Este trabalho estuda as propriedades fluorescentes e solvatocrômicas da cumarina e seus derivados visando contribuir na elucidação do comportamento do estado excitado dessas moléculas em misturas de solventes. Esta abordagem foi desenvolvida através de medidas que envolveram diferentes relações de solventes com constantes dielétricas distintas. Os máximos de excitação e emissão de fluorescência foram deslocados para o azul nas misturas com maior proporção do solvente orgânico e o deslocamento de Stokes foi menor em misturas com menor parâmetro de polaridade do solvente, Δf. A intensidade de emissão de cumarina foi extremamente sensível à polaridade e às diferentes conformações estruturais dos solventes. Estas conformações influenciaram diretamente no comportamento espectroscópico e explicam o desvio da linearidade da relação de Lippert-Mataga. A utilização de espectroscopia de fluorescência possibilita o conhecimento do comportamento destes derivados quando em diferentes ambientes, sendo de extrema importância para a identificação e caracterização desses compostos em formulações farmacêuticas.

This work studied the fluorescent and solvatochromic properties of coumarin and its derivatives aiming to contribute in the elucidation of the excited state behavior of the molecule in solvent mixtures. This approach has been developed through a set of measurements involving different solvent ratios, which present distinct dielectric constants. The excitation and fluorescence maxima were largely blue-shifted with increasing participation of the organic solvent and the Stokes shifts were unusually low in mixtures with lower solvent polarity parameter, Δf. The emission intensity of coumarin was extremely sensitive to the polarity and the different structural conformations of solvents. These results influenced the spectroscopic behavior and explain the deviation from the linearity of the Lippert-Mataga relationship. The use of fluorescence spectroscopy makes the understanding of the behavior of the systems studied when in the presence of different environments being extremely important for the identification and characterization of coumarin in different pharmaceutical formulations.

The use of artificial implants provides a palliative or permanent solution for individuals who have lost some bodily function through disease, an accident or natural wear. This functional loss can be compensated for by the use of medical devices produced from special biomaterials. Titanium alloy (Ti-6Al-4V) is a well-established primary metallic biomaterial for orthopedic implants, but the toxicity of the chemical components of this alloy has become an issue of concern. In this work, we used the MTT assay and micronucleus assay to examine the cytotoxicity and genotoxicity, respectively, of an extract obtained from this alloy. The MTT assay indicated that the mitochondrial activity and cell viability of CHO-K1 cells were unaffected by exposure to the extract. However, the micronucleus assay revealed DNA damage and an increase in micronucleus frequency at all of the concentrations tested. These results show that ions released from Ti-6Al-4V alloy can cause DNA and nuclear damage and reinforce the importance of assessing the safety of metallic medical devices constructed from biomaterials.

Several molecular methods, such as Southern blotting hybridization, Multilocus Sequence Typing, and DNA microsatellite analysis, have been employed to genotype Candida albicans. The genotype analysis allows to group strains in clades, that is, a group composed of one ancestor and its descendants. These genotype studies demonstrate that clades distribution is influenced by geographic area as well as that antifungal resistance is associated with particular clades. These findings suggested that C. albicans reproduces mainly in a clonal manner, with certain degree of DNA microevolution. Additionally, virulence factors and site of isolation have also been associated with clade specificity. The present article is a brief review about the methods used for Candida genotyping and the correlated clade systems established. Special emphasis is given to Ca3 hybridization, MLST, and Microsatellites. The present work is also focused on the phenotypic and physiological traits associated with Candida clades.

The aim of the present study was to evaluate the antifungal susceptibility profile of Trichosporon species isolated from different sources employing the Clinical and Laboratory Standards Institute (CLSI) method and E-test method. Thirty-four isolates of Trichosporon spp. and six CBS reference samples were tested for their susceptibility to Amphotericin B, 5-flucytosine, Fluconazole, Itraconazole, Voriconazole and Terbinafine. All species showed high Minimun Inhibitory Concentrations (MIC) for Itraconazole and susceptibility to Fluconazole, The comparison among the results obtained by the CLSI method and E-test revealed larger discrepancies among 5-flucytosine and Itraconazole. The present work provides epidemiological data that could influence therapeutic choices. Furthermore, the comparison between different methodologies could help to analyze results obtained by different laboratories.