Gastrointestinal cancer screening and surveillance programmes : a worldwide perspective : part 1

Part 2 of this article can be found through this link: https://www.um.edu.mt/library/oar//handle/123456789/13101Cancer is a leading cause of death worldwide and such deaths are projected to continue to rise, creating significant morbidity and mortality. Devising programmes to detect early cancer, aiming to achieve complete cure, has been high on the agenda of various professional bodies. This paper focuses on the various screening and surveillance programmes around the world, aiming at detecting early gastrointestinal malignancies. Starting with Barretts’ oesophagus, we shall see the different surveillance programmes across countries to detect premalignant stages of oesophageal cancer, while at the same time reviewing the only country in the world, China, which has an oesophageal cancer mass screening programme. Moving to gastric cancer, we shall review Japan’s screening programme, followed by other countries’ measures in surveilling premalignant gastric conditions. Colorectal cancer is the only gastrointestinal cancer where mass screening has been employed in various countries. This will be discussed in detail, with particular emphasis on the British and American systems. We shall also be discussing the surveillance programmes for moderate and high risk patients of colorectal cancer. Finally, we shall also review the different recommendations with regards to screening for hepatocellular carcinoma.peer-reviewe

Gastrointestinal cancer screening and surveillance programmes : a worldwide perspective : part 2

Part 1 of this article can be found through this link: https://www.um.edu.mt/library/oar//handle/123456789/12879Part 2 of this article. Cancer is a leading cause of death worldwide and such deaths are projected to continue to rise, creating significant morbidity and mortality. Devising programmes to detect early cancer, aiming to achieve complete cure, has been high on the agenda of various professional bodies. This paper focuses on the various screening and surveillance programmes around the world, aiming at detecting early gastrointestinal malignancies. Starting with Barretts’ oesophagus, we shall see the different surveillance programmes across countries to detect premalignant stages of oesophageal cancer, while at the same time reviewing the only country in the world, China, which has an oesophageal cancer mass screening programme. Moving to gastric cancer, we shall review Japan’s screening programme, followed by other countries’ measures in surveilling premalignant gastric conditions. Colorectal cancer is the only gastrointestinal cancer where mass screening has been employed in various countries. This will be discussed in detail, with particular emphasis on the British and American systems. We shall also be discussing the surveillance programmes for moderate and high risk patients of colorectal cancer. Finally, we shall also review the different recommendations with regards to screening for hepatocellular carcinoma.peer-reviewe

A high-speed permanent-magnet machine for fault-tolerant drivetrains

This paper details the design considerations of a permanent magnet (PM), three phase, high speed, synchronous machine for fault tolerant operation. A multidisciplinary approach to the optimal design of the machine is adopted targeted at minimising the additional losses resulting from faulty operating conditions and accounting for the remedial control strategy implemented. The design of a closed slot, 6 slots, 4 pole machine is presented. The machine is prototyped and tested to validate the analytical-computational performances predicted in the design and analysis stage under healthy and faulty condition

Accidental severe bronchial aspiration of barium uncovers diagnosis of bronchiectasis

A 77-year-old man, with a history of chronic obstructive pulmonary disease (COPD) and radiotherapy-treated laryngeal malignancy diagnosed 15 years prior, presented with a 1-year history of intermittent dysphagia. As a part of his investigations, a barium swallow was obtained; but during the initial phases of the procedure, the patient aspirated the contrast agent of barium sulphate. A chest radiograph (Fig. 1a), taken few minutes after the aspiration, showed barium within the different segments and subsegments of the bronchial tree bilaterally, and uncovered features, such as irregular dilatation of the bronchial tree, non-tapering of the bronchi, luminal filling defects and lack of bronchial side branches, characteristic of bronchiectasis. This incident precipitated an exacerbation of COPD with type II respiratory failure, requiring bronchodilators, intravenous antibiotics and non-invasive ventilation using a bilevel positive airway pressure machine. On recovery, direct laryngoscopy revealed post-radiotherapy changes but no evidence of tumour recurrence.peer-reviewe

A clinical practice audit of management and outcomes of patients presenting with chest pain to the Medical Admissions Unit

Acute central chest pain accounts for a significant proportion of emergency medical admissions. If chest pain evaluation is systematic & risk-based, it may prevent unnecessary admissions. This audit aims to observe various aspects of management of patients admitted with chest pain; areas needing review are identified and improvements on current practice are considered. The study observed the current practices in 292 admissions for chest pain to the Medical Admissions Unit over a 3 month period. The relative frequency of risk factors and utilisation of resources were observed. Ninety-one patients (31.2%) that were admitted with chest pain had a diagnostic ECG or raised cardiac enzymes. Twenty-one patients (7.2%) had an urgent exercise stress test (EST) whilst 27 patients (9.2%) had an urgent coronary angiogram. In all, 16 patients (5.5 %) were readmitted with a cardiac event and 8 patients (2.7%) died within 3 months. The presence of age >65, diabetes or hypertension were associated with a high rate of adverse events (13.9%, 16.4%, and 11.6% respectively).peer-reviewe

A SyR and IPM machine design methodology assisted by optimization algorithms

The design optimization of synchronous reluctance (SyR) machine and its extension to internal permanent magnet (IPM) motors for wide speed ranges is considered in this paper by means of a Finite Element Analysis-based multi-objective genetic algorithm (MOGA). The paper is focused on the rotor design, that is controversial key aspect of the design of high saliency SyR and IPM machines, due to the difficult modeling dominated by magnetic saturation. A three step procedure is presented, to obtain a starting SyR design with the optimal torque versus torque ripple compromise and then properly include PMs into the SyR geometry, given the desired constant power speed range of the final IPM machine. The designed rotors have been extensively analyzed by computer simulations and two SyR prototypes have been realized to demonstrate the feasibility of the design procedur

Design considerations for the tooth shoe shape for high-speed permanent magnet generators

This paper presents a study of the effects that the shoe shape of the teeth of electrical machines has on the performance and losses. This is done by considering a concentrated wound, high-speed permanent magnet generator. The paper investigates the influence of the tooth shoe shape on the machine magnetic circuit and the losses distribution based on analytical and finite-element analysis (FEA). A shape coefficient Kt is proposed to provide an optimized design reference. A comprehensive analytical tool able to study the variations of the machine performance parameters is proposed. The deduced optimization function is normalized using the non-equilibrium relative weighting method, and then, it is processed via a genetic algorithm to achieve the optimized design. FEA is used to validate the proposed analytical tool and the optimum design

Thermal investigation on HSPM with new alloy sleeve

This paper presents a developed copper-iron alloy which made as the rotor sleeve in a high speed permanent magnetic machine (HSPMG), whist investigating its benefits in improve machine thermal performance. The features of the new alloy is experimental tested against the performance, which includes the conductivity, the permeability, and thermal conductivity, and the variation of loss distribution inside machine with sleeve conductivity and permeability are studied. A fluid-thermal coupled analysis model is proposed, by using which the fluid velocity and temperature distribution are obtained via numerical analyzing. The variations of machine operating temperature with new material are evaluated

Improved damper cage design for salient-pole synchronous generators

The benefits of implementing a damper winding in salient-pole, synchronous generators are widely known and well consolidated. It is also well known that such a winding incurs extra losses in the machine due to a number of reasons. In order to improve the overall efficiency and performance of classical salient-pole, wound field, synchronous generators that employ the traditional damper cage, an improved amortisseur winding topology that reduces the inherent loss is proposed and investigated in this paper. This is essential in order to meet modern power quality requirements and to improve the overall performance of such ’classical’ machines. The new topology addresses the requirements for lower loss components without compromising the acceptable values of the output voltage total harmonic distortion and achieves this by having a modulated damper bar pitch. As vessel for studying the proposed concept, a 4MVA, salient-pole, synchronous generator is considered. A finite element model of this machine is first built and then validated against experimental results. The validated model is then used to investigate the proposed concept with an optimal solution being achieved via the implementation of a genetic algorithm optimization tool. Finally, the performance of the optimised machine is compared to the original design both at steady state and transient operating conditions

Radial force control for triple three-phase sectored SPM machines. Part II: Open winding fault tolerant control

A new advanced fault tolerant control technique for a triple three-phase Surface Permanent Magnet (SPM) machine is investigated in this paper. The machine has a nine-phase winding arranged in three sectors and supplied by three different Voltage Source Inverters (VSIs). The proposed current control technique is firstly exploited to avoid the radial force appearance in case of open winding of one machine sector. Then, the radial force fault tolerant control is improved to compensate for a bearing fault or another source of radial force in this open winding condition. Finite element simulations are used to validate the two proposed control techniques. Finally, advantages and drawbacks of the solution are highlighted