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Using a patient-informed regimen, we conducted an exploratory randomized, double-blind, placebo-controlled study to systematically investigate the effects of psilocybin in cluster headache.Sustained reductions in cluster headache burden after limited quantities of psilocybin-containing mushrooms are anecdotally reported, although to date there are no controlled studies investigating these effects.Participants were randomized to receive psilocybin (0.143 mg/kg) or placebo (microcrystalline cellulose) in a pulse of three doses, each ~5 days apart. Participants maintained headache diaries starting 2 weeks before and continuing through 8 weeks after the first drug session. A total of 16 participants were randomized to receive experimental drug and 14 were included in the final analysis.In the 3 weeks after the start of the pulse regimen, the change in cluster attack frequency was 0.03 (95% confidence interval [CI] -2.6 to 2.6) attacks/week with placebo (baseline 8.9 [95% CI 3.8 to 14.0]) and -3.2 (95% CI -8.3 to 1.9) attacks/week with psilocybin (baseline 9.6 [95% CI 5.6 to 13.6]; p = 0.251). Group difference in change from baseline had a moderate effect size (d = 0.69). The effect size was small in episodic participants (d = 0.35) but large in chronic participants (d = 1.25), which remained over the entire 8-week period measured (d = 0.81). Changes in cluster attack frequency were not correlated with the intensity of acute psychotropic effects during psilocybin administration. Psilocybin was well-tolerated without any unexpected or serious adverse events.Findings from this initial, exploratory study provide valuable information for the development of larger, more definitive studies. Efficacy outcomes were negative, owing in part to the small number of participants. The separation of acute psychotropic effects and lasting therapeutic effects underscores the need for further investigation into the mechanism(s) of action of psilocybin in headache disorders.

Background Brugada phenocopies clinical entities that have indistinguishable electrocardiographic (ECG) patterns from true congenital Brugada syndrome. However, they are induced by other clinical circumstances such as myocardial ischemia. The purpose of our study was to examine the clinical features and pathogenesis of ischemia-induced Brugada phenocopy (BrP). Methods Data from 17 cases of ischemia-induced BrP were collected from the International Registry (www.brugadaphenocopy.com). Data were extracted from these publications and authors were contacted to provide further insight into each case. Results Of the patients included in this study, 71% were male. Mean age was 59 ± 11 years (range: 38-76). Type-1 Brugada ECG pattern occurred in 15/17 (88%) of the cases, while a type-2 Brugada ECG pattern was observed in the other 2/17 (12%). In all cases, the Brugada ECG pattern resolved upon correction of the ischemia, indicating ischemia as the inducing circumstance. No arrhythmic events have been detected acutely or during the follow-up. Reported time to resolution ranged from 2 minutes to 5 hours. Provocative challenges using sodium channel blocking agents were performed in 7/17 cases (41%), and all failed to induce a Brugada ECG pattern (BrP Class A). The remaining 10/17 cases (59%) did not undergo provocative testing due to various clinical reasons. Conclusions Myocardial ischemia is a commonly reported etiology of BrP. Importantly, this study found no association between BrP induced by myocardial ischemia and sudden cardiac death or malignant ventricular arrhythmias.

We report a case of a 68-year-old man admitted to the emergency department with syncope preceded by rapid palpitations. His admission ECG demonstrated a sustained ventricular tachycardia (VT) originating from the right ventricular outflow tract (RVOT). This report highlights the importance of distinguishing ventricular tachycardia caused by arrhythmogenic right ventricular dysplasia (ARVD) from the more benign idiopathic RVOT-VT. Furthermore, we demonstrate the utility of the Fontaine leads placement in increasing the sensitivity for uncovering epsilon waves, a highly specific electrocardiographic feature that increases diagnostic accuracy in patients with ARVD.

We read the report by Prabhu et al. with great interest and noted their description of a Brugada ECG pattern in the context of phosphide poisoning. Their case is important as it contributes to our understanding of the varying etiologies of Brugada Phenocopy (BrP). This article is protected by copyright. All rights reserved. Language: en

A new method which allows the detection of the superconducting phase transition of high-Tc superconductors (HTSC) on a microscopic scale is reported. Micro-size holes in thin foils of superconducting material are examined in a transmission electron microscope at varying temperatures. The superconducting transition induces small changes in the image intensity within the holes, which can be detected by using electronic image analysis. Superconducting transition curves are then obtained for various types of high-Tc superconductors and for given values of the applied magnetic field.

A new method of measuring dislocation velocities in the bulk by TEM is presented. Jogs on dislocations are strong obstacles against dislocation motion during a low temperature deformation. They can be used as markers for the initial course of the dislocation lines and allow to measure the paths travelled by the free dislocation segments between the jogs. First results for the activation energy of the motion of screws and 60° dislocations (2 eV) and for the edges (1.8 eV) are reported. An edge dislocation is assumed to be a series of geometrical kinks. Its motion is interpreted as the collective motion of kinks and the activation energy is tentatively attributed to the kink migration energy. Eine neue Methode, Versetzungsgeschwindigkeiten im Inneren eines Kristalls mit TEM zu messen, wird vorgestellt. Jogs auf Versetzungen sind Hindernisse fur die Versetzungsbewegung bei einer Niedertemperatur-Verformung. Sie markieren die Ausgangslage der Versetzungen und ermoglichen, den Laufweg der freien Segmente zwischen den Jogs zu messen. Erste Ergebnisse fur die Aktivierungs-energien von Schrauben-, 60° - (2 eV), und Stufenversetzungen (1.8 eV) werden mitgeteilt. Es wird angenommen, eine Stufenversetzung sei eine Aneinanderreihung geometrischer Kinken und ihre Bewegung sei korrelierter Kinkenbewegung zuzuschreiben. Deshalb wird ihre Aktivierungsenergie versuchsweise der Kinkenwanderungsenergie zugeordnet.

Kink dynamics on dislocations in Si is studied in a wide stress range (up to 150 MPa) using the intermittent loading (IL) technique. At low stresses (0 to 7 MPa) a two-level IL is employed using selective etching to reveal the dislocations. Dependencies are obtained of the mean dislocation displacements on the pulse and pause durations, as well as on the sign and values of stresses acting during the pulse separation. Experimental data are analyzed in the framework of the kinetic model taking into account diffusion and drift of the kinks. A new method is employed for the measurements of the dynamical properties of geometrical kinks using a combination of IL and transmission electron microscopy (TEM). The displacements of the central parts of the pinned edge dislocations in dipoles are measured in the bulk of Si for different dipole widths in the temperature range 593 to 693 K. Assuming that the displacement of edge dislocation segments is determined by the motion of geometrical kinks, the quantitative parameters of kink motion are obtained by a comparison of the experimental data with computer simulations of the process. A correlation between the dynamical properties of geometrical kinks constituting an edge dislocation and the kink moving along 60° dislocations is discussed in the framework of the theories taking into account the influence of point defects and secondary Peierls relief on the processes of kink pair formation and spreading. [Russian Text Ignored].

Investigations of the precipitation of copper silicide on glide dislocations in thin Si foils are reported. Under certain conditions — existence of a sufficiently thick oxide layer on the specimen surface and copper in-diffusion in a TEM hot stage — precipitates at climbing dislocations are formed even at a very low temperature (200 °C). An influence of electron irradiation on the precipitation effect can be excluded. Es wird uber Untersuchungen zur Ausscheidung von Kupfersilicid an Gleitversetzungen in dunnen Si-Folien berichtet. Unter bestimmten Voraussetzungen — Existenz einer genugend dicken Oxidschicht auf der Probenoberflache und Eindiffusion des Kupfers im TEM-Heizhalter — werden sogar bei sehr niedrigen Temperaturen (200 °C) Ausscheidungen an kletternden Versetzungen gebildet. Ein Einflus von Elektronenbestrahlung auf den Ausscheidungseffekt kann ausgeschlossen werden.

Microstructural phenomena and phase transitions of the Nd-doped La1.85 Sr0 15 CuO4 system are studied in an electron microscope. In ion-milled samples, twin domains appear and disappear as expected at the high temperature phase transition. At temperatures below the high temperature transition, these twin domains show a very subtle behaviour. Ground material even in the orthorhombic phase shows no twins at all. In ion-thinned material a typical reduction of the domain size occurs after an electron illumination time of about one hour. Generally no reversible change of the twin configuration could be observed at the low temperature phase transition. Mikrostruktur and Phasenubergange von Nd-dotiertem La1.85 Sr0.15 CuO4 werden im Elektro-nenmikroskop untersucht. Wie erwartet, erscheinen und verschwinden Zwillingsbereiche am Hoch-temperaturphasenubergang in ionengedunnten Proben. Unterhalb dieses Phasenuberganges zeigen die Zwillingsbereiche ein sehr subtiles Verhalten. Gemorsertes Material zeigt selbst in der orthorhombischen Phase keine Zwillingsbildung. In ionengedunntem Material tritt eine typische Reduzierung der Bereichsgrose nach einer Bestrahlungszeit von etwa 1 h ein. Generell kann am Tieftempartur-Phasenubergang keine reversible Anderung der Zwillingskonfiguration beobachtet werden.

SUMMARY The stacking fault energies y of silicon (58 ± 6 mJ m−2) and germanium (75 ± 10 mJ m−2) were determined. Within the limits of accuracy γ was not found to change on doping with (13·8 mol m−3 (8 × 1018 cm−3) boron, and 1·17 mol m−3 (7 × 1017 cm−3) phosphorus). Freezing in dislocations under high shear stress reveals a different behaviour of screw dislocations: whereas these dislocations become wider in pure and p-silicon, they become narrower in n-silicon. From this we conclude the ratio of mobilities of the two 30° partials to be different in n- and p-silicon. Other observations on frozen dislocations are mentioned.

Using weak beam electron microscopy the stacking fault energy (SFE) of III-V compounds is determined by measuring the dissociation width of edge dislocations. The SFE corrected for the lattice parameters is given in meV/atom for GaAs, GaP, GaSb, InAs, InP, and InSb. As expected there is a strong correlation of the SFE with the ionicity of the bond. The different plasticity of the compounds is traced back to different dislocation velocities. Mit Weak-Beam-Elektronenmikroskopie wird die Stapelfehlerenergie (SFE) von III-V-Verbindungen durch Messung der Aufspaltungsweite von Stufenversetzungen bestimmt. Die SFE, korrigiert fur die Gitterparameter, wird in meV/Atom angegeben fur GaAs, GaP, GaSb, InAs, InP und InSb. Wie erwartet gibt es eine starke Abhangigkeit der SFE von der Ionizitat der Bindung. Die unterschiedliche Plastizitat der Verbindungen wird auf verschieden grose Versetzungsgeschwindigkeiten zuruckgefuhrt.