99 research outputs found
Application of Autologous Bone Marrow Derived Mesenchymal Stem Cells to an Ovine Model of Growth Plate Cartilage Injury
Injury to growth plate cartilage in children can lead to bone bridge formation and result in bone growth deformities, a significant clinical problem currently lacking biological treatment. Mesenchymal stem/stromal cells (MSC) offer a promising therapeutic option for regeneration of damaged cartilage, due to their self renewing and multi-lineage differentiation attributes. Although some small animal model studies highlight the therapeutic potential of MSC for growth plate repair, translational research in large animal models, which more closely resemble the human condition, are lacking. Our laboratory has recently characterised MSCs derived from ovine bone marrow, and demonstrated these cells form cartilage-like tissue when transplanted within the gelatin sponge, Gelfoam, in vivo. In the current study, autologous bone marrow MSC were seeded into Gelfoam scaffold containing TGF-β1, and transplanted into a surgically created defect of the proximal ovine tibial growth plate. Examination of implants at 5 week post-operatively revealed transplanted autologous MSC failed to form new cartilage structure at the defect site, but contributed to an increase in formation of a dense fibrous tissue. Importantly, the extent of osteogenesis was diminished, and bone bridge formation was not accelerated due to transplantation of MSCs or the gelatin scaffold. The current study represents the first work that has utilised this ovine large animal model to investigate whether autologous bone marrow derived MSC can be used to initiate regeneration at the injured growth plate
A review of elliptical and disc galaxy structure, and modern scaling laws
A century ago, in 1911 and 1913, Plummer and then Reynolds introduced their
models to describe the radial distribution of stars in `nebulae'. This article
reviews the progress since then, providing both an historical perspective and a
contemporary review of the stellar structure of bulges, discs and elliptical
galaxies. The quantification of galaxy nuclei, such as central mass deficits
and excess nuclear light, plus the structure of dark matter halos and cD galaxy
envelopes, are discussed. Issues pertaining to spiral galaxies including dust,
bulge-to-disc ratios, bulgeless galaxies, bars and the identification of
pseudobulges are also reviewed. An array of modern scaling relations involving
sizes, luminosities, surface brightnesses and stellar concentrations are
presented, many of which are shown to be curved. These 'redshift zero'
relations not only quantify the behavior and nature of galaxies in the Universe
today, but are the modern benchmark for evolutionary studies of galaxies,
whether based on observations, N-body-simulations or semi-analytical modelling.
For example, it is shown that some of the recently discovered compact
elliptical galaxies at 1.5 < z < 2.5 may be the bulges of modern disc galaxies.Comment: Condensed version (due to Contract) of an invited review article to
appear in "Planets, Stars and Stellar
Systems"(www.springer.com/astronomy/book/978-90-481-8818-5). 500+ references
incl. many somewhat forgotten, pioneer papers. Original submission to
Springer: 07-June-201
Large expert-curated database for benchmarking document similarity detection in biomedical literature search
Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency–Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research
Schwerpunktspezialisierung in Notfallradiologie: Vorschlag für ein europäisch abgestimmtes Curriculum
Introduction: Radiology plays a crucial role in the emergency care setting by delivering early and precise diagnoses under pressure of time, right at the beginning of patient treatment. Although there is a need for postgraduate education in emergency radiology, most of the national bodies responsible do not offer it in a uniform fashion and a general proof of qualification is missing in Europe. Therefore, the European Society of Radiology (ESR) has founded the (Sub-)Society of Emergency Radiology (ESER), prompting them to develop a European curriculum. This trend, which is currently also encouraged in many other non-radiological specialties which demand the highest professional qualifications, often lacks expertise in medical education.Goals: The goal of this article is the general description of the curricular planning process for a European postgraduate subspecialisation programme, using the example of Emergency Radiology (European Diploma in Emergency Radiology, EDER), including the utilisation of TOOLS and recommendations derived from comparable projects.Project description: The project was divided into partial steps: the timeline displayed in a GANTT chart, and tasks and responsibilities assigned in a RASCI matrix. The curriculum was iteratively developed using the KERN approach and steps were prioritised using the PARETO principle. Furthermore, the following TOOLS were used: limitations and needs assessment, SWOT analysis, formulating learning objectives and categorising them after MILLER and SCLO, and using BLOOM's taxonomy for cognitive learning objectives and operationalising them according to MAGER. Psychomotoric and affective learning objectives were assigned to CANMEDS roles, grouped by topic using CLUSTERING, and then mapped by MATRIX analysis to appropriate learning and evaluation methods. Striving for continuous improvement, the curriculum was finally embedded in curricular quality management.Results: The standardisation of the EDER access, considering the different national conditions, the minimisation of European learners' attendance phases, restricting expenses by best possible use of existing structures, respecting the requirements and retaining the support of the European umbrella society ESR, finishing the project by a specific deadline and the demands of continuous improvement were particular challenges. A curriculum with the eligibility of five years' speciality training in general radiology has evolved on schedule. The subspeciality training lasts at least one year and is divided into webinars, workshops during congresses (e.g. the annual ESR and ESER congresses) and one year practical training at the individual learner's corresponding local hospitals, which adhere to a catalogue of requirements, comparable to national educational policies. The curriculum is completed by passing a written and oral exam (diploma) and re-accreditation every five years.Conclusions: Despite complex requirements, the TOOLS utilised allowed an almost seamless, resource-minimised, professional, location-independent distributed development of a European subspeciality curriculum within one year. The definitive implementation is still due. If any deviations from the draft presented should become necessary in the future, the embedment in the curricular quality management will lead to a redirection in the right way and, furthermore, secure a continuous improvement in the best way possible.Einleitung: In der Notfallversorgung nimmt die Radiologie durch frühe und präzise Diagnosen unter hohem Zeitdruck bereits zu Beginn der Patientenbehandlung eine zentrale Rolle ein. Obwohl ein eigener Weiterbildungsbedarf in Notfallradiologie gegeben ist, bieten die zuständigen nationalen Gremien dies meist gar nicht oder aber uneinheitlich an und es fehlt in Europa grundsätzlich ein Qualifikationsnachweis. Daher hat die Europäische Gesellschaft für Radiologie (ESR) die Subgesellschaft der Europäischen Notfallradiologie (ESER) gegründet und diese zur Entwicklung eines europäischen Curriculums aufgefordert. Dies ist eine Entwicklung, die derzeit zwar in vielen weiteren, auch nicht-radiologischen, Spezialisierungsbereichen vergleichbar motiviert wird, hierfür in aller Regel trotz höchster Fachqualifikation allenfalls wenig medizindidaktische Expertise zur Verfügung steht. Zielsetzung: Ziel der Arbeit ist die grundsätzliche Beschreibung der Curriculumsplanung für eine postgraduierte europäische Schwerpunktspezialisierung am Beispiel der Notfallradiologie (European Diploma in Emergency Radiology, EDER) einschließlich der Angabe verwendeter TOOLS und der Ableitung von Empfehlungen für vergleichbare Projekte.Projektbeschreibung: Das Projekt wurde in Teilschritte zerlegt, der Zeitablauf in einem GANTT-Chart festgehalten und Aufgaben sowie Zuständigkeiten mittels RASCI-Matrix abgebildet. Das Curriculum wurde unter PARETO-Priorisierung in den Schritten nach KERN iterativ unter Verwendung folgender Tools entwickelt: Limitations-, Bedarfs- und SWOT-Analysen, Formulierung der Lernziele und Kategorisierung nach MILLER und SCLO, Taxonomierung kognitiver Lernziele nach BLOOM und Operationalisierung nach MAGER, Zuordnung von CANMEDS-Rollen zu psychomotorischen/affektiven Lernzielen. Diese wurden mittels CLUSTERING zu thematischen Gruppen zusammengefasst und anhand von MATRIX-Analysen die geeignetsten Veranstaltungsformen, lernpsychologischen Methoden und Evaluationsarten zugeordnet. Mit dem Bestreben einer kontinuierlichen Verbesserung erfolgte abschließend die Verankerung in einem curricularen Qualitätsmanagement.Ergebnisse: Besondere Herausforderungen waren die Vereinheitlichung des EDER-Zugangs bei sehr unterschiedlichen nationalen Voraussetzungen, die Minimierung von Präsenzphasen aufgrund des europäischen Teilnehmerkreises, eine Aufwandsminimierung durch bestmögliche Nutzung existierender Strukturen, die Berücksichtigung der Vorgaben des Europäischen Dachverbands ESR und Erhalt von deren Support, ein vorgegebenes Projektende zu gegebenem Stichtag sowie die Anforderung kontinuierlicher Verbesserung. Termingerecht entstand ein Curriculum, welches eine fünfjährige Weiterbildung in allgemeiner Radiologie als Zugang voraussetzt. Die mindestens einjährige Spezialisierung gliedert sich in Webinare, Präsenzworkshops während Kongressen (wie z.B. der ESR- und ESER-Jahreskongresse) sowie eine einjährige Weiterbildung an der jeweils lokalen klinischen Heimateinrichtung der Lernenden, welche sich nationalen Weiterbildungsordnungen vergleichbar zur Erfüllung eines speziellen Anforderungskatalogs verpflichtet. Den Abschluss des Curriculums bildet eine schriftliche und strukturierte mündliche Prüfung (Diplom) mit einer Re-Akkreditierung alle fünf Jahre.Schlussfolgerung: Die verwendeten Tools erlaubten trotz komplexer Vorgaben innerhalb eines Jahres eine nahezu reibungslose, ressourcenminimierte, professionelle und ortsunabhängig verteilte Entwicklung eines europäischen Schwerpunkt-Weiterbildungs-Curriculums. Die konkrete Umsetzung steht noch aus. Sollten hierbei Abweichungen von dem präsentierten Startvorschlag notwendig werden, so verspricht die gegebene Verankerung in ein curriculares Qualitätsmanagement dies zumindest zeitversetzt auffangen zu können und auch darüber hinaus eine kontinuierliche Verbesserung bestmöglich zu sichern
Logistik- und Simulationszentrum fuer KMU Leistungsangebote des Innovationskollegs 'Bildung eines vernetzten Logistik-und Simulationszentrums'. Weitere Forschungsprojekte. Sonderbroschuere 1997
Available from TIB Hannover: F98B2076 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
Circulating Blood Volume in Appropriate and Small for Gestational Age Full Term and Preterm Polycythaemic Infants
Cerebral and intestinal perfusion and metabolism in normocythemic hyperviscous hypoxic newborn pigs
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