1,354,602 research outputs found
Correction to: Histone deacetylase inhibitor ITF2357 (givinostat) reverts transformed phenotype and counteracts stemness in in vitro and in vivo models of human glioblastoma (Journal of Cancer Research and Clinical Oncology, (2019), 145, 2, (393-409), 10.1007/s00432-018-2800-8)
No full textIn the original publication, the 6th author’s first name and the last name was inverted and incorrectly published. The correct author name is Letizia Ferella
Optimization of a plant for treatment of industrial waste solutions: Experimental and process analysis
No full textThe present paper deals with the optimization of an industrial plant that treats waste solutions coming from different manufacturing processes. In particular, an extensive experimental work was carried out to understand whether some streams could be diverted from the distillation column in order to recover solvents, suitable as secondary fuel. Experimental tests, including four full factorial designs, optimized the consumption of reagents in the Fenton process: the specific consumptions were 0.65 g L−1 of H2O2 and 0.42 g L−1 of FeSO4·7H2O, when treating the evaporated fractions from multiple-effect evaporator, concentrator and dryer, diverted from the distillation column. The application of the Fenton process increased the abatement of the chemical oxygen demand (COD) and the oxygen uptake rate (OUR). The optimization of the feed entering the distillation column led to a water content lower than 5%vol in the distilled fraction: hence, such solvents could be used as additional fuel in a dual-fuel boiler. The economic analysis showed that it could be possible to save around 420,000 € y−1
A review on management and recycling of spent selective catalytic reduction catalysts
No full textCatalysts for selective catalytic reduction are widely used for the reduction of nitrogen oxides into gaseous nitrogen in many industrial applications. These catalysts usually contain titanium, tungsten, and vanadium. Due to the increasing demand, a new strategy for the management of end-of-life catalysts is urgent, in particular for the recovery of valuable metals and the reduction of the material disposed of. Titanium, tungsten, and vanadium shall be recovered and reused for the production of new catalysts or other products, to establish a circular economy approach. In this paper, a systematic review of the main strategies adopted for the management of spent catalysts was proposed and, in particular, an overview of the regeneration and rejuvenation techniques, the current processes for the recovery of such catalysts and the treatments patented. The present study found that among the recycling processes for the extraction of metals, those based on alkaline roasting and/or leaching are the most used: vanadium and tungsten are indeed water-soluble, so that can be easily separated from titania during the leaching stage. Instead, the acid leaching is not developed because of the downstream stages required to separate the three metals from each other. The recovery of the metals is currently negligible at full scale. For this reason, the recovery of titanium, tungsten, and vanadium with high extraction yields and grades shall be pursued in the future at a large scale, and the research shall be oriented towards this scope, whereas landfilling, that is still the main option in the management of this material, shall be penalized with a disposal fee
Neutrino physics with multi-ton scale liquid xenon detectors
No full textWe study the sensitivity of large-scale xenon detectors to low-energy solar neutrinos,
to coherent neutrino-nucleus scattering and to neutrinoless double beta decay. As
a concrete example, we consider the xenon part of the proposed DARWIN (Dark Matter
WIMP Search with Noble Liquids) experiment. We perform detailed Monte Carlo simulations
of the expected backgrounds, considering realistic energy resolutions and thresholds
in the detector. In a low-energy window of 2–30 keV, where the sensitivity to solar pp and
7Be-neutrinos is highest, an integrated pp-neutrino rate of 5900 events can be reached in a fiducial mass of 14 tons of natural xenon, after 5 years of data. The pp-neutrino flux could thus be measured with a statistical uncertainty around 1%, reaching the precision of solar model predictions. These low-energy solar neutrinos will be the limiting background to the dark matter search channel for WIMP-nucleon cross sections below ~2X 10-48 cm2 and WIMP masses around 50 GeV c 2, for an assumed 99.5% rejection of electronic recoils due to elastic neutrino-electron scatters. Nuclear recoils from coherent scattering of solar neutrinos will limit the sensitivity to WIMP masses below ~6 GeV c-2 to cross sections above ~4X10-45cm2. DARWIN could reach a competitive half-life sensitivity of 5.6X1026 y to the neutrinoless double beta decay of 136Xe after 5 years of data, using 6 tons of natural xenon in the central detector region
Monte Carlo studies and optimization for the calibration system of the Gerda experiment
No full textThe GERmanium Detector Array, GERDA, searches for neutrinoless double is decay in Ge-76 using bare highpurity germanium detectors submerged in liquid argon. For the calibration of these detectors 7 emitting sources have to be lowered from their parking position on the top of the cryostat over more than 5 m clown to the germanium crystals. With the help of Monte Carlo simulations, the relevant parameters of the calibration system were determined. It was found that three Th-228 sources with an activity of 20 kBq each at two different vertical positions will be necessary to reach sufficient statistics in all detectors in less than 4 h of calibration time. These sources will contribute to the background of the experiment with a total of (1.07 +/- 0.04(stat) (+0.13)(-0.19)(sys)) is 10(-4) ctsAkeV kg yr)) when shielded from below with 6 cm of tantalum in the parking position. (C) 2013 Elsevier B.V. All rights reserved
Maze
No full textUn niño construye un laberinto de ligustrina en el patio de su casa para la diversión de cachorros, el juego de exploración y alegría se convierte en un misterio verde que nunca para de crecer. Esta hecho con una técnica de ilustración digital con trazos de crayón que envuelve esta aventura guiando a los lectores por senderos ocultos y pasillos interminables.Escritores: Vitagliano, Marina
Ilustrador/Estudiante: Ferella, Mateo
Docente coordinador: Zeltner, Marcelo - Turno mañana
Área: Comunicación Visual
Audiencia: Infantil 2: 8 a 12 años
Institución beneficiaria seleccionada: JBA. Juan Bautista Alberdi-Isidro Casanova.Facultad de ArtesInfantil 2: 8 a 12 año
Implementazione della diagnostica molecolare multigenica nei percorsi di identificazione della predisposizione del carcinoma dell'ovaio e della mammella
No full textCirca il 5-10% delle neoplasie alla mammella e ovaio insorge perchè su base genetica si ereditano mutazioni patogenetiche predisponenti nei geni BRCA1 e BRCA2. Si tratta di geni oncosoppressori conosciuti principalmente per la loro funzione di sorveglianza dell’integrità genomica attraverso la riparazione delle rotture a doppio filamento del DNA. La trasmissione delle mutazioni su di essi avviene con modalità autosomica dominante ed i soggetti che ne sono portatori hanno un’elevata probabilità nel tempo di sviluppare la neoplasia. L’importanza clinica per lo studio di BRCA1 e BRCA2 ha un duplice risvolto, si può garantire ai soggetti in corso di patologia una terapia personalizzata e mettere a punto dei protocolli di prevenzione per tutti i soggetti portatori di mutazione deleteria ma ancora sani. Il progetto di ricerca, articolato in due momenti, ha previsto nella prima parte lo studio su 100 pazienti selezionati dal 1/9/2017 al 31/7/2022 in cui sono stati analizzati i geni BRCA1 e BRCA2 andando a ricercare tramite sequenziamento diretto tutte le mutazioni puntiformi presenti, è stato possibile includere nello studio anche l’analisi di grandi delezioni tramite tecnica QMPSF. Dall’analisi sono emerse numerose varianti di classe 1,2,3 oltre che di classe 5. Sono riportate, in particolare, tutte le varianti trovate nei pazienti analizzati tra il 2020 ed il 2021, per BRCA1: 24 mutazioni di classe 1 di cui 2 mai riportate su database, per BRCA2 42 mutazioni di classe 1, una in particolare trovata in 5 pazienti in condizione di omozigosi e 2 mutazioni di classe 5. La prima sull’esone 11 in due pazienti correlati tra loro e la seconda situata sull’esone 14 emersa in 4 pazienti correlati.
La seconda parte del progetto è stata dedicata alla comparazione dei risultati ottenuti dal sequenziamento diretto con quelli ricavati, analizzando una parte degli stessi pazienti (nello specifico 5), ma con tecnologia NGS Illumina. Durante gli anni di ricerca è stato possibile caratterizzare sul nostro territorio una mutazione founder non senso situata sull’esone 12 di BRCA1, c.4117G>T (p.Glu1373*) ed emersa in ben 17 famiglie originarie principalmente del comune di Tagliacozzo e lungo il decorso del fiume Liri
Screening di materiali tramite ICP-MS per caratterizzazione di background in esperimenti di bassa radioattività
No full textSearch for very rare astroparticle physics events, such as Neutrinoless Double Beta
Decay or direct Dark Matter interactions demands for extremely low background
environments and materials for the experiment construction. The former requirement
is fulfilled by underground laboratories, such as the Laboratori Nazionali del Gran
Sasso of INFN, where the overburden rock reduces the cosmic ray flux by six orders
of magnitude with respect to the sea level. The latter requirement, i.e., the material
selection and cleaning for low-background experiment, increasingly challenges the
international scientific community to develop new purification techniques and push
the sensitivity to the edge of instrumental limits. Indeed, given the variety of
materials used for the construction of experiments (i.e., metals, plastics, electronics
compounds, loaded liquids, pressurised gases) and the very low levels of radiocontamination required, versatile and cutting-edge purification and characterisation
techniques are needed.
Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is one of the most
suitable technique for material screening because of its versatility and additional
features such as high sensitivity (ppt level), short analysis time (days), small mass of
samples (mg), possibility to acquire many elements simultaneously, and development
of efficient analysis methods. Furthermore, several processes and chemical treatments
are involved in the production of the raw materials, thus the effect of each step on the
final product must be known in detail in order to be able to optimize the production
protocol from the radiopurity point of view. ICP-MS is the only screening technique
capable of investigating contaminations in all stages of production, for example
separating bulk contaminations from surface ones by means of progressive chemical
attacks.
In order to reach excellent results with ICP-MS, the workspace is crucial, because
environmental contaminations must be avoided. For this reason, clean-rooms are
ideal environment to perform both sample’s treatment and characterization through
ICP-MS.
My thesis work was developed at the Chemistry and Chemical Plants Service
of the Gran Sasso National Laboratories. I was involved in the development of
innovative techniques for the cleaning and characterization of materials. Especially
of the X and Y experiments.
In the framework of the LEGEND experiment, highly enriched germanium
crystals have been purified exploiting a chemical plant designed for this specific
purpose. A sequence of chemical reactions was tuned to convert metal germanium
crystals into high pure GeO2. The purification process was continuously monitored
online by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), in order to
verify the purification efficiency and the conversion rate from starting material to
final products.
Moreover, another material widely used to build inner structures and external
shields of astroparticle physics experiments is copper, which is one of the most
radiopure metal, easy to machine and suitable also for cryogenic applications. Given
the extremely low contaminations in thorium and uranium (10−12 – 10−15 g/g) in
copper, different approaches must be developed in order to reach low detection limits
at a level of 0.4 - 1 × 10−12 g/g). In this thesis, pre-concentration methods based on
matrix extractions were developed to maximize quantification of Th and U in several
samples of copper. On the other hand, also different materials (plastic, metals,
organic) have been characterized through ICP-MS analysis, developing different
treatments to solubilize them
Assessment of Hybrid Propulsion for Geostationary Transfer Orbits: a Mission Design Approach
No full textThe classic strategy to place a satellite in the geostationary orbit (GEO) relies on chemical propulsion. Starting from a low-Earth orbit, this solution allows acquiring the final GEO by applying, ideally, only two impulses. This option has proven to be effective, and grants short transfer times. On the other hand, the increase of power levels required by payloads in GEO satellites has paved the way to the all-electric solutions. In these satellites, the GEO is achieved by a low-thrust transfer, typically starting from a geostationary transfer o rbit. This strategy involves designing more efficient satellites (that is, less propellant is used in the transfer phase) at the cost of accounting for longer transfer times, which can be on the order of up to six months, depending on the thrust-to-mass authority [Kluever, 2010]. The two options available give rise to platforms having divergent features. On the one hand we have the fully chemical satellite, with short transfer times but large propellant masses, on the other hand, the fully electric satellite, with low propellant mass fractions but long transfer times. This dichotomy is too firm, and forbids widening the trade space in preliminary design of GEO satellites. A way to account for intermediate design solutions consists in allowing the two propulsion systems to coexist on the GEO platform [Kluever, 2015]. In principle, a hybrid propulsion system may lead to a family of design solutions that fill the gap between the two boundary solutions. Recent studies have shown that hybrid spacecraft have peculiar features when applied to missions to Mars, Moon, and NEOs [Mingotti, Topputo, Massari 2013]. However, a methodology to preliminary assess this kind of solutions is not established yet, and requires non-trivial procedure. In this paper we elaborate on the concept of hybrid propelled satellite for GEO applications. A preliminary design procedure is derived, which allows evaluating the usefulness of hybrid platforms for given payload. Elements of preliminary system design are combined to those of preliminary trajectory optimization. These involve power subsystem sizing, electric and chemical propulsion modeling, and multispiral, long-duration, low-thrust trajectory optimization. The overall benefits of hybrid GEO satellites are evaluated by using economical models as well. The results show that hybrid platforms may be conceived as a viable option to widen the trade space for the next generation of GEO satellites
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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