452 research outputs found

    An array of fabry-perot optical-channels for biological fluids analysis

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    This paper describes a biosystem (biological system) used to measure the concentration of biochemical substances in urine, serum, plasma or cerebrospinal fluid. Rather than just one channel, it comprises 16 optical-channels that enable the measurement of the concentration of 16 different biochemical substances. An array of 16 optical filters based on Fabry-Perot thin-films optical resonators has been designed. Each optical-channel is sensitive in a single wavelength with a full-width-half-maximum (FWHM) of 7 nm. The filter fabrication requires only four masks, used with different etch time. A commercially available band-pass optical filter with a band-pass wavelength in 450–650 nm is used. The biosystem requires only a white light source for illumination due the use of selective optical filters.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/1281/2000, POCTI/33747/ESE/1999 – Fundo Europeu para o Desenvolvimento Regional

    Biological microsystem for measuring uric acid in biological fluids

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    This paper describes a biological microsystem (bio-system) for measuring uric acid concentration in serum, plasma or urine. Its operation is based on optical absorption in a well-defined part of the visible spectrum. The bio-system is composed by two dies: one is fabricated in polystyrene and contains the microchannels and the other is fabricated in a CMOS standard process and contains the photodetector and readout electronics. The uric acid concentration is measured by using a mixture of 14µl of infinity™ uric acid reagent with 0.25µl of sample. The achieved sensitivity is 0.33 mg/dl (±0.6% of the value in urine of a healthy person), with a 1mm lightpath. Using an optical absorption method, a maximum peak at wavelength λ = 494 nm, is detected. This bio-system can be included in the group of low-cost disposable devices for biological fluids analysis.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/1281/2000, POCTI/33747/ESE/1999), FEDER

    Biomass allometry and carbon factors for a Mediterranean pine (Pinus pinea L.) in Portugal

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    Forests play an important role in the global carbon balance because they offset a large portion of the carbon dioxide emitted through human activities. Accurate estimates are necessary for national reporting of greenhouse gas inventories, carbon credit trading and forest carbon management but in Portugal reliable and accessible forest carbon measurement methodologies are still lacking for some species. The objective of this study was to provide forest managers with a comprehensive database of carbon factors and equations that allows estimating stand-level carbon stocks in Pinus pinea L. (P. pinea), regardless of the tree inventory information available. We produced aboveground biomass and stem volume equations, biomass expansion factors (BEF) by component as well as wood basic density (WBD) and component carbon fraction in biomass. A root-to-shoot ratio is also presented using data from trees in which the root system was completely excavated. We harvested 53 trees in centre and south Portugal covering different sizes (6.5 to 56.3 cm), ages (10 to 45 years) and stand densities (20 to 580 trees ha–1). The results indicate that aboveground allometry in P. pinea is not comparable with other pines and varies considerably with stand characteristics, highlighting the need to develop stand-dependent factors and equations for local or regional carbon calculations. BEFaboveground decreases from open (1.33 ± 0.03 Mg m–3) to closed stands (1.07 ± 0.01 Mg m–3) due to a change in biomass allocation pattern from stem to branches. Average WBD was 0.50 ± 0.01 Mg m–3 but varies with tree dimensions and the root-to-shoot ratio found was 0.30 ± 0.03. The carbon fraction was statistically different from the commonly used 0.5 factor for some biomass components. The equations and factors produced allow evaluating carbon stocks in P. pinea stands in Portugal, contributing to a more accurate estimation of carbon sequestered by this forest type

    Establishing the design space of a filtration-based operation for the concentration of human pluripotent stem cells

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    Stem cell manufacturing is often very challenging due to the complexity of the biological system. Quality-by-design (QbD), a risk-based framework based on relating process parameters and product quality, can cope with such complexity in process design [1] aiding to develop robust and reproducible unit operations. This work describes a shortcut approach for the design of tangential flow filtration for the concentration of human induced pluripotent stem cells (hiPSC), supported by design of experiments (DoE) approach. First, critical quality attributes (CQA), corresponding to the characteristics that ensure the final product quality, and critical process parameters (CPP), which directly affect cells’ CQA, are identified. Thereafter, a design space is developed, studying how a range of variability in CPP allows to achieve CQA [2]. Thus, CPP of shear rate, permeate flux and cell load were considered, and initially their impact on hiPSC recovery yield and viability responses was studied. A full factorial design confirmed significant interaction effects between all CPP, affecting both responses. The developed statistical model predicted that high shear rate (3000 s-1), permeate flux (250 LMH) and medium cell load (2 x 106 cell/cm2) would maximize both cell recovery yield and viability, where over 80% of hiPSC would be recovered after a volume reduction factor of 20 with high viability (over 93%). Such conditions were validated experimentally, and by performing a robustness analysis, the success rate of these operating conditions was assessed (65 - 70%). A parametric study was then conducted, identifying that increasing the shear rate (up to 3370 s-1) allowed to achieve the specified requirements for cell recovery yield (\u3e 80%) and viability (\u3e 90%) in 100% of the cases and no impact in hiPSC’s CQA in terms of identity, proliferation capacity and pluripotency was observed. References [1] Lipsitz YY et al, Nat. Biotechnol. 2016, 34, 393–400. [2] Food and Drug Administration, Guidance for Industry: Q8(R2) pharmaceutical development. The authors acknowledge iNOVA4Health Research Unit (LISBOA-01-0145-FEDER-007344), and Fundação para a Ciência e Tecnologia (FCT, Portugal) for funding the project CARDIOSTEM (MITP-TB/ECE/0013/2013), and the grants SFRH/BD/51940/2012 (MIT-Portugal), SFRH/BD/51573/2011

    Impactos Nutricionais E Produção De Pimentão Submetido à Deficiência Hídrica

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    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The sweet pepper is a solanaceous plant of American origin with large consumption in Brazil. In order to study the effects of water stress on the sweet pepper crop, an experiment was conducted in greenhouse. The treatments consisted of soil water content (100%, 85%, 70% and 55% of moisture in the soil field capacity) in a randomized block design with 6 replicates where the experimental units consisted of 16 plants. During the experiment (47, 62, 77 and 92 days after planting) levels of macronutrients (N, P, K, Ca, Mg and S) and micronutrients (B, Cu, Fe, Mn and Zn) present in each plant fraction and the dry mass of plants for the accumulation of these determination were determined. At harvest the number, width and length of fruits from each plant were obtained. Variables were subjected to Tukey test at 5% probability. The water content in the soil interfered significantly with productive variables. To the accumulation of nutrients in the dry matter (leaf + stem) the elements with higher absorption are ordered as follows: K> N> Ca> Mg> S> P and Fe>Mn> Zn> B> Cu. © 2016, Universidade Estadual Paulista - UNESP. All rights reserved.214724735CNPq, Conselho Nacional de Desenvolvimento Científico e TecnológicoConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Nonsteroidal anti-inflammatory drug hypersensitivity syndrome. A multicenter study I. clinical findings and in vitro diagnosis

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    ackground: We present the results obtained from the largest series of in vitro diagnostic tests ever reported in patients with clinically validated hypersensitivity to acetylsalicylic acid (ASA)/nonsteroidal anti-infl ammatory drugs (NSAID) compared with various categories of controls tolerating ASA/NSAIDs. This multicenter study, which was performed within the framework of the European Network for Drug Allergy (ENDA) group, showed that the basophil activation test (BAT), particularly when used with the 3 NSAIDs aspirin (ASA), diclofenac (DIC), and naproxen (NAP), allows us to confi rm the diagnosis of NSAID hypersensitivity syndrome. The results of the cellular allergen stimulation test (CAST) frequently correlate with those of the BAT, although not always. An unexpected fi nding was that basophil activation by NSAIDs is not an all-or-nothing phenomenon restricted to clinically hypersensitive patients, but that it also occurs in a dose-related manner in some NSAID-tolerant control individuals. Therefore, NSAID hypersensitivity appears as a shift in the normal pharmacological response to NSAIDs. These fi ndings allow us to formulate a new rational hypothesis about the mechanism of NSAID hypersensitivity syndrome, a mechanism that most authors continue to describe as “unknown.” Methods: We enrolled 152 patients with a history of hypersensitivity to NSAIDs and 136 control participants in 11 different centers between spring 2003 and spring 2006. Flowcytometric BAT was performed. Results: The most noteworthy results of our study were that 57% of 140 patients presented very clear-cut positive BAT results to multiple NSAIDs, and 16% were entirely negative. In about 27% of cases, positive results were obtained with 1 or 2 concentrations of a single NSAID. There is clearly a correlation between the results of BAT and CAST. Conclusions: BAT seems particularly indicated in patients with a clinical history of NSAID intolerance, and in whom a provocation test is not advisable for ethical, clinical, or other reasons

    Efeito da Gliricidia sepium sobre nutrientes do solo, microclima e produtividade do milho em sistema agroflorestal no Agreste Paraibano.

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    Gliricidia sepium é uma leguminosa arbórea que tem sido utilizada em sistemas em aléias no semi-árido nordestino por apresentar bom desenvolvimento em condições de estresse hídrico. Entretanto, há pouca informação disponível sobre o efeito da introdução dessa espécie nos agroecossistemas da região. No presente estudo, objetivou-se avaliar a influência da distância de plantas de Gliricidia sepium sobre características da cultura do milho e do solo e microclima no Agreste Paraibano. O estudo foi realizado no município de Esperança (PB), em área de 0,5 ha, onde, em 1996, foram plantadas fileiras de G. sepium espaçadas 6 m entre si e com 1 m entre as árvores. Nesta área, em 2002, foram delimitadas quatro parcelas de 6 x 8 m e, em cada parcela, foi estabelecido um transeto perpendicular às fileiras de árvores com três posições de amostragem: (1) nas fileiras de árvores (0 m); (2) a 1 m das fileiras de árvores, e (3) a 3 m de distância das fileiras de árvores. O delineamento experimental utilizado foi em blocos casualizados com quatro repetições. A massa seca de folhedo caído embaixo da fileira de árvores foi de 1.390 kg ha-1 e diminuiu, gradativamente, para 270 kg ha-1 a 3 m de distância das árvores. As concentrações de P, K e matéria orgânica leve (MOL) embaixo das árvores foram maiores do que a 1 e 3 m de distância das fileiras. As médias mensais das temperaturas mínimas do ar e do solo embaixo e a 3 m das árvores foram similares. Entretanto, as médias mensais das temperaturas máximas do solo e do ar foram de 6 e 2 °C mais altas a 3 m das árvores, respectivamente, ao longo do período de estudo. A umidade do solo foi significativamente menor embaixo das árvores do que a 1 e 3 m de distância. O milho produziu mais grãos e palha e acumulou mais nutrientes nas posições mais próximas das fileiras de G. sepium
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