Charge Transfer in Monomolecular Films and Metal-Organic Frameworks

Characterization and understanding of electronic properties of nanoscale systems is an important issue in modern nanotechnology including molecular and organic electronics. To advance in this topic, charge transfer (CT) properties of two specific nanoscale systems were analyzed in detail in this work. First, electron transfer (ET) dynamics in supported 2D assembles of molecular wires, self-assembled monolayers (SAMs), were studied by resonant Auger electron spectroscopy (RAES) in a combination with a so-called core hole clock (CHC) approach. A variety of suitable SAMs were custom-designed to address specific questions within the general framework of ET dynamics; most of these SAMs were equipped with nitrile tail groups, serving as a predefined site for the resonant excitation of an electron making the ET. The experiments showed a similar electronic coupling efficiency to coinage metal surfaces for the most frequently used S and Se anchors, solving a long-term controversy. Further, an efficient ET was found in acene-based SAM constituents, manifested by a quite low tunneling decay constant (beta) of 0.25 1/Å, similar to that of oligophenyls. In subsequent experiments on an analogous non-benzenoid system, the same ET properties as for its benzenoid isomer were found. As an ultimate proof of the approach, the nitrile groups were attached directly to the substrate, showing an ET time in the sub-fs region, as has been expected. A well-perceptible contribution of the ET process in the RAES [N1s]pi* spectra of pyridyl-substituted molecules revealed that pyridyl is a suitable resonant group for CHC and can be efficiently used as an alternative to nitrile, while NO2-functionalized SAM constitutents exhibited an inverse ET process. Second, static CT properties of surface-anchored metal-organic frameworks (SURMOFs) were studied, taking the basic and well-known HKUST-1 framework as a most suitable reference system. The measurements were performed with the custom-designed two-terminal junction setup and both pristine and guest-molecule loaded SURMOFs were investigated. The pristine SURMOFs showed CT properties similar to hybrid metal-organic molecular wires, as manifested by avery low beta value of 0.0006 1/Å. The CT experiments performed after the incorporation of the guest molecules, viz. ferrocen, TCNQ and its fluorinated analog F4-TCNQ, into the pores of the framework showed a significant increase in the current density. This increase was especially dramatic in the case of TCNQ, achieving up to 6 orders of magnitude. This finding verified a previously reported and highly announced result for this particular guest molecule, obtaining it, however, for the samples of well-controlled thickness, quality and orientation. At the same time, in contrast to the previous report, loading with F4-TCNQ resulted in a similar increase in the current density as for TCNQ, questioning the proposed CT model. These observations were made for several orientations of the SURMOF and different solvents used for the loading. Based on the experimental data, a novel superexchange mechanism for CT in the redox.-molecule-loades SURMOFs was proposed

Combined STN/SNr-DBS for the treatment of refractory gait disturbances in Parkinson's disease: study protocol for a randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>Severe gait disturbances in idiopathic Parkinson's disease (PD) are observed in up to 80% of all patients in advanced disease stages with important impact on quality of life. There is an unmet need for further symptomatic therapeutic strategies, particularly as gait disturbances generally respond unfavourably to dopaminergic medication and conventional deep brain stimulation of the subthalamic nucleus in advanced disease stages. Recent pathophysiological research pointed to nigro-pontine networks entrained to locomotor integration. Stimulation of the pedunculopontine nucleus is currently under investigation, however, hitherto remains controversial. The substantia nigra pars reticulata (SNr) - entrained into integrative locomotor networks - is pathologically overactive in PD. High-frequent stimulation of the substantia nigra pars reticulata preferentially modulated axial symptoms and therefore is suggested as a novel therapeutic candidate target for neuromodulation of refractory gait disturbances in PD.</p> <p>Methods</p> <p>12 patients with idiopathic Parkinson's disease and refractory gait disturbances under best individual subthalamic nucleus stimulation and dopaminergic medication will be enroled into this double-blind 2 × 2 cross-over clinical trial. The treatment consists of two different stimulation settings using <it>(i) </it>conventional stimulation of the subthalamic nucleus [STNmono] and <it>(ii) </it>combined stimulation of distant electrode contacts located in the subthalamic nucleus and caudal border zone of STN and substantia nigra pars reticulata [STN+SNr]. The primary outcome measure is the change of the cumulative 'axial score' (UPDRS II items '13-15' and UPRDS III items '27-31') at three weeks of constant stimulation in either condition. Secondary outcome measures include specific scores on freezing of gait, balance function, quality of life, non-motor symptoms, and neuropsychiatric symptoms. The aim of the present trial is to investigate the efficacy and safety of a three week constant combined stimulation on [STN+SNr] compared to [STNmono]. The results will clarify, whether stimulation on nigral contacts additional to subthalamic stimulation will improve therapeutic response of otherwise refractory gait disturbances in PD.</p> <p>Trial registration</p> <p>The trial was registered with the clinical trials register of <url>http://www.clinicaltrials.gov</url> (<a href="http://www.clinicaltrials.gov/ct2/show/NCT01355835">NCT01355835</a>)</p

Effectiveness and safety of opicapone in Parkinson’s disease patients with motor fluctuations: the OPTIPARK open-label study

Background The efficacy and safety of opicapone, a once-daily catechol-O-methyltransferase inhibitor, have been established in two large randomized, placebo-controlled, multinational pivotal trials. Still, clinical evidence from routine practice is needed to complement the data from the pivotal trials. Methods OPTIPARK (NCT02847442) was a prospective, open-label, single-arm trial conducted in Germany and the UK under clinical practice conditions. Patients with Parkinson’s disease and motor fluctuations were treated with opicapone 50 mg for 3 (Germany) or 6 (UK) months in addition to their current levodopa and other antiparkinsonian treatments. The primary endpoint was the Clinician’s Global Impression of Change (CGI-C) after 3 months. Secondary assessments included Patient Global Impressions of Change (PGI-C), the Unified Parkinson’s Disease Rating Scale (UPDRS), Parkinson’s Disease Questionnaire (PDQ-8), and the Non-Motor Symptoms Scale (NMSS). Safety assessments included evaluation of treatment-emergent adverse events (TEAEs) and serious adverse events (SAEs). Results Of the 506 patients enrolled, 495 (97.8%) took at least one dose of opicapone. Of these, 393 (79.4%) patients completed 3 months of treatment. Overall, 71.3 and 76.9% of patients experienced any improvement on CGI-C and PGI-C after 3 months, respectively (full analysis set). At 6 months, for UK subgroup only (n = 95), 85.3% of patients were judged by investigators as improved since commencing treatment. UPDRS scores at 3 months showed statistically significant improvements in activities of daily living during OFF (mean ± SD change from baseline: − 3.0 ± 4.6, p < 0.0001) and motor scores during ON (− 4.6 ± 8.1, p < 0.0001). The mean ± SD improvements of − 3.4 ± 12.8 points for PDQ-8 and -6.8 ± 19.7 points for NMSS were statistically significant versus baseline (both p < 0.0001). Most of TEAEs (94.8% of events) were of mild or moderate intensity. TEAEs considered to be at least possibly related to opicapone were reported for 45.1% of patients, with dyskinesia (11.5%) and dry mouth (6.5%) being the most frequently reported. Serious TEAEs considered at least possibly related to opicapone were reported for 1.4% of patients. Conclusions Opicapone 50 mg was effective and generally well-tolerated in PD patients with motor fluctuations treated in clinical practice. Trial registration Registered in July 2016 at clinicaltrials.gov (NCT02847442)

Wie kommt Inklusion in die Schulen? Einstellung zur Inklusion als Prädiktor der inklusionsbezogenen Fortbildungsmotivation von Lehrkräften

Wächter T, Gorges J. Wie kommt Inklusion in die Schulen? Einstellung zur Inklusion als Prädiktor der inklusionsbezogenen Fortbildungsmotivation von Lehrkräften. Zeitschrift für Erziehungswissenschaft. 2022.**Zusammenfassung** Fortbildungen zur inklusionsbezogenen Kompetenz- und Organisationsentwicklung an Schulen sind zentrale Erfolgsfaktoren für die Umsetzung der UN-Behindertenrechtskonvention in Deutschland. Eine positive Einstellung zu schulischer Inklusion seitens der Lehrkräfte sollte eine zentrale Rolle für die engagierte Teilnahme daran spielen. Die vorliegende Studie untersucht die Rolle von Einstellung zu Inklusion für die Fortbildungsmotivation von Lehrkräften (N = 166) mit Blick auf eine bevorstehende Fortbildung zur Kooperation an inklusiven Sekundar- und Gesamtschulen. Die Ergebnisse mehrebenenanalytischer Regressionsmodelle zeigen, dass Einstellung zu Inklusion die fortbildungsbezogene Erfolgserwartung sowie den teilnahmeförderlichen und -hinderlichen Wert signifikant vorhersagt. Eine Prüfung der prädiktiven Validität der Interaktion von fachlicher/sozialer und persönlicher Einstellungsdimension (i. S. von Wert × Erwartung) zeigt außerdem, dass eine stark ausgeprägte persönliche Einstellungsdimension (i. S. der Selbstwirksamkeit) die teilnahmehinderlichen Wertüberzeugungen reduzieren kann. Die Diskussion thematisiert theoretische und praktische Implikationen der Befunde.**Abstract** Professional development courses (PDC) to support inclusion-related competence and organizational development in schools are key success factors for the implementation of the UN Convention on the Rights of Persons with Disabilities in Germany. Teachers’ attitude towards inclusion in schools should play a central role in their participation in PDC. The present study investigated the role of attitude towards inclusion on teachers’ (N = 166) motivation for PDC regarding an upcoming training on cooperation in inclusive schools. The results of multilevel analyses showed that attitude towards inclusion significantly predicted course-related expectancy of success, task value that promotes participation, and task value that attenuates motivation to participate (i.e., cost). A test of the predictive validity of the interaction of instruction-related/social and person-related attitude (i.e., as in value-x-expectancy) revealed that a strong person-related attitude (i.e., self-efficacy) can attenuate the perception of course-related cost. The discussion addresses theoretical and practical implications of the findings