• 한국식품과학회지
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• 제24권2호
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• pp.111-116
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• 1992

역마이셀-효소반응계에서 팜유와 스테아르산으로부터 Rhizopus arrhizus 리파제의 에스테르교환 반응에 의한 코코아 버터 대용지 생산을 위한 연구를 실시하였다. HPLC를 이용하여 각 트리글리세리드의 정성 및 정량분석을 행하였다. 트리올레인과 스테아르산의 모델반응에서 Aerosol OT에 대한 물의 몰비율을 변화시켰을 때 그 비가 10일 때, 30mM 트리올레인에 대하여 3배의 스테아르산을 첨가했을 때 최대의 전환율을 보였다. 또 pH는 7.5, 온도는 $50^{\circ}C$에서 최대의 전환율을 보였다. 팜유와 스테아르산을 기질로 이용하였을 때는 팜유내의 POP, POO, SOO가 줄어든 반면 POS와 SOS가 생성, 증가되는 경향을 보였다. 본 연구에서 얻은 코코아 대용지의 POP. POS, SOS 등 트리글리세리드 조성은 시판되는 코코아 대용지보다 천연코코아 버터의 조성과 더욱 유사하였다.

• Journal of Animal Science and Technology
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• 제64권5호
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• pp.911-921
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• 2022

Maximum residue limits (MRL) for pesticides in feed have been set to protect public health and produce safe livestock products. In vivo experiments to establish MRL are essential, as livestock are commonly used to obtain reliable in vivo quantitative information. Here, we aimed to evaluate whether small laboratory animals can replace or reduce monogastric livestock in experiments to quantify pesticide residues in vivo after oral consumption through feed. First, 24 pigs and rats were randomly assigned to four groups and fed 0, 3, 9, or 30 mg/kg of sulfoxaflor. After four weeks, serum, muscle, fat, liver, kidney, and small intestine samples were collected, and sulfoxaflor residues were analyzed using liquid chromatography - tandem mass spectrometry. Sulfoxaflor residues in pig tissues were significantly correlated with those in rat tissues. Model equations were formulated based on the residual sulfoxaflor amount in pig and rat tissues. The calculated and measured sulfoxaflor residues in pigs and rats showed more than 90% similarity. Sulfoxaflor did not affect body weight gain, feed intake, or the feed conversion ratio. Therefore, we concluded that pesticide residue quantification in vivo to establish MRL could be performed using small laboratory animals instead of livestock animals. This would contribute to obtaining in vivo pesticide residue information and reducing large-scale livestock animal experiments.

• Journal of Animal Science and Technology
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• 제64권3호
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• pp.471-480
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• 2022

This experiment was conducted to determine the maximum dietary energy levels on growth performance and carcass characteristics of White Pekin duck. the Six dietary treatments were formulated based on their apparent metabolizable energy (AME) concentrations from 2,700 to 3,200 kcal/kg with a 100 kcal/kg gap to evaluate the accurate dietary AME requirement to address current knowledge and further issues for fulfilling the genetic potential of meat-type white Pekin ducklings. A total of 432 one-day-old male White Pekin ducklings were randomly allocated into one of six dietary treatments with six replicates (12 birds per pen). The diets were formulated as corn-soybean meal-based diets to meet or exceed the Nutrient Requirement of Poultry specification for meat-type ducks. Growth performance indices (i.e. average daily gain [ADG], average daily feed intake, feed conversion ratio) were measured weekly. Medium body weight (BW) ducklings from each pen were sacrificed to analyze the carcass traits and abdominal fat content on day 21. Obtained data were analyzed to estimate significant effect using the one-way ANOVA of IBM SPSS Statistics (Version, 25). If the p-value of the results were significant, differences in means among treatments were separated by Tukey's post hoc test. Significant differences were then analyzed with a linear and quadratic broken model to estimate the accurate concentration of AME. Ducklings fed higher dietary AME diets increased (p < 0.05) BW, ADG. Ducklings fed higher AME than 2,900 kcal/kg diets increased abdominal fat accumulation and leg meat portion. The estimated requirement by linear plateau method showed from 3,000.00 kcal/kg to 3,173.03 kcal/kg whereas the requirement by quadratic plateau method indicated from 3,100.00 kcal/kg to 3,306.26 kcal/kg. Collectively, estimated dietary requirements exhibit diverse results based on the measured traits and analysis methods. All the estimated requirements in this experiment present higher than previous research, the maximum requirement for the next diet formulation should be selected by the purpose of the diet.

• Geomechanics and Engineering
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• 제30권4호
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• pp.373-382
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• 2022

Unsaturated soil at high suctions is widespread. Many civil engineering projects are related to the hydro-mechanical behavior of unsaturated soils at high suctions, particularly in arid and semiarid areas. To investigate water retention behaviors of nine clayey soils (one is classified as fat clay and the others are classified as lean clay according to the unified soil classification system), the high suction (3.29-286.7 MPa) was imposed on the specimens at zero net stress by the vapor equilibrium technique. In this paper, the effect of void ratio on the water retention behavior at high suction was discussed in detail. Validation data showed that soil types, i.e., different mineralogical compositions, are critical in the soil water retention behavior at a high suction range. Second, the hysteresis behavior at a high suction range is mainly related to the clay content and the specific surface area. And the mechanism of water retention and hysteresis behavior at high suctions was discussed. Moreover, the maximum suction is not a unique value, and it is crucial to determine the maximum suction value accurately, especially for the shear strength prediction at high suctions. If the soil consists of hydrophilic minerals such as montmorillonite and illite, the maximum suction will be lower than 10⁶ kPa. Finally, using the area of hysteresis to quantify the degree of hysteresis at a high suction range is proposed. There was a good correlation between the area of hydraulic hysteresis and the specific surface area.

• Korean Journal of Radiology
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• 제22권5호
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• pp.829-839
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• 2021

Objective: To compare the diagnostic performance of contrast-enhanced radial T1-weighted gradient-echo 3-tesla (3T) magnetic resonance imaging (MRI) and computed tomography (CT) for the detection of visceral pleural surface invasion (VPSI). Visceral pleural invasion by non-small-cell lung cancer (NSCLC) can be classified into two types: PL1 (without VPSI), invasion of the elastic layer of the visceral pleura without reaching the visceral pleural surface, and PL2 (with VPSI), full invasion of the visceral pleura. Materials and Methods: Thirty-three patients with pathologically confirmed VPSI by NSCLC were retrospectively reviewed. Multidetector CT and contrast-enhanced 3T MRI with a free-breathing radial three-dimensional fat-suppressed volumetric interpolated breath-hold examination (VIBE) pulse sequence were compared in terms of the length of contact, angle of mass margin, and arch distance-to-maximum tumor diameter ratio. Supplemental evaluation of the tumor-pleura interface (smooth versus irregular) could only be performed with MRI (not discernible on CT). Results: At the tumor-pleura interface, radial VIBE MRI revealed a smooth margin in 20 of 21 patients without VPSI and an irregular margin in 10 of 12 patients with VPSI, yielding an accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and F-score for VPSI detection of 91%, 83%, 95%, 91%, 91%, and 87%, respectively. The McNemar test and receiver operating characteristics curve analysis revealed no significant differences between the diagnostic accuracies of CT and MRI for evaluating the contact length, angle of mass margin, or arch distance-to-maximum tumor diameter ratio as predictors of VPSI. Conclusion: The diagnostic performance of contrast-enhanced radial T1-weighted gradient-echo 3T MRI and CT were equal in terms of the contact length, angle of mass margin, and arch distance-to-maximum tumor diameter ratio. The advantage of MRI is its clear depiction of the tumor-pleura interface margin, facilitating VPSI detection.

• Asian-Australasian Journal of Animal Sciences
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• 제21권2호
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• pp.232-236
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• 2008

This experiment was performed to investigate the effects of two energy levels and four lysine:digestible energy (DE) ratios on the apparent digestibility of nutrients in finishing pigs. The experiment was conducted using a $2{\times}4$ randomized complete block (RCB) design with three replicates. Twenty-four cross-bred finishing barrows ((Landrace${\times}$Yorkshire)${\times}$Duroc) with an average body weight of $64.2{\pm}0.69kg$ were assigned to one of eight treatments. Each barrow was placed in an individual metabolism crate and dietary treatment and water was provided ad libitum. Diets were designed to contain lysine:ME ratios of 1.5, 1.8, 2.1 and 2.4 g/Mcal at 3.35 and 3.6 Mcal/kg of diet in a $4{\times}2$ factorial arrangement. Dry matter (DM), ash, Ca and P digestibility were not affected by energy density or lysine:DE ratios. Crude fat digestibility increased as the energy density increased from 3.35 to 3.6 Mcal of DE/kg. Increasing the lysine:DE ratio also increased crude protein digestibility. There were no interactions between energy density and lysine:DE ratio in terms of nutrient digestibility. Nitrogen excretion via feces was not affected by energy density and lysine:DE ratio, while nitrogen excretion via urine was significantly affected by energy density and lysine:DE ratio. The apparent digestibility of all amino acids except for isoluecine, arginine and aspartic acid as well as average values of essential amino (EAA), non-essential amino acids (NEAA) and total amino acid digestibility (p>0.05) were not affected by energy density. The apparent digestibility of all amino acids except for leucine, proline, alanine and tyrosine, NEAA and total amino acid digestibility were significantly affected by lysine: DE ratio (p<0.05). Interactive effects of energy and lysine:DE ratio also significantly affected amino acid digestibility except for isoleucine, alanine, cystine, leucine, phenylalanine, glutamine and proline (p<0.05). In conclusion, these results suggest that maintaining the appropriate lysine:DE ratio becomes more important as the energy density of the diet increases. Consequently, increasing the lysine:DE ratio can result in increased crude protein digestibility and urinary nitrogen excretion, although apparent protein digestibility and nitrogen excretion were not affected by energy density Furthermore, increasing the lysine:DE ratio also increased the apparent digestibility of essential amino acids, except for leucine, regardless of energy density. The optimum lysine:DE ratio for maximum essential amino acid digestibility of the $64.2{\pm}0.69kg$ pig is approximately 2.4 g of lysine/Mcal of DE.

• Preventive Nutrition and Food Science
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• 제3권3호
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• pp.267-271
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• 1998

To evaluate nutrient intakes of the first generation Korean -Americans in Hawaii, a dietary survey was conducted using a food frquency questionaire which included 139 food items most often consumed among Korean foods and American foods. The questionnaire surveyed 157 first generation Korean-Americans living in Hawaii. The 66.7~81.1% of first generation Korean-Americans in Hawaii were of healthy weight. The mean percentages of calories obtained from their dietary analyses were 61% carbohydrate, 23% fat and 16% protein. The calorie distribution of their diet appeared to be similiar between older women and older men, however it was seen that men consumed a higher percent of calories from fat than women among younger subjects. The mean dietary intakes for first generation Korean-Americans exceeded recommended intakes for protein, thiamin, niacin , vitamin A, vitamin C, folacin , phosphorus and iron , but the intakes of energy, riboflavin, vitamin B6 ,vitamin E, calcium and zinc were lower than the recommended dietary allowance for Americans. Compared with other groups based on age and gender , younger men had significantly(p<0.05) higher intakes of riboflavin, phosohrous, iron and zinc, and lower intake of folacin. Older subjects consumed significantly (p<0.05) less protein, riboflavin, vitamin B6 and zinc than did younger subjects, and most of the first generation Korean-Americans in Hawaii consumed adequate levels of saturated fatty acid . The ratio , however, of polyunsaturated fatty acid to saturated fatty acid in the diet of younger men was about 0.61, much lower than the recommeded ration of 1.0 and also was significantly (p<0.05) lower than that of other subjects. Moreover, cholesterol intakes of younger men were close th the maximum recommeded level of 300mg/day.

• 한국식품과학회지
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• 제24권3호
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• pp.251-255
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• 1992

라아드의 가소성 영역을 확대시켜 작업성을 향상시키기 위한 수단의 하나로서 무작위 에스테르교환을 이용하여, 에스테르화 라아드의 물리화학적 성질 및 파이제조용 유지에 대한 그 적용성을 검토하였다. 에스테르화 전후의 라아드의 지방산 조성 및 트리글리세라이드 조성은 변화가 없었다. 라아드는 에스테르화에 의하여 SFI $5{\sim}25$의 온도범위가 $18{\sim}29.5^{\circ}C$에서 $13{\sim}30^{\circ}C$로 변화하여 저온의 범위가$5^{\circ}C$ 정도 증가하였다. 특히, SFI $15{\sim}25$의 온도범위가 $18{\sim}23.5^{\circ}C$에서 $13{\sim}19.5^{\circ}C$로 저하하여 저온에서의 작업성이 향상됨으로써 겨울철에 이용시 유리할 것으로 판단된다. 에스테르화 라아드는 결정형의 변화로 인하여 신전성이 감소되어 파이 반죽의 층형성이 불가능하였다. 따라서, 에스테르화 라아드는 파이의 팽화율, 외관, 쇼트니스를 불량하게 하여, 단독 사용시 파이용 유지로서는 부적합하였다. 그러나, 에스테르화 라아드에 신전성이 우수한 유지를 혼합하여 사용할 경우, 파이 껍질의 제조는 가능했으며 50%까지 에스테르화 라아드를 혼합하여도 파이 껍질의 품질은 우수하였다.

• 한국축산식품학회지
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• 제42권4호
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• pp.712-722
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• 2022

In this study, we investigated the residual properties of tebuconazole-treated pigs. Twenty pigs were treated with different concentrations (0.25, 1.25, 2.5, 12.5, and 25 mg/kg bw/d) of tebuconazole for 28 d. Blood biochemistry, histology, and residual levels were analyzed using the VetTest analyzer, Masson's trichrome staining kit, and liquid chromatography-mass spectrometry, respectively. The final body weights were not significantly different between the control and treatment groups. Alkaline phosphatase, blood urea nitrogen, cholesterol, and gamma-glutamyl transpeptidase levels were significantly different from those of the control after exposure for 14 d. However, alanine aminotransferase levels showed changes only after exposure to pesticides for 28 d. The biochemical parameters were separated during the experimental period (14 d versus 28 d) by principal component analysis. Based on variable importance plots, blood urea nitrogen/creatinine ratio, blood urea nitrogen, glucose, and gamma-glutamyl transpeptidase are candidate biomarkers for tebuconazole exposure. The residual levels were observed at T4 (12.5 mg/kg bw/d) and T5 (25 mg/kg bw/d) in the liver and fat tissues, respectively. Fibrosis increased in the liver, kidney, and fat tissues, depending on the tebuconazole concentration. In conclusion, the residue limits of tebuconazole and the physiological changes caused by dietary tebuconazole in pigs provide important information for establishing maximum residue limits of pork and pork products.

• Journal of Biosystems Engineering
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• 제43권1호
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• pp.37-44
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• 2018

Purpose: The objective of this study was to investigate the high-efficiency anaerobic digestion of organic wastes with high fat content. Specifically, the analysis focused on biogas production performance with a focus on carbon number and the double bond count of the long-chain fatty acids (LCFAs), which are hydrolysis products of triglycerides. Methods: Experiments were performed under mesophilic anaerobic conditions with a feed-to-microorganism ratio (F/M) of 1.0. Biogas production performance was analyzed through biogas production patterns, lag-phase, and the time required for 90% biogas production (T90). Results: Biogas production increased when the content of unsaturated LCFAs (containing relatively large numbers of carbon atoms) increased. In substrate containing LCFAs with four or more double bonds, although the initial lag-phase in biogas production was shortened, development of a three-step lag-phase resulted in decreased biogas production. These results suggest that high rates of anaerobic digestion are possible when the LCFAs have high unsaturated fatty acid content with three or fewer double bonds. Conclusions: When various types of LCFAs are digested anaerobically, biogas production performance can be improved if the unsaturated fatty acid content and number of double bonds are optimized for maximum production.