• 제목/요약/키워드: Contrast phase

검색결과 833건 처리시간 0.023초

다양한 농도의 테트라사이클린로 처리된 치근면이 치주인대세포의 증식과 전개에 미치는 영향 (THE EFFECTS OF VARIOUS TETRACYCLINE HCL CONCENTRATION TREATED ROOW SURFACES ON PROLIFERATION AND SPREADING OF PERIODONTAL LIGAMENT CELLS)

  • 정오철;서조영
    • Journal of Periodontal and Implant Science
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    • 제24권3호
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    • pp.581-596
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    • 1994
  • 치근활택술만 시행한 군과 치근활택술후 테트라사이클린 25, 50, 75, 100, 150mg/ml 농도로 5분간 처리한 군 사이에 치근면에서의 치주인대세포에 대한 증식 및 전개에 미치는 효과를 비교하기 위해 심한 치주질환으로 이환된 치아를 발치하여 철저한 치근활택술을 시행한 후 치주질환에 이환된 치근면만을 이용하여 치근절편을 제작하였다. 5분간 절편을 각 농도별로 침수시킨 후 세포증식률을 알아보기 위해 각 절편을 24 well 조직배양기에 넣고 $1{\times}10^5$개의 치주인대세포를 가진 배양액 1ml씩을 넣어 6시간동안 배양 후, 새로운 배양기에 옮기고 24, 48, 72시간동안 배양하여 0.05% trypsin/0.02% EDTA로 처리하고 세포를 분리하여 광학위상차현미경을 이용하여 세포수를 측정하고 단위치근면적당 세포수를 계산하였다, 세포증식률의 실험에서는 24, 48, 72시간 모두에서 치근활택술군, 테트라사이클린 25, 150, 50, 75, 100mg/ml 처리군 순으로 세포 수가 증가함을 보였으며 각 군 모두에서도 시간경과에 따라 부착세포수도 증가하는 경향을 보였다. 24시간에서는 치근활택술군과 테트라사이클린 75mg/ml, 100mg/ml 처리군 사이, 48시간에서는 치근활택술군과 테트라사이클린 100mg/ml 처리군 사이, 72시간에서는 치근활택술군과 테트라사이클린 50, 75, 100mg/ml와 테트라사이클린 25mg/ml와 100mg/ml 사이에 통계학적으로 유의성을 보였다(p<0.05). 전반적으로 치근활택술군보다 테트라사이클린으로 처리한 치근면 특히 농도 100mg/ml 처리군에서 좋은 세포증식률을 보였으며 150mg/ml에서는 100mg/ml 처리군에 비해 세포 증식률이 감소하는 경향을 보였다. 주사전자현미경 관찰에서는 세포배양 30분 후에는 치근활택술군에서는 세포외형이 전반적으로 구형을 보이면서 부착된 양상을 보였고 테트라사이클린 처리군에서는 세포질이 방사형으로 약간 확장되고 중간부는 소기포로 덮히고 둥글게 보였다. 세포수에 있어서도 테트라사이클린 처리군이 더 많이 부착되어 있는 양상을 나타내었고 상아세관의 노출도 관찰할 수 있었다. 세포배양 6시간이 경과한 후 세포는 치근활택술군에서는 세포질이 방사형으로 확장되어 보이고, 테트라사이클린 처리군에서는 세포의 변연일부가 함몰되어 극성을 나타내기 시작했다. 세포배양 24시간이 경과한 후 치근활택술군에서는 세포가 뚜렷한 극성을 보이고 테트라사이클린 처리군에서는 조금 더 신장된 방추형을 보였다. 이상의 연구 결과, 치주인대세포의 전개는 치근면을 테트라사이클린으로 처리시 테트라사이클린 l00mg/ml 처리군이 50mg/ml 처리군보다 초기에는 약간 더 진전된 양상을 보였으나 시간이 경과함에 따라 거의 유사하게 나타났으며, 치근활택술군보다는 우수하게 진행되었고, 세포증식률에서는 테트라사이클린 100mg/ml 처리군이 가장 많은 세포수를 보였으므로 임상적용시에는 테트라사이클린 100mg/ml가 적절할 것으로 사료된다.

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스마트폰의 지각된 가치와 지속적 사용의도, 그리고 개인 혁신성의 조절효과 (An Empirical Study on Perceived Value and Continuous Intention to Use of Smart Phone, and the Moderating Effect of Personal Innovativeness)

  • 한준형;강성배;문태수
    • Asia pacific journal of information systems
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    • 제23권4호
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    • pp.53-84
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    • 2013
  • With rapid development of ICT (Information and Communications Technology), new services by the convergence of mobile network and application technology began to appear. Today, smart phone with new ICT convergence network capabilities is exceedingly popular and very useful as a new tool for the development of business opportunities. Previous studies based on Technology Acceptance Model (TAM) suggested critical factors, which should be considered for acquiring new customers and maintaining existing users in smart phone market. However, they had a limitation to focus on technology acceptance, not value based approach. Prior studies on customer's adoption of electronic utilities like smart phone product showed that the antecedents such as the perceived benefit and the perceived sacrifice could explain the causality between what is perceived and what is acquired over diverse contexts. So, this research conceptualizes perceived value as a trade-off between perceived benefit and perceived sacrifice, and we need to research the perceived value to grasp user's continuous intention to use of smart phone. The purpose of this study is to investigate the structured relationship between benefit (quality, usefulness, playfulness) and sacrifice (technicality, cost, security risk) of smart phone users, perceived value, and continuous intention to use. In addition, this study intends to analyze the differences between two subgroups of smart phone users by the degree of personal innovativeness. Personal innovativeness could help us to understand the moderating effect between how perceptions are formed and continuous intention to use smart phone. This study conducted survey through e-mail, direct mail, and interview with smart phone users. Empirical analysis based on 330 respondents was conducted in order to test the hypotheses. First, the result of hypotheses testing showed that perceived usefulness among three factors of perceived benefit has the highest positive impact on perceived value, and then followed by perceived playfulness and perceived quality. Second, the result of hypotheses testing showed that perceived cost among three factors of perceived sacrifice has significantly negative impact on perceived value, however, technicality and security risk have no significant impact on perceived value. Also, the result of hypotheses testing showed that perceived value has significant direct impact on continuous intention to use of smart phone. In this regard, marketing managers of smart phone company should pay more attention to improve task efficiency and performance of smart phone, including rate systems of smart phone. Additionally, to test the moderating effect of personal innovativeness, this research conducted multi-group analysis by the degree of personal innovativeness of smart phone users. In a group with high level of innovativeness, perceived usefulness has the highest positive influence on perceived value than other factors. Instead, the analysis for a group with low level of innovativeness showed that perceived playfulness was the highest positive factor to influence perceived value than others. This result of the group with high level of innovativeness explains that innovators and early adopters are able to cope with higher level of cost and risk, and they expect to develop more positive intentions toward higher performance through the use of an innovation. Also, hedonic behavior in the case of the group with low level of innovativeness aims to provide self-fulfilling value to the users, in contrast to utilitarian perspective, which aims to provide instrumental value to the users. However, with regard to perceived sacrifice, both groups in general showed negative impact on perceived value. Also, the group with high level of innovativeness had less overall negative impact on perceived value compared to the group with low level of innovativeness across all factors. In both group with high level of innovativeness and with low level of innovativeness, perceived cost has the highest negative influence on perceived value than other factors. Instead, the analysis for a group with high level of innovativeness showed that perceived technicality was the positive factor to influence perceived value than others. However, the analysis for a group with low level of innovativeness showed that perceived security risk was the second high negative factor to influence perceived value than others. Unlike previous studies, this study focuses on influencing factors on continuous intention to use of smart phone, rather than considering initial purchase and adoption of smart phone. First, perceived value, which was used to identify user's adoption behavior, has a mediating effect among perceived benefit, perceived sacrifice, and continuous intention to use smart phone. Second, perceived usefulness has the highest positive influence on perceived value, while perceived cost has significant negative influence on perceived value. Third, perceived value, like prior studies, has high level of positive influence on continuous intention to use smart phone. Fourth, in multi-group analysis by the degree of personal innovativeness of smart phone users, perceived usefulness, in a group with high level of innovativeness, has the highest positive influence on perceived value than other factors. Instead, perceived playfulness, in a group with low level of innovativeness, has the highest positive factor to influence perceived value than others. This result shows that early adopters intend to adopt smart phone as a tool to make their job useful, instead market followers intend to adopt smart phone as a tool to make their time enjoyable. In terms of marketing strategy for smart phone company, marketing managers should pay more attention to identify their customers' lifetime value by the phase of smart phone adoption, as well as to understand their behavior intention to accept the risk and uncertainty positively. The academic contribution of this study primarily is to employ the VAM (Value-based Adoption Model) as a conceptual foundation, compared to TAM (Technology Acceptance Model) used widely by previous studies. VAM is useful for understanding continuous intention to use smart phone in comparison with TAM as a new IT utility by individual adoption. Perceived value dominantly influences continuous intention to use smart phone. The results of this study justify our research model adoption on each antecedent of perceived value as a benefit and a sacrifice component. While TAM could be widely used in user acceptance of new technology, it has a limitation to explain the new IT adoption like smart phone, because of customer behavior intention to choose the value of the object. In terms of theoretical approach, this study provides theoretical contribution to the development, design, and marketing of smart phone. The practical contribution of this study is to suggest useful decision alternatives concerned to marketing strategy formulation for acquiring and retaining long-term customers related to smart phone business. Since potential customers are interested in both benefit and sacrifice when evaluating the value of smart phone, marketing managers in smart phone company has to put more effort into creating customer's value of low sacrifice and high benefit so that customers will continuously have higher adoption on smart phone. Especially, this study shows that innovators and early adopters with high level of innovativeness have higher adoption than market followers with low level of innovativeness, in terms of perceived usefulness and perceived cost. To formulate marketing strategy for smart phone diffusion, marketing managers have to pay more attention to identify not only their customers' benefit and sacrifice components but also their customers' lifetime value to adopt smart phone.

한국인에서 만성기관지염의 급성악화를 치료하기 위한 LB20304(Gemifloxacin) 160mg 또는 320mg 1일 1회 7일간 투여의 유효성과 안전성에 대한 연구 (A Randomized, Double-Blind Study to Assess the Efficacy and Safety of Oral LB20304 (Gemifloxacin) at Doses of 160mg or 320mg (Equivalent to 200mg or 400mg of the Mesylate Salt) Once Daily for 7 Days for the Treatment of Acute Exacerbations of Chronic Bronchitis (AECB) in Korean Adult Population)

  • 김영환;심영수;김원동;심태선;강홍모;최병휘;김재열;권오정;김호중;김주옥;정기석;현인규;모은경;이승준;남귀현;이계영;박재석
    • Tuberculosis and Respiratory Diseases
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    • 제55권1호
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    • pp.69-87
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    • 2003
  • 배 경 : Gemifloxacin은 그람음성 및 그람양성 균주에 대해서 모두 좋은 활성을 가지고 있는 fluoroquinolone 항균제로서, 임상균주를 이용한 in vitro 시험에서 다른 대조 quinolone에 비하여 S. pneumnoniae의 penicillin 내성 균주에 대해서 활성이 높을 뿐만 아니라, 다른 quinolone 항균제에 내성을 나타내는 S. pneumoniae 임상 균주에 대해서도 좋은 활성을 유지하는 것으로 밝혀져 만성기관지염의 급성악화(AECB)시 사용하기 적절한 치료제로 여겨진다. 목 적 : 한국인에서 AECB를 치료하기 위한 LB20304(gemifloxacin) 160mg 또는 320rng 1일 1회 7일간 투여의 유효성과 안전성을 평가하고자 하였다. 방 법 : Gemifloxacin 100mg과 위약을 1일 1회 7일간 경구 투여한 환자 67명, gemifloxacin 320mg을 1일 1회 7일간 경구 투여한 환자 70명의 환자를 대상으로 무작위 배정, 이중맹검, 병행 치료군, 다기관, 2상 임상시험으로 실시하였다. 결 과 : 두 치료군의 인구통계학적 특징과 임상적 및 흡연 기왕력 등 기저 상태는 대등하였다. Per-protocol(PP) 환자군에서, 추적관찰 시점(days 14-21) 및 치료종료 시점(days 7-10)에서의 임상적 반응은 gemifloxacin 100mg군이 각각 84.2%, 96.5%, 320mg군이 각각88.7%, 96.4%로 두 군간에 유의한 사이가 없었고(각각 p=0.49, p=0.99), 추적관찰 시점 및 치료종료 시점의 미생물학적 반응도 gemifloxacin 160mg군이 각각 78.9%, 81.8%, 320mg군이 각각 84.2%, 86.4%로 두 군간에 유의한 차이가 없었다(각각 p=0.68, p=0.68) 본 임상시험에서 치료 전에 많이 배양된 병원균으로는 S. pneumoniae(12/52), H. influenzae(10/52), K. pneumoniae(6/52), M. catarrhalis(3/52) 로 K. pneumoniae가 비교적 많이 배양된 점을 제외하고는 기존에 알려진 AECB 시 배양되는 병원균의 분포와 큰 차이가 없었다. S. pneumoniae, H. influenzae, K. pneumoniae, M. catarrhalis 등 주요 병원 균에 대한 MIC는 전반적으로 다른 quinolone 항균제보다 gemifloxacin이 더 낮았고, 특히 S. pneumoniae(3 PRSP, 7 ERSP 포함)에 대한 gemifloxacin의 MIC(${\leq}0.03ug/ml$)는 다른 quinolone, beta-lactam, macrolide 항균제보다 월등히 낮아 gemifloxacin 이 AECB의 치료에 매우 유용한 항균제임을 보여주었다. 안전성 결과에서는 gemifloxacin 160mg 및 320mg 투여군 모두 시험약과의 관련성을 배제할 수 없거나 관련이 의심되는 중대한 이상반용은 관찰되지 않았고, 치료 중 및 치료 후 30일 기간동안, 이상반응을 최소한 하나 이상 보고한 환자가 gemifloxacin 160mg군은 26.9%, 320mg군은 31.4%이었다. 가장 흔히 보고된 이상반응은 간효소 수치의 증가로서, 발생 빈도는 160mg군에서 1/67명(1.5%), 320mg군에서 5/70명(7.1%) 이었다. 간효소 수치의 증가로 인해 탈락한 환자는 없었고, 중증도(severity)는 모두 경도(mild)였으며, 별다른 처치 없이 정상으로 회복되었다. 전반적인 이상반응의 profile에서 치료군간 주요한 차이는 없었다. 결 론 : 본 임상시험의 결과, 한국인에서 AECB를 치료하기 위한 gemifloxacin 160mg 또는 320mg 1일 1회 7일간의 투여는 임상적 및 미생물학적으로 매우 유효하고 안전하였다.