• Applied Biological Chemistry
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• v.37 no.5
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• pp.414-420
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• 1994

Birnessite, pyrolusite and hausmannite were synthesized and tested for the ability to oxidize Cr(III) to Cr(VI). These oxides differed in zero point of charge, surface area, and crystallinity. The kinetic study showed that Cr(III) oxidation on the Mn-oxide surface is a first-order reaction. The reaction rate was various for different oxide at different conditions. Generally the reaction by hausmannite, containing Mn(III), was faster than the others, and oxidation by pyrolusite was much slower. Solution pH and initial Cr(III) concentration had a significant effect on the reaction. Inhibited oxidation at higher pH and initial Cr(III) concentration could be due to the chance of Cr(III) precipitation or complexing on the oxide surface. Oxidations by birnessite and hausmannite were faster at lower pH, but pyrolusite exhibited increased oxidation capacity at higher pH in the range between 3.0 and 5.0. Reactions were also temperature sensitive. Although calculated activation energies for the oxidation reactions at pH 3.0 were higher than the general activation energy for diffusion, there is no experimental evidence to suggest which reaction is the rate limiting step.

• Journal of Veterinary Clinics
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• v.25 no.6
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• pp.458-465
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• 2008

The purpose of this study is to characterize canine mesenchymal stem cells (MSCs) derived from bone marrow (BM) for use in research on the applications of stem cells in canine models of development, physiology, and disease. BM was harvested antemortem by aspiration from the greater tubercle of the humerus of 30 normal beagle dogs. Canine BM-derived MSCs were isolated according to methods developed for other species and were characterized based on their morphology, growth traits, cell-surface antigen profiles, differentiation repertoire, immunocytochemistry results, and neurotrophic factor expression in vitro. The canine MSCs exhibited a fibroblast-like morphology with a polygonal or spindle-shaped appearance and long processes; further, their cell-surface antigen profiles were similar to those of their counterparts in other species such as rodents and humans. The canine MSCs could differentiate into osteocytes and neurons on incubation with appropriate induction media. RT-PCR analysis revealed that these cells expressed NGF, bFGF, SDF-1, and VEGF. This study demonstrated that isolating canine MSCs from BM, stem-cell technology can be applied to a large variety of organ dysfunctions caused by degenerative diseases and injuries in dogs. Furthermore, our results indicated that canine MSCs constitutively secrete endogenous factors that enhance neurogenesis and angiogenesis. Therefore, these cells are potentially useful for treating dogs affected with various neurodegenerative diseases and spinal-cord injuries.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.458-463
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• 2016

New areas can be created by combining separate fields of study. Today, boundaries between fields are collapsing because of rapid progress in technologies, which is also the case in music. In 1969, jazz trumpeter and respected artist Miles Davis combined jazz, rock, and classical music into the fusion genre. Classical music is known to be strict, rigorous, and rigid, and it started to take a different form after experiments with musical crossovers. This study examines the potential of more diverse musical crossovers that musicians use to evolve a new genre. Several musicians in Korea have attempted musical crossovers by following global music trends. In the album, "Love and Peace," the classical music pieces "Flight of the Bumblebee" and Beethoven's "Fate" were arranged using a popular music style.

• The Journal of the Korea Contents Association
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• v.9 no.9
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• pp.411-422
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• 2009

The study seeks to explore essential factors that influence tourists' continual usage intentions to mobile tour information services. The variables such as characteristics of tour information service, accuracy, interactivity, context, ubiquitous connectivity, perceived usefulness, perceived ease of use were adopted from previous research and the hypotheses were developed on the basis of Davis's Technology Acceptance Mode(TAM). The survey was conducted by users who have previously experienced mobile tourism information service. Structural equation modeling was used to Investigate the relationships between the factors. The results showed that interactivity, context, perceived usefulness and perceived ease of use were found to have a positive impact on satisfaction. In particular, interactivity and context were found to be the most significant factors that influence reuse intentions. It suggests that increasing context and interactivity to make tourist trust about accuracy, ubiquitous connectivity is better than increasing perceived usefulness and perceived easiness. The identified factors that influence continual usage intentions on mobile services can be useful for analyzing the market trends and suggesting industrial guidelines of mobile services.

• The Korean Journal of Emergency Medical Services
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• v.1 no.1
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• pp.42-53
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• 1997

To offer basic data about the influential factors on patient's Satisfaction level for emergency medical services the authors were performed this study in 60 patients visited to emergency room of third stage general hospital in Taejeon city. Data were collected through interview with patients by using a 15 items' questionaire according to care subscale, teaching subscale of Likert's five stage quantitative scale and the tools developed by Barbara Davis. The data were analyzed by using the SPSS/PC computerized program for mean, standard deviation, percentage, ANOVA, t-test, and pearson correlation. The results are as followings ; 1. Satisfaction of emergency medical service were showed in care area, but not showed in teaching and total area 2. Satisfaction of sociodemographic characteristics were a statistically significant difference only marriage, that were the higher in marriaged than single(P<.0.05). 3. In the emergency situation characteristics the satisfaction accordings to the visit cause were lower in accident than disease group, the reason of hospital selection were in order trust, introduction group, distance, traffic, kinds, and score of satisfaction were showed each of 43.47, 51.27(P<.001), the transportation vehicle was the 119, hospital ambulance group. but were not a satistically significant difference. 4. The negative correlation was observed between satisfaction and the length of stay at ER and the longer length of stay at ER was showed the lower satisfaction. But the positive correlation was observed between satisfacton and the arrival time, patients who arrived ER from 6:00P.M. to midnight were more satisfied than patients who arrived other time. 5. The length of stay at ER was significantly different according to the reason of hospital selection, the reason of ER selection, the visitant cause and hopital decisioner. Especially the length of stay was much longer in accident group and unconscious group.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.2
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• pp.93-101
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• 2011

Korea has about 70% of its land classified as the mountain area, which has led to cut-slope being the result of substantial road and railway construction. However, there is currently a lack of research about the seismic retrofit design of a slope, even though many earthquakes have recently occurred at home and abroad. In this study, in order to investigate the stabilizing effect of piles against sliding during an earthquake, a series of 1 g shaking table tests and pseudo-static analyses were carried out. As a result, the stabilizing effect of piles against sliding during an earthquake was verified by the 1 g shaking table tests and the most effective result from the pseudo-static analyses was that the installation of the piles on the central part of the slope, where the failure surface included piles unlike the lower part and upper part of the slope. Furthermore, when the pile was installed on the central part of the slope, the change of the safety factor depending on the distance between the center of two piles was evaluated.

• Progress in Medical Physics
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• v.29 no.4
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• pp.150-156
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• 2018

This study aims to develop an improved Feldkamp-Davis-Kress (FDK) reconstruction algorithm using anisotropic total variation (ATV) minimization to enhance the image quality of low-dose cone-beam computed tomography (CBCT). The algorithm first applies a filter that integrates the Shepp-Logan filter into a cosine window function on all projections for impulse noise removal. A total variation objective function with anisotropic penalty is then minimized to enhance the difference between the real structure and noise using the steepest gradient descent optimization with adaptive step sizes. The preserving parameter to adjust the separation between the noise-free and noisy areas is determined by calculating the cumulative distribution function of the gradient magnitude of the filtered image obtained by the application of the filtering operation on each projection. With these minimized ATV projections, voxel-driven backprojection is finally performed to generate the reconstructed images. The performance of the proposed algorithm was evaluated with the catphan503 phantom dataset acquired with the use of a low-dose protocol. Qualitative and quantitative analyses showed that the proposed ATV minimization provides enhanced CBCT reconstruction images compared with those generated by the conventional FDK algorithm, with a higher contrast-to-noise ratio (CNR), lower root-mean-square-error, and higher correlation. The proposed algorithm not only leads to a potential imaging dose reduction in repeated CBCT scans via lower mA levels, but also elicits high CNR values by removing noisy corrupted areas and by avoiding the heavy penalization of striking features.

• Archives of Plastic Surgery
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• v.48 no.4
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• pp.361-365
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• 2021

Background Pain in the postoperative body contouring patient has traditionally been managed with narcotic medication. In an effort to minimize side effects and prevent addiction, plastic surgeons are searching for novel ways to provide adequate analgesia, one of which is nerve blocks. This study was conducted with a meta-analysis that evaluates the efficacy of these blocks for patients who undergo breast surgery. Methods A search of the PubMed/MEDLINE database for articles including the terms "post-operative analgesia" OR "postoperative pain management" AND "in plastic surgery" OR "in cosmetic surgery" OR "in elective surgery" in February 2019 generated five studies on elective breast augmentation and reduction mammoplasty that reported pain scores and quantities of opioids consumed. Independent samples t-tests, one-way analysis of variance, and a random effects model were implemented for evaluation. Results A total of 317 patients were identified as having undergone body contouring of the breast, about half of which received a nerve block. Pain scores on a 1-10 scale and opioid dose-equivalents were calculated. Those who were blocked had an average score of 2.40 compared to 3.64 for those who did not (P<0.001), and required an average of 5.20 less narcotic doses (P<0.001). Pain relief following subpectoral augmentation was best achieved with type-II blocks as opposed to type-I and type-II with serratus plane (P<0.001). Conclusions The opioid epidemic has extended to all surgical specialties. Implementation of a nerve block seems to be an efficacious and cost-effective mechanism to not only help with post-operative pain, but also lower the need for narcotics, especially in subpectoral augmentation.

• Journal of Korea Trade
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• v.25 no.1
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• pp.47-64
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• 2021

Purpose - This paper empirically analyzed the determinants of the online food market in Korea and Vietnam as representatives of the developed market and emerging market. The online food market can be regarded as having a high potential value. This study aims to suggest the appropriate implications for each developed market and emerging market by empirically comparing and analyzing customers' online food purchase determinants in the growth change of the online food market. Design/methodology - The empirical model of this study was established with the motif of the TAM+Trust model suggested by Nguyen et al.'s (2019) existing theoretical framework. Davis's (1989) TAM model was adopted to establish a framework related to the determinants that consumers would accept, for the online food purchasing method. Then, the trust variable is added to the framework which is regarded as an important effector especially in food related researches. In this study's comparative analysis, the multi-group structural equation modeling analysis was implemented. Findings - The main finding of this study can be summarized as that the moderating effect of nationality is significant. This means that there is an obvious difference between the developed online food market and the emerging online food market. In addition, as the growth of the online market changes, the significant determinants of consumers' attitudes and purchase intentions are somewhat different. However, the usefulness of online food purchasing methods and the trust of websites were analyzed as significant factors. Originality/value - Although the potential of the online food market is abundant, studies on the determinants of customer's attitude and purchase intention are insufficient. Moreover, comparative studies between countries have not been conducted in existing studies. Therefore, the research value of this paper can be explained in that it has suggested implications for the continued growth of the online food market.

• The Journal of Korean Medicine
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• v.43 no.1
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• pp.73-86
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• 2022

Objectives: In the health care industry, the influence of online reviews is growing. As medical services are provided mainly by providers, those services have been managed by hospitals and clinics. However, direct promotions of medical services by providers are legally forbidden. Due to this reason, consumers, like patients and clients, search a lot of reviews on the Internet to get any information about hospitals, treatments, prices, etc. It can be determined that online reviews indicate the quality of hospitals, and that analysis should be done for sustainable hospital marketing. Method: Using a Python-based crawler, we collected reviews, written by real patients, who had experienced Korean medicine, about more than 14,000 reviews. To extract the most representative words, reviews were divided by positive and negative; after that reviews were pre-processed to get only nouns and adjectives to get TF(Term Frequency), DF(Document Frequency), and TF-IDF(Term Frequency - Inverse Document Frequency). Finally, to get some topics about reviews, aggregations of extracted words were analyzed by using LDA(Latent Dirichlet Allocation) methods. To avoid overlap, the number of topics is set by Davis visualization. Results and Conclusions: 6 and 3 topics extracted in each positive/negative review, analyzed by LDA Topic Model. The main factors, consisting of topics were 1) Response to patients and customers. 2) Customized treatment (consultation) and management. 3) Hospital/Clinic's environments.