Application of chitosan in the control of fungal infections by dermatophytes

Dermatophytes are a group of fungi that can invade keratinized tissues of humans and other animals and produce an infection called Dermatophytosis. As chitosan possesses antimicrobial activity, it can potentially be used to treat dermatophytic infections. The main objective of this work was therefore, to evaluate the antifungal activity of chitosan upon some dermatophytes, namely Microsporum canis and Trychophyton rubrum. In view of this, Minimum Inhibitory (MICs) and Minimum Fungicidal Concentrations (MFCs) of chitosans upon the fungi were determined. Moreover, in order to understand the effect of chitosan on fungal activity, hair was infected with these fungi in the presence and absence of chitosan and Scanning Electron Microscopy (SEM) images were obtained and analyzed. Lastly, keratin-azure was used as substrate to evaluate the effect of chitosan on keratin degradation by M. canis and T. rubrum. The results showed that chitosan possesses antifungal activity against T. rubrum and M. canis, presenting MICs and MFCs ranging from 1.1 to 2.2 mg/mL. The antifungal activity of chitosan is concentration dependent. The analysis of SEM images of hair infected with these dermatophytes revealed that chitosan seems to have a protective effect on the hair, reducing the extent of damage when compared to the control. Chitosan also displayed important activity in preventing proteases’ action and in preventing hair damage. Based on the obtained results, it’s possible to conclude that chitosan showed relevant antifungal activity against dermatophytes, which opens good prospects to the use of chitosan as an alternative for the conventional fungal treatmentsinfo:eu-repo/semantics/publishedVersio

Small shrubby patches increase bird taxonomic and functional richness of wood-pastures

Wood-pastures are semi-natural systems that combine a grazed grassland with a tree layer. Shrubs are often controlled, mostly to improve grazing potential, resulting in a reduction of the available ecological niches. From a conservation perspective, it is thus important to identify management practices that counter this reduction. Our overall objective was to determine the value of small shrubby patches to increase the richness of wood-pasture bird communities. As study model we used Mediterranean oak wood-pastures in southern Portugal, locally known as montados. Birds and environmental variables were sampled in 50 m radius plots of wood-pasture with and without small shrubby patches (128–3748 m2, covering less than 0.5% of the study area), in winter (n = 54) and spring (n = 65). Species assemblages’ composition changed between seasons, but in both seasons the assemblages in plots with and without patches were statistically different. Seven species were statistically associated to the presence of patches, in winter and spring, increasing the richness of the respective assemblages. A comparison of the functional composition of communities of patches and matrix revealed that patches increased richness of landscapes by boosting the presence of species with functional traits uncommon in the ecologically simplified matrix. Their presence is promoted by resources added by the patches (e.g. nesting sites, protection, food), but the ranges of individual birds in general extended well beyond the patches. This study demonstrated that the presence of few and small shrubby patches can significantly enrich the bird communities of wood-pastures, both taxonomically and functionally, indicating that promoting them is a cost-effective management measure for these valuable systems.info:eu-repo/semantics/publishedVersio

Relação entre geologia, ventilação natural e concentração de gás radão: caso de estudo no noroeste de Portugal

Alto Minho region, Northwest of Portugal, presents high indoor radon concentrations due to the granitic nature of the soil. Indoor radon concentration is related to the amount of uranium and radium in the building foundation soil. According to the World Health Organization, it is proved that radon exposure in poorly ventilated buildings enhances lung cancer risk. An assessment campaign in a set of granitic buildings in the Alto Minho region, based on short-term measurements, was carried out with a specific focus on the influence of occupancy and ventilation actions performed by residents on the variation of radon concentration, indoor air temperature, and relative humidity. Results attained show to exist an influence of the air renovation on the reduction of radon concentration, therefore, buildings with low occupancy and reduced ventilation present higher indoor radon concentration and poor thermal comfort conditions. 67% of the evaluated buildings show radon concentrations below the reference value of 300 Bq.m−3 suggested by Portuguese regulation, highlighting the importance of human occupancy – mostly through passive ventilation processes – as a radon concentration mitigation factor. On the other hand, buildings sporadically occupied and, therefore, badly ventilated show higher indoor radon concentrations. Likewise, building where occupants reveal to have a lack of ventilation routine, present also high indoor radon concentrations.A região do Alto Minho, Noroeste de Portugal, apresenta altas concentrações de gás radão em ambientes interiores devido à natureza granítica do solo. A concentração no ar interior de gás radão está relacionada com a quantidade de urânio e rádio no solo de fundação do edifício. De acordo com a Organização Mundial de Saúde, está provado que a exposição ao gás radão em edifícios mal ventilados incrementa o risco de cancro do pulmão. Foi realizada uma campanha de instrumentação tendo como objeto de estudo um conjunto de edifícios graníticos na região do Alto Minho, baseada em medições de curta duração, tendo como foco específico, a influência da ocupação e da ventilação dos edifícios na variação da concentração de gás radão, temperatura do ar interior e humidade relativa. Os resultados obtidos mostram existir uma influência das ações de ventilação na redução da concentração de gás radão. Deste modo, edifícios com baixa ocupação e, portanto, com menor renovação do ar, apresentam elevada concentração de gás radão e deficientes condições de conforto térmico. De facto, 67% dos edifícios avaliados apresentam concentrações de gás radão abaixo do valor de referência de 300 Bq.m−3 indicado na regulamentação portuguesa, evidenciando a importância da ocupação humana e dos processos de ventilação natural adotados, como fator de mitigação da concentração de radão. Por outro lado, edifícios esporadicamente ocupados e, portanto, mal ventilados apresentam concentrações mais elevadas de radão. Da mesma forma, edifícios onde os ocupantes não têm hábitos de ventilação apresentam de igual forma concentrações de gás radão mais elevadas.info:eu-repo/semantics/publishedVersio

Joining sustainable design and internet of things technologies on campus : the IPVC smartbottle practical case

Higher education institutions (HEIs) are favored environments for the implementation of technological solutions that accelerate the generation of smart campi, given the dynamic ecosystem they create based on the involvement of inspired and motivated human resources (students, professors, and researchers), moving around in an atmosphere of advanced digital infrastructures and services. Moreover, HEIs have, in their mission, not only the creation of integrated knowledge through Research and Development (R&D) activities but also solving societal problems that address the academic community expectations concerning environmental issues, contributing, therefore, towards a greener society embodied within the United Nations (UN) Sustainable Development Goals (SDGs). This article addresses the design and implementation of a Smartbottle Ecosystem in which an interactive and reusable water bottle communicates with an intelligent water refill station, both integrated by the Internet of Things (IoT) and Information and Communications Technologies (ICT), to eliminate the use of single-use plastic water bottles in the premises of the Polytechnical Institute of Viana do Castelo (IPVC), an HEI with nearly 6000 students. Three main contributions were identified in this research: (i) the proposal of a novel methodology based on the association of Design Thinking and Participatory Design as the basis for Sustainable Design; (ii) the design and development of an IoT-enabled smartbottle prototype; and (iii) the usability evaluation of the proposed prototype. The adopted methodology is rooted in Design Thinking and mixes it with a Participatory Design approach, including the end-user opinion throughout the Smartbottle Ecosystem design process, not only for the product design requirements but also for its specification. By promoting a participatory solution tailored to the IPVC academic community, recycled plastic has been identified as the preferential material and a marine mammal was selected for the smartbottle shape, in the process of developing a solution to replace the single-use plastic bottles.7519-C505-DF9E | Ant?nio Jos? Candeias CuradoN/

CH4 production at moderate H2/CO2 pressures insights on the use of anaerobic granular sludge as biocatalyst

Introduction: The continuous increase in energy consumption and the intensive use of fossil fuels, lead to the emission of greenhouse gases (GHG) and, in particular, to an increase in the concentration of CO2 in the atmosphere. In this context, the improvement in global awareness and the demand for sustainable technologies and products strongly contribute to laid plans to combat climate change. CO2-to-CH4 conversion represents a cutting-edge solution for CO2 capture and use, contributing to the reduction of GHG emission. Catalytic conversion of CO2-to-CH4 have been investigated, however, the high cost associated to the catalysts employed limits their use on a large scale. Biological CO2 methanation can overcome the significant technical and economic challenges of catalytic CO2 methanation. The biological production of CH4 using CO2-rich gases together with H2 is a promising strategy for the production of bioproducts. Hydrogenotrophic methanogens have a crucial role on the direct conversion of CO2+H2 into CH4, hence the importance to study the specific hydrogenotrophic methanogenic activity (SHMA). Methodology: In this work, the effect of initial substrate (H2/CO2) pressure, from 100 to 500 kPa, on the SHMA, on CH4 production rate and on developed microbial communities were evaluated. Two different pressurized bioreactors were studied using anaerobic granular sludge as the biocatalyst and H2/CO2 (80:20, v/v) as sole carbon and energy source. Gaseous compounds were analyzed by GC and archaeal diversity within granular sludge was monitored by 16S r-RNA based techniques. Results: The results showed an increase in the SHMA as well as in the CH4 production rate with the increase of the initial H2/CO2 pressure. This results are very interesting since no inhibitory effects were observed on the microbial activity, demonstrating the resistance of the anaerobic granular sludge. The Illumina results showed that Methanosarcinales, Methanobacteriales and Methanomicrobiales were the three orders that prevailed in the pressurized system, for all the pressures tested. However, hydrogenotrophic methanogens from Methanobacterium and Methanospirillum genera slightly increased their relative abundance, varying from 38% (100 kPa) to 41% (500 kPa) and from 8% (100 kPa) to 12% (500 kPa), respectively. Conclusions: In conclusion, the archaeal community seems to be very stable when submitted to increasing H2/CO2 pressures, highlighting the potential of the anaerobic granular sludge as an efficient microbial platform for the production of added-value compounds from gaseous carbon waste streams.Portuguese Foundation for Science and Technology (FCT): POCI-01-0145-FEDER-031377; strategic funding of UIDB/04469/2020 unit; BioTecNorte operation (NORTE-01-0145-FEDER-000004); FCT doctoral grant PD/BD/128030/2016.info:eu-repo/semantics/publishedVersio

CH4 production at moderate H2/CO2 pressures - insights on the specific hydrogenotrophic methanogenic activity

CO2 is one of the main contributors to greenhouse gases (GHGs), being its emission to the atmosphere one of the major driver of global climate change. Biological methanation of CO2 using renewable H2 provides a promising approach to use of superplus renewable electrical power to produce a gaseous fuel. CH4 is considered an important renewable energy carrier, that has a wide range of applications such as natural gas for distribution. Hydrogenotrophic methanogens are key elements in the CO2/H2 methanation process. Thus the importance to study the specific hydrogenotrophic methanogenic activity (SHMA). The effect of the initial substrate (H2/CO2) pressure on the SHMA was investigated in two different pressurized bioreactors. The results suggest that in addition to the increase of the initial substrate pressure, also the bioreactor configuration influence the SHMA, which is crucial for the success of biological CO2 methanation technologies but also in anaerobic bioreactors treating wastewaters.info:eu-repo/semantics/publishedVersio

Rheological characterization under shear of a fraction of polymer produced via fermentation of whey-related media by Rahnella aquatilis

Production of lactan, a polysaccharide composed of mannose, galactose and galacturonic acid (at the ratio of 5:3:2), starting from a semidefined medium containing lactose via fermentation with Rahnella aquatilis was described previously. In this communication, such polysaccharide was produced from five alternative fermentation media: (1) a synthetic (defined) medium, plain whey (under (2) aerobic and (3) anaerobic conditions), (4) whey permeate and (5) whey with 2% NaCl (w/v). The effect of the concentration of polysaccharide, pH and ionic strength at harvest on the rheological properties of the polysaccharide was studied using lactan-enriched fractions recovered from each medium and analysed in solution under steady shear flow. Lactan solutions showed a shear-thinning behaviour in all cases, and increases in viscosity were observed at increasing concentrations of polysaccharide, as expected. The polysaccharide fraction produced from whey with 2% (w/v) NaCl and plain whey under anaerobic conditions exhibited lower viscosity than that produced from the other media, an observation that is associated with the lower concentration of polysaccharide. Post-harvest addition of salts (KCl or CaCl2) and changes in pH (3–11) affected slightly the viscosity of the polysaccharide solutions. q199

Blood flow of bubbles moving in microchannels with bifurcations

The gas embolism is a well-known phenomenon. Previous studies have been performed to understand the formation, the behavior and the influence of air bubbles in microcirculation. This study aims to investigate the flow of bubbles in a microchannel network with bifurcations. For that purpose, a microchannel network was fabricated by soft lithography. The working fluids used were composed by sheep red blood cells (RBCs) suspended in dextran 40 and two different hematocrits were studied, 5% and 10%. The in vitro blood flow was analyzed for a flow rate of lO ~-tllmin, by using an inverted microscope and a high-speed camera. It was possible to visualize the formation of the bubbles and their behavior along the network. The results show that the passage of air bubbles influences the cells local concentration, since a higher concentration of cells was seen upstream to the bubble and lower concentrations downstream to the bubble.This work was supported by Fundação para a Ciência e a Tecnologia (FCT), Portugal, under the strategic grants UID/EMS/04077/2019, UID/EEA/04436/2019 and UID/EMS/00532/2019. The authors are also grateful for the partial funding of FCT through the projects POCI-01-0145-FEDER-016861 (ref: PTDC/QEQ-FIT/4287/2014), NORTE-01-0145- FEDER-029394, NORTE-01-0145-FEDER-030171, funded by COMPETE2020, NOR1E2020, PORTUGAL2020, and FEDER. D. Bento acknowledges the PhD scholarship SFRH/BD/911921 2012 granted by FCT.info:eu-repo/semantics/publishedVersio

Pressurized syngas bioconversion: physiological and microbial characterization

ICBM-3 - 3rd International Conference on Biogas MicrobiologySyngas is composed mainly by CO, H2 and CO2 and its fermentation is a promising biological process to produce fuels or commodity chemicals. Experiments under increased initial syngas pressures, up to 5.2×105 Pa, were carried out to evaluate the effects on metabolites production and microbial communities structure. Two strategies were applied: NB non-adapted biomass and SB successively syngas-fed biomass. The rise of syngas pressure from 1.2×105 Pa up to 5.2×105 Pa led to a decrease on CO and H2 consumption rates and CH4 production rate. Moreover, when methanogenesis was partially inhibited, propionate and butyrate were the main metabolites produced from syngas. DGGE profiles showed differences on diversity and on similarity indices (SI) with changes in pressure. Regardless the syngas pressure employed, the archaeal communities had higher SI (above 70%) than bacterial community (48% to 62%). From the Illumina sequencing analysis, it was observed that the relative abundance of bacterial communities tend to decrease (72% to 46%), and archaeal communities increased (25% to 54%) by raising the pressure of syngas from 1.2×105 Pa to 5.2×105 Pa. In the inoculum and biomass incubated at 1.2×105 Pa syngas, 40% of total population were from Proteobacteria phylum and Deltraproteobacteria class and their abundance was reduced 4-fold at 5.2×105 Pa. As a direct effect of high pressures of syngas, organisms belonging to Firmicutes, Synergistetes and Thermotogae phyla increased over 10-fold. The predominant phylotypes at 3×105 Pa and 5.2×105 Pa were related to Methanobacterium genus (archaea) and to Eubacteriaceae, Synergistaceae and Syntrophobacteraceae families (bacteria). These results showed a microbial population enrichment suggesting a high specialization for the substrate.info:eu-repo/semantics/publishedVersio

Contributo para o conhecimento da biodiversidade marinha da ilha das Flores

XIII Expedição Científica do Departamento de Biologia - Flores e Corvo 2007.No âmbito da XIII Expedição Científica Flores e Corvo/2007, organizada pelo Departamento de Biologia da Universidade dos Açores, efectuaram-se várias observações e recolhas de organismos marinhos, utilizando 3 metodologias: mergulho (bentos), arrasto (plâncton) e prospecção no intertidal