Drawing in anatomy education: exploring its roles in teaching and assessment

This thesis consists of an investigation of the current use of visual representations, and drawing in particular, when teaching and assessing within anatomy education in medical studies. Although we know a lot about teachers’ use of visual representations and increasingly drawing, especially in the context of science education, less is known about the use of those tools by educators in the anatomical domain. Drawing is not currently systematically being used within assessment in anatomy education in UK medical schools, and its potential in assessment has not been investigated in depth. Four studies were conducted to answer the research questions set for this thesis. The first study investigated the way in which the teaching staff understand the use of visual representations in teaching, learning and assessment in anatomy. To answer this, observations of seven anatomy demonstrators were conducted within Year 1 dissection sessions, and interviews were conducted with the same demonstrators. The second study employed a real-world experimental design to explore if students’ drawings reveal changes in their understanding after dissection. Drawings from 98 Year 1 medical students were analysed in a within-subject crossover design, where students in the first condition drew the exterior of the heart before dissection in Week 1 and drew the superior mediastinum after dissection in Week 2. The order was reversed for students in the second condition. All drawings were analysed for their content and form with an extensive coding scheme that was developed for this thesis, as the existing coding approaches towards drawings were judged as inappropriate. The third study investigated the use of drawing to reveal changes in understanding as the medical degree progresses. Drawings of the exterior of the heart from 46 Year 3 students were analysed and compared to drawings from the Year 1 students. Finally, the fourth study investigated the way in which anatomy demonstrators understand drawing in the assessment of anatomical knowledge; eight artefact-based interviews were conducted with anatomy demonstrators. The findings offer important insights into the way in which visual representations and drawing in particular are being used by anatomy demonstrators within anatomy education and their perspectives on the use of drawing in teaching, learning and assessment. A significant contribution is also made to the knowledge regarding the use of drawing to assess understanding in spatially intensive domains, such as the anatomical one. This thesis also contributes to our knowledge of dissection as a method of teaching anatomy and the need for drawing training within this domain. Finally, the scheme for drawing analysis that was developed, evaluated and employed in this thesis can be considered a methodological contribution to the approaches of analysing drawings in the current literature

L1(0) ordering and magnetic interactions in FePt nanoparticles embedded in MgO and SiO2 shell matrices

FePt nanoparticles have been encapsulated in insulating and protective MgO shells, using a two step chemical process, in order to prevent sintering during the heat-treatment process required for the L1(0) ordering. The FePt nanoparticles were initially prepared using a standard polyol process and then dispersed in a magnesium oxide solution. As a basis for comparison FePt/SiO2 nanocomposites have been also synthesized using a modified aqueous sol-gel route as the second step. The magnetic and microstructural properties of FePt/MgO and FePt/SiO2 nanocomposites are compared with those of FePt nanoparticles. The presence of oxide matrices leads to more homogeneous microstructures and better magnetic properties. While higher coercivity values have been obtained in FePt/SiO2, the MgO matrix is proven to provide better physical and magnetic isolations of the FePt nanoparticles. However, for FePt:MgO molar ratios exceeding 1:20 no L1(0) ordering has been achieved

Computational angular oscillatory motion for a .50 caliber bullet type firing from a helicopter machine gun

Abstract The present study investigates the epicyclic pitching and yawing motion phenomenon of spinning symmetric projectiles applying the 6-DOF free flight dynamic simulation modelling for small-yaw flat-fire trajectories. The computational results are compared with the corresponding classical second order linear differential solution. The ammunition will be used is the .50 API M8 bullet tfiring from M2 machine gun launched horizontally from different firing angles on high-speed subsonic aircraft (helicopter). This analysis includes mean constant coefficients of the most significant aerodynamic forces, moments and Magnus effects, which have been taken from official tabulated database

Mid-term outcomes in the treatment of retroperitoneal sarcomas: a 12-year single-institution experience

Aim To present the experience from collective data regarding patients with retroperitoneal sarcomas that have been operated in and followed up by the University General Hospital of Patras in Rion, Greece, between 2009 and 2020. Methods A retrospective analysis of adult patients treated at our hospital with a diagnosis of primary retroperitoneal sarcoma who underwent tumour resection. Results Data from 29 patients were analysed. The mean age at diagnosis was 56.1 years; 55.2% of patients were male (n=16). Liposarcomas (on histology) were identified in 19 (65.5%) patients, leiomyosarcoma six (20.7%), and other histologic subtypes in four (13.8%) patients. Tumours >5cm were presented in 27 (93.1%) patients. Negative margins were attained in 13 (44.8%) of all patients who underwent surgical resection. Five (17.2%) patients received neoadjuvant radiation, four (13.8%) postoperative radiation, and three (10.3%) patients received both chemotherapy and radiation prior to surgery with the rest of the patients being treated with surgical excision alone. A 3-year follow-up was successful in 21 (72.4%) patients; five (23.8%) patients died. In total, 16 (55.2%) patients were found to have a local recurrence, with no significant difference in patients' age, gender, tumour size, histology, negative surgical margin (Ro) resection, neoadjuvant chemotherapy, or radiation therapy. There was a significant difference in the 3-year survival rate between patients having positive or negative surgical margins (p=0.027). Conclusion The higher 3-year survival rate in patients with retroperitoneal sarcomas when achieving Ro resection warrant further investigation with a larger sample size across different institutions

The genomic landscape of ANCA-associated vasculitis: Distinct transcriptional signatures, molecular endotypes and comparison with systemic lupus erythematosus

IntroductionAnti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAVs) present with a complex phenotype and are associated with high mortality and multi-organ involvement. We sought to define the transcriptional landscape and molecular endotypes of AAVs and compare it to systemic lupus erythematosus (SLE).MethodsWe performed whole blood mRNA sequencing from 30 patients with AAV (granulomatosis with polyangiitis/GPA and microscopic polyangiitis/MPA) combined with functional enrichment and network analysis for aberrant pathways. Key genes and pathways were validated in an independent cohort of 18 AAV patients. Co-expression network and hierarchical clustering analysis, identified molecular endotypes. Multi-level transcriptional overlap analysis to SLE was based on our published data from 142 patients.ResultsWe report here that “Pan-vasculitis” signature contained 1,982 differentially expressed genes, enriched in leukocyte differentiation, cytokine signaling, type I and type II IFN signaling and aberrant B-T cell immunity. Active disease was characterized by signatures linked to cell cycle checkpoints and metabolism pathways, whereas ANCA-positive patients exhibited a humoral immunity transcriptional fingerprint. Differential expression analysis of GPA and MPA yielded an IFN-g pathway (in addition to a type I IFN) in the former and aberrant expression of genes related to autophagy and mRNA splicing in the latter. Unsupervised molecular taxonomy analysis revealed four endotypes with neutrophil degranulation, aberrant metabolism and B-cell responses as potential mechanistic drivers. Transcriptional perturbations and molecular heterogeneity were more pronounced in SLE. Molecular analysis and data-driven clustering of AAV uncovered distinct transcriptional pathways that could be exploited for targeted therapy.DiscussionWe conclude that transcriptomic analysis of AAV reveals distinct endotypes and molecular pathways that could be targeted for therapy. The AAV transcriptome is more homogenous and less fragmented compared to the SLE which may account for its superior rates of response to therapy

Investigating the influence of the jet from three nozzle and spear design configurations on Pelton runner performance by numerical simulation

This paper reports the initial results of three dimensional CFD simulations of the jet – runner interactions in a twin jet horizontal axis Pelton turbine. More specifically, the analysis examines the impact of the nozzle and spear valve configuration on the performance of the runner. Previous research has identified that injectors with notably steeper nozzle and spear angles attain a higher efficiency than the industry standard. However, experimental testing of the entire Pelton system suggests that there appears to be an upper limit beyond which steeper angled designs are no longer optimal. In order to investigate the apparent difference between the numerical prediction of efficiency for the injector system and the obtained experimental results, four different jet configurations are analysed and compared. In the first configuration, the interaction between the runner and an ideal axisymmetric jet profile is investigated. In the final three configurations the runner has been coupled with the jet profile from the aforementioned injectors, namely the Standard design with nozzle and spear angles of 80° & 55° and two Novel designs with angles 110° & 70° and 150° & 90° respectively. The results are compared by examining the impact the jet shape has on the runner torque profile during the bucket cycle and the influence this has on turbine efficiency. All results provided incorporate the Reynolds-averaged Navier Stokes (RANS) Shear Stress Transport (SST) turbulence model and a two-phase Volume of Fluid (VOF) model, using the ANSYS® FLUENT® code. Therefore, this paper offers new insights into the optimal jet – runner interaction

Experimental investigation and analysis of the spear valve design on the performance of Pelton turbines:3 case studies

The impact of the nozzle and spear valve configuration on the performance of a Pelton turbine is investigated both experimentally and computationally. A previously published computational fluid dynamics (CFD) study has shown that injectors with noticeably steeper nozzle and spear angles, 110° and 70° respectively, attain a higher efficiency than the industry standard 80° and 55°. As a result, three injector design cases were manufactured for experimental testing. Two of those cases were the standard (80/55) design, with nozzle and spear tip angles of 80° and 55° and the Novel 1 design (110/70) with nozzle and spear tip angles of 110° and 70° based on previously published CFD optimisation studies. These studies showed that increasing the nozzle and spear angles to the upper limit of the investigated test plan gave higher efficiencies. The response surfaces suggested that the optimum nozzle and spear angles could be even steeper. That is why, an additional case, a third design (Novel 2) with even steeper angles (150/90) was also manufactured and tested. The experimental tests were carried out in a single jet operation using the upper injector on the Gilkes Pelton runner with series Z120 buckets. The results show that two novel injector design cases produce higher efficiencies than the standard design, when tested with a Pelton runner. An important gain of about 1% in efficiency is achieved at the Best Efficiency Point of the turbine. Furthermore, the improvement is even more pronounced at lower flow rates, where the spear valve opening is smaller and the geometry of the injector has even larger effect. To discuss and analyse these experimental observations, a further 2D axisymmetric CFD analysis is performed. This analysis shows a similar trend to the experimental results. The CFD results show that the largest amount of energy is lost at the region upstream of the nozzle exit, where the static pressure is converted into the dynamic pressure. This conversion starts earlier in case 1, the Standard injector design, at about twice the distance compared to the Novel designs, cases 2 and 3. Consequently, the flow must travel in this region at an increased velocity and it is shown that this region is longer in the Standard injector. Hence, its friction losses are higher. However, the differences between the designs calculated in CFD are about a factor of 2 lower than the experimental results, indicating that the 3D secondary flow mechanisms arising from the geometry upstream of the nozzle and spear tip also affect the performance of the spear valve and the Pelton runner. The mismatch between the efficiency increase magnitude observed experimentally and modelled using the axisymmetric case suggests that the steeper angle injectors cope better with secondary velocities in the flow

Experimental investigation and analysis of three spear valve designs on the performance of Turgo impulse turbines

Several numerical investigations into the impact of the spear and nozzle configuration of impulse turbine injectors can be found in the literature, however there is little or no experimental data available for the effect on Turgo impulse turbine performance. A recent 2D numerical Design of Experiments (DoE) study found that much steeper nozzle and spear angles than the industry standard produced higher efficiencies. This work was extended to compare the performance of an industry standard injector (with nozzle and spear angles of 80° and 55°) and an improved injector with much steeper angles of 110° and 70° using a full 3D simulation of the injector, guide vanes and first branch pipe. The impact of the jets produced by these injectors on the performance of a Turgo runner was also simulated. The results for both CFD tools used suggest that steeper injector nozzle and spear angles reduce the injector losses, showing an increase in efficiency of 0.76% for the Turgo 3D injector. In order to investigate the numerical results from the previous studies further, three Turgo impulse turbine injectors were manufactured by Gilbert Gilkes & Gordon Ltd for testing on the 9” Gilkes HCTI Turgo rig at the Laboratory of Hydraulic Machines, National Technical University of Athens (NTUA). The injector designs tested were the standard (80/55) design, with nozzle and spear tip angles of 80° and 55° and the Novel 1 design (110/70) with nozzle and spear tip angles of 110° and 70° based on previously published CFD optimisation studies. The optimisations in the previous studies showed that the nozzle and spear angles in the upper limit of the investigated test plan, which was much higher than current industry guidelines, gave higher efficiencies. The DoE response surfaces in that study suggested that the optimum nozzle and spear angles may be even steeper and therefore an additional, third design (Novel 2) with even steeper angles (150/90) was also manufactured and tested. This paper presents the experimental data obtained for the three injector designs which were tested in a Turgo model turbine at various rotating speeds and flow rates. The 70 kW Turgo was coupled to a 75kW DC generator which allowed continuous speed regulation. The inlet conditions into the Turgo model turbine were controlled by a high head adjustable speed multistage pump of nominal operation point Q=290 m3/h, H=130 m (coupled via a hydraulic coupler to a 200 kW induction motor) which pumped water from the 320 m3 main reservoir of the Lab. The tests were carried out in single jet and twin jet operation. Testing and calibration of all the sensors was carried out according to testing standard IEC 60193 Hydraulic turbines, storage pumps and pump-turbines – Model acceptance tests (IEC 60193:1999). The results show that the Novel 2 injector performs best overall, which is consistent with the results obtained in previous 2D injector simulations. The achieved turbine efficiency with this injector is of the order of 0.5-1% higher than the Standard design, for both single and twin jet operation. The Novel 1 injector’s performance is between the Standard and Novel 2 injectors overall. Some images of the jets were also taken at various openings and are presented to qualitatively analyse the impact of each injector design on the disturbances on the outside of the jet. A further 2D axisymmetric CFD analysis is carried out to validate the measurements and to analyse the mechanisms which lead to injector losses. The results found that the majority of the losses occur in the region just upstream of the nozzle exit, where the static pressure is converted into dynamic pressure and the flow accelerates. In the Standard design, this conversion begins sooner and the flow travels over a longer distance at higher velocities leading to an increase in the losses. The CFD results found the differences between the designs to be smaller than the experiments however the trend of the results was similar, suggesting that the steeper angle injectors achieve higher efficiencies and better jet quality. The next stage of this research is to carry out a CFD analysis of the three injector designs in 3D, including the guide vanes and branch pipes, to investigate the impact of the steeper angles on the secondary velocities within the jet and the impact this has on the runner performance

The role of soluble urokinase plasminogen activator receptor (suPAR) in patients with cancer: a review of the current literature

Aim Several biomarkers are currently used as diagnostic and prognostic tools in patients with cancer. Soluble urokinase plasminogen activator receptor (suPAR) is elevated in acute and chronic inflammatory procedures and several observational studies during the last 20 years have investigated its role in oncology. The purpose of this article was to review the current literature regarding suPAR’s role in clinical practice. Methods A systematic literature search of PubMed, Scopus, OpenGrey and Cochrane Library databases through September 2021 was conducted using the following search terms: “supar”or “soluble urokinase plasminogen receptor” and “cancer” or “malignancy”. Original articles reporting on suPAR’s role in the diagnosis, prognosis and prediction of therapeutic outcomes in patients with confirmed or suspected cancer were included. Results Among 45 found articles, the most were observational cohort studies. The included studies were further categorized by cancer site. SuPAR level was higher in patients with cancer compared to healthy controls, but its diagnostic and prognostic accuracy differs depending on the site of cancer. Conclusion SuPAR has promising aspects in the field of oncology and public health and future research should further investigate its use in clinical practice. As it is elevated in different types of cancer, it could potentially serve as an adjunctive tool for the mass screening of patients with non-specific signs of cancer, but larger cohort studies that support these findings must be conducted

Pneumomediastinum in the COVID-19 era: to drain or not to drain?

Pneumomediastinum (PNM) is a rare clinical finding, usually with a benign course, which is managed conservatively in the majority of cases. However, during the COVID-19 pandemic, an increased incidence of PNM has been observed. Several reports of PNM cases in COVID-19 have been reported in the literature and were managed either conservatively or surgically. In this study, we present our institutional experience of COVID-19 associated PNM, propose a management algorithm, and review the current literature. In total, 43 Case Series were identified, including a total of 747 patients, of whom 374/747 (50.1%) were intubated at the time of diagnosis, 168/747 (22.5%) underwent surgical drain insertion at admission, 562/747 (75.2%) received conservative treatment (observation or mechanical ventilation. Inpatient mortality was 51.8% (387/747), while 45.1% of the population recovered and/or was discharged (337/747). In conclusion, with increased incidence of PNM in COVID-19 patients reported in the literature, it is still difficult to assign a true causal relationship between PNM and mortality. We can, however, see that PMN plays an important role in disease prognosis.  Due to increased complexity, high mortality, and associated complications, conservative management may not be sufficient, and a surgical approach is needed