The aim of this study was to compare the trueness and precision of four intraoral scanners used in oral implantology.
Two stone models were prepared, representing a partially and a totally edentulous ...maxilla, with three and six implant analogues, respectively, and polyether-ether-ketone (PEEK) cylinders screwed on. The models were digitized with an industrial scanner (IScan D104I®) used as a reference, and with four intraoral scanners (Trios®; CS 3500®; Zfx Intrascan®; Planscan®). Five scans were taken for each model, using each different intraoral scanner. All datasets were loaded into reverse-engineering software (Geomagics 2012®), where intraoral scans were superimposed on the reference model, to evaluate general trueness, and superimposed on each other within groups, to evaluate general precision. General trueness and precision of any scanner were compared by model type, through an ANOVA model including scanner, model and their interaction. Finally, the distance and angles between simulated implants were measured in each group, and compared to those of the reference model, to evaluate local trueness.
In the partially edentulous maxilla, CS 3500® had the best general trueness (47.8 μm) and precision (40.8 μm), followed by Trios® (trueness 71.2 μm, precision 51.0 μm), Zfx Intrascan® (trueness 117.0 μm, precision 126.2 μm), and Planscan® (trueness 233.4 μm, precision 219.8 μm). With regard to general trueness, Trios® was significantly better than Planscan®, CS 3500® was significantly better than Zfx Intrascan® and Planscan®, and Zfx Intrascan® was significantly better than Planscan®; with regard to general precision, Trios® was significantly better than Zfx Intrascan® and Planscan®, CS 3500® was significantly better than Zfx Intrascan® and Planscan®, and Zfx Intrascan® was significantly better than Planscan®. In the totally edentulous maxilla, CS 3500® had the best performance in terms of general trueness (63.2 μm) and precision (55.2 μm), followed by Trios® (trueness 71.6 μm, precision 67.0 μm), Zfx Intrascan® (trueness 103.0 μm, precision 112.4 μm), and Planscan® (trueness 253.4 μm, precision 204.2 μm). With regard to general trueness, Trios® was significantly better than Planscan®, CS 3500® was significantly better than Zfx Intrascan® and Planscan®, and Zfx Intrascan® was significantly better than Planscan®; with regard to general precision, Trios® was significantly better than Zfx Intrascan® and Planscan®, CS 3500® was significantly better than Zfx Intrascan® and Planscan®, and Zfx Intrascan® was significantly better than Planscan®. Local trueness values confirmed these results.
Although no differences in trueness and precision were found between partially and totally edentulous models, statistically significant differences were found between the different scanners. Further studies are required to confirm these results.
The astrophysical S factor for the radiative capture d(p,γ)^{3}He in the energy range of interest for big bang nucleosynthesis (BBN) is calculated using an ab initio approach. The nuclear Hamiltonian ...retains both two- and three-nucleon interactions-the Argonne v_{18} and the Urbana IX, respectively. Both one- and many-body contributions to the nuclear current operator are included. The former retain for the first time, besides the 1/m leading order contribution (m is the nucleon mass), also the next-to-leading order term, proportional to 1/m^{3}. The many-body currents are constructed in order to satisfy the current conservation relation with the adopted Hamiltonian model. The hyperspherical harmonics technique is applied to solve the A=3 bound and scattering states. Particular attention is paid in this second case in order to obtain, in the energy range of BBN, an uncertainty on the astrophysical S factor of the order or below ∼1%. Then, in this energy range, the S factor is found to be ∼10% larger than the currently adopted values. Part of this increase (1%-3%) is due to the 1/m^{3} one-body operator, while the remaining is due to the new more accurate scattering wave functions. We have studied the implication of this new determination for the d(p,γ)^{3}He S factor on the deuterium primordial abundance. We find that the predicted theoretical value for ^{2}H/H is in excellent agreement with its experimental determination, using the most recent determination of the baryon density of the Planck experiment, and with a standard number of relativistic degrees of freedom N_{eff}=3.046 during primordial nucleosynthesis. This calls for a more accurate measurement of the astrophysical S factor in order to confirm the present predictions.
Bounds on very low reheating scenarios after Planck de Salas, P. F.; Lattanzi, M.; Mangano, G. ...
Physical review. D, Particles, fields, gravitation, and cosmology,
12/2015, Letnik:
92, Številka:
12
Journal Article
We describe a program for computing the abundances of light elements produced during Big Bang Nucleosynthesis which is publicly available at
http://parthenope.na.infn.it/. Starting from nuclear ...statistical equilibrium conditions the program solves the set of coupled ordinary differential equations, follows the departure from chemical equilibrium of nuclear species, and determines their asymptotic abundances as function of several input cosmological parameters as the baryon density, the number of effective neutrino, the value of cosmological constant and the neutrino chemical potential. The program requires commercial NAG library routines.
Program title: PArthENoPE
Catalogue identifier: AEAV_v1_0
Program summary URL:
http://cpc.cs.qub.ac.uk/summaries/AEAV_v1_0.html
Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland
Licensing provisions: Standard CPC licence,
http://cpc.cs.qub.ac.uk/licence/licence.html
No. of lines in distributed program, including test data, etc.: 10 033
No. of bytes in distributed program, including test data, etc.: 46 002
Distribution format: tar.gz
Programming language: Fortran 77
Computer: PC-compatible running Fortran on Unix, MS Windows or Linux
Operating system: Windows 2000, Windows XP, Linux
Classification: 1.2, 1.9, 17.8
External routines: NAG Libraries
Nature of problem: Computation of yields of light elements synthesized in the primordial universe.
Solution method: BDF method for the integration of the ODEs, implemented in a NAG routine.
Running time: 90 sec with default parameters on a Dual Xeon Processor 2.4 GHz with 2 GB RAM.
The neutrino energy density of the Universe can be conveniently parametrized in terms of the so-called effective number of neutrinos, Nνeff. This parameter enters in several cosmological observables. ...In particular it is an important input in those numerical codes, like CMBFAST, which are used to study the Cosmic Microwave Background anisotropy spectrum. By studying the neutrino decoupling with Boltzmann equations, one can show that this quantity differs from the number of massless neutrino species for an additional contribution due to a partial heating of neutrinos during the e± annihilations, leading to non-thermal features in their final distributions. In this Letter we review the different results obtained in the literature and perform a new analysis which takes into account, in a fully consistent way, the QED corrections at finite temperature to the photon and e± plasma equation of state. The value found for three massless active neutrinos is Nνeff=3.0395, in perfect agreement with the recommended value used in CMBFAST, Nνeff=3.04. We also discuss the case of additional relativistic relics and massive active neutrinos.
A
bstract
Minimal SO(10) grand unified models provide phenomenological predictions for neutrino mass patterns and mixing. These are the outcome of the interplay of several features, namely: i) the ...seesaw mechanism; ii) the presence of an intermediate scale where B-L gauge symmetry is broken and the right-handed neutrinos acquire a Majorana mass; iii) a symmetric Dirac neutrino mass matrix whose pattern is close to the up-type quark one. In this framework two
natural
characteristics emerge. Normal neutrino mass hierarchy is the only allowed, and there is an approximate relation involving both light-neutrino masses and mixing parameters. This differs from what occurring when horizontal flavour symmetries are invoked. In this case, in fact, neutrino mixing
or
mass relations have been separately obtained in literature. In this paper we discuss an example of such comprehensive mixing-mass relation in a specific realization of SO(10) and, in particular, analyse its impact on the expected neutrinoless double beta decay effective mass parameter 〈
m
ee
〉, and on the neutrino mass scale. Remarkably a lower limit for the lightest neutrino mass is obtained (
m
lightest
≳ 7
.
5 × 10
−
4
eV, at 3
σ
level).
Objectives
To investigate whether short (6‐mm) dental implants could be an alternative to sinus floor elevation (SFE) and placement of longer (≥10‐mm) implants in the posterior maxilla.
Materials and ...methods
Over a 3‐year period, all patients presenting with partial edentulism in the posterior maxilla were considered for inclusion in this randomized controlled trial. Patients were randomly chosen either to receive short (6‐mm) implants (test group TG) or to undergo SFE with simultaneous placement of standard‐length (≥10‐mm) implants (control group CG). SFE was performed using the lateral technique. In both groups, tapered implants (AnyRidge, MegaGen, Gyeongbuk, South Korea) were placed. All implants were loaded after 4 months of healing. At each annual follow‐up session, clinical and radiographic parameters were assessed. Primary outcomes were implant survival, stability (measured with the implant stability quotient ISQ), marginal bone loss (MBL), and complications; secondary outcomes were patient satisfaction and treatment time and cost.
Results
Thirty‐three patients were assigned to the TG and 20 to the CG. Forty‐five implants were inserted in each group. At 3 years, implant survival rates were 100% and 95.0% for the TG and CG, respectively; this difference was not statistically significant (P = 0.38). The mean ISQ values of the TG and CG did not differ at placement (68.2 vs. 67.8, P = 0.1), at delivery of the final restoration (69.5 vs. 69.4, P = 0.9), and after 1 year (71.0 vs. 71.5, P = 0.1); at 3 years, the CG had a significantly higher mean ISQ than the TG (72.4 vs. 71.6, P = 0.004). Mean MBL was significantly higher in the CG than in the TG, both at 1 year (0.14 mm vs. 0.21 mm, P = 0.006) and at 3 years (0.20 mm vs. 0.27 mm, P = 0.01). A few complications were reported. Surgical time and cost were significantly higher in the CG than in the TG (P < 0.0001). Patient satisfaction was high in both groups.
Conclusions
In this randomized controlled trial, results for short (6‐mm) implants were similar to those for longer (≥10‐mm) implants in augmented bone. Short implants might be preferable to SFE, because the treatment is faster and less expensive. Long‐term randomized controlled trials are required to confirm these results.
Transport of radon through materials is a process strongly influenced by several parameters characterizing the materials themselves, such as porosity, permeability, grain size, content of ...radionuclides and diffusion coefficient of this gas through the interstitial pores and/or fractures of material. In order to enlighten more on the radon transport mechanisms, we are carrying out a systematic study on both in-soil radon measurements and laboratory analysis. Laboratory measurements are carried out on different types of samples from geologically different sites in the East Sicily (Italy), to measure the exhalation rate of radon at different controlled physical conditions, varying the parameters of porosity and grain size, content of radio, in order to characterize the dependence of the process of radon transport by these parameters.
We report in particular preliminary results of our study on radionuclide content and on the radon exhalation rate from building materials used in Mt. Etna and in the Hyblean Plateau villages.
This study is important from the radioprotection point of view and could represent a contribution to better define the transport process of radon through fractured media to clarify on correlation between radon concentration and geodynamical, volcanic and tectonic, events.
► Measurements of radium content in building materials. ► Measurements of radon exhalation rate. ► Dependence on grain size.
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