1,034 research outputs found

    Extension and Validation of an Adult Gaming Addiction Scale

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    Video game addiction among adults is a serious mental health issue. Unfortunately, research on video game addiction is in its infancy and impeded by the lack of a valid and reliable measure for use with adults. Lemmens, Valkenburg, and Peter (2009) developed an adolescent video game addiction measure, the Gaming Addiction Scale (GAS); however, it has not been validated for use with an adult population. The primary aim of this study was to evaluate the appropriateness of the GAS for use with adults and evaluate whether the measure is a valid and reliable measure of adult video game addiction. The measure was administered to a population of 2,820 massively multiplayer online adult gamers through popular gaming websites. Factor analysis was conducted to evaluate whether the items sorted into the same seven underlying criteria (i.e., salience, tolerance, mood modification, relapse, withdrawal, conflict, and problems) of video game addiction as the original study. This analysis revealed a four-factor structure that differed from the adolescent version of the measure but still encompassed the seven criteria of gaming addiction in a coherent manner. The GAS exhibited strong reliability and concurrent validity with loneliness, life satisfaction, and time spent gaming. The GAS did not exhibit discriminant validity with a measure of social anxiety. A hypothesized moderating effect of time spent gaming on the relationship between video game addiction and playing with real-life friends was not supported. The GAS is reliable and compatible with current understandings and diagnostic criteria; it has potential as a useful measure of video game addiction for adults. Future research should focus on further validation of the measure for adults, and clarifying the relationship between social anxiety and gaming addiction

    Effect of 405 nm high-intensity narrow-spectrum light on osteoblast function

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    A significant portion of medical devices fail due to acquired infection, with infection rates after arthroplasty surgery between 1-4%, and considerably higher after revision surgery. To reduce the associated costs of infection, a new preventative method is required. High intensity narrow spectrum (HINS) 405 nm light is a new technology shown to have bactericidal effects on a range of medically important bacteria[1]. The effect of HINS-light on osteoblasts and bacteria were investigated to determine the potential of this technology to contribute to infection prevention in operating theatres, during surgery and postoperative dressing changes

    Superposition of DC voltage and submicrosecond impulses for energization of electrostatic precipitators

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    This paper discusses the development of an impulsive microelectrostatic precipitation technology, which uses superposition of submicrosecond high-field pulses and dc electric field. Short impulses allow the application of higher voltages to the ionization electrodes of a precipitation system without the initiation of breakdown. These higher levels of electric field generate higher ionic concentrations, resulting in more efficient charging of the airborne particles, and can potentially improve precipitation efficiency. This work is focused on the analysis of the behavior of impulsive positive corona discharges in a coaxial reactor designed for precipitation studies. The efficiency of precipitation of coarse and fine particles has been investigated using different dc and impulse voltage levels in order to establish optimal energization modes

    The triggered behavior of a controlled corona stabilised cascade switch

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    Corona stabilised switches have been shown to have advantages in pulse power switching applications due to their high repetition rates and low jitter. Work performed in recent years by the High Voltage Technologies Group within the Department of Electronic and Electrical Engineering at the University of Strathclyde has shown that the operating voltage range of such switches can be extended by using a multi-gap cascade configuration. One particular multi-gap topology was shown to operate under pressure at 100 kV with a switching jitter of 2ns. It has since been shown that by modifying the topology of the corona sources on the electrodes, it is possible to control the grading of the voltage distribution across the gaps in the cascade. The voltages across each gap and the self-break behaviour of the cascade were found to be in close agreement with the values predicted from the corona emission characteristics for the tested electrode topologies. This paper reports on a further examination of the behaviour of the corona controlled switching topology, where triggered operation of the switch has been investigated for different voltage distributions across the cascade gaps

    Quantifying bacterial transfer from patients to staff during burns dressing and bed changes : implications for infection control

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    Routine nursing activities such as dressing/bed changes increase bacterial dispersal from burns patients, potentially contaminating healthcare workers (HCW) carrying out these tasks. HCW thus become vectors for transmission of nosocomial infection between patients. The suspected relationship between %total body surface area (%TBSA) of burn and levels of bacterial release has never been fully established. Bacterial contamination of HCW was assessed by contact plate samples (n = 20) from initially sterile gowns worn by the HCW during burns patient dressing/bed changes. Analysis of 24 gowns was undertaken and examined for relationships between %TBSA, time taken for activity, and contamination received by the HCW. Relationships between size of burn and levels of HCW contamination, and time taken for the dressing/bed change and levels of HCW contamination were best described by exponential models. Burn size correlated more strongly (R2 = 0.82, p < 0.001) than time taken (R2 = 0.52, p < 0.001), with levels of contamination received by the HCW. Contamination doubled with every 6–9% TBSA increase in burn size. Burn size was used to create a model to predict bacterial contamination received by a HCW carrying out bed/dressing changes. This may help with the creation of burn-specific guidelines on protective clothing worn by HCW caring for burns patients

    Synergistic efficacy of 405 nm light and chlorinated disinfectants for the enhanced decontamination of Clostridium difficile spores

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    The ability of Clostridium difficile to form highly resilient spores which can survive in the environment for prolonged periods causes major contamination problems. Antimicrobial 405 nm light is being developed for environmental decontamination within hospitals, however further information relating to its sporicidal efficacy is required. This study aims to establish the efficacy of 405 nm light for inactivation of C. difficile vegetative cells and spores, and to establish whether spore susceptibility can be enhanced by the combined use of 405 nm light with low concentration chlorinated disinfectants. Vegetative cells and spore suspensions were exposed to increasing doses of 405 nm light (at 70–225 mW/cm2) to establish sensitivity. A 99.9% reduction in vegetative cell population was demonstrated with a dose of 252 J/cm2, however spores demonstrated higher resilience, with a 10-fold increase in required dose. Exposures were repeated with spores suspended in the hospital disinfectants sodium hypochlorite, Actichlor and Tristel at non-lethal concentrations (0.1%, 0.001% and 0.0001%, respectively). Enhanced sporicidal activity was achieved when spores were exposed to 405 nm light in the presence of the disinfectants, with a 99.9% reduction achieved following exposure to 33% less light dose than required when exposed to 405 nm light alone. In conclusion, C. difficile vegetative cells and spores can be successfully inactivated using 405 nm light, the sporicidal efficacy can be significantly enhanced when exposed in the presence of low concentration chlorinated disinfectants. Further research may lead to the potential use of 405 nm light decontamination in combination with selected hospital disinfectants to enhance C. difficile cleaning and infection control procedures

    Solid-state synthesis and characterization of σ-Alkane complexes, [Rh(L2)(η2,η2-C7H12)][BArF4] (L2 = bidentate chelating phosphine)

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    The use of solid/gas and single-crystal to single-crystal synthetic routes is reported for the synthesis and characterization of a number of σ-alkane complexes: [Rh(R2P(CH2)nPR2)(η2,η2-C7H12)][BArF4]; R = Cy, n = 2; R = iPr, n = 2,3; Ar = 3,5-C6H3(CF3)2. These norbornane adducts are formed by simple hydrogenation of the corresponding norbornadiene precursor in the solid state. For R = Cy (n = 2), the resulting complex is remarkably stable (months at 298 K), allowing for full characterization using single-crystal X-ray diffraction. The solid-state structure shows no disorder, and the structural metrics can be accurately determined, while the 1H chemical shifts of the Rh···H–C motif can be determined using solid-state NMR spectroscopy. DFT calculations show that the bonding between the metal fragment and the alkane can be best characterized as a three-center, two-electron interaction, of which σCH → Rh donation is the major component. The other alkane complexes exhibit solid-state 31P NMR data consistent with their formation, but they are now much less persistent at 298 K and ultimately give the corresponding zwitterions in which [BArF4]− coordinates and NBA is lost. The solid-state structures, as determined by X-ray crystallography, for all these [BArF4]− adducts are reported. DFT calculations suggest that the molecular zwitterions within these structures are all significantly more stable than their corresponding σ-alkane cations, suggesting that the solid-state motif has a strong influence on their observed relative stabilities

    Zero-dimensional chemical kinetic simulation of ROS/RNSin pulsed pulsed-discharge exposed water

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    The concentration variations of reactive oxygen/nitrogen species in water, such as H2O2, NO2 −, and NO3 − generated by pulsed-discharge plasma exposure, are calculated using reaction rates of chemical reactions and acid-base equilibrium in water. The calculated concentrations and pH values are in good agreement with measured data within the range where the significant changes of the measured data are observed. The rate constant for ONOOH generation is estimated to be 7.8 × 103 M−2 s−1, and this value is in good agreement with previously reported values. The generation rates of H2O2, NO2 −, and NO3 − are estimated to be 7.70 × 10−7, 4.10 × 10−7, and 1.10 × 10−7 M s−1, respectively

    Bactericidal effect of corona discharges in atmospheric air

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    The present paper explores the possibilities of using impulsive and steady-state corona discharges for bio-decontamination operations. A high tension tubular corona electrode was stressed with positive or negative dc voltage with magnitude up to 26 kV, and a grounded mesh was used as an opposite electrode. Different operational regimes of this corona generator were investigated for the production of ozone in air flow and the inactivation of microorganisms. The test microorganisms used in this work were Escherichia coli and Staphylococcus aureus, populations of which were seeded onto agar plates. These bacterial plates were located behind the grounded mesh electrode to assess bactericidal efficacy. The results show that corona discharges have a strong bactericidal effect, for example positive flashing corona discharges were able to reduce populations of the test microorganism by 94% within a 30-60 sec time interval. Negative steady-state corona discharges also produce noticeable bactericidal effect, reducing population of E. coli and S. aureus by more than 97% within 120 sec energisation interval. The bactericidal efficiency of different corona discharge modes and its correlation with ozone levels produced by these discharges is discussed. The results obtained in this work will help in the design and development of compact plasma systems for environmental application

    The influence of magnetite nano particles on the behavior of insulating oils for pulse power applications

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    The effects of the addition of magnetite nanoparticles on the breakdown strength of three insulating liquids have been examined. The liquids considered are: a mineral transformer oil; a synthetic ester liquid, Midel 7131, and a specialist high permittivity liquid for pulse power applications THESO. The expected increases in breakdown strength were observed in the mineral oil and synthetic ester liquids. However in the case of the high permittivity liquid no significant changes in the breakdown strength were observed. Possible explanations for the differences in the observed behavior for the THESO insulating liquid are discussed
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