Search results for "Ultra"
showing 10 items of 4451 documents
EFFECT OF IMAGE NORMALIZATION ON CAROTID PLAQUE CLASSIFICATION AND THE RISK OF IPSILATERAL HEMISFERIC ISCHEMIC EVENTS. RESULTS FROM THE ASYMPTOMATIC …
2005
The aim of this study was to determine the effect of image normalization on plaque classification and the risk of ipsilateral ischemic neurologic events in patients with asymptomatic carotid stenosis. The first 1,115 patients recruited to the Asymptomatic Carotid Stenosis and Risk of Stroke (ACSRS) study with a follow-up of 6 to 84 months (mean 37.1 months) were included in this study. Duplex ultrasonography was used for grading the degree of internal carotid artery stenosis and for plaque characterization (types 1-5), which was performed before and after image normalization. One hundred sixteen ipsilateral ischemic hemispheric events occurred. Image normalization resulted in 60% of plaques…
Integrated non invasive approach to atherosclerosis with cardiac CT and carotid ultrasound in patients with suspected coronary heart disease.
2015
The aim of the study was to compare the atherosclerotic disease in the coronary and carotid arteries in patients who underwent non-invasive imaging for suspected stable coronary artery disease (CAD).
Contribution of microscopy to the study of proliferating blood cells in Ciona intestinalis immune response
2010
Following an inflammatory stimulus such as the injection of erythrocytes into the tunic of Ciona intestinalis, hemocytes respond to events occurring in the tunic within a short time, and infiltrate the inflamed tissue being massively involved in the acute inflammatory response and capsule formation. The proliferative response of circulating hemocytes and pharynx assume particular interest as it is significantly enhanced during these defence reactions. Microscopy clearly may contribute to extend our understanding of the phenomenon showing interesting mitotic figures and hematogenic nodules with proliferative characteristics.
ULTRASOUND-ASSISTED AND ENZYME-ASSISTED EXTRACTION OF FRUCTANS AND PHENOLICS FROM PARSNIP (PASTINACA SATIVA L.)
2019
Parsnip (Pastinaca sativa L.) is a vegetable that gained attention due to its significant content of fructans, besides macronutrients and other biologically active compounds. The major compound of fructan class is inulin, an ingredient with prebiotic properties used in pharmaceutical and functional food industries. The main purpose of this study was to evaluate the extraction yield of fructans and phenolics in fresh and dried parsnip root following non-conventional techniques (ultrasound and enzyme -assisted extraction) and to compare it to that of the traditional method. Extraction was performed in water, as eco-friendly solvent. Ultrasound-assisted extraction was optimized for different e…
Correlazioni tra le velocità ultrasoniche e le caratteristiche petrografiche in ceramiche archeologiche: un primo approccio metodologico
2010
L’analisi delle velocità degli ultrasuoni permette di investigare i caratteri tessiturali e strutturali e di individuare la presenza di eventuali difetti localizzati all’interno del campione. La loro diffusione negli studi archeometrici è legata alla non distruttività e alla possibilità di fornire risultati accurati in tempo reale. In questo lavoro sono state effettuate numerose analisi petrografiche in sezione sottile e misure di velocità di propagazione degli ultrasuoni su reperti ceramici di interesse archeologico. In particolare sono stati selezionati ed analizzati ceramiche preistoriche ed anfore da trasporto del V-IV sec. a.C., caratterizzati da differente granulometria, composizione …
Effects of ligand substitution on the excited state dynamics of the Ru(dcbpy)(CO)2I2 complex
2003
Abstract Spectroscopic evidence suggest [PCCP 3 (2001) 1992] that illumination with visible light of the [trans-I-Ru(dcbpy)(CO)2I2] (dcbpy= 4,4′-dicarboxy-2,2′-bipyridine) complex in solution induces dissociation of a CO group followed by reorganization of the ligands and attachment of a solvent molecule. In the present study, we report results on excited state dynamics of this ruthenium complex and its photoproduct. Femtosecond transient absorption measurements reveal dominance of excited state absorption of the reactant and the photoproduct [cis-I-Ru(dcbpy)(CO)(Sol)I2] (Sol=ethanol or acetonitrile) in the visible spectral region. The time-resolved measurements for the reactant at 77 K ind…
Mechanism of excited state deactivation of indan-1-ylidene and fluoren-9-ylidene malononitriles.
2016
Herein, we report complementary computational and experimental evidence supporting the existence, for indan-1-ylidene malononitrile and fluoren-9-ylidene malononitrile, of a non-radiative decay channel involving double bond isomerisation motion. The results of UV-Vis transient absorption spectroscopy highlight that the decay takes place within hundreds of picoseconds. In order to understand the related molecular mechanism, photochemical reaction paths were computed by employing multiconfigurational quantum chemistry. The results indicate that the excited state deactivation occurs via concerted double bond twisting of the dicyanovinyl (DCV) unit coupled with a pyramidalisation of its substit…
Unveiling the nature of supramolecular crown ether–C60 interactions
2015
A series of exTTF-(crown ether)2 receptors, designed to host C60, has been prepared. The size of the crown ether and the nature of the heteroatoms have been systematically changed to fine tune the association constants, which were determined by a number of complementary spectroscopic techniques. Electrochemical measurements and transient absorption spectroscopy assisted in corroborating charge transfer in the ground state and in the excited state, leading to the formation of radical ion pairs featuring lifetimes in the range from 12 to 21 ps. To rationalize the nature of the exTTF-(crown ether)2$C60 stabilizing interactions, theoretical calculations have been carried out, suggesting a syner…
Isolation of a peptidic fraction from the goat cheese water-soluble extract by nanofiltration for sensory evaluation studies
1997
Abstract The effect of the small water-soluble peptides on the taste of cheeses has not been clarified yet because of the high difficulties to isolate them from the other water-soluble compounds. A new filtration method, nanofiltration, using ionizable membranes, allowed us to purify a peptidic fraction prepared from the permeate obtained by ultrafiltration (MWCO=1000) of a goat cheese water-soluble extract. A large proportion of mineral salts and a part of amino acids were eliminated from the nanofiltration retentate where a majority of small peptides were concentrated. The peptidic fraction was incorporated in a cheese model with known synergistic effectors such as mineral salts and amino…
The ultrasounds-ionic liquids synergy on the copper catalyzed azide-alkyne cycloaddition between phenyl acetylene and 4-azidoquinoline
2015
Abstract The effect of ultrasound irradiation on the copper catalyzed azide–alkyne cycloaddition between phenylacetylene and 4-azidoquinoline has been studied in solution of different ionic liquids. In particular, we used ionic liquids featuring both aliphatic and aromatic mono- and dications, as well as anions differing in size, symmetry and coordination ability. We also examined the influence of the ionic liquids structural features on the reaction outcomes, finding that under magnetic stirring reactivity is favorably affected by the solvent structural organization, while under sonochemical conditions an opposite trend was observed. In all cases examined, sonochemical activation leads to …