126 research outputs found
Predominance of Rotavirus P[4]G2 in a Vaccinated Population, Brazil
We identified 21 rotaviruses in 129 patients with diarrhea in a Brazilian city with high rotavirus vaccine coverage. All rotaviruses were genotype P[4]G2 with 1 mixed infection with P[NT]G9. Although virus predominance could have occurred randomly, the vaccine may be less protective against P[4]G2. Prospective surveillance is urgently needed
Characterization at 25°C of Sodium Hyaluronate in Aqueous Solutions Obtained by Transport Techniques
Mutual diffusion coefficients, D, were determined for aqueous solutions of sodium hyaluronate (NaHy) at 25°C and concentrations ranging from 0.00 to 1.00 g·dm-3 using the Taylor dispersion technique. From these experimental data, it was possible to estimate some parameters, such as the hydrodynamic radius Rh, and the diffusion coefficient at infinitesimal concentration, D0, of hyaluronate ion, permitting us to have a better understanding of the structure of these systems of sodium hyaluronate in aqueous solutions. The additional viscosity measurements were done and Huggins constant, kH, and limiting viscosity number, [η], were computed for interaction NaHy/water and NaHy/NaHy determination. © 2015, MDPI AG. All rights reserved.PTDC/AAC-CLI/118092/2010, FCT, Fuel Cycle TechnologiesFCT [PTDC/AAC-CLI/118092/2010]; Coimbra Chemistry Centre from the FCT [Pest-OE/QUI/UI0313/2014]; Centre of Polymer Systems [CZ.1.05/2.1.00/03.0111]; TBU in Zlin - specific university research and national budget of Czech Republic [IGA/FT/2013/015, IGA/FT/2014/018]; [SFRH/BD/72305/2010
Immobilization of L-asparaginase towards surface-modified carbon nanotubes
L-asparaginase (LA) is an enzyme that catalyzes L-asparagine hydrolysis into L-aspartic
acid and ammonia and is mainly applied in pharmaceutical and food industries. The LA
currently commercialized for pharmaceutical purposes is produced from two main
bacterial sources: recombinant Escherichia coli and Erwinia chrysanthemi. However,
some disadvantages are associated with its free form, such as the shorter half-life.
Immobilization of LA has been proposed as an efficient approach to overcome this
limitation. In this work, a straightforward method, including the functionalization of
multi-walled carbon nanotubes (MWCNTs) through a hydrothermal oxidation treatment
and the immobilization of LA by adsorption over pristine and modified MWCNTs was
investigated. Different operation conditions, including pH, contact time,
ASNase/MWCNT mass ratio, and the operational stability of the immobilized LA, were
evaluated. The characterization of the LA-MWCNT bioconjugate was addressed using
different techniques, namely Transmission Electron Microscopy (TEM),
Thermogravimetric analysis (TGA), and Raman spectroscopy. Functionalized MWCNTs showed promising results, with an immobilization yield and a relative recovered activity
of commercial LA above 95%, under the optimized adsorption conditions (pH 8, 60 min
of contact, and 1.510–3
g.mL-1
of LA). The LA-MWCNT bioconjugate also showed
improved enzyme operational stability (6 consecutive reaction cycles without activity
loss), proving its suitability for application in industrial processes.publishe
Immobilization of L-asparaginase towards surface-modified carbon nanotubes
L-asparaginase (ASNase, EC 3.5.1.1) is an enzyme that catalyzes L-asparagine hydrolysis into L-aspartic acid and
ammonia and is mainly applied in pharmaceutical and food industries [1]. The ASNase currently commercialized for pharmaceutical purposes is produced from two main bacterial sources: recombinant Escherichia coli
and Erwinia chrysanthemi. However, some disadvantages are associated with its free form, such as the shorter
half-life [2]. Immobilization of ASNase has been proposed as an efficient approach to overcome this limitation
[3]. In this work, a straightforward method, including the functionalization of multi-walled carbon nanotubes
(MWCNTs) through a hydrothermal oxidation treatment with nitric acid, and the immobilization of ASNase
by adsorption over pristine and modified MWCNTs was investigated. Different operation conditions, including pH, contact time, ASNase/MWCNT mass ratio, and the operational stability of the immobilized ASNase were
evaluated. The characterization of the ASNase-MWCNT bioconjugate was addressed using different techniques,
namely Transmission Electron Microscopy (TEM), Thermogravimetric analysis (TGA), and Raman spectroscopy.
Functionalized MWCNTs showed promising results, with an immobilization yield and a relative recovered activity of commercial ASNase above 95%, under the optimized adsorption conditions (pH 8, 60 min of contact
and 1.5´10–3 g.mL-1of ASNase). The ASNase-MWCNT bioconjugate also showed improved enzyme operational
stability (6 consecutive reaction cycles without activity loss), proving its suitability for application in industrial
processes.publishe
Predominance of rotavirus P[4]G2 in a vaccinated population, Brazil
We identified 21 rotaviruses in 129 patients with diarrhea in a Brazilian city with high rotavirus vaccine coverage. All rotaviruses were genotype P[4]G2 with 1 mixed infection with P[NT]G9. Although virus predominance could have occurred randomly, the vaccine may be less protective against P[4]G2. Prospective surveillance is urgently needed
Eficiência reprodutiva de matrizes bovinas de corte submetidas a três diferentes tipos de suplementação mineral
Piauí de plantas e gentes: Construção de coleções de referência de plantas úteis/econômicas como base para estudos arqueobotânicos.
Museum Studie
Efeito do armazenamento na compatibilidade de fungicidas e inseticidas, associados ou não a um polímero no tratamento de sementes de feijão
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