Hybrid copula mixed models for combining case-control and cohort studies in meta-analysis of diagnostic tests

Copula mixed models for trivariate (or bivariate) meta-analysis of diagnostic test accuracy studies accounting (or not) for disease prevalence have been proposed in the biostatistics literature to synthesize information. However, many systematic reviews often include case-control and cohort studies, so one can either focus on the bivariate meta-analysis of the case-control studies or the trivariate meta-analysis of the cohort studies, as only the latter contains information on disease prevalence. In order to remedy this situation of wasting data we propose a hybrid copula mixed model via a combination of the bivariate and trivariate copula mixed model for the data from the case-control studies and cohort studies, respectively. Hence, this hybrid model can account for study design and also due to its generality can deal with dependence in the joint tails. We apply the proposed hybrid copula mixed model to a review of the performance of contemporary diagnostic imaging modalities for detecting metastases in patients with melanoma

Effects of film thickness and mismatch strains on magnetoelectric coupling in vertical heteroepitaxial nanocomposite thin films

The phase field model is adopted to study the magnetoelectric coupling effects in vertical heteroepitaxial nanocomposite thin films. Both the lateral epitaxial strains between the film and the substrate and the vertical epitaxial strains between the ferroelectric and ferromagnetic phases are accounted for in the model devised. The effects of the film thickness on the magnetic-field- induced electric polarization (MIEP) are investigated. The results obtained show that the MIEP is strongly dependent on the film thickness, as well as on the vertical and lateral epitaxial strains. © 2011 American Institute of Physics.published_or_final_versio

Acoustic leakage in electromagnetic waveguides made from piezoelectric materials

We study the propagation of coupled acoustic and electromagnetic waves in a piezoelectric plate waveguide embedded in two half-spaces of another dielectric material. It is shown that certain waves are guided electromagnetically but not so acoustically and that these waves are effectively damped waves with acoustic leakage of energy. An estimate of the acoustic radiation damping is given. © 2007 American Institute of Physics.published_or_final_versio

LSD1 is essential for oocyte meiotic progression by regulating CDC25B expression in mice

Mammalian oocytes are arrested at prophase I until puberty when hormonal signals induce the resumption of meiosis I and progression to meiosis II. Meiotic progression is controlled by CDK1 activity and is accompanied by dynamic epigenetic changes. Although the signalling pathways regulating CDK1 activity are well defined, the functional significance of epigenetic changes remains largely unknown. Here we show that LSD1, a lysine demethylase, regulates histone H3 lysine 4 di-methylation (H3K4me2) in mouse oocytes and is essential for meiotic progression. Conditional deletion of Lsd1 in growing oocytes results in precocious resumption of meiosis and spindle and chromosomal abnormalities. Consequently, most Lsd1-null oocytes fail to complete meiosis I and undergo apoptosis. Mechanistically, upregulation of CDC25B, a phosphatase that activates CDK1, is responsible for precocious meiotic resumption and also contributes to subsequent spindle and chromosomal defects. Our findings uncover a functional link between LSD1 and the major signalling pathway governing meiotic progression

Graphene films printable on flexible substrates for sensor applications

Fifteen-layered graphene films have been successfully deposited onto flexible substrates using a commercial ink consisting of graphene particles dispersed in an acrylic polymer binder. A value of 74.9 × 105cm−2 was obtained for the density of defects, primarily located at the flake edges, from the ratio of the D and G Raman peaks located at 1345cm1 and 1575cm1 respectively. 0.5μm thick drop-cast films on interdigitated silver electrodes exhibited Ohmic conduction with a small activation energy of 12meV over the temperature range from 260K to 330K . The photo-thermoelectric effect is believed to be responsible for photoconduction through graphene films under illumination intensity of 10mWm-2 at 270 nm, corresponding to the UV absorption peak. The photo-transient decay at the bias of 1V involves two relaxation processes when the illumination is switched off and values of 8.9 × 103 and 4.3 × 104 are found for the relaxation time constant using the Kohlrauch stretched exponential function analysis.Dr. Indrani Banerjee is grateful to Commonwealth Association, UK for funding the present research work under the fellowship placement scheme (Grant reference INCF-2014-66). The studentship of Ms Faris is partially sponsored by the Air Force Office of Scientific Research, Air Force Material Command, USAF, under Grant No. FA9550-15-1-0123. We are also thankful to Miss V. M. Torrejon of Brunel University for support in computer graphics

Absolute magnitudes for late-type dwarf stars for Sloan photometry

We present a new formula for absolute magnitude determination for late-type dwarf stars as a function of (g-r) and (r-i) for Sloan photometry. The absolute magnitudes estimated by this approach are brighter than those estimated by colour-magnitude diagrams, and they reduce the luminosity function rather close to the luminosity function of Hipparcos.Comment: 11 pages, 9 figures and 5 tables, accepted for publication in A

Electron quantum interference in epitaxial antiferromagnetic NiO thin films

The electron reflectivity from NiO thin films grown on Ag(001) has been systematically studied as a function of film thickness and electron energy. A strong electron quantum interference effect was observed from the NiO film, which is used to derive the unoccupied band dispersion above the Fermi surface along the Γ-X direction using the phase accumulation model. The experimental bands agree well with first-principles calculations. A weaker electron quantum interference effect was also observed from the CoO film

Entrectinib-related myocarditis in a young female patient with metastatic non-small cell lung cancer

A 51-year-old woman presented with a 2-week history of off balance, left lower limb weakness and neglect and neck pain radiating down the right arm. Investigations revealed a metastatic, ROS1 fusion-positive, non-small cell lung cancer, and treatment with entrectinib, a recently approved multikinase inhibitor, was started. Two weeks after, she was admitted to the emergency department with new-onset pressure-like chest pain and dyspnoea. Laboratory evaluation showed elevated troponin and mild left ventricular systolic dysfunction with reduced global longitudinal strain on transthoracic echocardiogram. Cardiac magnetic resonance revealed mild oedema and non-ischaemic fibrosis. A diagnosis of drug-induced myocarditis was made. Cardioprotective medication with an angiotensin-converting enzyme inhibitor and a beta-blocker was started. Entrectinib was temporarily discontinued and restarted at a reduced dose after a multidisciplinary team meeting involving both the oncology and cardio-oncology teams. This is the second described case of entrectinib-induced myocarditis and the first one without eosinophilia

Fabrication and enhanced electrochemical performances of Mo03/graphene composite as anode material for lithium-ion batteries

Molybdenum trioxide (Mo0#)/graphene composite were prepared by integrating Mo03 and graphene in dimethylformamide (DMF). The morphology and structure of the materials were characterized by X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy. The electrochemical properties of Mo03/graphene composite with different ratios were studied as anode materials for lithium-ion batteries using galavanostatic charge-discharge and cyclic voltammetry. We observed that the Mo03/graphene anode with a weight ratio of 1:1 (Mo03 graphene) exhibits a high lithium storage capacity of 967 mA h g-1 at the current density of 500 mA g-1, satisfactory cycling stability and good rate capability

Effects of surface tension on the size-dependent ferroelectric characteristics of free-standing BaTiO3 nano-thin films

Intrinsic surface tension of nanoscale ferroelectric thin film tends to induce tensile stress in its surface layer, whereas the other portion of the film is subjected to compression to maintain mechanical balance. A continuum-based phase-field model accounting for such surface effect has been set up to investigate the evolution of domain structure and thickness-dependent ferroelectric properties of free-standing BaTiO 3 nano-thin films. It was observed that both remnant polarization and coercive field decrease with a decrease of film thickness and increase of surface tension, and that, for film thickness ranging from 10-20 nm, both properties decreased sharply at the surface strain 2-3ε 0 (ε 0 being the spontaneous strain). Further decrease in film thickness or increase in surface tension could result in loss of ferroelectricity. Such a critical state for the ferroelectric-to-paraelectric transition has also been established for the range of film thickness 4-20 nm. © 2011 American Institute of Physics.published_or_final_versio