Impact of Carbon Dioxide on the Non-Catalytic Thermal Decomposition of Methane

Economically and ecologically, the thermal decomposition of methane is a promising process for large scale hydrogen production. In this experimental study, the non-catalytic decomposition of methane in the presence of small amounts of carbon dioxide was analyzed. At large scales, natural gas or biomethane are possible feedstocks for the thermal decomposition and can obtain up to 5% carbon dioxide. Gas recycling can increase the amount of secondary components even further. Experiments were conducted in a packed flow reactor at temperatures from 1250 to 1350 K. The residence time and the amounts of carbon dioxide and hydrogen in the feed were varied. A methane conversion of up to 55.4% and a carbon dioxide conversion of up to 44.1% were observed. At 1300 K the hydrogen yield was 95% for a feed of methane diluted in nitrogen. If carbon dioxide was added to the feed at up to a tenth with regard to the amount of supplied methane, the hydrogen yield was reduced to 85%. Hydrogen in the feed decreases the reaction rate of the methane decomposition and increases the carbon dioxide conversion

Femtosecond laser-induced surface modification of the electrolyte in solid oxide electrolysis cells

Electrolyte-supported solid oxide cells are often used for steam electrolysis. Advantages are high mechanical stability and a low degradation rate. The aim of this proof of concept study was to use a femtosecond laser to process the electrolyte of an electrolyte-supported solid oxide cell and evaluate the effect of this laser treatment on the electrochemical performance. The femtosecond laser treatment induces a macroscopic and a superimposed microscopic structure. It can be proven that the electrolyte remains gas tight and the electrochemical performance increases independently of the laser parameters. The initial area-specific resistance degradation during a constant current measurement of 200 h was reduced from 7.9% for a non-treated reference cell to 3.2% for one of the laser-treated cells. Based on electrochemical impedance measurements, it was found that the high frequency resistance of the laser-treated cells was reduced by up to 20% with respect to the reference cell. The impedance spectra were evaluated by calculating the distribution of relaxation times, and in advance, a novel approach was used to approximate the gas concentration resistance, which was related to the test setup and not to the cell. It was found that the low frequency polarization resistance was increased for the laser-treated cells. In total, the area-specific resistance of the laser-treated cells was reduced by up to 14%

Etablierung des E2F1-Interaktoms metastasierungsrelevanter Faktoren durch Integration bioinformatischer und experimenteller Methoden

In dieser Arbeit wurde durch intensive Literatur- und Datenbankrecherche ein Protein-Protein/Gen-Interaktionsnetzwerk um den Transkriptionsfaktor E2F1 herum erstellt. Er ist Schlüsselfaktor für die epithelial-mesenchymale Transition (EMT), Voraussetzung für die Metastasierung. Eine anschließende bioinformatische Analyse identifizierte tumorspezifische Signaturen der E2F1-vermittelten EMT, welche experimentell und anhand von Patientendaten validiert wurden. Gemeinsame Zielgene des näher untersuchten E2F1-TGFβ-Interaktoms bieten mögliche Therapieziele für Krebspatienten.By intensive literature and database research we constructed a comprehensive map of interactions around the transcription factor E2F1, a key driver of the epithelial-mesenchymal transition (EMT) as a prerequisite for metastasis. The subsequent bioinformatics analysis of this map lead to the identification of tumour-specific molecular signatures of E2F1-driven EMT. These signatures were validated experimentally as well as on patient data. Common transcriptional targets of the investigated E2F1-TGFβ co-regulome might be suitable therapeutic targets for cancer patients

The emergence of a self-catalysing structure in abstract origin-of-life models

We formalize a class of abstract and simple biochemical models that have been proposed for understanding the origin of life. We then analyse conditions under which 'life-like' substructures will tend to arise in such models

Aminoglycerophospholipid flipping and P4-ATPases in Toxoplasma gondii

Lipid flipping in the membrane bilayers is a widespread eukaryotic phenomenon that is catalyzed by assorted P4-ATPases. Its occurrence, mechanism, and importance in apicomplexan parasites have remained elusive, however. Here we show that Toxoplasma gondii, an obligate intracellular parasite with high clinical relevance, can salvage phosphatidylserine (PtdSer) and phosphatidylethanolamine (PtdEtn) but not phosphatidylcholine (PtdCho) probes from its milieu. Consistently, the drug analogs of PtdCho are broadly ineffective in the parasite culture. NBD-PtdSer imported to the parasite interior is decarboxylated to NBD-PtdEtn, while the latter is not methylated to yield PtdCho, which confirms the expression of PtdSer decarboxylase but a lack of PtdEtn methyltransferase activity and suggests a role of exogenous lipids in membrane biogenesis of T. gondii. Flow cytometric quantitation of NBD-probes endorsed the selectivity of phospholipid transport and revealed a dependence of the process on energy and protein. Accordingly, our further work identified five P4-ATPases (TgP4-ATPase1-5), all of which harbor the signature residues and motifs required for phospholipid flipping. Of the four proteins expressed during the lytic cycle, TgP4-ATPase1 is present in the apical plasmalemma; TgP4-ATPase3 resides in the Golgi network along with its noncatalytic partner Ligand Effector Module 3 (TgLem3), whereas TgP4-ATPase2 and TgP4-ATPase5 localize in the plasmalemma as well as endo/cytomembranes. Last but not least, auxin-induced degradation of TgP4-ATPase1-3 impaired the parasite growth in human host cells, disclosing their crucial roles during acute infection. In conclusion, we show selective translocation of PtdEtn and PtdSer at the parasite surface and provide the underlying mechanistic and physiological insights in a model eukaryotic pathogen.Peer Reviewe

Predicting non-response in patient-reported outcome measures: results from the Swiss quality assurance programme in cardiac inpatient rehabilitation

Background Quality assurance programmes measure and compare certain health outcomes to ensure high quality care in the health care sector. The outcome health related quality of life (HRQOL) is typically measured by patient-reported outcome measures (PROMs). However, certain patient groups are less likely to respond to PROMs than others. This non-response bias can potentially distort results in quality assurance programmes. Our study aims to identify relevant predictors for non-response during assessment using the PROM MacNew Heart Disease questionnaire in cardiac rehabilitation. Methods This is a cross-sectional study based on data from the Swiss external quality assurance programme. All patients aged 18 years or older who underwent inpatient cardiac rehabilitation in 16 Swiss rehabilitation clinics between 2016 and 2019 were included. Patients’ sociodemographic and basic medical data were analysed descriptively by comparing two groups: non-responders and responders. We used a random intercept logistic regression model to estimate associations of patient characteristics and clinic differences with non-response. Results Of 24 572 patients, there were 33.3% non-responders and 66.7% responders. The mean age was 70; 31.0% were women. The regression model showed that being female was associated with non-response (odds ratio (OR) 1.22; 95% confidence interval (95% CI) 1.14–1.30), as well as having no supplementary health insurance (OR 1.49; 95% CI 1.39–1.59). Each additional year of age increased the chance of non-response by an OR of 1.02 (95% CI 1.02–1.02). Not being a first language speaker of German, French, or Italian increased the chance of non-response by an OR of 6.94 (95% CI 6.03–7.99). Patients admitted directly from acute care had a higher chance of non-response (OR 1.23; 95% CI 1.10–1.38), as well as patients being discharged back into acute care after rehabilitation (OR 3.89; 95% CI 3.00–5.04). Each point on the cumulative illness rating scale (CIRS) total score increased the chance of non-response by an OR of 1.05 (95% CI 1.04–1.05). Certain diagnoses also influenced the chance of non-response. Even after adjustment for known confounders, response rates differed substantially between the 16 clinics. Conclusion We have found significant non-response bias among certain patient groups, as well as across different treatment facilities. Measures to improve response rates among patients with known barriers to participation, as well as among different treatment facilities need to be considered, particularly when PROMs are being used for comparison of providers in quality assurance programmes or outcome evaluation

Plant species selection by free-ranging cattle in southern Bolivian tropical montane forests

The frequency of selection of functional groups and plant species by free-ranging cattle foraging in a diverse environment and its changes during the dry and the following prehumid seasons were investigated using direct observations and bite counting. The study was conducted at two sites in the Bolivian-Tucuman montane forests in southern Bolivia, by including datasets of a total of 16 animals. Across both study sites and the entire observation period (May to October/November), the cattle were found to select a broad spectrum of plant species from different functional groups. However, just a limited number of species made up a considerable contribution to overall plant selection. The functional group of the graminoids was selected most frequently, but their contribution to plant selection decreased significantly from 63.5% of total bites in May to 15.9% in September/October, in accordance with a decrease in availability. Selection of woody plants (shrubs and tree parts, the latter mainly in the form of leaf litter and fruits) increased with time, reaching its peak at the beginning of the prehumid season, while the herbs showed a curvilinear pattern of selection which was highest in August. Plant species belonging to the functional groups of ferns, climbers and epiphytes were also selected by the cattle, but generally at low relative proportions. Plant selection might be influenced by temporal differences in nutritional quality and availability of the preferred plant species and functional groups. Sampling behaviour seems to be the most likely reason for the inclusion of a broad range of plant species with overall low contribution to plant selectio

Pflanzenselektion durch freilebende Rinder in südbolivianischen Bergwäldern

The aim of the present research was to study the plant species selected by freeranging cattle in southern Bolivian subtropical mountain forests. The cattle were followed from May to November 2005 during 4-5 days/month in two study sites. The number of bites on the different plant species were recorded every 6 min. during 1 min. of actual observation. Additionally, plant availability was measured. The selection and availability data were ranked, giving rank number 1 to the most frequently selected plant species. Basing on this ranking system, species were categorized into four categories. Overall, 447 plant species were found in the study sites, whereof 364 were observed to be selected by the cattle. A low number of species (15, including indetermined leaf litter) made up the major part of plant selection (about 60%) and were classified as “main forage plants”, with the grass Ichnanthus pallens being the most selected plant species. Sixteen species were classified as “preferred”, 20 as “least preferred” and 121 as “neutral”