833 research outputs found

    Experimental characterisation of fatigue damage in single Z-pins

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    Z-pins have been shown to significantly improve delamination resistance and impact strength of carbon fibre reinforced (CFRP) composites. In this paper, an experimental investigation of the influence of different fatigue parameters (mean opening/sliding displacement, amplitude, frequency, number of cycles) on the through-thickness reinforcement (TTR) is presented. For mode I, it is shown that the degradation on pin behaviour during fatigue is mostly affected by the applied displacement amplitude. The degradation is primarily caused by surface wear. Due to the brittleness of the Z-pins, mode II fatigue does not have a significant effect for very small sliding displacements. Exceeding a critical displacement causes the pin to rupture within the very first cycles

    Creative minds and neurosciences…

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    Creativity is the ability to generate original ideas in the arts or sciences, leaving traditional stereotypes behind, ultimately introducing innovation to the social context in which they arise. It has been associated with "divergent thinking" which prioritizes the generation of multiple solutions, different from traditional ones. Some authors have observed creative individuals present higher incidence of affective disorders, possibly related to hypomania or disinhibition. Similarly, “creativity” has been described in patients with frontotemporal dementia, a brain region linked with creativity on fMRI. Creativity is one of the most salient characteristics that human beings possess.Creatividad es la habilidad de generar ideas originales en arte o ciencia, dejando atrás los estereotipos y produciendo innovaciones en el contexto social en el cual ocurren. Creatividad es asociada con pensamiento divergente que prioriza la generación de múltiples soluciones diferentes a las tradicionales. Algunos autores refirieron que era muy frecuente los trastornos afectivos en los pacientes creativos, esto probablemente mas relacionado a la hipomanía o la desinhibición como también ocurre en la demencia fronto-temporal. Estas regiones cerebrales fueron descriptas en los trabajos con resonancia funcional. La creatividad es una de las características mas relevantes que posee el ser humano

    Adding Recognition Discriminability Index to the Delayed Recall Is Useful to Predict Conversion from Mild Cognitive Impairment to Alzheimer's Disease in the Alzheimer's Disease Neuroimaging Initiative

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    Background: Ongoing research is focusing on the identification of those individuals with mild cognitive impairment (MCI) who are most likely to convert to Alzheimer's disease (AD). We investigated whether recognition memory tasks in combination with delayed recall measure of episodic memory and CSF biomarkers can predict MCI to AD conversion at 24-month follow-up. Methods: A total of 397 amnestic-MCI subjects from Alzheimer's disease Neuroimaging Initiative were included. Logistic regression modeling was done to assess the predictive value of all RAVLT measures, risk factors such as age, sex, education, APOE genotype, and CSF biomarkers for progression to AD. Estimating adjusted odds ratios was used to determine which variables would produce an optimal predictive model, and whether adding tests of interaction between the RAVLT Delayed Recall and recognition measures (traditional score and d-prime) would improve prediction of the conversion from a-MCI to AD. Results: 112 (28.2%) subjects developed dementia and 285 (71.8%) subjects did not. Of the all included variables, CSF Aβ1-42 levels, RAVLT Delayed Recall, and the combination of RAVLT Delayed Recall and d-prime were predictive of progression to AD (χ2 = 38.23, df = 14, p < 0.001). Conclusions: The combination of RAVLT Delayed Recall and d-prime measures may be predictor of conversion from MCI to AD in the ADNI cohort, especially in combination with amyloid biomarkers. A predictive model to help identify individuals at-risk for dementia should include not only traditional episodic memory measures (delayed recall or recognition), but also additional variables (d-prime) that allow the homogenization of the assessment procedures in the diagnosis of MCI.Fil: Russo, María Julieta. Fundación para la Lucha Contra las Enfermedades Neurológicas de la Infancia. Instituto de Investigaciones Neurológicas "Raúl Carrea"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Campos, Jorge. Fundación para la Lucha Contra las Enfermedades Neurológicas de la Infancia. Instituto de Investigaciones Neurológicas "Raúl Carrea"; ArgentinaFil: Vázquez, Silvia. Fundación para la Lucha Contra las Enfermedades Neurológicas de la Infancia. Instituto de Investigaciones Neurológicas "Raúl Carrea"; ArgentinaFil: Sevlever, Gustavo. Fundación para la Lucha Contra las Enfermedades Neurológicas de la Infancia. Instituto de Investigaciones Neurológicas "Raúl Carrea"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Allegri, Ricardo Francisco. Fundación para la Lucha Contra las Enfermedades Neurológicas de la Infancia. Instituto de Investigaciones Neurológicas "Raúl Carrea"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    World Health Organization have just launched a Blueprint for Dementia Research.: Some notes to boost dementia research in Latin America….

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    Dementia is the most important cause of disability and dependency in older adults and currently affects more than 55 million people, 60% of whom live in Low- and Middle-­Income Countries (LMIC). The number of people with dementia with increasing life expectancy will grow globally in the coming years, but even more in LMIC such as the Latin American (LA) countries

    Towards the Journal of Applied Cognitive Neuroscience

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    In his book The Structure of Science Evolution, Thomas Khum defines a paradigmas “a set of beliefs, values and accepted techniques that define the exercise of a scientific discipline”. A new paradigm is a change of vision, a reconstruction of our knowledge in the light of discoveries; in the words of Socratics, “all cognition is a recognition”.In his book The Structure of Science Evolution, Thomas Khum defines a paradigmas “a set of beliefs, values and accepted techniques that define the exercise of a scientific discipline”. A new paradigm is a change of vision, a reconstruction of our knowledge in the light of discoveries; in the words of Socratics, “all cognition is a recognition”

    Effects of dihydrotanshinone I on proliferation and invasiveness of paclitaxel-resistant anaplastic thyroid cancer cells

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    ATC is a very rare, but extremely aggressive form of thyroid malignancy, responsible for the highest mortality rate registered for thyroid cancer. In patients without known genetic aberrations, the current treatment is still represented by palliative surgery and systemic mono-or combined chemotherapy, which is often not fully effective for the appearance of drug resistance. Comprehension of the mechanisms involved in the development of the resistance is therefore an urgent issue to suggest novel therapeutic approaches for this very aggressive malignancy. In this study, we created a model of anaplastic thyroid cancer (ATC) cells resistant to paclitaxel and investigated the characteristics of these cells by analyzing the profile of gene expression and comparing it with that of paclitaxel-sensitive original ATC cell lines. In addition, we evaluated the effects of Dihydrotanshinone I (DHT) on the viability and invasiveness of paclitaxel-resistant cells. ATC paclitaxel-resistant cells highlighted an overexpression of ABCB1 and a hyper-activation of the NF-\u3baB compared to sensitive cells. DHT treatment resulted in a reduction of viability and clonogenic ability of resistant cells. Moreover, DHT induces a decrement of NF-\u3baB activity in SW1736-PTX and 8505C-PTX cells. In conclusion, to the best of our knowledge, the results of the present study are the first to demonstrate the antitumor effects of DHT on ATC cells resistant to Paclitaxel in vitro

    GSK2801 Reverses Paclitaxel Resistance in Anaplastic Thyroid Cancer Cell Lines through MYCN Downregulation

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    Anaplastic thyroid cancer (ATC) is a very rare, but extremely aggressive form of thyroid malignancy, responsible for the highest mortality rate registered for thyroid cancer. Treatment with taxanes (such as paclitaxel) is an important approach in counteracting ATC or slowing its progression in tumors without known genetic aberrations or those which are unresponsive to other treatments. Unfortunately, resistance often develops and, for this reason, new therapies that overcome taxane resistance are needed. In this study, effects of inhibition of several bromodomain proteins in paclitaxel-resistant ATC cell lines were investigated. GSK2801, a specific inhibitor of BAZ2A, BAZ2B and BRD9, was effective in resensitizing cells to paclitaxel. In fact, when used in combination with paclitaxel, it was able to reduce cell viability, block the ability to form colonies in an anchor-independent manner, and strongly decrease cell motility. After RNA-seq following treatment with GSK2801, we focused our attention on MYCN. Based on the hypothesis that MYCN was a major downstream player in the biological effects of GSK2801, we tested a specific inhibitor, VPC-70619, which showed effective biological effects when used in association with paclitaxel. This suggests that the functional deficiency of MYCN determines a partial resensitization of the cells examined and, ultimately, that a substantial part of the effect of GSK2801 results from inhibition of MYCN expression

    Latin-America, a road to prevention of cognitive impairment [Editorial]

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    Las demencias se caracterizan por un deterioro adquirido y persistente de una o más capacidades cognitivas, generalmente asociado a alteraciones conductuales y de severidad suficiente para llevar a una pérdida de la autonomía. Las principales causas de demencias son la enfermedad de Alzheimer, las cerebrovasculares y otros tipos de demencias. La demencia es la tercera causa de carga de enfermedad para discapacidad y muerte en personas mayores de 65 años. El envejecimiento poblacional viene aumentando sostenidamente en los últimos años, siendo esta problemática mayor en los países en vías de desarrollo como sucede en Latinoamérica. © Revista Colombiana de Ciencias Sociales.Dementias are characterized by an acquired and persistent deterioration of one or more cognitive capacities, generally associated with behavioral alterations and of sufficient severity to lead to a loss of autonomy. The main causes of dementia are Alzheimer's, cerebrovascular and other types of dementias. Dementia is the third leading cause of disease burden for disability and death in people over 65 years. Population aging has been increasing steadily in recent years, being this problem greater in the developing countries as it happens in Latin America. © Revista Colombiana de Ciencias Sociales

    Novel parametric reduced order model for aeroengine blade dynamics

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    © 2015 Elsevier Ltd. All rights reserved.The work introduces a novel reduced order model (ROM) technique to describe the dynamic behavior of turbofan aeroengine blades. We introduce an equivalent 3D frame model to describe the coupled flexural/torsional mode shapes, with their relevant natural frequencies and associated modal masses. The frame configurations are identified through a structural identification approach based on a simulated annealing algorithm with stochastic tunneling. The cost functions are constituted by linear combinations of relative errors associated to the resonance frequencies, the individual modal assurance criteria (MAC), and on either overall static or modal masses. When static masses are considered the optimized 3D frame can represent the blade dynamic behavior with an 8% error on the MAC, a 1% error on the associated modal frequencies and a 1% error on the overall static mass. When using modal masses in the cost function the performance of the ROM is similar, but the overall error increases to 7%. The approach proposed in this paper is considerably more accurate than state-of-the-art blade ROMs based on traditional Timoshenko beams, and provides excellent accuracy at reduced computational time when compared against high fidelity FE models. A sensitivity analysis shows that the proposed model can adequately predict the global trends of the variations of the natural frequencies when lumped masses are used for mistuning analysis. The proposed ROM also follows extremely closely the sensitivity of the high fidelity finite element models when the material parameters are used in the sensitivity
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