The magnetization process of classical Heisenberg magnets with non-coplanar cuboc ground states.

We consider a classical Heisenberg model on the kagomé and the square kagomé lattice, where at zero magnetic field non-coplanar cuboctahedral ground states with twelve sublattices exist if suitable exchange couplings are introduced between the other neighbors. Such 'cuboc ground states' are remarkable because they allow for chiral ordering. For these models, we discuss the magnetization process in an applied magnetic fieldby both numerical and analytical methods.

Delayed diagnosis of a transient ischemic attack caused by ChatGPT.

Techniques of artificial intelligence (AI) are increasingly used in the treatment of patients, such as providing a diagnosis in radiological imaging, improving workflow by triaging patients or providing an expert opinion based on clinical symptoms; however, such AI techniques also hold intrinsic risks as AI algorithms may point in the wrong direction and constitute a black box without explaining the reason for the decision-making process.This article outlines a case where an erroneous ChatGPT diagnosis, relied upon by the patient to evaluate symptoms, led to a significant treatment delay and a potentially life-threatening situation. With this case, we would like to point out the typical risks posed by the widespread application of AI tools not intended for medical decision-making.

Identification of brain functional connectivity during acute transcutaneous tibial nerve stimulation: A 3T fMRI study.

Objectives: A feasibility proof-of-concept study was conducted to assess the effects of acute tibial nerve stimulation (TNS) on the central nervous system in healthy volunteers using functional magnetic resonance imaging (fMRI).

Materials And Methods: Fourteen healthy volunteers were included in a prospective, single-site study conducted on a clinical 3T MRI scanner. Four scans of functional MRI, each lasting 6 min, were acquired: two resting-state fMRI scans (prior and following the TNS intervention) and in-between two fMRI scans, both consisting of alternating rest periods and noninvasive acute transcutaneous TNS (TTNS).

Metabolic profile of complete spinal cord injury in pons and cerebellum: A 3T 1H MRS study.

The aim of this exploratory study was the assessment of the metabolic profiles of persons with complete spinal cord injury (SCI) in three region-of-interests (pons, cerebellar vermis, and cerebellar hemisphere), with magnetic resonance spectroscopy, and their correlations to clinical scores. Group differences and association between metabolic and clinical scores were examined. Fifteen people with chronic SCI (cSCI), five people with subacute SCI (sSCI) and fourteen healthy controls were included.

Functional connectivity and amplitude of low-frequency fluctuations changes in people with complete subacute and chronic spinal cord injury.

After spinal cord injury (SCI), reorganization processes and changes in brain connectivity occur. Besides the sensorimotor cortex, the subcortical areas are strongly involved in motion and executive control. This exploratory study focusses on the cerebellum and vermis.

Towards lattice-gas description of low-temperature properties above the Haldane and cluster-based Haldane ground states of a mixed spin-(1,1/2) Heisenberg octahedral chain.

The rich ground-state phase diagram of the mixed spin-(1,1/2) Heisenberg octahedral chain was previously elaborated from effective mixed-spin Heisenberg chains, which were derived by employing a local conservation of a total spin on square plaquettes of an octahedral chain. Here we present a comprehensive analysis of the thermodynamic properties of this model. In the highly frustrated parameter region the lowest-energy eigenstates of the mixed-spin Heisenberg octahedral chain belong to flat bands, which allow a precise description of low-temperature magnetic properties within the localized-magnon approach exploiting a classical lattice-gas model of hard-core monomers.

Glutathione in the Pons Is Associated With Clinical Status Improvements in Subacute Spinal Cord Injury.

Objectives: In spinal cord injury (SCI), the primary mechanical injury is followed by secondary sequelae that develop over the subsequent months and manifests in biochemical, functional, and microstructural alterations, at the site of direct injury but also in the spinal cord tissue above and below the actual lesion site. Noninvasive magnetic resonance spectroscopy (MRS) can be used to assess biochemical modulation occurring in the secondary injury phase, in addition to and supporting conventional MRI, and might help predict and improve patient outcome. In this article, we aimed to examine the metabolic levels in the pons of subacute SCI by means of in vivo proton MRS at 3 T and explore the association to clinical scores.

Ionic and non-ionic intravenous X-ray contrast media: antibacterial agents?

X-ray contrast media have been reported to have inhibitory effects on bacterial growth. Despite its potentially beneficial effect on patients, these features of contrast media have received relatively little attention in the medical literature in the past decades. The aim of this review is to evaluate the literature concerning the bactericidal and bacteriostatic effects of X-ray contrast media, specifically if there is a known difference concerning these effects between ionic and non-ionic contrast media.

Doped or Quantum-Dot Layers as In Situ Etch-Stop Indicators for III/V Semiconductor Reactive Ion Etching (RIE) Using Reflectance Anisotropy Spectroscopy (RAS).

Reflectance anisotropy spectroscopy (RAS), which was originally invented to monitor epitaxial growth, can-as we have previously shown-also be used to monitor the reactive ion etching of III/V semiconductor samples in situ and in real time, as long as the etching rate is not too high and the abrasion at the etch front is not totally chaotic. Moreover, we have proven that-using RAS equipment and optical Fabry‒Perot oscillations due to the ever-shrinking thickness of the uppermost etched layer-the in situ etch-depth resolution can be as good as ±0.8 nm, employing a Vernier-scale type measurement and evaluation procedure.

Magnon Crystallization in the Kagome Lattice Antiferromagnet.

We present numerical evidence for the crystallization of magnons below the saturation field at nonzero temperatures for the highly frustrated spin-half kagome Heisenberg antiferromagnet. This phenomenon can be traced back to the existence of independent localized magnons or, equivalently, flatband multimagnon states. We present a loop-gas description of these localized magnons and a phase diagram of this transition, thus providing information for which magnetic fields and temperatures magnon crystallization can be observed experimentally.

Validation and Optimization of Barrow Neurological Institute Score in Prediction of Adverse Events and Functional Outcome After Subarachnoid Hemorrhage-Creation of the HATCH (Hemorrhage, Age, Treatment, Clinical State, Hydrocephalus) Score.

Background: The Barrow Neurological Institute (BNI) score, measuring maximal thickness of aneurysmal subarachnoid hemorrhage (aSAH), has previously shown to predict symptomatic cerebral vasospasms (CVSs), delayed cerebral ischemia (DCI), and functional outcome.

Objective: To validate the BNI score for prediction of above-mentioned variables and cerebral infarct and evaluate its improvement by integrating further variables which are available within the first 24 h after hemorrhage.

Methods: We included patients from a single center.

Author Correction: Maximizing and stabilizing luminescence from halide perovskites with potassium passivation.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Dark Subgap States in Metal-Halide Perovskites Revealed by Coherent Multidimensional Spectroscopy.

Metal-halide perovskites show excellent properties for photovoltaic and optoelectronic applications, with power conversion efficiencies of solar cell and LEDs exceeding 20%. Being solution processed, these polycrystalline materials likely contain a large density of defects compared to melt-grown semiconductors. Surprisingly, typical effects from defects (absorption below the bandgap, low fill factor and open circuit voltage in devices, strong nonradiative recombination) are not observed.

Chain Coupling and Luminescence in High-Mobility, Low-Disorder Conjugated Polymers.

Optoelectronic devices based on conjugated polymers often rely on multilayer device architectures, as it is difficult to design all the different functional requirements, in particular the need for efficient luminescence and fast carrier transport, into a single polymer. Here we study the photophysics of a recently discovered class of conjugated polymers with high charge carrier mobility and low degree of energetic disorder and investigate whether it is possible in this system to achieve by molecular design a high photoluminescence quantum yield without sacrificing carrier mobility. Tracing exciton dynamics over femtosecond to microsecond time scales, we show that nearly all nonradiative exciton recombination arises from interactions between chromophores on different chains.

Gadolinium-Based MRI Contrast Agents Induce Mitochondrial Toxicity and Cell Death in Human Neurons, and Toxicity Increases With Reduced Kinetic Stability of the Agent.

Objectives: This preclinical study was devised to investigate potential cellular toxicity in human neurons induced by gadolinium-based contrast agents (GBCAs) used for contrast-enhanced magnetic resonance imaging (MRI). Neurons modeling a subset of those in the basal ganglia were tested, because the basal ganglia region is 1 of 2 brain regions that displays the greatest T1-dependent signal hyperintensity changes.

Methods: Eight GBCAs were tested.

Short contacts between chains enhancing luminescence quantum yields and carrier mobilities in conjugated copolymers.

Efficient conjugated polymer optoelectronic devices benefit from concomitantly high luminescence and high charge carrier mobility. This is difficult to achieve, as interchain interactions, which are needed to ensure efficient charge transport, tend also to reduce radiative recombination and lead to solid-state quenching effects. Many studies detail strategies for reducing these interactions to increase luminescence, or modifying chain packing motifs to improve percolation charge transport; however achieving these properties together has proved elusive.

Motion in Magnetic Resonance: New Paradigms for Improved Clinical Diagnosis.

Recent innovations in magnetic resonance, involving both hardware and software, that effectively deal with motion-whether inadvertent on the part of the patient or due to respiration and cardiac contraction-are reviewed, emphasizing major current advances. New technology involving motion sensing (kinetic, respiratory, and beat) is enabling simpler, faster, and more robust monitoring of the sources of motion. This information is being integrated, with new innovative imaging approaches, to effectively manage motion and its impact on image quality.

Charge extraction via graded doping of hole transport layers gives highly luminescent and stable metal halide perovskite devices.

One source of instability in perovskite solar cells (PSCs) is interfacial defects, particularly those that exist between the perovskite and the hole transport layer (HTL). We demonstrate that thermally evaporated dopant-free tetracene (120 nm) on top of the perovskite layer, capped with a lithium-doped Spiro-OMeTAD layer (200 nm) and top gold electrode, offers an excellent hole-extracting stack with minimal interfacial defect levels. For a perovskite layer interfaced between these graded HTLs and a mesoporous TiO electron-extracting layer, its photoluminescence yield reaches 15% compared to 5% for the perovskite layer interfaced between TiO and Spiro-OMeTAD alone.

Exciton-Phonon Interactions Govern Charge-Transfer-State Dynamics in CdSe/CdTe Two-Dimensional Colloidal Heterostructures.

CdSe/CdTe core-crown type-II nanoplatelet heterostructures are two-dimensional semiconductors that have attracted interest for use in light-emitting technologies due to their ease of fabrication, outstanding emission yields, and tunable properties. Despite this, the exciton dynamics of these complex materials, and in particular how they are influenced by phonons, is not yet well understood. Here, we use a combination of femtosecond vibrational spectroscopy, temperature-resolved photoluminescence (PL), and temperature-dependent structural measurements to investigate CdSe/CdTe nanoplatelets with a thickness of four monolayers.

Post-operative cardiovascular complications and time to recurrence in meningioma patients treated with versus without pre-operative embolization: a retrospective cohort study of 741 patients.

Purpose: Preoperative embolization of radiographically suspected meningiomas is often performed to facilitate tumor resection. Its effects on the subsequent disease course of meningioma patients have not been studied in detail and randomized trials are lacking. The purpose of this study was to explore associations of preoperative meningioma embolization with postoperative outcome.

Observation of Vibronic-Coupling-Mediated Energy Transfer in Light-Harvesting Nanotubes Stabilized in a Solid-State Matrix.

Ultrafast vibrational spectroscopy is employed to obtain real-time structural information on energy transport in double-walled light-harvesting nanotubes at room temperature, stabilized in a host matrix to mimic the rigid scaffolds of natural light-harvesting systems. We observe evidence of a low-frequency vibrational mode at 315 cm, which transfers excitons from the outer wall of the nanotubes to a crossing point through which energy transfer to the inner wall can occur. This mode is furthermore absent in solution phase.

IL-10 Receptor Signaling Empowers Regulatory T Cells to Control Th17 Responses and Protect from GN.

Th17 cells are central pathogenic mediators of autoimmune disease, including many forms of GN. IL-10 receptor signaling (IL-10R) in regulatory T cells (Tregs) has been implicated in the downregulation of Th17 cells, but the underlying molecular mechanisms and functional relevance of this process remain unclear. We generated mice with Treg-specific IL-10Ra deficiency and subjected these mice to nephrotoxic serum-induced nephritis as a model of crescentic GN.

Long-range exciton transport in conjugated polymer nanofibers prepared by seeded growth.

Easily processed materials with the ability to transport excitons over length scales of more than 100 nanometers are highly desirable for a range of light-harvesting and optoelectronic devices. We describe the preparation of organic semiconducting nanofibers comprising a crystalline poly(di--hexylfluorene) core and a solvated, segmented corona consisting of polyethylene glycol in the center and polythiophene at the ends. These nanofibers exhibit exciton transfer from the core to the lower-energy polythiophene coronas in the end blocks, which occurs in the direction of the interchain π-π stacking with very long diffusion lengths (>200 nanometers) and a large diffusion coefficient (0.