Search results for "aves"

showing 10 items of 2443 documents

Characterization of phenolic pellets for ESR dosimetry in photon beam radiotherapy

2017

This work deals with the dosimetric features of a particular phenolic compound (IRGANOX 1076 ® ) for dosimetry of clinical photon beams by using electron spin resonance (ESR) spectroscopy. After the optimization of the ESR readout parameters (namely modulation amplitude and microwave power) to maximise the signal without excessive spectrum distortions, basic dosimetric properties of laboratory-made phenolic dosimeters in pellet form, such as reproducibility, dose–response, sensitivity, linearity and dose rate dependence were investigated. The dosimeters were tested by measuring the depth dose profile of a 6 MV photon beam. A satisfactory intra-batch reproducibility of the ESR signal of the …

Models MolecularPhotonBiophysicsMolecular ConformationIRGANOX 1076 ®RadiationSignal030218 nuclear medicine & medical imaging03 medical and health sciences0302 clinical medicineNuclear magnetic resonancePhenolsDosimetryDosimetrySpectroscopyMicrowavesRadiometryGeneral Environmental ScienceESRReproducibilityPhotonsDosimeterRadiationPhenolRadiotherapy2300ChemistryElectron Spin Resonance SpectroscopyRadiotherapy DosagePhotonBiophysic030220 oncology & carcinogenesisMicrowaveMicrowave
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Revisiting the cysteine-rich proteins encoded in the 3’-proximal open reading frame of the positive-sense single-stranded RNA of some monopartite fil…

2020

A reexamination of proteins with conserved cysteines and basic amino acids encoded by the 3 '-proximal gene of the positive-sense single-stranded RNA of some monopartite filamentous plant viruses has been carried out. The cysteines are involved in a putative Zn-finger domain, which, together with the basic amino acids, form part of the nuclear or nucleolar localization signals. An in-depth study of one of these proteins, p15 from grapevine B virus (GVB), has shown: (i) a three-dimensional structure with four alpha-helices predicted by two independent in silico approaches, (ii) the nucleolus as the main accumulation site by applying confocal laser microscopy to a fusion between p15 and the g…

Models MolecularProtein Conformation alpha-HelicalGrapevine virus BAgroinfiltrationEvolutionProtein ConformationProtein DomainProtein domainNicotiana benthamianaGene ExpressionBiologyEvolution MolecularOpen Reading Frames03 medical and health sciencesViral ProteinsProtein DomainsPlant CellsVirologyTobaccoGene expressionAmino Acid SequenceCloning MolecularGenePhylogeny030304 developmental biologyGenetics0303 health sciencesSequence Homology Amino Acid030306 microbiologyRNASettore AGR/12 - Patologia VegetaleGeneral Medicinebiology.organism_classificationVirologyRecombinant ProteinsPlant LeavesRNA silencingRNA ViralFlexiviridaeSequence AlignmentModel
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Synthesis and application of β-substituted Pauson-Khand adducts: trifluoromethyl as a removable steering group.

2013

The reaction between alkynes (I) and norbornadiene (II) affords the β-substituted Pauson—Khand adducts (III) as single regioisomers and the trifluoromethyl steering group can be easily removed in the presence of DBU and water.

Models MolecularTrifluoromethylMolecular StructureChemistryNorbornadienePauson–Khand reactionRegioselectivityStereoisomerismGeneral MedicineGeneral ChemistryChemistry Techniques SyntheticCatalysisAdductchemistry.chemical_compoundAlkynesStructural isomerOrganic chemistryPolycyclic CompoundsSteering groupMicrowavesSesquiterpenesChlorofluorocarbons MethaneAngewandte Chemie (International ed. in English)
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On Fourier integral operators with Hölder-continuous phase

2018

We study continuity properties in Lebesgue spaces for a class of Fourier integral operators arising in the study of the Boltzmann equation. The phase has a H\"older-type singularity at the origin. We prove boundedness in $L^1$ with a precise loss of decay depending on the H\"older exponent, and we show by counterexamples that a loss occurs even in the case of smooth phases. The results can be seen as a quantitative version of the Beurling-Helson theorem for changes of variables with a H\"older singularity at the origin. The continuity in $L^2$ is studied as well by providing sufficient conditions and relevant counterexamples. The proofs rely on techniques from Time-frequency Analysis.

Modulation spaceApplied Mathematics010102 general mathematicsMathematical analysisShort-time Fourier transformPhase (waves)Hölder conditionFourier integral operators; modulation spaces; short-time Fourier transform; Analysis; Applied Mathematics01 natural sciencesBoltzmann equationFourier integral operatorMathematics - Functional Analysis010101 applied mathematicsSingularityshort-time Fourier transformFourier integral operators0101 mathematicsLp spacemodulation spacesMathematical PhysicsAnalysisMathematics
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Microwave-Assisted Tandem Organocatalytic Peptide-Coupling Intramolecular aza-Michael Reaction: α,β-UnsaturatedN-Acyl Pyrazoles as Michael Acceptors

2014

Conjugated N-acyl pyrazoles have been successfully employed in the organocatalytic enantioselective intramolecular aza-Michael reaction as ester surrogates. Bifunctional squaramides under microwave irradiation provided the best results in this transformation. Furthermore, this protocol has been combined with a peptide-coupling reaction in a tandem sequence. The final products were easily converted into the corresponding ethyl esters.

Molecular StructureChemistryStereochemistryOrganic ChemistryEnantioselective synthesisEstersStereoisomerismStereoisomerismGeneral ChemistryConjugated systemAmidesCombinatorial chemistryCatalysisCatalysischemistry.chemical_compoundOrganocatalysisIntramolecular forceMichael reactionPyrazolesMicrowavesPeptidesBifunctionalChemistry - A European Journal
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Preliminary considerations on the monitoring of meteorological and environmental parameters in the Natural Reserves "Grotta di Santa Ninfa" and "Grot…

2009

Monitoring caves SicilySettore GEO/04 - Geografia Fisica E Geomorfologia
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Wave dynamics and turbulence in multimode optical systems

2021

The subject of this thesis essentially focuses on the experimental and theoretical study of optical turbulence in different types of nonlinear media. The first part of the manuscript is devoted to the study of thermalization and condensation of optical waves during their propagation in graded-index multimode fibers. The analysis based on the wave turbulence theory reveals that the disorder inherent to light propagation in an optical fiber induces a significant acceleration of the process of optical thermalization, which can clarify the mechanism of certain regimes of spatial beam cleaning recently reported in the literature. We show experimentally that the optical field relaxes during its p…

Multimode optical fibersNonlinear opticsWave condensationFibres optiques multimodesThermalisation d’ondes incohérentes[PHYS.PHYS] Physics [physics]/Physics [physics]Wave turbulenceOptique non linéaireThermalization of incoherent wavesSolitonsCondensation d’ondesTurbulence d’ondes
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Role of apoptosis in autoimmunity.

2004

Autoimmune diseases are characterized by the activity of autoreactive lymphocytes that produce antibodies targeting self tissue or organ for destruction. Although the pathogenesis of these diseases is poorly understood, during the past two decades basic research has indicated apoptosis as the pivotal molecular mechanism leading to autoimmunity. Recently cytokines have been invoked in the regulation of the apoptosis-related factors and death receptors in autoimmune target destruction. These research advances have contributed to the identification of mechanisms controlling autoimmunity for defining novel therapeutic strategies.

Multiple SclerosisbiologyImmunologyThyroiditis AutoimmuneApoptosisAutoimmunitymedicine.disease_causeapoptosiGraves DiseaseAutoimmunityAutoimmune DiseasesPathogenesisDiabetes Mellitus Type 1Basic researchApoptosisImmunologybiology.proteinMolecular mechanismmedicineImmunology and AllergyDeath ReceptorsAnimalsHumansAntibodyJournal of clinical immunology
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Multivariate-Analysis of Phytoplankton and Related Environmental-Factors, in a Shallow Hypertrophic Lake

1995

Data on some relevant environmental variables and phytoplankton species composition, collected from the hypertrophic shallow lake Albufera of Valencia (Spain) during 1980-88, were examined using Redundancy Analysis (RDA). The hydrological cycle of the lake is manipulated for rice cultivation in the area. Seasonality and the particular hydrological cycle of the lake were the principal factors influencing long-term phytoplankton dynamics. Annual or horizontal differences were less important than the seasonal factor. However, a trend of phosphate increase and underwater illumination decrease was observed between 1980 and 1988. These changes might be related to some species year-to-year variati…

Multivariate analysisEcologyfungiEnvironmental factorSampling (statistics)Aquatic ScienceSeasonalitymedicine.diseasemedicine.disease_causeWaves and shallow waterPhytoplanktonmedicineEnvironmental sciencePhysical geographyWater cycleEutrophicationHydrobiologia
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Background Correction and Multivariate Curve Resolution of Online Liquid Chromatography with Infrared Spectrometric Detection

2011

J.K. acknowledges the “V Segles” grant provided by the University of Valencia to carry out this study. Authors acknowledge the financial support of Ministerio de Educación y Ciencia (Projects AGL2007-64567 and CTQ2008-05719/BQU) and Conselleria d'Educació de la Generalitat Valenciana (Project PROMETEO 2010-055).

Multivariate statisticsPrincipal Component AnalysisChromatographySpectrophotometry InfraredInfraredChemistryAnalytical chemistrySubtractionPhase (waves)CarbohydratesSignalAnalytical ChemistryNitrophenolsNitrophenolchemistry.chemical_compoundPrincipal component analysisLeast-Squares AnalysisAbsorption (electromagnetic radiation)AlgorithmsChromatography High Pressure LiquidSoftware
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