6,325 research outputs found
Digital planning of composite customized veneers using Digital Smile Design: Evaluation of its accuracy and manufacturing
Objectives: This study aimed to evaluate the production of customized composite veneers starting from a two-dimensional (2D) digital preview using the Digital Smile System (DSS). Material and Methods: A photographic examination of 30 patients was performed by taking two digital pictures of the face and a digital preview through the DSS. Moreover, optical scans of the dental arches were obtained and the data were entered into a three-dimensional (3D) software to prepare a virtual preview. The standard tessellation language files were sent for production using CAD-CAM technology. The Friedman test, Bonferroni, and Dunn post hoc tests were used, comparing the linear measurements of the 2D and 3D plans and the final veneers (α =.05). Results: Significant differences emerged between the pictures and digital scans on the mesial–distal widths of the lateral incisors and canine. Linear measurements in the 2D plan were significantly different from those of the 3D plan, except for the height measures of incisors. No significant changes were found on comparing the parameters of the 2D and 3D plans with those of the final pieces. Conclusions: The customized veneers were clinically adequate and similar to 2D and 3D plans, although significant differences emerged between the picture and digital scans as well as between the 2D and 3D plans
Evidence for tidal interaction and merger as the origin of galaxy morphology evolution in compact groups
We present the results of a morphological study based on NIR images of 25
galaxies, with different levels of nuclear activity, in 8 Compact Groups of
Galaxies (CGs). We perform independently two different analysis: a isophotal
study and a study of morphological asymmetries. The results yielded by the two
analysis are highly consistent. For the first time, it is possible to show that
deviations from pure ellipses are produced by inhomogeneous stellar mass
distributions related to galaxy interactions and mergers. We find evidence of
mass asymmetries in 74% of the galaxies in our sample. In 59% of these cases,
the asymmetries come in pairs, and are consistent with tidal effects produced
by the proximity of companion galaxies. The symmetric galaxies are generally
small in size or mass, inactive, and have an early-type morphology. In 20% of
the galaxies we find evidence for cannibalism. In 36% of the early-type
galaxies the color gradient is positive (blue nucleus) or flat. Summing up
these results, as much as 52% of the galaxies in our sample could show evidence
of an on going or past mergers. Our observations suggest that galaxies in CGs
merge more frequently under ``dry'' conditions. The high frequency of
interacting and merging galaxies observed in our study is consistent with the
bias of our sample towards CGs of type B, which represents the most active
phase in the evolution of the groups. In these groups we also find a strong
correlation between asymmetries and nuclear activity in early-type galaxies.
This correlation allows us to identify tidal interactions and mergers as the
cause of galaxy morphology transformation in CGs.[abridge]Comment: 64 pages, 35 figures. Accepted for publication in Ap
Neuroendocrine carcinomas of the breast
INTRODUCTION: Neuroendocrine (NE) breast cancers encompass a heterogeneous group of tumours showing morphological features similar to those of NE neoplasms of the gut and lung and expressing one or more neuroendocrine markers (neuron specific enolase, chromogranins synaptophysin) in at least 50% of tumour cells. They are rare lesions representing about 2-3% of all breast cancers and affecting more frequently elderly patients.
AIM: Prospective observational study is to analyse the clinico-pathological aspects of NE carcinomas of the breast undergone surgical resection compared to breast carcinomas with a minor neuroendocrine component and to conventional invasive ductal or lobular cancers.
MATERIAL AND METHOD: Thirty-five consecutive breast carcinomas showing morphological features suggestive of an endocrine differentiation were selected among breast cancers undergone surgical treatment during the period of January 1979-December 2004.
RESULTS: The 35 patients were divided into two categories: 13 neuroendocrine carcinomas (NECs) and 22 ductal carcinomas with a minor neuroendocrine component (DC-NE). The average follow-up was 60 months. The patients with CNE developed breast cancer in an advanced age compared to the patients with infiltrating ductal carcinoma NAS or infiltrating lobular carcinoma. We did not find recurrent disease in the NEC group, while it was observed in 2 patients (9%) with DC-NE, in 6 cases (17%) with infiltrating ductal carcinoma NAS and in 7 cases (20%) with infiltrating lobular carcinoma.
DISCUSSION: The CNE compared with the infiltrating ductal and lobular carcinoma are statistically different in relation to the expression of the receptor of c-erb-B2, p53, progesterone, for the lymph node state at diagnosis and the risk of reappearance of breast tumour. Our study confirms the choice to consider the neuroendocrine carcinoma of the breast as a separate histological group and seems to suggest a less aggressiveness of this type of tumou
Dosimetric characterization of a synthetic single crystal diamond detector in a clinical 62 MeV ocular therapy proton beam
A synthetic single crystal diamond based Schottky photodiode was tested at INFN-LNS on the proton beam line (62 MeV) dedicated to the radiation treatment of ocular disease. The diamond detector response was studied in terms of pre-irradiation dose, linearity with dose and dose rate, and angular dependence. Depth dose curves were measured for the 62 MeV pristine proton beam and for three unmodulated range-shifted proton beams; furthermore, the spread-out Bragg peak was measured for a modulated therapeutic proton beam. Beam parameters, recommended by the ICRU report 78, were evaluated to analyze depth-dose curves from diamond detector. Measured dose distributions were compared with the corresponding dose distributions acquired with reference plane-parallel ionization chambers. Field size dependence of the output factor (dose per monitor unit) in a therapeutic modulated proton beam was measured with the diamond detector over the range of ocular proton therapy collimator diameters (5-30 mm). Output factors measured with the diamond detector were compared to the ones by a Markus ionization chamber, a Scanditronix Hi-p Si stereotactic diode and a radiochromic EBT2 film. Signal stability within 0.5% was demonstrated for the diamond detector with no need of any pre-irradiation dose. Dose and dose rate dependence of the diamond response was measured: deviations from linearity resulted to be within ±0.5% over the investigated ranges of 0.5-40.0 Gy and 0.3-30.0 Gy/min respectively. Output factors from diamond detector measured with the smallest collimator (5 mm in diameter) showed a maximum deviation of about 3% with respect to the high resolution radiochromic EBT2 film. Depth-dose curves measured by diamond for unmodulated and modulated beams were in good agreement with those from the reference plane-parallel Markus chamber, with relative differences lower than ±1% in peak-to-plateau ratios, well within experimental uncertainties. A 2.5% variation in diamond detector response was observed in angular dependence measurements carried-out by varying the proton beam incidence angle in the polar direction. The dosimetric characterization of the tested synthetic single crystal diamond detector clearly indicates its suitability for relative dosimetry in ocular therapy proton beams, with no need of any correction factors accounting for dose rate and linear energy transfer dependence
Expected performance of the ASTRI-SST-2M telescope prototype
ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) is an
Italian flagship project pursued by INAF (Istituto Nazionale di Astrofisica)
strictly linked to the development of the Cherenkov Telescope Array, CTA.
Primary goal of the ASTRI program is the design and production of an end-to-end
prototype of a Small Size Telescope for the CTA sub-array devoted to the
highest gamma-ray energy region. The prototype, named ASTRI SST-2M, will be
tested on field in Italy during 2014. This telescope will be the first
Cherenkov telescope adopting the double reflection layout in a
Schwarzschild-Couder configuration with a tessellated primary mirror and a
monolithic secondary mirror. The collected light will be focused on a compact
and light-weight camera based on silicon photo-multipliers covering a 9.6 deg
full field of view. Detailed Monte Carlo simulations have been performed to
estimate the performance of the planned telescope. The results regarding its
energy threshold, sensitivity and angular resolution are shown and discussed.Comment: In Proceedings of the 33rd International Cosmic Ray Conference
(ICRC2013), Rio de Janeiro (Brazil). All CTA contributions at arXiv:1307.223
Final performances of the X-ray Mirrors of the JET-X telescope
The Joint European Telesscope (JET-X) is one of the core scientific
instruments of the SPECTRUM-X-Gamma mission. JET-X was designed to study X-ray
emissions in the band 0.3-10 KeV. Its angular resolution is better than 20
arcsec; the values of the effective areas are 161 cm2 at 1.5 KeV and 69 cm2 at
8 Kev (for one telescope). The value of the HEW circle in function of the
off-axis angle is presented; it is found to be below 20 arcsec at 1.5 Kev and
around 23 arcsec at 8 KeV up to an off-axis angle of 12 arcmin.Comment: 2 pages, 1 ps figure. To be published in the Proceedings of the IAU
Symposium 188 THE HOT UNIVERSE, held in Kyoto (August 26-30, 1997) in
occasion of the XXIII IAU General Assembl
Synergy between the pharmacological chaperone 1-deoxygalactonojirimycin and the human recombinant alpha-galactosidase A in cultured fibroblasts from patients with Fabry disease.
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