152 research outputs found

    Balancing Surface Energy Terms for Stable Growth of Planar Surfaces

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    We investigate the driving forces that determine the growth mode of heteroepitaxial Ge layers grown from solution on Si substrates with orientations (001), (011) and (111) by transmission electron microscopy (TEM) and atomic force microscopy (AFM). Using liquid phase epitaxy, we can study the influences of strain and surface energy terms independently on effects due to limited surface diffusion. In (001) and (011) orientated layers, {111} faceted islands form (Stranski-Krastanov growth). In contrast, (111) orientated layers grow in a two-dimensional step flow growth mode (Frank-van der Merwe growth). We model these investigations in terms of energy minimisation considering surface energy reduction by formation of faceted islands and elastic strain energy relaxation by island formation. The strain energy relaxation by island formation is calculated by the finite element method. According to our considerations, two-dimensional growth is obtained by selective increase of the free surface energy of the low indices facet planes to a value higher than that of the substrate surface. Formation of faceted islands thus would increase the total surface energy; as a consequence, island formation is suppressed. By choosing the appropriate solvent and temperature in solution growth, we can provide for thermodynamically stable two-dimensional growth

    Vocal Fatigue als Indikator für komplexe Stimmstörungen – eine diagnostische und therapeutische Herausforderung

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    Eine alltagseinschränkende, pathologische Stimmermüdung (Vocal Fatigue) wird v. a. bei BerufssprecherInnen (z. B. LehrerInnen) zunehmend beobachtet und als Indikator für komplexe Stimmstörungen betrachtet. Da bislang wenig systematische Studien zu diesem Phänomen existieren, fehlt bislang eine einheitliche Diagnostik. Anhand der Kasuistik eines Berufssprechers werden Möglichkeiten einer strukturierten Erhebung von Vocal Fatigue vorgestellt und im Hinblick auf ihre laryngoskopischen, instrumentell akustischen („performance fatigue“) und subjektiven Merkmale („perceived fatigue“) diskutiert. Zudem wird eine Abgrenzung zu den Modellen Vocal Effort, Vocal Demand und Vocal Demand Response nach Hunter et al. (2020) vorgenommen. = Vocal fatigue is increasingly observed among professional voice users (e.g., teachers). This pathologic state is associated with restrictions in everyday life and is considered to be an indicator of complex voice disorders. Since there are few systematic studies on the phenomenon, there is currently no uniform definition or diagnostic workup. Based on the case study of a professional speaker, possibilities for a structured vocal fatigue assessment are presented. These are discussed with regard to their laryngoscopic, instrumental acoustic ("performance fatigue") and subjective symptom-related characteristics ("perceived fatigue"). In addition, a differentiation from the vocal effort, vocal demand, and vocal demand response models according to Hunter et al. (2020) is made. Keywords: Muscle tension dysphonia; Vocal Fatigue Index (VFI-D)

    Lentiviral gene therapy for X-linked chronic granulomatous disease

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    Chronic granulomatous disease (CGD) is a rare inherited disorder of phagocytic cells. We report the initial results of nine severely affected X-linked CGD (X-CGD) patients who received ex vivo autologous CD34+ hematopoietic stem and progenitor cell-based lentiviral gene therapy following myeloablative conditioning in first-in-human studies (trial registry nos. NCT02234934 and NCT01855685). The primary objectives were to assess the safety and evaluate the efficacy and stability of biochemical and functional reconstitution in the progeny of engrafted cells at 12 months. The secondary objectives included the evaluation of augmented immunity against bacterial and fungal infection, as well as assessment of hematopoietic stem cell transduction and engraftment. Two enrolled patients died within 3 months of treatment from pre-existing comorbidities. At 12 months, six of the seven surviving patients demonstrated stable vector copy numbers (0.4–1.8 copies per neutrophil) and the persistence of 16–46% oxidase-positive neutrophils. There was no molecular evidence of either clonal dysregulation or transgene silencing. Surviving patients have had no new CGD-related infections, and six have been able to discontinue CGD-related antibiotic prophylaxis. The primary objective was met in six of the nine patients at 12 months follow-up, suggesting that autologous gene therapy is a promising approach for CGD patients

    Early visual ERPs show stable body-sensitive patterns over a 4-week test period

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    Event-related potential (ERP) studies feature among the most cited papers in the field of body representation, with recent research highlighting the potential of ERPs as neuropsychiatric biomarkers. Despite this, investigation into how reliable early visual ERPs and body-sensitive effects are over time has been overlooked. This study therefore aimed to assess the stability of early body-sensitive effects and visual P1, N1 and VPP responses. Participants were asked to identify pictures of their own bodies, other bodies and houses during an EEG test session that was completed at the same time, once a week, for four consecutive weeks. Results showed that amplitude and latency of early visual components and their associated body-sensitive effects were stable over the 4-week period. Furthermore, correlational analyses revealed that VPP component amplitude might be more reliable than VPP latency and specific electrode sites might be more robust indicators of body-sensitive cortical activity than others. These findings suggest that visual P1, N1 and VPP responses, alongside body-sensitive N1/VPP effects, are robust indications of neuronal activity. We conclude that these components are eligible to be considered as electrophysiological biomarkers relevant to body representation

    Where you look matters for body perception: Preferred gaze location contributes to the body inversion effect

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    The Body Inversion Effect (BIE; reduced visual discrimination performance for inverted compared to upright bodies) suggests that bodies are visually processed configurally; however, the specific importance of head posture information in the BIE has been indicated in reports of BIE reduction for whole bodies with fixed head position and for headless bodies. Through measurement of gaze patterns and investigation of the causal relation of fixation location to visual body discrimination performance, the present study reveals joint contributions of feature and configuration processing to visual body discrimination. Participants predominantly gazed at the (body-centric) upper body for upright bodies and the lower body for inverted bodies in the context of an experimental paradigm directly comparable to that of prior studies of the BIE. Subsequent manipulation of fixation location indicates that these preferential gaze locations causally contributed to the BIE for whole bodies largely due to the informative nature of gazing at or near the head. Also, a BIE was detected for both whole and headless bodies even when fixation location on the body was held constant, indicating a role of configural processing in body discrimination, though inclusion of the head posture information was still highly discriminative in the context of such processing. Interestingly, the impact of configuration (upright and inverted) to the BIE appears greater than that of differential preferred gaze locations

    Donated chemical probes for open science.

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    Potent, selective and broadly characterized small molecule modulators of protein function (chemical probes) are powerful research reagents. The pharmaceutical industry has generated many high-quality chemical probes and several of these have been made available to academia. However, probe-associated data and control compounds, such as inactive structurally related molecules and their associated data, are generally not accessible. The lack of data and guidance makes it difficult for researchers to decide which chemical tools to choose. Several pharmaceutical companies (AbbVie, Bayer, Boehringer Ingelheim, Janssen, MSD, Pfizer, and Takeda) have therefore entered into a pre-competitive collaboration to make available a large number of innovative high-quality probes, including all probe-associated data, control compounds and recommendations on use (https://openscienceprobes.sgc-frankfurt.de/). Here we describe the chemical tools and target-related knowledge that have been made available, and encourage others to join the project

    Improving jitter and shimmer measurements in normal voices

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    Im deutschsprachigen Raum ist eine stetige Weiterentwicklung im Bereich der Stimmdiagnostik zu verzeichnen. Dies zeigt, dass Stimmstörungen zunehmend präziser zu diagnostizieren und somit gezielter zu therapieren sind. Die Stimmdiagnostik basiert auf subjektiven Eindrücken und objektiven akustischen Messverfahren. Nicht nur zur Erstdiagnostik wird die Stimmdiagnostik eingesetzt, sondern ebenso zur Zwischen- und Endevaluation einer Stimmtherapie. Angesichts der Tatsache, dass objektive Stimmfeldmessungen im Rahmen von evidenzbasiertem Arbeiten ein wichtiges Element geworden sind, häufig aber kritisiert wird, es lägen keine ausreichenden Normwerte für Stimmfeldmessungen vor, ist die Auseinandersetzung mit den objektiven Messergebnissen von besonderer Bedeutung. Was die computergestützten Messergebnisse von Jitter und Shimmer für die Praxis aussagen und was diese Ergebnisse für die Therapie bedeuten können, sind die Fragen, mit denen sich die Forschungspreisträgerin Meike Brockmann-Bauser in ihrer Arbeit auseinandersetzt. Angesiedelt ist diese Fragestellung im Spannungsfeld von Theorie und Praxis und sie zeigt erneut, wie wichtig die Weiterentwicklung der Theorie für die Praxis ist. Frau Brockmann-Bauser arbeitet mit ihrer Studie heraus, welch hohen Informationsgrad Jitter und Shimmer für den Therapeuten haben können. Dadurch erhöht die dbl-Forschungspreisträgerin die Relevanz von computergestützten Stimmfeldmessungen auch im Rahmen der evidenzbasierten Praxis. Der dbl-Forschungspreis, der vom Schulz-Kirchner Verlag dankenswerterweise mitgetragen wird, trägt dazu bei, wissenschaftliche Master- oder Promotionsarbeiten zu unterstützen, die einen wichtigen Beitrag dazu leisten, die aus intensiver theoretischer Arbeit gewonnenen Erkenntnisse zum Wohle der Patienten in der Praxis anzuwenden. Die vorliegende Studie trägt in herausragendem Maße dazu bei, neue Erkenntnisse in die Praxis integrieren zu können
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