Four-Step Domino Reaction Enables Fully Controlled Non-Statistical Synthesis of Hexaarylbenzene with Six Different Aryl Groups*

Hexaarylbenzene (HAB) derivatives are versatile aromatic systems playing a significant role as chromophores, liquid crystalline materials, molecular receptors, molecular-scale devices, organic light-emitting diodes and candidates for organic electronics. Statistical synthesis of simple symmetrical HABs is known via cyclotrimerization or Diels–Alder reactions. By contrast, the synthesis of more complex, asymmetrical systems, and without involvement of statistical steps, remains an unsolved problem. Here we present a generally applicable synthetic strategy to access asymmetrical HAB via an atom-economical and high-yielding metal-free four-step domino reaction using nitrostyrenes and α,α-dicyanoolefins as easily available starting materials. Resulting domino product—functionalized triarylbenzene (TAB)—can be used as a key starting compound to furnish asymmetrically substituted hexaarylbenzenes in high overall yield and without involvement of statistical steps. This straightforward domino process represents a distinct approach to create diverse and still unexplored HAB scaffolds, containing six different aromatic rings around central benzene core. © 2021 The Authors. Angewandte Chemie International Edition published by Wiley-VCH Gmb

Trap-Integrated Superconducting Nanowire Single-Photon Detectors with Improved RF Tolerance for Trapped-Ion Qubit State Readout

State readout of trapped-ion qubits with trap-integrated detectors can address important challenges for scalable quantum computing, but the strong rf electric fields used for trapping can impact detector performance. Here, we report on NbTiN superconducting nanowire single-photon detectors (SNSPDs) employing grounded aluminum mirrors as electrical shielding that are integrated into linear surface-electrode rf ion traps. The shielded SNSPDs can be successfully operated at applied rf trapping potentials of up to $\mathrm{54\,V_{peak}}$ at $\mathrm{70\,MHz}$ and temperatures of up to $\mathrm{6\,K}$, with a maximum system detection efficiency of $\mathrm{68\,\%}$. This performance should be sufficient to enable parallel high-fidelity state readout of a wide range of trapped ion species in typical cryogenic apparatus.Comment: 6 pages, 4 figures. The following article has been submitted to Applied Physics Letter

Anticonvulsants in the treatment of aggression in the demented elderly: an update

Complex psychopathological and behavioral symptoms, such as delusions and aggression against care providers, are often the primary cause of acute hospital admissions of elderly patients to emergency units and psychiatric departments. This issue resembles an interdisciplinary clinically highly relevant diagnostic and therapeutic challenge across many medical subjects and general practice. At least 50% of the dramatically growing number of patients with dementia exerts aggressive and agitated symptoms during the course of clinical progression, particularly at moderate clinical severity. METHODS: Commonly used rating scales for agitation and aggression are reviewed and discussed. Furthermore, we focus in this article on benefits and limitations of all available data of anticonvulsants published in this specific indication, such as valproate, carbamazepine, oxcarbazepine, lamotrigine, gabapentin and topiramate. RESULTS: To date, most positive and robust data are available for carbamazepine, however, pharmacokinetic interactions with secondary enzyme induction limit its use. Controlled data of valproate do not seem to support the use in this population. For oxcarbazepine only one controlled but negative trial is available. Positive small series and case reports have been reported for lamotrigine, gabapentin and topiramate. CONCLUSION: So far, data of anticonvulsants in demented patients with behavioral disturbances are not convincing. Controlled clinical trials using specific, valid and psychometrically sound instruments of newer anticonvulsants with a better tolerability profile are mandatory to verify whether they can contribute as treatment option in this indication

On Neutrino Oscillations and Time-Energy Uncertainty Relation

We consider neutrino oscillations as non stationary phenomenon based on Schrodinger evolution equation and mixed neutrino states with definite flavor. We demonstrate that for such states invariance under translations in time does not take place. We show that time-energy uncertainty relation plays a crucial role in neutrino oscillations. We compare neutrino oscillations with $K^{0}\leftrightarrows\bar K^{0}$, $B_{d}^{0}\leftrightarrows\bar B_{d}^{0}$ etc oscillations

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

Multiple Scenario Generation of Subsurface Models:Consistent Integration of Information from Geophysical and Geological Data throuh Combination of Probabilistic Inverse Problem Theory and Geostatistics

Neutrinos with energies above 1017 eV are detectable with the Surface Detector Array of the Pierre Auger Observatory. The identification is efficiently performed for neutrinos of all flavors interacting in the atmosphere at large zenith angles, as well as for Earth-skimming \u3c4 neutrinos with nearly tangential trajectories relative to the Earth. No neutrino candidates were found in 3c 14.7 years of data taken up to 31 August 2018. This leads to restrictive upper bounds on their flux. The 90% C.L. single-flavor limit to the diffuse flux of ultra-high-energy neutrinos with an E\u3bd-2 spectrum in the energy range 1.0 7 1017 eV -2.5 7 1019 eV is E2 dN\u3bd/dE\u3bd < 4.4 7 10-9 GeV cm-2 s-1 sr-1, placing strong constraints on several models of neutrino production at EeV energies and on the properties of the sources of ultra-high-energy cosmic rays

THz-Mikroskopie von additiv gefertigten Mikrostrukturen

THz microscopy was employed to investigate reflection and diffraction properties of additive manufactured structures in this thesis. These structures were irradiated by a far-infrared laser. The THz microscope was developed at the Institut für Elektrische Messtechnik und Grundlagen der Elektrotechnik. It generates three dimensional images by moving a sensor above a sample. The sensors are Josephson cantilevers, which consist of the high temperature superconductor YBa2Cu3O7 on LaAlO3 bicrystal substrates. These sensors are sensitive to high frequency electromagnetic radiation, static magnetic fields and temperature fields. A pre-characterization of the sensors is necessary. It can be performed in the THz microscope or in a separate setup. A scanning force procedure can be employed to collect topological data in addition. Furthermore, the Josephson cantilever can be complemented by other sensors such as pyroelectric detectors. These are also sensitive for high frequency radiation and are available at favorable prices. Though, they cannot reach the spatial resolution of the Josephson cantilever and not their frequency resolution. The far-infrared laser is optically pumped by a carbon dioxide laser. The Gaussian beam is quasi-optically coupled into the THz microscope by multiple mirrors and lenses. The calculated beam parameters are verified by measurements. Additive manufacturing processes offer the opportunity to manufacture prototypes for optical components very fast. The printing processes stereolithography (SLA), fused deposition modeling (FDM) and ceramic paste extrusion can be employed for different applications. Metrology is gaining importance in the field off additive manufacturing to obtain reproducible results. Diffraction gratings are optical components which are particularly suited for beam manipulation. Multiple diffraction gratings were calculated, constructed and eventually additively manufactured. These objects were implemented into the THz microscope and the diffraction patterns were investigated.In dieser Arbeit wird ein THz-Mikroskop eingesetzt, um additiv gefertigte Strukturen auf ihre Reflektions- und Beugungseigenschaften bei Bestrahlung mit einem Ferninfrarotlaser zu untersuchen. Das THz-Mikroskop wurde am Institut für Elektrische Messtechnik und Grundlagen der Elektrotechnik aufgebaut. Es erzeugt dreidimensionale Bilder durch die räumliche Bewegung eines Sensors oberhalb einer zu untersuchenden Probe. Hierbei kommen als Sensoren Josephson-Cantilever zum Einsatz, die aus dem Hochtemperatur-Supraleiter YBa2Cu3O7 auf LaAlO3 Bikristall-Substraten bestehen. Diese Sensoren sind für hochfrequente elektromagnetische Strahlung, statische Magnetfelder und Temperaturfelder empfindlich. Die hierfür vor dem Einsatz erforderliche Charakterisierung der Sensoren kann sowohl im THz-Mikroskop selbst, als auch in einem gesonderten Messaufbau erfolgen. Zusätzlich können im THz-Mikroskop auch topografische Daten mit einem Rasterkraft-Verfahren aufgenommen werden. Außerdem kann der Josephson-Cantilever durch andere Sensoren, wie beispielsweise pyroelektrische Detektoren, ergänzt werden. Diese sind ebenfalls empfindlich für hochfrequente elektromagnetische Strahlung und bieten eine günstige Alternative. Dabei erreichen sie aber weder die räumliche Auflösung des Josephson-Cantilevers noch dessen Frequenzauflösung. Der Ferninfrarotlaser wird durch einen Kohlendioxidlaser optisch gepumpt. Der gaußförmige Strahl wird über mehrere Spiegel und Linsen quasioptisch in das THz-Mikroskop eingekoppelt. Die berechneten Strahlparameter werden durch Messungen verifiziert. Additive Fertigungsverfahren bieten die Möglichkeit Prototypen für optische Komponenten sehr schnell zu fertigen. Die Verfahren der Stereolithografie (SLA), der Schmelzschichtung (FDM) und der keramische Pastendruck können für sehr unterschiedliche Anwendungen genutzt werden. Um reproduzierbare Ergebnisse zu erhalten, kommt der Metrologie im Bereich der Additiven Fertigung eine immer größer werdende Rolle zu. Beugungsgitter eignen sich besonders als optische Komponenten zur Strahlmanipulation. Diverse Beugungsgitter wurden ausgelegt, konstruiert und schließlich additiv gefertigt. Diese Objekte wurden abschließend im THz-Mikroskop eingebaut und die Beugungsmuster dreidimensional untersucht