5 resultados para 806
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)
Resumo:
The aim of the study was to verify whether post-menopausal hormone replacement therapy (HRT) modifies autoantibody titers against oxidized low-density lipoprotein (LDL) (anti-LDLoxi), against epitopes of oxidized apolipoprotein B100 and common carotid intima-media thickness (IMT) in these women. Sixty-eight women in pre-menopause (PMW) and 216 in post-menopause (POMW) were recruited; eighty-three had undergone HRT for at least 12 months, where 48 received conjugated estrogens alone (EHRT) and 35 received conjugated estrogen and medroxyprogesterone acetate (CHRT). ELISA was used to determine autoantibodies. Lipoprotein lipase (LPL), hepatic lipase (HL), cholesterol ester transfer protein (CETP) and phospholipid transfer protein (PLTP) activities were assayed by radiometric methods. IMT was measured using Doppler ultrasound. Anti-oxidized LDL and anti-D antibodies increased by 40% (p <= 0.003) and 42% (p <= 0.006), respectively, with menopause. There was a surprising and significant 7% reduction in anti-D2 antibody titers with HRT (p <= 0.050), indicating a positive effect of treatment on the immune response to oxidized LDL. Combined HRT decreased activities of HL and LPL. HRT did not change common carotid IMT, which was increased by 32% as expected after menopause (p <= 0.030). This study describes, for the first time, the protective effect of HRT on decreasing autoantibody titers against oxidized apolipoprotein B in LDL.
Resumo:
In this work, we investigate the limitation of the use of strength coefficients on double folding potentials to study the presence of the threshold anomaly in the elastic scattering of halo nuclei at near barrier energies. For this purpose, elastic angular distributions and reaction cross sections for the He-6 on Bi-209 are studied. (c) 2008 Elsevier B.V. All rights reserved.
Resumo:
Hypercycles are information integration systems which are thought to overcome the information crisis of prebiotic evolution by ensuring the coexistence of several short templates. For imperfect template replication, we derive a simple expression for the maximum number of distinct templates n(m). that can coexist in a hypercycle and show that it is a decreasing function of the length L of the templates. In the case of high replication accuracy we find that the product n(m)L tends to a constant value, limiting thus the information content of the hypercycle. Template coexistence is achieved either as a stationary equilibrium (stable fixed point) or a stable periodic orbit in which the total concentration of functional templates is nonzero. For the hypercycle system studied here we find numerical evidence that the existence of an unstable fixed point is a necessary condition for the presence of periodic orbits. (C) 2008 Elsevier Ltd. All rights reserved.
Resumo:
The crystal structure of a novel variety {[(Mg0.81Fe0.19)(H2O)(6)](H2O)(4)}{(UO2)[(P0.67As0.33)O-4]}(2) of the mineral saleeite is determined using X-ray diffraction (Bruker Smart diffractometer, lambda MoK alpha, graphite monochromator, 2 theta(max) = 56.62 degrees, R = 0.0321 for 2317 reflections, T = 100 K). The main crystal data are as follows: a = 6.952(6) angstrom, b = 19.865(5) , angstrom, c = 6.969(2) angstrom, beta = 90.806(4)degrees, space group P12(l)/n1, Z = 2, and P-calcd = 3.34 g/cm(3). It is shown that the structure is formed by alternating (along the [010] direction) anionic layers, which are composed of uranium bipyramids and T(P,As) tetrahedra, and cation layers consisting of M(Mg, Fe) octahedra and water molecules, which are joined through a system of asymmetric hydrogen bonds. The hydrogen atoms are located, the scheme of hydrogen bonds is established, and their geometric characteristics are calculated.
Resumo:
Agrobacterium tumefaciens is widely used for plant DNA transformation and more recently, has also been used to transform yeast, filamentous fungi and even human cells. Using this technique, we developed the first transformation protocol for the saprobic aquatic fungus Blastocladiella emersonii, a Blastocladiomycete localized at the base of fungal phylogenetic tree, which has been shown as a promising and interesting model of study of cellular function and differentiation. We constructed binary T-DNA vectors containing hygromycin phosphotransferase (hph) or enhanced green fluorescent protein (egfp) genes, under the control of Aspergillus nidulans trpC promoter and terminator sequences. 24 h of co-cultivation in induction medium (IM) agar plates, followed by transfer to PYG-agar plates containing cefotaxim to kill Agrobacterium tumefsciens and hygromycin to select transformants, resulted in growth and sporulation of resistant transformants. Genomic DNA from the pool o resistant zoospores were shown to contain T-DNA insertion as evidenced by PCR amplification of hph gene. Using a similar protocol we could also evidence the expression of enhanced green fluorescent protein (EGFP) in zoospores derived from transformed cells. This protocol can also open new perspectives for other non-transformable closely related fungi, like the Chytridiomycete class. (C) 2011 Elsevier Inc. All rights reserved.