• 환경생물
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• 제42권1호
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• pp.1-14
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• 2024

This study evaluated the risk of single and combined exposure to microplastics in zebrafish (Danio rerio) through biomarkers, such as survival rate, excretion rate, and histological alterations of organ systems. The experimental groups were the control(Cont.), single microplastics exposure group(MPs, 1.83%/fish total weight(g)), the copper group(Cu, 21.6 ㎍ L^-1), and a group with combined exposure to MPs and copper (MPs^*Cu). The experiment was conducted with individual exposure (7 days) for MP excretion rate analysis and group exposure (14 days) for biomarker analysis. The daily excretion rate of MPs tended to decrease in a time-dependent manner. The copper concentration in the body was not significantly different between single and combined copper exposure. The degeneration of mucous cells in the skin, capillary dilation of the gill lamella, increased intestinal mucous, hepatocyte hypertrophy, and the degeneration of glomeruli and renal tubules were observed in all exposure groups. These histological alterations showed the highest tendency in the MPs^*Cu group. In this study, the changes in biomarkers were attributed to the single effect of copper or the combined effect of copper and MPs rather than being solely influenced by MPs.

• 대한전자공학회논문지
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• 제25권8호
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• pp.966-971
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• 1988

AES was used to study oxygen adsorption due to the oxygen exposure at 300\ulcorner temperature and segregation of impurities due to annealing on polycrystal copper surface. The intensity of peak of CuM2, 3VV and CuL3 VV increased with annealing time and the peak of CKLL increased after Ar ion bombardment. The effect of oxygen adsorption on copper surface at 300\ulcorner was verified by the decreased of peak of CuM2, 3VV and CuL3 VV as oxygen exposure increase. The binding energy of copper atoms gradualy shifts from 0.7eV to 1.5eV of copper atoms gradually shifts from 0.7eV to 1.5eV after a oxygen exposure. After the oxygen exposure, the width at half the height of CuM2, 3VV is larger 2V*C/S by the effect of chemical liaison of the copper aton with oxygen atom.

• 한국환경과학회지
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• 제26권9호
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• pp.1013-1021
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• 2017

Exposure to Diesel Particulate Matter (DPM) potentially causes adverse health effects (e.g. respiratory symptoms, lung cancer). Due to a lack of data on Elemental Carbon (EC) exposure levels in underground copper ore mining (unlike other underground mining industries such as non-metallic and coal mining), this case study aims to provide individual miners' EC exposure levels, and information on their work practices including use of personal protective equipment. EC measurement was carried out during different work activities (i.e. drilling, driving a loader, plant fitting, plant operation, driving a Specialized Mining Vehicle (SMV)) as per NIOSH Method 5040. The copper miners were working 10 h/day and 5 days/week. This study found that the most significant exposures to EC were reported from driving a loader (range $0.02-0.42mg/m^3$). Even though there were control systems (i.e. water tanks and DPM filters) on the diesel vehicles, around 49.5% of the results were over the adjusted recommendable exposure limit ($0.078mg/m^3$). This was probably due to: (1) driver's frequently getting in and out of the diesel vehicles and opening the windows of the diesel vehicles, and (2) inappropriate maintenance of the diesel vehicles and the DPM control systems. The use of the P2 type respirator provided was less than 19.2%. However, there was no significant difference between the day shift results and the night shift results. In order to prevent or minimize exposure to EC in the copper ore mine, it is recommended that the miners are educated in the need to wear the appropriate respirator provided during their work shifts, and to maintain the diesel engine and emission control systems on a regular basis. Consideration should be given to a specific examination of the diesel vehicles' air-conditioning filters and the air ventilation system to control excessive airborne contaminants in the underground copper mine.

• Environmental Analysis Health and Toxicology
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• 제24권2호
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• pp.107-117
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• 2009

Metal pollution of aquatic ecosystems is a problem of economic and health importance. Information regarding molecular responses to metal exposure is sorely needed in order to identify potential biomarkers. To determine the effects of heavy metals on chironomids, the full-length cDNA of alcohol dehydrogenase (ADH3) from Chironomus riparius was determined through molecular cloning and rapid amplification of cDNA ends (RACE). The expression of ADH3 was analyzed under various cadmium and copper concentrations. A comparative and phylogenetic study among different orders of insects and vertebrates was carried out through analysis of sequence databases. The complete cDNA sequence of the ADH3 gene was 1134 bp in length. The sequence of C. riparius ADH3 shows a low degree of amino acid identity (around 70%) with homologous sequences in other insects. After exposure of C. riparius to various concentrations of copper, ADH3 gene expression significantly decreased within 1 hour. The ADH3 gene expression was also suppressed in C. riparius after cadmium exposure for 24 hour. However, the effect of cadmium on ADH3 gene expression was transient in C. riparius. The results show that the suppression of ADH3 gene by copper exposure could be used as a possible biomarker in aquatic environmental monitoring and imply differential toxicity to copper and cadmium in C. riparius larvae.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 추계학술발표대회 논문집
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• pp.39-42
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• 2004

Carbon nanofiber/Cu composite powder has been fabricated by electroless plating process. Microstructural evolution of the composite powder after heat treatment under vacuum, hydrogen and air environment was investigated. A dispersed carbon nanofiber coated by copper was produced at the as-plated condition. Carbon nanofiber is coated uniformly and densely with the plate shaped copper particles. The copper plates on the carbon nanofiber aggregate during the thermal exposure at elevated temperature in vacuum and hydrogen in order to reduce surface energy. The thermal exposure of the composite powder in air at $400^{\circ}C$ for 3 hours leads to the spherodization of the composite powder owing to oxidation of copper.

• 콘크리트학회논문집
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• 제20권6호
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• pp.773-784
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• 2008

동의 제련과정에서 생성되는 동슬래그의 건설용 골재 활용이 국내에서도 2004년부터 가능하게 되었으나, 현재까지 장기적인 안정성 즉, 내구성에 대한 충분한 판단자료가 미흡하여 실용화를 저해하는 한 요인으로 작용하고 있다. 본 연구에서는 동슬래그를 천연모래 (잔골재)의 부분 치환재로 사용한 콘크리트의 내구적 특성을 18 MPa 및 27 MPa급 상용 콘크리트에 대해 촉진 및 폭로 실험을 수행하여 규명하고, 이를 통해 동슬래그 콘크리트의 실용화를 가속시키기 위한 토대를 마련하고자 하였다. 실험결과, 동슬래그 30% 치환조건에서는 대부분의 천연모래를 사용한 배합과의 내구특성 차이가 크지 않은 것으로 나타났으며, 부순모래를 사용한 경우는 대체로 50% 치환조건과 유사한 것으로 확인되었다. 특히 8년간 진행된 폭로실험 결과에서도 천연모래만을 사용한 경우와 대비하여 동등한 정도의 내구성을 확보함은 물론, 저품위인 18 MPa 콘크리트의 경우에도 피복두께 20 mm까지 중성화에 도달하는 수명을 50년 이상 확보할 수 있음을 알 수 있었다.

• Fisheries and Aquatic Sciences
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• 제17권3호
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• pp.345-353
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• 2014

Copper has been widely used to control algae and pathogens in fish culture ponds. However, its toxic effects on fish depend not only on its concentration in the water but also on the water quality. A laboratory experiment was conducted to assess copper toxicity in the black rockfish Sebastes schlegeli using a panel of antioxidant enzymes, including glutathione (GSH), glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione reductase (GR) and superoxide dismutase (SOD), at different levels of copper at three water temperatures (WT, 18, 23, $28^{\circ}C$) for 4 days. After exposure to two copper concentrations (100 and $200{\mu}g/L$), GSH levels and GST activities increased significantly, depending on WT (P < 0.05) in the liver, gill, and kidney of the black rockfish. GPx and SOD activities decreased significantly with both increasing WT and copper treatment in the organs of black rockfish (P < 0.05). These changes can be seen as initial responses to temperature stress and as a sustained response to copper exposure. This also indicates that GSH and related enzymes activities were sensitive indexes to stress by toxicants such as copper. The present findings suggest that simultaneous stress due to temperature change and copper exposure can accelerate changes in enzymes activities in the black rockfish. This provides another example of synergism between environmental temperature and pollutants, which may have important implications for the survival of fish in polluted environments during seasonal warming and/or global climate change.

• Asian-Australasian Journal of Animal Sciences
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• 제33권3호
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• pp.506-514
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• 2020

Objective: We tested the hypothesis that increasing dietary copper (Cu) to gravid ewes would enhance brown adipose tissue (BAT) thermogenesis in their offspring. Methods: Twin-bearing ewes were assigned on d 70 of gestation to diets containing 3, 10, or 20 ppm dietary Cu (n = 8 per group). Twin lambs were assigned at birth to a cold (6℃) or warm (28℃) environmental chamber for 48 h. Blood was collected from ewes and from lambs and perirenal BAT was collected after 48 h in the environmental chambers. Results: Prenatal Cu exposure increased ewe plasma triiodothyronine (T₃) and thyroxine concentration (T₄) (p<0.01) but prenatal Cu exposure had no effect on lamb plasma concentrations of T₃, T₄, glucose, or nonesterified fatty acid concentration (p≥0.08). The high level of prenatal Cu exposure depressed 48-h rectal temperature (p = 0.03). Cold exposure decreased BAT norepinephrine (NE) and increased BAT dopamine (p≤0.01), but prenatal Cu exposure had no effect on BAT cytochrome C oxidase activity or BAT NE or dopamine (p≥0.07). However, BAT of lambs from high-Cu ewes maintained higher uncoupling protein-1 (UCP1) gene expression than BAT of lambs from low- and medium-Cu ewes following warm or cold exposure in environmental chambers (p = 0.02). Cold exposure caused near depletion of BAT lipid by 48 h (p<0.001), increased BAT cytochrome c oxidase activity (p<0.01), and depressed plasma fatty acid concentrations (p<0.001). Conclusion: Although prenatal Cu exposure increased BAT UCP1 expression during warm and cold exposure, prenatal cold Cu exposure depressed 48-h rectal temperature. Cold exposure decreased BAT lipid content by over 80% and decreased lamb plasma fatty acid concentration by over 40%, indicating that fuel reserves for thermogenesis were nearly depleted by 48 h of cold exposure.

• Corrosion Science and Technology
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• 제7권2호
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• pp.99-111
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• 2008

Copper was exposed unsheltered and sheltered in four humid tropical sites, representing urban, urban-industrial, urban-marine and rural environments. The corrosion rates and the sequence of corrosion product formation are presented and discussed in relation with climatic and atmospheric pollution parameters. Chemical compositions of corrosion products were found to depend on environments and duration of exposure. In all environments, cuprite was the predominating corrosion product that formed first and continuously increased during the exposure. Among the sulphur-containing corrosion products, posnjakite and brochantite were more frequently found and the first formed earlier. Nantokite was the most common chlorine-containing products for most cases, except the high-chloride environment, where atacamite was detected instead. The corrosion rate of copper was well indicated by the colour of patina. The red-purple colour corresponded to the high corrosion rate and the greenish grey colour corresponded to the low corrosion rate. Corrosion rate of sheltered copper in urban-marine environment increased with the exposure time.

• 한국어병학회지
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• 제27권1호
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• pp.57-65
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• 2014

구리 ($CuSO_4$)는 양식현장에서 부착 및 병원생물 억제 용도로 광범위하게 사용되고 있으나, 구리의 독성은 그 물질의 농도뿐만 아니라 수온에 의해서도 영향을 받는다. 본 연구에서는 조피볼락, Sebastes schlegeli에서 수온변화 (18, 23 및 $28^{\circ}C$)에 따른 구리의 독성을 혈액 및 혈청학적 요소로 평가하였다. 4일 동안 구리 (100 및 $200{\mu}g/L$)에 노출 시킨 후, 조사한 적혈구 수와 hematocrit 수치는 $28^{\circ}C$에서 유의한 상승을 보였고, total protein 농도는 온도가 증가함에 따라 glucose 농도와 함께 증가하는 경향을 보였다 (P<0.05). 그러나, 혈청 Ca와 Mg은 수온변화와 무관하게, $200{\mu}g/L$ 구간에서 유의한 증가를 보였다. ALT와 LDH와 같은 혈청 효소농도도 구리를 처리한 구간에서만 유의한 상승을 보였다. 이 결과는 혈청 무기 성분과 효소활성이 구리 노출에 따른 민감한 지표가 될 수 있음을 시사한다. 구리 (100 및 $200{\mu}g/L$)에 노출된 조피볼락의 혈청 cortisol 수치는 농도 및 수온 증가에 따라 현저한 증가를 보였다. 즉, 이러한 변화는 수온 스트레스에 대한 초기 반응이 구리노출에 따라 지속되었음을 의미한다. 결론적으로, 구리에 단독으로 노출되었을 때보다 수온 상승이 동반되었을 때, 혈액 및 혈청 유기성분 및 cortisol의 변동이 더욱 가속된 것으로 보인다.