72 research outputs found

    Fundamental efficiency bound for coherent energy transfer in nanophotonics

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    We derive a unified quantum theory of coherent and incoherent energy transfer between two atoms (donor and acceptor) valid in arbitrary Markovian nanophotonic environments. Our theory predicts a fundamental bound ηmax=γaγd+γa\eta_{max} = \frac{\gamma_a}{\gamma_d + \gamma_a} for energy transfer efficiency arising from the spontaneous emission rates γd\gamma_{d} and γa\gamma_a of the donor and acceptor. We propose the control of the acceptor spontaneous emission rate as a new design principle for enhancing energy transfer efficiency. We predict an experiment using mirrors to enhance the efficiency bound by exploiting the dipole orientations of the donor and acceptor. Of fundamental interest, we show that while quantum coherence implies the ultimate efficiency bound has been reached, reaching the ultimate efficiency does not require quantum coherence. Our work paves the way towards nanophotonic analogues of efficiency enhancing environments known in quantum biological systems.Comment: 5 pages, 4 figure

    The Smoking MUMS (Maternal Use of Medication and Safety) Study: protocol for a population-based cohort study using linked administrative data

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    Introduction: Approximately 14% of Australian women smoke during pregnancy. Although the risk of adverse outcomes is reduced by smoking cessation, less than 35% of Australian women quit smoking spontaneously during pregnancy. Evidence for the efficacy of bupropion, varenicline or nicotine replacement therapy as smoking cessation aids in the non-pregnant population suggest that pharmacotherapy for smoking cessation is worth exploring in women of childbearing age. Currently, little is known about the utilisation, effectiveness and safety of pharmacotherapies for smoking cessation during pregnancy; neither the extent to which they are used prior to pregnancy nor whether their use has changed in response to related policy reforms. The Smoking MUMS (Maternal Use of Medications and Safety) Study will explore these issues using linked person-level data for a population-based cohort of Australian mothers. Methods and analysis: The cohort will be assembled by linking administrative health records for all women who gave birth in New South Wales or Western Australia since 2003 and their children, including records relating to childbirth, use of pharmaceuticals, hospital admissions, emergency department presentations and deaths. These longitudinal linked data will be used to identify utilisation of smoking cessation pharmacotherapies during and between pregnancies and to explore the associated smoking cessation rates and maternal and child health outcomes. Subgroup and temporal analyses will identify potential differences between population groups including indigenous mothers and social security recipients and track changes associated with policy reforms that have made alternative smoking cessation pharmacotherapies available.Ethics and dissemination: Ethical approval has been obtained for this study. To enhance the translation of the project's findings into policy and practice, policy and clinical stakeholders will be engaged through a reference group and a policy forum will be held. Outputs from the project will include scientific papers and summary reports designed for policy audiences

    Tobacco policy reform and population-wide antismoking activities in Australia: the impact on smoking during pregnancy

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    Publisher's version (Ăștgefin grein)Introduction This study examined the impact of antismoking activities targeting the general population and an advertising campaign targeting smoking during pregnancy on the prevalence of smoking during pregnancy in New South Wales (NSW), Australia. Methods Monthly prevalence of smoking during pregnancy was calculated using linked health records for all pregnancies resulting in a birth (800 619) in NSW from 2003 to 2011. Segmented regression of interrupted time series data assessed the effects of the extension of the ban on smoking in enclosed public places to include licensed premises (evaluated in combination with the mandating of graphic warnings on cigarette packs), television advertisements targeting smoking in the general population, print and online magazine advertisements targeting smoking during pregnancy and increased tobacco tax. Analyses were conducted for all pregnancies, and for the population stratified by maternal age, parity and socioeconomic status. Further analyses adjusted for the effect of the Baby Bonus maternity payment. Results Prevalence of smoking during pregnancy decreased from 2003 to 2011 overall (0.39% per month), and for all strata examined. For pregnancies overall, none of the evaluated initiatives was associated with a change in the trend of smoking during pregnancy. Significant changes associated with increased tobacco tax and the extension of the smoking ban (in combination with graphic warnings) were found in some strata. Conclusions The declining prevalence of smoking during pregnancy between 2003 and 2011, while encouraging, does not appear to be directly related to general population antismoking activities or a pregnancy-specific campaign undertaken in this period.This research was supported by an Australian National Health and Medical Research Council Project Grant (#1028543) and AH is supported by a National Heart Foundation Future Leader Fellowship (#100411). The funders had no involvement in the study design; the collection, analysis or interpretation of the data; in the writing of the report or the decision to submit the report for publication.Peer Reviewe

    Varenicline is More Effective than Nicotine Replacement Therapy During Pregnancy: Findings from the Smoking MUMS (Maternal Use of Medications and Safety) Study

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    Introduction Studies in the general population suggest that varenicline is more effective than nicotine replacement therapy (NRT) for smoking cessation. However, clinical guidelines recommend against the use of varenicline during pregnancy and suggest NRT be used when the expected benefits outweigh the potential risks. Objectives and Approach We evaluated whether varenicline was more effective than NRT for smoking cessation when used during pregnancy. Routinely-collected records of all births (01/01/2011-12/31/2012) in New South Wales and Western Australia were used to identify a cohort of women who smoked during the first 20 weeks of pregnancy. Pharmaceutical dispensing data were then linked to identify varenicline or NRT dispensing in the first 20 weeks of pregnancy. Smoking cessation was defined as women reported not smoking after the first 20 weeks of pregnancy. Inverse probability of treatment weighting with propensity scores were used to account for differences between the two treatment groups. Results Overall, 117 women used varenicline and 135 NRT in the first 20 weeks of pregnancy. In the unweighted sample, more women who used varenicline quit smoking after the first 20 weeks than women using NRT (28.2% vs. 11.1%, crude rate difference:17.1%, 95% confidence intervals[CI]:7.4-26.8%). In the weighted sample, quitting rate was 12.7% (95%CI:0.8-24.6%) higher in pregnant smokers who used varenicline (27.4% vs. 14.7%) when compared to those who used NRT. Conclusion/Implications Pregnant smokers using varenicline were more likely to quit smoking than those using NRT. This information will assist healthcare providers to make informed recommendations, but data regarding safety of varenicline in pregnancy are also urgently needed. Future studies with greater statistical power are required to confirm our results

    Prevalence trends and individual patterns of antiepileptic drug use in pregnancy 2006‐2016: A study in the five Nordic countries, United States, and Australia

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    Publisher's version (Ăștgefin grein)Purpose: To describe recent international trends in antiepileptic drug (AED) use during pregnancy and individual patterns of use including discontinuation and switching. Methods: We studied pregnancies from 2006 to 2016 within linked population-based registers for births and dispensed prescription drugs from Denmark, Finland, Iceland, Norway, Sweden, and New South Wales, Australia and claims data for public and private insurance enrollees in the United States. We examined the prevalence of AED use: the proportion of pregnancies with ≄1 prescription filled from 3 months before pregnancy until birth, and individual patterns of use by trimester. Results: Prevalence of AED use in almost five million pregnancies was 15.3 per 1000 (n = 75 249) and varied from 6.4 in Sweden to 34.5 per 1000 in the publicly-insured US population. AED use increased in all countries in 2006-2012 ranging from an increase of 22% in Australia to 104% in Sweden, and continued to rise or stabilized in the countries in which more recent data were available. Lamotrigine, clonazepam, and valproate were the most commonly used AEDs in the Nordic countries, United States, and Australia, respectively. Among AED users, 31% only filled a prescription in the 3 months before pregnancy. Most filled a prescription in the first trimester (59%) but few filled prescriptions in every trimester (22%). Conclusions: Use of AEDs in pregnancy rose from 2006 to 2016. Trends and patterns of use of valproate and lamotrigine reflected the safety data available during this period. Many women discontinued AEDs during pregnancy while some switched to another AED.This study was funded by NordForsk as part of the Nordic Pregnancy Drug Safety Studies (NorPreSS) (Project No: 83539) and the Research Council of Norway as part of the International Pregnancy Drug Safety Studies (InPreSS) (Project No: 273366). Linkage of Danish data was supported by the Danish Council for Independent Research (Project No: DFF‐6110‐00019) and Karen Elise Jensens Fond (2016), and grant NNF18OC0052029 from Novo Nordisk Fonden (Li). Linkage of the Australian data was supported by an Australian National Health and Medical Research Council Project grant (No. 1028543). We thank Anders Engeland (Norwegian Institute of Public Health, University of Bergen, Norway), Anna Heino (National Institute for Health and Welfare, Finland), Mette NĂžrgaard (Aarhus University, Denmark), PĂ€r Karlsson (Karolinska Institutet, Sweden), Jennifer Yland (Harvard T.H. Chan School of Public Health, USA), Gregory Brill and Helen Mogun (Brigham and Women's Hospital & Harvard Medical School, USA) for providing assistance with analyses. The authors would like to thank the NSW Ministry of Health, the Australian Government Department of Health and Ageing and the Department of Human Services for providing data. The authors also thank the Centre for Health Record Linkage (CHeReL) and the Australian Institute for Health and Welfare for conducting the linkage of records.Peer Reviewe

    Most common principal diagnoses assigned to Australian emergency department presentations involving alcohol use: a multi‐centre study

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    Abstract: Objectives: Alcohol is the most widely consumed psychoactive substance in Australia and the consequences of alcohol consumption have enormous personal and social impacts. This study aimed to describe the principal diagnoses of emergency department (ED) presentations involving alcohol use in the previous 12 hours at eight hospitals in Victoria and the Australian Capital Territory, Australia. Methods: Twelve months’ data (1 July 2018 – 30 June 2019) were collected from eight EDs, including demographics, ICD‐10 codes, hospital location and self‐reported drinking in the preceding 12 hours. The ten most common ICD‐10 discharge codes were analysed based on age, sex and hospital geographic area. Results: ICD codes pertaining to mental and behavioural disorders due to alcohol use accounted for the highest proportion in most EDs. Suicide ideation/attempt was in the five highest ICD codes for all but one hospital. It was the second most common alcohol‐related presentation for both males and females. Conclusions: Alcohol plays a major role in a range of presentations, especially in relation to mental health and suicide. Implications for public health: The collection of alcohol involvement in ED presentations represents a major step forward in informing the community about the burden of alcohol on their health resources

    The association between moral disengagement, psychological distress, resistive self-regulatory efficacy and alcohol and cannabis use among adolescents in Sydney, Australia

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    Objective: The current study aimed to: (i) examine the estimated proportion of young Australian’s using alcohol and cannabis, and (ii) investigate a number of individual risk factors associated with use. Method: A total of 1022 students aged between 12 and 15 years (86% male) were recruited from ten independent schools in Sydney, Australia. All participants completed a questionnaire measuring demographics, levels of moral disengagement, psychological distress, self-regulatory efficacy to resist peer pressure to engage in transgressive behaviour, and alcohol and cannabis use. Results: Approximately 85% of participants reported having ever tried alcohol in their life, 31% reported having ever had a full serve of alcohol in their life, 9% reported binge drinking in the past 3 months, and 4% reported having ever tried cannabis in their life. Logistic regression analyses revealed higher moral disengagement and lower resistive selfregulatory efficacy were independent predictors of ever having a full serve of alcohol, binge drinking in the past 3 months and ever trying cannabis. Psychological distress was not associated with alcohol or cannabis use. Conclusions: A better understanding of the factors associated with early alcohol and cannabis use may help identify groups who have difficulties controlling use and aid the development of targeted prevention strategies for reducing use and related harms

    Refining an antidepressant-based indicator to improve the ascertainment of depression from Australian administrative data

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    ABSTRACT Objectives In the absence of whole-of-population data regarding depression in Australia, antidepressant supply identified through pharmaceutical data has been used by some as an indicator of depression. This approach has been criticised on the basis that up to 30% of antidepressants are prescribed for indications other than depression, including anxiety disorders, insomnia and pain. This study examines whether the identification of patients treated for depression can be improved by refining this antidepressant-based indicator via a series of pre-determined algorithms. Approach Pharmaceutical Benefits Scheme (PBS) and Medicare Benefits Scheme (MBS) records were linked to follow-up questionnaires completed between September 2012 and December 2014 by participants of the 45 and Up Study - a cohort study of residents of New South Wales, Australia, aged 45 years and older. After exclusions, 58,425 participants were included in the analyses. According to the basic antidepressant-based indicator, the supply of any antidepressant (Anatomical Therapeutic Chemical classification (ATC) code beginning with N06A) in the 30 days prior to the survey completion date was considered indicative of depression treatment in the last month. This algorithm was refined to: i) exclude tricyclic antidepressants (ATC code N06AA), which are commonly prescribed for insomnia and pain; and ii) re-categorise as ‘not treated for depression’ those antidepressant recipients who were also supplied an anxiolytic or sedative (ATC codes beginning with N05B and N05C) in the 12 months prior to the survey. Self-reported receipt of treatment for depression in the last month, from the questionnaire data, was used as a gold standard. Results The basic antidepressant-based indicator returned a sensitivity (Sn) of 59.9%, a positive predictive value (PPV) of 43.4% and a specificity (Sp) of 94.7%. When refined algorithm i) was applied, the PPV and Sp increased to 51.8% and 96.5% respectively, while Sn decreased to 54.6%. Refined algorithms ii) yielded similar PPVs and Sps to algorithm i) while Sns were lower. Further refinements to the indicator will be explored using primary care (MBS) data. Although MBS data do not contain diagnoses, they do contain indicators of when certain mental health services were provided, allowing for algorithms in which the prescription of antidepressants for mental health reasons is distinguished from their prescription for physical health problems. Conclusion The algorithms developed in this study can be applied to identify depression in future research based on Australian administrative health data. We acknowledge the Commonwealth Department of Human Services for supplying PBS and MBS data
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