511 research outputs found
Note Illustrative della Carta geologica d'Italia alla scala 1:50.000 F. 090 Aosta. Servizio Geologico d'Italia - ISPRA
No full text<p>Note illustrative redatte per il Foglio geologico n. 090 Aosta della Carta Geologica d'Italia alla scala 1:50.000. 144 pp.</p>
Value of 111In-Pentetreotide scintigraphy and 18F-FDG PET for Clinical Prognosis of Patients with Neuroedoncrine Neoplasms
No full textL'évolution clinique des tumeurs neuroendocrines (TNE) gastro-entéro- pancréatiques (GEP) reste difficile à prédire malgré l'existence de plusieurs biomarqueurs de sévérité. Les différences de captation tumorale à la scintigraphie à l'mIn-Pentetreotide et à la TEP au 18F-FDG (TEP FDG) pourraient refléter le degré de dé-différentiation cellulaire.
Des patients atteints de TNE et ayant bénéficié de ces deux modalités d'imagerie ont été rétrospectivement identifiés dans la base de données SwissNET, une base réunissant des informations sur ces patients en Suisse depuis 2008. La survie sans progression et la survie globale ont été recensées en fonction des résultats de l'imagerie fonctionnelle. La corrélation avec le grade histologique (classification OMS 2010) a également été analysée.
Nous avons identifié 31 patients ayant eu les deux modalités d'imagerie, que ce soit pour la tumeur primaire (21/31), les métastases (21/31) ou les deux (12/31). Le suivi moyen était de 36 mois (IC 95% 27-45). 21 patients avaient une maladie métastatique au moment du diagnostic, et 11 sont décédés pendant le suivi. 7/31 (22%) étaient des TNE de grade 1, 16/31 (52%) étaient des TNE de grade 2 et 8/31 (26%) étaient des TNE de grade 3, avec une corrélation proche de la signification statistique (p= 0.054) pour la TEP 18F-FDG. La survie sans progression était significativement plus défavorable dans le groupe positif à la TEP 18F-FDG (n=21), avec un temps médian de progression de 8 mois versus 51 mois dans le groupe négatif (n = 10), hazard ratio de 3.2 (IC 97.5% 1.1-9.5, p = 0.04). La survie globale avait tendance à être plus mauvaise dans le groupe positif à la TEP FDG avec une scintigraphie négative, avec un hazard ratio de 1.63 (IC 97.5% 0.11-21, p = 0.08). En ce qui concerne les résultats de la scintigraphie, nous n'avons pas retrouvé d'impact sur la survie, ni la progression.
Conclusion :
Ces données démontrent la valeur pronostic défavorable de la positivité à la TEP au 18F-FDG dans cette cohorte de patient
The IFUSP Race-track Microtron Booster Accelerator End magnets antisymmetric Perturbations
No full textWe will present measurements and calculations related to the antisymmetric perturbations, and comparisons with the symmetric ones, of the IFUSP race-track microtron booster accelerator end magnets. These perturbations were measured in planes situated at +/-12 mm of the middle plane, in a gap height of 4 cm, for a field distribution of about 0.1 T. The measurements were done in 1170 points, separated by a distance of 8 mm, using an automated system with a +/-1.5 mu T differential Hall probe. The race-track microtron booster is the second stage of the 30.0 MeV electron accelerator under construction at the Linear Accelerator Laboratory in which the required uniformity for the magnetic field is of about 10(-3). The method of correction employed to homogenize the IFUSP race-track microtron booster accelerator magnets assures uniformity of 10(-5) in an average field of 0.1 T, over an area of 700 cm(2). This method uses the principle of attaching to the pole pieces correction coils produced by etching techniques, with copper leads shaped like the isofield lines of the normal component of the magnetic field measured. The ideal planes, in which these measurements are done, are calculated and depend on the behavior of the magnetic field perturbations: symmetric or antisymmetric with reference to the middle plane of the magnet gap. These calculations are presented in this work and show that for antisymmetric perturbations there is no ideal plane for the correction of the magnetic field; for the symmetric one, these planes are at +/-60% of the half gap height, from the middle plane. So this method of correction is not feasible for antisymmetric perturbations, as will be shown. Besides, the correction of the symmetric portion of the field distribution does not influence the antisymmetric one, which almost does not change, and corroborates the theoretical predictions. We found antisymmetric perturbations of small intensity only in one of the two end magnets. However, they are not detected at +/- 1 mm of the middle plane and will not damage the electron beam
Design of the main racetrack microtron accelerator end magnets of the Institute of Physics of University of São Paulo
No full textThis work deals with the design of the Institute of Physics of the University of São Paulo (IFUSP) main racetrack microtron accelerator end magnets. This is the last stage of acceleration, comprised of an accelerating section (1.04 m) and two end magnets (0.1585 T), in which a 5.10 MeV beam, produced by a racetrack microtron booster has its energy raised up to 31.15 MeV after 28 accelerations. POISSON code was used to give the final configuration that includes auxiliary pole pieces (clamps) and auxiliary homogenizing gaps. The clamps create a reverse fringe field region and avoid the vertical defocusing and the horizontal displacement of the beam produced by extended fringe fields; PTRACE code was used to perform the trajectory calculations in the fringe field region. The auxiliary homogenizing gaps improve the field uniformity as they create a magnetic shower that provides uniformity of ±0.3%, before the introduction of the correcting coils that will be attached to the pole faces. This method of correction, used in the IFUSP racetrack microtron booster magnets, enabled uniformity of ±0.001% in an average field of 0.1 T and will also be employed for these end magnets. © 1999 The American Physical Society.Faculty of Technology Ctro. Estadual Educ. Tecn. P. Souza UNESP, São Paulo, SP, Praca Coronel Fernando Prestes 30, CEP 01124-060, São Paulo, SPInstitute of Physics University of São Paulo, São PauloFaculty of Technology Ctro. Estadual Educ. Tecn. P. Souza UNESP, São Paulo, S
Correcting coils in end magnets of accelerators
No full textWe present an empirical investigation of the correcting coils behavior used to homogenize the field distribution of the race-track microtron accelerator end magnets. These end magnets belong to the second stage of the 30.0 MeV cw electron accelerator under construction at IFUSP, the race-track microtron booster, in which the beam energy is raised from 1.97 to 5.1 MeV. The correcting coils are attached to the pole faces and are based on the inhomogeneities of the magnetic field measured. The performance of these coils, when operating the end magnets with currents that differ by ±10% from the one used in the mappings that originated the coils copper leads, is presented. For one of the magnets, adjusting conveniently the current of the correcting coils makes it possible to homogenize field distributions of different intensities, once their shapes are practically identical to those that originated the coils. For the other one, the shapes are changed and the coils are less efficient. This is related to intrinsic factors that determine the inhomogeneities. However, we obtained uniformity of 0.001% in both cases. © 1998 The American Physical Society.Faculty of Technology Ctro. Estadual de Educ. Technologica UNESP, Praca Coronel Fernando Prestes 30, CEP 01124-060, São Paulo, SPInstitute of Physics University of São Paulo, São PauloFaculty of Technology Ctro. Estadual de Educ. Technologica UNESP, Praca Coronel Fernando Prestes 30, CEP 01124-060, São Paulo, S
The IFUSP race-track microtron booster accelerator end magnets antisymmetric perturbations
No full textWe will present measurements and calculations related to the antisymmetric perturbations, and comparisons with the symmetric ones, of the IFUSP race-track microtron booster accelerator end magnets. These perturbations were measured in planes situated at +/-12 mm of the middle plane, in a gap height of 4 cm, for a field distribution of about 0.1 T. The measurements were done in 1170 points, separated by a distance of 8 mm, using an automated system with a +/-1.5 mu T differential Hall probe. The race-track microtron booster is the second stage of the 30.0 MeV electron accelerator under construction at the Linear Accelerator Laboratory in which the required uniformity for the magnetic field is of about 10(-3). The method of correction employed to homogenize the IFUSP race-track microtron booster accelerator magnets assures uniformity of 10(-5) in an average field of 0.1 T, over an area of 700 cm(2). This method uses the principle of attaching to the pole pieces correction coils produced by etching techniques, with copper leads shaped like the isofield lines of the normal component of the magnetic field measured. The ideal planes, in which these measurements are done, are calculated and depend on the behavior of the magnetic field perturbations: symmetric or antisymmetric with reference to the middle plane of the magnet gap. These calculations are presented in this work and show that for antisymmetric perturbations there is no ideal plane for the correction of the magnetic field; for the symmetric one, these planes are at +/-60% of the half gap height, from the middle plane. So this method of correction is not feasible for antisymmetric perturbations, as will be shown. Besides, the correction of the symmetric portion of the field distribution does not influence the antisymmetric one, which almost does not change, and corroborates the theoretical predictions. We found antisymmetric perturbations of small intensity only in one of the two end magnets. However, they are not detected at +/- 1 mm of the middle plane and will not damage the electron beam.UNESP, CEETEPS, Fac Technol, BR-01124060 São Paulo, BrazilUNESP, CEETEPS, Fac Technol, BR-01124060 São Paulo, Brazi
The IFUSP race-track microtron booster accelerator end magnets antisymmetric perturbations
No full textWe will present measurements and calculations related to the antisymmetric perturbations, and comparisons with the symmetric ones, of the IFUSP race-track microtron booster accelerator end magnets. These perturbations were measured in planes situated at +/-12 mm of the middle plane, in a gap height of 4 cm, for a field distribution of about 0.1 T. The measurements were done in 1170 points, separated by a distance of 8 mm, using an automated system with a +/-1.5 mu T differential Hall probe. The race-track microtron booster is the second stage of the 30.0 MeV electron accelerator under construction at the Linear Accelerator Laboratory in which the required uniformity for the magnetic field is of about 10(-3). The method of correction employed to homogenize the IFUSP race-track microtron booster accelerator magnets assures uniformity of 10(-5) in an average field of 0.1 T, over an area of 700 cm(2). This method uses the principle of attaching to the pole pieces correction coils produced by etching techniques, with copper leads shaped like the isofield lines of the normal component of the magnetic field measured. The ideal planes, in which these measurements are done, are calculated and depend on the behavior of the magnetic field perturbations: symmetric or antisymmetric with reference to the middle plane of the magnet gap. These calculations are presented in this work and show that for antisymmetric perturbations there is no ideal plane for the correction of the magnetic field; for the symmetric one, these planes are at +/-60% of the half gap height, from the middle plane. So this method of correction is not feasible for antisymmetric perturbations, as will be shown. Besides, the correction of the symmetric portion of the field distribution does not influence the antisymmetric one, which almost does not change, and corroborates the theoretical predictions. We found antisymmetric perturbations of small intensity only in one of the two end magnets. However, they are not detected at +/- 1 mm of the middle plane and will not damage the electron beam
Diagnosis and workup of 522 consecutive patients with neuroendocrine neoplasms in Switzerland.
No full textBACKGROUND
Neuroendocrine neoplasms (NENs) are difficult to diagnose. We used SwissNET data to characterise NEN patients followed in the two academic centres of western Switzerland (WS), and to compare them with patients followed in eastern Switzerland (ES) as well as with international guidelines.
METHOD
SwissNET is a prospective database covering data from 522 consecutive patients (285 men, 237 women) from WS (n = 99) and ES (n = 423).
RESULTS
Mean ± SD age at diagnosis was 59.0 ± 15.7 years. Overall, 76/522 experienced a functional syndrome, with a median interval of 1.0 (IQR: 1.0-3.0) year between symptoms onset and diagnosis. A total of 51/522 of these tumours were incidental. The primary tumour site was the small intestine (29%), pancreas (21%), appendix (18%) and lung (11%) in both regions combined. In all, 513 functional imaging studies were obtained (139 in WS, 374 in ES). Of these, 381 were 111In-pentetreotide scintigraphies and 20 were 68Ga-DOTATOC PET. First line therapy was surgery in 87% of patients, medical therapy (biotherapy or chemotherapy) in 9% and irradiation in 3% for both regions together.
CONCLUSION
Swiss NEN patients appear similar to what has been described in the literature. Imaging by somatostatin receptor scintigraphy (SRS) is widely used in both regions of Switzerland. In good accordance with published guidelines, data on first line therapy demonstrate the crucial role of surgery. The low incidence of biotherapy suggests that long-acting somatostatin analogues are not yet widely used for their anti-proliferative effects. The SwissNET initiative should help improve compliance with ENETS guidelines in the workup and care of NEN patients
The End Magnets of the Ifusp Race-track Microtron Booster
No full textThe end magnets of the IFUSP race-track microtron booster, second stage of the electron accelerator under construction at the Linear Accelerator Laboratory, are presented. They deflect, focus and return the beam to the accelerating section. Details about the project are discussed, Poisson code was used to give the final geometry of the end magnets. The end magnets incorporate auxiliary pole pieces (clamps) which create a reverse fringe field region that avoids the beam vertical defocusing and reduces the horizontal displacement produced by extended fringe fields (EFF). The small gap height used for the clamps provided reverse field distributions with fringe fields of short extensions, avoiding the traditional use of inactive clamps. Measurements and calculations concerning particle trajectories and reverse field distribution are presented. The floating wire technique, employing an original procedure to register orbits, was used to corroborate the calculated beam trajectories and represents a good experimental option in the lack of the accelerator beam. The experimental results showed agreement of about 0.1% with the calculations
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