• 동아시아식생활학회지
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• 제27권1호
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• pp.78-87
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• 2017

The objective of this study was to investigate the effects of various washing waters on the quality and safety characteristics of eggs during storage. Eggs were washed with tap water, 100 ppm of sodium hypochlorite, or 30 ppm of slightly acidic electrolyzed water and stored at $10^{\circ}C$ and $20^{\circ}C$. Effects of various washing waters on reduction of Salmonella Enteritidis and aerobic plate counts and survival of S. Enteritidis on egg shells were also analyzed at $10^{\circ}C$ and $20^{\circ}C$ for 25 days. As an index of quality, haugh unit, weight reduction, and pHs of egg white and egg yolk were measured. Reduction percentages of haugh unit and weight were higher at $20^{\circ}C$ than at $10^{\circ}C$. Egg qualities were less affected by tap water, slightly acidic electrolyzed water, and sodium hypochlorite, regardless of storage temperature. The greatest reductions in aerobic plate counts and S. Enteritidis were observed with slightly acidic electrolyzed water. The level of S. Enteritidis on egg shells gradually decreased during 20 days of storage at both $10^{\circ}C$ and $20^{\circ}C$, whereas S. Enteritidis survived longer at $20^{\circ}C$ than at $10^{\circ}C$. S. Enteritidis was not detected in eggs at $10^{\circ}C$, 2.13 log CFU/g of S. Enteritidis was detected in eggs washed with sodium hypochlorite after 20 days of storage at $20^{\circ}C$, indicating that S. Enteritidis penetrated into the egg shell during storage at $20^{\circ}C$. In conclusion, slightly acidic electrolyzed water increased microbial reduction and least affected quality of washed eggs. Thus, slightly acidic electrolyzed water can be recommended for washing of graded eggs, at retail markets.

• Nuclear Engineering and Technology
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• 제39권3호
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• pp.193-206
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• 2007

The Korea Atomic Energy Research Institute has developed an advanced fast reactor concept, KALIMER-600, which satisfies the Generation IV reactor design goals of sustainability, economics, safety, and proliferation resistance. The concept enables an efficient utilization of uranium resources and a reduction of the radioactive waste. The core design has been developed with a strong emphasis on proliferation resistance by adopting a single enrichment fuel without blanket assemblies. In addition, a passive residual heat removal system, shortened intermediate heat-transport system piping and seismic isolation have been realized in the reactor system design as enhancements to its safety and economics. The inherent safety characteristics of the KALIMER-600 design have been confirmed by a safety analysis of its bounding events. Research on important thermal-hydraulic phenomena and sensing technologies were performed to support the design study. The integrity of the reactor head against creep fatigue was confirmed using a CFD method, and a model for density-wave instability in a helical-coiled steam generator was developed. Gas entrainment on an agitating pool surface was investigated and an experimental correlation on a critical entrainment condition was obtained. An experimental study on sodium-water reactions was also performed to validate the developed SELPSTA code, which predicts the data accurately. An acoustic leak detection method utilizing a neural network and signal processing units were developed and applied successfully for the detection of a signal up to a noise level of -20 dB. Waveguide sensor visualization technology is being developed to inspect the reactor internals and fuel subassemblies. These research and developmental efforts contribute significantly to enhance the safety, economics, and efficiency of the KALIMER-600 design concept.

• 한국식품조리과학회지
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• 제32권3호
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• pp.333-341
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• 2016

Purpose: In this study, we comparatively investigated the nutrition knowledge, dietary attitude, and dietary behavior related to salt according to the types of dietary life style for differences between the groups. Methods: The survey was conducted between May 1 to July 31, 2014 among 500 adults aged >19 years in Seoul, Gyeonggi-do and Chungcheong-do areas. Results: Factor analysis of the dietary life style, indicated 4 factors including food convenience factor, food information emphasis factor, behavior factor of pursing food taste, and food purchase standard factor, which were classified into 3 groups according to differentiated dietary life style types; group 1 emphasized convenience and diversity of food, and price sensitiveness. and included subjects who had low interest in health and nutrition and were less likely to take care of their health through regular exercise,; group 2 emphasized food ingredients, food additives, usage and food purchase standards. and included subjects who were more likely to take care of their health through exercise and showed lower intake of fast food and less cases of eating out.; and group 3 showed relatively higher tendency toward dietary life style factors than the other two groups. The level of nutrition knowledge in sodium intake differed according to dietary life styles, and showed a significant difference in the dietary practice of sodium intake. Conclusion: Nutrition education on the healthy dietary habit of reducing sodium intake be based on ge and gender. In addition, an effort is required to improve behavior, interest, and attitude according to the important tendencies of the dietary life style.

• 한국식품과학회지
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• 제34권3호
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• pp.431-436
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• 2002

보통 옥수수 전분을 이용하여 저항전분을 제조할 때 저항 전분의 수율을 높일 수 있는 방법을 개발하기 위한 목적으로 가교결합 전분을 제조하고 annealing처리를 병행하였다. Annealing은 $40{\sim}60^{\circ}C$ 범위에서 실시하였고, 이와 비교하기 위하여 $70^{\circ}C$와 $100^{\circ}C$에서 열처리한 후 가교결합 전분을 제조하였다. RS 분석방법으로는 pancreain-gravimetric법(P/G법)을 사용하였다. 보통 옥수수전분과 고아밀로오스 옥수수전분으로 annealing하지 않고 가교결합 전분을 제조했을 때의 RS수율은 각각 14.7, 45.3%였고, annealing 한 후 가교결합 전분을 제조했을 때 28.0, 63.4%까지 증가하였다. 가교결합 전분의 팽윤력은 annealing 처리에 의해 영향받지 않았으나, 보통 옥수수전분으로 제조한 시료의 경우는 호화온도이상에서 열처리했을 때 팽윤력이 2배이상 증가하였다. 두가지 전분으로부터 제조된 가교결합 전분의 X-선 회절도와 주사전자현미경에 의한 특성 역시 annealing에 의해 영향받지 않았다.

• Restorative Dentistry and Endodontics
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• 제40권1호
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• pp.37-43
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• 2015

Objectives: Some antioxidants are believed to restore dentin bond strength after dental bleaching. This study was done to evaluate the influence of antioxidants on the bond strength of bleached bovine dentin. Materials and Methods: Thirty incisors were randomly assigned to 10 groups (two unbleached control and eight bleached groups:immediate bonding IB, 4 wk delayed bonding DB, 10% sodium ascorbate treated SA, 10% ${\alpha}$-tocopherol treated TP groups). Teeth in half of groups were subjected to thermal stress, whereas the remaining groups were not. Resin-dentin rods with a cross-sectional area of $2.25mm^2$ were obtained and microtensile bond strength was determined at a crosshead speed of 1 mm/min. Fifteen specimens were prepared for SEM to compare the surface characteristics of each group. The change in dentin bond strength from thermal stress and antioxidant treatment was evaluated using two-way analysis of variance (ANOVA) and Sheffe's post hoc test at a significance level of 95%. Results: The control group exhibited the highest bond strength values, whereas IB group showed the lowest value before and after thermocycling. The DB group recovered its bond strength similar to that of the control group. The SA and TP groups exhibited similar bond strength values with those of the control and DB groups before thermocycling. However, The TP group did not maintain bond strength with thermal stress, whereas the SA group did. Conclusions: Applying a 10% sodium ascorbate solution rather than 10% ${\alpha}$-tocopherol solution for 60 sec is recommended to maintain dentin bond strength when restoring non-vitally bleached teeth.

• Advances in Energy Research
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• 제4권3호
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• pp.189-202
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• 2016

This work emphasized optimum production of biodiesel using non-edible Prunus armeniaca (Bitter Apricot) oil via transesterification collected from the high altitude areas of Himachal Pradesh, India. In this study the author produced biodiesel through the process of transesterification by using an alkali catalyst with alcohol (methanol and ethanol), under the varying molar ratio (1:6, 1:9, 1:12), variable catalyst percentage (1% and 2%) and temperature ($70^{\circ}C$, $75^{\circ}C$, $80^{\circ}C$, $85^{\circ}C$). Furthermore, a few strong base catalysts were used that includes sodium hydroxide, potassium hydroxide, sodium metal and freshly prepared sodium methoxide. After screening the catalyst, response surface methodology (RSM) in connection with the central composite design (CCD) was used to statistically evaluate and optimize the biodiesel production operation using NaOH as catalyst. It was found that the production of biodiesel achieved an optimum level biodiesel yield with 97.30% FAME conversion under the following reaction conditions: 1) Methanol/oil molar ratio: 1:6, 2) Reaction time: 3h, 3) Catalyst amount: NaOH 2 wt. %, and 4) Reaction temperature: $85^{\circ}C$. The experimental results showed that the optimum production and conversion of biodiesel through the process of transesterification could be achieved under an optimal set of reaction conditions. The biodiesel obtained showed appropriate fuel properties as specified in ASTM, BIS and En- standards.

• 한국식품영양학회지
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• 제34권2호
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• pp.146-155
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• 2021

This study observed the anti-inflammatory effect of the polysaccharide derived from the mycelium of Tremella fuciformis in mice with colitis induced with dextran sulfate sodium (DSS). The experimental groups were normal, DSS, DSS-TFL50, DSS-TFH100, and suflasalazine. Body weights, colon lengths, and organ weights were measured, and the plasma level of pro-inflammatory cytokine and mRNA and protein expression in colon tissue were analyzed. Body weight loss, a symptom of DSS-induced colitis, was suppressed by DSS-TF and the speed of weight recovery proceeded rapidly. In addition, DSS-TF showed a significant inhibitory effect on the decrease of colon length typically caused by colon damage. TNF-α, IL-6 and IL-1β cytokine levels in plasma were reduced in DSS-TF and positive control groups. TNF-α, COX-2 and IL-1β mRNA expression in colon tissue were inhibited in DSS-TF and positive control, and it was significantly different from that of the DSS group. The protein expression of inflammation-related genes (IL-6, TNF-α and COX-2) in the colon tissue was significantly increased by DSS compared to that of the normal group, but by DSS-TFL50, DSS-TFH100 and sulfasalarin decreased. In conclusion, the polysaccharide derived from the mycelium of Tremella fuciformis showed the anti-inflammatory effect on DSS-induced colitis in mice.

• Journal of Microbiology and Biotechnology
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• 제32권10호
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• pp.1234-1244
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• 2022

Oral streptococci are considered as an opportunistic pathogen associated with initiation and progression of various oral diseases. However, since the currently-available treatments often accompany adverse effects, alternative strategy is demanded to control streptococci. In the current study, we investigated whether short-chain fatty acids (SCFAs), including sodium acetate (NaA), sodium propionate (NaP), and sodium butyrate (NaB), can inhibit the growth of oral streptococci. Among the tested SCFAs, NaP most potently inhibited the growth of laboratory and clinically isolated strains of Streptococcus gordonii under anaerobic culture conditions. However, the growth inhibitory effect of NaP on six different species of other oral streptococci was different depending on their culture conditions. Metabolic changes such as alteration of methionine biosynthesis can affect bacterial growth. Indeed, NaP enhanced intracellular methionine levels of oral streptococci as well as the mRNA expression level of methionine biosynthesis-related genes. Collectively, these results suggest that NaP has an inhibitory effect on the growth of oral streptococci, which might be due to alteration of methionine biosynthesis. Thus, NaP can be used an effective bacteriostatic agent for the prevention of oral infectious diseases caused by oral streptococci.

• Restorative Dentistry and Endodontics
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• 제48권1호
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• pp.1.1-1.11
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• 2023

Objectives: This study evaluated the dentinal penetration depth of 2.5% sodium hypochlorite (NaOCl) in root canals with and without preparation and different irrigant activation protocols. Materials and Methods: Sixty-three bovine mandibular incisors were randomly allocated to 6 groups (n = 10): G1, preparation + conventional needle irrigation (CNI); G2, preparation + passive ultrasonic irrigation (PUI); G3, preparation + Odous Clean (OC); G4, no preparation + CNI; G5, no preparation + PUI; G6, no preparation + OC; and CG (negative control; n = 3). Samples were filled with crystal violet for 72 hours. Irrigant activation was performed. Samples were sectioned perpendicularly along the long axis, 3 mm and 7 mm from the apex. Images of the root thirds of each block were captured with a stereomicroscope and analyzed with an image analysis software. One-way analysis of variance, followed by the Tukey post hoc test, and the Student's t-test were used for data analysis, with a significance level of 5%. Results: The NaOCl penetration depth was similar when preparation was performed, regardless of the method of irrigation activation (p > 0.05). In the groups without preparation, G6 showed greater NaOCl penetration depth (p < 0.05). The groups without preparation had a greater NaOCl penetration depth than those with preparation (p = 0.0019). Conclusions: The NaOCl penetration depth was similar in groups with root canal preparation. Without root canal preparation, OC allowed deeper NaOCl penetration. The groups without preparation had greater NaOCl penetration than those undergoing root canal preparation.

• Journal of Microbiology and Biotechnology
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• 제33권1호
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• pp.35-42
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• 2023

This study aimed to identify the therapeutic ability of a novel toll-like receptor (TLR) 5 agonist, KMRC011, on ulcerative colitis induced by Citrobacter rodentium and dextran sulfate sodium in a C57BL/6N mouse model. Ulcerative colitis was induced in the mice by the oral administration of 1% dextran sulfate sodium in sterile drinking water for seven days ad libitum, followed by C. rodentium infection on the seventh day by intra-gastric administration (DSS-CT group). KMRC011 was administered intramuscularly at both 24 h and 15 min before (Treatment 1 group), and at both 15 min and 24 h after (Treatment 2 group) the C. rodentium infection. The length of the large intestine and histopathological counts were significantly greater and mucosal thickness was significantly thinner in the Treatment 1 group compared to the DSS-CT and Treatment 2 groups. Il-6 and Il-10 mRNA expression levels were upregulated, while Ifn-γ and Tnf-α mRNA expression levels were significantly downregulated in the Treatment 1 group, compared to the DSS-CT group. NF-κB p65 expression level was elevated due to ulcerative colitis in the DSS-CT group, but was significantly downregulated in the Treatment 1 group. Overall, KMRC011 showed protective effects against murine colitis by inhibiting NF-κB signaling.