Preoperative Imaging of Charcot Neuroarthropathy in Diabetic Patients: Comparison of Ring PET, Hybrid PET, and Magnetic Resonance Imaging

Introduction: The treatment of Charcot neuroarthropathy in the feet of diabetic patients has undergone fundamental changes in the last few years. Formerly, treatment was almost exclusively limited to nonoperative measures; since the late 1990s, however, current practice has shifted to early, stage-appropriate surgical therapy. The objective of this prospective study was to investigate the value of two types of positron emission tomography (PET) in the preoperative evaluation of diabetic patients with Charcot foot deformities. Materials and Methods: Ring 18FFDG (2-fluoro-2-deoxy-glucose) and hybrid PET were compared to magnetic resonance imaging (MRI). MRI, ring PET, and hybrid PET imaging were used as part of the preoperative evaluation of 16 patients with type II diabetes mellitus. The diagnosis of Charcot neuropathy of the foot requiring operative treatment had been made on the basis of clinical and radiographic criteria. Results: Of 39 Charcot lesions confirmed at surgery, 37 were detected by ring PET, 30 by hybrid PET, and 31 by MRI. Conclusions: PET (ring or hybrid) can be used in the evaluation of patients with metal implants that would compromise the accuracy of MRI. Another advantage of PET is its ability to distinguish between inflammatory and infectious soft-tissue lesions, and between osteomyelitis and Charcot neuroarthropathy. The differentiation between Charcot neuroarthropathy and florid osteomyelitis provides the surgeon with important additional information that often is unavailable from MRI. Because it provides important additional data, ring PET may be preferable to radiography and MRI in the preoperative evaluation of patients with Charcot neuroarthropathy of the foot. Hybrid PET, because of its poorer resolution compared to ring PET, appears less suitable for routine clinical application

Auswirkung von Setzungseffekten und variabler Randporosität auf die Leistung von Hochtemperatur-Schüttspeichern

Zur Flexibilisierung fossil befeuerter Kraftwerke sowie für den Betrieb von Kraftwerken im Bereich der erneuerbaren Energien sind effiziente thermische Hochtemperaturenergiespeicher von entscheidender Bedeutung. In solarthermischen Turmkraftwerken ermöglichen sie den Betrieb in Zeiten ohne direkte Sonneneinstrahlung, in fossilen Kraftwerken verbessern sie die Betriebsflexibilität. Im geforderten Temperaturbereich von 500-1000°C bieten sich direktdurchströmte Feststoffspeicher mit den Wärmeträgern Luft oder Rauchgas als Speichertechnologie an. Diese als Regeneratorspeicher bekannte Technologie wird in der Stahl- und Glasindustrie eingesetzt, dort werden keramische Formsteine als Speichermaterial verwendet. Für den Einsatz in Kraftwerksanwendungen ist eine Verbesserung der Kosteneffizienz notwendig, welche mit herkömmlichen Inventaroptionen jedoch schwer erreichbar ist. Schüttungen bieten sich als Alternative zu Formsteinen an, bergen aber erhebliche thermomechanische und strömungsmechanische Risiken. Die Ausführung als horizontal durchströmter Speicher mindert durch die verminderte Schütthöhe die thermomechanischen Risiken auf Grund reduzierter Eigengewichtsbelastung. Im Fokus dieses Beitrags steht die strömungsmechanische Untersuchung der Auswirkung von Realeffekten in Schüttungen wie die verminderte Randporosität und die Ausbildung einer Bypassströmung durch Setzungseffekte bei horizontal durchströmten Speichern. Durch diese Effekte sinkt in den betroffenen Bereichen der Strömungswiderstand was zu einer stärkeren Durchströmung führt. Daraus resultiert eine ungleichförmige thermische Be- und Entladung des Speichers, welche zu einem Verlust an Leistung führen kann. Der Beitrag quantifiziert diese Effekte mittels instationärer CFD-Berechnungen für den zyklischen Speicherbetrieb. Die Einzeleffekte werden separiert und ihre Auswirkung auf die thermische Leistung anhand von Kenngrößen ermittelt

Spatial location and its relevance for terminological inferences in bio-ontologies

<p>Abstract</p> <p>Background</p> <p>An adequate and expressive ontological representation of biological organisms and their parts requires formal reasoning mechanisms for their relations of physical aggregation and containment.</p> <p>Results</p> <p>We demonstrate that the proposed formalism allows to deal consistently with "role propagation along non-taxonomic hierarchies", a problem which had repeatedly been identified as an intricate reasoning problem in biomedical ontologies.</p> <p>Conclusion</p> <p>The proposed approach seems to be suitable for the redesign of compositional hierarchies in (bio)medical terminology systems which are embedded into the framework of the OBO (Open Biological Ontologies) Relation Ontology and are using knowledge representation languages developed by the Semantic Web community.</p

Double layer charging driven carbon dioxide adsorption limits the rate of electrochemical carbon dioxide reduction on Gold.

Electrochemical CO[Formula: see text] reduction is a potential route to the sustainable production of valuable fuels and chemicals. Here, we perform CO[Formula: see text] reduction experiments on Gold at neutral to acidic pH values to elucidate the long-standing controversy surrounding the rate-limiting step. We find the CO production rate to be invariant with pH on a Standard Hydrogen Electrode scale and conclude that it is limited by the CO[Formula: see text] adsorption step. We present a new multi-scale modeling scheme that integrates ab initio reaction kinetics with mass transport simulations, explicitly considering the charged electric double layer. The model reproduces the experimental CO polarization curve and reveals the rate-limiting step to be *COOH to *CO at low&nbsp;overpotentials, CO[Formula: see text] adsorption at intermediate&nbsp;ones, and CO[Formula: see text] mass transport at high overpotentials. Finally, we show the Tafel slope to arise from the electrostatic interaction&nbsp;between the dipole of&nbsp;*CO[Formula: see text] and the interfacial field. This work highlights the importance of surface charging for electrochemical kinetics and mass transport

Die Rolle p16INK4a-gesteuerter Signalwege in der Zytokin-induzierten Seneszenz

Das Ziel dieser Arbeit war es, die Rolle des Tumorsuppressors p16INK4a bei der Immuntherapie mit Tag-spezifischen Th1-Zellen im RIP1-Tag2 Mausmodell zu untersuchen. Hierzu wurden RIP1-Tag2 Mäuse zunächst in vivo mit Tag-Th1 Zellen behandelt. Dies führte zu einer geringeren Anzahl an Ki67-positiven, proliferierenden Tumorzellen und ging mit einer Induktion von p16INK4a einher. Anschließend wurde der Effekt der Th1-Zytokine IFN und TNF auf Tumorzellen in vitro untersucht. Auch hier kam es unter dem Einfluss von IFN und TNF zu einer verringerten Proliferation der Tumorzellen und einer vermehrten Expression von p16INK4a. Eine vermehrte Transkription von p16INK4a (CKDN2a) konnte jedoch nicht beobachtet werden. Auch die Aktivität des Seneszenzmarkes SA-β-Gal war in den Tumorzellen durch die IFN und TNF Behandlung verstärkt. Analog zu der in den murinen Tumorzellen beobachteten p16INK4a Induktion unter dem Einfluss von IFN und TNF kam es unter der Th1-Zytokintherapie auch in Zellen der humanen Rhabdomyosarkomzelllinie A204 zu einer vermehrten p16INK4a Expression. Um die funktionelle Rolle von p16INK4a bei der Induktion des Zellzyklusarrests durch die IFN und TNF Behandlung zu untersuchen, wurde ein Kockdown von p16INK4a mittels shRNA durchgeführt. Ohne funktionell aktives p16INK4a kam es einerseits zu einer deutlich beschleunigten Proliferation der Tumorzellen, andererseits konnte durch die Behandlung mit IFN und TNF kein Zellzyklusarrest mehr induziert werden

Analysis of plasma elastase levels in early and late onset preeclampsia

Background: Circulatory neutrophils have been reported to be activated in preeclampsia. It has been suggested that maternal plasma levels of elastase may serve as a possible cell-free marker to quantify such activation. Although plasma elastase levels have been found to be elevated in cases with manifest preeclampsia and eclampsia, this has not yet been examined in cases with early and late onset preeclampsia. We have now examined this aspect. Methods: In this retrospective study, maternal plasma samples were examined from eight cases with early onset preeclampsia (34weeks of gestation) and an equal number of gestational age matched normotensive term controls. Plasma concentrations of elastase were measured by ELISA using a commercially available assay. Results: Plasma elastase concentrations were significantly elevated the preeclampsia study group when compared to the normotensive control group (median=139.2ng/ml versus median=72.1ng/ml; P=0.0025). These elevations remained significant when the preeclampsia study group was stratified into case with early onset preeclampsia (median=118.8ng/ml versus median=62.2ng/ml; P=0.03), but jailed failed to attain significance for those cases with late onset preeclampsia (median=181.3ng/ml versus median=86.3ng/ml; P=0.061). Conclusions: Our data indicate that elastase levels are elevated in both early and late onset forms of preeclampsia, and imply that the activation of neutrophils may be more acute in the former than in the latter (238 words

Scoliosis correction with pedicle screws in Duchenne muscular dystrophy

This report describes the spinal fixation with pedicle-screw-alone constructs for the posterior correction of scoliosis in patients suffering from Duchene muscular dystrophy (DMD). Twenty consecutive patients were prospectively followed up for an average of 5.2years (min 2years). All patients were instrumented from T3/T4 to the pelvis. Pelvic fixation was done with iliac screws similar to Galveston technique. The combination of L5 pedicle screws and iliac screws provided a stable caudal foundation. An average of 16 pedicle screws was used per patient. The mean total blood loss was 3.7l, stay at the intensive care unit was 77h and hospital stay was 19days. Rigid stabilisation allowed immediate mobilisation of the patient in the wheel chair. Cobb angle improved 77% from 44° to 10°, pelvic tilt improved 65% from 14° to 3°. Lumbar lordosis improved significantly from 20° to 49°, thoracic kyphosis remained unchanged. No problems related to iliac fixation, no pseudarthrosis or implant failures were observed. The average percentage of predicted forced vital capacity (%FVC) of the patients was 55% (22-94%) preoperatively and decreased to 44% at the last follow-up. There were no pulmonary complications. One patient with a known cardiomyopathy died intraoperatively due to a sudden cardiac arrest. The rigid primary stability with pedicle screws allowed early mobilisation of the patients, which helped to avoid pulmonary complication