• 환경생물
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• 제30권2호
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• pp.128-135
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• 2012

본 연구는 말똥성게(Hemicentrotus pulcherrimus)의 생식세포 및 pluteus 유생을 이용하여 중금속인 납(lead, Pb)과 아연(zinc, Zn)의 독성을 조사였다. H. pulcherrimus 배우자 및 배아에 미치는 Pb과 Zn의 독성은 각각 31, 63, 125, 250, 500 ppb 및 16, 31, 63, 125, 250 ppb의 농도에서 조사하였다. 0.5 M KCl 용액을 이용하여 방란 및 방정을 유도하였고, 수정률 및 정상 배아발생률의 조사는 수정 후 각각 10분 및 64시간째 관찰하여 시행하였다. Pb 노출 시 수정률은 대조군과 비교하여 유의적인 변화가 없었다. 그러나 정상 배아발생률은 농도가 높을수록 농도의존적으로 유의적인 감소를 보였다. Zn을 노출시켰을 경우 수정률과 정상 배아발생률은 농도가 높을수록 농도의존적인 유의적 감소를 나타냈다. H. pulcherrimus의 정상 배아 발생에 대한 독성치는 각각 Pb (반수 영향농도 ($EC_{50}$) 45.13 ppb, 95% Cl 40.12~50.05 ppb), Zn (반수영향농도 ($EC_{50}$) 19.82 ppb, 95% Cl 18.26~21.31 ppb)로 나타났다. 또한 Pb과 Zn의 무영향농도(NOEC)는 각각 <31.25 ppb 및 <15.63 ppb로 나타났고, 최소영향농도(LOEC)는 31.25 및 15.63 ppb로 나타났다. 본 연구 결과, H. pulcherrimus의 초기 배아발생 과정은 Pb과 Zn 등의 중금속에 높은 민감성을 보인다. 따라서 H. pulcherrimus는 해양생태계 위해 평가를 위한 시험생물로서 사용이 가능하다고 사료된다.

• 마이크로전자및패키징학회지
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• 제30권3호
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• pp.56-63
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• 2023

본 연구에서는 졸-겔 IGZO(Indium-Gallium-Zinc Oxide) 박막을 만들고 이에 전자빔을 조사 한 후 박막 트랜지스터로 제작하여 전자빔 조사가 박막 트랜지스터의 전기적 특성에 미치는 영향을 비교 분석하였다. 특히 전자빔이 조사되는 환경을 대기 중과 질소 분위기(<200 ppm O₂)로 두고 전자빔 조사 선량 세기를 100kGy와 200kGy로 각각 조사한 후 350℃ 온도에서의 열처리만 진행한 비교군과 비교 분석을 진행하였다. 전자빔 조사에 따른 졸-겔 IGZO 박막의 물성 변화를 분석하기 위해 UV-Visible spectroscopy, X-ray diffraction(XRD)와 X-ray photoelectron spectroscopy(XPS)를 분석 결과, 전자빔 조사 전·후의 모든 조건 하에서 가시광 영역에서의 80% 이상의 높은 투과도를 보여줌을 확인할 수 있었고, XRD 분석 결과를 통해 전자빔 조사와 관계없이 비정질 특성을 유지함을 확인하였다. 특히 전자빔 조사에 따라 졸-겔 IGZO 박막에 화학적 조성 변화가 있음을 확인하였는데, 질소 분위기에서 전자빔을 조사하게 되면 M-O결합과 관련된 peak이 차지하는 비율이 높아짐을 확인할 수 있었다. 질소 분위기에서 전자빔이 조사된 TFT들은 on/off 비율, 전자 이동도에서 향상된 특성을 보여주었으며, 시간에 따라 트랜지스터의 특성들(on/off 비율, 문턱전압, 전자이동도, 하위임계값 스윙)의 수치 또한 큰 변화 없이 유지됨이 확인되어, 졸-겔 공정 TFT 제작에 있어서 질소 분위기에서의 전자빔 조사공정이 IGZO기반 박막 트랜지스터의 전기적특성의 개선에 기여할 수 있을 것으로 기대된다.

• 한국환경보건학회지
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• 제20권2호
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• pp.64-72
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• 1994

Tolerance to toxic effects of cadmium (Cd), including lethality has been shown following pretreatment with cadmium and zinc. This study was designed to determine if tolerance also develops to Cd-induced hepatotoxicity and renal toxicity. Three groups of rats (A, B, C), each consisting of 108 rats, were studied and each group was divided into three subgroups (1, 2, 3), 12 rats for each subgroup. Rats were subcutaneously pretreated with saline (A), CdCl$_2$ (0.5 mg/kg, B), and ZnCl$_2$ (13.0 mg/kg, C) during time periods of 5 days. At the end of the period, rats were challenged with CdCIa (3.0 and 6.0 mg/kg) by intraperitoneal injection. As for the cadmium levels in rat tissues after pretreatments, it was highest in the liver. Then kidney, heart, blood and muscle followed it in that order. After 24, 48 and 96 hours of intraperitoneal injection by challenge doses the concentration of cadmium in liver and kidney increased proportionally to the increase of challenge dosage. However metallothioneins in liver and kidney were increased by the pretreatment of cadmium and zinc. These data indicate the liver is a major target organ of acute Cd poisoning, and suggest that cadmium induced hepatic injury, via release of Cd-MT, may play and important role in the nephrotoxicity observed in response to short-term exposure to cadmium. This result suggests that increasing cadmium concentrations, gradually accumulating in liver and kidney as the result of the pretteatmerit, served to induced the synthesis of metallothionein, thus making them resistant to the challenge from cadmium.

• ALGAE
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• 제26권3호
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• pp.265-275
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• 2011

This study examined the bioaccumulation of the heavy metals copper (Cu) and zinc (Zn) by the giant kelp, Macrocystis pyrifera, by exposing meristematic kelp tissue to elevated metal concentrations in seawater within laboratory aquaria. Specifically, we carried out two different experiments. The first examined metal uptake under a single, ecologically-relevant elevation of each metal (30 ppb Cu and 100 ppb Zn), and the second examined the relationships between varying levels of the metals (i.e., 15, 39, 60, 120, 240, and 480 ppb Cu, and 50, 100, 200, 300, 500, and 600 ppb Zn). Both experiments were designed to contrast the uptake of the metals in isolation (i.e., when only one metal concentration was elevated) and in combination (i.e., when both metals' concentrations were elevated). Following three days of exposure to the elevated metal concentrations, we collected and analyzed the M. pyrifera tissues using inductively coupled plasma atomic emissions spectroscopy. Our results indicated that M. pyrifera bioaccumulated Cu in all treatments where Cu concentrations in the seawater were elevated, regardless of whether Zn concentrations were also elevated. Similarly, M. pyrifera bioaccumulated Zn in treatments where seawater Zn concentrations were elevated, but this occurred only when we increased Zn alone, and not when we simultaneously increased Cu concentrations. This suggests that elevated Cu concentrations inhibit Zn uptake, but not vice versa. Following this, our second experiment examined the relationships among varying seawater Cu and Zn concentrations and their bioaccumulation by M. pyrifera. Here, our results indicated that, as their concentrations in the seawater rise, Cu and Zn uptake by M. pyrifera tissue also rises. As with the first experiment, the presence of elevated Zn in the water did not appear to affect Cu uptake at any concentration examined. However, although it was not statistically significant, we observed that the presence of elevated Cu in seawater appeared to trend toward inhibiting Zn uptake, especially at higher levels of the metals. This study suggests that M. pyrifera may be useful as a bio-indicator species for monitoring heavy metal pollution in coastal environments.

• The Korean Journal of Physiology and Pharmacology
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• 제14권2호
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• pp.91-97
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• 2010

Epidermal keratinocytes overgrow in response to ultraviolet-B (UVB), which may be associated with skin photoaging and cancer development. Recently, we found that HIF-$1{\alpha}$ controls the keratinocyte cell cycle and thereby contributes to epidermal homeostasis. A further study demonstrated that HIF-$1{\alpha}$ is down-regulated by UVB and that this process is involved in UVB-induce skin hyperplasia. Therefore, we hypothesized that the forced expression of HIF-$1{\alpha}$ in keratinocytes would prevent UVB-induced keratinocyte overgrowth. Among several agents known to induce HIF-$1{\alpha}$, pyrithione-zinc (Py-Zn) overcame the UVB suppression of HIF-$1{\alpha}$ in cultured keratinocytes. Mechanistically, Py-Zn blocked the degradation of HIF-$1{\alpha}$ protein in keratinocytes, while it did not affect the synthesis of HIF-$1{\alpha}$. Moreover, the p21 cell cycle inhibitor was down-regulated after UVB exposure, but was robustly induced by Py-Zn. In mice repeatedly irradiated with UVB, the epidermis became hyperplastic and HIF-$1{\alpha}$ disappeared from nuclei of epidermal keratinocytes. However, a cream containing Py-Zn effectively prevented the skin thickening and up-regulated HIF-$1{\alpha}$ to the normal level. These results suggest that Py-Zn is a potential agent to prevent UVB-induced photoaging and skin cancer development. This work also provides insight into a molecular target for treatment of UVB-induced skin diseases.

• 한국해양공학회지
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• 제24권5호
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• pp.60-66
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• 2010

Zinc has a number of characteristics that make it well suited for use as a coating to protecting iron and steel products from corrosion. Its excellent corrosion resistance in most environments accounts for its successful use as a protective coating on a variety of products and in many exposure conditions. The excellent field performance of zinc coatings results from their ability to form dense, adherent films that corrode at a rate that ranges from 1% to 10% of the corrosion rate of ferrous materials, depending on the environment. Recently, EU RoHS and EU ELV prohibited the use of materials that adversely affect the environment, such as Pb, Hg, Cd, and $Cr^{+6}$. In this study, environmentally-friendly, Cr-free solutions (epoxy solution, acrylic solution, and urethane solution S-700) and organic/inorganic solution with Si; LRO-317) were used to evaluate the corrosion resistance of zinc-coated steel subjected to a saltwater spray for 72 hours. The coating of urethane solution (S-700) was best among the three kinds of solution with heat treatment during five minutes at $190^{\circ}F$. Test specimens with S-700 and LRO-317 coating were heat treated in a drying oven at 170, 180, 190, 200, and $210^{\circ}C$ for five minutes. The results show that the optimum corrosion resistance was $190^{\circ}C$ in EGI and $170^{\circ}C$ in HDGI, respectively.

• Journal of Preventive Medicine and Public Health
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• 제28권2호
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• pp.421-432
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• 1995

The influence of lead exposure on renal function was studied. Eighty nine lead exposed workers who worked in 2 storage battery factories, and seventy one control workers were chosen for this study. Blood lead(PbB) and zinc protoporphyrin in whole blood(ZPP) were selected as indicators of lead exposure. As indicators of renal function, urinary N-acetyl-$\beta$-D-glucosaminidase(NAG), blood urea nitrogen(BUN), serum creatinine(S-Cr), total protein in urine(U-TP),and serum uric acid(S-Ua) were selected. The results obtained were as follows: 1. While the mean values of lead exposure indicators of lead workers were significantly different from non-exposed ones, the mean values of NAG, U-TP, BUN and S-Cr of renal function indicators of exposed were also significantly different from non-exposed but their mean values were all within normal limits. 2. BUN, logarithmic U-TP, logarithmic NAG and S-Cr showed statistically significant correlation with PbB. 3. The proportion of workers whose values of renal function indicators were over the normal limits(NAG7.5 U/g Cr ; U-TP10.9 mg/dl ; BUN20 mg/dl ; S-Crl.2 mg/dl ; S-Ua7.0 mg/dl) by the level of lead absorption in terms of PbB and ZPP were calculated. The proportion of workers with over the normal limits of U-TP among total workers showed the dose-response relationship. When age is adjusted, U-TP showed significantly strong dose-response relationship with the level of PbB and ZPP.

• Toxicological Research
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• 제31권4호
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• pp.347-354
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• 2015

Excess manganese (Mn) is neurotoxic. Increased manganese stores in the brain are associated with a number of behavioral problems, including motor dysfunction, memory loss and psychiatric disorders. We previously showed that the transport and neurotoxicity of manganese after intranasal instillation of the metal are altered in Hfe-deficient mice, a mouse model of the iron overload disorder hereditary hemochromatosis (HH). However, it is not fully understood whether loss of Hfe function modifies Mn neurotoxicity after ingestion. To investigate the role of Hfe in oral Mn toxicity, we exposed Hfe-knockout ($Hfe^{-/-}$) and their control wild-type ($Hfe^{+/+}$) mice to $MnCl_2$ in drinking water (5 mg/mL) for 5 weeks. Motor coordination and spatial memory capacity were determined by the rotarod test and the Barnes maze test, respectively. Brain and liver metal levels were analyzed by inductively coupled plasma mass spectrometry. Compared with the water-drinking group, mice drinking Mn significantly increased Mn concentrations in the liver and brain of both genotypes. Mn exposure decreased iron levels in the liver, but not in the brain. Neither Mn nor Hfe deficiency altered tissue concentrations of copper or zinc. The rotarod test showed that Mn exposure decreased motor skills in $Hfe^{+/+}$ mice, but not in $Hfe^{-/-}$ mice (p = 0.023). In the Barns maze test, latency to find the target hole was not altered in Mn-exposed $Hfe^{+/+}$ compared with water-drinking $Hfe^{+/+}$ mice. However, Mn-exposed $Hfe^{-/-}$ mice spent more time to find the target hole than Mn-drinking $Hfe^{+/+}$ mice (p = 0.028). These data indicate that loss of Hfe function impairs spatial memory upon Mn exposure in drinking water. Our results suggest that individuals with hemochromatosis could be more vulnerable to memory deficits induced by Mn ingestion from our environment. The pathophysiological role of HFE in manganese neurotoxicity should be carefully examined in patients with HFE-associated hemochromatosis and other iron overload disorders.

• Asian-Australasian Journal of Animal Sciences
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• 제33권12호
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• pp.1940-1947
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• 2020

Objective: Combination of two stressors on alteration of mineral footprints in animals needs due attention to meet maximum production and welfare, particularly in grazing sheep. This study tested whether ewes (Ovis aries) exposed to water deprivation and thermal-humidity stressors had altered mineral footprints in their wool, serum, urine, and feces. Methods: Nine ewes (age = 3 years; mean body weight = 41±3.5 kg) were divided among a control group with free access to water, and treatment groups with water deprivation lasting either 2 h (2hWD) or 3 h (3hWD) after feeding. Using a 3×3 Latin square design, animals were assigned to treatment groups for three sampling periods of 21 days each (n = 9). Blood was collected by jugular venipuncture. Wool was collected at the end of periods 2 and 3. Metabolic crates designed with metal grated floors were used for urine and feces collection. We measured sodium (Na), magnesium (Mg), phosphorus (P), chloride (Cl), calcium (Ca), manganese (Mn), copper (Cu), iron (Fe), and zinc (Zn). Results: The wool mineral levels did not differ between the treatment groups, although K was marginally lower (p = 0.10) in the 2hWD group. The serum and urine mineral levels did not differ between the treatments (p>0.05). Fecal K was significantly lower in the 2hWD group than in the other groups (p≤0.05). Conclusion: In conclusion, water deprivation and thermal-humidity exposure altered the excretion of K, but not of other minerals, in the wool, urine, feces, or serum of ewes. Thus, no additional mineral supplementation is needed for water deprived ewes during thermalhumidity exposure.

• 생태와환경
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• 제53권2호
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• pp.165-172
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• 2020

중금속은 다양한 경로를 통해 환경 중 배출되어 서식 생물에 노출되며 체내 다양한 생리학적 불균형을 유도한다. 본 연구에서는 수서생물지표종으로 이용되는 깔따구(Chironomus riparius)를 이용하여 야외 중금속(Al, Aluminum; Cr, Chromium; Cu, copper; Mn, Manganese; Zn, Zinc) 농도 노출에 따른 다양한 분자발현 반응과 상관성을 분석하였다. 생물 체내 분자 반응을 관찰하기 위해 heat shock protein 40, 70, 90 (HSP40, 70, 90), cytochrome 450(CYP450), Glutathione S-transferase (GST) and Serine-type endopeptidase (SP)를 이용하였다. 그 결과, 스트레스 분자마커로 이용되는 HSPs 유전자들은 중금속 노출된 개체들에서 대조군보다 높은 경향을 보였으며 Cu 노출 시 가장 높은 발현을 나타냈다. 해독에 관여하는 CYP450과 GST 유전자 발현 결과, Cr과 Cu에서는 다른 노출군에 비해 높은 발현 경향을 나타냈다. SP 유전자 발현 결과 Al을 제외한 모든 노출군이 대조군과 유사한 발현 패턴을 보였다. 이와 같은 연구 결과는 실내에서 환경 중 존재하는 실제 농도를 반영한 독성실험을 통해 노출물질과 농도에 따라 특이적으로 발현하는 분자마커 패턴을 보고하였다. 또한, 수생태계로 유입되는 중금속이 하천에 서식하는 생물에 주는 유해 영향에 대한 정보와 분자 지표 유전자들의 현장 적용 가능성을 보여준다.