609 research outputs found
C) for Space Missions
No full textThis paper presents a tutorial on the Tracking, Telemetry, and Command (TT&C) for spacecraft and satellite missions. In particular, it provides a thorough summary of the design of the TT&C, starting from elementary system aspects and going down to the details of the on-board TT&C subsystem design, its units, and the physical layer. The paper is then complemented with a description of emerging TT&C techniques and technologies, the standardization framework, and practical examples of actual spacecraft design of European space missions. The here-presented tutorial is thought for professionals (also in other telecommunication engineering fields) willing to face the challenges and state-of-the-art of the TT&C, and know more about this fundamental function that allows us to control and monitor our spacecraft on a daily basis
Forensic Sciences in Italy
No full textThis chapter illustrates how forensic sciences are organised and applied in Italy. It provides a brief overview of how the legal framework in which forensic sciences are inserted functions and then goes on to illustrate the complex world of forensic science activity in Italy, divided between the Polizie Scientifiche of the Carabinieri, of the Polizia di Stato and of universities. Services, organisation, training and scientific activity are among the aspects dealt with, as well as the history and present-day scenario of genetics, toxicology, pathology, anthropology, entomology, fibre analysis, computer sciences and other main forensic disciplines
DETERMINATION DE LA COCAINE SUR UNE PIECE EN GLYCOPOLYETHYLENE: COMPARAISON DES TECHNIQUES
No full textA Case of Primary Localized Small Bowel Amyloidosis Studied by 18F-Choline and Contrast-Enhanced 18F-FDG PET/CT
No full textAmyloidosis is a rare hereditary or acquired protein deposition disorder with different etiologies, characterized by pathological protein deposition essentially in nearly any organs or tissues. There are 2 major forms: primary and secondary amyloidosis. Moreover, it is possible to have systemic or localized disease. The localized form of amyloidosis affecting the small intestine is rare, and it is characterized by the formation of precursor proteins at the site of the lesion. We report a case of localized small bowel amyloidosis studied by F-choline and F-FDG-iodinated PET/CT performed for staging an aggressive prostatic cancer
Inspection on the Mechanism of SARS-CoV-2 Inhibition by Penciclovir: A Molecular Dynamic Study
No full textIn recent years, humanity has had to face a critical pandemic due to SARS-CoV-2. In the rapid search for effective drugs against this RNA-positive virus, the repurposing of already existing nucleotide/nucleoside analogs able to stop RNA replication by inhibiting the RNA-dependent RNA polymerase enzyme has been evaluated. In this process, a valid contribution has been the use of in silico experiments, which allow for a rapid evaluation of the possible effectiveness of the proposed drugs. Here we propose a molecular dynamic study to provide insight into the inhibition mechanism of Penciclovir, a nucleotide analog on the RNA-dependent RNA polymerase enzyme. Besides the presented results, in this article, for the first time, molecular dynamic simulations have been performed considering not only the RNA-dependent RNA polymerase protein, but also its cofactors (fundamental for RNA replication) and double-strand RNA
Chromatographic micro-procedure for trace determination of phenobarbital in blood serum
No full textVolumes of 100 μl of serum were sufficient for the determination of therapeutic levels of phenobarbital. The isolation procedure was performed using a column method with a hydrophobic adsorbent, graphitized carbon black (Carbopack B). With this method the quantitative (98.1%) recovery of phenobarbital was measured. By suitable choice of experimental conditions, a highly selective purification of the drug can be obtained, thus eliminating various sources of error during quantitation due to the presence in the final samples of endogenous compounds. For the quantitation procedure, another type of graphitized carbon black (Carbopack C) suitably modified was used for gas chromatography. Calibration curves showed no chemisorption effect along the column even on injecting 5 ng of phenobarbital. Some practical aspects of the procedure for improving the reliability of the results are discussed
Constitutive Formulations for Concrete with Recycled Aggregates
No full textIn this Chapter, a thermodynamically consistent gradient model is proposedfor natural aggregate concrete and then, modified to take into account theaddition of different contents of recycled aggregates and its influence on concretemechanical response. A particular and simple form of gradient-based plasticity isconsidered, where the state variables are the only ones of non-local character. Afterdescribing the material formulation for natural and recycled aggregate concretes,the model calibration is performed with experimental data taken from literature.A comprehensive numerical analysis is presented, where the effects of the recycledaggregate content on the performance of concrete in pre and post-peak behavior areevaluated and discussed, for different stress states. Finally, the ability of the modelto capture the variation of mechanical response of concrete with different recycledaggregate contents is demonstrated for different mechanical tests.Fil: Caggiano, Antonio. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; ArgentinaFil: Etse, Jose Guillermo. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Centro de Métodos Numéricos y Computacionales en Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Folino, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires; ArgentinaFil: Ripani, Marianela. Universidad de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Construcciones y Estructuras. Laboratorio de Materiales y Estructuras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vrech, Sonia Mariel. Universidad Nacional de Tucumán; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentin
Coarse-Grained Simulation of the Adsorption of Water on Au(111) Surfaces Using a Modified Stillinger–Weber Potential
No full textFor reproducing the behavior of water molecules adsorbed on gold surfaces in terms of density of both bulk and interfacial water and in terms of structuring of water on top of gold atoms, the implementation of a multibody potential is necessary, thus the Stillinger–Weber potential was tested. The goal is using a single nonbonded potential for coarse-grained models, without the usage of explicit charges. In order to modify the angular part of the Stillinger–Weber potential from a single cosine to a piecewise function accounting for multiple equilibrium angles, employed for Au–Au–Au and Au–Au–water triplets, it is necessary to create a version of the simulation package LAMMPS that supports the assignment of multiple favored angles. This novel approach is able to reproduce the data obtained using quantum mechanical calculations and density profiles of both bulk and adsorbed water molecules obtained using classical polarizable force fields.publishe
DIFFERENZE TRA STELI RETTI CON ESTESO RIVESTIMENTO IN IDROSSIAPATITE E POSSIBILI IMPLICAZIONI CLINICHE
No full textRecentemente sono stati introdotti diversi steli femorali apparentemente alquanto simili per geometria e per estensione del rivestimento in idrossiapatite (HA). Lo scopo di questo studio è stato di valutare le caratteristiche geometriche di 5 di questi steli per verificare se possono essere utilizzati in modo intercambiabile o se, invece, dovrebbero essere utilizzati con indicazioni differenti.
MATERIALI E METODI Sono stati analizzati i diametri coronali e sagittali a livello prossimale (calcar), intermedio e distale (1cm prossimale al tip dello stelo) in tutte le taglie di 5 steli apparentemente simili, ossia lo stelo Corail (Depuy), Avenir Mueller (Zimmer), Polarstem (Smith&Nephiew), Trendhip (Aesculap) e H-max (Lima). Di ciascuno stelo è stato poi calcolato il “Flare-Index” (FI) ed il “Tapered- index” ossia il rapporto tra il diametro prossimale e distale e tra l’area dello stelo calcolata su un taglio assiale a livello prossimale e distale, rispettivamente. Per l’analisi statistica sono stati utilizzati tests non parametrici (Kruskan-Wallis e il Mann-Whitney).
RISULTATI
La lunghezza dello stelo è risultata variare tra 115 (Corail) e 134 mm (Trendhip) nella taglia più piccola e tra 169 (Trendhip) e 190mm (Corail) in quella più grande. L’angolo meta-diafisario è risultato variare tra 163° e 171°. L’analisi statistica ha evidenziato una differenza significativa (p=0.001) tra il diametro coronale prossimale dei vari steli mentre i diametri sagittali non hanno evidenziato differenze significative. Una differenza significativa è stata anche riscontrata tra i vari steli nel flare-index ed il tapered-index (p=0.003 e p=0.001).
DISCUSSIONE
I risultati hanno evidenziato che esistono differenze geometriche significative tra i vari steli analizzati per cui alcuni di questi steli hanno una forma decisamente più a cuneo di altri. Questi risultati suggeriscono che nei femori di tipo A di Dorr, sarebbe preferibile utilizzare uno stelo con un tapered index più elevato in modo da evitare una fissazione prevalentemente diafisaria, mentre l’opposto, ossia uno stelo con basso tapered index, dovrebbe essere preferito nei femori di tipo C.
CONCLUSIONI
Gli steli in titanio con esteso rivestimento in HA tipo Corail, per quanto simili in apparenza, presentano significative differenze nella loro geometria. La conoscenza di tali differenze può essere di aiuto al chirurgo nello scegliere lo stelo più idoneo alla morfologia del femore da operare.Background
Several tapered stems with similar geometry and extensive hydroxyapatite coating have recently been introduced. It is not clear, however, whether they share the same design or whether exhibit any difference that might affect their clinical performances.
Hypothesis
We analysed 5 look-alike tapered titanium femoral stem with extensive hydroxyapatite coating to establish whether they exhibit similar geometric features and may therefore be used indifferently when a cementless stem is indicated.
Methods
Fifty stems of 5 different brands were analysed. Measurements including stem length, coronal and sagittal diameters, length stem shoulder and meta-diaphyseal angle were performed on digitalized templates. The ratio between the proximal and distal coronal diameters of the stems and that between the proximal and distal cross-sectional area were calculated as a flare index and tapered index, respectively. Measurements were compared on all available sizes of each brand and on selected comparable sizes showing a similar coronal diameter in the middle portion of the stem.
Results
The coronal and sagittal diameters between brands differed up to 4.4 mm and 3.3 mm, respectively. A significant difference between stems of different brands was found in the flare index and tapered indexes when either all available sizes or only comparable sizes were analysed. A significant difference was also found among the different brands in the length of stem shoulder and in the meta-diaphyseal angle.
Conclusions
Look-alike tapered stems should not be used indifferently since they may actually exhibit different geometric features potentially affecting their clinical performances
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