Vital Functions Contribute to the Spread of Extracellular Fluids in the Brain: Comparison Between Life and Death

Vascular pulsations, contractions of vascular smooth muscle cells and breathing have been reported to foster movement and clearance of interstitial and cerebrospinal fluids from the brain. The aim of this study was to estimate the contribution of these vital functions. We compared the spread of an injected hydrophilic tracer (Fluoro-Emerald, a 10 kDa fluorescein-coupled dextran amine) in the brains of live anesthetized and sacrificed rats at 30 and 90 min after injection. To determine the overall pattern of distribution of tracers, we created 3D-reconstructions of the horizontal transections of the whole brain. Immunofluorescence staining with laminin and collagen IV was performed to determine the pattern of distribution of tracer in relation to the cerebrovascular basement membranes. We found that diffusion was widely restricted to the periventricular region in sacrificed rats with no spread to the contralateral hemisphere, while the bulk flow occurred along the vasculature and reached the surface and the contralateral hemisphere as soon as 30 min after injection in live anesthetized animals. The tracer appeared to be localized along the vascular basement membranes and along fiber tracts as reported previously. Thus, our data indicate that vital functions are essential for the remote movement of extracellular fluids within the cerebral parenchyma

Apitherapy: Usage And Experience In German Beekeepers

This study aimed to investigate the practice of apitherapy - using bee products such as honey, pollen, propolis, royal jelly and bee venom to prevent or treat illness and promote healing - among German beekeepers and to evaluate their experiences with these therapies. A questionnaire incorporating two instruments on beekeepers’ physical and mental health and working practice was included in three German beekeeping journals and readers were asked to complete it. The instrument included questions on the use of apitherapy. Simple descriptive methods, bivariate correlation, cross-tabulation and one-way ANOVA were used to analyze the data. Altogether 1059 completed questionnaires were received. The beekeepers reported the most effective and favorable therapeutic effects with honey, followed by propolis, pollen and royal jelly. The factors associated with successful experiences were: age, number of hives tended, health consciousness, positive experiences with one product and self-administration of treatment. Beekeepers were asked for which condition they would employ propolis and pollen. They reported that they used propolis most frequently to treat colds, wounds and burns, sore throats, gum disorders and also as a general prophylactic, while pollen was most commonly used as a general prophylactic and, less frequently, in treating prostate diseases. No adverse experiences were reported. The potential benefit of bee products is supported by the positive experiences of a large group of beekeepers who use some of these products to treat a wide range of conditions. The indications and treatments given here may be important in selecting bee products and designing future trials

Quantification of Fracture Roughness by Change Probabilities and Hurst Exponents

The objective of the current study is to utilize an innovative method called “change probabilities” for describing fracture roughness. In order to detect and visualize anisotropy of rock joint surfaces, the roughness of one-dimensional profiles taken in different directions is quantified. The central quantifiers, change probabilities, are based on counting monotonic changes in discretizations of a profile. These probabilities, which usually vary with the scale, can be reinterpreted as scale-dependent Hurst exponents. For a large class of Gaussian stochastic processes, change probabilities are shown to be directly related to the classical Hurst exponent, which generalizes a relationship known for fractional Brownian motion. While related to this classical roughness measure, the proposed method is more generally applicable, therefore increasing the flexibility of modeling and investigating surface profiles. In particular, it allows a quick and efficient visualization and detection of roughness anisotropy and scale dependence of roughness

Auswertung von Gefäßstrukturen in Laserscanning-Volumendaten

Inhalt der vorliegenden Arbeit ist die Vorstellung einer bildanalytischen Methodik zur räumlich bezogenen Quantifizierung morphologischer und topologischer Reifungsparameter von in vitro gewachsenem Fettgewebe. Diese Reifungsparameter sollen später Rückschlüsse auf die am Gewebewachstum beteiligten Wachstumsparameter im Hinblick auf deren Optimierung erlauben und somit als Grundlage einer qualitativen Analyse des Gewebes für die plastisch rekonstruktive Chirurgie dienen. Die Berechnung der einzelnen Reifungsparameter erfolgt im Rahmen einer Bildverarbeitungskette. Diese umfasst die Glättung und Ausheilung der aus dem Gewebe gewonnenen Volumendatensätze mittels eines gekoppelten anisotropen nichtlinearen Reaktionsdiffusionssystems, die Ermittlung des Bedeckungsgrades der kapillaren Strukturen mit Muskelzellen, die Berechnung der Kompaktheit, eine Skelettierung der Volumendatensätze und die Vektorisierung des entstandenen Skelettes. Anhand von Beispielen wird die Wirkungsweise sowohl der einzelnen Bildverarbeitungsschritte als auch der gesamten Bildverarbeitungskette dargestellt. Die Oberfläche der Blutgefäße des Gewebes und deren Skelett werden zum besseren Verständnis der extrahierten Reifungsparameter visualisiert. Eine statistische Auswertung der gewonnenen Reifungsparameter soll Informationen zur Verbesserung der Oxygenierungs- und Ernährungssituation des in vitro gewachsenen Gewebes liefern. Abschließend werden Ergebnisse der Analyse von Volumendatensätzen und des Vergleichs zur bisherigen Messmethode vorgestellt und diskutiert

Classification of Microglial Morphological Phenotypes Using Machine Learning

Microglia are the brain’s immunocompetent macrophages with a unique feature that allows surveillance of the surrounding microenvironment and subsequent reactions to tissue damage, infection, or homeostatic perturbations. Thereby, microglia’s striking morphological plasticity is one of their prominent characteristics and the categorization of microglial cell function based on morphology is well established. Frequently, automated classification of microglial morphological phenotypes is performed by using quantitative parameters. As this process is typically limited to a few and especially manually chosen criteria, a relevant selection bias may compromise the resulting classifications. In our study, we describe a novel microglial classification method by morphological evaluation using a convolutional neuronal network on the basis of manually selected cells in addition to classical morphological parameters. We focused on four microglial morphologies, ramified, rod-like, activated and amoeboid microglia within the murine hippocampus and cortex. The developed method for the classification was confirmed in a mouse model of ischemic stroke which is already known to result in microglial activation within affected brain regions. In conclusion, our classification of microglial morphological phenotypes using machine learning can serve as a time-saving and objective method for post-mortem characterization of microglial changes in healthy and disease mouse models, and might also represent a useful tool for human brain autopsy samples

Application of a new ray tracing framework to the analysis of extended regions in Si solar cell modules

While ray tracing of solar cells was established decades ago, ray tracing of entire modules has met obstacles, mainly because module optics are affected by geometric structures varying over a large scale of dimensions. In this paper, we introduce a ray tracing framework that is based on a modular structure made up of separate plugins. While existing plugins can be used for common effects such as light sources, absorption in materials, etc., specialized plug-ins can be written by users to handle problem-specific properties. We demonstrate the functionality of our approach by ray tracing a test module containing 9 crystalline Si solar cells. Good agreement between light-beam induced current (LBIC) measurements and ray tracing is achieved

Calibrating spectrometers for measurements of the spectral irradiance caused by solar radiation

Measuring the spectral irradiance of solar radiation is required in many fields of science and technology. In this work, we present an in-depth discussion of the measuring procedure and required corrections for such measurements. We also describe our measurement uncertainty analysis, which is based on a Monte-Carlo procedure in accordance with the Guide to the expression of uncertainty in measurement (JCGM, Paris, 2008). For this purpose, fifteen uncertainty sources are identified, analyzed and described analytically. As a specific application example, we describe the instrumentation and procedure for determining the spectral irradiance of a solar simulator at the ISO/IEC 17 025 accredited solar cell calibration laboratory ISFH CalTeC and the corresponding measurement uncertainty analysis. Moreover, we provide a Python implementation for this calculation along with the paper. We show that for state-of-the-art instrumentation, significant uncertainty contributions arise from the reference lamp (primary calibration standard), stray light and signal-to-noise ratio. If sharp spectral features are present (which is common, e.g. for Xenon lamps), spectral bandwidth and wavelength uncertainty also contribute significantly to the overall uncertainty. © 2020 BIPM & IOP Publishing Lt

Preparation and Characterization of [Au(CF3)xF3−x(SIMes)] (x=1–3) Complexes

Trifluoromethylation of [AuF3(SIMes)] with the Ruppert–Prakash reagent TMSCF3 in the presence of CsF yields the product series [Au(CF3)xF3−x(SIMes)] (x=1–3). The degree of trifluoromethylation is solvent dependent and the ratio of the species can be controlled by varying the stoichiometry of the reaction, as evidenced from the 19F NMR spectra of the corresponding reaction mixtures. The molecular structures in the solid state of trans‐[Au(CF3)F2(SIMes)] and [Au(CF3)3(SIMes)] are presented, together with a selective route for the synthesis of the latter complex. Correlation of the calculated SIMes affinity with the carbene carbon chemical shift in the 13C NMR spectrum reveals that trans‐[Au(CF3)F2(SIMes)] and [Au(CF3)3(SIMes)] nicely follow the trend in Lewis acidities of related organo gold(III) complexes. Furthermore, a new correlation between the Au−Ccarbene bond length of the molecular structure in the solid state and the chemical shift of the carbene carbon in the 13C NMR spectrum is presented

Corrigendum: Calibrating spectrometers for measurements of the spectral irradiance caused by solar radiation (2020 Metrologia 57 065027)

We correct an error in equation (60) of the original publication