2,244 results match your criteria: "Universitat Dortmund[Affiliation]"
Nano Lett
January 2020
Experimentelle Physik 2 , Technische Universität Dortmund, 44227 Dortmund , Germany.
CdSe colloidal nanoplatelets are studied by spin-flip Raman scattering in magnetic fields up to 5 T. We find pronounced Raman lines shifted from the excitation laser energy by an electron Zeeman splitting. Their polarization selection rules correspond to those expected for scattering mediated by excitons interacting with resident electrons.
View Article and Find Full Text PDFPhys Rev Lett
November 2019
INFN Sezione di Bologna, Bologna, Italy.
Results are reported from a search for the rare decays B_{s}^{0}→τ^{±}μ^{∓} and B^{0}→τ^{±}μ^{∓}, where the τ lepton is reconstructed in the channel τ^{-}→π^{-}π^{+}π^{-}ν_{τ}. These processes are effectively forbidden in the standard model, but they can potentially occur at detectable rates in models of new physics that can induce lepton-flavor-violating decays. The search is based on a data sample corresponding to 3 fb^{-1} of proton-proton collisions recorded by the LHCb experiment in 2011 and 2012.
View Article and Find Full Text PDFPhys Chem Chem Phys
February 2020
Stanford PULSE Institute, SLAC National Accelerator Laboratory, USA. and SLAC National Accelerator Laboratory, USA.
The recent demonstration of isolated attosecond pulses from an X-ray free-electron laser (XFEL) opens the possibility for probing ultrafast electron dynamics at X-ray wavelengths. An established experimental method for probing ultrafast dynamics is X-ray transient absorption spectroscopy, where the X-ray absorption spectrum is measured by scanning the central photon energy and recording the resultant photoproducts. The spectral bandwidth inherent to attosecond pulses is wide compared to the resonant features typically probed, which generally precludes the application of this technique in the attosecond regime.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
February 2020
Rheinische Friedrich-Wilhelms-Universität Bonn, Kekulé-Institut für Organische Chemie und Biochemie, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany.
Two new heterobimetallic cages, a trigonal-bipyramidal and a cubic one, were assembled from the same mononuclear metalloligand by adopting the molecular library approach, using iron(II) and palladium(II) building blocks. The ligand system was designed to readily assemble through subcomponent self-assembly. It allowed the introduction of steric strain at the iron(II) centres, which stabilizes its paramagnetic high-spin state.
View Article and Find Full Text PDFNat Commun
November 2019
Department of Physics, University of Zurich, 8057, Zurich, Switzerland.
Molecular reactivity is determined by the energy levels and spatial extent of the frontier orbitals. Orbital tomography based on angle-resolved photoelectron spectroscopy is an elegant method to study the electronic structure of organic adsorbates, however, it is conventionally restricted to systems with one single rotational domain. In this work, we extend orbital tomography to systems with multiple rotational domains.
View Article and Find Full Text PDFACS Chem Biol
December 2019
Department of Multi-Modal Molecular (M3) Biology , Institute of Molecular and Cell Biology, 61 Biopolis Drive , 138673 Singapore.
The transcriptional co-regulators YAP (Yes-associated protein) and TAZ (transcriptional coactivator with PDZ-binding motif) are the vertebrate downstream effectors of the Hippo signaling pathway that controls various physiological and pathological processes. YAP and TAZ pair with the TEAD (TEA domain) family of transcription factors to initiate transcription. We previously identified a tractable pocket in TEADs, which has been physiologically shown to bind palmitate.
View Article and Find Full Text PDFNat Commun
November 2019
Department of Chemistry, and Materials Science Division Lawrence Berkeley, National Laboratory University of California, Berkeley, CA, 94720, USA.
The origins of spin lifetimes in quantum systems is a matter of importance in several areas of quantum information. Spectrally mapping spin relaxation processes provides insight into their origin and motivates methods to mitigate them. In this paper, we map nuclear relaxation in a prototypical system of [Formula: see text] nuclei in diamond coupled to Nitrogen Vacancy (NV) centers over a wide field range (1 mT-7 T).
View Article and Find Full Text PDFNat Commun
November 2019
Department of Physics and Astronomy, University of Sheffield, Sheffield, S3 7RH, UK.
Unique structural and optical properties of atomically thin two-dimensional semiconducting transition metal dichalcogenides enable in principle their efficient coupling to photonic cavities having the optical mode volume close to or below the diffraction limit. Recently, it has become possible to make all-dielectric nano-cavities with reduced mode volumes and negligible non-radiative losses. Here, we realise low-loss high-refractive-index dielectric gallium phosphide (GaP) nano-antennas with small mode volumes coupled to atomic mono- and bilayers of WSe[Formula: see text].
View Article and Find Full Text PDFRadiat Prot Dosimetry
June 2020
Materialprüfungsamt NRW, Marsbruchstr. 186, 44287 Dortmund, Germany.
A new thermoluminescence albedo dosemeter with improved properties is developed as part of the TL-DOS project. The dosemeter measures the neutron and photon whole-body dose of radiation workers. The TL-DOS neutron dosemeter is presented and its results of well-known field measurements as well as field calibrations are shown.
View Article and Find Full Text PDFThis Letter presents the observation and measurement of electroweak production of a same-sign W boson pair in association with two jets using 36.1 fb^{-1} of proton-proton collision data recorded at a center-of-mass energy of sqrt[s]=13 TeV by the ATLAS detector at the Large Hadron Collider. The analysis is performed in the detector fiducial phase-space region, defined by the presence of two same-sign leptons, electron or muon, and at least two jets with a large invariant mass and rapidity difference.
View Article and Find Full Text PDFPhys Rev Lett
October 2019
INFN Sezione di Bologna, Bologna, Italy.
We report the observation of a new structure in the Λ_{b}^{0}π^{+}π^{-} spectrum using the full LHCb data set of pp collisions, corresponding to an integrated luminosity of 9 fb^{-1}, collected at sqrt[s]=7, 8, and 13 TeV. A study of the structure suggests its interpretation as a superposition of two almost degenerate narrow states. The masses and widths of these states are measured to be m_{Λ_{b}(6146)^{0}}=6146.
View Article and Find Full Text PDFChembiochem
December 2019
Vrije Universiteit Amsterdam, Department of Chemistry and Pharmaceutical Sciences, De Boelelaan 1083, 1081 HV, Amsterdam, The Netherlands.
The acyl-binding UNC119 proteins mediate the activation and transport of various N-myristoylated proteins. In particular, UNC119a plays a crucial role in the completion of cytokinesis. Herein, we report the use of a lipidated peptide originating from the UNC119 binding partner Gnat1 as the basis for the design of lipidated, stabilized α-helical peptides that target UNC119a.
View Article and Find Full Text PDFNano Lett
December 2019
Dipartimento di Scienza dei Materiali , Università degli Studi di Milano-Bicocca, via Roberto Cozzi 55 , I-20125 Milano , Italy.
Colloidal CdSe nanocrystals (NCs) overcoated with an ultrathick CdS shell, also known as dot-in-bulk (DiB) structures, can support two types of excitons, one of which is core-localized and the other, shell-localized. In the case of weak "sub-single-exciton" pumping, emission alternates between the core- and shell-related channels, which leads to two-color light. This property makes these structures uniquely suited for a variety of photonic applications as well as ideal model systems for realizing complex excitonic quasi-particles that do not occur in conventional core/shell NCs.
View Article and Find Full Text PDFSci Adv
October 2019
Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany.
Electron paramagnetic resonance (EPR) spectroscopy on protein single crystals is the ultimate method for determining the electronic structure of paramagnetic intermediates at the active site of an enzyme and relating the magnetic tensor to a molecular structure. However, crystals of dimensions typical for protein crystallography (0.05 to 0.
View Article and Find Full Text PDFBioorg Chem
December 2019
Lehrstuhl für Analytische Chemie, Institut für Umweltforschung, Fakultät für Chemie und Chemische Biologie, Universität Dortmund, Otto-Hahn-Straße 6, 44221 Dortmund, Nordrhein-Westfalen, Germany.
The paper addressed shortcoming with highly precise and selective 3D structural analysis of native cyclodextrins in mixture using ions observable at low m/z-region by ESI- and APCI-mass spectrometry. Because of, the quantitative and structural analyses of CDs, in general, are vexed by a set of complications. The study outlines our own stochastic dynamic approaches to the latter issues based on new model relations, quantifing the measurable MS outcome intensity.
View Article and Find Full Text PDFMed Phys
December 2019
Institut für Medizinische Strahlenphysik und Strahlenschutz, Klinikum Dortmund, D-44137, Dortmund, Germany.
Purpose: Measurement of the modulation transfer function (MTF) is performed by evaluating the response of an imaging system to a predefined input. To obtain accurate results when using an edge phantom, the detector input signal must resemble an ideal step function. The MTF of megavoltage (MV) imagers used in radiotherapy has been measured with highly absorbing edge phantoms fabricated from thick metal blocks.
View Article and Find Full Text PDFPhys Rev E
August 2019
Fakultät Physik, Technische Universität Dortmund, 44221 Dortmund, Germany.
A broad survey of viscoelastic data demonstrates that van der Waals, hydrogen-bonded, and ionic liquids, as well as polymeric, inorganic, and metallic melts share a structural relaxation pattern virtually insensitive to their morphological details. This mechanical simplicity is connected with that characterizing the fast reorientation dynamics prevailing in liquids devoid of a distinguishable secondary susceptibility peak. By these means one is able to uncover a generic spectral pattern which rationalizes the recently reported "universality" of relaxation strength vs stretching of the dielectric response of viscous liquids, significantly broadening the framework in which their relaxation behavior is assessed.
View Article and Find Full Text PDFBiophys Chem
November 2019
Institut für Physikalische und Theoretische Chemie, Universität Regensburg, 93040 Regensburg, Germany. Electronic address:
Molecular simulations based on classical force fields are a powerful method for shedding light on the complex behavior of biomolecules in solution. When cosolutes are present in addition to water and biomolecules, subtle balances of weak intermolecular forces have to be accounted for. This imposes high demands on the quality of the underlying force fields, and therefore force field development for small cosolutes is still an active field.
View Article and Find Full Text PDFChemistry
December 2019
Abteilung Chemische Biologie, Max-Planck-Institut für Molekulare Physiologie, Otto-Hahn-Straße 11, 44227, Dortmund, Germany.
A "branching-folding" synthetic strategy that affords a range of diverse cyclic benzo-sulfonamide scaffolds is presented. Whereas different annulation reactions on common ketimine substrates build the branching phase of the scaffold synthesis, a common hydrogenative ring-expansion method, facilitated by an increase of the ring-strain during the branching phase, led to sulfonamides bearing medium-sized rings in a folding pathway. Cell painting assay was successfully employed to identify tubulin targeting sulfonamides as novel mitotic inhibitors.
View Article and Find Full Text PDFPhys Rev Lett
August 2019
CERN, Geneva, Switzerland.
This Letter describes the observation of the light-by-light scattering process, γγ→γγ, in Pb+Pb collisions at sqrt[s_{NN}]=5.02 TeV. The analysis is conducted using a data sample corresponding to an integrated luminosity of 1.
View Article and Find Full Text PDFCharged-particle fragmentation functions for jets azimuthally balanced by a high-transverse-momentum, prompt, isolated photon are measured in 25 pb^{-1} of pp and 0.49 nb^{-1} of Pb+Pb collision data at 5.02 TeV per nucleon pair recorded with the ATLAS detector at the Large Hadron Collider.
View Article and Find Full Text PDFPhys Rev Lett
August 2019
INFN Sezione di Bologna, Bologna, Italy.
A time-dependent analysis of the B_{s}^{0}→ϕγ decay rate is performed to determine the CP -violating observables S_{ϕγ} and C_{ϕγ} and the mixing-induced observable A_{ϕγ}^{Δ}. The measurement is based on a sample of pp collision data recorded with the LHCb detector, corresponding to an integrated luminosity of 3 fb^{-1} at center-of-mass energies of 7 and 8 TeV. The measured values are S_{ϕγ}=0.
View Article and Find Full Text PDFACS Nano
September 2019
Experimentelle Physik 2 , Technische Universität Dortmund, 44227 Dortmund , Germany.
Colloidal InP core nanocrystals are taking over CdSe-based nanocrystals, notably in optoelectronic applications. Despite their use in commercial devices, such as display screens, the optical properties of InP nanocrystals and especially their relation to the exciton fine structures remain poorly understood. In this work, we show that the ensemble magneto-optical properties of InP-based core/shell nanocrystals investigated in strong magnetic fields up to 30 T are strikingly different from other colloidal nanostructures.
View Article and Find Full Text PDFPhys Chem Chem Phys
September 2019
Institute of Chemical Kinetics and Combustion, SB RAS, 630090 Novosibirsk, Russia. and Novosibirsk State University, 630090 Novosibirsk, Russia.
Using all-atom molecular dynamics simulations of aqueous solutions of the globular protein SNase, the dynamic behavior of water molecules and cosolvents (trimethylamine-N-oxide (TMAO) and urea) in the hydration shell of the protein was studied for different solvent compositions. TMAO is a potent protein-stabilizing osmolyte, whereas urea is known to destabilize proteins. For molecules that are initially located in successive narrow layers at a given distance from the protein, the mean displacements and the distribution of displacements for short time intervals are calculated.
View Article and Find Full Text PDFCogn Process
November 2019
Elastic Lightweight Robotics Group, Robotics Research Institute, Technische Universität Dortmund, Dortmund, Germany.
Bayesian cognitive modeling has become a prominent tool for the cognitive sciences aiming at a deeper understanding of the human mind and applications in cognitive systems, e.g., humanoid or wearable robotics.
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