125 research outputs found
Proposta para automatizar o mapa de telefonema interurbano para a Embrapa.
O objetivo deste trabalho é descrever uma proposta de Mapas de Telefonemas Interurbanos (MTIs) automatizada, a qual foi implementada com sucesso na Embrapa Informática Agropecuária e pode, com algumas adaptações, servir para outras unidades da Embrapa usarem.bitstream/CNPTIA/9873/1/comuntec19.pdfAcesso em: 29 maio 2008
Produção de lipase a partir de Candida rugosa NRRL Y-95 utilizando meio de cultura contendo resíduos agroindustriais
As lipases (E.C. 3.1.1.3) são um grupo de enzimas capazes de catalisar a
hidrólise da ligação éster de triacilgliceróis, gerando ácidos graxos livres e glicerol. As
lipases microbianas são muito utilizadas nas aplicações industriais nas áreas de
alimentos, síntese orgânica e farmacêutica. Neste trabalho, visando à produção de lipase
a partir da levedura Candida rugosa foram utilizados meios de cultura alternativos
compostos por melaço, milhocina e águas russas. As fermentações foram conduzidas em
agitador rotatório a 30 °C e 170 rpm. Testaram-se quatro meios contendo diferentes
combinações dos resíduos acima mencionados. O meio contendo melaço 10 g/L,
milhocina 4 g/L e águas russas 1,0 %(v/v) foi o que propiciou a produção de enzima com
maior atividade intracelular 269 ± 10 U/L frente ao substrato pNFL (p-nitrofenil laurato).
Esses resultados demonstram que o referido meio alternativo contendo resíduos
agroindustriais é adequado para a produção de lipase
Two-step purification of epilactose produced by cellobiose 2-epimerase from Caldicellulosiruptor saccharolyticus
Epilactose is a functional sugar that can be produced from lactose using cellobiose 2-epimerase and it is considered a developing prebiotic. In that sense, the development of strategies to produce and purify epilactose is key for its wider use in the food industry. The aim of this work was to establish a food-grade purification strategy suitable to be scaled-up to an industrial level. Firstly, the epilactose was produced by enzymatic epimerization of lactose in a reaction catalyzed by the recombinant cellobiose 2-epimerase from Caldicellulosiruptor saccharolyticus produced by Saccharomyces cerevisiae. Then, to remove the unreacted lactose, a screening study was performed to find a suitable -galactosidase enzyme with high lactose hydrolysis capacity but low ability to convert the epilactose. The elimination of the generated monosaccharides was then attempted by microbial treatment using different microorganisms and using activated charcoal. The bakers yeast S. cerevisiae was proven to be the most suitable microorganism for glucose and galactose removal from the reaction mixture. Overall, an attractive and food-grade two-step process for epilactose recovery was established, resulting in a purity and yield of 87% and 76.4%, respectively. Additionally, the INFOGEST 2.0 static in vitro simulation of gastrointestinal food digestion was used, for the first time, to assess the resistance of epilactose (77% resistance) to the upper gastrointestinal tract conditions, reinforcing its potential to be used as prebiotic.BBC and JMF acknowledge their doctoral grants (SFRH/BD/
132324/2017 and SFRH/BD/147286/2019, respectively) from the
Portuguese Foundation of Science and Technology (FCT). This study was
supported by FCT under the scope of the strategic funding of UIDB/
04469/2020 unit.info:eu-repo/semantics/publishedVersio
Smart optical sensors for internet of things: integration of temperature monitoring and customized security physical unclonable functions
Nowadays, the Internet of Things (IoT) has an astonishingly societal impact in which healthcare
services stand out. Amplified by the COVID-19 pandemic scenario, challenges include the development
of authenticatable smart IoT devices with the ability to simultaneously track people and sense in realtime human body temperature aiming to infer a health condition in a contactless and remote way through
user-friendly equipment such as a smartphone. Univocal smart labels based on quick response (QR) codes
were designed and printed on medical substrates (protective masks and adhesive) using flexible organicinorganic luminescent inks. Luminescence thermometry and physical unclonable functions (PUFs) are
simultaneously combined allowing non-contact temperature detection, identification, and connection with
the IoT environment through a smartphone. This is an intriguing example where luminescent inks based
on organic-inorganic hybrids modified by lanthanide ions are used to fabricate a smart label that can sense
temperature with remarkable figures of merit, including maximum thermal sensitivity of Sr = 1.46 %K−1
and temperature uncertainty of δT = 0.2 K, and an authentication methodology accuracy, precision, and
recall of 96.2%, 98.9%, and 85.7%, respectively. The methodology proposed is feasibly applied for the
univocal identification and mobile optical temperature monitoring of individuals, allowing the control of the
access to restricted areas and the information transfer to medical entities for post medical evaluation towards
a new generation of mobile-assisted eHealth (mHealth).publishe
Functional mobile-based two-factor authentication by photonic physical unclonable functions
Given the rapid expansion of the Internet of Things and because of the concerns around counterfeited goods, secure and resilient cryptographic systems are in high demand. Due to the development of digital ecosystems, mobile applications for transactions require fast and
reliable methods to generate secure cryptographic keys, such as Physical Unclonable Functions (PUFs). We demonstrate a compact and
reliable photonic PUF device able to be applied in mobile-based authentication. A miniaturized, energy-efficient, and low-cost token was
forged of flexible luminescent organic–inorganic hybrid materials doped with lanthanides, displaying unique challenge–response pairs (CRPs)
for two-factor authentication. Under laser irradiation in the red spectral region, a speckle pattern is attained and accessed through conventional charge-coupled cameras, and under ultraviolet light-emitting diodes, it displays a luminescent pattern accessed through hyperspectral
imaging and converted to a random intensity-based pattern, ensuring the two-factor authentication. This methodology features the use of
a discrete cosine transform to enable a low-cost and semi-compact encryption system suited for speckle and luminescence-based CRPs.
The PUF evaluation and the authentication protocol required the analysis of multiple CRPs from different tokens, establishing an optimal
cryptographic key size (128 bits) and an optimal decision threshold level that minimizes the error probability.publishe
The effect of salts on the liquid–liquid phase equilibria of PEG600 + salt aqueous two-phase systems
Six new ATPSs were prepared by combining polyethylene glycol PEG600 with potassium citrate, dipotassium hydrogen phosphate, sodium formate, potassium formate, sodium sulfate, and lithium sulfate. Complete phase diagrams, including the binodal curve and three tie-lines, were determined at 23 °C. The experimental data obtained for the binodal curve were successfully adjusted to the Merchuk equation, and the reliability of tie-line data was confirmed using the equations suggested by Othmer–Tobias and Bancroft. The ability of each ion to induce ATPS formation was investigated. Na+ proved to be more effective in ATPS formation than K+ and Li+. For potassium salts, the order observed for the effectiveness of the anions was: HPO42– > C6H5O73– > HCO2–. Regarding the sodium salts, it was found that SO42– is clearly more effective than HCO2–. The position of the ions in the Hofmeister series and their free energy of hydration (ΔGhyd) were used to explain the ability of the ions to induce PEG salting-out. Furthermore, the effective excluded volume (EEV) of the salts was determined and the following order was found: Na2SO4 > K2HPO4 > Li2SO4 > K3C6H5O7 > NaCHO2 > KCHO2. Similar order was obtained when analyzing the size of the heterogeneous regions, suggesting the practical use of EEV as a comparison parameter between different ATPSs.This work is partially supported by project PEst-C/EQB/LA0020/2011, financed by FEDER through COMPETE-Programa Operacional Factores de Competitividade and by FCT-Fundacao para a Ciencia e a Tecnologia. Sara Silverio acknowledges her Ph.D. grant from FCT (SFRH/BD/43439/2008)
Aplicação de marcadores moleculares na conservação e melhoramento de um rebanho da raça Santa Inês.
0 objetivo deste trabalho foi caracterizar a distribuiçao da variabilidade genetica dentro de um Nucleo de Conservaçao da raça Santa Ines a partir do usa de marcadores moleculares. Foram utilizados 17 locos em 191 individuos do rebanho de Santa Ines da Embrapa Tabuleiros Costeiros, Sergipe. Os resultados obtidos mostraram que existe variabilidade genetica significativa existente dentro do nucleo com valores de Heterezigosidade media observada de 0,702 e de conteudo de informaçao polimorfica (PIC) de 0,704. Outras analises intrapopulacionais mostraram que 29% dos locos analisados nao estao em Equilfbrio de Hardy-Weinberg (p<0,01) e apresentaram excesso de homozigotos (p<0,05). A partir do fndice de proporçao de alelos compartilhados entre todos os individuos analisados, foi feito um dendrograma para estimar quais seriam os animais mais proximos ou mais distantes dentro do rebanho, com especial atençao para os 10 machos reprodutores. Tres agrupamentos principais foram identificados e em todos existe pelo menos um reprodutor do rebanho. Esse tipo de analise e importante, pais ira auxiliar o manejo reprodutivo do rebanho bem com servira de ferramenta complementar para os programas de melhoramento classico que se iniciaram dentro deste Nucleo de Conservaçao
AVALIAÇÃO DA INFLUÊNCIA DA VARIABILIDADE DE ÓLEOS NO MICROENCAPSULAMENTO DE FÁRMACOS HIDROFÍLICOS DE BAIXO PESO MOLECULAR POR EMULSIFICAÇÃO A/O
A obtenção de micropartículas por técnicas de emulsificação assumiu grande relevância para o microencapsulamento de fármacos hidrofílicos. O trabalho avalia o uso de diferentes óleos vegetais para o processo de obtenção de micropartículas por emulsificação a/o e observa sua influência no encapsulamento de fármacos de baixo peso molecular
Evaluation of the BAX® system for the detection of Salmonella spp. in naturally contaminated chicken meat
Avaliação do apoio social e da auto-estima por indivíduos coronariopatas, segundo o sexo
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