objective: corrosion resistance is among the most important properties of metal alloys used in the oral cavity. consumption of acidic foods reduces the salivary ph and intensifies the corrosion of brackets and orthodontic wires. this study aimed to compare electro galvanic corrosion of different orthodontic brackets and wires and determine the amount of ions released into acidic artificial sali...

The iron-dependent regulator (IdeR) protein in Mycobacterium tuberculosis, and its better characterized homologue, the diphtheria toxin repressor (DtxR) from Corynebacterium diphtheriae, are iron-dependent regulatory proteins that control gene expression in response to iron availability in bacteria. IdeR regulates several genes required for iron uptake and storage including those involved in th...

Divalent metal ions play a crucial role in catalysis by many RNA and protein enzymes that carry out phosphoryl transfer reactions, and defining their interactions with substrates is critical for understanding the mechanism of biological phosphoryl transfer. Although a vast amount of structural work has identified metal ions bound at the active site of many phosphoryl transfer enzymes, the numbe...

Phosphatidylcholine vesicles harboring the lipophilic metal ion carrier A23187 in the bilayer and encapsulating ethylenediamine tetraacetic acid (EDTA) exhibit broadly varied, pH-dependent affinity for Cu2+, Pb2+, Cd2+, and Ca2+ at micromolar levels. Initial rates of uptake by these metal-sorbing vesicles (MSVs) is strongly dependent on the metal ion affinity of A23187 and the dissociation rate...

Carbonic anhydrase contains one firmly bound zinc ion per enzyme molecule (1). The metal ion, which can be dissociated in the presence of a chelating agent, is essential for catalytic activity, and it has been suggested that it is a part of the active site (2). Some other divalent metal ions also activate the metal-free enzyme. For example, Co2+ gives 45oj, of the activity of the native enzyme ...

mn(tpp)cl catalyzes cooxidation of olefin in the singlet oxygenation of sulfid. mn(tpp)cl is able to transfer an oxygen atom from a peroxidic intermediate generated in singlet oxygenation of sulfide to a metal ion affording metal 0x0 species which is responsible for epoxidation. this system leads to allcenes epoxidation such as styrene and cyclooctene. epoxidation of cyclohexene produces cycloh...

Immobilized metal-ion affinity (IMA) adsorption is a collective term that is used to include all kinds of adsorptions where the metal ion serves as the characteristic and most essential part of adsorption center. Of all the IMA techniques, immobilized metal-affinity chromato graphy (IMAC) has been gaining popularity as the choice of purification technique for proteins. IMAC represents a separat...

STANDARD METAL-ON-METAL TOTAL HIP REPLACEMENT *Moroni A, **Savarino L, *Cadossi M, **Greco M, **Baldini N, *Giannini S * Rizzoli Orthopaedic Institute, Bologna, Italy **Laboratory for Pathophysiology of Orthopaedic Implants, Rizzoli Orthopaedic Institute, Bologna, Italy [email protected] INTRODUCTION Modern metal-on-metal (MOM) hip resurfacing has been introduced as a less invasive method of join...

Many dsDNA viruses encode DNA-packaging terminases, each containing a nuclease domain that resolves concatemeric DNA into genome-length units. Terminase nucleases resemble the RNase H-superfamily nucleotidyltransferases in folds, and share a two-metal-ion catalytic mechanism. Here we show that residue K428 of a bacteriophage terminase gp2 nuclease domain mediates binding of the metal cofactor M...

The present investigation was undertaken to evaluate the adsorption effectiveness of pecan shell-based granular activated carbons (GACs) in removing metal ions (Cu(2+), Pb(2+), Zn(2+)) commonly found in municipal and industrial wastewater. Pecan shells were activated by phosphoric acid, steam or carbon dioxide activation methods. Metal ion adsorption of shell-based GACs was compared to the meta...