772 research outputs found

    Klonale Verwandtschaft von Hodgkin-Lymphomen und deren Rezidiven

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    Zusammenfassung: In dieser Studie untersuchten wir, ob es sich bei Rezidiven von klassischen Hodgkin-Lymphomen (HL) um Rezidive im engeren Sinn oder aber um klonal unverwandte SekundĂ€rtumoren handelt. Die Untersuchungen erfolgten an formalinfixierten, paraffineingebetteten Gewebeproben von 11Patienten. Hodgkin- bzw. Sternberg-Reed-Riesenzellen wurden nach immunhistochemischer Markierung mit CD30 mittels Laser mikrodisseziert und die FragmentlĂ€ngen des Schwerkettenimmunglobulin-Gens (IgH) unter Verwendung von FR3- und J-Konsensusprimern analysiert. Zwei FrĂŒhrezidive nach einer HL-Erstdiagnose zeigten klonale Verwandschaft zu den PrimĂ€rtumoren, wĂ€hrend 3 von 4FrĂŒhrezidiven nach einem Erst- oder Zweitrezidiv nicht mit dem vorangegangenen HL verwandt waren. Drei SpĂ€trezidive waren mit dem ursprĂŒnglichen HL klonal unverwandt. Wir schließen daraus, dass es sich bei so genannten "Rezidiven" von HL z.T. um klonal unverwandte Zweitneoplasien handeln kann, was möglicherweise von therapeutischer Relevanz sein könnt

    PSAP-Expression in einem primÀren prÀsakralen neuroendokrinen Tumor: Verwechslungsmöglichkeit mit einem Prostatakarzinom

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    Zusammenfassung: PrimĂ€re prĂ€sakrale neuroendokrine Tumoren sind eine seltene EntitĂ€t mit weniger als 30 beschriebenen FĂ€llen in der Literatur. Wir berichten hier ĂŒber einen autoptisch diagnostizierten prĂ€sakralen neuroendokrinen Tumor, der aufgrund seiner Lokalisation, Morphologie und immunhistochemischen PositivitĂ€t fĂŒr prostataspezifische saure Phosphatase (PSAP) zu Lebzeiten des Patienten als metastasiertes Prostatakarzinom fehldiagnostiziert wurde. Dies ist der erste Fallbericht, der eine Expression von PSAP und des Somatostatinrezeptors in dieser EntitĂ€t dokumentiert

    Phase diagrams of period-4 spin chains consisting of three kinds of spins

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    We study a period-4 antiferromagnetic mixed quantum spin chain consisting of three kinds of spins. When the ground state is singlet, the spin magnitudes in a unit cell are arrayed as (s-t, s, s+t, s) with integer or half-odd integer s and t (0 <= t < s). The spin Hamiltonian is mapped onto a nonlinear sigma model (NLSM) in a previously developed method. The resultant NLSM includes only two independent parameters originating from four exchange constants for fixed s and t. The topological angle in the NLSM determines the gapless phase boundaries between disordered phases in the parameter space. The phase diagrams for various s and t shows rich structures. We systematically explain the phases in the singlet-cluster-solid picture.Comment: 8 pages (16 figures included

    Experimental validation of the quadratic constitutive relation in supersonic streamwise corner flows

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    The quadratic constitutive relation is a simple extension to the linear eddy-viscosity hypothesis and has shown some promise in improving the computation of flow along streamwise corner geometries. In order to further investigate these improvements, the quadratic model is validated by comparing RANS simulations of a Mach 2.5 wind tunnel flow with high-quality experimental velocity data. Careful set up and assessment of computations using detailed characterisation data of the overall flow field suggests a minimum expected discrepancy of approximately 3% for any experimental–computational velocity comparisons. The corner regions of the rectangular cross-section wind tunnel exhibit velocity differences of 7% between experimental data and computations with linear eddy-viscosity models, but these discrepancies are reduced to 4–5% when the quadratic constitutive relation is used. This improvement can be attributed to a better prediction of the corner boundary-layer structure, due to computations reproducing the stress-induced streamwise vortices which are known to exist in this flow field. However, the strength and position of these vortices do not correspond exactly with those in the measured flow. A further observation from this study is the appearance of additional, non-physical vortices when the value of the quadratic coefficient in the relation exceeds the recommended value of 0.3.This material is based upon work supported by the US Air Force Office of Scientific Research under award number FA9550–16–1–0430

    An Aeroacoustic Investigation of a Tiltwing eVTOL Concept Aircraft

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    With the advancement in electric battery design, aircraft designers and manufacturers are no longer constrained to established configurations. Developments in Vertical Take-off and Landing (VTOL) aircraft have also been seen in recent times through the design of modern tiltrotor aircraft such as the AW609 and the V-280 Valor. The combination of these developments allowed engineers to propose designs which utilise the vertical take-off and landing capabilities of a tiltrotor aircraft with electrically driven propulsion systems, deemed eVTOL (Electrically driven Vertical Take-off and Landing). This investigation aims to develop an understanding of the aeroacoustic emissions associated with an eVTOL aircraft, due to acoustics being one of the key components in future certification. The study will consist of an investigation into the baseline design, followed by an optimisation study aiming to reduce the amount of noise generated

    Drimolen: a new hominid-bearing site in Gauteng, South Africa.

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    Performativity, fabrication and trust: exploring computer-mediated moderation

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    Based on research conducted in an English secondary school, this paper explores computer mediated moderation as a performative tool. The Module Assessment Meeting (MAM) was the moderation approach under investigation. I mobilise ethnographic data generated by a key informant, and triangulated with that from other actors in the setting, in order to examine some of the meanings underpinning moderation within a performative environment. Drawing on the work of Ball (2003), Lyotard (1979) and Foucault (1977, 1979), I argue that in this particular case performativity has become entrenched in teachers’ day-to-day practices, and not only affects those practices but also teachers’ sense of self. I suggest that MAM represented performative and fabricated conditions and (re)defined what the key participant experienced as a vital constituent of her educational identities - trust. From examining the case in point, I hope to have illustrated for those interested in teachers’ work some of the implications of the interface between technology and performativity

    Race and sex: teachers' views on who gets ahead in schools?

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    The research reported here was part of a large study of the impact of age, disability, race and sex on the teaching profession in England. The basic question asked in this research was how do these factors interact with career aspirations and achievements of classteachers, promoted teachers and headteachers? There were three different data sources: a large postal survey drawn from diverse geographic regions across England with over 2000 respondents; face‐to‐face individual interviews with over 100 teachers in 18 case study schools from across all of the main regions of England; discussions with special interest groups of teachers. Not surprisingly, the answer to the above question was complex. Nonetheless, the paper's conclusion highlights some of the noteworthy themes across this broad sample of teachers from primary, secondary and special schools
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