2,737 research outputs found

    Primeiro registo do tubarão-anão, Squaliolus laticaudus (Smith & Radcliffe, 1912) nos Açores, estendendo a sua distribuição ocidental no Atlântico Nordeste

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    A presente nota documenta a primeira observação do tubarão-anão, Squaliolus laticaudus (Smith & Radcliffe, 1912), nos Açores, estendendo a sua distribuição ocidental no Atlântico Nordeste até ao arquipélago. A ocorrência da espécie nos arquipélagos macaronésicos é igualmente discutida.ABSTRACT: This paper reports the first observation of the spined pygmy shark, Squaliolus laticaudus, from the Azores, extending its westernmost distribution in the North-eastern Atlantic as far as this archipelago. The occurrence of this species in the Macaronesian archipelagos is also discussed

    Staining techniques for ageing tope shark, Galeorhinus galeus (Linnaeus, 1758), from the Azores : a comparison based on precision analysis.

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    A vertebrae sample of tope shark, Galeorhinus galeus (Linnaeus, 1758), stratified by sizeclasses,was used to test between different staining techniques of enhancing vertebral growth ring visibility. Four techniques were tested: alizarin red, silver nitrate and cobalt nitrate staining, and the “deep-coned vertebrae” technique. The latter was discarded due to its unsuitability for tope shark vertebrae. The cobalt nitrate original protocol was modified. Upon staining, each vertebra was subject to three replicated independent readings, by a single reader. Within-reader consistency and bias of growth ring counts determination were evaluated using four different precision indices: percent of agreement (PA), average percent error (APE), coefficient of variation (V) and index of precision (D). Results indicated that the vertebrae stained with the cobalt nitrate technique showed both better optic enhancement of growth rings and higher degree of count consistency, comparatively to the alizarin red and silver stained vertebrae. Conclusively, the cobalt nitrate was the most efficient staining technique upon tope shark vertebrae, among the methods tested herein

    Low-Phytotoxic Deep Eutectic Systems as Alternative Extraction Media for the Recovery of Chitin from Brown Crab Shells

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    Funding Information: This work was financed by Portugal 2020 through the European Regional Development Fund (ERDF) in the frame of Operational Competitiveness and Internationalization Program (POCI) in the scope of the project MultiBiorefinery—POCI-01-0145-FEDER-016403, co-financed by national funds through the FCT/MEC. Additional funding was received from PTDC/EQU-EQU/29851/2017 project, financed by national funds (FCT/MEC); and from ERC-2016-CoG 725034 grant agreement, financed by the European Union’s Horizon 2020 (European Research Council). This work was also supported by the funding received from INTERFACE Program, through the Innovation, Technology and Circular Economy Fund (FITEC); and from iNOVA4Health (UIDB/04462/2020) and the Associate Laboratory for Green Chemistry—LAQV (UIDB/50006/2020), programs financially supported by FCT/MEC, through national funds. This work has also received support from COST Action CA18224 through an STSM Grant. Liliana A. Rodrigues, Alexandre Paiva, and Ana A. Matias have also received financial support from FCT through the SFRH/BD/116002/2016, IF/01146/2015, and IF/00723/2014 grants, respectively. The authors are grateful to Tejo Ribeirinho Lda. for kindly supplying the biomass used in this work. Publisher Copyright: © 2021 American Chemical Society.The versatility of chitin and its derivatives has allowed their utilization in a wide range of applications, from wastewater treatment to pharmaceutical or biomedical industries. However, even though the extraction method used industrially is extremely efficient, it involves the use of strong acids and bases and results in the disposal of large quantities of toxic effluents. Deep eutectic systems (DESs) have emerged as a promising new class of alternative solvents, including for chitin recovery. Yet, the assessment of their toxicity has often been neglected. Therefore, in this work, the phytotoxicity of choline chloride (ChCl)/organic acid-based DESs toward wheat seeds was evaluated by measuring different growth parameters and stress biomarkers. DESs were then explored for the efficient recovery of chitin contained in brown crab shell residues at varying conditions of temperature and processing time as well as with and without water addition. The obtained chitin was then characterized through different analytical techniques and compared to a standard as well as to chitin obtained by a conventional acid/alkaline hydrolysis. Results have shown that by applying a ChCl/lactic acid-based DES (which was the system that showed the least phytotoxic effects on wheat; EC50 ≥ 1.6 mg/mL) at 130 °C, it was possible to obtain pure chitin (up to 98%) with characteristics similar to those presented by commercial chitin or chitin recovered by conventional hydrolysis in a shorter time (more than 8-fold faster), thus suggesting that ChCl/organic acid-based DESs can truly represent a low-phytotoxic alternative extraction media for the recovery of chitin from the crab shell biomass.publishersversionpublishe

    Tailor made degradable ureteral stents from natural origin polysaccharides

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    A urinary stent is defined as a thin tube, which is inserted in the ureter to prevent or treat the obstruction of urine flow from the kidney. Silicone, latex, polyvinylchloride and polyurethanes are the most widely used materials for the preparation of stents. Nonetheless, severe clinical complications may result from the use of these materials such as fracture, encrustation and infection. In some of the cases, the ureteral stents are temporary and it is often required a second surgery to remove the stent. The main complications with ureteral stents are dislocation, infection, and blockage by encrustation [1]. Recently, a tendency has been noticed favouring less invasive approaches (e.g. pharmacological or catheterization) in treating patients who exhibit symptoms or signs of urinary retention [2]. Currently, nearly 100% of the people who have an urological stent are likely to develop a bacterial infection within 30 days, which increases morbidity threefold [1]. Different types of temporary and permanent stents have been introduced into urological practice to relieve obstructions [3]. Particular attention should be devoted to polymers as they represent a highly versatile class of materials. Despite the fact that silicon continues to be the gold standard material for urological stents, there have been fast developments in manufacturing processes, as well as the introduction of new biodegradable materials in order to overcome the drawbacks of the available products. Polyurethane continues to be the most widely used material for polymeric stents; however it frequently promotes biofilm formation and bacterial adhesion leading to severe infections [2]. The concerns regarding existing stents are the motivation to design new biodegradable urological stent systems based on natural polymers, specifically polysaccharides, which present inherent biocompatibility, anti-bacterial properties and that can be tailor-made into a custom suitable stent for a particular patient

    Optimal design of THEDES based on Perillyl Alcohol and Ibuprofen

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    Therapeutic deep eutectic systems (THEDES) have dramatically expanded their popularity in the pharmaceutical field due to their ability to increase active pharmaceutical ingredients (APIs) bioavailability. However, their biological performance has not yet been carefully scrutinized. Herein, THEDES based on the binary mixture of perillyl alcohol (POH) and ibuprofen (IBU) were prepared using different molar ratios. Our comprehensive strategy includes the characterization of their thermal and structural behavior to identify the molar ratios that successfully form deep eutectic systems. The in vitro solubility of the different systems prepared has demonstrated that, unlike other reported examples, the presence of the terpene did not affect the solubility of the anti-inflammatory agent in a physiological simulated media. The biological performance of the systems was studied in terms of their antimicrobial activity against a wide panel of microorganisms. The examined THEDES showed relevant antimicrobial activity against all tested microbial strains, with the exception of P. aeruginosa. A synergistic effect from the combination of POH and IBU as a eutectic system was verified. Furthermore, the cytotoxic profile of these eutectic systems towards colorectal cancer (CRC) in vitro cell models was also evaluated. The results provide the indication that the cell viability varies in a dose-dependent manner, with a selective THEDES action towards CRC cells. With tunable bioactivities in a ratio-dependent manner, THEDES enhanced the antimicrobial and anticancer properties, representing a possible alternative to conventional therapies. Therefore, this study provides foreseeable indications about the utility of THEDES based on POH and IBU as strong candidates for novel active pharmaceutical systems.Foundation for Science and Technology (FCT), through project PTDC/BBB-490 EBB/1676/2014–Des.Zyme, Light2Skin-PTDC/CTM-CTM/29813/2017 and ERC-2016-CoG 725034 (ERC Consolidator Grant Des.solve). E.S. would also like to acknowledge the financial support by the FCT through the doctoral grant with reference number SFHR/BD/143902/2019. J.M.S. would also like to acknowledge the financial support by the FCT through the post-doctoral grant with reference number SFRH/BPD/116779/201

    Water and carbon dioxide: green solvents for the extraction of collagen/gelatin from marine sponges

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    "Publication Date (Web): December 23, 2014"Marine sponges are extremely rich in natural products and are considered a promising biological resource. The major objective of this work is to couple a green extraction process with a natural origin raw material to obtain sponge origin collagen/gelatin for biomedical applications. Marine sponge collagen has unique physicochemical properties, but its application is hindered by the lack of availability due to inefficient extraction methodologies. Traditional extraction methods are time consuming as they involve several operating steps and large amounts of solvents. In this work, we propose a new extraction methodology under mild operating conditions in which water is acidified with carbon dioxide (CO2) to promote the extraction of collagen/gelatin from different marine sponge species. An extraction yield of approximately 50% of collagen/gelatin was achieved. The results of Fourier transformed infrared spectroscopy (FTIR), circular dichroism (CD), and differential scanning calorimetry (DSC) spectra suggest a mixture of collagen/gelatin with high purity, and the analysis of the amino acid composition has shown similarities with collagen from other marine sources. Additionally, in vitro cytotoxicity studies did not demonstrate any toxicity effects for three of the extracts.The authors are grateful for financial support of FCT through Grant EXP/QEQ:EPS/0745/2012, SWIMS (Subcritical Water Isolation of compounds from Marine Sponges). The funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement numbers REGPOT-CT2012-316331-POLARIS and KBBE-2010-266033 (project SPECIAL), as well as from ERDF under the project "Novel smart and biomimetic materials for innovative regenerative medicine approaches" RLI-ABMR-NORTE-01-0124-FEDER-000016), cofinanced by North Portugal Regional Operational Programme (ON.2,O Novo Norte), under the National Strategic Reference Framework (NSRF) are also gratefully ackowledged. The authors are also truly thankfull to Prof. Micha flan (Tel Aviv University, Israel), Dr. Ronald Osinga (Porifarma, The Netherlands), Dr. Antonio Sara and Dr. Martina Milanese (Studio Associato GAIA, Italy), and Dr. Joana Xavier (University of Azores) for the kind offer of marine sponges samples

    Surface modification of silica-based marine sponge bioceramics induce hydroxyapatite formation

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    Marine biomaterials are a new emerging area of research with significant applications. Recently, researchers are dedicating considerable attention to marine-sponge biomaterials for various applications. We have focused on the potential of biosilica from Petrosia ficidormis for novel biomedical/industrial applications. A bioceramic structure from this sponge was obtained after calcination at 750ºC for 6 hours in a furnace. The morphological characteristics of the 3D architecture were evaluated by scanning electron microscopy (SEM) and micro-computed tomography revealing a highly porous and interconnected structure. The skeleton of Petrosia ficidormis is a siliceous matrix composed of SiO2, which does not present inherent bioactivity. Induction of bioactivity was attained by subjecting the bioceramics structure to an alkaline treatment (KOH 2M) and acidic treatment (HCl 2M) for 1 and 3 hours. In vitro bioactivity of the bioceramics structure was evaluated in simulated body fluid (SBF), after 7 and 14 days. Observation of the structures by SEM, coupled with spectroscopic elemental analysis (EDS), has shown that the surface morphology presented a calcium-phosphate CaP coating, similar to hydroxyapatite (HA). The determination of the Ca/P ratio, together with the evaluation of the characteristic peaks of HA by infra-red spectroscopy and X-ray diffraction, have proven the existence of HA. In vitro biological performance of the structures was evaluated using an osteoblast cell line andthe acidic treatment has shown to be the most effective treatment. Cells were seeded on the bioceramics structures and their morphology, viability and growth was evaluated by SEM, MTS assay and DNA quantification, respectively, demonstrating that cells are able to grow and colonize the bioceramic structures.Alexandre Barros is grateful for financial support of FCT through Grant EXP/QEQ-EPS/0745/2012, SWIMS - Subcritical Water Isolation of compounds from Marine Sponges. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under Grant REGPOT-CT2012-316331-POLARIS and under Grant no KBBE-2010-266033 (project SPECIAL). Funding from the project "Novel smart and biomimetic materials for innovative regenerative medicine approaches" RL1-ABMR-NORTE-01-0124-FEDER-000016) cofinanced by North Portugal Regional Operational Programme (ON.2 - O Novo Norte), under the National Strategic Reference Framework (NSRF) is also acknowledged

    Bioresorbable ureteral stents from natural origin polymers

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    In this work, stents were produced from natural originpolysaccharides. Alginate, gellan gum, and a blend ofthese with gelatin were used to produce hollow tube (stents)following a combination of templated gelation and criticalpoint carbon dioxide drying. Morphological analysis of thesurface of the stents was carried out by scanning electronmicroscopy. Indwelling time, encrustation, and stability ofthe stents in artificial urine solution was carried out up to 60days of immersion. In vitro studies carried out with simulatedurine demonstrated that the tubes present a high fluid uptakeability, about 1000%. Despite this, the materials are able tomaintain their shape and do not present an extensive swellingbehavior. The bioresorption profile was observed to behighly dependent on the composition of the stent and it canbe tuned. Complete dissolution of the materials may occurbetween 14 and 60 days. Additionally, no encrustation wasobserved within the tested timeframe. The ability to resistbacterial adherence was evaluated with Gram-positive Staphylococcus aureus and two Gram-negatives Escherichia coliDH5 alpha and Klebsiella oxytoca. For K. oxytoca, no differenceswere observed in comparison with a commercialstent (BiosoftVR duo, Porges), although, for S. aureus alltested compositions had a higher inhibition of bacterialadhesion compared to the commercial stents. In case ofE. coli, the addition of gelatin to the formulations reducedthe bacterial adhesion in a highly significant manner comparedto the commercial stents. The stents produced by thedeveloped technology fulfill the requirements for ureteralstents and will contribute in the development of biocompatible and bioresorbable urinary stents.Contract grant sponsor: the European Union Seventh Framework Programme (FP7/2007-2013); contract grant number: REGPOT-CT2012-316331POLARIS Contract grant sponsor: Novel smart and biomimetic materials for innovative regenerative medicine approaches”; contract grant number: RL1 – ABMR – NORTE-01-0124-FEDER-000016; North Portugal Regional Operational Programme (ON.2 – O Novo Norte), National Strategic Reference Framework (NSRF), European Regional Development Fund (ERDF) Contract grant sponsor: FCT post-doc; contract grant numbers: SFRH/BPD/39333/2007, SFRH/BPD/90533/20

    Accuracy of different handgrip values to identify mobility limitation in older adults

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    BACKGROUND/OBJECTIVE: Mobility limitation is commonly the first sign of impaired physical function and predisposes older adults to disability. Moreover, recent epidemiological studies have classified neuromuscular strength as the best explanator of mobility limitation. However, existing cutoffs have not been adequately analyzed regarding accuracy. Therefore, our aims were to define and compare the accuracy of different cutoff points of handgrip strength for the identification of mobility limitation. METHODS: Cross-sectional study with 5783 participants from the SABE (Saúde, Bem-Estar e Envelhecimento [Health, Wellbeing and Aging]) and ELSA (English Longitudinal Study of Ageing) cohorts aged 60 years or older. Handgrip strength was measured using a dynamometer. Walking speed <0.8 m/s was considered mobility limitation. Receiver operating characteristic curves and probabilities of presenting mobility limitation were calculated. RESULTS: Handgrip strength <32 kg for men and <21 kg for women demonstrated good diagnostic accuracy for mobility limitation, with 49.1% sensitivity and 79.8% specificity for men and 58.6% sensitivity and 72.9% specificity for women. The fully adjusted models had an area under the curve of 0.82 for men and 0.83 for women, with odds of presenting mobility limitation of 1.88 [95% CI: 1.50 - 2.37] for men and 1.89 [95% CI: 1.57 - 2.27] for women. CONCLUSIONS: The results of this study support the accuracy of handgrip strength as a clinical marker of mobility limitation. Furthermore, manual dynamometry is easily incorporated into clinical practice, has a good cost-benefit, besides being a simple, valid, reliable and effective method for use in both the scientific community and outpatient practice

    Preparation of macroporous alginate-based aerogels for biomedical applications

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    Aerogels are a special class of ultra-light porous materials with growing interest in biomedical applications due to their open pore structure and high surface area. However, they usually lack macroporosity, while mesoporosity is typically high. In this work, carbon dioxide induced gelation followed by expansion of the dissolved CO2 was performed to produce hybrid calcium-crosslinked alginate-starch hydrogels with dual meso- and macroporosity. The hydrogels were subjected to solvent exchange and supercritical drying to obtain aerogels. Significant increase in macroporosity from 2 to 25 % was achieved by increasing expansion rate from 0.1 to 30 bar/min with retaining mesoporosity (BET surface and BJH pore volume in the range 183 â 544 m2/g and 2.0 â 6.8 cm3/g, respectively). In vitro bioactivity studies showed that the alginate-starch aerogels are bioactive, i.e. they form hydroxyapatite crystals when immersed in a simulated body fluid solution. Bioactivity is attributed to the presence of calcium in the matrix. The assessment of the biological performance showed that the aerogels do not present a cytotoxic effect and the cells are able to colonize and grow on their surface. Results presented in this work provide a good indication of the potential of the alginate-starch aerogels in biomedical applications, particularly for bone regeneration. aerogels, alginate, starch, tissue engineering, supercritical fluids, CO2 induced gelation. (undefined
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