نتایج جستجو برای: heavy metal ions
تعداد نتایج: 412588 فیلتر نتایج به سال:
The interaction between some heavy metal ions such as of Pb(II), Cd(II) and Cu(II) ions from aqueous solution adsorbed by single walled carbon nanotube (SWCNTs) and carboxylate group functionalized single walled carbon nanotube (SWCNT-COOH) surfaces were studied by atomic absorption spectroscopy. The effect of contact time, pH, initial concentration of ion, ionic strength and temperature on the...
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...
To study the extent of removal of Cu(II) ions from the electroplating industrial effluent, metal resistant fungal strain of Penicillium janthinellum was selected for the present study. Response surface methodology was used to optimize the sorption process variables i.e. temperature (20-40 oC), biomass concentration (0.5-2.5 mg/l), pH (2.0-6.0) and initial concentration of metal ions (20-100 mg/...
In this study, we have carried out a characterization of the quenching effect produced by some commonly encountered metal ions (Co2+, Cu2+, Ni2+, Pb2+, Cd2+, As5+) on the photoluminescence of water suspensions of open-cage fullerene quantum dots prepared with a modified Hummers method. The response to heavy-metal ions occurs through a selective quenching of the PL emission and modifications of ...
A method to functionalize single-walled carbon nanotubes (SWNTs) in a field-effect transistor (FET) device for the selective detection of heavy-metal ions is presented. In this method, peptide-modified polymers were electrochemically deposited onto SWNTs and the selective detection of metal ions was demonstrated by choosing appropriate peptide sequences. The signal transduction mechanism of the...
The SmtB/ArsR family of prokaryotic metalloregulatory transcriptional repressors represses the expression of operons linked to stress-inducing concentrations of di- and multivalent heavy metal ions. Derepression results from direct binding of metal ions by these homodimeric "metal sensor" proteins. An evolutionary analysis, coupled with comparative structural and spectroscopic studies of six Sm...
The increasing occurrence of hospital-acquired infections and the emerging problems posed by antibiotic-resistant microbial strains have both contributed to the escalating cost of treatment. The presence of infection at the wound site can potentially stall the healing process at the inflammatory stage, leading to the development of a chronic wound. Traditional wound treatment regimes can no lon...
Heavy-metal ions and organic mercurials are known to have a pronounced inhibitory action on many enzymes (see Dixon & Webb, 1958). It is generally accepted that these reagents are reactive towards sulphydryl groups (see Gurd & Wilcox, 1956; Cecil & McPhee, 1959; Boyer, 1959) and also towards other groups (Sohler, Seibert, Kreke & Cook, 1952; Myrback, 1957). A detailed investigation of the effec...
This study presents a fluorescence-based microbial sensor for the detection of metal ions as a novel analytical tool for environmental applications. Our results demonstrate the effectiveness of whole-cell sensors in the selective detection of gold ions. Two heavy-metal-tolerant proteobacteria, Cupriavidus metallidurans and Ralstonia eutropha, were examined and showed great specificity. This wor...
Metal ions are essential for growth, but in excess, these compounds can become highly toxic. Both plants and animals have adapted numerous ways to maintain metal homeostasis while mitigating detrimental effects of excess metals ions, including the metalchelating proteins metallothionein (MT) and phytochelatin. Although phytochelatins have been shown to play an important role in the detoxificati...
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