• Asian-Australasian Journal of Animal Sciences
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• 제29권8호
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• pp.1166-1172
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• 2016

This study was conducted to determine the effect of dietary supplementation of liquid DL-methionine hydroxy analog free acid (DL-MHA) on growth performance and gastrointestinal conditions of piglets. One hundred and eighty crossbred barrow piglets (Large White${\times}$Landrace, body weight: $12.48{\pm}0.33kg$) were divided into three groups with ten replications of six piglets each. Piglets received DL-MHA in diet at a concentration of 0 (control group), 0.15%, or 0.24%. The results indicated that increasing the standardized ileal digestible (SID) of sulfur amino acids (SAA) to lysine (SID SAA:Lys) ratio by supplementation of DL-MHA tended to increase (quadratic; p<0.10) weight gain and ADG, and showed slightly greater (linear; p<0.10) gain:feed ratio. The pH in the diet and cecum linearly decreased (p<0.01), whereas pH in colon had a quadratic response (p<0.01) with increasing supplementation of DL-MHA. By greater supplementation of DL-MHA, the population of Lactobacillus spp. in rectum was likely to increase (quadratic; p<0.10), but Escherichia coli population in the diet was reduced (quadratic; p<0.05). Acetic acid concentration and total short-chain fatty acids in cecum linearly increased (p<0.05), whereas valeric acid in cecum quadratically increased (p<0.05) with increasing DL-MHA levels. Moreover, the villous height of the jejunum quadratically increased (p<0.01) as the supplementation of DL-MHA was increased. It is concluded that the addition of DL-MHA in diet improved the growth performance and the morphology of gastrointestinal tract of piglets.

• 한국환경보건학회지
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• 제37권6호
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• pp.418-428
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• 2011

Objectives: The purpose of this study was to examine the cross-sectional relationship between low blood lead levels and increasing blood pressure among Korean adults using a nationally representative sample of the Korean population: the Korea National Health and Nutrition Examination Survey (KNHANES) 2008. Methods: A total of 918 subjects aged 40 and older and not currently being treated for hypertension participated in this study. Information about age, gender, smoking status, alcohol consumption, education level, and the use of anti-hypertensive medication was collected. The blood pressure was defined as the mean of the second and the third measurements after three time measurements. Lead levels were determined by an analysis of blood samples. Multiple linear and logistic regression analyses were implemented after adjusting for covariates including age, gender, educational level, smoking status, alcohol consumption, and BMI. Results: This study showed that the average differences in systolic and diastolic blood pressure comparing the lowest to highest quintile of blood lead were 4.33 mmHg (95% CI, 0.66-8.00; p for trend = 0.027) and 2.66 mmHg (95% CI, 0.26-5.06; p for trend = 0.021), respectively. After multivariate adjustment for covariates, the prevalence odds ratio (POR) of subjects in the highest quintile was associated with a 1.70-fold increase in the risks of hypertension (95% CI, 0.83-3.49; p for trend test = 0.112) over those in the lowest quintile of blood lead concentration, However, it was not statistically significant. Conclusions: This study provided evidence for an association between low- levels of blood lead and elevations in blood pressure and risk for hypertension in the general population of Korea.

• Journal of Microbiology and Biotechnology
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• 제22권9호
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• pp.1264-1270
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• 2012

The ecotoxicological effects of nanomaterials on animal, plant, and soil microorganisms have been widely investigated; however, the nanotoxic effects of plant-soil interactive systems are still largely unknown. In the present study, the effects of ZnO nanoparticles (NPs) on the soil-plant interactive system were estimated. The growth of plant seedlings in the presence of different concentrations of ZnO NPs within microcosm soil (M) and natural soil (NS) was compared. Changes in dehydrogenase activity (DHA) and soil bacterial community diversity were estimated based on the microcosm with plants (M+P) and microcosm without plants (M-P) in different concentrations of ZnO NPs treatment. The shoot growth of M+P and NS+P was significantly inhibited by 24% and 31.5% relative to the control at a ZnO NPs concentration of 1,000 mg/kg. The DHA levels decreased following increased ZnO NPs concentration. Specifically, these levels were significantly reduced from 100 mg/kg in M-P and only 1,000 mg/kg in M+P. Different clustering groups of M+P and M-P were observed in the principal component analysis (PCA). Therefore, the M-P's soil bacterial population may have more toxic effects at a high dose of ZnO NPs than M+P's. The plant and activation of soil bacteria in the M+P may have a less toxic interactive effect on each of the soil bacterial populations and plant growth by the ZnO NPs attachment or absorption of plant roots surface. The soil-plant interactive system might help decrease the toxic effects of ZnO NPs on the rhizobacteria population.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.283-283
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• 2017

The objective of the present study is to analyze the lactic acid bacteria (LAB) effects on rye silage fermentation at different stages. Different stages (Booting, Heading, Flowering, and Late flowering stage) of rye were collected from the National livestock farm, National Institute of Animal Science, South Korea. Rye sample was inculcated with lactic acid bacteria and incubated at the anaerobic condition for three months. The nutrient profile such as crude protein (CP), Acid detergent fibre, Neutral detergent fibre and total digestibility nutrients were increased in both control and LAB inculcated samples at all the stages of rye forage. The pH of rye silage was reduced at both stages by LAB inoculation as compared with control. The lactate content was increased in all stages of rye sample by LAB. The acetate concentration and butyrate was reduced in LAB inoculated rye sample. However, acetate concentration was slightly high in LAB inculcated rye at heading and late flowering stage. The LAB population was greater in LAB inoculated rye sample as compared with control sample. However, the massive population was noted in booting stage of rye than the other stages. It indicates the inoculated LAB is the main reason for increasing fermentation quality in the sample through pH reduction by lactate production. Overall results suggest that the isolated lactic acid bacterium is the potent strain that could be suitable for rye forage fermentation at different stages.

• Ocean Science Journal
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• 제40권2호
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• pp.91-100
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• 2005

Bioassay using the marine bacteria, Vibrio fischeri and rotifer, Brachionus plicatilis, and chemical analyses were conducted to assess the toxicity of the various sewage sludges, one of the major ocean dumped materials in the Yellow Sea of Korea. Sludge elutriates extracted by filtered seawater were used to estimate the ecotoxicity of the sludge. Chemical characterization included the analyses of organic contents, heavy metals, and persistent organic pollutants in sludge. Bacterial bioluminescent inhibition (15 min), rotifer mortality (24 hr) and rotifer population growth inhibition (48 hr) assay were conducted to estimate the sludge toxicity. EC50 15 min (inhibition concentration of bioluminescence after 15 minutes exposed) values by Microtox(R) bioassay clearly revealed different toxicity levels depending on the sludge sources. Highest toxicity for the bacteria was found with the sludge extract from dyeing waste and followed by industrial waste, livestock waste, and leather processing waste. Clear toxic effects on the bacteria were not found in the sludge extract from filtration bed sludge and rural sewage sludge. Consistent with Microtox(R) results, rotifer neonate mortality and population growth inhibition test also showed highest toxicity in dyeing waste and low in filtration bed and rural sewage sludge. High concentrations of persistent organic pollutants (POPs) and heavy metals were measured in the samples from the industrial wastes, leather processing plant waste sludge, and urban sewage sludge. However, there was no significant correlation between pollutant concentration levels and the toxicity values of the sludge. This suggests that the ecotoxicity in addition to the chemical analyses of various sludge samples must be estimated before release of potential harmful waste in the natural environment as part of an ecological risk assessment.

• Plant Biotechnology Reports
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• 제4권1호
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• pp.23-27
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• 2010

Quantitative trait loci (QTLs) controlling ability of somatic embryogenesis were identified in soybean. A frame map with 204-point markers was developed using an RI population consisting of 117 $F_{11}$ lines derived from a cross between cultivar 'Keburi' and a weedy soybean 'Masshokutou Kou 502'. The parents differed greatly in their abilities of somatic embryogenesis using immature cotyledons as explants. The ability of somatic embryogenesis was evaluated in five different experiments: the $F_{11}$ (evaluated in 1998) and $F_{15}$ (2002) generations cultured on basal media supplemented with $40\;mg\;l^{-1}$ 2,4-D (2,4-D1998 and 2,4-D2002), $F_{14}$ (2001) generation on medium with $40\;mg\;l^{-1}$ 2,4-D and high sucrose concentration [2,4-D2001 ($30\;g\;l^{-1}$ sucrose)], and the $F_{11}$ (1998) and $F_{12}$ (1999) generations on medium with $10\;mg\;l^{-1}$ NAA (NAA1998 and NAA1999). The RILs showed wide and continuous variations in each of the five experiments. In the composite interval mapping analysis, 2 QTLs were found in group 8 (D1b + W, LOD = 5.42, $r^2$ = 37.5) in the experiment of 2,4-D1998 and in group 6 (C2, LOD = 6.03, $r^2$ = 26.0) in the experiment of 2,4-D2001 (high concentration sucrose). In both QTLs, alleles of 'Masshokutou Kou 502' with high ability of somatic embryogenesis contributed to the QTLs. For the other three experiments, no QTL was detected in the criteria of LOD >3.0, suggesting the presence of minor genes.

• KSBB Journal
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• 제19권6호
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• pp.451-456
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• 2004

교반배양시 배지에 첨가되는 에탄올의 농도가 증가할수록 $Cel^-$ mutant의 발생율이 증가하므로 $1.5\%$ 에탄올이 첨가된 배지의 경우 500 rpm보다 높은 교반속도를 유지해야 효과적으로 $Cel^-$ mutant의 발생이 억제되고 BC 생산량을 증가시킬 수 있다. 교반 배양과 같은 강한 shear stress의 배양환경 하에서는 진탕배양의 경우와 달리 $1.0\%$ 에탄올을 분할공급하더라도 BC 생산의 효율성을 높일 수 없었다. Phosphate ion이 첨가된 배지보다 첨가되지 않은 배지에서 BC 생산량이 더 높았다. 배지조성 중 아세트산의 농도를 $1.0\%$로 증가시키면 균체의 건조중량은 변화가 없었으나 BC 생산량이 감소되었다. 배양액의 pH 제어는 BC의 생산에는 영향을 미치지 않았으나 균체의 성장과 WSPS의 생산을 향상시켰다.

• Reproductive and Developmental Biology
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• 제28권1호
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• pp.7-12
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• 2004

This study was performed to establish the effective culture condition for the establishment of clonal lines from porcine fetal fibroblast cells. Fibroblasts derived from a pig fetus (Day 50) were cultured and passaged two times before use. A single cell was seeded in 96-well plates, cultured in medium supplemented with different concentrations of FBS, catalase or $\beta$-mercaptoethanol ($\beta$ME), and classified by cell size and morphology. Cells were passaged two times into 4-well dish before freezing. The establishment efficiencies were not different among different concentrations of FBS (0.3 to 5.1%). However, population doubling time (PDT) was significantly decreased by increasing the FBS concentration (P＜0.05). The establishment efficiency of $\beta$ME-added group (10.4%) was significantly higher than those of catalase-added and control groups (3.5%, and 3.5%, respectively, p＜0.05), and PDT was significantly decreased (23.6 vs 28.1, and 25.5 h, respectively, p＜0.05). However, catalase did not show a positive effect on the establishment efficiency. Cell size and morphology did not affect the establishment efficiency and PDT of clonal lines. The result of present study shows that the establishment efficiency of clonal cell lines can be enhanced by the culture in media supplemented with 30% FBS and $\beta$ME.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2004년도 춘계학술대회
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• pp.311-314
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• 2004

바이오디젤 (지방산 메틸에스테르)을 기반으로 하여 생산된 합성윤활유 베이스에 대한 독성을 분석 평가하였다. OECD 207의 방법에 의거하여 인공토양(artifical soil)에서 300$\~$600 mg의 지렁이를 선별하였다. 0.01, 0.1, 1, 10, 100과 1,000 mg/kg의 각 농도별로 선별된 지렁이를 10마리씩 넣고 수분 $31\~37\%$, 온도 $20{\pm}2^{\circ}C$와 PH 6.0 $\pm$ 0.5를 조절하여 14일간 지렁이의 반수치사농도(lethal concentration when $50\%$ of the population were killed, $LC_{50}$)를 측정하였다. 합성윤활유의 측정 된 반수치사농도($LC_{50}$)는 1,555 mg/kg로 측정되었으며, 유의 확률이 < 0.02로서 유의수준 $5\%$에서 유의함을 알 수 있었다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제22권3호
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• pp.233-241
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• 2019

Purpose: Vitamin D deficiency is a condition widespread throughout the world. Recent studies have suggested that vitamin D deficiency was associated with obesity and metabolic syndrome. The purpose of the study was to examine the relationship between vitamin D deficiency and nonalcoholic fatty liver disease (NAFLD) in adolescents. Methods: The data were obtained from the Korean National Health and Nutrition Examination Survey from 2008-2014. A total of 3,878 adolescents were included in the study. Vitamin D deficiency was defined as a 25-hydroxyvitamin D concentration <20 ng/mL and suspected NAFLD was defined as an alanine transaminase concentration >30 U/L. Results: Vitamin D deficiency was noted in 78.9% of the studied population. Age, body mass index, waist circumference, and blood pressure, glucose, cholesterol, and triglyceride levels were significantly higher in adolescents with suspected NAFLD than in adolescents without suspected NAFLD, while the mean vitamin D level was significantly lower in adolescents with suspected NAFLD. The multivariate-adjusted odds of suspected NAFLD were higher with increased age, male gender, obesity, and metabolic syndrome. Individuals with vitamin D deficiency were at higher risk of suspected NAFLD (odds ratio, 1.77; 95% confidence interval, 1.07-2.95) after adjusting for age, gender, obesity, and metabolic syndrome. Conclusion: Vitamin D deficiency was associated with suspected NAFLD, independent of obesity and metabolic syndrome, in adolescents.