A continuous solvent- and oil-free method to prepare injectable PEGylated fibrinogen cell-laden microparticles

Injectable biomaterials with in situ cross-linking reactions have been suggested to minimize the invasiveness associated with most implantation procedures. However, problems related with the rapid liquid-to-gel transition reaction can arise because it is difficult to predict the reliability of the reaction and its end products, as well as to mitigate cytotoxicity to the surrounding tissues. An alternative minimally invasive approach to deliver solid implants in vivo is based on injectable microparticles, which can be processed in vitro with high fidelity and reliability, while showing low cytotoxicity. Their delivery to the defect can be performed by injection through a small diameter syringe needle. We present a new methodology for the continuous, solvent- and oil-free production of photopolymerizable microparticles containing encapsulated human dermal fibroblasts. A precursor solution of cells in photo-reactive PEG-fibrinogen (PF) polymer was transported through a transparent injector exposed to light-irradiation before being atomized in a jet-in-air nozzle. Shear rheometry data provided the cross-linking kinetics of each PF/cell solution, which was then used to determine the amount of irradiation required to partially polymerize the mixture prior to atomization. The partially polymerized drops fell into a gelation bath for further polymerization. The system was capable of producing cell-laden microparticles with high cellular viability, with an average diameter of between 88.1 µm to 347.1 µm and a dispersity of between 1.1 and 2.4, depending on the parameters chosen.

A calculadora gráfica na promoção da escrita matemática na aprendizagem de modelos contínuos não lineares: um estudo com alunos do 11.º ano de Matemática B

Relatório de estágio de mestrado em Ensino de Matemática no 3.º Ciclo do Ensino Básico e no Ensino Secundário

Recycled asphalt mixtures produced with high percentage of different waste materials

The use of sustainable solutions in construction is not just an option, but is increasingly becoming a need of the Society. Thus, nowadays the recycling of waste materials is a growing technology that needs to be continuously improved, namely by researching new solutions for waste valorisation and by increasing the amount of wastes reused. In the paving industry, the reuse of reclaimed asphalt (RA) is becoming common practice, but needs further research work. Thus, this study aims to increase the incorporation of RA and other waste materials in the production of recycled asphalt mixtures in order to improve their mechanical, environmental and economic performance. Recycled mixtures with 50% RA were analysed in this study, including: i) RA selection, preparation and characterization; ii) incorporation of other waste materials as binder additives or modifiers, like used motor oil (UMO) and waste high density polyethylene (HDPE); iii) production of different mixtures (without additives; with UMO; with UMO and HDPE) and comparison of their performance in order to assess the main advantages of each solution. With this study it was concluded that up to 7.5 % of UMO and 4.0 % of HDPE can be used in a new modified binder for asphalt mixtures with 50 % of RA, which have excellent properties concerning the rutting with WTS = 0.02 mm/103 cycles, the fatigue resistance with ε6 = 160.4, and water sensitivity with an ITSR of 81.9 %.

HLT Hilotec: self-building manual for sustainable housing

The future of the construction industry will require changes at many levels. One is the ability of companies to adapt to new challenges, converting needs to opportunities and simultaneously contributing to the solving of social and environmental problems. In the coming decades we will see a change in attitude in the industry, with a strong tendency to adopt natural and recycled materials, as well as bet on green technology and social innovation oriented to emerging countries. On the other hand, emerging countries have a high demand for housing construction on a large scale, but the current techniques in the developed countries for building requires a large amount of natural resources and skilled labor. This contextualization brings sustainability problems for the construction sector in emerging countries, often with scarce natural resources and with the construction sector underdeveloped. Through a cooperative action between the construction company Mota-Engil Engineering and the University of Minho in Portugal, a construction technology was developed based on the use of Compressed Earth Blocks as part of a social concept for innovative small houses, favoring the adoption of local and natural materials and with the main premise of being dedicated to self-construction. The HiLoTec project - Development of a Sustainable Self-Construction System for Developing Countries was based on this idea. One of the several results of this project is this construction manual. To Mota-Engil the project was a platform for incubation of knowledge about earth construction and to obtain a constructive solution validated technically and scientifically, suitable to be implemented in the markets where it operates. For the University of Minho the project was an opportunity to strengthen skills in research, laboratory and scientific development, through the development of engineering studies, architecture and sustainability, as well as supporting the doctoral scholarships and dissemination of scientific publications. May the knowledge of this project be of benefit, in the future, for the welfare of those who build a HiLoTec house.

Candida bracarensis: Evaluation of virulence factors and its tolerance to Amphotericin B and Fluconazole

Candida bracarensis is an uncommon Candida species found during an epidemiological study of candidiasis performed in Braga, Portugal. Initially, it was identified as C. glabrata, but recently detailed analyses pointed out their differences. So, little information is still available about C. bracarensis virulence factors and antifungal susceptibilities. Therefore, the main goal of this work is to evaluate the ability of C. bracarensis to form biofilms, to produce hydrolytic enzymes (proteases, phospholipases and hemolysins), as well as its susceptibility to amphotericin B and fluconazole. It was shown, for the first time, that all C. bracarensis strains were able to form biofilms and display proteinase and hemolytic activities. Moreover, although planktonic cells presented antifungal susceptibility, amphotericin B and fluconazole were unable to inhibit biofilm formation and eradicate pre-formed biofilms. Due to the propensity of C. bracarensis to display antifungal resistance and virulence attributes, the control of these emerging pathogens is recommended.

Modeling microbes: New methods for integrated metabolic and regulatory network reconstruction

PhD Thesis in Bioengineering

Magnetoelectric CoFe2O4/polyvinylidene fluoride electrospun nanofibres

Magnetoelectric 0-1 composites comprising CoFe2O4 (CFO) nanoparticles in polyvinylidene fluoride (PVDF) polymerfibre matrix have been prepared by electrospinning. The average diameter of the electrospun composite fibres D is ~ 325 nm, independently of nanoparticle content, and the amount of crystalline polar β phase is strongly enhanced when compared to pure PVDF polymer fibres. The piezoelectric response of these electroactive nanofibres is modified by an applied magnetic field, thus evidencing the magnetoelectric character of the CFO/PVDF 0-1 composites.

Search for vector-like B quarks in events with one isolated lepton, missing transverse momentum and jets at s√= 8 TeV with the ATLAS detector

A search has been performed for pair production of heavy vector-like down-type (B) quarks. The analysis explores the lepton-plus-jets final state, characterized by events with one isolated charged lepton (electron or muon), significant missing transverse momentum and multiple jets. One or more jets are required to be tagged as arising from b-quarks, and at least one pair of jets must be tagged as arising from the hadronic decay of an electroweak boson. The analysis uses the full data sample of pp collisions recorded in 2012 by the ATLAS detector at the LHC, operating at a center-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 20.3 fb−1. No significant excess of events is observed above the expected background. Limits are set on vector-like B production, as a function of the B branching ratios, assuming the allowable decay modes are B→Wt/Zb/Hb. In the chiral limit with a branching ratio of 100% for the decay B→Wt, the observed (expected) 95% CL lower limit on the vector-like B mass is 810 GeV (760 GeV). In the case where the vector-like B quark has branching ratio values corresponding to those of an SU(2) singlet state, the observed (expected) 95% CL lower limit on the vector-like B mass is 640 GeV (505 GeV). The same analysis, when used to investigate pair production of a colored, charge 5/3 exotic fermion T5/3, with subsequent decay T5/3→Wt, sets an observed (expected) 95% CL lower limit on the T5/3 mass of 840 GeV (780 GeV).

Removal of Erythrosine B dye from water effluents using crop waste pumpkin seed hulls as adsorbent

Erythrosine B is widely used for coloring in various applications, especially in the food industry, despite its already proved toxicity and carcinogenicity. The agrowaste pumpkin seed hulls were applied as potential adsorbent for the removal of Erythrosine from aqueous solutions. Adsorption mechanism and kinetics were analyzed for design purposes. The seed hulls were characterized by specific techniques before and after dye retention. It was found that the attachment of Erythrosine B molecules on adsorbent surface may be attributed to the interactions between carboxyl and/or carbonyl groups of both dye and agrowaste wall components. A univariate approach followed by a factorial design was applied to study and analyze the experimental results as well as to estimate the combined effects of the process factors on the removal efficiency and dye uptake. Adsorption mechanism may be predominantly due to intraparticle diffusion, dependent on pore size. The four equilibrium models applied fitted the data well; the maximum adsorption capacity for Erythrosine was 16.4 mg/g. The results showed that adsorbent is effective for Erythrosine B removal for a large concentration range in aqueous solutions (5400 mg/L) in batch systems.

A breakthrough on Amanita phalloides poisoning: an effective antidotal effect by polymyxin B

Amanita phalloides is responsible for more than 90 % of mushroom-related fatalities, and no effective antidote is available. a-Amanitin, the main toxin of A. phalloides, inhibits RNA polymerase II (RNAP II), causing hepatic and kidney failure. In silico studies included docking and molecular dynamics simulation coupled to molecular mechanics with generalized Born and surface area method energy decomposition on RNAP II. They were performed with a clinical drug that shares chemical similarities to a-amanitin, polymyxin B. The results show that polymyxin B potentially binds to RNAP II in the same interface of a-amanitin, preventing the toxin from binding to RNAP II. In vivo, the inhibition of the mRNA transcripts elicited by a-amanitin was efficiently reverted by polymyxin B in the kidneys. Moreover, polymyxin B significantly decreased the hepatic and renal a-amanitin-induced injury as seen by the histology and hepatic aminotransferases plasma data. In the survival assay, all animals exposed to a-amanitin died within 5 days, whereas 50 % survived up to 30 days when polymyxin B was administered 4, 8, and 12 h post-a-amanitin. Moreover, a single dose of polymyxin B administered concomitantly with a-amanitin was able to guarantee 100 % survival. Polymyxin B protects RNAP II from inactivation leading to an effective prevention of organ damage and increasing survival in a-amanitin-treated animals. The present use of clinically relevant concentrations of an already human-use-approved drug prompts the use of polymyxin B as an antidote for A. phalloides poisoning in humans.

Analysis of a Local HIV-1 Epidemic in Portugal Highlights Established Transmission of non-B and -G Subtypes

Existing data supports Portugal as the Western Europe country with highest HIV-1 subtype diversity. However, detailed phylogenetic studies of Portuguese HIV-1 epidemics are still scarce. Thus, our main goal was to analyze the phylodynamics of a local HIV-1 infection in the Portuguese region of Minho. Molecular epidemiological analysis was applied to data from 289 HIV-1 infected individuals followed in the reference Hospital of the province of Minho, Portugal, in which isolated viruses had been sequenced between 2000 and 2012. Viruses of the G (29.1%) and B (27.0%) subtypes were the most frequent, followed by recombinant forms (17.6%), C (14.5%), F1 (7.3%) and A1 (4.2%) subtypes. Multinomial logistic regression revealed that the odds of being infected with A1 and F1 subtype increased over the years when compared with B, G, C or recombinant viruses. As expected, polyphyletic patterns suggesting multiple and old introductions of subtypes B and G were found. However, transmission clusters of non-B and -G viruses among native individuals were also found with the dates of the most recent common ancestor estimated to the early 2000s. Our study supports that the HIV-1 subtype diversity in the Portuguese region of Minho is high and has been increasing in a manner that is apparently driven by factors other than immigration and international travel. Infections with A1 and F1 viruses in the region of Minho are becoming established and were mainly found in sexually transmitted clusters, reinforcing the need for more efficacious control measures targeting this infection route.

Clivagem e caracterização de frutalina recombinante produzida em Escherichia coli

Dissertação de mestrado integrado em Engenharia Biomédica (área de especialização em Engenharia Clínica)

La formación b-learning en el máster de español segunda lengua y lengua extranjera de la Universidade do Minho: innovación pedagógica y desafíos educativos

En el actual marco de creciente innovación pedagógica, debido entre otros factores, a la irrupción de nuevas herramientas informáticas, la enseñanza a distancia (e-learning y/o b-learning) va ocupando cada vez más espacio en la oferta educativa de diversas instituciones. En esta dirección, en la Universidade do Minho, y concretamente en el Área de Estudos Espanhóis e Hispano-Americanos,[1] hemos dedicado considerables esfuerzos a la ampliación de nuestra oferta desde 2010: primero en la elaboración e implementación del Curso de Formación Especializada en Español Lengua Extranjera, modalidad b-learning (3 ediciones; 2010-2013), y, actualmente, con el Máster Universitario en Español Lengua Segunda / Lengua Extranjera (vid. www.melsle.ilch.uminho.pt), también b-learning. En las siguientes páginas, nos proponemos compartir una serie de experiencias y reflexiones que han ido surgiendo durante estos años acerca de la formación universitária de profesores de Español Lengua Extranjera, en general, con recurso a la modalidade b-learning; para ello, nos centraremos en los siguientes aspectos: (i) caracterización general y problematización de la enseñanza a distancia en la Universidade do Minho; (ii) descripción del Máster Universitario en Español Lengua Segunda / Lengua Extranjera, acerca del cual detallaremos algunas prácticas adoptadas, relacionadas com la enseñanza e-learning como, por ejemplo, (iii) la coordinación pedagógica o (iv) los enfoques metodológicos adoptados a partir de la experiencia de una Unidad Curricular concreta.

Analysis of events with b-jets and a pair of leptons of the same charge in pp collisions at √s=8 TeV with the ATLAS detector

An analysis is presented of events containing jets including at least one b-tagged jet, sizeable missing transverse momentum, and at least two leptons including a pair of the same electric charge, with the scalar sum of the jet and lepton transverse momenta being large. A data sample with an integrated luminosity of 20.3 fb−1 of pp collisions at s√=8 TeV recorded by the ATLAS detector at the Large Hadron Collider is used. Standard Model processes rarely produce these final states, but there are several models of physics beyond the Standard Model that predict an enhanced rate of production of such events; the ones considered here are production of vector-like quarks, enhanced four-top-quark production, pair production of chiral b′-quarks, and production of two positively charged top quarks. Eleven signal regions are defined; subsets of these regions are combined when searching for each class of models. In the three signal regions primarily sensitive to positively charged top quark pair production, the data yield is consistent with the background expectation. There are more data events than expected from background in the set of eight signal regions defined for searching for vector-like quarks and chiral b′-quarks, but the significance of the discrepancy is less than two standard deviations. The discrepancy reaches 2.5 standard deviations in the set of five signal regions defined for searching for four-top-quark production. The results are used to set 95% CL limits on various models.

Synthesis, antiangiogenesis evaluation and molecular docking studies of 1-Aryl-3-[(thieno[3,2-b]pyridin-7-ylthio)phenyl]ureas: Discovery of a new substitution pattern for type II VEGFR-2 Tyr kinase inhibitors

The synthesis and biological evaluation of novel 1-aryl-3-[2-, 3- or 4-(thieno[3,2-b]pyridin-7-ylthio)phenyl]ureas 3, 4 and 5 as VEGFR-2 tyrosine kinase inhibitors, are reported. The 1-aryl-3-[3-(thieno[3,2-b]pyridin-7-ylthio)phenyl]ureas 4a-4h, with the arylurea in the meta position to the thioether, showed the lowest IC50 values in enzymatic assays (10-206 nM), the most potent compounds 4d-4h (IC50 10-28 nM) bearing hydrophobic groups (Me, F, CF3 and Cl) in the terminal phenyl ring. A convincing rationalization was achieved for the highest potent compounds 4 as type II VEGFR-2 inhibitors, based on the simultaneous presence of: (1) the thioether linker and (2) the arylurea moiety in the meta position. For compounds 4, significant inhibition of Human Umbilical Vein Endothelial Cells (HUVECs) proliferation (BrdU assay), migration (wound-healing assay) and tube formation were observed at low concentrations. These compounds have also shown to increase apoptosis using the TUNEL assay. Immunostaining for total and phosphorylated (active) VEGFR-2 was performed by Western blotting. The phosphorylation of the receptor was significantly inhibited at 1.0 and 2.5 microM for the most promising compounds. Altogether, these findings point to an antiangiogenic effect in HUVECs.