Microfluidic smartphone quantitation of <i>Escherichia coli</i> in synthetic urine

In spite of the clinical need, there is a major gap in rapid diagnostics for identification and quantitation of E. coli and other pathogens, also regarded as the biggest bottleneck in the fight against the spread of antimicrobial resistant bacterial strains. This study reports for the first time an optical, smartphone-based microfluidic fluorescence sandwich immunoassay capable of quantifying E. coli in buffer and synthetic urine in less than 25 min without sample preparation nor concentration. A limit of detection (LoD) up to 240 CFU/mL, comensurate with cut-off for UTIs (103-105 CFUs/mL) was achieved. Replicas of full response curves performed with 100-107 CFUs/mL of E. coli K12 in synthetic urine yielded recovery values in the range 80-120%, assay reproducibility below 30% and precision below 20%, therefore similar to high-performance automated immunoassays. The unrivalled LoD was mainly linked to the 'open fluidics' nature of the 10-bore microfluidic strips used that enabled passing a large volume of sample through the microcapillaries coated with capture antibody. The new smartphone based test has the potential of being as a rapid, point-of-care test for rule-in of E. coli infections that are responsible for around 80% of UTIs, helping to stop the over-prescription of antibiotics and the monitoring of patients with other symptomatic communicable diseases caused by E. coli at global scale.</p

Concentration of tea extracts by osmotic evaporation: optimisation of process parameters and effect on antioxidant activity

In this work, the concentration process of three different tea extracts (medicinal Rosil No. 6, Black, and Forest Fruit teas) using the osmotic evaporation (OE) process, was studied. The effect of the OE process on the content of phenolic compounds and antioxidant activity was evaluated. The concentration process was carried out in a hollow-fibre membrane contactor with an effective surface area of 0.54 m2. The tea extract was circulated through the shell side of the contactor, while a concentrated osmotic solution (CaCl2 5 M) was circulated inside the fibres. The flux, the driving force, and the mass transfer coefficient were evaluated. A decrease of the water flux over time was observed and was attributed only to the decrease of the driving force, caused by the dilution of the osmotic solution. Using a surface area/feed volume ratio of 774 m2 m3, it is possible to reach a tea concentration of 40% (w/w) in 5 h, with a constant water flux and without losing the phenolic content and antioxidant potential in most teasinfo:eu-repo/semantics/publishedVersio

The role of bacteria in pine wilt disease: insights from microbiome analysis.

Pine Wilt Disease (PWD) has a significant impact on Eurasia pine forests. The microbiome of the nematode (the primary cause of the disease), its insect vector, and the host tree may be relevant for the disease mechanism. The aim of this study was to characterize these microbiomes, from three PWD-affected areas in Portugal, using Denaturing Gradient Gel Electrophoresis, 16S rRNA gene pyrosequencing, and a functional inference-based approach (PICRUSt). The bacterial community structure of the nematode was significantly different from the infected trees but closely related to the insect vector, supporting the hypothesis that the nematode microbiome might be in part inherited from the insect. Sampling location influenced mostly the tree microbiome (P < 0.05). Genes related both with plant growth promotion and phytopathogenicity were predicted for the tree microbiome. Xenobiotic degradation functions were predicted in the nematode and insect microbiomes. Phytotoxin biosynthesis was also predicted for the nematode microbiome, supporting the theory of a direct contribution of the microbiome to tree-wilting. This is the first study that simultaneously characterized the nematode, tree and insect-vector microbiomes from the same affected areas, and overall the results support the hypothesis that the PWD microbiome plays an important role in the disease's development

Vegetable proteins and milk puddings

In recent years, interest in animal free foods has increased tremendously due to factors like BSE crisis, rise of nutritionally dependent illnesses, like diabetes type II, cardiovascular and digestive diseases, along with ethic orientations of denying animal intakes of any kind. The use of proteins from leguminous seeds as an alternative to the animal proteins in dairy desserts was studied. Lupin, pea and soya protein isolates were used in combination with k- carrageenan, gellan and xanthan gum, in order to obtain a synergistic effect. Milk puddings were also produced for comparison. Texture studies suggested that mixed protein /polysaccharide systems, with vegetable proteins and k- carrageenan or gellan gum, would be good systems to develop vegetable gelled desserts. Rheological oscillatory measurements were carried out to clarify the kinetics of gelation and characterise the microstructure of the best performing products. Results from time sweep tests showed that formulations with gellan gum present an industrial advantage over formulations with k-carrageenan, since the maturation time for gellan gels is of the order of 5 /10 h compared with 4 /6 days in the case of k-carrageenan. All the mixed gels presented the typical weak gel structure; therefore, it was possible to perform steady-state measurements, which allowed the observation of a shear-thinning behaviour for all gels

Interesse patrimonial dos aspectos geológicos e geomorfológicos da região de Aveleda-Baçal, Parque Natural de Montesinho, NE de Portugal

O Parque Natural de Montesinho (PNM) fica situado no Nordeste de Portugal, abrange a parte norte dos concelhos de Vinhais e Bragança e engloba as serras da Coroa e Montesinho. Geologicamente o PNM situa-se nas unidades autóctones da Zona Centro Ibérica e nas unidades parautóctones e alóctones da Zona Galiza-Trás-os-Montes. Nesta primeira abordagem acerca do Património Geológico do PNM, faz-se a análise da região situada entre Aveleda e Baçal, cuja clareza das formas de relevo e a definição das relações com a geologia e com a tectónica, no seio de uma área protegida, são razões para a sua valorização. Assim, no presente trabalho descrevem-se e interpretam-se os aspectos geomorfológicos desta região. A partir de locais de observação estabelecidos é possível constatar que a região de Aveleda-Baçal corresponde ao bloco abatido de um graben controlado por falhas de orientação NNE-SSW, com destaque para a falha de Portelo que origina uma escarpa pelo soerguimento do bloco ocidental e abatimento a leste. No bloco ocidental deste acidente tectónico estão representados restos de uma superfície de aplanamento a cotas superiores a 900 metros (superfície de Espinhosela) e para norte a serra de Montesinho (1481 m), um bloco mais elevado de topos relativamente aplanados

Saccharomyces cerevisiae: a versatile eukaryotic system in virology

The yeast Saccharomyces cerevisiae is a well-established model system for understanding fundamental cellular processes relevant to higher eukaryotic organisms. Less known is its value for virus research, an area in which Saccharomyces cerevisiae has proven to be very fruitful as well. The present review will discuss the main achievements of yeast-based studies in basic and applied virus research. These include the analysis of the function of individual proteins from important pathogenic viruses, the elucidation of key processes in viral replication through the development of systems that allow the replication of higher eukayotic viruses in yeast, and the use of yeast in antiviral drug development and vaccine production

Structural characterization of the Aspergillus niger citrate transporter CexA uncovers the role of key residues S75, R192 and Q196

Supplementary data associated with this article can be found in the online version at doi:10.1016/j.csbj.2023.04.025.The Aspergillus niger CexA transporter belongs to the DHA1 (Drug-H+ antiporter) family. CexA homologs are exclusively found in eukaryotic genomes, and CexA is the sole citrate exporter to have been functionally characterized in this family so far. In the present work, we expressed CexA in Saccharomyces cerevisiae, demonstrating its ability to bind isocitric acid, and import citrate at pH 5.5 with low affinity. Citrate uptake was independent of the proton motive force and compatible with a facilitated diffusion mechanism. To unravel the structural features of this transporter, we then targeted 21 CexA residues for site-directed mutagenesis. Residues were identified by a combination of amino acid residue conservation among the DHA1 family, 3D structure prediction, and substrate molecular docking analysis. S. cerevisiae cells expressing this library of CexA mutant alleles were evaluated for their capacity to grow on carboxylic acid-containing media and transport of radiolabeled citrate. We also determined protein subcellular localization by GFP tagging, with seven amino acid substitutions affecting CexA protein expression at the plasma membrane. The substitutions P200A, Y307A, S315A, and R461A displayed loss-of-function phenotypes. The majority of the substitutions affected citrate binding and translocation. The S75 residue had no impact on citrate export but affected its import, as the substitution for alanine increased the affinity of the transporter for citrate. Conversely, expression of CexA mutant alleles in the Yarrowia lipolytica cex1Δ strain revealed the involvement of R192 and Q196 residues in citrate export. Globally, we uncovered a set of relevant amino acid residues involved in CexA expression, export capacity and import affinity.This work was supported by the Strategic Programme UID/BIA/04050/2020 and the project LA/P/0069/2020 granted to the Associate Laboratory ARNET, both funded by Portuguese funds through the FCT-IP. J.A. acknowledges the FCT and the Doctoral Program in Applied and Environmental Microbiology for the PD/BD/150584/2020 PhD grant and a COST Action CA18113 Short-Term Scientific Mission grant (EuroMicropH). M.S.S. acknowledges the Norte2020 for the UMINHO/BD/25/2016 PhD grant with the re ference NORTE-08-5369-FSE-000060. I.S-S. was supported by the program contract FCTUMINHO/Norma transitória from the Legal Regime of Scientific Employment (RJEC)

Phenolic acids, cinnamic acid, and ergosterol as cosmeceutical ingredients: Stabilization by microencapsulation to ensure sustained bioactivity

The global cosmetic industry is constantly searching for new ingredients with multifunctional properties. In this context, phenolic compounds (p-hydroxybenzoic, p-coumaric, and protocatechuic acids), cinnamic acid and ergosterol were evaluated for their anti-inflammatory, anti-tyrosinase and antimicrobial activities, and thereafter microencapsulated by the atomization/coagulation technique. After characterization (morphology, particle size distribution and encapsulation efficiency), the microencapsulated compounds were incorporated into a semi-solid base cream and their performance evaluated comparatively with the use of the free forms. The cosmeceutical formulations were checked regarding the presence of the bioactive compounds by HPLC-DAD, and for their physicochemical properties (colour and pH). The obtained results demonstrated the anti-tyrosinase, anti-inflammatory and antimicrobial activities of the individual compounds that, after incorporation, have shown a decreasing pattern along time. On the contrary, the formulations incorporating the microencapsulated bioactive compounds gave rise to a gradual release, ensuring bioactivity maintenance. These results underline the advantage of using microencapsulation to preserve and ensure the controlled release of bioactive species in cosmeceutical formulations.info:eu-repo/semantics/publishedVersio

Avaliação de alternativas aos revestimentos com alcatrão de hulha para estruturas de aço total ou parcialmente imersas em estuário e água do mar

Na procura de revestimentos anticorrosivos para protecção de estruturas de aço total ou parcialmente imersas em estuário e água do mar, que sejam alternativas mais ecológicas aos revestimentos com alcatrão de hulha ainda utilizados, foi desenvolvido um projecto no qual se comparam revestimentos epoxídicos comerciais com um revestimento de alcatrão de hulha epoxídico de referência, também comercial. Este trabalho inclui, para além da avaliação da protecção anticorrosiva dos revestimentos envolvidos no projecto, quer em laboratório, quer em exposição natural em estuário (rios Sado e Tejo) e em mar (Sines) durante quatro anos, a caracterização laboratorial das tintas integradas nos diferentes esquemas de pintura que deram origem aos revestimentos em estudo. Os resultados da avaliação no fim de dois anos de exposição natural, complementados com os ensaios em laborató permitiram concluir que dois dos quatro revestimentos alternativos estudados apresentaram melhor comportamento anticorrosivo do que o revestimento com alcatrão de hulha epoxídico usado como referência