Spin-Dependent WIMPs in DAMA?

We investigate whether the annual modulation observed in the DAMA experiment can be due to a weakly-interacting massive particle (WIMP) with an axial-vector (spin-dependent; SD) coupling to nuclei. We evaluate the SD WIMP-proton cross section under the assumption that such scattering accounts for the DAMA modulation, and we do the same for a SD WIMP-neutron cross section. We show that SD WIMP-proton scattering is ruled out in a model-independent fashion by null searches for energetic neutrinos from WIMP annihilation in the Sun, and that SD WIMP-neutron scattering is ruled out for WIMP masses > 20 GeV by the null result with the DAMA Xe detector. A SD WIMP with mass < 20 GeV is still compatible, but only if the SD WIMP-neutron interaction is four orders of magnitude greater than the WIMP-proton interaction.Comment: 4 pages, 2 figure

New Contribution to Scattering of Weakly Interacting Massive Particles on Nuclei

A weakly interacting massive particle (WIMP) is perhaps the most promising candidate for the dark matter in the Galactic halo. The WIMP detection rate in laboratory searches is fixed by the cross section for elastic WIMP-nucleus scattering. Here we calculate the contribution to this cross section from two-nucleon currents from pion exchange in the nucleus and show that it may, in some cases, be comparable to the one-nucleon current that has been considered in prior work and perhaps help resolve the discrepancies between the various direct dark-matter search experiments. We provide simple expressions that allow these new contributions to be included in current calculations

Adiabatic Control of Spin-Wave Propagation using Magnetisation Gradients

Spin waves are of large interest as data carriers for future logic devices. However, due to the strong anisotropic dispersion relation of dipolar spin-waves in in-plane magnetised films the realisation of two-dimensional information transport remains a challenge. Bending of the energy flow is prohibited since energy and momentum of spin waves cannot be conserved while changing the direction of wave propagation. Thus, non-linear or non-stationary mechanisms are usually employed. Here, we propose to use reconfigurable laser-induced magnetisation gradients to break the system's translational symmetry. The resulting changes in the magnetisation shift the dispersion relations locally and allow for operating with different spin-wave modes at the same frequency. Spin-wave momentum is first transformed via refraction at the edge of the magnetisation gradient region and then adiabatically modified inside it. Along these lines the spin-wave propagation direction can be controlled in a broad frequency range with high efficiency

Kontrolle des prä-mRNA Spleißens durch das Tetrazyklin-Aptamer

In dieser Arbeit wurde ein RNA-Schalter entwickelt, welcher das alternative Spleißen eines Kassetten-Exons mithilfe eines Tetrazyklin-bindenden (Tc) Aptamers reguliert. Hierfür wurde entweder die Zugänglichkeit der 3’ Spleißstelle (SS) oder des Verzweigungspunktes (BP) durch das Aptamer reguliert, indem diese Stellen in den P1 Stamm des Aptamers integriert wurden. Durch dieses Design ist die Spleißstelle in Abwesenheit von Tc für das Spleißosom zugänglich, in Anwesenheit von Tc wird sie durch eine stabilisierte Aptamerstruktur blockiert. Zur Kontrolle des Spleißens wurden verschiedene Konstrukte angefertigt, die sich in der Sequenz und Stabilität des P1 Stammes sowie der relativen Lage des Aptamers zur Spleißstelle unterscheiden. Die Ergebnisse zeigen, dass Konstrukte mit einem stabileren Stamm das Spleißen besser regulieren können. Hierbei war zu beobachten, dass eine Stabilisierung des P1 Stammes nahe der Bindetasche den Regulationsfaktor verbessern konnte, eine Stabilisierung am anderen Ende zeigte jedoch keinen Effekt auf die Regulation. Fünf Konstrukte, die eine signifikante Spleißregulation in einem Minigensystem aufwiesen, wurden auf ihre Übertragbarkeit im Kontext einer vollständigen mRNA (Luziferase-Reportergen, Kontrolle des humanen Transkriptionsfaktors MAX und Kontrolle des B-Zell-Rezeptors CD20) getestet. Für alle Konstrukte konnte gezeigt werden, dass sie in den drei Genen erfolgreich das Spleißen regulieren. Hierzu wurde das Aptamer komplett mit dem Kassetten-Exon und Teile der beiden flankierenden Introns übertragen. Bei der Insertionsstelle wurde darauf geachtet, dass es sich um eine natürliche Intronposition handelt. War eine solche nicht vorhanden, wurde eine Sequenz gesucht, die Ähnlichkeiten zu den Insertionsstellen in bereits erfolgreich angewandten Systemen hatte. Diese Ergebnisse zeigen, dass ein Kontext-unabhängiges aptamer-kontrolliertes Exon entwickelt werden konnte, mit dem die Kontrolle jedes beliebigen Gens möglich sein sollte. Das Exon zeigt eine dosisabhängige, zelltypunabhängige Regulation, die außerdem unabhängig von der Expressions-stärke des jeweiligen Gens ist. Basierend auf der konditionalen Expression des Rezeptors CD20 durch das aptamer-kontrollierte Exon konnte ein Suizidgen aufgebaut werden, das es ermöglicht, Zellen gezielt abzutöten. Durch Tc kommt es zu einer erhöhten Expression von CD20, wodurch die Zellen in Gegenwart von Rituximab absterben. Die Anwendung eines solchen Systems könnte im Bereich der Krebstherapie oder als Sicherheitsschalter in der Gentherapie liegen

New Approaches in Drug Dependence: Opioids

Purpose of Review: This article aims to provide an overview of standard and adjunctive treatment options in opioid dependence in consideration of therapy-refractory courses. The relevance of oral opioid substitution treatment (OST) and measures of harm reduction as well as heroin-assisted therapies are discussed alongside non-pharmacological approaches. Recent Findings: Currently, recommendation can be given for OST with methadone, buprenorphine, slow-release oral morphine (SROM), and levomethadone. Heroin-assisted treatment using diamorphine shall be considered as a cost-effective alternative for individuals not responding to the afore-mentioned opioid agonists in order to increase retention and reduce illicit opioid use. The modalities of application and the additional benefits of long-acting formulations of buprenorphine should be sufficiently transferred to clinicians and the eligible patients; simultaneously methods to improve planning of actions and self- management need to be refined. Regarding common primary outcomes in research on opioid treatment, evidence of the effectiveness of adjunctive psychological interventions is scarce. Summary: Maintaining a harm reduction approach in the treatment of opioid addiction, a larger range of formulations is available for the prescribers. Embedding the pharmacological, ideally individualized treatment into a holistic, structure-giving concept also requires a reduction of fragmentation of ancillary services available, drug policies, and treatment philosophies on a global scale

Methylphenidate for Attention-Deficit and Hyperactivity Disorder in Adult Patients With Substance Use Disorders: Good Clinical Practice

Attention-deficit and hyperactivity disorder (ADHD) is a widespread neurodevelopmental disorder in children and adolescents, persisting into adulthood in a majority of them. ADHD and substance use disorders (SUDs) commonly co-occur in the clinical adult population. The higher-than-normal prevalence rates of SUDs in people with ADHD indicate increased risk for developing SUD. This narrative review deals with the question of whether or not adults with both disorders should be treated with methylphenidate (MPH), addressing specific issues surrounding this form of treatment. MPH is considered as first-line pharmacotherapy for ADHD. However, because of its stimulant-like reinforcing properties, MPH has a significant addictive potential to which persons with SUDs are especially susceptible. Appropriate treatment is therefore complex. Because of concerns about misuse and diversion of MPH medication, clinicians may be reluctant to use MPH to manage ADHD symptoms in these patients. However, it is essential to diagnose and treat ADHD adequately as appropriate therapy reduces the impairments, as well as the risk of developing comorbid disorders and poor treatment response. MPH should not be deprived of these patients because of the risk for misuse, especially as several strategies can be applied to minimize this risk. To conclude, carefully applied guideline-based diagnostics to clarify the potential presence of ADHD as well as a responsible prescription practice in a well-defined therapeutic setting with reliable monitoring of medication intake and regular consultations are essential conditions for a safe and proficient MPH treatment of ADHD in patients with SUD

Co-occurring Mental Disorders in Transitional Aged Youth With Substance Use Disorders – A Narrative Review

Adolescence and emerging adulthood are often referred to as youth. Transitional psychiatry addresses this target group, which considers patients between 15 and 25 years of age. Substance use usually begins and peaks at this stage of life. Psychiatric disorders, foremost attention-deficit/hyperactivity disorder, and affective disorders, conduct disorders, and first-episodes psychosis frequently appear in early life stages. This review aims to provide a broad overview of transitional-aged youth's most common psychiatric comorbidities with substance use disorders. A literature search was conducted in Embase and Pubmed, and the main findings are described narratively. We present main findings for the following comorbidities: attention-deficit/hyperactivity disorder, conduct disorder, personality disorders, affective disorders, psychotic disorders, and the phenomena of overdose and suicidality. In conclusion, co-occurring mental health disorders are common and appear to facilitate the development of substance use disorders and exacerbate their overall course. Substance use also affects the severity and course of comorbid psychiatric disorders. Overall, data on transition-age youth with substance use disorders are highly inconsistent. Universal screening and treatment guidelines do not yet exist but should be aimed for in the future