• Applied Chemistry for Engineering
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• v.34 no.3
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• pp.258-263
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• 2023

In this study, conductive polymers and the enzyme tyrosinase (Tyr) were deposited on the surface of a screen printed carbon electrode (SPCE), which can be fabricated as a disposable sensor chip, and applied to the detection of bisphenol F (BPF), an endocrine disruptor with proven links to male diseases and thyroid disorders, using electrochemical methods. On the surface of the SPCE working electrode, which was negatively charged by oxygen plasma treatment, a positively charged conductive polymer, poly(diallyldimethyl ammonium chloride) (PDDA), a negatively charged polymer compound, poly(sodium 4-styrenesulfonate) (PSS), and another layer of PDDA were layered by electrostatic attraction in the order of PDDA, PSS, and finally PDDA. Then, a layer of Tyr, which was negatively charged due to pH adjustment to 7.0, was added to create a PDDA-PSS-PDDA-Tyr sensor for BPF. When the electrode sensor is exposed to a BPF solution, which is the substrate and target analyte, 4,4'-methylenebis(cyclohexa-3,5-diene-1,2-dione) is generated by an oxidation reaction with the Tyr enzyme on the electrode surface. The reduction process of the product at 0.1 V (vs. Ag/AgCl) generating 4,4'-methylenebis(benzene-1,2-diol) was measured using cyclic and differential pulse voltammetries, resulting in a change in the peak current with respect to the concentration of BPF. In addition, we compared the detection performance of BPF using an ionic liquid electrolyte as an alternative to phosphate-buffered saline, which has been used in many previous sensing studies. Furthermore, the selectivity of bisphenol S, which acts as an interfering substance with a similar structure to BPF, was investigated. Finally, we demonstrated the practical applicability of the sensor by applying it to analyze the concentration of BPF in real samples prepared in the laboratory.

• Applied Biological Chemistry
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• v.20 no.2
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• pp.221-227
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• 1977

Contents of proline and chloride in halophytes were $80-1700\;{\mu}g/gfw$ and 0.13-0.45 mM/gfw respectively. The content of proline was inversely proportional to that of chloride. Rhizomes of Phargmites communis Trin, a halophyte, were grown in non-saline medium and then taken to saline treatment for one or two weeks. Growth of P. communis was inhibited when salinized with 0.25M NaCl. Total nitrogen decreased and alcohol soluble nitrogen and proline increased when growth was retarded. The quantity of Fraction 1 protein decreased at 0.25M NaCl treatment. The accumulation of proline at high concentration in P. communis suggested that it might play a role in osmotic adjustment.

• Journal of Animal Science and Technology
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• v.53 no.4
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• pp.333-339
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• 2011

The present study was performed to investigate the effects of pre- and post-weaning feeding programs on growth of pigs. A total of 24 litters (avg. 10.6 piglets/litter) born from multiparous (Yorkshire ${\times}$ Landrace) dams ${\times}$ Duroc sires were provided with neither creep feed (CF) nor milk replacer ("CON"), 200 gm CF/litter/d from the 15th day of lactation ("MIN"), or CF and milk replacer ad libitum for 7 h during the daytime from the 7th day ("MAX") through weaning at d 21 of age. Sixty-eight weanling pigs selected randomly from each of CON and MIN were provided with phases 1, 2 and 3 nursery diets for 7, 14, and 13 days, respectively, in two pens; an equal number of piglets from MAX received the same diets for 6, 10, and 18 days, respectively. Subsequently, all pigs were fed grower 1 and 2 diets sequentially up to d 95 and 135, respectively. The entire pre- and post-weaning feeding trial was repeated three times under a split-plot design of experiment. Initial and final weights and ADG of the suckling pigs did not differ between MAX/MIN and CON. However, final wt of MAX adjusted for initial wt, which was 0.17-kg less in MAX than in CON, was greater than that of CON by 0.31kg, whereas the difference between MIN and CON in final wt barely changed after the adjustment. Growth of the animals during the nursery and growing phases was not affected by the feeding program, whereas d 55 and 135 BW, as well as d 6 BW, were highly correlated with weaning weight (r=0.81, 0.57, and 0.76; P<0.001, <0.05, and <0.001, respectively). In conclusion, results suggest that provision of creep feed and milk replacer from early lactation may be effective for increasing weight gain of light piglets, but that limited provision of creep feed during late lactation or extension of the duration of phases 1 and 2 vs. 3 nursery diets for several days is unlikely to influence the growth of pigs during the corresponding and subsequent periods.

• Journal of Nutrition and Health
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• v.52 no.6
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• pp.581-592
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• 2019

Purpose: This study investigated major dietary patterns among healthy Korean adults using cluster analysis and analyzed the relationship between energy intake and skeletal muscle mass. Methods: This study was conducted using the data from the 2008 ~ 2010 Korea National Health and Nutrition Survey. The data of 7,922 subjects aged 30 years and over, without any missing values, were included in the final analysis. K-means cluster analyses were conducted to identify the dietary patterns of the study subjects, which were based on the energy intake from 21 food groups using a 24-h recall method. The changes in energy intake with each dietary pattern, according to quartiles of skeletal muscle mass, were investigated. Results: Three dietary patterns were identified for both men and women: 'Flour, Animal fat', 'White rice' and 'Healthy mixed diet'. The association between energy intake and skeletal muscle mass for both men and women was significant only in the 'White rice' dietary pattern. In the 'White rice' pattern, the energy intake increased up to > 300 kcal from the lowest to the highest quartile of skeletal muscle mass after adjustment for covariates. Within the 'White rice' pattern, skeletal muscle mass was linearly associated with energy intake in all the age groups in men. Conclusion: Energy intake was significantly associated with changes in skeletal muscle mass only in the 'White rice' pattern. Furthermore, the degree of association between the change in skeletal muscle mass and energy intake differed according to gender. These results indicate that the association between skeletal muscle mass and energy intake may be specific to Korean people who are accustomed to a traditional Korean diet.

• The Journal of Korean Society for Radiation Therapy
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• v.12 no.1
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• pp.91-104
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• 2000

Recently linear accelerator in radiation therapy in asymmetric field has been easily used since the improvement and capability of asymmetrical field adjustment attached to the machine. It has been thought there have been some significant errors in dose calculation when asymmetrical radiation fields have been utilized in practice of radiation treatments if the fundamental data for dose calculation have been measured in symmetrical standard fields. This study investigated how much the measured data of dose distributions and their isodose curves are different between in asymmetrical and symmetrical standard fields, and how much there difference affect the error in dose calculation in conventional method measured in symmetrical standard field. The distributions of radiation dose were measured by photon diode detector in the water phantom (RFA-300P, Scanditronix, Sweden) as tissue equivalent material on utilization of 6 MV linear accelerator with source surface distance (SSD) 1000 mm. The photon diode detector has the velocity of 1 mm per second from water surface to 250 mm depth in the field size of $40mm{\times}40mm\;to\;250mm{\times}250mm\;symmetric\;field\;and\;40mm{\times}20mm\;to\;250mm{\times}125mm$ asymmetrical fields. The measurements of percent depth dose (PDD) and subsequent plotting of their isodose curves were performed from water surface to 250mm dmm from Y-center axis in $100mm{\times}50mm$ field in order to absence the variability of depth dose according to increasing field sizes and their affects to plotted isodose curves. The difference of PDD between symmetric and asymmetric field was maximum $4.1\%\;decrease\;in\;40mm{\times}20mm\;field,\;maximum\;6.6\%\;decrease\;in\;100mm{\times}50mm\;and\;maximum\;10.2\%\;decrease\;200mm{\times}100mm$, the larger decrease difference of PDD as the greater field size and as greater the depth, The difference of PDD between asymmetrical field and equivalent square field showed maximum $2.4\%\;decrease\;in\;60mm{\times}30mm\;field,\;maximum\;4.8\%\;decrease\;in\;150mm{\times}75mm\;and\;maximum\;6.1\%\;decrease\;in\;250mm{\times}125mm$, and the larger decreased differenced PDD as the greater field size and as greater the depth, these differences of PDD were out of $5\%$ of dose calculation as defined by international Commission on radiation unit and Measurements(ICRU). In the dose distribution of asymmetrical field (half beam) the plotted isodose curves were observed to have deviations by decreased PDD as greater as the blocking of the beam moved closer to the central axis, and as the asymmetrical field increased by moving the block 10 mm keeping away from the central axis, the PDD increased and plotted isodose curves were gradually more flattened, due to reduced amount of the primary beam and the fraction of low energy soft radiations by passing thougepth in asymmetrical field by moving independent jaw each 10 h beam flattening filter. As asymmetrical radiation field as half beam radiation technique is used, the radiation dosimetry calculated in utilizing the fundamental data which measured in standard symmetrical field should be converted on bases of nearly measured data in asymmetrical field, measured beam data flies of various asymmetrical field in various energy and be necessary in each institution.