47 research outputs found
Estudo da utilização no pré-operatório de medicamentos ou drogas fitoterápicas que alteram a coagulação sangüínea
Complementary and Alternative Medicine Use by Breast Cancer Patients at Time of Surgery Which Increases the Potential for Excessive Bleeding
Serious adverse effects between herbal remedies and conventional drugs taken simultaneously
SUDDEN POLARIZATION IN THE TWISTED, PHANTOM STATE OF TETRAPHENYLETHYLENE DETECTED BY TIME-RESOLVED MICROWAVE CONDUCTIVITY
SUDDEN POLARIZATION IN THE TWISTED, PHANTOM STATE OF TETRAPHENYLETHYLENE DETECTED BY TIME-RESOLVED MICROWAVE CONDUCTIVITY
SUDDEN POLARIZATION IN THE TWISTED, PHANTOM STATE OF TETRAPHENYLETHYLENE DETECTED BY TIME-RESOLVED MICROWAVE CONDUCTIVITY
Photoexcitation of the symmetrical molecules tetraphenylethylene and tetra-p-methoxyphenylethylene dissolved in saturated hydrocarbon solvents results in a transient increase in the dielectric loss of the solutions as monitored using the nanosecond time-resolved microwave conductivity (TRMC) technique. This provides direct evidence for the dipolar, or ''zwitterionic'', nature of the 1p* phantom state formed from S1 by rotation around the central carbon-carbon bond. Dipole relaxation occurs mainly by charge inversion between the two energetically equivalent zwitterionic configurations, Z+/-, on a timescale of several picoseconds. A minimum dipole moment of ca. 7.5 D for the individual Z+/- states is found. The fluorescence of TPE in alkane solvents has two decay components, one with a decay time less than 200 ps and a second with a decay time of 1.9 ns. The former (lambda(max) almost-equal-to 490 nm) is assigned to emission from the partially relaxed S1 state prior to twisting. The latter (lambda(max) almost-equal-to 540 nm) is assigned to emission from a small, ca. 1%, concentration of the relaxed S1 state in equilibrium with the 1p* state in saturated hydrocarbon solvent
SUDDEN POLARIZATION IN THE TWISTED, PHANTOM STATE OF TETRAPHENYLETHYLENE DETECTED BY TIME-RESOLVED MICROWAVE CONDUCTIVITY
Complementary therapies and children
The definitive version is available at www.blackwell-synergy.comElaborates on the effectiveness of complementary and alternative therapies in children. Community acceptance received by alternative therapy. Differences in prevalence.RTL Coupe