42 research outputs found

    Quantum materials with strong spin-orbit coupling : challenges and opportunities for materials chemists

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    ASG acknowledges funding through an EPSRC Early Career Fellowship EP/T011130/1.Spin-orbit coupling is a quantum effect that can give rise to exotic electronic and magnetic states in the compounds of the 4d and 5d transition metals. Exploratory synthesis, chemical tuning and structure-property characterisation of such compounds is an increasingly active area of research with both fundamental and application-related outlooks, but requires great care with regards to the chemistry of these materials that has not always been considered. This Perspective will give an accessible introduction to topical materials with strong spin-orbit coupling, their crystal chemistry, and their structure-property relationships, which overlaps with the contemporary investigation of some of the same materials within different communities. It will also outline some of the challenges faced in their synthesis and characterisation, and the contributions that materials chemists can make to overcoming these.Publisher PDFPeer reviewe

    A medical hand tool physical interaction evaluation approach for prototype testing using patient care simulators

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    peer-reviewedThe purpose of this study was to develop and test a physical ergonomics assessment approach for medical device handles. The method assesses wrist posture and force of exertion simultaneously by task element. Electrogoniometers and EMG sensors were connected through a data acquisition module for synchronization with video recordings of trials. Task analysis of video recordings were performed offline with Observer XT software. Average posture and force data across several repetitions of individual task elements were calculated and presented in a format suitable for informing product designers of specific issues during a test trial. A handle comfort questionnaire is proposed to survey subjective responses. The evaluation approach was applied to an endoscope needle in sampling a biopsy from the stomach wall using a gastrointestinal track simulator with ten physician surrogates. The results showed that for all task elements the wrist was in extension (33 degrees-45 degrees). Peak muscle forces ranged from 28% to 68% MVC across the three muscles studied. Muscle peak forces were above ACGIH HAL maximum threshold limits for four of the seven task elements, and above the action limit for all seven task elements for two muscles. The handle comfort questionnaire data also supported the high muscle force findings, and also on force distribution on the handle due to contact stresses. This combined approach could be used to collect and report detailed early stage ergonomics data from user trials on patient care simulators. The approach is proposed for use by medical device designers at the design stage of new products using prototypes, but it could also be used on existing products with real patients. (C) 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.ACCEPTEDpeer-reviewe

    Salivary cytokines as biomarkers of periodontal diseases

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    Periodontal disease is time consuming and expensive to treat and therefore its prevention, early detection and management are issues which, if effectively addressed, are likely to yield considerable health-care benefit (97). However, despite numerous advances in our understanding of the pathogenesis of chronic inflammatory diseases, periodontitis is still only diagnosed once connective tissue and bone destruction has occurred. Furthermore, monitoring disease progression is a highly skilled and technically demanding process, involving measurement of bleeding on probing, probing depth and attachment loss coupled with radiographic assessment and (subjective) visual observations (76). It would be highly desirable to develop biomarkers for early detection of periodontal disease and to identify progression because current diagnostic approaches do not reflect current disease activity but simply assess the cumulative effects of historical tissue destruction (53). Rational diagnosis would also have concomitant patient benefit because the paucity of evidence-based knowledge of disease progression in individual patients may lead to unintentional clinical mismanagement (97). In addition, studies of the salivary mediators associated with disease may help in the development of novel therapies aimed at controlling cytokine bioavailability (e.g. through anti-cytokine antibodies, antagonists or soluble receptors) or by targeting the intracellular signaling pathways they activate, approaches which have been successful in the treatment of other chronic inflammatory diseases, such as rheumatoid arthritis (60, 91, 95). Cytokines have been defined as soluble factors produced by one (immune) cell that act on another cell within the same milieu (26). However, it is now recognized that the range of molecules with cytokine-like activity can be extended to include, for example, growth factors and adipokines, which also have immunoregulatory functions. Importantly, cytokine functions often overlap or merge, building a complex immunoregulatory network in the immune system that is often perturbed in disease. It is increasingly appreciated that cytokines have vital roles in the development and homeostasis of numerous cell types and, in a wide range of tissues, have roles in resolution of inflammation, wound healing, repair and regeneration. In the following review, the term ‘cytokine’ will be used in this broad context. In addition to direct analysis of cytokines, the levels of molecules such as matrix metalloproteinases and tissue inhibitors of metalloproteinases, which are regulated by cytokines, have also been given considerable attention as potential periodontitis biomarkers, as reviewed elsewhere in this volume of Periodontology 2000

    Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

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    Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    Dynamic activity of the upper limb: effects on shoulder fatigue and discomfort

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    Musculo-Skeletal Disorders (MSDs) of back pain and upper limbs are the most common occupational injury group in Ireland (HSA, 2007). Across Europe upper limb related MSDs account for over 45% of the total number of reported cases of occupational ill health and injuries (EUROSTAT, 2004). MSD risk factors include poor posture, repetitive or forceful movements, fast paced work, vibration and poor ergonomic conditions, and affect muscles, tendons, ligaments and blood circulation. High task repetition can lead to residual fatigue, which over time can result in damage to tissues. But the role of repetition can often be overly simplified in job evaluation and in the study of its relationship with occupational MSDs. This thesis focuses on the role of dynamic loading of the upper limb (with emphasis on the shoulder) as part of a broader interpretation of repetition as a risk factor for upper limb MSDs. Two case studies and five laboratory experiments were conducted. The case studies demonstrated high levels of muscle activity and movement variability. This thesis proposes that dynamic loading of the upper limb is multifactorial comprising cycle time, movement frequency, muscle activity variability, work/rest regime and posture variability. Quantitative testing (using electromyography and electrogoniometers) as well as qualitative testing (discomfort) methods was used to study musculoskeletal strain. The laboratory experiments tested combinations of these factors at various levels to test for main effects. Taguchi methods were used to model the effects of physical factors on the perception of discomfort in the shoulder region. The studies for the distal part of the upper limb revealed that high movement frequency within the shoulder’s safe range of motion (0-40° flexion, 0-30°) abduction did not increase the average electrical activity of the forearm muscles above the level of 50%MVE, even for the heaviest tasks of load lifting. This suggests that the shoulder muscles may not be affected by heavy loading in the hands as anticipated. Results from collective study of shoulder movement frequencies, work/rest regimes, postures and loads using a Taguchi experiment design and regression analyses were used to test and model shoulder discomfort effects. The findings of low levels of EMG fatigue recorded across many of the experimental conditions indicate that for the Upper Trapezius high movement frequency dynamic contractions may affect the rate of the Motor Unit (MU) recruitment in order to protect the muscle from overloading, at least in short duration treatments. There is a need to further investigate the effects of interactions of repetition with other factors on MU recruitment patterns in the muscles of the upper limb

    A medical hand tool physical interaction evaluation approach for prototype testing using patient care simulators

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    The purpose of this study was to develop and test a physical ergonomics assessment approach for medical device handles. The method assesses wrist posture and force of exertion simultaneously by task element. Electrogoniometers and EMG sensors were connected through a data acquisition module for synchronization with video recordings of trials. Task analysis of video recordings were performed offline with Observer XT software. Average posture and force data across several repetitions of individual task elements were calculated and presented in a format suitable for informing product designers of specific issues during a test trial. A handle comfort questionnaire is proposed to survey subjective responses. The evaluation approach was applied to an endoscope needle in sampling a biopsy from the stomach wall using a gastrointestinal track simulator with ten physician surrogates. The results showed that for all task elements the wrist was in extension (33 degrees-45 degrees). Peak muscle forces ranged from 28% to 68% MVC across the three muscles studied. Muscle peak forces were above ACGIH HAL maximum threshold limits for four of the seven task elements, and above the action limit for all seven task elements for two muscles. The handle comfort questionnaire data also supported the high muscle force findings, and also on force distribution on the handle due to contact stresses. This combined approach could be used to collect and report detailed early stage ergonomics data from user trials on patient care simulators. The approach is proposed for use by medical device designers at the design stage of new products using prototypes, but it could also be used on existing products with real patients. (C) 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved
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