Transition-Metal-Doping of CaO as Catalyst for the OCM Reaction, a Reality Check

In this study, first-row transition metal-doped calcium oxide materials (Mn, Ni, Cr, Co., and Zn) were synthesized, characterized, and tested for the OCM reaction. Doped carbonate precursors were prepared by a co-precipitation method. The synthesis parameters were optimized to yield materials with a pure calcite phase, which was verified by XRD. EPR measurements on the doped CaO materials indicate a successful substitution of Ca2+ with transition metal ions in the CaO lattice. The materials were tested for their performance in the OCM reaction, where a beneficial effect towards selectivity and activity effect could be observed for Mn, Ni, and Zn-doped samples, where the selectivity of Co- and Cr-doped CaO was strongly reduced. The optimum doping concentration could be identified in the range of 0.04-0.10 atom%, showing the strongest decrease in the apparent activation energy, as well as the maximum increase in selectivity

Transition-Metal-Doping of CaO as Catalyst for the OCM Reaction, a Reality Check

In this study, first-row transition metal-doped calcium oxide materials (Mn, Ni, Cr, Co., and Zn) were synthesized, characterized, and tested for the OCM reaction. Doped carbonate precursors were prepared by a co-precipitation method. The synthesis parameters were optimized to yield materials with a pure calcite phase, which was verified by XRD. EPR measurements on the doped CaO materials indicate a successful substitution of Ca2+ with transition metal ions in the CaO lattice. The materials were tested for their performance in the OCM reaction, where a beneficial effect towards selectivity and activity effect could be observed for Mn, Ni, and Zn-doped samples, where the selectivity of Co- and Cr-doped CaO was strongly reduced. The optimum doping concentration could be identified in the range of 0.04-0.10 atom%, showing the strongest decrease in the apparent activation energy, as well as the maximum increase in selectivity.DFG, 390540038, EXC 2008: Unifying Systems in Catalysis "UniSysCat

MicroRNA 10a Marks Regulatory T Cells

MicroRNAs (miRNAs) are crucial for regulatory T cell (Treg) stability and function. We report that microRNA-10a (miR-10a) is expressed in Tregs but not in other T cells including individual thymocyte subsets. Expression profiling in inbred mouse strains demonstrated that non-obese diabetic (NOD) mice with a genetic susceptibility for autoimmune diabetes have lower Treg-specific miR-10a expression than C57BL/6J autoimmune resistant mice. Inhibition of miR-10a expression in vitro leads to reduced FoxP3 expression levels and miR-10a expression is lower in unstable “exFoxP3” T cells. Unstable in vitro TGF-ß-induced, iTregs do not express miR-10a unless cultured in the presence of retinoic acid (RA) which has been associated with increased stability of iTreg, suggesting that miR-10a might play a role in stabilizing Treg. However, genetic ablation of miR-10a neither affected the number and phenotype of natural Treg nor the capacity of conventional T cells to induce FoxP3 in response to TGFβ, RA, or a combination of the two. Thus, miR-10a is selectively expressed in Treg but inhibition by antagomiRs or genetic ablation resulted in discordant effects on FoxP3

The Open Anchoring Quest Dataset: Anchored Estimates from 96 Studies on Anchoring Effects

People’s estimates are biased toward previously considered numbers (anchoring). We have aggregated all available data from anchoring studies that included at least two anchors into one large dataset. Data were standardized to comprise one estimate per row, coded according to a wide range of variables, and are available for download and analyses online (https://metaanalyses.shinyapps.io/OpAQ/). Because the dataset includes both original and meta-data it allows for fine-grained analyses (e.g., correlations of estimates for different tasks) but also for meta-analyses (e.g., effect sizes for anchoring effects)

Übergangsmetall dotiertes Kalziumoxid als Modellkatalysator für die Sauerstoffaktivierung in der oxidativen Kupplung von Methan (OCM) Reaktion

To find alternative feedstocks for the chemical industry, the oxidative coupling of methane (OCM) reaction was developed in the 1980s, allowing the production of ethylene from methane. Though, being the topic of many investigations in the last 40 years, the success so far is limited and a yield of 30% has yet to be surpassed. One major issue of the reaction is the activation of methane. With a dissociation energy of 423 kJ/mol, highly reactive materials or high reaction temperatures are needed. Controlling the activation of the oxidant is essential to avoid an overoxidation of the desired products and achieve high selectivity. Since many materials have been screened as a suitable catalyst for the OCM without a breakthrough, basic research is necessary to understand the limiting factors of this reaction. In physical experiments, calcium oxide was found to show interesting interactions with oxygen when doped with transition metals, strongly reducing the oxygen dissociation barrier, making these materials an interesting target to study oxidation catalysts. In this work, first-row transition metal-doped calcium oxide materials (0.1 atom% Mn, Ni, Cr, Co, and Zn) were synthesized, characterized, and tested for the OCM reaction. First, doped carbonate precursors were prepared by a co-precipitation method. The synthesis parameters were optimized to yield materials with a pure calcite phase, which was verified by XRD. EPR measurements on the Mn-doped CaO materials indicate a successful substitution of Ca2+ with Mn2+ in the CaO lattice. The materials were tested for their performance in the OCM reaction, where a beneficial towards selectivity and activity effect could be observed for Mn-, Ni-, and Zn-doped samples, where the selectivity of Co- and Cr-doped CaO was strongly reduced. The optimum doping concentration could be identified in the range of 0.05-0.10 atom%, showing the strongest decrease in the apparent activation energy, as well as the maximum increase in selectivity. The overall improvement of the catalyst was though was only minor. In situ Raman, IR, and TG experiments revealed the formation of carbonates during the reaction. Hydroxide species, or oxygen species were not found. To investigate the oxygen activation capabilities of the materials, SSTIKA experiments were performed and a pulsed isotopic scrambling technique was developed and implemented and numerically simulated. Though giving not much insight on the role of the dopant, the contamination of the surface by water and carbon dioxide could be identified as the limiting factor for the OCM on basic oxides. Due to the blocking of the active sites of the by- and side-products of the OCM reaction, high temperatures are needed to regenerate the catalyst surface.Um alternative Ausgangsstoffe für die chemische Industrie zu finden, wurde in den 1980er Jahren die oxidative Kupplung der Methanreaktion (OCM) entwickelt, die die Herstellung von Ethylen aus Methan ermöglicht. Obwohl dies in den letzten 40 Jahren Gegenstand vieler Untersuchungen war, ist der bisherige Erfolg begrenzt und eine Ausbeute von 30% wurde bisher noch nicht übertroffen. Ein Hauptproblem der Reaktion ist die Aktivierung von Methan. Bei einer Dissoziationsenergie von 423 kJ/mol werden hochreaktive Reaktanden oder hohe Reaktionstemperaturen benötigt. Die Kontrolle der Aktivierung des Oxidationsmittels ist somit wichtig, um eine Überoxidation der gewünschten Produkte zu vermeiden und eine hohe Selektivität zu erreichen. Da bereits viele Materialien ohne signifikanten Durchbruch als Katalysator für das OCM gescreent wurden, ist weitere Grundlagenforschung erforderlich, um die begrenzenden Faktoren dieser Reaktion zu verstehen. Es wurde festgestellt, dass Calciumoxid interessante Wechselwirkungen mit Sauerstoff zeigt, wenn es mit Übergangsmetallen dotiert ist, wodurch die Sauerstoffdissoziationsbarriere stark verringert werden kann, was diese Materialien zu interessanten Materialien für die Untersuchung von Oxidationskatalysatoren machen. In dieser Arbeit wurden mit Übergangsmetallen dotierte Calciumoxidmaterialien (0,1 Atom-% Mn, Ni, Cr, Co und Zn) synthetisiert, charakterisiert und für die OCM-Reaktion getestet. Zunächst wurden dotierte Carbonatvorläufer durch ein Co-Präzipitationsverfahren hergestellt. Die Syntheseparameter wurden optimiert, um Materialien mit einer reinen Calcit Phase zu erhalten, welche durch XRD verifiziert wurde. EPR-Messungen an den Mn-dotierten CaO-Materialien zeigen eine erfolgreiche Substitution von Ca2+ durch Mn2+ im CaO-Gitter. Die Materialien wurden auf ihre Leistung in der OCM-Reaktion getestet, wobei Verbesserung der Selektivität und der Aktivität für Mn-, Ni- und Zn-dotierte Proben beobachtet werden konnte, bei Co- und Cr-dotiertem CaO war die Selektivität stark verringert. Die optimale Dotierungskonzentration wurde im Bereich von 0,05 bis 0,10 Atom-% gefunden, wo die stärkste Abnahme der scheinbaren Aktivierungsenergie sowie die maximale Zunahme der Selektivität gefunden wurde. Die Gesamtverbesserung des Katalysators war jedoch nur gering. In-situ-Raman-, IR- und TG-Experimente zeigten die Bildung von Carbonaten während der Reaktion. Hydroxidspezies oder Sauerstoffspezies wurden nicht gefunden. Um die Sauerstoffaktivierungsfähigkeiten der Materialien zu untersuchen, wurden SSTIKA-Experimente durchgeführt und eine gepulste Isotopen-Scrambling-Technik entwickelt, implementiert und numerisch simuliert. Obwohl nicht viel Erkenntnis über die Rolle des Übergangsmetalls erlangt wurde, konnte die Kontamination der Oberfläche durch Wasser und Kohlendioxid als limitierender Faktor für das OCM auf basischen Oxiden identifiziert werden. Aufgrund der Blockierung der aktiven Stellen durch Bei- und Nebenprodukte der OCM-Reaktion sind hohe Temperaturen erforderlich, um die Katalysatoroberfläche zu regenerieren.DFG, 53182490, Unifying Concepts in Catalysi

Circulating miR-let7a levels predict future diagnosis of chronic thromboembolic pulmonary hypertension

Abstract Distinct patterns of circulating microRNAs (miRNAs) were found to be involved in misguided thrombus resolution. Thus, we aimed to investigate dysregulated miRNA signatures during the acute phase of pulmonary embolism (PE) and test their diagnostic and predictive value for future diagnosis of chronic thromboembolic pulmonary hypertension (CTEPH). Microarray screening and subsequent validation in a large patient cohort (n = 177) identified three dysregulated miRNAs as potential biomarkers: circulating miR-29a and miR-720 were significantly upregulated and miR-let7a was significantly downregulated in plasma of patients with PE. In a second validation study equal expression patterns for miR-29a and miR-let7a regarding an acute event of recurrent venous thromboembolism (VTE) or deaths were found. MiR-let7a concentrations significantly correlated with echocardiographic and laboratory parameters indicating right ventricular (RV) dysfunction. Additionally, circulating miR-let7a levels were associated with diagnosis of CTEPH during follow-up. Regarding CTEPH diagnosis, ROC analysis illustrated an AUC of 0.767 (95% CI 0.54–0.99) for miR-let7a. Using logistic regression analysis, a calculated patient-cohort optimized miR-let7a cut-off value derived from ROC analysis of ≥ 11.92 was associated with a 12.8-fold increased risk for CTEPH. Therefore, miR-let7a might serve as a novel biomarker to identify patients with haemodynamic impairment and as a novel predictor for patients at risk for CTEPH

Multi-scale analysis of integrated c1 (Ch4 and co2) utilization catalytic processes: Impacts of catalysts characteristics up to industrial-scale process flowsheeting, part i: Experimental analysis of catalytic low-pressure co2 to methanol conversion

A multi-aspect analysis of low-pressure catalytic hydrogenation of CO2 for methanol production is reported in the first part (part I) of this paper. This includes an extensive review of distinguished low-pressure catalytic CO2-hydrogenation systems. Specifically, the results of the conducted systematic experimental investigation on the impacts of synthesis and micro-scale characteristics of the selected Cu/ZnO/Al2O3 model-catalysts on their activity and stability are discussed. The performance of the investigated Cu/ZnO/Al2O3 catalysts, synthesized via different methods, were tested under a targeted range of operating conditions in this research. Specifically, the performances of these tested Cu/ZnO/Al2O3 catalysts with regard to the impacts of the main operating parameters, namely H2/CO2 ratio (at stoichiometric-3-, average-6-and high-9-ratios), temperature (in the range of 160–260 ˚C) and the lower and upper values of physically achievable gas hourly space velocity (GHSV) (corresponding to 200 h−1 and 684 h−1, respectively), were analyzed. It was found that the catalyst prepared by the hydrolysis co-precipitation method, with a homogenously distributed copper content over its entire surface, provides a promising methanol yield of 21% at a reaction temperature of 200 ˚C, lowest tested GHSV, highest tested H2/CO2 ratio (9) and operating pressure (10 bar). This is in line with other promising results so far reported for this catalytic system even in pilot-plant scale, highlighting its potential for large-scale methanol production. To analyze the findings in more details, the thermal-reaction performance of the system, specifically with regard to the impact of GHSV on the CO2-conversion and methanol selectivity, and yield were experimentally investigated. Moreover, the stability of the selected catalysts, as another crucial factor for potential industrial operation of this system, was tested under continual long-term operation for 150 h, the reaction-reductive shifting-atmospheres and also even after introducing oxygen to the catalyst surface followed by hydrogen reduction-reaction tests. Only the latter state was found to affect the stable performance of the screened catalysts in this research. In addition, the reported experimental reactor performances have been analyzed in the light of equilibrium-based calculated achievable performance of this reaction system. In the performed multi-scale analysis in this research, the requirements for establishing a selective-stable catalytic performance based on the catalyst-and reactor-scale analyses have been identified. This will be combined with the techno– economic performance analysis of the industrial-scale novel integrated process, utilizing the selected catalyst in this research, in the form of an add-on catalytic system under 10 bar pressure and H2/CO2 ratio (3), for efficiently reducing the overall CO2-emission from oxidative coupling of methane reactors, as reported in the second part (part II) of this paper

Genetic Dissection of Aversive Associative Olfactory Learning and Memory in <i>Drosophila</i> Larvae

<div><p>Memory formation is a highly complex and dynamic process. It consists of different phases, which depend on various neuronal and molecular mechanisms. In adult <i>Drosophila</i> it was shown that memory formation after aversive Pavlovian conditioning includes—besides other forms—a labile short-term component that consolidates within hours to a longer-lasting memory. Accordingly, memory formation requires the timely controlled action of different neuronal circuits, neurotransmitters, neuromodulators and molecules that were initially identified by classical forward genetic approaches. Compared to adult <i>Drosophila</i>, memory formation was only sporadically analyzed at its larval stage. Here we deconstruct the larval mnemonic organization after aversive olfactory conditioning. We show that after odor-high salt conditioning larvae form two parallel memory phases; a short lasting component that depends on cyclic adenosine 3’5’-monophosphate (cAMP) signaling and <i>synapsin</i> gene function. In addition, we show for the first time for <i>Drosophila</i> larvae an anesthesia resistant component, which relies on <i>radish</i> and <i>bruchpilot</i> gene function, protein kinase C activity, requires presynaptic output of mushroom body Kenyon cells and dopamine function. Given the numerical simplicity of the larval nervous system this work offers a unique prospect for studying memory formation of defined specifications, at full-brain scope with single-cell, and single-synapse resolution.</p></div

Dosimetric benefit of MR-guided online adaptive radiotherapy in different tumor entities: liver, lung, abdominal lymph nodes, pancreas and prostate

Background: Hybrid magnetic resonance (MR)-Linac systems have recently been introduced into clinical practice. The systems allow online adaption of the treatment plan with the aim of compensating for interfractional anatomical changes. The aim of this study was to evaluate the dose volume histogram (DVH)-based dosimetric benefits of online adaptive MR-guided radiotherapy (oMRgRT) across different tumor entities and to investigate which subgroup of plans improved the most from adaption. Methods: Fifty patients treated with oMRgRT for five different tumor entities (liver, lung, multiple abdominal lymph nodes, pancreas, and prostate) were included in this retrospective analysis. Various target volume (gross tumor volume GTV, clinical target volume CTV, and planning target volume PTV) and organs at risk (OAR) related DVH parameters were compared between the dose distributions before and after plan adaption. Results: All subgroups clearly benefited from online plan adaption in terms of improved PTV coverage. For the liver, lung and abdominal lymph nodes cases, a consistent improvement in GTV coverage was found, while many fractions of the prostate subgroup showed acceptable CTV coverage even before plan adaption. The largest median improvements in GTV near-minimum dose (D-98%) were found for the liver (6.3%, p < 0.001), lung (3.9%, p < 0.001), and abdominal lymph nodes (6.8%, p < 0.001) subgroups. Regarding OAR sparing, the largest median OAR dose reduction during plan adaption was found for the pancreas subgroup (-87.0%). However, in the pancreas subgroup an optimal GTV coverage was not always achieved because sparing of OARs was prioritized. Conclusion: With online plan adaptation, it was possible to achieve significant improvements in target volume coverage and OAR sparing for various tumor entities and account for interfractional anatomical changes

Aversive olfactory memory after odor-high salt conditioning lasts up to four hours

<p><b>A:</b> Schematic drawing of the used two odor reciprocal training paradigm. During training, thirty larvae receive the odor n-amylacetate (AM) paired with an aversive reinforcer (high salt concentration) while benzaldehyde (BA) was presented alone (AM^Salt / BA^Pure) (Group 1). Group 2 receives the reverse contingency (AM^Pure / BA^Salt). The training was three times repeated. During test both odors are presented on opposite sides. After 5 minutes the number of larvae on each odor side is counted for both reciprocally trained groups and a performance index (PI) is calculated that quantifies associative olfactory memory. <b>B:</b> Flowchart that summarizes the details of the behavioral paradigm in an alternative way. This representation is used throughout the manuscript. Note, for simplification the reciprocally trained group is not shown. <b>C:</b> Larval aversive olfactory memory using three training repetitions was tested in wild type larvae at different time points after conditioning ranging from 0–300 minutes. The aversive memory is stable up to four hours (One sample t test, p<0.05 for t = 0-250min; p>0.05 for t = 300min). The memory decay was fitted into an exponential decay function (nonlinear regression analysis, R² = 0.257, τ = -145.9). Memory performance significantly different from random distribution (p<0.05) is indicated in black, random distribution (p≥0.05) in light grey. Sample size is n = 16 for each group. All data are given as means ± s.e.m.</p