Mild-to-moderate hip osteoarthritis and hip bracing influence hip and knee biomechanics during 90° turns while walking

Background Turning movements are frequently encountered during daily life and require more frontal and transverse hip mobility than straight walking. Thus, analysis of turning might be an insightful addition in the evaluation of conservative treatment approaches for hip osteoarthritis patients. The study objective was to quantify the effects of mild-to-moderate symptomatic hip osteoarthritis on lower-body turning biomechanics and evaluate the effects of hip bracing in this cohort. Methods Biomechanical analysis of 90° step and spin turns in 21 persons with hip osteoarthritis and 21 healthy controls (case-control-study) and intervention study on the effects of hip bracing in hip osteoarthritis participants. Hip and knee kinematics and dynamics were compared using independent sample t-tests or one-way repeated measure ANOVAs. Findings Persons with hip osteoarthritis have reduced peak hip extension and sagittal and transverse hip range of motion during turning. During the spin turn reduced hip adduction and frontal hip range of motion were found. Bracing increased the movement velocity at turn initiation and limited the transverse hip range of motion during both turns but increased knee peak adduction and internal rotation moments during spin turns. Interpretation Persons with hip osteoarthritis present altered hip kinematics during 90° spin turns in all movement planes. Their inclusion during clinical movement analysis might facilitate the detection of mobility deficits at an early disease stage. Bracing led to higher movement velocity at turn initiation without increasing load at the hip joint and reduced transverse hip range of motion, avoiding the painful reaching of range of motion endpoints

Detecting Excess Biofilm Thickness in Microbial Electrolysis Cells by Real‐Time In‐Situ Biofilm Monitoring

Long-term stable operation of bioelectrochemical systems (BES) presupposes the avoidance of mass transfer limitations of the electroactive biofilm. Excessive pH-gradients from bulk to electrode interface or substrate limitations of the electroactive biofilm are known to diminish the electrical performance of BES. In this study the impact of the morphology of a mixed-species electroactive biofilm cultivated on the electrical performance of a microbial electrolysis cell (MEC) was investigated to identify the optimal biofilm for real-life applications in wastewater treatment. Noninvasive monitoring by means of optical coherence tomography and an industrial biofilm sensor allowed for a real-time evaluation of the morphology of the biofilm. The maximum current density of approximately 3.5 A/m² was found for a mean biofilm thickness in the range of 100–150 µm, beyond which thicker biofilms caused mass transfer limitations. Along with local biofilm detachment a continuous decline in efficiency demonstrates the need for active biofilm control to adjust the biofilm thickness

Analyse von Störungen und Dispositionen im ÖPNV

In dieser Arbeit werden Störungen und Dispositionen im ÖPNV mit unterschiedlichen Methoden untersucht. Es werden Interviews und Beobachtungen innerhalb von Leitstellen durchgeführt sowie Daten aus dem ITCS ausgewertet. Daraus werden Einflussfaktoren auf die Disposition des öffentlichen Verkehrs abgeleitet. Wesentliche Erkenntnis hieraus ist, dass die Interaktion mit dem MIV einen entscheidenden Einfluss auf die Verlässlichkeit des ÖPNV hat

Spectral gap properties of perturbed periodic media

We analyze periodic operators on $\mathbb{R}^n$ and small perturbations of these operators. The perturbation is periodic in $n−1$ directions and has bounded support in the remaining direction. We show that, when the perturbation has a sign, every spectral gap for the unperturbed operator is reduced by the perturbation. We develop a general theory that can be applied to elliptic operators, to systems such as that of linear elasticity, and to Maxwell’s equations

Synthese und Charakterisierung von neuartigen Spirohexen-modifizierten Nukleosiden für die Markierung von DNA mittels bioorthogonaler Reaktionen

Die gezielte chemische Modifikation von Nukleinsäuren eröffnet neue Möglichkeiten zur spezifischen Visualisierung biologischer Prozesse. Besonders bioorthogonale Reaktionen, wie die Diels-Alder-Reaktion mit inversem Elektronenbedarf (iEDDA) oder Photoclick-Reaktionen, haben sich als leistungsfähige Werkzeuge in der chemischen Biologie etabliert. Die vorliegende Dissertation befasst sich mit der Entwicklung und Anwendung neuartiger, chemisch modifizierter Nukleoside und Peptidnukleinsäuren zur dynamischen Visualisierung zellulärer Prozesse in vitro und in vivo. Im ersten Teil der Arbeit werden Spirohexen-modifizierte Nukleoside und Oligonukleotide synthetisiert und hinsichtlich ihrer Reaktivität in iEDDA- sowie Photoclick-Reaktionen untersucht. Dabei liegt der Fokus auf dem Einfluss der Nukleobasen und der Linkerstruktur auf die Reaktionskinetik und die Fluoreszenzintensität. Spirohexene bieten aufgrund ihrer hohen Ringspannung und chemischen Stabilität ein bislang unerforschtes Potenzial als Reportergruppe in Oligonukleotiden und eignen sich durch ihre duale Funktionalität sowohl für iEDDA- als auch Photoclick-Markierungen. Der zweite Teil der Arbeit widmet sich der Synthese von verschieden modifizierten acpcPNA-Sonden, welche mit den Fluorophoren Cy3 oder Atto647N markiert werden. Ziel ist es, mittels Förster-Resonanzenergietransfer (FRET) die Hybridisierung mit der sonic hedgehog-mRNA in Zebrafisch-Embryonen sichtbar zu machen. Durch die hohe Stabilität der PNA/RNA- und PNA/DNA-Duplexe im Vergleich zu natürlichen Nukleinsäuren wird eine effizientere Hybridisierung und ein stärkerer FRET-Effekt erwartet, was die Sensitivität der Fluoreszenzsignale in vivo verbessert

Enhanced grating characterization method for absorbing X-ray gratings by bidirectional angular X-ray transmission

High-quality X-ray absorption gratings are essential for grating-based X- ray phase-contrast imaging. Bidirectional angular X-ray transmission measurements, as proposed in this work, allow for large-area and nondestructive characterization of these gratings. A custom setup consisting of two rotational axes is used to measure the transmission of X-ray absorption gratings under rotation. From the transmission values and rotation angles, pixelwise transmission profiles are reconstructed. From these transmission profiles, parameter maps that carry information about the microstructure of the grating are retrieved via a fitting procedure. Compared to unidirectional angular X- ray transmission measurements, more detailed and complementary parameter maps are obtained, revealing more defects and parameter variations. Apart from duty cycle, absorber height, and absorber inclination, the bidirectional measurements also provide access to grating lamella rotation on the substrate and to auxiliary structures introduced to increase grating stability. Furthermore, a novel correction technique is introduced to address projective distortions in individual radiographs caused by the rotations. This method relies on calibration phantom measurements to track the movement of registration points under the same rotations as the gratings. Based on the movement of the registration points, the distortions are reconstructed, and appropriate deformation vector fields are calculated and applied to measurement data, achieving a correction with a precision of about two pixels

Employing variance component estimation for point cloud based geometric surface representation by B-splines

When it comes to the significance assessment of interepochal displacements, great reliance on the stochastic information related to the point clouds introduced in the estimation of the geometric representation of the analysed surface is present. Possible uncertainty sources in point clouds are instrument-, environment- or object sided. Further, the chosen mathematical model for point cloud approximation may introduce an uncertainty budget ascribed as model uncertainty. The present contribution employs variance component estimation (VCE) in the course of geometric point cloud approximation with tensor product B-spline surfaces. A method using the BIQUE-estimation of the variance components is used. It enables considering overlapping variance components. Here, those are related to measurement and model uncertainties. The aim of the article is to investigate whether a realistic estimation of the components can be achieved by means of the VCE in particular with regard to the separation between measurement and model uncertainty. The former include the distance and angular components whilst the model uncertainty is set up using covariance functions. For that, a B-spline surface with comparably superior complexity, whilst describing an identical geometric surface course as the functionally employed surface representation, is generated. Artificial altering of the more complex surface establishes the model uncertainty as distance between equally parametrized sampled points. Results based on simulated data show that variance components are separable and estimable if the model uncertainty exceeds measurement uncertainty, and only points affected by model deviations are included in the VCM setup