223 research outputs found

    Devices to fight catheter-related infections

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    Healthcare-Associated Infections (HAI) affect ~1.7 M people in the USA and 4.1 M in Europe, contributing to 99,000 and 37,000 deaths/year, respectively. Catheter-related infections are the most frequent cause of HAI, leading to life-threatening complications and colossal medical costs. Current prevention/treatment options – sterilization protocols, lock solutions, systemic antibiotic administration – are inefficient and lead to bacterial resistance, a huge threat to public health. This review addresses the existing solutions in the market – mostly catheter caps –, and emerging alternatives, to fight catheter-related infections. Graphene-based biomaterials arise as interesting weapons against these infections, particularly in combination with light: their photothermal and photodynamic properties boost their own antimicrobial action, allowing them to kill bacteria without contributing to bacterial resistance.Healthcare-Associated Infections (HAI) affect ~1.7 M people in the USA and 4.1 M in Europe, contributing to 99,000 and 37,000 deaths/year, respectively. Catheter-related infections are the most frequent cause of HAI, leading to life-threatening complications and colossal medical costs. Current prevention/treatment options – sterilization protocols, lock solutions, systemic antibiotic administration – are inefficient and lead to bacterial resistance, a huge threat to public health. This review addresses the existing solutions in the market – mostly catheter caps –, and emerging alternatives, to fight catheter-related infections. Graphene-based biomaterials arise as interesting weapons against these infections, particularly in combination with light: their photothermal and photodynamic properties boost their own antimicrobial action, allowing them to kill bacteria without contributing to bacterial resistance.Peer Reviewe

    Probiotic potential of fructo-oligosaccharides produced by Aspergillus ibericus

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    The gastrointestinal tract harbours a diverse and dynamic microbial community that directly impacts human health. Prebiotics, such as fructo-oligosaccharides (FOS), play a crucial role in the modulation of colonic microbiota, reducing pathophysiological disorders and associated chronic diseases. The prebiotic potential of FOS produced by a newly isolated strain Aspergillus ibericus was studied. FOS fermentability by the probiotic Lactobacillus rhamnosus was evaluated. L. rhamnosus was grown in de Man-Rogosa-Sharpe (MRS) broth, with different carbon sources: glucose (positive control), no sugar (negative control), microbial-derived FOS from A. ibericus and Raftilose®P95, a non-microbial commercial FOS sample (from Beneo-Orafti, Belgium). A final concentration of 2 % (w/v) in sugar was used. Fermentation was carried out in a 96-well microplate and a shake flask, for 24 h, at 37 ºC, with an agitation of 120 rpm. Biomass growth was analysed by optical density at 620 nm. The consumption of sugars and the production of short chain fatty acids (SCFA) and lactate was quantified by HPLC. Maximum cell growth was reached at approximately 12 h, for all carbon sources. The highest growth was achieved for glucose samples, followed by the microbial-derived FOS, then Raflitose and finally the negative control. Although the microbial-derived FOS promoted great cellular growth, only kestose (GF2), together with residual amounts of glucose and sucrose presented in the sample, were consumed. This may explain the two different slopes exhibited during the exponential phase growth. Most likely hypothesis is that probiotic bacteria was cleaving GF2 in the first hours of fermentation, using only the smallest sugars present for growing. And Nystose (GF3) and fructofuranosylnystose (GF4) were not consumed, even when prolonging the fermentation up to 48 h. SCFA identified were valerate and propionate, as well as succinate, formate, acetate, iso-butyrate and nbutirate, although in lower amount. Higher amount of SCFA and lactate were determined while growing in the microbial-derived FOS, as compared to the commercial sample. Overall, lactate was the main metabolite produced during the fermentations. In conclusion, the prebiotic potential of microbial-derived FOS synthesized by A. ibericus was demonstrated, providing promising indication of its usability as food ingredient with strong prebiotic features.info:eu-repo/semantics/publishedVersio

    Experimental characterization of a microfluidic device based on passive crossflow filters for blood fractionation

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    The separation of red blood cells (RBCs) from blood plasma and the analysis of individual RBCs are of great importance, as they provide valuable information regarding the health of their donor. Recent developments in microfluidics and microfabrication have contributed to the fabrication of microsystems with complex features to promote the separation and analysis of RBCs. In this work, the separation capacity of a multi-step crossflow microfluidic device was evaluated by using a blood analogue fluid made by Brij L4 micelles and human RBCs separated from whole blood, suspended in a solution with hematocrits (Ht) of 0.5 and 1%. All the samples collected at the outlets of the device were experimentally analyzed and compared. The absorbance spectrum was also measured for the prepared blood samples. The results indicate that the tested blood analogue fluid has exhibited a flow behavior similar to that of blood. In addition, the optical absorbance spectrophotometry revealed that it was possible to evaluate the separation efficiency of the microfluidic device, concluding that the concentration of cells was lower at the most lateral outside outlets of the microchannel due to the cumulative effect of the multiple cross-flow filters

    Maternal sensitivity and mother-infant attachment are associated with antibiotic uptake in infancy

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    Attachment security has been associated with health status and symptom reporting. In this longitudinal study, we investigated the association between antibiotics uptake by infants at 9-months and mother-infant attachment at 12-months. Logistic regression analyses indicated that lower maternal sensitivity was associated with increased odds of antibiotic uptake. Furthermore, 89.7% of insecure-ambivalent infants consumed antibiotics, which contrasted with 32.5% of avoidant infants and 21.5% of secure infants. This study suggests that maternal behavior and mother-infant attachment impact on antibiotic consumption, which is worrying because antibiotics may lead to several health problems later in life and antibiotic-resistance.info:eu-repo/semantics/publishedVersio

    Dietary intake of young portuguese handball players

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    The aim of this study was to analyse dietary intake (macronutrients and micronutrients) in young female and male handball athletes. A transversal study was performed with young handball players from sub 16 and 18 Portuguese Handball Federation, who volunteered to participate in this study. Anthropometric (weight and height measure), nutritional intake (using food frequency questionnaire) and position in the game were evaluated. The final sample comprised 64 athletes (48.4% female and 51.6% male). The mean age was 16± 1 years, average body mass index was higher in females (24.1± 3.5kg/m2) than males (23.8± 3.0 kg/m2). Mean energy intake per day was significantly lower in females than males 2167.4± 1185.0 and 2952.9± 1315.8 kcal/day (p= 0.015, 95CI), respectively. According to the recommendations from food, most of the young handball athletes reported a generally higher dietary intake (protein intake was near to the upper recommendation limit; the carbohydrate intake was below and the fat intake higher) and a lower for some micronutrients. A process to identify the athletes that need nutritional support should be considered by handball coaches to optimise their performance and safeguard their healthTo all athletes and their coaches who contributed to the study and to the Portuguese Handball Federationinfo:eu-repo/semantics/publishedVersio

    Hydrolysis of α-lactalbumin by cardosin A immobilized on highly activated supports

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    In the present research effort, production of derivatives of cardosin A (a plant protease) encompassing full stabilization of its dimeric structure has been achieved, via covalent, multi-subunit immobilization onto highly activated agarose-glutaraldehyde supports. Boiling such enzyme derivatives in the presence of sodium dodecyl sulfate and β-mercaptoethanol did not lead to leaching of enzyme, thus providing evidence for the effectiveness of the attachment procedure. Furthermore, the cardosin A derivatives prepared under optimal conditions presented ca. half the specific activity of the enzyme in soluble form, and were successfully employed at laboratory-scale trials to perform (selective) hydrolysis of α-lactalbumin (α-La), one of the major proteins in bovine whey. Hydrolysates of α-La were assayed for by the OPA method, as well as by FPLC, SDS–PAGE and HPLC. Thermal inactivation of the immobilized cardosin A was also assessed at 40, 50 and 55 °C; at these temperatures, no thermal denaturation took place during incubation for 48 h. The highest degree of hydrolysis was attained by 5 h reaction, at 55 °C and pH 5.2. SDS–PAGE of α-La hydrolysates displayed bands corresponding to low molecular weight peptides. Our results suggest that cardosin A in immobilized form is a good candidate to bring about proteolysis in the dairy industry, namely in whey processing

    Visualization and measurements of blood cells flowing in microfluidic systems and blood rheology: a personalized medicine perspective

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    Hemorheological alterations in the majority of metabolic diseases are always connected with blood rheology disturbances, such as the increase of blood and plasma viscosity, cell aggregation enhancement, and reduction of the red blood cells (RBCs) deformability. Thus, the visualizations and measurements of blood cells deformability flowing in microfluidic devices (point-of-care devices) can provide vital information to diagnose early symptoms of blood diseases and consequently to be used as a fast clinical tool for early detection of biomarkers. For instance, RBCs rigidity has been correlated with myocardial infarction, diabetes mellitus, hypertension, among other blood diseases. In order to better understand the blood cells behavior in microfluidic devices, rheological properties analysis is gaining interest by the biomedical committee, since it is strongly dependent on the interactions and mechanical cells proprieties. In addition, the development of blood analogue fluids capable of reproducing the rheological properties of blood and mimic the RBCs behavior at in vitro conditions is crucial for the design, performance and optimization of the microfluidic devices frequently used for personalized medicine. By combining the unique features of the hemorheology and microfluidic technology for single-cell analysis, valuable advances in personalized medicine for new treatments and diagnosis approach can be achieved.This project has been funded by Portuguese national funds of FCT/MCTES (PIDDAC) through the base funding from the following research unit: UIDB/04077/2020, UIDB/00319/2020 and UIDB/00532/2020. The authors are also grateful for the partial funding of FCT through the projects NORTE-01-0145-FEDER-029394, NORTE-01-0145-FEDER-030171, funded by COMPETE2020, NORTE2020, PORTUGAL2020, and FEDER.Diana Pinho acknowledges the PhD scholarship SFRH/BD/89077/2012 attributed by FCT

    New benzo[a]phenoxazines bearing the (4,6-dichloro-1,3,5-triazin-2-yl)amino group: synthesis and photophysical properties

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    Synthesis of new benzo[a]phenoxazinium chlorides possessing the (4,6-dichloro-1,3,5- triazin-2-yl)amino at 5-amino function of the heterocycles is described. The preliminary photophysical properties of these compounds in anhydrous ethanol when acidified with TFA or basified with TEAH is also investigated, as well as their response in aqueous media. These benzo[a]phenoxazinium chlorides exhibited fluorescence with maximum emission wavelengths between 628 and 676 nm, in anhydrous ethanol and water.Thanks are due to the Fundação para a Ciência e Tecnologia (FCT, Portugal) for financial support to the NMR portuguese network (PTNMR, Bruker Avance III 400-Univ. Minho), FCT and FEDER (European Fund for Regional Development)-COMPETE-QREN-EU for financial support to the Research Centres CFUM [PEst-C/FIS/UI0607/2011 (F-COMP-01-0124-FEDER-022711)] and CQ/UM [PEst-C/QUI/UI0686/2013(FCOMP-01-0124-FEDER-022716)]. A post-doctoral grant to B. R. Raju (SFRH/BPD/62881/2009) is also acknowledged to FCT, POPH-QREN, FSE.info:eu-repo/semantics/publishedVersio

    Sirtuins’ deregulation in bladder cancer: SIRT7 is implicated in tumor progression through epithelial to mesenchymal transition promotion

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    Sirtuins are emerging players in cancer biology and other age-related disorders, and their putative role in bladder cancer (BlCa) remains elusive. Further understanding of disease biology may allow for generation of more effective pathway-based biomarkers and targeted therapies. Herein, we aimed to illuminate the role of sirtuins’ family in BlCa and evaluate their potential as disease biomarkers and therapeutic targets. SIRT1-7 transcripts and protein levels were evaluated in a series of primary BlCa and normal bladder mucosa tissues. SIRT7 knockdown was performed through lentiviral transduction in MGHU3, 5637 and J82 cells and its functional role was assessed. SIRT1, 2, 4 and 5 expression levels were significantly lower in BlCa, whereas SIRT6 and 7 were overexpressed, and these results were corroborated by TCGA cohort analysis. SIRT7 transcript levels were significantly decreased in muscle-invasive vs. papillary BlCa. In vitro studies showed that SIRT7 downregulation promoted cells migration and invasion. Accordingly, increased EMT markers expression and decreased E-Cadherin (CDH1) was observed in those BlCa cells. Moreover, increased EZH2 expression and H3K27me3 deposition in E-Cadherin promoter was found in sh-SIRT7 cells. We demonstrated that sirtuins are globally deregulated in BlCa, and specifically SIRT7 downregulation is implicated in EMT, fostering BlCa invasiveness through EZH2-CDH1 axis.This research was supported by the Research Center of the Portuguese Oncology Institute of Porto (CI-IPOP–FBGEBC-27 and PI 74-CI-IPOP-19-2016), by Fundação para a Ciência e Tecnologia (FCT) (PhD fellowships SFRH/BD/112673/2015 to S.M.-R and SFRH/BD/92786/2013 to C.S.G.; IF/00601/2012 to B.M.C.), and by Fundo Europeu de Desenvolvimento Regional (FEDER) (post-doctoral fellowships IPO/ESTIMANORTE01-0145-FEDER-000027 to V.M.-G. and COMPETE/FEDER/FCT_CI-IPOP-BPD/UID/DTP/00776/2013 to I.G.)

    A systematic review and bibliometric analysis of wildland fire behavior modeling

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    Wildland fires have become a major research subject among the national and international research community. Different simulation models have been developed to prevent this phenomenon. Nevertheless, fire propagation models are, until now, challenging due to the complexity of physics and chemistry, high computational requirements to solve physical models, and the difficulty defining the input parameters. Nevertheless, researchers have made immense progress in understanding wildland fire spread. This work reviews the state-of-the-art and lessons learned from the relevant literature to drive further advancement and provide the scientific community with a comprehensive summary of the main developments. The major findings or general research-based trends were related to the advancement of technology and computational resources, as well as advances in the physical interpretation of the acceleration of wildfires. Although wildfires result from the interaction between fundamental processes that govern the combustion at the solid- and gas-phase, the subsequent heat transfer and ignition of adjacent fuels are still not fully resolved at a large scale. However, there are some research gaps and emerging trends within this issue that should be given more attention in future investigations. Hence, in view of further improvements in wildfire modeling, increases in computational resources will allow upscaling of physical models, and technological advancements are being developed to provide near real-time predictive fire behavior modeling. Thus, the development of two-way coupled models with weather prediction and fire propagation models is the main direction of future work.This work was supported by the Portuguese Foundation for Science and Technology (FCT) within the R&D Units Project Scope UIDB/00319/2020 (ALGORITMI) and R&D Units Project Scope UIDP/04077/2020 (METRICS) and through project: PCIF/GRF/0141/2019: “O3F—An Optimization Framework to reduce Forest Fire
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