Development of paper-based color test-strip for drug detection in aquatic environment: Application to oxytetracycline

The wide use of antibiotics in aquaculture has led to the emergence of resistant microbial species. It should be avoided/minimized by controlling the amount of drug employed in fish farming. For this purpose, the present work proposes test-strip papers aiming at the detection/semi-quantitative determination of organic drugs by visual comparison of color changes, in a similar analytical procedure to that of pH monitoring by universal pH paper. This is done by establishing suitable chemical changes upon cellulose, attributing the paper the ability to react with the organic drug and to produce a color change. Quantitative data is also enabled by taking a picture and applying a suitable mathematical treatment to the color coordinates given by the HSL system used by windows. As proof of concept, this approach was applied to oxytetracycline (OXY), one of the antibiotics frequently used in aquaculture. A bottom-up modification of paper was established, starting by the reaction of the glucose moieties on the paper with 3-triethoxysilylpropylamine (APTES). The so-formed amine layer allowed binding to a metal ion by coordination chemistry, while the metal ion reacted after with the drug to produce a colored compound. The most suitable metals to carry out such modification were selected by bulk studies, and the several stages of the paper modification were optimized to produce an intense color change against the concentration of the drug. The paper strips were applied to the analysis of spiked environmental water, allowing a quantitative determination for OXY concentrations as low as 30 ng/mL. In general, this work provided a simple, method to screen and discriminate tetracycline drugs, in aquaculture, being a promising tool for local, quick and cheap monitoring of drugs.

New molecularly-imprinted polymer for carnitine and its application as ionophore in potentiometric selective membranes

Carnitine (CRT) is a biological metabolite found in urine that contributes in assessingseveral disease conditions, including cancer. Novel quick screening procedures for CRT are therefore fundamental. This work proposes a novel potentiometric device where molecularly imprinted polymers (MIPs) were used as ionophores. The host-tailored sites were imprinted on a polymeric network assembled by radical polymerization of methacrylic acid (MAA) and trimethylpropane trimethacrylate (TRIM). Non-imprinted polymers (NIPs) were produced as control by removing the template from the reaction media. The selective membrane was prepared by dispersing MIP or NIP particles in plasticizer and poly(vinyl chloride), PVC, and casting this mixture over a solid contact support made of graphite. The composition of the selective membrane was investigated with regard to kind/amount of sensory material (MIP or NIP), and the need for a lipophilic additive. Overall, MIP sensors with additive exhibited the best performance, with near-Nernstian response down to ~ 1 × 10− 4 mol L− 1, at pH 5, and a detection limitof ~ 8 × 10− 5 mol L− 1. Suitable selectivity was found for all membranes, assessed by the matched potential method against some of the most common species in urine (urea, sodium, creatinine, sulfate, fructose and hemoglobin). CRT selective membranes including MIP materials were applied successfully to the potentiometric determination of CRT in urine samples.

Specific label-free and real-time detection of oxidized low density lipoprotein (oxLDL) using an immunosensor with three monoclonal antibodies

Increased levels of plasma oxLDL, which is the oxidized fraction of Low Density Lipoprotein (LDL), are associated with atherosclerosis, an inflammatory disease, and the subsequent development of severe cardiovascular diseases that are today a major cause of death in modern countries. It is therefore important to find a reliable and fast assay to determine oxLDL in serum. A new immunosensor employing three monoclonal antibodies (mAbs) against oxLDL is proposed in this work as a quick and effective way to monitor oxLDL. The oxLDL was first employed to produce anti-oxLDL monoclonal antibodies by hybridoma cells that were previously obtained. The immunosensor was set-up by selfassembling cysteamine (Cyst) on a gold (Au) layer (4 mm diameter) of a disposable screen-printed electrode. Three mAbs were allowed to react with N-hydroxysuccinimide (NHS) and ethyl(dimethylaminopropyl)carbodiimide (EDAC), and subsequently incubated in the Au/Cys. Albumin from bovine serum (BSA) was immobilized further to ensure that other molecules apart from oxLDL could not bind to the electrode surface. All steps were followed by various characterization techniques such as electrochemical impedance spectroscopy (EIS) and square wave voltammetry (SWV). The analytical operation of the immunosensor was obtained by incubating the sensing layer of the device in oxLDL for 15 minutes, prior to EIS and SWV. This was done by using standard oxLDL solutions prepared in foetal calf serum, in order to simulate patient's plasma with circulating oxLDL. A sensitive response was observed from 0.5 to 18.0 mg mL 1 . The device was successfully applied to determine the oxLDL fraction in real serum, without prior dilution or necessary chemical treatment. The use of multiple monoclonal antibodies on a biosensing platform seemed to be a successful approach to produce a specific response towards a complex multi-analyte target, correlating well with the level of oxLDL within atherosclerosis disease, in a simple, fast and cheap way.

Os efeitos da intervenção no reconto e nas narrativas de experiência pessoal em crianças de idade pré-escolar

As competências narrativas emergem desde cedo, e vão sendo adquiridas ao longo do desenvolvimento da criança. No entanto não significa que se desenrolam do mesmo modo em todos as crianças pois crianças com dificuldades na produção narrativa poderão ter necessidade de um ensino específico e estruturado. Sendo a narrativa um aspeto importante da linguagem, é fundamental agir o mais cedo possível para prevenir futuros problemas, tanto no percurso académico como social. Tendo por base as questões em torno da produção narrativa, o presente estudo tem como objetivo compreender a influência da intervenção narrativa no reconto e nas narrativas de experiência pessoal em oito crianças do pré-escolar (5/6 anos), estando um dos participantes diagnosticado com uma condição do espetro do autismo. Ao longo do estudo, todos os participantes foram sendo avaliados pela escala Narrative Language Measures durante 10 sessões e quanto à intervenção narrativa denominada Campeões de histórias consistiu em 21 sessões com duração média de 25 minutos. Neste estudo recorremos ao delineamento experimental de linha de base múltipla, o que nos permitiu analisar o desempenho de cada participante ao longo do tempo. Os resultados revelaram que através da intervenção narrativa houve um aumento na cotação dos testes da escala em todos os participantes, inclusive na criança com condição do espetro autista, e que esses se mantiveram sempre acima dos níveis basais após um período de duas semanas sem intervenção. Deste modo, podemos concluir que a intervenção narrativa produziu efeitos relevantes quer no reconto, quer nas narrativas de experiência pessoal dos participantes e que se apresenta como uma intervenção económica, rápida e eficaz.

Label-free Detection of Microcystin-LR in Waters Using Real-Time Potentiometric Biosensors Based on Single-Walled Carbon Nanotubes Imprinted Polymers

Microcystin-LR (MC-LR) is a dangerous toxin found in environmental waters, quantified by high performance liquid chromatography and/or enzyme-linked immunosorbent assays. Quick, low cost and on-site analysis is thus required to ensure human safety and wide screening programs. This work proposes label-free potentiometric sensors made of solid-contact electrodes coated with a surface imprinted polymer on the surface of Multi-Walled Carbon NanoTubes (CNTs) incorporated in a polyvinyl chloride membrane. The imprinting effect was checked by using non-imprinted materials. The MC-LR sensitive sensors were evaluated, characterized and applied successfully in spiked environmental waters. The presented method offered the advantages of low cost, portability, easy operation and suitability for adaptation to flow methods.

Disposable solid state probe for optical screening of chlorpromazine

We are presenting a simple, low-cost and rapid solid-state optical probe for screening chlorpromazine (CPZ) in aquacultures. The method exploits the colourimetric reaction between CPZ and Fe(III) ion that occurs at a solid/liquid interface, the solid layer consisting of ferric iron entrapped in a layer of plasticized PVC. If solutions containing CPZ are dropped onto such a layer, a colour change occurs from light yellow to dark pink or even light blue, depending on the concentration of CPZ. Visual inspection enables the concentration of CPZ to be estimated. The resulting colouration was also monitored by digital image collection for a more accurate quantification. The three coordinates of the hue, saturation and lightness system were obtained by standard image processing along with mathematical data treatment. The parameters affecting colour were assessed and optimized. Studies were conducted by visible spectrophotometry and digital image acquisition, respectively. The response of the optimized probe towards the concentration of CPZ was tested for several mathematical transformations of the colour coordinates, and a linear relation was found for the sum of hue and luminosity. The limit of detection is 50 μM (corresponding to about 16 μg per mL). The probe enables quick screening for CPZ in real water samples with prior sample treatment.

Functional and molecular characterization of SR45, a plant-specific factor involved in sugar and stress signaling in Arabidopsis thaliana

Dissertation presented to obtain the Ph.D degree in Molecular Biology

Performance Analysis of IEEE 802.15.6 Contention-based MAC Protocol

IEEE International Conference on Communications (IEEE ICC 2015). 8 to 12, Jun, 2015, IEEE ICC 2015 - Communications QoS, Reliability and Modeling, London, United Kingdom.

Mutilations Due to Medical Disorders in Children

Soft-tissue and bone necrosis, although rare in childhood, occasionally occur in the course of infectious diseases, either viral or bacterial, and seem to be the result of hypoperfusion on a background of disseminated intravascular coagulation. Treatment consists in correction of septic shock and control of necrosis. Necrosis, once started, shows extraordinarily rapid evolution, leading to soft-tissue and bone destruction and resulting in anatomic, functional, psychological, and social handicaps. Ten mutilated children were treated from January 1986 to January 1999 in Hospital de Dona Estefaˆ nia, Lisbon, Portugal. One was recovering from hemolytic-uremic syndrome with a severe combined immunodeficiency, another malnourished, anemic child had malaria, and three had chicken pox (in one case complicated by meningococcal septicemia). There were three cases of meningococcal and two of pyocyanic septicemia (one in a burned child and one in a patient with infectious mononucleosis). The lower limbs (knee,leg, foot) were involved in five cases, the face (ear, nose, lip) in four, the perineum in three, the pelvis (inguinal region, iliac crest) in two, the axilla in one, and the upper limb (radius, hand) in two. Primary prevention is based on early recognition of risk factors and timely correction. Secondary prevention consists of immediate etiologic and thrombolytic treatment to restrict the area of necrosis. Tertiary prevention relies on adequate rehabilitation with physiotherapy and secondary operations to obtain the best possible functional and esthetic result.

Nitrite biosensing via selective enzymes—a long but promising route

Sensors 2010, 10, 11530-11555

Impacto da Introdução de Baterias de armazenamento de Energia em Smart Grids

De forma a não comprometer o conforto ou a qualidade de vida, nos dias de hoje, é obrigatório que a energia elétrica esteja presente. Sendo indispensável, torna-se necessário assegurar que a sua distribuição seja feita da forma mais qualitativa possível. Uma resposta rápida e eficaz a possíveis falhas que ocorram na rede, irá garantir a tal qualidade de serviço desejada. Para isso, a automatização dos processos é uma grande evolução e objetivo de concretização do setor elétrico. Neste contexto surge o conceito de Smart Grid, que tem como principal objetivo a combinação entre o setor elétrico e a evolução da tecnologia. A par desta característica, estes tipos de redes vêm também trazer evoluções no âmbito ambiental, pois a produção de energia elétrica é feita, maioritariamente, por fontes de energia renovável. Este projeto incide na análise das vantagens técnicas e económicas da inclusão de equipamentos que detêm capacidades de armazenamento de energia, as Baterias de Armazenamento de Energia (BAE), neste tipo de redes. Para tal, procedeu-se à utilização do método do Despacho Económico, que tem como principal objetivo a determinação dos níveis de produção de todas as unidades geradoras do sistema, satisfazendo a carga, ao mais baixo custo de produção. Com este método, foram criados vários cenários de estudo com vista a validar todo o propósito deste projeto. Nesta dissertação, é também realizado um estudo de viabilidade económica destes equipamentos de armazenamento de energia.

Avaliação e Otimização do Consumo de Água no Processo e do Sistema de Tratamento de Efluentes

O elevado consumo de água associado à escassez deste recurso contribuiu para que alternativas de reutilização/reciclagem de água fossem estudadas que permitam diminuir o seu consumo e minimizar a dependência das indústrias. Monitorizar e avaliar os consumos de água, a nível industrial, é imprescindível para assegurar uma gestão sustentável dos recursos hídricos, sendo este o objetivo da presente dissertação. As alternativas encontradas na unidade industrial em estudo foram a substituição do equipamento sanitário e o aproveitamento do efluente tratado para operações de lavagem e/ou arrefecimento por contacto direto. A maioria do equipamento sanitário não é eficiente, tendo-se proposto a substituição desse sistema por um de menor consumo que permitirá uma poupança de 30 % no consumo de água, que corresponderá a 12 149,37 €/ano, sendo o retorno do investimento estimado em 3 meses. O efluente industrial na entrada da ETAR e nas diferentes etapas - tratamento primário de coagulação/floculação; tratamento secundário ou biológico em SBR; tratamento terciário de coagulação/floculação - foi caracterizado através da medição da temperatura, pH, oxigénio dissolvido e pela determinação da cor, turvação, sólidos suspensos totais (SST), azoto total, carência química de oxigénio (CQO), Carência Bioquímica de Oxigénio ao fim de 5 dias (CBO5) e razão CBO5/CQO. Esta caracterização permitiu avaliar o efluente industrial bruto que se caracteriza por um pH alcalino (8,3 ± 1,7); condutividade baixa (451 ± 200,2 μS/cm); elevada turvação (11 255 ± 8812,8 FTU); cor aparente (63 670 ± 42293,4 PtCo) e cor verdadeira (33 621 ± 19547,9 PtCo) elevadas; teores elevados de CQO (24 753 ± 11806,7 mg/L O2) SST (5 164 ± 3845,5 mg/L) e azoto total (718 mg/L) e um índice de biodegradabilidade baixo (razão CBO5/CQO de 1,4). Este estudo permitiu verificar que a eficiência global do tratamento do efluente foi 82 % na remoção da turvação, 83 % na remoção da cor aparente, 96 % na remoção da cor verdadeira, 85 % na remoção da CQO e 30 % na remoção dos SST. Quanto às eficiências de remoção associadas ao tratamento primário no que diz respeito à turvação, cor aparente, CQO e SST, apresentam valores inferiores aos referidos na literatura para o mesmo tipo de tratamento em efluentes similares. As eficiências de remoção obtidas no tratamento secundário são inferiores às do tratamento primário: turvação, cor aparente, CQO e SST, pelo que procurou-se otimizar a primeira etapa do processo de tratamento Neste estudo de otimização estudou-se a influência de cinco coagulantes – Sulfato de Alumínio, PAX XL – 10, PAX 18, cloreto de ferro e a conjugação de PAX 18 com sulfato de ferro - e seis floculantes – Superfloc A 150, Superfloc A 130, PA 1020, Ambifloc 560, Ambifloc C58 e Rifloc 54 - no tratamento físico-químico do efluente. O PAX 18 e o Ambifloc 560 UUJ foram os que apresentaram as mais elevadas eficiências de remoção (99,85 % na cor, 99,87 % na turvação, 90,12 % na CQO e 99,87 % nos SST). O custo associado a este tratamento é de 1,03 €/m3. Pela comparação com os critérios de qualidade no guia técnico ERSAR, apenas o parâmetro da CQO excede o valor, contudo o valor obtido permite diminuir os custos associados a um tratamento posterior para remoção da CQO remanescente no efluente residual tratado.

An immunofluorescence test for diagnosis of ophthalmic herpes in a mouse corneal model

Herpes simplex virus type 1 (HSV-1) ophthalmic disease is the most common cause of corneal blindness in humans world-wide. Current culture techniques for HSV take several days and commercially available HSV laboratory based diagnostic techniques vary in sensitivity. Our study was conducted to evaluate the use of a quicker and simpler method to herpes ophthalmic diagnosis. Corneal smears were made by firm imprints of infected mouse eyes to glass slides, after smears were fixated with cold acetone, and an indirect immunofluorescence (IIF) method was performed using monoclonal antibodies in a murine model of ophthalmic herpes. Eye swabs from infected mice were inoculated in Vero cells for virus isolation. Cytology and histology of the eye were also performed, using hematoxylin-eosin routine. Mouse eyes were examined by slit-lamp biomicroscopy for evidence of herpetic disease at various times postinoculation. We made a comparative evaluation of sensitivity, specificity and speed of methods for laboratory detection of HSV. Our results indicate that this IIF method is quick, sensitive, specific and can be useful in the diagnosis of ophthalmic herpes as demonstrated in an animal model.

Validation of QuEChERS method for organochlorine pesticides analysis in tamarind (Tamarindus indica) products: Peel, fruit and commercial pulp

In this study a citrate-buffered version of QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method for determination of 14 organochlorine pesticides (OCPs) residues in tamarind peel, fruit and commercial pulp was optimized using gas chromatography (GC) coupled with electron-capture detector (ECD) and confirmation by GC tandem mass spectrometry (GC–MS/MS). Five procedures were tested based on the original QuEChERS method. The best one was achieved with increased time in ultrasonic bath. For the extract clean-up, primary secondary amine (PSA), octadecyl-bonded silica (C18) and magnesium sulphate (MgSO4) were used as sorbents for tamarind fruit and commercial pulp and for peel was also added graphitized carbon black (GCB). The samples mass was optimized according to the best recoveries (1.0 g for peel and fruit; 0.5 g for pulp). The method results showed the matrix-matched calibration curve linearity was r2 > 0.99 for all target analytes in all samples. The overall average recoveries (spiked at 20, 40 and 60 μg kg−1) have been considered satisfactory presenting values between 70 and 115% with RSD of 2–15 % (n = 3) for all analytes, with the exception of HCB (in peel sample). The ranges of limits of detection (LOD) and quantification (LOQ) for OCPs were for peel (LOD: 8.0–21 μg kg−1; LOQ: 27–98 μg kg−1); for fruit (LOD: 4–10 μg kg−1; LOQ: 15–49 μg kg−1) and for commercial pulp (LOD: 2–5 μg kg−1; LOQ: 7–27 μg kg−1). The method was successfully applied in tamarind samples being considered a rapid, sensitive and reliable procedure.

Acute postsurgical suppurative parotitis: current prevalence at Hospital das Clínicas, São Paulo University Medical School

Postsurgical acute suppurative parotitis is a bacterial gland infection that occurs from a few days up to some weeks after abdominal surgical procedures. In this study, the authors analyze the prevalence of this complication in Hospital das Clínicas/São Paulo University Medical School by prospectively reviewing the charts of patients who underwent surgeries performed by the gastroenterological and general surgery staff from 1980 to 2005. Diagnosis of parotitis or sialoadenitis was analyzed. Sialolithiasis and chronic parotitis previous to hospitalization were exclusion criteria. In a total of 100,679 surgeries, 256 patients were diagnosed with parotitis or sialoadenitis. Nevertheless, only three cases of acute postsurgical suppurative parotitis associated with the surgery were identified giving an incidence of 0.0028%. All patients presented with risk factors such as malnutrition, immunosuppression, prolonged immobilization and dehydration. In the past, acute postsurgical suppurative parotitis was a relatively common complication after major abdominal surgeries. Its incidence decreased as a consequence of the improvement of perioperative antibiotic therapy and postoperative support. In spite of the current low incidence, we believe it is important to identify risks and diagnose as quick as possible, in order to introduce prompt and appropriate therapeutic measures and avoid potentially fatal complications with the evolution of the disease.