Um sistema microcontrolado para o monitoramento on-line, in situ e remoto de pH, condutividade e temperatura de águas

A portable microcontrolled system is proposed to monitor conductivity, temperature and pH in on-line, in situ and remote way from a water reservoir faraway 200 m. The system comprises two modules: one for data reception (located in laboratory) and another for data acquisition/transmission (located near water reservoir). It uses a microcontroller and a transceiver to remote data transmission/reception by radio frequency. Variations of water parameters were simultaneously monitored without interruption during a period of ten hours with a relative error about 4.0 %. The developed system showed simple, stable, accurate, robust and low-cost to determine parameters of water in field

Desenvolvimento de um fluorímetro microcontrolado para determinação de clorofila a em águas superficiais

In this work a portable fluorimeter was developed and used for determination of chlorophyll a in water samples. The instrument was constructed using the following components: a microcontroller (PIC18F4550), two LEDs as light source, a multichannel photodiode (TCS-230) as detector and a digital display. LEDs with maximum emission at 405 and 760 nm were used. The detector is equipped with three internal optical filters inside with maximum sensitivity at 480, 540 and 690 nm besides the possible use without the optical filter with high sensitivity in the visible spectral region with maximum sensitivity at 680 nm. The microcontroller works as central processing unit controlling all components of the instrument by a program previously recorded in its memory eliminating the need of a microcomputer. The fluorimeter was calibrated using standard solutions of fluorescein and rhodamine 6G in HCl 1.0 x 10-5 mol L-1 and performance was compared with a commercial spectrofluorimeter, and the results are in agreement at a confidence level of 95%. A linear response range for fluorescein was obtained between 0.5 and 100.0 x 10-6 mol L-1 and a correlation coefficient of 0.996 and for rhodamine 6G a linear response range between 0.2 and 10.0 x 10-6 mol L-1 was obtained and a correlation coefficient of 0.989. The fluorimeter was used for determination of chlorophyll a in water samples and blue algae culture medium. The results were compared with a spetrophotometric method and were in agreement at a confidence level of 95%. A linear range of between 2.5 and 1333.6 x 10-6 g L-1 for chlorophyll a was obtained with a correlation coefficient of 0.995. The concentration range attend the requirements of CONAMA resolution n° 357 that classifies the water quality covering the concentrations of 10.0, 30.0 and 60.0 x 10-6 g L-1 for different classes of water. The fluorimeter is inexpensive, easy to use shows, low power consumption allowing the feed with batteries, small size (10 cm x 20 cm x 15 cm) and with weight of 0.76 kg. The fluorimeter can be used to determine species with excitation at 405 and or 476 nm and emission across the visible range with excellent performance.Universidade Federal de Sao CarlosNeste trabalho foi desenvolvido um fluorímetro portátil para determinação de clorofila a em águas superficiais. O instrumento foi construído utilizando os seguintes componentes: um microcontrolador (PIC18F4550), dois LEDs como fonte de radiação, um fotodiodo multicanal (TCS-230) como detector e um mostrador digital. Foram utilizados LEDs com máximo de emissão em 405 e 476 nm. O detector utilizado é dotado de três filtros ópticos internos com máximos de transmissão em 480, 540 e 680 nm permitindo, ainda a sua utilização sem os filtros com elevada sensibilidade em toda a região do espectro visível(máximo em torno de 690 nm). O microcontrolador atua como unidade central de processamento sendo todos os componentes do instrumento controlados por ele a partir de um programa previamente gravado em sua memória, dispensando o uso de um microcomputador. O fluorímetro construído foi calibrado utilizando soluções de fluoresceína e rodamina 6G em solução de HCl 1,0 x 10-5 mol L-1 e o desempenho foi comparado com um espectrofluorímetro de bancada, sendo os resultados obtidos concordantes a nível de confiança de 95%. Foi obtida uma faixa de resposta linear para fluoresceína entre 0,5 e 100,0 x 10-6 mol L-1 e um coeficiente de correlação de 0,996 e para rodamina 6G uma faixa linear de resposta entre 0,2 e 10,0 x 10-6 mol L-1 e um coeficiente de correlação de 0,989. A instrumentação desenvolvida foi utilizada para a determinação de clorofila a em amostras de água superficiais e em amostras de meio de cultura de algas azuis e os resultados foram concordantes ao nível de significância de 95 % quando comparados com um método comparativo espectrofotométrico. Para a clorofila a obteve-se uma faixa de concentração entre 2,5 e 1333,6 x 10-6 g L-1 e um coeficiente de correlação linear de 0,995. O intervalo obtido atende à resolução CONAMA n° 357 que dispõe sobre a classificação da qualidade de corpos d água que estabelece as concentrações de 10,0, 30,0 e 60,0 x 10-6 g L-1 para os diferentes tipos de classes de águas. O fluorímetro construído é de baixo custo, de fácil utilização, de baixo consumo de corrente permitindo sua utilização com pilhas ou baterias e de reduzidas dimensões (10 cm x 20 cm x 15 cm) com massa total de 0,76 kg. O fluorímetro pode ser utilizado na determinação de espécies com excitação em 405 e/ou 476 nm e emissão em toda a faixa do visível com excelente desempenho

Development and application of a photometer/fluorometer micro-controlled with led rgb for determination of analytes of analytic interest

In this work, a photometer/fluorometer micro-controlled (P2FM) multifunctional, portable, communicated by USB 2.0, robust, easy handling and with low consumption of energy was developed. The P2FM was built using a micro-controlled (PIC-18F2455) as central unit of process (CPU), two tricolors LEDs (470, 528, 621 nm) as source of radiation, a multichannel sensor (TCS3200) and the management program wrote in Visual Studio. One of the two LED was used as radiation source for photometric mode. The TCS-3200 is a multichannel sensor with four photosensitive tracks: 480, 540, 750 e 830 nm, being that selection of track is performed by program controlled. The management program operates sending functions for microcontroller, record of dates and storage of signal (*.txt) through of USB port 2.0 (5.0 VCC, 300 mA). The P2FM is compact, with 3.5 cm × 7.0 cm × 8.5 cm size and 159.4 g of weight, considered as a portable device. In the program is selected of function mode: photometer or fluorimeter. In the analytic performance test by photometric mode, were used three solutions amaranth (AM), blue light (AB) and tartrazine (TT). The detection limits obtained were 1.6 × 10−7, 5.4 × 10−7 e 1.9 × 10−6 mol L−1 for AM, AB and TT, respectively. The quantification limits obtained were 4.8 × 10−7, 1.6 × 10−6 e 5.9 × 10−6 mol L−1 for AM, AB and TT, respectively. The correlation coefficients were AM = 0.997, AB = 0.975 and TT = 0.994. The analytic performance for fluorometric mode was carried using in both fluorescein (FL) and Rodamine 6G (R6G) solutions, were obtained a detection limit of 8.3 × 10−8 and 4.79 × 10−8 mol L−1, respectively for FL and R6G. The correlations coefficients were 0.997 for FL and 0.999 for R6G. Also, the proposed device was successfully used to sulphite determination in drinks, total hardness in water, determination of stability constant and study of stoichiometry of a chromogenic complex, aiming to show any applications of photometer/fluorimeter. The constant of formation obtained was 5.04 × 1018 is concordant with that presented in previous reports 6.2 × 1018. In sulphite determinations on eight samples of drinks, the paired studen’s t-test showed that reference method and photometric method using P2FM was 0.66 times smaller than critic value (2.36, α = 0.05). The total hardness in water was determined by fluorometric method, being that the P2FM showed best sensibility 8.94 × 106 that a determination using the RF5301/PC spectrofluorometer. The paired studen’s t-test (α = 0.05) no showed significant differences, calculated t (0.36) small than tabulated t (2.01).Não recebi financiamentoUm fotômetro/fluorímetro microcontrolado (P2FM) multifuncional, portátil, comunicado via USB 2.0, robusto, de fácil operação e com baixo consumo de energia foi desenvolvido neste trabalho. O P2FM foi construído utilizando-se um microcontrolador (PIC-18F2455) como unidade central de processamento (CPU), dois LEDs tricolores (470, 528, 621 nm) como fonte de radiação, um sensor multicanal (TCS3200), e o programa de gerenciamento escrito em Visual Studio. Um dos LED foi utilizado como fonte de radiação para o modo fotométrico e o outro para o modo fluorimétrico. O TCS-3200 é um sensor multicanal com quatro faixas fotossensíveis: 480, 540, 750 e 830 nm, sendo que a seleção da faixa é realizada via programa de controle. O programa de gerenciamento atua no envio de funções para o microcontrolador, registro de dados e armazenamento do sinal (*.txt) através da porta USB 2.0 (5,0 VCC, 300 mA). O P2FM é compacto, com dimensões de 3,5 cm × 7,0 cm × 8,5 cm e massa de 159,4 g, configurando-se um instrumento portátil. No programa é selecionado o modo de funcionamento: fotométrico ou fluorimétrico. Nos testes de desempenho analítico no modo fotométrico foram empregadas soluções dos corantes amaranto (AM), azul brilhante (AB) e tartrazina (TT). Os limites de detecção obtidos foram 1,6 × 10, 5,4 × 107 e 1,9 × 106 mol L1 para AM, AB e TT, respectivamente. Os limites de quantificação obtidos foram 4,8 × 107, 1,6 × 10 e 5,9 × 106 mol L1 para AM, AB e TT, respectivamente. Os coeficientes de correlação foram: AM = 0,997, AB = 0,975 e TT = 0,994. O desempenho analítico no modo fluorimétrico foram realizados empregando-se soluções de fluoresceína (FL) e Rodamina 6G (R6G), sendo obtidos um limite de detecção de 8,3 × 108 e 4,79 × 108 mol L1, respectivamente para FL e R6G. Os coeficientes de correlação foram 0,997 para FL e 0,999 para R6G. Ademais, o instrumento proposto foi aplicado com sucesso na determinação de sulfito em bebidas, dureza total em água e determinação da constante de estabilidade e estequiometria de um complexo cromogênico, objetivando mostrar algumas aplicações do fotômetro/fluorímetro. A constante de formação obtida (5,04 × 1018) está em consonância com aquela apresentada na literatura, 6,2 × 1018. Na determinação de sulfito em oito amostras de bebidas, o teste t-pareado mostrou que método de referência e o método fotométrico usando P2FM foi de 0,66 menor do que o valor crítico (2,36, α = 0,05). A dureza da água foi determinada empregando-se o método fluorimétrico, sendo que o P2FM apresentou melhor sensibilidade 8,94 × 106 que a determinada empregandose o espectrofluorímetro (RF5301/PC). O teste t-pareado (α = 0,05) mostrou que não há diferença significativa, t critico (0,36) menor que o t crítico (2,01)

Gene Expression Profiling Specifies Chemokine, Mitochondrial and Lipid Metabolism Signatures in Leprosy

<div><p>Herein, we performed microarray experiments in Schwann cells infected with live <i>M. leprae</i> and identified novel differentially expressed genes (DEG) in <i>M. leprae</i> infected cells. Also, we selected candidate genes associated or implicated with leprosy in genetic studies and biological experiments. Forty-seven genes were selected for validation in two independent types of samples by multiplex qPCR. First, an <i>in vitro</i> model using THP-1 cells was infected with live <i>Mycobacterium leprae</i> and <i>M. bovis</i> bacillus Calmette-Guérin (BCG). In a second situation, mRNA obtained from nerve biopsies from patients with leprosy or other peripheral neuropathies was tested. We detected DEGs that discriminate <i>M. bovis</i> BCG from <i>M. leprae</i> infection. Specific signatures of susceptible responses after <i>M. leprae</i> infection when compared to BCG lead to repression of genes, including <i>CCL2</i>, <i>CCL3</i>, <i>IL8</i> and <i>SOD2</i>. The same 47-gene set was screened in nerve biopsies, which corroborated the down-regulation of <i>CCL2</i> and <i>CCL3</i> in leprosy, but also evidenced the down-regulation of genes involved in mitochondrial metabolism, and the up-regulation of genes involved in lipid metabolism and ubiquitination. Finally, a gene expression signature from DEG was identified in patients confirmed of having leprosy. A classification tree was able to ascertain 80% of the cases as leprosy or non-leprous peripheral neuropathy based on the expression of only <i>LDLR</i> and <i>CCL4</i>. A general immune and mitochondrial hypo-responsive state occurs in response to <i>M. leprae</i> infection. Also, the most important genes and pathways have been highlighted providing new tools for early diagnosis and treatment of leprosy.</p></div

Clustering of differentially expressed genes in nerve biopsies of leprosy and non-leprous patients peripheral neuropathy.

<p>The left graph displays a dendrogram representing the 1D clusterization of genes and the 2D map corresponding to the levels of standardized gene expression profiles (z-score), while the graph on the right displays the three significant clusters (pink, blue and yellow). Red dotted lines in the dendrogram (up-left) indicate weak unions, discouraged by the Bayesian clustering analysis. Values represented in the dendrogram branches correspond to log-odds of the union of corresponding branches. Gray lines in the graphs on the right indicate gene z-scores on leprosy and non-leprous samples, while black solid and dotted lines represent the mean and CI95% of the mean for all genes belonging to each cluster, respectively. Solid pink, blue and yellow lines indicate the mean of all genes in all samples belonging to the leprosy and non-leprous groups.</p

Discrimination between leprosy and non-leprous patients with peripheral neuropathy by combination of LDLR and CCL4 expression.

<p>Graph of a trained classification tree, where rounded rectangles represent internal nodes and hexagons represent terminal nodes. Percentages in each node represent the proportion of specified observations in each group.</p

Gene expression from nerve biopsies from leprosy and non-leprous patients with peripheral neuropathy.

<p>Among the 47-gene set only genes that showed at least a suggestive result (n = 15) are presented. Two-tailed levels of significance less than or equal to 0.01 (**), 0.05 (*) and 0.1 (^.) were considered as “highly significant”, “significant”, and “suggestive”, respectively. A total of 50 samples non-leprous patients (white columns) and 35 samples from leprosy samples (black columns).</p