79 research outputs found
ANEM: A rotating composite target to produce an atmospheric-like neutron beam at the LNL SPES facility
A fast neutron (E> MeV) irradiation facility is under development at the 70 MeV SPES proton cyclotron at LNL (Legnaro, Italy) to investigate neutron-induced Single Event Effects (SEE) in microelectronic devices and systems. After an overview on neutron-induced SEE in electronics, we report on the progress in the design of ANEM (Atmospheric Neutron EMulator), a water-cooled rotating target made of Be and W to produce neutrons with an energy spectrum similar to that of neutrons produced by cosmic rays at sea-level. In ANEM, the protons from the cyclotron alternatively impinge on two circular sectors of Be and W of different areas; the effective neutron spectrum is a weighted combination of the spectra from the two sectors. In this contribution, we present the results of thermal-mechanical Finite Element Analysis (ANSYS) calculations of the performance of the ANEM prototype. The calculations at this stage indicate that ANEM can deliver fast neutrons with an atmospheric-like energy spectrum and with an integral flux [Formula: see text](1-70 MeV) [Formula: see text]107 n cm[Formula: see text]s[Formula: see text] that is 3Ă—109 more intense than the natural one at sea-level: a very competitive flux for SEE testing
Heavy-ion test report of LTC1668 DAC - LiteBIRD-NOTE-84
This document presents the results of a heavy-ion test program carried out on the Linear Technology LT1668 16-bit 50 Msps DAC (LTC1668IG) to identify single-event effects. In particular, it was studied the detection of single-event latch-up (SEL), single-event upsets (SEU), and single-event transients (SET) due to heavy-ions radiation. The tests were performed at the heavy-ion facility Tandem-ALPI at INFN Legnaro National Laboratory (Italy) in February 2021 and June 2022 for a total irradiation time of ~51 hours
Fast neutron production at the LNL Tandem from the Li(N,xn)X reaction
Fast neutron beams are of relevance for many scientific and industrial
applications. This paper explores fast neutron production using a TANDEM
accelerator at the Legnaro National Laboratories, via an energetic ion beam (90
MeV ) onto a lithium target. The high energy models for nuclear
collision of FLUKA foresee large neutron yields for reactions of this kind. The
experiment aimed at validating the expected neutron yields from FLUKA
simulations, using two separate and independent set-ups: one based on the
multi-foil activation technique, and the other on the time of flight technique,
by using liquid scintillator detectors.
The results of the experiment show clear agreement of the measured spectra
with the FLUKA simulations, both in the shape and the magnitude of the neutron
flux at the measured positions. The neutron spectrum is centered around the 8
MeV range with mild tails, and a maximum neutron energy spanning up to 50 MeV.
These advantageous results provide a starting point in the development of
fast neutron beams based on high energy ion beams from medium-sized accelerator
facilities
Effect of chemokine receptor CXCR4 on hypoxia-induced pulmonary hypertension and vascular remodeling in rats
<p>Abstract</p> <p>Background</p> <p>CXCR4 is the receptor for chemokine CXCL12 and reportedly plays an important role in systemic vascular repair and remodeling, but the role of CXCR4 in development of pulmonary hypertension and vascular remodeling has not been fully understood.</p> <p>Methods</p> <p>In this study we investigated the role of CXCR4 in the development of pulmonary hypertension and vascular remodeling by using a CXCR4 inhibitor AMD3100 and by electroporation of CXCR4 shRNA into bone marrow cells and then transplantation of the bone marrow cells into rats.</p> <p>Results</p> <p>We found that the CXCR4 inhibitor significantly decreased chronic hypoxia-induced pulmonary hypertension and vascular remodeling in rats and, most importantly, we found that the rats that were transplanted with the bone marrow cells electroporated with CXCR4 shRNA had significantly lower mean pulmonary pressure (mPAP), ratio of right ventricular weight to left ventricular plus septal weight (RV/(LV+S)) and wall thickness of pulmonary artery induced by chronic hypoxia as compared with control rats.</p> <p>Conclusions</p> <p>The hypothesis that CXCR4 is critical in hypoxic pulmonary hypertension in rats has been demonstrated. The present study not only has shown an inhibitory effect caused by systemic inhibition of CXCR4 activity on pulmonary hypertension, but more importantly also has revealed that specific inhibition of the CXCR4 in bone marrow cells can reduce pulmonary hypertension and vascular remodeling via decreasing bone marrow derived cell recruitment to the lung in hypoxia. This study suggests a novel therapeutic approach for pulmonary hypertension by inhibiting bone marrow derived cell recruitment.</p
Direct Identification of the Meloidogyne incognita Secretome Reveals Proteins with Host Cell Reprogramming Potential
The root knot nematode, Meloidogyne incognita, is an obligate parasite that causes significant damage to a broad range of host plants. Infection is associated with secretion of proteins surrounded by proliferating cells. Many parasites are known to secrete effectors that interfere with plant innate immunity, enabling infection to occur; they can also release pathogen-associated molecular patterns (PAMPs, e.g., flagellin) that trigger basal immunity through the nematode stylet into the plant cell. This leads to suppression of innate immunity and reprogramming of plant cells to form a feeding structure containing multinucleate giant cells. Effectors have generally been discovered using genetics or bioinformatics, but M. incognita is non-sexual and its genome sequence has not yet been reported. To partially overcome these limitations, we have used mass spectrometry to directly identify 486 proteins secreted by M. incognita. These proteins contain at least segmental sequence identity to those found in our 3 reference databases (published nematode proteins; unpublished M. incognita ESTs; published plant proteins). Several secreted proteins are homologous to plant proteins, which they may mimic, and they contain domains that suggest known effector functions (e.g., regulating the plant cell cycle or growth). Others have regulatory domains that could reprogram cells. Using in situ hybridization we observed that most secreted proteins were produced by the subventral glands, but we found that phasmids also secreted proteins. We annotated the functions of the secreted proteins and classified them according to roles they may play in the development of root knot disease. Our results show that parasite secretomes can be partially characterized without cognate genomic DNA sequence. We observed that the M. incognita secretome overlaps the reported secretome of mammalian parasitic nematodes (e.g., Brugia malayi), suggesting a common parasitic behavior and a possible conservation of function between metazoan parasites of plants and animals
Hippocampal and neocortical interactions during context discrimination: Electrophysiological evidence from the rat
CMOS sensors in 90 nm fabricated on high resistivity wafers: Design concept and irradiation results
Secondary electron yield of Au and Al2O3 surfaces from swift heavy ion impacts in the 2.5-7.9 MeV/amu energy range
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