2,353 results match your criteria: "Institute of Experimental Physics[Affiliation]"

'Young crystallographers' rejuvenate crystallography in Germany.

Acta Crystallogr E Crystallogr Commun

March 2024

Institut für Umwelt- und Naturwissenschaften, Universität Freiburg, Freiburg, Baden-Wurttemberg 79104, Germany.

Since its founding in 2013, the Young Crystallographers (YC) have become one of the most active working groups not only within their parent organization, the German Crystallographic Society (DGK), but also among other young crystallographers' groups in Europe and the world. The aim of the YC is and always has been to support early-career researchers in the diverse fields of crystallography and the rejuvenation of the field on a national scale. Over the past decade, we have curated events, platforms, and educational content tailored to foster collaboration and knowledge transfer among young crystallographers.

View Article and Find Full Text PDF

Eukaryotic mRNAs undergo cotranscriptional 5'-end modification with a 7-methylguanosine cap. In higher eukaryotes, the cap carries additional methylations, such as A─a common epitranscriptomic mark unique to the mRNA 5'-end. This modification is regulated by the Pcif1 methyltransferase and the FTO demethylase, but its biological function is still unknown.

View Article and Find Full Text PDF

This work presents a spectroscopic and photocatalytic comparison of water splitting using yttrium iron garnet (YFeO, YIG) and hematite (α-FeO) photoanodes. Despite similar electronic structures, YIG significantly outperforms widely studied hematite, displaying more than an order of magnitude increase in photocurrent density. Probing the charge and spin dynamics by ultrafast, surface-sensitive XUV spectroscopy reveals that the enhanced performance arises from (1) reduced polaron formation in YIG compared to hematite and (2) an intrinsic spin polarization of catalytic photocurrents in YIG.

View Article and Find Full Text PDF

The first search for scalar leptoquarks produced in τ-lepton-quark collisions is presented. It is based on a set of proton-proton collision data recorded with the CMS detector at the LHC at a center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 138  fb^{-1}. The reconstructed final state consists of a jet, significant missing transverse momentum, and a τ lepton reconstructed through its hadronic or leptonic decays.

View Article and Find Full Text PDF

Alignment of each optical element at a synchrotron beamline takes days, even weeks, for each experiment costing valuable beam time. Evolutionary algorithms (EAs), efficient heuristic search methods based on Darwinian evolution, can be utilized for multi-objective optimization problems in different application areas. In this study, the flux and spot size of a synchrotron beam are optimized for two different experimental setups including optical elements such as lenses and mirrors.

View Article and Find Full Text PDF

Energy dissipation and the transfer rate of adsorbed molecules do not only determine the rates of chemical reactions but are also a key factor that often dictates the growth of organic thin films. Here, we present a study of the surface dynamical motion of cobalt phthalocyanine (CoPc) on Ag(100) in reciprocal space based on the helium spin-echo technique in comparison with previous scanning tunnelling microscopy studies. It is found that the activation energy for lateral diffusion changes from 150 meV at 45-50 K to ≈100 meV at 250-350 K, and that the process goes from exclusively single jumps at low temperatures to predominantly long jumps at high temperatures.

View Article and Find Full Text PDF
Article Synopsis
  • mRNA-based drugs are rapidly advancing, particularly as viral vaccines, with potential uses in various diseases due to their easy and adaptable production process.
  • The structure of mRNA components, especially modifications at the 5' cap, significantly influences its effectiveness and longevity in medical applications.
  • This study focuses on synthesizing modified cap analogues and testing these compounds for their ability to act as translation inhibitors and improve mRNA preparation.
View Article and Find Full Text PDF

Eukaryotic initiation factor 4E (eIF4E) is a pivotal protein involved in the regulatory mechanism for global protein synthesis in both physiological and pathological conditions. MicroRNAs (miRNAs) play a significant role in regulating gene expression by targeting mRNA. However, the ability of miRNAs to regulate eIF4E and its phosphorylation remains relatively unknown.

View Article and Find Full Text PDF

Molecular sequence data have transformed research on cryptogams (e.g., lichens, microalgae, fungi, and symbionts thereof) but methods are still strongly hampered by the small size and intermingled growth of the target organisms, poor cultivability and detrimental effects of their secondary metabolites.

View Article and Find Full Text PDF

Surface plasmon polaritons (SPPs) can confine and guide light in nanometer volumes and are ideal tools for achieving electric field enhancement and the construction of nanophotonic circuitry. The realization of the highest field strengths and fastest switching requires confinement also in the temporal domain. Here, we demonstrate a tapered plasmonic waveguide with an optimized grating structure that supports few-cycle surface plasmon polaritons with >70 THz bandwidth while achieving >50% light-field-to-plasmon coupling efficiency.

View Article and Find Full Text PDF

Plastic deformation of low/high density polyethylene (LDPE/HDPE) was analyzed in this work using positron annihilation lifetime spectroscopy (PALS). It was shown that in undeformed LDPE, both the mean ortho-positronium lifetime (τ) and its dispersion (σ), corresponding to the average size and size distribution of the free-volume pores of the amorphous component, respectively, were clearly higher than in HDPE. This effect was induced by a lower and less uniform molecular packing of the amorphous regions in LDPE.

View Article and Find Full Text PDF

ψ(2S) Suppression in Pb-Pb Collisions at the LHC.

Phys Rev Lett

January 2024

INFN, Sezione di Pavia, Pavia, Italy.

The production of the ψ(2S) charmonium state was measured with ALICE in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV, in the dimuon decay channel. A significant signal was observed for the first time at LHC energies down to zero transverse momentum, at forward rapidity (2.

View Article and Find Full Text PDF

A search for dark matter in events with a displaced nonresonant muon pair and missing transverse momentum is presented. The analysis is performed using an integrated luminosity of 138  fb^{-1} of proton-proton (pp) collision data at a center-of-mass energy of 13 TeV produced by the LHC in 2016-2018. No significant excess over the predicted backgrounds is observed.

View Article and Find Full Text PDF

Rotational diffusion of colloidal microspheres near flat walls.

Soft Matter

February 2024

Institute of Experimental Physics of Condensed Matter, Heinrich-Heine University, Düsseldorf, Germany.

Recently, colloids with an off-center fluorescent core and homogeneous composition have been developed to measure the rotational diffusivity of microparticles using 3D confocal microscopy in refractive index-matched suspensions. Here, we show that the same particles may be imaged using a standard fluorescence microscope to yield their rotational diffusion coefficients. Trajectories of the off-center core may be combined with known expressions for the correlation decay of particle orientations to determine an effective rotational diffusivity.

View Article and Find Full Text PDF
Article Synopsis
  • The optical behavior of 2D perovskites relies heavily on excitons, which can be manipulated by altering the thickness of the perovskite layers.
  • Researchers studied the exciton fine structure in a specific 2D perovskite by varying the number of inorganic layers from 1 to 4.
  • Their findings reveal splitting of excitonic states across different confinement levels and show how the optical properties transition from 2D to 3D as the layer thickness increases.
View Article and Find Full Text PDF

Moiré excitons (MXs) are electron-hole pairs localised by the periodic (moiré) potential forming in two-dimensional heterostructures (HSs). MXs can be exploited, e.g.

View Article and Find Full Text PDF

Griffiths-like behavior and magnetocaloric properties of rare-earth silicide TbCoSi.

J Phys Condens Matter

February 2024

Intermetallics and Non-Linear Optics Laboratory, Department of Physics, National Institute of Technology, Tiruchirappalli 620 015, India.

Novel rare-earth silicide, TbCoSicompound, crystallizes in LuCoGastructure, a distorted substitution variant of thestructure. The compound exhibits a complex magnetic state, with a ferromagnetic transition at 58 K, followed by successive antiferromagnetic transitions at 24 K and 8 K, respectively. Isothermal and magnetic hysteresis studies indicate the prominence of competing antiferro and ferromagnetic interactions in the compound.

View Article and Find Full Text PDF

This Letter reports the observation of WZγ production and a measurement of its cross section using 140.1±1.2  fb^{-1} of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider.

View Article and Find Full Text PDF

The first evidence for the Higgs boson decay to a Z boson and a photon is presented, with a statistical significance of 3.4 standard deviations. The result is derived from a combined analysis of the searches performed by the ATLAS and CMS Collaborations with proton-proton collision datasets collected at the CERN Large Hadron Collider (LHC) from 2015 to 2018.

View Article and Find Full Text PDF

We aimed to determine effects of aliskiren, a direct renin inhibitor, loaded onto polymeric nanoparticles on the (pro)renin receptor (), angiotensin II type 1 receptor (), and angiotensin-converting enzyme () gene expression in the heart of spontaneously hypertensive rats (SHR). Twelve-week-old male SHRs were divided into an untreated group and groups treated with powdered aliskiren or aliskiren-loaded nanoparticles (25 mg/kg/day). After three weeks, the accumulation of aliskiren, distribution of polymeric nanoparticles, gene expression of and receptors and , and protein expression of NADPH oxidase along with the conjugated diene (CD) concentration were analyzed.

View Article and Find Full Text PDF

Electrodeposited Heusler Alloys-Based Nanowires for Shape Memory and Magnetocaloric Applications.

Materials (Basel)

January 2024

Centre for Progressive Materials, Technology, and Innovation Park, Pavol Jozef Safarik University in Kosice, Tr. SNP 1, 040 11 Kosice, Slovakia.

In this article, the downsizing of functional Heusler alloys is discussed, focusing on the published results dealing with Heusler alloy nanowires. The theoretical information inspired the fabrication of novel nanowires that are presented in the results section of the article. Three novel nanowires were fabricated with the compositions of NiFeGa, NiFeIn, and NiFeSn.

View Article and Find Full Text PDF

Histidine residues contribute to numerous molecular interactions, owing to their structure with the ionizable aromatic side chain with pK close to the physiological pH. Herein, we studied how the two histidine residues, His115 and His160 of the catalytic subunit of human protein kinase CK2, affect the binding of the halogenated heterocyclic ligands at the ATP-binding site. Thermodynamic studies on the interaction between five variants of hCK2α (WT protein and four histidine mutants) and three ionizable bromo-benzotriazoles and their conditionally non-ionizable benzimidazole counterparts were performed with nanoDSF, MST, and ITC.

View Article and Find Full Text PDF

All-Glass 100 mm Diameter Visible Metalens for Imaging the Cosmos.

ACS Nano

January 2024

John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States.

Metasurfaces, optics made from subwavelength-scale nanostructures, have been limited to millimeter-sizes by the scaling challenge of producing vast numbers of precisely engineered elements over a large area. In this study, we demonstrate an all-glass 100 mm diameter metasurface lens (metalens) comprising 18.7 billion nanostructures that operates in the visible spectrum with a fast -number (/1.

View Article and Find Full Text PDF
Article Synopsis
  • - The study investigates the strange quark content of protons by measuring the production cross section of W bosons and charm quarks in proton-proton collisions at 13 TeV, using data from the CMS detector at the LHC.
  • - W bosons are identified through their decays into leptons (electrons or muons) and neutrinos, while charm quarks are tagged by detecting muons or secondary vertices in jets.
  • - The measurements, which reach a precision of 1%, include both inclusive and differential analyses based on the transverse momentum and pseudorapidity of the leptons, and the results are compared with advanced theoretical predictions in quantum chromodynamics.
View Article and Find Full Text PDF

The measurement of Z boson production is presented as a method to determine the integrated luminosity of CMS data sets. The analysis uses proton-proton collision data, recorded by the CMS experiment at the CERN LHC in 2017 at a center-of-mass energy of 13. Events with Z bosons decaying into a pair of muons are selected.

View Article and Find Full Text PDF