Spectroscopic characterization and theoretical simulation of 1,4-diallylquinoxaline-2,3-dione self dimer.

Room temperature UV-vis absorption and emission spectra of the 1,4-diallylquinoxaline-2,3-dione (DAQX) are measured in solution at different concentrations. Even at very low concentration (approximately 10(-7)M), DAQX is shown to form ground state van der Waals dimers and excited dimers. These later species do not seem to rearrange into an excimer geometry. The theoretical simulation of the dimer, performed using the analytical atom-atom pair potential described below, predicts a non sandwich face-to-reverse slipped structure with head-to-tail orientation. The allowed absorption transitions, calculated using ZINDO/S package, reproduce satisfactory the experimental spectrum for both the monomer and the simulated dimer.

Ultraviolet-visible spectroscopic study of 3,5-dithio-2,7-dimethyl-[1,2,4]-triazepine: qualitative analysis of tautomeric behaviour.

Room temperature UV-vis absorption spectra of the tautomeric system 3,5-dithio-2,7-dimethyl-[1,2,4]-triazepine in solution, in acetonitrile (CH3CN), are measured at different water volume percentages. The comparison of the obtained measures to the calculated allowed absorption transitions, using ZINDO/S package, reveals the coexistence of all the tautomeric forms in aprotic polar solution with a high dominance of the dithione form. The solute-water hydrogen bond, which seems to be of 1:n-type, favours the dithiol and monothiol conformers to the detriment of the dithione one. Further experimental investigations lead to the result that standing at ambient Laboratory conditions in the dark favours the dithione tautomeric isomer, while standing at indirect sunlight shifts the tautomeric equilibrium away from this species.

[Cardiogenic shock in the acute phase of myocardial infarction]. / Le choc cardiogenique a la phase aigue de l'infarctus du myocarde.

Cardiogenic shock (CC) is the most common cause of death in acute myocardial infarction (MI) and it has been often associated with fatal evolution. The aim of this study is to emphasize the positive impact of myocardial revascularisation especially percutaneous coronary angioplasty (PTCA) on short and mid term survival of 35 patients hospitalised for acute MI with CC. All the 11 patients who were on conventional therapy died, whereas the hospital mortality rate of the 24 patients who underwent primary PTCA was 41%. PTCA in CC complicating MI is highly effective and reduces the mortality rate in the literature from 80% to 40%. For this reason PTCA should be performed in each case of MI with CC seen in the first 6 hours.

[Contracted endocardial fibroelastosis in children: report of a case]. / La fibroelastose endocardique contractée de l'enfant: a propos d'un cas.

Endocardial fibroelastosis is un uncommon disease and it has a very bad prognosis since fatal evolution is usual before 2 years old. We report the case of a 20 years old woman who is affected with the contracted form of this disease associated with atrial septal defect (ASD) and mitral regurgitation. This disease was discovered by endocardial biopsy when she was 4 years old and underwent surgical resection of endocardial fibrosis, a patch on the ASD and mitral valve replacement. She was rehospitalised 15 years later with heart failure although continuous digitoxin therapy.