Search results for " gold"
showing 10 items of 278 documents
Intrecci preziosi Arti Decorative Siciliane a Malta 1565-1798
2016
Il volume indaga opere e artisti siciliani quasi totalmente inediti attivi sull'Isola dei Cavalieri nel periodo compreso tra il 1565, anno della fondazione di La Valletta, e il 1798, allorché Malta fu conquistata da Napoleone Bonaparte. Interessanti figure di orafi e argentieri emerse da un’approfondita ricerca archivistica, e superbi manufatti quali argenti, coralli, alabastri, avori e ceroplastiche parte di collezioni pubbliche e private maltesi vengono studiati in relazione al più ampio contesto riguardante gli scambi artistici e culturali tra le due isole del Mediterraneo. The book deals with Sicilian artifacts and artists almost entirely unpublished active on the Island of Knights in t…
Interaction of Gold with Co-Condensed and Grafted HMS-SH Silica: A 29Si {1H} CP-MAS NMR Spectroscopy, XRD, XPS and Au LIII EXAFS Study
2010
Hexagonal mesoporous silica (HMS) is functionalised with mercaptopropyl groups by adopting two different procedures ; co-condensation and grafting. In both cases tetraethylorthosilicate (TEOS) and 3-mercaptopropyltriethoxysilane (3-MPTES) are used as the silicon and sulfur precursors, respectively. The obtained materials are analysed by several techniques such as N 2 sorption, TG-DTA, XRD, SAXS and-solid state 29 Si { 1 H} CP-MAS NMR spectroscopy. By taking advantage of the chemical interaction between gold and the -SH groups, the effect of the thiol addition procedure on the supporting capability of the functionalised silica is evaluated by depositing gold through the incipient wet impregn…
Reactivity of antitumor coinage metal-based N-heterocyclic carbene complexes with cysteine and selenocysteine protein sites
2021
Abstract The reaction of the antitumor M(I)-bis-N-heterocyclic carbene (M(I)-NHC) complexes, M = Cu, Ag, and Au, with their potential protein binding sites, i.e. cysteine and selenocysteine, was investigated by means of density functional theory approaches. Capped cysteine and selenocysteine were employed to better model the corresponding residues environment within peptide structures. By assuming the neutral or deprotonated form of the side chains of these amino acids and by considering the possible assistance of an external proton donor such as an adjacent acidic residue or the acidic component of the surrounding buffer environment, we devised five possible routes leading to the binding o…
Bioprospective of Sorbus aucuparia leaf extract in development of silver and gold nanocolloids
2010
At the present time the bioprospective field is a dynamic area of research. The rapid biosynthesis of silver and gold nanoparticles without using toxic chemicals is reported here. Sorbus aucuparia is omnipresent in Europe. The aqueous leaves extract of the plant were used as reducing agent for the synthesis of silver and gold nanoparticles from their salt solutions. The synthesized nanoparticles were spherical, triangular and hexagonal in shape with an average size of 16 and 18nm for silver and gold, respectively. Different extract quantities, metal concentrations, temperatures and contact times were investigated to find their effect on nanoparticles synthesis. The resulting silver and gold…
Protocol for development of various plants leaves extract in single-pot synthesis of metal nanoparticles
2012
This article is aimed to extend a simple protocol for preparation of various plant leaves extract and their application to green synthesis of the metallic nanoparticles. Five plant leaves extract showed mild reduction and stabilization ability for silver and gold nanoparticles (AgNPs and AuNPs) at room temperature. The particle size range varied from 25 to 42 nm and 21 to 47 nm for AgNPs and AuNPs, respectively. Plant leaves extract-mediated nanoparticles were characterized to confirm the shape, size, crystallinity, and content using different spectroscopic investigations. Differences in stability of nanoparticles at different pH were also measured by zeta potential.
Enhanced catalytic electrochemical reduction of dissolved oxygen with ultracleancucurbituril[7]-capped gold nanoparticles
2014
Gold nanoparticles capped with cucurbituril[7] have been prepared in the absence of metallic cations and organic ligands. Remarkably, these nanohybrids encapsulate dissolved oxygen and are highly active in electrochemical reduction. The effect of the presence of sodium and ammonium salts on this catalysed process is also analysed.
Isolation of human milk whey proteins by solid phase extraction with a polymeric material modified with gold nanoparticles
2017
Abstract This work describes a method for the isolation of human milk whey proteins by solid-phase extraction (SPE) with a polymeric material modified with gold nanoparticles. Human serum albumin, α-lactalbumin, lactoferrin and lysozyme were selected as target proteins to establish the performance of SPE support. Several experimental variables (pH and ionic strength) that affect the SPE protocol were investigated to achieve the maximum extraction efficiency. Under optimal conditions, the SPE sorbent gave excellent recoveries, and offered a high permeability and reusability (> 20 times). The feasibility of this methodology was successfully demonstrated by isolating the target proteins in a m…
Solid-phase extraction based on ground methacrylate monolith modified with gold nanoparticles for isolation of proteins
2015
In this study, a novel polymeric material functionalized with gold nanoparticles (AuNPs) was prepared as solid-phase extraction (SPE) sorbent for isolation of proteins. The sorbent was synthesized from a powdered poly(glycidyl-co-ethylene dimethacrylate) monolith, and modified with ammonia, followed by immobilization of AuNPs on the pore surface of the material. To evaluate the performance of this SPE support, proteins were selected as test solutes, being the extraction conditions and other parameters (loading capacity and regenerative ability of sorbent) established. The results indicated that this sorbent could be employed to selectively capture proteins according to their pI, on the basi…
CCDC 1892914: Experimental Crystal Structure Determination
2019
Related Article: Rosa Adam, Marta Mon, Rossella Greco, Lucas H. G. Kalinke, Alejandro Vidal-Moya, Antonio Fernandez, Richard E. P. Winpenny, Antonio Dom��nech-Carb��, Antonio Leyva-P��rez, Donatella Armentano, Emilio Pardo, Jes��s Ferrando-Soria|2019|J.Am.Chem.Soc.|141|10350|doi:10.1021/jacs.9b03914
GFP immunogold staining, from light to electron microscopy, in mammalian cells.
2012
GFP has emerged as an important reporter for monitoring gene expression, protein localization, cell transformation and cell lineage. The development of GFP as a marker in many different biological systems has emphasized the need to image GFP at high resolution. GFP immunogold labeling with colloidal gold particles becomes essential for electron microscopy (EM) ultrastructural detection. Because of the small size, colloidal gold particles require silver enhancement, a procedure to increase the size of the particle as well as gold toning to stabilize the silver layer. GFP preembedding immunogold staining enables high quality cellular-ultrastructural EM analysis mainly for two reasons, on one …