1,085 research outputs found

    Nitric Oxide Regulates Neurogenesis in the Hippocampus following Seizures

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    Hippocampal neurogenesis is changed by brain injury. When neuroinflammation accompanies injury, activation of resident microglial cells promotes the release of inflammatory cytokines and reactive oxygen/nitrogen species like nitric oxide (NO). In these conditions, NO promotes proliferation of neural stem cells (NSC) in the hippocampus. However, little is known about the role of NO in the survival and differentiation of newborn cells in the injured dentate gyrus. Here we investigated the role of NO following seizures in the regulation of proliferation, migration, differentiation, and survival of NSC in the hippocampus using the kainic acid (KA) induced seizuremouse model. We show that NO increased the proliferation of NSC and the number of neuroblasts following seizures but was detrimental to the survival of newborn neurons. NO was also required for the maintenance of long-term neuroinflammation. Taken together, our data show that NO positively contributes to the initial stages of neurogenesis following seizures but compromises survival of newborn neurons.Foundation for Science and Technology (FCT, Portugal); COMPETE; FEDER [PTDC/SAU-NEU/102612/2008, PTDC/NEU-OSD/0473/2012, PEst-C/SAU/LA0001/2013-2014, PEst-OE/EQB/LA0023/2013-2014]; FCT, Portugal [SFRH/BPD/78901/2011, SFRH/BD/77903/2011

    Polyphenol metabolite pyrogallol-o-sulfate decreases microglial activation and vegf in retinal pigment epithelium cells and diabetic mouse retina

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    Funding Information: The authors acknowledge Fundacao para a Ciencia e Tecnologia for funding (PD/BD/114251/2016 scholarship to D.F. Santos; EXPL-BIM-MEC-1433-2013; PTDC/BTM/ORG/28121/2017 grants to G.A.Silva) and iNOVA4Health ? UIDB/Multi/04462/2020, a program financially supported by Funda??o para a Ci?ncia e Tecnologia/Ministerio da Educacao e Ciencia through national funds and co-funded by FEDER under the PT2020 Partnership Agreement, is also acknowledged. C.N.S. also acknowledges the European Research Council (ERC) under the European Union?s Horizon 2020 Research and Innovation Programme under Grant Agreement No. 804229. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.(Poly)phenol-derived metabolites are small molecules resulting from (poly)phenol metab-olization after ingestion that can be found in circulation. In the last decade, studies on the impact of (poly)phenol properties in health and cellular metabolism accumulated evidence that (poly)phenols are beneficial against human diseases. Diabetic retinopathy (DR) is characterized by inflammation and neovascularization and targeting these is of therapeutic interest. We aimed to study the effect of pyrogallol-O-sulfate (Pyr-s) metabolite in the expression of proteins involved in retinal glial acti-vation, neovascularization, and glucose transport. The expression of PEDF, VEGF, and GLUT-1 were analyzed upon pyrogallol-O-sulfate treatment in RPE cells under high glucose and hypoxia. To test its effect on a diabetic mouse model, Ins2Akita mice were subjected to a single intraocular injection of the metabolite and the expression of PEDF, VEGF, GLUT-1, Iba1, or GFAP measured in the neural retina and/or retinal pigment epithelium (RPE), two weeks after treatment. We observed a significant decrease in the expression of pro-angiogenic VEGF in RPE cells. Moreover, pyrogallol-O-sulfate significantly decreased the expression of microglial marker Iba1 in the diabetic retina at different stages of disease progression. These results highlight the potential pyrogallol-O-sulfate metabolite as a preventive approach towards DR progression, targeting molecules involved in both inflammation and neovascularization.publishersversionpublishe

    An assessment of geotubes performance in coastal protection

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    The Ofir spit is located at the estuary of Cavado River (NW coast of Portugal), and is the natural protection of Esposende city, ensuring also the navigability of the river and preventing from the maritime invasion of its estuary or the flooding of the riverine part of that city. It has been subjected to the actions of nature, especially from the Atlantic Ocean, known for its energetic regime and, more recently, those of human activities. Considering that, in Portugal, the use of geosynthetics on coastal protection is not yet a usual solution, it is relevant to investigate it, especially in this case of high-energy wave agitation. The paper presents a summary on the interventions conducted to the sandbank along time, it refers also the solution implemented as well as the monitoring campaign conducted after December 2015, discussing its results and the viability of the structure itself as a permanent solution.publishersversionpublishe

    La concepción de los cuidados de enfermería dirigida a los prestadores de cuidados se refleja en la documentación

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    Abstract Background: Caregivers must acquire knowledge and develop skills that ensure the safety of the care delivered and guarantee their own self-care. Nurses take on the role of facilitators in this transition process, with nursing information systems being used as tools to safeguard the continuity and quality of care. Objective: To understand nursing care design for caregivers. Methodology: This is a mixed method study with a descriptive exploratory research design, analyzing 163 files of caregiver documentation and using a questionnaire (N = 72). Results: It was possible to identify the underreporting of caregivers. Caregivers were predominantly elderly women with moderate burden who reported difficulties in instrumental activities and needed support from an additional caregiver or a formal support network. Conclusion: Identifying the needs and difficulties of caregivers combined with the observed underreporting strengthens the need for bringing the models in use closer to the models presented, thus translating this process into an improvement of quality standards in nursing care for caregivers.Enquadramento: A assunção do papel de cuidador exige a aquisição de conhecimentos e habilidades, garantindo a segurança dos cuidados à pessoa cuidada e assegurar o seu próprio autocuidado. O enfermeiro assume o papel de facilitador neste processo de transição, sendo os sistemas de informação em enfermagem uma ferramenta que garante a continuidade e qualidade dos cuidados. Objetivo: Compreender a conceção de cuidados de enfermagem relativa ao prestador de cuidados. Metodologia: Estudo descritivo exploratório com abordagem mista, através da análise da documentação do prestador de cuidados em 163 processos e aplicação de um questionário (N = 72). Resultados: Identificou-se subnotificação no prestador de cuidados. Estes eram predominantemente mulheres, com idade avançada e sobrecarga moderada. Expressaram dificuldades nas atividades instrumentais e necessidade de apoio de outro cuidador/redes formais. Conclusão: A identificação das necessidades e dificuldades do prestador de cuidados em confronto com a subnotificação observada reforça a necessidade de uma aproximação dos modelos em uso aos modelos expostos, traduzindo este processo numa melhoria dos padrões de qualidade em enfermagem dirigida aos prestadores de cuidadosMarco contextual: La asunción del papel de cuidador requiere la adquisición de conocimientos y habilidades, lo que garantiza la seguridad de los cuidados a la persona cuidada y asegura su propio autocuidado. El enfermero asume el papel de facilitador en este proceso de transición, y los sistemas de información de enfermería son una herramienta que garantiza la continuidad y la calidad de los cuidados. Objetivo: Comprender la concepción de los cuidados de enfermería en relación con el cuidador. Metodología: Estudio descriptivo exploratorio con un enfoque mixto, para el cual se analizó la documentación del proveedor de cuidados en 163 procesos y se aplicó un cuestionario (N = 72). Resultados: Se identificó un subregistro en el cuidador. Eran predominantemente mujeres, con una edad avanzada y una sobrecarga moderada. Manifestaron dificultades en las actividades instrumentales y necesidad de apoyo de otro cuidador/redes formales. Conclusión: La identificación de las necesidades y dificultades del cuidador frente al subregistro observado refuerza la necesidad de una aproximación de los modelos en uso a los modelos expuestos, lo que traduce este proceso en una mejora de los estándares de calidad en enfermería dirigidos a los cuidadoresinfo:eu-repo/semantics/publishedVersio

    Influence of opacifiers on dimensional stability and detail reproduction of maxillofacial silicone elastomer

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    <p>Abstract</p> <p>Background</p> <p>We evaluated the influence of chemical disinfection and accelerated aging on the dimensional stability and detail reproduction of a silicone elastomer containing one of two opacifiers.</p> <p>Methods</p> <p>A total of 90 samples were fabricated from Silastic MDX 4-4210 silicone and divided into groups (n = 10) according to opacifier content (barium sulfate or titanium dioxide) and disinfectant solution (neutral soap, Efferdent, or 4% chlorhexidine). The specimens were disinfected 3 times per week during 60 days and then subjected to accelerated aging for 1008 hours. Dimensional stability and detail reproduction tests were performed after specimens' fabrication (baseline), chemical disinfection and periodically during accelerated aging (252, 504, and 1008 hours). The results were analyzed using 3-way repeated-measures ANOVA and the Tukey HSD test (α = 0.05).</p> <p>Results</p> <p>All groups exhibited dimensional changes over time. The opacifier (p = .314), period (p < .0001) and their interactions (p = .0041) affected the dimensional stability of the silicone. Statistical significant dimensional differences occurred between groups with (0.071) and without opacifiers (0.053). Accelerated aging influenced the dimensional stability of the samples. All groups scored 2 in the detail reproduction tests, which represents the fully reproducing of three test grooves with accurate angles.</p> <p>Conclusions</p> <p>Incorporation of opacifiers alters the dimensional stability of silicones used in facial prosthetics, but seems to have no influence on detail reproduction. Accelerated aging is responsible for most of the dimensional changes in Silastic MDX4 4210, but all dimensional changes measured in this study remained within the limits of stability necessary for this application.</p

    Potential of injectable dextrin-based hydrogel for biomedical applications

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    Bone tissue engineering is a very challenging and promising field, which handles with the limitations of bone regenerative capacity and the failure of current orthopedic implants [1]. This work describes the preparation and characterization of an injectable dextrinbased hydrogel (oDex) through dextrin oxidation followed by cross-linking with a dihydrazide [2]. In vitro and in vivo experiments allowed to conclude that this system can carry and stabilize cells, nanogels, Bonelike® granules [3] and other biomolecules. This is a promising biomaterial due to its biocompatibility, and potential to promote an adequate environment for bone regeneration, which was increased by the combined bioactive molecules. Its injectability allows a minimal invasive surgical procedure with decreased patient morbidity, lower infection risk and reduced scar formation. Furthermore, an adequate sterilization protocol for this kind of material was established. The tight collaboration between University of Minho and Bioskin S.A. company, envisioning technology transfer and product valorization, has resulted in a published international patent of the product (WO2011070529A2) [4]. Currently, the submission of a request for the authorization for the clinical trials is being planned

    Age and growth of the smooth hammerhead, Sphyrna zygaena, in the Atlantic Ocean: comparison with other hammerhead species

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    The smooth hammerhead Sphyrna zygaena (Sphyrnidae) is a pelagic shark occasionally caught as bycatch in pelagic longline fisheries, but is one of the least studied of all pelagic sharks. Age and growth of S. zygaena was studied along a wide Atlantic region covering both the northern and southern hemispheres. Data from 304 specimens, caught between October 2009 and September 2014, ranging in size from 126 to 253 cm fork length (FL), were analysed. Growth models were fitted using the three-parameter von Bertalanffy growth function (VBGF) re-parameterized to calculate L0 (size at birth). Growth models were fitted to the sample data and data from several back-calculation models. The model fit to the quadratic modified Dahl-Lea back-calculated data seems to be the most appropriate to describe growth in this species, with resulting growth parameters of Linf = 285 cm FL, k = 0.09 year−1 for males and Linf = 293 cm FL, k = 0.09 year−1 for females. Compared with other species of the same genus, estimated growth coefficients for S. zygaena seem to fall in the low to middle range. Although further work is still needed, this study adds to knowledge of the vital life-history parameters of smooth hammerheads in the Atlantic Ocean, which can be used in the management and conservation of this species.Programa Operacional Potencial Humano: IF/00253/2014info:eu-repo/semantics/publishedVersio

    Disruption of the inositol phosphorylceramide synthase gene affects Trypanosoma cruzi differentiation and infection capacity

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    Sphingolipids (SLs) are essential components of all eukaryotic cellular membranes. In fungi, plants and many protozoa, the primary SL is inositol-phosphorylceramide (IPC). Trypanosoma cruzi is a protozoan parasite that causes Chagas disease (CD), a chronic illness for which no vaccines or effective treatments are available. IPC synthase (IPCS) has been considered an ideal target enzyme for drug development because phosphoinositol-containing SL is absent in mammalian cells and the enzyme activity has been described in all parasite forms of T. cruzi. Furthermore, IPCS is an integral membrane protein conserved amongst other kinetoplastids, including Leishmania major, for which specific inhibitors have been identified. Using a CRISPR-Cas9 protocol, we generated T. cruzi knockout (KO) mutants in which both alleles of the IPCS gene were disrupted. We demonstrated that the lack of IPCS activity does not affect epimastigote proliferation or its susceptibility to compounds that have been identified as inhibitors of the L. major IPCS. However, disruption of the T. cruzi IPCS gene negatively affected epimastigote differentiation into metacyclic trypomastigotes as well as proliferation of intracellular amastigotes and differentiation of amastigotes into tissue culture-derived trypomastigotes. In accordance with previous studies suggesting that IPC is a membrane component essential for parasite survival in the mammalian host, we showed that T. cruzi IPCS null mutants are unable to establish an infection in vivo, even in immune deficient mice

    Nanostructured electrospun fibers with self-assembled cyclo-L-Tryptophan-L-Tyrosine dipeptide as piezoelectric materials and optical sd harmonic generators

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    The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/ma16144993/s1, Figure S1: Experimental setup for piezoelectric measurements; Figure S2: FTIR spectra; Figure S3: TGA spectra; Figure S4: DSC spectra. References [43,44] are cited in the supplementary materials.The potential use of nanostructured dipeptide self-assemblies in materials science for energy harvesting devices is a highly sought-after area of research. Specifically, aromatic cyclo-dipeptides containing tryptophan have garnered attention due to their wide-bandgap semiconductor properties, high mechanical rigidity, photoluminescence, and nonlinear optical behavior. In this study, we present the development of a hybrid system comprising biopolymer electrospun fibers incorporated with the chiral cyclo-dipeptide L-Tryptophan-L-Tyrosine. The resulting nanofibers are wide-bandgap semiconductors (bandgap energy 4.0 eV) consisting of self-assembled nanotubes embedded within a polymer matrix, exhibiting intense blue photoluminescence. Moreover, the cyclo-dipeptide L-Tryptophan-L-Tyrosine incorporated into polycaprolactone nanofibers displays a strong effective second harmonic generation signal of 0.36 pm/V and shows notable piezoelectric properties with a high effective coefficient of 22 pCN−1, a piezoelectric voltage coefficient of ge f f = 1.2 VmN−1 and a peak power density delivered by the nanofiber mat of 0.16 µWcm−2. These hybrid systems hold great promise for applications in the field of nanoenergy harvesting and nanophotonics.This research was funded by Fundação para a Ciência e Tecnologia through FEDER (European Fund for Regional Development)-COMPETE-QREN-EU (ref. UID/FIS/04650/2013 and UID/FIS/04650/2019) and E-Field “Electric-Field Engineered Lattice Distortions (E-FiELD)” for optoelectronic devices, ref. PTDC/NAN-MAT/0098/2020, POCI-01-0247-FEDER-045939

    Age effects on EEG correlates of the Wisconsin card sorting test

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    Body and brain undergo several changes with aging. One of the domains in which these changes are more remarkable relates with cognitive performance. In the present work, electroencephalogram (EEG) markers (power spectral density and spectral coherence) of age-related cognitive decline were sought whilst the subjects performed the Wisconsin Card Sorting Test (WCST). Considering the expected age-related cognitive deficits, WCST was applied to young, mid-age and elderly participants, and the theta and alpha frequency bands were analyzed. From the results herein presented, higher theta and alpha power were found to be associated with a good performance in the WCST of younger subjects. Additionally, higher theta and alpha coherence were also associated with good performance and were shown to decline with age and a decrease in alpha peak frequency seems to be associated with aging. Additionally, inter-hemispheric long-range coherences and parietal theta power were identified as age-independent EEG correlates of cognitive performance. In summary, these data reveals age-dependent as well as age-independent EEG correlates of cognitive performance that contribute to the understanding of brain aging and related cognitive deficits.The work was partially funded by the European Commission (FP7): “SwitchBox” (Contract HEALTH‐F2‐2010‐259772) and co‐financed by the Portuguese North Regional Operational Program (ON.2 – O Novo Norte) under the National Strategic Reference Framework (QREN), through the European Regional Development Fund (FEDER). This work was also co‐sponsored by FCT – Foundation for Science and Technology and Compete Program with the project reference FCOMP‐01‐0124‐FEDER‐021145 (PTDC/SAU‐ENB/118383/2010) and Agência De Inovação “DoIT ‐ Desenvolvimento e Operacionalização da Investigação de Translação” (project no. 13853, PPS4‐MyHealth), funded by Fundo Europeu de Desenvolvimento Regional (FEDER) through the Programa Operacional Factores de Competitividade (POFC)
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