Front-end Electronics and Optimal Ganging Schemes for Single Photon Detection with Large Arrays of SiPMs in Liquid Argon

The operation of large arrays of silicon photomultipliers (SiPM) in tanks of noble liquids requires low noise, low power front-end amplifiers, able to operate reliably in the cryogenic environment. A suitable amplifier needs to be paired with a proper SiPM ganging scheme, meaning the series/parallel combination of SiPMs at its input. This paper presents a simple model to estimate the ganging scheme that gives the best signal to noise ratio once the basic electrical characteristics of the SiPM and amplifier are known. To prove the validity of the model, we used an amplifier based on discrete components, which achieves a white voltage noise in the 0.25-0.37 nV/$\surd$Hz range at liquid nitrogen temperature, while drawing 2-5 mW of power. Combined with the optimal ganging scheme obtained with the model, the amplifier demonstrated excellent single photon sensitivity up to 96 6x6 mm$^2$ SiPMs (total area 34.6 cm$^2$, S/N $\simeq$ 8-11). The measured results are in a good match with calculated values, predicting the possibility to achieve a clear separation of photoelectron peaks also with larger areas

evaluation of liver fibrosis concordance analysis between noninvasive scores apri and fib 4 evolution and predictors in a cohort of hiv infected patients without hepatitis c and b infection

Background. There is lack of data on the incidence of liver fibrosis (LF) progression in patients with human immunodeficiency virus (HIV) monoinfection and risk factors for LF. Methods. We performed an observational prospective study in a cohort of HIV-infected patients who had initiated highly active antiretroviral therapy (HAART). FIB-4 and aspartate aminotransferase (AST)-to-platelet ratio index (APRI) were assessed. The concordance between the 2 scores was assessed by weighted kappa coefficient. Kaplan-Meier analysis was used to estimate the incidence of LF. Cox regression analysis was used to assess the predictors of transition. Results. A total of 1112 patients were observed for a mean of 2249 days of follow-up. The concordance between FIB-4 and APRI was moderate (kappa = .573). The incidence of transition to higher FIB-4 classes was 0.064 (95% confidence interval [CI], 0.056―0.072) per person-year of follow-up (PYFU), whereas the incidence of transition to higher APRI classes was 0.099 (95% CI, 0.089-0.110) per PYFU. The incidence of transition to FIB-4 >3.25 was 0.013 per PYFU (95% CI, 0.010-0.017) and 0.018 per PYFU (95% CI, 0.014―0.022) for APRI >1.5. In multivariate analyses, for transition to higher classes, HIV RNA level 3.25 and APRI> 1.5 as study outcomes. Conclusions. Overall, our results suggest a possible benefit associated with earlier HAART initiation, provided that the effectiveness of HAART is sustained and treatment with DDX is avoided

Emotional abuse interacts with borderline personality in adolescent inpatients with binge-purging eating disorders

Purpose Childhood abuse is associated with an increased risk of developing eating disorders (EDs) as well as personality disorders (PDs). However, their interaction is still uncertain, particularly in adolescents. This study investigates the correlations between childhood emotional neglect (CEN), childhood emotional abuse (CEA), and obsessive-compulsive and borderline personality styles in female adolescent inpatients with eating disorders (EDs). Methods One hundred and twenty-eight inpatients (ages 14-18) were assessed, 54 were diagnosed with restricting-type anorexia nervosa (AN-R) and 33 with a binge-purging ED [BP-ED; comprising patients with binge-purging type anorexia nervosa (AN-BP), n = 15, and bulimia nervosa (BN), n = 18]. Fifty healthy participants made up the control group (CG). CEN and CEA were assessed with the Childhood Trauma Questionnaire, while the Personality Style and Disorder Inventory was implemented to determine personality styles. Results A MANOVA revealed a significant main effect of CEA on spontaneous-borderline personality style [F(8,119) = 17.1, p < 0.001, η2 = 0.126], as well as a main effect of ED group on spontaneous-borderline [F(2,119) = 3.1, p = 0.048, η2 = 0.050]. A significant interaction between ED group, CEA, and spontaneous-borderline was found [F(2,119) = 3.5, p = 0.034, η2 = 0.055] with BP-ED showing significantly higher scores in CEA (9.3 ± 4.0) and in spontaneous-borderline (14.2 ± 6.2). Conclusions Considering CEA and borderline personality style in adolescent inpatients with BN or AN-BP may help improve the understanding of the etiology and maintenance of BP-ED and provide more effective treatment targets. Level of evidence Level III, case–control analytic study

Clinical Risk Factors for Skin Cancer in a Cohort of Kidney and Heart Transplant Recipients: A Case Control Study

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First bolometric measurement of the two neutrino double beta decay of 100^{100}Mo with a ZnMoO4_4 crystals array

The large statistics collected during the operation of a ZnMoO$_4$ array, for a total exposure of 1.3 kg $\cdot$ day of $^{100}$Mo, allowed the first bolometric observation of the two neutrino double beta decay of $^{100}$Mo. The observed spectrum of each crystal was reconstructed taking into account the different background contributions due to environmental radioactivity and internal contamination. The analysis of coincidences between the crystals allowed the assignment of constraints to the intensity of the different background sources, resulting in a reconstruction of the measured spectrum down to an energy of $\sim$300 keV. The half-life extracted from the data is T$_{1/2}^{2\nu}$= [7.15 $\pm$ 0.37 (stat) $\pm$ 0.66 (syst)] $\cdot$ 10$^{18}$ y.Comment: 6 pages, 2 figure, Accepted for publication in Journal of Physics G: Nuclear and Particle Physic

Large area Si low-temperature light detectors with Neganov-Luke effect

Next generation calorimetric experiments for the search of rare events rely on the detection of tiny amounts of light (of the order of 20 optical photons) to discriminate and reduce background sources and improve sensitivity. Calorimetric detectors are the simplest solution for photon detection at cryogenic (mK) temperatures. The development of silicon based light detectors with enhanced performance thanks to the use of the Neganov-Luke effect is described. The aim of this research line is the production of high performance detectors with industrial-grade reproducibility and reliability.Comment: 4 pages, 2 figure

The Two-Phase Flow Separator Experiment Breadboard Model: Reduced Gravity Aircraft Results

Life support systems in space depend on the ability to effectively separate gas from liquid. Passive cyclonic phase separators use the centripetal acceleration of a rotating gas-liquid mixture to carry out phase separation. The gas migrates to the center, while gas-free liquid may be withdrawn from one of the end plates. We have designed, constructed and tested a breadboard that accommodates the test sections of two independent principal investigators and satisfies their respective requirements, including flow rates, pressure and video diagnostics. The breadboard was flown in the NASA low-gravity airplane in order to test the system performance and design under reduced gravity conditions