Neutron irradiation effect on SiPMs up to Φneq\Phi_{neq} = 5 ×\times 1014^{14} cm−2^{-2}

Silicon Photo-Multipliers (SiPM) are becoming the photo-detector of choice for increasingly more particle detection applications, from fundamental physics to medical and societal applications. One major consideration for their use at high-luminosity colliders is the radiation damage induced by hadrons, which leads to a dramatic increase of the dark count rate. KETEK SiPMs have been exposed to various fluences of reactor neutrons up to $\Phi_{neq}$ = 5$\times$10$^{14}$ cm$^{-2}$ (1 MeV equivalent neutrons). Results from the I-V, and C-V measurements for temperatures between $-$30$^\circ$C and $+$30$^\circ$C are presented. We propose a new method to quantify the effect of radiation damage on the SiPM performance. Using the measured dark current the single pixel occupation probability as a function of temperature and excess voltage is determined. From the pixel occupation probability the operating conditions for given requirements can be optimized. The method is qualitatively verified using current measurements with the SiPM illuminated by blue LED light

Inverse Low Gain Avalanche Detectors (iLGADs) for precise tracking and timing applications

Low Gain Avalanche Detector (LGAD) is the baseline sensing technology of the recently proposed Minimum Ionizing Particle (MIP) end-cap timing detectors (MTD) at the Atlas and CMS experiments. The current MTD sensor is designed as a multi-pad matrix detector delivering a poor position resolution, due to the relatively large pad area, around 1 $mm^2$; and a good timing resolution, around 20-30 ps. Besides, in his current technological incarnation, the timing resolution of the MTD LGAD sensors is severely degraded once the MIP particle hits the inter-pad region since the signal amplification is missing for this region. This limitation is named as the LGAD fill-factor problem. To overcome the fill factor problem and the poor position resolution of the MTD LGAD sensors, a p-in-p LGAD (iLGAD) was introduced. Contrary to the conventional LGAD, the iLGAD has a non-segmented deep p-well (the multiplication layer). Therefore, iLGADs should ideally present a constant gain value over all the sensitive region of the device without gain drops between the signal collecting electrodes; in other words, iLGADs should have a 100${\%}$ fill-factor by design. In this paper, tracking and timing performance of the first iLGAD prototypes is presented.Comment: Conference Proceedings of VCI2019, 15th Vienna Conference of Instrumentation, February 18-22, 2019, Vienna, Austri

A Comprehensive Characterization of the TI-LGAD Technology

Pixelated low-gain avalanche diodes (LGADs) can provide both precision spatial and temporal measurements for charged particle detection; however, electrical termination between the pixels yields a no-gain region, such that the active area or fill factor is not sufficient for small pixel sizes. Trench-isolated LGADs (TI-LGADs) are a strong candidate for solving the fill-factor problem, as the p-stop termination structure is replaced by isolated trenches etched in the silicon itself. In the TI-LGAD process, the p-stop termination structure, typical of LGADs, is replaced by isolating trenches etched in the silicon itself. This modification substantially reduces the size of the no-gain region, thus enabling the implementation of small pixels with an adequate fill factor value. In this article, a systematic characterization of the TI-RD50 production, the first of its kind entirely dedicated to the TI-LGAD technology, is presented. Designs are ranked according to their measured inter-pixel distance, and the time resolution is compared against the regular LGAD technology

Monitoring COPD patients: systemic and bronchial eosinophilic inflammation in a 2-year follow-up

Background: High blood eosinophils seem to predict exacerbations and response to inhaled corticosteroids (ICS) treatment in patients with chronic obstructive pulmonary disease (COPD). The aim of our study was to prospectively evaluate for 2 years, blood and sputum eosinophils in COPD patients treated with bronchodilators only at recruitment. Methods: COPD patients in stable condition treated with bronchodilators only underwent monitoring of lung function, blood and sputum eosinophils, exacerbations and comorbidities every 6 months for 2 years. ICS was added during follow-up when symptoms worsened. Results: 63 COPD patients were enrolled: 53 were followed for 1 year, 41 for 2 years, 10 dropped-out. After 2 years, ICS was added in 12/41 patients (29%) without any statistically significant difference at time points considered. Blood and sputum eosinophils did not change during follow-up. Only FEV1/FVC at T0 was predictive of ICS addition during the 2 year-follow-up (OR:0.91; 95% CI: 0.83–0.99, p = 0.03). ICS addition did not impact on delta (T24-T0) FEV1, blood and sputum eosinophils and exacerbations. After 2 years, patients who received ICS had higher blood eosinophils than those in bronchodilator therapy (p = 0.042). Patients with history of ischemic heart disease increased blood eosinophils after 2 years [p = 0.03 for both percentage and counts]. Conclusions: Blood and sputum eosinophils remained stable during the 2 year follow-up and were not associated with worsened symptoms or exacerbations. Almost 30% of mild/moderate COPD patients in bronchodilator therapy at enrollment, received ICS for worsened symptoms in a 2 year-follow-up and only FEV1/FVC at T0 seems to predict this addition. History of ischemic heart disease seems to be associated with a progressive increase of blood eosinophils

Time course of exercise capacity in patients recovering from covid-19-associated pneumonia

Objective: High prevalences of muscle weakness and impaired physical performance in hospitalized patients recovering from COVID-19-associated pneumonia have been reported. Our objective was to determine whether the level of exercise capacity after discharge would affect long-term functional outcomes in these patients. Methods: From three to five weeks after discharge from acute care hospitals (T0), patients underwent a six-minute walk test (6MWT) and were divided into two groups according to the distance walked in percentage of predicted values: <75% group and ≥75% group. At T0 and three months later (T1), patients completed the Short Physical Performance Battery and the Euro Quality of Life Visual Analogue Scale, and pulmonary function and respiratory muscle function were assessed. In addition, a repeat 6MWT was also performed at T1. Results: At T0, 6MWD values and Short Physical Performance Battery scores were lower in the <75% group than in the ≥75% group. No differences were found in the Euro Quality of Life Visual Analogue Scale scores, pulmonary function variables, respiratory muscle function variables, length of hospital stay, or previous treatment. At T1, both groups improved their exercise capacity, but only the subjects in the <75% group showed significant improvements in dyspnea and lower extremity function. Exercise capacity and functional status values returned to predicted values in all of the patients in both groups. Conclusions: Four weeks after discharge, COVID-19 survivors with exercise limitation showed no significant differences in physiological or clinical characteristics or in perceived health status when compared with patients without exercise limitation. Three months later, those patients recovered their exercise capacity

Classifying new anti-tuberculosis drugs: Rationale and future perspectives

The classification of anti-tuberculosis (TB) drugs is important as it helps the clinician to build an appropriate anti-TB regimen for multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB cases that do not fulfil the criteria for the shorter MDR-TB regimen. The World Health Organization (WHO) has recently approved a revision of the classification of new anti-TB drugs based on current evidence on each drug. In the previous WHO guidelines, the choice of drugs was based on efficacy and toxicity in a step-down manner, from group 1 first-line drugs and groups 2-5 second-line drugs, to group 5 drugs with potentially limited efficacy or limited clinical evidence. In the revised WHO classification, exclusively aimed at managing drug-resistant cases, medicines are again listed in hierarchical order from group A to group D. In parallel, a possible future classification is independently proposed. The aim of this viewpoint article is to describe the evolution in WHO TB classification (taking into account an independently proposed new classification) and recent changes in WHO guidance, while commenting on the differences between them. The latest evidence on the ex-group 5 drugs is also discussed

Investigation of nitrogen enriched silicon for particle detectors

This article explores the viability of nitrogen enriched silicon for particle physics application. For that purpose silicon diodes and strip sensors were produced using high resistivity float zone silicon, diffusion oxygenated float zone silicon, nitrogen enriched float zone silicon and magnetic Czochralski silicon. The article features comparative studies using secondary ion mass spectrometry, electrical characterization, edge transient current technique, source and thermally stimulated current spectroscopy measurements on sensors that were irradiated up to a fluence of 1015 neq/cm2. Irradiations were performed with 23 MeV protons at the facilities in Karlsruhe (KIT), with 24 GeV/c protons at CERN (PS-IRRAD) and neutrons at the research reactor in Ljubljana. Secondary ion mass spectrometry measurements give evidence for nitrogen loss after processing, which makes gaining from nitrogen enrichment difficult

controlling the disease

Surveillance and outbreak reports Surveillance of extensively drug-resistant tuberculosis in Europe, 2003-2007 15 by I Devaux, D Manissero, K Fernandez de la Hoz, K Kremer, D van Soolingen, on behalf of the EuroTB network Analysis of tuberculosis treatment outcomes in the European Union and European Economic Area: efforts needed towards optimal case management and control 21 by D Manissero, V Hollo, E Huitric, C Ködmön, A Amato-Gauci Risk of developing tuberculosis from a school contact: retrospective cohort study