242 research outputs found
Amphitrite fauveli sp.n. (Polychaeta: Terebellidae) из Бискайского и Кадисского заливов (Северо-Восточная Атлантика)
A new species of Amphitrite is described from two different regions in the NE
Atlantic: the Bay of Biscay and the Gulf of Cadiz. Amphitrite fauveli sp.n. differs from other
Amphitrite species with cirriform branchiae mainly by having a smaller number of
nephridial papillae (four pairs) and by lacking eyespots. In the Bay of Biscay, the new
species occurred on the slope of two submarine canyons — Saint Nazaire (1105 m depth)
and the head of a Cap Breton canyon tributary (214 m depth), associated with coral
framework (Madrepora oculata Linnaeus, 1758 and Lophelia pertusa (Linnaeus, 1758) in
Saint Nazaire canyon, Dendrophyllia cornigera (Lamarck, 1816) in the Cap Breton
tributary). In the Gulf of Cadiz the species was collected from the crater of two mud
volcanoes (Darwin and Captain Arutyunov), at depths between 1100 and 1317 m.Описан новый вид Amphitrite из двух районов Северо-Восточной Атлан-
тики: Бискайского и Кадисского заливов. Amphitrite fauveli sp.n. отличается от других
видов Amphitrite с усиковидными жабрами в основном меньшим числом нефриди-
альных папилл (четыре пары) и отсутствием глаз. В Бискайском заливе вид встреча-
ется на склонах двух подводных каньонов — Сен-Назер (на 1105 м) и в вершине
притока каньона Кейп-Бретон (214 м), в ассоциации коралловых рифов (Madrepora
oculata Linnaeus, 1758 и Lophelia pertusa (Linnaeus, 1758) в каньоне Сен-Назер и
Dendrophyllia cornigera (Lamarck, 1816) в каньоне Кейп-Бретон). В Кадисском заливе вид собран в кратере двух иловых вулканов (Дарвин и Капитан Арутюнов), на
глубине 1100–1317 м.publishe
Red mud-based geopolymers with tailored alkali diffusion properties and pH buffering ability
This study develop novel porous red mud (RM) based geopolymers and evaluates their potential to ensure prolonged pH control. Several properties of the novel geopolymers were examined including buffering ability, alkalis leaching behaviour, mineralogical composition, microstructure and physical properties. Two experimental plans were defined to evaluate the influence of porosity and RM content on those properties. The pH values of the eluted water and geopolymers OH ions leaching have been determined over time showing that total OH ions and the leaching rate can be tailored by controlling the geopolymers porous structure and the availability of free alkaline species. The lower pH gradient over 28th d (1.64 pH units) was achieved by combining a 0.025 wt% pore forming agent (aluminium powder) with 45 wt% MK replacement by red mud.
A high and prolonged buffer capacity was accomplished, proving that red mud-based geopolymers have potential to be applied as pH buffering material.This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement.info:eu-repo/semantics/publishedVersio
Are organic falls bridging reduced environments in the deep sea?: Results from colonization experiments in the Gulf of Cadiz
Organic falls create localised patches of organic enrichment and disturbance where enhanced degradation is mediated by diversified microbial assemblages and specialized fauna. The view of organic falls as “stepping stones” for the colonization of deep-sea reducing environments has been often loosely used, but much remains to be proven concerning their capability to bridge dispersal among such environments. Aiming the clarification of this issue, we used an experimental approach to answer the following questions: Are relatively small organic falls in the deep sea capable of sustaining taxonomically and trophically diverse assemblages over demographically relevant temporal scales Are there important depth- or site-related sources of variability for the composition and structure of these assemblages? Is the proximity of other reducing environments influential for their colonization? We analysed the taxonomical and trophic diversity patterns and partitioning (α- and β-diversity) of the macrofaunal assemblages recruited in small colonization devices with organic and inorganic substrata after 1-2 years of deployment on mud volcanoes of the Gulf of Cádiz. Our results show that small organic falls can sustain highly diverse and trophically coherent assemblages for time periods allowing growth to reproductive maturity, and successive generations of dominant species. The composition and structure of the assemblages showed variability consistent with their biogeographic and bathymetric contexts. However, the proximity of cold seeps had limited influence on the similarity between the assemblages of these two habitats and organic falls sustained a distinctive fauna with dominant substrate-specific taxa. We conclude that it is unlikely that small organic falls may regularly ensure population connectivity among cold seeps and vents. They may be a recurrent source of evolutionary candidates for the colonization of such ecosystems. However, there may be a critical size of organic fall to create the necessary intense and persistent reducing conditions for sustaining typical chemosymbiotic vent and seep organisms
Paramytha ossicola sp. nov. (Polychaeta, Ampharetidae) from mammal bones: Reproductive biology and population structure
Sunken whale carcasses, known as “whale falls”, deliver large, but relatively ephemeral pulses of organic material to the seafloor and serve as habitat for unique assemblages of deep-sea fauna that include generalist-scavenging species, chemosynthetic fauna and bone-specialist species. Despite the great deal of interest that fauna associated with whale falls have attracted, very little is known about this fauna in the deep Atlantic Ocean. Here we describe a new species of Ampharetidae that was found in an experiment using cow carcasses in the Setúbal Canyon (NE Atlantic), as a surrogate of a whale fall. Further, we analyse the size and structure of the population at two different times and use histological analyses to investigate the reproductive biology of this new species. We propose that Paramytha ossicola sp. nov. is a bone-specialist adapted for life in ephemeral habitats. Reproductive traits include rapid maturation, continuous and non-synchronous gametogenesis. Recruitment seems to be controlled by habitat availability and biological interactions that result in post-settlement mortality.publishe
Cork extractives exhibit thermo-oxidative protection properties in polypropylene-cork composites and as direct additives for polypropylene
The thermo-oxidative stability of polypropylene (PP) in composites containing 15 wt.% of cork and the performance of selected cork extracts as stabilizing additives for PP was evaluated by Oxidation Induction Time (OIT) and by Oxidation Onset Temperature (OOT). The results showed that cork increases the OIT of PP in the composite and it was identified that the cork extractives fraction is responsible for such behavior. Selected cork extracts with high antioxidant capacity (determined by dpph radical scavenging and oxygen reactive absorbance capacity assays) were compounded by extrusion with PP in 0.5 and 1.5 wt.%. It was found that the ethanol extract is the most effective as thermo-oxidative stabilizer for PP. At the loading level of 1.5%, the OIT increases from 3.8 (neat PP) to 29.7 min at 200 °C and from 1.2 (neat PP) to 9.0 min at 220 °C. The OOT also increases from 216 °C (neat PP) to 247 °C. Mechanical tests, performed on PP loaded with the cork extracts, showed that the presence of these extracts has no significant effect on the polymer mechanical performance. The results demonstrate the suitability of cork as a source of thermo-oxidative stabilizing additives for the formulation of polyolefins, and enable the exploitation of new routes of cork valorization.The authors are grateful to Amorim Cork Composites for providing the cork powder raw material. Ivo Aroso and Emanuel Fernandes are grateful for financial support of FCT through grants SFRH/BD/42273/2007 and SFRH/BPD/96197/2013, respectively. Funding was also granted from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no REGPOT-CT2012-316331-POLARIS and from Project "Novel smart and biomimetic materials for innovative regenerative medicine approaches (Ref.: RL1-ABMR-NORTE-01-0124-FEDER-000016)" co-financed by North Portugal Regional Operational Programme (ON.2 - O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF)
Functionalized cork-polymer composites (CPC) by reactive extrusion using suberin and lignin from cork as coupling agents
High density polyethylene (HDPE) and cork powder were compounded in a co-rotating twin-screw
extruder to obtain cork-polymer composites (CPC) with improved properties. Benzoyl peroxide (BPO)
was used as initiator agent, and suberin or lignin isolated from cork enhanced filler-matrix bonding
and promoted mechanical reinforcement with environmental benefits. The novel composites were characterised
in terms of dimensional stability, evolution of morphology, thermal and mechanical properties
and their performance was compared with that of composites containing polyethylene-grafted maleic
anhydride (PE-g-MA) as coupling agent. As expected, composites with coupling agent present higher
mechanical properties, lower water uptake and thickness swelling variation. Suberin acts as plasticizer
with antioxidant benefits, while lignin works as a coupling agent, improving tensile modulus and
maximum strength. Increasing lignin content does not improve the mechanical properties but improves
thermal stability.The work was performed within the project of Corticeira Amorim S.G.P.S. on the development of new products based in/with cork. The authors gratefully acknowledge the financial support, through the COMPETE/QREN/EU funding program in the project with acronym NovelComp (QREN FCOMP-01-0202-FEDER-003107). The authors acknowledge the Portuguese Foundation for Science and Technology (FCT) and POPH/FSE for the doctoral Grants to E.M.F. (SFRH/BD/71561/2010) and I.M.A. (SFRH/BD/42273/2007)
Inhibition of HMG-CoA reductase activity and cholesterol permeation through Caco-2 cells by caffeoylquinic acids from Vernonia condensata leaves
AbstractThe aim of this study was to provide scientific knowledge to support the use of Vernonia condensata Baker, Asteraceae, beverages for their alleged hypocholesterolemic properties by testing their action as HMG-CoA reductase inhibitors and their capacity to lower dietary cholesterol permeation. Chlorogenic acid, and other caffeoylquinic acids derivatives were identified as the main components of these beverages by LC–MS/MS. No changes in the composition were notice after the in vitro gastrointestinal digestion and no toxicity against Caco-2 and HepG2 cell lines was detected. Cholesterol permeation through Caco-2 monolayers was reduced in 37% in the presence of these herbal teas, and the caffeoylquinic acids permeated the monolayers in 30–40% of their initial amount in 6h. HMG-CoA reductase activity was reduced with these beverages, showing an IC50 of 217μgml−1. It was concluded that caffeoylquinic acids, the major components, justified 98% of the enzyme inhibition measured
Efficacy and cytotoxicity of binary mixtures as root canal filling solvents
Objectives: This study reports the efficacy of two solvent mixtures on the dissolution of gutta-percha and AH Plus sealer, together with the cytotoxicity. Methods: Methyl ethyl ketone (MEK), orange oil, tetrachloroethylene, MEK/tetrachloroethylene (1:1), MEK/orange oil (1:1), and chloroform (control) were tested. Twelve groups (n = 15) of standardized stainless-steel molds filled with softened gutta-percha cones and twelve (n = 15) filled with AH Plus were immersed in the corresponding mixture or individual solvent, in an ultrasonic bath, for either 2 or 5 min. The effect of the solvents was assessed qualitatively by a topographical analysis (scanning electron microscopy) and chemical analysis (Fourier transform infrared spectroscopy), and quantitatively by a weight loss and viscoelastic property (dynamic mechanical analysis) evaluation. The cytotoxicity was assessed on MG63 human osteoblastic cells. Results: The mixtures did not show the formation of new compounds. Both presented significantly higher efficacies compared to their individual solvents, suggesting a synergistic effect. Their dissolution efficacy was similar to that of chloroform, showing high cytocompatibility. Conclusions: The proposed strategy, incorporating ultrasound agitation and profiting from the synergy of adequate solvents, might enhance root canal cleanliness allowing a single-step procedure to dissolve gutta-percha and the sealer remnants, while assuring cytocompatibility with the periapical tissues.This article was supported by National Funds through FCT—Fundação para a Ciência e a Tecnologia,I.P.-V., within CINTESIS, R & D Unit (reference UIDB/4255/2020)
Water and carbon dioxide: green solvents for the extraction of collagen/gelatin from marine sponges
"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
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
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