No abstract

Recent studies have shown that continuous wave laser irradiation induces contraction of vascular smooth muscle, except at powers far below the threshold for tissue ablation. To determine the corresponding effects of pulsed laser irradiation on vascular smooth muscle tone, vascular rings of rabbit thoracic aorta were mounted isometrically with 1 g tension in Krebs-bicarbonate buffer and irradiated with 308 or 351 nm from an excimer laser through a 400-,um optical fiber. A total of250 exposures were performed with 1-6.5 mJ/pulse (fluence=0.8-5.5 J/cm2),

The application of Raman spectroscopy to the determination of the aromatic content of gasolines and aviation fuels is reported. Since aromatic components have very high Raman cross-sections owing to large polarizability changes under laser excitation, bands from these components will dominate specific Raman spectral regions. It is expected, therefore, that Raman scattering will be a particularly useful approach to broadly characterizing the fuel hydrocarbon makeup for aromatic content and the properties of fuels which are inftuenced by aromatic content.