Search results for "calor"
showing 10 items of 866 documents
Sirtuins and Aging: is there a Role for Resveratrol?
2016
Prolonged human life duration is consequently associated with a higher incidence of chronic diseases. Aging is a very complex process in which genetic, environmental and cellular pathways are involved. Along with aging, longevity has been linked with Sirtuins. Sirtuin enzymes are a family of highly conserved protein deacetylases that have been linked with calorie restriction and aging by modulating energy metabolism, genomic stability and stress resistance. Aim of this brief review is to describe Sirtuins’ influence on the conditions that worsen the physiological aging. We will also report the beneficial effects of the polyphenol resveratrol on these molecules and the possible therapeutical…
What are the roles of calorie restriction and diet quality in promoting healthy longevity?
2014
Epidemiological and experimental data indicate that diet plays a central role in the pathogenesis of many age-associated chronic diseases, and in the biology of aging itself. Data from several animal studies suggest that the degree and time of calorie restriction (CR) onset, the timing of food intake as well as diet composition, play major roles in promoting health and longevity, breaking the old dogma that only calorie intake is important in extending healthy lifespan. Data from human studies indicate that long-term CR with adequate intake of nutrients results in several metabolic adaptations that reduce the risk of developing type 2 diabetes, hypertension, cardiovascular disease and cance…
New insights in the formation of silanol defects in silicalite-1 by water intrusion under high pressure.
2010
International audience; The "water-silicalite-1" system is known to act as a molecular spring. The successive intrusion-extrusion cycles of liquid water in small crystallites (6 × 3 × 0.5 μm(3)) of hydrophobic silicalite-1 were studied by volumetric and calorimetric techniques. The experiments displayed a decrease of the intrusion pressure between the first intrusion-extrusion cycle and the consecutive ones, whereas the extrusion pressures remained unchanged. However, neither XRD studies nor SEM observations revealed any structural and morphological modifications of silicalite-1 at the long-range order. Such a shift in the value of the intrusion pressure after the first water intrusion-extr…
Study of phase composition, photocatalytic activity, and photoluminescence of TiO2 with Eu additive produced by the extraction-pyrolytic method
2021
The Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2. The work was also partially supported by the LZP grant 2020/2-0074. R. Burve has been supported by the project “Synthesis of nanostructured materials based on titanium dioxide and tin dioxide and investigation of their physicochemical properties” Nr. MP-2019/7, for strengthening scientific personnel capacity 2019/2020 at the Riga Technical University. Authors are grateful to Dr. K. Šmits for the microscopic measurements and SEM images.
A study of the effect of molecular and aerosol conditions in the atmosphere on air fluorescence measurements at the Pierre Auger Observatory
2010
The air fluorescence detector of the Pierre Auger Observatory is designed to perforin calorimetric measurements of extensive air showers created by Cosmic rays of above 10(18) eV. To correct these measurements for the effects introduced by atmospheric fluctuations, the Observatory contains a group Of monitoring instruments to record atmospheric conditions across the detector site, ail area exceeding 3000 km(2). The atmospheric data are used extensively in the reconstruction of air showers, and are particularly important for the correct determination of shower energies and the depths of shower maxima. This paper contains a summary of the molecular and aerosol conditions measured at the Pierr…
Beads of Acryloylated Polyaminoacidic Matrices Containing 5-Fluorouracil for Drug Delivery
2002
Spherical polymeric microparticles have been prepared by a reverse phase suspension polymerization technique. The starting polymer was alpha,beta-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA), partially derivatized with glycidylmethacrylate (GMA). PHEA-GMA copolymer (PHG) was crosslinked in the presence of N,N'-dimethylacrylamide (DMAA) or N,N'-ethylenebisacrylamide (EBA). 5-fluorouracil was incorporated into PHG-DMAA or PHG-EBA beads both during and after the crosslinking process. Swelling studies revealed a high affinity toward aqueous medium, influenced by the presence of 5-fluorouracil. The in vitro release study showed that the release rate depends on the chemical structure of the beads…
Hydrolysis of dioxouranium(VI): a calorimetric study in NaClaq and NaClO4aq, at 25°C
2004
Abstract We report the results of a calorimetric study on the hydrolysis of UO 2 2+ in different ionic media (NaClO 4 aq , NaCl aq ) at 25 °C. Experiments in NaCl were performed at different ionic strength, at I ≤1 mol l −1 . The species considered in both ionic media were UO 2 (OH) + , (UO 2 ) 2 (OH) 2 2+ and (UO 2 ) 3 (OH) 5 + , and in addition (UO 2 ) 3 (OH) 4 2+ and (UO 2 ) 3 (OH) 7 − in NaCl aq . The dependence on ionic strength of enthalpy changes in NaCl aq was expressed by the simple linear equation Δ H pq =Δ H ° pq + aI 1/2 ( a , empirical parameter). Comparison with literature findings is given and some recommended values are reported.
Complex formation of copper( ), nickel( ) and zinc( ) with ethylophosphonoacetohydroxamic acid: solution speciation, synthesis and structural charac…
2019
We present herein the thermodynamic and X-ray characterisation of a novel ethyl phosphonohydroxamic acid-based Cu( ) metallacrown, predominating in solution in a broad pH range.
Extended Investigation of the Aqueous Self-Assembling Behavior of a Newly Designed Fluorinated Surfactant
2009
The physicochemical behavior of the newly synthesized fluorinated 5-hydroxyamino-3-perfluoroheptyl-1,2,4-oxadiazin-6-one (PFHO) surfactant was investigated. Thermal analysis showed that the pure surfactant is thermally stable under an inert atmosphere to 135 degrees C, which is several degrees higher than the melting point (99 degrees C). PFHO is rather active at the water/air interface where it assumes a standing up configuration. It exhibits an enhanced self-assembling behavior; accordingly, the critical micellar concentrations at some temperatures are 2 orders of magnitude lower than those of a similar surfactant having the same phobicity, such as sodium perfluorooctanoate. Even in the d…
Continuous fractionation of poly[(dimethylimino)decamethylene bromide] and molecular weight dependence of the glass transition
1995
30 g of the ionene poly[(dimethylimino)decamethylene bromide] were fractionated by a continuous counter-current extraction method (CPF) using ethylene glycol monoethyl ether as the solvent and diisopropyl ether as the non-solvent component. The efficiency of the separation was checked by viscometry and gel-permeation chromatography (GPC) measurements. Eight fractions of different molar mass were prepared for differential scanning calorimetry (DSC) experiments. With bromide as counter-ion, the glass transition temperature of the ionene increases from ca. 60 to 85°C as the intrinsic viscosity of this material (in 0,4 M aqueous solutions of KBr at 25°C) rises from ca. 14 to 22 mL/g. When bromi…