1,911 research outputs found

    Neural correlates of spelling difficulties in Alzheimer`s disease

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    Alzheimer's disease (AD) is associated with a general cognitive decline that affects the memory and language domains. Thus, an oral production deficit with a lexical-semantic origin has been widely observed in these patients. Their written production capacities, however, have been much less studied. We assessed the spelling abilities of 22 AD patients and a group of matched healthy controls with a test battery including written picture naming and word and pseudoword dictation tests, as well as text dictation and spontaneous writing tasks. The results of the AD patients in the discriminative tasks were then entered into voxel-based morphometry analyses along with their grey matter volumes. The patient group presented a selective impairment for word dictation, which contrasted with a spared capacity to spell pseudowords, and showed more difficulties for words with arbitrary and rule-based orthography. Moreover, they also produced less complete syntactic units in the spontaneous writing task. These results point out the lexical-semantic, as opposed to sublexical, nature of the spelling deficit associated to AD. In addition, we recognized a mainly left-lateralized cortical network, including areas in the posterior inferior temporal lobe and the superior region of the parietal cortex, which might be responsible for this impairment. Other regions, such as the putamen, were also associated to the deficit. The results of this study, hence, improve our understanding of the neuropsychological and neuroanatomical mechanisms that underlie the cognitive symptoms associated to AD

    Current Stage of Marine Ceramic Grafts for 3D Bone Tissue Regeneration

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    Bioceramic scaffolds are crucial in tissue engineering for bone regeneration. They usually provide hierarchical porosity, bioactivity, and mechanical support supplying osteoconductive properties and allowing for 3D cell culture. In the case of age-related diseases such as osteoarthritis and osteoporosis, or other bone alterations as alveolar bone resorption or spinal fractures, functional tissue recovery usually requires the use of grafts. These bone grafts or bone void fillers are usually based on porous calcium phosphate grains which, once disposed into the bone defect, act as scaffolds by incorporating, to their own porosity, the intergranular one. Despite their routine use in traumatology and dental applications, specific graft requirements such as osteoinductivity or balanced dissolution rate are still not completely fulfilled. Marine origin bioceramics research opens the possibility to find new sources of bone grafts given the wide diversity of marine materials still largely unexplored. The interest in this field has also been urged by the limitations of synthetic or mammalian-derived grafts already in use and broadly investigated. The present review covers the current stage of major marine origin bioceramic grafts for bone tissue regeneration and their promising properties. Both products already available on the market and those in preclinical phases are included. To understand their clear contribution to the field, the main clinical requirements and the current available biological-derived ceramic grafts with their advantages and limitations have been collected.This research was partially supported by the European Union projects 0245_IBEROS_1_E and 0302_CVMAR_I_1_P, both from Interreg V-A Spain-Portugal (POCTEP 2015) and BLUEHUMAN EAPA_151/2016 from INTERREG Atlantic Area, European Regional Development Fund. Moreover, regional funds from Competitive Reference Groups (GRC) ED431C 2016/008 and ED431C 2017_51 and Research networks ED431D 2017/13 both from Xunta de Galicia (Spain) are also acknowledged. P. Diaz-Rodriguez and M. López-Alvarez are thankful for the funding support provided by 0245_IBEROS_1_E from EU Interreg V-A Spain-Portugal (POCTEP) project 2017/13 both from Xunta de Galicia (Spain) are also acknowledged. P. Diaz-Rodriguez and M. López-Alvarez are thankful for the funding support provided by 0245_IBEROS_1_E from EU Interreg V-A Spain-Portugal (POCTEP) project.S

    Metric potential of a 3D measurement system based on digital compact cameras

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    P. 4178-4194This paper presents an optical measuring system based on low cost, hogh resolution digital cameras. Once the cameras are synchronised, the portable and adjuntable system can be used to observe living beings, bodies in motion, or deformations of very different sizes. Each of the cameras has been modelled individually and studied with regard to the photogrammetric potential of the system. We have investigated the photogrammetric precision obtained from the crossing of rays, the repeatability of results, and the accuracy of the coordinates obtained. Systematic and random errors are identified in validity assessment of the definition of the precision of the system from crossing of rays or from marking residuals in images. The results have clearly demonstrated the capability of a low-cost multiple-camera system to measure with sub-millimetre precision.S

    Geometric Stability and Lens Decentering in Compact Digital Cameras

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    P. 1553-1572A study on the geometric stability and decentering present in sensor-lens systems of six identical compact digital cameras has been conducted. With regard to geometrical stability, the variation of internal geometry parameters (principal distance, principal point position and distortion parameters) was considered. With regard to lens decentering, the amount of radial and tangential displacement resulting from decentering distortion was related with the precision of the camera and with the offset of the principal point from the geometric center of the sensor. The study was conducted with data obtained after 372 calibration processes (62 per camera). The tests were performed for each camera in three situations: during continuous use of the cameras, after camera power off/on and after the full extension and retraction of the zoom-lens. Additionally, 360 new calibrations were performed in order to study the variation of the internal geometry when the camera is rotated. The aim of this study was to relate the level of stability and decentering in a camera with the precision and quality that can be obtained. An additional goal was to provide practical recommendations about photogrammetric use of such cameras.S

    Geometric stability and lens decentering in compact digital cameras

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    P. 1553-1572A study on the geometric stability and decentering present in sensor-lens systems of six identical compact digital cameras has been conducted. With regard to geometrical stability, the variation of internal geometry parameters (principal distance, principal point position and distortion parameters) was considered. With regard to lens decentering, the amount of radical and tangential displacement resulting from decentering distortion was related with the precision of the camera and with the offset of the principal point from the geometric center of the sensor. The study was conducted with data obtained after 372 calibration processes (62 per camera). The tests were performed for each camera in three situations: during continuous use of the cameras, after camera power off/on and after the full extension and retraction of the zoom-lens.S

    Review article laser-induced hyperthermia on graphene oxide composites

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    Background: Hyperthermia-based therapies have shown great potential for clinical applications such as for the antitumor and antipathogenic activities. Within all strategies, the so-called photothermal therapy proposes to induce the hyperthermia by the remote laser radiation on a photothermal conversion agent, in contact with the target tissue. Methods: This paper reviews the most relevant in vitro and in vivo studies focused on NIR laser-induced hyperthermia due to photoexcitation of graphene oxide (GO) and reduced graphene oxide (rGO). Relevant parameters such as the amount of GO/rGO, the influence of the laser wavelength and power density are considered. Moreover, the required temperature and exposure time for each antitumor/antipathogenic case are collected and unified in a thermal dose parameter: the CEM43. Results: The calculated CEM43 thermal doses revealed a great variability for the same type of tumor/strain. In order to detect potential tendencies, the values were classified into four ranges, varying from CEM4360ºC). Conclusions: The ability of GO/rGO as effective photothermal conversion agents to promote a controlled hyperthermia is proven. The variability found for the CEM43 thermal doses on the reviewed studies reveals the potentiality to evaluate, for each application, the use of lower temperatures, by modulating time and/or repetitions in the dosesMinisterio de Ciencia e Innovación del Gobierno de España | Ref. BIOHEAT (PID 2020- 115415RB-100)Xunta de Galicia | Ref. GRC (ED431C 2021/49

    Prevalence of Apical Periodontitis in patients with Multiple Myeloma

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    Aim Previous reports have been analyzed the prevalence/association of apical periodontitis (AP) with systemic diseases. The present study aims to analyze the prevalence of healthy/diseased periapex and endodontic treatments in patients with Multiple Myeloma (MM) and compare the results with those of control subjects. Methodology Panoramic radiographs of 50 individuals with MM were evaluated and compared with 50 controls that were sex and age matched exactly with the diseased group. Radiographic analysis was performed by 2 two experienced endodontists under standardized conditions. The periapical status (presence or not of AP) was assessed using the periapical index (PAI). Data included systemic health, technical quality of root fillings, total number of teeth, quality of restoration, and periapical status. Statistical evaluation of differences between groups included used chi-squared tests and Fisher?s exact tests. The prevalence of root canal-treated teeth was 10.11% in the MM group and 12.05% in the control group (p=0.90). The average root canal-treated teeth in the test group was 2,34 and 2.48 in the control group, where the difference was statistically significant (p=0.05). AP in 1 or more teeth was found in 86 % and in 78% of the patients in the MM and the control groups, respectively. When analyzed by subject, there was no statistically significant difference in the prevalence of AP (p>0.72). Similarly there was also no statistically significant difference in the prevalence of PA (p=0.85), when analyzed by tooth, AP was found in 63.2% and 62.9% in MM and control groups. The presence of AP and endodontic treatment was not significantly different in individuals with MM compared with control subjects. Future studies are needed to elucidate and confirm the association between MM and AP

    LA SOLUCIÓN DE PROBLEMAS DESDE LA ENSEÑANZA CARTOGRÁFICA EN LA FORMACIÓN DEL PROFESOR DE GEOGRAFÍA

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    La formación didáctica inicial del profesional de las carreras pedagógicas resulta esencial en el contexto actual de la educación superior cubana para dar respuesta a las demandas sociales. En este sentido, el empleo de métodos que estimulan la actividad cognoscitiva del estudiante para dirigir la solución de problemas en la práctica educativa constituye una alternativa importante a considerar. La formación didáctica posibilita que los estudiantes adquieran modos de actuación positivos hacia la ciencia en correspondencia con el método científico y la vida cotidiana, lo que permite la solución de problemas profesionales. En tal sentido, en el artículo se presentan actividades para la solución de problemas que se presentan desde la enseñanza de la Cartografía en cuanto al desarrollo de habilidades, las cuales responden al proyecto: la formación didáctica del estudiante licenciado en educación para dirigir la solución de problemas. Dentro de la metodología utilizada se destaca el enfoque dialéctico-materialista como método general. Se aplicaron métodos propios de la investigación pedagógica entre los que se distinguen fundamentalmente: el histórico-lógico, analítico-sintético, el inductivo-deductivo y métodos empíricos como la entrevista y la observación; los que facilitaron sintetizar los referentes más importantes del tema, su ordenamiento e integración hasta llegar a generalizaciones

    Liderazgo & clima organizacional de un hospital pediátrico cubano. Visión de enfermeras jefas y asistenciales

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    Objective: Describe experiences of nurses heads and clinical nurses on the causes that may affect the organizational climate of pediatric services in a Cuban hospital. Method: Qualitative and exploratory study done in the months of April - December, 2018 with 14 heads nurses and 11 healthcare nurses, belonging to the Pediatric University Hospital "Paquito Gonzales Cueto", Province of Cienfuegos, Cuba. The data were collected with the focus group technique; the narratives were processed through content analysis based on the theoretical framework of organizational climate with the central category of leadership. The research was evaluated by the Ethical-Scientific Committee of the reference hospital. Results: Four subcategories of content analysis emerged based on the theoretical framework. The most important was “ideology of a manager “followed by "continuous improvement" "listening for relational harmony" and "sense of belonging". Conclusions: the main causes as affecting organizational climate are related to the characteristics of the leader and the possibilities of overcoming them and the rest of the staff.describir experiencias vividas de enfermeras jefas y enfermeras asistenciales sobre las causas que pueden afectar el clima organizacional de los servicios pediátricos en un hospital cubano. Método: estudio cualitativo de tipo exploratorio realizado en los meses de abril-diciembre, año 2018 con 14 enfermeras jefas y 11 enfermeras asistenciales, pertenecientes al Hospital Pediátrico Universitario “Paquito González Cueto”, Provincia de Cienfuegos, Cuba. Los datos se recogieron con la técnica de grupo focal, las narrativas fueron procesadas mediante análisis de contenido en base al referencial teórico de clima organizacional con la categoría central de liderazgo. La investigación fue evaluada por Comité Ético-Científico de hospital de referencia. Resultados: emergieron cuatro subcategorías del análisis de contenido con base en el referencial teórico. La de mayor peso fue “ideario de un directivo” seguida de “mejoramiento continuo” “escucha para la armonía relacional” y “sentido de pertenecía”. Conclusiones: las principales causas que afectan el clima organizacional se relacionan con las características del líder y las posibilidades de superación de ellos y del resto del personal

    Effect of high pressure homogenization and heat treatment on physical properties and stability of almond and hazelnut milks

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    [EN] The effect of high pressure homogenisation (HPH) and heat treatments on physicochemical properties and physical stability of almond and hazelnut milks was studied. Vegetable milks were obtained and homogenised by applying 62, 103 and 172 MPa (MF1, MF2 and MF3, respectively). Untreated and MF3 samples were also submitted to two different heat treatments (85ºC/30 min (LH) or 121ºC/15 min (HH)). Physical and structural properties of the products were greatly affected by heat treatments and HPH. In almond milk, homogenised samples showed a significant reduction in particle size, which turned from bimodal and polydisperse to monodisperse distributions. Particle surface charge, clarity and Whiteness Index were increased and physical stability of samples was improved, without affecting either viscosity or protein stability. Hazelnut beverages showed similar trends, but HPH notably increased their viscosity while change their rheological behaviour, which suggested changes in protein conformation. HH treatments caused an increment of particle size due to the formation oil droplet-protein body clusters, associated with protein denaturation. Samples submitted to the combined treatment MF3 and LH showed the greatest stability.The authors acknowledge the financial support provided by Universitat Politecnica de Valencia (Valencia, Spain) for the project (PAID 05-11-2740). Author N. Bernat appreciates the Conselleria de Eduacion of Valencia (Spain) for a FPI Grant (Programa VALi + d para investigadores en formacion. ACIF/2011).Bernat Pérez, N.; Cháfer Nácher, MT.; Rodríguez García, J.; Chiralt, A.; González Martínez, MC. (2015). Effect of high pressure homogenization and heat treatment on physical properties and stability of almond and hazelnut milks. Food Science and Technology. 62:488-496. https://doi.org/10.1016/j.lwt.2014.10.045S4884966
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