Mapping the Binding Sites of UDP and Prostaglandin E2 Glyceryl Ester in the Nucleotide Receptor P2Y6

Cyclooxygenase-2 catalyzes the biosynthesis of prostaglandins from arachidonic acid and the biosynthesis of prostaglandin glycerol esters (PG-Gs) from 2-arachidonoylglycerol. PG-Gs are mediators of several biological actions such as macrophage activation, hyperalgesia, synaptic plasticity, and intraocular pressure. Recently, the human UDP receptor P2Y₆ was identified as a target for the prostaglandin E2 glycerol ester (PGE₂-G). Here, we show that UDP and PGE₂-G are evolutionary conserved endogenous agonists at vertebrate P2Y₆ orthologs. Using sequence comparison of P2Y₆ orthologs, homology modeling, and ligand docking studies, we proposed several receptor positions participating in agonist binding. Site-directed mutagenesis and functional analysis of these P2Y₆ mutants revealed that both UDP and PGE₂-G share in parts one ligand-binding site. Thus, the convergent signaling of these two chemically very different agonists has already been manifested in the evolutionary design of the ligand-binding pocket.     

Membranbasierte Bereitstellung von CO2 für die dezentrale Algenproduktion in einer Bioenergiefassade

This study emphasizes the importance of a sustainable energy supply with regard to climate change. A way is shown how a de-centralized heat supply in urban areas with renewable energies can be combined with algae production. The decentrally generated CO₂ emissions are made usable for biomass production by means of membrane separation technology. The operating behavior of the CO₂-selective membrane materials was observed over an operating period of almost 10 years. This provides solid evidence of the operability of the polymer membrane and membrane module technology. It enables further optimization of the separation process for future applications, also in a wider range of applications.     

Enhancement of biosludge dewatering using proteins through dual conditioning

In pulp and paper mills, effective biosludge dewatering is essential in wastewater treatment to reduce the large volume of biosludge that needs to be treated and disposed. The dewatering process normally requires the use of polymers from petroleum-based sources. This study explores the potential of using cationic proteins such as protamine for biosludge dewatering through dual conditioning with a small amount of a synthetic anionic polymer such as anionic polyacrylamide (APAM). The results show that dual conditioning provides substantial synergistic enhancements in dewatering. The maximum cake solids content of biosludge achieved by adding protamine (7.5%) alone was 12%. By dual conditioning with a small amount of APAM (0.1%), not only the cake solids content was increased to 16%, but also the amount of protamine addition was substantially lowered to 2%. These results, coupled with the change in zeta potential of the particles in the biosludge samples, suggest that the cationic protamine reduced the negative charge of the particles, allowing smaller particles to agglomerate and providing a positively charged framework for the subsequent addition of the negatively charged APAM. After adding APAM, substantial floc-bridging occurred, allowing smaller flocs to aggregate into larger flocs. These synergistic effects can lower the wastewater treatment cost by reducing the amount of synthetic polymer and by applying low-value proteins from natural sources.     

Manufacturing and deformation behavior of alumina and zirconia helical springs at room temperature

Ceramic helical springs with identical dimensions were produced by hard machining from alumina, alumina toughened zirconia (ATZ), and tetragonal zirconia polycrystals (TZP) stabilized with different oxides. According to the results of the spring constant determination under deformation rates of 3 mm/min, the deformation behavior of all ceramic springs obeys to Hook's law. However, variation of the deformation rate, tests under constant load, and spring recovery behavior revealed differences in the deformation behavior of alumina, TZP, and ATZ springs. Alumina springs exhibited time-independent deformation in all tests. In contrast, anelastic deformation at room temperature was demonstrated in all springs containing TZP. This deformation is completely reversible over a period of several days. Anelastic behavior is particularly pronounced in Y-TZP springs, whereas Ce-TZP springs exhibit comparatively very low but still reliably detectable anelasticity. Oxygen vacancies in the TZP ceramic are considered the most likely explanation for the anelastic behavior of TZP springs at room temperature.     

Analytical determination of compounds released during pyrolysis,smoldering, and combustion experiments with insulation materials from renewable resources

Obviously, the use of insulation materials from renewable resources in buildings could provide benefits regarding environmental protection and sustainable management. Nevertheless, their market share in Germany is estimated to be about 7% because of a partial lack of knowledge about their properties, and therefore, of construction certifications. This work was intended to close a knowledge gap concerning emissions during pyrolysis, smoldering, and combustion of commercial insulating materials made from wood, cellulose, meadow grass, hemp, jute, cork, and seaweed as well as polystyrene for comparison reasons. Laboratory-scale experiments were conducted and the measurement of thermal decomposition products was done with gas chromatography combined with mass spectrometry (GC/MS). It was realized that almost all the products could be assigned to the following eight substance classes: carbohydrates, aldehydes/ketones, carbonic acids/esters, substituted phenols, furans, aliphatic hydrocarbons, substituted benzenes, and polycyclic aromatic hydrocarbons. Substance spectra were generated that showed certain conformities, especially between the insulating materials made from wood, cellulose, and meadow grass as well as hemp and jute. Comparisons of the sum of peak areas in the GC/MS-chromatograms provided indications of the relative extent of thermal decomposition product emissions. Calculations according to (∑peak areas _{renewable material})/(∑peak areas _polystyrene) revealed factors between 0.18 (wood, cork) and 0.028 (meadow grass). In the thermal emissions, defined hazardous substances or substance groups were frequently measured. These were included in a toxicity evaluation by which, inter alia, advantages of the natural products compared to polystyrene could be demonstrated.     

Detailed Thermal Evaluation of Brazed Plate Heat Exchanger Using Infrared Thermography

Infrared thermography of brazed plate heat exchangers for evaporators and condensers recently was used to quantify maldistribution. With the knowledge of the secondary fluids heat transfer coefficient and a given secondary fluids distribution, the local heat transfer coefficient of the primary fluid (refrigerant) and its distribution to the channels can be calculated. A sensitivity analysis shows ± 10 % difference of the surface temperature to the wall center temperature at the expected ratios of heat transfer coefficients. The method is presented in this paper using an exemplary infrared picture.     

UXO and environmental risk factors impacting EOD operations in German waters**

This article presents risk factors that are associated with the handling of unexploded ordnance (UXO) during explosive ordnance disposal (EOD) operations in German waters. The construction of offshore wind parks and the German immediate action program are expected to increase the number of EOD operations. Existing literature and guidelines do not offer a structured and reproducible framework for assessing EOD risk. To fill this gap, a network of EOD risk factors was developed by means of a literature review and validation via expert consultation. The study was scoped to “personnel and equipment at the EOD location” as the risk receptor and “undesired detonation” as the undesired event under investigation. Factors are subdivided into UXO factors that depend on the object that should be handled and factors that describe the object's surrounding environment. While the former can be researched by an EOD expert, the latter must be measured on site or acquired from a model. Each of these factors contributes to risk, some directly and others indirectly via other factors. The complexity of the resulting network, with its 33 factors, demonstrates the need for a reliable and reproducible model to quantify EOD risk. Its purpose is not to replace EOD experts but to aid them in their decision-making process. Such a tool can provide valuable support for the high-cost and high-risk EOD operations.     

Darstellung und selektive Komplexbildung von Bisorganylsulfiden auf [2.2.2]Paracyclophan‐Basis

The synthesis of a variety of novel functionalized bisorganyl sulfides 2 – 10 based on the [2.2.2]paracyclophane skeleton is described. The aim was to increase the endohedral silver(I) complexation of the unsubstituted [2.2.2]paracyclophane 1 by combining the cyclophane framework with a sulfur containing pendant arm bearing an additional π‐donor. The complexation behaviour of the new ligands was studied by liquid–liquid extraction from aqueous into organic solution. The new ligands reveal a higher extraction with a decreased selectivity for silver(I) compared to 1 caused by preferential interactions with the sulfur donor atoms in the molecule. Molecular modeling calculations show the different coordination patterns for the 1:1‐, 1:2‐ and 2:1‐complexes (M:L) formed in the organic phase.     

Boroleucine-Derived Covalent Inhibitors of the ZIKV Protease

The Zika virus (ZIKV) remains a potential threat to the public health due to the lack of both an approved vaccination or a specific treatment. In this work, a series of peptidic inhibitors of the ZIKV protease with boroleucine as P1 residue was synthesized. The highest affinities with K_i values down to 8 nM were observed for compounds with basic residues in both P2 and P3 position and at the N-terminus. The low potency of reference compounds containing leucine, leucine-amide or isopentylamide as P1 residue suggested a covalent binding mode of the boroleucine-derived inhibitors. This was finally proven by crystal structure determination of the most potent inhibitor from this series in complex with the ZIKV protease.     

Underwater UXO detection using magnetometry on hovering AUVs

The EU-funded project BASTA (Boost Applied munition detection through Smart data inTegration and AI workflows,  http://www.basta-munition.eu ) aimed at improving underwater unexploded ordnance (UXO) detection approaches and advancing data acquisition techniques. One aspect of the project was performing autonomous underwater vehicle (AUV)-based magnetic measurements. In this paper, we present the first results of integrating three submersible fluxgate magnetometers to a Girona 500 AUV in the context of underwater UXO detection. The hovering capabilities of these AUVs allow them to maintain a fixed position or to precisely navigate at very low velocities and altitudes. The magnetic sensors are rigidly attached to the nose of the AUV at a lateral distance of 2 m and are arranged in the shape of a vertical triangle, thereby allowing for the calculation of three spatial magnetic gradients. A series of surveys was performed when visiting several munitions dumpsites in the German Baltic Sea. Furthermore, we successfully conducted a test survey with surrogate objects of known magnetic moments in a naval port basin in Kiel, Germany. With a noise floor of approximately 2 nT, the system is capable of reliably detecting munitions similar in size to 81 mm shells from altitudes of 1 m above the seafloor. For ground-truthing purposes and for a concluding confirmation or rejection of a UXO suspicion, the AUV is equipped with a high-resolution camera system. This newly developed system aims at improving the industry standard's technical potentials of autonomously discriminating between hazardous UXO and anthropogenic debris or rocks and therefore reducing the number of target points before underwater UXO clearance campaigns.