2,724 research outputs found
Neutron irradiation effect on SiPMs up to = 5 10 cm
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 =
510 cm (1 MeV equivalent neutrons). Results from the I-V,
and C-V measurements for temperatures between 30C and 30C
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
Improving tuberculosis surveillance in Europe is key to controlling the disease.
As underlined by the joint ECDC and World Health Organization Regional Office for Europe TB report, launched on 18 March the importance of good surveillance to stem this trend cannot be underestimated.
Where do we go with surveillance in Europe? Can we do more? How many MDR and XDR TB cases occur because of sub-optimal patient management?
This issue of Eurosurveillance casts light on these important questions with four interesting articles.
The results of the studies reported in this issue of Eurosurveillance allow us to point out some key topics:
\u2022The completeness of reporting information (including treatment outcomes), the proportion of culture-confirmed TB cases reported as well as the proportion of strains on which DST for both first- and second-line drugs is performed and reported are still sub-optimal overall in Europe. The relevance of these pitfalls goes beyond the \u201csimple\u201d surveillance limitation, having the potential to affect other important TB control pillars, e.g. infection control and case-management.
\u2022MDR and XDR TB still persist in Europe. The high proportion of MDR TB identified among new TB cases reported by certain countries indicates that sub-optimal infection control practices are likely to occur, while the high percentage of MDR TB notified among retreatment cases is probably the result of sub-optimal case management in the past decade
Applicability of the shorter 'Bangladesh regimen' in high multidrug-resistant tuberculosis settings
In spite of the recent introduction of two new drugs (delamanid and bedaquiline) and a few repurposed compounds to treat multidrug-resistant and extensively drug-resistant tuberculosis (MDR- and XDR-TB), clinicians are facing increasing problems in designing effective regimens in severe cases. Recently a 9 to 12-month regimen (known as the 'Bangladesh regimen') proved to be effective in treating MDR-TB cases. It included an initial phase of 4 to 6 months of kanamycin, moxifloxacin, prothionamide, clofazimine, pyrazinamide, high-dose isoniazid, and ethambutol, followed by 5 months of moxifloxacin, clofazimine, pyrazinamide, and ethambutol. However, recent evidence from Europe and Latin America identified prevalences of resistance to the first-line drugs in this regimen (ethambutol and pyrazinamide) exceeding 60%, and of prothionamide exceeding 50%. Furthermore, the proportions of resistance to the two most important pillars of the regimen - quinolones and kanamycin - were higher than 40%. Overall, only 14 out of 348 adult patients (4.0%) were susceptible to all of the drugs composing the regimen, and were therefore potentially suitable for the 'shorter regimen'. A shorter, cheaper, and well-tolerated MDR-TB regimen is likely to impact the number of patients treated and improve adherence if prescribed to the right patients through the systematic use of rapid MTBDRsl testing
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 ; 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
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
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
Multidrug- and extensively drug-resistant tuberculosis
We evaluated risk factors and treatment outcomes associated with multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) in Germany in 2004–2006. In 177 (4%) of 4,557 culture-positive TB cases, Mycobacterium tuberculosis isolates were identified as MDR TB; an additional 7 (0.15%) met criteria for XDR TB. Of these 184 patients, 148 (80%) were born in countries of the former Soviet Union. In patients with XDR TB, hospitalization was longer (mean ± SD 202 ± 130 vs. 123 ± 81 days; p = 0.015) and resistance to all first-line drugs was more frequent (36% vs. 86%; p = 0.013) than in patients with MDR TB. Seventy-four (40%) of these 184 patients received treatment with linezolid. Treatment success rates ranged from 59% for the entire cohort (59% for MDR TB and 57% for XDR TB) to 87% for those with a definitive outcome (n = 125; 89% for MDR TB and 80% for XDR TB). Extensive drug susceptibility testing and availability of second- and third-line drugs under inpatient management conditions permit relatively high treatment success rates in MDR- and XDR TB
Brittle asthma: still on board?
(1) Background: “Brittle Asthma” was considered an asthma clinical phenotype and deemed to be life-threatening in the early 2000s; then, this definition disappeared. The purpose of this review is to examine what has historically been referred to as this term and see whether it may be applied to modern clinical practice, thus acquiring fresh relevance and meaning. (2) Methods: A non-systematic search of the literature was conducted using both MeSH and free-text phrases. No limitations on the research design or type of publication were applied. (3) Results: Reliable data regarding “Brittle Asthma” are lacking due to the paucity of current data and the few studies available. After a few years of reworking, it was divided into two sub-classes: one characterized by a wide PEF variability despite high-dose therapy and the other by sudden acute attacks in otherwise apparently normal airway functions or well-controlled asthma. Their characteristics were hardly defined because of their low prevalence. Data regarding risk factors, atopy, mechanisms, and treatments were analyzed. (4) Conclusions: Over time, different terminology has been introduced to define asthma severity and control. It would be worth investigating whether the term “Brittle Asthma” previously used may be helpful to find new hints to stratify patients and improve disease management
Treatment Outcomes of Patients With Multidrug-Resistant and Extensively Drug-Resistant Tuberculosis According to Drug Susceptibility Testing to First- and Second-line Drugs: An Individual Patient Data Meta-analysis
The clinical validity of drug susceptibility testing (DST) for pyrazinamide, ethambutol, and second-line antituberculosis drugs is uncertain. In an individual patient data meta-analysis of 8955 patients with confirmed multidrug-resistant tuberculosis, DST results for these drugs were associated with treatment outcome
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