65 research outputs found

    O6-[(2”,3”-O-Isopropylidene-5”-O-tbutyldimethylsilyl)pentyl]- 5â€Č-O-tbutyldiphenylsilyl-2â€Č,3â€Č-O-isopropylideneinosine

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    Cyclic adenosine diphosphate ribose (cADPR) is a cyclic nucleotide involved in the Ca2+ homeostasis. In its structure, the northern ribose, bonded to adenosine through an N1 glycosidic bond, is connected to the southern ribose through a pyrophosphate bridge. Due to the chemical instability at the N1 glycosidic bond, new bioactive cADPR derivatives have been synthesized. One of the most interesting analogues is the cyclic inosine diphosphate ribose (cIDPR), in which the hypoxanthine replaced adenosine. The efforts for synthesizing new linear and cyclic northern ribose modified cIDPR analogues led us to study in detail the inosine N1 alkylation reaction. In the last few years, we have produced new flexible cIDPR analogues, where the northern ribose has been replaced by alkyl chains. With the aim to obtain the closest flexible cIDPR analogue, we have attached to the inosine N1 position a 2”,3”-dihydroxypentyl chain, possessing the two OH groups in a ribose-like fashion. The inosine alkylation reaction afforded also the O6-alkylated regioisomer, which could be a useful intermediate for the construction of new kinds of cADPR mimics

    A Borehole Muon Telescope for Underground Muography

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    Radiographic imaging with muons by absorption, also called Muon Radiography or Muography, is a methodology based on the characteristic of the matter to be crossed by high energy muons. This physical property allows muons to pass through the material with a measurable degree of absorption depending on the density of the material. Muon Radiography applies to several different situations and is particularly suitable for investigating subsoil of civil or archaeological interest. This kind of applications needs the muon detector to be installed below the target region. A novel borehole cylindrical detector has been built and tested for use in harsh conditions and for limited space installations. It is based on the past expertise with scintillator detectors and is composed of two types of scintillating elements, bar-shaped and arcshaped. Due to its size, it can be easily installed in drilled holes of 25 cm in diameter or more, typically economical to make. Here, we describe the idea, commissioning, and some preliminary results

    Evaluation of Legionella Air Contamination in Healthcare Facilities by Different Sampling Methods: An Italian Multicenter Study

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    Healthcare facilities (HF) represent an at-risk environment for legionellosis transmission occurring after inhalation of contaminated aerosols. In general, the control of water is preferred to that of air because, to date, there are no standardized sampling protocols. Legionella air contamination was investigated in the bathrooms of 11 HF by active sampling (Surface Air System and CoriolisÂźÎŒ) and passive sampling using settling plates. During the 8-hour sampling, hot tap water was sampled three times. All air samples were evaluated using culture-based methods, whereas liquid samples collected using the CoriolisÂźÎŒ were also analyzed by real-time PCR. Legionella presence in the air and water was then compared by sequence-based typing (SBT) methods. Air contamination was found in four HF (36.4%) by at least one of the culturable methods. The culturable investigation by CoriolisÂźÎŒ did not yield Legionella in any enrolled HF. However, molecular investigation using CoriolisÂźÎŒ resulted in eight HF testing positive for Legionella in the air. Comparison of Legionella air and water contamination indicated that Legionella water concentration could be predictive of its presence in the air. Furthermore, a molecular study of 12 L. pneumophila strains confirmed a match between the Legionella strains from air and water samples by SBT for three out of four HF that tested positive for Legionella by at least one of the culturable methods. Overall, our study shows that Legionella air detection cannot replace water sampling because the absence of microorganisms from the air does not necessarily represent their absence from water; nevertheless, air sampling may provide useful information for risk assessment. The liquid impingement technique appears to have the greatest capacity for collecting airborne Legionella if combined with molecular investigation

    Thirty years of precise gravity measurements at Mt. Vesuvius: an approach to detect underground mass movements

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    Since 1982, high precision gravity measurements have been routinely carried out on Mt. Vesuvius. The gravity network consists of selected sites most of them coinciding with, or very close to, leveling benchmarks to remove the effect of the elevation changes from gravity variations. The reference station is located in Napoli, outside the volcanic area. Since 1986, absolute gravity measurements have been periodically made on a station on Mt. Vesuvius, close to a permanent gravity station established in 1987, and at the reference in Napoli. The results of the gravity measurements since 1982 are presented and discussed. Moderate gravity changes on short-time were generally observed. On long-term significant gravity changes occurred and the overall fields displayed well defined patterns. Several periods of evolution may be recognized. Gravity changes revealed by the relative surveys have been confirmed by repeated absolute measurements, which also confirmed the long-term stability of the reference site. The gravity changes over the recognized periods appear correlated with the seismic crises and with changes of the tidal parameters obtained by continuous measurements. The absence of significant ground deformation implies masses redistribution, essentially density changes without significant volume changes, such as fluids migration at the depth of the seismic foci, i.e. at a few kilometers. The fluid migration may occur through pre-existing geological structures, as also suggested by hydrological studies, and/or through new fractures generated by seismic activity. This interpretation is supported by the analyses of the spatial gravity changes overlapping the most significant and recent seismic crises

    Epidemiologia del morbillo nella regione Marche: analisi descrittiva dei casi segnalati in area vasta 2 nel 2017

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    INTRODUZIONE: Nel 2016 i casi di morbillo segnalati In Italia tramite Sistema di Sorveglianza Integrata Morbillo e Rosolia, ammontavano a 844; giĂ  nel primo semestre del 2017 questa cifra risulta quintuplicata, con tre decessi correlati a complicanze (dati ISS). Nelle Marche si Ăš registrato un aumento dei casi rispetto al 2016 pari a circa 9 volte, passando da 6 a 53 segnalazioni. Il presente studio descrive da un punto di vista epidemiologico i casi segnalati in AV2 nei primi mesi del 2017. MATERIALI E METODI: Sono stati identificati 23 casi di morbillo, di cui uno non confermato, registrati tra gennaio ed agosto 2017 dal Servizio di Igiene e SanitĂ  Pubblica di Ancona. La conferma dei casi si Ăš basata su indagini di laboratorio. Dei casi identificati sono stati valutati caratteristiche anagrafiche, socioeconomiche e fattori di esposizione, indagati dal SISP tramite inchiesta epidemiologica. I dati raccolti sono stati analizzati con metodo statistico ed elaborati tramite programma STATA; infine sono stati confrontati con quelli nazionali, per identificare corrispondenze o scostamenti dalla media. RISULTATI: Il 65,2% dei soggetti Ăš risultato avere piĂč di 14 anni, con un’etĂ  media pari a 23,2 anni e una leggera prevalenza nel sesso maschile (56,5%). L’82,6% non ha ricevuto la vaccinazione MPR, l’8,7% ha ricevuto una singola dose, due soggetti non ricordano. Il 69,6% dei casi sono risultati autoctoni, di cui quattro infezioni contratte fuori regione; tre casi sono stati dichiarati di probabile importazione. I sintomi piĂč frequenti, oltre all’esantema, sono risultati febbre, congiuntivite, rinite e tosse. In un caso si sono manifestate complicanze (stomatite e cheratocongiuntivite). Il 43,5% dei pazienti ha avuto un accesso al Pronto Soccorso e per il 47,8% si Ăš reso necessario il ricovero. Tra i casi descritti sono stati identificati sei focolai epidemici, due dei quali correlati a permanenza in PS. Tre casi (13%) si sono verificati tra operatori sanitari. CONCLUSIONI: I casi di morbillo segnalati in AV2 sono rappresentativi di quanto sta accadendo a livello nazionale. L’epidemia in corso Ăš correlabile ai bassi tassi vaccinali regionali, ben al di sotto della soglia di sicurezza minima. Lo studio, dunque, conferma il bisogno di incentivare le campagne vaccinali, quali uniche armi a disposizione della salute pubblica

    Probing the reactivity of nebularine N1-oxide. A novel approach to C-6 C-substituted purine nucleosides

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    A novel approach to the synthesis of purine nucleoside analogues, featuring the reaction of the C6-N1-O-aldonitrone moiety of 9-ribosyl-purine (nebularine) N1-oxide with some representative dipolarophiles, as well as Grignard reagents, is reported. Addition of Grignard reagents to the electrophilic C-6 carbon of the substrate allows a facile access to C-6 C-substituted purine nucleosides without using metal catalysts. 1,3-Dipolar cycloaddition processes lead to novel nucleoside analogues via opening, degradation or ring-enlargement of the pyrimidine ring of the base system of the first-formed isoxazoline or isoxazolidine cycloadduc

    Quantitative accuracy of177Lu SPECT imaging for molecular radiotherapy

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    The purpose of this study is to investigate the optimal reference geometry for gamma camera calibration. Yet another question of interest was to assess the influence of the number of 3D Ordered Subsets Expectation Maximization (3D-OSEM) updates on activity quantification for SPECT imaging with177Lu. The accuracy of177Lu activity quantification was assessed both in small and in large objects. Two different reference geometries, namely a cylindrical homogeneous phantom and a Jaszczak 16 ml sphere surrounded by cold water, were used to determine the gamma camera calibration factor of a commercial SPECT/CT system. Moreover, the noise level and the concentration recovery coefficient were evaluated as a function of the number of 3D-OSEM updates by using the SPECT/CT images of the reference geometry phantoms and those of a cold Jaszczak phantom with three hot spheres (16ml, 8ml and 4ml), respectively. The optimal choice of the number of 3D-OSEM updates was based on a compromise between the noise level achievable in the reconstructed SPECT images and the concentration recovery coefficients. The quantitative accuracy achievable was finally validated on a test phantom, where a spherical insert composed of two concentric spheres was used to simulate a lesion in a warm background. Our data confirm and extend previous observations. Using the calibration factor obtained with the cylindrical homogeneous phantom and the Jaszczak 16 ml sphere, the recovered activity in the test phantom was underestimated by -16.4% and -24.8%, respectively. Our work has led us to conclude that gamma camera calibration performed with large homogeneous phantom outperforms calibration executed with the Jaszczak 16ml sphere. Furthermore, the results obtained support the assumption that approximately 50 OSEM updates represent a good trade-off to reach convergence in small volumes, meanwhile minimizing the noise level
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