Stress singularities and the formation of birefringent strands in stagnation flows of dilute polymer solutions

We consider stagnation point flow away from a wall for creeping flow of dilute polymer solutions. For a simplified flow geometry, we explicitly show that a narrow region of strong polymer extension (a birefringent strand) forms downstream of the stagnation point in the UCM model and extensions, like the FENE-P model. These strands are associated with the existence of an essential singularity in the stresses, which is induced by the fact that the stagnation point makes the convective term in the constitutive equation into a singular point. We argue that the mechanism is quite general, so that all flows that have a separatrix going away from the stagnation point exhibit some singular behaviour. These findings are the counterpart for wall stagnation points of the recently discovered singular behaviour in purely elongational flows: the underlying mechanism is the same while the different nature of the singular stress behaviour reflects the different form of the velocity expansion close to the stagnation point.Comment: 15 pages, 6 figure

Imaging of Primitive Neuroectodermal Tumor (PNET) by Technetium-99m Tetrofosmin

Purpose. Tc-99m tetrofosmin launched for myocardial studies has recently also shown a good detectability for several tumors. Data on PNET imaging by Tc-99m tetrofosmin are not yet available

F-Fluorodeoxyglucose (FDG)-PET features of focal nodular hyperplasia (FNH) of the liver

PET imaging. The lesions were found incidentally. The 18F-FDG PET of Vienna, Vienna, Austria imaging was performed with a dedicated PET tomograph after intravenous injection of 300-370 MBq 18F-FDG. The 18F-FDG accumulation in the lesions was (semi)quantified by calculating the standardized uptake value (SUV) and SUV has been corrected for the lean body mass (LBM). Eight patients with liver metastases spread from melanoma (nΩ2) and colorectal carcinoma (nΩ6) served as controls. The size of the FNH lesions and of the control group ranged from 2.0 to 8.5 cm (mean 4.83 cm∫2.37) and from 1.5 to 6 cm (mean 3.28∫1.52), respectively. Results: While in malignant liver lesions the accumulation of 18F-FDG was significantly increased, all FNH lesions showed normal or even decreased accumulation of 18F-FDG. In FNH lesions, SUV ranged between 1.5 and 2.6 (mean 2.12∫0.38), whereas all liver metastases showed an increased SUV rang- PET is a new imaging method that has been successfully applied to image malignant tumors. While a large number of studies has been published in the last years about the usefulness of 18F-FDG PET in a variety of malignant diseases, the glucose metabolism of FNH in vivo has not bee

Treatment of Concurrent Thrombotic Thrombocytopenic Purpura and Graves’ Disease: A Report on Two Cases

Graves’ disease (GD) and thrombotic thrombocytopenic purpura (TTP) are autoimmune diseases caused by autoantibodies against the TSH receptor (TRAb) and the enzyme ADAMTS13. We here report on two patients with concurrent GD and TTP, who achieved sustained remission of both conditions with the TTP treatment regimen and thiamazole. Both patients suffered from relapsing TTP and were diagnosed with GD concomitantly at the time of relapse. They were treated with steroids, plasma exchange, rituximab, and thiamazole. This therapy induced complete remission of TTP. TRAb levels also decreased rapidly and both patients developed subclinical hypothyroidism three and five weeks later. Our observations suggest that TTP and GD may be concomitant and that GD possibly triggers a relapse of TTP. The combination of thyrostatic treatment and immunosuppression with PE, rituximab, and steroids is able to induce rapid and prolonged remission of GD

Radionuklidtherapie von Knochenmetastasen mittels Radium-223. DGN-Handlungsempfehlung

This document describes the guideline for therapy of bone metastases with radium-223 ((223)Ra) published by the Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften in Germany (AWMF) under the auspices of the Deutsche Gesellschaft für Nuklearmedizin (DGN), Östereichische Gesellschaft für Nuklearmedizin (OGN), and Schweizerische Gesellschaft für Nuklearmedizin (SGNM). This guidance is based on an interdisciplinary consensus. These recommendations are a prerequisite for the quality management in the treatment of patients with bone metastases from prostate cancer using (223)Ra. They are aimed at guiding nuclear medicine specialists in selecting candidates to receive therapy and to deliver the treatment in a safe and effective manner. The document contains background information and definitions. It covers the rationale, indications and contraindications for therapy with (223)Ra. Essential topics are the requirements for institutions performing the therapy, which patient data have to be available prior to performance of therapy, and how treatment has to be carried out technically and organisationally. Moreover, essential elements of follow-up and aftercare are specified. As a matter of principle, the treatment inclusive aftercare has to be realised in close cooperation with the involved medical disciplines

Value of combined 6-[18F]fluorodihydroxyphenylalanine PET/CT for imaging of neuroendocrine tumours

18F-DOPA-PET/CT yields a high sensitivity and specificity in the detection of NET. The clinical impact was highly relevant as changes in therapy were observed in more than a quarter of the patients

Measuring Success in Family Businesses: The Concept of Configurational Fit

The problems associated with measuring success in small businesses are primarily caused by a lack of comparable data due to the ambiguity of success and by subjective biases. Success evaluation is dominated by the estimates of business owners, who tend to overestimate overall success and internal strengths. However, reliable success measurement instruments would be useful for small business owners/managers as well as small business policymakers. The main purposes of this article are to compare various measures of success, to explore the differences in their outcomes, and to analyze whether a model of success measurement using configurational fit can be used to overcome subjective biases. The study is based on a recent survey of 103 small family-owned businesses in the eastern Austrian border region. Our analysis of the data confirmed the existence of the measurement problems mentioned above. While some individual indicators show significant biases as well as effects due to company age, size and industry, the aggregated indicator based on the concept of configurational fit seems to be an appropriate means of overcoming most of these drawbacks.(author's abstract