Computational Simulation: Selected Applications In Medicine, Dentistry, And Surgery

This article presents the use of computational modelling software (e.g. ANSYS) for the purposes of simulating, evaluating and developing medical and surgical practice. We provide a summary of computational simulation mo delling that has recently been employed through effective collaborations between the medical, mathematical and engineering research communities. Here, particular attention is being paid to the modelling of medical devices as well as providing an overview o f modelling bone, artificial organs and microvascular blood flows in the machine space of a High Performance Computer (HPC)

The renewable energy potential of the Maltese Islands

The potential of renewable energies is presented for the territory of the Republic of Malta. These are in the main sun, wind and biogas. Taking the base year 2003 for comparing the percentage contribution of electricity generated from renewables to that generated from fossil-fuelled power stations, it was found that rooftop solar photovoltaic systems could produce 9.1%, onshore wind farms could offset 5.4% and the offshore wind potential lies in the region of 3.4%. Energy from waste could contribute another 5.6%, while widespread solar water heating in domestic buildings could offset 4.8%. Economic analysis of applying renewable energy power systems under the present constraints is carried out. A range of barriers to the use of renewable energy devices is described. The currently available incentives are listed and a number of measures that could be implemented to allow widespread applications of renewable energies are suggestedpeer-reviewe

Computational Non-Newtonian Hemodynamics of Small Vessels

The significance of non-Newtonian hemodynamics of small blood vessels is addressed via the description and critical discussion of cogent models within Computational Fluid Dynamics (CFD) software, in this case ANSYS-CFX. Several applicable hemodynamical shear-thinning models are presented and the relevance with respect to prediction of Shear Strain Rate (SSR) rigorously examined, in order to critically evaluate salient literature. It is found that the small vessels explored, in line with the aforementioned literature, that non-Newtionian evaluation of the fluid behavior is indeed negligible. The work presented herein is a precursor to investigation of more complex geometries and hemodynamic simulations, which are being actively researched. This is a technical note which attempts to address the significance of Newtonian/non-Newtonian flows in small blood vessels

Early expansion of CD38+ICOS+ GC Tfh in draining lymph nodes during influenza vaccination immune response

T follicular helper (Tfh) cells provide critical help to B cells during the germinal center (GC) reaction to facilitate generation of protective humoral immunity. Accessing the human lymph node (LN) to study the commitment of CD4 T cells to GC Tfh cell differentiation during in vivo vaccine responses is difficult. We used ultrasound guided fine needle biopsy to monitor recall responses in axillary LNs to seasonal influenza vaccination in healthy volunteers. Specific expansion of GC cell subsets occurred exclusively within draining LNs five days postvaccination. Draining LN GC Tfh and precursor-Tfh cells express higher levels of CD38, ICOS, and Ki67, indicating they were significantly more activated, motile, and proliferating, compared to contralateral LN cells. These observations provide insight into the early expansion phase of the human Tfh lineage within LNs during a vaccine induced memory response and highlights early LN immune responses may not be reflected in the periphery

Murder in Jerba : honour, shame and hospitality among Maltese in Ottoman Tunisia

Little is known about the sizeable Maltese communities developing along the southern and eastern shores of the Mediterranean in the mid-nineteenth century and the extent to which the migrants reproduced Maltese cultural traditions and practices overseas. This article considers this question through a microhistorical analysis of events culminating in the murder of a Maltese woman in the Ottoman Regency of Tunis in 1866. A close reading of transcripts from the interrogation of witnesses and the accused, all members of a Maltese community in Jerba reveals their shared cultural practices and beliefs surrounding the provision of hospitality, honour and shame. Viewed from this perspective, the curious responses of the witnesses to the murder of their compatriot become meaningful, and the crime is reframed as an honour killing.peer-reviewe

Training in infectious diseases across Europe in 2021 - a survey on training delivery, content and assessment

Objectives: To define the status of infectious diseases (ID) as an approved specialty in Europe; to enumerate the number of specialists (in general and in relation to the overall population) and specialist trainees and describe the content, delivery and evaluation of postgraduate training in ID in different countries.Methods: Structured web-based questionnaire surveys in March 2021 of responsible national authorities, specialist societies and individual country representatives to the Section of Infectious Diseases of the European Union for Medical Specialties. Descriptive analysis of quantitative and qualitative responses.Results: In responses received from 33/35 (94.3%) countries, ID is recognized as a specialty in 24 and as a subspecialty of general internal medicine (GIM) in eight, but it is not recognized in Spain. The number of ID specialists per country varies from <5 per million inhabitants to 78 per million inhabitants. Median length of training is 5 years (interquartile range 4.0–6.0 years) with variable amounts of preceding and/or concurrent GIM. Only 21.2% of countries (7/33) provide the minimum recommended training of 6 months in microbiology and 30% cover competencies such as palliative care, team working and leadership, audit, and quality control. Training is monitored by personal logbook or e-portfolio in 75.8% (25/33) and assessed by final examinations in 69.7% (23/33) of countries, but yearly reviews with trainees only occur in 54.5% (18/33) of countries.Conclusions: There are substantial gaps in modernization of ID training in many countries to match current European training requirements. Joint training with clinical microbiology (CM) and in multidisciplinary team working should be extended. Training/monitoring trainers should find greater focus, together with regular feedback to trainees within many national training programmes.peer-reviewe

Two-phase distribution in the vertical flow line of a domestic wet central heating system

The theoretical and experimental aspects of bubble distribution in bubbly two-phase flow are reviewed in the context of the micro bubbles present in a domestic gas fired wet central heating system. The latter systems are mostly operated through the circulation of heated standard tap water through a closed loop circuit which often results in water supersaturated with dissolved air. This leads to micro bubble nucleation at the primary heat exchanger wall, followed by detachment along the flow. Consequently, a bubbly two-phase flow characterises the flow line of such systems. The two-phase distribution across the vertical and horizontal pipes was measured through a consideration of the volumetric void fraction, quantified through photographic techniques. The bubble distribution in the vertical pipe in down flow conditions was measured to be quasi homogenous across the pipe section with a negligible reduction in the void fraction at close proximity to the pipe wall. Such a reduction was more evident at lower bulk fluid velocities

The association between pleural fluid exposure and survival in pleural mesothelioma

Background Most patients with malignant pleural mesothelioma (MPM) seek treatment with malignant pleural effusion (MPE). In vitro evidence suggests that MPE may not be a simple bystander of malignancy, but rather potentially has biological properties that improve cancer cell survival and promote cancer progression. If this is the case, MPE management may need to shift from current symptomatic strategies to aggressive fluid removal to impact survival. Research Question Is there an association between pleural fluid exposure and survival in MPM? Study Design and Methods Data from 761 patients who received a diagnosis of MPM between 2008 and 2018 were collected from patient medical records in three UK pleural units. Data included factors previously identified as influencing prognosis in MPM. Medical imaging was reviewed for presence, size, and duration of pleural effusion. Time-dependent covariate analysis of pleural fluid exposure and survival (model included weight loss, serum albumin, hemoglobin, MPM subtype, performance status, chemotherapy, and age) and multivariate Cox regression analysis of pleurodesis and survival were conducted. Results Median overall survival was 278 days (interquartile range, 127-505 days; 95% CI, 253-301 days). Pleural fluid exposure duration showed no association with survival (hazard ratio, 1.0; 95% CI, 1.0-1.0). Median survival was 473, 378, and 258 days with complete, partial, and no pleurodesis (P = .008). Interpretation Pleurodesis success seems to be associated with improved survival; however, it is unclear whether duration of MPM exposure to pleural fluid is associated with survival within the limitations of this retrospective study. Future prospective studies are required to assess this potentially important mechanism

Photodynamic therapy of subfoveal choroidal neovascularization: clinical and angiographic examples

BACKGROUND: Conventional photocoagulation of subfoveal choroidal neovascularization (CNV) is often accompanied by visual loss due to thermal damage to adjacent retinal structures. Photodynamic therapy (PDT) allows vascular occlusion by selective photochemical destruction of vascular endothelial cells only. In a pilot study we evaluated the use of PDT in CNV. METHODS: In a clinical phase I/II trial, patients with subfoveal CNV were treated with PDT. Benzoporphyrin derivative monoacid ring A (BPD) was used as sensitizer at a drug dose of 6 mg/m2 or 12 mg/m2. Irradiation was performed via a diode laser emitting at 690 nm coupled into a slit lamp. Safe and maximum tolerated light doses were defined by dose escalation from 25 to 150 J/cm2. Photodynamic effects were documented ophthalmoscopically and angiographically. RESULTS: Sixty-one patients received a single course of BPD-PDT. Preliminary results suggest no damage to retinal structures within the treated area clinically. Retinal perfusion was not altered, while CNV demonstrated immediate absence of fluorescein leakage in the majority of lesions subsequent to PDT. At optimized parameters (6 mg/m2 and 50 J/cm2) complete cessation of leakage from classic CNV occurred in 100% of cases at 1 week and in 50% at week 4. In 70-80% of classic CNV, leakage reappeared at week 12, but markedly less than before treatment. CONCLUSION: PDT allows temporary absence of leakage from CNV with preservation of visual acuity. The long-term prognosis of CNV secondary to age-related macular degeneration treated with repeated courses of PDT is being evaluated in a phase III trial