1,922 research outputs found

    Análise e comparação filogenética de expansinas presentes em Urochloa decumbens cv Basilick.

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    O objetivo deste trabalho foi analisar 4 expansinas de Urochloa decumbens, verificando a similaridade e a homologia delas com as de outras plantas

    Família defensiva de peptídeos antimicrobianos em Urochloa.

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    O capim-braquiária é muito utilizado no Brasil, principalmente no cerrado, como forrageira devido a sua alta adaptabilidade a variados solos, como solos ácidos ou pobres em nutrientes; e apresenta alta cobertura e produção de biomassa. Os peptídeos antimicrobianos são moléculas proteicas pequenas produzidas por todos os seres vivos como parte do sistema imune inato para combater infecções e patógenos. Peptídeos antimicrobianos vegetais possuem um amplo espectro de atividades antimicrobianas contra fitopatógenos e a grande maioria deles é ativa contra fungos, enquanto alguns são inibidores de bactérias e insetos herbívoros. Deste modo, o objetivo deste trabalho foi verificar e identificar a presença de peptídeos antimicrobianos da família das defensinas em U. decumbens por meio da comparação entre as sequências do transcriptoma da planta contra as sequências de aminoácidos de peptídeos antimicrobianos. O transcriptoma da planta foi fornecido pela EMBRAPA Gado de Corte (Campo Grande, MS), obtido pela extração de RNA de plantas expostas a condições de estresse (com alumínio) e sem estresse (sem alumínio). As sequências dos peptídeos antimicrobianos foram baixadas do banco de dados online CAMP e foram formatadas em FASTA em um banco local no computador da FCBA, UFGD. Foi utilizado o blast local para fazer o alinhamento entre os 164.920 transcritos únicos da U. decumbens e as 5.906 sequências de peptídeos antimicrobianos. Deste alinhamento obteve-se 3.161 similaridades com 251 peptídeos diferentes. Para a análise dos resultados utilizou-se o MySQL, separando-os em famílias de acordo com a classificação do banco de dados CAMP e selecionando um grupo amostral para a construção das árvores filogenéticas. A partir desta análise, obteve-se 261 similaridades com 52 peptídeos diferentes dentro da família das defensinas. A maioria dos peptídeos antimicrobianos identificados possui atividade antifúngica ou antimicrobiana, e são de origem vegetal o que condiz com os transcritos da gramínea

    Performances of keystone geometry micro-strip gas chambers

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    Abstract The performances of micro-strip gas chamber detectors with CF 4 counting gas have been tested with a 241 Am α source. The behaviour of the gain as a function of gas pressure, the dependence of the energy resolution on gas pressure and anode voltage, and the gain variation along the strip length due to the keystone geometry of the micro-strip pads are reported. An empirical response function to describe such a position dependence of the gain is proposed

    Universal hydrophilic coating of thermoplastic polymers currently used in microfluidics

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    A number of materials used to fabricate disposable microfluidic devices are hydrophobic in nature with water contact angles on their surface ranging from 80 to over 100. This characteristic makes them unsuitable for a number of microfluidic applications. Both the wettability and analyte adsorption parameters are highly dependent on the surface hydrophobicity. In this article, we propose a general method to coat the surface of five materials: polydimethylsiloxane (PDMS), cyclic olefin copolymer (COC), polyethylene terephthalate (PET), polycarbonate (PC), and polytetrafluoroethylene (PTFE). This fast and robust process, which is easily implementable in any laboratory including microfabrication clean room facilities, was devised by combining gas-phase and wet chemical modification processes. Two different coatings that improve the surface hydrophilicity were prepared via the "dip and rinse" approach by immersing the plasma oxidized materials into an aqueous solution of two different poly(dimethylacrylamide) copolymers incorporating a silane moiety and functionalized with either N-acryloyloxysuccinimide (NAS) (poly(DMA-NAS-MAPS) or glycidyl methacrylate (GMA) (poly(DMA-GMA-MAPS). The coating formation was confirmed by contact angle (CA) analysis comparing the variation of CAs of uncoated and coated surfaces subjected to different aging treatments. The antifouling character of the polymer was demonstrated by fluorescence and interferometric detection of proteins adsorbed on the surafce. This method is of great interest in microfluidics due to its broad applicability to a number of materials with varying chemical compositions

    Physical Activity Classification for Elderly People in Free Living Conditions

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    Physical activity is strongly linked with mental and physical health in the elderly population and accurate monitoring of activities of daily living (ADLs) can help improve quality of life and well-being. This study presents and validates an inertial sensors-based physical activity classification system developed with older adults as the target population. The dataset was collected in free living conditions without placing constraints on the way and order of performing ADLs. Four sensor locations (chest, lower back, wrist, and thigh) were explored to obtain the optimal number and combination of sensors by finding the best tradeoff between the system's performance and wearability. Several feature selection techniques were implemented on the feature set obtained from acceleration and angular velocity signals to classify four major ADLs (sitting, standing, walking, and lying). Support vector machine was used for the classification of the ADLs. The findings show the potential of different solutions (single-sensor or multi-sensor) to correctly classify the ADLs of older people in free living conditions. Considering a minimal set-up of a single sensor, the sensor worn at the L5 achieved the best performance. A two-sensor solution (L5 + thigh) achieved a better performance with respect to a single-sensor solution. On the other hand, considering more than two sensors did not provide further improvements. Finally, we evaluated the computational cost of different solutions and it was shown that a feature selection step can reduce the computational cost of the system and increase the system performance in most cases. This can be helpful for real-time applications
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