Time filter

Source Type

Santa Cruz Cabralia, Brazil

Souza R.C.,Sao Paulo State University | Junqueira J.C.,Sao Paulo State University | Rossoni R.D.,Sao Paulo State University | Pereira C.A.,Sao Paulo State University | And 2 more authors.
Lasers in Medical Science | Year: 2010

This study was to evaluate specific effects of photodynamic therapy (energy density 15.8 J/cm2, 26.3 J/cm2 and 39.5 J/cm2) using methylene blue, toluidine blue and malachite green as photosensitizers and low-power laser irradiation on the viability of Candida albicans. Suspensions of C. albicans containing 106 cells/ml were standardized in a spectrophotometer. For each dye, 120 assays, divided into four groups according to the following experimental conditions, were carried out: laser irradiation in the presence of the photosensitizer; laser irradiation only; treatment with the photosensitizer only; no exposure to laser light or photosensitizer. Next, serial dilutions were prepared and seeded onto Sabouraud dextrose agar for the determination of the number of colony-forming units per milliliter (CFU/ml). The results were subjected to analysis of variance and the Tukey test (P<0.05). Photodynamic therapy using the photosensitizers tested was effective in reducing the number of C. albicans.. The number of CFU/ml was reduced by between 0.54 log10 and 3.07 log10 and depended on the laser energy density used. Toluidine blue, methylene blue and malachite green were effective photosensitizers in antimicrobial photodynamic therapy against C. albicans, as was low-power laser irradiation alone. © Springer-Verlag London Ltd 2009.

Paschoal F.,Federal Rural University of Rio de Janeiro | Vieira F.M.,Federal Rural University of Rio de Janeiro | Cezar A.D.,Castelo Branco University | Luque J.L.,Federal Rural University of Rio de Janeiro
Journal of Parasitology | Year: 2014

Dichelyne (Cucullanellus) tornquisti n. sp. is described from the intestine of the marine fish Orthopristis ruber (Haemulidae) of Rio de Janeiro, Brazil. The new species differs from the congeners by the location of the deirids (same level) and the excretory pore (posterior) in relation to esophagus-intestinal junction and by papillae 5 to 9 not forming a subventral line. It is the first Dichelyne species described from fish family Haemulidae in the Brazilian coastal zone. © American Society of Parasitologists 2014.

Pinto Neto O.,Castelo Branco University | Pinto Neto O.,National Institute for Space Research | Pinto I.R.C.A.,National Institute for Space Research | Pinto O.,National Institute for Space Research
Journal of Atmospheric and Solar-Terrestrial Physics | Year: 2013

The goal of this article is to investigate the influence of solar activity on thunderstorm activity in Brazil. For this purpose, thunder day data from seven cities in Brazil from 1951 to 2009 are analyzed with the wavelet method for the first time. To identify the 11-year solar cycle in thunder day data, a new quantity is defined. It is named TD1 and represents the power in 1-year in a wavelet spectrum of monthly thunder day data. The wavelet analysis of TD1 values shows more clear the 11-year periodicity than when it is applied directly to annual thunder day data, as it has been normally investigated in the literature. The use of this new quantity is shown to enhance the capability to identify the 11-year periodicity in thunderstorm data. Wavelet analysis of TD1 indicates that six out seven cities investigated exhibit periodicities near 11 years, three of them significant at a 1% significance level (p<0.01). Furthermore, wavelet coherence analysis demonstrated that the 11-year periodicity of TD1 and solar activity are correlated with an anti-phase behavior, three of them (the same cities with periodicities with 1% significance level) significant at a 5% significance level (p<0.05). The results are compared with those obtained from the same data set but using annual thunder day data. Finally, the results are compared with previous results obtained for other regions and a discussion about possible mechanisms to explain them is done. The existence of periodicities around 11 years in six out of seven cities and their anti-phase behavior with respect to 11-year solar cycle suggest a global mechanism probably related to a solar magnetic shielding effect acting on galactic cosmic rays as an explanation for the relationship of thunderstorm and solar activity, although more studies are necessary to clarify its physical origin. © 2013 Elsevier Ltd.

Vilela S.F.G.,Sao Paulo State University | Junqueira J.C.,Sao Paulo State University | Barbosa J.O.,Sao Paulo State University | Majewski M.,Sao Paulo State University | And 2 more authors.
Archives of Oral Biology | Year: 2012

Objectives: The organization of biofilms in the oral cavity gives them added resistance to antimicrobial agents. The action of phenothiazinic photosensitizers on oral biofilms has already been reported. However, the action of the malachite green photosensitizer upon biofilm-organized microorganisms has not been described. The objective of the present work was to compare the action of malachite green with the phenothiazinic photosensitizers (methylene blue and toluidine blue) on Staphylococcus aureus and Escherichia coli biofilms. Methods: The biofilms were grown on sample pieces of acrylic resin and subjected to photodynamic therapy using a 660-nm diode laser and photosensitizer concentrations ranging from 37.5 to 3000 μM. After photodynamic therapy, cells from the biofilms were dispersed in a homogenizer and cultured in Brain Heart Infusion broth for quantification of colony-forming units per experimental protocol. For each tested microorganism, two control groups were maintained: one exposed to the laser radiation without the photosensitizer (L+PS-) and other treated with the photosensitizer without exposure to the red laser light (L-PS+). The results were subjected to descriptive statistical analysis. Results: The best results for S. aureus and E. coli biofilms were obtained with photosensitizer concentrations of approximately 300 μM methylene blue, with microbial reductions of 0.8-1.0 log 10; 150 μM toluidine blue, with microbial reductions of 0.9-1.0 log 10; and 3000 μM malachite green, with microbial reductions of 1.6-4.0 log 10. Conclusion: Greater microbial reduction was achieved with the malachite green photosensitizer when used at higher concentrations than those employed for the phenothiazinic dyes. © 2011 Elsevier Ltd. All rights reserved.

Campos L.A.,Castelo Branco University | Pereira V.L.,Castelo Branco University | Muralikrishna A.,Federal University of Sao Paulo | Albarwani S.,Sultan Qaboos University | And 2 more authors.
Frontiers in Physiology | Year: 2013

Heart rate and blood pressure are the most important vital signs in diagnosing disease. Both heart rate and blood pressure are characterized by a high degree of short term variability from moment to moment, medium term over the normal day and night as well as in the very long term over months to years. The study of new mathematical algorithms to evaluate the variability of these cardiovascular parameters has a high potential in the development of new methods for early detection of cardiovascular disease, to establish differential diagnosis with possible therapeutic consequences. The autonomic nervous system is a major player in the general adaptive reaction to stress and disease. The quantitative prediction of the autonomic interactions in multiple control loops pathways of cardiovascular system is directly applicable to clinical situations. Exploration of new multimodal analytical techniques for the variability of cardiovascular system may detect new approaches for deterministic parameter identification. A multimodal analysis of cardiovascular signals can be studied by evaluating their amplitudes, phases, time domain patterns, and sensitivity to imposed stimuli, i.e., drugs blocking the autonomic system. The causal effects, gains, and dynamic relationships may be studied through dynamical fuzzy logic models, such as the discrete-time model and discrete-event model. We expect an increase in accuracy of modeling and a better estimation of the heart rate and blood pressure time series, which could be of benefit for intelligent patient monitoring. We foresee that identifying quantitative mathematical biomarkers for autonomic nervous system will allow individual therapy adjustments to aim at the most favorable sympathetic-parasympathetic balance. © 2013 Campos, Pereira, Muralikrishna, Albarwani, Brás and Gouveia.

Discover hidden collaborations