472 research outputs found
Association between cigarette smoking and serum lipid levels in a italian cohort: the Brisighella Heart Study.
No full textRIPTIDE: A novel recoil-proton track imaging detector for fast neutrons
No full textNeutron detectors are an essential tool for the development of many research fields, as nuclear, particle and astroparticle physics as well as radiotherapy and radiation safety. Since neutrons cannot directly ionize, their detection is only possible via nuclear reactions. Consequently, neutron-based experimental techniques are related to the detection of charged particle or electromagnetic radiation originating from neutron-induced reactions. The study of fast neutrons is often based on the neutron-proton elastic scattering reaction. In this case, the ionization induced by the recoil protons in a hydrogenous material constitutes the basic information for the design and development of neutron detectors. Although experimental techniques have continuously improved and refined, so far, proton-recoil track imaging is still weak in laboratory rate environments because of the extremely small detection efficiency. To address this deficiency, we propose a novel recoil-proton track imaging system in which the light deriving from a fast scintillation signal is used to perform a complete reconstruction in space and time of the event. In particular, we report the idea of RIPTIDE (RecoIl Proton Track Imaging DEtector): an innovative system which combines a plastic scintillator coupled to imaging devices, based on CMOS technology, or micro channel plate sensors. The proposed apparatus aims at providing neutron spectrometry capability by stereoscopically imaging the recoil-protons tracks, correlating the spatial information with the time information. RIPTIDE intrinsically enable the online analysis of the ionization track, thus retrieving the neutron direction and energy, without spoiling the overall efficiency of the detection system. Finally, the spatial and topological event reconstruction enables particle discrimination - a crucial requirement for neutron detection - by deducing the specific energy loss along the track
"RIPTIDE" - an innovative recoil-proton track imaging detector
No full textNeutron detectors perform key tasks in many research fields as nuclear, particle and astroparticle physics as well as neutron dosimetry, radiotherapy, and radiation protection. Neutron detectors exhibiting tracking capability are still missing, although several approaches to neutron momentum reconstruction have been proposed. In this context, we aim at developing a novel RecoIl-Proton Track Imaging DEtection system "RIPTIDE", in which the light output of a fast scintillation signal is used to perform a complete reconstruction in space and time of the neutron-proton elastic scattering. The 3D track reconstruction is going to be implemented by state-of-the-art high-sensitivity imaging detector (CMOS, MCP-Timepix). Preliminary Geant4 simulations of the proposed set-up show up a good detection efficiency in a compact active volume. The envisaged electronic readout can be easily adapted according to a specific application (event-by-event mode or integration mode). The system can be rescaled by increasing the detection volume or by combining several detection modules. Further developments of the basic detection technique can be adapted for fast charged particle detection tracking as well
Validation of epicardial ventricular tachycardia criteria through left ventricular pacing in patients with non-ischaemic dilated cardiomyopathy: insights from a cardiac resynchronization therapy cohort
No full textUnattended compared to traditional blood pressure measurement in patients with rheumatoid arthritis: a randomised cross-over study
No full textBackground: Hypertension is characterised by a high prevalence, low awareness and poor control among rheumatoid arthritis (RA) patients. Correct blood pressure (BP) measurement is highly important in these subjects. The “unattended” BP measurement aims to reduce the “white-coat effect,” a phenomenon associated with cardiovascular risk. Data on “unattended” BP measurement in RA and its impact on hypertensive organ damage are very limited. Methods: BP was measured in the same patient both traditionally (“attended” BP) and by the “unattended” protocol (3 automated office BP measurements, at 1-min intervals, after 5 min of rest, with patient left alone) by a randomised cross-over design. Patients underwent clinical examination, 12-lead electrocardiography and trans-thoracic echocardiography to evaluate cardiac damage. Results: Sixty-two RA patients (mean age 67 ± 9 years, 87% women) were enrolled. Hypertension was diagnosed in 79% and 66% of patients according to ACC/AHA and ESC/ESH criteria, respectively. Concordance correlation coefficients between the two techniques were 0.55 (95%, CI 0.38–0.68) for systolic BP and 0.73 (95%, CI 0.60–0.82) for diastolic BP. “Unattended” (121.7/68.6 mmHg) was lower than “attended” BP (130.5/72.8 mmHg) for systolic and diastolic BP (both p <.0001). Among the two techniques, only “unattended” systolic BP showed a significant association with left ventricular mass (r = 0.11; p =.40 for “attended” BP; r = 0.27; p =.036 for unattended BP; difference between slopes: z = 3.92; p =.0001). Conclusions: In RA patients, “unattended” BP is lower than traditional (“attended”) BP and more closely associated with LV mass. In these patients, the “unattended” automated BP measurement is a promising tool which requires further evaluation.KEY MESSAGES “Unattended” automated blood pressure registration, aimed to reduce the “white-coat effect” is lower than “attended” value in rheumatoid arthritis patients. “Unattended” blood pressure is more closely associated with left ventricular mass than “attende” registration
Aumentare i tassi di risposta al trattamento antiipertensivo: la terapia combinata a dose fissa lercanidipina/enalapril.
No full textAlthough many efforts paid to prevention and treatment of the hypertension, mortality and morbidity hypertension-related is still unacceptably high. This is largely due to the difficulty in mantaining the blood pressure values strictly below the goal recommended by guidelines. As confirmed by recent intervention trials, more than half of hypertensive patients treated with a single drug regime not adeguately controls its blood pressure. On this base, current guidelines have recommended the use of combination therapy as first-line treatment in high or very high risk patients or when blood pressure is above the goal of 20/10 mmHg (>160/100 mmHg). In these patients blocking two or more blood pressure regulatory systems provides a more effectve reduction in blood pressure with a parallell reduction of cardiovascular events. Calcium Channel Blockers (CCBs) and Angiotensin Converting Enzyme (ACE) inhibitors (ACE-I) administered in combination can complemement each other in lowering blood pressure. Recently a fixed-dose combinations of lercanidipine (10 mg) plus enalapril (20 mg) has been approved in some E.C. countries: here we review both the rationale and the available clinical data for the use of this combination in hypertensive patients
Riptide: a proton-recoil track imaging detector for fast neutrons
No full textAbstract: Riptide is a detector concept aiming to track fast neutrons. It is based on neutron-proton
elastic collisions inside a plastic scintillator, where the neutron momentum can be measured by imaging
the scintillation light. More specifically, by stereoscopically imaging the recoil proton tracks, the
proposed apparatus provides neutron spectrometry capability and enable the online analysis of the
specific energy loss along the track. In principle, the spatial and topological event reconstruction
enables particle discrimination, which is a crucial property for neutron detectors. In this contribution,
we report the advances on the Riptide detector concept. In particular, we have developed a Geant4
optical simulation to demonstrate the possibility of reconstructing with sufficient precision the tracks
and the vertices of neutron interactions inside a plastic scintillator. To realistically model the optics of
the scintillation detector, mono-energetic protons were generated inside a 6 × 6 × 6 cm3 cubic BC-408
scintillator, and the produced optical photons were propagated and then recorded on a scoring plane
corresponding to the surfaces of the cube. The photons were then transported through an optical
system to a 2 × 2 cm2 photo sensitive area with 1 Megapixel. Moreover, we have developed two
different analysis procedures to reconstruct 3D tracks: one based on data fitting and one on Principal
Component Analysis. The main results of this study will be presented with a particular focus on the
role of the optical system and the attainable spatial and energy resolution
Riptide: a proton-recoil track imaging detector for fast neutrons
No full textRiptide is a detector concept aiming to track fast neutrons. It is based on neutron-proton elastic collisions inside a plastic scintillator, where the neutron momentum can be measured by imaging the scintillation light. More specifically, by stereoscopically imaging the recoil proton tracks, the proposed apparatus provides neutron spectrometry capability and enable the online analysis of the specific energy loss along the track. In principle, the spatial and topological event reconstruction enables particle discrimination, which is a crucial property for neutron detectors. In this contribution, we report the advances on the Riptide detector concept. In particular, we have developed a Geant4 optical simulation to demonstrate the possibility of reconstructing with sufficient precision the tracks and the vertices of neutron interactions inside a plastic scintillator. To realistically model the optics of the scintillation detector, mono-energetic protons were generated inside a 6 × 6 × 6 cm3 cubic BC-408 scintillator, and the produced optical photons were propagated and then recorded on a scoring plane corresponding to the surfaces of the cube. The photons were then transported through an optical system to a 2 × 2 cm2 photo sensitive area with 1 Megapixel. Moreover, we have developed two different analysis procedures to reconstruct 3D tracks: one based on data fitting and one on Principal Component Analysis. The main results of this study will be presented with a particular focus on the role of the optical system and the attainable spatial and energy resolution
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