A method for the simultaneous spectrophotometric determination of cadmium, copper and zinc based on the formation of their complexes with 1,5-bis(di-2-pyridylmethylene)thiocarbonohydrazide is proposed. The absorption curves of these complexes overlap severely in the scanning range 380-480 nm. The analyte concentrations are calculated by a least squares fit of the pure spectra to the mixture spe...

For this paper, a fully integrated and highly miniaturized electrochemical sensor was designed and fabricated on a silicon substrate. A solvothermal-assisted reduced graphene oxide named "TRGO" was then successfully micro-patterned using a lithography technique, followed by the electrodeposition of bismuth (Bi) on the surface of the micro-patterned TRGO for the electrochemical detection of heav...

The penicillinase plasmids, a series of extrachromosomal resistance factors in Staphylococcus aureus, were found to carry determinants of resistance to a series of inorganic ions as well as resistance to penicillin and, in some cases, erythromycin. Most of the ions involved were inhibitory but not lethal to the bacteria; the resistance markers conferred an increase in resistance by comparison w...

Methyl parathion hydrolase (MPH, E.C.3.1.8.1), isolated from the soil-dwelling bacterium Pseudomonas sp. WBC-3, is a Zn(II)-containing enzyme that catalyzes the degradation of the organophosphate pesticide methyl parathion. We have determined the structure of MPH from Pseudomonas sp. WBC-3 to 2.4 angstroms resolution. The enzyme is dimeric and each subunit contains a mixed hybrid binuclear zinc...

In this study, the ability of adsorbing Cd2+ ions of Plesiomonas shigelloides was discovered. Herein, the method and mechanisms of adsorbing Cd2+ ions from aqueous solutions is discussed. The cadmium-resistant bacterium was collected from the sediment of Harbin section of the Songhua River in China, and then isolated, identified and characterized. The isolated strain was identified as Plesiomon...

The effects of cadmium administered via ambient water or food on plasma ions of the Af­ rican freshwater cichlid Oreochromis mossambicus were studied for 2, 4, 14, and 35 days, in low cal­ cium (0.2 mM) and high calcium (0.8 mM) water. In low calcium water, an environmentally relevant concentration of 10 fig/L water-borne cadmium in­ duced a significant and dramatic hypocalcemia on days 2 and 4...

Although heavy metal ions are known to be toxic to the central nervous system (CNS), the mechanisms by which the CNS may protect itself from initial challenges of such toxic ions is unknown. The choroid plexus is the principal site of formation of the cerebrospinal fluid (CSF) which bathes the brain. We have determined in rats and rabbits that after intraperitoneal administration of lead, cadmi...

The application of batch injection analysis to the determination of trace metals in samples of volume s 100 ~1 by square wave anodic stripping voltammetry has been investigated in detail, using a programmable electronic micropipette. The in situ formation of a mercury film on a glassy carbon electrode substrate, the influence of preconcentration time, injection rate and injected volume of analy...