174 research outputs found
Constructal design of an arterial bypass graft
Arterial bypass grafts tend to fail after some years due to intimal hyperplasia\u2014an abnormal proliferation of smooth muscle cells that leads to stenosis and graft occlusion.
In this regard and on the basis of the constructal design method, this study seeks to investigate the effect of geometric parameters\u2014stenosis degree, junction angle, and diameter ratio\u2014on the flow
through a bypass graft circumventing an idealized, partially stenosed coronary artery.
The computational model assumes a steady\u2010state Newtonian fluid flow through an artery stenosis degree from 25% to 75%.
A computational fluid dynamics model and a response surface methodology were employed to assess the effects of the project parameters on pressure drop.
As diameter ratio increases to 1 and the junction angle decreases to 30\ub0, the pressure drop decreases and there is a considerable dependence of pressure drop on the stenosis degree.
The effects of the diameter ratio are more pronounced than those of junction angle on the velocity field and wall shear stress.
The application of the constructal design method in hemodynamicsmight be a good alternative to provide configurations with enhanced performance and to provide valuable
results to the understanding of biological flows
Preventive and Therapeutic Euphol Treatment Attenuates Experimental Colitis in Mice
BACKGROUND: The tetracyclic triterpene euphol is the main constituent found in the sap of Euphorbia tirucalli. This plant is widely known in Brazilian traditional medicine for its use in the treatment of several kinds of cancer, including leukaemia, prostate and breast cancers. Here, we investigated the effect of euphol on experimental models of colitis and the underlying mechanisms involved in its action. METHODOLOGY/PRINCIPAL FINDINGS: Colitis was induced in mice either with dextran sulfate sodium (DSS) or with 2,4,6-trinitrobenzene sulfonic acid (TNBS), and the effect of euphol (3, 10 and 30 mg/kg) on colonic injury was assessed. Pro-inflammatory mediators and cytokines were measured by immunohistochemistry, enzyme-Linked immunoabsorbent assay (ELISA), real time-polymerase chain reaction (RT-PCR) and flow cytometry. Preventive and therapeutic oral administration of euphol attenuated both DSS- and TNBS-induced acute colitis as observed by a significant reduction of the disease activity index (DAI), histological/microscopic damage score and myeloperoxidase (MPO) activity in colonic tissue. Likewise, euphol treatment also inhibited colon tissue levels and expression of IL-1β, CXCL1/KC, MCP-1, MIP-2, TNF-α and IL-6, while reducing NOS2, VEGF and Ki67 expression in colonic tissue. This action seems to be likely associated with inhibition of activation of nuclear factor-κB (NF-κB). In addition, euphol decreased LPS-induced MCP-1, TNF-α, IL-6 and IFN-γ, but increased IL-10 secretion from bone marrow-derived macrophages in vitro. Of note, euphol, at the same schedule of treatment, markedly inhibited both selectin (P- and E-selectin) and integrin (ICAM-1, VCAM-1 and LFA-1) expression in colonic tissue. CONCLUSIONS/SIGNIFICANCE: Together, these results clearly demonstrated that orally-administered euphol, both preventive or therapeutic treatment were effective in reducing the severity of colitis in two models of chemically-induced mouse colitis and suggest this plant-derived compound might be a potential molecule in the management of inflammatory bowel diseases
Papaya (Carica papaya) foot rot (Phytophthora palmivora) reduction due to phosphites
Em processament
Reaction of papaya genotypes to black-spot and foot-rot
Genótipos de mamoeiro (Carica papaya) ('NT Red', 'Golden', 'Baixinho de St. Amália', 'Sunrise Solo', 'Cross Paris', 'Tailândia Verde', 'Tailândia Roxo', 'Tailândia Roxão', 'Sekati' e 'Tainung-1') foram avaliados quanto à reação à varíola (Asperisporium caricae) e à podridão-do-pé (Phytophthora palmivora). O estudo foi conduzido em uma área com plantas naturalmente infectadas com ambos os patógenos e sob telado utilizando solo naturalmente infestado com P. palmivora. A severidade de varíola foi avaliada usando-se uma escala, de 1 (0-3% da superfície coberta por lesões) a 6 (>de 50% da superfície coberta por lesões). As avaliações foram feitas entre março e abril / 2003 e entre outubro 2003 e fevereiro 2004. A podridão-do-pé foi avaliada, no campo, por incidência em cada cultivar nos mesmos períodos. Nos experimentos sob telado a severidade da doença por P. palmivora foi avaliada em cada planta utilizando-se a seguinte escala: 0- sem sintomas; 1- até 50% de murcha; 2- de 51 a 100% de murcha; 3- morta. Quanto à varíola, verificou-se que plantas de 'Sekati' (grupo Formosa) apresentaram os menores valores médios finais de severidade da doença na folhagem (2,0) enquanto que, 'Golden' (3,1) e'NT Red' (3,7) apresentaram os maiores. Nos frutos, 'Tailândia Roxão' (1,6), 'Tailândia Verde' (1,7) e 'Sekati' (1,7) apresentaram os menores valores de varíola, enquanto que, 'Tailândia Roxo' (2,3), 'Cross Paris' (2,5), e 'Sunrise Solo' (3,1) apresentaram os maiores. Quanto à podridão do pé, 'Tailândia Roxão' (grupo Formosa) apresentou a menor quantidade de doença, enquanto que, 'Golden', 'Sunrise Solo e 'NT Red' apresentaram os maiores valores.Papaya (Caryca papaya) genotypes ('NT Red', 'Golden', 'Baixinho de St. Amália', 'Sunrise Solo', 'Cross Paris', 'Tailândia Verde', 'Tailândia Roxo', 'Tailândia Roxão', 'Sekati' and 'Tainung-1') were evaluated for resistance to black-spot (Asperisporium caricae) and foot-rot (Phytophthora palmivora). The study was conducted in an area where both pathogens occurred naturally and in a greenhouse using soil naturally infested with P. palmivora. Black-spot severity was evaluated using a scale, from 1 (0-3% of the surface covered by lesions) to 6 (> of 50% of the surface covered by lesions). The evaluations were made between March / 2003 and April / 2003 and between October / 2003 and February / 2004. Foot-rot was evaluated, on the field trial, by counting the total number of plants with yellowing or wilt symptoms in the same period. On the greenhouse trials P. palmivora severity was evaluated in each plant using a scale from 0 (no wilt symptoms) to 3 (plant death). In relation to black-spot, the genotype 'Sekati' of the Formosa group presented the lowest average value of severity (2,0) on the foliage while ''Golden' (3,1) and NT Red' (3,7) had the largest. 'Tailândia Roxão' (1,6), 'Tailândia Verde' (1,7) and 'Sekati' (1,7) also had the lowest averages of severity on the fruit, while, 'Tailândia Roxo' (2,3), 'Cross Paris' (2,5), and 'Sunrise Solo' (3,1) presented the largest. In relation to foot rot, 'Tailândia Roxão' (Formosa group) presented low amount of disease and 'Golden', 'Sunrise Solo, and 'NT Red' presented higher values
Mapping the stellar population and gas excitation of MaNGA galaxies with MEGACUBES. Results for AGN versus control sample
We present spaxel-by-spaxel stellar population fits for the 10 thousand
MaNGA datacubes. We provide multiple extension fits files, nominated as
MEGACUBES, with maps of several properties as well as emission-line profiles
that are provided for each spaxel. All the MEGACUBES are available through a
web interface (https://manga.linea.org.br/ or
http://www.if.ufrgs.br/~riffel/software/megacubes/). We also defined a final
Active Galactic Nuclei (AGN) sample, as well as a control sample matching the
AGN host galaxy properties. We have analysed the stellar populations and
spatially resolved emission-line diagnostic diagrams of these AGNs and compared
them with the control galaxies sample. We find that the relative fractions of
young (56 Myr) and intermediate-age (100 Myr 2 Gyr) show
predominantly a positive gradient for both AGNs and controls. The relative
fraction of intermediate-age stellar population is higher in AGN hosts when
compared to the control sample, and this difference becomes larger for higher
[O III] luminosity AGNs. We attribute this to the fact that extra gas is
available in these more luminous sources and that it most likely originates
from mass-loss from the intermediate-age stars. The spatially resolved
diagnostic diagrams reveal that the AGN emission is concentrated in the inner
0.5 (effective radius) region of the galaxies, showing that the AGN
classification is aperture dependent and that emission-line ratios have to be
taken together with the H equivalent width for proper activity
classification. We present a composite "BPT+WHAN" diagram that produces a more
comprehensive mapping of the gas excitation.Comment: Accepted for publication in MNRA
Euphol, a tetracyclic triterpene, from Euphorbia tirucalli induces autophagy and sensitizes temozolomide cytotoxicity on glioblastoma cells
Glioblastoma (GBM) is the most frequent and aggressive type of brain tumor. There are limited therapeutic options for GBM so that new and effective agents are urgently needed. Euphol is a tetracyclic triterpene alcohol, and it is the main constituent of the sap of the medicinal plant Euphorbia tirucalli. We previously identified anti-cancer activity in euphol based on the cytotoxicity screening of 73 human cancer cells. We now expand the toxicological screening of the inhibitory effect and bioactivity of euphol using two additional glioma primary cultures. Euphol exposure showed similar cytotoxicity against primary glioma cultures compared to commercial glioma cells. Euphol has concentration-dependent cytotoxic effects on cancer cell lines, with more than a five-fold difference in the IC50 values in some cell lines. Euphol treatment had a higher selective cytotoxicity index (0.64-3.36) than temozolomide (0.11-1.13) and reduced both proliferation and cell motility. However, no effect was found on cell cycle distribution, invasion and colony formation. Importantly, the expression of the autophagy-associated protein LC3-II and acidic vesicular organelle formation were markedly increased, with Bafilomycin A1 potentiating cytotoxicity. Finally, euphol also exhibited antitumoral and antiangiogenic activity in vivo, using the chicken chorioallantoic membrane assay, with synergistic temozolomide interactions in most cell lines. In conclusion, euphol exerted in vitro and in vivo cytotoxicity against glioma cells, through several cancer pathways, including the activation of autophagy-associated cell death. These findings provide experimental support for further development of euphol as a novel therapeutic agent for GBM, either alone or in combination chemotherapy.The work was supported by the Amazonia Fitomedicamentos (FITO05/2012) Ltda. and Barretos Cancer Hospital, all from Brazil
RENDIMENTO DE GRÃOS, ÍNDICE DE COLHEITA E COMPONENTES DO RENDIMENTO DE TRÊS CULTIVARES DE ARROZ IRRIGADO
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