• Nutrition Research and Practice
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• 제17권5호
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• pp.1028-1041
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• 2023

BACKGROUND/OBJECTIVES: This study aimed to analyze the potential of school meals in South Korea as a sustainable tool to reduce carbon emissions by focusing on animal- vs. plant-based protein foods. MATERIALS/METHODS: By using a stratified proportional allocation method, 536 out of the 11,082 schools nationwide were selected including 21 kindergartens, 287 elementary-, 120 middle- and 108 high schools. A total of 2,680 meals served for 5 consecutive days (June 21-25, 2021) were collected. We analyzed the average serving amounts of protein foods (animal- vs. plant-based) per meal and then, calculated the estimated average amounts of carbon emission equivalents per meal by applying the conversion coefficients. The t-test and analysis of variance were used for statistical analyses (α = 0.05). RESULTS: The average serving amount of animal-based protein foods per meal was 12.5 g, which was approximately 3 times higher than that of plant-based ones (3.8 g) (P < 0.001); the Meat-group had the highest average amount of 17.0 g, followed by Egg-group (9.6 g), Fish-group (7.6 g), and Beans-and-Nuts-group (3.8 g) (P < 0.05). Specifically, pork (25.1 g) was ranked first, followed by poultry (19.6 g), processed meat products (18.0 g). The estimated average amount of carbon emission equivalents of animal-based protein foods per meal was 80.1 g CO₂e, which was approximately 31 times higher than that of plant-based ones (2.6 g CO₂e) (P < 0.001); the Meat-group had the highest average amount of 120.3 g CO₂e, followed by Fish-group (44.5 g CO₂e), Egg-group (25.9 g CO₂e), and Beans-and-Nuts-group (2.6 g CO₂e) (P < 0.05). Specifically, processed meat products (270.8 g CO₂e) were ranked first, followed by pork (91.7 g CO₂e), and processed fish products (86.6 g CO₂e). CONCLUSIONS: The results implied that school meals with plant-based alternatives could be a sustainable tool to improve carbon footprint.

• 충청수학회지
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• 제34권1호
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• pp.17-26
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• 2021

The purpose of this paper is to determine the structure of the crystallographic group 𝚷 of the 4-dimensional solvable Lie group Sol ⁴_m,n that the translation subgroup of 𝚷, 𝚪 := 𝚷; ∩ Sol⁴_m,n, is generated by the particular elements.

• 농업과학연구
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• 제47권1호
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• pp.131-138
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• 2020

The aim of this study was to evaluate the effect of aflatoxin B₁ (AFB₁) on in vitro rumen fermentation at various dose levels of 0 (T₁), 100 (T₂), 200 (T₃), and 300 (T₄) ppb in a wheat straw-based buffalo diet. The results show that the truly degradable dry matter, truly degradable organic matter, gas production, microbial biomass production and partitioning factor values in the control group (T₁) were higher (p < 0.05) than those of the T₂, T₃, and T₄ groups. The total volatile fatty acids, acetate, propionate, and butyrate values in the control group (T₁) were higher (p < 0.05) than those of the T₂, T₃, and T₄ groups. The partitioning factor value in the control group (T₁) was higher (p < 0.05) than those of the T₂, T₃, and T₄ groups. The partitioning factor values of the T₂ and T₃ groups were higher (p < 0.05) than that of the T₄ group. There was no significant variation in the partitioning factor value between the T₂ and T₃ group. The acetate : propionate (A : P) ratio in the control group (T₁) was lower (p < 0.05) than those of the T₂, T₃, and T₄ groups. The A : P ratio in the T₂ group was lower (p < 0.05) than those of the T₃ and T₄ groups. It was concluded that different levels of AFB₁ contamination in feed significantly affect the in vitro rumen fermentation characteristics. Thus, these findings could help to determine the influences of AFB₁ in a wheat straw-based buffalo diet. Additionally, it is necessary to manage AFB₁ contamination in ruminants.

• Restorative Dentistry and Endodontics
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• 제25권2호
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• pp.193-201
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• 2000

Prostaglandins (PGs) and Leukotrienes (LTs) have been implicated in the genesis of pulpal and periapical inflammation. In this study, the relationships among $PGE_2$, 6-keto-PG $F_1{\alpha}$ (a stable metabolite of $PGI_2$) and $LTB_4$ concentrations in inflamed pulp and periapical lesions were discussed. Pulp tissue were obtained in routine endodontic treatment and periapical lesions in periapical surgery after clinical diagnoses were made. These specimens were divided into four groups as normal pulp group (Control group), acute pulpitis group, chronic pulpitis group, and periapical lesion group. Pulp tissue and periapical lesions were stored in liquid nitrogen. The concentration of $PGE_2$, $PGI_2$ and $LTB_4$ were measured with ELISA. The data were analyzed by one-way ANOVA. Significantly higher levels of $PGE_2$, 6-keto-PG $F_1{\alpha}$ a and $LTB_4$ were found in acute pulpitis group than chronic pulpitis group and periapical lesion group(p<0.05). Periapical lesion group showed significantly higher mean concentrations of $PGE_2$ and $LTB_4$ than chronic pulpitis group. In control and chronic pulpitis group, significant higher levels of $PGI_2$ than $PGE_2$ and $LTB_4$ were found. These results suggested that the high levels of $PGE_2$ and $LTB_4$ in periapical lesions may be due to rich endothelium., fibroblast and lymphocyte known as the main producers of $PGE_2$ and $LTB_4$. $PGI_2$ may be thought to one of the most abundant PGs in normal pulp tissue.

• The Journal of Advanced Prosthodontics
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• 제13권4호
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• pp.237-245
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• 2021

PURPOSE. This study aimed to compare the microshear bond strength (µSBS) of dual-cure resin cement in CAD-CAM zirconia after different cleaning techniques. MATERIALS AND METHODS. Fifty discs of zirconia-based ceramic from Ivoclar Vivadent were embedded in acrylic resin. The discs were divided into five groups according to the cleaning methods used: Group 1: drying with spraying + sandblasting with Al₂O₃; Group 2: washed with water and dried with spraying + sandblasting with Al₂O₃;Group 3: washed with distilled water and dried with spraying + sandblasting with Al₂O₃ + zirconium oxide (Ivoclean); Group 4: washed with distilled water and dried with spraying + sandblasting with Al₂O₃ + potassium hydroxide (Zirclean); and Group 5: washed with distilled water and dried with spraying + sandblasting with Al₂O₃ + 1% NaClO. All of the groups were contaminated with artificial saliva for 1 minute and then cleaned. Statistical analyses were performed using ANOVA and Tukey's tests. RESULTS. There were statistically significant differences among all groups for µSBS (P < .05). The group treated with zirconium oxide (Group 3) showed the highest µSBS (18.75 ± 0.23 MPa). CONCLUSION. When applied to zirconia, the cleaning methods affected the bonding with resin cement differently.

• The Journal of Advanced Prosthodontics
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• 제14권2호
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• pp.96-107
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• 2022

PURPOSE. Microstructural and physico-mechanical characterization of highly translucent zirconia, prepared by milling technology (CAD-CAM) and repeated firing cycles, was the main aim of this in vitro study. MATERIALS AND METHODS. Two groups of samples of two commercial highly-translucent yttria-stabilized dental zirconia, VITA YZ-HT^White (Group A) and Zolid HT + White (Group B), with dimensions according to the ISO 6872 "Dentistry - Ceramic materials", were prepared. The specimens of each group were divided into two subgroups. The specimens of the first subgroups (Group A₁ and Group B₁) were merely the sintered specimens. The specimens of the second subgroups (Group A₂ and Group B₂) were subjected to 4 heat treatment cycles. The microstructural features (microstructure, density, grain size, crystalline phases, and crystallite size) and four mechanical properties (flexural strength, modulus of elasticity, Vickers hardness, and fracture toughness) of the subgroups (i.e. before and after heat treatment) were compared. The statistical significance between the subgroups (A₁/A₂, and B₁/B₂) was evaluated by the t-test. In all tests, P values smaller than 5% were considered statistically significant. RESULTS. A homogenous microstructure, with no residual porosity and grains sized between 500 and 450 nm for group A and B, respectively, was observed. Crystalline yttria-stabilized tetragonal zirconia was exclusively registered in the X-ray diffractograms. The mechanical properties decreased after the heat treatment procedure, but the differences were not statistically significant. CONCLUSION. The produced zirconia ceramic materials can be safely (i.e., according to the ISO 6872) used in extensive fixed prosthetic restorations, such as substructure ceramics for three-unit prostheses involving the molar restoration and substructure ceramics for prostheses involving four or more units. Consequently, milling technology is an effective manufacturing technology for producing zirconia substructures for dental fixed all-ceramic prosthetic restorations.

• 대한정형외과학회지
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• 제56권1호
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• pp.68-75
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• 2021

목적: 견관절의 운동 기능에 대한 평가는 견관절 질환의 진단 및 경과를 파악하는 데 있어 중요하다. 본 연구는 정상군 및 견관절질환을 가진 환자군에 대해 깊이 센서 기반 동작 분석 시스템을 통한 관절 운동을 동적으로 분석하여 문헌 고찰과 함께 보고하는 바이다. 대상 및 방법: 70명의 피험자가 연구에 참여하였으며 정상군 30명과 견관절 질환을 가진 환자 40명으로 분류하였다. 견관절 질환을 가진 환자 40명은 4가지 질환(회전근개 파열, 유착성 활액막염, 충돌 증후군, 회전근개 관절병증)으로 세분화하였다. 총 3회 반복된 외전 및 내전 운동 시 시간에 따른 각도를 깊이 센서 기반 동작 분석 시스템으로 측정하였으며, 최대 외전 각도, 최대 외전 각 속도, 최대 내전 각속도, 외전/내전 시간 비를 계산하였다. 상기 매개 변수들에 대해 정상군 30명과 환자군 40명을 비교하는 한편, 정상군 30명과 4가지 질환군별 10명, 총 5개 군을 비교하였다. 결과: 견관절 질환을 가진 환자군에서는 정상군에 비해 감소된 최대 외전 각도(θ_max), 최대 외전 각속도(ω_max), 최대 내전 각속도(ω_min)를 보였으며, 증가된 외전/내전 시간 비(t_abd/t_add)를 보였다. 세분화된 질환군별 비교에서는 최대 외전 각도(θ_max)와 최대 외전각속도(ω_max)가 정상군에 비해 유착성 활액막염 환자군 및 회전근개 관절병증 환자군에서 감소되었고, 외전/내전 시간 비(t_abd/t_add)가 정상군에 비해 유착성 활액막염 환자군, 회전근개 파열 환자군 및 회전근개 관절병증 환자군에서 증가되었다. 결론: 깊이 센서 기반 동작 분석 시스템을 사용한 견관절의 운동 분석을 통해 관절 운동 범위뿐 아니라 각속도 등의 동적 운동 변수를 측정할 수 있었으며, 이를 통해 견관절의 더 정확한 기능 평가 및 심도 있는 질환의 이해가 가능할 것이다.

• Bulletin of the Korean Chemical Society
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• 제31권1호
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• pp.23-24
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• 2010

• 한국의학물리학회지:의학물리
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• 제35권1호
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• pp.16-19
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• 2024

A new E_n score of the proficiency test (PT) is formulated; it is applicable when a correlation exists between the reference and participant's values. Based on the uncertainty propagation rule given in ISO/IEC Guide 98-3 (GUM:1995), the E_n score covering the correlation case is newly developed for the PT. The new E_n score will be applied in a future PT organized by the Korea Research Institute of Standards and Science (KRISS) dosimetry team. The new E_n score will enhance measurement traceability and contribute to improving the quality management system of participants in the KRISS PT by avoiding performance underestimation.

• 호남수학학술지
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• 제44권2호
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• pp.296-309
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• 2022

In this paper, we establish the Fricke Group Γ_F (N) which is a new special group of Non-Euclidean Crystallograhic (NEC) group. We obtain this group whose congruence subgroup Γ₀(N) is expanded with Fricke reflection $F(z)={\frac{1}{N{\bar{z}}}}$. Then, we research and calculate the structure of signature and fundamental domain of this group. And then, we calculate the number of boundary components in the signature for this group. Finally, we find the 2, 3, ∞ valued link periods of these boundary components with the H. Jaffee technique.