Comparing two asthma diagnoses using a prospective cohort of young children

Introduction Asthma is the most common chronic illness of childhood and places a large burden on the health care system. Asthma prevalence is commonly measured in national surveys by questionnaire. In Ontario, the Ontario Asthma Surveillance Information System (OASIS) developed a validated health claims diagnosis algorithm using health administrative data. Objectives and Approach The primary objective of this study was to measure the agreement between the health claims diagnosis algorithm (OASIS diagnosis algorithm) and questionnaire diagnosis (TARGet Kids! diagnosis) of asthma in children younger than 6 years of age. Secondary objectives were to identify concordant and discordant pairs, and to identify factors associated with disagreement. A comparison study including 3368 children participating in the TARGet Kids! practice based research network between 2008 and 2013 in Toronto, Canada. OASIS diagnosis algorithm and TARGet Kids! diagnosis asthma cases were compared using kappa statistic, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Results Prevalence of asthma was estimated to be 15% by the OASIS diagnosis algorithm and 7% by TARGet Kids! diagnosis. The Kappa statistic was 0.47 (95% CI: 0.42 – 0.51), sensitivity 82\%, specificity 90%, PPV 38% and NPV 98% for OASIS diagnosis algorithm using TARGet Kids! diagnosis as the criterion standard. There were 3011 concordant pairs (2820 true negatives and 191 true positives) and 357 discordant pairs (315 false positives and 42 false negatives). Statistically significant factors associated with false positives included: male sex, higher zBMI and history of allergy. No statistically significant factors associated with false negatives were identified. Conclusion/Implications OASIS diagnosis algorithm had high sensitivity, specificity, and NPV but low PPV relative to TARGet Kids! diagnosis of asthma. Although, the OASIS diagnosis may identify more asthma cases in young children, its diagnostic properties are similar in older children and it may be a useful tool for longitudinal asthma surveillance

Downregulation of hypoxia-inducible factor-1α by RNA interference alleviates the development of collagen-induced arthritis in rats

Rheumatoid arthritis (RA) is the most common type of autoimmune arthritis. Hypoxia-inducible factor-1α (HIF-1α) as a transcription factor in response to hypoxia suggests that it could be a potential therapeutic target for the treatment of RA. In this study, we assessed whether the HIF pathway blockade attenuates the manifestations of RA in the collagen-induced arthritis (CIA) rat model. We constructed a short hairpin RNA (shRNA) lentiviral expression vector targeting HIF-1α (pLVX-shRNA-HIF-1α) and to achieve HIF-1α RNA interference. Quantitative RT-PCR, immunofluorescence staining, and western blot were used to detect the expressions of HIF-1α, vascular endothelial growth factor (VEGF), phsopho (p)-p65, and p-IКBɑ mRNA and protein, respectively. Micro-computed tomography was used to investigate joint morphology at different time points after CIA induction. Moreover, enzyme-linked immunosorbent assay (ELISA) was used to monitor the expression of inflammatory cytokines. In vitro analyses revealed that pLVX-shRNA-HIF-1α effectively inhibited the expression of HIF-1α and VEGF and led to the activation of p-65 and p-IКBɑ, as well as decreased proinflammatory cytokine expression in cell culture. Inhibition of HIF-1α in rats decreased signs of a systemic inflammatory condition, together with decreased pathological changes of RA. Moreover, downregulation of HIF-1α expression markedly reduced the synovitis and angiogenesis. In conclusion, we have shown that pharmacological inhibition of HIF-1 may improve the clinical manifestations of RA

Superconductivity in a layered cobalt oxyhydrate Na0.31_{0.31}CoO2⋅_{2}\cdot1.3H2_{2}O

We report the electrical, magnetic and thermal measurements on a layered cobalt oxyhydrate Na$_{0.31}$CoO$_{2}\cdot$1.3H$_{2}$O. Bulk superconductivity at 4.3 K has been confirmed, however, the measured superconducting fraction is relatively low probably due to the sample's intrinsic two-dimensional characteristic. The compound exhibits weak-coupled and extreme type-II superconductivity with the average energy gap $\Delta_{a}(0)$ and the Ginzburg-Landau parameter $\kappa$ of $\sim$ 0.50 meV and $\sim$ 140, respectively. The normalized electronic specific heat data in the superconducting state well fit the $T^{3}$ dependence, suggesting point nodes for the superconducting gap structure.Comment: 4 pages, 3 figure

Electrical Properties of In Situ Synthesized Ag-Graphene/Ni Composites

Ag/Ni composite contact materials are widely used in low-voltage switches, appliances, instruments, and high-precision contacts due to their good electrical conductivity and processing properties. The addition of small amounts of additives can effectively improve the overall performance of Ag/Ni contact materials. Graphene has good applications in semiconductors, thermal materials, and metal matrix materials due to its good electrical and thermal conductivity and mechanical properties. In this paper, Ag-graphene composites with different added graphene contents were prepared by in situ synthesis of graphene oxide (GO) and AgNO3 by reduction at room temperature using ascorbic acid as a reducing agent. The Ag-graphene composites and nickel powder were ball-milled and mixed in a mass ratio of 85:15. The Ag-graphene/Ni was tested as an electrical contact material after the pressing, initial firing, repressing, and refiring processes. Its fusion welding force and arc energy were measured. The results show a 12% improvement in electrical conductivity with a graphene doping content of approximately 0.3 wt% compared to undoped contacts, resulting in 33.8 IACS%. The average contact fusion welding force was 49.49 cN, with an average reduction in the fusion welding force of approximately 8.04%. The average arc ignition energy was approximately 176.77 mJ, with an average decrease of 13.06%. The trace addition of graphene can improve the overall performance of Ag/Ni contacts and can promote the application of graphene in electrical contact materials

Effect of La and Mo co-doping on the properties of AgSnO2 contact material

For the shortage of the AgSnO _2 contact material, the models of SnO _2 , La–SnO _2 , Mo–SnO _2 , and La–Mo–SnO _2 were built to calculate their electrical and mechanical properties based on the first principles of density functional theory in this study. The La-Mo co-coped SnO _2 is the most stable of all the models according to the enthalpy change and the impurity formation energy. By analyzing the energy band structure and density of states, the doped models are still the direct bandgap semiconductor materials. The valence band moves up and the conduction band moves down after doped, reducing the band gap and enhancing the conductivity. With the reduced energy for carrier transition, the electrical performance of La-Mo co-doped SnO _2 is improved best. The mechanical properties of SnO _2 were completely improved by La-Mo co-doping with the calculation results. The doped SnO _2 materials were prepared by sol-gel method and the doped AgSnO _2 materials were prepared by powder metallurgy method. The x-ray diffraction experiment, hardness, conductivity and wettability experiment had been taken. And the experimental results show that the AgSnO _2 can be improved comprehensively by La-Mo co-doping, verifying the conclusions of the simulation. It provides an effective method for the preparation of high-performance contact materials

Study on Simulation and Experiment of Cu, C-Doped Ag/Ni Contact Materials

Ag/Ni contact material with greenery and good performance is a cadmium-free silver-based contact material that has been vigorously developed in recent years. However, Ag/Ni contact material has poor welding resistance. Based on the first principles of density functional theory, the interface model of Cu, C-doped Ag/Ni was established. The work of separation and interfacial energy of interface models showed that doping can improve the interfacial bonding strength and interfacial stability, with C-doped Ag/Ni having the strongest stability and interfacial bonding strength. It can be seen from the population and density of state that covalent bonds exist between Ag and Ni atoms of the Ag/Ni phase interface at the electronic structure level. Finally, the doped Ag/Ni contact material was prepared by the powder metallurgy method. Through the arc energy and welding force in the electrical contact experiment, it was obtained that the welding resistance of C-doped Ag/Ni was better than Cu-doped Ag/Ni contact material, which verified the correctness of the simulation results. Overall, the present study provides a theoretical method for the screening of doping elements to improve the performance of Ag/Ni contact material