157 research outputs found

    Fatigue of sintered porous materials based on 316L stainless steel under uniaxial loading

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    The paper presents the results of fatigue tests of sintered porous 316L austenitic stainless steel with different porosity. An analysis was conducted into the parameters obtained from the hysteresis loop in the load cycle (changes in the value of Young’s modulus, maximum and minimum stress). Fatigue life of the porous material of varying density according to the relationship Manson–Coffin was determined.Наведено результати втомних випробовувань зразків аустенітної сталі 316L з рівнями пористості 26, 33 і 41%. Проаналізовано параметри, отримані із петлі гістерезису в циклі навантаження – зміну модуля Юнґа, максимальних і мінімальних напружень. Використовуючи залежність Mенсона–Коффіна, визначили втомну міцність пористих матеріалів з різним ступенем загущення.Представлены результаты усталостных испытаний образцов аустенитной стали 316L с уровнями пористости 26, 33 и 41%. Проанализированы параметры, полученные из петли гистерезиса в цикле нагрузки – изменения модуля Юнга, максимальных и минимальных напряжений. Используя зависимость Mенсона–Коффина, определили усталостную прочность пористых материалов с различным уровнем плотности

    Principles of nociceptive coding in the anterior cingulate cortex.

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    The perception of pain is a multidimensional sensory and emotional/affective experience arising from distributed brain activity. However, the involved brain regions are not specific for pain. Thus, how the cortex distinguishes nociception from other aversive and salient sensory stimuli remains elusive. Additionally, the resulting consequences of chronic neuropathic pain on sensory processing have not been characterized. Using in vivo miniscope calcium imaging with cellular resolution in freely moving mice, we elucidated the principles of nociceptive and sensory coding in the anterior cingulate cortex, a region essential for pain processing. We found that population activity, not single-cell responses, allowed discriminating noxious from other sensory stimuli, ruling out the existence of nociception-specific neurons. Additionally, single-cell stimulus selectivity was highly dynamic over time, but stimulus representation at the population level remained stable. Peripheral nerve injury-induced chronic neuropathic pain led to dysfunctional encoding of sensory events by exacerbation of responses to innocuous stimuli and impairment of pattern separation and stimulus classification, which were restored by analgesic treatment. These findings provide a novel interpretation for altered cortical sensory processing in chronic neuropathic pain and give insights into the effects of systemic analgesic treatment in the cortex

    Environmental enrichment promotes resilience to neuropathic pain-induced depression and correlates with decreased excitability of the anterior cingulate cortex.

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    Depression is a common comorbidity of chronic pain with many patients being affected. However, efficient pharmacological treatment strategies are still lacking. Therefore, it is desirable to find additional alternative approaches. Environmental enrichment has been suggested as a method to alleviate pain-induced depression. However, the neuronal mechanisms of its beneficial effects are still elusive. The anterior cingulate cortex (ACC) plays a central role in processing pain-related negative affect and chronic pain-induced plasticity in this region correlates with depressive symptoms. We studied the consequences of different durations of environmental enrichment on pain sensitivity and chronic pain-induced depression-like behaviors in a mouse model of neuropathic pain. Furthermore, we correlated the behavioral outcomes to the activity levels of pyramidal neurons in the ACC by analyzing their electrophysiological properties ex vivo. We found that early exposure to an enriched environment alone was not sufficient to cause resilience against pain-induced depression-like symptoms. However, extending the enrichment after the injury prevented the development of depression and reduced mechanical hypersensitivity. On the cellular level, increased neuronal excitability was associated with the depressive phenotype that was reversed by the enrichment. Therefore, neuronal excitability in the ACC was inversely correlated to the extended enrichment-induced resilience to depression. These results suggest that the improvement of environmental factors enhanced the resilience to developing chronic pain-related depression. Additionally, we confirmed the association between increased neuronal excitability in the ACC and depression-like states. Therefore, this non-pharmacological intervention could serve as a potential treatment strategy for comorbid symptoms of chronic pain

    Probing the dynamics and structure of confined benzene in MCM-41 based catalysts

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    A combination of Molecular Dynamics (MD) simulations and Quasielastic Neutron Scattering (QENS) experiments has been used to investigate the dynamics and structure of benzene in MCM-41 based catalysts. QENS experiments of benzene as both an unconfined liquid and confined in the catalyst Pt/MCM-41 find that the mobility of benzene decreases upon confinement as shown by the decreased diffusion coefficients. Complementary MD simulations on benzene in MCM-41 show agreement with the QENS experiments when using a novel fully flexible model of MCM-41. Structural information from the MD simulations show that benzene in MCM-41 has a significantly different structure from that of the bulk liquid; with benzene molecules closer together and no prefered orientation

    Grieving, Therapy, Cinema and Kieslowski's Trois Couleurs: Rouge

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    Cultural associations with red are potent. They include blood and intense passion, injury and death, love and life; and all these are authentic indications of Kieslowski’s themes. Yet in this film the connotations of the colour are not exclusively traditional because the heroine, a model, will have her image displayed on a gigantic scarlet billboard to promote bubble gum. The model’s glamorous, colour-saturated but transient world and the grey existence of an emotionally constipated senex come into contact. The initially hostile contact between this ill-matched pair brings them not into each other’s arms – this is no romantic comedy – but, through discovery of each other’s weaknesses and strengths, to a degree of completion (not perfection) in which conscious and unconscious are better aligned. In part they are moved by synchronicities in which the life of a young advocate begins to echo the judge’s past. Not only this factor (which extends the reach of the drama beyond the odd couple) but the ever present cultural socio-cultural background of advertising and judicial morality generalise the issues of the main protagonists across the European collective. Eventually the unforgettable calamity with which the film ends brings into focus the characteristics of the main protagonists from the entire trilogy that renders them psychologically convincing survivors

    Bulk and Confined Benzene-Cyclohexane Mixtures Studied by an Integrated Total Neutron Scattering and NMR Method

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    From Springer Nature via Jisc Publications RouterHistory: accepted 2021-04-10, registration 2021-04-10, pub-electronic 2021-04-23, online 2021-04-23, pub-print 2021-08Publication status: PublishedFunder: Engineering and Physical Sciences Research Council; doi: http://dx.doi.org/10.13039/501100000266; Grant(s): N008995, N009304Abstract: Herein mixtures of cyclohexane and benzene have been investigated in both the bulk liquid phase and when confined in MCM-41 mesopores. The bulk mixtures have been studied using total neutron scattering (TNS), and the confined mixtures have been studied by a new flow-utilising, integrated TNS and NMR system (Flow NeuNMR), all systems have been analysed using empirical potential structure refinement (EPSR). The Flow NeuNMR setup provided precise time-resolved chemical sample composition through NMR, overcoming the difficulties of ensuring compositional consistency for computational simulation of data ordinarily found in TNS experiments of changing chemical composition—such as chemical reactions. Unique to the liquid mixtures, perpendicularly oriented benzene molecules have been found at short distances from the cyclohexane rings in the regions perpendicular to the carbon–carbon bonds. Upon confinement of the hydrocarbon mixtures, a stronger parallel orientational preference of unlike molecular dimers, at short distances, has been found. At longer first coordination shell distances, the like benzene molecular spatial organisation within the mixture has also found to be altered upon confinement

    Dynamic metabolic patterns tracking neurodegeneration and gliosis following 26S proteasome dysfunction in mouse forebrain neurons

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    Metabolite profling is an important tool that may better capture the multiple features of neurodegeneration. With the considerable parallels between mouse and human metabolism, the use of metabolomics in mouse models with neurodegenerative pathology provides mechanistic insight and ready translation into aspects of human disease. Using 400MHz nuclear magnetic resonance spectroscopy we have carried out a temporal region-specifc investigation of the metabolome of neuron-specifc 26S proteasome knockout mice characterised by progressive neurodegeneration and Lewy-like inclusion formation in the forebrain. An early signifcant decrease in N-acetyl aspartate revealed evidence of neuronal dysfunction before cell death that may be associated with changes in brain neuroenergetics, underpinning the use of this metabolite to track neuronal health. Importantly, we show early and extensive activation of astrocytes and microglia in response to targeted neuronal dysfunction in this context, but only late changes in myo-inositol; the best established glial cell marker in magnetic resonance spectroscopy studies, supporting recent evidence that additional early neuroinfammatory markers are needed. Our results extend the limited understanding of metabolite changes associated with gliosis and provide evidence that changes in glutamate homeostasis and lactate may correlate with astrocyte activation and have biomarker potential for tracking neuroinfammation

    Creative methods: problematics for inquiry and pedagogy in health and social care

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    This article provides an overview of initial discussions emerging from the Creative Methods Network, an informal organisation concerned with the use of the creative arts in research, teaching and practice in health and social care. Key issues are presented and contextualised with regard to the current conditions in which health and social care research and education is practised. Our own discussions have come to question the seeming dominance of governance within professional education programmes in which there is a primary focus on developing technical skill and capacity. Such governance often extends itself to the measurement of the implementation of these technical skills and this is set against concerns about the absence of creativity and the humanities in the educational programmes of caring for human beings. Consequently, the article reflects a view that the use of the creative arts and humanities in the education of the human caring professions is being eroded away in favour of technical-rational reasoning. It is argued that this then presents an important problem manifested in an emphasis on established and quantifiable knowledge transfer which inhibits other forms of knowledge generation. For the purposes of this discussion we have viewed this problem through the lenses offered by Foucault and Bourdieu

    Molybdenum (Mo) increases endogenous phenolics, proline and photosynthetic pigments and the phytoremediation potential of the industrially important plant Ricinus communis L. for removal of cadmium from contaminated soil.

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    Cadmium (Cd) in agricultural soil negatively affects crops yield and compromises food safety. Remediation of polluted soil is necessary for the re-establishment of sustainable agriculture and to prevent hazards to human health and environmental pollution. Phytoremediation is a promising technology for decontamination of polluted soil. The present study investigated the effect of molybdenum (Mo) (0.5, 1.0 and 2.0 ppm) on endogenous production of total phenolics and free proline, plant biomass and photosynthetic pigments in Ricinus communis plants grown in Cd (25, 50 and 100 ppm) contaminated soils and the potential for Cd phytoextraction. Mo was applied via seed soaking, soil addition and foliar spray. Foliar sprays significantly increased plant biomass, Cd accumulation and bioconcentration. Phenolic concentrations showed significantly positive correlations with Cd accumulation in roots (R 2 = 0.793, 0.807 and 0.739) and leaves (R 2 = 0.707, 721 and 0.866). Similarly, proline was significantly positively correlated with Cd accumulation in roots (R 2 = 0.668, 0.694 and 0.673) and leaves (R 2 = 0.831, 0.964 and 0.930). Foliar application was found to be the most effective way to deliver Mo in terms of increase in plant growth, Cd accumulation and production of phenolics and proline
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