2,430 research outputs found

    Approaching stimuli bias attention in numerical space

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    Increasing evidence suggests that common mechanisms underlie the direction of attention in physical space and numerical space, along the mental number line. The small leftward bias (pseudoneglect) found on paper-and-pencil line bisection is also observed when participants ‘bisect’ number pairs, estimating (without calculating) the number midway between two others. Here we investigated the effect of stimulus motion on attention in numerical space. A two-frame apparent motion paradigm manipulating stimulus size was used to produce the impression that pairs of numbers were approaching (size increase from first to second frame), receding (size decrease), or not moving (no size change). The magnitude of pseudoneglect increased for approaching numbers, even when the final stimulus size was held constant. This result is consistent with previous findings that pseudoneglect in numerical space (as in physical space) increases as stimuli are brought closer to the participant. It also suggests that the perception of stimulus motion modulates attention over the mental number line and provides further support for a connection between the neural representations of physical space and number

    Bone lengthening osteogenesis, a combination of intramembranous and endochondral ossification: an experimental study in sheep

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    We evaluated the morphological features of the newly formed tissue in an experimental model of tibial callotasis lengthening on 24 lambs, aged from 2 to 3 months at the time of operation. A unilateral external fixator prototype Monotube Triax® (Stryker Howmedica Osteonics, New Jersey) was applied to the left tibia. A percutaneous osteotomy was performed in a minimally traumatic manner using a chisel. Lengthening was started 7 days after surgery and was continued to 30 mm. The 24 animals were randomly divided into three groups of 8 animals each: in Group 1, lengthening took place at a rate of 1 mm/day for 30 days; in Group 2, at a rate of 2 mm/day for 15 days; in Group 3, at a rate of 3 mm/day for 10 days. In each group, 4 animals were killed 2 weeks after end of lengthening, and the other 4 animals at 4 weeks after end of lengthening. To assess bony formation in the distraction area, radiographs were taken every 2 weeks from the day of surgery. To study the process of vascularization, we used Spalteholz’s technique. After killing, the tibia of each animal was harvested, and sections were stained with hematoxylin and eosin, Masson’s trichrome, and Safranin-O. Immunohistochemistry was performed, using specific antibodies to detect collagens I and II, S100 protein, and fibronectin. A combination of intramembranous and endochondral ossification occurred together at the site of distraction. Our study provides a detailed structural characterization of the newly formed tissue in an experimental model of tibial lengthening in sheep and may be useful for further investigations on callotasis

    Advances in Meniscal Tissue Engineering

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    Meniscal tears are the most common knee injuries and have a poor ability of healing. In the last few decades, several techniques have been increasingly used to optimize meniscal healing. Current research efforts of tissue engineering try to combine cell-based therapy, growth factors, gene therapy, and reabsorbable scaffolds to promote healing of meniscal defects. Preliminary studies did not allow to draw definitive conclusions on the use of these techniques for routine management of meniscal lesions. We performed a review of the available literature on current techniques of tissue engineering for the management of meniscal tears

    Effect of oxidizing and reducing atmospheres on Ba(Ti0.90Zr0.10)O3:2V ceramics as characterized by piezoresponse force microscopy

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    The effect of annealing atmospheres (At amb, N2 and O2) on the electrical properties of Ba(Ti0.90Zr0.10)O3:2V (BZT10:2V) ceramics obtained by the mixed oxide method was investigated. X-ray photoelectron spectroscopy (XPS) analysis indicates that oxygen vacancies present near Zr and Ti ions reduce ferroelectric properties, especially in samples treated in an ambient atmosphere (At amb). BZT10:2V ceramics sintered in a nitrogen atmosphere showed better dielectric behaviour at room temperature with a dielectric permittivity measured at a frequency of 10 kHz equal to 16800 with dielectric loss of 0.023. Piezoelectric force microscopy (PFM) images reveal improvement in the piezoelectric coefficient by sintering the sample under nitrogen atmosphere. Thus, BZT10:2V ceramics sintered under a nitrogen atmosphere can be useful for practical applications which include nonvolatile digital memories, spintronics and data-storage media

    Behçet's disease: New insight into the relationship between procoagulant state, endothelial activation/damage and disease activity

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    Background: Behçet disease (BD) is associated with a prothrombotic state of unknown origin that may lead to life-threatening events. Calibrated Automated Thrombogram (CAT) and Rotational Thromboelastometry (ROTEM) are two global haemostasis assays that may reveal new insights into the physiopathological mechanisms of the disease and its procoagulant condition. Methods. 23 BD patients who had no signs or symptoms of current thrombosis and 33 age- and sex-matched controls were included in the study. We performed ROTEM and CAT tests and assessed erythrocyte count, platelet count, platelet contribution to clot formation and plasma levels of tissue-type plasminogen activator, plasminogen activator inhibitor type 1 (PAI-1), fibrinogen, C-reactive protein (CRP), thrombin-antithrombin III complex (TAT), D-dimer and E-selectin (ES). Results: Both ROTEM and CAT tests showed a hypercoagulable state in the BD patients. Plasma levels of PAI-1, fibrinogen, TAT, CRP and ES were significantly increased in this group compared to controls. The disease activity (DA) was significantly correlated with levels of ES and the maximum clot firmness, and this last one, in turn, correlated with rising levels of ES, PAI-1, CRP and fibrinogen. CAT parameters did not correlate with DA or ES. Conclusions: Both ROTEM and CAT tests reveal that patients with BD have a procoagulant state even in the absence of thrombosis. ROTEM test indicates that increased levels of fibrinogen and PAI-1 may be involved in the prothrombotic state of this pathology, while platelets do not significantly contribute. Moreover, CAT assay demonstrate that plasma from BD patients is able to generate more thrombin than controls in response to the same stimulus and that this effect is independent of the DA and the endothelial impairment suggesting the involvement of another factor in the hypercoagulable state observed in BD patients. This study also shows that endothelium activation/damage may be a contributing factor in both the procoagulant and clinical conditions of BD, as shown by the direct correlation between ES levels, ROTEM parameters and DAThis work was supported by grants from FIS PS09/00531 and FIS PI12/0183

    Vacuum tribological behaviour of self lubricant quasicrystalline composite coatings

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    High temperature resistant self-lubricant coatings are needed in space vehicles for components that operate at high temperatures and/or under vacuum. Thick composite lubricant coatings containing quasicrystalline alloys (QC) as the hard phase for wear resistance, have been deposited by thermal spray. The coatings also comprise lubricating materials (silver and BaF2-CaF2 eutectic) and NiCr as the tough component. This paper describes the vacuum tribological properties of TH103, a coating belonging to this family, with excellent microstructural quality. The coating was deposited by HVOF and tested under vacuum on a pin-on-disc tribometer. Different loads, linear speeds and pin materials were studied. The pin scars and disc wear tracks were characterized by EDS-SEM. A minimum mean steady friction coefficient of 0.32 was obtained employing a X-750 Ni superalloy pin in vacuum conditions under 10 N load and 15 cm/s linear speed, showing moderate wear of the disc and low wear of the pin

    Synthesis and characterization of a click-assembled 18-atom macrocycle that displays selective AXL kinase inhibitory activity

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    A novel macrocyclic construct consisting of a pyrazolopyrimidine scaffold concatenated to a benzene ring through two triazoles has been developed to investigate uncharted chemical space with bioactive potential. The 18-atom macrocycle was assembled via a double copper-catalyzed alkyne−azide cycloaddition (CuAAC) reaction between 1,3- bis(azidomethyl)benzene and a bis-propargylated pyrazolo[3,4-d]pyrimidine core. The resulting macrocycle was functionalized further into a multicyclic analog that displays selective inhibitory activity against the receptor tyrosine kinase AXL.O.C.-L. and B.L. thank Spain Ministry of Education, Culture and Sport and the Erasmus + Traineeship programme for funding, respectively. C.T. thanks the CMVM for a Principal’s Scholarship. F.F. acknowledges support from Universidad de Granada. SHM and AU-B are grateful to Scottish Power and CRUK for funding

    Fatores que influenciam o processo de ensino aprendizagem no curso de Ciências Contábeis do ponto de vista acadêmico

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    Da realidade refletida pelo campo de trabalho atual, pode ser resumido o seguinte cenário: milhares de contadores são graduados, todos os anos, em centenas de IESs brasileiras, enquanto ganham volume as reclamações do mercado quanto às limitações dos novos profissionais, os quais seriam despreparados para atender às exigências do mercado de trabalho. Diante desse contexto, se torna cada vez mais relevante a necessidade de estudar como ocorre o processo de ensinoaprendizagem nessa área, tendo em vista que o conhecimento dos fatores que influenciam esse processo (ensino-aprendizagem) é fundamental para o desenvolvimento de ações que visem à melhoria da formação do profissional contábil. Esta pesquisa buscou verificar quais são os fatores que mais influenciam e dificultam o processo de ensino-aprendizagem, numa visão acadêmica, especificamente na opinião dos alunos do Curso de Ciências Contábeis da Universidade Estadual do Centro-Oeste - UNICENTRO. O principal procedimento realizado foi uma aplicação de         questionário envolvendo os alunos que estão cursando o 1º, 2º e 3º ano, na sede da instituição em Guarapuava e no campus avançado de Chopinzinho, abrangendo um total de 241 acadêmicos, dos quais 209 responderam ao questionário, o qual constava de 6 (seis) questões fechadas que, por sua vez, apresentavam cinco sugestões de respostas encontradas na bibliografia educacional e que guardavam relação com o ensino-aprendizagem. Após análise dos resultados, concluiu-se que, na opinião dos alunos dessa Instituição, o uso de uma metodologia de ensino que proporciona a participação dos alunos em sala de aula, é um fator determinante para facilitar a aprendizagem. Também, verificou-se que os discentes têm disposição para se dedicarem ao estudo em sala de aula desde que motivados por metodologia de ensino adequada, sendo essa resposta unânime entre os que responderam o questionário. Tendo por base esses resultados, esta pesquisa propõe uma metodologia para o ensino-aprendizagem da Contabilidade
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