An optical system for examination of biological tissue includes a light source, a light detector, optics and electronics. These inhibitors have utility in a variety of therapeutic areas including sexual dysfunction. A fluid is circulated between the first region and the second region for transferring of the solar thermal energy. Intravascular devices such as guidewires, stents and the like can be formed of this high strength CoNiCr alloy. A signal point generating apparatus generates a first and second symbols to be transmitted by first and second antennas, respectively. At least part of the support extending from the central region towards the peripheral region includes a stratified structure consisting of a superposition of at least two sheets joined together.