997 resultados para 164-994B
Resumo:
Anaerobic methane oxidation (AMO) was characterized in sediment cores from the Blake Ridge collected during Ocean Drilling Program (ODP) Leg 164. Three independent lines of evidence support the occurrence and scale of AMO at Sites 994 and 995. First, concentration depth profiles of methane from Hole 995B exhibit a region of upward concavity suggestive of methane consumption. Diagenetic modeling of the concentration profile indicates a 1.85-m-thick zone of AMO centered at 21.22 mbsf, with a peak rate of 12.4 nM/d. Second, subsurface maxima in tracer-based sulfate reduction rates from Holes 994B and 995B were observed at depths that coincide with the model-predicted AMO zone. The subsurface zone of sulfate reduction was 2 m thick and had a depth integrated rate that compared favorably to that of AMO (1.3 vs. 1.1 nmol/cm**2/d, respectively). These features suggest close coupling of AMO and sulfate reduction in the Blake Ridge sediments. Third, measured d13CH4 values are lightest at the point of peak model-predicted methane oxidation and become increasingly 13C-enriched with decreasing sediment depth, consistent with kinetic isotope fractionation during bacterially mediated methane oxidation. The isotopic data predict a somewhat (60 cm) shallower maximum depth of methane oxidation than do the model and sulfate reduction data.
Resumo:
Estrogen is known to stimulate the proliferation and basement membrane invasiveness of the MCF-7 human breast cancer cell line. We have compared the new steroidal antiestrogen ICI 164,384, the triphenylethylene 4-hydroxytamoxifen (OHT), and the benzothiophene LY 117018, for their effects on the proliferation and invasiveness of the MCF-7 cell line and its antiestrogen-resistant variant LY-2. While all three antiestrogens blocked the proliferative effects of 17β-estradiol on MCF-7 cells, OHT and LY 117018, but not ICI 164,384 stimulated their proliferation in the absence of estrogen. The proliferative effects of OHT and LY 117018 were blocked by ICI 164,384. Basement membrane invasiveness of MCF-7 cells was stimulated by 17β-estradiol and OHT, but not LY 117018 or ICI 164,384. Both ICI 164,384 and Ly 117018 were able to block the invasiveness induced by either 17β-estradiol or OHT. The LY-2 antiestrogen-resistant variant of the MCF-7 cell line showed increased basal proliferation, and responded only slightly to estrogen. ICI 164,384, but not OHT or LY 117018 antagonized the effects of 17β-estradiol, but did not reduce proliferation below control levels. The LY-2 line was not resistant to the antiestrogenic effects of LY 117018 or ICI 164,384 on invasiveness, and was stimulated by LY 117018 for this parameter. Thus, ICI 164,384 is a pure antiestrogen for MCF-7 cell proliferation and invasiveness, and may offer clinical advantage over nonsteroidal antiestrogens which can stimulate these activities in tumor models in vitro.
Resumo:
Contenido: Dios en la filosofía (cont.) / Octavio N. Derisi -- El acto constitutivo del conocimiento y de la cognoscibilidad o verdad / Octavio N. Derisi -- Presupuestos necesarios para una recta formulación del concepto de ciencia práctica / Federico Mihura Seeber -- Filosofía tomista, educación y teología en Fray Alberto García Vieyra O.P. 1912-1985 / Alberto Caturelli -- Notas y comentarios -- Bibliografía
Resumo:
O Senador Afonso Arinos (PFL-RJ), Presidente da Comissão de Sistematização da Assembleia Nacinal Constituinte (ANC), debate diversos assuntos polêmicos com o Presidente da ANC, Deputado Ulysses Guimarães (PMDB-SP) e lideranças partidárias. Ele é favorável ao adiamento da decisão dos temas polêmicos, para evitar um número exagerado de artigos na nova Constituição. O ator José Dumond pede a população que ocupe seu espaço na discussão da Constituinte. O Deputado Eduardo Moreira (PMDB-SC) defende emenda do Deputado Eduardo Jorge (PT-SP) que beneficia aposentados. No Plenário, o Senador Francisco Rollemberg (PMDB-SE) pede a transferência, para o Estado de Sergipe, de uma grande área pertencente ao Estado da Bahia. O Deputado João Machado Rollemberg (PFL-SE) apoia essa ideia, porque a região não está sendo assistida pelo Estado da Bahia. O Deputado Gil César (PMDB-MG) almeja a negociação da dívida externa, para que o Brasil continue tendo acesso aos capitais externos.