A series of dyads of general formula Ru(bpy)(2)(bpy-ph(n)-DQ)(4+) (n = 1-5), based on a Ru(II) polypyridine unit as photoexcitable donor, a set of oligo-p-phenylene bridges with 1-5 modular units, and a cyclo-diquaternarized 2,2'-bipyridine (DQ(2+)) as electron acceptor unit, have been synthesized. Their spectroscopic and photophysical properties have been investigated in CH(3)CN and CH(2)Cl(2) by time-resolved emission and absorption spectroscopy in the nanosecond and picosecond time scale. The experimental study has also been complemented with a computational investigation carried out on the whole series of dyads.
View Article and Find Full Text PDFTwo families of dyad and triad systems based on perylene monoimide (PMI), quaterthiophene (QT), and 9,10-bis(1,3-dithiol-2-ylidene)-9,10-dihydroanthracene (extended tetrathiafulvalene, exTTF) molecular components have been designed and synthesized. The dyads (D1 and D2) are of the PMI-QT type and the triads (T1 and T2) of the PMI-QT-exTTF type. The two families differ in the saturated or unsaturated nature of the linker groups (ethynylene in D1 and T1, ethylene in D2 and T2) that bridge the molecular components.
View Article and Find Full Text PDFA 1,2-bis(2-methylbenzothiophene-3-yl)maleimide model ( DAE) and two dyads in which this photochromic unit is coupled, via a direct nitrogen-carbon bond ( Ru-DAE) or through an intervening methylene group ( Ru-CH 2-DAE ), to a ruthenium polypyridine chromophore have been synthesized. The photochemistry and photophysics of these systems have been thoroughly characterized in acetonitrile by a combination of stationary and time-resolved (nano- and femtosecond) spectroscopic methods. The diarylethene model DAE undergoes photocyclization by excitation at 448 nm, with 35% photoconversion at stationary state.
View Article and Find Full Text PDFIntroduction: A multi-centre study has been conducted, during 2005, by means of a questionnaire posted on the Italian Society of Emergency Medicine (SIMEU) web page. Our intention was to carry out an organisational and functional analysis of Italian Emergency Departments (ED) in order to pick out some macro-indicators of the activities performed. Participation was good, in that 69 ED (3,285,440 admissions to emergency services) responded to the questionnaire.
View Article and Find Full Text PDFBackground: Prolonged mechanical ventilation and the consequently long stay in the intensive care unit (ICU) appear to be important infection risk factors in patients undergoing liver transplant.
Methods: We analyzed the data relating to 70 liver transplants performed on 67 patients during the past year's activities. For each patient we have considered the presence of preoperative pulmonary alterations, the first radiological result of the postoperative thorax, the PaO(2)/FiO(2) ratio recorded in the peroperative phase immediately after induction of general anesthesia (T0), and arrival at the ICU at the end of the operation (T1).