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

Design by analysis of ductile failure and buckling in torispherical pressure vessel heads

Thin shell torispherical pressure vessel heads are known to exhibit complex elastic-plastic deformation and buckling behaviour under static pressure. In pressure vessel Design by Analysis, the designer is required to assess both of these behaviour modes when specifying the allowable static load. The EN and ASME boiler and pressure vessel codes permit the use of inelastic analysis in design by analysis, known as the direct route in the EN Code. In this paper, plastic collapse or gross plastic deformation loads are evaluated for two sample torispherical heads by 2D and 3D FEA based on an elastic-perfectly plastic material model. Small and large deformation effects are considered in the 2D analyses and the effect of geometry and load perturbation are considered in the 3D analysis. The plastic load is determined by applying the ASME twice elastic slope criterion of plastic collapse and an alternative plastic criterion, the Plastic Work Curvature criterion. The formation of the gross plastic deformation mechanism in the models is considered in relation to the elastic-plastic buckling response of the vessels. It is concluded that in both cases, design is limited by formation of an axisymmetric gross plastic deformation in the knuckle of the vessels prior to formation of non-axisymmetric buckling modes

Gross plastic deformation of axisymmetric pressure vessel heads

The gross plastic deformation and associated plastic loads of four axisymmetric torispherical pressure vessels are determined by two criteria of plastic collapse: the ASME twice elastic slope (TES) criterion and the recently proposed plastic work curvature (PWC) criterion. Finite element analysis was performed assuming small and large deformation theory and elastic–perfectly plastic and bilinear kinematic hardening material models. Two plastic collapse modes are identified: bending-dominated plastic collapse of the knuckle region in small deformation models and membrane-dominated plastic collapse of the cylinder or domed end in large deformation models. In both circumstances, the PWC criterion indicates that a plastic hinge bending mechanism leads to gross plastic deformation and is used as a parameter to identify the respective plastic loads. The results of the analyses also show that the PWC criterion leads to higher design loads for strain hardening structures than the TES criterion, as it takes account of the effect of strain hardening on the evolution of the gross plastic deformation mechanism

Cysts of the jaws

The clinical behaviour of cysts of the jaws has been under close scrutiny over the last few years as it has been found that there is in some types a distinct risk of recurrence. This recurrence may occur even after as long as 20 years, so that long term follow-up is essential. The clinical and histological features may be important clues in determining the prognosis and the risk of recurrence of the various jaw cysts. The data of jaw cysts seen at the Dental Department, St. Luke's Hospital, Malta during the decade 1960 – 1969 is collected in order to establish a base line for future comparative studies. There were 49 patients with cysts of the jaws and histological examination was made in 31 cases. The preponderance of periodontal cysts (30.6%) agrees with most large surveys reported, as does the percentage incidence (16.3%) of dentigerous cysts.peer-reviewe

Relationship of hyperglycaemia, hypoglycaemia, and glucose variability to atherosclerotic disease in type 2 diabetes

Objective: Type 2 diabetes mellitus (T2DM) is known to be associated with increased cardiovascular risk. The aim of this study was therefore to investigate the independent effects of hyperglycaemia, hypoglycaemia, and glucose variability on microvascular and macrovascular disease in T2DM. Methods. Subjects with T2DM of 7.8mmol/L (β=15.83, p=0005) was the sole independent predictor of albuminuria in generalised linear regression. Conclusions. This study demonstrates that hypoglycaemia is associated with the occurrence of atherosclerotic disease while hyperglycaemia is associated with microvascular disease in a Caucasian population with T2DM of recent duration.peer-reviewe

Improving myocardial protection : the key variables which affect troponin release after CABG

Background: Myocardial cell ischaemic injury during cardiopulmonary bypass and aortic crossclamp remains a key limiting factor to patient outcomes in coronary artery bypass grafting. Troponin I has been shown to be an effective indicator of myocardial ischaemic injury and achieves peak levels early post-operatively. Methods: All consenting CABG patients from one centre, during a one year period, were recruited. All surgeries were performed using identical techniques besides the cardioplegia volume and number of doses. Troponin I levels were checked regularly post-operatively until a peak troponin I level was ascertained. All the patient demographics, crossclamp times, bypass times and cardioplegia dosing were analysed using multiple combinations of statistical tools. Results: 172 patients were included in the study and cardiopulmonary bypass (CPB) time was found to be significant as a single variable (p=0.033). The combination of CBP time and ischaemia time (p=0.002) and the combination of CPB time and multidose cardioplegia (p=0.009), were both found to significantly affect peak troponin I levels. Another analysis was performed on the volume of cardioplegia used. While this was not significant as an individual variable it did become significant when combined with ischaemia time at a threshold total cardioplegia volume of 750mls (p=0.026).Conclusions: The conclusion therefore is that using over 750mls of cardioplegia in multiple doses will safely protect against an ischaemia time of up to 62min. However there is no protection against the CPB time, which proved to have the most impact on myocardial cell damage in our practice.peer-reviewe

Desarrollo de una aplicación web para la configuración de instalaciones de energía solar fotovoltaica

[ES] La meta perseguida con la realización de este trabajo es crear una plataforma web para ayudar en el cálculo y montaje de instalaciones de energía solar en la Comunitat Valenciana. Esta plataforma permitirá encontrar la ubicación, el tipo, la cantidad y la superficie de paneles solares que tendría que instalar para alcanzar a la potencia deseada. Esta plataforma web es una herramienta que ha sido desarrollada para la empresa TECHNO SUN, en la que el autor del Trabajo Fin de Máster se encuentra realizando las prácticas actualmente. Esta plataforma está compuesta de un visor cartográfico y de ventanas y menús para definir parámetros de cálculo. Se necesita hacer una plataforma web con dos elementos: Un visor cartográfico y una base de datos de dispositivos eléctricos. Desde el punto de vista de la computación serán necesarias las siguientes funcionalidades: cálculos astronómicos (orientación del sol), cálculos meteorológicos (radiación solar) y cálculos electrotécnicos (equipos fotovoltaicos). Para la realización de este proyecto es necesario poner en práctica varias de las habilidades desarrolladas a lo largo del máster, especialmente en las asignaturas "Desarrollo web y Geoportales", "Aplicaciones geoespaciales en Dispositivos Móviles" y "Programación para Aplicaciones Geoespaciales". Por ejemplo, hay que crear una pagina web con un visor con los lenguajes HTML, JS y CSS, y al mismo tiempo, para completar el trabajo, será necesario desarrollar los cálculos de energía (astronómicos, meteorológicos y electrotécnicos) con un módulo Python. Ambos elementos se comunican mediante Django, el framework de desarrollo web de Python.[EN] The aim of this work is to create a web platform to help in the setup of solar energy installations in the Valencian Community. This platform will allow to find the location, type, quantity, and surface of solar panels that required to reach the desired power. This web platform is a tool developed for the company TECHNO SUN, where the author is currently doing a work placement. This platform consists of a map viewer and a series of windows and menues to define input parameters. It is necessary to make a web platform with two elements: A cartographic viewer and a database of electrical devices. From a computational point of view, the following will be needed: Astronomical calculations (sun orientation), meteorological calculations (solar radiation) and electrotechnical calculations (photovoltaic equipment). In order to achieve the goals of this project, it will be necessary to put into practice several of the skills developed throughout the master's degree and especially in the classes of Programming, Web Development and Mobile Application Development. For example, it is necessary to create a web page with a viewer with the languages HTML, JS and CSS. At the same time, in order to complete the work, it is also required to conduct energy calculations (astronomical, meteorological and electrotechnical) with a Python module. Both components are linked with Django, the standard Python web development framework.Camilleri, A. (2021). Desarrollo de una aplicación web para la configuración de instalaciones de energía solar fotovoltaica. Universitat Politècnica de València. http://hdl.handle.net/10251/174229TFG

Evaluation of flight parameters during approach and landing phases by applying principal component analysis

This paper adopts an unsupervised learning technique, Principal Component Analysis (PCA) to analyze flight data. While the flight parameters for a stable approach have been established for a while, the paper reevaluates these flight parameters using PCA for a set of airports across the United States of America. Some flight parameters were found to be more sensitive to some airports. The parameters have been cross-checked with experts in the industry to better interpret their significance.peer-reviewe

On the range equation for a hybrid-electric aircraft

This paper proposes a new range equation for hybrid-electric aircraft. The paper revisits the theory of the range equation for a hybrid-electric aircraft with constant power split published earlier in the literature and proposes a new efficiency-based definition of the degree of hybridization (φ), one which includes the efficiencies of the electric or fuel-powered drivetrain. The paper shows that the efficiencies of the respective drivetrains play a significant role in the range estimation of the hybrid-electric aircraft. The paper makes use of a case study to show the relationship between battery energy density, powertrain efficiency and modification in the definition of the degree of hybridization φ with aircraft range. We show that for every aircraft design, there is a battery energy density threshold, for which the aircraft range becomes independent of the degree of hybridization. Below this threshold, the range decreases with an increase in the degree of hybridization. Conversely, beyond this threshold, the aircraft range increases with the degree of hybridization. Our study finds that the new definition of φ has shifted this threshold significantly upwards compared to earlier publications in the literature. This makes the design of an aircraft with a high degree of hybridization less optimistic.peer-reviewe