Critical wetting of a class of nonequilibrium interfaces: A mean-field picture

A self-consistent mean-field method is used to study critical wetting transitions under nonequilibrium conditions by analyzing Kardar-Parisi-Zhang (KPZ) interfaces in the presence of a bounding substrate. In the case of positive KPZ nonlinearity a single (Gaussian) regime is found. On the contrary, interfaces corresponding to negative nonlinearities lead to three different regimes of critical behavior for the surface order-parameter: (i) a trivial Gaussian regime, (ii) a weak-fluctuation regime with a trivially located critical point and nontrivial exponents, and (iii) a highly non-trivial strong-fluctuation regime, for which we provide a full solution by finding the zeros of parabolic-cylinder functions. These analytical results are also verified by solving numerically the self-consistent equation in each case. Analogies with and differences from equilibrium critical wetting as well as nonequilibrium complete wetting are also discussed.Comment: 11 pages, 2 figure

Biomaterials as Tendon and Ligament Substitutes: Current Developments

Tendon and ligament have specialized dynamic microenvironment characterized by a complex hierarchical extracellular matrix essential for tissue functionality, and responsible to be an instructive niche for resident cells. Among musculoskeletal diseases, tendon/ligament injuries often result in pain, substantial tissue morbidity, and disability, affecting athletes, active working people and elder population. This represents not only a major healthcare problem but it implies considerable social and economic hurdles. Current treatments are based on the replacement and/or augmentation of the damaged tissue with severe associated limitations. Thus, it is evident the clinical challenge and emergent need to recreate native tissue features and regenerate damaged tissues. In this context, the design and development of anisotropic bioengineered systems with potential to recapitulate the hierarchical architecture and organization of tendons and ligaments from nano to macro scale will be discussed in this chapter. Special attention will be given to the state-of-the-art fabrication techniques, namely spinning and electrochemical alignment techniques to address the demanding requirements for tendon substitutes, particularly concerning the importance of biomechanical and structural cues of these tissues. Moreover, the poor innate regeneration ability related to the low cellularity and vascularization of tendons and ligaments also anticipates the importance of cell based strategies, particularly on the stem cells role for the success of tissue engineered therapies. In summary, this chapter provides a general overview on tendon and ligaments physiology and current conventional treatments for injuries caused by trauma and/or disease. Moreover, this chapter presents tissue engineering approaches as an alternative to overcome the limitations of current therapies, focusing on the discussion about scaffolds design for tissue substitutes to meet the regenerative medicine challenges towards the functional restoration of damaged or degenerated tendon and ligament tissues.Portuguese Foundation for Science and Technology for the post-doctoral grant (SFRH/BPD/111729/2015) and for the projects Recognize (UTAP-ICDT/CTM-BIO/0023/2014) and POC I-01-0145-FEDER-007

Polyester-based photocrosslinkable bioadhesives for wound closure and tissue regeneration support

Photocrosslinkable surgical adhesives provide many advantages when compared with traditional methods used in wound closure. This work aimed to develop UV-curable biodegradable adhesives based on lactic acid and PCL oligomers. Both materials were functionalized with 2-isocyanatoethyl acrylate (AOI). Subsequently, the photoinitiator (Irgacure® 2959) was added to the blend and then, the final materials were irradiated under UV light for two different times: 30 s and 2 min. After production of adhesives, its physicochemical properties were evaluated through FTIR-ATR and TGA, as well as its rheology, dynamic water contact angle, swelling capacity and hydrolytic degradation. Furthermore, the biocompatibility of the produced adhesives was also characterized in contact with human dermal fibroblasts cells. The antimicrobial activity of the materials was assessed by using Staphylococcus aureus and Escherichia coli, as bacterial models.info:eu-repo/semantics/publishedVersio

The African hind's (Cephalopholis taeniops, serranidae) use of artificial reefs off Sal Island (Cape Verde): a preliminary study based on acoustic telemetry

The African hind Cephalopholis taeniops (Valenciennes, 1828) is one of the most important commercial demersal species caught in the Cape Verde archipelago. The species is closely associated with hard substrate and is one of the main attractions for SCUBA divers. In January 2006 a former Soviet fishing vessel - the Kwarcit - was sunk off Santa Maria Bay (Sal Island). Young C. taeniops are commonly observed in this artificial reef (AR). In order to investigate the species' use of the AR, 4 specimens were captured and surgically implanted underwater with Vemco brand acoustic transmitters. The fish were monitored daily with an active telemetry receiver for one week after release. Simultaneously, an array of 3 passive VR2 / VR2W receivers was set for 63 days, registering data that allowed an analysis of spatial, daily and short term temporal activity patterns. The results showed site fidelity to the AR, with no migrations to the nearby natural reef. The method used allowed to register a consistent higher activity during daytime and a preference for the area opposite the dominant current

Species of Fusarium isolated from river and sea water of Southeastern Spain and pathogenicity on four plant species

Species of Fusarium were isolated from water samples collected from the Andarax River and coastal sea water of the Mediterranean in Granada and Almería provinces of southeastern Spain. In total, 18 water samples were analyzed from the Andarax River, and 10 species of Fusarium were isolated: Fusarium anthophilum, F. acuminatum, F. chlamydosporum, F. culmorum, F. equiseti, F. verticillioides, F. oxysporum, F. proliferatum, F. solani, and F. solani. When considering the samples by their origins, 77.8% of the river water samples yielded at least one species of Fusarium , with F. oxysporum comprising 72.2% of the total isolates. In the case of marine water, 45.5% of the samples yielded at least one species of Fusarium, with F. solani comprising 36.3% of the total isolates. The pathogenicity of 41 isolates representing nine of the species collected from river an sea water during the study ws evluated on barley, kohlrabe, melon, and tomato. Inoculation with F. acuminatum, F. chlamydosporum, F. culmorum, F. equiseti, F. verticillioides, F. oxysporum, F. proliferatum F. solani, and F. sambucinum resulted in pre-and post-emergence damping off. Pathogenicity of Fusarium isolates did not seem to be related to the origin of the isolates (sea water or fresh water). However, the presence of pathogenic species of Fusarium in river water flowing to the sea could indicate long-distance dispersal in natural water environment

MEtop – a top FCNC event generator

In this work we present a new Monte Carlo generator for Direct top and Single top production via flavour-changing neutral currents (FCNC). This new tool calculates the cross section and generates events with Next-to-Leading order precision for the Direct top process and Leading-Order precision for all other FCNC single top processes. A set of independent dimension six FCNC operators has been implemented - including four-fermion operators - where at least one top-quark is present in the interaction.This work is partially supported by the Portuguese Fundacao para a Ciencia e a Tecnologia (FCT) under contracts CERN/FP/123619/2011 and PTDC/FIS/117951/2010. RS is also partially supported by an FP7 Reintegration Grant, number PERG08-GA-2010-277025 and by PEst-OE/FIS/UI0618/2011. RC is funded by FCT through the grant SFRH/BPD/45198/2008

Environmental remediation promoted by silver nanoparticles biosynthesized by eucalyptus leaves extract

A simple and low-cost green synthesis method was optimized to prepare stable silver nanoparticles (AgNP) using aqueous Eucalyptus globulus leaves extract. This green method allows to obtain AgNP with spherical morphology and variable size around 25 nm, and it is dependent of the reaction temperature and concentration of the plant extract. AgNP stability was followed during 3 months by zeta potential measurements and a negative zeta range from 30.7 to 33.6 was determined. Biogenic-stabilized AgNP exhibited dual-functional properties as effective in environmental remediation with bacterial growth inhibition and dye photodegradation. Staphylococcus aureus and Escherichia coli were tested for antibacterial activity, and considerable inhibitory activity was found. High photocatalytic degradation of indigo carmine (IC) dye was performed in the presence of the AgNP as catalysts under sunlight irradiation. The degradation efficiency after 2 h of reaction was 37 %, 83 % and 98 % in the presence of UV light, visible light and sunlight irradiation, respectively. The germination of corn kernels test was used to determine the toxicity of the treated IC solutions and the results showed low toxicity after the photodegradation process.V.R. thanks to Fundação para Ciência e Tecnologia, FCT (Portugal) for her Ph.D. grant (SFRH/BD/141073/2018). P⋅F-S. would like to express their gratitude to the Spanish Ministry of Economy and Competitiveness for their postdoctoral grant (Reference FJC2021-046978-I). This research work has been funded by FCT/MCTES (PIDDAC) over the projects: CQ-UM (UID/QUI/0686/2020), CEB (UIDB/04469/2020) and LABBELS (LA/P/0029/2020), and project BioTecNorte (operation NORTE-01-0145-FEDER-000004), supported by the Northern Portugal Regional Operational Program (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF).info:eu-repo/semantics/publishedVersio

Intracellular nucleic acid delivery by the supercharged dengue virus capsid protein

© 2013 Freire et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Supercharged proteins are a recently identified class of proteins that have the ability to efficiently deliver functional macromolecules into mammalian cells. They were first developed as bioengineering products, but were later found in the human proteome. In this work, we show that this class of proteins with unusually high net positive charge is frequently found among viral structural proteins, more specifically among capsid proteins. In particular, the capsid proteins of viruses from the Flaviviridae family have all a very high net charge to molecular weight ratio (> +1.07/kDa), thus qualifying as supercharged proteins. This ubiquity raises the hypothesis that supercharged viral capsid proteins may have biological roles that arise from an intrinsic ability to penetrate cells. Dengue virus capsid protein was selected for a detailed experimental analysis. We showed that this protein is able to deliver functional nucleic acids into mammalian cells. The same result was obtained with two isolated domains of this protein, one of them being able to translocate lipid bilayers independently of endocytic routes. Nucleic acids such as siRNA and plasmids were delivered fully functional into cells. The results raise the possibility that the ability to penetrate cells is part of the native biological functions of some viral capsid proteins.This work was supported by Fundação para a Ciência e Tecnologia – Ministério da Educação e Ciência (FCT-MEC, Portugal) [PTDC/QUI-BIQ/112929/2009], by the European Union [projects FP7-PEOPLE IRSES (MEMPEPACROSS) and FP7-HEALTH-F3-2008-223414 (LEISHDRUG)], by the Spanish Ministry of Economy and Competitiveness (SAF2011-24899), the Generalitat de Catalunya (2009 SGR 492), by the Brazilian Conselho Nacional de Desenvolvimento Científico e Tecnoloógico (CNPq), Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), and the National Institute of Science and Technology in Dengue (INCT-Dengue). JMF also acknowledges FCT-MEC for Ph.D. fellowship SFRH/BD/70423/2010

Integrating DGSs and GATPs in an Adaptative and Collaborative Blended-Learning Web-Environment

The area of geometry with its very strong and appealing visual contents and its also strong and appealing connection between the visual content and its formal specification, is an area where computational tools can enhance, in a significant way, the learning environments. The dynamic geometry software systems (DGSs) can be used to explore the visual contents of geometry. This already mature tools allows an easy construction of geometric figures build from free objects and elementary constructions. The geometric automated theorem provers (GATPs) allows formal deductive reasoning about geometric constructions, extending the reasoning via concrete instances in a given model to formal deductive reasoning in a geometric theory. An adaptative and collaborative blended-learning environment where the DGS and GATP features could be fully explored would be, in our opinion a very rich and challenging learning environment for teachers and students. In this text we will describe the Web Geometry Laboratory a Web environment incorporating a DGS and a repository of geometric problems, that can be used in a synchronous and asynchronous fashion and with some adaptative and collaborative features. As future work we want to enhance the adaptative and collaborative aspects of the environment and also to incorporate a GATP, constructing a dynamic and individualised learning environment for geometry.Comment: In Proceedings THedu'11, arXiv:1202.453