28,040 research outputs found

    Nephrectomy for a case of intrarenal dermoid cyst: was it an appropriate decision?

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    Dermoid cyst in a kidney is rarely seen. We report a case of intrarenal dermoid cyst which mimics malignant renal tumour and discuss the dilemma in managing this disease

    An integrated wind risk warning model for urban rail transport in Shanghai, China

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    The integrated wind risk warning model for rail transport presented has four elements: Background wind data, a wind field model, a vulnerability model, and a risk model. Background wind data uses observations in this study. Using the wind field model with effective surface roughness lengths, the background wind data are interpolated to a 30-m resolution grid. In the vulnerability model, the aerodynamic characteristics of railway vehicles are analyzed with CFD (Computational Fluid Dynamics) modelling. In the risk model, the maximum value of three aerodynamic forces is used as the criteria to evaluate rail safety and to quantify the risk level under extremely windy weather. The full model is tested for the Shanghai Metro Line 16 using wind conditions during Typhoon Chan-hom. The proposed approach enables quick quantification of real- time safety risk levels during typhoon landfall, providing sophisticated warning information for rail vehicle operation safety

    In vitro assessment of the toxicity of lead (Pb2+) to phycocyanin

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    © 2017 Elsevier Ltd This work reports the influence of lead (Pb2+) on fluorescence characteristics and protein structure of phycocyanin molecules experimentally in vitro. The fluorescence intensity decreases with the increasing concentration of Pb2+ from 0 to 5 × 10−5 mol L−1, showing the fluorescence quenching of phycocyanin by Pb2+. The quenching process is suggested to be static regarding the calculation results and the experimental results of time-resolved fluorescence decay profiles. The synchronous fluorescence spectra show that the effect of Pb2+ on the Tyr residues of phycocyanin is more significant than the Trp residues. The forming of aggregation by the interaction of Pb2+ with phycocyanin molecules is suggested from the results of resonance light scattering spectra. The UV–Vis spectra of the protein skeleton of phycocyanin have a red-shift of about 10 nm with increasing the Pb2+ concentration from 0 to 5 × 10−5 mol L−1, indicating a change in the protein skeleton and its secondary structure. With the increasing Pb2+ concentration, the two negative peaks (209 nm and 218 nm) on circular dichroism spectra become smaller, showing a decrease of the α-helix structure. These results may give people a deeper understanding of that how the heavy metal (Pb2+) can affect the chemo-physical properties of phycocyanin

    Predictable Disruption Tolerant Networks and Delivery Guarantees

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    This article studies disruption tolerant networks (DTNs) where each node knows the probabilistic distribution of contacts with other nodes. It proposes a framework that allows one to formalize the behaviour of such a network. It generalizes extreme cases that have been studied before where (a) either nodes only know their contact frequency with each other or (b) they have a perfect knowledge of who meets who and when. This paper then gives an example of how this framework can be used; it shows how one can find a packet forwarding algorithm optimized to meet the 'delay/bandwidth consumption' trade-off: packets are duplicated so as to (statistically) guarantee a given delay or delivery probability, but not too much so as to reduce the bandwidth, energy, and memory consumption.Comment: 9 page

    A primitive machine learning tool for the mechanical property prediction of multiple principal element alloys

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    Multi-principal element alloys (MPEAs) are produced by combining metallic elements in what is a diverse range of proportions. MPEAs reported to date have revealed promising performance due to their exceptional mechanical properties. Training a machine learning (ML) model on known performance data is a reasonable method to rationalise the complexity of composition dependent mechanical properties of MPEAs. This study utilises data from a specifically curated dataset, that contains information regarding six mechanical properties of MPEAs. A parser tool was introduced to convert chemical composition of alloys into the input format of the ML models, and a number of ML models were applied. Finally, Gradio was used to visualise the ML model predictions and to create a user-interactive interface. The ML model presented is an initial primitive model (as it does not factor in aspects such as MPEA production and processing route), however serves as a an initial user tool, whilst also providing a workflow for other researchers

    Comparison of methods to determine point-to-point resistance in nearly rectangular networks with application to a ‘hammock’ network

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    Considerable progress has recently been made in the development of techniques to exactly determine two-point resistances in networks of various topologies. In particular, two types of method have emerged. One is based on potentials and the evaluation of eigenvalues and eigenvectors of the Laplacian matrix associated with the network or its minors. The second method is based on a recurrence relation associated with the distribution of currents in the network. Here, these methods are compared and used to determine the resistance distances between any two nodes of a network with topology of a hammock

    The Fermi level effect in III-V intermixing: The final nail in the coffin?

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    Copyright 1997 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. This article appeared in Journal of Applied Physics 81, 2179 (1997) and may be found at
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