40 research outputs found

    Characterization of the in vivo cardiac electrophysiologic effects of high-dose cocaine in closed-chest, anesthetized dogs with normal hearts

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    OBJECTIVE: To characterize the cardiac electrophysiologic effects of cocaine. METHODS: In 8 dogs (9-13 kg), electrophysiologic parameters and programmed stimulation were undertaken using transvenous catheters at baseline, and after cocaine intravenous infusion (12 mg/kg bolus followed by 0.22 mg/kg/min for 25 minutes). RESULTS: Cocaine plasma levels (n=5) rose to 6.73± 0.56 mg/mL. Cocaine did not affect sinus cycle length and arterial pressure. Cocaine prolonged P wave duration (54±6 vs 73±4 ms, P<0.001), PR interval (115±17 vs 164±15 ms, P<0.001), QRS duration (62±10 vs 88±14 ms, P<0.001), and QTc interval (344±28 vs 403±62 ms, P=0.03) but not JT interval (193±35 vs 226±53 ms, NS). Cocaine prolonged PA (9±6 vs 23±8 ms, P<0.001), AH (73±16 vs 92±15 ms; P=0.03), and HV (35±5 vs 45±3ms; P<0.001) intervals and Wenckebach point (247±26 vs 280±28 ms, P=0.04). An increase occurred in atrial (138±8 vs 184± 20 ms; P<0.001) and ventricular (160±15 vs 187±25 ms; P=0.03) refractoriness at a cycle length of 300 ms. Atrial arrhythmias were not induced in any dog. Ventricular fibrillation (VF) was induced in 2/8 dogs at baseline and 4/8 dogs after cocaine. CONCLUSION: High doses of cocaine exert significant class I effects and seem to enhance inducibility of VF but not of atrial arrhythmias.Universidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM)UNIFESP, EPMSciEL

    The BINGO Project: III. Optical design and optimization of the focal plane

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    Context. The Baryon Acoustic Oscillations from Integrated Neutral Gas Observations (BINGO) telescope was designed to measure the fluctuations of the 21 cm radiation arising from the hyperfine transition of neutral hydrogen. It is also aimed at measuring the baryon acoustic oscillations (BAO) from such fluctuations, thereby serving as a pathfinder to future, deeper intensity mapping surveys. The requirements for the Phase 1 of the projects consider a large reflector system (two 40 m-class dishes in a crossed-Dragone configuration) illuminating a focal plane with 28 horns to measure the sky, with two circular polarizations in a drift scan mode to produce measurements of the radiation in intensity (I) as well as the circular (V) polarization. Aims. In this paper, we present the optical design for the instrument. We describe the optical arrangement of the horns in the focal plane to produce a homogeneous and well-sampled map after the end of Phase 1, as well as the intensity and polarization properties of the beams. Our analysis provides an optimal model for the location of the horns in the focal plane, producing a homogeneous and Nyquist-sampled map after the nominal survey time. Methods. We used the GRASP package to model the focal plane arrangement and performed several optimization tasks to arrive at the current configuration, including an estimation of the sidelobes corresponding to the diffraction patterns of the two mirrors. The final model for the focal plane was defined through a combination of neural network and other direct optimization methods. Results. We arrived at an optimal configuration for the optical system that includes the focal plane positioning and the beam behavior of the instrument. We present an estimate of the expected sidelobes both for intensity and polarization, as well as the effect of band averaging on the final sidelobes, as well as an estimation of the cross-polarization leakage for the final configuration. Conclusions. We conclude that the chosen optical design meets the requirements for the project in terms of polarization purity and area coverage as well as a homogeneity of coverage so that BINGO can perform a successful BAO experiment. We further conclude that the requirements on the placement and rms error on the mirrors are also achievable so that a successful experiment can be conducted

    The BINGO project: I. Baryon acoustic oscillations from integrated neutral gas observations

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    Context. Observations of the redshifted 21-cm line of neutral hydrogen (HI) are a new and powerful window of observation that offers us the possibility to map the spatial distribution of cosmic HI and learn about cosmology. Baryon Acoustic Oscillations from Integrated Neutral Gas Observations (BINGO) is a new unique radio telescope designed to be one of the first to probe baryon acoustic oscillations (BAO) at radio frequencies. Aims. BINGO has two science goals: cosmology and astrophysics. Cosmology is the main science goal and the driver for BINGO's design and strategy. The key of BINGO is to detect the low redshift BAO to put strong constraints on the dark sector models and test the ICDM (cold dark matter) model. Given the versatility of the BINGO telescope, a secondary goal is astrophysics, where BINGO can help discover and study fast radio bursts (FRB) and other transients, as well as study Galactic and extragalactic science. In this paper, we introduce the latest progress of the BINGO project, its science goals, describing the scientific potential of the project for each goal and the new developments obtained by the collaboration. Methods. BINGO is a single dish transit telescope that will measure the BAO at low-z by making a 3D map of the HI distribution through the technique of intensity mapping over a large area of the sky. In order to achieve the project's goals, a science strategy and a specific pipeline for cleaning and analyzing the produced maps and mock maps was developed by the BINGO team, which we generally summarize here. Results. We introduce the BINGO project and its science goals and give a general summary of recent developments in construction, science potential, and pipeline development obtained by the BINGO Collaboration in the past few years. We show that BINGO will be able to obtain competitive constraints for the dark sector. It also has the potential to discover several FRBs in the southern hemisphere. The capacity of BINGO in obtaining information from 21-cm is also tested in the pipeline introduced here. Following these developments, the construction and observational strategies of BINGO have been defined. Conclusions. There is still no measurement of the BAO in radio, and studying cosmology in this new window of observations is one of the most promising advances in the field. The BINGO project is a radio telescope that has the goal to be one of the first to perform this measurement and it is currently being built in the northeast of Brazil. This paper is the first of a series of papers that describe in detail each part of the development of the BINGO project

    The BINGO project: II. Instrument description

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    Context. The measurement of diffuse 21-cm radiation from the hyperfine transition of neutral hydrogen (Hi signal) in different redshifts is an important tool for modern cosmology. However, detecting this faint signal with non-cryogenic receivers in single-dish telescopes is a challenging task. The BINGO (Baryon Acoustic Oscillations from Integrated Neutral Gas Observations) radio telescope is an instrument designed to detect baryonic acoustic oscillations (BAOs) in the cosmological Hi signal, in the redshift interval 0:127 ≤ z ≤ 0:449. Aims. This paper describes the BINGO radio telescope, including the current status of the optics, receiver, observational strategy, calibration, and the site. Methods. BINGO has been carefully designed to minimize systematics, being a transit instrument with no moving dishes and 28 horns operating in the frequency range 980 ≤ v ≤ 1260 MHz. Comprehensive laboratory tests were conducted for many of the BINGO subsystems and the prototypes of the receiver chain, horn, polarizer, magic tees, and transitions have been successfully tested between 2018-2020. The survey was designed to cover ∼13% of the sky, with the primary mirror pointing at declination δ = -15°. The telescope will see an instantaneous declination strip of 14:75. Results. The results of the prototype tests closely meet those obtained during the modeling process, suggesting BINGO will perform according to our expectations. After one year of observations with a 60% duty cycle and 28 horns, BINGO should achieve an expected sensitivity of 102μK per 9.33MHz frequency channel, one polarization, and be able to measure the Hi power spectrum in a competitive time frame

    Research Letter-Behavioral effects of Kielmeyera coriacea   extract in rats

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    <b>Efeito ansiolítico e sedativo do extrato combinado de <em>Passiflora alata</em> Dryander e <em>Valeriana officinalis</em> L. em ratos</b> - DOI: 10.4025/actascihealthsci.v27i2.1379

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    Este trabalho investigou o efeito do extrato combinado de Passiflora alata Dryander e Valeriana officinalis L. (EPV) em ratos submetidos aos testes do labirinto em cruz elevado (LCE) e campo aberto (TCA). Nenhum efeito foi detectado após o tratamento agudo ou repetido por 3 ou 7 dias com EPV (5, 10 or 20 mg/kg, gavagem) no LCE e TCA. Entretanto, ratos tratados por 15 dias com EPV (20 mg/kg) mostraram aumento na porcentagem de entradas e tempo gasto nos braços abertos no LCE, sem alterar a atividade locomotora no TCA, comparado ao controle. Diazepan (droga de referência, i.p.), aumentou os mesmos parâmetros analisados no LCE e OFT após o tratamento agudo ou por 15 dias. O tratamento agudo com 300 ou 600 mg/kg do EPV diminuiu significativamente a atividade locomotora no TCA. Estes resultados mostram que EPV produz efeito ansiolítico e sedativo, com ampla margem de segurança para o efeito ansiolític

    Anxiolytic and sedative effects of a combined extract of Passiflora alata Dryander and Valeriana officinalis L. in rats = Efeito ansiolítico e sedativo do extrato combinado de Passiflora alata Dryander e Valeriana officinalis L. em ratos

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    This work investigated the effects of a combined extract of Passiflora alata Dryander and Valeriana officinalis L. (EPV) in rats under going elevated plus maze (EPM) and open-field test (OFT). No effects were detected after acute or repeated (3 or 7-days) treatment with EPV (5, 10 or 20 mg/kg, by gavage), on the EPM or the OFT. However, rats treated for 15 day (20 mg/kg) with EPV showed increased percentage of entries and time spent in the open arms on the EPM without alter locomotor activity in the OFT compared to control group. Acute or a 15 day administration of diazepam (2 mg/kg, i.p.),increased the same parameters on the EPM and OFT. Acute treatment with 300 or 600 mg/kg of EPV, decreased the locomotor activity in the OFT. Results suggest anxiolytic and sedative effects for the EPV and reveal a wide dose range for the anxiolytic effect.Este trabalho investigou o efeito do extrato combinado de Passiflora alata Dryander e Valeriana officinalis L. (EPV) em ratos submetidosaos testes do labirinto em cruz elevado (LCE) e campo aberto (TCA). Nenhum efeito foi detectado após o tratamento agudo ou repetido por 3 ou 7 dias com EPV (5, 10 or 20 mg/kg, gavagem) no LCE e TCA. Entretanto, ratos tratados por 15 dias com EPV (20 mg/kg) mostraram aumento na porcentagem de entradas e tempo gasto nos braços abertosno LCE, sem alterar a atividade locomotora no TCA, comparado ao controle. Diazepan (droga de referência, i.p.), aumentou os mesmos parâmetros analisados no LCE e OFT após o tratamento agudo ou por 15 dias. O tratamento agudo com 300 ou 600 mg/kg do EPV diminuiu significativamente a atividade locomotora no TCA. Estes resultadosmostram que EPV produz efeito ansiolítico e sedativo, com ampla margem de segurança para o efeito ansiolítico

    Role of 5-HT 1A receptors in antidepressant-like effect of dichloromethane fraction of Kielmeyera coriacea in rats subjected to the forced swim test

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    Objective : We examined the involvement of 5-HT neurotransmission on the antidepressant-like effect of the dichloromethane (DcM) fraction of an extract from Kielmeyera coriacea stems. Materials and Methods : Male Wistar rats treated chronically (45 days, gavage) with the DcM fraction received an intradorsal raphe nucleus (DRN) microinjection of saline or 5-HT 1A receptor ligands and were evaluated in the forced swimming test (FST) and in the open-field test (OFT). Results : The DcM fraction (5.0 mg/kg) reduced immobility time in the FST without altering locomotion in the OFT. IntraDRN microinjection of the 5-HT 1A receptor agonist, (+)-8-OH-DPAT (0.10; 0.20 or 0.33 μg) increased immobility time and reduced locomotion at the higher dose whereas the 5-HT1A antagonists, (-)-pindolol (0.10; 0.20 or 0.40 μg) or WAY100635 (0.11; 0.22 or 0.43 μg) did not produce any effect in the behavioral tests. IntraDRN (+)-8-OH-DPAT (0.20 or 0.33 μg) in rats treated with the DcM fraction (5.0 mg/kg) blocked the changes in the immobility time or in locomotion produced by each drug. Intra-DRN (-)-pindolol (0.10 μg) or WAY100635 (0.43 μg) in rats treated with a subactive dose of the DcM fraction (4.0 mg/kg) synergistically reduced immobility time in the FST. Conclusion : The DcM fraction of Kielmeyera coriacea produced an antidepressant-like effect in the FST and interacted with 5-HT 1A receptor ligands. Activation of 5-HT 1A receptors into DRN by (+) 8-OH-DPAT produced detectable changes in the FST or in the OFT
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