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Papers by carina martins

A Adenite Eqüina, também conhecida como garrotilho, é uma enfermidade infecto-contagiosa que cara... more A Adenite Eqüina, também conhecida como garrotilho, é uma enfermidade infecto-contagiosa que caracteriza-se por aumento de volume de linfonodos da região de garganta, secreção nasal purulenta, febre e tosse.Este trabalho tem por objetivo avaliar a presença de Streptococcus equi em lavados de bolsa gutural e a relação destes achados com a análise sorológica e clínica de eqüinos. Foram avaliados 7 eqüinos escolhidos ao acaso, sem raça definida, de diferentes sexos e idades oriundos da região sul do Rio Grande do Sul. Foi realizado exame clínico geral, onde foram avaliados os sinais vitais, e exame específico do sistema respiratório, onde foi feita avaliação completa das vias aéreas superiores e inferiores, incluindo a endoscopia do trato superior como meio auxiliar. Esta avaliação foi conduzida a fim de correlacionar os achados sorológicos e microbiológicos com o estado geral do animal. A análise sorológica, feito por Testes de ELISA, não demonstraram a presença de anticorpos específicos para S. equi em nenhum dos casos. As amostras de lavado da bolsa gutural destinadas a cultura bacteriana, apresentaram flora polimicrobiana, não sendo possível isolar os estreptococos.da bolsa gutural. Através dos resultados, observa -se que há necessidade de continuar esse trabalho, visto que não foram encontrados resultados conclusivos.Quando identificado S. equi na bolsa gutural, o animal deve ser isolado por ser considerado um reservatório da doença, evitando desta forma, a disseminação do agente da adenite eqüina pelo rebanho.

Spectrochimica Acta Part A-molecular and Biomolecular Spectroscopy, 2009

The conformational isomerism of 2-chlorocyclopentanone and 2-bromocyclopentanone has been determi... more The conformational isomerism of 2-chlorocyclopentanone and 2-bromocyclopentanone has been determined through the solvent dependence of the 1H NMR 3JHH coupling constants, theoretical calculations and infrared data, using the solvation theory for the treatment of NMR data. In 2-chlorocyclopentanone, the energy difference (E Ψ- e - EΨ- a), in the isolated molecule at B3LYP level of theory, between the pseudo-equatorial ( Ψ- e) and pseudo-axial ( Ψ- a) conformers is 0.42 kcal mol -1, which decreases in CCl 4 and in acetonitrile solutions, in good agreement with infrared data ( νC dbnd O ), despite the uncertainties of the latter method. The conformational equilibrium for 2-bromocyclopentanone is also between the Ψ- e and Ψ- a conformations, with an energy difference ( EΨ- e - EΨ- a), in the isolated molecule at B3LYP level of theory, is 0.85 kcal mol -1 which decreases in CCl 4 and in acetonitrile solutions, also in good agreement with infrared data.

Journal of Molecular Structure-theochem, 2005

Conformational preferences and orbital interactions of N,N-dimethyl-2-fluoroacetamide (1), N,N-di... more Conformational preferences and orbital interactions of N,N-dimethyl-2-fluoroacetamide (1), N,N-dimethyl-2-chloroacetamide (2), N,Ndimethyl-2-bromoacetamide (3) and N,N-dimethyl-2-iodoacetamide (4) were analyzed using experimental infra-red data, theoretical calculations and NBO analysis. The conformational equilibria of compounds 1-4 can be represented by their cis and gauche rotamers. The gauche form of 1 is stable in the vapor phase and in a non-polar solvent, but the cis is predominant in a polar solvent. For 2-4 the gauche form is more stable than the cis, in both the vapor and liquid phases. These conformational preferences were attributed to the orbital interaction between two antibonding orbitals, p* C]O /s* C-X . This unexpected interaction was possibly due to the high (0.3) electron density on p* C]O , which results from the interaction between one nitrogen lone pair and p* C]O .

Spectrochimica Acta Part A-molecular and Biomolecular Spectroscopy, 2009

Density functional theory (DFT) and time-dependent DFT (TDDFT) methods have been used to investig... more Density functional theory (DFT) and time-dependent DFT (TDDFT) methods have been used to investigate the adsorption site effect of Raman scattering for neutral and charged pyridine-Ag 4 complexes. The calculated results show that the SERS spectra are strongly dependent on adsorption site and the configuration of new complexes. The normal Raman spectra of neutral and charged pyridine-Ag 4 complexes are similar with that of isolated pyridine but with an enhancement factor below 10 times. This enhancement is ascribed to ground state chemical enhancement. The pre-surface-enhanced Raman scattering (SERS) spectra were calculated at 1256 nm, 769 nm and 744.3 nm, which are nearly resonant with the charge transfer excited states S 2 for neutral and charged pyridine-Ag 4 complexes, respectively. We obtain the enhancement factor about 10 4 to 10 5 in pre-SERS spectra which is mainly caused by charge transfer resonance Raman enhancement. The three-dimensional cube representation is also applied to describe the photoinduced CT, which are considered as direct evidence of chemical enhancement, between pyridine and two isomers of Ag 4 clusters.

Chemical Physics Letters, 2010

The infrared spectrum of 2-bromocyclohexanone in the vapor phase was obtained for the first time,... more The infrared spectrum of 2-bromocyclohexanone in the vapor phase was obtained for the first time, and the m C@O intensity for the more polar equatorial conformer was surprisingly found to be higher than for the axial form, suggesting its larger population, opposite to calculations. Theoretical data for dimeric models showed that attractive intermolecular interactions in the equatorial-equatorial dimer are dominant, but this is not enough to explain the spectroscopic behavior, since the axial-axial dimer remains more stable. The higher C@O molar absorptivity in the equatorial form is therefore invoked to explain its more intense C@O band, as confirmed by charge calculations.

A Adenite Eqüina, também conhecida como garrotilho, é uma enfermidade infecto-contagiosa que cara... more A Adenite Eqüina, também conhecida como garrotilho, é uma enfermidade infecto-contagiosa que caracteriza-se por aumento de volume de linfonodos da região de garganta, secreção nasal purulenta, febre e tosse.Este trabalho tem por objetivo avaliar a presença de Streptococcus equi em lavados de bolsa gutural e a relação destes achados com a análise sorológica e clínica de eqüinos. Foram avaliados 7 eqüinos escolhidos ao acaso, sem raça definida, de diferentes sexos e idades oriundos da região sul do Rio Grande do Sul. Foi realizado exame clínico geral, onde foram avaliados os sinais vitais, e exame específico do sistema respiratório, onde foi feita avaliação completa das vias aéreas superiores e inferiores, incluindo a endoscopia do trato superior como meio auxiliar. Esta avaliação foi conduzida a fim de correlacionar os achados sorológicos e microbiológicos com o estado geral do animal. A análise sorológica, feito por Testes de ELISA, não demonstraram a presença de anticorpos específicos para S. equi em nenhum dos casos. As amostras de lavado da bolsa gutural destinadas a cultura bacteriana, apresentaram flora polimicrobiana, não sendo possível isolar os estreptococos.da bolsa gutural. Através dos resultados, observa -se que há necessidade de continuar esse trabalho, visto que não foram encontrados resultados conclusivos.Quando identificado S. equi na bolsa gutural, o animal deve ser isolado por ser considerado um reservatório da doença, evitando desta forma, a disseminação do agente da adenite eqüina pelo rebanho.

Spectrochimica Acta Part A-molecular and Biomolecular Spectroscopy, 2009

The conformational isomerism of 2-chlorocyclopentanone and 2-bromocyclopentanone has been determi... more The conformational isomerism of 2-chlorocyclopentanone and 2-bromocyclopentanone has been determined through the solvent dependence of the 1H NMR 3JHH coupling constants, theoretical calculations and infrared data, using the solvation theory for the treatment of NMR data. In 2-chlorocyclopentanone, the energy difference (E Ψ- e - EΨ- a), in the isolated molecule at B3LYP level of theory, between the pseudo-equatorial ( Ψ- e) and pseudo-axial ( Ψ- a) conformers is 0.42 kcal mol -1, which decreases in CCl 4 and in acetonitrile solutions, in good agreement with infrared data ( νC dbnd O ), despite the uncertainties of the latter method. The conformational equilibrium for 2-bromocyclopentanone is also between the Ψ- e and Ψ- a conformations, with an energy difference ( EΨ- e - EΨ- a), in the isolated molecule at B3LYP level of theory, is 0.85 kcal mol -1 which decreases in CCl 4 and in acetonitrile solutions, also in good agreement with infrared data.

Journal of Molecular Structure-theochem, 2005

Conformational preferences and orbital interactions of N,N-dimethyl-2-fluoroacetamide (1), N,N-di... more Conformational preferences and orbital interactions of N,N-dimethyl-2-fluoroacetamide (1), N,N-dimethyl-2-chloroacetamide (2), N,Ndimethyl-2-bromoacetamide (3) and N,N-dimethyl-2-iodoacetamide (4) were analyzed using experimental infra-red data, theoretical calculations and NBO analysis. The conformational equilibria of compounds 1-4 can be represented by their cis and gauche rotamers. The gauche form of 1 is stable in the vapor phase and in a non-polar solvent, but the cis is predominant in a polar solvent. For 2-4 the gauche form is more stable than the cis, in both the vapor and liquid phases. These conformational preferences were attributed to the orbital interaction between two antibonding orbitals, p* C]O /s* C-X . This unexpected interaction was possibly due to the high (0.3) electron density on p* C]O , which results from the interaction between one nitrogen lone pair and p* C]O .

Spectrochimica Acta Part A-molecular and Biomolecular Spectroscopy, 2009

Density functional theory (DFT) and time-dependent DFT (TDDFT) methods have been used to investig... more Density functional theory (DFT) and time-dependent DFT (TDDFT) methods have been used to investigate the adsorption site effect of Raman scattering for neutral and charged pyridine-Ag 4 complexes. The calculated results show that the SERS spectra are strongly dependent on adsorption site and the configuration of new complexes. The normal Raman spectra of neutral and charged pyridine-Ag 4 complexes are similar with that of isolated pyridine but with an enhancement factor below 10 times. This enhancement is ascribed to ground state chemical enhancement. The pre-surface-enhanced Raman scattering (SERS) spectra were calculated at 1256 nm, 769 nm and 744.3 nm, which are nearly resonant with the charge transfer excited states S 2 for neutral and charged pyridine-Ag 4 complexes, respectively. We obtain the enhancement factor about 10 4 to 10 5 in pre-SERS spectra which is mainly caused by charge transfer resonance Raman enhancement. The three-dimensional cube representation is also applied to describe the photoinduced CT, which are considered as direct evidence of chemical enhancement, between pyridine and two isomers of Ag 4 clusters.

Chemical Physics Letters, 2010

The infrared spectrum of 2-bromocyclohexanone in the vapor phase was obtained for the first time,... more The infrared spectrum of 2-bromocyclohexanone in the vapor phase was obtained for the first time, and the m C@O intensity for the more polar equatorial conformer was surprisingly found to be higher than for the axial form, suggesting its larger population, opposite to calculations. Theoretical data for dimeric models showed that attractive intermolecular interactions in the equatorial-equatorial dimer are dominant, but this is not enough to explain the spectroscopic behavior, since the axial-axial dimer remains more stable. The higher C@O molar absorptivity in the equatorial form is therefore invoked to explain its more intense C@O band, as confirmed by charge calculations.