Abstract
We studied the light yield of a pure polystyrene slide
coated with wavelength-shifter molecules, coupled to a
photomultiplier, using
β
-
particles from a
90
Sr
source, as a possible ...easy-to-build, low-cost plastic scintillator
detector. Comparison measurements were performed with an uncoated
polystyrene slide as well as with uncoated and coated PMMA slides,
the latter which can only produce Cherenkov light when being
traversed by charged particles. The results with the single (double)
coated polystyrene slides show about 4.9 (6.3) times higher detected
photon yield compared to the uncoated slide. For comparison, the
light yield of a polystyrene-based extruded plastic scintillator
material doped with PTP and POPOP was measured as well. The
absolute detected light yield motivates future studies for
developing easy-to-build, low-cost polystyrene-based plastic
scintillator detectors.
Abstract As a prototype detector for the SHiP Surrounding Background Tagger (SBT), we constructed a cell (120 cm × 80 cm × 25 cm) made from corten steel that is filled with liquid scintillator (LS) ...composed of linear alkylbenzene (LAB) and 2,5-diphenyloxazole (PPO). The detector is equipped with two Wavelength-shifting Optical Modules (WOMs) for light collection of the primary scintillation photons. Each WOM consists of an acrylic tube that is dip-coated with a wavelength-shifting layer on its surface. Via internal total reflection, the secondary photons emitted by the molecules of the wavelength shifter are guided to a ring-shaped array of 40 silicon photomultipliers (SiPMs) coupled to the WOM for light detection. The granularity of these SiPM arrays provides an innovative method to gain spatial information on the particle crossing point. Several improvements in the detector design significantly increased the light yield with respect to earlier proof-of-principle detectors. We report on the performance of this prototype detector during an exposure to high-energy positrons at the DESY II test beam facility by measuring the collected integrated yield and the signal time-of-arrival in each of the SiPM arrays. The resulting detection efficiency and reconstructed energy deposition of the incident positrons are presented, as well as the spatial and time resolution of the detector. These results are then compared to Monte Carlo simulations.
Microcapsules with organic–inorganic hybrid shells can be used as functionally responsive delivery systems that are attractive for a broad range of applications. Hybrid-shell microcapsules have often ...been synthesized by the assembly of solid inorganic nanoparticles and polymers. Efforts to extend this approach to microfluidic emulsification have been hampered by problems with clogging and flow instabilities when utilizing dispersions of solid particles. In this work, hybrid shell microcapsules are synthesized through the reaction of liquid precursors, eliminating the use of solid dispersions. Our microfluidic water–oil–water emulsification technique also enables the preparation of hybrid-shell microcapsules with thicker and more robust shells compared to alternative techniques. By utilizing bridged-silane precursors to form the hybrid material, we demonstrate hybrid-shell microcapsules with independently tunable functional and mechanical/barrier properties. This independent tuning of physical and functional properties allows for the production of functional organic–inorganic hybrid shell microcapsules that can be tailored to meet the demands of a wide range of applications.
Background:As conservation of whole blood samples undergoing white blood cell (WBC) differential performed by flow cytometry (Hematoflow) is needed, we evaluated the effects of two commercially ...available fixatives, namely TransfixTM and Streck Cell PreservativeTM.Methods:We focused on 15 normal samples and on 13 various pathological samples. We compared the two fixatives and cold- or room- temperature effects on various parameters provided by the Hematoflow system.Results:We observed that, even after 2 hours of sample treatment, the conservative methods led to significant modifications of the cell percentages due to substantial variations of the epitope expression.Conclusion:None of the different conservation methods is really reliable for WBC differential performed by flow cytometry and thus samples should be analyzed promptly or stored at 4°C.
Abstract
We measured the surface tension of linear alkylbenzene (LAB)
HYBLENE 113 mixed with Diphenyloxazole (PPO) as well as of pure LAB
HYBLENE 113 as part of material studies for the ...liquid-scintillator
based surround background tagger (SBT) in the proposed SHiP
experiment. The measurement was performed using the iron wire method
and the surface tension for linear alkyl benzene HYBLENE 113 plus
PPO was found to be (30.0 ± 0.6) mN/m 22.0 ± 0.5°C and
for pure HYBLENE 113, (29.2 ± 0.6) mN/m at
21.0 ± 0.5°C.
The Search for Hidden Particles (SHiP) Collaboration has proposed a general-purpose experimental facility operating in beam-dump mode at the CERN SPS accelerator to search for light, feebly ...interacting particles. In the baseline configuration, the SHiP experiment incorporates two complementary detectors. The upstream detector is designed for recoil signatures of light dark matter (LDM) scattering and for neutrino physics, in particular with tau neutrinos. It consists of a spectrometer magnet housing a layered detector system with high-density LDM/neutrino target plates, emulsion-film technology and electronic high-precision tracking. The total detector target mass amounts to about eight tonnes. The downstream detector system aims at measuring visible decays of feebly interacting particles to both fully reconstructed final states and to partially reconstructed final states with neutrinos, in a nearly background-free environment. The detector consists of a 50
m
long decay volume under vacuum followed by a spectrometer and particle identification system with a rectangular acceptance of 5 m in width and 10 m in height. Using the high-intensity beam of 400
GeV
protons, the experiment aims at profiting from the
4
×
10
19
protons per year that are currently unexploited at the SPS, over a period of 5–10 years. This allows probing dark photons, dark scalars and pseudo-scalars, and heavy neutral leptons with GeV-scale masses in the direct searches at sensitivities that largely exceed those of existing and projected experiments. The sensitivity to light dark matter through scattering reaches well below the dark matter relic density limits in the range from a few
MeV
/
c
2
up to 100 MeV-scale masses, and it will be possible to study tau neutrino interactions with unprecedented statistics. This paper describes the SHiP experiment baseline setup and the detector systems, together with performance results from prototypes in test beams, as it was prepared for the 2020 Update of the European Strategy for Particle Physics. The expected detector performance from simulation is summarised at the end.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The SHiP-charm project was proposed to measure the associated charm production induced by 400 GeV/c protons in a thick target, including the contribution from cascade production. An optimisation run ...was performed in July 2018 at CERN SPS using a hybrid setup. The high resolution of nuclear emulsions acting as vertex detector was complemented by electronic detectors for kinematic measurements and muon identification. Here we present first results on the analysis of nuclear emulsions exposed in the 2018 run, which prove the capability of reconstructing proton interaction vertices in a harsh environment, where the signal is largely dominated by secondary particles produced in hadronic and electromagnetic showers within the lead target.
Abstract
Funding Acknowledgements
Type of funding sources: Public hospital(s). Main funding source(s): University of Buenos Aires
Background
Cortisol is a stress marker in patients with acute ...coronary syndrome (ACS) and it has a permissive effect on the actions of hormones that increase glucose production. Its association with blood glucose levels in diabetic and non-diabetic patients could help to understand the relationship between stress, hyperglycaemia and mortality.
Methods
Prospective and observational single-centre study. All patients admitted with a diagnosis of ACS to the coronary care unit of a University Hospital were included. The age, sex and clinical characteristics were recorded, along with the clinical outcomes. On admission, blood samples were obtained to measure serum glucose (SG) and cortisol (SC).
Results
Over a total of 149 patients, 35.37% had a diagnosis of ST-segment elevation ACS. Median age was 69 (60.1 – 79) years, 61.1% were male, 59.5% were hypertense, 18.2% dyslipidemic, 23% smokers, and 28.4% diabetics. Total mortality during hospitalization was 6.8%, and cardiovascular mortality was 6.1%.
We observed a significantly higher SC and SG on admission in patients who died (table 1), with a mild and positive correlation between them (Spearman’s rho = 0.24, p = 0.005). Diabetic patients had a higher SG on admission 191.1 mg/dl (157.5 – 250,8) vs. 116.0 mg/dl (99.0 – 141.0), < 0.001. Diabetes was not associated with mortality, although correlation between glucose and cortisol remained constant in diabetics and non-diabetics (figure 1).
Conclusion
Hypercortisolemia and hyperglycaemia were associated with an increased in-hospital mortality. Although hyperglycemia confers a worse prognosis, we found that its correlation with cortisol was constant in diabetics and non-diabetics. This suggests that hyperglycaemia could be a surrogate stress marker, not related to diabetes as a risk factor in an acute setting. Serum glucose and cortisol on admission LaboratorySurvivorsNon-survivorsp-valueGlucose (mg/dL)128 (101 - 163)156 (134.5 - 197.2)0.04Cortisol (ug/dL)13.7 (7,98 - 23.65)43.7 (34.6 - 50.0)0.0004Abstract Figure. Serum cortisol and glucose on admission.
The main demographic revoulution in modern history has been the increased survival of children - the gradual elimination of the biological waste linked to the high mortality of the past. This volume ...examines the trends of early-age mortality across time and space and the methodological and theoretical problems inherent in such studies. It widens the discussion beyond the standard European focus by including data from Asian and American sources, showing that they offer enormous potential for researchers. At the same time, it makes clear the need for cautious treatment of historical data and points towards the design of techniques for appraising their quality, correcting distortions, and filling gaps. The analysis demonstrates that levels of infant and child mortality are linked not only to material conditions of life but also to social and cultural factors. The authors argue that a better understanding of these interactions can only come from an interdisciplinary approach, where demography joins forces with biology, medicine, public health, and social and economic history.
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