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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Effect of ethanol and low dietary copper on perinatal and postweanling copper utilization in the rat

Baek, Jong Ho 01 November 1988 (has links)
The hypotheses of this research were (1) to test if the antagonistic effect of ethanol on liver copper could be seen within a short period when ethanol ingestion, low dietary copper and high metabolic demand represented by either pregnancy plus lactation or rapid growth are simultaneously present and (2) to test if ethanol ingestion would exaggerate a marginal dietary copper status to an obvious copper deficiency. Pregnant rats were fed liquid diets containing either 0.75 (low) or 3.75 (control) mg copper/L with or without 30% of kcal from ethanol throughout gestation and the first 15 days of lactation. Maternal ethanol intake failed to exaggerate a marginal copper status to a copper deficient anemia in both dams and pups as estimated by concentrations of hemoglobin and liver iron and oxidase activity of the copper-metalloenzyme ceruloplasmin. However, maternal ethanol intake did depress maternal liver copper concentration when diet copper was low (interactive effect P<0.05). This effect was specific for liver because other tissue copper concentration was unaffected by ethanol. Although ethanol depressed total pup liver copper concentration regardless of dietary copper level, the interactive effect seen in maternal liver was reflected in copper content of the pup liver metallothionein fraction eluted from a Sephadex G-75 column. At least part of the depressive effect of ethanol on pup liver copper can be explained by elevated pup serum corticosterone (r=-0.61, P<0.001), a hormone known to enhance loss of neonatal liver copper by way of biliary excretion. On the other hand, the copper status of weanling female rats which were fed liquid diets containing either 0.5 (low) or 2.5 (control) mg copper/L for 5 weeks was unaffected by ethanol. Results demonstrate that the depressive effect of ethanol on liver copper can be seen within a period of weeks rather than months when ethanol ingestion, low dietary copper and pregnancy plus lactation are simultaneously present in contrast to non-pregnancy. This ethanol and copper interaction during reproduction, however, can not be detected if only either serum copper or oxidase activity of ceruloplasmin is used as an indicator of copper status. / Graduation date: 1989
2

The assessment of copper and zinc removal from highway stormwater runoff using Apatite II™

Huang, Hsiao-Wen 31 May 2012 (has links)
Copper and zinc are heavy metals commonly present in highway stormwater runoff. Discharge of these metals to surface waters inhabited by sensitive aquatic species including threatened and endangered salmonids has necessitated the need for improved treatment techniques. Although copper is of the greater toxicological concern, zinc is often present at concentrations several times higher than copper and may compete with copper during adsorptive treatment processes. In the current study, the ability biogenic fish-bone based alternative adsorbent, Apatite II™, for copper and zinc removal from synthetic stormwater runoff was evaluated. Batch experiments were employed to examine equilibrium removal and rapid small scale column tests (RSSCT) were used to simulate dynamic operation in continuous systems. In both batch and continuous systems, the release of phosphate and calcium were observed, and Apatite II™ achieved high removal efficiencies. The removal of copper and zinc was likely due to a combination of processes including adsorption, ion exchange and precipitation. Precipitation played a dominant role in copper removal and the release of phosphate and pH buffering appear to drive this process. While precipitation was also quite important for zinc removal, adsorptive removal also played a role. The findings from the current study provide a general understanding of the performance of copper and zinc removal from stormwater runoff using Apatite II™. / Graduation date: 2012

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