Novel measurement system for respiratory aerosols and droplets in indoor environments

The SARS-CoV-2 pandemic has created a great demand for a better understanding of the spread of viruses in indoor environments. A novel measurement system consisting of one portable aerosol-emitting mannequin (emitter) and a number of portable aerosol-absorbing mannequins (recipients) was developed that can measure the spread of aerosols and droplets that potentially contain infectious viruses. The emission of the virus from a human is simulated by using tracer particles solved in water. The recipients inhale the aerosols and droplets and quantify the level of solved tracer particles in their artificial lungs simultaneously over time. The mobile system can be arranged in a large variety of spreading scenarios in indoor environments and allows for quantification of the infection probability due to airborne virus spreading. This study shows the accuracy of the new measurement system and its ability to compare aerosol reduction measures such as regular ventilation or the use of a room air purifier.     

Comparative techno-economic assessment of a large-scale hydrogen transport via liquid transport media

A large-scale point to point hydrogen transport is one strategy for a prospective energy import scenario for certain countries. The case for a hydrogen transport from Australia to Japan has been addressed in several studies. However, most studies lack transparency and detailed insights into the made assumptions thus a fair evaluation of different transport pathways is challenging. To address this issue, we developed a model where a large-scale point to point hydrogen transport of liquid hydrogen is compared with the transport via liquid organic hydrogen carrier (LOHC), namely via methyl cyclohexane and hydrogenated dibenzyl toluene. We analyzed, where energy is required along the different pathways, where hydrogen losses do occur and how the costs are put together. Furthermore, the influence of hydrogen feed costs is also considered. For hydrogen production costs of 5 €₂₀₁₈/kg_H2 the total delivery costs are in the range of 6.40– 8.10 €₂₀₁₈/kg_H2.     

Inflammation and bone metabolism in rheumatoid arthritis. Pathogenetic viewpoints and therapeutic possibilities

BACKGROUND: Systemic osteoporosis is a common and pathogenetically heterogenous complication in rheumatoid arthritis. Various factors such as disease activity, dosage and duration of glucocorticoid treatment and immobilization are involved in pathogenesis of osteoporosis in rheumatoid arthritis. INFLAMMATION AND BONE METABOLISM: Proinflammatory cytokines secreted by immunocompetent cells have a role in the regulation of the activity of osteoblasts and osteoclasts. The effects of these proinflammatory cytokines include the inhibition of bone formation and an increase in bone resorption. Interleukin-6 and nitric oxide induced in osteoblasts by proinflammatory cytokines are likely to be important mediators between these cytokines and the function of osteoblasts and osteoclasts. Furthermore, disease activity dependent changes in the secretion of glucocorticoids and in vitamin D metabolism may be involved in the pathogenesis of osteoporosis in this disease. Alteration of bone remodeling associated with immobilization is an important factor of systemic bone loss in rheumatoid arthritis. CONCLUSION: The inflammatory process in rheumatoid arthritis may cause penarticular and systemic bone loss by various cytokine and hormone mediated mechanisms. Concluding from these pathogenetic mechanisms, bisphosphonates and active vitamin D metabolites are likely to be effective therapeutic options in osteoporosis associated with rheumatoid arthritis.     

Has risk associated with smoking increased? Results from the Copenhagen Center for Prospective Population Studies

BACKGROUND: Two recent much cited publications have raised the concern that risk associated with cigarette smoking has so far been underestimated. In this study we wish to determine whether excess all-cause mortality associated with smoking has increased during the last 20-30 years in a study population representative of the general Danish population and whether any such changes relate to changes in smoking behaviour. METHODS: Pooled data from three prospective population studies conducted in Copenhagen with detailed information on smoking habits. A total of 31,194 subjects, 17,669 males and 13,525 females, initially examined between 1964 and 1992 with examinations repeated at intervals from 1-10 years, were followed until 1995 for all-cause mortality. Relative mortality risk in smokers versus never-smokers was calculated within periods of five calendar years and compared throughout the study period. RESULTS: Male smokers' exposure did not change during the study period whereas female smokers' exposure to tobacco increased in terms of age at smoking onset, quantity smoked and depth of inhalation. During follow-up 5744 males and 2900 females died. In males, death rate ratios (comparing continuous smokers with never-smokers) did not change in the study period. In females, ratios increased from 1964-1978 to 1979-1994 by a factor of 1.3 (95% confidence interval 1.0-1.8). CONCLUSIONS: In agreement with the observed changes in smoking habits, excess mortality in male smokers did not increase whereas excess mortality in female smokers increased slightly.     

EU-Weißbuch Erneuerbare Energien und die Ergebnisse von Kyoto

The Kyoto Protocol to the United Nationsl Framework Convention on Climate Change gives a target for the reduction of greenhouse gases in the EU and most associated states of 8% from 1990 levels to 2010. The European Commissions Whitebook on Renewable Energy is setting a target of doubling the share of Renewable Energy from 6% now to 12% in 2010 for the European Union. There is no contradiction between these targets.     

Compound formation in the mercury-cadmium-tellurium-oxygen system

We report on compound formation in the system HgCdTeO. Samples were prepared by solid state reaction of mixtures of the binary oxide components. Specific phases were identified and characterized by X-ray and microprobe techniques. For some of these compounds small single crystals could be prepared and structural data of which are reported. Three groups of phases could be distinguished, most of them being of low symmetry, with Te in +4, +6, and in mixed oxidation states. The monotellurites HgTeO₃ and CdTeO₃ are structurally different and exhibit a large miscibility gap, whereas for the di-tellurites complete solid solution between CdTe₂O₅ and HgTe₂O₅ was found. As to the tellurates, phases with the compositions MTeO₄ and M₃Te₂O₉ (M = Hg, Cd) have been prepared. The Cd₃Te₂O₉-structure is stabilized by 30 mole% Hg. Another tellurate, monoclinic Hg₂TeO₄, was found to be isomorphous to the respective selenate and sulfate and is identical with the mineral magnolite. The interaction of Te₂O₅ with the metal oxides led to the formation of mixed valence compounds with both Te(+4) and Te(+6) of the types M₂Te₂O₇ and MTe₂O₆.     

Characterisation of a 300× photovoltaic concentrator system with one-axis tracking

A solar concentrator with one-axis tracking is being developed at our institute. This concentrator system achieves a high geometrical concentration ratio of 300 using a parabolic trough mirror and a three-dimensional second stage consisting of compound parabolic concentrators. The design of the system as well as the characterisation of the second stage is described in this paper.     

A subunit interaction in chloroplast ATP synthase determined by genetic complementation between chloroplast and bacterial ATP synthase genes

F1F0-ATP synthases utilize protein conformational changes induced by a transmembrane proton gradient to synthesize ATP. The allosteric cooperativity of these multisubunit enzymes presumably requires numerous protein-protein interactions within the enzyme complex. To correlate known in vitro changes in subunit structure with in vivo allosteric interactions, we introduced the beta subunit of spinach chloroplast coupling factor 1 ATP into a bacterial F1 ATP synthase. A cloned atpB gene, encoding the complete chloroplast beta subunit, complemented a chromosomal deletion of the cognate uncD gene in Escherichia coli and was incorporated into a functional hybrid F1 ATP synthase. The cysteine residue at position 63 in chloroplast beta is known to be located at the interface between alpha and beta subunits and to be conformationally coupled, in vitro, to the nucleotide binding site > 40 A away. Enlarging the side chain of chloroplast coupling factor 1 beta residue 63 from Cys to Trp blocked ATP synthesis in vivo without significantly impairing ATPase activity or ADP binding in vitro. The in vivo coupling of nucleotide binding at catalytic sites to transmembrane proton movement may thus involve an interaction, via conformational changes, between the amino-terminal domains of the alpha and beta subunits.