Emulsion formation and stabilization by biomolecules: the leading role of cellulose

Emulsion stabilization by native cellulose has been mainly hampered because of its insolubility in water. Chemical modification is normally needed to obtain water-soluble cellulose derivatives. These modified celluloses have been widely used for a range of applications by the food, cosmetic, pharmaceutic, paint and construction industries. In most cases, the modified celluloses are used as rheology modifiers (thickeners) or as emulsifying agents. In the last decade, the structural features of cellulose have been revisited, with particular focus on its structural anisotropy (amphiphilicity) and the molecular interactions leading to its resistance to dissolution. The amphiphilic behavior of native cellulose is evidenced by its capacity to adsorb at the interface between oil and aqueous solvent solutions, thus being capable of stabilizing emulsions. In this overview, the fundamentals of emulsion formation and stabilization by biomolecules are briefly revisited before different aspects around the emerging role of cellulose as emulsion stabilizer are addressed in detail. Particular focus is given to systems stabilized by native cellulose, either molecularly-dissolved or not (Pickering-like effect).Financially support by the Portuguese Foundation for Science and Technology, FCT, via the projects PTDC/AGR-TEC/4814/2014, PTDC/ASP-SIL/30619/2017 and researcher grant IF/01005/2014. RISE Research Institutes of Sweden AB and PERFORM, a competence platform in Formulation Science at RISE, are acknowledged for additional financing. This research has been supported by Treesearch.se.info:eu-repo/semantics/publishedVersio

Species gap analysis in DNA barcode reference libraries of marine non-indigenous species in the Azores archipelago

Coastal regions are widely recognised for their ecologic and socio-economic importance. The spread of invasive species, along with global climate change, overexploitation, pollution and habitat destruction, is a major threat to coastal ecosystems (Solan et al. 2004). Some of these species, in particular macroalgae and invertebrates, can spread quickly and become invasive, causing severe ecologic and economic impacts. When prevention fails, the early detection and surveillance of NIS could be essential for coordinating a timely and effective response to invasions. Marine ecosystems on oceanic islands, such as Azores, can be especially prone to invasions by non-indigenous species since they are characterized by a small number of native species and by a high availability of empty niches, and thus, the list of NIS is relatively long (Micael et al. 2014). There are no doubts that traditional morphology-based methods have highly contributed to the current knowledge about NIS communities inhabiting Portuguese coastal waters, including the Portuguese oceanic islands (Micael et al. 2014, Chainho et al. 2015). However, the hurdles associated with morphological methods may compromise the early detection and monitoring of the most risky species. On the other hand, DNA-based tools promise advantages over traditional ones, particularly the identification of individuals and life stages that cannot be recognized by using morphological approaches (Darling and Mahon 2011). Plus, most surveys typically target specific species or taxonomic groups, which may neither accurately represent overall ecosystems’ condition nor allow an early detection of NIS. Due to the above-mentioned reasons, it becomes a priority to develop and optimize novel detection methods capable to overcome some of these challenges and that would allow an early detection and ease the monitoring of NIS in coastal ecosystems. Particularly, the combination of DNA barcoding with high-throughput sequencing (HTS) renders metabarcoding the capacity to bolster current biodiversity assessments techniques (Cristescu 2014). Within this approach, genetic information can be obtained through the use of standardized DNA barcode markers targeting a wide taxonomic range of organisms in mixed specimens or environmental samples (Cristescu 2014). DNA-based tools promise a number of potential benefits over traditional methods, including increased sensitivity and specificity as well as greater throughput and cost effectiveness. However, the success of DNA-based methods is greatly dependent on the availability, taxonomic coverage and reliability of reference sequence databases, whose deficiencies can potentially compromise species identifications through HTS (Briski et al. 2016). In this study we conducted a species-gap analysis of DNA barcode sequences available for marine NIS occurring in the Azores archipelago in the Barcode of Life Data System V4 (BOLD V4) (Ratnasingham and Hebert 2007) and in the GenBank (https://www.ncbi.nlm.nih.gov/genbank/). The list of NIS occurring in Azores was compiled from a wide variety of sources, mainly from literature searches through scientific papers and reports, including recent field and taxonomic studies, and supplemented with existing databases and this is the list that was submitted to the 2019 interim ICES WGITMO report (International Council for the Exploration of the Sea; Working Group on Introductions and Transfers of Marine Organisms). The taxonomic classification of the compiled NIS followed the AlgaeBase and World Register of Marine Species (WoRMS) databases. A checklist of 80 marine NIS occurring in Azores archipelago was compiled and the species in the list were checked for the presence of public sequences on both BOLD v4 and GenBank databases. The species in the list were distributed by three kingdoms: i) Animalia (48 species), ii) Plantae (30 species) and iii) Chromista (2 species), comprehending 10 phyla. The most well represented phyla with NIS were Chordata (15 species), Mollusca and Bryozoa (both with 8 species) within Animalia, and Rhodophyta within Plantae (26 species); while the only represented phyla within Chromista was Ochrophyta with 2 species. In total, 3,884 sequences belonging to 25 different markers were found for the 80 species, published in BOLD and GenBank. Among these published sequences, the COI-5P is the most well represented loci, with 3,224 records belonging to 44 species. However, from the total species in the list, 25 were still missing a DNA sequence, which corresponded to ca. 31% of the total NIS. In addition, within sequenced species ca. 14% were singletons (i.e. only one sequence available). Animalia NIS were the most well represented with sequences, missing only for ca. 27% of the species, while for Chromista and Plantae the gap of missing species was higher than 35%. The current study allowed us to characterize the gaps in available sequences in public repositories for marine NIS occurring in the Azores archipelago. Actions developing DNA-based tools should be a priority for detection and effective management of biological invasions. DNA-based tools would allow the detection of early developmental stages or smaller organisms, reducing the time from introduction to discovery and increasing the success of NIS control and/or eradication (Holman et al. 2018). However, the gaps found in reference libraries can have strong implications for an accurate species identification through DNA-based tools. Prioritization efforts should be conducted in order to fulfil these gapsFCT – Fundação para a Ciência e a Tecnologia, I.P., in the scope of the project PTDC/BIA-BMA/29754/2017 and by FEDER funds through the Operational Programme for Competitiveness Factors - COMPETE and by National Funds through FCT - Foundation for Science and Technology under the UID/BIA/50027/2013 and POCI-01-0145-FEDER-00682

Highly selective and sensitive detection of toxic metals by fluorescent Bicyclic Calix[4]arene-based sensors

Este trabalho foi financiado pelo Concurso Anual para Projetos de Investigação, Desenvolvimento, Inovação e Criação Artística (IDI&CA) 2016 do Instituto Politécnico de Lisboa. Código de Referência IPL/2016/NoSeMeTox_ISELDevelopment of fast and portable chemosensors for trace detection of toxic metals, in particular those which are mostly present in the environment due to natural phenomenon and human activities (e.g. cadmium, mercury and lead), is a challenging area of current research.1 Calixarenes are one of the most widespread scaffolds in host-guest chemistry because of their rigid structures, which make them perfect candidates for complexation studies with ions and neutral molecules. Metal ions commonly bind at the lower rim of the calixarene moiety. Host-guest interaction can be enhanced by proper choice of additional binding sites containing nitrogen, oxygen, sulfur or a combination of them, and specifically designed calixarene architectures. Exploring the inherent capabilities of certain fluorescent calixarene-based compounds for establishing strong host:guest interactions, several sensing materials have been developed and tested by us towards the detection of neutral molecular species.2. We report in this communication the chemosensing ability of CALIX-OCP-CBZ and CALIX-OCP (Scheme 1) towards the detection of toxic metals, either by using the sensing element in fluid phase or solid state.info:eu-repo/semantics/publishedVersio

Gaps in DNA sequence libraries for macaronesian marine macroinvertebrates imply decades till completion and robust monitoring

Aim: DNA metabarcoding has great potential to improve biomonitoring in island's marine ecosystems, which are highly vulnerable to global change and non-indigenous species (NIS) introductions. However, the depth and accuracy of the taxonomic identifications are mainly dependent on reference libraries containing representative and reliable sequences for the targeted species. In this study, we evaluated the gaps in the availability of DNA sequences and their accuracy for macroinvertebrates inhabiting Macaronesia's shallow marine habitats. Location: Macaronesia (Azores, Madeira, Selvagens, Canaries). Methods: Checklists of marine invertebrates occurring above 50 m depth were compiled using public databases and published checklists. The availability of cytochrome c oxidase subunit I (COI) and 18S rRNA (18S) gene sequences was verified in BOLD and GenBank. Finally, COI data were audited to check the congruence between morphospecies and Barcode Index Numbers (BINs). Results: The taxonomic coverage of different phyla was greater for COI but unbalanced and variable among archipelagos. NIS were better represented in genetic databases (up to 73% and 59%, for COI and 18S, respectively) than native species (up to 47% and 31%, for COI and 18S, respectively). NIS displayed a higher number of discordant records, and native species, a higher quantity of cases of multiple BINs. Notably, DNA sequences generated from specimens collected from Macaronesia were found in less than 10% of the species. Projection of the rates of accretion of DNA sequences suggests that decades will be needed to complete these reference libraries. Main conclusions: The level of completion of reference libraries for Macaronesia's marine macroinvertebrates is generally poor. Without a solid effort to speed up the production of sequence data (i.e. generate more DNA barcodes), the ability to employ DNA-based biomonitoring of such vulnerable fauna is compromised. The high levelsof suspected hidden diversity further deepen the expected gaps and reinforce the vulnerability of this endemism-rich fauna.Fundacao para a Ciencia e a Tecnologia, Grant/Award Number: EECIND/00667/2017, POCI-01-0145-FEDER-006821, PTDC/BIA-BMA/29754/2017, UID/BIA/50027/2019-2020 and UIDB/04050/202

Biopolymer films doped with silver(I) coordination polymers against bacterial biofilms

This report describes a template-mediated self-assembly synthesis, full characterization, and structural features of two new silver-based bioactive coordination polymers (CPs) as well their immobilization into acrylated epoxidized soybean oil (ESOA) biopolymer films for antimicrobial applications. The 3D silver(I) CPs [Ag4(8-H2pma)2]n·4nH2O (1) and [Ag5(6-H0.5tma)2(H2O)4]n·2nH2O (2) were generated from AgNO3 and pyromellitic (H4pma) or trimesic (H3tma) acid, also using N,N-dimethylethanolamine (Hdmea) as a template. Both 1 and 2 feature the intricate 3D layer-pillared structures driven by distinct polycarboxylate blocks. Topological analysis revealed binodal nets with the flu and tcj/hc topology in 1 and 2, respectively. These CPs were used to create new hybrid materials, namely by doping the [ESOA]n biopolymer films with very low amounts of 1 and 2 (0.05, 0.1, and 0.5%). Their antimicrobial activity and ability to inhibit bacterial biofilm formation was investigated in detail against both Gram-positive (Staphylococcus epidermidis and Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacteria. Both silver(I) coordination polymers and derived biopolymer films showed activity against all the tested bacteria in a concentration dependent manner. Compound 1 was far more active, especially in preventing biofilm formation, with mean bacterial load reductions ranging from 3.7 to 4.3 log against the four bacteria (99.99% bacterial eradication). Thus, the present study expands the antibiofilm applications of CP-doped biopolymers, offering new perspectives and promising results for the design of functional biomaterials (Scheme 1).This work was supported by the Foundation for Science and Technology (FCT) and Portugal 2020 (projects PTDC/QUI-QIN/29697/2017, LISBOA-01-0145-FEDER-029697, UIDB/00100/2020, UIDP/00100/2020, IPL/2020/HyBioPol and REM2013), contracts CEECIND/02725/2018 and CEECIND/00194/2020.info:eu-repo/semantics/publishedVersio

Effect of bio-functional MAO layers on the electrochemical behaviour of highly porous Ti

Ti foams are attractive for orthopaedic applications due to reduced Young's modulus and ability of bone ingrowth. However, poor corrosion behaviour and lack of bioactivity are yet to be overcome. In the present work, highly porous Ti samples were processed by powder metallurgy with space holder technique and bio-functionalized by micro-arc oxidation, resulting in nano/micro structured TiO2 surfaces containing bioactive elements. The electrochemical behaviour of these bio-functionalized highly porous Ti surfaces was evaluated through potentiodynamic polarization and EIS in physiological solution at body temperature. Results showed that bio-functionalization improved the corrosion behaviour of highly porous Ti. However, increased macro-porosity led to an increased corrosion rate.This work is supported by FCT with the reference project UID/EEA/04436/2019, M-ERA NET/0001/2015 project, and Programa de Accoes Universitarias Integradas Luso-Francesas' (PAUILF TC-12_14). CQE is financed by FCT under Pluriannual contract 2020-2023. The authors also gratefully acknowledge the "Investissements d'avenir" programs (nos. ANR-11-IDEX-0003-02 and ANR-10-EQPX-37 MATMECA Grant) for financial support on Micro-CT analysis

Changes in bone Pb accumulation: Cause and effect of altered bone turnover

Notice: this is the author’s version of a work that was accepted for publication in Bone. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Bone, [Vol 64 (2014 Jul)] DOI 10.1016/j.bone.2014.04.021"This paper assesses the magnitude of Pb uptake in cortical and trabecular bones in healthy animals and animals with altered balance in bone turnover, and the impact of exposure to Pb on serum markers of bone formation and resorption. The results reported herein provide physiological evidence that Pb distributes differently in central compartments in Pb metabolism, such as cortical and trabecular bone, in healthy animals and animals with altered balance in bone turnover, and that exposure to Pb does have an impact on bone resorption resulting in OC-dependent osteopenia. These findings show that Pb may play a role in the etiology of osteoporosis and that its concentration in bones varies as a result of altered bone turnover characteristic of this disease, a long standing question in the field. In addition, data collected in this study are consistent with previous observations of increased half-life of Pb in bone at higher exposures. This evidence is relevant for the necessary revision of current physiologically based kinetic models for Pb in humans.

TiO2 bioactive implant surfaces doped with specific amount of Sr modulate mineralization

One of the main problems that remain in the implant industry is poor osseointegration due to bioinertness of implants. In order to promote bioactivity, calcium (Ca), phosphorus (P) and strontium (Sr) were incorporated into a TiO2 porous layer produced by micro-arc oxidation. Ca and P as bioactive elements are already well reported in the literature, however, the knowledge of the effect of Sr is still limited. In the present work, the effect of various amounts of Sr was evaluated and the morphology, chemical composition and crystal structure of the oxide layer were investigated. Furthermore, in vitro studies were carried out using human osteoblast-like cells. The oxide layer formed showed a triplex structure, where higher incorporation of Sr increased Ca/P ratio, amount of rutile and promoted the formation of SrTiO3 compound. Biological tests revealed that lower concentrations of Sr did not compromise initial cell adhesion neither viability and interestingly improved mineralization. However, higher concentration of Sr (and consequent higher amount of rutile) showed to induce collagen secretion but with compromised mineralization, possibly due to a delayed mineralization process or induced precipitation of deficient hydroxyapatite. Ca-P-TiO2 porous layer with less concentration of Sr seems to be an ideal candidate for bone implants.This work was supported by FCT with the reference projects UID/EEA/04436/2019, M-ERA-NET/0001/2015 and FCT/CAPES Procs.. 4.4.1.00. Also the support of FAPESP is acknowledged (Proc. 2017/24300-4). A.I. Costa is very grateful for the PhD grant through NORTE-08-5369-FSE-000051 project. The authors would like to thank the LABNANO/CBPF and Centro Nacional de Biologia Estrutural e Bioimagem (Cenabio) in Rio de Janeiro for technical support during electron microscopy work

Boosting cultural heritage in rural communities through an ICT platform: the Viv@vó project

Rural regions concentrate on themselves a very rich set of ancestral traditions. The perpetuation of such traditions has been achieved through transmission between generations. Unfortunately, all this knowledge is typically elders-centered and it lacks effective processes of digitalization, storage and providing-systems for that all this heritage can effectively be perpetuated through future generations that are digital-born. From this base, it was created a project case study limited to the Portuguese Northeast region, named Viv@vó – living in the grandma's house. This paper presents the ICT platform that was created in this project and some main achievements during the project development process. Tourism and mainly experience and cultural heritage tourism are growing in tourist’s interests. Rural regions have an untapped potential for this slice of tourism industry. Rural regions have an enormous collection of ancestral knowledge that we are responsible to deliver to future generations as an inheritance to which they are entitled.The present work was developed under the Viv@vó Project: "Living in the Grandma's House", with the reference NORTE-01- 0145-FEDER-023637, financed by the Regional Operational Program of the North, Notice 02/SAICT/2016.info:eu-repo/semantics/publishedVersio