• Journal of Nutrition and Health
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• v.56 no.1
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• pp.1-11
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• 2023

Purpose: Obesity is associated with alterations in vitamin D metabolism and elevation of parathyroid hormone (PTH). Increased PTH level in obesity is likely one of the factors contributing to the dysregulation of vitamin D metabolism. We investigated the effects of lowering the PTH level in high-fat diet-induced obese mice on vitamin D metabolism. Methods: Five-week-old male C57BL/6N mice were fed either with control (10% energy as fat) or high-fat (60% energy as fat) diets ad libitum for 12 weeks, and vehicle or cinacalcet HCl (30 ㎍/g body weight) was gavaged daily during the final week of the experiment. The following groups were studied: CON (control diet + vehicle), HFD (high-fat diet + vehicle), and HFD-CIN (high-fat diet + cinacalcet HCl). PTH, 1,25-dihydroxyvitamin D (1,25[OH]₂D), 25-hydroxyvitamin D (25[OH]D), calcium, and phosphate levels in circulation, and the expression of genes related to vitamin D metabolism in the liver and kidneys were determined. Results: Renal 1α-hydroxylase expression in the HFD group was higher than that in the CON group despite the lack of a difference in the PTH levels between the 2 groups. The plasma PTH level in the HFD-CIN group was 60% lower than that in the HFD group (p < 0.05). In parallel, the HFD-CIN group had lower adipose tissue amount (9% lower), renal 1α-hydroxylase expression (48% lower), and plasma 1,25(OH)₂D concentration (38% lower) than the HFD group. Conclusion: Lowering the PTH levels in high-fat diet-induced obese mice recovered the expression of renal 1α-hydroxylase and might be associated with lower amounts of white adipose tissue.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.15 no.1
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• pp.34-38
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• 2005

Effects of pH level and slurry particle size on material removal rate and planarization of langasite single crystal wafer have been examined. Higher material removal rate was obtained with lower pH level slurries while the planarization was found to be determined by average particle size of colloidal silica slurries. Slurries containing 0.045 ㎛ amorphous silica particles showed the best polishing effect without any scratches on the surface. Effective particle number has a strong effect on the surface planarization and the removal rate, so that the lower effective particle numbers produced low removal rate but the better planarization results.

• Korean Journal of Computational Design and Engineering
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• v.21 no.4
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• pp.378-388
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• 2016

As the needs for the mega-sized, high-rise and irregular shape of building increase, domestic application of BIM in construction industry is increasing in recent years. In this circumstance, interests in BIM modeling and modeling detail level have been also increased. BIM that is based on a three-dimensions, requires a specific and precise building expressions. And model expression level required for each phase such as design, construction, and maintenance of the construction project could be different as its needs. Because that it is not clear to define the criteria for the expression level of construction BIM model, It is difficult to decide how detail and what to model is appropriate in the practical application of BIM model. It could be the reason why the productivity in construction project became lower and lower. In this study we consider the way how to improve the productivity of BIM and analyze the appropriate representation level of construction BIM model through the experts' survey. The results of study could suggest the basis for an appropriate expression level of construction BIM model.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.6
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• pp.1839-1851
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• 1991

Fatigue crack behavior is studied through the two-level rotary bending test with the deep non-through radial holed notch specimens of low carbon steels(SM22C). The main factors investigated are the effects of the damage zone size around crack tip and phenomena of closing or opening of the crack tip. Obtained results are summarized as follows. Fatigue crack behavior in second level stressing slightly lower than fatigue limit is closely related to the size of damage zone produced by the first level stress higher than fatigue limit and to the phenomena of crack closing and opening for the second level stress. The non-propagating crack limit condition depends upon the crack length l$_{1}$ propagated under the first level stress and the magnitude of second level stress .sigma.$_{2}$ lower than the fatigue limit. The non-propagating crack limit condition is expressed by following eq. $\sigma_2^{6.1}{\times}l_{1}=7.35{\times}10^{6}[(kg_{f}mm^{6.1}(mm)]$

• Journal of Nutrition and Health
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• v.29 no.10
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• pp.1072-1079
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• 1996

This study was performed to elucidate the mechanism of dietary protein level on renal function through lipid and eicosanoids metabolism. Male rats of 337.8$\pm$5.7g body weight were undergone unilateral nephrectomy or sham-operation. The rats were divided into high protein(40% casein), normal protein(15% casein) and low protein(8% casein) diet groups and fed experimental diets ad libitum for 24 weeks. The results are summarized as follows. Serum total lipid, cholesterol and HDL-cholesterol of rats in 15% and 40% casein groups were higher than those of 8% casein group. But serum triglyceride was affected neither by uninephrectomy nor by dietary protein level. Serum thromboxane(TX) B2 and 6-keto prostaglandin F1$\alpha$ increased with increasing dietary protein level. Serum prostaglandin(PG) E2 was not affected by uninephrectomy nor by dietary protein level. Urinary PGE2 and TXB2 excretion tended to be lower in uninephrectomized groups. Renal tissue concentration of TXB2 was lower in uninephrectomized groups and in high protein group. These results suggest the possibility that the effects of dietary protein level on renal function could be due to changes in lipid and eicosanoids metabolism.

• Journal of Community Nutrition
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• v.6 no.2
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• pp.97-102
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• 2004

A cross-sectional epidemiologic study was conducted to evaluate vitamin C nutritional status by assessing dietary intake and blood vitamin C level and to identify the relationships between dietary vitamin C intake, serum vitamin C level and blood lead level in Korean lead workers. The study population was 118 lead workers from two battery manufacturing factories and 63 non-lead-exposed controls. A food consumption survey was conducted by the 24-hr recall method to determine the dietary vitamin C intake level. The anthropometric measurements, blood collection, and survey were performed between September and November, 2000. Blood lead levels and serum vitamin C levels were measured using an atomic absorption spectrometer and high performance liquid chromatography, respectively. Vitamin C nutritional status of Korean lead workers was lower than that of the control group, in terms of both dietary intake and the biochemical index: the mean daily dietary intake level of vitamin C of lead workers was 65.9mg (94% RDA), while that of controls was 132.6mg(189% RDA) ; and the serum vitamin C status of lead workers (0.10mg/dl) was significantly lower than that of controls (1.08mg/dl ; p<0.001). Both dietary vitamin C intake and serum vitamin C levels showed a significant negative correlation with blood lead level (p<0.001), which indicates that strategies of dietary management to promote the health of Korean lead workers should focus on promoting the vitamin C intakes of individuals.

• Computers and Concrete
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• v.6 no.5
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• pp.357-376
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• 2009

In the design of concrete columns, it is important to provide some nominal flexural ductility even for structures not subjected to earthquake attack. Currently, the nominal flexural ductility is provided by imposing empirical deemed-to-satisfy rules, which limit the minimum size and maximum spacing of the confining reinforcement. However, these existing empirical rules have the major shortcoming that the actual level of flexural ductility provided is not consistent, being generally lower at higher concrete strength or higher axial load level. Hence, for high-strength concrete columns subjected to high axial loads, these existing rules are unsafe. Herein, the combined effects of concrete strength, axial load level, confining pressure and longitudinal steel ratio on the flexural ductility are evaluated using nonlinear moment-curvature analysis. Based on the numerical results, a new design method that provides a consistent level of nominal flexural ductility by imposing an upper limit to the axial load level or a lower limit to the confining pressure is developed. Lastly, two formulas and one design chart for direct evaluation of the maximum axial load level and minimum confining pressure are produced.

• English Language & Literature Teaching
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• v.17 no.1
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• pp.1-16
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• 2011

Listening has been a neglected research area despite the crucial role it plays. The present investigation was aimed at examining how the provision of topical knowledge and learners' listening proficiency level affect learners' listening performance under four different preparatory activity conditions: topical knowledge, vocabulary list, language structure, and no activity. A total of 134 participants, assigned to the four different activity groups, took part in the study. The results revealed that the learners who were provided with topical knowledge before listening performed significantly better than the other learners, followed by the vocabulary list group and language structure group, which might be attributed to the activation of their content schemata. The learners who did not perform any preparatory activities achieved the lowest scores. When it comes to the impact of listening proficiency, it was revealed that learners' proficiency level had a significant influence on learners' listening performance, and there was a significant interaction between the learners' level of listening proficiency and preparatory activity. Providing relevant knowledge was effective for both higher level and lower level learners, whereas teaching vocabulary before listening was effective for higher level learners but was not for lower level ones. Based on the results, some pedagogical implications and suggestions for future research were discussed.

• Journal of Mechanical Science and Technology
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• v.15 no.7
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• pp.1002-1012
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• 2001

The work reported here is an extensive study of tendon response to multiple cyclic tests including 3% constant peak strain level test (A-type test), 3% constant peak strain level test with two rest periods (B-type test), and 3∼4% different peak strain level test (C-type test). A sufficient number of specimens were tested at each type of the test to statistically evaluate many changes in response during testing and differences in response between each type of the test. In cyclic tests, there were decreses (relaxations) in the peak stresses and hysteresis, increases in the slack strains, and during lower peak strain level (3%) cyclic block after higher peak strain level (4%) cyclic block in the C-type tests. Considering the results of this study and those of the other study of multiple cyclic tests with rest periods by Hubbard and Chun, 1985, recovery phenomena during the rest periods occurred predominantly at the beginning of the rest periods. Consistently in both studies, the effects of rest periods were small and transient compared to the effects of the cyclic extensions. The recovery with cycles at lower peak strain level (3%) after higher peak strain level (4%) in the C-type test has not been previously documented. This recovery seems to be a natural phenomena in tissue behavior so that collagenous structures recover during periods of decreased demand.

• Journal of Korean Academy of Nursing
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• v.27 no.2
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• pp.341-352
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• 1997

The study was to examine the relationships among health promoting lifestyle, level of anxiety, and perceived health status and to reveal those variables. affecting health promoting lifestyle in Korean immigrants in the United States. The subjects were 425 adults chosen from Korean religious and social organizations located in New York from April 25th through July 5th. 1996. Data analyses were conducted by using Pearson correlation coefficients, t-test, ANOVA, and stepwise multiple regression. The results were as follows : Health promoting lifestyle was significantly different according to age, religion. occupation, and the length of residence in the US. Those insured and those with no chronic conditions revealed a significantly higher score in health promoting lifestyle. Significant differences in the level of anxiety were found according to education, marital status, occupation, family income, and the length of residence. Those with no chronic conditions experienced a significantly lower level of anxiety. In the subscales of the health promoting lifestyle profile, self-actualization and interpersonal relationship revealed higher scores, whereas the scores of stress management, health responsibility, and exercise were lower. Those subjects whose perceived health status was very good, showed the lowest level of anxiety and the highest score on the health promoting lifestyle profile. Negative correlations were observed between the health promoting lifestyle profile and the level of anxiety, and between the perceived health status and the level of anxiety. Health promoting lifestyle was significantly predicted by the level of anxiety(22.0%), age(2.0%), health insurance(1.1%), respectively.