• 한국환경과학회지
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• 제17권4호
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• pp.439-449
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• 2008

Algicidal bacterium was isolated from sea water during the declining period of Cochlodinium polykrikoides blooms and this bacterium had a significant algicidal activity against C. polykrikoides. In this study, algicidal bacterium was identified on the basis of biochemical and chemotaxonomic characteristics, and analysis of 16S rDNA sequences. The algicidal bacterium showed 98.6% homology with Micrococcus luteus ATCC $381^T$. Therefore, this bacterium was designated Micrococcus luteus SY-13. The optimal culture conditions of the algicidal bacterium was $25^{\circ}C$, initial pH 8.0, and 3.0% NaCl concentration. M. luteus SY-13 is assumed to produce secondary metabolites which have algicidal activity. When 10% culture filtrate of this strain was applied to C. polykrikoides ($1.0\;{\times}\;10^4\;cells/ml$) cultures, over 98% of C, polykrikoides cells were destroyed within 6 hours. The culture filtrate of M. luteus SY-13 exhibited similar algicidal activity after heat-treatment at $121^{\circ}C$ for 15 min. While algicidal activity remained in filtrates with pH adjusted to 8.0, loss of algicidal activity occurred when the pHs of filtrates were adjusted to over 9.0 or heat-treated at $121{\times}180^{\circ}C$ for 1 hour. M. luteus SY-13 showed significant algicidal activities against C. polykrikoides (98.9%) and a wide algicidal range against various harmful algal bloom (HAB) species. However, there was no algicidal effect on diatom and marine livefood organisms except Isocrysis galbana. These results suggest that M. luteus SY-13 could be a candidate for use in the control of HABs.

• 한국자동차공학회논문집
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• 제19권4호
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• pp.78-83
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• 2011

Natural gas is one of the most promising alternatives to gasoline and diesel fuels because of its high thermal efficiency and lower harmful emissions, including $CO_2$. Although the high octane value of natural gas increases engine output and efficiency due to the high compression ratio, this fuel is prone to such difficulties as a narrow limit of inflammability and a slow combustion speed in the lean burn operation domain, leading to unstable combustion and higher emissions of harmful exhaust gases. Hydrogen blended with natural gas can extend the lean burn limit while maintaining stable, efficient combustion and achieving lower NOx, hydrocarbon and green house gas emissions. In this study, the effect of hydrogen addition on an engine performance and NOx emission characteristics was investigated in a heavy duty natural gas engine. The results showed that thermal efficiency was increased and NOx emissions were reduced due to the expansion of lean operation range under stable operation. NOx emission can be significantly reduced with the retard of spark advance timing.

• 한국수정란이식학회지
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• 제26권3호
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• pp.165-169
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• 2011

The present study investigated the physiological evaluation of cloned mini-pigs in a transportable isolator. Transportable isolator was designed and manufactured by our research team for transporting gnotobiotic pig. Until now, no previous reports are available regarding the physiological activities and harmful effects when pigs were transported in this isolator. Five cloned mini-pigs of 1~2 year (s) old female with a body weight between 80~90 kg were used. The effects of transportable isolator on stress-related hormone, adrenocorticotrophic hormone (ACTH) and cortisol levels, and heart rate were evaluated. In addition, it was also examined the effects of transportable isolator on blood chemistry factors (alanine aminotransferase: ALT, aspartate aminotransferase: AST, blood urea nitrogen: BUN, glucose, and creatinine). Blood was sampled just before the beginning of transport (T0), at the end of transport (30min after the transport; T1), and 30 min after the end of transport (T2). At the same time, heart rate was also evaluated. As a result, heart rate had no significant (p>0.05) differences at the various-time points of study (T0, T1, T2). However, heart rate was slightly higher than normal range in T1 and T2. The ACTH level was higher than normal range. Whereas, the cortisol level was lower than normal range. There were no statistical significant differences both ACTH and cortisol level between different time groups. Also, there were no significant differences in blood chemistry factors. Therefore, our present study shows that transportable isolator has no harmful effect on stress and physiological condition in cloned mini-pigs.

• Childhood Kidney Diseases
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• 제20권2호
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• pp.45-49
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• 2016

Purpose: This study was performed to evaluate the effects of cyclosporine-A (CsA) on linear growth in pediatric patients with steroid-dependent (SDNS) or resistant nephrotic syndrome (SRNS). Methods: Thirty-five pediatric patients with SDNS or SRNS undergoing glucocorticoid (GC) and/or CsA treatment were retrospectively reviewed. Seventeen patients were treated with GC alone and 18 were treated with GC and CsA. The cumulative doses of GC and CsA were quantified (mg/kg/day). Linear growth during the follow-up period was defined as the difference in Z-score between the initial and final height according to the follow-up period (${\Delta}$ height Z score/year). The associations between linear growth and clinical parameters were analyzed. Results: The linear growth of patients in the two groups was not significantly different (P=0.262). The ${\Delta}$ height Z score/year did not show a significant correlation with the cumulative doses of CsA, but was negatively correlated with the cumulative dose of GC and positively correlated with the Z score for height at the time of diagnosis. Conclusion: In children with SDNS or SRNS undergoing GC therapy, added CsA treatment may not have harmful effects on linear growth.

• Journal of Nutrition and Health
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• 제36권3호
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• pp.255-261
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• 2003

Food irradiation has been steadily increasing in many countries in line with increasing international trade and concerns about naturally occurring harmful contaminants in food. Although irradiation provides an excellent safeguard for the consumer by destroying almost 100% of harmful bacteria, it is necessary to ensure the safety of irradiated foods. This study was performed to investigate the effect of an irradiated diet on lipid peroxidation in the plasma, liver, small intestinal mucosa, and lymphocyte DNA damage in mice. Eight-week old ICR mice were assigned to two groups to receive either non-irradiated or irradiated (10 kGy) diets containing 20.38% fish powder and 6.06% sesame seeds for 4 weeks. The resulting changes in the degrees of lipid peroxidation were evaluated based on the level of plasma and liver thiobarbituric acid reactive substance (TBARS), transmission electron micrograph of jejunal mucosa, and free radical-induced oxidative DNA damage in lymphocytes, as measured by alkaline comet assay (single cell gel electrophoresis). The peroxide values of the gamma irradiated diet were measured every week, and the sample for comet assay was taken at the end of the four week experimental period. There was no significant difference in food efficiency ratio between the two groups. The peroxide values of the diet were immediately increased to 35.5% after gamma irradiation and kept on increasing during storage. After 4 weeks, no differences in tissue or plasma TBARS value were observed between the two groups, but epithelial cells of jejumum showed osmiophillic laminated membranous structures, considered as myelin figures,. The oxidative DNA damage expressed as tail moment (TM) increased 30% in the blood lymphocytes of the mice fed the irradiated diet. In conclusion, the comet assay sensitively detected differences in lymphocyte DNA damage after feeding with the irradiated diet for 4 weeks. However, in order to ensure the safety of irradiated foods, it would be more useful to conduct a long-term feeding regimen using an irradiated diet and examine the level of lipid peroxidation and the state of oxidative stress in a greater range of organs.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 추계학술대회
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• pp.127-127
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• 2018

Probiotics are microorganisms that have beneficial effects on the health of the host. The health promoting effect by probiotics influences suppressing harmful bacteria, prevention of constipation, blood cholesterol reduction and regulation of blood pressure. Prebiotics are used to promote the growth or activity of microorganisms. Synbiotics, which are a mixture of probiotics and prebiotics, synergize in the intestines by complementing each other. Synbiotics not only improves the viability of the probiotics while passing through the gastrointestinal tract, maintain intestinal homeostasis, but also regulate balance of harmful and useful bacterial growth. Glycine max Merr (GMM) has been widely used in Asian countries to treat cancer, obesity, oxidative stress and imbalanced immune diseases. In addition, it has been reported that dietary fiber-rich grains promote bowel movements and prevent constipation. In this study, we investigated the viability of LactobacillIus buchneri (L.buchneri) strains, known as lactic acid bacteria under conditions of gastric fluid and intestinal fluid to determine the suitability of L.buchneri as probiotics. The adhesion ability of L.buchneri to caco-2 cells was also confirmed. The present studies showed that GMM extract promoted the growth and activity of L.buchneri strains as prebiotics. Also, this results suggested that the mixture of L.buchneri and GMM extract can helps maintain intestinal health and healthy body as synbiotics and health functional food material.

• 한국안전학회지
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• 제15권1호
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• pp.72-79
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• 2000

In recent, occupational diseases in harmful working places become a social issue. It is the well-known fact that a respiration in polluted working places exert a serious effect on health of workers. Accordingly, the cutting off contaminants air originally is the best way to improve working environments. In these cases, ventilation systems should be essentially installed to dilute or exhaust the contaminated indoor air. In this study, we investigated the characteristics of ventilation system of the noxious gas in working indoor places with natural ventilation by using COMET. The numerical simulations were carried out the natural ventilation with two phase(air, dust). For turbulent flow, Reynolds stresses were closed by the standard $\kappa$-$\varepsilon$ model. The results are as follows ; 1) In the natural exhaust in the working place, the flows of the central region have a more rapid velocity vector than the right and left one. 2) Numerical results show that the distribution of contaminants concentration have greater influence on convection than the case of diffusion by government of velocity vectors. 3) To observe the velocity variation with distance, three location of distance are considered. As results, it shows that the velocity are 0.075(m/s) at y=5(m), 10(m) and mean concentration are raised 10.6% at y=5(m), 10(m). 4) We have presented the useful data for the adequate counterplan in the harmful working places by carrying out the various investigation of the natural ventilation.

• 한국안전학회지
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• 제21권5호
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• pp.28-33
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• 2006

The rapidly advanced industrial society takes advantage of high-technology, but it also suffered from the side effects such as various diseases by contamination. Of these problems, air pollution is considered as the most important problem nowadays. Air contamination is not only limited outdoors, but it also causes more serious effect in our indoor air environment. Depending on the notion that indoor air effects physical health seriously, the needs of the air cleaner is more earnest. Therefore, the main purpose of this study is to develop the air cleaner to meet the standard and get rid of poisonous and harmful material from the atmosphere by using a Corona Discharge. According to the purpose of this study, We set the negative ion generator, the UV, $TiO_{2}$ optical catalyzer, the electrical dust collector and the air filter in series order. It emits a lot of negative ions. We use these ions to purify harmful factors and contaminated materials. We collect the dust using static power that comes from the discharge of corona. At the same time, we try to develop the air cleaner to keep the air quality to meet the standard and kill the various viruses using UV LED and $TiO_{2}$ optical catalyzer. In this study, we use the UV LED that is smaller and efficient than a existing UV lamp. What is more, the UV LED has a features that a stabilizer occupying much space is not needed any more.

• 한국방사선학회논문지
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• 제2권1호
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• pp.11-16
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• 2008

방사선은 의학, 이공학, 농학, 기타 산업분야 등에서 사용영역이 매우 넓고 방사선이용기술의 개발로 방사선의 이용 빈도는 계속 증가되고 있다. 방사선의 인류에 대한 공헌은 지대하지만 생체에 미치는 영향으로 인하여 방사선에 의한 장해 또한 간과할 수 없는 부분이다. 방사선을 유효적절하게 이용하면서 장해를 방지하기 위해서는 방사선을 정확하게 계측하여야 하며 이에 따른 연구와 교육이 철저하게 이루어 져야만 한다. 본 연구에서는 유비쿼터스 컴퓨팅기술을 이용하여 생체에 유해한 작용을 하는 방사선을 방사선선원에 접근하지 않고 무선으로 시간과 장소에 제한 없이 방사선을 계측할 수 있는 방안을 제안하였다. 제안된 방안의 구현은 무선전송 기술은 CDMA망을 이용하였고, 임베디드시스템(embedded system)을 PDA에 내장한 후, 고정된 IP를 가지는 방사선계측시스템에 PDA를 CDMA망에 접속하여 계측값을 디스플레이 하였다. 본 연구에서 제안된 방안을 이용한다면 인간이 유해한 방사선선원에 접근하지 않고 선원에 배치된 고정된 IP를 가지고 있는 방사선계측시스템을 통하여 CDMA망으로 PDA에 표시된 계측값을 읽을 수 있게 될 것이다.

• 정신신체의학
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• 제6권1호
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• pp.70-78
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• 1998

Alternative medicine is defined as the practices used for the prevention and the treatment of diseases that are not taught widely in medical schools, nor generally available inside hospitals. Alternative medicine or therapy is of growing interest to the general public. We conducted a survey to determine the prevalence and patterns of using alternative medicine such as herbal medicine acupuncture, folk medicine, health food and diet, yoga, qi therapy, shiatsu, chiropractics, homeopathy etc.. Based on 794 completed questionnaires, 484 respondents(61%) reported using at least one form of alternative medicine for their medical problems. The major medical conditions for which they used alternative medicine were back pain(85.6%), arthritis(85.4%), hypertension(85.2%), cerebrovascular disorders(86.4%), and insomnia(84.6%). The types of alternative medicine frequently used were herbal medicine, acupuncture, folk medicine, and health food. The reasons why the vast majority of people sought after alternative medicine was that: less side-effect, it is not harmful, it is more effective, there is a shorter waiting time, and a better explanation fur the conditions and a kinder therapist. We found that the frequency of using alternative medicine in the health care system was high. Physicians need to be more aware that many patients may be using alternative medicine. Further survey of the nation-wide prevalence of alternative medicine, and scientific study into the efficacy of this medicine should be followed. In the meantime, we suggest paying attention to possible harmful effects caused by some sorts of alternative medicine.