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The resonance energies for electron attachment to the chloromethanes are evaluated by means of bound and continuum multiple scattering Xα calculations. The results closely reproduce the experimental electron transmission spectroscopy data and confirm their previous assignment. Electron transmission and dissociative attachment spectra of monochloroalkanes are also reported, in order to obtain information on the effects of branching at the substituted carbon atom and of alkyl chain length on the resonance and chlorine anion production energies.

BackgroundRhabdomyomas are the most common type of cardiac tumors in children. Anatomically, they can be considered as hamartomas. They are usually randomly diagnosed antenatally or postnatally sometimes presenting in the neonatal period with haemodynamic compromise or severe arrhythmias although most neonatal cases remain asymptomatic. Typically rhabdomyomas are multiple lesions and usually regress spontaneously but are often associated with tuberous sclerosis complex (TSC), an autosomal dominant multisystem disorder caused by mutations in either of the two genes, TSC1 or TSC2. Diagnosis of tuberous sclerosis is usually made on clinical grounds and eventually confirmed by a genetic test by searching for TSC genes mutations.MethodsWe report our experience on 33 cases affected with rhabdomyomas and diagnosed from January 1989 to December 2012, focusing on the cardiac outcome and on association with the signs of tuberous sclerosis complex. We performed echocardiography using initially a Philips Sonos 2500 with a 7,5/5 probe and in the last 4 years a Philips IE33 with a S12-4 probe. We investigated the family history, brain, skin, kidney and retinal lesions, development of seizures, and neuropsychiatric disorders.ResultsAt diagnosis we detected 205 masses, mostly localized in interventricular septum, right ventricle and left ventricle. Only in 4 babies (12%) the presence of a mass caused a significant obstruction. A baby, with an enormous septal rhabdomyoma associated to multiple rhabdomyomas in both right and left ventricular walls died just after birth due to severe heart failure. During follow-up we observed a reduction of rhabdomyomas in terms of both number and size in all 32 surviving patients except in one child. Eight patients (24,2%) had an arrhythmia and in 2 of these cases rhabdomyomas led to Wolf-Parkinson-White Syndrome. For all patients the arrhythmia spontaneously totally disappeared or was reduced gradually. With regarding to association with tuberous sclerosis, we diagnosed tuberous sclerosis clinically in 31 babies (93,9%).ConclusionRhabdobyomas are tumors with favorable prognosis because they frequently do not cause symptoms and they often regress in numbers and size. Nevertheless, due to frequent association with tuberous sclerosis complex and the resulting neurological impairment, the prognosis can result unfavorable.

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The electron transmission spectra of the fluoro~, bromo~, and iodomethanes (except CH 2 F 2 ) and of some monohaloalkanes are reported. The resonance energies for electron attachment to the halomethanes have also been evaluated by means of bound and continuum multiple scattering Xa calculations, which closely reproduce the low~energy experimental data. A large electron affinity increase is observed on going from the fluorine to the heavier halogen derivatives, while within each series of halides the electron affinity increases with increasing number of halogen atoms. The ground anion state is found to be stable in CHBr 3 , CBr 4 , and in all the iodomethanes except CH31. The fragment anion production, as a function of the electron impact energy, has been measured for some of the compounds under investigation, in order to obtain experimental information on anion states very close to zero energy or slightly stable, which are not accessible in electron transmission.

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