5,035 research outputs found
“Network per l’ uso integrato di osservazioni e modelli per valutare nel bacino centrale del Mediterraneo il trasporto degli aerosol ed il loro impatto sul clima”.
No full textPRIN 2007-2009, (Prot. 20004023850), Coordinatore Nazionale: Maria Rita Perrone (Finanziamento totale dell’ Unita’ di Lecce 100 kEuro
Travelling concepts in der interkulturellen Literatur (Franco Biondi, Gino Chiellino, Francesco Micieli)
No full textA Stereoselective Tyrosinase Model Compound Derived from an m-Xylyl-L-histidine Ligand
No full textThe aim of mimicking enzyme activity represents an important motivation for the development of new catalysts. A challenging objective is the development of chiral complexes for bioinspired enantioselective oxidation reactions. Herein, we report a new chiral dinuclear copper(II) complex based on a m-xylyl-bis(histidine) ligand (mXHI) as a biomimetic catalyst for tyrosinase and catechol oxidase. The new ligand improves a previous system also containing two tridentate N-3 units derived from l-histidine that were connected by a short, rigid ethanediamine bridge. In mXHI the bridge is provided by the more extended m-xylyl moiety. The dicopper(II) complex [Cu-2(mXHI)](4+) was studied as a catalyst for stereoselective oxidations of enantiomeric couples of chiral catechols of biological interest (L/D-dopa, L/D-dopa methyl ester, and (R/S)-norepinephrine), showing excellent discrimination capability, particularly for the methyl esters of dopa enantiomers. The catechol oxidation was studied in acetate buffer as slightly acidic medium, and a role of acetate as bridging ligand between the two coppers, preorganizing the dinuclear center in a more catalytic efficient structure, could be established. The oxidation of beta-naphthol and 3,5-ditertbutylphenol was studied as a model monophenolase reaction. The oxidation proceeds stoichiometrically, and the partial incorporation of O-18 into beta-naphthol when the reaction was performed using 18O2 suggests the existence of two competitive reaction pathways, a genuine monooxygenase mechanism and a radical pathway. However, the more challenging reaction on derivatives of l-/d-tyrosine did not lead to the desired monooxygenase product but only to products of radical oxidation. Complex [Cu-2(mXHI)](4+) was also used for the catalytic sulfoxidation of thioanisole in the presence of hydroxylamine as cosubstrate, in a preliminary attempt to model the reaction of external monooxygenases. The reaction proceeds with 25 turnovers, but the enantiomeric excess of sulfoxide was modest
Assessment of a Dual-Wavelength Compensation Technique for Displacement Sensors Using Plastic Optical Fibers
No full textThe paper analyzes the performance of a dual-wavelength technique devised to compensate power fluctuations in intensity-modulated plastic optical fiber sensors, which were specifically conceived for the measurement of displacements in industrial and civil applications. These sensors retrieve the displacement from the variation of the attenuation along the light path and use two signals at different wavelengths to compensate for the effects of parasitic quantities, such as temperature and strains along the fiber. The theoretical behavior of the compensation technique is presented, and the results of experiments carried out with different combinations of signal wavelengths and plastic fibers are reported. The experimental setup has proved that, by proper choice of the compensation signal wavelength, it is possible to monitor displacements in the range (0 to 10) mm, even for low received power and under severe perturbation conditions, thus significantly improving the long-term stability of the sensor
EARLINET MEASUREMENTS OF THE AEROSOL EXTINCTION-TO-BACKSCATTER RATIO
No full textReviewed and revised papers presented at the 21st International Laser Radar Conference (ILRC), 8-12 July, 2002, Quebec, Canada, L. R. Bissonnette, G. Roy, and G. Vallee Editors, 301-30
Elas também matam: o romance policial de Maria Alice Barroso, Ana Callado e Kátia Rebello
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão, Programa de Pós-Graduação em Literatura, Florianópolis, 2009.Disponibilizado em PDF apenas o capítulo 1.A presente dissertação aborda o processo de transposição e adaptação dos modelos do romance policial norte-americano e europeu à narrativa policial brasileira de autoria feminina, categorizada em três momentos. O primeiro momento enfoca a construção do romance policial de enigma através do romance de Maria Alice Barroso, Quem matou Pacífico?. O segundo momento privilegia o texto de Ana Arruda Callado, Uma aula de matar, expressando a ruptura com o modelo clássico e a consolidação do novo cânone, agora com o romance noir. O terceiro momento é configurado pelo romance policial brasileiro contemporâneo que mescla os elementos canônicos do enigma e do noir, no romance de Kátia Rebello, Olhos de vidro. Encerram o trabalho considerações, questionamentos e reflexões sobre o romance policial brasileiro de autoria feminina.Disponibilizado em PDF apenas o capítulo 1
Lidar Characterization of Volcanic Dust Performed by European Aerosol Research Lidar Network (EARLINET project) during Etna’s Eruption
No full textREVIEWED AND REVISED PAPERS PRESENTED AT THE 21ST INTERNATIONAL LASER RADAR CONFERENCE (ILRC), 8-12 JULY, 2002, QUEBEC, CANADA, L. R. BISSONNETTE, G. ROY, AND G. VALLEE EDITORS, 313-31
Selective inhibition of cyclooxygenase (COX) isoenzymes and neuroinflammation
No full textMicroglia, the immune cells of the brain, are one of the key mediators of neuroinflammation.
Microglial activation leads these cells to produce various proinflammatory
and neurotoxic substances.
Several in vitro and in vivo studies have demonstrated that a decrease in the
levels of pro-inflammatory mediators in microglia can attenuate the severity of
neuro-degenerative diseases, including AD, PD, ALS, MS and Huntingtons
disease. Thus, regulation of excessive microglial activation should be of
therapeutic value especially in neuro-degenerative disorders.
Cyclooxygenase(COX) is a key enzyme in the conversion of arachidonic acid
into prostaglandins and other lipid mediators. It is widely accepted that this
enzyme play a pivotal role in the neuro-inflammatory process exacerbation. Two
COX isoforms are known: COX-1, constitutively expressed in most tissues,
classically considered as the isoform primarily responsible for maintaining the
homeostasis by mediating physiological responses, and COX-2, which
represents the inducible form, mainly activated in response to inflammatory
stimuli. In this respect, recent studies have also indicated a previously
unrecognized pro-inflammatory role of COX-1 in the pathophysiology of acute
and chronic neurological disorders. Consequently, it was reconsidered the
potential beneficial effect of COX-1 inhibition in the treatment of neuroinflammation
[1].
These findings prompted us to investigate the behaviour of two selective COX-1
inhibitors such as P6 (COX-1 IC50= 0.5 mM and COX-2 IC50 >100 mM) and P10
(COX-1 IC50= 0.09 mM and COX-2 IC50 = 2.49 mM) [2] in an in vitro experimental
model of inflammation, represented by mouse N13 microglial cells activated by
lipopolysaccharide (LPS) [3]. LPS is a component of the outer cell wall of gramnegative
bacteria and is well known as an inducer of inflammatory responses.
New selective COX-1 inhibitors are here proposed also as useful tools in
pharmacological studies to investigate the role of COX-1 isoenzyme in neuroinflammation
or more in general in all the investigations in which only COX-1
needs to be selectively inhibited.
The results of this study as well as their rationale will be presented and
discussed.
References:
1. Perrone, M.G.; Scilimati, A.; Simone, L., Vitale, P. Curr. Med. Chem.2010,17, 3769-805.
2. Di Nunno. L., Vitale, P., Scilimati, A., Tacconelli, S.; Patignani, P. J. Med. Chem. 2004, 47, 4881-90.
3. Calvello, R.; Panaro, M.A.; Carbone, M.L.; Cianciulli, A.; Perrone, M.G.; Vitale, P.; Malerba, P.; Scilimati,
A. Biochem. Pharmacol.,2011, submitted for publication
O curso de licenciatura em educação física da Universidade Federal de Santa Catarina: suas concepções de ensino e de educação física
No full textDissertação (mestrado) - Universidade Federal de Santa Maria. Centro de Educação Fisica e Desporto
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