• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.260-260
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• 1994

Mammalian pyruvate dehydrogenase complex(PDC) enzyme consists of multiple oopies of three major oligomeric enzymes-El, E2 E3. And protein X is one of the enzymatic constituents which is tightly bound to E2 subunit This complex enzyme is responsible for the oxidative decarboxylation of pyruvate producing of acetyl CoA which is a key intermediate for the entry of carbohydrates into the TCA cycle for its complete metabolic conversion to CO$_2$. And the overall activity of the complex enzyme is regulated via covalent nodification of El subunit by a El specific phosphatase ad kinase. Protein X has lipoyl moiety that undergoes reduction and acetylation during ezymatic reaction and has been known h be involved in the binding of E3 subunit to E2 core and in the regulatory activity of kinase. The purification of protein X has not been achieved majorly because of its tight binding to E2 subunit The E2-protein X subcomplex was obtained by the established methods and the detachment of protein X from E2 was accomplished in the 0.1M borate buffer containing 150mM NaCl. During the storage of the subcomplex in frozen state at -70$^{\circ}C$, the E2 subunit was precipitated and the dissociated protein X was obtained by cntrifegation into the supernatant The verification of protein X was accomplished by (1)the migration on SDS-PAGE, (2)acetylation by 〔2$\^$-l4/C〕 pyruvate, and (3)internal amino acid sequence analysis of tryptic digested enzyme.

• Toxicological Research
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• v.31 no.3
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• pp.279-288
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• 2015

N-nitrosamines, which are classified as carcinogens by IARC and US EPA, can be easily found in various foods. They are reaction products between nitrogen oxide and secondary amines, but can also be generated during fermentation. Ever since the 1960s, when nitrite, used as a preservative in processed meats, was suspected to generate N-nitrosamines, the usage of the food additive has been debated. However, the benefit of nitrite in food supply could not be ignored and the risk-benefit analysis has become a key issue in the use of the additive. For a risk analysis, an accurate estimation of the hazardous material is necessary; therefore, analytical methods for nitrosamines have continuously evolved from the 1950s. Solid supported liquid-liquid extraction and solid phase extractions have replaced the distillation for the clean-up steps, and tandem mass spectrometry is employed for higher selectivity and sensitivity. In the present study, for a better estimation of N-nitrosamine intake, the total diet study samples were prepared for the N-nitrosamines analysis. In order to obtain the most sensitive results, a partial preparation procedure was developed and modified for different food matrices. Among seven N-nitrosamines (N-nitrosodimethylamine, N-nitrosomethylethylamine, N-nitrosodiethylamine, N-nitrosodibutylamine, N-nitrosopiperidine, N-nitrosopyrrolidine, and N-nitrosomorpholine) analyzed in the present study, N-nitrosodiethylamine has shown the highest detection rate in agricultural foods, while N-nitrosodimethylamine has appeared most frequently in livestock and fishery food products. The concentration of N-nitrosodimethylamine was the highest in seasoning.

• Archives of Plastic Surgery
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• v.33 no.6
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• pp.711-714
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• 2006

Purpose: Contralateral reduction mammaplasty at the time of breast reconstruction using autogenous tissue gives aesthetically improved results in the patients with mammary hypertrophy or ptosis. It also reduces required flap size for reconstruction and permits discarding zones of poor perfusion, decreasing flap size-related problems such as partial flap loss or fat necrosis. Considering the high rate of bilaterality of breast cancer, it also provides a good opportunity for exploration and occult cancer diagnosis in such high risk group patients. Methods: We retrospectively reviewed 45 consecutive patients who underwent simultaneous breast reconstruction and contralateral reduction mammaplasty was performed about surgical technique, pathologic diagnosis, and subsequent treatment. Results: Three occult breast cancers were found in 45 patients(6.7%); one was microinvasive, and the other two were invasive carcinomas and their mean diameter was 1.2 cm. One patient underwent subsequent breast conserving mastectomy, adjuvant radiation and chemotherapy. The others underwent only radiation and hormone therapy. They were followed up for 10 to 42 months without evidence of recurrence or metastasis. Conclusion: Occult breast cancer diagnosed in reduction mammaplasty specimen will lead to good prognosis due to its early detection. Treatment options depend on pathologic finding, stage, marginal status, and the timing of diagnosis. We recommend adequate markings for orientation and margins, excision with sufficient margin, and confirmation by frozen biopsy for suspected lesions.

• The Journal of the Korea Contents Association
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• v.13 no.12
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• pp.428-438
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• 2013

In the highly competitive coffee market, each coffee shop is striving to improve customer loyalty by providing a high level of service quality. To deepen our understanding of service quality in the coffee shop market, this study identifies the key elements of service quality of coffee shops and investigates their impacts on decision-making processes of female university students. This study also investigates the effects of customer satisfaction and brand image on customer loyalty in a coffee shop market. Moreover, it considers the two critical customer loyalty: repurchasing intention and recommendation intention. Data collected from 206 female university students were empirically tested against a research model using partial least squares. Analysis results showed that service product and service delivery significantly affect customer satisfaction and brand image whereas service intangible and service environment do not significantly influence on them. Customer satisfaction and brand image play an important role on the formation of repurchasing and recommendation intention.

• Applied Biological Chemistry
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• v.44 no.3
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• pp.153-161
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• 2001

In order to isolate genes involved in ecdysteroids biosynthesis in plants, total RNA was isolated from Achyranthes japonica Nakai, and RT-PCR was performed using degenerate primers selected based on the results of multi-alignment of four cytochrome P450 genes from plants and a putative ecdysone 20-hydroxylase gene from an insect. Fourteen partial cDNA clones showing unique base sequences were obtained, out of which six showed homologies at the levels of nucleotide and amino acid sequences to the other cytochrome P450 genes known to be involved in the ecdysteroid biosynthesis. Of the six clones, four showed relatively high homologies to a putative ecdysone 20-hydroxylase gene isolated from an insect.

• Journal of Distribution Science
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• v.15 no.2
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• pp.111-120
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• 2017

Purpose - Service employees who work at airline check-in counters in airport are typically employed to undergo emotional labor. Emotional labor of airport service employees is an important managerial issue that must be solved. This study attempts to examine the underlying mechanism of emotional labor on turnover intention. It focuses on the consequences of emotional labor of service employees. The purpose of this study is to examine and empirically test how the two-types of emotional labor(deep-acting & surface-acting) of service employees differently affect the level of their job satisfaction and job stress. It also investigates the relationship between job satisfaction, job stress, and turnover intention. For this purpose, first, this study identified the structural relationship between emotional labor, job satisfaction, job stress, and turnover intention. Second, it investigated the mediating effects of job satisfaction between deep-acting and turnover intention. Research design, data, and methodology - To empirically test these structural relationships among research variables, data were collected by a interview from service manager of domestic airline companies and survey from 179 service employees who are working at single domestic airline check-in counters in airports in Korea using a self-rating questionnaire with total 19 items dealing with emotional labor, job satisfaction, job stress, and turnover intention. To test the research hypotheses, collected data were analyzed by confirmatory factor analysis (CFA) and structure equation model (SEM). Results - This study obtains meaningful research results. The results from this study are as follows. First, deep-acting has a positive effect on job satisfaction, whereas, deep-acting has a negative effect on job satisfaction. Second, surface-acting has a positive effect on job stress, whereas, the effects of surface-acting on job satisfaction did not show statistically significant result. Also, job satisfaction has partial mediating roles to the relationship between deep-acting and turnover intention. Conclusions - Based on the results of this empirical study, emotional labor of service employees is one of the key factors influencing their job satisfaction and job stress. In particular, deep-acting is the important factor in emotional labor to increase job satisfaction and reduce job stress. Finally, theoretical, managerial implications, and research limitations are mentioned in discussion parts.

• Membrane and Water Treatment
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• v.7 no.5
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• pp.417-431
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• 2016

Poly(vinylidene fluoride) (PVDF) powder was treated with aqueous sodium hydroxide to obtain partially defluorinated fluoropolymers with expected properties such as improving hydrophilicity and fouling resistance. Raman spectrum and FT-IR results confirmed the existence of conjugated carbon double bonds after alkaline treatment. As the concentration increased, the degree of defluorination increased. The morphology and structure of membranes were examined. The permeation performance was investigated. The results showed that membrane's hydrophilicity increased with increase of the percentage of alkaline treated PVDF powder. Moreover, in terms of the water contact angle, it decreased from $92^{\circ}$ to a minimum of $68^{\circ}$; while water up take increased from 128 to 138%. Fluxof pure water and the cleaning efficiency increased with the increase of alkaline treated PVDF powder. The fouling potential also decreased with the increase of the percentage of alkaline treated PVDF powder. The reason that makes blending PVDF show different characteristics because of partial defluorination, which led the formation of conjugated C = C bonds and the inclusion of oxygen functionalities. The polyene structure followed by hydroxide attack to yield hydroxyl and carbonyl groups. Therefore, the hydrophilicity of blending membrane was improved. The SEM and porosity measurements showed that no obvious variations of the pore dimensions and structures for blend membranes were observed. Mechanical tests suggest that the high content of the alkaline treated PVDF result in membranes with less tolerance of tensile stress and higher brittleness. TGA results exhibited that the blend of alkaline treated PVDF did not change membrane thermal stability.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.5
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• pp.615-621
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• 2007

AMP-activated protein kinase alpha 2 (PRKAA2) plays a key role in regulation of fatty acid and cholesterol metabolism. This study investigated the porcine PRKAA2 gene as a positional candidate for intramuscular fat and backfat thickness traits in pig chromosome 6. A partial fragment of the porcine PRKAA2 gene, amplified by PCR, contained a putative intron 3 including a part of exon 3 and 4, comparable with that of human PRKAA2 gene. Within the fragment, several single nucleotide polymorphisms were identified using multiple sequence alignments. Of these, TaqI restriction enzyme polymorphism was used for genotyping various pig breeds including Korean reference family. Using linkage and physical mapping, the porcine PRKAA2 gene was mapped in the region between microsatellite markers SW1881 and SW1680 on chromosome 6. Allele frequencies were quite different among pig breeds. The full length cDNA of the porcine PRKAA2 (2,145 bp) obtained by RACE containing 1,656 bp open reading frame of deduced 552 amino acids, had sequence identities with PRKAA2 of human (98.2%), rat (97.8%), and mouse (97.5%). These results suggested that the porcine PRKAA2 is a positional candidate gene for fat deposition trait at near telomeric region of the long arm of SSC 6.

• The Journal of the Korea Contents Association
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• v.15 no.11
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• pp.447-455
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• 2015

In the highly competitive coffee market, it is important to understand consumer purchase mechanism. Although consumers repeat decision-making about coffee purchase, most studies on service management do not consider habit construct. This study identifies repurchase intention and service habit as key drivers of comsumer purchase. Moreover, thus study investigates the effects of consumer satisfaction, perceived service quality, and brand awareness on consumer's purchase behavior. Data collected from 233 female university students were empirically tested against a research model using partial least squares. The analysis results showed that service habit significantly influences comsumer purchase, whereas purchase intention does not affect it. Both consumer satisfaction and brand awareness play an important role on the formation of service habit. Moreover, the results found that perceived service quality significantly affects consumer satisfaction.

• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.251-257
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• 2000

Chitin synthases are identified as key enzymes of chitin biosynthesis in most of the fungi. Among them, chitin synthase II has been reported to be and essential enzyme in chitin biosynthesis, and exists as a membrane-bound form. To search and screen new antifungal agents from natural resources to inhibit chitin synthase II, the assay conditions were established using the enzyme isolated from Saccharomyces cerevisiae ECY38-38A(pAS6) that overproduces only chitin synthase II. This enzyme was activated only by partial proteolysis with trypsin. Its actibity reached the maximum at $80{\;}\mu\textrm{g}/ml$ of trypsin and was strongly stimulated by 2.0 mM $Co^{2+}$, 1.0 nM UDP-[$^{14}C$]-GicNAc, and 32 mM free-GlcNAc. Under these assay conditions, the highest chitin synthase II activity was observed by incubation at $30^{\circ}C$ for 90 min. However, and extremely narrow range of organic solvents up to as much as 25% of DMSO and 25% of MeOH was useful for determining optimal assay conditions. After a search or potent inhibitors of chitin synthase II from natural resources, prodigiosin was isolated from Serratia marcescens and purified by solvent extration and silica gel column chromatographies. The structure of prodigiosin was determined by UV, IR, Mass spectral, and NMR spectral analyses. Its molecular weight and formula were found to be 323 and $C_{20}H_{25}N_{3}O$, respectively. Prodigiosin ingibited chitin synthase II by 50% at the concentration of $115{\;}\mu\textrm{g}/ml$.