• Macromolecular Research
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• 제17권10호
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• pp.734-738
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• 2009

Biodegradable, pH-sensitive, glycol chitosan (GC) hydrogels were prepared using divinyl adipate (DVA) as a crosslinker and acetic acid as a catalyst. DVA has highly reactive double vinyl ester groups and GC contains a high density of hydroxyl groups, with two in every glucosamine unit. The transesterification reaction between vinyl esters and hydroxyl groups produced crosslinked GC hydrogels. The initial crosslinking reaction was monitored by measuring the viscosity of the reaction mixture. When DVA was added to the GC solution and heated to $50^{\circ}C$, the viscosity of the GC solution gradually increased, implying a crosslinking reaction and hydrogel formation. A new peak from the ester group was observed in the FTIR spectra of the GC hydrogels, confirming the crosslinking reaction. The synthesized GC hydrogel showed pH-dependent water absorbency, mainly due to the presence of amine groups ($-NH_2$) at the C-2 position of the glucosamine unit of GC. The water absorbency greatly increased at acidic pH and slightly decreased at alkaline pH. The GC hydrogel gradually degraded in $37^{\circ}C$ water due to hydrolysis of the ester bonds, which were intermolecular crosslinking sites. A red dye, 5-carboxyltetramethyl-rhodamine (CTMR), was entrapped in the GC hydrogels as a model compound. CTMR was released from GC hydrogels in two steps: an initial burst release mainly due to desorption and diffusion, and a second sustained release possibly due to gradual degradation.

• 한국식품영양학회지
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• 제10권4호
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• pp.539-543
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• 1997

중국부추 및 백석부추의 휘발성 풍미 성분을 분석하기 위하여 dynamic head space 방법으로 정유성분을 분리한 다음 GC 및 GC-MS를 이용하여 성분을 확인하였다. 즉 중국부추에서는 sulfide류가 20종, alcohol이 5종,benzene이 1종 그리고 aldehyde는 2종이 확인되었고 백석부추에서는 sulfide류가 19종, alcohol이 10종, benzene이 2종, 그리고 aldehyde는 1종, furan이 1종 확인되었다.

• 한국식품영양학회지
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• 제9권2호
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• pp.217-222
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• 1996

We studied about analyzing carbamate pesticides, organochlorine, organophosphorus pesticides simultaneously using by GC/MSD. For this, instead of HPLC which is generally used in analyzing carbamate pesticides, GC was used and all hydrogen of -NH group in carbamate pesticides were substituted for trifluoroacetyl group which is stable at heat And eight pesticide resdidues were not detected in nine samples circulated in the city.

• 생명과학회지
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• 제5권2호
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• pp.20-20
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• 1995

The aroma components of commercial green teas picked inAugust were collected and identified. The extract of aroma compounds in green tea were accoimplished by a modified rotary evaporation. The concentrated wxtracts were analyzed and identified by GC and GC-MS. In GC analysis, T$_{R}$ value of GC represented bt KI value which standardized. The most abundant components of green teas picked in August were 1-Penten-3-ol, trans, trans-2, 4-heptadienal, linalool, $\beta$-ionone and nerolidol.

• 생명과학회지
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• 제5권2호
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• pp.76-80
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• 1995

The aroma components of commercial green teas picked inAugust were collected and identified. The extract of aroma compounds in green tea were accoimplished by a modified rotary evaporation. The concentrated wxtracts were analyzed and identified by GC and GC-MS. In GC analysis, T$_{R}$ value of GC represented bt KI value which standardized. The most abundant components of green teas picked in August were 1-Penten-3-ol, trans, trans-2, 4-heptadienal, linalool, $\beta$-ionone and nerolidol.

• 한국가금학회지
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• 제29권1호
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• pp.7-12
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• 2002

본 연구의 목적은 게르마늄을 함유한 비특이 면역증가제를 산란계에 급여하였을 때 계란품질 및 면역반응에 미치는 영향을 조사하기 위하여 실시하였다. 사양시험은 32주령 ISA Brown 산란계 144수를 공시하였으며, 처리구로는 대조구(CON; 기초사료), 대조구 사료 내 게르마늄이 0.5 ppm(GC0.5), 1.0ppm(GC1.00) 처리구로 구성되었다. 총 40 일간의 사양시험 기간동안, 난각강도에 있어서는 GC0.5처리구가 대조구 및 GC10. 처리구보다 유의적으로 낮게 평가되었다(quadratic effect, p<0.01). 난각두께에 있어서는 대조구와 처리구간에 통계적으로 유의적인 차이는 보이지 않았다. 난황색은 대조구와 처리구간에 유의적인 차이를 보이지 않았으며, 난황계수에 있어서는 GC1.0 처리구가 다른 처리구와 비교하여 높게 평가되었다(quadratic effect, P<0.02). 혈청내 총 콜레스테롤 및 중성지질 함량에 있어서는 GC의 첨가수준이 증가함에 따라 감소하는 경향을 나타내었으나 유의적인 차이는 보이지 않았다. 또한, 혈청 내 HDL 및 LDL+VLDL 콜레스테롤 함량에 있어서는 GC0.5 처리구가 다른 처리구와 비교하여 가장 낮게 평가되었으나 유의적인 차이는 보이지 않았다. 혈중 내 적혈구 및 백혈구 농도는 비특이 면역증가제의 첨가수준이 증가함에 따라 유의적으로 증가하는 경향을 나타내었다(linear effect, p<0.01) . 혈중내 hematocrit 함량은 대조구와 비교하여 게르마늄 용질액을 첨가함에 따라 유의적으로 증가하는 경향을 보였다(linear effect, p<0.01). 결론적으로, 산란계 사료내 GC의 첨가는 난각특성에는 영향을 미치지 못하는 것으로 사료되나, 산란계의 면역활성화를 유도할 수 있을 것으로 사료된다.

• 대기
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• 제32권3호
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• pp.235-246
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• 2022

A large number of MJO skill metrics and process-oriented MJO simulation metrics have been developed by previous studies including the MJO Working Group and Task Force. To assess models' successes and shortcomings in the MJO simulation, a standardized set of diagnostics with the additional set of dynamics-oriented diagnostics are applied. The Global Coupled (GC) model developed for the operation of the climate prediction system is used with the comparison between the GC2 and GC3.1. Two GC models successfully capture three-dimensional dynamic and thermodynamic structure as well as coherent eastward propagation from the reference regions of the Indian Ocean and the western Pacific. The low-level moisture convergence (LLMC) ahead of the MJO deep convection, the low-level westerly and easterly associated with the coupled Rossby-Kelvin wave and the upper-level divergence are simulated successfully. The GC3.1 model simulates a better three-dimensional structure of MJO and thus reproduces more realistic eastward propagation. In GC2, the MJO convection following the LLMC near and east of the Maritime Continent is much weaker than observation and has an asymmetric distribution of both low and upper-level circulation anomalies. The common shortcomings of GC2 and GC3.1 are revealed in the shorter MJO periods and relatively weak LLMC as well as convective activity over the western Indian Ocean.

• Journal of Microbiology and Biotechnology
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• 제32권7호
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• pp.938-948
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• 2022

Gastric cancers (GC) are generally malignant tumors, occurring with high incidence and threatening public health around the world. Circular RNAs (circRNAs) play crucial roles in modulating various cancers, including GC. However, the functions of circRNAs and their regulatory mechanism in colorectal cancer (CRC) remain largely unknown. This study focuses on both the role of circCOL1A2 in CRC progression as well as its downstream molecular mechanism. Quantitative polymerase chain reaction (qPCR) and western blot were adopted for gene expression analysis. Functional experiments were performed to study the biological functions. Fluorescence in situ hybridization (FISH) and subcellular fraction assays were employed to detect the subcellular distribution. Luciferase reporter, RNA-binding protein immunoprecipitation (RIP), co-immunoprecipitation (Co-IP), RNA pull-down, and immunofluorescence (IF) and immunoprecipitation (IP) assays were used to explore the underlying mechanisms. Our results found circCOL1A2 to be not only upregulated in GC cells, but that it also propels the migration and invasion of GC cells. CircCOL1A2 functions as a competing endogenous RNA (ceRNA) by sequestering microRNA-1286 (miR-1286) to modulate ubiquitin-specific peptidase 10 (USP10), which in turn spurs the migration and invasion of GC cells by regulating RFC2. In sum, CircCOL1A2 sponges miR-1286 to promote cell invasion and migration of GC by elevating the expression of USP10 to downregulate the level of RFC2 ubiquitination. Our study offers a potential novel target for the early diagnosis and treatment of GC.

• Clinical and Experimental Reproductive Medicine
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• 제24권2호
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• pp.267-271
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• 1997

Apoptosis, programmed cell death, is posulated to occur in granulosa cells in ovarian follicular atresia. bcl-2 gene serves as protector from apoptosis and, thus, is associated with increased cell survival. TRPM-2 gene expression has been implicated as a trigger of apoptosis in rat prostate, uterus and mammary gland. Our objective was to determine if bcl-2 and TRPM-2 are expressed in luteinized human GC and, therefore, have regulatory functions for apoptosis in GC. Human GC were obtained via oocyte retrival from the infertile patients stimulated with exogeneous gonadotropins while undergoing IVF. GC were isolated from follicular fluid using Percoll gradient centrifugation. The GC were further purified with anti-CD45 magnetic beads to remove contaminating WBC's. RT-PCR were performed to analyze the mRNA expression of bcl-2 and TRPM-2 in the GC. The PCR primers were designed to amplify a 195 bp fragment of bcl-2 and a 174 bp fragment of TRPM-2. The PCR products were electrophoresed on 4% agarose gel. Three separate experiments indicated that both bcl-2 and TRPM-2 are concurrently expressed in human GC. We cultured granulosa cells with FSH (1 ng/ml) for 1 day to investigate the relative changes of TRPM-2 mRNA level with RNAse protection assay. When we cultured GC with serum free medium for 1 day TRPM-2 mRNA level increased with 1.3 fold, however it was decreased 0.64 fold with FSH. Therefore we conclude that bcl-2 and TRPM-2 are concurrently expressed and that the interaction of their products may be involved in GC apoptosis. And TRPM-2 may be regulated with FSH.

• 한국식품과학회지
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• 제35권3호
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• pp.353-358
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• 2003

지금까지 거의 보고되지 않은 동물간의 비린내 불쾌취를 밝히는 것을 목적으로, 연속수증기증류에 의해 얻어진 가열돼지간의 휘발성 농축물중에 포함된 화합물을 분리 동정하여, 가열에 의해서도 없어지지 않고 잔존하는 비린내물쾌취를 검토하였다. 또한, GC 분석시, GC-O를 이용하여 각 휘발성화합물의 냄새를 평가하였다. 그 결과, 간은 가열하는 것에 의해 특이적인 비린내불쾌취가 소실되지 않으며, 여전히 잔존함이 확인되었다. 동정된 69종의 화합물중 비린내를 갖는 (E,E)-2,4-heptadienal(fishy) 및 금속취를 갖는 1-octen-3-one, hexanol의 존재를 확인하였다. 또한 가열돼지간의 불쾌취 형성에 기여하는 것으로 생각되어지는 (E)-2-nonenal(cardboard-like), (Z)-4-decenal(cardboard-like), (E,E)-2,4-decadienal(deep-fried) 등 낮은 한계값을 갖는 aldehyde 류의 생성을 확인하였다. 동정된 69종의 화합물중 40종류의 성분은 본 연구에서 처음으로 가열 돼지간의 휘발성성분으로 동정되었다. 1-Octen-3-one, hexanol, (E)-2-nonenal, (Z)-4-decenal, (E,E)-2,4-heptadienal 등은 특징적인 냄새를 나타내며, 돼지간의 불쾌취 형성에 있어 중요한 화합물로 사료된다. 이들 alkanal, alkenal 및 alkanone류는 돼지간에 다량 함유된 불포화지방산의 산화 반응생성물로, 그 일부는 가열처리에 의한 분해생성물인 것으로 사료된다.