL after 6 months of treatment. Results: The mean age of women at the time of detection of cervical cancer was $52.3{\pm}11.29$ years (Range 30-75 years). Six months survival was 92.53%. The mean global health score of cervical cancer patients after six months of treatment was 59.52, which was significantly higher than the pre-treatment score of 50.15 (p=0.00007). Physical, cognitive and emotional functioning improved significantly (p<0.05) after treatment. Fatigue, pain, insomnia and appetite loss improved but episodes of diarrhea increased after treatment. The mean "symptoms score" using EORTC QLQ-CX24 post treatment was 20.0 which was significantly lower as compared to the pre- treatment score 30.0 (p<0.00001). Sexual enjoyment and sexual functioning decreased significantly after treatment. Conclusions: QOL of newly diagnosed cervical cancer patients improved significantly following chemo-radio therapy. Enhancement was also demonstrated on three of the five functional scales of EORTC QLQ-C30. To further improve QOL, interventions focusing on social and psychological support and physical rehabilitation may be needed.