225 research outputs found
Recommended from our members
Measurement of the inclusive charmless semileptonic branching ratio of B mesons and determination of vertical bar V-ub vertical bar
We report a measurement of the inclusive charmless semileptonic branching fraction of B mesons in a sample of 89x10(6) B(b) over bar events recorded with the BABAR detector at the Y(4S) resonance. Events are selected by fully reconstructing the decay of one B meson and identifying a charged lepton from the decay of the other B meson. The number of signal events is extracted from the mass distribution of the hadronic system accompanying the lepton and is used to determine the ratio of branching fractions B((B) over bar --> X(u)l (v) over bar)/B((B) over bar --> Xl (v) over bar) = [2.06 +/- 0.25(stat) +/- 0.23(syst) +/- 0.36(theo)] x 10(-2). Using the measured branching fraction for inclusive semileptonic B decays, we find B((B) over bar --> X(u)l (V) over bar) = [2.24+/-0.27(stat) +/- 0.26(syst) +/- 0.39(theo)] x 10(-3) and derive the Cabibbo-Kobayashi-Maskawa matrix element parallel toV(ub)parallel to = [4.62 +/- 0.28(stat) +/- 0.27(syst) +/- 0.48(theo)] x 10(-3)
Photomodulation of oxidative metabolism and electron chain enzymes in rat liver mitochondria. Photochem Photobiol
ABSTRACT Low-level laser irradiation has been applied in a variety of laboratory studies and clinical trials for photobiostimulation over the last three decades. Considerable skepticism exists regarding the concept of photostimulation within the medical community. One of the major difficulties with photoirradiation research is that it lacks experimentally supportable mechanisms for the alleged photobiostimulatory effects. This study was undertaken to determine whether oxidative metabolism and electron chain enzymes in rat liver mitochondria can be modulated by photoirradiation. Oxygen consumption, phosphate potential, and energy charge of rat liver mitochondria were determined following photoirradiation. Activities of mitochondrial enzymes were analyzed to assess the specific enzymes that are directly involved with the photostimulatory process. An argon-dye laser at a wavelength of 660 nm and at a power density of 10 mW/cm2 was used as a photon source. Photoirradiation significantly increased oxygen consumption (0.6 J/cm2 and 1.2 J/cm2, P < 0.05), phosphate potential, and the energy charge (1.8 J/cm2 and 2.4 J/cm2, P < 0.05) of rat liver mitochondria and enhanced the activities of NADH : ubiquinone oxidoreductase, ubiquinol : ferricytochrome C oxidoreductase and ferrocytochrome C : oxygen oxidoreductase (0.6 J/cm2, 1.2 J/cm2, 2.4 J/cm2 and 4.8 J/cm2, P < 0.05). The activities of succinate ubiquinone oxidoreductase, ATPase, and lactate dehydrogenase were not affected by photoirradiation
- …