120 research outputs found

    Recovery of strength after reduced pediatric fractures of the forearm, wrist or hand; A prospective study

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    INTRODUCTION: The way strength recovers after reduction of pediatric fractures of the upper extremity has not previously been the specific scope of research. This is remarkable, since strength measurements are often used as an outcome measure in studies on trauma of the upper extremity. The aim of this study was to evaluate how strength recovers after sustainment of fractures of the forearm, wrist or hand treated by closed or open reduction in children and adolescents in the first 6 months after trauma. How much strength is lost at 6 weeks, 3 months and 6 months after trauma, and is this loss significant? Are there differences in the pattern of recovery between children who underwent a different treatment? And finally, which of the following factors are associated with an increase in the ratio between affected grip strength and expected strength: type of fracture, cast immobilization, occurrence of complications, and degree of pain? DESIGN: Prospective observational study. PARTICIPANTS: Children and adolescents aged 4-18 years with a reduced fracture of the forearm, wrist or hand. METHODS: Grip strength, key grip and three-jaw chuck grip were measured twice in each hand 6 weeks, 3 months and 6 months after trauma. Details on fracture type and location, treatment received, cast immobilization and complications were obtained. Hand-dominance and pain were verbally confirmed. RESULTS: Loss of strength was more prominent and prolonged the more invasive the treatment, hence most extensive in the group receiving open reduction with internal fixation (ORIF), intermediate in the group receiving closed reduction with percutaneous pinning (CRIF), and least extensive in the group undergoing closed reduction without internal fixation (CR). Besides time passed, gender and age were of significant influence on strength, although there was no difference in pattern of recovery over time between children who received a different treatment. In the period of 6 weeks to 3 months after trauma, female gender, type of fracture sustained and occurrence of an unwanted event were associated with an increased ratio between affected and expected grip strength. For the later phase of recovery, between 3 and 6 months, this was only true for the occurrence of an unwanted event

    Numerical study of the coupling between the instantaneous blade loading/power of an axial wind turbine and upstream turbulence at high Reynolds numbers

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    Little is known about how the range of scales in the approaching turbulent flow can interact dynamically with wind turbines and influence its ability to produce power. Here, a numerical study of a horizontal-axis wind turbine at different Reynolds numbers (corresponding to different tip speed ratios) has been conducted to investigate the instantaneous turbine response to upstream turbulence. A computational approach, combining large eddy simulation with actuator line modelling, is adopted. Comparison between Power Spectral Density (PSD) of the turbine thrust/power and PSD of the velocity at the rotor plane and one rotor diameter upstream of it confirms that there is a coupling between the instantaneous turbine thrust/power and the upstream turbulence (one diameter upstream of the turbine) for frequencies below a critical frequency. Furthermore, it has been shown for the first time, that PSD of the turbine thrust/power and the velocity PSD at the rotor plane are very similar, indicating that the instantaneous turbine thrust/power and the velocity at the rotor plane are coupled for all frequencies. This means that the PSD of velocity at the rotor plane or shortly behind it can provide interesting information for the instantaneous turbine loads that are very important for the turbine operational life.N/

    Numerical study of the coupling between the instantaneous blade loading/power of an axial wind turbine and upstream turbulence at high Reynolds numbers

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    Little is known about how the range of scales in the approaching turbulent flow can interact dynamically with wind turbines and influence its ability to produce power. Here, a numerical study of a horizontal-axis wind turbine at different Reynolds numbers (corresponding to different tip speed ratios) has been conducted to investigate the instantaneous turbine response to upstream turbulence. A computational approach, combining large eddy simulation with actuator line modelling, is adopted. Comparison between Power Spectral Density (PSD) of the turbine thrust/power and PSD of the velocity at the rotor plane and one rotor diameter upstream of it confirms that there is a coupling between the instantaneous turbine thrust/power and the upstream turbulence (one diameter upstream of the turbine) for frequencies below a critical frequency. Furthermore, it has been shown for the first time, that PSD of the turbine thrust/power and the velocity PSD at the rotor plane are very similar, indicating that the instantaneous turbine thrust/power and the velocity at the rotor plane are coupled for all frequencies. This means that the PSD of velocity at the rotor plane or shortly behind it can provide interesting information for the instantaneous turbine loads that are very important for the turbine operational life.N/

    The Physics of Star Cluster Formation and Evolution

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    © 2020 Springer-Verlag. The final publication is available at Springer via https://doi.org/10.1007/s11214-020-00689-4.Star clusters form in dense, hierarchically collapsing gas clouds. Bulk kinetic energy is transformed to turbulence with stars forming from cores fed by filaments. In the most compact regions, stellar feedback is least effective in removing the gas and stars may form very efficiently. These are also the regions where, in high-mass clusters, ejecta from some kind of high-mass stars are effectively captured during the formation phase of some of the low mass stars and effectively channeled into the latter to form multiple populations. Star formation epochs in star clusters are generally set by gas flows that determine the abundance of gas in the cluster. We argue that there is likely only one star formation epoch after which clusters remain essentially clear of gas by cluster winds. Collisional dynamics is important in this phase leading to core collapse, expansion and eventual dispersion of every cluster. We review recent developments in the field with a focus on theoretical work.Peer reviewe

    Worldwide trends in diabetes since 1980: a pooled analysis of 751 population-based studies with 4.4 million participants

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    Background: One of the global targets for non-communicable diseases is to halt, by 2025, the rise in the age-standardised adult prevalence of diabetes at its 2010 levels. We aimed to estimate worldwide trends in diabetes, how likely it is for countries to achieve the global target, and how changes in prevalence, together with population growth and ageing, are affecting the number of adults with diabetes.Methods: We pooled data from population-based studies that had collected data on diabetes through measurement of its biomarkers. We used a Bayesian hierarchical model to estimate trends in diabetes prevalence—defined as fasting plasma glucose of 7·0 mmol/L or higher, or history of diagnosis with diabetes, or use of insulin or oral hypoglycaemic drugs—in 200 countries and territories in 21 regions, by sex and from 1980 to 2014. We also calculated the posterior probability of meeting the global diabetes target if post-2000 trends continue.Findings: We used data from 751 studies including 4?372?000 adults from 146 of the 200 countries we make estimates for. Global age-standardised diabetes prevalence increased from 4·3% (95% credible interval 2·4–7·0) in 1980 to 9·0% (7·2–11·1) in 2014 in men, and from 5·0% (2·9–7·9) to 7·9% (6·4–9·7) in women. The number of adults with diabetes in the world increased from 108 million in 1980 to 422 million in 2014 (28·5% due to the rise in prevalence, 39·7% due to population growth and ageing, and 31·8% due to interaction of these two factors). Age-standardised adult diabetes prevalence in 2014 was lowest in northwestern Europe, and highest in Polynesia and Micronesia, at nearly 25%, followed by Melanesia and the Middle East and north Africa. Between 1980 and 2014 there was little change in age-standardised diabetes prevalence in adult women in continental western Europe, although crude prevalence rose because of ageing of the population. By contrast, age-standardised adult prevalence rose by 15 percentage points in men and women in Polynesia and Micronesia. In 2014, American Samoa had the highest national prevalence of diabetes (>30% in both sexes), with age-standardised adult prevalence also higher than 25% in some other islands in Polynesia and Micronesia. If post-2000 trends continue, the probability of meeting the global target of halting the rise in the prevalence of diabetes by 2025 at the 2010 level worldwide is lower than 1% for men and is 1% for women. Only nine countries for men and 29 countries for women, mostly in western Europe, have a 50% or higher probability of meeting the global target.Interpretation: Since 1980, age-standardised diabetes prevalence in adults has increased, or at best remained unchanged, in every country. Together with population growth and ageing, this rise has led to a near quadrupling of the number of adults with diabetes worldwide. The burden of diabetes, both in terms of prevalence and number of adults affected, has increased faster in low-income and middle-income countries than in high-income countries

    Female chromosome X mosaicism is age-related and preferentially affects the inactivated X chromosome

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    To investigate large structural clonal mosaicism of chromosome X, we analysed the SNP microarray intensity data of 38,303 women from cancer genome-wide association studies (20,878 cases and 17,425 controls) and detected 124 mosaic X events42Mb in 97 (0.25%) women. Here we show rates for X-chromosome mosaicism are four times higher than mean autosomal rates; X mosaic events more often include the entire chromosome and participants with X events more likely harbour autosomal mosaic events. X mosaicism frequency increases with age (0.11% in 50-year olds; 0.45% in 75-year olds), as reported for Y and autosomes. Methylation array analyses of 33 women with X mosaicism indicate events preferentially involve the inactive X chromosome. Our results provide further evidence that the sex chromosomes undergo mosaic events more frequently than autosomes, which could have implications for understanding the underlying mechanisms of mosaic events and their possible contribution to risk for chronic diseases

    Detectable clonal mosaicism and its relationship to aging and cancer

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    In an analysis of 31,717 cancer cases and 26,136 cancer-free controls from 13 genome-wide association studies, we observed large chromosomal abnormalities in a subset of clones in DNA obtained from blood or buccal samples. We observed mosaic abnormalities, either aneuploidy or copy-neutral loss of heterozygosity, of >2 Mb in size in autosomes of 517 individuals (0.89%), with abnormal cell proportions of between 7% and 95%. In cancer-free individuals, frequency increased with age, from 0.23% under 50 years to 1.91% between 75 and 79 years (P = 4.8 × 10(-8)). Mosaic abnormalities were more frequent in individuals with solid tumors (0.97% versus 0.74% in cancer-free individuals; odds ratio (OR) = 1.25; P = 0.016), with stronger association with cases who had DNA collected before diagnosis or treatment (OR = 1.45; P = 0.0005). Detectable mosaicism was also more common in individuals for whom DNA was collected at least 1 year before diagnosis with leukemia compared to cancer-free individuals (OR = 35.4; P = 3.8 × 10(-11)). These findings underscore the time-dependent nature of somatic events in the etiology of cancer and potentially other late-onset diseases

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Mudança organizacional: uma abordagem preliminar

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