Search results for "Optical"
showing 10 items of 7671 documents
Mid-infrared supercontinuum generation in chalcogenide and telluride fibers for sensor devices
2019
This thesis reports on the progress made during my PhD concerning supercontinuum generation and its application in two types of materials: chalcogenide and tellurite glasses. Concerning the chalcogenide axis, two new arsenic-free compositions are developed: Ge20Se60Te20 and Ge20Se70Te10. Thermal and optical properties of these two glasses are studied and two types of fibers are manufactured: a step-index fiber and a suspended core fiber. The generation of supercontinuum in these two fibres, pumped by an optical parametric amplifier, gives competitive results compared to the current state of the art of supercontinuum generation in chalcogenide fibres. Supercontinuums widening between 2 and 1…
Manganese carbonyl terpyridyl complexes: their synthesis, characterization and potential application as CO-release molecules
2014
MnI carbonyl terpyridyl complexes have been synthesized and characterized. The tricarbonyl derivative exhibits interesting behaviors for controlled CO-release by both thermal and photosynthetic pathways.
Reversible switching of the electronic ground state in a pentacoordinated Cu(ii) complex.
2013
International audience; An easy reversible switching of the electronic ground state in a pentacoordinated copper(ii) complex is reported for the first time. The simple protonation of a carboxylic group in a Cu(ii) complex with a {dx(2)-y(2)}(1) electronic configuration leads to a flip of the ground electronic configuration from {dx(2)-y(2)}(1) to {dz(2)}(1) in the metal ion.
<title>A portable device for optical assessment of the cardiovascular condition</title>
2003
A hand-held prototype device for detection and processing of the tissue-remitted optical signals has been developed and tested. The photoplethysmography (PPG) principle was applied to follow the dilation and contraction of skin blood vessels during the cardiac cycle. Cardiovascular condition of the monitored person was assessed by temporal analysis of the recorded PPG signals as well as by shape analysis of the mean single-period PPG signals.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Nondestructive fluorescence-based quantification of threose-induced collagen cross-linking in bovine articular cartilage.
2012
Extensive collagen cross-linking affects the mechanical competence of articular cartilage: it can make the cartilage stiffer and more brittle. The concentrations of the best known cross-links, pyridinoline and pentosidine, can be accurately determined by destructive high-performance liquid chromatography (HPLC). We explore a nondestructive evaluation of cross-linking by using the intrinsic fluorescence of the intact cartilage. Articular cartilage samples from bovine knee joints were incubated in threose solution for 40 and 100 h to increase the collagen cross-linking. Control samples without threose were also prepared. Excitation-emission matrices at wavelengths of 220 to 950 nm were acquir…
Stereoselective construction of the tetracyclic scalarane skeleton from carvone
1999
The tetracyclic scalarane skeleton 22 has been constructed from (S)-(+)-carvone using two intramolecular Diels–Alder reactions as key synthetic steps. Abad Somovilla, Antonio, Antonio.Abad@uv.es ; Agullo Blanes, M Consuelo, Consuelo.Agullo@uv.es ; Cuñat Romero, Ana Carmen, Ana.Cunat@uv.es ; Llosa Blasco, Maria Carmen, Carmen.Llosa@uv.es
Surface-plasmon hopping along coupled coplanar cavities
2007
International audience; We report on surface-plasmon propagation along coupled coplanar cavities periodically distributed in an otherwise unperturbed plasmonic crystal. We show that the dispersion of particular Bloch modes can exhibit multiple energy gaps that can be adjusted by choosing the cavity size. For resonant sizes, the composite crystals composed of juxtaposed cavities can support plasmon modes at frequencies within the gap of the unperturbed grating. In this case, we demonstrate that the surface-plasmon propagation relies on a hopping mechanism.
Discovery of new G-quadruplex binding chemotypes
2013
We report here on the discovery and preliminary evaluation of a novel non-macrocyclic low molecular weight quadruplex-stabilizing chemotype. The lead compounds, based on a furan core, show high G-quadruplex stabilisation and selectivity as well as potent in vitro anti-proliferative activity.
Polyketides from the marine-derived fungus Aspergillus falconensis: In silico and in vitro cytotoxicity studies.
2020
Abstract Fermentation of the marine-derived fungus Aspergillus falconensis, isolated from sediment collected from the Red Sea, Egypt on solid rice medium containing 3.5% NaCl yielded a new dibenzoxepin derivative (1) and a new natural isocoumarin (2) along with six known compounds (3–8). Changes in the metabolic profile of the fungus were induced by replacing NaCl with 3.5% (NH4)2SO4 that resulted in the accumulation of three further known compounds (9–11), which were not detected when the fungus was cultivated in the presence of NaCl. The structures of the new compounds were elucidated by HRESIMS and 1D/2D NMR as well as by comparison with the literature. Molecular docking was conducted fo…
Electrokinetic Properties which Control the Coagulation of Silicate Cement Suspensions during Early Age Hydration
1998
The coagulation of cement particles during early age hydration has been previously identified as the first step of the setting and hardening of cement pastes. By hydrating Ca3SiO5and a silicate-rich clinker under controlled conditions, a correlation between the coagulation of the suspensions and the electrokinetic properties of particles is established. The zeta potential, and hence the surface charge, of particles in suspension depends on the calcium content of the medium. At low concentrations of Ca2+, the zeta potential of Ca3SiO5particles, calcium silicate hydrate (C–S–H), and clinker is negative (<−30 mV) and the suspensions are well dispersed. A strong coagulation occurs at intermedia…