6,196 research outputs found
Impacts of in vivo and in vitro exposures to tamoxifen: comparative effects on human cells and marine organisms
Tamoxifen (TAM) is a first generation-SERM administered for hormone receptor-positive (HER+) breast cancer in both pre- and post-menopausal patients and may undergo metabolic activation in organisms that share similar receptors and thus face comparable mechanisms of response. The present study aimed to assess whether environmental trace concentrations of TAM are bioavailable to the filter feeder M. galloprovincialis (100 ng L-1) and to the deposit feeder N. diversicolor (0.5, 10, 25 and 100 ng L-1) after 14 days of exposure. Behavioural impairment (burrowing kinetic), neurotoxicity (AChE activity), endocrine disruption by alkali-labile phosphate (ALP) content, oxidative stress (SOD, CAT, GPXs activities), biotransformation (GST activity), oxidative damage (LPO) and genotoxicity (DNA damage) were assessed. Moreover, this study also pertained to compare TAM cytotoxicity effects to mussels and targeted human (i.e. immortalized retinal pigment epithelium - RPE; and human transformed endothelial cells - HeLa) cell lines, in a range of concentrations from 0.5 ng L-1 to 50 μg L-1. In polychaetes N. diversicolor, TAM exerted remarkable oxidative stress and damage at the lowest concentration (0.5 ng L-1), whereas significant genotoxicity was reported at the highest exposure level (100 ng L-1). In mussels M. galloprovincialis, 100 ng L-1 TAM caused endocrine disruption in males, neurotoxicity, and an induction in GST activity and LPO byproducts in gills, corroborating in genotoxicity over the exposure days. Although cytotoxicity assays conducted with mussel haemocytes following in vivo exposure was not effective, in vitro exposure showed to be a feasible alternative, with comparable sensitivity to human cell line (HeLa).info:eu-repo/semantics/publishedVersio
Monoamniotic twins discordant for body stalk anomaly
Body stalk anomaly is a rare malformation. This anomaly in monozygotic twins is extremely unusual. We describe a case of monoamniotic pregnancy discordant for body stalk anomaly diagnosed at 11 weeks. Ultrasound showed a fetus with a large anterior abdominal wall defect, anomaly of the spine and no evidence of lower extremities and other with a normal morphology. As far as our concern, only three monoamniotic pregnancies discordant for this malformation were reported. Our case represents the fourth reported monoamniotic pregnancy discordant for body stalk anomaly with diagnosis made by ultrasound and the second diagnosed in the first trimester
Electric dipole and magnetic quadrupole moments of the boson via a CP-violating vertex in effective Lagrangians
The possibility of nonnegligible electric dipole ()
and magnetic quadrupole () moments induced by the most general
vertex is examined via the effective Lagrangian technique. It is assumed
that new heavy fermions induce an anomalous CP-odd component of the
vertex, which can be parametrized by an -invariant
dimension-six operator. This anomalous contribution, when combined with the
standard model CP-even contribution, lead to CP-odd electromagnetic properties
of the boson, which are characterized by the form factors and . It is found that is divergent, whereas is finite,
which reflects the fact that the latter cannot be generated at the one-loop
level in any renormalizable theory. Assuming reasonable values for the unknown
parameters, we found that e-cm,
which is eight orders of magnitude larger than the SM prediction and close to
the upper bound derived from the neutron electric dipole moment. The estimated
size of the somewhat less-studied moment is of the order of
e-cm^2, which is fifteen orders of magnitude above the SM
contribution.Comment: 7 pages, 6 figures, REVTEX styl
Instruções para o cultivo do maracujá em Sergipe.
Botânica, clima e solo, produção de mudas, preparo do solo e plantio, condução e poda , adubação e tratos culturais, polinização artificial, pragas, doençaas, colheita e rendimento.bitstream/item/44457/1/CPATC-DOCUMENTOS-5-INSTRUCOES-PARA-O-CULTIVO-DO-MARACUJA-EM-SERGIPE-FL-13123A.pd
Tunneling effects on impurity spectral function in coupled asymmetric quantum wires
The impurity spectral function is studied in coupled double quantum wires at
finite temperatures. Simple anisotropy in the confinement direction of the
wires leads to finite non-diagonal elements of the impurity spectral function
matrix. These non-diagonal elements are responsible for tunneling effects and
result in pronounced extra peak in the impurity spectral function up to
temperatures as high as 20 K.Comment: Accepted in Phys. Rev.
Biosorption of heavy metal and dyes : a promising technology leather wastewater treatment
The presence of dyes and heavy metals is usual in industrial processes like chrome tanning in tannery industry and their removal may be an environmental problem. Different techniques were developed and applied for the treatment of dyes and heavy metals in effluents. Among them, adsorption showed to be an economic, simple operation and an effective technique. Zeolites have a strong affinity for cations of transition metals, but only little affinity for anions and non-polar organic molecules. The application of a zeolite to heavy metal removal may be improved by the presence of microorganisms. The aim of this work is the treatment of an effluent containing dyes and toxic metals. Several operation parameters such as pH, concentration and kinetic behavior were studied. This innovative process for treating dyes and heavy metal effluents showed that the zeolite-biomass system is able to perform the removal of a combination of Azure B and chromium(VI). A mixture of dye and metal solutions was treated reaching a removal higher than 50% in the case of chromium (VI) and higher than 99% for dye, in 8 days
Application of zeolite-Arthrobacter viscosus system for the removal of heavy metal and dye : chromium and azure B
A hybrid system combining the ion-exchange properties of a NaY zeolite and the characteristics of the bacterium Arthrobacter viscosus was investigated to treat polluted effluents with dye and toxic metals. In this study, the dye and the metal ion employed were a thiazine dye, Azure B, and chromium (VI), respectively. Initially, the removal of dye by the zeolite was tested. The analysis of dye equilibrium isotherms data was done using Langmuir, Freundlich, Sips and Redlich–Peterson models. Redlich–Peterson model gave the better fitting to data. In the dye adsorption studies, pseudo-second order kinetics showed the more reliable results. Operating at the optimised conditions in the treatment of single pollutants, a mixture of dye and metal solutions was treated reaching a removal higher than 50% for chromium (VI) and higher than 99% for dye, in 8 days.This work was supported by Fundacao para a Ciencia e Tecnologia (FCT-Portugal) and Xunta de Galicia under programme 08MDS034 314PR. The authors are grateful to University of Vigo for financial support of the research of Emilio Rosales under a mobility grant
Seleção de plantas matrizes de maracujazeiro em Sergipe.
bitstream/item/87938/1/CPATC-PESQ.-AND.-21-97.pd
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