Spatial and temporal evaluations of the liquid argon purity in ProtoDUNE-SP

Liquid argon time projection chambers (LArTPCs) rely on highly pure argon to ensure that ionization electrons produced by charged particles reach readout arrays. ProtoDUNE Single-Phase (ProtoDUNE-SP) was an approximately 700-ton liquid argon detector intended to prototype the Deep Underground Neutrino Experiment (DUNE) Far Detector Horizontal Drift module. It contains two drift volumes bisected by the cathode plane assembly, which is biased to create an almost uniform electric field in both volumes. The DUNE Far Detector modules must have robust cryogenic systems capable of filtering argon and supplying the TPC with clean liquid. This paper will explore comparisons of the argon purity measured by the purity monitors with those measured using muons in the TPC from October 2018 to November 2018. A new method is introduced to measure the liquid argon purity in the TPC using muons crossing both drift volumes of ProtoDUNE-SP. For extended periods on the timescale of weeks, the drift electron lifetime was measured to be above 30 ms using both systems. A particular focus will be placed on the measured purity of argon as a function of position in the detector

Angiotensin actions on the isolated rat uterus during the estrous cycle: Influence of resting membrane potential and uterine morphology

The involvement of AT(1) and AT(2) receptor subtypes in the response of the isolated rat uterus to angiotensin 11 (AngII) was studied throughout the estrous cycle. the AngII potency varied during the different estrous cycle phases, as indicated by significantly different pD(2) values. No significant differences were observed in AngII metabolism among different estrous phases. Morphological analysis indicated that external and internal myometrium layers were thicker during estrus. in addition, the highest resting membrane potential was also observed during this phase, when compared with the proestrus and diestrus phases. the AngII-induced uterine contractions were blocked by losartan. Different losartan pD(2) values were observed. PD123319 had no effect on the contractile response to AngII. the results also indicate that estrous cycle-dependent changes in AngII potency are correlated with uterine morphological and/or membrane potential changes. Copyright (C) 2002 S. Karger AG, Basel.USP, FCFRP, Pharmacol Lab, Sch Pharmaceut Sci, BR-14040903 Ribeirao Preto, SP, BrazilUSP, Sch Med, Dept Pharmacol, Ribeirao Preto, BrazilUSP, Sch Dent, Dept Morphol Stomatol & Physiol, Ribeirao Preto, BrazilUNIFESP, Dept Biophys, Ribeirao Preto, BrazilUNIFESP, Dept Biophys, Ribeirao Preto, BrazilWeb of Scienc

Role of ventral medullary catecholaminergic neurons for respiratory modulation of sympathetic outflow in rats

Sympathetic activity displays rhythmic oscillations generated by brainsteminspiratory and expiratory neurons. Amplification of these rhythmic respiratory-related oscillations is observed in rats under enhanced central respiratory drive or during development of neurogenic hypertension. Herein, we evaluated the involvement of ventral medullary sympatho-excitatory catecholaminergic C1 neurons, using inhibitory Drosophila allatostatin receptors, for the enhanced expiratory-related oscillations in sympathetic activity in rats submitted to chronic intermittent hypoxia (CIH) and following activation of both peripheral (hypoxia) and central chemoreceptors (hypercapnia). Pharmacogenetic inhibition of C1 neurons bilaterally resulted in reductions of their firing frequency and amplitude of inspiratory-related sympathetic activity in rats in normocapnia, hypercapnia or after CIH. In contrast, hypercapnia or hypoxia-induced enhanced expiratory-related sympathetic oscillations were unaffected by C1 neuronal inhibition. Inhibition of C1 neurons also resulted in a significant fall in arterial pressure and heart rate that was similar in magnitude between normotensive and CIH hypertensive rats, but basal arterial pressure in CIH rats remained higher compared to controls. C1 neurons play a key role in regulating inspiratory modulation of sympathetic activity and arterial pressure in both normotensive and CIH hypertensive rats, but they are not involved in the enhanced late-expiratory-related sympathetic activity triggered by activation of peripheral or central chemoreceptors