Synthesis and thermal properties of strontium and calcium peroxides

A practical synthesis and a discussion of some chemical properties of pure strontium peroxide and calcium peroxide are presented. The general synthesis of these peroxides involves precipitation of their octahydrates by addition of H2O2 to aqueous ammoniacal Sr(NO3)2 or CaCl2. The octahydrates are converted to the anhydrous peroxides by various dehydration techniques. A new x-ray diffraction powder pattern for CaO2 x 8H2O is given from which lattice parameters a=6.212830 and c=11.0090 were calculated on the basis of the tetragonal crystal system

Studienlandschaft Schwingbachtal: an out-door full-scale learning tool newly equipped with augmented reality

This paper addresses education and communication in hydrology and geosciences. Many approaches can be used, such as the well-known seminars, modelling exercises and practical field work but out-door learning in our discipline is a must, and this paper focuses on the recent development of a new out-door learning tool at the landscape scale. To facilitate improved teaching and hands-on experience, we designed the Studienlandschaft Schwingbachtal. Equipped with field instrumentation, education trails, and geocache, we now implemented an augmented reality App, adding virtual teaching objects on the real landscape. The App development is detailed, to serve as methodology for people wishing to implement such a tool. The resulting application, namely the Schwingbachtal App, is described as an example. We conclude that such an App is useful for communication and education purposes, making learning pleasant, and offering personalized options

Unprecedented Retention Capabilities of Extensive Green Roofs—New Design Approaches and an Open-Source Model

Green roofs are a proven measure to increase evapotranspiration at the expense of runoff, thus complementing contemporary stormwater management efforts to minimize pluvial flooding in cities. This effect has been quantified by numerous studies, ranging from experimental field campaigns to modeling experiments and even combinations of both. However, up until now, most green roof studies consider standard types of green roof dimensions, thus neglecting varying flow length in the substrate. For the first time, we present a comprehensive investigation of green roofs that involves artificial rainfall experiments under laboratory conditions (42 experiments in total). We consider varying flow length and slope. The novelty lies especially in the consideration of flow lengths beyond 5 m and non-declined roofs. This experimental part is complemented by numerical modeling, employing the open-source Catchment Modeling Framework (CMF). This is set-up for Darcy and Richards flow in the green roof and calibrated utilizing a multi-objective approach, considering both runoff and hydraulic head. The results demonstrate that through maximizing flow length and minimizing slope, the runoff coefficient (i.e., percentage of rainfall that becomes runoff) for a 100 years design rainfall is significantly decreased: from ~30% to values below 10%. These findings are confirmed through numerical modeling, which proves its value in terms of achieved model skill (Kling-Gupta Efficiency ranging from 0.5 to 0.95 with a median of 0.78). Both the experimental data and the numerical model are published as open data and open-source software, respectively. Thus, this study provides new insights into green roof design with high practical relevance, whilst being reproducible

Seismic monitoring and analysis of deep geothermal projects in St Gallen and Basel, Switzerland

Monitoring and understanding induced seismicity is critical in order to estimate and mitigate seismic risk related to numerous existing and emerging techniques for natural resource exploitation in the shallow-crust. State of the art approaches for guiding decision making, such as traffic light systems, rely heavily on data such as earthquake location and magnitude that are provided to them. In this context we document the monitoring of a deep geothermal energy project in St Gallen, Switzerland. We focus on the issues of earthquake magnitude, ground motion and macroseismic intensity which are important components of the seismic hazard associated to the project. We highlight the problems with attenuation corrections for magnitude estimation and site amplification that were observed when trying to apply practices used for monitoring regional seismicity to a small-scale monitoring network. Relying on the almost constant source-station distance for events in the geothermal ‘seismic cloud' we developed a simple procedure, calibrated using several ML > 1.3 events, which allowed the unbiased calculation of ML using only stations of the local monitoring network. The approach determines station specific ML correction terms that account for both the bias of the attenuation correction in the near field and amplification at the site. Since the smallest events (ML < −1) were only observed on a single borehole instrument, a simple relation between the amplitude at the central borehole station of the monitoring network and ML was found. When compared against magnitudes computed over the whole network this single station approach was shown to provide robust estimates (±0.17 units) for the events down to ML = −1. The relation could then be used to estimate the magnitude of even smaller events (ML < −1) only recorded on the central borehole station. Using data from almost 2700 events in Switzerland, we then recalibrated the attenuation correction, extending its range of validity from a minimum source-station distance of 20 km down to 1 km. Based on this we could determine the component of the previously derived station specific ML corrections due to local amplification. We analysed ground-motion and detailed macroseismic reports resulting from the 2013 July 20 St Gallen ML = 3.5 ± 0.1 (Mw = 3.3-3.5 ± 0.1) ‘main shock' and compared it to a similar ML = 3.4 ± 0.1 event (Mw = 3.2 ± 0.1) that occurred in 2006 at another deep geothermal project in Basel, Switzerland. Differences in ground motion amplitudes between the Basel and St Gallen events and to an extent, the associated macroseismic observations, were investigated in terms of the different source terms: Mw for long-period motions and the source-corner frequency (related to the source rupture velocity and stress-drop) for short period

Succinate receptor 1 inhibits mitochondrial respiration in cancer cells addicted to glutamine

Cancer cells display metabolic alterations to meet the bioenergetic demands for their high proliferation rates. Succinate is a central metabolite of the tricarboxylic acid (TCA) cycle, but was also shown to act as an oncometabolite and to specifically activate the succinate receptor 1 (SUCNR1), which is expressed in several types of cancer. However, functional studies focusing on the connection between SUCNR1 and cancer cell metabolism are still lacking. In the present study, we analyzed the role of SUCNR1 for cancer cell metabolism and survival applying different signal transduction, metabolic and imaging analyses. We chose a gastric, a lung and a pancreatic cancer cell line for which our data revealed functional expression of SUCNR1. Further, presence of glutamine (Gln) caused high respiratory rates and elevated expression of SUCNR1. Knockdown of SUCNR1 resulted in a significant increase of mitochondrial respiration and superoxide production accompanied by an increase in TCA cycle throughput and a reduction of cancer cell survival in the analyzed cancer cell lines. Combination of SUCNR1 knockdown and treatment with the chemotherapeutics cisplatin and gemcitabine further increased cancer cell death. In summary, our data implicates that SUCNR1 is crucial for Gln-addicted cancer cells by limiting TCA cycle throughput, mitochondrial respiration and the production of reactive oxygen species, highlighting its potential as a pharmacological target for cancer treatment

OntoKin: An Ontology for Chemical Kinetic Reaction Mechanisms.

An ontology for capturing both data and the semantics of chemical kinetic reaction mechanisms has been developed. Such mechanisms can be applied to simulate and understand the behavior of chemical processes, for example, the emission of pollutants from internal combustion engines. An ontology development methodology was used to produce the semantic model of the mechanisms, and a tool was developed to automate the assertion process. As part of the development methodology, the ontology is formally represented using a web ontology language (OWL), assessed by domain experts, and validated by applying a reasoning tool. The resulting ontology, termed OntoKin, has been used to represent example mechanisms from the literature. OntoKin and its instantiations are integrated to create a knowledge base (KB), which is deployed using the RDF4J triple store. The use of the OntoKin ontology and the KB is demonstrated for three use cases-querying across mechanisms, modeling atmospheric pollution dispersion, and as a mechanism browser tool. As part of the query use case, the OntoKin tools have been applied by a chemist to identify variations in the rate of a prompt NOx formation reaction in the combustion of ammonia as represented by four mechanisms in the literature

Perspectives of Ultra Cold Atoms Trapped in Magnetic Micro Potentials

Recent work on magnetic micro traps for ultracold atoms is briefly reviewed. The basic principles of operation are described together with the loading methods and some of the realized trap geometries. Experiments are discussed that study the interaction between atoms and the surface of micro traps as well as the dynamics of ultracold gases in wave guides are discussed. The results allow for an outlook towards future directions of research

An Ontology and Semantic Web Service for Quantum Chemistry Calculations.

The purpose of this article is to present an ontology, termed OntoCompChem, for quantum chemistry calculations as performed by the Gaussian quantum chemistry software, as well as a semantic web service named MolHub. The OntoCompChem ontology has been developed based on the semantics of concepts specified in the CompChem convention of Chemical Markup Language (CML) and by extending the Gainesville Core (GNVC) ontology. MolHub is developed in order to establish semantic interoperability between different tools used in quantum chemistry and thermochemistry calculations, and as such is integrated into the J-Park Simulator (JPS)-a multidomain interactive simulation platform and expert system. It uses the OntoCompChem ontology and implements a formal language based on propositional logic as a part of its query engine, which verifies satisfiability through reasoning. This paper also presents a NASA polynomial use-case scenario to demonstrate semantic interoperability between Gaussian and a tool for thermodynamic data calculations within MolHub.This project is supported by the National Research Foundation (NRF), Prime Minister’s Office, Singapore under its Campus for Research Excellence and Technological Enterprise (CREATE) programme, and by the Alexander von Humboldt foundation

First clinical experience of high-power ablation of atrial fibrillation with a novel contact force-sensing gold-tip catheter

Background: Contact force (CF)-sensing catheters are commonly used in the field of radiofrequency (RF) ablation to treat atrial fibrillation (AF). Increasing ablation power (e.g., 50 W) has been suggested as a method to reduce procedure times whilst creating safe and lasting lesions. Methods: We report the first clinical evidence of a 50 W point-by-point RF ablation in 25 consecutive patients with symptomatic AF using a novel CF-sensing catheter with a gold tip (AlCath Force, BIOTRONIK). We collected and analyzed procedural and ablation parameters. The safety and efficacy of the catheter were evaluated. Results: Altogether, 985 RF lesions in 25 patients were created with a mean number of 39.4 +/- 16.3 lesions per patient. The total skin-to-skin procedure time was 116.1 +/- 35.1 min, and the mean total area dose product was 10.9 +/- 5.1 Gy*cm2. The mean RF time per procedure was 13.2 +/- 6.6 min. The mean RF time per lesion was 20.2 +/- 8.4 s. The mean CF was 15.7 +/- 7.6 g. We observed a mean force time integral of 274.7 +/- 11.1 gs (range: 53 to 496 gs). Acute procedural success, defined as entrance and exit block in all pulmonary veins, could be obtained in all cases. No procedure- or device-related serious adverse events were observed. No audible steam pops occurred. Optical inspection of the catheter after the procedure showed neither charring nor clotting. Conclusions: We provide the first evidence for the safety and efficacy of 50 W ablation using the AlCath Force gold-tip catheter. These data must be supported by a larger multi-center study

Hydroxycarboxylic acid receptor 3 and GPR84: Two metabolite-sensing G protein-coupled receptors with opposing functions in innate immune cells

G protein-coupled receptors (GPCRs) are key regulatory proteins of immune cell function inducing signaling in response to extracellular (pathogenic) stimuli. Although unrelated, hydroxycarboxylic acid receptor 3 (HCA3) and GPR84 share signaling via Gαi/o proteins and the agonist 3-hydroxydecanoic acid (3HDec). Both receptors are abundantly expressed in monocytes, macrophages and neutrophils but have opposing functions in these innate immune cells. Detailed insights into the molecular mechanisms and signaling components involved in immune cell regulation by GPR84 and HCA3 are still lacking. Here, we report that GPR84-mediated pro-inflammatory signaling depends on coupling to the hematopoietic cell-specific Gα15 protein in human macrophages, while HCA3 exclusively couples to Gαi protein. We show that activated GPR84 induces Gα15-dependent ERK activation, increases intracellular Ca2+ and IP3 levels as well as ROS production. In contrast, HCA3 activation shifts macrophage metabolism to a less glycolytic phenotype, which is associated with anti-inflammatory responses. This is supported by an increased release of anti-inflammatory IL-10 and a decreased secretion of pro-inflammatory IL-1β. In primary human neutrophils, stimulation with HCA3 agonists counteracts the GPR84-induced neutrophil activation. Our analyses reveal that 3HDec acts solely through GPR84 but not HCA3 activation in macrophages. In summary, this study shows that HCA3 mediates hyporesponsiveness in response to metabolites derived from dietary lactic acid bacteria and uncovers that GPR84, which is already targeted in clinical trials, promotes pro-inflammatory signaling via Gα15 protein in macrophages