Cognitive behavioural therapy to treat stress and insomnia: A randomized wait list‐controlled trial of two online courses

This randomized, wait list-controlled trial aimed to evaluate the efficacy of the cognitive behavioural therapy-based online e-learning course stressfit for better stress management and the cognitive behavioural therapy for insomnia-based online course SweetDreams for coping with insomniac problems. The course modules offer state of the art psychoeducation and cognitive behavioural strategies concerning different aspects of stress, sleep and insomnia. They provide practice-oriented exercises for self-reflection, as well as a variety of evidence-based methods and measures to increase self-efficacy when dealing with stress or insomnia. Study participants were randomly assigned to the three test conditions stressfit, SweetDreams or a wait list. Participants filled in questionnaires on a wide range of scales relevant to stress and insomnia at three points in time (before, 4 weeks after, and 3 months after the treatment). Of the 588 participants in total, data from 347 participants (59%) were finally included in the data analyses. Data analyses showed that both courses yielded significant positive effects compared with the wait list condition 4 weeks and to some degree 3 months after completion in relation to insomnia symptoms, physical and psychological wellbeing, life satisfaction and general health (General Health Questionnaire), as well as on satisfaction with and effectiveness of coping with stress and sleep disorders. In conclusion, SweetDreams and stressfit proved to be feasible and effective online cognitive behavioural therapy (for insomnia) tools to reduce insomnia and stress symptoms on a broad variety of scales at the 4-weeks measurement point as well as at the 3-months follow-up

Orientation distributions of vacuum-deposited organic emitters revealed by single-molecule microscopy

This work was supported by the Volkswagen Foundation (No. 93404) and the DFG-funded Research Training Group “Template-Designed Organic Electronics (TIDE)”, RTG2591. M.C.G. acknowledges support from the Alexander von Humboldt Stiftung through the Humboldt-Professorship. A.M. acknowledges funding from the European Union’s Horizon 2020 research and innovation programme under Marie Skłodowska-Curie grant agreement No. 101023743 (PolDev).The orientation of luminescent molecules in organic light-emitting diodes strongly influences device performance. However, our understanding of the factors controlling emitter orientation is limited as current measurements only provide ensemble-averaged orientation values. Here, we use single-molecule imaging to measure the transition dipole orientation of individual emitter molecules in a state-of-the-art thermally evaporated host and thereby obtain complete orientation distributions of the hyperfluorescence-terminal emitter C545T. We achieve this by realizing ultra-low doping concentrations (10−6 wt%) of C545T and minimising background levels to reliably measure its photoluminescence. This approach yields the orientation distributions of >1000 individual emitter molecules in a system relevant to vacuum-processed devices. Analysis of solution- and vacuum-processed systems reveals that the orientation distributions strongly depend on the nanoscale environment of the emitter. This work opens the door to attaining unprecedented information on the factors that determine emitter orientation in current and future material systems for organic light-emitting devices.Publisher PDFPeer reviewe

PCF-Based Cavity Enhanced Spectroscopic Sensors for Simultaneous Multicomponent Trace Gas Analysis

A multiwavelength, multicomponent CRDS gas sensor operating on the basis of a compact photonic crystal fibre supercontinuum light source has been constructed. It features a simple design encompassing one radiation source, one cavity and one detection unit (a spectrograph with a fitted ICCD camera) that are common for all wavelengths. Multicomponent detection capability of the device is demonstrated by simultaneous measurements of the absorption spectra of molecular oxygen (spin-forbidden b-X branch) and water vapor (polyads 4v, 4v + δ) in ambient atmospheric air. Issues related to multimodal cavity excitation, as well as to obtaining the best signal-to-noise ratio are discussed together with methods for their practical resolution based on operating the cavity in a “quasi continuum” mode and setting long camera gate widths, respectively. A comprehensive review of multiwavelength CRDS techniques is also given

Tomography studies of human foreskin fibroblasts on polymer yarns

Cell culture experiments are usually performed as in vitro studies based on 2D seeding and characterization (light microscopy). With respect to the in vivo situation, however, 2D studies are often inappropriate due to the 3D character of living tissue in nature. Textiles with their versatile 3D structures are chosen as suitable scaffolds in tissue engineering for 3D in vitro studies. Micro-computed tomography using X-rays (?CT) belongs to the most promising techniques for isotropic, noninvasive 3D characterization. Using synchrotron radiation (SR?CT) the spatial resolution can be extended to the sub-micrometer range well below cell size. ?CT does not need vacuum conditions making experiments in the hydrated state possible, as we show by data from SR?CT acquired at second and third-generation synchrotron sources. We seeded human foreskin fibroblasts on polymer multifilament yarns. These composites, embedded in a hydrogel or fluid, are held in thin-walled glass capillaries. Since the composites consist of light elements, the cells have to be labeled for visualization by the use of highly absorptive agents, osmium and gold. In order to hold the label concentration as low as possible, we present a way to choose the photon energy for which the minimum concentration is reached. Differences in threshold selection for second- and third-generation synchrotron sources are pointed out, revealing the advantages of both types with respect to quantitative analysis. The study is based on appropriate staining methods and protocols developed in our laboratory. With the results we demonstrate that SR?CT yields images similar to established electron and light microscopy but uncovers also the microstructure in 3D space

Nondestructive three-dimensional evaluation of biocompatible materials by microtomography using synchrotron radiation

Microtomography based on synchrotron radiation sources is a unique technique for the 3D characterization of different materials with a spatial resolution down to about 1 micrometers . The interface between implant materials (metals, ceramics and polymers) and biological matter is nondestructively accessible, i.e. without preparation artifacts. Since the materials exhibit different x-ray absorption, it can become impossible to visualize implant material and tissue, simultaneously. Here, we show that coating of polymer implants, which are invisible in bone tissue, does not only improve the interfacial properties but also allows the imaging of the interface in detail. Titanium implants, on the other hand, absorb the x-rays stronger than bone tissue. The difference, however, is small enough to quantify the bone formation near interface. Another advantage of microtomography with respect to classical histology is the capability to examine samples in a hydrated state. We demonstrate that ceramic hollow spheres can be imaged before sintering and fibroblasts marked by OsO4 are visible on polymer textiles. Consequently, scaffolds of different materials designed for tissue engineering and implant coatings can be optimized on the basis of the tomograms

Silk Fiber-Reinforced Hyaluronic Acid-Based Hydrogel for Cartilage Tissue Engineering

A continuing challenge in cartilage tissue engineering for cartilage regeneration is the creation of a suitable synthetic microenvironment for chondrocytes and tissue regeneration. The aim of this study was to develop a highly tunable hybrid scaffold based on a silk fibroin matrix (SM) and a hyaluronic acid (HA) hydrogel. Human articular chondrocytes were embedded in a porous 3-dimensional SM, before infiltration with tyramine modified HA hydrogel. Scaffolds were cultured in chondropermissive medium with and without TGF-β1. Cell viability and cell distribution were assessed using CellTiter-Blue assay and Live/Dead staining. Chondrogenic marker expression was detected using qPCR. Biosynthesis of matrix compounds was analyzed by dimethylmethylene blue assay and immuno-histology. Differences in biomaterial stiffness and stress relaxation were characterized using a one-step unconfined compression test. Cell morphology was investigated by scanning electron microscopy. Hybrid scaffold revealed superior chondro-inductive and biomechanical properties compared to sole SM. The presence of HA and TGF-β1 increased chondrogenic marker gene expression and matrix deposition. Hybrid scaffolds offer cytocompatible and highly tunable properties as cell-carrier systems, as well as favorable biomechanical properties

3D Synchrotron Imaging of a Directionally Solidified Ternary Eutectic

For the first time, the microstructure of directionally solidified ternary eutectics is visualized in three dimensions, using a high-resolution technique of X-ray tomography at the ESRF. The microstructure characterization is conducted with a photon energy, allowing to clearly discriminate the three phases Ag2Al, Al2Cu, and α-Aluminum solid solution. The reconstructed images illustrate the three-dimensional arrangement of the phases. The Ag2Al lamellae perform splitting and merging as well as nucleation and disappearing events during directional solidification