• Journal of Life Science
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• v.26 no.2
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• pp.226-233
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• 2016

Vascular smooth muscle cell (VSMC) apoptosis has been identified in various vascular diseases, including atherosclerosis and restenosis after angioplasty, and has been known to precipitate atherosclerotic plaque instability and rupture. Oxysterols are known as inducers of apoptosis in VSMC, and 7-ketocholesterol (7KC) is the major nonenzymically formed oxysterol in atherosclerotic lesions. The precise mechanism underlying VSMC apoptosis is still poorly understood. In this study, we investigated whether 7KC causes apoptosis, and characterized its apoptotic mechanisms in primary cultured rat aortic VSMC. Cell viability was assessed by MTT assay and trypan blue assay. Apoptosis was assessed by flow cytometry, immunofluorescence, immunoprecipitation, and Western blot analyses. 7KC markedly decreased the VSMC viability in a time- and concentration-dependent manner, and increased the production of 4-hydroxynonenal (HNE), a major end-product of lipid peroxidation, which also decreased the VSMC viability. Pretreatment with 2,4-dinitrophenylhydrazine, a well-known reagent of lipid peroxidation-derived aldehydes, significantly restored the 7KC-decreased viability of VSMC. Furthermore, HNE, as well as 7KC, reduced the level of total Akt, a major mediator of cell survival. The 7KC-decreased level of total Akt was significantly restored by pretreatments with 2,4-dinitrophenylhydrazine and N-acetylcysteine. Lactacystin, a proteasome inhibitor, protected VSMC against apoptosis and Akt degradation, but did not inhibit HNE production. In the immunoprecipitation assay, 7KC increased HNE-modified Akt. From the results, it seems that, in atherosclerotic lesions, 7KC induces HNE production in VSMC, and this HNE binds to Akt, proceeding to proteasomal degradation of Akt, through which mechanism the atherosclerotic plaque instability may be facilitated.

• Defense and Technology
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• no.1 s.227
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• pp.48-59
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• 1998

한반도 안보상황이 어떠한 상태가 되던간에 가장 중요한 것은 우리의 안보역량 확보 여부에 달려있다. 우리의 생존을 지키고 국가위상에 걸맞는 군사력의 유지는 필수적인 것이다. 과학기술과 첨단 무기체계가 주도할 미래의 정보전쟁에 대비하기 위해서는 군사기술의 자립이 매우 중요한 과제이다.

• 어항어장
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• s.27
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• pp.56-59
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• 1994

최근 UR협정의 타결로 우리나라의 수산업은 새로운 전환점을 맞고 있다. 영세하고 마구잡이식의 원시적인 어업은 스스로 도태될 수 밖에 없고, 경쟁력이 있는 것만이 생존할 수 밖에 없게 되었다. 즉 자원절약적이고 비환경파괴적인 수산업의 중요성이 강조되고 있는 것이다.

• The Korean Journal of Applied Statistics
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• v.11 no.2
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• pp.269-285
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• 1998

One of the most important issues in the area of clinical trial research is the determination of the sample size required to insure a specified power in detecting a real or clinically relevant difference of a stated magnitude. Increasingly, medical journals are requiring authors to provide information on the sample size needed to detect a given difference. We restrict our attention to the designs far comparirng two survival distributions. These are concerned with the survival time which is defined as the interval from a baseline(e.g. randomization) to failure (e.g. death, recurrence of disease). Survival times axe right censored when patients have not foiled by the time of analysis or have been loss to follow-up during the trial. For different types of clinical trials for comparing survival distributions, there have been marry research in sample size determination. We review the existing literature concerning commonly used sample size formulae in the design of randomized clinical trials, and compare the assumption, the power and the sample size calculation of these methods. We also compare by simulation the expected power and observed power of each method under various circumstances. As a result, guidelines in terms of practical usage are provided.

• Korean journal of applied entomology
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• v.49 no.3
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• pp.241-249
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• 2010

Two groups of entomopathogenic bacteria, Xenorhabdus and Photorhabdus, are known to suppress insect immune responses by inhibiting eicosanoid biosynthesis. This study used these bacterial culture broths to develop novel biochemical insecticides against the diamondback moth, Plutella xylostella. Though the bacterial culture broths alone showed little insecticidal activity, they significantly enhanced pathogenicity of Bacillus thuringiensis against the fourth instar larvae of P. xylostella. Sterilization of the bacterial culture broth by autoclaving or $0.2\;{\mu}m$ membrane filtering did not influence the synergistic effect on the pathogenicity of B. thuringiensis. Three metablites identified in the culture broth of X. nematophila also showed similar synergistic effects. In field test, both entomopathogenic bacterial culture broth also enhanced the control efficacy of B. thuringiensis against P. xylostella.

• The Journal of the Korea Contents Association
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• v.20 no.5
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• pp.291-302
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• 2020

Korean popular music industry, which is lead by "Idol group", has forsaken their fandom all over the world. Therefore, idol groups has become not only an artist but also the most influential people in the Korean economy. A global idol group with a strong fandom can earn more than a trillion-dollar by attracting their global fan's interest in Korea. In other words, it is considerably important to carry the idol to a successful conclusion. This study tries to expect whether the idols can be survived or not at a certain point after their debut by ANN, Decision Tree, Random Forest. We decide that certain point as the three-year and eight-year after their debut, because it is their break-even point year and the year after their average renewal of the contract. In addition, this study also explains which feature is the most important to their survival by feature importance and Logistic regression. In conclusion, features like the number of idol competitors, the number of debut members and the number of the genre are significant. These results shed light on the efficient management of K-Pop idol to improve industrial competitiveness.

• Journal of Ginseng Research
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• v.10 no.2
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• pp.133-140
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• 1986

Ginseng saponin had an effect on the proliferation and viability of cultured murine thymocytes. When the thymocytes were cultured in various concentrations of ginseng saponin, the number of thymocytes increased at $10^{-5}$% ginseng saponin but decreased at $10^{-5}$%. There was little change in the number of thymocytes when cultured in IL 2(Interleukin 2), a factor known for its influence on the proliferation and maturation of thymocytes. When the thymocytes were cultured in various concentrations of IL 2 with $10^{-5}$% ginseng saponin, the number of total cells increased at 1.5% or 3% IL 2 when cultured for 9 hours, or at 6% IL 2 for 12, 24, or 48 hours. But there was little change in the number of viable cells. In vitro, ginseng saponin had an effect on the activity of ADA(Adenosine Deaminase), an enzyme known to affect the production of IL 2. There was a 25% increase in the activity of ADA in the presence of $10^{-5}$% ginseng saponin.

• 한국벤처창업학회:학술대회논문집
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• 2018.11a
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• pp.187-192
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• 2018

현재 급변하는 정보기술, 다양성을 추구하는 시장의 니즈, 미리 예측하지 못한 다양한 형태의 경쟁자 등의 출현으로 인해 경영환경이 급변하고 있는 것은 더 이상 새로운 현상이라고 보기는 어렵다. 이와 같이 급변하는 경영 환경은 기업 간 경쟁 심화를 불러일으키고 있으며, 경쟁 심화는 생존 및 발전을 위해 기업 특성에 맞지 않는 무분별한 전략을 활용하면서 오히려 역효과를 내고 있다는 문제를 야기하고 있다. 특히 변화하고 있는 환경 내 벤처기업 및 창업기업들의 경우 창업 후 생존율이 점차 낮아지면서 일반 기업들에 비해 경쟁력을 갖춘 기업을 찾아보기 어려운 것이 현실이다. 이에 벤처기업들은 도태되지 않고 생존하기 위해경쟁력을 강화시킬 수 있는 다양한 전략을 구사하고 있다. 벤처기업은 하나의 비즈니스 생태계 내 유기적 생명체로서 진화하기 위해 제품이나 산업의 수명주기와 마찬가지로 창업기, 초기 성장기, 고도 성장기, 성숙기, 쇠퇴기 등의 정형화된 단계를 거친다. 따라서 벤처기업은 무차별적인 전략을 통해 기업의 생존 및 성장을 도모 하는 것이 아니라 해당 기업이 놓인 수명주기 단계별로 전략, 조직 구조, 의사결정방식, 통제유형 등을 상이하게 판단하고 이에 적절한 전략을 수행해야 한다. 예를 들어, 동일 생산요소를 투입하더라도 이를 적용할 수 있는 지식이 있는 경우 더 높은 가치 창출이 가능(Aghion & Howitt, 1992) 하지만 창업 초창기의 기업은 고도 성장기의 기업보다 보유한 지식 수준 및 경험이 상대적으로 낮기 때문에 다양한 협력을 필요로 한다. 그러나 현재의 여러 선행연구들은 기업이 처한 상황을 고려하지 않은 단편적인 대처 방안이거나 혹은 부분적인 방법론을 제공하는 수준에 그치고 있다는 한계가 있다(이병헌 외, 2014). 따라서 본 연구에서는 '2016년 벤처기업정밀실태조사' 데이터를 기반으로 기업의 외부 협력 정도 및 벤처기업 지원제도 활용 정도가 경쟁력과 성과에 미치는 영향이 기업의 수명주기별로 상이하다고 보고 관련 전략 프레임워크를 제시하고자 한다.

• KSBB Journal
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• v.16 no.5
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• pp.486-492
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• 2001

The antimutagenic mechanism of the fraction III(RG III)separated from the water extract of Rehmannia glutionosa was investigated by Escherichia. coli GW and B/r strains. RG-III treatment did not affect the ${\beta}$-galactosidase activity E. coli GW-1060, 1106, 1107 and 1105. These results indicated that RG-III did not induce RecA protein amplification and did not also prevent the proteolytic cleavage of LexA. The bio-antimutagenicity and survival effect of RG-III on 4-nitroquinoline 1-oxide(4NQO), N-methyl-N-nitor-N\`-nitrosoguanidine(MNING) were investigate by E. coli B/r strains with have different pathway of DNA repai. RG-III slightly increased the survival of 4NQO-treated WP2, WP2s, WP67, CM561, CM611 cells, but the reactivation of survival cannot ve explained by the repair mode. RG-III caused the decrease of mutagenicity and lethality treated with MNNG in ZA159 despite of the increase in WP2, WP2s, WP67, CW561, CM611. Compared with bio-antimutagenic effects of RG-III on 4NQO, greatly increased antimutagenic effects of RG-III were observed with all the E. coli B/r strains tested, but less active in ZA159. These results suggest that RG-III was identified as a blocking agent for preventing the 4NQO induced mutagenesis, and may act as chl-products.

• Korean Journal of Weed Science
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• v.15 no.1
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• pp.63-72
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• 1995

This study was carried out to isolate the soil bacteria degrading herbicide napropamide [N,N-diethyl-2-(1-naphthoxy)-propionamide] from the clayey loam soil tested and to clarify the characteristics of the napropamide-degrading bacteria. Twenty strains of the gram-positive and the gram-negative bacteria were isolated and identified from the clayey loam soil tested. Most of them were vigorously proliferated at 100ppm of napropamide and two strains of Staphylococcus spp., Corynebacterium spp. II and Other spp. II were very tolerated to napropamide even at the concentration of 1500ppm. Staphylococcus spp. II and Actinobacillus spp. II of the isolated bacteria degraded more than 20% of the treated napropamide. These two strains could not utilize napropamide as sole nitrogen sources, but could use this compound as sole carbon sources. Napropamide was rapidly decomposed by Staphylococcus spp. II at one-time application and at three-time application of napropamide, but wasn't at two-time application of napropamide.