219 research outputs found

    Multifunctional metal-organic frameworks : from academia to industrial applications

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    After three decades of intense and fundamental research on metal-organic frameworks (MOFs), is there anything left to say or to explain? The synthesis and properties of MOFs have already been comprehensively described elsewhere. It is time, however, to prove the nature of their true usability: technological applications based on these extended materials require development and implementation as a natural consequence of the up-to-known intensive research focused on their design and preparation. The current large number of reviews on MOFs emphasizes practical strategies to develop novel networks with varied crystal size, shape and topology, being mainly devoted to academic concerns. The present survey intends to push the boundaries and summarise the state-of-the-art on the preparation of promising (multi) functional MOFs in worldwide laboratories and their use as materials for industrial implementation. This review starts, on the one hand, to describe several tools and striking examples of remarkable and recent (multi) functional MOFs exhibiting outstanding properties (e.g., in gas adsorption and separation, selective sorption of harmful compounds, heterogeneous catalysis, luminescent and corrosion protectants). On the other hand, and in a second part, it intends to use these examples of MOFs to incite scientists to move towards the transference of knowledge from the laboratories to the industry. Within this context, we exhaustively review the many efforts of several worldwide commercial companies to bring functional MOFs towards the daily use, analysing the various patents and applications reported to date. Overall, this review goes from the very basic concepts of functional MOF engineering and preparation ending up in their industrial production on a large scale and direct applications in society

    Book of Abstracts of SPE 2021

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    Book of Abstracts of SPE 202

    Tailoring Upconversion and Morphology of Yb/Eu Doped Y2O3 Nanostructures by Acid Composition Mediation

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    The authors also acknowledge funding from the European Commission through the projects 1D-NEON (H2020-NMP-2015, grant 685758-21D). The work was also partially funded by the Nanomark collaborative project between INCM (Imprensa Nacional-Casa da Moeda) and CENIMAT/i3N. P.A. Carvalho acknowledges support from the Research Council of Norway through grants 275752 and 197405/F50.The present study reports the production of upconverter nanostructures composed by a yttrium oxide host matrix co-doped with ytterbium and europium, i.e., Y2O3:Yb3+/Eu3+. These nanostructures were formed through the dissociation of yttrium, ytterbium and europium oxides using acetic, hydrochloric and nitric acids, followed by a fast hydrothermal method assisted by microwave irradiation and subsequent calcination process. Structural characterization has been carried out by X-ray diffraction (XRD), scanning transmission electron microscopy (STEM) and scanning electron microscopy (SEM) both coupled with energy dispersive X-ray spectroscopy (EDS). The acid used for dissociation of the primary oxides played a crucial role on the morphology of the nanostructures. The acetic-based nanostructures resulted in nanosheets in the micrometer range, with thickness of around 50 nm, while hydrochloric and nitric resulted in sphere-shaped nanostructures. The produced nanostructures revealed a homogeneous distribution of the doping elements. The thermal behaviour of the materials has been investigated with in situ X-Ray diffraction and differential scanning calorimetry (DSC) experiments. Moreover, the optical band gaps of all materials were determined from diffuse reflectance spectroscopy, and their photoluminescence behaviour has been accessed showing significant differences depending on the acid used, which can directly influence their upconversion performance.publishersversionpublishe

    Unveiling the mechanism of action of 7α-acetoxy-6β-hydroxyroyleanone on an mrsa/visa strain: Membrane and cell wall interactions

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    UIDB/00100/2020 PTDC/MED-QUI/29036/2017 CEECIND/03414/2018 UIDB/04378/2020 PTDC/BIA-MIC/31645/2017 UID/DTP/04138/2019 UID/DTP/04567/2019 CBIOS/PRUID/BI1/2017 UIDB/04567/2020 UID/AMB/50017 UIDP/50017/2020 UIDB/50017/2020The number of cases of failure in the treatment of infections associated with resistant bacteria is on the rise, due to the decreasing efficacy of current antibiotics. Notably, 7α-Acetoxy-6β-hydroxyroyleanone (AHR), a diterpene isolated from different Plectranthus species, showed antibacterial activity, namely against Methicillin-resistant Staphylococcus aureus (MRSA) strains. The high antibacterial activity and low cytotoxicity render this natural compound an interesting alternative against resistant bacteria. The aim of this study is to understand the mechanism of action of AHR on MRSA, using the MRSA/Vancomycin-intermediate S. aureus (VISA) strain CIP 106760, and to study the AHR effect on lipid bilayers and on the cell wall. Although AHR interacted with lipid bilayers, it did not have a significant effect on membrane passive permeability. Alternatively, bacteria treated with this royleanone displayed cell wall disruption, without revealing cell lysis. In conclusion, the results gathered so far point to a yet undescribed mode of action that needs further investigation.publishersversionpublishe

    Roots and rhizomes of wild Asparagus: Nutritional composition, bioactivity and nanoencapsulation of the most potent extract

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    The nutritional composition and bioactive properties of roots and rhizomes of Asparagus stipularis were evaluated. Antioxidant activity of extracts obtained by infusion was evaluated using free radicals scavenging and reducing power methods. Porcine liver primary cell was used to check the hepatotoxicity of infusions. Results revealed that Asparagus samples are likely a source of nutrients, such as dietary fibre and essential fatty acids. HPLC-DAD-ESI/MS characterization of infusions allowed the identification and quantitation of 7 phenolic compounds, all hydroxycinnamoyl derivatives, with caffeic acid as the most abundant. Roots infusion contained the highest amounts of these compounds. It also exhibited the highest antioxidant activity in all assays, with EC50 values of 0.44 ± 0.01, 0.98 ± 0.03 and 0.64 ± 0.01 mg/mL for DPPH, ABTS and FRAP assays, respectively, with no toxicity towards PLP2 primary cell cultures (GI50 > 400 μg/mL). PLGA nanoparticles loaded with root extract were prepared using solvent-evaporation double emulsion method. Nanoparticles size was about 260 nm and a polydispersity index around 0.1, with a zeta potential of about -36 mV, as well as a good encapsulation efficiency of approximately 83%. Their morphology was analysed by SEM and spherical polymeric nanoparticles with a smooth surface were observed. FTIR and DSC were also performed, which allowed corroborating the efficacy of the encapsulation and to confirm the production of a stable and robust system to load Asparagus extracts. The developed nanoparticles are expected to be used as delivery systems for bioactive compounds of A. stipularis and they could be used as an innovative dietary supplement.The UCM authors would like to thank to ALIMNOVA Research Group (UCM GR105/18) and Spanish Government through the project PID2019-109365RA-I00. Authors are also grateful to Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020), LAQV (UIDB/50006/2020), CCMar (UIDB/04326/2020), CBIOS (UIDB/ 04567/2020) and iBB-IST (UIDB/04565/2020). A. Fernandes contract was provided by National funding by FCT, P. I., through the institutional scientific employment program-contract. The authors are also grateful to FEDER-Interreg España-Portugal programme for financial support through the project 0377_Iberphenol_6_E. The GIP-USAL is financially supported by the Spanish Government through the project AGL2015- 64522-C2-2-R.info:eu-repo/semantics/publishedVersio

    Oral vaccination of fish against vibriosis using spore-display technology

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    Publisher Copyright: Copyright © 2022 Gonçalves, Santos, Coutinho, Pedrosa, Curado, Machado, Costas, Bonneville, Serrano, Carvalho, Díaz-Rosales, Oliva-Teles, Couto and Serra.Oral vaccines are highly demanded by the aquaculture sector, to allow mass delivery of antigens without using the expensive and labor-intensive injectable vaccines. These later require individual handling of fish, provoking stress-related mortalities. One possible strategy to create injection-free vaccine delivery vehicles is the use of bacterial spores, extremely resistant structures with wide biotechnological applications, including as probiotics, display systems, or adjuvants. Bacterial spores, in particular those of Bacillus subtilis, have been shown to behave as mucosal vaccine adjuvants in mice models. However, such technology has not been extensively explored against fish bacterial disease. In this study, we used a laboratory strain of B. subtilis, for which a variety of genetic manipulation tools are available, to display at its spores surface either a Vibrio antigenic protein, OmpK, or the green fluorescence protein, GFP. When previously vaccinated by immersion with the OmpK- carrying spores, zebrafish survival upon a bacterial challenge with V. anguillarum and V. parahaemolyticus, increased up to 50 - 90% depending on the pathogen targeted. Further, we were able to detect anti-GFP-antibodies in the serum of European seabass juveniles fed diets containing the GFP-carrying spores and anti-V. anguillarum antibodies in the serum of European seabass juveniles fed the OmpK-carrying spores containing diet. More important, seabass survival was increased from 60 to 86% when previously orally vaccinated with in-feed OmpK- carrying spores. Our results indicate that B. subtilis spores can effectively be used as antigen-carriers for oral vaccine delivery in fish.publishersversionpublishe

    Staphylococcus aureus Survives with a Minimal Peptidoglycan Synthesis Machine but Sacrifices Virulence and Antibiotic Resistance

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    Many important cellular processes are performed by molecular machines, composed of multiple proteins that physically interact to execute biological functions. An example is the bacterial peptidoglycan (PG) synthesis machine, responsible for the synthesis of the main component of the cell wall and the target of many contemporary antibiotics. One approach for the identification of essential components of a cellular machine involves the determination of its minimal protein composition. Staphylococcus aureus is a Gram-positive pathogen, renowned for its resistance to many commonly used antibiotics and prevalence in hospitals. Its genome encodes a low number of proteins with PG synthesis activity (9 proteins), when compared to other model organisms, and is therefore a good model for the study of a minimal PG synthesis machine. We deleted seven of the nine genes encoding PG synthesis enzymes from the S. aureus genome without affecting normal growth or cell morphology, generating a strain capable of PG biosynthesis catalyzed only by two penicillin-binding proteins, PBP1 and the bi-functional PBP2. However, multiple PBPs are important in clinically relevant environments, as bacteria with a minimal PG synthesis machinery became highly susceptible to cell wall-targeting antibiotics, host lytic enzymes and displayed impaired virulence in a Drosophila infection model which is dependent on the presence of specific peptidoglycan receptor proteins, namely PGRP-SA. The fact that S. aureus can grow and divide with only two active PG synthesizing enzymes shows that most of these enzymes are redundant in vitro and identifies the minimal PG synthesis machinery of S. aureus. However a complex molecular machine is important in environments other than in vitro growth as the expendable PG synthesis enzymes play an important role in the pathogenicity and antibiotic resistance of S. aureus

    Meta-analysis of multidecadal biodiversity trends in Europe

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    Local biodiversity trends over time are likely to be decoupled from global trends, as local processes may compensate or counteract global change. We analyze 161 long-term biological time series (15-91 years) collected across Europe, using a comprehensive dataset comprising similar to 6,200 marine, freshwater and terrestrial taxa. We test whether (i) local long-term biodiversity trends are consistent among biogeoregions, realms and taxonomic groups, and (ii) changes in biodiversity correlate with regional climate and local conditions. Our results reveal that local trends of abundance, richness and diversity differ among biogeoregions, realms and taxonomic groups, demonstrating that biodiversity changes at local scale are often complex and cannot be easily generalized. However, we find increases in richness and abundance with increasing temperature and naturalness as well as a clear spatial pattern in changes in community composition (i.e. temporal taxonomic turnover) in most biogeoregions of Northern and Eastern Europe. The global biodiversity decline might conceal complex local and group-specific trends. Here the authors report a quantitative synthesis of longterm biodiversity trends across Europe, showing how, despite overall increase in biodiversity metric and stability in abundance, trends differ between regions, ecosystem types, and taxa.peerReviewe
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