Nuclear Modification Factor of Neutral Pions in the Forward and Backward Regions in p-Pb Collisions.

The nuclear modification factor of neutral pions is measured in proton-lead collisions collected at a center-of-mass energy per nucleon of 8.16 TeV with the LHCb detector. The π^{0} production cross section is measured differentially in transverse momentum (p_{T}) for 1.

First Observation of a Doubly Charged Tetraquark and Its Neutral Partner.

A combined amplitude analysis is performed for the decays B^{0}→D[over ¯]^{0}D_{s}^{+}π^{-} and B^{+}→D^{-}D_{s}^{+}π^{+}, which are related by isospin symmetry. The analysis is based on data collected by the LHCb detector in proton-proton collisions at center-of-mass energies of 7, 8, and 13 TeV. The full data sample corresponds to an integrated luminosity of 9  fb^{-1}.

Long-Lived Exciton Coherence in Mixed-Halide Perovskite Crystals.

Compositional engineering of the optical properties of hybrid organic-inorganic lead halide perovskites is crucial for the realization of efficient solar cells and light-emitting devices. We study the effect of band gap fluctuations on coherent exciton dynamics in a mixed FACsPbIBr perovskite crystal by using photon echo spectroscopy. We reveal a narrow homogeneous exciton line width of 16 μeV at a temperature of 1.

Observation of a J/ψΛ Resonance Consistent with a Strange Pentaquark Candidate in B^{-}→J/ψΛp[over ¯] Decays.

An amplitude analysis of B^{-}→J/ψΛp[over ¯] decays is performed using 4400 signal candidates selected on a data sample of pp collisions recorded at center-of-mass energies of 7, 8, and 13 TeV with the LHCb detector, corresponding to an integrated luminosity of 9  fb^{-1}. A narrow resonance in the J/ψΛ system, consistent with a pentaquark candidate with strangeness, is observed with high significance. The mass and the width of this new state are measured to be 4338.

Pushing the Upper Limit of Nucleophilicity Scales by Mesoionic N-Heterocyclic Olefins.

A series of mesoionic, 1,2,3-triazole-derived N-heterocyclic olefins (mNHOs), which have an extraordinarily electron-rich exocyclic CC-double bond, was synthesized and spectroscopically characterized, in selected cases by X-ray crystallography. The kinetics of their reactions with arylidene malonates, ArCH=C(CO Et) , which gave zwitterionic adducts, were investigated photometrically in THF at 20 °C. The resulting second-order rate constants k (20 °C) correlate linearly with the reported electrophilicity parameters E of the arylidene malonates (reference electrophiles), thus providing the nucleophile-specific N and s parameters of the mNHOs according to the correlation lg k (20 °C)=s (N+E).

Dissecting the Molecular Origin of -Tensor Heterogeneity and Strain in Nitroxide Radicals in Water: Electron Paramagnetic Resonance Experiment versus Theory.

Nitroxides are common EPR sensors of microenvironmental properties such as polarity, numbers of H-bonds, pH, and so forth. Their solvation in an aqueous environment is facilitated by their high propensity to form H-bonds with the surrounding water molecules. Their - and -tensor elements are key parameters to extracting the properties of their microenvironment.

Electron Induced Nanoscale Nuclear Spin Relaxation Probed by Hyperpolarization Injection.

We report on experiments that quantify the role of a central electronic spin as a relaxation source for nuclear spins in its nanoscale environment. Our strategy exploits hyperpolarization injection from the electron as a means to controllably probe an increasing number of nuclear spins in the bath and subsequently interrogate them with high fidelity. Our experiments are focused on a model system of a nitrogen vacancy center electronic spin surrounded by several hundred ^{13}C nuclear spins.

Breathing porous liquids based on responsive metal-organic framework particles.

Responsive metal-organic frameworks (MOFs) that display sigmoidal gas sorption isotherms triggered by discrete gas pressure-induced structural transformations are highly promising materials for energy related applications. However, their lack of transportability via continuous flow hinders their application in systems and designs that rely on liquid agents. We herein present examples of responsive liquid systems which exhibit a breathing behaviour and show step-shaped gas sorption isotherms, akin to the distinct oxygen saturation curve of haemoglobin in blood.

Inhibition of Pertussis Toxin by Human α-Defensins-1 and -5: Differential Mechanisms of Action.

Whooping cough is a severe childhood disease, caused by the bacterium , which releases pertussis toxin (PT) as a major virulence factor. Previously, we identified the human antimicrobial peptides α-defensin-1 and -5 as inhibitors of PT and demonstrated their capacity to inhibit the activity of the PT enzyme subunit PTS1. Here, the underlying mechanism of toxin inhibition was investigated in more detail, which is essential for developing the therapeutic potential of these peptides.

Accounting for time dependency in meta-analyses of concordance probability estimates.

Recent years have seen the development of many novel scoring tools for disease prognosis and prediction. To become accepted for use in clinical applications, these tools have to be validated on external data. In practice, validation is often hampered by logistical issues, resulting in multiple small-sized validation studies.

Local solvation structures govern the mixing thermodynamics of glycerol-water solutions.

Glycerol is a major cryoprotective agent and is widely used to promote protein stabilization. By a combined experimental and theoretical study, we show that global thermodynamic mixing properties of glycerol and water are dictated by local solvation motifs. We identify three hydration water populations, , bulk water, bound water (water hydrogen bonded to the hydrophilic groups of glycerol) and cavity wrap water (water hydrating the hydrophobic moieties).

Universal magnetic proximity effect in ferromagnet-semiconductor quantum well hybrid structures.

Hybrid ferromagnet-semiconductor systems possess new outstanding properties, which emerge when bringing magnetic and semiconductor materials into contact. In such structures, the long-range magnetic proximity effect couples the spin systems of the ferromagnet and semiconductor on distances exceeding the carrier wave function overlap. The effect is due to the effective p-d exchange interaction of acceptor-bound holes in the quantum well with d-electrons of the ferromagnet.

Does an immigrant teacher help immigrant students cope with negative stereotypes? Preservice teachers' and school students' perceptions of teacher bias and motivational support, as well as stereotype threat effects on immigrant students' learning.

Can immigrant school students profit from an immigrant teacher sharing their minority background? We investigate preservice teachers' (Study 1;  = 26.29 years; 75.2% female) and school students' (Study 2;  = 14.

Next-generation PET/CT imaging in meningioma-first clinical experiences using the novel SSTR-targeting peptide [F]SiTATE.

Background: Somatostatin-receptor (SSTR)-targeted PET/CT provides important clinical information in addition to standard imaging in meningioma patients. [F]SiTATE is a novel, F-labeled SSTR-targeting peptide with superior imaging properties according to preliminary data. We provide the first [F]SiTATE PET/CT data of a large cohort of meningioma patients.

Simultaneous observation of halogen-lone pair and halogen-π interactions of ferrocene derivatives under cryogenic conditions.

Contrasting cryosolutions and matrix isolation infrared spectroscopy, we investigate weak intermolecular interactions in complexes of iodo trifluoroethene (CFI) and ,-dimethyl ferrocenyl amine as well as the parent ferrocene. In liquid xenon, solely the C-I⋯N halogen bond can be observed, while the confined environment in solid argon allows for the characterization of C-I⋯π and π⋯π bonded complexes.

C-C Coupling of Carbene Molecules on a Metal Surface in the Presence of Water.

A novel surface-confined C-C coupling reaction involving two carbene molecules and a water molecule was studied by scanning tunneling microscopy in real space. Carbene fluorenylidene was generated from diazofluorene in the presence of water on a silver surface. While in the absence of water, fluorenylidene covalently binds to the surface to form a surface metal carbene, and water can effectively compete with the silver surface in reacting with the carbene.

A von Hámos spectrometer for diamond anvil cell experiments at the High Energy Density Instrument of the European X-ray Free-Electron Laser.

A von Hámos spectrometer has been implemented in the vacuum interaction chamber 1 of the High Energy Density instrument at the European X-ray Free-Electron Laser facility. This setup is dedicated, but not necessarily limited, to X-ray spectroscopy measurements of samples exposed to static compression using a diamond anvil cell. Si and Ge analyser crystals with different orientations are available for this setup, covering the hard X-ray energy regime with a sub-eV energy resolution.

Extending Chirality in Group XIV Metallatranes.

The syntheses of the racemic amino alcohol -N(CHCMeOH)(CMeCHOH)(CHCHMeOH) (H, ) and its representative N(CHCMeOH)(CMeCHOH)(CHC()HMeOH) (H, ) with the stereogenic carbon center being -configured are reported. Also reported are the stannatranes SnO-Bu () SnO-Bu () and germatranes GeOEt () and GeOEt () as well as the trinuclear tin oxocluster [(μ-O)(μ-O--Bu){Sn}] (). NMR and IR spectroscopy, electrospray ionization mass spectrometry (ESI MS), and single crystal X-ray diffraction analysis characterize these compounds.

Crystal structures and Hirshfeld surface analyses of tetra-kis-(4,5-di-hydro-furan-2-yl)silane and tetra-kis-(4,5-di-hydro-furan-2-yl)germane.

The title compounds Si(CHO) () and Ge(CHO) () are di-hydro-furyl compounds of silicon and germanium and are useful building blocks for the functionalization of these elements. Both structures crystallize in space group 2/ in the monoclinic crystal system with two mol-ecules in the asymmetric unit: the Si and Ge atoms adopt slightly distorted tetra-hedral geometries, while the CHO moieties exhibit shallow envelope conformations. Through a Hirshfeld surface analysis of the structures, inter-actions within the crystal packing could be elucidated: compound features a polymeric chain in the (101) plane C-H⋯O hydrogen bonds whereas in C-H⋯O hydrogen bonds create a polymeric chain in the (010) plane.

Molecular Rearrangements in Protomembrane Models Probed by Laurdan Fluorescence.

Lipid membranes are a key component of living systems and have been essential to the origin of life. One hypothesis for the origin of life assumes the existence of protomembranes with ancient lipids formed by Fischer-Tropsch synthesis. We determined the mesophase structure and fluidity of a prototypical decanoic (capric) acid-based system, a fatty acid with a chain length of 10 carbons, and a lipid system consisting of a 1:1 mixture of capric acid with a fatty alcohol of equal chain length (C10 mix).

Silver-based coordination polymers assembled by dithioether ligands: potential antibacterial materials despite received ideas.

We report on the first examples on the antibacterial activity towards Gram-negative and Gram-positive bacteria of 2D silver-based coordination polymers obtained by self-assembly with acetylenic dithioether ligands. Their structure imparts a good stability that allows a sustainable release of Ag in the media.

Diazoalkenes: From an Elusive Intermediate to a Stable Substance Class in Organic Chemistry.

Over decades diazoalkenes (R C=C=N ) were postulated as reactive intermediates in organic chemistry even though their direct spectroscopic detection proved very challenging. In the 1970/80ies several groups probed their existence mainly indirectly by trapping experiments or directly by matrix-isolation studies. In 2021, our group and the Severin group reported independently the synthesis and characterization of the first room-temperature stable diazoalkenes, which initiated a rapidly expanding research field.

Modulating Liquid-Liquid Transitions and Glass Formation in Zeolitic Imidazolate Frameworks by Decoration with Electron-Withdrawing Cyano Groups.

The liquid phase of metal-organic frameworks (MOFs) is key for the preparation of melt-quenched bulk glasses as well as the shaping of these materials for various applications; however, only very few MOFs can be melted and transformed into stable glasses. Here, the solvothermal and mechanochemical preparation of a new series of functionalized derivatives of ZIF-4 (Zn(im), where im = imidazolate and ZIF = zeolitic imidazolate framework) containing the cyano-functionalized imidazolate linkers CNim (4-cynanoimidazolate) and dCNim (4,5-dicyanoimidazolate) is reported. The strongly electron-withdrawing nature of the CN groups facilitates low-temperature melting of the materials (below 310 °C for some derivatives) and the formation of microporous ZIF glasses with remarkably low glass-transition temperatures (down to only about 250 °C) and strong resistance against recrystallization.

Spin-Flip Raman Scattering on Electrons and Holes in Two-Dimensional (PEA) PbI Perovskites.

The class of Ruddlesden-Popper type (PEA) PbI perovskites comprises 2D structures whose optical properties are determined by excitons with a large binding energy of about 260 meV. It complements the family of other 2D semiconductor materials by having the band structure typical for lead halide perovskites, that can be considered as inverted compared to conventional III-V and II-VI semiconductors. Accordingly, novel spin phenomena can be expected for them.