40 research outputs found
Italian guidelines for primary headaches: 2012 revised version
The first edition of the Italian diagnostic and therapeutic guidelines for primary headaches in adults was published in J Headache Pain 2(Suppl. 1):105â190 (2001). Ten years later, the guideline committee of the Italian Society for the Study of Headaches (SISC) decided it was time to update therapeutic guidelines. A literature search was carried out on Medline database, and all articles on primary headache treatments in English, German, French and Italian published from February 2001 to December 2011 were taken into account. Only randomized controlled trials (RCT) and meta-analyses were analysed for each drug. If RCT were lacking, open studies and case series were also examined. According to the previous edition, four levels of recommendation were defined on the basis of levels of evidence, scientific strength of evidence and clinical effectiveness. Recommendations for symptomatic and prophylactic treatment of migraine and cluster headache were therefore revised with respect to previous 2001 guidelines and a section was dedicated to non-pharmacological treatment. This article reports a summary of the revised version published in extenso in an Italian version
Sputter growth and magnetic properties of exchange-biased La[sub 1/4]Ca[sub 3/4]MnO[sub 3]âLa[sub 2/3]Sr[sub 1/3]MnO[sub 3] epitaxial bilayers
International audienc
Characterization of coke on H-gallosilicate (MFI) propane aromatization catalyst: influence of coking conditions on nature and removal of coke
Coke deposited on H-gallosilicate (MFI) in the propane aromatization at different temperatures (400-600°C), space velocities (770-82 500
cm<SUP>3</SUP> g<SUP>-1</SUP> h<SUP>-1</SUP>) and periods (7-125 or 240 h) has been characterized by <SUP>13</SUP>C CP-MAS NMR, ESR, IR, thermal analysis,
GC-MS analysis of soluble (or soft) coke and temperature-programmed oxidation (TPO). The nature of coke and its removal from the zeolite are found to be
strongly influenced by its coking conditions, particularly temperature and space velocity used in the propane aromatization. However, the period of coking
has only a small or no effect on both the nature and removal of coke. In the high temperature (550°C) aromatization at low space velocity, the coke
formed is insoluble (or hard) and non-volatile in nature; it consists of highly polycondensed aromatics having graphite-like character. Its removal is
possible only by oxidative treatment at high temperature. However, with the decrease in the coking temperature, the coke nature is gradually changed from
highly polyaromatics to low polyaromatics. Also the coke removal by oxidative treatment becomes easier; it can be effected at lower temperatures. At the
coking temperature of 400°C, the coke formed is completely soluble/very soft in nature and consists mainly of methyl substituted pyrenes. It is
volatile in nature and can be removed simply by its desorption at high temperature (600°C). The high temperature (550°C) coke formed at very high
space velocity (82 500 cm<SUP>3</SUP> g<SUP>-1</SUP> h<SUP>-1</SUP>) is less hard than that formed at low space velocities (≤3100 cm<SUP>3</SUP>
g<SUP>-1</SUP> h<SUP>-1</SUP>). The formation of CO and CO<SUB>2</SUB> upon coke oxidation is also strongly influenced by the coking conditions and hence by
the nature of the coke
Growth and relaxation mechanisms in La0.66Sr0.33MnO3 manganites deposited on SrTiO3(0 0 1) and MgO(0 0 1)
International audienc
Ătudes par diffraction haute rĂ©solution et rĂ©flectivitĂ© de films minces Ă©pitaxiĂ©s
The studies we present concern the general researches involved in order to understand the growth mechanisms of thin films deposited on oriented substrates. Among the different investigation technics of the thin layers, X-ray diffraction and reflectivity will be discussed through two applications. In a first step, thediffraction presented, illustrated by reciprocal space mapping, will give information about the layer state of stress and the lattice distorsion of LaSrMnO deposited on SrTiO. The results obtained are discussed and compared to those given by electron microscopy. In a second step, we will present an application of reflectivity concerning a very roughness surface of platinum deposited on MgO showing an island growth process. We will verify that reflectivity can lead to the determination of the recovered rate of the surface, even if some problems exist in the simulation of the whole data set. Results obtained in electron microscopy will complete those issued from reflectivity.Les Ă©tudes que nous allons prĂ©senter sont Ă replacer dans le contexte gĂ©nĂ©ral de la comprĂ©hension des mĂ©canismes de croissance des films minces dĂ©posĂ©s sur des substrats orientĂ©s. Parmi les diverses techniques d'investigations des couches minces, la diffraction et la rĂ©flectivitĂ© des rayons X vont ĂȘtre abordĂ©es Ă travers deux applications. Nous verrons tout d'abord que la diffraction, illustrĂ©e par la cartographie en deux dimension du rĂ©seau rĂ©ciproque, permet de remonter Ă l'Ă©tat de contrainte ainsi qu'Ă la dĂ©formation de la maille de LaSrMnO dĂ©posĂ© sur SrTiO. Les rĂ©sultats dĂ©duits de ces mesures seront discutĂ©s et comparĂ©s Ă ceux obtenus en microscopie Ă©lectronique. Dans la suite de l'article, nous verrons une des applications de la rĂ©flectivitĂ©, sur une surface trĂšs perturbĂ©e de platine dĂ©posĂ© sur MgO et prĂ©sentant une croissance en Ăźlots. Nous verrons que la rĂ©flectivitĂ© permet d'estimer le taux de recouvrement de la surface, mais que des problĂšmes persistent dans la simulation de l'intĂ©gralitĂ© des donnĂ©es expĂ©rimentales. Les rĂ©sultats obtenus en MET viendront complĂ©ter ceux issus de la rĂ©flectivitĂ©
Hydroliquefaction of green wastes to produce fuels
International audienceThe direct liquefaction of a biomass composed of a mixture of wastes (straw, wood and grass) was studied using Nickel Raney as catalyst and tetralin as a solvent. Tetralin allows to solubilize green waste from 330 °C at relatively low hydrogen pressure, and avoids the recondensation of the intermediate products. The green waste deoxygenation results mainly from a decarboxylation reaction. The addition of Raney Ni in the feed, increases the gas yield due to methane formation, without diminishing the yield in solvolysis oil. The catalyst hydrogenolyses the small molecules present in the light fraction. Moreover, it improves the quality of the oil by increasing the hydrogen transfer between the solvent and the solvolysis oil. As a consequence, the oxygen content decreases and the yield of oil soluble in hexane strongly increases. The catalyst allows to obtain straight long chain alkanes (C13-C26), which result from the hydrogenation of the extractives compounds of the green waste
Structural, magnetic, transport, and magneto-optical properties of single crystal La2/3Sr1/3MnO3 thin films
International audienc