800 research outputs found

    Invasive Techniken in der Notfallmedizin: IV. Koniotomie im Notarztdienst

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    Zusammenfassung: Die Koniotomie im Notarztdienst ist eine sehr invasive Methode zur Atemwegssicherung. Sie ist aber unabdingbar, wenn andere weniger invasive Verfahren der Atemwegssicherung misslingen oder sich situationsabhängig als nicht zweckmäßig erweisen. Für die Durchführung wurden verschiedene Verfahren beschrieben, die in anatomisch-chirurgische Präpariertechniken und Punktionsverfahren unterteilt werden können. Das im jeweiligen Notarztsystem bevorzugte Verfahren orientiert sich meist an abteilungsüblichen Standards, die vom klinischen Vorgehen abgeleitet werden. Ausbildungs- und Trainingsmöglichkeiten für die einzelnen Verfahren bestehen in der Intensivmedizin, am Leichenpräparat und am Phantom. In dieser Arbeit werden verschiedene Methoden der Koniotomie besprochen sowie eine anatomische Präpariertechnik und 2Punktionsverfahren im Detail dargestell

    Spin dephasing and photoinduced spin diffusion in high-mobility 110-grown GaAs-AlGaAs two-dimensional electron systems

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    We have studied spin dephasing and spin diffusion in a high-mobility two-dimensional electron system, embedded in a GaAs/AlGaAs quantum well grown in the [110] direction, by a two-beam Hanle experiment. For very low excitation density, we observe spin lifetimes of more than 16 ns, which rapidly decrease as the pump intensity is increased. Two mechanisms contribute to this decrease: the optical excitation produces holes, which lead to a decay of electron spin via the Bir-Aranov-Pikus mechanism and recombination with spin-polarized electrons. By scanning the distance between the pump and probe beams, we observe the diffusion of spin-polarized electrons over more than 20 microns. For high pump intensity, the spin polarization in a distance of several microns from the pump beam is larger than at the pump spot, due to the reduced influence of photogenerated holes.Comment: 4 pages, 3 figure

    Imaging the Ettingshausen effect and cryogenic thermoelectric cooling in a van der Waals semimetal

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    Attaining viable thermoelectric cooling at cryogenic temperatures is of major fundamental and technological interest for novel electronics and quantum materials applications. In-device temperature control can provide a more efficient and precise thermal environment management as compared to the conventional global cooling. Here we develop nanoscale cryogenic imaging of a magneto-thermoelectric effect and demonstrate absolute cooling and an ultrahigh Ettingshausen effect in exfoliated WTe2 Weyl semimetal flakes at liquid He temperatures. Application of a current and perpendicular magnetic field gives rise to cooling via generation of electron-hole pairs on one side of the sample and heating by their recombination at the opposite side. In contrast to bulk materials, the cooling process is found to be nonmonotonic in magnetic field and device size. The derived model of magneto-thermoelectricity in mesoscopic semimetal devices shows that the cooling efficiency and the induced temperature profiles are governed by the interplay between sample geometry, electron-hole recombination length, magnetic field, and flake and substrate heat conductivities. The findings open the way for direct integration of microscopic thermoelectric cooling and for temperature landscape engineering in novel van der Waals devices

    CD137 (4-1BB) stimulation leads to metabolic and functional reprogramming of human monocytes/macrophages enhancing their tumoricidal activity

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    Abstract Immunotherapies have heralded a new era in the cancer treatment. In addition to checkpoint inhibitors, agonistic antibodies against co-stimulatory immune receptors hold the potential to invoke efficient antitumor immunity. Targeting CD137 has gained momentum based on its ability to drive NK- and T-cell-based responses. CD137-engaging mAbs have already entered clinical trials for different types of tumors showing promising results. Despite the efforts to translate CD137-mediated immunotherapy into clinical practice, little remains known regarding the role of CD137 in human monocytes/macrophages. We found CD137 being expressed on monocytes of healthy controls and at even higher levels in patients with multiple myeloma or CLL. CD137HI(GH) monocytes displayed a distinct phenotypic, transcriptomic, and metabolic profile. They possessed an increased phagocytic capacity enabling superior antibody-dependent phagocytosis (ADPC) of multiple myeloma and lymphoma cells that were treated with anti-CD38 or anti-CD20 mAbs. Triggering CD137 promoted both metabolic and tumoricidal activity in an extracellular signal-regulated kinase (ERK)-dependent fashion. In addition, we observed a phenotypic, transcriptomic, and functional skewing towards a M1-like phenotype. Overall, we introduce CD137 as a positive immune checkpoint on human monocytes/macrophages, which can have therapeutic implications especially in view of synergistic effects when combining CD137 agonists with tumor-targeting antibodies

    Multi-particle azimuthal correlations in p-Pb and Pb-Pb collisions at the CERN Large Hadron Collider

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    Measurements of multi-particle azimuthal correlations (cumulants) for charged particles in p-Pb and Pb-Pb collisions are presented. They help address the question of whether there is evidence for global, flow-like, azimuthal correlations in the p-Pb system. Comparisons are made to measurements from the larger Pb-Pb system, where such evidence is established. In particular, the second harmonic two-particle cumulants are found to decrease with multiplicity, characteristic of a dominance of few-particle correlations in p-Pb collisions. However, when a Δη|\Delta \eta| gap is placed to suppress such correlations, the two-particle cumulants begin to rise at high-multiplicity, indicating the presence of global azimuthal correlations. The Pb-Pb values are higher than the p-Pb values at similar multiplicities. In both systems, the second harmonic four-particle cumulants exhibit a transition from positive to negative values when the multiplicity increases. The negative values allow for a measurement of v2{4}v_{2}\{4\} to be made, which is found to be higher in Pb-Pb collisions at similar multiplicities. The second harmonic six-particle cumulants are also found to be higher in Pb-Pb collisions. In Pb-Pb collisions, we generally find v2{4}v2{6}0v_{2}\{4\} \simeq v_{2}\{6\}\neq 0 which is indicative of a Bessel-Gaussian function for the v2v_{2} distribution. For very high-multiplicity Pb-Pb collisions, we observe that the four- and six-particle cumulants become consistent with 0. Finally, third harmonic two-particle cumulants in p-Pb and Pb-Pb are measured. These are found to be similar for overlapping multiplicities, when a Δη>1.4|\Delta\eta| > 1.4 gap is placed.Comment: 25 pages, 11 captioned figures, 3 tables, authors from page 20, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/87

    Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at sNN\sqrt{s_{NN}} = 5.02 TeV

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    Two-particle angular correlations between unidentified charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum range 0.7 <pT,assoc<pT,trig< < p_{\rm{T}, assoc} < p_{\rm{T}, trig} < 5.0 GeV/cc is examined, to include correlations induced by jets originating from low momen\-tum-transfer scatterings (minijets). The correlations expressed as associated yield per trigger particle are obtained in the pseudorapidity range η<0.9|\eta|<0.9. The near-side long-range pseudorapidity correlations observed in high-multiplicity p-Pb collisions are subtracted from both near-side short-range and away-side correlations in order to remove the non-jet-like components. The yields in the jet-like peaks are found to be invariant with event multiplicity with the exception of events with low multiplicity. This invariance is consistent with the particles being produced via the incoherent fragmentation of multiple parton--parton scatterings, while the yield related to the previously observed ridge structures is not jet-related. The number of uncorrelated sources of particle production is found to increase linearly with multiplicity, suggesting no saturation of the number of multi-parton interactions even in the highest multiplicity p-Pb collisions. Further, the number scales in the intermediate multiplicity region with the number of binary nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/161

    An integrative approach to more nuanced estimates of personality–job–performance relations

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    This is the final version. Available on open access from Wiley via the DOI in this recordData availability statement: The data that support the findings of this study are openly available on OSF at https://osf.io/ys72j/?view_only=f48aeaf9414d46fb81019186030afbdcRecent research has suggested that self- and other-ratings of personality may provide different information about personality, which can be captured in the trait–reputation–identity (TRI) model. Based on the TRI model, we investigate the link between personality and aligned job performance criteria on domain and aspect levels of the Big Five personality traits. In five samples (overall N = 571 triplets of target self-ratings and two coworker other-ratings), we investigated the relationships between the shared information on personality and shared information about job performance. We found that all personality domains showed substantial criterion validity in predicting the corresponding job-performance dimensions. Furthermore, we found stronger estimates for aspects of agreeableness and openness. We discuss theoretical and practical implications for target replacement and performance management

    A distinct CD38+CD45RA+ population of CD4+, CD8+, and double-negative T cells is controlled by FAS.

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    The identification and characterization of rare immune cell populations in humans can be facilitated by their growth advantage in the context of specific genetic diseases. Here, we use autoimmune lymphoproliferative syndrome to identify a population of FAS-controlled TCRαβ+ T cells. They include CD4+, CD8+, and double-negative T cells and can be defined by a CD38+CD45RA+T-BET- expression pattern. These unconventional T cells are present in healthy individuals, are generated before birth, are enriched in lymphoid tissue, and do not expand during acute viral infection. They are characterized by a unique molecular signature that is unambiguously different from other known T cell differentiation subsets and independent of CD4 or CD8 expression. Functionally, FAS-controlled T cells represent highly proliferative, noncytotoxic T cells with an IL-10 cytokine bias. Mechanistically, regulation of this physiological population is mediated by FAS and CTLA4 signaling, and its survival is enhanced by mTOR and STAT3 signals. Genetic alterations in these pathways result in expansion of FAS-controlled T cells, which can cause significant lymphoproliferative disease
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