451 research outputs found
Feasibility of an electrostatic energy harvesting device for CFCs aircraft
A novel energy harvesting concept is proposed for treating local electrostatic energy produced on flying composite
aircrafts. This work focuses on the feasibility research on collecting static charges with capacitive collectors. The
existing energy harvesting system and the electrification of the typical carbon fibre composites (CFCs) aircraft has
been reviewed. The detailed model experiments were then designed to characterize different configurations for
electrostatic energy harvesting on aeroplane. In the lab, the static charge was produced by a corona discharging
device, and a capacitor or a metal sheet was put in the electric field to collect the charges under four different
configurations. After that, the rest results for these configurations were analysed, which is followed by the
discussion about the results application on the aircraft. This work has proved that it is feasible to collect the local
static electricity on flying aircraft, and it could provide a new direction of energy harvesting system in aviation field
Procedures for performing Meta-Analyses of the accuracy of tools for binary classification
La evaluación de la precisión en la clasificación binaria debe contemplar dos indicadores no independientes: verdaderos positivos y falsos positivos. Se han propuesto varios índices. Estos han sido estimados en algunos tests para la detección temprana o cribaje. Resumimos y revisamos los principales métodos propuestos para realizar meta-análisis que evalúan la precisión de este tipo de instrumentos. Se aplican a los resultados de 14 estudios que informan de estimaciones de la precisión del test AUDIT. La agregación directa no permite el uso de los procedimientos meta-analíticos; la
estimación separada de la sensibilidad y la especificidad no reconoce que no son independientes; el método de la curva ROC-resumen trata la precisión y el umbral como factores fijos y tiene limitaciones para manejar el papel potencial de las covariables. Los modelos Normal Bivariado y Jerárquico de la curva ROC Resumen son estadísticamente rigurosos y son capaces de incorporar las covariables adecuadamente. Ambos métodos permitieron analizar la asociación entre el género de la muestra y el comportamiento del AUDITThe assessment of accuracy in binary classification tools must take into account two non-independent rates: true positives and false positives. A variety of indices have been proposed. They have been estimated for tests employed for early detection or screening purposes. We summarize and review the main methods proposed for performing a meta-analysis that assesses the accuracy of this type of tools. They are applied to the results from 14 studies that report estimates of the accuracy of the AUDIT. The method of direct
aggregation does not allow the use of meta-analytic procedures; the separate estimation of sensitivity and specificity does not acknowledge that they are not independent; the SROC method treats accuracy and threshold as fixed effects and has limitations to deal with the potential role of covariates. The Normal Bivariate (NB) model and the Hierarchical Summary ROC (HSROC) model are statistically rigorous and can deal with the covariates properly. They allowed analyzing the association between the gender composition of the sample and the way the test AUDIT behaves in the exampleEste trabajo ha sido financiado por el Ministerio de Ciencia y Tecnología, Proyecto PSI2009-1207
Regulation of South China Sea throughflow by pressure difference
Author Posting. © American Geophysical Union, 2016. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 121 (2016): 4077–4096, doi:10.1002/2015JC011177.Sea Surface Height (SSH) data from the European Centre for Medium-Range Weather Forecasts-Ocean Reanalysis System 4 (ECMWF-ORAS4) are used to determine the pressure difference in connection with variability of the South China Sea ThroughFlow (SCSTF) from 1958 to 2007. Two branches of SCSTF, the Karimata-Sunda Strait ThroughFlow (KSSTF) and the Mindoro Strait ThroughFlow (MSTF), are examined. Using the ensemble empirical mode decomposition method (EEMD), time series of pressure difference and volume transport are decomposed into intrinsic mode functions and trend functions, with the corresponding variability on different time scales. Pressure difference agrees with the KSSTF volume transport on decadal time scale; while for the MSTF, pressure difference varies similarly with volume transport on interannual time scale. Separating the dynamic height difference into the thermal and haline terms, for the KSSTF more than half of the dynamic height difference (32 cm) is due to the thermal contributions; while the remaining dynamic height difference (23 cm) is due to the haline contributions. For the MSTF, the dynamic height difference (29 cm) is primarily due to the thermal contribution (26 cm).This work was
supported by the Strategic Priority
Research Program of the Chinese
Academy of Sciences (grant
XDA11010304), the National Natural
Science Foundation of China (grant
number 41306015 and 41476013) and
the Independent Research Project
Program of State Key Laboratory of
Tropical Oceanography (grant
LTOZZ1603).2016-12-1
MiR-103a targeting Piezo1 is involved in acute myocardial infarction through regulating endothelium function
Background: Acute myocardial infarction (AMI) is commonly known as the heart attack. The molecular events involved in the development of AMI remain unclear. This study was to investigate the expression of miR-103a in patients with high blood pressure (HBP) and AMI patients with and without HBP, as well as its effect on endothelial cell functions.
Methods: MiR-103a expression in plasma and peripheral blood mononuclear cells (PBMCs) was measured by real-time polymerase chain reaction (PCR). The regulatory effect of miR-103a on Piezo1 gene was identified by a luciferase reporter system. The role of miR-103a in endothelial cells was evaluated by the capillary tube formation ability and cell viability of human umbilical vein endothelial cells (HUVECs).
Results: The plasma miR-103a concentration was significantly elevated in patients with HBP alone, AMI alone, and comorbidity of AMI and HBP. The miR-103a expression in PBMCs in patients with AMI and HBP was significantly higher than the one in healthy controls (p < 0.05), however miR-103a expression in PBMCs was not significantly different among patients with HBP alone, patients with AMI alone, and healthy controls. MiR-103a targeted Piezo1 and inhibited Piezo1 protein expression, which subsequently reduced capillary tube formation ability and cell viability of HUVECs.
Conclusions: MiR-103a might be a potential biomarker of myocardium infarction and could be used as an index for the diagnosis of AMI. It may be involved in the development of HBP and onset of AMI through regulating the Piezo1 expression.
Electrical instability of amorphous indium-gallium-zinc oxide thin film transistors under monochromatic light illumination
The electrical instability behaviors of a positive-gate-bias-stressed amorphous indium-gallium-zinc oxide (a-IGZO) thin film transistor(TFT) are studied under monochromatic light illumination. It is found that as the wavelength of incident light reduces from 750 nm to 450 nm, the threshold voltage of the illuminated TFT shows a continuous negative shift, which is caused by photo-excitation of trapped electrons at the channel/dielectric interface. Meanwhile, an increase of the sub-threshold swing (SS) is observed when the illumination wavelength is below 625 nm (∼2.0 eV). The SS degradation is accompanied by a simultaneous increase of the field effect mobility (μFE) of the TFT, which then decreases at even shorter wavelength beyond 540 nm (∼2.3 eV). The variation of SS and μFE is explained by a physical model based on generation of singly ionized oxygen vacancies (Vo⁺) and double ionized oxygen vacancies (Vo²⁺) within the a-IGZO active layer by high energy photons, which would form trap states near the mid-gap and the conduction band edge, respectively.This work was supported by the State Key Program for
Basic Research of China under Grant Nos. 2010CB327504,
2011CB922100, 2011CB301900; the National Natural Science
Foundation of China under Grant Nos. 60825401,
60936004, 11104130, BK2011556, and BK2011050
Double-edged sword of diabetes mellitus for abdominal aortic aneurysm
IntroductionDiabetes mellitus (DM) has been proved to contribute to multiple comorbidities that are risk factors for abdominal aortic aneurysm (AAA). Remarkably, evidences from epidemiologic studies have demonstrated a negative association between the two disease states. On the other hand, hyperglycemic state was linked to post-operative morbidities following AAA repair. This review aims to provide a thorough picture on the double-edged nature of DM and major hypoglycemic medications on prevalence, growth rate and rupture of AAA, as well as DM-associated prognosis post AAA repair.MethodsWe performed a comprehensive search in electronic databases to look for literatures demonstrating the association between DM and AAA. The primary focus of the literature search was on the impact of DM on the morbidity, enlargement and rupture rate, as well as post-operative complications of AAA. The role of antidiabetic medications was also explored.ResultsRetrospective epidemiological studies and large database researches associated the presence of DM with decreased prevalence, slower expansion and limited rupture rate of AAA. Major hypoglycemic drugs exert similar protective effect as DM against AAA by targeting pathological hallmarks involved in AAA formation and progression, which were demonstrated predominantly by animal studies. Nevertheless, presence of DM or postoperative hyperglycemia was linked to poorer short-term and long-term prognosis, primarily due to greater risk of infection, longer duration of hospital stays and death.ConclusionWhile DM is a positive factor in the formation and progression of AAA, it is also associated with higher risk of negative outcomes following AAA repair. Concomitant use of antidiabetic medications may contribute to the protective mechanism of DM in AAA, but further studies are still warranted to explore their role following AAA repair
Removal of Formaldehyde Using Highly Active Pt/TiO 2
Formaldehyde (HCHO) is one of the major indoor air pollutants. TiO2 supported Pt catalysts were prepared by sol-gel method and used to eliminate HCHO at room temperature without irradiation. The reduced Pt/TiO2 catalyst (denoted as Pt/TiO2-H2) showed much higher activity than that calcined in air (denoted as Pt/TiO2-air). More than 96% of the conversion of HCHO was obtained over 0.5 wt% Pt/TiO2-H2, on which highly dispersed metallic Pt nanoparticles with very small size (~2 nm) were identified. Metallic Pt rather than cationic Pt nanoparticles provide the active sites for HCHO oxidation. Negatively charged metallic Pt nanoparticles facilitate the transfer of charge and oxygen species and the activation of oxygen
Differential expression and correlation of immunoregulation related piRNA in rheumatoid arthritis
BackgroundAlthough PIWI-interacting RNAs (piRNAs) have recently been associated with germline development and many human diseases, their expression pattern and relationship in autoimmune diseases remain indistinct. This study aimed to investigate the presence and correlation of piRNAs in rheumatoid arthritis (RA).MethodsWe first analyzed the expression profile of piRNAs using small RNA sequencing in peripheral leukocytes of three new-onset untreated RA patients and three healthy controls (HCs). We then selected piRNAs related to immunoregulation by bioinformatics analysis and verified them in 42 new-onset RA patients and 81 HCs by RT-qPCR. Furthermore, a receiver operating characteristic curve was generated to quantify the diagnostic performance of these piRNAs. A correlation analysis was conducted to observe the link between piRNA expression and RA clinical characteristics.ResultsA total of 15 upregulated and 9 downregulated piRNAs among 1,565 known piRNAs were identified in peripheral leukocytes of RA patients. Dysregulated piRNAs were enriched in numerous pathways related to immunity. After selection and validation, two immunoregulation piRNAs (piR-hsa-27620 and piR-hsa-27124) were significantly elevated in RA patients and have good abilities to distinguish patients from controls, which have the potential to serve as biomarkers. PIWI and other proteins implicated in the piRNA pathway were also associated with RA
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