Search results for " light"
showing 10 items of 1141 documents
Size characterisation of Au nanoparticles by ICP-MS coupling techniques
2006
In modern nanotechnology the properties of nanoparticles (NPs) in different application fields is mainly dependent on their size and their size distribution. This paper aims to develop a reliable method for the size characterisation of Au NPs. Basing on the combination of two different separation techniques (liquid chromatography and gel electrophoresis), coupled on-line to inductively coupled plasma-mass spectrometry (ICP-MS), we study the separation of Au NP standards. Separations by liquid chromatography show size dependent retention behaviour with good reproducibility (RSD < 1%). The results are compared with complementary methods like dynamic light scattering (DLS) and transmission ele…
Structural stability and properties of three isoforms of the major light-harvesting chlorophyll a/b complexes of photosystem II.
2008
AbstractThree isoforms of the major light-harvesting chlorophyll (Chl) a/b complexs of photosystem II (LHCIIb) in the pea, namely, Lhcb1, Lhcb2, and Lhcb3, were obtained by overexpression of apoprotein in Escherichia coli and by successfully refolding these isoforms with thylakoid pigments in vitro. The sequences of the protein, pigment stoichiometries, spectroscopic characteristics, thermo- and photostabilities of different isoforms were analysed. Comparison of their spectroscopic properties and structural stabilities revealed that Lhcb3 differed strongly from Lhcb1 and Lhcb2 in both respects. It showed the lowest Qy transition energy, with its reddest absorption about 2 nm red-shifted, an…
Determining the efficiency of optical sources using a smartphone's ambient light sensor
2017
This work reports the use of a smartphone’s ambient light sensor as a valuable tool to study and characterize the efficiency of an optical source. Here, we have measured both luminous efficacy and efficiency of several optical sources (incandescent bulb and halogen lamp) as a function of the electric power consumed and the distance to the optical detector. The illuminance of LEDs as a function of the distance to the optical detector is characterized for different wavelength emissions. Analysis of the results confirms an inverse-square law of the illuminance with the detector–source distance and shows good agreement with values obtained by classical experiments. This experience will trigger …
Interphase FISH assays for the detection of translocations with breakpoints in immunoglobulin light chain loci
2002
Many B-cell malignancies bear chromosomal translocations juxtaposing immunoglobulin (IG) genes with oncogenes, resulting in deregulated expression of the latter. Translocations affecting the IG heavy chain (IGH) locus in chromosomal region 14q32 are most prevalent. However, variant translocations involving the IG kappa (IGK) locus in 2p12 or the IG lambda (IGL) locus in 22q11 occur recurrently in B-cell neoplasias. No routine methods for the detection of all breakpoints involving IG light chain loci independently of the translocation partner have been described. For this reason, we have designed 2 novel interphase fluorescence in situ hybridization (FISH) assays using differentially labeled…
Nuit(s) et Territoire(s) : pratiques nocturnes, sciences sociales diurnes ?
2014
National audience
Spatial analysis of the relationship between mortality from cardiovascular and cerebrovascular disease and drinking water hardness
2004
Journal Article; Research Support, Non-U.S. Gov't; Reproduced with permission from Environmental Health Perspectives. Previously published scientific papers have reported a negative correlation between drinking water hardness and cardiovascular mortality. Some ecologic and case-control studies suggest the protective effect of calcium and magnesium concentration in drinking water. In this article we present an analysis of this protective relationship in 538 municipalities of Comunidad Valenciana (Spain) from 1991-1998. We used the Spanish version of the Rapid Inquiry Facility (RIF) developed under the European Environment and Health Information System (EUROHEIS) research project. The strateg…
Deciphering metal-induced oxidative damages on glycated albumin structure and function
2014
Background: Metal ions such as copper or zinc are involved in the development of neurodegenerative pathologies and metabolic diseases such as diabetes mellitus. Albumin structure and functions are impaired following metal-and glucose-mediated oxidative alterations. The aim of this study was to elucidate effects of Cu(II) and Zn(II) ions on glucose-induced modifications in albumin by focusing on glycation, aggregation, oxidation and functional aspects. Methods: Aggregation and conformational changes in albumin were monitored by spectroscopy, fluorescence and microscopy techniques. Biochemical assays such as carbonyl, thiol groups, albumin-bound Cu, fructosamine and amine group measurements w…
Evaluation of multifunctional liposomes in human blood serum by light scattering.
2014
To overcome the limited functionality of "stealth" lipids based on linear poly(ethylene glycol) (PEG) chains, hyperbranched polyether-based lipids that bear multiple hydroxyl groups for further chemical modification may be a suitable replacement. This study focuses on the development and characterization of "stealth" liposomes modified with a novel hyperbranched polyglycerol lipid (cholesterol-PEG30-hbPG23). An emphasis was placed on the stability of these liposomes in comparison to those containing a linear PEG derivative (cholesterol-PEG44) directly in human blood serum, characterized via dynamic light scattering (DLS). Polymer lipid contents were varied between 0 and 30 mol %, resulting …
Primary Plasma Cell Leukemia Associated with Adult Fanconi Syndrome
2006
Abstract Primary plasma cell leukemia (PCL) is a rare variant of multiple myeloma that occurs de novo in patients without a history of plasma cell disorder. We describe a case of λ PCL that showed a prolonged survival of 2 years and 6 months associated with a generalized dysfunction of the proximal renal tubule. On presentation, the patient had anemia (hemoglobin level, 11 g/dL), thrombocytopenia (platelet count, 102,000/μL), and renal insufficiency (creatinine level, 2.75 mg/dL; creatinine clearance, 19 mL per minute; urea, 71 mg/dL). In addition to the common clinical picture, our case showed proteinuria (30 mg/dL), glycosuria (150 mg/dL) with normal glycemia, low uric acid concentration …
Preparation and cytotoxic properties of goethite-based nanoparticles covered with decyldimethyl(dimethylaminoethoxy) silane methiodide
2010
The present work describes the synthesis, physico-chemical and biological properties of the first water-soluble goethite nanoparticles covered with biologically active components: oleic acid and cytotoxic decyldimethyl(dimethylaminoethoxy)silane methiodide. The structure of initial goethite nanoparticles synthesized was proved by XRD analysis and the rough estimation of nanoparticles core size gave the value of 8 nm. The size of colloidal water-soluble nanoparticles, determined by dynamic light scattering, was within 19–35 nm. Magnetic properties and cytotoxicity (against HT-1080 and MG-22A tumor cell lines) of the nanoparticles obtained were investigated. Copyright © 2009 John Wiley & Sons…