Objective: The most common methods to calculate energy costs are based on measured oxygen uptake during walking a standardized distance or time. Unfortunately, it is unclear which method is most reliable to determine energy cost of walking in stroke survivors. The objective of this study was to evaluate the 3 most commonly used methods for calculating oxygen consumption and -cost by assessing test-retest reliability and measurement error in community dwelling chronic stroke survivors during a 6 Minute Walk Test. Methods: In this secondary analysis of a longitudinal study, reproducibility of the outcome of walking distance, walking speed, oxygen consumption and oxygen cost from 3 methods (Kendall's tau, assumed steady-state and total walking time oxygen consumption) were determined using Intraclass Correlation Coefficient, Standard Error of Measurement and Smallest Detectable Change. Results: 20 from the 31 participants successfully performed the 6 minute walk test-retest within a timeframe of 1 month. Within the 2 tests the reproducibility of walking distance and walking speed was high. The 3 methods to determine reproducibility for oxygen cost and oxygen consumption were considered good (Kendall's tau), good (assumed steady-state) and excellent (total walking time). Conclusions: The method using oxygen consumption and -cost over the total walking time resulted in the highest reproducibility considering the Intraclass Correlation Coefficient, its 95% Confidence Interval, and smaller absolute differences.
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From an evidence-based perspective, cardiopulmonary exercise testing (CPX) is a well-supported assessment technique in both the United States (US) and Europe. The combination of standard exercise testing (ET) [i.e. progressive exercise provocation in association with serial electrocardiograms (ECGs), haemodynamics, oxygen saturation, and subjective symptoms] and measurement of ventilatory gas exchange amounts to a superior method to: (i) accurately quantify cardiorespiratory fitness (CRF), (ii) delineate the physiologic system(s) underlying exercise responses, which can be applied as a means to identify the exercise-limiting pathophysiological mechanism(s) and/or performance differences, and (iii) formulate function-based prognostic stratification. Cardiopulmonary ET certainly carries an additional cost as well as competency requirements and is not an essential component of evaluation in all patient populations. However, there are several conditions of confirmed, suspected, or unknown aetiology where the data gained from this form of ET is highly valuable in terms of clinical decision making.1
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From an evidence-based perspective, cardiopulmonary exercise testing (CPX) is a well-supported assessment technique in both the United States (US) and Europe. The combination of standard exercise testing (ET) (ie, progressive exercise provocation in association with serial electrocardiograms [ECG], hemodynamics, oxygen saturation, and subjective symptoms) and measurement of ventilatory gas exchange amounts to a superior method to: 1) accurately quantify cardiorespiratory fitness (CRF), 2) delineate the physiologic system(s) underlying exercise responses, which can be applied as a means to identify the exercise-limiting pathophysiologic mechanism(s) and/or performance differences, and 3) formulate function-based prognostic stratification. Cardiopulmonary ET certainly carries an additional cost as well as competency requirements and is not an essential component of evaluation in all patient populations. However, there are several conditions of confirmed, suspected, or unknown etiology where the data gained from this form of ET is highly valuable in terms of clinical decision making
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Objectives: To cross-validate the existing peak rate of oxygen consumption (VO2peak) prediction equations in Dutch law enforcement officers and to determine whether these prediction equations can be used to predict VO2peak for groups and in a single individual. A further objective was to report normative absolute and relative VO2peak values of a sample of law enforcement officers in the Netherlands. Material and Methods: The peak rate of oxygen consumption (ml×kg–1×min–1) was measured using a maximal incremental bicycle test in 1530 subjects, including 1068 male and 461 female police officers. Validity of the prediction equations for groups was assessed by comparing predicted VO2peak with measured VO2peak using paired t-tests. For individual differences limits of agreement (LoA) were calculated. Equations were considered valid for individuals when the difference between measured and predicted VO2peak did not exceed ±1 metabolic equivalent (MET) in 95% of individuals. Results: None of the equations met the validity criterion of 95% of individuals having ±1 MET difference or less than the measured value. Limits of agreement (LoAs) were large in all predictions. At the individual level, none of the equations were valid predictors of VO2peak (ml×kg–1×min–1). Normative values for Dutch law enforcement officers were presented. Conclusions: Substantial differences between measured and predicted VO2peak (ml×kg–1×min–1) were found. Most tested equations were invalid predictors of VO2peak at group level and all were invalid at individual levels.
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Introduction Physical activity is suggested to be important for low back pain (LBP) but a major problem is the limited validity of the measurement of physical activities, which is usually based on questionnaires. Physical fitness can be viewed as a more objective measurement and our question was how physical activity based on self-reports and objective measured levels of physical fitness were associated with LBP. Materials and methods We analyzed cross-sectional data of 1,723 police employees. Physical activity was assessed by questionnaire (SQUASH) measuring type of activity, intensity, and time spent on these activities. Physical fitness was based on muscular dynamic endurance capacity and peak oxygen uptake (VO2 peak). Severe LBP, interfering with functioning, was defined by pain ratings C4 on a scale of 0–10. Results Higher levels of physical fitness, both muscularand aerobic, were associated with less LBP (OR: 0.54; 95%CI: 0.34–0.86, respectively, 0.59: 95%CI: 0.35–0.99). For self-reported physical activity, both a low and a high level of the total physical activity pattern were associated with an increase of LBP (OR: 1.52; 95%CI: 1.00–2.31, respectively, 1.60; 95%CI: 1.05–2.44). Conclusion These findings suggest that physical activity of an intensity that improves physical fitness may be important in the prevention of LBP
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Arsenic contamination of groundwater is a major public health concern worldwide. The problem has been reported mainly in southern Asia and, especially, in Bangladesh. Slow-sand filters (SSF) augmented with iron were proven to be a simple, low-cost and decentralized technique for the treatment of arsenic-contaminated sources. In this research, three pilot-scale SSF (flowrate 6 L·h−1) were tested regarding their capability of removing arsenic from groundwater in conditions similar to those found in countries like Bangladesh (70 µg As(III) L−1, 26 °C). From the three, two filters were prepared with mixed media, i.e., sand mixed with corrosive iron matter (CIM filter) and iron-coated sand (ICS filter), and a third conventional SSF was used as a reference. The results obtained showed that the CIM filter could remove arsenic below the World Health Organization (WHO) guideline concentration of 10 µg·L−1, even for inlet concentrations above 150 µg·L−1. After 230 days of continuous operation the arsenic concentration in the effluent started increasing, indicating depletion or saturation of the CIM layer. The effluent arsenic concentration, however, never exceeded the Bangladeshi standard of 50 µg·L−1 throughout the whole duration of the experiments.
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This systematic review aims to get insight into the feasibility of cardiopulmonary exercise testing (CPET) in patients with cancer prior to a physical exercise programme. We will focus on quality (defined as the adherence to international guidelines for methods of CPET) and safety of CPET. Furthermore, we compare the peak oxygen uptake (V̇O2peak) values of patients with cancer with reference values for healthy persons to put these values into a clinical perspective. A computer aided search with ‘cardiopulmonary exercise testing’ and ‘cancer’ using MEDLINE, EMBASE, Pedro, CINAHL® and SPORTDiscus™ was carried out. We included studies in which CPET with continuous gas exchange analysis has been performed prior to a physical exercise programme in adults with cancer. Twenty studies describing 1158 patients were eligible. Reported adherence to international recommendations for CPET varied per item. In most studies, the methods of CPET were not reported in detail. Adverse events occurred in 1% of patients. The percentage V̇O2peak of reference values for healthy persons varied between 65% and 89% for tests before treatment, between 74% and 96% for tests during treatment and between 52% and 117% for tests after treatment. Our results suggest that CPET is feasible and seems to be safe for patients with cancer prior to a physical exercise programme. We recommend that standard reporting and quality guidelines should be followed for CPET methods. The decreased V̇O2peak values of patients with cancer indicate that physical exercise should be implemented in their standard care.
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Schepen in moeilijkheden op zee leveren vaak besluitvormingsproblemen op tussen de scheepseigenaar/kapitein en de kuststaat. Kuststaten en met name de lokale overheden willen een probleem schip graag zo ver mogelijk weg sturen van hun gebied terwijl de eigenaar/kapitein zijn schip graag zo snel mogelijk naar de kust, een beschutte locatie of haven wil brengen. Het onderzoek geeft onderbouwing voor de besluitvorming rond schepen in moeilijkheden, zowel voor de zeescheepvaart als de betrokken besluitvormers van oeverstaten. Het product van het project is: een, op uitgewerkte scenario’s per scheepstype en lading gebaseerde besluitvormingsprocedure voor zeeschepen in moeilijkheden
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With a market demand for low cost, easy to produce, flexible and portable applications in healthcare, energy, biomedical or electronics markets, large research programs are initiated to develop new technologies to provide this demand with new innovative ideas. One of these fast developing technologies is organic printed electronics. As the term printed electronics implies, functional materials are printed via, e.g. inkjet, flexo or gravure printing techniques, on to a substrate material. Applications are, among others, organic light emitting diodes (OLED), sensors and Lab-on-a-chip devices. For all these applications, in some way, the interaction of fluids with the substrate is of great importance. The most used substrate materials for these low-cost devices are (coated) paper or plastic. Plastic substrates have a relatively low surface energy which frequently leads to poor wetting and/or poor adhesion of the fluids on the substrates during printing and/ or post-processing. Plasma technology has had a long history in treating materials in order to improve wetting or promote adhesion. The µPlasma patterning tool described in this thesis combines a digital inkjet printing platform with an atmospheric dielectric barrier discharge plasma tool. Thus enabling selective and local plasma treatment, at atmospheric pressure, of substrates without the use of any masking materials. In this thesis, we show that dependent on the gas composition the substrate surface can either be functionalized, thus increasing its surface energy, or material can be deposited on the surface, lowering its surface energy. Through XPS and ATR-FTIR analysis of the treated (polymer) substrate surfaces, chemical modification of the surface structure was confirmed. The chemical modification and wetting properties of the treated substrates remained present for at least one month after storage. Localized changes in wettability through µPlasma patterning were obtained with a resolution of 300µm. Next to the control of wettability of an ink on a substrate in printed electronics is the interaction of ink droplets with themselves of importance. In printing applications, coalescence of droplets is standard practice as consecutive droplets are printed onto, or close to each other. Understanding the behaviour of these droplets upon coalescence is therefore important, especially when the ink droplets are of different composition and/or volume. For droplets of equal volume, it was found that dye transport across the coalescence bridge could be fully described by diffusion only. This is as expected, as due to the droplet symmetry on either side of the bridge, the convective flows towards the bridge are of equal size but opposite in direction. For droplets of unequal volume, the symmetry across the bridge is no longer present. Experimental analysis of these merging droplets show that in the early stages of coalescence a convective flow from the small to large droplet is present. Also, a smaller convective flow of shorter duration from the large into the small droplet was identified. The origin of this flow might be due to the presence of vortices along the interface of the bridge, due to the strong transverse flow to open the bridge. To conclude, three potential applications were showcased. In the first application we used µPlasma patterning to create hydrophilic patterns on hydrophobic dodecyl-trichlorosilane (DTS) covered glass. Capillaries for a Lab-on-a-chip device were successfully created by placing two µPlasma patterned glass slides on top of each other separated by scotch tape. In the second application we showcased the production of a RFID tag via inkjet printing. Functional RFID-tags on paper were created via inkjet printing of silver nanoparticle ink connected to an integrated circuit. The optimal operating frequency of the produced tags is in the range of 860-865 MHz, making them usable for the European market, although the small working range of 1 m needs further improvement. Lastly, we showed the production of a chemresistor based gas sensor. In house synthesised polyemeraldine salt (PANi) was coated by hand on top of inkjet printed silver electrodes. The sensor proved to be equally sensitive to ethanol and water vapour, reducing its selectivity in detecting changes in gas composition.
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This research paper looks at a selection of science-fiction films and its connection with the progression of the use of television, telephone and print media. It also analyzes statistical data obtained from a questionnaire conducted by the research group regarding the use of communication media.
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