Search results for "Spectrum analysis"
showing 10 items of 287 documents
Bishistidyl heme hexacoordination, a key structural property in Drosophila melanogaster hemoglobin
2005
Hemoglobins at high concentration have been isolated long ago from some insect larvae living in hypoxic environments. Conversely, a monomeric hemoglobin has been discovered recently in the fruit fly Drosophila melanogaster as intracellular protein expressed both in larvae and in the adult fly. Such a finding indicates that the oxygen supply in insects may be more complex than previously thought, relying not only on O2 diffusion through the tubular tracheal system, but also on carrier-mediated transport and storage. We present here the crystal structure of recombinant D. melanogaster hemoglobin at 1.20 A resolution. Spectroscopic data show that the protein displays a hexacoordinated heme, wh…
The skeleton of the staghorn coral Acropora millepora: molecular and structural characterization.
2014
15 pages; International audience; The scleractinian coral Acropora millepora is one of the most studied species from the Great Barrier Reef. This species has been used to understand evolutionary, immune and developmental processes in cnidarians. It has also been subject of several ecological studies in order to elucidate reef responses to environmental changes such as temperature rise and ocean acidification (OA). In these contexts, several nucleic acid resources were made available. When combined to a recent proteomic analysis of the coral skeletal organic matrix (SOM), they enabled the identification of several skeletal matrix proteins, making A. millepora into an emerging model for biomi…
Impact of T-cell-mediated immune response on xenogeneic heart valve transplantation: short-term success and mid-term failure.
2017
Objectives Allogeneic frozen cryopreserved heart valves (allografts or homografts) are commonly used in clinical practice. A major obstacle for their application is the limited availability in particular for paediatrics. Allogeneic large animal studies revealed that alternative ice-free cryopreservation (IFC) results in better matrix preservation and reduced immunogenicity. The objective of this study was to evaluate xenogeneic (porcine) compared with allogeneic (ovine) IFC heart valves in a large animal study. Methods IFC xenografts and allografts were transplanted in 12 juvenile merino sheep for 1-12 weeks. Immunohistochemistry, ex vivo computed tomography scans and transforming growth fa…
Surface-Enhanced Raman Study of the Interactions between Tripodal Cationic Polyamines and Polynucleotides
2011
Raman and surface-enhanced Raman spectra of new DNA/RNA-binding compounds consisting of three imidazole (Im) and three pyridine (Py) rings connected by tripodal polyaminomethylene linkages were obtained by the near-infrared excitation at 1064 nm. Study of interactions of Im and Py polyamines with single-stranded RNA polynucleotides (poly A, poly G, poly C, poly U), double-stranded DNA polynucleotides (poly dAdT-poly dAdT, poly dGdC-poly dGdC) and calf thymus DNA (ct-DNA) by surface-enhanced Raman spectroscopy (SERS) reveals unambiguous enhancement of the Raman scattering from the small molecules as well as appearance of new bands in spectra associated mainly with nucleobases. The SERS exper…
Determination of ultratrace bismuth in milk samples by atomic fluorescence spectrometry.
2003
Abstract A sensitive procedure was developed for determination of bismuth (Bi) in milk samples by hydride generation atomic fluorescence spectrometry (HG–AFS) after microwave-assisted sample digestion with HNO3 and H2O2. The method provides a sensitivity of 1832 fluorescence units (ng/mL) with a detection limit of 0.01 ng/mL, which corresponds to 20 pg absolute limit of detection, equivalent to 0.50 ng/g in the original sample. Application of the methodology to cow milk samples from the Spanish market showed the presence of Bi at a concentration of 11.8–28.8 ng/g, which compared well with data obtained after dry ashing of samples and with data obtained by inductively coupled plasma–mass spe…
Strategies for annotation and curation of translational databases: the eTUMOUR project
2012
Altres ajuts: LSHC/CT2004-503094 The eTUMOUR (eT) multi-centre project gathered in vivo and ex vivo magnetic resonance (MR) data, as well as transcriptomic and clinical information from brain tumour patients, with the purpose of improving the diagnostic and prognostic evaluation of future patients. In order to carry this out, among other work, a database-the eTDB-was developed. In addition to complex permission rules and software and management quality control (QC), it was necessary to develop anonymization, processing and data visualization tools for the data uploaded. It was also necessary to develop sophisticated curation strategies that involved on one hand, dedicated fields for QC-gene…
A selective microscale x-ray fluorescence analyzing method for determination of trace elements
1973
Abstract A new selective X-ray fluorescence analyzing method for trace element determination has been developed. In this method each trace element is measured independently. The excitation source is an X-ray tube that has a changeable anode and a variable high voltage. The exciting radiation is shaped with critical absorbers. The sample is viewed at backward angles through an absorber to reduce backscattered radiation. The estimated accuracy of this method is of the order of 10 per cent in thesub-ppm range of trace element concentration in organic samples. Measurement times are of the order of a few minutes.
Poisoning histories in the Italian renaissance: The case of Pico Della Mirandola and Angelo Poliziano.
2018
Giovanni Pico della Mirandola and Angelo Poliziano were two of the most important humanists of the Italian Renaissance. They died suddenly in 1494 and their deaths have been for centuries a subject of debate. The exhumation of their remains offered the opportunity to study the cause of their death through a multidisciplinary research project. Anthropological analyses, together with documentary evidences, radiocarbon dating and ancient DNA analysis supported the identification of the remains attributed to Pico. Macroscopic examination did not reveal paleopathological lesions or signs related to syphilis. Heavy metals analysis, carried out on bones and mummified tissues, showed that in Pico's…
Trap Spectroscopy by the Glow Rate Technique using Bleaching of Colour Centres
2002
An application of the glow rate technique (GRT) for analysis of the parameters of thermostimulated decay of colour centres is presented using the data on the decay of radiation defects in LiBaF 3 :Fe crystals created by X rays at 300 K. The GRT offers a procedure for evaluation of the mean activation energy as a function of temperature in the case of arbitrary thermostimulated relaxation kinetics represented by the trap distribution function. The experimental procedure involves at least two subsequent measurements of thermostimulated decay kinetics at different heating rates. It is shown that the decay of the F type centres is governed by interaction of mobile anion vacancies with F A and F…
Optical rogue-wave-like extreme value fluctuations in fiber Raman amplifiers
2008
International audience; We report experimental observation and characterization of rogue wave-like extreme value statistics arising from pump-signal noise transfer in a fiber Raman amplifier. Specifically, by exploiting Raman amplification with an incoherent pump, the amplified signal is shown to develop a series of temporal intensity spikes whose peak power follows a power-law probability distribution. The results are interpreted using a numerical model of the Raman gain process using coupled nonlinear Schrödinger equations, and the numerical model predicts results in good agreement with experiment.