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        검색결과 12

        1.
        2020.12 구독 인증기관 무료, 개인회원 유료
        L-ascorbic acid (L-AA; vitamin C) induces apoptosis in cancer cells. This study aimed to elucidate the molecular mechanisms of L-AA-induced apoptosis in human laryngeal epidermoid carcinoma Hep-2 cells. L-AA suppressed the viability of Hep-2 cells and induced apoptosis, as shown by the cleavage and condensation of nuclear chromatin and increased number of Annexin V-positive cells. L-AA decreased Bcl-2 protein expression but upregulated Bax protein levels. In addition, cytochrome c release from the mitochondria into the cytosol and activation of caspase-9, -8, and -3 were enhanced by L-AA treatment. Furthermore, apoptosis-inducing factor (AIF) and endonuclease G (EndoG) were translocated into the nucleus during apoptosis of L-AA-treated Hep-2 cells. L-AA effectively inhibited the constitutive nuclear factor-κB (NF-κB) activation and attenuated the nuclear expression of the p65 subunit of NF-κB. Interestingly, L-AA treatment of Hep-2 cells markedly activated Akt and mitogen-activated protein kinase (MAPK; extracellular signal-regulated kinase 1/2, p38, and c-Jun N-terminal kinase [JNK]) and and LY294002 (Akt inhibitor), SB203580 (p38 inhibitor) or SP600125 (a JNK inhibitor) decreased the levels of Annexin V-positive cells. These results suggested that L-AA induces the apoptosis of Hep-2 cells via the nuclear translocation of AIF and EndoG by modulating the Bcl- 2 family and MAPK/Akt signaling pathways.
        4,000원
        2.
        2019.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 운전 중 외부 소음으로 유발된 스트레스를 줄이기 위한 방법으로 심박변화율의 상관관계 분석의 선행연구와 음원의 주파수에서 운전자로 하여금 안정상태를 유발하는 음악과 소음 발생 시 심전도의 변화가 있는 지의 여부를 규명하기 위한 목적이다. 매년 자동차의 증가로 인하여 운전자 및 동승자가 외부 소음으로부터 스트레스가 증가하는 추세이다. 자동차 운전 시 외부 소음에 의한 스트레스는 불안, 면역약화, 우울, 심장 질환 등 여러 가지 질병을 일으키고 있다. 따라서 외부 소음으로부터 스트레스를 줄이기 위한 자동차 시뮬레이터를 실시하여 여러 가지 청각 자극을 주어 운전자가 반응하는 연구를 진행하였다. RM-ANOVA (Repeated Measures-ANOVA) 통계분석 결과, 집단별 유의차가 인정되었다(ρ<0.05). 사후 검정을 통해 어떤 요인 간의 차이가 발생하는지를 알아보았다. 사후검정 결과는 요인1(안정) 과 요인2(시뮬레이션운전), 요인1(안정)과 요인3(운전+경찰사이렌), 요인1(안정)과 요인4(운전+경찰사이렌+음악)에서 유의한 차이를 발견할 수 있었다. 또한, 교감신경계 활성도가 가장 높은 집단은 운전+경찰사이렌+음악을 실시한 요인 4이며, 다음으로 운전+경찰사이렌인 요인 3이며, 다음으로 운전을 실시한 요인 2, 마지막으로 안정기 순으로 나타났다. 결론적으로 운전 중 경찰 사이렌 소리를 들려주어도 심전도의 변화는 유의차가 인정되지 않았다. 또한, 사이렌 소리에 안정된 주파수의 음악을 들려주어도 심전도의 변화에 차이가 발생하지 않았다(ρ<0.01). 향후 연구에서는 운전 중 심전 도의 안정을 찾을 수 있는 여러 가지 음악을 들려주어서 심전도가 안정화되는 음악을 찾는 연구방법이 선행되어야 할 것이다.
        4,000원
        7.
        2005.12 구독 인증기관 무료, 개인회원 유료
        This study was conducted to test whether the transgenic cattle pass the transgene to their progeny through germ cells, and whether the transgene is expressed in the mammary gland of ransgenic cows. Two male ransgenic calves were born from IVF-derived embryos injected with bovine β-casein/human lactoferrin fusion gene and then grew up to be reproducible. Semen was collected from a transgenic bull after 18 mon of age and then frozen. Bovine oocytes matured in vitro were fertilized with spermatozoa of the transgenic bull and cultured in 50㎕ drops of CRlaa medium supplemented with 3 mg/mL BSA. After 48 h of culture, cleaved embryos were determined for the presence of transgenes by DNA polymerase chain reaction (PCR). Proportion of transgene positives among bovine embryos fertilized with sperm of the transgenic bull was 20.9% (28/134). One of transgenic bulls did not produce transgenic sperm. Out of 34 calves produced from recipient heifers inseminated with semen of the other bull, 3 (8.8%) were transgenic animals (2 females and 1 male). Thus, one transgenic bull showed a low transmission frequency below Mendelian levels in both the IVF-derived embryos and his progeny. It was demonstrated by Southern blot that copy numbers of the transgene in the transgenic progeny enhanced about 1.8 times as compared to those of the founder bull The results demonstrate that the transgenic bull carrying human lactoferrin gene could pass his transgene to the progeny through germ cells, although he is a germ-line mosaic.
        4,000원
        8.
        2008.06 KCI 등재 서비스 종료(열람 제한)
        We have proposed modeling methods of mariners' standard behavior for collision avoidance by analyzing mariners' recognition process in a previous study. As a subsequent study, the aim of this study is to build a model of mariners' execution process which is one of six processes in the condition of collision avoidance. In this study, thus, the structure of mariners' information processing on the process of taking avoiding actions is described and the relation between mariners' behavior and necessary factors in the process is analyzed. And then we have built a model of mariners' standard behavior for execution process based on the characteristics of mariners in ship-handling, which are obtained from the international collaborative research on human factors. It is tried to define the contents of execution process based on the standard behavior of mariners for collision avoidance and to formulate information processing of mariners.
        9.
        2008.03 KCI 등재 서비스 종료(열람 제한)
        The safety degree of navigation for collision avoidance is closely related with the combination between mariner's behavior and navigational environment. The condition of navigational environment is mainly decided by navigable waters, ship traffic, rule of road, sea state, weather and so on. Especially, the condition of navigable waters and ship traffic in navigational environment are ones of the important factors to attain safe navigation when mariners are underway and crossing, head on or overtaking situation. Thus this paper is to analyze the characteristics of mariner's behavior for collision avoidance caused by ship traffic and navigable waters by analyzing the contents of questionnaire and the results of international collaborative research. As a result, it can be concluded that the density of ship traffic and the area of navigable waters affect mariner's ship handling for collision avoidance.
        10.
        2007.06 KCI 등재 서비스 종료(열람 제한)
        We've investigated the characteristics on mariner's behavior in the collision situation through a full-mission ship handling simulator and considered that it's necessary to model the standard avoiding behavior of mariners in order to apply the obtained results more widely and effectively. Thus we described the contents of standard avoiding behavior taken by mariners in the collision situation and established the concept of the standard model based on human factors for collision avoidance in a previous study. As a following study, this paper is to propose the method of modeling on mariners' standard behavior for collision avoidance by analyzing the contents of mariner's information processing and the related factors using regression analysis. As a result, we confirmed the influence of relating factors to avoiding behavior in mariner's deciding decisions and proposed the modeling method of mariners' standard behavior for collision avoidance with a example of recognition model.
        11.
        2007.06 KCI 등재 서비스 종료(열람 제한)
        Human factors have been considered the primary reason of marine accidents. Especially, the collision between vessels is mostly mused by human behavior. However, there have not been many researches to clarify the reason of marine accidents mused by human factors quantitatively. In order to understand human factors and to enhance safe navigation systematically, using a full mission ship-handling simulator, we've investigated the characteristics of avoiding behavior taken by mariners. Further in order to apply the characteristics more widely and effectively, it's necessary to formulate the standard behavior for ship-handling in the condition of collision avoidance. Is this study, therefore, we intended to propose the concept to model the mariner's standard behavior on the handling of collision avoidance as the first step. As a result, we confirmed the contents of information processing in ship-handling that mariner's generally taking to avoid collision.
        12.
        2003.12 KCI 등재 서비스 종료(열람 제한)
        It can be said that the relationship between the maneuvering ability of operators and the navigational environment affects the safe degree of navigation in the collision avoidance situation. In order to reduce the occurrence probability of accident and to maintain the safety, it is necessary to clarify the relationship between human behavior and navigational environment. In this study, therefore, we analyzed and discussed the relationship between the maneuvering characteristics and the safety focused on human behavior as a fundamental factor of marine accidents using ship handling simulator and questionnaire. As a result, we concluded that navigational environment changes variously and the maneuvering ability of operators also varies with the navigational environment, and the ship handling characteristics strongly affect the occurrence probability of accident.