Search results for "ZINC"

Prediction of structural and thermodynamic properties of zinc-blende AlN: molecular dynamics simulation

2004

Abstract Structural and elastic properties of AlN are investigated by using a molecular dynamics simulation based on the Tersoff empirical interatomic potential. Both of zinc-blende and rock-salt structures are discussed. The calculated bulk properties and elastic constants agree well with the available experimental and theoretical data. The Thermodynamic properties in zinc-blende structure are also predicted including the Debye temperature, melting temperature, heat capacity, linear thermal coefficient. This study is helpful to understand the bahviour of physical properties of AlN when the temperature varies.

Corrigendum to “Zinc oxide nanoparticles mediated cytotoxicity, mitochondrial membrane potential and level of antioxidants in presence of melatonin” …

2021

Electrochemical and spectroscopic characterization of cobalt and zinc diaza‐18‐crown‐6 porphyrins and of a zinc dioxocyclam porphyrin

2000

The synthesis and electrochemical characterization of ‘crowned’ and ‘dioxocyclam’ metalloporphyrins containing Co(II) or Zn(II) metal ions is presented. Each complex is also characterized by mass spectrometry in addition to a variety of spectroscopic techniques (UV-vis, FTIR, ESR (in the case of Co(II)) and 1H and 13CNMR spectroscopy).

Effects of Metal-Organic Chemical Vapour Deposition grown seed layer on the fabrication of well aligned ZnO nanorods by Chemical Bath Deposition

2011

Well aligned, long and uniform ZnO nanorods have been reproducibly fabricated adopting a two-steps Metal-Organic Chemical Vapour Deposition (MOCVD) and Chemical Bath Deposition (CBD) fabrication approaches. Thin (<100 nm) ZnO buffer layers have been seeded on silicon substrates by MOCVD and ZnO layers have been subsequently grown, in form of well textured nanorods, using CBD. It has been found that the structure and thickness of the seed layer strongly influence the final morphology and the crystal texturing of ZnO nanorods as well as the CBD growth rate. There is, in addition, a strong correlation between morphologies of CBD grown ZnO nanorods and those of the seed layer underneath. Thus, …

Proenzyme Structure and Activation of Astacin Metallopeptidase

2010

Proteolysis is regulated by inactive (latent) zymogens, with a prosegment preventing access of substrates to the active-site cleft of the enzyme. How latency is maintained often depends on the catalytic mechanism of the protease. For example, in several families of the metzincin metallopeptidases, a >cysteine switch> mechanism involves a conserved prosegment motif with a cysteine residue that coordinates the catalytic zinc ion. Another family of metzincins, the astacins, do not possess a cysteine switch, so latency is maintained by other means. We have solved the high resolution crystal structure of proastacin from the European crayfish, Astacus astacus. Its prosegment is the shortest struc…

Facile formation of a meso–meso linked porphyrin dimer catalyzed by a manganese(iv)–oxo porphyrin

2011

A manganese(IV)-oxo porphyrin catalyzes C-C bond formation between zinc porphyrins at the meso-position with a two-electron oxidant to afford the meso-meso linked porphyrin dimer efficiently. The meso-meso linked dimer is formed via formation of the porphyrin radical cation, and the rate-determining step in the catalytic cycle is the formation of a manganese(IV)-oxo porphyrin with a two-electron oxidant.

Singlet and triplet energy transfer rate acceleration by additions of clusters in supramolecular pigment-organometallic cluster assemblies

2011

Both S(1) and T(1) energy transfer rates (porphyrin → cluster) increase from mono- to di- to tetracarboxylate[tetraphenyl-(zinc)porphyrin] adducts with [Pd(3)(dppm)(3)(CO)](2+) clusters.

Functional and structural insights into astacin metallopeptidases

2012

The astacins are a family of multi-domain metallopeptidases with manifold functions in metabolism. They are either secreted or membrane-anchored and are regulated by being synthesized as inactive zymogens and also by colocalizing protein inhibitors. The distinct family members consist of N-terminal signal peptides and pro-segments, zincdependent catalytic domains, further downstream extracellular domains, transmembrane anchors, and cytosolic domains. The catalytic domains of four astacins and the zymogen of one of these have been structurally characterized and shown to comprise compact ~200-residue zinc-dependent moieties divided into an N-terminal and a C-terminal sub-domain by an active-s…

Characterization of two Lactococcus lactis zinc membrane proteins, Llmg_0524 and Llmg_0526, and role of Llmg_0524 in cell wall integrity

2015

Background Due to its extraordinary chemical properties, the cysteine amino acid residue is often involved in protein folding, electron driving, sensing stress, and binding metals such as iron or zinc. Lactococcus lactis, a Gram-positive bacterium, houses around one hundred cysteine-rich proteins (with the CX2C motif) in the cytoplasm, but only a few in the membrane. Results In order to understand the role played by this motif we focused our work on two membrane proteins of unknown function: Llmg_0524 and Llmg_0526. Each of these proteins has two CX2C motifs separated by ten amino-acid residues (CX2CX10CX2C). Together with a short intervening gene (llmg_0525), the genes of these two protein…

Zinc oxide and indium tin oxide thin films for the growth and characterization ofShewanella loihicaPV-4 electroactive biofilms

2011

Transition metal oxides (TMO) electrodes provide a suitable platform for spectroscopy- and microscopy-based investigation of viable electroactive biofilms (EABs). Commercially available TMOs, such as indium titanium oxide (ITO), are produced from rare and expensive elements. Thus, there is a significant need to explore alternative technology to meet the demand. ZnO-based TMOs are low-cost and have excellent electrochemical properties. In this study, we report for the first time a model EAB of Shewanella loihica PV-4 on ZnO films deposited on perspex substrates via pulsed laser deposition (PLD). Commercially available ITO electrodes were also used for comparison. 480 Virulence Volume 2 Issue…