The effect of the following parameters on the infiltration characteristics of bilayer SiC sub p preforms by the alloy Al-10.77 wt.% Si-9.7 wt.% Mg was investigated and quantified: process ...temperature, infiltration time, SiC particle size, percentage porosity in the preform and preform layer height. The contribution of each of these parameters and their interactions to the height of infiltration are determined. In addition, an optimized process for enhanced infiltration is suggested and validated. The parameter that most significantly affects the height of infiltration is the interaction between porosity and the preform layer height. This interaction has a contribution of 42% on the variability of the infiltration height. It is followed by the infiltration temperature and the interaction between particle size and percentage porosity, which contributions are 25% and 23%, respectively. A verification test with the optimum parameters shows good agreement with the projected value of height of infiltration.
Bildgebung des Brustkorbs Bittner, R. C; Pech, M
Pneumologe,
11/2005, Letnik:
2, Številka:
6
Journal Article
Viele Veränderungen im Bereich von Thoraxwand, Zwerchfell und Pleura lassen sich bereits sonographisch klären. Ein Malignomstaging erfordert jedoch ein Schnittbildverfahren. Die MSCT ist hier das ...Verfahren der Wahl. Bei oberflächennahen thorakalen Prozessen ist die MRT mit überlegener Weichteildarstellung eine echte Alternative. Das gilt auch für Tumoren im Bereich der Thoraxapertur. Die mediastinale Routine(differenzial)diagnostik bzw. das Staging erfolgt mit der MSCT einschließlich Rekonstruktionen in beliebigen Ebenen. Die Analyse der bekannten differenzialdiagnostischen Parameter wie Dichtewerte, Morphologie und Kontrastmittelaufnahmeverhalten ist Standard. Der endobronchiale Ultraschall dürfte das Lymphknotenstaging und transbronchiale Biopsien erheblich verbessern. Der transösophageale Ultraschall wird gezielt für spezielle Fragestellungen im Mediastinum eingesetzt. Bei schwerer Kontrastmittelunverträglichkeit und schwerer Niereninsuffizienz kann die MRT als Alternativverfahren dienen. Die PET ist in der mediastinalen Lymphknotendiagnostik bereits etabliert. Die Zukunft in der thorakalen Diagnostik gehört der PET-CT mit der Kombination von Stoffwechseldarstellung plus exakte anatomische Zuordnung. Nachverarbeitungsverfahren der digitalen Datensätze umfassen z. B. virtuelle Endoskopien, 3D-Oberflächen- oder -Volumendarstellungen.
Abstract Background context The risk of stroke because of carotid retraction during an anterior cervical spine surgery as well as the risk of bleeding complications after an anterior cervical ...corpectomy under deep anticoagulation and antiplatelet therapy is a surgical issue poorly addressed in the literature. Purpose To describe the feasibility and safety of a simultaneous carotid endarterectomy and anterior corpectomy and fusion under deep anticoagulation in a patient with a cervical spinal cord compression and a severe carotid artery stenosis. Study design Case report. Methods The authors describe the case of a 79-year-old man who had a 1-month history of progressive pain in the neck and left arm, associated with progressive weakness in the left arm and leg. He also presented a history of coronaropathy and bilateral severe carotid stenosis for which he was receiving a regimen of antiplatelet therapy. Results The cervical magnetic resonance imaging demonstrated a C4–C5 disc herniation migrating down to C5. His condition worsened rapidly during hospitalization prompting a rapid decompression. Given the necessity of a C5 corpectomy and the risk of stroke during anterior cervical spine surgery, it was therefore decided to undertake the surgical procedure under efficient anticoagulant and antiplatelet therapy. A combined endarterectomy and spinal decompression and fusion were then performed. The postoperative course was uneventful, and the patient recovered neurologically. Conclusions This case suggests that such a combined carotid endarterectomy and cervical corpectomy with fusion under anticoagulant and antiplatelet therapy is feasible. However, even if the unique clinical presentation of our patient led us to undertake such a surgical strategy, therapeutic decision in patients presenting with both severe carotid stenosis and cervical spinal cord compression should rely on a case-by-case analysis.
We report a multi-resolution search for anisotropies in the arrival directions of cosmic rays detected at the Pierre Auger Observatory with local zenith angles up to \(80^\circ\) and energies in ...excess of 4 EeV (\(4 \times 10^{18}\) eV). This search is conducted by measuring the angular power spectrum and performing a needlet wavelet analysis in two independent energy ranges. Both analyses are complementary since the angular power spectrum achieves a better performance in identifying large-scale patterns while the needlet wavelet analysis, considering the parameters used in this work, presents a higher efficiency in detecting smaller-scale anisotropies, potentially providing directional information on any observed anisotropies. No deviation from isotropy is observed on any angular scale in the energy range between 4 and 8 EeV. Above 8 EeV, an indication for a dipole moment is captured; while no other deviation from isotropy is observed for moments beyond the dipole one. The corresponding \(p\)-values obtained after accounting for searches blindly performed at several angular scales, are \(1.3 \times 10^{-5}\) in the case of the angular power spectrum, and \(2.5 \times 10^{-3}\) in the case of the needlet analysis. While these results are consistent with previous reports making use of the same data set, they provide extensions of the previous works through the thorough scans of the angular scales.
Irreversible Elektroporation Liehr, U-b; Wendler, Jj; Blaschke, S ...
Urologe. Ausgabe A,
12/2012, Letnik:
51, Številka:
12
Journal Article
Lokale Ablationsverfahren stehen in der Onkologie im Fokus aktueller Entwicklungen. Vorrangiges Ziel ist es, ohne Kompromittieren der onkologischen Ergebnisse, Organe und Organfunktionen zu erhalten. ...Die Irreversible Elektroporation (IRE) ist ein neues Ablationsverfahren und beruht auf einer induzierten Zellapoptose nach Applikation von Starkstromimpulsen ohne thermische Schädigung des Zielgewebes und benachbarter Strukturen. 2005 erstmals publiziert, wird die IRE aktuell in einigen onkologischen Fachgebieten präklinischen und klinischen Untersuchungen unterzogen, die Ergebnisse sind bisher vielversprechend. Die IRE könnte eine deutliche Entwicklung in der Ablationstherapie beim Nierenzellkarzinom (NZK) bedeuten, der entscheidende Wirknachweis für das lokale NZK steht jedoch bisher aus. In dieser Arbeit werden eigene präklinische und erste klinische Untersuchungen und Ergebnisse dargestellt, diskutiert und mit anderen Ablationstechniken verglichen, um die aktuelle Wertigkeit der IRE aufzuzeigen. Local ablation techniques are a major focus of current developments in oncology. The primary aim is to retain organs and preserve organ functions without compromising the oncological outcome. Irreversible electroporation (IRE) is a novel ablation technique that involves the application of high-voltage pulses to induce cell apoptosis without causing thermal damage to the target tissue or adjacent structures. First published in 2005 IRE is currently undergoing preclinical and clinical trials in several areas of oncology and the initial results have been promising. The IRE technique could be a significant development in ablation treatment for renal cell carcinoma (RCC) but decisive proof of its effectiveness for local RCC has not yet been provided. This study presents the results of preclinical and initial clinical trials which are discussed and compared with those of other ablation techniques in order to demonstrate the current value of IRE.PUBLICATION ABSTRACT
Cyclosporine A (CsA) is a widely used immunosuppressant which possesses significant side effects including nephrotoxicity and systemic arterial hypertension. In this work we evaluated the effects of ...CsA on human umbilical endothelial cell proliferation (HUVEC). Treatment of endothelial cells with CsA inhibited cell proliferation, and was correlated with an increase of interleukin-6 (IL-6) production and IL-6 mRNA expression. Addition of exogenous IL-6 also significantly altered cell proliferation. Furthermore, neutralization of endogenous IL-6 with a specific monoclonal antibody concomitantly with CsA treatment completly restored HUVEC proliferation. These results suggest that CsA-induced inhibition of HUVEC proliferation is mediated through an augmentation of IL-6 synthesis.
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