• 한국식품위생안전성학회지
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• 제38권1호
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• pp.31-36
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• 2023

본 연구는 집단급식소에서 제공되는 빈도수가 높은 비가열 및 가열조리 엽경채류에 사용되는 차아염소산나트륨 수에 대하여 미생물적 안전성을 평가하고자 수행되었다. 비병원성 대장균과 장출혈성 대장균의 칵테일(E. coli O157:H7)을 엽경채류(초기 균수 7-8 log CFU/g)에 인위적으로 오염시킨 후 차아염소산나트륨을 5분간 침지 후 흐르는 물에 3번 씻어서 생균수를 측정하였다. 실험 결과 초기 오염물질에 비해 살균효과가 1-2 log CFU/g 저감화하여 대조군에 대해 유의적인 차이가 있었다(P<0.05). 잎채소의 특성에 따라 약간의 차이가 있었는데 표면적이 클수록, 덜 거칠고 잎이 부드러울수록 살균효과가 높았다. 200 mg/kg으로 처리하였을 때 100 mg/kg에 비해 0.1-0.3 log CFU/g만큼 효과가 더 감소하였으나 농도 증가에 따른 유의적 차이는 없었다(P>0.05). 그러므로 학교급식위생관리지침에서 제시한 기준 이상으로 차아염소산나트륨 농도를 높이는 것은 불필요하다고 판단된다. 그러나 잎채소는 일반적으로 미생물의 초기 오염도가 높기 때문에 차아염소산나트륨 처리만으로는 안전한 수준의 저감을 달성하기 어려워 생물학적 위험이 잔존한다. 따라서 여름철에 가열하지 않은 잎채소의 대체 조리방법을 개발하는 것이 안전성에 보다 효과적인 것으로 판단된다.

• Nuclear Engineering and Technology
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• 제54권6호
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• pp.2120-2134
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• 2022

A hypothetical core destructive accident (HCDA) has received widespread attention as one of the most serious accidents in sodium-cooled fast reactors. This study combined recent advantages in numerical methods to realize realistic modeling of the complex fluid-structure interactions during HCDAs in a full-scale sodium-cooled fast reactor. The multi-material arbitrary Lagrangian-Eulerian method is used to describe the fluid-structure interactions inside the container. Both the structural deformations and plug rises occurring during HCDAs are evaluated. Two levels of expansion energy are considered with two different reactor models. The simulation results show that the container remains intact during an accident with small deformations. The plug on the top of the container rises to an acceptable level after the sealing between the it and its support is destroyed. The methodology established in this study provides a reliable approach for evaluating the safety feature of a container design.

• 한국식품과학회지
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• 제38권1호
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• pp.140-142
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• 2006

이전의 연구 결과에 나타난 바 있는 막걸리 중 ochratoxin A의 낮은 회수율(<50%)은 시료 내 본 곰팡이독소의 추출 혹은 전처리 과정의 개선이 필요함을 지적하였다. 본 연구에서 막걸리 시료의 균질화에 이용되던 추출 용액을 PBS 용액 대신 3% sodium bicarbonate 용액으로 채택할 경우, 80% 이상의 첨가된 ochratoxin A가 회수되어 그 검출이 용이해졌다. 한편 개선된 해당 분석법의 막걸리 시료에 대한 적용 가능성을 알아보기 위하여 국내 시판 중인 살균막걸리 30점을 대상으로 분석한 결과 밀 막걸리 2점에서 ochratoxin A가 검출되었고(0.8, 2.1 ppb), 그 결과를 다시 HPLC-ESI-MS로 확정하였다. 본 연구를 통해 수행된 개선된 시료 전처리 방법(3% sodium bicarbonate)과 병행된 IAC 및 HPLC-FD 분석법은 막걸리를 대상으로 한 ochratoxin A의 오염 조사에 유효한 분석법임이 확인되었다.

• 한국생활과학회지
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• 제22권4호
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• pp.693-705
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• 2013

This study was conducted to identify adults' knowledge, dietary behavior related to sodium, the attitude towards a low-salt diet, and to examine the relation between these variables. The participants were 366 adults in Jeonbuk area. The data were analyzed using Pearson correlation coefficients, ANOVA and Duncan test with SPSS v. 12.0. The score for participants' knowledge about sodium was 12.32 points of a possible 16, the score for dietary behavior related to sodium was 45.74 points of a possible 70, and their score for attitude towards a low-salt diet was 30.35 points of a possible 50. The knowledge showed significant differences by gender (p<.05), and concern about health (p<.05). The dietary behavior of sodium use showed significant differences by gender (p<.001), age (p<.001), educational level (p<.05), job (p<.001), income (p<.05), BMI (p<.05), smoking (p<.01), drinking (p<.01), exercise (p<.05), regularity of health checkup (p<.001), and concern about health (p<.01). The attitude towards a low-salt diet showed significant differences by gender (p<.001), age (p<.001), job (p<.001), income (p<.001), smoking (p<.05), regularity of health checkup (p<.001), and concern about health (p<.001). There was a significant positive correlation between knowledge about sodium, dietary behavior related to sodium, attitude towards a low-salt diet. Dietary behavior related to sodium showed a positive correlation with attitudes towards a low-salt diet. In conclusion, it is necessary to consider the related factors for the development and implementation of systematic education programs that can encourage and promote preventive dietary behavior for disease, e.g. stomach cancer, and hypertension among adults.

• Investigative Magnetic Resonance Imaging
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• 제22권1호
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• pp.65-70
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• 2018

The objective of this study was to describe a radiofrequency (RF) coil design for in vivo sodium magnetic resonance imaging (MRI) for use in small animals. Accumulating evidence has indicated the importance and potential of sodium imaging with improved magnet strength (> 7T), faster gradient, better hardware, multi-nucleus imaging methods, and optimal coil design for patient and animal studies. Thus, we developed a saddle-shaped sodium volume coil with a diameter/length of 30/30 mm. To evaluate the efficiency of this coil, bench-level measurement was performed. Unloaded Q value, loaded Q value, and ratio of these two values were estimated to be 352.8, 211.18, and 1.67, respectively. Thereafter, in vivo acquisition of sodium images was performed using normal mice (12 weeks old; n = 5) with a two-dimensional gradient echo sequence and minimized echo time to increase spatial resolution of images. Sodium signal-to-noise ratio in mouse kidneys (renal cortex, medulla, and pelvis) was measured. We successfully acquired sodium MR images of the mouse kidney with high spatial resolution (approximately 0.625 mm) through a combination of sodium-proton coils.

• 한국약용작물학회지
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• 제23권6호
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• pp.446-453
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• 2015

Background : Excessively high concentration of sodium ion causednutrient deficiency and significantly decrease growth. This study was carried out to determine the limiting concentration range of sodium ion in the soil of ginseng field. Methods and Results : The growth of the ginseng cultivar Chunpoong reduced with increase in salinity, and the rate of growth reduction was higher in shoots than that of roots. Particularly, ginseng plants cultivated at high level of nitrate nitrogen or sodium may suffer delayed development and stunted growth. Chlorophyll damage occurred on the leaves of ginseng planted in relatively high levels (> $0.2cmol^+/kg$) of sodium ion, as determined by the fluorescence reaction. The incidence of physiological disorder in ginseng cultivated at 249 sites was correlated with the concentration of sodium ion in the soils. About 74% of ginseng fields in which physiological disorders occurred had concentrations of sodium ion in soil greater than $0.2cmol^+/kg$. In contrast, the concentration of sodium ions at 51 of 85 sites where no damage occurred was relatively ($0.05cmol^+/kg-0.15cmol^+/kg$). Conclusions : The concentration of sodium ion in soil of ginseng fields can be classified into three levels optimum (${\leq}0.15$), permissible allowance (0.15 - 0.2) and excessive (> 0.2).

• Journal of Nutrition and Health
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• 제18권3호
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• pp.194-200
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• 1985

The purpose of this study was to investigate sodium intake and protein metabolism for pregnant women in Korea. The relationship between salt consumption and hypertension, electrolyte changes in pregnancy, and the tendency of weight gain of pregnant women were also examined. The dietary survey and twelve or twenty-four hour's urine collection was performed in this study. The subjects were pregnant women who came to gynecology clinic for prenatal care from July to August in 1984. The results were as follows: 1) Intakes of calorie and iron of Korean pregnant women were 2,036 Kcal and 16mg per day per person. The calorie composition consists of 65% carbohydrate, 16% protein, and 19% lipids. The average level of all nutrients was about 87% of Korean Recommended Dietary Allowances. 2) The sodium intakes in pregnant women estimated by dietary survey was 318.6 mEq Na (7,966 mg Na), which is equivalent to 20.2 g NaCl. 3) Daily sodium excretion was 112.5 mEq per liter, that is equal to 147.4 mEq. Potassium excretion was 24.95 mEq per liter and creatinine excretion was 594.0 mg per day. 4) There were statistically significant correlations between sodium intake and the excretions of sodium, potassium and creatinine. The blood pressure was positively correlated with sodium intakes. As sodium and potassium ratio was increased, systolic blood pressure and diastolic blood pressure were also significantly increased 5) Urinary nitrogen and creatinine ratio known to be reliable index for nutritional status of protein was 5.5 : 1. These values were comparable to the values in American pregnant women. 6) The weight gain during the pregnancy was examined. There was little weight gain during the first trimester, because of nausea, vomit and decrease of appetite. The weight gain during the second trimester was 4.9Kg, and 11.1Kg for third trimester.

• Asian-Australasian Journal of Animal Sciences
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• 제22권1호
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• pp.82-89
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• 2009

Two in vitro experiments were conducted to examine the effects of propionate precursors in the dicarboxylic acid pathway on ruminal fermentatation characteristics, $CH_4$ production and degradation of feed by rumen microbes. Fumarate or malate as sodium salts (Exp. 1) or acid type (Exp. 2) were added to the culture solution (150 ml, 50% strained rumen fluid and 50% artificial saliva) to achieve final concentrations of 0, 8, 16 and 24 mM, and incubated anaerobically for 0, 1, 3, 6, 9 and 12 h at $39^{\circ}C$. For both experiments, two grams of feed consisting of 70% concentrate and 30% ground alfalfa (DM basis) were prepared in a nylon bag, and were placed in a bottle containing the culture solution. Addition of fumarate or malate in both sodium salt and acid form increased (p<0.0001) pH of culture solution at 3, 6, 9 and 12 h incubations. The pH (p<0.0001) and total volatile fatty acids (VFA, p<0.05) were enhanced by these precursors as sodium salt at 3, 6 and 9 h incubations, and pH (p<0.001) and total VFA (p<0.01) from fumarate or malate in acid form were enhanced at a late stage of fermentation (9 h and 12 h) as the addition level increased. pH was higher (p<0.001) for fumarate than for malate as sodium salt at 3 h and 6 h incubations. Propionate ($C_3$) proportion was increased (p<0.0001) but those of $C_2$ (p<0.05) and $C_4$ (p<0.01 - p<0.001) were reduced by the addition of sodium salt precursors from 3 h to 12 incubation times while both precursors in acid form enhanced (p<0.011 - p<0.0001) proportion of $C_3$ from 6h but reduced (p<0.018 - p<0.0005) $C_4$ proportion at incubation times of 1, 3, 9 and 12 h. Proportion of $C_3$ was increased (p<0.05 - p<0.0001) at all incubation times by both precursors as sodium salt while that of $C_3$ was increased (p<0.001) from 6h but $C_4$ proportion was decreased by both precursors in acid form as the addition level increased. Proportion of $C_3$ was higher (p<0.01 - p<0.001) for fumarate than malate as sodium salt from 6 h incubation but was higher for malate than fumarate in acid form at 9 h (p<0.05) and 12 h (p<0.01) incubation times. Increased levels (16 and 24 mM) of fumarate or malate as sodium salt (p<0.017) and both precursors in acid form (p<0.028) increased the total gas production, but no differences were found between precursors in both chemical types. Propionate precursors in both chemical types clearly reduced (p<0.0001 - p<0.0002) $CH_4$ production, and the reduction (p<0.001 - p<0.0001) was dose dependent as the addition level of precursors increased. The $CH_4$ generated was smaller (p<0.01 - p<0.0001) for fumarate than for malate in both chemical types. Addition of fumarate or malate as sodium type reduced (p<0.004) dry matter degradation while both precursors in both chemical types slightly increased neutral detergent fiber degradability of feed in the nylon bag.

• The Korean Journal of Physiology
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• 제25권1호
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• pp.69-79
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• 1991

To evaluate the acute and chronic effects of potassium on aldosterone response to different amounts of sodium intake, two series of experiments were conducted. In the first series of experiments, when the plasma K level was increased acutely by KCI infusion $(20\;{\mu}g/kg/min\;for\;20 min)$, plasma aldosterone concentration increased in both low Na and high Na groups. However, the aldosterone response to K infusion was significantly greater in the low Na than in the high Na groups. In the second series of experiments, rats fed a high K diet chronically showed a significantly higher plasma K level than those fed a low K diet. However, plasma Na level was maintained relatively constant independent of the Na intake. Both the plasma renin activity (PRA) and aldosterone levels were inversely related to the Na intake. There was a highly positive correlation between aldosterone level and PRA over a wide range of sodium intakes. However, the slope of the correlation line was distinctly steeper in the K-repleted than in the K-depleted rats. The above results indicate that the adrenotropic action of acute K load was augmented in the presence of high plasma renin levels. However, when plasna K level was elevated chronically by a high-K diet, aldosterone secretion was markedly stimulated, although the plasma lenin levels were suppressed.

• Journal of Nutrition and Health
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• 제50권2호
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• pp.180-191
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• 2017

본 연구는 전북지역 345명의 초등학교 교사들을 대상으로 교사들의 나트륨 영양지식, 나트륨 식행동, 저염식 태도수준을 파악하고 교사들의 식생활지도 수행과의 관계를 조사하고자 하였으며, 그 결과를 요약하면 다음과 같다. 조사대상자의 나트륨에 대한 지식에 대한 총점은 16점 중 12.92점이며 '소금을 적게 섭취하면 고혈압, 심혈관 질환, 위암, 골다공증 등의 질병을 예방할 수 있다'가 가장 높은 정답률을 보였고, '신선한 야채와 과일을 많이 먹으면 다량의 칼륨이 나트륨을 몸 밖으로 배출시켜 준다'가 가장 낮은 정답률을 보였다. 조사대상자의 나트륨관련 식행동에 대한 총점은 70점 중 46.85점이며 '젓갈이나 장아찌가 식탁에 없으면 섭섭하다'가 가장 높았고, '라면, 국수 등을 먹을 때 김치를 꼭 먹는다'가 가장 낮은 점수를 보였다. 조사대상자의 저염식 태도에 대한 총점은 50점 중 33.63점이며 '염분에 대한 정보가 주어진다면 저염 식품을 선택하겠다'가 가장 높았고, '가공식품이나 스낵 속의 나트륨 함량을 확인한다'가 가장 낮은 점수를 보였다. 조사대상자의 식생활지도 수행에 대한 총점은 80점 중 59.95점이며 '학생들과 함께 급식을 한다'가 가장 잘 이루어지나 '식품영양표시를 이용하여 저나트륨 식품을 선택하도록 지도한다'와 '급식 시 학생들이 잘 접하지 않은 음식이 나오면 그 음식의 유래나 영양가 등을 학생들에게 설명해 준다'가 잘 이루어지지 않는 것으로 나타났다. 조사대상자의 일반적인 특성에 따른 나트륨에 대한 지식은 고혈압약 복용, 스트레스 정도에서 통계적으로 유의한 차이를 보였다. 나트륨 관련 식행동은 성별, 근무경력, BMI, 흡연, 음주, 건강에 대한 관심, 스트레스 정도에서 통계적으로 유의한 차이를 보였다. 저염식 태도는 성별, 결혼 유무, 근무경력, 음주, 운동, 건강에 대한 관심, 스트레스 정도에서 통계적으로 유의한 차이를 보였다. 식생활지도 수행은 결혼유무, 연령, 근무경력, 음주, 건강검진, 건강에 대한 관심, 스트레스 정도에서 통계적으로 유의한 차이를 보였다. 나트륨에 대한 지식, 나트륨 섭취 식행동, 저염식 태도 및 식생활 지도 수행간의 관계는 나트륨에 대한 지식은 나트륨 섭취 식행동 (r = 0.252, p < 0.01)간에 낮은 상관관계를 보였다. 나트륨 섭취 식행동은 저염식 태도 (r = 0.319, p < 0.01)간에 낮은 상관관계를 나타냈고, 저염식 태도와 식생활 지도 수행 (r = 0.435, p < 0.01)간에는 순 상관관계를 보였다. 이상의 결과, 전북지역 초등교사의 나트륨에 대한 지식수준과 식생활지도 수행정도는 보통수준이나 나트륨 섭취 식행동과 저염식태도는 낮은 수준으로 나타났다. 교사들의 교육경력에 따라서 나트륨관련 지식수준의 차이는 없었으나 장기근무 교사일수록 또한 본인의 건강에 대한 관심이 높을수록 나트륨 섭취 식행동, 저염식 태도 및 식생활지도 수행점수가 높았다. 그러나 고혈압약을 복용하고 있음에도 불구하고 나트륨관련 지식이 낮은 것을 볼 때 교사대상의 나트륨관련 질병 등에 대한 영양교육의 필요성이 매우 높겠다. 본 연구결과 교사들의 나트륨관련 지식과 나트륨관련 식행동 간에 낮으나 어느 정도의 상관관계가 있으므로 근무기간이 짧은 교사의 경우는 직무연수 등을 통하여 나트륨에 대한 정보를 정확하게 전달하여 교사들 스스로 올바른 식생활관리가 가능하도록 할뿐만 아니라 장기적으로 학생들의 식생활지도가 잘 이루어지도록 하여야 하겠다. 따라서 초등교사의 식생활지도 수행에 좀 더 긍정적인 영향을 미칠 수 있도록 나트륨에 대한 지식 및 저염식 태도 등 식생활에서 실천 가능한 교육 프로그램 및 교육매체 개발 등을 위한 영양교사와의 협조체계가 필요하며 이를 위한 교육청 및 학교행정부서의 적극적인 지원이 필요하겠다.