OBJECTIVE A study with human volunteers was conducted to ascertain whether a low intake of copper (Cu) would exacerbate the response to a deficient intake of magnesium (Mg). METHODS Nineteen postmenopausal women, age 47 to 78 y, completed a metabolic unit study as designed. For 162 d, nine women were fed a diet containing 1.0 mg of Cu/2000 kcal and 10 women were fed 3.0 mg of Cu/2000 kcal. Di...

Resting tryosinase was diamagnetic between 1.4 K and 200 K. Redox titration showed that it, but not apotyrosinase, contained a titrable group, E’, = $0.36 volt (pH 7.0), R = 2. Upon denaturation with acid under strictly anaerobic conditions, the EPR-detectable copper increased from less than 5 % of the copper present to about 100%. It is concluded that the active site of the enzyme contains a p...

Superconformal electrodeposition is explained based on a local growth velocity that increases with coverage of a catalytic species adsorbed on the copper-electrolyte interface. For dilute concentration of the catalyst precursor in the electrolyte, local coverage in fine features changes more due to interface area change than by accumulation from the electrolyte, yielding superconformal growth. ...

The redeposition of sputtered material on the target in a Grimm-type glow-discharge lamp was studied by means of an ion microprobe mass analyser (IMMA) using 1602+ ions as bombarding species. The target was an aluminium disc with a cylindrical copper insertion, one mm in diameter. The lamp was operated at currents of 50 mA and 100 mA and a voltage of 1200 V. It is estimated that 17% of the copp...

In the manufacture of printed circuit boards, the copper dissolved during etching can be used to replace the copper needed for plating using a liquid ion-exchange agent. Extraction and stripping studies demonstrated the feasibility. The quality of the etchant was not affected by the presence of the ion-exchange agent. Good-quality deposits were plated from the stripping solution with a current ...

Sea-water samples collected by a variety of clean sampling techniques yielded consistent results for copper, cadmium, zinc, and nickel, which implies that representative, uncontaminated samples were obtained. A dithiocarbamate extraction method coupled with atomic absorption spectrometry and electro,thermal atomization is described which is essentially 100% quantitative for each of the four met...

in order to study the effect of different levels of nitrogen and copper on yield and nutrients concentrations and nitrate in broccoli head, an experiment was conducted based on a factorial combinations of five levels of nitrogen (0, 100, 200, 300 and 400 kg/ha) and three levels of copper (0, 2.5 and 5 kg/ha) that were applied to soil as ammonium sulfate and copper sulfate respectively, in three...

The purpose of this work was to evaluate differences in dose resulting from the use of copper aperture inserts compared to lead-alloy (Cerrobend) aperture inserts for electron beam therapy. Specifically, this study examines if copper aperture inserts can be used clinically with the same commissioning data measured using lead-alloy aperture inserts. The copper inserts were acquired from .decimal...

Lobsters were fed cadmium-rich oysters for 28 days, and the induction of cadmium metallothionein and its relation to concentrations of cadmium, copper, and zinc in the digestive gland and gills was determined. A portion of the tissues also was retained for determining the cytosolic distribution of these metals by gel filtration and ion-exchange chromatography. The digestive gland contained a ma...

The structure and microhardness of Cu-Ta joints produced by explosive welding were studied. It was found that, during explosive welding, an intermediate layer 20⋯40  μ m thick with a finely dispersed heterophase structure, formed between the welded copper and tantalum plates. The structure of the layer was studied by scanning and transmission electron microscopy. Microvolumes with tantalum part...