27 research outputs found
The lead-glass electromagnetic calorimeters for the magnetic spectrometers in Hall C at Jefferson Lab
The electromagnetic calorimeters of the various magnetic spectrometers in
Hall C at Jefferson Lab are presented. For the existing HMS and SOS
spectrometers design considerations, relevant construction information, and
comparisons of simulated and experimental results are included. The energy
resolution of the HMS and SOS calorimeters is better than , and pion/electron () separation of about 100:1 has been
achieved in energy range 1 -- 5 GeV. Good agreement has been observed between
the experimental and simulated energy resolutions, but simulations
systematically exceed experimentally determined suppression factors by
close to a factor of two. For the SHMS spectrometer presently under
construction details on the design and accompanying GEANT4 simulation efforts
are given. The anticipated performance of the new calorimeter is predicted over
the full momentum range of the SHMS. Good electron/hadron separation is
anticipated by combining the energy deposited in an initial (preshower)
calorimeter layer with the total energy deposited in the calorimeter.Comment: 22 pages, 33 figure
Memory retrieval improvement by Heteropterys aphrodisiaca in aging rats
Few data exists about the pharmacological properties of Heteropterys aphrodisiaca O. Mach. (Malpighiaceae), which is native to the scrubland regions of Brazil. The present study investigated the effects of oral treatment with H. aphrodisiaca extract (BST0298) on the learning and memory of young (3-6 months) and aged (21-23 months) rats, and compared the in vitro antioxidant activity of three lots collected in different years. An improvement in the number of sessions to learn the task was observed in the left/right discrimination test in aged rats treated for 45 days with 25 mg/kg (7.0 ± 0.5; p=0.005) or 50 mg/kg (7.6 ± 0.6; p=0.012) compared with control old rats (11.0 ± 1.6). On the other hand, pre-treatment did not improve the performance of scopolamine-treated mice in the passive avoidance test. The in vitro malondialdehyde test showed that all three different extracts presented similar antioxidant activity. The flavonoids astilbin, isoastilbin and neoastilbin were isolated from the extract and may contribute to the biological activity. These results suggest that repeated treatment with H. aphrodisiaca improves learning and memory, probably by a non-muscarinic mechanism.Existem poucos dados disponíveis sobre as propriedades farmacológicas da Heteropterys aphrodisiaca O. Mach. (Malpighiaceae), nativa da região do pantanal brasileiro. O presente estudo investigou o efeito do tratamento oral com um extrato de H. aphrodisiaca (BST0298) sobre a memória e aprendizagem de ratos jovens (3-6 meses) e idosos (21-23 meses) e comparou a atividade antioxidante in vitro de três lotes, coletados em diferentes anos. Melhora quanto ao número de sessões necessárias para aprender a tarefa foi observada no teste de discriminação direita/esquerda em ratos idosos tratados por 45 dias com doses de 25 mg/kg (7,0 ± 0,5; p=0,005) e 50 mg/kg (7,6 ± 0,6; p=0,012) comparados com ratos idosos controle (11,0 ± 1,6). Por outro lado, o pré-tratamento com o extrato não melhorou o desempenho de camundongos tratados com escopolamina no teste da esquiva passiva. Em relação à avaliação da atividade antioxidante in vitro pelo teste do malonodialdeído, os três lotes analisados apresentaram atividade antioxidante semelhante. Os flavonóides astilbina, isoastilbina e neoastilbina foram isolados do extrato e podem contribuir para a atividade biológica. Estes resultados sugerem que a administração repetida de H. aphrodisiaca melhora a memória e aprendizagem provavelmente por um mecanismo não muscarínico
Preliminary in vitro assessment of the potential toxicity and antioxidant activity of Ceiba speciosa (A. St.-Hill) Ravenna (Paineira)
ABSTRACT The bark tea of Ceiba speciosa, a tropical tree of the Malvaceae family, is used in the Northwestern Region of Rio Grande do Sul state, Brazil, to reduce blood cholesterol levels. However, there are no scientific data on the efficacy and safety of this plant. The aim of the present study was to evaluate the in vitro antioxidant and toxic potential of bark extracts of C. speciosa. We performed a preliminary phytochemical analysis by high-performance liquid chromatography-diode array detection (HPLC-DAD) and evaluated the oxidative damage to proteins and lipids, the radical scavenging effect, and genotoxicity of the lyophilized aqueous extract (LAECs) and the precipitate obtained from the raw ethanol extract (Cs1). The phytochemical profile demonstrated the presence of phenolic and flavonoid compounds. The LAECs and Cs1 prevented damage to lipids and proteins at concentrations of 50 and 10 µg/mL. They also showed a scavenging effect on 2,2-diphenyl-1-pricril-hydrazyl (DPPH) radicals in a concentration-dependent manner. Furthermore, no genotoxic effect was observed at concentrations of 10, 5 and 2 µg/mL in the Comet assay. The present study is the first evaluation regarding the characterization of C. speciosa and its safety, and the results demonstrate its antioxidant potential and suggest that its therapeutic use may be relatively safe
Inhibitory effects of ghrelin on sexual behavior: Role of the peptide in the receptivity reduction induced by food restriction in mice
Ghrelin (Ghr) is a gut/hypothalamus peptide with inhibitory actions on reproductive physiology; however, there are no previous reports of its role on estrous behavior. Under the hypothesis that the increase of plasma Ghr during food restriction (FR) is responsible for receptivity reduction, we intended to evaluate the receptivity percentage of female mice subjected to: exp. 1) acute and chronic FR and Ghr administration (3 nmol/animal/day, s. c.) and exp. 2) the co-administration of a ghrelin antagonist [ant=(d-Lys3)-GHRP-6; 6 nmol/animal/day s. c.]. All females were ovariectomized, primed with steroids, trained, and randomly subjected every week to each one of several protocols, followed by a behavioral test. Experiment 1 (n=8): basal, no treatment; acute FR (aFR), 24-h fasting; chronic FR (cFR), 50% FR for 5 days; acute ghrelin (aGhr), Ghr 30 min before test and chronic ghrelin (cGhr), Ghr for 5 days. Except for cGhr, all treatments significantly decreased the percentage of receptivity (mean±SEM): basal 61.9±6.0, aFR 33.1±8.1, cFR 18.8±7.7, aGhr 45.6±10.6, p<0.05 vs. basal. In exp. 2 (n=11), except for cFR+ant (55.0±6.4) the co-administration of the antagonist reversed the deleterious effects detected in exp. 1: basal 70.9±5.4; aFR+ant 72.3±7.6; aGhr+ant 73.6±4.7. As expected, the administration of vehicle or antagonist alone did not modify receptivity. Besides, we found a significant correlation between percentage of body weight loss and percentage of receptivity reduction (r=0.62, p=0.0004). This is the first study demonstrating that ghrelin is able to inhibit female mice sexual behavior and that is involved, at least in part, in receptivity reduction after food scarcity.Fil: Bertoldi, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Luque, E. M.. Universidad Nacional de Cordoba. Facultad de Ciencias Medicas. Instituto de Fisiologia Profesor Oscar Orias;Fil: Carlini, Valeria Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; ArgentinaFil: Vincenti, Laura María. Universidad Nacional de Cordoba. Facultad de Ciencias Medicas. Instituto de Fisiologia Profesor Oscar Orias;Fil: Stutz, Graciela. Universidad Nacional de Cordoba. Facultad de Ciencias Medicas. Instituto de Fisiologia Profesor Oscar Orias;Fil: Santillán, M.E.. Universidad Nacional de Cordoba. Facultad de Ciencias Medicas. Instituto de Fisiologia Profesor Oscar Orias;Fil: Ruiz, R. D.. Universidad Nacional de Cordoba. Facultad de Ciencias Medicas. Instituto de Fisiologia Profesor Oscar Orias;Fil: Fiol de Cuneo, Marta. Universidad Nacional de Cordoba. Facultad de Ciencias Medicas. Instituto de Fisiologia Profesor Oscar Orias;Fil: Martini, Ana Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; Argentin
The effect of chronic ingestion of ethanol on modulation of granulomatous inflammation in experimental schistosomiasis in mice Efeito da ingestão crônica de etanol na modulação da resposta inflamatória granulomatosa no fígado de camundongos infectados por Schistosoma mansoni
We studied the role of ethanol on the modulation of liver granulomata around Schistosoma mansoni eggs in mice. Albino mice, receiving 7% ethanol as the sole drinking liquid, at 60 and 90 days post-infection, presented smaller granulomata than controls did, when sacrificed at 120 days post-infection. No differences in diameters could be observed, when ethanol was given 4 months before up to 120 days after infection. The results suggested that modulation of schistosome granulomata by ethanol ingestion varies with time and duration of drug consumption.<br>Estudamos a modulação da resposta inflamatória granulomatosa em torno de ovos de S. mansoni no fígado de camundongos albinos (Mus musculus), que receberam 7% de etanol como única fonte de líquido. Os animais que receberam etanol aos 60 e 90 dias após a infecção apresentaram granulomas menores do que os controles, quando sacrificados aos 120 dias após a infecção. Não houve diferença no diâmetro dos granulomas quando a ingestão de etanol foi iniciada 4 meses antes e prolongada até 120 dias após a infecção. Nossos resultados indicam que a modulação da inflamação granulomatosa varia de acordo com o tempo e a duração da ingestão do etanol