290 research outputs found

    Iodine Vacancy Redistribution in Organicā€“Inorganic Halide Perovskite Films and Resistive Switching Effects

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138254/1/adma201700527_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138254/2/adma201700527-sup-0001-S1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138254/3/adma201700527.pd

    Nanoionic Resistiveā€Switching Devices

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    Advances in the understanding of nanoscale ionic processes in solidā€state thin films have led to the rapid development of devices based on coupled ionicā€“electronic effects. For example, ionā€driven resistiveā€switching (RS) devices have been extensively studied for future memory applications due to their excellent performance in terms of switching speed, endurance, retention, and scalability. Recent studies further suggest that RS devices are more than just resistors with tunable resistance; instead, they exhibit rich and complex internal ionic dynamics that equip them with native informationā€processing capabilities, particularly in the temporal domain. RS effects induced by the migration of different types of ions, often driven by an electric field, are discussed. It is shown that, by taking advantage of the different state variables controlled by the ionic processes, important synaptic functions can be faithfully implemented in solidā€state devices and networks. Recent efforts on improving the controllability of ionic processes to optimize device performance are also discussed, along with new opportunities for material design and engineering enabled by the ability to control ionic processes at the atomic scale.Solidā€state resistiveā€switching devices driven by nanoscale ionic processes are reviewed, with the focus on the rich ionic dynamics that enable natural implementation of a range of biological synaptic and neuron functions. Efforts to control ion redistribution at the atomic scale have led to improved device performance, and enabled applications based on reconfigurable nanostructures and materials through controlled ionic processes in solidā€state devices.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151267/1/aelm201900184_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151267/2/aelm201900184.pd

    Adipose Tissue-Resident Immune Cells in Obesity and Type 2 Diabetes

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    Inflammation is an important contributor to the pathogenesis of obesity-related type 2 diabetes (T2D). Adipose tissue-resident immune cells have been observed, and the potential contribution of these cells to metabolic dysfunction has been appreciated in recent years. This review focused on adipose tissue-resident immune cells that are dysregulated in the context of obesity and T2D. We comprehensively overviewed emerging knowledge regarding the phenotypic and functional properties of these cells and local factors that control their development. We discussed their function in controlling the immune response cascade and disease progression. We also characterized the metabolic profiles of these cells to explain the functional consequences in obese adipose tissues. Finally, we discussed the potential therapeutic targeting of adipose tissue-resident immune cells with the aim of addressing novel therapeutic approaches for the treatment of this disease

    Optimizing the thermoelectric performance of zigzag and chiral carbon nanotubes

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    Using nonequilibrium molecular dynamics simulations and nonequilibrium Green's function method, we investigate the thermoelectric properties of a series of zigzag and chiral carbon nanotubes which exhibit interesting diameter and chirality dependence. Our calculated results indicate that these carbon nanotubes could have higher ZT values at appropriate carrier concentration and operating temperature. Moreover, their thermoelectric performance can be significantly enhanced via isotope substitution, isoelectronic impurities, and hydrogen adsorption. It is thus reasonable to expect that carbon nanotubes may be promising candidates for high-performance thermoelectric materials

    Spatiotemporal patterns of particulate matter (PM) and associations between PM and mortality in Shenzhen, China

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    DOI: 10.1186/s12889-016-2725-6Background: Most studies on air pollution exposure and its associations with human health in China have focused on the heavily polluted industrial areas and/or mega-cities, and studies on cities with comparatively low air pollutant concentrations are still rare. Only a few studies have attempted to analyse particulate matter (PM) for the vibrant economic centre Shenzhen in the Pearl River Delta. So far no systematic investigation of PM spatiotemporal patterns in Shenzhen has been undertaken and the understanding of pollution exposure in urban agglomerations with comparatively low pollution is still limited. Methods: We analyze daily and hourly particulate matter concentrations and all-cause mortality during 2013 in Shenzhen, China. Temporal patterns of PM (PM2.5 and PM10) with aerodynamic diameters of 2.5 (10) Ī¼m or less (or less (including particles with a diameter that equals to 2.5 (10) Ī¼m) are studied, along with the ratio of PM2.5 to PM10. Spatial distributions of PM10 and PM2.5 are addressed and associations of PM10 or PM2.5 and all-cause mortality are analyzed. Results: Annual average PM10 and PM2.5 concentrations were 61.3 and 39.6 Ī¼g/m3 in 2013. PM2.5 failed to meet the Class 2 annual limit of the National Ambient Air Quality Standard. PM2.5 was the primary air pollutant, with 8.8 % of days having heavy PM2.5 pollution. The daily PM2.5/PM10 ratios were high. Hourly PM2.5 concentrations in the tourist area were lower than downtown throughout the day. PM10 and PM2.5 concentrations were higher in western parts of Shenzhen than in eastern parts. Excess risks in the number of all-cause mortality with a 10 Ī¼g/m3 increase of PM were 0.61 % (95 % confidence interval [CI]: 0.50ā€“0.72) for PM10, and 0.69 % (95 % CI: 0.55ā€“0.83) for PM2.5, respectively. The greatest ERs of PM10 and PM2.5 were in 2-day cumulative measures for the all-cause mortality, 2-day lag for females and the young (0ā€“65 years), and L02 for males and the elder (>65 years). PM2.5 had higher risks on all-cause mortality than PM10. Effects of high PM pollution on mortality were stronger in the elder and male. Conclusions: Our findings provide additional relevant information on air quality monitoring and associations of PM and human health, valuable data for further scientific research in Shenzhen and for the on-going discourse on improving environmental policie

    Living in Two Cultures: Chinese Canadiansā€™ Perspectives on Health

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    OBJECTIVES: Chinese people have distinctive perspectives on health and illness that are largely unrecognized in Western society. The purpose of this descriptive study was to develop a profile of Chinese immigrantsā€™ beliefs and practices related to diet, mental and social health, and sexual health. METHODS: A quantitative survey with descriptive and correlational analyses was employed to examine 100 first-generation Chinese immigrants living in four urban centres across Canada (Vancouver, Toronto, Halifax, and St. Catharines). RESULTS: Although most Chinese immigrants preferred a Chinese diet, where they resided affected the groceries they bought and the meals they ate. Almost all participants reported their mental health was important to them and most felt comfortable discussing mental health issues with others. However, only a third would see a psychiatrist if they believed they had a mental health problem. Most participants believed social relationships were important for their health. Only a small number of participants, however, preferred making friends with mainstream Caucasian Canadians. More men than women believed sexuality contributed to health and were comfortable talking about sexual health. CONCLUSION: Chinese immigrants should be encouraged to be more engaged in the larger community in order to fully integrate themselves into Canadian society while still being encouraged to retain their healthy practices. These findings may help educators and practitioners enhance their understandings of Chinese immigrantsā€™ perspectives on health and develop culturally competent education and services in health care and health promotion.Social Sciences and Humanities Research Council of Canada (SSHRC) and Sport Canada Joint Initiative Gran

    Theory-based Causal Transfer: Integrating Instance-level Induction and Abstract-level Structure Learning

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    Learning transferable knowledge across similar but different settings is a fundamental component of generalized intelligence. In this paper, we approach the transfer learning challenge from a causal theory perspective. Our agent is endowed with two basic yet general theories for transfer learning: (i) a task shares a common abstract structure that is invariant across domains, and (ii) the behavior of specific features of the environment remain constant across domains. We adopt a Bayesian perspective of causal theory induction and use these theories to transfer knowledge between environments. Given these general theories, the goal is to train an agent by interactively exploring the problem space to (i) discover, form, and transfer useful abstract and structural knowledge, and (ii) induce useful knowledge from the instance-level attributes observed in the environment. A hierarchy of Bayesian structures is used to model abstract-level structural causal knowledge, and an instance-level associative learning scheme learns which specific objects can be used to induce state changes through interaction. This model-learning scheme is then integrated with a model-based planner to achieve a task in the OpenLock environment, a virtual ``escape room'' with a complex hierarchy that requires agents to reason about an abstract, generalized causal structure. We compare performances against a set of predominate model-free reinforcement learning(RL) algorithms. RL agents showed poor ability transferring learned knowledge across different trials. Whereas the proposed model revealed similar performance trends as human learners, and more importantly, demonstrated transfer behavior across trials and learning situations.Comment: Accepted to AAAI 2020 as an ora

    Evaluation of the reporting quality of clinical practice guidelines on gliomas using the RIGHT checklist

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    Background: The reporting quality of clinical practice guidelines (CPGs) for gliomas has not yet been thoroughly assessed. The International Reporting Items for Practice Guidelines in Healthcare (RIGHT) statement developed in 2016 provides a reporting framework to improve the quality of CPGs. We aimed to estimate the reporting quality of glioma guidelines using the RIGHT checklist and investigate how the reporting quality differs by selected characteristics. Methods: We systematically searched electronic databases, guideline databases, and medical society websites to retrieve CPGs on glioma published between 2018 and 2020. We calculated the compliance of the CPGs to individual items, domains and the RIGHT checklist overall. We performed stratified analyses by publication year, country of development, reporting of funding, and impact factor (IF) of the journal. Results: Our search revealed 20 eligible guidelines. Mean overall adherence to the RIGHT statement was 54.6%. Eight CPGs reported more than 60% of the items, and five reported less than 50%. All guidelines adhered to the items 1a, 3, 7a, 13a, while no guidelines reported the items 17 or 18b (see http://www.rightstatement.org/right-statement/checklist for a description of the items). Two of the seven domains, "Basic information" and "Background", had mean reporting rates above 60%. The "Review and quality assurance" domain had the lowest mean reporting rate, 12.5%. The reporting quality of guidelines published in 2020, guidelines developed in the United States, and guidelines that reported funding tended to be above average. Conclusions: The reporting quality of CPGs on gliomas is low and needs improvement. Particular attention should be paid on reporting the external review and quality assurance process. The use of the RIGHT criteria should be encouraged to guide the development, reporting and evaluation of CPGs
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