LUNA MV Proposal 2018-2022

We have described the scientific activity we propose to perform during the first 5 year running time of the new 3.5 MV single-ended accelerator which will be installed under Gran Sasso at the beginning of 2018. The accelerator will provide hydrogen, helium and carbon (also doubly ionized) high current beams and it will be devoted to the study of those thermonuclear reactions that determine and shape both stellar evolution and the nucleosynthesis of most elements in the Universe. In particular, we are planning to start by measuring a reaction we have already studied with the 400 kV accelerator: 14N(p,γ) 15O. It is the bottleneck reaction of the CNO cycle and its precise extrapolation within the solar Gamow peak will allow to infer the metallicity of the central region of the Sun from the forthcoming measurement of the CNO neutrino flux. 12C+12C is the flagship of this 5 year program. This reaction is the trigger of the C burning in stars. In particular, its rate determines the lower stellar-mass limit for the C ignition. This limit separates the progenitors of white dwarfs, novae and type Ia supernovae, from those of core-collapse supernovae, neutron stars and stellar-mass black holes. 12C+12C will be measured on one of the two beam lines at the completion of the 14N(p,γ) 15O study, alternating in time with the measurement of 13C(α,n)16O on the other beam line. The other reaction responsible for neutron generation inside stars, 22Ne(α,n)25Mg, will then be the last measurement foreseen by this proposal

Treponema denticola in Disseminating Endodontic Infections

Treponema denticola is a consensus periodontal pathogen that has recently been associated with endodontic pathology. In this study, the effect of mono-infection of the dental pulp with T. denticola and with polymicrobial “red-complex” organisms (RC) (Porphyromonas gingivalis, Tannerella forsythia, and T. denticola) in inducing disseminating infections in wild-type (WT) and severe-combined-immunodeficiency (SCID) mice was analyzed. After 21 days, a high incidence (5/10) of orofacial abscesses was observed in SCID mice mono-infected with T. denticola, whereas abscesses were rare in SCID mice infected with the red-complex organisms or in wildtype mice. Splenomegaly was present in all groups, but only mono-infected SCID mice had weight loss. T. denticola DNA was detected in the spleen, heart, and brain of mono-infected SCID mice and in the spleen from mono-infected wild-type mice, which also had more periapical bone resorption. The results indicate that T. denticola has high pathogenicity, including dissemination to distant organs, further substantiating its potential importance in oral and linked systemic conditions

Analysis of elliptically polarized states in vertical-cavity-surface-emitting lasers

We study the elliptically polarized states in the spin-flip model for vertical-cavity-surface-emitting lasers. The stability analysis reveals some unexpected features. In correspondence with particular values of the birefringence parameter, which are shown to scale very simply with the ratio of the spin-flip rate to the linewidth enhancement factor, the stability domain can be quite large. Moreover, in some cases two different dynamical regimes can arise from the destabilization of the elliptically polarized states, and they can coexist in a finite interval of the pump parameter. Finally, we show that the bifurcation from the lower frequency linearly polarized state to the elliptically polarized states can be subcritical when the linewidth enhancement factor is roughly smaller than 1

PIXE and ToF-SIMS analysis of streaker samplers filters

This paper presents methodological innovations introduced in the characterisation of urban aerosol collected in Italy in a recent campaign. Two complementary ion beam analysis (IBA) techniques were used to analyse Nuclepore filters used in continuous streaker samplers to collect airborne particles in four Italian towns. Na to Pb elemental concentrations were obtained by particle induced X-ray emission (PIXE), while time of flight secondary ion mass spectrometry (ToF-SIMS) produced, on the same samples, time trends for several elements and molecular fragments. In addition, light attenuation measurements were used as a tracer for black carbon. The data produced by these three techniques was merged into a unique data set to address the characterisation of particulate matter sources. Correlations between elemental concentration trends (PIXE) and relative trends for molecular fragments (ToF-SIMS) and black carbon (light attenuation) have been studied by cluster and principal component analysis

Spectroscopic and morphological data assessing the apatite forming ability of calcium hydroxide-releasing materials for pulp capping

A pulp capping material must perform as a barrier and protect the dental pulpal complex by inducing the formation of a new dentin bridge or dentin-like tissue. Being a favorable condition for the healing process, the apatite forming ability of TheraCal (light-curable Portland-dimethacrylate cement) and Dycal (calcium hydroxide-based) pulp capping materials was studied in two simulated body fluids, i.e. Dulbecco's Phosphate Buffered Saline (DPBS) and Hank's Balanced Salt Solution (HBSS). The cements were analyzed before and after soaking in these media for different times (1\u201328 days) by ESEM-EDX, micro-Raman and IR spectroscopy. This data article refers to \u201cAn in vitro study on dentin demineralization and remineralization: collagen rearrangements and influence on the enucleated phase\u201d (Di Foggia et al., 2019)

EEG correlation at a distance: a re-analysis of two studies using a machine learning approach

Background: In this paper, data from two studies relative to the relationship between the electroencephalogram (EEG) activities of two isolated and physically separated subjects were re-analyzed using machine-learning algorithms. The first dataset comprises the data of 25 pairs of participants where one member of each pair was stimulated with a visual and an auditory 500 Hz signals of 1 second duration. The second dataset consisted of the data of 20 pairs of participants where one member of each pair received visual and auditory stimulation lasting 1 second duration with on-off modulation at 10, 12, and 14 Hz. Methods and Results: Applying a 'linear discriminant classifier' to the first dataset, it was possible to correctly classify 50.74% of the EEG activity of non-stimulated participants, correlated to the remote sensorial stimulation of the distant partner. In the second dataset, the percentage of correctly classified EEG activity in the non-stimulated partners was 51.17%, 50.45% and 51.91%, respectively, for the 10, 12, and 14 Hz stimulations, with respect the condition of no stimulation in the distant partner. Conclusions: The analysis of EEG activity using machine-learning algorithms has produced advances in the study of the connection between the EEG activities of the stimulated partner and the isolated distant partner, opening new insight into the possibility to devise practical application for non-conventional "mental telecommunications" between physically and sensorially separated participants

An Easy Route to Enantiomerically Enriched 7- and 8-Hydroxystearic Acids by Olefin Metathesis - Based Approach

The synthesis of enantiomerically enriched 7- and 8-hydroxystearic acids (7- and 8-HSA) has been successfully accomplished starting from chiral non racemic 1-pentadecen-4-ol and 1-tetradecen-4-ol respectively. Their Yamaguchi\u2019s esterification with 4-pentenoic and 5-hexenoic acids respectively afforded the suitable dienic esters which were submitted to ring closing metathesis reaction. After hydrogenation and basic hydrolysis of the complex reaction mixture, chiral non racemic 7- and 8-HSA were obtained in about 40% total yield

Light extinction estimates using the IMPROVE algorithm: The relevance of site-specific coefficients

Atmospheric aerosol and gases affect visibility by scattering and absorbing the incoming radiation (Watson, 2002; Pitchford et al, 2007). While the role of gases is relatively well understood, the effect of particulate matter (PM) is more complicated to be assessed since it depends on several factors such as particles size distribution and chemical composition as well as meteorological parameters (e.g. relative humidity \u2013 RH). The U.S. Interagency Monitoring of Protected Visual Environments (IMPROVE) network proposed a method to retrieve atmospheric light extinction coefficient (bext, Mm-1) in national parks from compositional and meteorological data (Malm et al, 1994; Watson, 2002). The result of this approach (often called chemical light extinction) allows the evaluation of visibility indicators such as visual range (VR) via the Koschmieder equation VR=3.912/bext. In this study we tailored the IMPROVE equation using site-specific dry mass extinction efficiencies and hygroscopic growth functions in order to obtain bext estimates which better reflect the typical atmospheric characteristics of the sampling site and period. The revised formulation was tested for the first time in the urban area of Milan, for two weeks during the winter season in 2015. Moreover, it was applied to a large and fully characterized dataset referred to PM1 samples collected in winter 2012. Following the IMPROVE algorithm (Malm et al, 1994; Watson, 2002; Pitchford et al, 2007) the chemical light extinction equation used in this work was: bext = k1 x f1(RH) x [AMSUL] + k2 x f2(RH) x [AMNIT] + k3 x f3(RH) [OM] + k4 x [fine soil] + bap + 0.60 x [coarse mass] + 0.33 x [NO2] (ppb) + Rayleigh scattering, where inputs are the concentrations of the five major PM components (ammonium sulphate - AMSUL, ammonium nitrate AMNIT, organic matter - OM, fine soil, coarse mass) in \u3bcg m-3, NO2 concentration (in ppb), Rayleigh scattering by gases (Mm-1) and aerosol light absorption coefficient (bap, Mm-1) measured with a home-made polar photometer on PTFE filters. Dry mass extinction efficiencies (k1-k4, m2 g-1) for every chemical component of interest were calculated considering size distributions measured in Milan (Vecchi et al, 2012), particles densities and complex refractive indices (Watson, 2002). Furthermore, hygroscopic growth functions fi(RH), defined as the ratios between ambient and dry aerosol scattering coefficients bsp), were also calculated (using hygroscopic growth factors taken from the literature) and were applied to those PM components (AMSUL, AMNIT and OM), whose bsp are enhanced by their water uptake at medium-high RH values. It is worthy to note that in the original IMPROVE algorithm (Malm et al, 1994; Watson, 2002) the hygroscopic growth function f(RH) is calculated referring only to AMSUL ygroscopic properties and it is applied also to AMNIT, whereas OM is considered as non-hygroscopic. Non-negligible discrepancies were found between tailored dry mass extinction efficiencies and the original IMPROVE ones. Furthermore, differences between calculated fi(RH) and IMPROVE hygroscopic growth function were found. The methodology here described was applied to a PM1 dataset thus retrieving the extinction contribution given by the different PM1 components as well as by the major aerosol sources. Both methodological and experimental results will be shown in the presentation. This work shows that \u2013 due to the large variability in size distributions and aerosol composition at sites with different characteristics (e.g. urban, industrial, rural) \u2013 it is advisable to calculate site-specific k1-k4 and fi(RH) coefficients instead of using the original IMPROVE ones, which refer to aerosol properties measured at U.S. national parks

Nitrogen functionalized carbon nanostructures supported Pd and Au-Pd NPs as catalyst for alcohols oxidation

Two different carbon nanotubes (CNTs) PR24-PS and Baytubes were functionalized by oxidation with nitric acid and further amination with gaseous NH3. Thus Au and Au-Pd nanoparticles were prepared by PVA/NaBH4 system and anchored on the surface of pristine CNTs and N-CNTs (Nitrogen functionalized carbon nanotubes). TEM analysis revealed that the introduction of nitrogen functionalities improves the dispersion of the metal nanoparticles on the surface of the support. This phenomena leads to an improved activity of N-CNTs based catalysts with the respect of pristine CNTs when tested in the liquid phase oxidation of alcohols

The Influence of the Matrix on the Apatite-Forming Ability of Calcium Containing Polydimethylsiloxane-Based Cements for Endodontics

This study aimed to characterize the chemical properties and bioactivity of an endodontic sealer (GuttaFlow Bioseal) based on polydimethylsiloxane (PDMS) and containing a calcium bioglass as a doping agent. Commercial PDMS-based cement free from calcium bioglass (GuttaFlow 2 and RoekoSeal) were characterized for comparison as well as GuttaFlow 2 doped with dicalcium phosphate dihydrate, hydroxyapatite, or a tricalcium silicate-based cement. IR and Raman analyses were performed on fresh materials as well as after aging tests in Hank's Balanced Salt Solution (28 d, 37 degrees C). Under these conditions, the strengthening of the 970 cm(-1) Raman band and the appearance of the IR components at 1455-1414, 1015, 868, and 600-559 cm(-1) revealed the deposition of B-type carbonated apatite. The Raman I-970/I-638 and IR A(1010)/A(1258) ratios (markers of apatite-forming ability) showed that bioactivity decreased along with the series: GuttaFlow Bioseal > GuttaFlow 2 > RoekoSeal. The PDMS matrix played a relevant role in bioactivity; in GuttaFlow 2, the crosslinking degree was favorable for Ca2+ adsorption/complexation and the formation of a thin calcium phosphate layer. In the less crosslinked RoekoSeal, such processes did not occur. The doped cements showed bioactivity higher than GuttaFlow 2, suggesting that the particles of the mineralizing agents are spontaneously exposed on the cement surface, although the hydrophobicity of the PDMS matrix slowed down apatite deposition. Relevant properties in the endodontic practice (i.e., setting time, radiopacity, apatite-forming ability) were related to material composition and the crosslinking degree