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J Phys Chem A ; 122(23): 5142-5152, 2018 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-29786443


The nonlinear optical response of some O-doped polycyclic aromatic hydrocarbons (PAHs) is systematically investigated in the present work aiming to understand the influence of structural effects on their nonlinear optical response. In that view, the third-order nonlinear optical properties of these PAHs were measured under 4 ns visible (532 nm) and infrared (1064 nm) laser excitation. The O-doped PAHs were found to exhibit large saturable absorption and negative sign nonlinear refraction under visible excitation, increasing both with the addition of naphthalene units and with the number of O atoms. Their nonlinear optical response was found to be negligible under infrared excitation. Similar measurements performed on thin films of these PAHs have shown that they maintain their large nonlinear optical response even in the solid state, confirming their high potential for optoelectronic and photonic applications.

Chemistry ; 23(10): 2363-2378, 2017 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-27897357


The synthesis of O-doped polyaromatic hydro- carbons in which two polycyclic aromatic hydrocarbon sub units are bridged through one or two O atoms has been achieved. This includes high-yield ring-closure key steps that, depending on the reaction conditions, result in the formation of furanyl or pyranopyranyl linkages through intramolecular C-O bond formation. Comprehensive photophysical measurements in solution showed that these compounds have exceptionally high emission yields and tunable absorption properties throughout the UV/Vis spectral region. Electrochemical investigations showed that in all cases O annulation increases the electron-donor capabilities by raising the HOMO energy level, whereas the LUMO energy level is less affected. Moreover, third-order nonlinear optical (NLO) measurements on solutions or thin films containing the dyes showed very good values of the second hyperpolarizability. Importantly, poly(methyl methacrylate) films containing the pyranopyranyl derivatives exhibited weak linear absorption and NLO absorption compared to the nonlinearity and NLO refraction, respectively, and thus revealed them to be exceptional organic materials for photonic devices.

BMJ Case Rep ; 20152015 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-26424820


Dysplasia epiphysealis hemimelica is a rare developmental disorder which affects the epiphyses. We report a case of the disease located in the ankle joint, referred to our clinic with the initial misdiagnosis of a Salter-Harris 3 type fracture of the distal epiphysis of the tibia. After correct diagnosis, the patient was treated surgically with the excision of the cartilaginous masses. Taking an accurate medical history and performing adequate imaging studies is essential in diagnosing and treating this disease. Fracture-like epiphyseal configurations in patients with no history of injury should raise suspicion of periarticular developmental disorders.

Doenças do Desenvolvimento Ósseo/patologia , Fêmur/anormalidades , Tíbia/anormalidades , Articulação do Tornozelo/patologia , Doenças do Desenvolvimento Ósseo/diagnóstico , Doenças do Desenvolvimento Ósseo/cirurgia , Cartilagem/patologia , Criança , Erros de Diagnóstico , Epífises/patologia , Fêmur/patologia , Fêmur/cirurgia , Humanos , Imageamento Tridimensional , Imagem por Ressonância Magnética , Masculino , Dor/diagnóstico , Doenças Raras , Tíbia/patologia , Tíbia/cirurgia , Tomografia Computadorizada por Raios X
J Pediatr Orthop B ; 14(2): 92-6, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15703517


Urine glycosaminoglycan concentrations were measured in 24-h urine samples collected from ninety children (30 children with Perthes disease, 30 with transient synovitis and 30 control participants). Significantly decreased levels of urine glycosaminoglycans were found in Perthes disease patients compared with those with transient synovitis and the control group.

Glicosaminoglicanos/urina , Articulação do Quadril , Doença de Legg-Calve-Perthes/diagnóstico , Sinovite/diagnóstico , Biomarcadores/urina , Estudos de Casos e Controles , Criança , Pré-Escolar , Estudos de Coortes , Progressão da Doença , Feminino , Glicosaminoglicanos/metabolismo , Humanos , Doença de Legg-Calve-Perthes/complicações , Doença de Legg-Calve-Perthes/urina , Masculino , Probabilidade , Recidiva , Valores de Referência , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Sinovite/complicações , Sinovite/urina