• 생물환경조절학회지
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• 제29권3호
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• pp.306-312
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• 2020

본 연구에서는 여름철 고온기 시설재배시 수시차광이 내부환경과 오이 생리적 반응에 미치는 영향을 검토하였다. 온실차광이 오이의 고온 스트레스 완화 정도를 추정하기 위하여 잎 온도, 엽기온차, 최대 카르복실화속도, 최대 전자전달 속도, 열파괴, 광호흡과 같은 오이의 생리적 반응을 측정 분석하였다. 오이 시설하우스의 차광율은 90% 수시차광, 40% 수시차광, 무차광 3수준의 실험 조건으로 하였다. 90% 수시차광은 외부 일사량이 650 W·m^-2일 때 차광되도록 하였다. 기온, 일사량, 엽온, 엽기온차, 광호흡은 90%의 수시차광에서 40% 수시차광과 무차광 처리 보다 낮은 값을 나타내었다. 최대 카르복실화속도, 광호흡율은 90% 수시차광 온실이 다른 처리구보다 유의하게 낮은 것으로 나타났다. 고온저항성을 나타내는 thermal breakdown 값은 90%의 수시차광에서 다른 처리구 보다 유의하게 높은 것으로 나타났다. 따라서, 90% 수시차광이 여름철 오이 재배에 있어 고온스트레스를 덜받는 생육환경을 조성하였다는 결과를 얻었다.

• 한국식품과학회지
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• 제40권2호
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• pp.146-151
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• 2008

불용성 ${\beta}$-1,3-glucan의 물에 대한 수용성과 젤 형성능을 향상시키기 위해 회분식 혹은 반연속식 반응과 촉매로서 NaBr 첨가 및 무첨가 조건을 연구하였다. NaBr 무첨가 반응의 경우 회분식 및 반연속식에서 NaBr 첨가반응에 비해 반응종결시간이 각각 100, 150%씩 늦어졌으나 물에 대한 용해도, 젤 형성능 등의 이화학적 성질은 NaBr 첨가 조건과 동일하게 향상 되었다. 반응시간의 차이는 나타나지만 회분식 반응에서 NaBr 첨가 여부에 관계없이 0.5 N NaOH 20 mL를 소비하여 ${\beta}$-1,3-glucan의 특이적 산화 전환의 이론적 수준인 100% 수율을 보였으나 회수된 산화물은 NaBr 무첨가 반응의 수율이 NaBr 첨가 반응보다 약 7-8% 낮았다. 높은 산화수율을 보인 ${\beta}$-1,3-glucan의 반연속식 공정 연구를 통해 산화반응물의 대량 생산이 가능하여 천연 소재, 기능성식품, 음료 및 주류 등의 산업에 널리 응용될 수 있을 것으로 기대된다. 특히 NaBr을 첨가하지 않고서도 특이적인 산화반응을 유도함으로써 안전성이 확보된 산화 ${\beta}$-1,3-glucan을 생산할 수 있음을 확인하였다.

• Journal of Nutrition and Health
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• 제35권2호
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• pp.207-212
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• 2002

Acetyl-CoA carboxylase (ACC) is the enzyme that controls no devo fatty acid biogynthesis, and this enzyme catalyzes the carboxylation pathway of acetyl-CoA to malonyl-CoA. Acetyl-CoA carboxylase gene expression was regulated by nutritional and hormonal status. The present study was performed to identify the regulation mechanism of ACC gene promoter I. The fragments of ACC promoter I -1.2-kb region wert recombined to pGL3-Basic vector with luciferase as a reporter gene. The primary hepatocytes from the rat were used to investigate the hormonal regulation of ACC promoter I activity. ACC PI (-1.2)/Luc plasmid was trtransferred into primary hepatocytes using lipofectin. Activity of luciferase was increased two-fold by 10-9M, three-fold by 10-8M, 10-6M, 3.5-fold by 10-6M, and 4.5-fold by 10-7M insulin treatment, respectively. In the presence of dexamethasone (1 $\mu$M), the effects of insulin increased about 1.5-fold, showing the additional effects of dexamethasone. Moreover, the activity of luciferase increased with insulin+dexamethasone, insulin+T3, dexamethasone+T3, and dexamethasone+insulin+T3 treatment approximately 6-, 4-, 6.5-, and 10-fold, respectively. Therefore it can be postulated that 1) these hormones coordinately regulate acetyl-CoA caroxylase gene expression via regulation of promoter activity, 2) the -1.2-kb region of ACC promoter I may have the response element sequences for insulin, dexamethasone, and T3.

• Journal of the Korean Wood Science and Technology
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• 제48권2호
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• pp.231-244
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• 2020

As a way of finding value-added materials from waste medium density fiberboard (MDF), this study characterized cellulose nanocrystals (CNCs) isolated by ammonium persulfate (APS) oxidation using recycled MDF fibers. Chemical composition of the recycled MDF fibers was done to quantify α-cellulose, hemicellulose, lignin, nitrogen, ash and extractives. The APS oxidation was performed at 60 ℃ for 16 h, followed by ultrasonication, which resulted in a CNC yield of 11%. Transmission electron microscope images showed that rod-like CNCs had an average length and diameter of 167±47 nm and 8.24±2.28 nm, respectively, which gave an aspect ratio of about 20. The conductometric titration of aqueous CNCs suspension resulted in a carboxyl content of 0.24 mmol/g and the degree of oxidation was 0.04. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy clearly showed the presence of carboxyl group on the CNCs prepared by the APS oxidation. The change of pH of the aqueous CNC suspension from 4 to 7 converted the carboxyl group to sodium carboxylate group. These results showed that the APS oxidation was facile and CNCs had a one-step preparation method, and thus suggested an optimization of the oxidation condition in future.

• Journal of Nutrition and Health
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• 제30권3호
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• pp.299-306
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• 1997

Vitamin K takes part in both blood coagulation and bone metabolism via the carboxylation of glutamate residues. This study was performed to examine the relationship between dietary phylloquinone intake and bone mineral denisty(BMD) among postmenopausal Korean women (n=70, age=56). The bone mineral density of the lumbar spine and femoral neck were measured by dual X-ray absorptiometry(DEXA). Daily intakes of phylloquinone and calcium were assessed using a food frequency questionnarie. As a results, body weigh, height and body mass index were not correlated with BMD. However, the number of years since monopause and daily intakes of calcium were significantly correlated with BMD. Although daily intakes of phylloquinone were not correlated with BMD, women with relatively high BMD consumed more phylloquinone than those with lower BMD. The average daily phylloquinone and calcium intakes of the 70 postmenopausal women were 725.8ug/day, ten times more than the American RDA and 406.7mg/day, 1/2 of the American RDA for those nutrients, respectively. The major food sources for phylloquinone were seaweed, spinach and kale, whereas the food sources of calcium were milk, sardines, and yogrut. Further studies are needed to clarify the effects of dietary phyloquinone on its serum levels and BMD.

• Journal of Nutrition and Health
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• 제32권3호
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• pp.287-295
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• 1999

This study was conducted to observe the effect of vitamin K on bone metabolism in postmenopausal women. Twenty-four healthy postmenopausal women recruited for this one-month, double-blind controlled study. Before and after daily administration of 1.0mg of phylloquinone the levels of serum vitamin K, osteocalcin, under-carboxylated osteocalcin, and urinary deoxy-phyidinoline were measured. The serum vitamin K concentration of Koran women as well as the average dietary intake of vitamin K was shown to be higher than the average levels of foreign women. However, no correlation between serum vitamin K concentration and vitamin K intake was found. Also, serum vitamin K concentration showed no special correlation with either bone mineral density or bone turnover markers in the study group. However, women with low serum vitamin K concentration(vitamin K-low group)had lower bone mineral density levels. After supplementation with 1.0mg/day of vitamin K, there were no changes in the levels of serum vitamin K, osteocalcin, ucOC, or u-DPD. Vitamin K supplementation did not seem to have any positive effects on bone metabolism through carboxylation. It can, however, be expected that vitamin K supplementation has a positive effect on bone metabolism in postmenopausal women with especially low serum vitamin K concentrations.

• 대한화학회지
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• 제55권1호
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• pp.86-91
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• 2011

수산화나트륨과 과산화 무기산을 사용하여 흑색 액체로부터 수산화 리그닌과 과산화 리그닌을 얻었다. 과산화 리그닌을 10% HCl을 사용하여 가수분해하여 가수분해 리그닌을 얻었다. 카르복실화와 인산화과정을 거쳐 카르복시 리그닌과 인산화 리그닌을 얻었다. 에피클로르히드린을 사용하여 가교 리그닌도 얻었다. 이들 얻어진 리그닌들을 적외선분광법, 열김량분석, 시차열분석법으로 분석 하였다. 이들 얻어진 리그닌의 금속이온 흡착효과를 조사하였다. 과산화 리그닌이 수산화된 리그닌 보다 흡착 능력이 우수하였다.

• 생물환경조절학회지
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• 제31권1호
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• pp.77-77
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• 2022

• The Korean Journal of Ecology
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• 제28권5호
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• pp.321-326
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• 2005

안산 공단지대에 식재되어 있는 잣나무와 리기다소나무의 생장 저하의 실태와 그 원인을 구명하기 위하여 생장 및 생리학적 반응을 중심으로 대조구와 비교 고찰하였다. 피해구에 식재 되어 있는 두 수종의 침엽 내 Mn, F 그리고 Cl의 농도는 대조구에 비하여 유의적으로 높았으며, 2년생 3년생으로 갈수록 급격히 그 농도가 증가하였다. 또한 필수 영양 원소인 P와 클로로필 함량은 피해구가 대조구에 비하여 유의적으로 감소하였으며, 또한 침엽의 연령이 증가함에 따라 급격히 감소하였음을 알 수 있었다. 한편, 피해구에 식재되어 있는 두 수종의 최대 광합성률, 양자수율$(\Phi)$, 카르복실레이션효율(CE)등의 광합성 능은 대조구에 비하여 현저히 감소하였다. 이상과 같이 독성 원소의 축적 및 필수 영양 원소의 부족 등 환경 스트레스에 의한 수목 생리활동의 저하가 수목 생장 저하의 직접적인 원인으로 판단된다.

• Journal of Applied Biological Chemistry
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• 제51권6호
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• pp.262-271
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• 2008

Natural abundances of stable isotopes of nitrogen and carbon (${\delta}^{15}N$ and ${\delta}^{13}C$) are being widely used to study N and C cycle processes in plant and soil systems. Variations in ${\delta}^{15}N$ of the soil and the plant reflect the potentially variable isotope signature of the external N sources and the isotope fractionation during the N cycle process. $N_2$ fixation and N fertilizer supply the nitrogen, whose ${\delta}^{15}N$ is close to 0%o, whereas the compost as. an organic input generally provides the nitrogen enriched in $^{15}N$ compared to the atmospheric $N_2$. The isotope fractionation during the N cycle process decreases the ${\delta}^{15}N$ of the substrate and increases the ${\delta}^{15}N$ of the product. N transformations such as N mineralization, nitrification, denitrification, assimilation, and the $NH_3$ volatilization have a specific isotope fractionation factor (${\alpha}$) for each N process. Variation in the ${\delta}^{13}C$ of plants reflects the photosynthetic type of plant, which affects the isotope fractionation during photosynthesis. The ${\delta}^{13}C$ of C3 plant is significantly lower than, whereas the ${\delta}^{13}C$ of C4 plant is similar to that of the atmospheric $CO_2$. Variation in the isotope fractionation of carbon and nitrogen can be observed under different environmental conditions. The effect of environmental factors on the stomatal conductance and the carboxylation rate affects the carbon isotope fractionation during photosynthesis. Changes in the environmental factors such as temperature and salt concentration affect the nitrogen isotope fractionation during the N cycle processes; however, the mechanism of variation in the nitrogen isotope fractionation has not been studied as much as that in the carbon isotope fractionation. Isotope fractionation factors of carbon and nitrogen could be the integrated factors for interpreting the effects of the environmental factors on plants and soils.