703 research outputs found

    Die solitäre abszedierende Osteomyelitis des Kieferköpfchens: Eine Rarität

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    Zusammenfassung: Fall: Es wird über den seltenen Fall einer solitären abszedierenden, sekundär chronischen Osteomyelitis des linken Processus condylaris berichtet. Aus dem Abszessmaterial wurde der Keim Haemophilus aphrophilus isoliert. Therapeutisch erfolgte eine Resektion des Processus condylaris mit Sofortrekonstruktion des Kondylus mithilfe einer Kopfendoprothese. Diskussion: Mögliche Ursachen für diese seltene Lokalisation einer sekundär chronischen Osteomyelitis werden anhand der Literatur aufgearbeitet und dem vorliegenden Fall gegenübergestellt. Schlussfolgerung: Als mögliche Ursache wird eine Keiminokulation durch die Nadel bei einer Lokalanästhesie, eine bakterielle Kontamination während der Zahnextraktion oder eine hämatogene Aussaat durch den Extraktionsvorgang angenomme

    Observations on pulpal response to carbon dioxide laser drilling of dentine in healthy human third molars

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    Preservation of pulpal health is the primary prerequisite for successful application of laser systems in the hard tissue management of vital teeth. The purpose of this study was to investigate the short and long-term pulpal effects to cavity preparations in healthy human teeth using carbon dioxide (CO2) laser. A total of seven, healthy, third molars that were scheduled to be removed due to space problems were used. After the laser drilling, the occlusal cavities were closed temporarily, and the teeth were extracted 7days (n=5) and 3 months (n=2) after the operation. The specimens were fixed, decalcified, subdivided and processed for light and transmission electron microscopy. Seven days postoperatively all the five teeth that had been irradiated with the CO2 laser did not reveal any pathological changes in the pulpo-dentine complex. Three months postoperatively the two teeth that were prepared with the laser showed subtle but distinct apposition of tertiary dentine that was lined with intact odontoblasts. One of the specimens at 3 months revealed the presence of a mild, but very circumscribed, pulpal infiltration of chronic inflammatory cells subjacent to the cavity preparation. The latter is unlikely to be due to a direct effect of the laser irradiation but a possible consequence of microleakage of oral antigens and/or other tissue-irritating molecules through the temporary restoration and the remaining dentine thickness (RDT). Although these preliminary histological results suggest that the CO2 laser under investigation induced only minimal response of the dentine-pulp complex when used as a hard-tissue drilling tool, with specific energy settings, pulse duration within thermal relaxation time and emitting radiations at 9.6μm of wavelength, larger clinical trials involving various types of teeth are necessary to reach definite conclusions for large-scale clinical application of the laser devic

    Die kondyläre Metastasierung: Literaturrecherche und ein Fallbericht

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    Zusammenfassung: Hintergrund: Kondyläre Metastasen sind eine Rarität. In der Literaturrecherche entsprachen nur 23 der insgesamt 69 gefundenen Fälle den Kriterien von Meyer u. Shklar. Fallbericht: Bei einem 48-jährigen Mann mit Schmerzen im linken Kiefergelenk wurde im linken Kondylus eine solitäre Metastase eines kurz zuvor operierten Lungenkarzinoms gefunden. Aufgrund der ausgedehnten Umgebungsinfiltration erfolgte eine kurative Radiatio. Im Verlauf traten weitere Skelettmetastasen auf. Diskussion: Kieferköpfchenmetastasen unterscheiden sich bezüglich ihres Verlaufs kaum von den Metastasen des extraartikulären Kieferbereiches. Unter den metastasierenden Tumoren rangiert das Mammakarzinom als Primärtumor an erster Stelle, gefolgt vom Lungenkarzinom. Klinisch und radiologisch können keine spezifischen Parameter für eine Diagnosestellung angegeben werden. Bei der Differenzialdiagnostik der Gelenkserkrankungen sollte jedoch insbesondere bei Patienten mit bekannten Primärtumoren und Gelenksbeschwerden sowie radiologischen Auffälligkeiten eine mögliche Metastasierung berücksichtigt werden. Die Diagnose sollte für eine entsprechende Therapieplanung histologisch gesichert werden. Das therapeutische Vorgehen ist in der Regel palliativ, da die Grunderkrankung bei Diagnosestellung einer Kieferköpfchenmetastase zumeist weit fortgeschritten is

    Extracting the depolarization coefficient D_NN from data measured with a full acceptance detector

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    The spin transfer from vertically polarized beam protons to Lambda or Sigma hyperons of the associated strangeness production pp -> pK Lambda (Sigma) is described with the depolarization coefficient D_NN. As the polarization of the hyperons is determined by their weak decays, detectors, which have a large acceptance for the decay particles, are needed. In this paper a formula is derived, which describes the depolarization coefficient D_NN by count rates of a 4 pi detector. It is shown, that formulas, which are given in publications for detectors with restricted acceptance, are specific cases of this formula for a 4 pi detector.Comment: Accepted for publication by Nuclear Instruments and Methods in Physics Research Section

    Polarization Analysis of p̄ Produced in pA Collisions

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    A quite simple procedure for the generation of a polarized antiproton beam could be worked out if antiprotons are produced with some polarization. In order to investigate this possibility measurements of the polarization of produced antiprotons have been started at a CERN/PS test beam. The polarization will be determined from the asymmetry of the elastic antiproton scattering at a liquid hydrogen target in the CNI region for which the analyzing power is well known. The data are under analysis and an additional measurement is done in 2018. Details on the experiment and the ongoing data analysis will be given

    High precision measurement of the associated strangeness production in proton proton interactions

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    A new high precision measurement of the reaction pp -> pK+Lambda at a beam momentum of 2.95 GeV/c with more than 200,000 analyzed events allows a detailed analysis of differential observables and their inter-dependencies. Correlations of the angular distributions with momenta are examined. The invariant mass distributions are compared for different regions in the Dalitz plots. The cusp structure at the N Sigma threshold is described with the Flatt\'e formalism and its variation in the Dalitz plot is analyzed.Comment: accepted for publication in Eur. Phys. J.

    First Model-Independent Measurement of the Spin Triplet pΛp\Lambda Scattering Length from Final State Interaction in the pppK+Λ\vec{p}p \rightarrow pK^{+}\Lambda Reaction

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    The pppK+Λ\vec{p}p \rightarrow pK^{+}\Lambda reaction has been measured with the COSY-TOF detector at a beam momentum of 2.7GeV/c2.7\,\mathrm{GeV}/c. The polarized proton beam enables the measurement of the beam analyzing power by the asymmetry of the produced kaon (ANKA_N^{K}). This observable allows the pΛp\Lambda spin triplet scattering length to be extracted for the first time model independently from the final-state interaction in the reaction. The obtained value is at=(2.551.39+0.72stat.±0.6syst.±0.3theo.)fma_{t} = (-2.55 ^{+0.72}_{-1.39} {}_{\textrm{stat.}} \pm 0.6_{\textrm{syst.}} \pm 0.3_{\textrm{theo.}})\mathrm{fm}. This value is compatible with theoretical predictions and results from model-dependent analyses.Comment: Revised version as accepted for publication in PR

    How to measure the parity of the Θ+\Theta^+ in pp\vec p\vec p collisions

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    Triggered by a recent paper by Thomas, Hicks and Hosaka, we investigate which observables can be used to determine the parity of the Θ+\Theta^+ from the reaction ppΣ+Θ+\vec p\vec p \to \Sigma^+\Theta^+ near its production threshold. In particular, we show that the sign of the spin correlation coefficient AxxA_{xx} for small excess energies yields the negative of the parity of the Θ+\Theta^+. The argument relies solely on the Pauli principle and parity conservation and is therefore model--independent.Comment: References completed, discussion on possible influence of background added; conclusions unchange

    Status of the PANDA barrel DIRC

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    The PANDA experiment at the future Facility for Antiproton and Ion Research in Europe GmbH (FAIR) at GSI, Darmstadt will study fundamental questions of hadron physics and QCD using high-intensity cooled antiproton beams with momenta between 1.5 and 15 GeV/c. Hadronic PID in the barrel region of the PANDA detector will be provided by a DIRC (Detection of Internally Reflected Cherenkov light) counter. The design is based on the successful BABAR DIRC with several key improvements, such as fast photon timing and a compact imaging region. Detailed Monte Carlo simulation studies were performed for DIRC designs based on narrow bars or wide plates with a variety of focusing solutions. The performance of each design was characterized in terms of photon yield and single photon Cherenkov angle resolution and a maximum likelihood approach was used to determine the π/K separation. Selected design options were implemented in prototypes and tested with hadronic particle beams at GSI and CERN. This article describes the status of the design and R&D for the PANDA Barrel DIRC detector, with a focus on the performance of different DIRC designs in simulation and particle beams
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