From pre-ceramic polymer to high-toughness ceramic: An SLA 3D printing approach

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Can we quickly and thoroughly assess pain with the PACSLAC-II? : a convergent validity study in long-term care residents suffering from dementia.

Abstract : A previous study found that the modified version of the Pain Assessment Checklist for Seniors with Limited Ability to Communicate (PACSLAC-II) is a valid tool to assess pain in elderly individuals suffering from dementia and who are unable to communicate verbally. The primary objective of this study was to confirm the convergent validity of the PACSLAC-II using direct evaluation of long-term care residents in real-life situations, using two other well-validated pain assessment scales (i.e., PACSLAC and Pain Assessment in Advanced Dementia [PAINAD]). A secondary objective was to document and compare the time required to complete and score each assessment scale. During two potentially painful procedures (i.e., transfer/mobilization), 46 long-term care residents (mean age = 83 ± 10 years) suffering from dementia were observed by three independent evaluators, each using one of the assessment scales (randomly assigned). Correlational analyses and analysis of variance were used to evaluate the association between each scale and to compare scoring time. The PACSLAC (r = 0.61) and the PAINAD (r = 0.65) were both moderately associated with the PACSLAC-II (all p values < .001). The PAINAD's average scoring time (63 ± 19 seconds) was lower than the PACSLAC-II's (96 ± 2 seconds), which was lower than the PACSLAC's (135 ± 53 seconds) (all p values < .001). These results suggest that the PACSLAC-II is a valid tool for assessing pain in individuals with dementia. The time required to complete and score the PACSLAC-II was reasonable, supporting its usefulness in clinical settings

The assessment of pain in older people: UK National Guidelines

We are facing a huge increase in the older population over the next 30 years. This brings an anticipated increase in the prevalence of chronic pain and with this comes the challenge of assessment of pain in many varied settings. Our first iteration of this document was published in 2007. But there has been a proliferation of literature and research since then, so we have developed a new set of guidelines. Different patterns and sites of pain were seen in men and women. Age differences suggest that pain prevalence increased with age up to 85 years and then decreased. The available studies on barriers and attitudes to pain management point towards an adherence to bio-medically orientated beliefs about pain, concern amongst clinicians in relation to activity recommendations, and a negative orientation in general towards patients with chronic painful conditions. A multidisciplinary approach to the assessment and treatment of pain is essential, but the assessment is a complex process which is hampered by many communication issues, including cognitive ability and socio-cultural factors. Such issues are part of the UK ageing population. Structured pain education should be implemented that provides all health professionals (whether professionally or non-professionally trained) with standardised education and training in the assessment and management of pain according to level of experience. Although subjective, patient self-report is the most valid and reliable indicator of pain and it may be necessary to ask questions about pain in different ways in order to elicit a response. A number of valid and reliable self-report measures are available and can be used even when moderate dementia exists. The Numerical Rating Scale or verbal descriptors can be used with people who have mild to moderate cognitive impairment. For people with severe cognitive impairment Pain in Advanced Dementia (PAINAD) and Doloplus-2 are recommended. PAINAD and Doloplus-2 scales continue to show positive results in terms of reliability and validity. There has been no recent evaluation of the Abbey pain scale although it is widely used throughout the UK. There is a need for more research into pain assessment using the collaborative role of the multidisciplinary team in all care settings. Self-report questionnaires of function are limited in their ability to capture the fluctuations in capacity and ability. The concentration on items of relevance to the population of interest means that issues of personal relevance can be obscured. Strong associations were seen between pain and depressed mood with each being a risk factor for the other. Additionally, loneliness and social isolation were associated with an increased risk of pain. Clinicians should be cognisant that social isolation and or depressive signs and symptoms may be indicators of pre-existing pain or a predictor of future pain onset. There are a number of evidence based guidelines on pain assessment in older people with or without cognitive impairment from around the world, including Australia and Europe

Littératie communautaire : analyse de la production documentaire et revue de la littérature

Cet article vise à clarifier le concept de littératie communautaire et en produire une définition afin de mieux comprendre ses champs d’étude et d’action. La méthodologie repose sur une recherche documentaire comprenant une analyse bibliométrique et une revue systématique de la littérature réalisée sur un corpus de textes anglo-américains, incluant quelques textes en français, et hispanophones. Les résultats de cette recherche révèlent que le concept de littératie communautaire s’appuie sur une série de dimensions constitutives : la différence et la diversité, la situation locale, un dispositif critique et éthique, la délimitation et le continuum des littératies. Cette analyse documentaire particulièrement complète et ces résultats permettront d’enrichir les approches théoriques et pratiques tout en favorisant l’engagement des différents actrices et acteurs en matière de littératie communautaire.This article aims to clarify the concept of community literacy and produce a definition in order to better understand its fields of study and action. The methodology is based on a literature search including a bibliometric analysis and a systematic review of the literature conducted on a corpus of Anglo-American and Spanish-language texts. The results of this research reveal that the concept of community literacy is based on a series of constitutive dimensions: difference and diversity, locality, critical and ethical agency, delineation and continuum of literacies. This comprehensive review of the literature and these findings will enrich theoretical and practical approaches while fostering the engagement of different actors in community literacy

Unprecedented Octanuclear Dy^III Cluster Exhibiting Single-Molecule Magnet Behavior

An unprecedented Dy₈ cluster, [Dy₈(μ₄-O)­(μ₃-OH)₈(vht)₄(NO₃)₂(H₂O)₈]­(NO₃)₄, composed of two fused and distorted [Dy₄(μ₃-OH)₄]⁸⁺ cubane units is reported. The bridging of the two cubanes occurs through a planar μ₄-O (oxide) moiety, and leads to the largest reported distortion of the Dy-O-Dy angles within a [Dy₄(OH)₄] cubane core. In turn, this leads to clear zero-field slow relaxation of the magnetization, characteristic of single-molecule magnets (SMMs). Further magnetic analyses suggest that the relaxation may be largely dictated by quantum tunneling of the magnetization and Raman processes

Additive manufacturing of polymer derived ceramics: Materials, methods, and applications

Owing to freedom of design, simplicity, and ability to handle complex structures, additive manufacturing (AM) or 3D printing of ceramics represents a promising enabling technology and has already been used to produce geometrically complex ceramic components and ceramic metamaterials. Consequently, novel applications for additively manufactured ceramics, which leverage their structural, high temperature, and chemical-resistant properties, have been proposed in areas ranging from electrical engineering and micro/nanoelectronics to chemical engineering to biology. Polymer derived ceramics (PDCs) represent a relatively new class of materials within additive manufacturing. PDCs enable the development of ceramic parts patterned via low-cost polymer 3D printing methods followed by pyrolysis in a high temperature process in which the polymer itself forms a ceramic often in the absence of any ceramic filler. PDCs have served as a feedstock for various 3D printing techniques for which a wide range of physiochemical factors can be tailored to optimize the ceramic manufacturing processes. In particular, the silicon and carbon-rich polymeric microstructure of PDCs offers a high degree of tunability and potential to achieve a closely defined combination of functional, thermomechanical, and chemical properties. In this review, we cover mechanisms underlying the design and manufacture of ceramics via 3D printing and pyrolysis of preceramic polymers, focusing on chemical formulations, printing technologies, and the mechanical performance of the ceramic network from microscale to scale. We also summarize experimental data from the literature and present qualitative and quantitative comparisons between different AM routes to provide a comprehensive review for 3D printing of PDCs and to highlight potential future research.</p

Continuous synthesis of high-entropy alloy nanoparticles by in-flight alloying of elemental metals

Abstract High-entropy alloy (HEA) nanoparticles (NPs) exhibit unusual combinations of functional properties. However, their scalable synthesis remains a significant challenge requiring extreme fabrication conditions. Metal salts are often employed as precursors because of their low decomposition temperatures, yet contain potential impurities. Here, we propose an ultrafast ( 5000 K) is employed for rapid heating/cooling (103 − 105 K s−1), and demonstrates the synthesis of CrFeCoNiMo HEA NPs ( ~ 50 nm) at a high rate approaching 35 g h−1 with a conversion efficiency of 42%. Our thermofluid simulation reveals that the properties of HEA NPs can be tailored by the plasma gas which affects the thermal history of NPs. The HEA NPs demonstrate an excellent light absorption of > 96% over a wide spectrum, representing great potential for photothermal conversion of solar energy at large scales. Our work shows that the thermal plasma process developed could provide a promising route towards industrial scale production of HEA NPs

Deconvolution volumetric additive manufacturing

Abstract Volumetric additive manufacturing techniques are a promising pathway to ultra-rapid light-based 3D fabrication. Their widespread adoption, however, demands significant improvement in print fidelity. Currently, volumetric additive manufacturing prints suffer from systematic undercuring of fine features, making it impossible to print objects containing a wide range of feature sizes, precluding effective adoption in many applications. Here, we uncover the reason for this limitation: light dose spread in the resin due to chemical diffusion and optical blurring, which becomes significant for features ⪅0.5 mm. We develop a model that quantitatively predicts the variation of print time with feature size and demonstrate a deconvolution method to correct for this error. This enables prints previously beyond the capabilities of volumetric additive manufacturing, such as a complex gyroid structure with variable thickness and a fine-toothed gear. These results position volumetric additive manufacturing as a mature 3D printing method, all but eliminating the gap to industry-standard print fidelity