186 research outputs found

    Elastin-like-recombinamers multilayered nanofibrous scaffolds for cardiovascular applications

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    Producción CientíficaCoronary angioplasty is the most widely used technique for removing atherosclerotic plaques in blood vessels. The regeneration of the damaged intima layer after this treatment is still one of the major challenges in the field of cardiovascular tissue engineering. Different polymers have been used in scaffold manufacturing in order to improve tissue regeneration. Elastin-mimetic polymers are a new class of molecules that have been synthesized and used to obtain small diameter fibers with specific morphological characteristics. Elastin-like polymers produced by recombinant techniques and called elastin-like recombinamers (ELRs) are particularly promising due to their high degree of functionalization. Generally speaking, ELRs can show more complex molecular designs and a tighter control of their sequence than other chemically synthetized polymers Rodriguez Cabello et al (2009 Polymer 50 5159–69, 2011 Nanomedicine 6 111–22). For the fabrication of small diameter fibers, different ELRs were dissolved in 2,2,2-fluoroethanol (TFE). Dynamic light scattering was used to identify the transition temperature and get a deep characterization of the transition behavior of the recombinamers. In this work, we describe the use of electrospinning technique for the manufacturing of an elastic fibrous scaffold; the obtained fibers were characterized and their cytocompatibility was tested in vitro. A thorough study of the influence of voltage, flow rate and distance was carried out in order to determine the appropriate parameters to obtain fibrous mats without beads and defects. Moreover, using a rotating mandrel, we fabricated a tubular scaffold in which ELRs containing different cell adhesion sequences (mainly REDV and RGD) were collected. The stability of the scaffold was improved by using genipin as a crosslinking agent. Genipin-ELRs crosslinked scaffolds show a good stability and fiber morphology. Human umbilical vein endothelial cells were used to assess the in vitro bioactivity of the cell adhesion domains within the backbone of the ELRs.2018-08-0

    Controlled Production of Elastin-like Recombinamer Polymer-Based Membranes at a Liquid–Liquid Interface by Click Chemistry

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    Producción CientíficaDiffusion of organic and inorganic molecules controls most industrial and biological processes that occur in a liquid phase. Although significant efforts have been devoted to the design and operation of large-scale purification systems, diffusion devices with adjustable biochemical characteristics have remained difficult to achieve. In this regard, micrometer-scale, bioinspired membranes with tunable diffusion properties have been engineered by covalent cross-linking of two elastin-like recombinamers (ELRs) at a liquid−liquid interface. The covalent approach selected provides the desired ELR-based membranes with structural support, and modulation of the concentration of the polypeptides employed confers direct control of the thickness, pore size, and diffusive properties over a broad range of molecular weights (4−150 kDa). The recombinant and versatile nature of the proteinaceous building blocks employed further paves the way to engineering bioactive motifs within the membrane scaffold, thereby widening their applicability in the biological field.The authors are grateful for funding from the Spanish Government (MAT2016-78903-R, RTI2018-096320-B-C22), the Ministerio de Educacion, Cultura y Deporte para la ́ Formacion de Profesorado Universitario to MG (FPU15- ́ 00448), the Junta de Castilla y Leon (VA317P18), the Interreg ́ V A España Portugal POCTEP (0624_2IQBIONEURO_6_E), and the Centro en Red de Medicina Regenerativa y Terapia Celular de Castilla y Leo

    Faunal behavior in response to near bottom water dynamics in a marine protected area (Cantabrian Sea, southern Bay of Biscay)

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    A set of lander deployments in a deep marine protected area (MPA; El Cachucho) combining environmental sensors and a baited camera provided insight on the relationship between faunal behavior and oceanographic dynamics. Landers were deployed at different depths, ranging from 500 to 960 m for a period of 24–26 h. A total of 10,989 photographs were downloaded and synchronized using a time code with all the environmental variables recorded (pressure, temperature, salinity, water current, and direction). Total richness accounted for 41 species of different taxonomic groups (21 fishes, 11 crustaceans, 6 echinoderms, and 3 molluscs). The most abundant species were Synaphobranchus kaupii, Mora moro, Phycis blennoides, Helicolenus dactylopterus, and Etmopterus spinax. Arrival times (Tarr) and maximum number of individuals (Nmax) greatly differed among stations. Cluster analysis showed two main faunal groups in relation to depth: those close to the top of the bank and those in the flanks. Species densities were estimated using Priede's equations and compared with those obtained in previous studies using trawl samplers. The relation of species with environmental variables showed high variability depending on the location of the station and the associated variables (depth, current, and water masses). Near-bottom dynamics were consistent with previously known oceanographic patterns at the bank, dominated by background anticyclonic recirculation along the flanks overlaid by strong tidal cycles. Current and hydrography tidally driven phases showed an evident effect in the arrival of species at some locations. Species appeared during specific periods matching the beginning of the flooding phase or end of the ebb phase. Movement rates (cm s−1) were estimated for some invertebrate species, such as crabs (Bathynectes maravigna, 0.66; Pagurus sp., 0.09), the gasteropod Colus gracilis (0.15), and echinoderms (Cidaris cidaris, 0.04; Araeosoma fenestratum, 0.23)

    Bone strength index at Tibia and standing broad jump in adolescent swimmers

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    Measurement of broad jump is a simple, economical and non-invasive test that provides valuable information on muscular strength and power in youth lower limbs,and has been shown to be related to bone health..

    Borrelia chilensis, a new member of the Borrelia burgdorferi sensu lato complex that extends the range of this genospecies in the Southern Hemisphere

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    Borrelia burgdorferi sensu lato (s.l.), transmitted by Ixodes spp. ticks, is the causative agent of Lyme disease. Although Ixodes spp. ticks are distributed in both Northern and Southern Hemispheres, evidence for the presence of B. burgdorferi s.l. in South America apart from Uruguay is lacking. We now report the presence of culturable spirochetes with flat-wave morphology and borrelial DNA in endemic Ixodes stilesi ticks collected in Chile from environmental vegetation and long-tailed rice rats (Oligoryzomys longicaudatus). Cultured spirochetes and borrelial DNA in ticks were characterized by multilocus sequence typing and by sequencing five other loci (16S and 23S ribosomal genes, 5S–23S intergenic spacer, flaB, ospC). Phylogenetic analysis placed this spirochete as a new genospecies within the Lyme borreliosis group. Its plasmid profile determined by polymerase chain reaction and pulsed-field gel electrophoresis differed from that of B. burgdorferi B31A3. We propose naming this new South American member of the Lyme borreliosis group B. chilensis VA1 in honor of its country of origin.This work was supported by grant 5R01 AI48856-07 from N.I.H to F.C.C.Peer reviewe

    Validity of a food-frequency questionnaire for estimating calcium intake in adolescent swimmers

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    Introduction: accurate estimates of the intake of specific nutrients such as calcium (Ca) are crucial to correctly rank or classify subjects in the distribution of intakes. Therefore, we aimed to estimate the relative validity of a food frequency questionnaire (FFQ) for measuring Ca intake in two different groups of healthy adolescents, a normoactive control group and a physically active group of swimmers with 2 non-consecutive 24h recalls (2 x 24HR) collected as the reference method. Methods: Pearson correlations, agreement between the 24HR and the FFQ at an individual level and questionnaire’s ability to assign individuals to the same quartile of intake as the 24HR were calculated. Results: mean daily Ca intakes were 564.6 mg (SD 232.0) and 895.9 mg (SD 343.1) for the 2 x 24HR and FFQ respectively in controls (P < 0.001); and 731.9 mg (SD 299.8) and 979.8 mg (SD 408.5) for the 2 x 24HR and FFQ respectively in swimmers (P < 0.001). Pearson correlations were 0.52 for controls and 0.47 for swimmers after correcting for intra-variability. Cross-classification analysis indicated that 73.7% of controls and 63.1% of swimmers were classified correctly or in the adjacent category. Also, the 89% of the control group and 79% of swimmers were classified correctly with the FFQ according to the dietary reference intake (DRI) of 1300 mg/d. Conclusions: for both groups, the FFQ tended to overestimate Ca intake, however it demonstrated fairly good ability to classify subjects into extremes of Ca intake and identified adolescents having Ca intakes lower than the dietary reference intake

    Demersal and epibenthic communities of sedimentary habitats in the Avilés Canyon System, Cantabrian Sea (NE Atlantic)

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    The aim of this study was to describe the epibenthic and demersal communities of the Avilés Canyon System (ACS) in relation to the environmental variables that characterize their biotope. ACS (Cantabrian Sea, NE Atlantic) was recently included in the Natura 2000 network as a Site of Community Importance (SCI). Data of faunal biomass derived from 6 surveys carried out using beam trawl and otter trawls in 2009 and 2010 within INDEMARES and ERDEM projects. Data were divided into two groups to obtain information about the two ecological compartments: benthic and demersal. The total number of species used in this analysis ascended to 116 in the case of benthic organisms and 110 in the case of demersal. Hierarchical clustering analysis was applied to obtain groups of samples similar in terms of species composition for the two ecological components. Depth was the main discriminating factor for grouping hauls, showing high consistency of bathymetric range independently from the compartment examined. Six groups were identified by depth as follows: medium shelf (∼100–200 m), external shelf (∼150–300m), shelf break (∼300–400 m), upper-slope (∼500–700 m), upper middle-slope (∼700–1100 m), and lower-middle-slope (1200–1500 m). SIMPER analysis on biomass values was performed to determine the structure of the faunal assemblages observed for each group in both compartments. Using biomass values for the analysis allowed for the exploration of groups playing important roles in ecosystem functioning and energy fluxes taking place on the sedimentary bottom of this SCI. Finally, CCA analysis revealed that the main environmental drivers were depth, broad scale bathymetric position index (BPI), near-bottom salinity, sedimentary type, and dynamics related variables (Q50 phy and So). This study gives an inventory of the soft bottom assemblages along a very wide depth range (100–1500 m) inside a SCI, linking both epibenthic and demersal communities with the biotope preferences. This study contributes to fundamental knowledge on soft-bottom communities as a pre-requisite, necessary for the next steps in terms of management framework in the SCI

    Intermediate snowpack melt-out dates guarantee the highest seasonal grasslands greening in the Pyrenees

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    In mountain areas, the phenology and productivity of grassland are closely related to snow dynamics. However, the influence that snow melt timing has on grassland growing still needs further attention for a full understanding, particularly at high spatial resolution. Aiming to reduce this knowledge gap, this work exploits 1 m resolution snow depth and Normalized Difference Vegetation Index observations acquired with an Unmanned Aerial Vehicle at a sub-alpine site in the Pyrenees. During two snow seasons (2019–2020 and 2020–2021), 14 NDVI and 17 snow depth distributions were acquired over 48 ha. Despite the snow dynamics being different in the two seasons, the response of grasslands greening to snow melt-out exhibited a very similar pattern in both. The NDVI temporal evolution in areas with distinct melt-out dates reveals that sectors where the melt-out date occurs in late April or early May (optimum melt-out) reach the maximum vegetation productivity. Zones with an earlier or a later melt-out rarely reach peak NDVI values. The results obtained in this study area, suggest that knowledge about snow depth distribution is not needed to understand NDVI grassland dynamics. The analysis did not reveal a clear link between the spatial variability in snow duration and the diversity and richness of grassland communities within the study area

    Assessing the sensitivity of data-limited methods for resources in the Atlantic waters

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    ICES Annual Science Conference 2021, online 6-10 SeptemberLength-based methods have been widely applied to estimate biological parameters and to under-stand the dynamics of marine resource populations within the category of data-limited stocksThe authors thank the financial support of the project IMPRESS (RTI2018-099868-B-I00) project, ERDF, Ministry of Science, Innovation and Universities - State Research Agency, and also of GAIN (Xunta de Galicia), GRC MERVEX (nº IN607-A 2018-4)N
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