4,589 research outputs found

    Damaging micromechanisms characterization in a ferritic-pearlitic ductile cast iron

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    The analysis of the damaging micromechanisms in Ductile Cast Irons is often focused on ferritic matrix. Up to ten years ago, for this grades of DCIs, the main damaging micromechanism was identified with the graphite elements - ferritic matrix debonding. More recent experimental results showed the presence of an internal gradient of mechanical properties in the graphite elements and the importance of other damaging micromechanisms, with a negligible importance of the graphite elements - ferritic matrix debonding mechanism. In this work, damaging micromechanisms development in a ferritic - pearlitic DCI have been investigated by means of tensile tests performed on mini-tensile specimens and observing the specimens lateral surfaces by means of a scanning electro microscope (SEM) during the tests ("in-situ" tests). Experimental results have been compared with the damaging micromechanisms observed in fully ferritic and fully pearlitic DCIs

    3D mosaic documentation using close range photogrammetry

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    The paper describes the close range photogrammetric survey of a roman mosaic stored at Regional Archaeological Museum “Antonino Salinas” in Palermo (Italy). The aim of the work is the production of a full-scale representation (scale 1:1) of the mosaic useful for documentation and restoration processes. The research has allowed evaluating limit and potentiality of image-based approach using photogrammetric and computer vision (Structure for Motion) techniques in a context where the metric point of view is a very important factor

    Wood exploitation and food supply at the border of the Roman Empire: the case of the vicus of Thamusida - Sidi Ali ben Ahmed (Morocco)

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    This paper presents the results of inter-disciplinary work drawing on archaeobotanical and archaeometric studies to trace the agroforestry landscape and the supply economy at the vicus of Thamusida in north-west Morocco at the border of the Roman Empire. The available data indicate the self-sufficiency of the settlement in both forestry and agricultural products throughout the period investigated from the end of the 1st century BC to the beginning of the 4th century AD. Charcoal data testify to the presence of a Quercus suber forest in the close surroundings of the site and its exploitation for a variety of forestry products such as timber, fuelwood, cork, and probably also leaves and acorns to feed livestock. The overwhelming presence of Q. suber in the archaeological layer investigated clearly indicates that this forest was under human influence prior to Roman occupation and was already partially degraded. Charred seed and fruit remains suggest that the diet of both troops and civilians was mainly based on locally grown products and that all the inhabitants of the site had access to good cereals such as barley, naked wheats and pulses with large seeds such as horse bean and pea; quality fruits, such as olive and grape, were also produced locally for fresh consumption. Organic residue analyses of the contents of ceramic vessels and plastered vats allowed archaeobotanical data to be complemented, thereby shedding light on some of the imports at Thamusida. Despite the remote location of this settlement, imported goods such as oil and wine were transported here in amphorae from different parts of the Empire

    Stress triaxiality influence on damaging micromechanisms in a pearlitic ductile cast iron

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    In the last decades, damaging micromechanisms in ductile cast irons (DCIs) have been widely investigated, considering both the matrix microstructure and the loading conditions influence. Considering the graphite nodules, they were initially considered as voids embedded and growing in a ductile metal matrix (especially considering ferritic ductile cast irons). Recent experimental results allowed to identify a more complex role played by the graphite nodules, depending on the matrix microstructure.In this work, damaging micromechanisms in a pearlitic DCI were investigated by means of tensile tests performed on notched specimen, mainly focusing the role played by graphite elements and considering thestress triaxiality influence

    Damaging micromechanisms characterization in a ferritic-pearlitic ductile cast iron

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    The analysis of the damaging micromechanisms in Ductile Cast Irons is often focused on ferritic matrix. Up to ten years ago, for this grades of DCIs, the main damaging micromechanism was identified with the graphite elements – ferritic matrix debonding. More recent experimental results showed the presence of an internal gradient of mechanical properties in the graphite elements and the importance of other damaging micromechanisms, with a negligible importance of the graphite elements – ferritic matrix debonding mechanism. In this work, damaging micromechanisms development in a ferritic – pearlitic DCI have been investigated by means of tensile tests performed on mini-tensile specimens and observing the specimens lateral surfaces by means of a scanning electro microscope (SEM) during the tests (“in-situ” tests). Experimental results have been compared with the damaging micromechanisms observed in fully ferritic and fully pearlitic DCI

    Identification of murine phosphodiesterase 5A isoforms and their functional characterization in HL-1 cardiac cell line

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    Phosphodiesterase 5A (PDE5A) specifically degrades the ubiquitous second messenger cGMP and experimental and clinical data highlight its important role in cardiac diseases. To address PDE5A role in cardiac physiology, three splice variants of the PDE5A were cloned for the first time from mouse cDNA library (mPde5a1, mPde5a2 and mPde5a3). The predicted amino acidic sequences of the three murine isoforms are different in the N-terminal regulatory domain. mPDE5A isoforms were transfected in HEK293T cells and they showed high affinity for cGMP and similar sensitivity to sildenafil inhibition. RT-PCR analysis showed that mPde5a1, mPde5a2 and mPde5a3 had differential tissue distribution. In the adult heart, mPde5a1 and mPde5a2 were expressed at different levels whereas mPde5a3 was undetectable. Overexpression of mPDE5As induced an increase of HL-1 number cells which progress into cell cycle. mPDE5A1 and mPDE5A3 overexpression increased the number of polyploid and binucleated cells, mPDE5A3 widened HL-1 areas and modulated hypertrophic markers more efficiently respect to the other mPDE5A isoforms. Moreover, mPDE5A isoforms had differential subcellular localization: mPDE5A1 was mainly localized in the cytoplasm, mPDE5A2 and mPDE5A3 were also nuclear localized. These results demonstrate for the first time the existence of three PDE5A isoforms in mouse and highlight their potential role in the induction of hypertrophy. This article is protected by copyright. All rights reserved

    Perceived Job Insecurity and Depressive Symptoms Among Italian Dentists: The Moderating Role of Fear of COVID-19

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    Containment measures adopted to reduce the spread of coronavirus disease 2019 (COVID-19) have produced a general perception of job insecurity. Dentists have been highly affected by such measures, as they represent an easy source of contagion. As perceived job insecurity is associated with psychological distress and Italian dentists have been highly affected by the COVID-19 outbreak in terms of potential financial loss and the risk of being infected, this study aimed at assessing whether the fear of COVID-19 moderated the effect of perceived job insecurity on depressive symptoms. This cross-sectional online study has included 735 Italian dentists recruited during the lockdown and ranging in age from 27 to 70 years old (495 men and 240 women). A quantile regression model with an inference based on the median and with an interaction term between the fear of COVID-19 and perceived job insecurity has been used to estimate the hypothesized associations. The results indicated that both perceived job insecurity and fear of COVID-19 were positively associated with depressive symptoms, and that the effect of perceived job insecurity on depressive symptoms was weaker among those with a low fear of COVID-19. The findings may inform public health policies for dentists in relation to reducing the risk of developing negative mental health outcomes

    Effect of mofezolac-galactose distance in conjugates targeting cyclooxygenase (COX)-1 and CNS GLUT-1 carrier

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    Neuroinflammation is the earliest stage of several neurological and neurodegenerative diseases. In the case of neurodegenerative disorders, it takes place about 15â 20 years before the appearance of specific neurodegenerative clinical symptoms. Constitutive microglial COX-1 is one of the pro-inflammatory players of the neuroinflammation. Novel compounds 3, 14 and 15 (Galmof0, Galmof5and Galmof11, respectively) were projected, and their synthetic methodologies developed, by linking by an ester bond, directly or through a C5 or C11 unit linker the highly selective COX-1 inhibitor mofezolac (COXs selectivity index > 6000) to galactose in order to obtain substances capable to cross blood-brain barrier (BBB) and control the CNS inflammatory response. 3, 14 and 15 (Galmofs) were prepared in good to fair yields. Galmof0(3) was found to be a selective COX-1 inhibitor (COX-1 IC50= 0.27 μM and COX-2 IC50= 3.1 μM, selectivity index = 11.5), chemically and metabolically stable, and capable to cross Caco-2 cell monolayer, resembling BBB, probing that its transport is GLUT-1-mediated. Furthermore, Galmof0(3) powerfully inhibits PGE2release higher than mofezolac (1) in LPS-stimulated mouse BV2 microglial cell line, a worldwide recognized neuroinflammation model. In addition, Fingerprints for Ligands and Proteins (FLAP) was used to explain the different binding interactions of Galmofs with the COX-1 active site

    Recurrent transient global amnesia as presenting symptoms of CADASIL

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    Despite transient global amnesia is considered unusual in Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and causal relation is still unclear, this report suggests to consider CADASIL in those patients with recurrent transient global amnesia, especially when MRI shows multifocal hyperintensities affecting the cerebral white matter or when it is followed by cognitive decline

    Effects of P4 Antagonist RU486 on VEGF and Its Receptors' Signaling during the In Vivo Transition from the Preovulatory to Periovulatory Phase of Ovarian Follicles

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    The development of an adequate blood vessel network is crucial for the accomplishment of ovarian follicle growth and ovulation, which is necessary to support the proliferative and endocrine functions of the follicular cells. Although the Vascular Endothelial Growth Factor (VEGF) through gonadotropins guides ovarian angiogenesis, the role exerted by the switch on of Progesterone (P4) during the periovulatory phase remains to be clarified. The present research aimed to investigate in vivo VEGF-mediated mechanisms by inducing the development of periovulatory follicles using a pharmacologically validated synchronization treatment carried out in presence or absence of P4 receptor antagonist RU486. Spatio-temporal expression profiles of VEGF, FLT1, and FLK1 receptors and the two major MAPK/ERKs and PI3K/AKT downstream pathways were analyzed on granulosa and on theca compartment. For the first time, the results demonstrated that in vivo administration of P4 antagonist RU486 inhibits follicular VEGF receptors' signaling mainly acting on the theca layer by downregulating the activation of ERKs and AKTs. Under the effect of RU486, periovulatory follicles' microarchitecture did not move towards the periovulatory stage. The present evidence provides new insights on P4 in vivo biological effects in driving vascular and tissue remodeling during the periovulatory phase
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