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尹大遠,朴鍾演,張牧淳,朴贊元 江原大學校 産業技術硏究所 1993 産業技術硏究 Vol.13 No.-
To analyze dynamic characterics for a motorcar, the creating and the hammering test methods are introduced. This paper has studied the method of computing the natural frequency of the impulse wave on a tire, the decay constant which determines the absorption capability for the impulsive force. Moreover we have examined the reliability for the decay constant calculated, in this paper theoritical results are agreed with the simulated ones.
이대원,박현우,진병래,정영호,박영목,강석권 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.2
미생물 살충제로 사용되고 있는 B. thuringiensis를 모기유충방제에 적용하기 위한 시도는 B. thuringiensis가 수서생태계에서 부유하지 못하고 가라앉으며, 생활환을 이루지 못한다는 문제점으로 인해 적용에 어려움이 있다. 따라서 본 연구는 모기유충에 강한 독성을 갖는 B. thuringiensis subsp. morrisoni PG-14의 cryIVD 유전자를 모기유충의 먹이인 cyanobactrium에 도입하기 위하여 발현벡터 pCYASK 5-1을 제작하고, cyanobacterium Synechocystis PCC6803에 형질전환시켜, 세포내에서 cryIVD 유전자의 발현과 뇌염모기에 대한 독성을 조사하였다. 그 결과 형질전환체 내에서 cryIVD 발현은 immunoblot 분석을 통해 B. thuringiensis subsp. morrisoni PG-14에서 발현된 단백질과 같은 분자량으로 발현되는 것을 확인하였으며, 모기유충에 대한 형질전환체의 독성은 1.40×10^6 cells/ml 농도에서 약 80%의 치사율을 나타내었다. Bacillus thuringiensis subsp. morrisoni PG-14 is a gram-positive soil bacterium producing mosquitocidal parasporal inclusions composed of several crystal proteins. Among these crystal protein genes, cryIVD gene is one of major component which has 72 kDa in size. However, these parasporal inclusions sink quickly from the surface of water where mosquito larval feeding occurred. To develope mosquitocidal cyanobacterium, therefore, we constructed the expression vector, pCYASK 5-1 harboring cryIVD gene. The expression vector, pCYASk5-1 was transformed into the cyanobacterium Synechocystis PCC6803 reported as a natural mosquito larval food source and the transformants were selected with kanamycin. Expression of cryIVD gene in transformant was characterized by SDS-polyacrylamide gel electrophoresis (PAGE) and immunoblot analysis. The mosquitocidal activity of a transformant was determined electrophoresis (PAGE) and immunoblot analysis. The mosquitocidal activity of a transformant was determined with Culex tritaeniorhynchus. The results showed that the transformed cyanobacterium is toxic to mosquito larvae and will be expected as a potential agent that is used for mosquito control.
H9c2 심근 세포주에서 외인성 nitric oxide가 허혈에 의한 세포 독성에 미치는 영향
정성구,장현용,김명천,고영관,정주호,배영미,박원서,김대중,유영민,김성수,임성빈 대한응급의학회 2001 대한응급의학회지 Vol.12 No.4
Background: Nitric oxide(NO) is known to have protective effects on an ischemic heart and to exert triggering effects on ischemic preconditioning. However, the effects of NO during the ischemic period have not been investigated. To investigate the role of exogenous nitric oxide in a model of ischemic heart cell death, we studied the effects of ischemic preconditioning and ischemia in a normal and an ischemic buffer. Methods: Rat cardiac myoblast cells(H9c2) were cultured in a normal and an ischemic buffered medium. For the ischemic culture of heart cells, the cells were cultured in a dessicator with GasPak for 5 hrs. In ischemic preconditioning, the cells were pretreated with ischemic buffer for 5 min and then perfused with normal medium for 30 min. For the measurement of the cytotoxicity, a MTT(3-4-Sdimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide) assay was performed. A DAPI(4',6-diamidino-2-phenylindole dihydrochloride) staining procedure and a flow cytometry analysis were performed to confirm apoptotic cell death by ischemia. Results: Cell viability, as determined by using a MTT assay, showed that the preconditioned group treated with NO showed more cell death than with the not-preconditioned groups in both normal and ischemic buffers. But, In normal medium and not-preconditioned groups, NO showed protective effect according to the concentrations(100,1000μM) . No treatment with NO produced the different results. In normal medium, the protective effect of ischemic preconditioning was demonstrated, but no protective effect of ischemic preconditioning could be seen in the case of the ischemic buffer. The DAPI staining and flow cytometry analysis of heart cells showed characteristic apoptotic features. Conclusion: NO added in the ischemic phase had deterious effects on heart cells. Ischemic preconditioning was more harmful than ischemia alone. The toxicity of the cells was characteristic apoptosis.
Resveratrol Inhibits Inflammation Induced by Heat-Killed Listeria monocytogenes
Park, Dae-Weon,Kim, Jin-Sik,Chin, Byung-Rho,Baek, Suk-Hwan The Korean Society of Food Science and Nutrition 2012 Journal of medicinal food Vol.15 No.9
Resveratrol is a polyphenolic compound in red wine that has antioxidant and cardioprotective effects in animal models. Listeria monocytogenes is a pathogen that mainly affects immunocompromised individuals and is initially detected at the cell surface or in phagosomes by toll-like receptor 2. Many antioxidants also exert anti-inflammatory activities; therefore, we evaluated the anti-inflammatory properties of resveratrol by studying the various inflammatory responses induced by heat-killed L. monocytogenes (HKLM). Resveratrol strongly blocked HKLM-induced NADPH oxidase-1 mRNA and reactive oxygen species production by macrophages. Resveratrol also suppressed monocyte chemotactic protein-1 expression, cyclooxygenase-2 expression, prostaglandin production, inducible nitric oxide (NO) synthase expression, and NO production induced by HKLM. We investigated the signaling pathway involved in the resveratrol effect. HKLM stimulated glycogen synthase kinase <TEX>$3{\beta}$</TEX> (<TEX>$GSK3{\beta}$</TEX>) and extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation. The involvement of <TEX>$GSK3{\beta}$</TEX> and ERK1/2 was tested using inhibitors. While the <TEX>$GSK3{\beta}$</TEX> inhibitor LiCl potentiated the effect of HKLM, the MEK inhibitor U0126 blocked these responses. Additionally, pretreatment with resveratrol blocked phosphorylation of both kinases induced by HKLM. These results suggest that HKLM is strong inducer of inflammatory mediators, and that the inhibitory effect of resveratrol may be mediated by the <TEX>$GSK3{\beta}$</TEX> and ERK1/2 pathways.
Dae-Weon Park,Kheewoong Baek,김재룡,Jae-Jin Lee,Sang-Ho Ryu,Byung-Rho Chin,백석환 생화학분자생물학회 2009 Experimental and molecular medicine Vol.41 No.3
Resveratrol is a polyphenolic compound in red wine that has anti-oxidant and cardioprotective effects in animal models. Reactive oxygen species (ROS) and monocyte chemotactic protein-1 (MCP-1) play key roles in foam cell formation and atherosclerosis. We studied LPS-mediated foam cell formation and the effect of resveratrol. Resveratrol pretreatment strongly suppressed LPS-induced foam cell formation. To determine if resveratrol affected the expression of genes that control ROS generation in macrophages, NADPH oxidase 1 (Nox1) was measured. Resveratrol treatment of macrophages inhibited LPS-induced Nox1 expression as well as ROS generation, and also suppressed LPS-induced MCP-1 mRNA and protein expression. We investigated the upstream targets of Nox1 and MCP-1 expression and found that Akt-forkhead transcription factors of the O class (FoxO3a) is an important signaling pathway that regulates both genes. These inhibitory effects of resveratrol on Nox1 expression and MCP-1 production may target to the Akt and FoxO3a signaling pathways.
Park, Jung-Weon,Yang, Tae-Whan,Kim, Yun-Kyung,Choi, Byung-Min,Kim, Hai-Joong,Park, Dae-Won The Korean Pediatric Society 2014 Clinical and Experimental Pediatrics (CEP) Vol.57 No.3
Purpose: Administration of antiretroviral drugs to mothers and infants significantly decreases mother-to-child human immunodeficiency virus (HIV) transmission; cesarean sections and discouraging breastfeeding further decreases this risk. The present study confirmed the HIV status of babies born to mothers infected with HIV and describes the characteristics of babies and mothers who received preventive treatment. Methods: This study retrospectively analyzed medical records of nine infants and their mothers positive for HIV who gave birth at Korea University Ansan Hospital, between June 1, 2003, and May 31, 2013. Maternal parameters, including HIV diagnosis date, CD4+ count, and HIV ribonucleic acid (RNA) copy number, were analyzed. Infant growth and development, HIV RNA copy number, and HIV antigen/antibody test results were analyzed. Results: Eight HIV-positive mothers delivered nine babies; all the infants received antiretroviral therapy. Three (37.5%) and five mothers (62.5%) were administered single- and multidrug therapy, respectively. Intravenous zidovudine was administered to four infants (50%) at birth. Breastfeeding was discouraged for all the infants. All the infants were negative for HIV, although two were lost to follow-up. Third trimester maternal viral copy numbers were less than 1,000 copies/mL with a median CD4+ count of $325{\mu}L$ ($92-729{\mu}L$). Among the nine infants, two were preterm (22.2%) and three had low birth weights (33.3%). Conclusion: This study concludes that prophylactic antiretroviral therapy, scheduled cesarean section, and prohibition of breastfeeding considerably decrease mother-to-child HIV transmission. Because the number of infants infected via mother-to-child transmission may be increasing, studies in additional regions using more variables are necessary.
시공오차가 있는 선기초기둥에 공장제작보의 설치가 용이한 탑다운공사용 접합기술개발
김승원 ( Seung Weon Kim ),정희원 ( Hee Weon Jung ),박대영 ( Dae Yung Park ),김동건 ( Dong Gun Kim ),박주현 ( Joo Hyun Park ) 한국건축시공학회 2011 한국건축시공학회 학술발표대회 논문집 Vol.11 No.1
Almost prefounded columns for top-down construction certainly have construction tolerances in plan and plumbness. Therefore, it is very difficult to connect prefabricated beams to prefounded columns at each floor level after excavation by usual top-down connection method and this usual connection method leads to long construction time, increasing cost and decreasing quality. This paper presents a new method for connecting prefabricated beam to prefounded column with GROUT-JACKET CONNECTION SYSTEM consisting of sleeve, bearing-shear bands and grout. Details and illustrations of the connections and applications by GROUT-JACKET CONNECTION SYSTEM for the top-down construction are also included in this paper.
A study on the synthesis of fine nickel hydroxide crystalline powder using the taylor fluid flow
Park, Il-Jeong,Kim, Dae-Weon,Jung, Hang-Chul The Korea Association of Crystal Growth 2017 韓國結晶成長學會誌 Vol.27 No.5
In this study, nickel hydroxide crystalline powders were synthesized by continuous reaction in the taylor fluid flow using nickel chloride, nickel sulphate and sodium hydroxide as raw materials and compared with those prepared by a conventional batch type reaction. The crystallinity of nickel hydroxide prepared by the Taylor fluid flow reaction was higher than that of nickel hydroxide obtained by batch reaction. The particle size of nickel hydroxide decreased about 2.5 to 3.6 times, and the specific surface area was increased.