Dari de Oliveira Toginho Filho

A Low-Cost NIR Digital Photometer Based on InGaAs Sensors for the Detection of Milk Adulterations With Water

The adulteration of milk with water is a very common problem, which reduces its nutritional value and industrial yield, and can also represent a major risk of contamination. The standard method for detecting this kind of fraud is the cryoscopy, which fails when the adulteration is done along with other substances. Therefore, there is a need for new and more robust techniques for this purpose. With this goal, we propose a prototype of a digital photometer to quantify water added to milk. This is a microcontrolled, portable device, which uses three LEDs with emission in the near-infrared (IR) region and was developed without the use of lenses, filters, or moving parts. This equipment measures the transmittance of IR radiation through milk samples to assess the addition of water. In this paper, we present the results of experiments that were conducted with diluted milk samples containing 0%-25% of added water, using the proposed equipment and the standard method of cryoscopy. In the measurements of the percentage of added water, the mean absolute error was <;1%. In terms of repeatability, in two sets of ten measurements, we obtained absolute deviations from the average corresponding to less than 0.7% of added water. Results show that the prototype response is similar to the one of a commercial cryoscope but faster.

Effects of light on biological systems.

Although nowadays light sources such as LASERs (Light Amplification by Stimulated Emission of Radiation) and LEDs (Light Emitting Diodes) are largely used in several therapeutic areas, the scientific basis of their effects on biological systems still is relatively unknown by the academic community. In this study, a brief revision about effects of light on biological systems is presented. Low power light sources such as LEDs may be used as an alternative therapeutic method or be used associated to the conventional methods, having the advantage of being a low cost method and of proven efficiency in the treatment of ulcers and other diseases.

Light-emitting diodes at 940 nm attenuate colitis-induced inflammatory process in mice

Inflammatory bowel disease (IBD) presents intense inflammatory infiltrate, crypt abscesses, ulceration and even loss of function. Despite the clinical relevance of IBD, its current therapy remains poorly effective. Infrared wavelength phototherapy shows therapeutic potential on inflammation. Our goal was to evaluate whether light-emitting diodes (LED) at 940nm are capable of mitigating the colitis-induced inflammatory process in mice. Forty male Swiss mice were assigned into five groups: control; control treated with LED therapy; colitis without treatment; colitis treated with LED therapy; colitis treated with Prednisolone. Experimental colitis was induced by acetic acid 7.5% (pH2.5) rectal administration. LED therapy was performed with light characterized by wavelength of 940nm, 45nm bandwidth, intensity of 4.05J/cm(2), total power of 270mW and total dose of 64.8J for 4min in a single application. Colitis-induced intestinal transit delay was inhibited by LED therapy. Colitis caused an increase of colon dimensions (length, diameter, total area) and colon weight (edema), which were inhibited by LED therapy. LED therapy also decreased colitis-induced tissue gross lesion, myeloperoxidase activity, microscopic tissue damage score and the presence of inflammatory infiltrate in all intestinal layers. Furthermore, LED therapy inhibited colitis-induced IL-1β, TNF-α, and IL-6 production. We conclude LED therapy at 940nm inhibited experimental colitis-induced colon inflammation in mice, therefore, rendering it a promising therapeutic approach that deserves further investigation.

Effects of near-infrared LED therapy on experimental tooth replantation in rats.

BACKGROUND/AIM Dental avulsion damages periodontal tissues and may induce dentoalveolar ankylosis and root resorption after replantation. The aim of this work was to evaluate the effects of light-emitting diode (LED) therapy after tooth replantation. MATERIAL AND METHODS The upper right incisors of 36 male Wistar rats were extracted and replanted after 15 min. The control group (Co, n = 18) was submitted to replantation and the LED group (n = 18) was submitted to replantation and LED therapy (940 nm, 4 J cm-2 ) for three consecutive days (0, 24, and 48 h). Six animals from each group were euthanized at 7, 14, and 21 days for histological analysis. The upper left incisors were used as a negative control. Data were compared using the Fisher exact test, considering P < 0.05. RESULTS After 7 days, the Co (73.3%) and LED (72.2%) groups presented areas of periodontal ligament necrosis. However, periodontal ligament necrosis was more frequent in the LED group at 14 (70%, P < 0.05) and 21 days (43.2%, P < 0.05) in relation to the Co group (33 and 21.6%). Inflammatory cell infiltration was more frequent in the Co group at 7 days (100%) than the LED group (24.4%, P < 0.05), but increased in the LED group after 21 days (83.3%, P < 0.05). Bone necrosis was more frequent in the LED group after 14 (79%, P < 0.05) and 21 days (60%, P < 0.005) than in the Co group (45% and 20%). Bone repair was evident in the Co group at 14 days. All of the replanted teeth had pulp necrosis. CONCLUSION The results suggest that the application of LED therapy up to 48 h after tooth replantation may delay periodontal ligament repair.

Effects of light-emitting diodes phototherapy on autonomic modulation of footballers

O objetivo do estudo foi verifi car o efeito da fototerapia com diodos emissores de luz (LED fototerapia) durante uma semana de treinamento sobre a modulacao parassimpatica e estresse percebido em atletas de futebol. Fizeram parte da amostra 18 atletas (Idade: 21,2 ± 2,6 anos; Peso: 73 ± 7,2 kg; Estatura: 178,0 ± 6,2 cm.). Pre e apos uma semana de pre-temporada foram realizadas coletas da frequencia cardiaca de repouso e a avaliacao subjetiva de estresse e recuperacao foi obtida por meio do “daily analysis of life demands for athletes” (DALDA). Os atletas foram aleatorizados em dois grupos, com nove atletas cada, grupo LED fototerapia (LED) e grupo placebo (PLA). O tratamento foi aplicado nos membros inferiores nos musculos do quadriceps e biceps femoral todos os dias apos a ultima sessao de treinamento. A aplicacao foi realizada de maneira “duplo cego”. ANCOVA de medidas repetidas foi utilizada para verifi car o efeito do tratamento sobre modulacao autonomica. O treinamento realizado por ambos os grupos foi o mesmo tanto em duracao quanto intensidade. Da mesma forma, nao houve diferenca entre os grupos nos parâmetros de carga interna. Foi observado efeito da semana nos parâmetros media dos intervalos RR (Rrmedio - LED: pre = 1033,4 ± 150,7 ms pos = 1056,7 ± 114,8 ms; PLA: pre = 962 ± 150,8 ms pos = 1016,8 ± 173,5 ms), desvio padrao dos intervalos RR normais (SDNN - LED: pre = 101 ± 37,3 ms pos = 92,3 ± 27,5 ms; PLA: pre = 97,5 ± 34,9 ms pos = 108,7 ± 16,4 ms), e razao baixa e alta frequencia (LF/HF - LED: pre = 1,7 ± 0,7 pos = 1,4 ± 0,6; PLA: pre = 3,7 ± 3,4 pos = 3,4 ± 2,1) para ambos os grupos. Alem disso, houve pequenas alteracoes nas fontes (pre = 1 ± 1; pos = 0 ± 1) e sintomas (‘melhor que normal’ pre = 5 ± 1; pos = 4 ± 4; ‘normal’ pre = 19 ± 7; pos = 21 ± 3) do DALDA para o grupo LED. A LED fototerapia nao apresentou efeito sobre a modulacao autonomica, mas proporcionou pequenas alteracoes nas fontes e sintomas de estresse.O objetivo do estudo foi verifi car o efeito da fototerapia com diodos emissores de luz (LED fototerapia) durante uma semana de treinamento sobre a modulacao parassimpatica e estresse percebido em atletas de futebol. Fizeram parte da amostra 18 atletas (Idade: 21,2 ± 2,6 anos; Peso: 73 ± 7,2 kg; Estatura: 178,0 ± 6,2 cm.). Pre e apos uma semana de pre-temporada foram realizadas coletas da frequencia cardiaca de repouso e a avaliacao subjetiva de estresse e recuperacao foi obtida por meio do “daily analysis of life demands for athletes” (DALDA). Os atletas foram aleatorizados em dois grupos, com nove atletas cada, grupo LED fototerapia (LED) e grupo placebo (PLA). O tratamento foi aplicado nos membros inferiores nos musculos do quadriceps e biceps femoral todos os dias apos a ultima sessao de treinamento. A aplicacao foi realizada de maneira “duplo cego”. ANCOVA de medidas repetidas foi utilizada para verifi car o efeito do tratamento sobre modulacao autonomica. O treinamento realizado por ambos os grupos foi o mesmo tanto em duracao quanto intensidade. Da mesma forma, nao houve diferenca entre os grupos nos parâmetros de carga interna. Foi observado efeito da semana nos parâmetros media dos intervalos RR (Rrmedio - LED: pre = 1033,4 ± 150,7 ms pos = 1056,7 ± 114,8 ms; PLA: pre = 962 ± 150,8 ms pos = 1016,8 ± 173,5 ms), desvio padrao dos intervalos RR normais (SDNN - LED: pre = 101 ± 37,3 ms pos = 92,3 ± 27,5 ms; PLA: pre = 97,5 ± 34,9 ms pos = 108,7 ± 16,4 ms), e razao baixa e alta frequencia (LF/HF - LED: pre = 1,7 ± 0,7 pos = 1,4 ± 0,6; PLA: pre = 3,7 ± 3,4 pos = 3,4 ± 2,1) para ambos os grupos. Alem disso, houve pequenas alteracoes nas fontes (pre = 1 ± 1; pos = 0 ± 1) e sintomas (‘melhor que normal’ pre = 5 ± 1; pos = 4 ± 4; ‘normal’ pre = 19 ± 7; pos = 21 ± 3) do DALDA para o grupo LED. A LED fototerapia nao apresentou efeito sobre a modulacao autonomica, mas proporcionou pequenas alteracoes nas fontes e sintomas de estresse.

Anemometer 3D Based on Ultrasound

The environmental variables influence in the development of plants and animals. One of these variables is the wind, which can be responsible to change the growing of plants and spread diseases. Therefore, the measure of wind speed is necessary to agriculture. Usually, such measuring is done by use of anemometers working with wind cocks which work in only two dimensions, measuring the wind speed and direction by a mechanical system. One disadvantage of this approach is the existence of mobile parts which does not render accurate speed measures, due to air friction and equipment inertia. In this work, an ultrasonic anemometer which measures the direction and speed of the air in three dimensions is presented. Such anemometer use only four piezoelectric sensors arranged in two orthogonal axes non-competitors. So that, joining together the points of each sensor it was get a structure in the form of a regular tetrahedron. The wind speed in three directions can be measured inferring the necessary time (transit time) so that a pulse of ultrasound, sent for one of the sensors, reaches the others three. Moreover, the tetrahedron-shaped structure allows to measure in four different coordinate systems. This adds redundancy to the system so that a better precision in the measures can be achieved. This measurement is performed by a microcontroller and is done to make the system immune to variations of temperature and air humidity. The microcontroller is also responsible for storage of data and later sending them to a microcomputer.