591 research outputs found
The effects of a common stainless steel orthodontic bracket on the diagnostic quality of cranial and cervical 3T-MR images: a prospective, case-control study
Abstract
OBJECTIVES:
To evaluate the effect of orthodontic stainless steel brackets and two different types of archwires (stainless steel and nickel-titanium) on the diagnostic quality of 3T-MR images.
METHODS:
This prospective, case-control study was conducted following STROBE guidelines. The imaging protocol consisted of the axial Fluid Attenuated Inversion Recovery (FLAIR) and axial oblique double echo proton density (PD) and weighted/turbo spin echo (TSE) T2-weighted sequences for brain, paranasal sinuses and cervical region evaluation; sagittal TSE T2w, sagittal TSE T1w and axial T2* Gradient echo sequences (GRE) sequences for the cervical vertebrae; axial and coronal TSE T2w images for the head and neck structures; and sagittal, axial and coronal PD and TSE T2-weighted sequences for the temporo-mandibular joint. Two experts in neuroradiology evaluated the images. The statistical analysis was performed at the level of anatomical districts. The following statistical methods were used: descriptive statistics, Cohen's kappa coefficient (k), Kruskal-Wallis test, pairwise comparisons using the Dunn-Bonferroni approach. Significance was set at p≤0.05.
RESULTS:
80 patients were included, providing 80 MRI. The presence of stainless steel brackets with or without archwires negatively influenced the MR images of the cervical region, paranasal sinuses, head and neck region and cervical vertebrae but did not influence the MR images of brain and temporomandibular joint regions.
CONCLUSIONS:
Patients with a stainless steel multi-bracket orthodontic appliance should remove it before cervical vertebrae, cervical region, paranasal sinuses and head and neck MRI scans. The brain and temporomandibular joint regions MRI should not require the removal of such appliances
Astro MBSE: overview on requirement management approaches for astronomical instrumentation
Systems Engineering requires the involvement of different engineering disciplines: Software, Electronics, Mechanics
(often nowadays together as Mechatronics), Optics etc. Astronomical Instrumentation is no exception to this. A critical
point is the handling of the requirements, their tracing, flow down and the interaction with stakeholders (flow up) and
subsystems (flow down) in order to have traceable and methodical evolution and management.
In the Italian Astronomical Community, we are developing methodologies and tools to share the expertise in this field
among the different projects. In this paper we will focus on the requirement management approach among different
projects (ground and space based, …). The target and synthesis of tis work will be a support framework for the
Requirement management of the Italian Astronomical Community (INAF) projects
Astro MBSE: model based system engineering synthesized for the Italian astronomical community
Systems Engineering requires the involvement of different engineering disciplines: Software, Electronics, Mechanics
(often nowadays together as Mechatronics), Optics etc. Systems Engineering of Astronomical Instrumentation is no
exception to this. A critical point is the handling of the different point of view introduced by these disciplines often
related to different tools and cultures. Model Based Systems Engineering (MBSE) approach can help the Systems
Engineer to always have a complete view of the full system. Moreover, in an ideal situation, all of the information
resides in the model thus allowing different views of the System without having to resort to different sources of
information, often outdated. In the real world, however, this does not happen because the different actors (Optical
Designers, Mechanical Engineers, Astronomers etc.) should adopt the same language and this is clearly, at least
nowadays and for the immediate future, close to impossible.
In the Italian Astronomical Community, we are developing methodologies and tools to share the expertise in this field
among the different projects. In this paper we present the status of this activity that aims to deliver to the community
proper tools and template to enable a uniformed use of MBSE (friendly name Astro MBSE) among different projects
(ground and space based, …). We will analyze here different software and different approaches. The target and synthesis
of this work will be a support framework for the MBSE based system Engineering activity to the Italian Astronomical
Community (INAF)
Skywalking in the city: Glass platforms and the architecture of vertigo
The paper explores the ambivalent concept of vertigo and its significance for contemporary architecture.
It examines in particular the rise of elevated glass platforms through concepts of transparency, experience, and kinaesthesia.
Proposes that these emerging design features constitute a kind of ‘sixth façade’.
Discusses this phenomenon as a spatial manifestation of the experience economy.
Concludes by highlighting the rise of ‘architectures of vertigo’ in relation to wider social imperatives
IL TRATTAMENTO DELLE DISLIPIDEMIE NELLA PREVENZIONE PRIMARIA DELLE MALATTIE CARDIOVASCOLARI: LE INDICAZIONI PER LA PRATICA CLINICA
Le dislipidemie rappresentano uno dei più importanti fattori causali della arteriosclerosi e delle sue complicanze d’organo, come l’infarto del miocardico, l’ictus e la vasculopatia periferica. Il loro appropriato trattamento rappresenta la base degli interventi di prevenzione primaria delle malattie cardiovascolari su base ischemica. In generale, per dislipidemia si intende una condizione clinica nella quale sono presenti alterazioni qualitative e/o quantitative dei lipidi e delle lipoproteine plasmatiche
Solar radiation effects on the Sardinia Radio Telescope performances
The Sardinia Radio Telescope, a 64-metre diameter fully steerable radio telescope operated by INAF, will be upgraded in order to extend its current operating frequency range 0.3-26.5 GHz up to 116 GHz, thanks to a National Operational Program (PON) funding assigned to INAF by the Italian Ministry of University and Research. The PON project is organized in nine Work Packages, one of which is dedicated to the accomplishment of a sophisticated metrology system designed to monitor the cause of the pointing errors and the reflector surface deformations. The entire antenna structure will therefore be equipped with a network of sensors, like thermal sensors, inclinometers, accelerometers, collimators, anemometers, strain gauges and others, to study environmental stresses and how they affect the SRT performances. This work is devoted to the investigation of the thermal stress effects produced by solar radiation. In particular, two analyses are carried out to confirm the relevance of a thorough temperature monitoring system, both conducted using Finite Element Analysis. First, a possible approach for the simulation of realistic thermal scenarios due to insolation is proposed and the effects on the pointing accuracy are analysed. Second, a feasible method to study the impacts that a differential heating of the Back Up Structure (BUS) produces on the radio telescope main reflector surface is presented. Finally, these effects are analysed as optical aberrations and modelled in terms of Zernike polynomials
Feasibility Study of a W-Band Multibeam Heterodyne Receiver for the Gregorian Focus of the Sardinia Radio Telescope
We report on the feasibility study of a W-band multibeam heterodyne receiver for the Sardinia Radio Telescope (SRT), a general purpose fully steerable 64-m diameter antenna located on the Sardinia island, Italy, managed by INAF ('Istituto Nazionale di Astrofisica,' Italy). The W-band front-end is designed for the telescope Gregorian focal plane and will detect both continuum and molecular spectral lines from astronomical sources and radio emission from the Sun in the 3 mm atmospheric window. The goal specification of the receiver is a focal plane array operating in dual-linear polarization with a front-end consisting of feed-horns placed in cascade with waveguide Orthomode Transducers (OMTs) and LNAs (Low Noise Amplifiers) cryogenically cooled at 20 K. The instantaneous FoV (Field of View) of the telescope is limited by the shaping of the 64-m primary and 7.9-m secondary mirrors. The cryogenic modules are designed to fit in the usable area of the focal plane and provide high-quality beam patterns with high antenna efficiency across the 70 - 116 GHz Radio Frequency (RF) band. The FoV covered by the array is arcmin2, unfilled, with separation between contiguous elements of 43 arcsec. Dual-sideband separation (2SB) down-conversion mixers are designed to be placed at the cryostat output and arranged in four four-pixel down-conversion modules with 4 - 12 GHz Intermediate Frequency (IF) bands (both Upper Side Band and Lower Side Band selectable for any pixel and polarization). The receiver utilizes a mechanical derotator to track the parallactic angle
A double-blind, randomized, multicenter, Italian study of frovatriptan versus almotriptan for the acute treatment of migraine
The objective of this study was to evaluate patients’ satisfaction with acute treatment of migraine with frovatriptan or almotriptan by preference questionnaire. One hundred and thirty three subjects with a history of migraine with or without aura (IHS 2004 criteria), with at least one migraine attack in the preceding 6 months, were enrolled and randomized to frovatriptan 2.5 mg or almotriptan 12.5 mg, treating 1–3 attacks. The study had a multicenter, randomized, double blind, cross-over design, with treatment periods lasting <3 months. At study end patients assigned preference to one of the treatments using a questionnaire with a score from 0 to 5 (primary endpoint). Secondary endpoints were pain free and pain relief episodes at 2 and 4 h, and recurrent and sustained pain free episodes within 48 h. Of the 133 patients (86%, intention-to-treat population) 114 of them expressed a preference for a triptan. The average preference score was not significantly different between frovatriptan (3.1 ± 1.3) and almotriptan (3.4 ± 1.3). The rates of pain free (30% frovatriptan vs. 32% almotriptan) and pain relief (54% vs. 56%) episodes at 2 h did not significantly differ between treatments. This was the case also at 4 h (pain free: 56% vs. 59%; pain relief: 75% vs. 72%). Recurrent episodes were significantly (P < 0.05) less frequent under frovatriptan (30% vs. 44%), also for the attacks treated within 30 min. No significant differences were observed in sustained pain free episodes (21% vs. 18%). The tolerability profile was similar between the two drugs. In conclusion, our study suggests that frovatriptan has a similar efficacy of almotriptan in the short-term, while some advantages are observed during long-term treatment
Be social, be agile: team engagement with Redmine
System engineering and project-team management are essential tools to ensure the project success and the
Redmine is a valuable platform for the work organization and for a system engineered approach. We review in
this work the management needs related to our project, and suggest the possibility that they fit to many research
activities with a similar scenario: small team, technical difficulties (or unknowns), intense activity sprints and
long pauses due to external schedule management, a large degree of shared leadership. We will then present
our implementation with the Redmine, showing that the use of the platform resulted in a strong engagement
and commitment of the team. The explicit goal of this work is also to rise, at least internally, the awareness
about team needs and available organizational tools and methods; and to highlight a shareable approach to team management and small scale system engineering
Sardinia Array Demonstrator: Instrument Overview and Status
In the framework of the Square Kilometer Array (SKA) project, the Italian Institute for Astrophysics (INAF) has addressed several efforts in the design and prototyping of aperture arrays for low-frequency radio astronomical research. The Sardinia Array Demonstrator (SAD) is a national project aimed to develop know-how in this area and to test different architectural technologies and calibration algorithms. SAD consists of 128 prototypical dual-polarized Vivaldi antennas designed to operate at radio frequencies below 650 MHz. The antennas will be deployed at the Sardinia Radio Telescope’s site with a versatile approach able to provide two different array configurations: (i) all antennas grouped in one large station or (ii) spread among a core plus few satellite stations. This paper provides an overview of the SAD project from an instrumental point of view, and illustrates its status after 2 years from its start
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