Monitoring of surface deformation and microseismicity applied to radioactive waste disposal through hydraulic fracturing at Oak Ridge National Laboratory

Low-level liquid nuclear wastes are disposed of at Oak Ridge National Laboratory by the hydrofracture process. Wastes are mixed with cement and other additives to form a slurry that is injected into shale of low permeability at 300 m depth. The slurry spreads radially along bedding plane fractures before setting as a grout. Different methods for monitoring the location and behavior of the fractures have been investigated. Radioactive grout sheets can be located by gamma-ray logging of cased observation wells. Two other methods are based on the fact that the ground surface is deformed by the injection. The first entails surface leveling of a series of benchmarks; uplift up to 2.5 cm occurs. The second method involves use of tiltmeters that are sensitive and measure ground deformation in real time during an injection. Both methods show subsidence during the weeks following an injection. Interpretive models for the tiltmeter data are based on the elastic response of isotropic and anisotropic media to the inflation of a fluid-filled fracture. A fourth monitoring method is based on microseismicity. Geophone arrays were used to characterize the fracture process and to provide initial assessment of the feasibility of using seismic measurements to map the fractures as they form. An evaluation of each method is presented. 8 refs., 6 figs

Medical students’ preparedness for professional activities in early clerkships

Background Sufficient preparedness is important for transitions to workplace participation and learning in clinical settings. This study aims to analyse medical students’ preparedness for early clerkships using a three-dimensional, socio-cognitive, theory-based model of preparedness anchored in specific professional activities and their supervision level. Methods Medical students from a competency-based undergraduate curriculum were surveyed about preparedness for 21 professional activities and level of perceived supervision during their early clerkships via an online questionnaire. Preparedness was operationalized by the three dimensions of confidence to carry out clerkship activities, being prepared through university teaching and coping with failure by seeking support. Factors influencing preparedness and perceived stress as outcomes were analysed through step-wise regression. Results Professional activities carried out by the students (n = 147; 19.0%) and their supervision levels varied. While most students reported high confidence to perform the tasks, the activity-specific analysis revealed important gaps in preparation through university teaching. Students regularly searched for support in case of difficulty. One quarter of the variance of each preparedness dimension was explained by self-efficacy, supervision quality, amount of prior clerkship experience and nature of professional activities. Preparedness contributed to predicting perceived stress. Conclusions The applied three-dimensional concept of preparedness and the task-specific approach provided a detailed and meaningful view on medical students’ workplace participation and experiences in early clerkships

Expression of survivin detected by immunohistochemistry in the cytoplasm and in the nucleus is associated with prognosis of leiomyosarcoma and synovial sarcoma patients

<p>Abstract</p> <p>Background</p> <p>Survivin, a member of the inhibitor of apoptosis-protein family suppresses apoptosis and regulates cell division. It is strongly overexpressed in the vast majority of cancers. We were interested if survivin detected by immunohistochemistry has prognostic relevance especially for patients of the two soft tissue sarcoma entities leiomyosarcoma and synovial sarcoma.</p> <p>Methods</p> <p>Tumors of leiomyosarcoma (n = 24) and synovial sarcoma patients (n = 26) were investigated for their expression of survivin by immunohistochemistry. Survivin expression was assessed in the cytoplasm and the nucleus of tumor cells using an immunoreactive scoring system (IRS).</p> <p>Results</p> <p>We detected a survivin expression (IRS > 2) in the cytoplasm of 20 leiomyosarcomas and 22 synovial sarcomas and in the nucleus of 12 leiomyosarcomas and 9 synovial sarcomas, respectively. There was no significant difference between leiomyosarcoma and synovial sarcoma samples in their cytoplasmic or nuclear expression of survivin. Next, all sarcoma patients were separated in four groups according to their survivin expression in the cytoplasm and in the nucleus: group 1: negative (IRS 0 to 2); group 2: weak (IRS 3 to 4); group 3: moderate (IRS 6 to 8); group 4: strong (IRS 9 to 12). In a multivariate Cox's regression hazard analysis survivin expression detected in the cytoplasm or in the nucleus was significantly associated with overall survival of patients in group 3 (RR = 5.7; P = 0.004 and RR = 5.7; P = 0.022, respectively) compared to group 2 (reference). Patients whose tumors showed both a moderate/strong expression of survivin in the cytoplasm and a moderate expression of survivin in the nucleus (in both compartments IRS ≥ 6) possessed a 24.8-fold increased risk of tumor-related death (P = 0.003) compared to patients with a weak expression of survivin both in the cytoplasm and in the nucleus.</p> <p>Conclusion</p> <p>Survivin protein expression in the cytoplasma and in the nucleus detected by immunohistochemistry is significantly associated with prognosis of leiomyosarcoma and synovial sarcoma patients.</p

Alloxan-Induced Diabetes Triggers the Development of Periodontal Disease in Rats

BACKGROUND: Periodontal disease in diabetic patients presents higher severity and prevalence; and increased severity of ligature-induced periodontal disease has been verified in diabetic rats. However, in absence of aggressive stimuli such as ligatures, the influence of diabetes on rat periodontal tissues is incompletely explored. The aim of this study was to evaluate the establishment and progression of periodontal diseases in rats only with diabetes induction. METHODOLOGY/PRINCIPAL FINDINGS: Diabetes was induced in Wistar rats (n = 25) by intravenous administration of alloxan (42 mg/kg) and were analyzed at 1, 3, 6, 9 and 12 months after diabetes induction. The hemimandibles were removed and submitted to radiographical and histopathological procedures. A significant reduction was observed in height of bone crest in diabetic animals at 3, 6, 9 and 12 months, which was associated with increased numbers of osteoclasts and inflammatory cells. The histopathological analyses of diabetic rats also showed a reduction in density of collagen fibers, fibroblasts and blood vessels. Severe caries were also detected in the diabetic group. CONCLUSIONS/SIGNIFICANCE: The results demonstrate that diabetes induction triggers, or even co-induces the onset of alterations which are typical of periodontal diseases even in the absence of aggressive factors such as ligatures. Therefore, diabetes induction renders a previously resistant host into a susceptible phenotype, and hence diabetes can be considered a very important risk factor to the development of periodontal disease

Entwicklung von Entrustable Professional Activities für den ärztlichen Berufsbeginn an der Charité Berlin

Background: Entrustable Professional Activities (EPAs) have emerged as a new approach to operationalise the workplace performance expectations for the transition from under- to postgraduate medical training. However, the transferability of such EPAs from one context to another appears limited. In this article, we report on the results of our approach to define a full set of core EPAs for entry into residency with the expectation to be performed under distant supervision. Methods: The EPA development involved a modified, three round Delphi study, conducted at the Charité - Universitätsmedizin Berlin. The supervision level was operationalised as supervisor being distantly available and findings being reviewed. The threshold for consent was reaching a content validity index of a least 80%. The Delphi study involved experienced physicians (n=45) and resulted in a set of core EPAs with the descriptions of the categories: title, specification/limitations, conditions and implications of entrustment decision, knowledge, skills, and attitude, link to competencies and assessment sources. Results: The response rates were 76-80% in the Delphi rounds. Key to the content validation process for the performance expectation was deciding on "to act under distant supervision". The results are full descriptions of 12 core EPAs, organised into 5 overarching EPA domains. Conclusions: Our systematic approach yielded the definition of 12 core EPAs for entry into residency at the level of "act with distant supervision" according to the practice in our context. This report may support other medical schools who plan to implement EPAs into their curricula.Hintergrund: Entrustable Professional Activities (EPAs) haben sich als ein neues Konzept etabliert, um die Erwartungen an ärztliche Berufsanfänger am Arbeitsplatz zu operationalisieren. Die Übertragbarkeit von EPAs von einem auf den anderen Kontext ist nur begrenzt möglich. In diesem Artikel berichten wir über die Ergebnisse unseres Vorgehens, ein komplettes Set an Kern-EPAs zu entwickeln, die ärztliche Berufsanfänger unter entfernter Aufsicht ausführen können sollten.Methode: Die Entwicklung der EPAs erfolgte mittels einer modifizierten, aus 3 Runden bestehenden Delphi-Studie an der Charité - Universitätsmedizin, Berlin. Als Aufsichtsgrad wurde festgelegt, dass supervidierende Ärzte mit zeitlicher Verzögerung zur Verfügung stehen und Wichtiges nachgeprüft wird. Ein Content Validity Index von mindestens 80% wurde als Grenze für den Konsens festgelegt. Die Delphi-Studie wurde mit erfahrenen Ärzten durchgeführt (n=45) und resultierte in ein Set von EPAs, die jeweils folgende Kategorien beinhalten: Titel; Spezifikationen/Limitationen; Bedeutung der Entrustment-Entscheidung; Kenntnisse, Fertigkeiten und Haltungen; Kompetenzbereiche und Assessment.Ergebnisse: Der Rücklauf in den Delphi-Runden lag zwischen 76-80%. Voraussetzung für den inhaltlichen Validierungsprozess der Kerntätigkeiten war die Festlegung des Supervisionslevels auf "unter entfernter Aufsicht handeln". Die Ergebnisse sind vollständige Beschreibungen von 12 EPAs, eingeordnet in 5 übergeordnete EPA-Domänen.Schlussfolgerungen: Unser systematisches Vorgehen ergab die Definition von 12 Kern-EPAs für ärztliche Berufsanfänger mit dem Aufsichtsgrad "unter entfernter Aufsicht handeln" für die Anwendung in unserem Kontext. Dieser Bericht soll andere medizinische Fakultäten unterstützen, die eine Implementierung von EPAs in ihre Curricula planen