1,100 research outputs found

    Evaluation of an Internet–Short Message Service–Based Intervention for Promoting Physical Activity in Hong Kong Chinese Adolescent School Children: A Pilot Study

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    Evaluation of acceptability and preliminary efficacy of an Internet and short message service (SMS) intervention for promoting physical activity (PA) in Hong Kong Chinese school children. An 8-week quasi-experimental study non-randomly assigned 78 school children (mean age=12.8 years) to (a) an intervention group that received a stage-matched, Internet PA program two times a week and tailored SMS messages daily; or (b) a no-treatment control. Data were collected from September 2008 until June 2009. Acceptability measures included exposure rate and participant\u27s satisfaction. Efficacy measures were changes in stage of motivational readiness (SMR) and self-reported PA level. Intervention participants demonstrated significant pre-post increments in SMR (Z=−2.558, p=0.011) and self-reported PA level [F(1, 76)=4.50, p=0.04]. There was a non-significant trend between groups in both SMR (p=0.24) and PA (p=0.13). Despite the similar ratings of satisfaction between Internet (M=3.12±0.74) and SMS (M=3.12±0.84), participants displayed distinct patterns of exposure with 66% exhibiting a weekly login rate of 0.5 times/person and an average of 3.75 minutes/visit/person. In contrast, 79% of participants read an average of 1.3 SMS/person/week and 47% voluntarily replied to 3.8 SMS/person. These findings demonstrate the acceptability and preliminary efficacy of an Internet-SMS-based intervention for promoting PA in Hong Kong school children. The divergent exposure rates between the Internet and SMS may be a unique pattern for adolescents in early SMR. Future research should be cognizant of the importance of SMR since it may influence utilization and/or adherence

    Reliability and validity of the short Hong Kong Chinese Self-Regulation of Learning Self-Report Scale (SRL-SRS-C)

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    Objectives: This study translated and shortened the original English, six-factor, Self-Regulated Learning Self-Report Scale (SRL-SRS). This version was subsequently assessed for its reliability and validity, for use in a Hong Kong Chinese adolescent population. Design and methods: The SRL-SRS was translated into Chinese following the back-translation procedure. Exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and test–retest reliability analysis, were conducted on a sample of 314 Hong Kong Chinese adolescents aged 12–17 years (mean age = 13.2 years, SD = .99; male = 155) from one Hong Kong secondary school. Cross-validation was conducted on a second sample of adolescents (n = 477; mean age = 14.92 years; male = 283) from three Hong Kong secondary schools. Results: EFA results supported the original six-factor model. Subsequent CFA results supported the short version with sufficient goodness-of-fit statistics (comparative fit index; CFI = 0.93; Tucker–Lewis index (TLI) = 0.92; root square mean error of approximation (RMSEA; 95% CI) = 0.0047 (0.041 – 0.053); SRMR = 0.044). Further support was also found by cross-validation in the second sample (CFI = 0.915; TLI = 0.906; RMSEA = 0.052; SRMR = 0.043). Internal consistency analysis revealed that Cronbach's α ranged from.72 to .89 for all subscales (sample 1); test–retest reliability analysis (sample 1) produced Intra-class Correlation Coefficient (ICC) values ranging from .69 to .80 for all subscales. Conclusions: The short SRL-SRS-C is a sufficiently reliable and valid instrument to measure self-regulation of learning in a Chinese adolescent population. In addition, the SRL-SRS-C has demonstrated sufficient content, construct validity, and test–retest reliability

    Investigating the association of self-regulated learning skills and physical activity in Hong Kong Chinese and Scottish adolescents

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    Zimmerman's self-regulated learning (SRL) model focusses on how individuals are able to make improvements through a cyclical and systematic method of learning how to adapt to ever-changing environments; however, this model is not widely applied in a physical activity (PA) behaviour change context. As such, this cross-sectional study examined the relationship between six SRL skills (planning, self-monitoring, self-evaluation, reflection, effort and self-efficacy) and PA in 480 Chinese (aged 11–19 years; M = 14.9, SD = 1.8; male = 61.3%) and 411 Scottish (aged 12–16 years; M = 13.8, SD = 1.4; male = 47.9%) adolescents. Moderate-to-vigorous intensity PA was significantly higher for Scottish (M = 48.58, SD = 26.01, p = .0005) compared to Chinese adolescents (M = 31.14, SD = 22.26). All SRL variables significantly explained a small amount of variance in moderate-to-vigorous intensity PA, in both Chinese (ΔR 2 = .021, F(2, 461) = 6.320, p = .005) and Scottish (ΔR 2 = .020, F(2, 376) = 8.427, p = .013) adolescents; and reflection was a significant predictor of PA (Chinese p = .027; Scottish p = .003) in both samples. Despite PA differences, in both groups a similar pattern in the relationship between SRL and PA emerged, as well the importance of reflection in this relationship. It is understood that SRL skills may not necessarily come naturally to adolescents and may require explicit training, therefore, research focussing on the development of these SRL skills alongside PA, with a particular emphasis on reflection, may positively influence adolescent PA behaviour change

    Prenatal antidepressant use and risk of attention-deficit/hyperactivity disorder in offspring:population based cohort study

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    textabstractObjective To assess the potential association between prenatal use of antidepressants and the risk of attention-deficit/hyperactivity disorder (ADHD) in offspring. Design Population based cohort study. Setting Data from the Hong Kong population based electronic medical records on the Clinical Data Analysis and Reporting System. Participants 190 618 children born in Hong Kong public hospitals between January 2001 and December 2009 and followed-up to December 2015. Main outcome measure Hazard ratio of maternal antidepressant use during pregnancy and ADHD in children aged 6 to 14 years, with an average follow-up time of 9.3 years (range 7.4-11.0 years). Results Among 190 618 children, 1252 had a mother who used prenatal antidepressants. 5659 children (3.0%) were given a diagnosis of ADHD or received treatment for ADHD. The crude hazard ratio of maternal antidepressant use during pregnancy was 2.26 (P<0.01) compared with non-use. After adjustment for potential confounding factors, including maternal psychiatric disorders and use of other psychiatric drugs, the adjusted hazard ratio was reduced to 1.39 (95% confidence interval 1.07 to 1.82, P=0.01). Likewise, similar results were observed when comparing children of mothers who had used antidepressants before pregnancy with those who were never users (1.76, 1.36 to 2.30, P<0.01). The risk of ADHD in the children of mothers with psychiatric disorders was higher compared with the children of mothers without psychiatric disorders even if the mothers had never used antidepressants (1.84, 1.54 to 2.18, P<0.01). All sensitivity analyses yielded similar results. Sibling matched analysis identified no significant difference in risk of ADHD in siblings exposed to antidepressants during gestation and those not exposed during gestation (0.54, 0.17 to 1.74, P=0.30). Conclusions The findings suggest that the association between prenatal use of antidepressants and risk of ADHD in offspring can be partially explained by confounding by indication of antidepressants. If there is a causal association, the size of the effect is probably smaller than that reported previously

    Validation of the Physical Activity Questionnaire for Older Children (PAQ-C) among Chinese Children *

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    Objective This study initially validates the Chinese version of the Physical Activity Questionnaire for Older Children (PAQ-C), which has been identified as a potentially valid instrument to assess moderate-to-vigorous physical activity (MVPA) in children among diverse racial groups. Methods The psychometric properties of the PAQ-C with 742 Hong Kong Chinese children were assessed with the scale's internal consistency, reliability, test-retest reliability, confirmatory factory analysis (CFA) in the overall sample, and multistep invariance tests across gender groups as well as convergent validity with body mass index (BMI), and an accelerometry-based MVPA. Results The Cronbach alpha coefficient (?=0.79), composite reliability value (?=0.81), and the intraclass correlation coefficient (?=0.82) indicate the satisfactory reliability of the PAQ-C score. The CFA indicated data fit a single factor model, suggesting that the PAQ-C measures only one construct, on MVPA over the previous 7 days. The multiple-group CFAs suggested that the factor loadings and variances and covariances of the PAQ-C measurement model were invariant across gender groups. The PAQ-C score was related to accelerometry-based MVPA (r=0.33) and inversely related to BMI (r=-0.18). Conclusion This study demonstrates the reliability and validity of the PAQ-C in Chinese children

    Counterion Condensation and Fluctuation-Induced Attraction

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    We consider an overall neutral system consisting of two similarly charged plates and their oppositely charged counterions and analyze the electrostatic interaction between the two surfaces beyond the mean-field Poisson-Boltzmann approximation. Our physical picture is based on the fluctuation-driven counterion condensation model, in which a fraction of the counterions is allowed to ``condense'' onto the charged plates. In addition, an expression for the pressure is derived, which includes fluctuation contributions of the whole system. We find that for sufficiently high surface charges, the distance at which the attraction, arising from charge fluctuations, starts to dominate can be large compared to the Gouy-Chapmann length. We also demonstrate that depending on the valency, the system may exhibit a novel first-order binding transition at short distances.Comment: 15 pages, 8 figures, to appear in PR

    Wild Type and Mutant 2009 Pandemic Influenza A (H1N1) Viruses Cause More Severe Disease and Higher Mortality in Pregnant BALB/c Mice

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    BACKGROUND: Pregnant women infected by the pandemic influenza A (H1N1) 2009 virus had more severe disease and higher mortality but its pathogenesis is still unclear. PRINCIPAL FINDINGS: We showed that higher mortality, more severe pneumonitis, higher pulmonary viral load, lower peripheral blood T lymphocytes and antibody responses, higher levels of proinflammatory cytokines and chemokines, and worse fetal development occurred in pregnant mice than non-pregnant controls infected by either wild type (clinical isolate) or mouse-adapted mutant virus with D222G substitution in hemagglutinin. These disease-associated changes and the lower respiratory tract involvement were worse in pregnant mice challenged by mutant virus. Though human placental origin JEG-3 cell line could be infected and proinflammatory cytokines or chemokines were elevated in amniotic fluid of some mice, no placental or fetal involvement by virus were detected by culture, real-time reverse transcription polymerase chain reaction or histopathological changes. Dual immunofluorescent staining of viral nucleoprotein and type II alveolar cell marker SP-C protein suggested that the majority of infected alveolar epithelial cells were type II pneumocytes. CONCLUSION: The adverse effect of this pandemic virus on maternal and fetal outcome is largely related to the severe pulmonary disease and the indirect effect of inflammatory cytokine spillover into the systemic circulation

    Immunoassays Based on Penicillium marneffei Mp1p Derived from Pichia pastoris Expression System for Diagnosis of Penicilliosis

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    BACKGROUND: Penicillium marneffei is a dimorphic fungus endemic in Southeast Asia. It can cause fatal penicilliosis in humans, particularly in HIV-infected people. Diagnosis of this infection is difficult because its clinical manifestations are not distinctive. Specialized laboratory tests are necessary to establish a definitive diagnosis for successful management. We have demonstrated previously that a cell wall mannoprotein Mp1p, abundant in P. marneffei, is a potential biomarker for diagnosis of P. marneffei infections. In the present study, we describe immunoassays based on Mp1p derived from the yeast Pichia pastoris expression system. METHODOLOGY/PRINCIPAL FINDINGS: We generated monoclonal antibodies (MAbs) and rabbit polyclonal antibodies (PAbs) against Mp1p expressed in P. pastoris. Subsequently, we developed two Mp1p antigen capture ELISAs which employed MAbs for both the capture and detecting antibodies (MAb-MAb pair) or PAbs and MAbs as the capture and detecting antibodies (PAbs-MAb pair) respectively. The two Mp1p antigen ELISAs detected Mp1p specifically in cultures of P. marneffei yeast phase at 37-40 degrees C and had no cross-reaction with other tested pathogenic fungi. The sensitivities and specificities of the two antigen assays were found to be 55% (11/20) and 99.6% (538/540) for MAb-MAb Mp1p ELISA, and 75% (15/20) and 99.4% (537/540) for PAbs-MAb Mp1p ELISA performed using 20 sera with culture-confirmed penicilliosis, and 540 control sera from 15 other mycosis patients and 525 healthy donors. Meanwhile, we also developed an anti-Mp1p IgG antibody ELISA with an evaluated sensitivity of 30% (6/20) and a specificity of 98.5% (532/540) using the same sera. Furthermore, combining the results of Mp1p antigen and antibody detection improved the sensitivity of diagnosis to 100% (20/20). CONCLUSIONS/SIGNIFICANCE: Simultaneous detection of antigen and antibody using the immunoassays based on Mp1p derived from P. pastoris greatly improves detection sensitivity. The procedures should be useful for the routine diagnosis of penicilliosis.published_or_final_versio

    Hall Measurements on Carbon Nanotube Paper Modified With Electroless Deposited Platinum

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    Carbon nanotube paper, sometimes referred to as bucky paper, is a random arrangement of carbon nanotubes meshed into a single robust structure, which can be manipulated with relative ease. Multi-walled carbon nanotubes were used to make the nanotube paper, and were subsequently modified with platinum using an electroless deposition method based on substrate enhanced electroless deposition. This involves the use of a sacrificial metal substrate that undergoes electro-dissolution while the platinum metal deposits out of solution onto the nanotube paper via a galvanic displacement reaction. The samples were characterized using SEM/EDS, and Hall-effect measurements. The SEM/EDS analysis clearly revealed deposits of platinum (Pt) distributed over the nanotube paper surface, and the qualitative elemental analysis revealed co-deposition of other elements from the metal substrates used. When stainless steel was used as sacrificial metal a large degree of Pt contamination with various other metals was observed. Whereas when pure sacrificial metals were used bimetallic Pt clusters resulted. The co-deposition of a bimetallic system upon carbon nanotubes was a function of the metal type and the time of exposure. Hall-effect measurements revealed some interesting fluctuations in sheet carrier density and the dominant carrier switched from N- to P-type when Pt was deposited onto the nanotube paper. Perspectives on the use of the nanotube paper as a replacement to traditional carbon cloth in water electrolysis systems are also discussed
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