Optimizing performances of CsI(Tl) crystals with a photodiode readout

Tests are described concerning the performances of CsI(Tl) crystals. Particular care was dedicated to the study of the light production and collection of the crystals, that appear to be significantly a⁄ected both by the choice of the wrapping materials and by the details of the binding technique. A functional relation between the light pulse height and the coupling of the crystal#photodiode system was deduced. Finally, the influence of this coupling on the energy resolution of the detector is discussed. ( 1999 Elsevier Science B.V. All rights reserved

Performances of keystone geometry micro-strip gas chambers

Abstract The performances of micro-strip gas chamber detectors with CF 4 counting gas have been tested with a 241 Am α source. The behaviour of the gain as a function of gas pressure, the dependence of the energy resolution on gas pressure and anode voltage, and the gain variation along the strip length due to the keystone geometry of the micro-strip pads are reported. An empirical response function to describe such a position dependence of the gain is proposed

Congenital adrenal hyperplasia: a qualitative study on disease and treatment, doubts, anguishes and relationships (part I)

OBJECTIVE: To understand the meanings/thoughts of a group of parents, patients and physicians regarding congenital adrenal hyperplasia (CAH), and to evaluate their anguishes, doubts and anxieties. METHODS: We selected 21 subjects: 7 pediatric endocrinologists from five Brazilian Public Health System institutions, 9 parents and 6 patients with CAH, according to the qualitative research model. Three of the studied categories are presented: disease and treatment, doubts and anguishes and relationships. RESULTS: Parents' main anguishes relate to the situation of an unnamed sex at birth. A sense of loneliness when dealing with the disease is the major anguish among patients, whereas physicians show hopelessness with the passivity parents and patients. CONCLUSIONS: The apparent submissiveness of patients/parents during consultations must be evaluated cautiously. University Hospitals outpatient clinic dynamics have a direct effect on this behavior: physicians do not talk openly with parents who in turn do not talk with their children, whereas patients chose to protect their parents from additional suffering. Thus, some miscommunication is noticeable among these subjects. These observations suggest that a special mindful measure should be built for these patients.OBJETIVO: Compreender significados e pensamentos de um grupo de pais, pacientes e médicos sobre a hiperplasia adrenal congênita (HAC) e analisar angústias, dúvidas e ansiedades. MÉTODOS: Foram selecionados 21 sujeitos: 7 especialistas de cinco instituições do Sistema Único de Saúde (SUS), 9 familiares e 6 pacientes com HAC, seguindo padrões da pesquisa qualitativa. Neste artigo, apresentaram-se três categorias: doença e tratamento, dúvidas e angústias e relacionamentos. RESULTADOS: As principais angústias dos pais relacionam-se à indefinição sexual ao nascimento. Para pacientes, a angústia maior relaciona-se ao sentimento de solidão ao lidar com a doença e seu tratamento, enquanto médicos mostram-se inconformados com a passividade dos pais/pacientes. CONCLUSÕES: A passividade de pacientes/familiares nas consultas deve ser avaliada com cautela, pois a dinâmica do ambulatório dos hospitais-escola tem efeito neste comportamento: os médicos não conversam abertamente com os pais, enquanto estes não conversam com seus filhos, que, por sua vez, poupam os pais de mais sofrimento. Constatou-se dificuldade de comunicação entre esses vários sujeitos. Essas observações permitem sugerir que uma medida especial de atenção a esses pacientes deva ser construída.Universidade Federal de São Paulo (UNIFESP) Departamento de MedicinaHospital Infantil Darcy VargasUNIFESP Departamento de PediatriaHospital e Maternidade São LuizUNIFESP, Depto. de MedicinaUNIFESP, Depto. de PediatriaSciEL

Asteroseismology using quadrupolar f-modes revisited: breaking of universal relationships in the slow hadron-quark conversion scenario

In this work, we consider polar perturbations and we calculate the frequency and damping time of the quadrupolar fundamental f -mode of compact objects, constructed using a wide range of model-independent hybrid equations of state that include quark matter. We give special attention to the impact of the hadron-quark conversion speed that, in the slow case, gives rise to a branch of slow stable hybrid stars. Moreover, we study the validity of universal relationships proposed in the literature and find out that none of them remains valid when slow stable hybrid stars are taken into account. This fact could constrain the applicability of asteroseismology methods with fundamental modes designed to estimate the properties of pulsating compact objects. We hope that this result could be tested with the start up of the third-generation gravitational wave observatories, which might shed some light on the f -mode emission from compact objects.Comment: 13 pages, 13 figures. Comments are welcom

Optimizing performances of CsI(Tl) crystals with a photodiode readout

Abstract Tests are described concerning the performances of CsI(Tl) crystals. Particular care was dedicated to the study of the light production and collection of the crystals, that appear to be significantly affected both by the choice of the wrapping materials and by the details of the binding technique. A functional relation between the light pulse height and the coupling of the crystal#photodiode system was deduced. Finally, the influence of this coupling on the energy resolution of the detector is discussed

Prostate Cancer Treatment-Related Toxicity: Comparison between 3D-Conformal Radiation Therapy (3D-CRT) and Volumetric Modulated Arc Therapy (VMAT) Techniques

Objective: This paper illustrates the results of a mono-institutional registry trial, aimed to test whether gastrointestinal (GI) and genitourinary (GU) toxicity rates were lower in localized prostate cancer patients treated with image-guided volumetric modulated arc therapy (IG-VMAT) compared to those treated with IG-3D conformal radiation therapy (IG-3DCRT). Materials and Methods: Histologically proven prostate cancer patients with organ-confined disease, treated between October 2008 and September 2014 with moderately hypofractionated radiotherapy, were reviewed. Fiducial markers were placed in the prostate gland by transrectal ultrasound guide. The prescribed total dose was 70 Gy in 28 fractions. The mean and median dose volume constraints for bladder and rectum as well as total volume of treatment were analyzed as potentially prognostic factors influencing toxicity. The Kaplan–Meier method was applied to calculate survival. Results: Overall, 83 consecutive patients were included. Forty-two (50.6%) patients were treated with 3D-CRT and 41 (49.4%) with the VMAT technique. The median follow-up for toxicity was 77.26 months for the whole cohort. The VMAT allowed for a dose reduction to the rectum and bladder for the large majority of the considered parameters; nonetheless, the only parameter correlated with a clinical outcome was a rectal dose limit V66 > 8.5% for late GI toxicity G ≥ 2 (p = 0.045). Rates of G ≥ 2 toxicities were low among the whole cohort of these patients treated with IGRT. The analysis for rectum dose volume histograms (DVHs) showed that a severe (grade ≥ 2) late GI toxicity was related with the rectal dose limit V66 > 8.5% (p = 0.045). Conclusions: This study shows that moderate hypofractionation is feasible and safe in patients with intermediate and high-risk prostate cancer. Daily IGRT may decrease acute and late toxicity to organs at risk and improve clinical benefit and disease control rate, cutting down the risk of PTV geographical missing. The adoption of VMAT allows for promising results in terms of OAR sparing and a reduction in toxicity that, also given the small sample, did not reach statistical significance

Više-fragmentna tvorba u reakcijama 32S+58,64Ni NA 11 A MeV

The characteristic features of the 32S+58,64Ni reaction at 11 A MeV have been investigated to evidence the possible rise of multi-fragmentation processes at low excitation energies. The importance of such phenomena consists in the fact that they could represent the signature of a nuclear phase transition from a liquid to a gas region. Evidence of multi-fragment production is displayed by the present data; even if the yield of such events is compatible with the predictions of statistical models, the partition of the mass of the decaying system cannot be easily reproduced. Some preliminary indications of isospin effects are suggested by looking at the differences between the two reacting systems.Istraživali smo značajke reakcije 32S+ 58,64Ni na 11 A MeV radi pronalaženja mogućeg porasta više-fragmentnih procesa na nižim uzbudnim energijama. Važnost se tih pojava sastoji u tome što bi one mogle predstavljati znakove nuklearnog faznog prijelaza od tekućeg u plinsko stanje. Znakovi tvorbe više fragmenata vide se u dobivenim podacima; no čak ako je i prinos tih događaja u skladu s predviđanjima statističkog modela, razdioba mase sustava koji se raspada ne uspijeva se objasniti. Usporedba dviju reakcija ukazuje na moguće izospinske efekte

Više-fragmentna tvorba u reakcijama 32S+58,64Ni NA 11 A MeV

The characteristic features of the 32S+58,64Ni reaction at 11 A MeV have been investigated to evidence the possible rise of multi-fragmentation processes at low excitation energies. The importance of such phenomena consists in the fact that they could represent the signature of a nuclear phase transition from a liquid to a gas region. Evidence of multi-fragment production is displayed by the present data; even if the yield of such events is compatible with the predictions of statistical models, the partition of the mass of the decaying system cannot be easily reproduced. Some preliminary indications of isospin effects are suggested by looking at the differences between the two reacting systems.Istraživali smo značajke reakcije 32S+ 58,64Ni na 11 A MeV radi pronalaženja mogućeg porasta više-fragmentnih procesa na nižim uzbudnim energijama. Važnost se tih pojava sastoji u tome što bi one mogle predstavljati znakove nuklearnog faznog prijelaza od tekućeg u plinsko stanje. Znakovi tvorbe više fragmenata vide se u dobivenim podacima; no čak ako je i prinos tih događaja u skladu s predviđanjima statističkog modela, razdioba mase sustava koji se raspada ne uspijeva se objasniti. Usporedba dviju reakcija ukazuje na moguće izospinske efekte