334 research outputs found

    Health hazards of ultrafine metal and metal oxide powders

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    Study reveals that suggested threshold limit values are from two to fifty times lower than current recommended threshold limit values. Proposed safe limits of exposure to the ultrafine dusts are based on known toxic potential of various materials as determined in particle size ranges

    Theorizing the Principles of Sustainable Production in the context of Circular Economy and Industry 4.0.

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    The concept of Sustainable Production is evolving with changes triggered by the emergence of new economic and industrial models such as Circular Economy and Industry 4.0. However, most studies that currently link these concepts are based on the principles of Sustainable Production defined 20 years ago. Therefore, the primary aim of this study is to redefine the principles that should govern Sustainable Production operations in the transition towards a Circular Economy and smart industry models. To this end, an initial proposal of 11 principles was shared with 11 world-class experts (academics and practitioners) and a consensus proposal was sought through a Delphi Panel. Ten principles emerged from this study, which were evaluated by experts according to criteria of significance, parsimony, semantic consistency and empirical adequacy. Additionally, to study the relationships between the ten principles, the Interpretative Structural Model (ISM) technique was applied. The ISM technique identified which principles are independent of or dependent on each other and established relationships between the principles. The findings suggest that Principle 5 ("Prioritize employees' well-being"), Principle 6 ("Enhance management commitment to sustainability"), Principle 9 ("Measure and optimize sustainable processes") and Principle 10 ("Boost the use of sustainable technologies") help to establish an ideal context to enhance the development of the rest of the principles that characterize Sustainable Production. The presentation of the ten principles opens new possibilities for researchers while helping managers to better understand sustainability in terms of production and, therefore contribute to achieving SDG 12

    Analyzing the alignment between the Green Lean and Circular strategies: Towards a Circular Lean approach

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    Green Lean tools are aligned with the Circular Economy strategy as they aim at reducing waste, however, they miss the creation of value through waste. Therefore, this paper investigates whether the current implementation of the Green Lean strategy promotes the introduction of the Circular philosophy to achieve sustainable management production processes. It analyses how the resources were managed by implementing the different strategies and tools presented in Green Lean case studies under the lens of Circular Economy, and highlights future research paths on the Circular Lean integration. An analysis of the implementation of Green Lean case studies, selected through a Systematic Literature Review, from the manufacturing sector is conducted.The majority of Green Lean implementations were aimed at minimizing waste, which is aligned with the narrowing strategy of Circular Economy and only a few cases studies aimed at closing the production cycles. Even though the main results indicate that being eco-efficient is a good starting point to move towards sustainability, from a Circular Economy point of view, this approach could remain limited. Therefore, the current contribution of Green Lean to the implementation of circular practices is limited. It can be concluded that introducing the circular philosophy in the Green Lean methodology can be achieved through redirecting Green Lean from waste reduction towards a value creation focus. The originality of this paper is that it provides a critical review of the literature on the topic of Green Lean integration and Circular Economy

    Theorizing the principles of sustainable production in the context of circular economy and industry 4.0

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    The concept of Sustainable Production is evolving with changes triggered by the emergence of new economic and industrial models such as Circular Economy and Industry 4.0. However, most studies that currently link these concepts are based on the principles of Sustainable Production defined 20 years ago. Therefore, the primary aim of this study is to redefine the principles that should govern Sustainable Production operations in the tran- sition towards a Circular Economy and smart industry models. To this end, an initial proposal of 11 principles was shared with 11 world-class experts (academics and practitioners) and a consensus proposal was sought through a Delphi Panel. Ten principles emerged from this study, which were evaluated by experts according to criteria of significance, parsimony, semantic consistency and empirical adequacy. Additionally, to study the rela- tionships between the ten principles, the Interpretative Structural Model (ISM) technique was applied. The ISM technique identified which principles are independent of or dependent on each other and established relation- ships between the principles. The findings suggest that Principle 5 (“Prioritize employees' well-being”), Principle 6 (“Enhance management commitment to sustainability”), Principle 9 (“Measure and optimize sustainable pro- cesses”) and Principle 10 (“Boost the use of sustainable technologies”) help to establish an ideal context to enhance the development of the rest of the principles that characterize Sustainable Production. The presentation of the ten principles opens new possibilities for researchers while helping managers to better understand sustainability in terms of production and, therefore contribute to achieving SDG 12

    Atherosclerosis regression and TP receptor inhibition: effect of S18886 on plaque size and composition—a magnetic resonance imaging study

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    Aims Endothelial dysfunction, platelet hyperactivity, and inflammation play a crucial role in atherogenesis. A growing body of evidence suggests that inhibition of the thromboxane A2 (TxA2 or TP) receptor may improve endothelial function and reduce the inflammatory component of atherosclerosis in addition to its demonstrated antiplatelet activity. Consequently, we sought to assess the effect of a novel TP receptor antagonist S18886, on atherosclerotic lesion progression and composition by serial non-invasive magnetic resonance imaging (MRI). Methods and results S18886 was compared with control in an experimental model of established aortic atherosclerosis in New Zealand White rabbits (n=10). The animals underwent MRI of the abdominal aorta at the time of randomization and at the end of treatment. Subsequently, animals were euthanized and specimens were stained for histopathology and immunohistochemistry with anti-α-actin antibodies for vascular smooth muscle cells (VSMC), anti-RAM-11 for macrophages, anti-caspase-3 for apoptotic cells, anti-MMP-1 for metalloproteinases, and anti-endothelin-1 (ET-1) as a marker of endothelial dysfunction. MRI analysis revealed a significant reduction in total vessel area (TVA) and vessel wall area (VWA) in the S18886 group (P<0.05). Immunostaining analysis showed a significant decrease in RAM-11, caspase-3, MMP-1, ET-1 and an increase in α-actin in the treated group (P<0.05 vs. control). Conclusion Inhibition of the TP receptor by S18886 causes a regression of advanced atherosclerotic plaques. In addition, the reduction in the markers for macrophages, apoptotic cells, metalloproteinases, and endothelin-1 and the increase in VSMC, suggests that S18886 may not only halt the progression of atherosclerosis, but also transform lesions towards a more stable phenotype. The possibility of combining antithrombotic and antiatherosclerotic activity by means of the administration of TP inhibitors deserves further investigation in a clinical settin

    Theorizing the principles of sustainable production in the context of Circular Economy and Industry 4.0

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    The concept of Sustainable Production is evolving with changes triggered by the emergence of new economic and industrial models such as Circular Economy and Industry 4.0. However, most studies that currently link these concepts are based on the principles of Sustainable Production defined 20 years ago. Therefore, the primary aim of this study is to redefine the principles that should govern Sustainable Production operations in the tran-sition towards a Circular Economy and smart industry models. To this end, an initial proposal of 11 principles was shared with 11 world-class experts (academics and practitioners) and a consensus proposal was sought through a Delphi Panel. Ten principles emerged from this study, which were evaluated by experts according to criteria of significance, parsimony, semantic consistency and empirical adequacy. Additionally, to study the rela-tionships between the ten principles, the Interpretative Structural Model (ISM) technique was applied. The ISM technique identified which principles are independent of or dependent on each other and established relation-ships between the principles. The findings suggest that Principle 5 ("Prioritize employees' well-being"), Principle 6 ("Enhance management commitment to sustainability"), Principle 9 ("Measure and optimize sustainable pro-cesses") and Principle 10 ("Boost the use of sustainable technologies") help to establish an ideal context to enhance the development of the rest of the principles that characterize Sustainable Production. The presentation of the ten principles opens new possibilities for researchers while helping managers to better understand sustainability in terms of production and, therefore contribute to achieving SDG 12

    A new mindset for circular economy strategies: case studies of circularity in the use of water

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    In a circular economy (CE) environment, it is important to make good and efficient use of resources and consider that the waste generated in production processes can be a valuable resource. However, the tools and methodologies conventionally used to analyze and evaluate production systems are based on techniques focused on linear production management models, where the primary purpose is to reduce the treatment and management of waste as much as possible and where productive and environmental efficiency are not evaluated simultaneously. Changing the paradigm from a linear to a circular economy requires that a new strategy for production systems be defined, one that makes production processes simultaneously circular and efficient (in terms of quality and productivity). In this context, a holistic vision is needed when implementing CE strategies. Therefore, the main aim of this paper is to provide evidence, through two real case studies in the use of water, that the management of this resource without considering systemic thinking may not be the most circular solution. Main results showed that improvements based on the traditional approach of reducing resource use cannot provide the best results if they are supported only by current process consumption without considering the circularity of resources

    Calorimetric Investigation of Copper Binding in the N-Terminal Region of the Prion Protein at Low Copper Loading: Evidence for an Entropically Favorable First Binding Event

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    Although the Cu<sup>2+</sup>-binding sites of the prion protein have been well studied when the protein is fully saturated by Cu<sup>2+</sup>, the Cu<sup>2+</sup>-loading mechanism is just beginning to come into view. Because the Cu<sup>2+</sup>-binding modes at low and intermediate Cu<sup>2+</sup> occupancy necessarily represent the highest-affinity binding modes, these are very likely populated under physiological conditions, and it is thus essential to characterize them in order to understand better the biological function of copper–prion interactions. Besides binding-affinity data, almost no other thermodynamic parameters (e.g., Δ<i>H</i> and Δ<i>S</i>) have been measured, thus leaving undetermined the enthalpic and entropic factors that govern the free energy of Cu<sup>2+</sup> binding to the prion protein. In this study, isothermal titration calorimetry (ITC) was used to quantify the thermodynamic parameters (<i>K</i>, Δ<i>G</i>, Δ<i>H</i>, and <i>T</i>Δ<i>S</i>) of Cu<sup>2+</sup> binding to a peptide, PrP­(23–28, 57–98), that encompasses the majority of the residues implicated in Cu<sup>2+</sup> binding by full-length PrP. Use of the buffer <i>N</i>-(2-acetomido)-aminoethanesulfonic acid (ACES), which is also a well-characterized Cu<sup>2+</sup> chelator, allowed for the isolation of the two highest affinity binding events. Circular dichroism spectroscopy was used to characterize the different binding modes as a function of added Cu<sup>2+</sup>. The <i>K</i><sub>d</sub> values determined by ITC, 7 and 380 nM, are well in line with those reported by others. The first binding event benefits significantly from a positive entropy, whereas the second binding event is enthalpically driven. The thermodynamic values associated with Cu<sup>2+</sup> binding by the Aβ peptide, which is implicated in Alzheimer’s disease, bear striking parallels to those found here for the prion protein

    Loss of Octarepeats in Two Processed Prion Pseudogenes in the Red Squirrel, Sciurus vulgaris

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    The N-terminal region of the mammalian prion protein (PrP) contains an ‘octapeptide’ repeat which is involved in copper binding. This eight- or nine-residue peptide is repeated four to seven times, depending on the species, and polymorphisms in repeat number do occur. Alleles with three repeats are very rare in humans and goats, and deduced PrP sequences with two repeats have only been reported in two lemur species and in the red squirrel, Sciurus vulgaris. We here describe that the red squirrel two-repeat PrP sequence actually represents a retroposed pseudogene, and that an additional and older processed pseudogene with three repeats also occurs in this species as well as in ground squirrels. We argue that repeat numbers may tend to contract rather than expand in prion retropseudogenes, and that functional prion genes with two repeats may not be viable
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