189 research outputs found

    The Need for an Inclusive Framework for Students\u27 Thinking in School Geometry

    Get PDF
    This study is the outcome of a research that investigated how students who were assigned varying levels of geometric thinking attempted problems requiring some amount of algebraic thinking in geometry. The study reports that students’ thinking in geometry also requires facility with algebra and as such there is a need for a framework that provides a more inclusive view of what constitutes geometric thinking in school mathematics

    Microbubble Therapies

    Get PDF

    Self-Assembly of Peptides to Nanostructures

    Get PDF
    The formation of well-ordered nanostructures through self-assembly of diverse organic and inorganic building blocks has drawn much attention owing to their potential applications in biology and chemistry. Among all organic building blocks, peptides are one of the most promising platforms due to their biocompatibility, chemical diversity, and resemblance with proteins. Inspired from the protein assembly in biological systems, various self-assembled peptide structures have been constructed using several amino acids and sequences. This review focuses on this emerging area, the recent advances in peptide self-assembly, and formation of different nanostructures, such as tubular, fibers, vesicles, spherical, and red coil structures. While different peptide nanostructures are discovered, potential applications will be explored in drug delivery, tissue engineering, wound healing, and surfactants

    The role of contrast enhanced ultrasonography in post-operative surveillance of endovascular aortic aneurysm stent graft repair

    Get PDF
    MD (Res)Abdominal aortic aneurysms are common and responsible for many deaths. They are treated increasingly by EndoVascular Aneurysm Repair (EVAR) rather than conventional surgery. Approximately 25% of EVAR patients require re-intervention to prevent aneurysm enlargement which can rupture despite previous repair. All EVAR patients undergo life-long surveillance for complications such as stent-graft migration or endoleak. Computed Tomography (CT) has been the ‘gold-standard’ for surveillance accounting for 65% of EVAR costs, and exposes patients to cumulative radiation and nephrotoxic contrast. Duplex Ultrasound Scanning (DUS) has been proposed as an alternative for surveillance with lesser cost and patient risk. However, clinical studies have reported varying results. The addition of microbubble contrast significantly improves endoleak detection rates, making it comparable with CT. The physical properties that affect endoleak detection with DUS have not been determined. It is also unknown specifically which endoleaks’ detection are improved by Contrast Enhanced Aortic Duplex UltraSound Scanning (CEADUSS). To investigate the physical properties of endoleaks, I constructed an EVAR phantom model with a simulated endoleak of variable velocity (fast/slow), position (near/far) and plane (anterior/lateral/posterior). Preliminary studies investigated the behavior of microbubble contrast in the phantom system, and then laboratory experiments tested subjects over 36 variable endoleaks using DUS and CEADUSS. These laboratory experiments were translated clinically with a pilot study of CEADUSS in 10 patients with endoleaks on CT not detected by DUS, undefined endoleak type or origin, or a sac enlargement with no endoleak present. My experiments reveal an insight into factors influencing ultrasound endoleak detection. With this knowledge, the use of these modalities for surveillance protocols can be increased, reducing current CT burden, radiation and nephrotoxic contrast exposure, and overall EVAR cost. Clinical assessment of an endoleak, specifically noting physical characteristics (plane, position and velocity) will improve detection and surveillance

    Making visible a teacher’s pedagogical reasoning: an aspect of pedagogical documentation

    Get PDF
    Much of a teacher’s practice and professional learning remains unseen despite recent calls to incorporate practice-based and inquiry-based approaches to improve mathematics instruction. Although the idea of pedagogical reasoning and action can provide a way to unpack these unseen aspects of practice, it remains to be seen how a teacher’s actions and thinking can be made visible. In this paper, we present a case of how a teacher’s pedagogical reasoning is made visible through pedagogical documentation, which suggests the possibility of using documentation to unpack these unseen aspects of a teacher’s practices.This study was funded by Singapore Ministry of Education (MOE) under the MOE Academy Fund Programme (AFD 06/17 CBH) and administered by National Institute of Education (NIE), Nanyang Technological University, Singapore

    Acute Pancreatitis Secondary to a Perivaterian Duodenal Diverticular Abscess

    Get PDF
    A 46-year-old previously fit lady was admitted with acute pancreatitis. She had no history of gallstones. She was not on any medications and consumed minimal amounts of alcohol. On subsequent investigations as to the causative factor, she was found at ultrasound to have an air-fluid filled cystic structure posterior to the head of pancreas which was compressing the common bile duct. Further magnetic resonance imaging and computer tomography scans showed that this cystic lesion was located around the ampulla of Vater. A diagnosis of a perivaterian abscess was made. At endoscopy, a large contained abscess was seen which was successfully drained. She made a full and uneventful recovery
    corecore