Search results for "dati"
showing 10 items of 8549 documents
An Autonomous System to Take Angular Thermal-Infrared Measurements for Validating Satellite Products
2015
An autonomous system for field land surface temperature (LST) measurements taken at different observation angles was developed to be deployed easily at any conventional meteorological tower station. The system permits ground-truth data to be acquired on a continuous basis, and angularly scans land and sky hemispheres with a single thermal-infrared (TIR) radiometer. This paper describes the autonomous angular system and the methodology to assess ground-truth LST and relative-to-nadir emissivity data from system measurements. Ground-truth LSTs were used to validate satellite-retrieved LST products at two experimental sites (rice crop and shrubland areas). The relative-to-nadir emissivity valu…
Thermal and thermo-oxidative stability and kinetics of decomposition of PHBV/sisal composites
2017
The decomposition behaviours of composites made of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and sisal were assessed in terms of thermal stability and decomposition kinetics, under inert and oxidative conditions, by means of multi-rate linear non-isothermal thermogravimetric experiments. A statistical design of experiments was applied to study the influence of the addition of sisal (0-10-20-30%wt), the presence coupling agent (Yes/No) and the applied conditions of work (inert or oxidative). An improvement of the thermal and thermo-oxidative stability of PHBV with the addition of sisal was observed for all cases. An accurate methodology based on iso-conversional methods was applied…
Oxidation-responsive and "clickable" poly(ethylene glycol) via copolymerization of 2-(methylthio)ethyl glycidyl ether
2016
Poly(ethylene glycol) (PEG) is a widely used biocompatible polymer. We describe a novel epoxide monomer with methyl-thioether moiety, 2-(methylthio)ethyl glycidyl ether (MTEGE), which enables the synthesis of well-defined thioether-functional poly(ethylene glycol). Random and block mPEG-b-PMTEGE copolymers (Mw/Mn = 1.05-1.17) were obtained via anionic ring opening polymerization (AROP) with molecular weights ranging from 5 600 to 12 000 g·mol-1. The statistical copolymerization of MTEGE with ethylene oxide results in a random microstructure (rEO = 0.92 ± 0.02 and rMTEG E = 1.06 ± 0.02), which was confirmed by in situ 1H NMR kinetic studies. The random copolymers are thermorespon…
Protein tyrosine nitration and thiol oxidation by peroxynitrite-strategies to prevent these oxidative modifications.
2013
The reaction product of nitric oxide and superoxide, peroxynitrite, is a potent biological oxidant. The most important oxidative protein modifications described for peroxynitrite are cysteine-thiol oxidation and tyrosine nitration. We have previously demonstrated that intrinsic heme-thiolate (P450)-dependent enzymatic catalysis increases the nitration of tyrosine 430 in prostacyclin synthase and results in loss of activity which contributes to endothelial dysfunction. We here report the sensitive peroxynitrite-dependent nitration of an over-expressed and partially purified human prostacyclin synthase (3.3 μM) with an EC50 value of 5 μM. Microsomal thiols in these preparations effectively co…
A competitive reactivity study on the oxidative cyclization of thiosemicarbazones into 1,3,4-thiadiazoles
2022
Abstract In order to obtain useful insights on the mechanism of formation of 2(3H)-imino-1,3,4-thiadiazoles by oxidative cyclization of aldehyde thiosemicarbazones with Cu(II) or Fe(III) salts, a competitive reactivity study was performed on a suitable set of diversely substituted substrates, by means of HPLC techniques. This approach enabled to exploit Hammett’s equation without performing otherwise difficult-to-run kinetic experiments. The results presented herein support the hypothesis that the formation of the thiadiazole ring is induced by the attack of the oxidizing Lewis acid metal cation onto the imine-like nitrogen atom of the thiosemicarbazone substrate. Beyond mechanistic interpr…
Analyse du caractère dynamique des recommandations dans l'industrie cinématographique : le cas des franchises de films
2016
The release of motion picture sequels by studios led to the emergence of interaction effects between sequels over the time and in consequence altering models predicting the box office. If some scholars have examined these interaction effects, they were limited to the box office revenues. The paper proposes an extension of the interaction effects to third-party recommendations. The results – covering 123 sequels – demonstrate the dynamic and persistent nature of the recommendations.
Cuerpos de energía: Formas alternativas de ser-en-el-mundo
2020
Based on an ethnographic approach, this paper explores how members of a new age spiritual movement known as ?Llave Mariana? (LLM) build and experience their bodies. At the same time, it develops a thick description of their ritual practices and later it analyzes, delving fundamentally into the phenomenological perspective, how these members shape and transform their forms of self-perception, experience, and representation of others and the environment. Finally, it considers the implications these spiritual practices have in the search and consolidation of alternative ways of being-in-the-world
(no title)
2017
Biological invasions are recognized as a significant evolutionary factor over short time scales. In particular, their effect is well recorded on the genetic structure of populations, the patterns of phenotypic evolution and the richness of parasite fauna associated to invasive populations. This study aims at quantifying the consequences of a biological invasion according to these three levels (genetical, phenotypical and parasitological) taking as example the Mozambique tilapia Oreochromis mossambicus. This African cichlid is characterized by an unusual conservation status since it is both (i) ranked among the world's worst invasive species due to its global dispersion during the 20th centu…
Estrés por disulfuro en pancreatitis aguda experimental. Implicaciones fisiopatológicas
2014
El estrés oxidativo se define como la alteración en el equilibrio entre las especies oxidantes y antioxidantes, a favor de las primeras. Mientras que hay muchos tipos de daño oxidativo, cada vez más pruebas sugieren un papel importante en la oxidación de proteínas en múltiples enfermedades. Los puentes disulfuro se forman en el citosol durante el estrés oxidativo y funcionan como intercambiadores redox. El glutatión es un tripéptido y es uno de los principales antioxidantes, lo que le confiere un papel clave en numerosas funciones celulares. El estado redox del glutatión se considera el mejor indicador de estrés oxidativo en las células, ya que refleja el equilibrio entre el estado antioxid…