• 한국환경과학회지
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• 제25권5호
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• pp.727-736
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• 2016

The ambient mass concentration and chemical composition of the $PM_{2.5}$ were determined at the highland site with 1,100 m above sea level on Jeju Island from June 2013 to November 2014. Yearly averaged mass concentration of $PM_{2.5}$ was $11.97{\pm}8.63{\mu}g/m^3$. $PM_{2.5}$ concentrations were highest during the spring, while they tended to be lowest during the summer. Eight water soluble ionic species attributed 45.5% to $PM_{2.5}$ mass. $SO{_4}^{2-}$, $NO_3{^-}$ and $NH_4{^+}$ were major ions, which occupied to 27.9%, 3.7% and 12.3%, respectively. The greatest contributors to total mass concentration of water-soluble ions contained in $PM_{2.5}$ were sulfate, ammonium and nitrate. These three ions accounted for 96.6% in total ions mass concentration of $PM_{2.5}$. We could infer that these three secondary ions exist mostly in the form of $(NH_4)_2SO_4$ and $NH_4NO_3$. $Ca^{2+}$ and $Mg^{2+}$ had a good relationship and with r=0.9. The molar ratio of $Mg^{2+}/Ca^{2+}$ in this study was lower than the value observed in sea water and higher than that in soil dust, indicating that these two ions originated from other sources rather than ocean and soil dust in this study.

• Clinical Nutrition Research
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• 제12권4호
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• pp.320-335
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• 2023

Literature showed that soluble fiber has beneficial effects on cardiometabolic risk factors and leptin and adiponectin serum levels. Our aim in this meta-analysis was to determine the effect of soluble fiber supplementation on leptin and adiponectin serum levels. A systematic search was conducted using PubMed, Scopus, and ISI Web of Science for eligible trials up to December 2021. A random-effects model was used to pool calculated effect sizes. Our analysis showed that soluble fiber supplementation did not significantly affect adiponectin (standardized mean difference [SMD], -0.49 Hedges's, 95% confidence interval [CI], -1.20, 0.21, p value = 0.167; I² = 95.4, p value < 0.001) and leptin (SMD, -0.8 Hedges's, 95% CI, -1.70, 0.08, p value = 0.076; I² = 94.6, p value < 0.001) concentrations in comparison with placebo. However, in the subgroup, soluble fiber supplementation had a significant improvement in leptin concentration in overweight and obese patients (SMD, -0.22 Hedges's, 95% CI, -0.43, -0.01, p value = 0.048) and a non-significant beneficial effect in adiponectin level in female (SMD, 0.29 Hedges's, 95% CI, -0.13, 0.71, p value = 0.183) and diabetic patients (SMD, 0.32 Hedges's, 95% CI, -0.67, 1.32, p value = 0.526). A non-linear association between soluble fiber dosage and adiponectin (p_{non-linearity} < 0.001) was observed. Soluble fiber supplementation could not change the circulatory leptin and adiponectin levels. However, beneficial effects were seen in overweight and obese leptin, and increases in adiponectin may also be observed in female and diabetic patients. Further studies are needed to confirm this results.

• Natural Product Sciences
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• 제21권3호
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• pp.176-184
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• 2015

In our search for natural soluble epoxide hydrolase (sEH) inhibitors from plants, an extract of the dried whole plants of Euphorbia supina Rafin was found to significantly inhibit sEH activity in vitro. Phytochemical investigation of E. supina resulted in isolation of 17 compounds (1 - 17), including triterpenes (1 - 4), phenolic compounds (5 - 8), and flavonoid derivatives (9 - 17). The structures of the isolated compounds were established mainly by extensive analysis of the 1D and 2D NMR, and MS data. All of the isolated compounds were evaluated for their sEH inhibitory activity. Among the isolated phenolic compounds, 8 was identified as a significant inhibitor of sEH, with an IC₅₀ value of 15.4 ± 1.3 μM. Additionally, a kinetic analysis of isolated compounds (2, 5, 8 - 11, 13, and 17) indicated that the inhibitory effects of flavonoid derivatives 10 and 11 were of mixed-type, with inhibitory constants (K_i) ranging from 3.6 ± 0.8 to 21.8 ± 1.0 μM, whereas compounds 2, 5, 8, 9, 13, and 17 were non-competitive inhibitors with inhibition K_i values ranging from 3.3 ± 0.2 to 39.5 ± 0.0 μM.

• Journal of Microbiology and Biotechnology
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• 제32권3호
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• pp.287-293
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• 2022

The hydroxylation of methane (CH₄) is crucial to the field of environmental microbiology, owing to the heat capacity of methane, which is much higher than that of carbon dioxide (CO₂). Soluble methane monooxygenase (sMMO), a member of the bacterial multicomponent monooxygenase (BMM) superfamily, is essential for the hydroxylation of specific substrates, including hydroxylase (MMOH), regulatory component (MMOB), and reductase (MMOR). The diiron active site positioned in the MMOH α-subunit is reduced through the interaction of MMOR in the catalytic cycle. The electron transfer pathway, however, is not yet fully understood due to the absence of complex structures with reductases. A type II methanotroph, Methylosinus sporium 5, successfully expressed sMMO and hydroxylase, which were purified for the study of the mechanisms. Studies on the MMOH-MMOB interaction have demonstrated that Tyr76 and Trp78 induce hydrophobic interactions through π-π stacking. Structural analysis and sequencing of the ferredoxin domain in MMOR (MMOR-Fd) suggested that Tyr93 and Tyr95 could be key residues for electron transfer. Mutational studies of these residues have shown that the concentrations of flavin adenine dinucleotide (FAD) and iron ions are changed. The measurements of dissociation constants (K_ds) between hydroxylase and mutated reductases confirmed that the binding affinities were not significantly changed, although the specific enzyme activities were significantly reduced by MMOR-Y93A. This result shows that Tyr93 could be a crucial residue for the electron transfer route at the interface between hydroxylase and reductase.

• 대한수학회보
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• 제47권4호
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• pp.687-691
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• 2010

In this article we will prove that a generalized radical group satisfying the maximal condition for subnormal subgroups of infinite order (the minimal condition for subnormal subgroups of infinite index, respectively) is soluble-by-finite. Such result generalizes that obtained by D. H. Paek in [5].

• 한국환경보건학회지
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• 제33권5호
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• pp.408-421
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• 2007

The concentration characteristics of atmospheric particle matters (PM) including $PM_{2.5},\;PM_{10}$, and TSP were evaluated through the measurement data of PM_{2.5}$ (fine particulate), PM_{10-2.5}$ (coarse particulate), and PM_{over-10}$ collected using a MCI (multi-nozzle cascade impactor) sampler of a three-stage filter pack in spring of 2006 in Iksan area. During the sampling period of 10-15 March and 24 days from 8 April to 2 May, 32 samples for PM of each size fractions were collected, and then measured for PM mass concentrations and water-soluble inorganic ion species. Average concentrations of $PM_{2.5},\;PM_{10}$, TSP were $57.9{\pm}44.1mg/m^3$, $96.6{\pm}89.1mg/m^3$, and $114.8{\pm}99.7mg/m^3$, respectively. Water-soluble inorganic ion fractions to PM mass were found to be 36.5%, 18.0%, and 11.1% for $PM_{2.5}$, $PM_{10-2.5}$ and $PM_{over-10}$, respectively. By showing the high concentrations of PM samples during Asian dust events, those three fractions of PM were distinguished between the samples of Asian dust event and the samples of no event. However, the increase of PM concentrations observed during Asian dust events showed a different pattern for some Asian dust events. The differences of those three fractions in the size distribution may depend on differences on place of occurrence of Asian dust storm and course of transport from China continent to Iksan area in Korea. However, the extent of PM mass contribution during Asian dust events was generally dominated by the coarse particles rather than the fine fraction of PM. The variations of water-soluble inorganic ion species concentration in those three PM fractions between the samples of Asian dust event and the samples of no event were also discussed in this study.

• Asian-Australasian Journal of Animal Sciences
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• 제33권12호
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• pp.1985-1990
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• 2020

Objective: The objective of this experiment was to investigate the effects of fat-soluble vitamin injection on plasma and tissue vitamin status in nursery pigs. Methods: A total of 16 pigs (initial body weight: 7.15±1.1 kg) were allotted to 2 treatments at d 7 post-weaning. Pigs were fed a corn-soybean meal-based basal diet with no supplemental vitamin A and i.m. injected with 300,000 IU of retinyl palmitate, 900 IU of d-α-tocopherol and 30,000 IU of vitamin D₃ with control pigs having no vitamin injection. Blood (d 0, 3, 7, and 14 post-injection) and tissue samples (liver, brain, heart, lung, and muscle; d 7 and 14 post-injection) were collected from pigs. Retinyl palmitate, retinol, and α-tocopherol concentrations were analyzed in plasma and tissues, while plasma was assayed for 25-hydroxycholecalciferol (25-OHD₃). Results: Plasma retinol and 25-OHD₃ concentrations increased by the vitamin injection from d 3 to 14 post-injection (p<0.05) whereas plasma retinyl palmitate was detected only in the vitamin treatment at d 3 and 7 post-injection (115.51 and 4.97 ㎍/mL, respectively). Liver retinol, retinyl palmitate, and retinol+retinyl palmitate concentrations increased by retinyl palmitate injection at d 7 and 14 post-injection (p<0.05) whereas those were not detected in the other tissues. The d-α-tocopherol injection increased α-tocopherol concentrations in plasma at d 3 and 7 post-injection (p<0.05) and in liver, heart (p<0.10), and muscle (p<0.05) at d 7 post-injection. Conclusion: Fat-soluble vitamin injection increased plasma status of α-tocopherol, retinol, retinyl palmitate and 25-OHD₃. As plasma levels decreased post-injection, vitamin A level in liver and vitamin E level in muscle, heart and liver increased. The α-tocopherol found in plasma after injection was distributed to various tissues but retinyl palmitate only to the liver.

• 한국식품저장유통학회지
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• 제30권1호
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• pp.170-178
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• 2023

본 연구에서는 복숭아 나뭇가지를 이용하여 열수 추출하고 얻어진 추출물에 대해 유기용매를 이용하여 극성별 분획을 실시하였으며, 열수추출물 및 분획물의 항산화 활성과 관련된 총페놀 함량, DPPH 및 ABTS⁺ 라디칼 소거능, α-glucosidase 및 α-amylase 저해능을 측정하였다. DPPH 라디칼 소거능 측정에서는 페놀성 물질의 함량을 가장 많이 나타낸 EtOAc 가용부의 IC₅₀값이 3.82±1.6 ㎍/mL로 가장 우수한 활성을 나타내었고, ABTS⁺ 라디칼 소거활성 평가에서도 EtOAc 분획물에서 IC₅₀값이 16.5±0.7 ㎍/mL로 강한 라디칼 소거활성을 나타내었다. 항당뇨 활성과 관련된 효소인 α-glucosidase 및 α-amylase 저해능 평가에서도 우수한 라디칼소거능을 나타낸 EtOAc 분획물에서 IC₅₀값이 각 38.2±1.6 및 69.6±6.1 ㎍/mL로 다른 유기용매 분획물에 비해 우수한 저해 활성임을 확인하였다. 이러한 결과는 복숭아 나뭇가지 추출물이 항산화 및 항당뇨 효능을 가지며, 새로운 천연물 유래의 기능성 신소재 발굴을 위한 기초자료로 이용 가능할 것으로 사료된다.

• 자원환경지질
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• 제55권4호
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• pp.389-398
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• 2022

비소 및 중금속으로 오염된 토양 내 함량과 농작물로 전이되는 함량 간의 관련성을 도출하기 위한 연구가 지속적으로 수행되고 있으나 두 함량 간의 낮은 상관성으로 인하여 명확한 결과가 도출되지 못하고 있다. 이 연구에서는 토양 내 비소 전함량과 단일용출 가용성 함량뿐만 아니라 토양의 물리·화학적 특성을 함께 고려하여 백미로 전이되는 비소 함량을 예측하는 통계학적 모델을 만들고자 하였다. 토양 특성 중 pH, 단일용출 가용성 함량, 유기물 함량에 따라 순차적으로 토양을 분류하며 회귀분석을 통한 예측 모델을 도출하였다. 80개의 백미 내 비소 함량과 토양 내 비소 전함량 및 Mehlich 가용성 함량 간의 상관계수는 각각 0.533과 0.493으로 낮았다. 그러나 토양을 pH, Mehlich 가용성 함량에 대한 전함량, 유기물 함량으로 순차적으로 분류하여 모델을 도출한 결과, ① pH가 6.5보다 높은 13개의 토양은 0.963, ② pH가 6.5 이하이고 As_Tot/As_Mehlich 비가 높은 15개의 토양은 0.849, ③ pH가 6.5 이하이고 As_Tot/As_Mehlich 비가 낮으며 8.5% 이하의 유기물을 함유한 30개의 토양은 0.935로 예측력이 크게 증가하였다. 이 연구에서 도출된 토양 분류에 따른 백미 전이 함량 예측 모델은 비소 오염 토양에 대해 신뢰성 있는 백미 재배 기준을 설정하는데 의미있는 방법론을 제안할 수 있을 것이다.

• 한국식품저장유통학회지
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• 제30권2호
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• pp.190-204
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• 2023

Because of their short harvest season, large quantities of persimmons must often be processed within a limited time. Therefore, new methods to extend their storage life are required. This study examined the effects of chlorine dioxide (ClO₂) gas fumigation for various treatment periods on the storage quality of astringent persimmons Cheongdobansi under low-temperature conditions. The conditions consisted of continuous treatment with ClO₂, treatment for 2 weeks with ClO₂, and no treatment, all of which are stored at low temperatures. Control samples (storage 0 days) without any treatment were prepared and all experiments were conducted for 10 weeks at two-week intervals. The ClO₂ gas treatment maintained the moisture content, color value, hardness, soluble tannin content, and sensory characteristics. However, ClO₂ gas treatment did not affect the soluble solids, pH, and total sugar content. In particular, continuous treatment with ClO₂ maintained the storage quality after 6-8 weeks of storage, particularly the hardness and weakness (sensory evaluation). The results suggest the potential of continuous treatment with ClO₂ as a highly effective method for maintaining the freshness of Cheongdobansi.