• Environmental Analysis Health and Toxicology
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• v.19 no.2
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• pp.191-200
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• 2004

Zinc (Zn) is an essential element in biological process, however inadequate Zn status in general population have been recognized. To update the knowledge for Zn-cadmium (Cd) interaction, we studied the intestinal uptake and transport, and the expression of metal transporter proteins (divalent metal transporter 1, DMT1 ; metal transporter protein 1, MTP1 ; zinc transporter 1, ZnTl ; metallothionein 1 , MT1) in duodenum after Cd exposure using Zn deficient animal model. Rats were led Zn deficient (ZnD, 0.5-1.0 mgZn/kg) or Zn supplemented (ZnS, 50mg Zn/kg) diet for 4 weeks, and followed single administration of $^{109}$ CdCl$_2$orally. The body Zn flatus and tissue Cd concentration were determined at 24 hrs after Cd administration. Total body burden of Cd and Cd absorption index (AI, %) were estimated based on the tissue Cd analyzed. DMT1, MTP1, ZnTl and MT1 mRNA were analyzed by using RT-PCR method. Feeding of Zn deficient diet for 4 weeks produced a reduced body weight gain and a depletion of body Zn. Tissue Cd concentration, body burden of Cd and Cd absorption index were higher in the ZnD diet fed rats than the ZnS diet red rats. Especially, Cd concentration in the small intestine (duodenum, jejunum and ileum) and the colon of FeD diet fed rats were higher markedly than in the FeS diet group. The expression levels of DMT1, MTP1 and ZnT1 mRNA in FeD diet fed rats were similar to the FeS diet. The level of MT1 mRNA expression was significantly lower in the FeD than the FeS diet fed rats. Taken together, theses results indicate that Zn deficiency in diet induce an increased intestinal absorption and tissue retention of Cd, and down -regulate the MT1 expression in the intestine which might be play a part of role in Cd absorption and transport in mammalian. These findings suggest that deficiency of essential metal could be enhanced the toxicity of toxic, non-esstial metals through the metal-metal interaction.

• ALGAE
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• v.26 no.3
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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.

• Journal of the Korean Vacuum Society
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• v.7 no.3
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• pp.201-207
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• 1998

We have investigated about interface characteristics between ZnO thin films and metal electrodes when ZnO and metal electrodes were fabricated as piezoelectric vibrators. At this, ZnO thin films were deposited by rf reactive magnetron sputtering method. After fabricating piezoelectric vibrator of Cr/ZnO/Cr structure with optimum condition, we analyse interface characteristics between ZnO thin films and metal electrodes by I-V measurement. AES depth profile, SEM and C-V measurement. From these measurements we found that ZnO piezoelectric vibrators showed good property when they fabricated as Cr/$SiO_2$/ZnO/Cr structure. And we could confirm these things by driving, and measuring vibration displacement of piezoelectric vibrator with $SiO_2$diffusion barrier.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.813-816
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• 2002

We investigate the junction between CdZnTe and a variety of metals with the aim of determining whether the choice of metal can improve the performance of X-ray image detectors, in particular minimizing the dark current. The samples consist of $5{\mu}m$ thick CdZnTe with top electrodes formed from In, Al, and Au. For each metal, current transients following application of valtages from -10V to 10V are measured for up to 1 hour. We find that dark currents depending on the metal used. The current is controlled by hole injection at the metal-CdZnTe junction and there is consistent trend with the metal's work function possibly and it seems that metal to CdZnTe layer junction is ohmic contact.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.4
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• pp.422-425
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• 2004

In this study, the AZO thin films were prepared as a function of oxygen gas flow ratio at room temperature by FTS(Facing Targets Sputtering) apparatus using Zn:Al(metal)-Zn:Al(metal) or Zn(metal)-ZnO:Al(ceramic). The film thickness, crystalline and electric properties of AZO thin film was evaluated by $\alpha$-step, XRD and 4-point probe. In the results, the resistivity of AZO thin film was shown the lowest value about 8${\times}$10$^{-2}$ $\Omega$-cm(Zn:Al-Zn:Al), 3${\times}$10$^{-1}$ $\Omega$-cm(Zn-ZnO:Al) at the oxygen gas flow ratio 0.3. And the AZO thin film has good crystalline at oxygen gas flow ration 0.4, using Zn:Al-Zn:Al targets.

• Journal of the Korea Institute of Building Construction
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• v.14 no.6
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• pp.505-513
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• 2014

The purpose of this study is to evaluate the corrosion protective properties of a Zn-Sn metal spray method according to the contents of Zn and Sn by a CASS test and the electrochemical theory. In the experiment, the CASS test and the electrochemical test were conducted to investigate the corrosion protective property of the Zn-Sn Metal Spray system, the Zinc galvanizing system, and the heavy duty coating system. As a result, it was confirmed that the Zn-Sn (65:35) Metal Spray system had very high corrosion protective property through the electrochemical characteristic as comparison with the other anti-corrosion systems and was very effective to prevent steel products from corrosion.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.4
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• pp.155-159
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• 2008

In this work, we report synthesis of free-standing ZnO/Zn core-shell micro-polyhedrons using metal Zn pellets as a source material by the thermal chemical vapor deposition process. Scanning and transmission electron microscopy measurements were introduced to investigate morphologies and structural properties of as-grown ZnO/Zn core-shell micro-polyhedrons. It was found that micro-polyhedrons were composed of inner single-crystalline metal Zn surrounded by single-crystalline ZnO nanorod arrays. The inner single crystalline metal Zn with micro-scale diameter has a hexagonal crystal structure. Diameter and height of ZnO nanorods covering the metal Zn surface are below 10 nm and 100 nm, respectively. It was also confirmed that c-axis oriented ZnO nanorods are single crystalline with a hexagonal crystal structure.

• Journal of Pharmaceutical Investigation
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• v.36 no.6
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• pp.371-375
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• 2006

Neomycin coupled to a polymer matrix via a metal linker was prepared and evaluated for prolonging antibacterial activity. Microcrystallized cellulose was chemically modified to cellulose xanthate(MCX) to afford metal binding sites. MCX was treated with Cu(II), Fe(III) or Zn(II) followed by reaction with neomycin (Ne). The release of Ne from MCX-Zn(II)-Ne was investigated and its activity duration was measured by ditch plate method. The amount of metal bound to MCX was 0.36 mmol/g matrix, 0.26 mmol/g matrix and 0.56 mmol/g matrix for Cu(II), Zn(II) and Fe(III), respectively. Ne bound to MCX-metal chelates was 0.006 mmol, 0.07 mmol and 0.01 mmol per g MCX for Cu(II), Zn(II) and Fe(III), respectively. The Ne release from MCX-Zn(II)-Ne was sustained even after seven washes, whereas Ne from MC/Zn(II)/Ne mixture was almost completely released in two washes. Antibacterial activity was prolonged with MCX-Zn(II)-Ne and MCX-Fe(III)-Ne, but not with MCX-Cu(II)-Ne when compared with that of free Ne. Taken together, these results suggest that neomycin coupled to MCX via a proper metal linker has a potential as a polymeric antibacterial agent with sustained activity.

• Journal of Fashion Business
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• v.4 no.1
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• pp.25-32
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• 2000

The purpose of this study was to suggest the knowlege and scientific information of the damage according to the heavy metal exposure level of hair coloring manipulations. The study was investigated variations of the heavy metal contents(Pb, Zn, Cu, Mn, Fe, Ni) in hairdye and human hairs by 1 and 2 times of hair coloring manipulations. The results were as follows; 1. Mean heavy metal contents in colorant of hairdye were 0.250ppm(Pb), 33.650ppm(Zn), 0.800ppm(Cu), 0.675ppm(Mn), 31.050ppm(Fe), 1.700ppm(Ni). In oxidant of hairdye, It were 0.225ppm(Pb), 35.450ppm(Zn), 0.575ppm(Cu), 0.075ppm(Mn), 16.600ppm(Fe), 1.500ppm(Ni). 2. Mean heavy metal contents were 2.950ppm(Pb), 29.000ppm(Zn), 9.400ppm(Cu), 1.075ppm(Mn), 40.775ppm(Fe), 1.950ppm(Ni) in virgin hairs, 3.025ppm(Pb), 40.250ppm(Zn), 9.650ppm(Cu), 1.350ppm(Mn), 42.900ppm(Fe), 2.200ppm(Ni) in 1 time of coloring hairs, 3.350ppm(Pb), 51.650ppm(Zn), 10.950ppm(Cu), 1.475ppm(Mn), 44.350ppm(Fe), 2.225ppm(Ni) in 2 times of coloring hairs.

• Journal of Environmental Science International
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• v.11 no.7
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• pp.729-735
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• 2002

In order to examine the inhibition effect of other heavy metal ions on the removal of heavy metal ions by crab shell in aqueous solution, 10 heavy metal ions $(Cr^{3+},\;Cd^{2+},\;Ni^{2+},\;Zn^{2+},\;Hg^{2+},\;Cu^{2+},\;Mn^{2+],\;Fe^{2+},\;Fe^{3+},\;Pb^{2+})$ were used as single heavy metal ions and mixed heavy metal ions, respectively. In single heavy metal ions, $Pb^{2+},\;Cr^{3+},\;Cu^{2+}$ were well removed by crab shell, however, $Cd^{2+},\;Ni^{2+},\;Zn^{2+},\;Mn^{2+}$ were not. The heavy metal removal increased as the increase of covalent index (Xm$^2$r), and the relationship classified heavy metal ions as 2 heavy metal groups $(Fe^{3+},\;Fe^{2+},\;Cu^{2+},\; Cr^{3+},\;Mn^{2+},\;Ni^{2+},\;Zn^{2+}\;group\;and\;Pb^{2+},\;Hg^{2+},\;Cd^{2+}\;group)$. In mixed heavy metal ions, the removals of $Fe^{2+},\;Fe^{3+},\;Pb^{2+},\;Cu^{2+}$ as 0.49 m㏖/g, regardless of the existence of other heavy metal ions, were similar to the result of single heavy metal ions experiment. The removals of $Mn^{2+},\;Cd^{2+},\;Ni^{2+}$ decreased as the existence of other heavy metal ions, however, the removal of $Zn^{2+},\;Cr^{3+},\;Hg^{2+}$ increased.