5 research outputs found

    S-PDR: A Novel Pedestrian Dead Reckoning Algorithm with step-based attitude corrections for Free-Moving Handheld devices

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    Mobile location-based services (MLBS) are attracting attention for their potential public applications and personal use. MLBS can be used for a variety of applications such as location-based advertisement, smart shopping, smart cities, health applications, emergency response, and even gamming. The majority of these applications are used in indoor environments where the well established GNSS navigation solutions are hindered or even unavailable and hence they rely on alternative navigation solutions such Inertial Navigation Systems (INS). To date, the main challenges for MLBS is to provide accurate and reliable navigation solution under varying circumstances such as indoor or outdoor, while reducing system cost and having real-time applicability, which is achieved through the use of MEMS technology. However, MEMS sensors suffer from high errors and noise to signal ratio that results in quick divergence of the INS solution, hence the need for aiding. This thesis aims at providing a Pedestrian Dead Reckoning (PDR) solution that uses off-the-shelf sensors in mobile devices to provide short term reliable navigation solution that helps reduce the complexity and frequency of relying on aiding techniques through developing a novel PDR system S-PDR . S-PDR utilizes a novel step detection technique that is motion-mode and use-case invariant, an attitude correction technique that can provide corrections as frequently as a step-by-step basis, and an enhanced PCA-based heading estimation. Testing results in comparison to XSense MTi G-710 which is a high-end MEMS sensor show that S-PDR provide reliable short-term navigation solution with final positioning error that is up to 6 meters after 3 minutes operation time, outperforming the on-board fusion solution provided by the XSense. The short term enhancement of the PDR solution reliability can help reduce the operational complexity of aiding navigation systems such as RF-based indoor navigation and Magnetic Map Matching as it reduces the frequency by which these aiding techniques are required and applied

    A Smartphone Step Counter Using IMU and Magnetometer for Navigation and Health Monitoring Applications

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    The growing market of smart devices make them appealing for various applications. Motion tracking can be achieved using such devices, and is important for various applications such as navigation, search and rescue, health monitoring, and quality of life-style assessment. Step detection is a crucial task that affects the accuracy and quality of such applications. In this paper, a new step detection technique is proposed, which can be used for step counting and activity monitoring for health applications as well as part of a Pedestrian Dead Reckoning (PDR) system. Inertial and Magnetic sensors measurements are analyzed and fused for detecting steps under varying step modes and device pose combinations using a free-moving handheld device (smartphone). Unlike most of the state of the art research in the field, the proposed technique does not require a classifier, and adaptively tunes the filters and thresholds used without the need for presets while accomplishing the task in a real-time operation manner. Testing shows that the proposed technique successfully detects steps under varying motion speeds and device use cases with an average performance of 99.6%, and outperforms some of the state of the art techniques that rely on classifiers and commercial wristband products

    Accumulation of oxysterols in the erythrocytes of COVID-19 patients as a biomarker for case severity

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    Abstract Background Due to the high risk of COVID-19 patients developing thrombosis in the circulating blood, atherosclerosis, and myocardial infarction, it is necessary to study the lipidome of erythrocytes. Specifically, we examined the pathogenic oxysterols and acylcarnitines in the erythrocyte homogenate of COVID-19 patients. These molecules can damage cells and contribute to the development of these diseases. Methods This study included 30 patients and 30 healthy volunteers. The erythrocyte homogenate extract was analyzed using linear ion trap mass spectrometry combined with high-performance liquid chromatography. The concentrations of oxysterols and acylcarnitines in erythrocyte homogenates of healthy individuals and COVID-19 patients were measured. Elevated levels of toxic biomarkers in red blood cells could initiate oxidative stress, leading to a process known as Eryptosis. Results In COVID-19 patients, the levels of five oxysterols and six acylcarnitines in erythrocyte homogenates were significantly higher than those in healthy individuals, with a p-value of less than 0.05. The mean total concentration of oxysterols in the red blood cells of COVID-19 patients was 23.36 ± 13.47 μg/mL, while in healthy volunteers, the mean total concentration was 4.92 ± 1.61 μg/mL. The 7-ketocholesterol and 4-cholestenone levels were five and ten times higher, respectively, in COVID-19 patients than in healthy individuals. The concentration of acylcarnitines in the red blood cell homogenate of COVID-19 patients was 2 to 4 times higher than that of healthy volunteers on average. This finding suggests that these toxic biomarkers may cause the red blood cell death seen in COVID-19 patients. Conclusions The abnormally high levels of oxysterols and acylcarnitines found in the erythrocytes of COVID-19 patients were associated with the severity of the cases, complications, and the substantial risk of thrombosis. The concentration of oxysterols in the erythrocyte homogenate could serve as a diagnostic biomarker for COVID-19 case severity. Graphical abstrac

    Etodolac Fortified Sodium Deoxycholate Stabilized Zein Nanoplatforms for Augmented Repositioning Profile in Human Hepatocellular Carcinoma: Assessment of Bioaccessibility, Anti-Proliferation, Pro-Apoptosis and Oxidant Potentials in HepG2 Cells

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    This work aimed to enhance the purposing profile of Etodolac (ETD) in Human Hepatocellular Carcinoma (HCC) HepG2 cells using sodium deoxycholate stabilized zein nanospheres (ETD-SDZN NSs). ETD-SDZN NSs were formulated using the nan-precipitation method and were characterized, in particular, in terms of mean particle size, zeta potential, encapsulation efficiency, colloidal stability and bioaccessibility. Estimations of cytotoxicity, cellular uptake, cell cycle progression, Annexin-V staining, mRNA expression of apoptotic genes and oxidative stress evaluations were conducted. The ETD-SDZN NSs selected formula obtained an average particle size of 113.6 ± 7.4 nm, a zeta potential value of 32.7 ± 2.3 mV, an encapsulation efficiency of 93.3 ± 5.2%, enhanced bioaccessibility and significantly reduced IC50 against HepG2 cells, by approximately 13 times. There was also enhanced cellular uptake, accumulation in G2-M phase and elevated percentage cells in pre-G1 phase, significant elevated mRNA expression of P53, significant reduced expression of Cyclin-dependent kinase 1 (CDK1) and Cyclooxygenase-2 (COX-2) with enhanced oxidative stress by reducing glutathione reductase (GR) level, ameliorated reactive oxygen species (ROS) generation and lipid peroxidation outputs. ETD-SDZN NSs obtained a supreme cell death-inducing profile toward HepG2 cells compared to free ETD. The method of formulation was successful in acquiring the promising profile of ETD in HCC as a therapeutic molecule due to ameliorated cellular uptake, proapoptotic and oxidant potentials
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