The underlying objective of this external quality assessment (EQA) conducted by the German Quality Assurance Initiative (QuIP) was to evaluate the accuracy of different ROS1 testing methods in a multicenter approach. We evaluated the diagnostic performance of immunohistochemistry (IHC), in situ hybridization (ISH) and RNA/DNA sequencing (NGS) on non-small cell lung cancer (NSCLC) tissue samples. Samples were thoroughly pretested using IHC, ISH and RNA/DNA NGS, before starting the external EQA. The test cohort consisted of ten specimens each, including five ROS1 positive and five ROS1 negative samples for IHC/ISH and four ROS1 positive and six ROS1 negative samples for NGS. Twenty test sets were available for IHC and ISH, twenty-one test sets for NGS. The participants were provided with two unstained tumor slides for IHC/ISH and three unstained tumor slides for NGS and the results were submitted within 14 days via an online questionnaire. IHC has the highest passing rate with 90% (18/20 participants) while five different antibodies (Cell Signaling, DCS, Epitomics, Medac, Ventana) were used. The sensitivity for the IHC part was 96.9% and the specificity was 93.5%. ISH had the second highest passing rate (85%) with probes from Abbott Molecular and Zytovision and the sensitivity was 94% and the specificity was 97%. From 17 participants who used fluorescent ISH (FISH) 15 passed the ring trial and two out of three participants who used chromogenic ISH (CISH). The NGS samples were mainly processed with kits from ThermoFisher, Illumina and Archer and reached a sensitivity of 93.8% and a specificity of 99.1%. The NGS part had a passing rate of 76%. All three methods (IHC, ISH, NGS) produced reliable results for formalin-fixed samples within the different institutions and IHC achieved the highest passing rate. The highest sensitivity was observed for IHC whereas the highest specificity was seen for NGS. Most institutions used more than one method to confirm ROS1 positive samples. The German institutions seem to be well-positioned with regard to ROS1 testing in NSCLC patients, however the limited tissue availability may hamper the application of NGS for routine diagnostics.

The heat load of the original cryomodules for the continuous electron beam accelerator facility is similar to 50% higher than the target value of 100 W at 2.07 K for refurbished cavities operating at an accelerating gradient of 12.5 MV/m. This issue is due to the quality factor of the cavities being similar to 50% lower in the cryomodule than when tested in a vertical cryostat, even at low RF field. Previous studies were not conclusive about the origin of the additional losses. We present the results of a systematic study of the additional losses in a five-cell cavity from a decommissioned cryomodule after attaching components, which are part of the cryomodule, such as the cold tuner, theHe tank, and the cold magnetic shield, prior to cryogenic testing in a vertical cryostat. Flux-gate magnetometers and temperature sensors are used as diagnostic elements. Different cool-down procedures and tests in different residual magnetic fields were investigated during the study. Three flux-gate magnetometers attached to one of the cavities installed in the refurbished cryomodule C50-12 confirmed the hypothesis of high residual magnetic field as a major cause for the increased RF losses.

In planar GaAs microcavities in a magnetic field up to 5 T perpendicular to the structure growth plane, under conditions of resonant pulsed pumping to a point close to the inflection point of the lower dispersion curve, Zeeman splitting of the spin sublevels of the polariton condensate is observed. This is accompanied by a significant change in the degree of circular polarization and the second-order correlator g2(0). It is found that the correlator is different for the spin sublevels of the polariton condensate, split in a magnetic field. In particular, correlator measurements indicate different condensation thresholds for the spin sublevels. The correlator values initially differing in terms of the absence of a field increase, reach a maximum, and then decrease and become equal for different polarizations in a field of 5 T.

Despite their name polariton lasers do not rely on stimulated emission of cavity photons. The less stringent threshold conditions are the cause that bosonic polariton lasers can outperform standard lasers in terms of their threshold currents. The part-light and part-matter quasiparticles called polaritons, can undergo a condensation process into a common energy state. The radiated light from such a system shares many similarities with the light emitted from a conventional photon laser, even though the decay of the polaritons out of the finite lifetime cavity is a spontaneous process. We discuss properties of polariton condensates in GaAs based microcavities. The system’s response to an external magnetic field is used as a reliable tool to distinguish between polariton laser and conventional photon laser. In particular, we will discuss the realization of an electrically pumped polariton laser, which manifests a major step towards the exploitation of polaritonic devices in the real world.

We report on the fabrication of gallium arsenide (GaAs)/air distributed Bragg reflector microresonators with indium gallium arsenide quantum wells. The structures are studied via momentum resolved photoluminescence spectroscopy which allows us to investigate a pronounced optical mode quantization of the photonic dispersion. We can extract a length parameter from these quantized states whose upper limit can be connected to the lateral physical extension of the microcavity via analytical calculations. Laser emission from our microcavity under optical pumping is observed in power dependent investigations. (C) 2014 AIP Publishing LLC.

In this work, we combine a systematic experimental investigation of the power- and temperature-dependent evolution of the spatial coherence function, g^{(1)}(r), in a one dimensional exciton-polariton channel with a modern microscopic numerical theory based on a stochastic master equation approach. The spatial coherence function g^{(1)}(r) is extracted via high-precision Michelson interferometry, which allows us to demonstrate that in the regime of nonresonant excitation, the dependence g^{(1)}(r) reaches a saturation value with a plateau, which is determined by the intensity of the pump and effective temperature of the crystal lattice. The theory, which was extended to allow for treating incoherent excitation in a stochastic frame, matches the experimental data with good qualitative and quantitative agreement. This allows us to verify the prediction that the decay of the off-diagonal long-range order can be almost fully suppressed in one dimensional condensate systems.

We report exciton-polariton laser operation under electrical pumping. The hybrid light-matter nature of this lasing system is probed by measuring the exciton-polariton Zeeman-splitting, which clearly reveals that this laser remains in the strong coupling regime.

Aim: Despite standard therapy for GBM, median survival is 1-2 years. Abnormal epidermal growth factor receptor (EGFR) expression and signaling are common in GBM. ABT-414 is a unique antibody-drug conjugate, with a toxic payload (monomethylauristatin F) targeted to active EGFR or mutant EGFRvIII, that has demonstrated high antitumor activity in preclinical GBM tumor models.

Polycrystalline GaN fibers have been produced by the polymer-derived-ceramic (PDC) technique. The wurtzite-polymorphic fibers appear to emerge from complex nucleation and grain growth mechanisms, being mostly unconstrained during initial polymer to ceramic conversion. The importance of carrier polymer architecture and alignment is highlighted towards controlled microstructure.

Polariton lasers do not rely on stimulated emission of cavity photons, which sets stringent conditions on the threshold current in a conventional laser. Indeed, it has been demonstrated in optically pumped systems, that bosonic polariton lasers can outperform standard lasers in terms of their threshold power. The polaritons, which are part light and part matter quasiparticles, can undergo a condensation process into a common energy state. The radiated light from such a system shares many similarities with the light emitted from a conventional photon laser, even though the decay of the polaritons is a spontaneous process. We discuss properties of polariton lasers and condensates in GaAs based microcavities. Special emphasis is given to the system’s response to an applied magnetic field. We introduce the magnetic field interactions as a reliable tool to distinguish a polariton laser from a conventional photon laser device. In particular, we will discuss the first successful realization of an electrically pumped polariton laser, which marks a promising step towards the exploitation of polaritonic devices in the real world. We believe that our work can be extended to devices operated at room temperature by transferring the technology to large bandgap semiconductors, or even to GaAs samples with a modified layer design.

The potential of novel, carbon and nitrogen doped Ti-oxides for application as Pt-free catalyst for the oxygen reduction reaction (ORR) in polymer electrolyte fuel cell cathodes was systematically investigated in model studies under well defined reaction conditions. Ti oxide was prepared by a sol-gel process; doping of titania with N and C was performed via reactive incorporation during the sol-gel processing and the subsequent calcination step, using the Ti-alkoxide precursor and urea, which is added during the sol-gel synthesis, as carbon source and urea also as nitrogen source. Optimizing the chemical composition of the catalyst was performed by varying the calcination temperature or the amount of urea. Characterization of the resulting material by X-ray photoelectron spectroscopy (XPS) identified Ti–O–C, Ti–O–N and O–Ti–N building blocks, providing clear evidence for the incorporation of N and C into the TiOx lattice; the concentrations of the species depend on the calcination temperature and on the amount of urea added. Doping with nitrogen was found to significantly improve the ORR performance compared to non-doped TiOx, with the extent depending on the calcination temperature and the N:Ti ratio. Correlations between ORR activity and the lattice composition and crystallinity are discussed. Finally, the activity for oxidation/reduction of the ORR intermediate hydrogen peroxide was tested, yielding similar trends but less pronounced effects than obtained for the ORR.

We comparably investigate the diamagnetic shift of an uncoupled quantum well exciton with a microcavity exciton-polariton condensate on the same device. The sample is composed of multiple GaAs quantum wells in an AlAs microcavity, surrounded by a Bragg reflector and a sub-wavelength high contrast grating reflector. Our study introduces an independent and easily applicable technique, namely, the measurement of the condensate diamagnetic shift, which directly probes matter contributions in polariton condensates and hence discriminates it from a conventional photon laser.

We observe a strong variation of the Zeeman splitting of exciton polaritons in microcavities when switching between the linear regime, the polariton lasing, and photon lasing regimes. In the polariton lasing regime the sign of Zeeman splitting changes compared to the linear regime, while in the photon lasing regime the splitting vanishes. We additionally observe an increase of the diamagnetic shift in the polariton lasing regime. These effects are explained in terms of the nonequilibrium "spin Meissner effect."

Polariton lasing under electrical pumping is observed in a GaAs multi-quantum-well microcavity diode. Lasing in the strong-coupling regime is unambiguously evidenced by detection of Zeeman-split emission in an external magnetic field as a result of the polaritons’ excitonic content.

We present a diode incorporating a large number (12) of GaAs quantum wells that emits light from exciton-polariton states at room temperature. A reversely biased tunnel junction is placed in the cavity region to improve current injection into the device. Electroluminescence studies reveal two polariton branches which are spectrally separated by a Rabi splitting of 6.5 meV. We observe an anticrossing of the two branches when the temperature is lowered below room temperature as well as a Stark shift of both branches in a bias dependent photoluminescence measurement.

We report on pronounced magneto-optical effects of trapped polariton modes in a single InGaAs quantum well microresonator with a lithographically defined modulation of the cavity length. In our optical polariton traps with diameters ranging from 1 to 10 μm, a confinement potential of 7.5 meV is achieved. In magnetic-field dependent experiments, a diamagnetic shift and a Zeeman splitting of the trap-modes are observed which confirms that the polaritonic nature of the quantized emission modes are preserved even for traps as small as 1 μm. Furthermore, focusing on theoretical estimates using a simple model, we have identified a clear correlation between the polaritons' magnetic response and their excitonic fraction, corresponding to the Hopfield coefficients of the composite particles.