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Confocal microscopy is an established technique with manifold applications that offers the capability to perform nondestructive through‐plane imaging. However, depth resolution typically decreases when focusing below the surface of a sample, which limits the applicability. A computational model is introduced that calculates the axial resolution, its decay, and the attenuation coefficient from confocal through‐plane scans of translucent layers. The model is benchmarked with different polymers and objectives (air, water, oil) using a confocal Raman microscope. The algorithm requires a single through‐plane scan that allows to identify the sample by signal intensity differences. It fits the point spread function of the objective at the top and bottom interface of the specimen to extract the resolution at both interfaces and the attenuation coefficient of the sample. It provides robust outputs on various and even multilayered samples if the signal‐to‐noise ratio of the input is sufficient and if the layers are planar and homogeneous. The algorithm of the model is provided open‐source for MATLAB and Python. Quantifying microscope resolution in through‐plane scans can improve image analysis in multiple fields, and this study is a comprehensive proof‐of‐concept for the presented model. It establishes an accessible tool to quantify the depth resolution of confocal microscopy.

A sustainable hydrogen economy relies on fuel cells and electrolyzers, which heavily depend on ion-conducting perfluoroalkylated materials such as Nafion or Aquivion. Together with other perfluorinated alkyl substances, their environmental accumulation, and the rising awareness of risks to human health stress the need for alternative materials. Based on block-co-polymers from octylstyrene and pentafluorostyrene, we present nanostructured proton-exchange membranes. In contrast to problematic perfluorinated alkyl constituents, the involved aromatic fluorine atoms allow mild functionalizations to form tetrafluorostyrene sulfonic acid. Meanwhile, the nonpolar block reduces the stiffness of the material. By introducing a new preparation technique, controlled mitigation of the thiol cross-linking allows membrane self-reinforcement during drying. The reinforcing cross-links enhance the dissolution stability and reduce the water uptake after 24 h down to 33 wt% at 85 °C. Cross-section imaging visualizes the influence of varying di- and tetrablock-co-polymer backbones on the membrane nanostructure with sizes between 20 and 35 nm. The membranes feature proton conductivities comparable to commercial materials at low humidity levels, surpassing commercial Nafion XL at 87 % relative humidity with up to 79 mS cm−1 at 105 °C. As first successful H2/air fuel cell tests achieve maximum power densities of up to 0.7 W cm−2, the nanostructured polymer membranes are a promising candidate for future fuel cell and electrolyzer applications without problematic perfluorinated alkyl substances.

Abstract The perfluorinated sulfonic acid membranes used in direct alcohol fuel cells cause low faradaic efficiency and performance due to alcohol absorption and permeation. Thus, a measurement setup is sought that enables a direct evaluation of the suitability of polymer electrolytes for this application. A 3D‐printed diffusion cell setup capable of measuring the interaction between the organic solvents, such as alcohols, and a proton exchange membrane via confocal Raman microscopy is introduced. The cell design employs flow channels to mimic the flow fields of electrochemical cell tests. Exemplarily, information on the interaction of membranes like Nafion 212 and the composite membrane Nafion XL with 1 m solutions of organic solvents such as 2‐propanol, acetone, and ethanol are provided to demonstrate the applicability of this setup. The Raman diffusion cell is capable of quantifying the preferred solvent uptake, which is characterized by the sorption coefficient, the permeability, and the concentration gradient within the membrane. These properties can be obtained in situ and in a time‐resolved manner. Thus, this diffusion cell setup is a powerful and accessible tool for screening membrane compatibility with various liquids.

Summary: High-entropy alloys are claimed to possess superior stability due to thermodynamic contributions. However, this statement mostly lies on a hypothetical basis. In this study, we use on-line inductively coupled plasma mass spectrometer to investigate the dissolution of five representative electrocatalysts in acidic and alkaline media and a wide potential window targeting the most important applications. To address both model and applied systems, we synthesized thin films and carbon-supported nanoparticles ranging from an elemental (Pt) sample to binary (PtRu), ternary (PtRuIr), quaternary (PtRuIrRh), and quinary (PtRuIrRhPd) alloy samples. For certain metals in the high-entropy alloy under alkaline conditions, lower dissolution was observed. Still, the improvement was not striking and can be rather explained by the lowered concentration of elements in the multinary alloys instead of the synergistic effects of thermodynamics. We postulate that this is because of dissolution kinetic effects, which are always present under electrocatalytic conditions, overcompensating thermodynamic contributions.

Abstract Tetrahedral amorphous carbon (ta‐C) coatings have the potential to protect biomedical implants from wear and increase their service life. This study elucidates the biocompatibility, mechanical properties, adhesion, and wear resistance of ta‐C coatings fabricated by physical vapor deposition on cobalt‐chromium‐molybdenum (CoCr) and titanium (Ti64) alloys as well as ultrahigh molecular weight polyethylene (UHMWPE). Satisfactory cytocompatibility is verified using contact angle and surface tension measurements as well as indirect and direct cell testing. Scratch testing demonstrates excellent adhesion to the substrates and as confirmed by nanoindentation, the coatings represent an up to 13‐fold and 182‐fold increase in hardness on the hard and soft materials. In metal pin‐on‐UHMWPE disk sliding experiments under simulated body fluid lubrication, the wear rates of the disk are reduced by 48% (against CoCr) and 73% (against Ti64) while the pin wear rates are reduced by factors of 20 (CoCr) and 116 (Ti64) compared to uncoated pairings. From optical and laser scanning microscopy, Raman measurements, and particle analyses, it is shown that the underlying substrates remain well protected. Nonetheless, focused ion beam scanning electron microscopy revealed coating process‐related and thermally driven subductions as well as tribologically induced near‐surface fatigue, which can potentially constitute critical wear mechanisms.

Dissolution of Ir catalysts varies widely between PEM water electrolysers and aqueous electrolytes. Here, we systematically investigate this finding and propose that stabilization of the catalysts over time and overestimated ionomer acidity are the main contributors to the dissolution discrepancy.

Mast cell neoplasms are one of the most frequently diagnosed malignancies in dogs. The clinical picture, course, and prognosis vary substantially among patients, depending on the anatomic site, grade and stage of the disease. The most frequently involved organ is the skin, followed by hematopoietic organs (lymph nodes, spleen, liver, and bone marrow) and mucosal sites of the oral cavity and the gastrointestinal tract. In cutaneous mast cell tumors, several grading and staging systems have been introduced. However, no comprehensive classification and no widely accepted diagnostic criteria have been proposed to date. To address these open issues and points we organized a Working Conference on canine mast cell neoplasms in Vienna in 2019. The outcomes of this meeting are summarized in this article. The proposed classification includes cutaneous mast cell tumors and their sub-variants defined by grading- and staging results, mucosal mast cell tumors, extracutaneous/extramucosal mast cell tumors without skin involvement, and mast cell leukemia (MCL). For each of these entities, diagnostic criteria are proposed. Moreover, we have refined grading and staging criteria for mast cell neoplasms in dogs based on consensus discussion. The criteria and classification proposed in this article should greatly facilitate diagnostic evaluation and prognostication in dogs with mast cell neoplasms and should thereby support management of these patients in daily practice and the conduct of clinical trials.

Methylated polycyclic aromatic hydrocarbons (PAHs) are suspected to be some of the toxic compounds in crude oil towards marine life and are needed as single compounds for environmental studies. 1-, 3- and 6-methylchrysene (3a,b,c) were prepared as single isomers by photochemical cyclization of the corresponding stilbenoids in the Mallory reaction using stoichiometric amounts of iodine in 82-88% yield. 2-methylchrysene (3d) was prepared by photochemical cyclization where the regioselectivity was controlled by elimination of an ortho-methoxy group under acidic oxygen free conditions in 72% yield. These conditions failed to form 4-methylchrysene from the corresponding stilbenoid. All stilbenoids were made from a common naphthyl Wittig salt and suitably substituted benzaldehydes. We have also demonstrated that methylchrysenes can be oxidized to the corresponding chrysenecarboxylic acids by KMnO4 in modest yields.

We present the first results of an anion exchange ionomer membrane, hexamethyl-p-terphenyl poly(benzimidazolium) (HMT-PMBI), in a vanadium redox flow battery. Anion exchange membranes exhibit superior vanadium crossover suppression compared to proton exchange membranes due to the Gibbs–Donnan effect. HMT-PMBI was benchmarked against a similarly thin Nafion XL membrane which allowed us to compare differences based solely on chemical properties of the ionomer materials. We report cycling data of 45 cycles at a current density of 150 mA/cm2 with excellent coulombic efficiency of >99.4%, energy efficiency of 80.6–74.2% and a low ohmic resistance of 0.219–0.255 Ω cm2. In addition, a three times lower self-discharge rate is obtained for the HMT-PMBI membrane compared to Nafion XL. HMT-PMBI is therefore a potential alternative for PFSA based ionomers in VRFB applications. Keywords: Anion exchange membrane, Vanadium redox flow battery, Energy storage, HMT-PMBI, Coulombic efficiency

We present a novel membrane electrode assembly (MEA) fabrication method for proton exchange membrane water electrolysis (PEMWE). Inspired by previous work on PEM fuel cells (PEMFCs), we fabricated PEMWE-MEAs via direct membrane deposition (DMD). DMD-MEAs were fabricated by spray coating the membrane directly onto the cathode electrode – in this case, a carbon cloth substrate with microporous layer coated with Pt/C. The complete DMD-MEAs consisted of the membrane-cathode compound assembled with an anode electrode, which is a porous titanium fiber substrate coated with IrO2. Polarization experiments of DMD-MEAs show promising results: In comparison to a reference catalyst coated membrane (CCM) and a porous transport electrode (PTE) type MEA using a freestanding Nafion 117 membrane, we found very good electrochemical performances for DMD-MEAs. DMD-MEAs show slightly higher activation losses than the reference CCM. However, DMD-MEAs seem to exhibit reduced ohmic and mass transport losses compared to those manufactured using the CCM approach. Compared to the PTE-type reference DMD shows improvements for all three loss mechanisms. Similar as for PEMFCs, DMD may allow for a simplified fabrication route and higher degree of design freedom in PEMWE-MEA manufacturing due to the simple layer by layer fabrication approach. Keywords: PEM water electrolysis, Direct membrane deposition, Porous transport electrodes

Background. Systematic studies on factitious disorders and malingering in large populations are rare. To address this issue, we performed a nationwide epidemiological study in Norway on the incidence of these diagnoses in an unselected patient population. In particular, we tried to confirm the diagnoses and to estimate the contribution of Munchausen syndrome to the spectrum of factitious disorders. Methods. We analyzed data obtained from the Norwegian Patient Registry (NPR), which provided a deidentified list of all patients from 2008 to 2016 who had received the ICD-10 diagnosis of F68.1 or the diagnosis code Z76.5. Results. Altogether, 237 patients (99 females; 138 males) received a diagnosis of F68.1. Code Z76.5 was applied to 52 patients (12 females; 40 males), all diagnosed within health institutions. Three of 1700 specialists (somatic specialist, psychologist, or psychiatrist) in private practice had diagnosed a factitious disorder in altogether 87 patients. After contacting these specialists, we could identify no true case of F68.1. For 24 of 146 patients who were equally distributed by gender within health institutions, we managed to identify the diagnosing healthcare providers. Of these 24 patients, only 11 correctly qualified for code F68.1. Only two female patients qualified for a Munchausen syndrome diagnosis. Conclusions. There is a male predominance for the diagnosis of malingering. An earlier suspicion of a female predominance for Munchausen syndrome is upheld. There is significant underdiagnosing and misdiagnosing for both conditions and for factitious disorders in general. To separate the most serious form of factitious disorders from milder forms and to facilitate more systematic research, we recommend a specific ICD diagnosis for Munchausen syndrome.

A highly available infrastructure is a premise for capable railway operation of high quality. Therefore, maintenance is necessary to keep railway infrastructure elements available. Railway switches, especially, are critical because they connect different tracks and allow a train to change its moving direction without stopping. Their inspection, maintenance and repair have long been identified as a cost driver. Switch failures, particularly, are responsible for a comparable high number of failures and delay minutes. The reduction of failures would not only save maintenance costs, but also let more trains arrive on time and hence increase the attractiveness of the railway transport. Therefore, upcoming failures need to be revealed early enough to allow an effective planning and execution of failure preventing maintenance activities. Research is exploring ways to predict the remaining useful life of switches. This paper presents an approach to predict the remaining useful life (RUL) of railway switch engine failures. The development is based on measurement data of the electrical power consumption of switch engines. The two year time series of 29 switches of Deutsche Bahn was recorded by a commercial switch diagnostic system leading to roughly 250 000 measurement tuples. Since earlier researched showed that the electrical data alone is not sufficient enough, additional data is integrated. It takes into account the dependency of the switch condition data from climatic conditions and certain properties of the switch construction type. Predicting a RUL is quite challenging in many PHM applications. To avoid common problems with uncertainty in measurement data, a long prediction horizon (month) of small time units (hours) and to stabilise end user acceptance the approach transforms the RUL prediction problem into a classification problem of multiple classes. It, then, uses two different supervised classification techniques, Artificial Neural Networks (aNN) and Support Vector Machines (SVM), to predict the RUL in the form of classes. However, as known from the no free lunch-theorem of classification, there is no ultimately best performing technique. The success depends on the problem and data structure as well as on the parametrisation of the technique or the selected algorithm respectively. Especially aNN and SVM have a high number of possible parametrisations. They can fail the task or result in a very good performance under the heavy influence of their parametrisation. Hence, it is an important aspect of this paper to share how the different parameters effect the RUL prediction and which parameters result in maximum performance. In order to compare the performance, two metrics are chosen, the Matthews Correlation Coefficient (MCC) as single value metric and a visualisation of the confusion matrix as more comprehensible metric. Finally, deriving those parameters maximising the RUL prediction results enables one of the two classification techniques to reveal upcoming failures of the switch engine early enough to prevent them.

The railway and mass transportation system is composed of industrial goods with substantial capital investments and long life cycles. This applies to rolling stock like trains, locomotives, wagons, and even more to the infrastructure like signaling, catenary, tracks, bridges, and tunnels. The lifespan of rolling stock is 30 to 40 years while the infrastructure is used 30 to 60 years even more than 100 years in case of tunnels and bridges. As in other industrial goods, the cost drivers are determined in the early design phases but realized mainly during a long time of operation. Maintenance is one of the main cost drivers but essential to a reliable, capable, and – above all – safe operation.

Schule ist ein integraler Bestandteil ihres Quartiers. Gleichzeitig – und besonders in Anbetracht der wachsenden Zahl an Ganztagsschulen – spielt sie eine zentrale Rolle für die Lebenswelt und für die Identitätsbildung ihrer Schülerinnen und Schüler. Vor dem Hintergrund der hieraus resultierenden Verantwortung von Lehrerinnen und Lehrern, die räumlichen Bedingungen ihrer Lehrpraxis zu beachten, diskutiert der vorliegende Beitrag den Nutzen empirischer Sozialraumforschung als Teil humangeographischer Lehrerbildung. Zunächst stellen wir verschiedene Konzepte sozialraumanalytischer Forschung vor. Als besonders fruchtbar erscheinen uns lebensweltorientierte Ansätze, die Praktiken der Raumaneignung einbeziehen. Anschließend werden die geographischen und erkenntnistheoretischen Kompetenzen, die erreicht werden können, detailliert vorgestellt. In einem dritten Teil stellen wir ein einjähriges Lehrmodul vor, das wir an der Goethe-Universität Frankfurt entwickelt und erprobt haben, um die identifizierten Anforderungen an humangeographische Bildung zu erfüllen. Der Beitrag schließt mit einer kritischen Evaluation unserer bisherigen Lehrerfahrung sowie drei didaktischen Vorschlägen, die helfen sollen, das Potential der Sozialraumanalyse in der Lehrerbildung voll auszuschöpfen.

During its prolonged period of gestation, the fetal guinea pig gradually develops a striking hyperlipemia (plasma triglycerides ca. 500–1500 mg/dl) and fatty liver (hepatic triglycerides ca. 25% of wet weight). The parenchymal cells of the liver contain not only many fat droplets in the cytoplasm, but also large numbers of osmiophilic particles, interpreted as precursors of plasma lipoproteins, within profiles of the cisternae and secretory vesicles of the Golgi apparatus. Similar particles are found in intercellular spaces, in the space of Disse, and in the hepatic sinusoids. Near the end of gestation, these particles enlarge to the size range characteristic of chylomicrons secreted from the intestinal mucosa after ingestion of fat. At the same time, the hyperlipemia increases and is characterized by the accumulation of particles resembling chylomicrons morphologically and chemically. The results are interpreted as evidence of intense hepatic synthesis and secretion of very low density lipoproteins which may be related to the extensive transplacental transport of free fatty acids known to occur in this species. After birth, the hyperlipemia subsides rapidly and the hepatic steatosis more gradually. The blood plasma of the guinea pig fetus also contains moderate amounts of low density and high density lipoproteins. The latter decrease to barely detectable levels during the first 2 wk of postnatal life. Comparably low levels of high density lipoproteins are found in nonpregnant and pregnant adults.