29 research outputs found

    A TEMPERATURE-CONTROLLED ELECTROCHEMICAL MICROSCALE PLATFORM FOR BIOMOLEMULAR BINDING STUDIES

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    Electrochemical detection of nucleic acids has been a very important research area in the past several decades. In this research field, the stability of the nucleic acid structure is important and crucial for many aspects of nucleic acid metabolism. Also the binding of small molecule ligands to nucleic acids and resulting increase in stability of the nucleic acids can play a key role in many context including DNA-targeted therapy against various cancers, bacteria or viruses. Melting curve analysis using electrochemical detection, as a new method to characterize nucleic acids' stability and interactions between small molecules, provides high sensitivity and is also well suited for high-throughput formats. This thesis describes efforts to develop melting curve analysis using electrochemical detection method on a temperature-controlled microscale platform

    Unveiling the Mechanism of Plasma-Catalytic Low-Temperature Water–Gas Shift Reaction over Cu/γ-Al<sub>2</sub>O<sub>3</sub> Catalysts

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    The water-gas shift (WGS) reaction is a crucial process for hydrogen production. Unfortunately, achieving high reaction rates and yields for the WGS reaction at low temperatures remains a challenge due to kinetic limitations. Here, nonthermal plasma coupled to Cu/γ-Al2O3 catalysts was employed to enable the WGS reaction at considerably lower temperatures (up to 140 °C). For comparison, thermal-catalytic WGS reactions using the same catalysts were conducted at 140-300 °C. The best performance (72.1% CO conversion and 67.4% H2 yield) was achieved using an 8 wt % Cu/γ-Al2O3 catalyst in plasma catalysis at ∼140 °C, with 8.74 MJ mol-1 energy consumption and 8.5% H2 fuel production efficiency. Notably, conventional thermal catalysis proved to be ineffective at such low temperatures. Density functional theory calculations, coupled with in situ diffuse reflectance infrared Fourier transform spectroscopy, revealed that the plasma-generated OH radicals significantly enhanced the WGS reaction by influencing both the redox and carboxyl reaction pathways

    Preparation of Highly Crystalline TiO2 Nanostructures by Acid-assisted Hydrothermal Treatment of Hexagonal-structured Nanocrystalline Titania/Cetyltrimethyammonium Bromide Nanoskeleton

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    Highly crystalline TiO2 nanostructures were prepared through a facile inorganic acid-assisted hydrothermal treatment of hexagonal-structured assemblies of nanocrystalline titiania templated by cetyltrimethylammonium bromide (Hex-ncTiO2/CTAB Nanoskeleton) as starting materials. All samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The influence of hydrochloric acid concentration on the morphology, crystalline and the formation of the nanostructures were investigated. We found that the morphology and crystalline phase strongly depended on the hydrochloric acid concentrations. More importantly, crystalline phase was closely related to the morphology of TiO2 nanostructure. Nanoparticles were polycrystalline anatase phase, and aligned nanorods were single crystalline rutile phase. Possible formation mechanisms of TiO2 nanostructures with various crystalline phases and morphologies were proposed

    Parallel fuzzy resolution inference on fuzzy neural logic network

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    1993 IEEE International Conference on Fuzzy Systems82-8

    Rule-based reasoning using extended neural logic network

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    Proceedings of the International Joint Conference on Neural Networks21405-140885OF

    Integrated shell for developing connectionist expert systems

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    Proceedings of the International Joint Conference on Neural Networks32889-289285OF

    Resilient Factor Graph-Based GNSS/IMU/Vision/Odo Integrated Navigation Scheme Enhanced by Noise Approximate Gaussian Estimation in Challenging Environments

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    The signal blockage and multipath effects of the Global Navigation Satellite System (GNSS) caused by urban canyon scenarios have brought great technical challenges to the positioning and navigation of autonomous vehicles. In this paper, an improved factor graph optimization algorithm enhanced by a resilient noise model is proposed. The measurement noise is resilient and adjusted based on an approximate Gaussian distribution-based estimation. In estimating and adjusting the noise parameters of the measurement model, the error covariance matrix of the multi-sensor fusion positioning system is dynamically optimized to improve the system accuracy. Firstly, according to the approximate Gaussian statistical property of the GNSS/odometer velocity residual sequence, the measured data are divided into an approximate Gaussian fitting region and an approximate Gaussian convergence region. Secondly, the interval is divided according to the measured data, and the corresponding variational Bayesian network and Gaussian mixture model are used to estimate the innovation online. Further, the noise covariance matrix of the adaptive factor graph-based model is dynamically optimized using the estimated noise parameters. Finally, based on low-cost inertial navigation equipment, GNSS, odometer, and vision, the algorithm is implemented and verified using a simulation platform and real-vehicle road test. The experimental results show that in a complex urban road environment, compared with the traditional factor graph fusion localization algorithm, the maximum improvement in accuracy of the proposed algorithm can reach 65.63%, 39.52%, and 42.95% for heading, position, and velocity, respectively

    Ligand-Based Stability Changes in Duplex DNA Measured with a Microscale Electrochemical Platform

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    Development of technologies for rapid screening of DNA secondary structure thermal stability and the effects on stability for binding of small molecule drugs is important to the drug discovery process. In this report, we describe the capabilities of an electrochemical, microdevice-based approach for determining the melting temperatures (Tm) of electrode-bound duplex DNA structures. We also highlight new features of the technology that are compatible with array development and adaptation for high-throughput screening. As a foundational study to exhibit device performance and capabilities, melting-curve analyses were performed on 12-mer DNA duplexes in the presence/absence of two binding ligands: diminazene aceturate (DMZ) and proflavine. By measuring electrochemical current as a function of temperature, our measurement platform has the ability to determine the effect of binding ligands on Tm values with high signal-to-noise ratios and good reproducibility. We also demonstrate that heating our three-electrode cell with either an embedded microheater or a thermoelectric module produces similar results. The &#916;Tm values we report show the stabilizing ability of DMZ and proflavine when bound to duplex DNA structures. These initial proof-of-concept studies highlight the operating characteristics of the microdevice platform and the potential for future application toward other immobilized samples
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