101 research outputs found

    Effect of population-based training programs on bystander willingness to perform cardiopulmonary resuscitation

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    Objective. This study was performed to determine the factors related to unwillingness of bystanders to perform cardiopulmonary resuscitation (CPR), and improvement of willingness among the lay public after CPR training. Design. Retrospective design Methods. We collected questionnaires received from laypersons attending CPR training courses implemented by the CPR Improvement Program of Chang Gung Memorial Foundation. Pre- and post-training questionnaires were given to participants attending CPR training courses between September 2013 and January 2014. Results. Among the 401 respondents at pre-training, higher educational level (odds ratio, 3.605; 95% confidence interval [CI], 3.055 – 8.284) and previous CPR training (odds ratio, 1.754; 95% CI, 1.049 – 2.932) were significantly associated with willingness to perform bystander CPR. Significant improvements in willingness to perform conventional CPR and hands-only CPR on a stranger were observed after training (P = 0.016 and P < 0.0001, respectively). Approximately half of the respondents claimed that fear of doing further harm was the primary reason for their lack of willingness to administer conventional CPR on a stranger. Conclusions. We showed that CPR training significantly increased the rate of willingness to perform CPR on strangers as well as acquaintances among the lay public. This study also showed that fear of doing further harm was the most significant barrier after training. This concern should be addressed in future training programs

    Quantum Oscillation Signatures of Fermi Arcs in Tunnel Magnetoconductance

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    Fermi-arc surface states of Weyl semimetals exhibit a unique combination of localization to a surface and connectivity to the bulk Weyl fermions that can move along the localization direction. We predict anomalous quantum-oscillation signatures of Fermi arcs in the tunnel mangetoconductance across an interface between two Weyl semimetals. These oscillations stem from a momentum-space analog of Aharonov-Bohm interference of electrons moving along the interface Fermi arcs, driven by an external magnetic field normal to the interface. The Fermi arcs' connectivity to the bulk enables their characterization via transport normal to the interface, while their localization manifests in a strong field-angle anisotropy of the oscillations. This combination distinguishes these anomalous oscillations from conventional Shubnikov-de Haas oscillations and makes them identifiable even in complex oscillation spectra of real materials.Comment: 4 + 6 page

    Magnetic Breakdown and Chiral Magnetic Effect at Weyl-Semimetal Tunnel Junctions

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    We investigate magnetotransport across an interface between two Weyl semimetals whose Weyl nodes project onto different interface momenta. Such an interface generically hosts Fermi arcs that connect Weyl nodes of identical chirality in different Weyl semimetals (homochiral connectivity) -- in contrast to surface Fermi arcs that connect opposite-chirality Weyl nodes within the same Weyl semimetal (heterochiral connectivity). We show that electron transport along the arcs with homochiral connectivity, in the presence of a longitudinal magnetic field, leads to a universal longitudinal magnetoconductance of e2/he^2/h per magnetic flux quantum. Furthermore, a weak tunnel coupling can result in a close encounter of two homochiral-connectivity Fermi arcs, enabling magnetic breakdown. Above the breakdown field the interface Fermi arc connectivity is effectively heterochiral, leading to a saturation of the conductance

    Evaluating a peer-to-peer storage system in presence of malicious peers

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    International audienceWe present a peer-to-peer based storage system and evaluate its resistance in the presence of malicious peers. To do so, we resort to simulation of the actual code borrowed from the production system. Our analysis allows to identify the main threats, prioritise them and propose directions for mitigating the attacks

    Synthesis and characterisation of Li11RE18M4O39−δ: RE = Nd or Sm; M = Al, Co or Fe

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    Four new phases of general formula, Li11RE18M4O39−δ: REM = NdAl, NdCo, SmCo, SmFe, have been synthesised and characterised. The NdAl phase, and probably the others, is isostructural with the NdFe analogue, but some cation disorder and partial site occupancies prevent full structural refinement of powder neutron diffraction data. The NdCo phase also forms a solid solution with variable Li content (and charge compensation by either oxygen vacancies or variable transition metal oxidation state). The NdAl phase is a modest conductor of Li+ ions whereas the other three phases are electronic conductors, attributed to mixed valence of the transition metal ions. Subsolidus phase diagrams for the systems Li2O–Nd2O3– Al2O3, ‘CoO’ have been determined and an additional new phase, LiCoNd4O8, which appears to have a K2NiF4-related superstructure, identified

    A study on the influence of lithium plating on battery degradation

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    Within Li-ion batteries, lithium plating is considered as one of the main reasons behind the capacity fade that occurs during low temperature and fast charging conditions. Previous studies indicate that plating is influenced by the levels of loss of lithium inventory (LLI) and the loss of active material (LAM) present in a battery. However, it is not clear from the literature on how lithium plating influences battery degradation in terms of LAM and LLI. Quantifying the undesirable impacts of lithium plating can help in understanding its impact on battery degradation and feedback effects of previous lithium plating on the formation of present plating. This study aims to quantify the degradation modes of lithium plating: LLI, LAM at the electrode level. A commercial Li-ion cell was first, aged using two different cases: with and without lithium plating. Second, a degradation diagnostic method is developed to quantify the degradation modes based on their measurable effects on open-circuit voltage (OCV) and cell capacity. The results highlight that LAMNE and LLI levels under the fast charge profile are increased by 10% and 12%, respectively, compared to those under the less aggressive charge profile. Further, limitations of the degradation analysis methods are discussed

    Factors Affecting Psychological and Health-Related Quality-of-Life Status in Children and Adolescents with Congenital Heart Diseases

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    Congenital heart disease (CHD), a severe cardiac defect in children, has unclear influences on young patients. We aimed to find the impacts of differently structure heart defects and various treatments on psychology and health-related quality of life (HRQoL) in CHD children and adolescents. CHD patients aged between 6 and 18 years old visited our hospital from 1 May 2018 to 31 September 2018, and their principal caregivers were asked to participate. We used two validated questionnaires, Children Depression Inventory-TW (CDI-TW) and Child Health Questionnaire—Parent Form 50 (CHQ-PF 50), to evaluate CHD patients’ psychological and HRQoL conditions. Participants were grouped based on their cardiac defects and previous treatments. We analyzed the results via summary independent-samples t-test with post hoc Bonferroni correction and multivariant analysis. Two hundred and seventy-seven children and their principal caregivers were involved. There was no apparent depressive condition in any group. Single cardiac defect patients exhibited similar HRQoL to controls; simultaneously, those with cyanotic heart disease (CyHD), most multiple/complex CHDs children and adolescents, and those who received invasive treatments had poorer HRQoL. CyHD impacted the most on patients’ psychological and HRQoL status. Patients with sole cardiac defect could live near-normal lifes; on the other hand, CyHD had the worst effects on patients’ psychology and HRQoL

    Intracranial bleeding due to vitamin K deficiency: advantages of using a pediatric intensive care registry

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    Item does not contain fulltextAIM: To determine the incidence of late intracranial vitamin K deficiency bleeding (VKDB) in The Netherlands using the Dutch Pediatric Intensive Care Evaluation (PICE) registry. METHODS: The PICE registry was used to identify all infants who were admitted to a Dutch pediatric intensive care unit (PICU) with intracranial bleeding between 1 January 2004 and 31 December 2007. Cases of confirmed late intracranial VKDB were used to calculate the incidence for each year. To estimate the completeness of ascertainment of the PICE registry, data from 2005 were compared with general surveillance data from that year. RESULTS: In the 4-year study period, 16/64 (25%) of the infants admitted with intracranial bleeding had late intracranial VKDB, resulting in an overall incidence of 2.1/100,000 live births (95% confidence interval 1.2-3.5). The single-year incidence varied markedly between 0.5 and 3.3 per 100,000 live births. All five ascertained cases in 2005 were identified using the PICE registry, while general surveillance identified only three. CONCLUSIONS: The PICE registry allows ongoing monitoring of the incidence of late intracranial VKDB and appears to be associated with a higher rate of completeness than general surveillance. We propose the use of pediatric intensive care registries to assess the efficacy of national vitamin K prophylactic regimens
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