159 research outputs found

    The use of birefringence for predicting the stiffness of injection moulded polycarbonate discs

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    Polycarbonate discs were injection molded with different sets of molding conditions. The parameters studied were the flow rate, melt- and mold-temperature. The discs were subjected to three point support flexural tests. Those tests are specially intended for injection molded discs because of their inherent non-flatness. The through-thickness molecular orientation was assessed by birefringence measurements along and across the flow direction using the wedge method. This method is ideal to measure the birefringence of materials that are difficult to cut with a microtome. The through-thickness stiffness of the discs was calculated from the measured birefringence distributions. A composite model of the disc was used in the Algor finite element method (FEW package to simulate the flexural tests

    Voorwoord: Smullen, voor de laatste keer (met ons)

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    Nieuwe handen komen uit de mouw. Frisse koppen zullen de volgende BB vullen en vormgeven. Het oude team haalt zuchtend, steundend en kreunend de laatste deadline net weer nie

    The influence of different intermittent myofeedback training schedules on learning relaxation of the trapezius muscle while performing a gross-motor task

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    The aim of this study was to investigate the influence of different intermittent myofeedback training schedules, as provided by a Cinderella-based myofeedback system, on learning relaxation and resistance to extinction of the trapezius muscle, in subjects performing a unilateral gross-motor task. Eighteen healthy subjects performed the task without and with feedback to study baseline and learning relaxation. Subsequently, resistance to extinction was investigated by performing the task without feedback. The gross-motor task consisted of continuously moving the dominant arm between three target areas at a constant pace. Subjects were randomly assigned into three groups, characterized by the sequence of feedback schedules with which the task was performed on 3 consecutive days. Auditory feedback was provided after a 5-, 10-, or 20-s interval when a pre-set level of 80% rest was not reached. Bipolar surface electromyography recordings performed at the dominant upper trapezius muscle were quantified using relative rest time (RRT) and root mean square (RMS) parameters. Learning relaxation was defined as an increase in RRT and a decrease in RMS values. Results showed the highest RRT levels as well as a decrease in RMS for the 10-s schedule. Additionally, the 10-s schedule was unique in its ability to elevate muscular rest above the 20% level, which may be considered relevant in preventing myalgia. None of the three schedules showed resistance to extinction. It was concluded that the 10-s interval was preferred over the 5- and 20-s schedules in learning trapezius relaxation in subjects performing a unilateral gross-motor task

    Effects of Ambulant Myofeedback Training and Ergonomic Counselling in Female Computer Workers with Work-Related Neck-Shoulder Complaints: A Randomized Controlled Trial

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    Objective: To investigate the effects of ambulant myofeedback training including ergonomic counselling (Mfb) and ergonomic counselling alone (EC), on work-related neck-shoulder pain and disability. Methods: Seventy-nine female computer workers reporting neck-shoulder complaints were randomly assigned to Mfb or EC and received four weeks of intervention. Pain intensity in neck, shoulders, and upper back, and pain disability, were measured at baseline, immediately after intervention, and at three and six months follow-up. Results: Pain intensity and disability had significantly decreased immediately after four weeks Mfb or EC, and the effects remained at follow up. No differences were observed between the Mfb and EC group for outcome and subjects in both intervention groups showed comparable chances for improvement in pain intensity and disability. Conclusions: Pain intensity and disability significantly reduced after both interventions and this effect remained at follow-up. No differences were observed between the two intervention groups

    Impact of maternal body mass index and gestational weight gain on pregnancy complications : an individual participant data meta-analysis of European, North American and Australian cohorts

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    Objective To assess the separate and combined associations of maternal pre-pregnancy body mass index (BMI) and gestational weight gain with the risks of pregnancy complications and their population impact. Design Individual participant data meta-analysis of 39 cohorts. Setting Europe, North America, and Oceania. Population 265 270 births. Methods Information on maternal pre-pregnancy BMI, gestational weight gain, and pregnancy complications was obtained. Multilevel binary logistic regression models were used. Main outcome measures Gestational hypertension, pre-eclampsia, gestational diabetes, preterm birth, small and large for gestational age at birth. Results Higher maternal pre-pregnancy BMI and gestational weight gain were, across their full ranges, associated with higher risks of gestational hypertensive disorders, gestational diabetes, and large for gestational age at birth. Preterm birth risk was higher at lower and higher BMI and weight gain. Compared with normal weight mothers with medium gestational weight gain, obese mothers with high gestational weight gain had the highest risk of any pregnancy complication (odds ratio 2.51, 95% CI 2.31- 2.74). We estimated that 23.9% of any pregnancy complication was attributable to maternal overweight/obesity and 31.6% of large for gestational age infants was attributable to excessive gestational weight gain. Conclusions Maternal pre-pregnancy BMI and gestational weight gain are, across their full ranges, associated with risks of pregnancy complications. Obese mothers with high gestational weight gain are at the highest risk of pregnancy complications. Promoting a healthy pre-pregnancy BMI and gestational weight gain may reduce the burden of pregnancy complications and ultimately the risk of maternal and neonatal morbidity.Peer reviewe

    Early signaling, referral, and treatment of adolescent chronic pain: a study protocol

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    <p>Abstract</p> <p>Background</p> <p>Chronic pain is prevalent among young people and negatively influences their quality of life. Furthermore, chronic pain in adolescence may persist into adulthood. Therefore, it is important early on to promote the self-management skills of adolescents with chronic pain by improving signaling, referral, and treatment of these youngsters. In this study protocol we describe the designs of two complementary studies: a signaling study and an intervention study.</p> <p>Methods and design</p> <p>The signaling study evaluates the Pain Barometer, a self-assessed signaling instrument for chronic pain in adolescents. To evaluate the feasibility of the Pain Barometer, the experiences of youth-health care nurses will be evaluated in semi-structured interviews. Also, we will explore the frequencies of referral per health-care provider. The intervention study evaluates Move It Now, a guided self-help intervention via the Internet for teenagers with chronic pain. This intervention uses cognitive behavioural techniques, including relaxation exercises and positive thinking. The objective of the intervention is to improve the ability of adolescents to cope with pain. The efficacy of Move It Now will be examined in a randomized controlled trial, in which 60 adolescents will be randomly assigned to an experimental condition or a waiting list control condition.</p> <p>Discussion</p> <p>If the Pain Barometer is proven to be feasible and Move It Now appears to be efficacious, a health care pathway can be created to provide the best tailored treatment promptly to adolescents with chronic pain. Move It Now can be easily implemented throughout the Netherlands, as the intervention is Internet based.</p> <p>Trial registration</p> <p>Dutch Trial Register NTR1926</p

    Assessing the performance of maternity care in Europe: A critical exploration of tools and indicators

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    Background: This paper critically reviews published tools and indicators currently used to measure maternity care performance within Europe, focusing particularly on whether and how current approaches enable systematic appraisal of processes of minimal (or non-) intervention in support of physiological or "normal birth". The work formed part of COST Actions IS0907: "Childbirth Cultures, Concerns, and Consequences: Creating a dynamic EU framework for optimal maternity care" (2011-2014) and IS1405: Building Intrapartum Research Through Health - an interdisciplinary whole system approach to understanding and contextualising physiological labour and birth (BIRTH) (2014-). The Actions included the sharing of country experiences with the aim of promoting salutogenic approaches to maternity care. Methods: A structured literature search was conducted of material published between 2005 and 2013, incorporating research databases, published documents in english in peer-reviewed international journals and indicator databases which measured aspects of health care at a national and pan-national level. Given its emergence from two COST Actions the work, inevitably, focused on Europe, but findings may be relevant to other countries and regions. Results: A total of 388 indicators were identified, as well as seven tools specifically designed for capturing aspects of maternity care. Intrapartum care was the most frequently measured feature, through the application of process and outcome indicators. Postnatal and neonatal care of mother and baby were the least appraised areas. An over-riding focus on the quantification of technical intervention and adverse or undesirable outcomes was identified. Vaginal birth (no instruments) was occasionally cited as an indicator; besides this measurement few of the 388 indicators were found to be assessing non-intervention or "good" or positive outcomes more generally. Conclusions: The tools and indicators identified largely enable measurement of technical interventions and undesirable health (or pathological medical) outcomes. A physiological birth generally necessitates few, or no, interventions, yet most of the indicators presently applied fail to capture (a) this phenomenon, and (b) the relationship between different forms and processes of care, mode of birth and good or positive outcomes. A need was identified for indicators which capture non-intervention, reflecting the reality that most births are low-risk, requiring few, if any, technical medical procedures
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