291 research outputs found
Effectiveness of cardiac resynchronization therapy in heart failure patients with valvular heart disease: comparison with patients affected by ischaemic heart disease or dilated cardiomyopathy. The InSync/InSync ICD Italian Registry
AimsTo analyse the effectiveness of cardiac resynchronization therapy (CRT) in patients with valvular heart disease (a subset not specifically investigated in randomized controlled trials) in comparison with ischaemic heart disease or dilated cardiomyopathy patients.Methods and resultsPatients enrolled in a national registry were evaluated during a median follow-up of 16 months after CRT implant. Patients with valvular heart disease treated with CRT (n = 108) in comparison with ischaemic heart disease (n = 737) and dilated cardiomyopathy (n = 635) patients presented: (i) a higher prevalence of chronic atrial fibrillation, with atrioventricular node ablation performed in around half of the cases; (ii) a similar clinical and echocardiographic profile at baseline; (iii) a similar improvement of LVEF and a similar reduction in ventricular volumes at 6-12 months; (iv) a favourable clinical response at 12 months with an improvement of the clinical composite score similar to that occurring in patients with dilated cardiomyopathy and more pronounced than that observed in patients with ischaemic heart disease; (v) a long-term outcome, in term of freedom from death or heart transplantation, similar to patients affected by ischaemic heart disease and basically more severe than that of patients affected by dilated cardiomyopathy.ConclusionIn 'real world' clinical practice, CRT appears to be effective also in patients with valvular heart disease. However, in this group of patients the outcome after CRT does not precisely overlap any of the two other groups of patients, for which much more data are currently available
Synthesis of conjugated oligomers and polymers: the organometallic way
Results of special interest in the field of organometallic
chemistry directed towards the synthesis of conjugated
oligomers and polymers are reviewed. Methodologies
widely employed in the synthesis of well-defined molecules
and based on the transition metal catalyzed coupling
reactions of various organometallic (B, Sn, Si, Mg and Zn)
reagents have been more recently extended to build up polyor
oligo-meric conjugated molecular architectures.
Although the focus of the present work is on transition
metal cross-coupling or homo-coupling processes, other
useful organometallic routes, such as metathesis reactions
and acetylene polymerization, have also been dealt with.
Owing to their higher versatility with respect to the nonorganometallic
processes commonly used for the synthesis
of these materials, the approaches presented allow the
realization of more complex molecular structures, which are
nowadays required in many electronic and optoelectronic
applications. The use of organometallic strategies has been
discussed from a synthetic organic chemist’s point of view,
and advantages and limitations of the different
methodologies reviewed have been highlighted. Some
attention has also been paid to the properties of the resulting
materials and to their dependence on the procedure
followed and the framework obtained
Organometallic strategies for the synthesis of conjugated oligomers
: In this account we report our contribution to the synthesis of conjugated oligomers with defined structure. The targets of our work are oligoenes, oligophenylenevinylenes, also with fluorinated vinylene units, oligophenylenes and oligomers with thiophene-arylene or thiophene-anthraquinone units. The synthetic strategies developed in our research group are based on transition-metal catalyzed coupling reactions
Organometallic chemistry directed towards the synthesis of electroactive materials: stereoselective routes to extended polyconjugated systems
Various synthetic methodologies involving organometallic reagents and leading to conjugated oligomers and polymers are presented. Polyenes and oligomers of poly(paraphenylenevinylene) with well-defined length of the conjugated system were prepared by straightforward synthetic procedures based upon organometallic derivatives of silicon or boron. Fluorinated oligo(para-phenylenes) containing up to five aromatic rings were easily obtained by homocoupling reaction promoted by copper(I) thiophenecarboxylate. The Stille cross-coupling reaction was applied to the synthesis of poly(para-phenylenevinylene) polymers with various substituents on the aromatic rings. Some relevant electro-optical properties of these materials are also discussed
A NEW APPROACH TO SILYLATED KETONES AND DICARBONYL-COMPOUNDS WITH A CONJUGATED (ALL-E) DIENE OR TRIENE STRUCTURE
Silylated ketones and dicarbonyl compounds with a conjugated diene or triene structure are obtained by electrophilic substitution reactions between (1E,3E)-1,4-bis(trimethylsilyl)buta-1,3-diene or (1E,3E,5E)-1,6-bis(trimethylsilyl)hexa-1,3,5-triene and acyl chlorides in the presence of aluminium trichloride
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