18 research outputs found

    Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

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    The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

    Localization solution for underwater robots using low-cost single-beam SONAR and IMU

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    This project proposes an underwater robot localization system that utilizes low-cost SONAR and IMU sensors to estimate a robot's position in an underwater environment. The proposed system leverages the ability of SONAR to measure distance and detect obstacles in the robot's surrounding environment, while IMU provides information about the robot's orientation and acceleration. By fusing the data from both sensors, the proposed system aims to provide a more accurate and robust localization solution compared to using either sensor in isolation. The project includes the implementation of appropriate algorithms for sensor data processing, sensor fusion, and position estimation. The effectiveness of the proposed system will be evaluated through experimental testing in a controlled underwater environment. The expected outcome of this project is a low-cost underwater robot localization system that can be used for various underwater applications such as underwater exploration, environmental monitoring, and pipeline inspection.Bachelor of Engineering (Mechanical Engineering

    Low-cost underwater localisation using single-beam echosounders and inertial measurement units

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    Underwater robot localisation is challenging as it cannot rely on sensors such as the GPS due to electromagnetic wave attenuation or optical cameras due to water turbidity. SONARs are immune to these issues, hence they are used as alternatives for underwater navigation despite lower spatial and temporal resolution. Single-beam SONARs are sensors whose main output is distance. When combined with a filtering algorithm like the Kalman filter, these distance readings can correct localisation data obtained by inertial measurement units. Compared to multi-beam imaging SONARs, the single-beam SONARs are inexpensive to integrate into underwater robots. Therefore, this study aims to develop a low-cost localisation solution utilizing single-beam SONARs and pressure-based depth sensors to correct dead-reckoning linear localisation data using Kalman filters. From experiments, a single-beam SONAR per degree of freedom was able to correct localisation data, without the need of complicated data fusion methods.Nanyang Technological UniversitySubmitted/Accepted versionThis paper is done as part of the work conducted under the SAAB-NTU Joint Lab with support from SAAB Singapore Pte. Ltd, SAAB AB, NTU Robotics Research Centre (RRC) and NTU Sports and Recreational Centre (NTU-SRC)

    Expression of recombinant human Apolipoprotein A-IMilano in Nicotiana tabacum

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    Abstract Apolipoprotein A-IMilano (Apo A-IMilano) is a natural mutant of Apolipoprotein. It is currently the only protein that can clear arterial wall thrombus deposits and promptly alleviate acute myocardial ischemia. Apo A-IMilano is considered as the most promising therapeutic protein for treating atherosclerotic diseases without obvious toxic or side effects. However, the current biopharmaceutical platforms are not efficient for developing Apo A-IMilano. The objectives of this research were to express Apo A-IMilano using the genetic transformation ability of N. tabacum. The method is to clone the coding sequence of Apo A-IMilano into the plant binary expression vector pCHF3 with a Flag/His6/GFP tag. The constructed plasmid was transformed into N. tabacum by a modified agrobacterium-mediated method, and transformants were selected under antibiotic stress. PCR, RT-qPCR, western blot and co-localization analysis was used to further verify the resistant N. tabacum. The stable expression and transient expression of N. tabacum were established, and the pure product of Apo A-IMilano was obtained through protein A/G agarose. The results showed that Apo A-IMilano was expressed in N. tabacum with a yield of 0.05 mg/g leaf weight and the purity was 90.58% ± 1.65. The obtained Apo A-IMilano protein was subjected to amino acid sequencing. Compared with the theoretical sequence of Apo A-IMilano, the amino acid coverage was 86%, it is also found that Cysteine replaces Arginine at position 173, which indicates that Apo A-IMilano, a mutant of Apo A-I, is accurately expressed in N. tabacum. The purified Apo A-IMilano protein had a lipid binding activity. The established genetic modification N. tabacum will provide a cost-effective system for the production of Apo A-IMilano. Regarding the rapid propagation of N. tabacum, this system provides the possibility of large-scale production and accelerated clinical translation of Apo A-IMilano. Graphical Abstrac
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