Photodynamic potential of curcumin and blue LED against streptococcus mutans in a planktonic culture

Background: The photodynamic therapy (PDT) involves the use of light of specific wavelength to activate a nontoxic photosensitizing agent or dye in the presence of oxygen for eradication of target cells. In dentistry, this therapy is used to suppress the growth of microorganisms involved directly with dental decay and periodontitis process. There are evidences that curcumin dye is able to control microbial activity when illuminated with specific wavelength. The purpose of this study was to evaluate the in vitro efficacy of PDT using curcumin dye (Cur-C) in combination with a blue LED (L) device on a planktonic model of Streptococcus mutans ( S. mutans). Methods: Suspensions (0.5mL) containing S. mutans at 1×107CFUmL-1 were prepared and divided into 4 groups: Group C-L- (control: no treatment and 1 experimental condition), Group C+L- (curcumin at 3 different concentrations: 2000; 4000 and 8000μM and 3 experimental conditions), Group C-L+ (LED at 3 different dosages: 24, 48 and 72Jcm-2 and 3 experimental conditions), and Group C+L+ (PDT group: curcumin at respective concentrations combined to LED dosages and 9 experimental conditions). Samples of each experimental condition were cultured in Petri dishes of BHI agar. Incubation in micro-aerophilia at 37°C for 48h was performed for subsequent visual counting of CFU/mL. Data were transformed into log10 and analyzed by two-way ANOVA and Tukey's test at p<0.05. Results: Group C. +. L+, in specific experimental conditions, demonstrated a log bacterial reduction 70% higher than Group C. -. L-. Both groups C. -. L+ and C. +. L- presented a slight decrease in log bacterial counting. Conclusion: This in vitro method was able to reduce the number of S. mutans in a planktonic suspension. © 2013 Elsevier B.V.

Resonant properties, of modified triangular plasmonic nanoparticles with higher field concentration

In this paper, we present an analysis of the resonant response of modified triangular metallic nanoparticles with polynomial sides. The particles are illuminated by an incident plane wave and the method of moments is used to solve numerically the electromagnetic scattering problem. We investigate spectral response and near field distribution in function of the length and polynomial order of the nanoparticles. Our results show that in the analyzed wavelength range (0.5-1.8) µm these particles possess smaller number of resonances and their resonant wavelengths, near field enhancement and field confinement are higher than those of the conventional triangular particle with linear sides.

Wavelength assignment using a hybrid evolutionary computation to reduce cross-phase modulation

In this paper, we propose a hybrid methodology based on Graph-Coloring and Genetic Algorithm (GA) to solve the Wavelength Assignment (WA) problem in optical networks, impaired by physical layer effects. Our proposal was developed for a static scenario where the physical topology and traffic matrix are known a priori. First, we used fixed shortest-path routing to attend demand requests over the physical topology and the graph-coloring algorithm to minimize the number of necessary wavelengths. Then, we applied the genetic algorithm to solve WA. The GA finds the wavelength activation order on the wavelengths grid with the aim of reducing the Cross-Phase Modulation (XPM) effect; the variance due to the XPM was used as a function of fitness to evaluate the feasibility of the selected WA solution. Its performance is compared with the First-Fit algorithm in two different scenarios, and has shown a reduction in blocking probability up to 37.14% when considered both XPM and residual dispersion effects and up to 71.42% when only considered XPM effect. Moreover, it was possible to reduce by 57.14% the number of wavelengths.

Effect of 808 nm low-level laser therapy in exercise-induced skeletal muscle fatigue in elderly women

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effects of Low-Level Laser Therapy on Biceps Braquialis Muscle Fatigue in Young Women

Objective: This study aims to investigate the effects of low-level laser therapy (LLLT) on biceps brachi muscular fatigue in 20 young females. Background data: Exhausting physical activity leads to muscular fatigue, which could decrease muscular strength, and may cause impairment in motor control and muscle pain. Several biochemical and biophysical resources have been studied in an attempt to accelerate the recovery of muscle fatigue. Among these, LLLT is emphasized. Methods: Twenty subjects were randomized in one laser group and one placebo group in two sessions of a crossover design experimental procedure; the second session taking place within 7 days of the first. In the first session, subjects underwent a collection of surface electromyographic (SEMG) data of the biceps brachii muscle, followed by active or placebo LLLT at the same muscle, followed then by another EMG sample of biceps brachii. Blood samples were collected five times during the experimental procedure. Second session procedures were identical to the first, with exception of LLLT, which was the opposite of the first session. The fatigue protocol consisted of 60sec of elbow flexion-extension movement performed with 75% of one maximum repetition. Blood lactate, EMG fatigue, and the number of elbow flexion-extension repetitions during the fatigue protocol were used to evaluate the effects of laser therapy (808nm wavelength, 100mW output power, power density of 35.7 W/cm(2), 70sec each point and 7J/point on eight points). Results: No statistical differences were found for eletromyographic fatigue and blood lactate values between groups. Mean numbers of elbow flexion-extension repetitions were 22.6 +/- 7.58 after placebo, and 25.1 +/- 9.89 after active LLLT group, but these differences were not statistically significant (p=0.342). Conclusions: LLLT had limited effects on delaying muscle fatigue in a young female sample, although a tendency was observed in the active laser group toward showing lower electromyography fatigue of biceps brachii muscle. No intergroup differences were found in the number of muscle contractions and lactate concentration.

The use of instantaneous phase for improving sparse arrays images

Sparse arrays have pitch larger than half-wavelength (lambda/2) and there is a reduced number of elements in comparison with a full-populated array. Consequently, there is a reduction in cost, data acquisition and processing. However, conventional beamforming techniques result in large side and grating lobes, and consequently in image artifacts. In this work the instantaneous phase of the signals is used in a beamforming technique instead of the instantaneous amplitudes to improve images obtained from sparse arrays configurations. A threshold based on a statistical analysis and the number of signals used for imaging is applied to each pixel, in order to determine if that pixel is related to a defect or not. Three sets of data are used to evaluate the technique, considering medical and non-destructive testing: a simulated point spread function, a medical phantom and an aluminum plate with 2 lambda-, 7 lambda- and lambda-pitch, respectively. The conventional amplitude image is superposed by the image improved by the instantaneous phase, increasing the reflectors detectability and reducing artifacts for all cases, as well as dead zone for the tested plate.

Streptococcus Mutans Photoinactivation by Combination of Short Exposure of a Broad-Spectrum Visible Light and Low Concentrations of Photosensitizers

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Phenomenological Interpretation of Impedance/Capacitance Measurements on Organic Electronic Devices Under Illumination

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Structure of the polypeptide crotamine from the Brazilian rattlesnake Crotalus durissus terrificus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Stability-indicating LC method for the determination of cephalothin in lyophilized powder for injection

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Photo-Induced Conductivity of Heterojunction GaAs/Rare-Earth Doped SnO2

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Tailoring Thermal Transport Property of Graphene through Oxygen Functionalization

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Investigation of the structural, optical and dielectric properties of highly (100)-oriented (Pb0.60Ca0.20Sr0.20)TiO3 thin films on LaNiO3 bottom electrode

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Structural, dielectric, ferroelectric and optical properties of PBCT, PBST and PCST complex thin films on LaNiO3 metallic conductive oxide layer coated Si substrates by the CSD technique

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The perspective of the teaching of arts projected by H. Gardner and the National Syllabus Parameters - (arts) of elementary school

In a concise way, the article reports part of the Master of Arts dissertation in Music entitled The meaning of the teaching of Arts in H. Gardner's perspective, presented in the IAUNESP [Arts Institute-State of Sao Paulo University] in 2008. Some considerations on the Statutory Law n. 11.769/08 were added to the original text. The produced research had an exploratory nature and a theoretical mark. Some texts by Howard Gardner, by the psychologist Eliane Leao, as well as the text of the National Syllabus Parameters-Art, from the Department of Elementary Education, served as a foundation for this article. The intended aim was to demonstrate to what extent the pedagogical proposition of the Arts Education projected by H. Gardner is similar to the one proposed by the National Syllabus Parameters, and which would the benefits be in this age group of an artistic sensitizing work for the development of the individual's personality.