• Journal of Preventive Medicine and Public Health
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• 제25권1호
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• pp.34-43
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• 1992

To investigate the effect of hyperoxia on EKG findings and to evaluate the applicability of EKG as noninvasive monitoring index of oxygen toxicity, 38 rabbits were continuously exposed to 6 different conditions-3 hyperbaric oxygenations (HBO-2.5, 3.5 and 5ATA, 100% $O_2$), normobaric oxygenation (NBO,100% $O_2$), hyperbaric aeration (HBA-5ATA, 21% $O_2$) and normobaric aeration (NBA, 21% $O_2$)-for 120 minutes and their EKG and time to dyspnea and convulsion were recorded. Dyspnea and death were observed in exposure conditions of HBO-3.5 and HBO-5 (Positive rate of dyspnea 10%, 100%, death : 10%, 25%, respectively) only, and convulsion in 4 oxygenation groups (NBO;20%, HBO-2.5;20%, HBO-3.5;20%, HBO-5;88%). Abnormal EKG findings included arrhythmia and ST-T changes and the incidences was increasing with doses(partial pressure of oxygen). In addition to EKG change, findings observed during exposure were dyspnea and convulsion in the order of appearance and when non specific ST-T change was accepted as positive(abnormal) finding, the frequency of abnormal EKG was statistically significant(p<0.01), but when it was excluded from positive results, the frequency of EKG change was not significant(p>0.05). These results suggest that the effect of hyperoxia on heart is myocardial ischemia and arrhythmia, that oxygenation more than 3.5ATA causes myocardial damage in 120 minutes exposure, and that EKG is valuable as monitoring index of oxygen toxicity.

• 한국환경과학회지
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• 제4권3호
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• pp.259-267
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• 1995

This study was conducted to evaluate the effects of pressure and dissolved oxygen concentration on the activated slut비e and to determine the optimum depth of deep shaft process. Some results from this study were summarized as follows. 1. It is considered that low sludge product in the activated sludge system maintaining high dissolved oxygen concentration is attributed to the increase of endogeneous respiration rate caused by the increase of aerobic zone in the sludge floe. 2. The increase of dissolved oxygen concentration does not affect to the increase of organic removal efficiency greatly and therefore the limiting factor is the substrate transfer into the inner part of floe. 3. The yield coefficient, Y is decreased in proportion to the increase of oxygen concentration. In this study, Y values arre ranged from 0.70 to 0.41 according to the variation of dissolved oxygen concentration from 18.0mg/$\ell$ to 258 mg/$\ell$. 4. The optimum depth of deep shaft process should be determined within the limits of non-toxicity to the microorganism and it is about loom in this study.

• 한국수산과학회지
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• 제30권5호
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• pp.874-881
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• 1997

곤쟁이 Neomysis awatschensis의 치하와 성체에 대한 중금속의 급성독성 수준과 아치사 농도에서 생존, 성장, 탈피 및 산소소비에 미치는 cadmium, copper 및 chromium의 독성을 검토하였다. Cadmium, copper 및 chromium에 대한 곤쟁이 성체의 $96hr-LC_{50}$은 각각 20.2, 11.3, $670.4\;{\mu}g/\ell$, 치하에서는 각각 3.4, 1.9 및 $49.4\;{\mu}g/\ell$이었다. 성체와 치하의 $96hr-LC_{50}$을 기준으로 중금속의 독성은 copper>cadmium>chromium 순이었다. 치하를 각 중금속의 아치사 농도에 40일간 노출시키면서 생존, 성장 및 탈피에 미치는 영향을 조사한 결과, 생존율은 cadmium이 $\geq1.0\;{\mu}g/\ell,\;copper\geq0.6\;{\mu}/\ell$에서 유의한 감소를 보였다. 성장률은 cadmium $2.0\;{\mu}g/\ell$와 copper $\geq1.2\;{\mu}g/\ell$의 농도에서 유의한 감소가 관찰되었으나 탈피기간에는 영향이 없었다. 산소소비량은 중금속 농도가 높을수록 감소하였고, 대조구의 산소소비량을 기준으로 하여 중금속 농도에 따른 산소 소비량은 cadmium과 copper는 $5\;{\mu}g/\ell$ chromium은 $10\;{\mu}g/\ell$ 농도에서 약 $50\%$ 감소하였다. 이상의 결과로부터 하구역에 cadmium이 $\geq1.0\;{\mu}g/\ell$, copper가 $\geq0.6\;{\mu}g/\ell$ 농도가 존재할 경우 곤쟁이의 분포와 개체군의 크기에는 많은 영향을 미칠 것으로 사료된다.

• Journal of the Korean Wood Science and Technology
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• 제43권5호
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• pp.548-557
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• 2015

This study investigated environmental assessments of leachate containing formaldehyde from medium density fiberboard (MDF) disposed in laboratory-scale simulated landfills. Environmental impact assessment of leachate was conducted by measuring formaldehyde, toxicity, biochemical oxygen demand (BOD), chemical oxygen demand (COD), bacterial enumeration, and pH. Amount of formaldehyde in leachate from MDF in soil decreased to the level of soil only treatment by 28 days, and toxicity decreased as the amount of formaldehyde decreased. BOD and COD levels in leachate from the treatments containing MDF exceeded permissible discharge levels of BOD or COD throughout the experimental period. The pH levels of all treatment were within permissible discharge range except on day 0. Fewer bacteria were observed in leachate from MDF in soil treatment than other treatments (MDF only, cured UF resin in soil, and soil only). Consequently, the leachate from disposal of MDF in soil detrimentally affect on environment. However, soil buffered formaldehyde leaching and pH on leachate in this study. Waste MDF may be required the pre-water soaking treatment for leaching formaldehyde to reclaim on land.

• Toxicological Research
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• 제30권3호
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• pp.193-198
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• 2014

Degradation of glucose is aberrantly increased in hyperglycemia, which causes various harmful effects on the liver. Methylglyoxal is produced during glucose degradation and the levels of methylglyoxal are increased in diabetes patients. In this study we investigated whether methylglyoxal induces mitochondrial impairment and apoptosis in HepG2 cells and induces liver toxicity in vivo. Methylglyoxal caused apoptotic cell death in HepG2 cells. Moreover, methylglyoxal significantly promoted the production of reactive oxygen species (ROS) and depleted glutathione (GSH) content. Pretreatment with antioxidants caused a marked decrease in methylglyoxal-induced apoptosis, indicating that oxidant species are involved in the apoptotic process. Methylglyoxal treatment induced mitochondrial permeability transition, which represents mitochondrial impairment. However, pretreatment with cyclosporin A, an inhibitor of the formation of the permeability transition pore, partially inhibited methylglyoxal-induced cell death. Furthermore, acute treatment of mice with methylglyoxal increased the plasma levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), indicating liver toxicity. Collectively, our results showed that methylglyoxal increases cell death and induces liver toxicity, which results from ROS-mediated mitochondrial dysfunction and oxidative stress.

• 한국동물생명공학회지
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• 제36권1호
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• pp.2-8
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• 2021

Dimethachlor is a synthetic herbicide, belonging to the chloroacetanilide group, that inhibits the undesirable growth of weeds via the suppression of very long-chain fatty acid synthesis. Although dimethachlor has been shown to run off from agricultural fields into aquatic ecosystems, the toxicity of dimethachlor on aquatic invertebrates and vertebrates is unknown. In our study, we assessed the toxicity of dimethachlor on developing zebrafish embryos by analyzing viability, hatching ability, and phenotypic changes. Embryonic viability decreased from 48 h post-fertilization (hpf) at the highest concentration of dimethachlor. Decreased hatching ratio, shortened body length, and pathological changes in the eye, heart, and yolk sac were observed at sub-lethal concentrations. Additionally, dimethachlor increased the number of apoptotic cells and level of reactive oxygen species 120 hpf. Our results indicate that dimethachlor may act as an anti-developmental toxicant when accumulated in an aquatic environment.

• 생명과학회지
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• 제26권12호
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• pp.1458-1465
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• 2016

본 연구는 oxidative stress에 의한 세포죽음 분석의 이상적인 모델로 사용되는 HT22세포를 이용하여 천문동 에탄올추출물의 glutamate에 의한 oxidative toxicity에 대한 신경보호 효과를 살펴보았다. 이를 위해 cell viability, lactate dehydrogenase (LDH), 그리고 세포죽음형태, reactive oxygen species (ROS), mitochondria membrane potential (MMP) 등에 대한 flow cytometry 및 Western blot분석을 이용하였다. 천문동 추출물의 처리는 cell viability 및 LDH분석에서 glutamate에 의한 cell toxicity를 저하시키며, 특히 apoptotic cell death를 현저히 감소시켰다. ROS 및 MMP분석 결과, 천문동 추출물은 ROS의 형성을 저하시키며 glutamate에 의해 저하된 MMP를 현저히 회복시켜 주었다. 이와 관련된 단백질 발현을 보면, 천문동 추출물은 PARP 및 HO-1의 발현을 억제하였다. 이상의 결과는 천문동 추출물이 HT22해마세포에서 ROS형성저해 및 MMP회복에 의해 세포죽음을 완화시켜 보호작용을 하는 것으로 사료되며 oxidative toxicity관련 질환에 적용 가능할 것으로 보여 진다.

• 한국환경보건학회지
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• 제28권2호
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• pp.71-80
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• 2002

To evaluate the skin toxicity of topical cyclohexane application (25mg/$\textrm{cm}^2$) was sequentially applied to the rat skin for four days. On the histopathological findings in the light micrographs, neutrophils and engulfed neutrophils are seen, and many cytoplasmic processes were appeared in proliferated layer whereas in the dermis area, increased numbers of fibroblast, accumulation of neutrophil and lipid droplets are demonstrated. On the other hand, applying the cyclohexane to the rat skin led to the remarkable rise of cutaneous xanthine oxidase activity and similar activities of superoxide dismutase and glutathione peroxidase and glutathione content and declined activity of glutathione S-transferase compared with control group. Especially the remarkably decreased activity of aniline hydroxylase (AH) was appeared in skin as little as scarcely determined. Furthermore, the applying the cyclohexane to skin led to the significantly increased activity of hepatic AH and alcohol dehydrogenase. These results indicate that oxygen free radical and intermediate metabolite of cyclohexane may be responsible for structural changes in skin by cyclohexane application to rat skin.

• 한국식품영양학회지
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• 제25권4호
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• pp.1016-1022
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• 2012

In order to investigate the effects of 70% EtOH extract obtained from Hovenia dulcis Thunberg on enzymes relating reactive oxygen intermediate, cancer-stricken animals induced by DEN (N,N-diethylnitrosamine) were recovered by administering the extract of Hovenia dulcis Thunberg. It showed that there was no effect on the generation of superoxide radical by the extract of Hovenia dulcis Thunberg. However, considering the increase of the activity of Cu, Zn-SOD and Mn-SOD in the tested animal class, the extract of Hovenia dulcis Thunberg could participate directly in removing of superoxides. The experimented-animals treated with the extract of Hovenia dulcis Thunberg showed an increase in the activity of the enzymes, catalase and glutathione peroxidase, which can eliminate hydrogen peroxide pertained in liver tissue. The extract of Hovenia dulcis Thunberg seemed to have some factors that accelerate the oxidation. Also, the extract of Hovenia dulcis Thunberg showed effects on the enzymes relating to the active oxygen toxicity which could be an indicator of aging and body toxicity.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.142.1-142.1
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• 2003

Excessive accumulation of beta-amyloid (A$\beta$) peptides is one of the leading hypotheses to explain neurodegenerative processes in Alzheimer's disease (AD). It has been suggested that $A\beta$ toxicity is associated with increases in reactive oxygen species. whose overproduction may in turn initiate neurotoxic events. (omitted)