3 resultados para Heyn, Piet, 1578-1629.
em Greenwich Academic Literature Archive - UK
Resumo:
The adsorption of a C60 monolayer on a graphite substrate was modelled via molecular dynamics simulation covering a significant period of 160 picoseconds. The final configuration of C60s agrees closely with that observed in a scanning tunnelling microscopy (STM) experiment. Clusters of adsorbed molecules were then selected and their STM-like images were computed via the Keldysh Green function method.
Resumo:
The surface-enhanced Raman scattering (SERS) spectra of rhodanine adsorbed on silver nanoparticles have been examined using 514.5 and 632.8 nm excitation. There is evidence that, under the experimental conditions used, rhodanine undergoes a nanoparticle surface-induced reaction resulting in the formation of a dimeric species via the active methylene group in a process which is analogous to the Knoevenagel reaction. The experimental observations are supported by DFT calculations at the B3-LYP/cc-pVDZ level. Calculated energies for the interaction of the E and Z isomers of the dimers of rhodanine with silver nanoparticles support a model in which the (intra-molecular hydrogen bonded) E isomer dimer is of lower energy than the Z isomer. A strong band, at 1566 cm(-1), in the SERS spectrum of rhodanine is assigned to the nu(C=C) mode of the dimer species.
Resumo:
The incidence of hypertension is increasing as the number of patients with obesity and diabetes mellitus increases. Hypertension results when the peripheral vascular resistance is increased, the blood viscosity is elevated and/or the flow of blood through the main arteries is impeded. Chronic hypertension results in enlarged heart, myocardial damage and lung and renal abnormalities. While some causative factors such as obesity can be controlled, others for example genetics are more difficult to treat because often there is more than one factor involved. This paper explores how essential and secondary factors contribute to the incidence of hypertension and the physiological changes resulting from raised blood pressure. It proposes that although traditional treatment has some success, nurse-led clinics are having better success not only in controlling raised blood pressure but also in reducing cardiac, pulmonary and renal morbidity. It is more cost-effective, staff is more productive and clients are more compliant with treatment.