880 research outputs found

    structures of annulenes and model annulene systems in the ground and lowest excited states

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    The paper introduces general considerations on structural properties of aromatic, antiaromatic and non-aromatic conjugated systems in terms of potential energy along bond length alternation and distortion coordinates, taking as examples benzene, cyclobutadiene and cyclooctatetraene. Pentalene, formally derived from cyclooctatetraene by cross linking, is also considered as a typical antiaromatic system. The main interest is concerned with [n]annulenes and model [n]annulene molecular systems, n ranging from 10 to 18. The rich variety of conformational and configurational isomers and of dynamical processes among them is described. Specific attention is devoted to bridged [10]- and [14]annulenes in the ground and lowest excited states as well as to s-indacene and biphenylene. Experimental data obtained from vibrational and electronic spectroscopies are discussed and compared with ab initio calculation results. Finally, porphyrin, tetraoxaporphyrin dication and diprotonated porphyrin are presented as annulene structures adopting planar/non-planar geometries depending on the steric hindrance in the inner macrocycle ring. Radiative and non-radiative relaxation processes from excited state levels have been observed by means of time-resolved fluorescence and femtosecond transient absorption spectroscopy. A short account is also given of porphycene, the structural isomer of porphyrin, and of porphycene properties

    Thermal denaturation of proteins and chemical equilibrium

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    Aripiprazole LAI two-injection start in a 16 year-old adolescent with schizophrenia

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    Aripiprazole long-acting injection (LAI) is approved for the treatment of schizophrenia in adults. Recently, Europe and Canada approved the use of the two-injection start regimen: two separate injections of 400-mg long-acting aripiprazole along with a single 20-mg dose of oral aripiprazole. Aripiprazole showed efficacy in the treatment of adolescents with acute schizophrenia in several controlled trials, leading to its approval for 13- to 17-year-old adolescents with schizophrenia by the EMA. However, the LAI formulation still remains off-label in adolescents

    CHECKLIST DE CIRURGIA SEGURA: UM CAMINHO À SEGURANÇA DO PACIENTE

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    O checklist de cirurgia segura da Organização Mundial da Saúde é uma ferramenta útil para diminuir eventos adversos em hospitais, porém sua implantação efetiva ainda é um desafio. Em outubro do ano de 2004 a Organização Mundial de Saúde (OMS) lançou a “Aliança Mundial para Segurança do Paciente”, que visa à conscientização para melhora da segurança dos cuidados, além do desenvolvimento de políticas e estratégias na atenção à saúde. Um dos ‘Desafios Mundiais para a Segurança do Paciente’, que pretende identificar os itens mais significativos do risco à segurança do paciente, é ‘Cirurgia Segura Salva Vidas'
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