Valentina Cabras

Ring 20 syndrome mosaicism and epilepsy: a case with duplication of two BAC clones in 20q11.21-q11.22 defined by genome array-CGH

Herein, we report an unusual case of ring 20 mosaicism in a 15-year-old non-dysmorphic girl with epilepsy refractory to drug therapy. Ring 20 syndrome is a rare condition still not well characterised both at the genetic and clinical levels. It was described for the first time by Borgaonkar and Bolling1 as a genetic syndrome. To date, about 60 mostly sporadic cases of patients have been reported with de novo ring formation. This syndrome is characterised by a large degree of phenotypic variability, in association with a characteristic form of epilepsy, refractory to any pharmacological therapy with non-convulsive status epilepticus and cognitive problems. The first seizures occur in the first years of life and represent the first clinical signs. Further clinical signs are mental retardation of varying degrees, and behavioural disorders. The case reported showed an unusual ring chromosome 20 mosaicism associated with epilepsy and generalised tonic clonic seizures refractory to drug therapy and behaviour disorders. Cytogenetic analysis, performed on cultured peripheral blood, revealed the presence of ring 20 mosaicism in 40% of the metaphases examined (20 out of 50). The patient, the firstborn of non-consanguineous healthy parents, was born after a normal pregnancy. The neonatal period followed a normal course, with increases in weight–height and psychomotor development. The parents reported …

Formation of metallic silver and copper in non-aqueous media by ultrasonic radiation

Concentrated suspensions of silver and copper salts in silicone oil were heated to 200 °C and irradiated with ultrasonic energy for different time durations. Characterization of the products was done using X-ray powder diffraction. In most cases, metallic Ag or Cu were obtained, together with their oxide forms Ag2O and Cu2O. The salts, used as precursors, do not dissolve in silicone oil but rather form a heterogeneous system, and we assume that local heating, caused by the acoustic cavitation, enhanced their thermal decomposition and the formation of metallic particles. It was found that the presence of silver particles enhances the formation of metallic copper. This phenomenon was observed in the experiment with the acetate salts mixture.

Coordination polymers based on dithiophosphato/dithiophosphonato nickel complexes and linear 1,4-di(3-pyridyl)buta-1,3-diyne ligand

Abstract The reactions between ligand 1,4-di(3-pyridyl)buta-1,3-diyne (L) and the differently P-substituted dithiophosphato [Ni((RO)2PS2)2] [R = Me (1), Et (2)] and dithiophosphonato [Ni((4-MeOC6H4)(RO)PS2)2] [R = Me (3), Et (4)] nickel complexes have been performed, and the solid state structures of the resulting coordination polymers [1·L]∞–[4·L]∞ investigated. L acts as spacer between the complex units driving the formation of zig-zag polymeric chains. Inter-chain interactions involving the P-substituents have been discussed and the different supramolecular 3D-constructs described. The L donor ability has been confirmed also by spectrophotometric determination of the formation constants of the species 1·2L, 2·2L and 1·2L, and by theoretical studies. The reactivity of the ligand 1,4-di(3-pyridyl)buta-1,3-diyne (L) towards differently P-substitued phosphorodithioato NiII complexes along with the equilibrium formation constants in solution, and the solid state structures of the resulting coordination polymers [1·L]∞, [2·L]∞, [3·L]∞, and [4·L]∞ are presented.

Mechanosynthesis of coordination polymers based on dithiophosphato and dithiophosphonato NiII complexes and 1,4-di(3-pyridinyl)buta-1,3-diyne ligand

Abstract In recent decades the mechanosynthesis of Coordination Polymers (CPs) has consolidated as a powerful method for the formation of coordination bonds. The aim of this study regards the environmental friendly mechanosynthesis of coordination polymers by milling the neutral square planar NiII complexes [((MeO)2PS2)2Ni] (1), [((EtO)2PS2)2Ni] (2), [((MeO–C6H4)(MeO))PS2)2Ni] (3), [((MeO–C6H4)(EtO))PS2)2Ni] (4), with the organic ligand 1,4-di(3-pyridyl)buta-1,3-diyne (L). Using these substrates, several mechanosynthesis were performed via Net Grinding (NG) and Liquid Assisted Grinding (LAG) approaches. A mechanochemical trend concerning the general inverse correlation between melting point of reagents and reactivity has been observed, highlighting a possible mechanism for these reactions under mechanical conditions.

Facile synthesis of SiO2 nanoparticles for biomedical applications

Silica nanoparticles ( SiO 2 NPs) for biomedical applications have been prepared by using a facile modified Stober-synthesis. Potassium borohydride ( KBH 4 ) has been introduced in the synthesis procedure in order to control NP size. Several samples have been prepared varying tetraethylorthosilicate (TEOS) concentration, and using different process conditions (temperature, reaction time and atmosphere). In order to study the influence of the process conditions on the NP size, morphology and properties, several characterization techniques were used. Size and morphology of the as-prepared SiO 2 NPs have been studied by using Transmission Electron Microscope (TEM) and Dynamic Light Scattering (DLS) techniques. Structural characterization was carried out by X-ray powder diffraction. To investigate the SiO 2 NP fluorescence emission properties the fluorescence spectroscopy was also used.

Cryptic Chromosome Rearrangements in Five Patients, with Normal and/or Abnormal Karyotypes, Associated with Mental Retardation, Autism and/or Epilepsy, Detected by BAC Genome Array-CGH

This report describes the usefulness of the BAC genome array-CGH platform in the detection of cryptic rearrangements. We examined ten patients with normal and/or abnormal karyotypes and dysmorphic features, associated with mental retardation, autism and/or epilepsy. This approach led us to discover further cryptic chromosomal rearrangements, not previously detected by conventional cytogenetic procedures, and allowed us to better delineate genotype/phenotype correlation. Our experience shows the validity of the BAC platform as a reliable method for genome-wide screening of chromosomal aberrations in patient with idiopathic mental retardation and/or in association with autism and epilepsy.