• 생명과학회지
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• 제33권11호
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• pp.859-867
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• 2023

루페올은 5환성 트리테르펜의 일종으로 많은 질병에 치료 효과가 있는 것으로 보고되었으나, 인슐린 저항성에 미치는 영향은 명확하지 않다. 본 연구에서는 3T3-L1 지방세포에서 루페올의 IRS-1 인산화 억제능을 통해 인슐린 저항성 개선효과를 조사하였다. 3T3-L1 세포를 배양하고 TNF-α를 24시간 동안 처리하여 인슐린 저항성을 유도하였다. 서로 다른 농도의 루페올(15, 30 μM) 또는 100 nM의 rosiglitazone을 처리한 세포를 배양한 후, 용해된 세포를 이용하여 western blotting을 시행하였다. 실험결과 루페올은 지방세포에서 TNF-α에 의해 유발되는 인슐린 신호전달의 음성 조절자와 염증 활성화 단백질 kinase에 대한 개선 효과를 나타냈다. 인슐린 신호전달의 음성 조절자인 PTP-1B와 JNK의 활성 및 IKK와 염증활성화 단백질키나아제의 활성을 억제하였다. 또한, 루페올은 IRS-1의 serine 인산화는 하향 조절하고 tyrosine 인산화는 상향 조절하였다. 그 후, 하향 조절된 PI3K/AKT 경로가 활성화되고, GLUT 4의 세포막 전위가 자극되어, 결과적으로 인슐린 저항성이 유도된 3T3-L1 지방세포에서에서 세포내 포도당 흡수가 증가하였다. 본 연구결과, 루페올은 3T3-L1 지방세포에서 인슐린 신호전달 및 염증 활성화 단백질 kinsase들의 음성 조절인자를 억제하여, IRS-1의 serine 인산화를 하향 조절함으로써 TNF-α 유발 인슐린 저항성을 개선할 수 있을 것으로 사료된다.

• 지식경영연구
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• 제16권4호
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• pp.191-213
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• 2015

With the advancement of virtual reality technology, virtual reality contents and devices are being competitively released. This research deals with an early stage adoption model of a motion-sensing input device which enhances the user experience of these virtual reality contents and devices. In contrast to the previous research on the adoption or resistance of innovative products, this work compares and analyzes the antecedents in MIR(Model of Innovation Resistance) of resistance-perspective as well as those in UTAUT2(Extended Unified Theory of Acceptance and Use of Technology) and IDT(Innovation Diffusion Theory) of adoption-perspective, and suggests a resistance-incorporated adoption model from a new viewpoint. The analysis of questionnaire data indicates the following results: Performance expectancy, effort expectancy, price value, hedonic motivation in UTAUT2 and visibility in IDT have a significant negative influence on innovation resistance. Compatibility in IDT and MIR exerts a positive influence on perceived value. Social influence and hedonic motivation in UTAUT2 positively relates to perceived value. Higher innovation resistance results in lower perceived value, with innovation resistance and perceived value negatively and positively affecting intention to use, respectively.

• Journal of Electrochemical Science and Technology
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• 제13권2호
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• pp.208-212
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• 2022

In this paper, we report the effects of temperature on the deterioration of graphite-based negative electrodes during the longterm cycling of lithium-ion batteries (LIBs). After cycling 75 Ah pouch-type LIB full cells at temperatures of 45℃ (45-Cell) and 25℃ (25-Cell) until their end of life, we expected to observe changes in the negative electrode according to the temperature. The thickness of the negative electrode of the cell was greater after cycling; that of the electrode of 45-Cell (144 ㎛) was greater than that of the electrode of 25-Cell (109 ㎛). Cross-sectional scanning electron microscopy analysis confirmed that by-products caused this increase in the thickness of the negative electrode. The by-products that formed on the surface of the negative electrode during cycling increased the surface resistance and decreased the electrical conductivity. Voltage profiles showed that the negative electrode of 25-Cell exhibited an 84.7% retention of the initial capacity, whereas that of 45-Cell showed only a 70.3% retention. The results of this study are expected to be relevant to future analyses of the deterioration characteristics of the negative electrode and battery deterioration mechanisms, and are also expected to provide basic data for advanced battery design.

• Journal of Information Technology Applications and Management
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• 제19권4호
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• pp.41-59
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• 2012

This study examines the roles of user resistance and social influences on the acceptance and continuous usage of smartphones at different stages of adoption. The respondents were classified into three groups according to their innovation adoption stage : non-user group, the potential user group and the trial user group. Theories relevant to user resistance, social influences including normative social influences and informational social influences, as well as user adoption and continuance behavior were reviewed and integrated into our research model. In order to verify the proposed structured equation model, we conducted an online survey by targeting mobile phone users and collected data to be analyzed through a partial least squares (PLS) test. This study tested whether there exists differences in the effects of user resistance and different types of social influence on user's adoption or continuance intetion among these three groups. The results showed that user resistance exists in all adopter groups and that it has significant negative influences on intention to use a smartphone. The findings also revealed that user resistance can be enhanced or resolved by two types of social influence; informational social influence resolves user resistance regardless of the adopter category, while normative social influence enhances the user resistance of potential users. Furthermore, the findings show that social influence regardless of the type positively affects user intention. Several theoretic and practical implications pertaining to the results are discussed.

• Journal of Oral Medicine and Pain
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• 제45권1호
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• pp.17-21
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• 2020

Osteomyelitis of the jaw infected with Coagulase-Negative Staphylococci (CNS) is rarely reported in the Oral and Maxillofacial Region. Staphylococcus is a part of the normal body flora, but it may be cause severe infections and CNS are often described as the important pathogens in nosocomial infections. Although many studies on prevalence and antibiotics of Staphylococcus aureus have been done, but many of these studies focus only on Methicillin-resistant S. aureus and not on methicillin-resistant coagulase-negative Staphylococci (MRCNS). There was a less study about CNS or MRCNS infections in the Oral and Maxillofacial Region. This report describes a case of a 41-year-old male patient who developed osteomyelitis caused by MRCNS on condyle after open reduction and internal fixation and suggests guideline for the prevention of postoperative infection and appropriate recommendation for treatment and control.

• Journal of Microbiology and Biotechnology
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• 제29권1호
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• pp.1-10
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• 2019

Gram-negative pathogens, such as Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii, pose a serious threat to public health worldwide, due to high rates of antibiotic resistance and the lack of development of novel antimicrobial agents targeting Gram-negative bacteria. The outer membrane (OM) of Gram-negative bacteria is a unique architecture that acts as a potent permeability barrier against toxic molecules, such as antibiotics. The OM is composed of phospholipids, lipopolysaccharide (LPS), outer membrane ${\beta}-barrel$ proteins (OMP), and lipoproteins. These components are synthesized in the cytoplasm or in the inner membrane, and are then selectively transported to the OM by the specific transport machines, including the Lol, BAM, and Lpt pathways. In this review, we summarize recent studies on the assembly systems of OM components and analyze studies for the development of inhibitors that target these systems. These analyses show that OM assembly machines have the potential to be a novel attractive drug target of Gram-negative bacteria.

• 한국경영정보학회:학술대회논문집
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• 한국경영정보학회 2008년도 춘계학술대회
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• pp.17-22
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• 2008

The emergence of open source software (OSS) with its successful projects and its most prominent advantages creates a vast interest among academics and practitioners. However, it has been found that focusing on the developments of OSS to be successful is not adequate and the adoption of OSS by uses is also very important. Although there are a great number of useful and easy to use OSS has been developed, the adoption of OSS and usage in the market is very low. Based on the technology equity implementation model (EIM), this study examines user resistance in the adoption of OSS (i.e., switching from the current system to OSS). A survey has done regarding the adoption of Linux as the case of study. We have found that user resistance to change has negative effect on adoption intention, and switching benefits, switching costs and perceived value have significant relationships with user resistance to change.

• International Journal of Contents
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• 제8권3호
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• pp.12-19
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• 2012

This study investigated what factors affect consumers' decision making concerning the adoption of smart TVs. For this purpose, the integrated adoption model that consists of six major constructs from the diffusion of innovation theory (DIT), the technology acceptance model (TAM), and the model of innovation resistance(MIR) was employed. To collect data, an online survey was used. Data collected were analyzed with the structural equation model (SEM). Findings showed that the innovativeness has a positive influence on the both of perceived usefulness and perceived ease of use. It was also shown that both of perceived usefulness and perceived ease of use affect the intention to use smart TVs in a positive way. The innovation resistance has a negative influence on the intention to use. The mediating role of the innovation resistance was also found. The implications of these results are discussed.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제45권6호
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• pp.324-331
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• 2019

Objectives: This study investigated the types and antibiotic sensitivity of bacteria in odontogenic abscesses. Materials and Methods: Pus specimens from 1,772 patients were collected from affected areas during incision and drainage, and bacterial cultures and antibiotic sensitivity tests were performed. The number of antibiotic-resistant bacteria was analyzed relative to the total number of bacteria that were tested for antibiotic susceptibility. Results: Bacterial cultures from 1,772 patients showed a total of 2,489 bacterial species, 2,101 gram-positive and 388 gram-negative. For penicillin G susceptibility tests, 2 out of 31 Staphylococcus aureus strains tested showed sensitivity and 29 showed resistance. For ampicillin susceptibility tests, all 11 S. aureus strains tested showed resistance. In ampicillin susceptibility tests, 46 out of 50 Klebsiella pneumoniae subsp. pneumoniae strains tested showed resistance. Conclusion: When treating odontogenic maxillofacial abscesses, it is appropriate to use antibiotics other than penicillin G and ampicillin as the first-line treatment.

• Journal of Microbiology and Biotechnology
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• 제33권7호
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• pp.857-863
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• 2023

Pathogenic bacteria that colonize the human intestinal tract have evolved strategies to overcome acidic conditions when they pass through the gastrointestinal tract. Amino acid-mediated acid resistance systems are effective survival strategies in a stomach that is full of amino acid substrate. The amino acid antiporter, amino acid decarboxylase, and ClC chloride antiporter are all engaged in these systems, and each one plays a role in protecting against or adapting to the acidic environment. The ClC chloride antiporter, a member of the ClC channel family, eliminates negatively charged intracellular chloride ions to avoid inner membrane hyperpolarization as an electrical shunt of the acid resistance system. In this review, we will discuss the structure and function of the prokaryotic ClC chloride antiporter of amino acid-mediated acid resistance system.