• 대한원격탐사학회지
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• 제39권6_3호
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• pp.1779-1790
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• 2023

위성 자료의 성능이 크게 개선됨에 따라 최근에는 위성을 이용하여 광범위한 영역에 대한 실시간 안개 탐지 알고리즘들이 개발되고 있다. 한반도 주변을 관측하는 기상위성 중 관측주기가 10분으로 시간해상도가 가장 우수한 GEO-KOMPSAT-2A/Advanced Meteorological Imager (GK2A/AMI)는 공간해상도가 500 m이다. 반면 GEO-KOMPSAT-2B/Geostationary Ocean Color Imager-II (GK2B/GOCI-II)는 해상도가 250 m지만, 1시간 주기로 관측하고 가시채널만 보유하고 있다. 따라서 본 연구에서는 한반도 주변에서 발생하는 안개를 10분 및 250 m 해상도로 탐지하기 위해 GK2AB 융합 안개 탐지 알고리즘(Fog Detection Algorithm, FDA)인 GK2AB FDA를 개발하였다. GK2AB FDA는 세 파트로 구성된다. 첫 번째로 현업 운용중인 GK2A 안개 탐지 알고리즘(GK2A FDA)으로 10분 및 500 m 해상도로 안개를 탐지한다. 두 번째 단계에서는 두 위성 자료 간 시공간 일치, 태양천정각과 파장역 차이를 보정한 GK2A normalized visible (NVIS)의 10분 변화량을 이용하여 GK2B NVIS를 10분 간격으로 외삽한다. 마지막 단계에서는 외삽된 GK2B NVIS, 태양천정각, GK2A FDA 산출물 등을 입력자료로 기계학습(의사결정나무)을 이용하여 개발된 GK2AB FDA로 지리적위치에 따라 안개를 탐지(250 m, 10분)한다. GK2AB FDA의 훈련에는 6개 사례, 검증에는 4개 사례가 이용되었다. GK2AB FDA의 정량적 검증에는 지상관측 시정, 풍속 그리고 상대습도 자료를 이용하였다. GK2AB FDA는 GK2A FDA에 비해 공간해상도가 4배 증가함에 따라 안개 및 비안개 화소가 보다 자세히 구분되었다. 또한 검증방법에 관계없이 GK2A FDA에 비해 probability of detection (POD)은 높고 Hanssen-Kuiper Skill score (KSS)는 높거나 비슷함을 보여 안개 탐지 수준이 개선된 것으로 보인다. 하지만 일부 사례에서는 GK2AB FDA의 false alarm ratio (FAR)와 Bias가 크게 나타나 안개를 과대탐지하는 문제를 보이고 있다.

• Preventive Nutrition and Food Science
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• 제5권4호
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• pp.189-193
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• 2000

Preservative and antimutagenic effects of green tea leaves added Chinese cabbage kimchi (GK1, GK2, GK3, and GK4 : 1, 2, 3 and 4 of green tea leaves (GTL) in proportion of 100 of salted Chinese cabbage were added to kimchi) were compared to those of the Chinese cabbage kimchi without GTL (control kimchi, CK). Fermentation period of GKs was further delayed than that of CK. The initial pH and acidity between GKs an CK were similar, but the time reach optimally ripened status of kimchi (pH 4.3) was different. CK took 6 days, while GK1, GK2, GK3 and GK4 took 6, 10, 12 and 14 days at 10℃, respectively. The growth of Leuconostoc sp. and Lactobacilus sp. in GKs delayed comparing to those in FCK. Among GKs, as the added amount of green tea leaves increased, the growth of lactic acid bacteria was retarded. The antimutagenic effects of juices from GKs and CK were studied against aflatoxin B₁(AFB₁) in the Ames test on Salmonella typehimurium TA100 and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in the SOS chromotest using E. coli PQ37. Juices from optimally ripened GKs (pH 4.3) showed 52∼76% inhibition rates against the indirect mutagen, aflatoxin B₁ induced mutagenicity while 49% inhibition rate by CK in the Ames test. Juices from GKs and CK showed 44∼67% and 36% inhibition rate against direct mutagen, MNNG (70 ng/assay) induce mutagenicity in the SOS chromotest. Thus GKs delayed fermentation period of kimchi and exhibited higher antimutagenic activity than CK.

• 생명과학회지
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• 제25권5호
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• pp.557-567
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• 2015

고부가가치 돌산갓 김치를 개발하고자 다시마를 주원료로 한 혼합조미농축액(CSS)과 표고버섯을 주원료로 한 혼합조미농축액 (CSL)을 첨가하여 각각 GK-A, GK-B 2종의 갓김치를 제조하였다. $4^{\circ}C$, 80일간 발효실험을 한 결과 GK-A군이 무기질, 식이섬유 함량이 높고 pH저하 및 산도 상승 지연 효과를 나타내었다. 염도는 70일째 이후 유의적 차이는 없었고, 환원당 함량은 대조군 보다 조미농축액 첨가군이 높게 나타났다. 유산균 Leuconostoc sp. 균수는 실험군이 대조군에 비하여 많았고, 적숙기를 지나면서 증가하는 Lactobacillus sp.는 대조군이 발효 20일째부터 증가하였다. 명도는 담근 초기에서 30일까지는 대조군이 높고, 황색도는 GK-B군이 20일부터 높아져 갈변 가능성이 높았다. 경도는 GK-A군이 담금 초기와 10일째 높은 수치를 나타내었다. 유리아미노산 GK-A군이 aspartic acid과 glutamic acid 함량이 전 기간에서 유의적으로 높았다(p<0.05). 단맛계 아미노산의 함량은 GK-A군이 발효 0일, 10일, 30일째 함량에서 다른 군에 비해 유의적으로 높은 수준을 나타내었다(p<0.05). 관능검사 결과는 GK-A가 가장 기호도가 우수하였다. 이상의 결과를 종합적으로 검토한 결과, 다시마를 주원료로 하여 만든 혼합조미농축액 CSS를 90 g 첨가하여 담근 GK-A군이 소비자에게 맛과 영양을 제공할 수 있는 새로운 돌산갓김치 상품으로 가능성이 있을 것으로 기대된다.

• Journal of Microbiology and Biotechnology
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• 제13권5호
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• pp.660-665
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• 2003

High-level expression of Thermus caldophilus GK24 alkaline phosphatase (Tca APase) was achieved in Escherichia coli using the pET-based expression plasmids, pEAP1 and pEAP2. In the case of plasmid pEAP2, the signal peptide region of Tca APase was replaced by the PelB leader peptide of expression vector pET-22b(+). Furthermore, the expression level was somewhat higher than that of plasmid pEAPl. A rapid purification procedure of Tca APase overproduced in E. coli was developed which involved heating to denature E. coli proteins followed by HiTrap Heparin HP column chromatography. Optimal temperature and pH and $Mg^{2+}$ dependence of the recombinant Tca APase were similar to those of native enzyme isolated from T. caldophilus GK24.

• Journal of Ginseng Research
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• 제45권6호
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• pp.631-641
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• 2021

Background: Main bioactive constituents and pharmacological functions of ripened red ginseng berry (Panax ginseng Meyer) have been frequently reported. Yet, the research gap targeting the beneficial activities of transformed green ginseng berries has not reported elsewhere. Methods: Ginsenosides of new green berry cultivar K-1 (GK-1) were identified by HPLC-QTOF/MS. Ginsenosides bioconversion in GK-1 by bgp1 enzyme was confirmed with HPLC and TLC. Then, mechanisms of GK-1 and β-glucosidase (bgp1) biotransformed GK-1 (BGK-1) were determined by Quantitative Reverse Transcription-Polymerase Chain Reaction and Western blot. Results: GK-1 possesses highest ginsenosides especially ginsenoside-Re amongst seven ginseng cultivars including (Chunpoong, Huangsuk, Kumpoong, K-1, Honkaejong, Gopoong, and Yunpoong). Ginseng root's biomass is not affected with the harvest of GK-1 at 3 weeks after flowering period. Then, Re is bioconverted into a promising pharmaceutical effect of Rg2 via bgp1. According to the results of cell assays, BGK-1 shows decrease of tyrosinase and melanin content in α-melanocyte-stimulating hormone challenged-murine melanoma B16 cells. BGK-1 which is comparatively more effective than GK-1 extract shows significant suppression of the nuclear factor (NF)-κB activation and inflammatory target genes, in LPS-stimulated RAW 264.7 cells. Conclusion: These results reported effective whitening and anti-inflammatory of BGK-1 as compared to GK-1.

• Journal of Microbiology and Biotechnology
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• 제29권5호
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• pp.820-826
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• 2019

This study evaluated the anti-inflammatory potential of a grasshopper ketone (GK) isolated from the brown alga Sargassum fulvellum on lipopolysaccharide (LPS)-induced RAW 264.7 murine macrophage cell line. GK was isolated and purified from the n-hexane fraction and its structure was verified on the basis of NMR spectroscopic data. GK up to $100{\mu}g/ml$ is not cytotoxic to RAW 264.7, and is an effective inhibitor of LPS-induced NO production in RAW 264.7 cells. The production of pro-inflammatory cytokines, including IL-6, $IL-1{\beta}$, and $TNF-{\alpha}$ was found significantly reduced in $0.1-100{\mu}g/ml$ dose ranges of GK treatment (p < 0.05). We confirmed the dose-dependent and significant inhibition of iNOS and COX-2 proteins expression. In addition, it has been shown that GK induces anti-inflammatory effects by inhibiting MAPKs (ERK, JNK, and p38) and $NF-{\kappa}B$ p65 phosphorylation. Our results show that the anti-inflammatory properties of GK may be due to the inhibition of the $NF-{\kappa}B$ and MAPKs pathways, which are associated with the attenuation of cytokine secretion.

• 대기
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• 제24권2호
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• pp.265-281
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• 2014

Currently, Korea is developing a Cheollian follow-on satellite program, named as Geostationary Korea Multipurpose Satellite 2 (GK-2), which consists of two satellites. One satellite (GK-2A) is dedicated to the meterological mission, while the second one (GK-2B) hosts two main payloads for the ocean and environmental application. As GK-2A is dedicated to the meteorological mission unlike Cheollian, there have been discussions on the possibility of transferring the responsibilities of the GK-2A program to the Korea Meteorological Administration. To help resolve any consumptive disputes or to find an efficient way for the GK-2A program, the events happened after the successful launch of the first meteorological satellite TIROS-1 in the U.S. in April 1960 are investigated. With the successful demonstration of usefulness of TIROS-1 for the meteorological applications, organizations such as the Weather Bureau and the Department of Defense, responsible for the real time application of the TIROS 1 data, strongly requested for an operational meteorological satellite program which resulted in the plan for the National Operational Meteorological Satellite System (NOMSS). The plan was strongly supported by Kennedy Adminstration and was put forwarded for the new program under the responsibility of Weather Bureau to the Congress. However, the responsible Committee on Science and Aeronautics sided with NASA and requested major revision of the responsibility. Due to many unfavorable conditions, Weather Bureau accepted the requests and signed with NASA on the agreement for the operational meteorological satellite. However, with the delay of Nimbus satellite which is planned to be used for the prototype of the operational satellite and changes of the unfavorable situations, the Weather Bureau could draw a second agreement with NASA. The new agreement reflected most propositions requested by the Weather Bureau for the NOMSS plan. Until now the second agreement is regarded as the basic principles for the operational meteorological satellite program in the U.S. This study investigates the backgrounds and processes of the second agreement and its implications for the GK-2 program.

• BMB Reports
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• 제30권5호
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• pp.356-361
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• 1997

We cloned a cDNA (pPRC-1) which was comprised of 841 nucleotides from the cDNA library of a male ICR mouse submandibular gland ($SMG^+$). The nucleotide sequences of pPRC-1 were identical to those of exons 2 and 3 of the mGK-21 gene, a potentially functional glandular kallikrein identified in a Balb/c mouse, except for one nucleotide residue. Although this substitution changes Ile (ATT) in pPRC-1 to Val (GTT) in mGK-21, this difference has been explained by strain polymorphism. From the amino acid sequences predicted from its cDNA, we speculated that mGK-21 gene products/pGK21 consist of 261 amino acids including the $NH_2$-terminal signal peptide (residues 1~17), the short propeptide (residues 17~24), and the active peptide (residues 25~261). Although we did not demonstrate the enzyme activity of pGK21, it was assumed that pGK 21 was involved in the maturation of certain bioactive polypeptide(s) in mouse SMG for the following reasons : (a) mGK-21 gene was apparently expressed in a male ICR mouse SMG: (b) the proposed active site $His^{65}$, $Asp^{120}$, and $Ser^{213}$ residues were completely conserved in pGK21 just like other glandular kallikreins; (c) the cloned cDNA was translated to a predicted 27 kDa polypeptide chain in vitro: (d) the 27 kDa polypeptide chain produced by CHO cells was produced to a putative active form by trypsin.

• Preventive Nutrition and Food Science
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• 제19권4호
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• pp.281-290
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• 2014

The aim of the present study was to evaluate the anti-diabetic, anti-inflammatory, antioxidant potential, and total phenolic content (TPC) of green and red kohlrabi cultivars. Anti-diabetic and anti-inflammatory activities were evaluated via protein tyrosine phosphatase (PTP1B) and rat lens aldose reductase inhibitory assays and cell-based lipopolysaccharide (LPS)-induced nitric oxide (NO) inhibitory assays in RAW 264.7 murine macrophages. In addition, scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical, and peroxynitrite ($ONOO^-$) were used to evaluate antioxidant potential and TPC was selected to assess phytochemical characteristics. Between the two kohlrabi cultivars, red kohlrabi (RK) had two times more TPC than green kohlrabi (GK) and showed significant antioxidant effects in DPPH, ABTS, and $ONOO^-$ scavenging assays. Likewise, methanol (MeOH) extracts of RK and GK inhibited LPS-induced NO production in a dose dependent manner that was further clarified by suppression of iNOS and COX-2 protein production. The MeOH extracts of RK and GK exhibited potent inhibitory activities against PTP1B with the corresponding $IC_{50}$ values of $207{\pm}3.48$ and $287{\pm}3.22{\mu}g/mL$, respectively. Interestingly, the RK MeOH extract exhibited significantly stronger anti-inflammatory, anti-diabetic, and antioxidant effects than that of GK MeOH extract. As a result, our study establishes that RK extract with a higher TPC might be useful as a potent anti-diabetic, antioxidant, and anti-inflammatory agent.

• Mycobiology
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• 제29권4호
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• pp.218-223
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• 2001

A rapid radicle assay for prescreening antagonistic bacteria to Phytophthora capsic4 causal agent of Phytophthora blight of pepper was developed. Sixty-four bacterial strains with in vitro antifungal activity selected out of 1,400 strains isolated from soils of Ansung, Chunan, Koyang, and Paju, Korea in 1998 were used for development of the bioassay. Uniformly germinated pepper seeds dipped in bacterial cells for 3 hours were placed near the edges of growing mycelia of P. capsici on water agar containing 0.02% glucose. Five-week-old pepper plants(cv. Nockwang) were inoculated to compare with results of the radicle assay developed in this study. For plant inoculation, pepper seeds were sown in potting mixtures incorporated with the bacterial strains, then transplanted into steam-sterilized soils 3 weeks later. Plants were hole-inoculated with zoospores of P. capsici 2 weeks after transplanting. Disease incidence and severity were determined in radicle and plant assessments, respectively. In radicle assay, six strains, GK-B15, GK-B25, OA-B26, OA-B36, PK-B09, and VK-B14 consistently showed the significant(P=0.05) disease reduction against radicle infection by the fungus, four of which also did in plant assessments. Strains OA-B36 and GK-B15 consistently reduced the fungal infection in both the radicle assay and the plant assessment. Therefore, prescreening strains using the radicle assay developed in this study followed by plant assay could reduce time and labor, and improved the possibility of selecting antagonistic bacteria for control of Phytophthora blight of peppers.