126,548 research outputs found
Characterization of the Outer Barrel Modules for the upgrade of the ALICE Inner Tracking System
No full textThe Inner Tracking System (ITS) Upgrade of the ALICE detector at CERN is one of the major upgrades that will take place in 2019–2020. This paper regards the construction procedure and the electrical characterization of the Outer Barrel Module. This is the building element of the four outer layers of the ITS and it is realized assembling together fourteen Monolithic Active Silicon Pixel Sensors with a space precision of the order of few microns. The challenge of the production chain, the characterization test procedure and the results of the first produced prototypes will be shown
Studies for a Micro Vertex System in a EIC Detector using Monolithic Active Pixel Sensors
No full textMore than thirty years after Quantum Chromo-Dynamics (QCD)
was rst proposed as the fundamental theory of the strong force, very little is still
known about the dynamical basis of the hadron structure. We still don't know com-
pletely where fundamental quantities of the nucleons like spin came from or what
is the space distribution of gluons in nucleons. To investigate these fundamental
questions a new Electron Proton/Ion Collider (eRHIC) is proposed to be built at
Brookhaven National Laboratory. The inner tracking system of the detector in this
collider will require very high granularity, very low material budget, hermetic cover-
age and a radiation hard design. For this detector it will be crucial to identify tracks
of charged low momentum leptons at high rapidities. In this talk, an overview will
be given on the eRHIC collider project at BNL, on the present design of the eRHIC
detector. Further it will be shown that Monolithic Active Pixel Sensor (MAPS)
realized with CMOS technology satisfy all these requirements and rst test results
of these sensors will be provided
Silicon Sensors beam test at the Trento proton-line
No full textThe Trento Proton Line is a proton source with energy range between 70 and 230 MeV used for both biological and instrumentation test and measurements.
This beam line is very useful for silicon sensors characterization.
Two set-up were tested in 2018 and 2019: MAPS pixel sensor and SiPM
High dose rate irradiations simulations and measurements at the TIFPA-INFN x-ray station
No full textThe TIFPA-INFN center is equipped with a 3 kW tungsten anode x-ray irradiation station
used for biological and biophysics irradiations on cells and radiation damage studies on silicon
sensors. Since in recent years the importance for high dose rate irradiations is emerging,
not only for solid state silicon radiation damage studies but primarily for flash irradiation
activities on cells for oncological studies, it is becoming mandatory to explore the limits
of the irradiation stations. In this talk the station spectrum simulation realized with the
spekpy python code for different operative station configurations and the corresponding dose
rate measurements realized with a PTW FarmerChamber will be described
Ionizing and Non-Ionizing Energy Loss irradiation studies with 70-230 MeV protons at the Trento Proton Therapy Center
No full textProton induced Ionizing and Non-Ionizing energy loss campaigns are required studies for silicon sensors
and electronic devices qualification when designed for medical, space and high energy physics
applications.
The Experimental Area of the Trento Proton Therapy Center offers the possibility to perform these
studies using a 70-230 MeV proton beam designed for medical treatment of oncological patients. This
area, used only for non medical applications, is equipped with two beamlines reserved for biological
experiments, silicon sensor tests and electronic device qualifications. One of these lines is also
equipped with a unique passive beam modulator system, called double ring, where large area proton
irradiation on silicon sensors and electronic devices can be performed.
In this talk a description of the beam parameters and irradiation regime possibilities will be given,
and also the description of a new set-up used in September 2020 for single event upset rate measurement
on a electronic device
Un tracciatore per particelle cariche nello spazio basato sul sensore ALPIDE
No full textI sensori al silicio di tipo pixel monolitici attivi
(MAPS) sono sempre piu’ impiegati come
rivelatori di particelle cariche per via del loro
ridotto spessore, la bassa tensione di
svuotamento necessaria e la possibilita' di
realizzarli con processi CMOS commerciali.
Sono in corso degli studi di fattibilita’ per
tracciatori spaziali basati sul sensore ALPIDE,
sviluppato al CERN per il progetto Alice ITS
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Operational experience and aging studies of the CDF Run II Silicon Vertex Detector
No full textThe Collider Detector at Fermilab (CDF) pursues a broad physics program at Fermilab’s Tevatron
proton-antiproton collider. Since its commissioning in early 2001 the CDF Run II detector delivered
about 10 fb−1 of integrated luminosity of data. CDF has installed 8 layers of silicon microstrip
detectors. In this talk will be described the operational challenge encountered over the past 10 years
and present detailed detector performance results with emphasis on radiation damage of the silicon
sensors
Pharmacological and neurobiological studies on Neuropeptide S and its receptor
No full textNeuropeptide S (NPS) is the last neuropeptide identified via reverse pharmacology techniques. NPS
selectively binds and activates a previously orphan GPCR, now named NPSR, producing intracellular Ca2+
mobilization and stimulation of cAMP levels. Biological functions modulated by the NPS/NPSR system
include anxiety, arousal, locomotion, food intake, learning and memory, pain and drug addiction. In our
laboratories we provided further evidence that NPS injected supraspinally in mice acts as a stimulatory
anxiolytic. In fact, in the mouse righting reflex (RR) test, NPS (0.01- 1 nmol, i.c.v.) was able to reduce in a
dose dependent manner the percent of animals losing the RR in response to diazepam (15mg/kg, i.p.) and
their sleep time. Furthermore, NPS in the same range of doses caused a significant increase in locomotor
activity (LA) in mice. These effects were associated with a clear anxiolytic-like action elicited by NPS in the
mouse elevated plus maze (EPM) test, open field (OF) test and stress-induced hyperthermia (SIH) assay.
Thus NPS evokes an unique pattern of behavioural effects: stimulation associated with anxiolysis. To deeply
investigate the biological roles played by the NPS/NPSR system the development of pharmacological (i.e.
selective NPSR ligands, particularly antagonists) and genetic (i.e. receptor knockout animals) tools are
needed. In collaboration with the medicinal chemistry group of the University of Ferrara, we performed a
series of classical structure-activity (SAR) studies on NPS sequence. Specifically, NPS positions 2, 3, 4 and
5 were investigated in details, since they were demonstrated to be crucial for NPS bioactivity. Studies
focussed on NPS position 5 led to the identification and the in vitro and in vivo pharmacological
characterization of the first generation of NPSR peptide antagonists. In vitro, in HEK293 cells stably
expressing the mouse NPSR, [D-Cys(tBu)5]NPS up to 100 μM did not stimulate Ca2+ mobilization but was
able to counteract in a competitive manner the stimulatory action of NPS (pA2: 6.44). In vivo, in the RR test,
[D-Cys(tBu)5]NPS at 10 nmol was inactive per se but dose dependently antagonized the arousal-promoting
action of NPS 0.1 nmol. [D-Val5]NPS acted in vitro as a pure NPSR antagonist, with a pKB of 6.54 in
inhibition experiments. In vivo, in LA test, [D-Val5]NPS at 10 nmol completely blocked the stimulatory
effect evoked by NPS. In a further medicinal chemistry study, the potent NPSR antagonist [tBu-D-Gly5]NPS
was identified. In vitro, [tBu-D-Gly5]NPS did not stimulate calcium mobilization but blocked the stimulant
action of NPS with a pKB of 7.06 7. In vivo, in RR assay, [tBu-D-Gly5]NPS (0.1-10 nmol, i.c.v.) was inactive
per se but dose dependently antagonized the arousal-promoting action of NPS 0.1 nmol. Similarly in the LA
assay [tBu-D-Gly5]NPS (0.1-10 nmol, i.c.v.) was inactive per se but was able to counteract the stimulatory
effect evoked by 0.1 nmol NPS in a dose dependent manner. SHA 68 has been previously identified as the
first non peptide NPSR antagonist. In our laboratories we further assessed the pharmacological profile of
SHA 68 in vitro and in vivo. In vitro SHA 68 was inactive per se up to 10 μM while it antagonized NPSstimulated
Ca2+ mobilization in a competitive manner showing a pA2 value of 8.06. In vivo, in the mouse RR
assay, SHA68 50 mg/kg i.p. fully prevented the arousal promoting action of NPS 0.1 nmol. In LA
experiments, SHA 68 50 mg/kg i.p. was able to partially counteract the stimulant effects elicited by NPS 0.1
nmol. Instead, the anxiolytic-like effects of NPS 0.1 nmol in mouse OF test were slightly reduced by SHA
68. Collectively these data demonstrated the exclusive involvement of NPSR in the arousal promoting and
locomotor stimulant effects of NPS. Finally, we backcrossed on the CD-1 strain the NPSR knockout mice
originally generated on the 129Sv/Ev genetic background. A first phenotype analysis revealed no locomotor
differences between NPSR(+/+) and NPSR(-/-) mice, with the exception of rearing behaviour that was
reduced in knockout animals. Furthermore, the behaviour of NPSR(+/+) and NPSR(-/-) mice in the EPM, OF
and SIH tests is superimposable. Similarly no differences were detected in the novel object recognition,
forced swimming, RR and formalin assays. However, the stimulant actions of 1 nmol NPS in RR and in LA
test could be detected in NPSR(+/+) but not in NPSR(-/-) mice. Collectively these data demonstrated that
endogenous NPS/NPSR system does not play a role in the control of locomotion, anxiety, depression and
memory, at least under the present experimental conditions. These results demonstrated that the NPS
stimulant effects are selectively due to NPSR activation, corroborating the findings obtained with NPSR
antagonists. In conclusion, the research activity performed during the PhD program led to the identification
of the first generation of NPSR peptide antagonists. The use of these research tools in parallel with knockout
studies generated converging evidence on the biological effects induced by the selective activation of NPSR
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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