Search results for "CERAMICS"
showing 10 items of 1599 documents
Multielectron oxidation in a ferromagnetically coupled dinickel(ii) triple mesocate.
2015
Triple-stranded dinuclear nickel(ii) complexes of the meso-helicate type have been obtained from the new N,N'-1,3-phenylenebis(pyrazine-2-carboxamidate) ligand; they possess a multielectron redox behaviour featuring up to four stepwise, one-electron oxidation reactions of the two ferromagnetically coupled Ni(II) ions to afford the putative high-valent dinickel(iii) and dinickel(iv) species, as supported by theoretical calculations.
Multi-responsive copolymers: using thermo-, light- and redox stimuli as three independent inputs towards polymeric information processing
2011
We report on triple responsive polymers, exhibiting a distinct and reversible lower critical solution temperature in water that can be altered by light and redox stimuli, and we suggest their evaluation for molecular information processing.
Electrochromic polyoxometalate material as a sensor of bacterial activity
2015
L. fermentum, a bacterium of human microbiota, acts as an electron donor to the electrochromic [P2MoVI18O62]6. Since, the reductive capacity of L. fermentum correlates with its metabolic activity, the reaction with [P2MoVI18O62]6- affords a means of evaluating its activity. Following this logic, we have concluded that vancomycin severely affects the activity of L. fermentum whereas omeprazole does not.
Human endothelial cell-based assay for endotoxin as sensitive as the conventional Limulus Amebocyte Lysate assay
2014
AbstractEndotoxin, also known as lipopolysaccharide (LPS) produced by bacteria can be present in any liquid or on any biomaterial even if the material is sterile. Endotoxin in mammals can cause fever, inflammation, cell and tissue damage and irreversible septic shock and death. In the body, endothelial cells making up the blood vasculature and endothelial cells in vitro rapidly react to minute amounts of endotoxin resulting in a rapid induction of the cell adhesion molecule E-selectin. In this study we have used immunofluorescent staining to evaluate the expression of E-selectin on human microvascular endothelial cells from the skin (HDMEC) and human umbilical vein endothelial cells (HUVEC)…
Digital signal processing for relaxation data conversion
2005
Abstract The origins, philosophy and basic practical aspects are considered for an approach of digital data transformations for broadband dielectric relaxation spectroscopy and other relaxation experiments carrying out direct and inverse integral transforms with kernels depending on the ratio or product of arguments. The approach is based on the concept that the mentioned data transformations represent a filtering problem on a logarithmic scale allowing one to implement the transforms by digital functional filters with the logarithmic sampling. As an example, digital Kramers–Kronig transformers are considered.
Development of a long-lasting ventricular catheter impregnated with a combination of antibiotics.
2003
A ventricular silicone catheter impregnated with a combination of rifampin and a quinolone was developed in order to prevent ventricular shunt related infections. As model substance for the quinolones we used sparfloxacin, because of its specific physicochemical properties resulting in a quantitative detection also in the presence of a second antibiotic. In our study we focused especially on an optimization of the antibiotic release out of the impregnated catheters in order to develop long lasting devices with a broad antimicrobial spectrum. A release-optimized catheter was tested with an in vitro colonization test and additionally with a method developed to examine the spread of bacteria o…
Cubic and rhombohedral Ba4Lu3F17:Er3+ in transparent glass ceramics: Crystallization and upconversion luminescence
2018
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Upconversion luminescence of a transparent glass ceramics with hexagonal Na(Gd,Lu)F4 nanocrystals
2017
Novel Er3+ doped transparent glass ceramics containing hexagonal Na(Gd,Lu)F4 nanocrystals were prepared from oxyfluoride glasses. The distribution of rare earth ions in the crystalline and glassy phase has been analyzed by X-ray diffraction and erbium luminescence decay kinetics measurement. A strong deviation of rare earth ion content in fluoride nanocrystals in comparison to the base glass has been observed. Preferential incorporation of Gd3+ over Lu3+ ions in the fluoride lattice leads to the stabilization of hexagonal Na(Gd,Lu)F4 structure and prevents the formation of cubic fluorite type solid solutions. A considerable enhancement of upconversion luminescence correlates with the format…
Electron paramagnetic resonance and photoluminescence investigation of europium local structure in oxyfluoride glass ceramics containing SrF2 nanocry…
2017
Different compositions of europium doped aluminosilicate oxyfluoride glass ceramics prepared in air atmosphere have been studied by electron paramagnetic resonance (EPR) and optical spectroscopy methods. X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements show presence of homogenously distributed SrF2 nanocrystals after the heat treatment of the precursor glass. Efficient Eu3+ incorporation in the high symmetry environment of glass ceramics is observed from the photoluminescence spectra. EPR spectra indicate Eu3+ → Eu2+ reduction upon precipitation of crystalline phases in the glass matrix. For composition abundant with Eu2+ in the glassy state such behaviour is …
Protein mapping of calcium carbonate biominerals by immunogold
2007
The construction of metazoan calcium carbonate skeletons is finely regulated by a proteinaceous extracellular matrix, which remains embedded within the exoskeleton. In spite of numerous biochemical studies, the precise localization of skeletal proteins has remained for a long time as an elusive goal. In this paper, we describe a technique for visualizing shell matrix proteins on the surface of calcium carbonate crystals or within the biominerals. The technique is as follows: freshly broken pieces of biominerals or NaOCl then EDTA-etched polished surfaces are incubated with an antibody elicited against one matrix protein, then with a secondary gold-coupled antibody. After silver enhancement,…