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51.
Henrique AL Ribeiro Luis Sordo Vieira Yogesh Scindia Bandita Adhikari Matthew Wheeler Adam Knapp William Schroeder Borna Mehrad Reinhard Laubenbacher 《Journal of the Royal Society Interface》2022,19(189)
Aspergillus species are ubiquitous environmental moulds, with spores inhaled daily by most humans. Immunocompromised hosts can develop an invasive infection resulting in high mortality. There is, therefore, a pressing need for host-centric therapeutics for this infection. To address it, we created a multi-scale computational model of the infection, focused on its interaction with the innate immune system and iron, a critical nutrient for the pathogen. The model, parameterized using published data, was found to recapitulate a wide range of biological features and was experimentally validated in vivo. Conidial swelling was identified as critical in fungal strains with high growth, whereas the siderophore secretion rate seems to be an essential prerequisite for the establishment of the infection in low-growth strains. In immunocompetent hosts, high growth, high swelling probability and impaired leucocyte activation lead to a high conidial germination rate. Similarly, in neutropenic hosts, high fungal growth was achieved through synergy between high growth rate, high swelling probability, slow leucocyte activation and high siderophore secretion. In summary, the model reveals a small set of parameters related to fungal growth, iron acquisition and leucocyte activation as critical determinants of the fate of the infection. 相似文献
52.
Séverine Goscinny Hermann Unterluggauer Jasmin Aldrian Vincent Hanot Sonja Masselter 《Food Analytical Methods》2012,5(5):1177-1185
A straightforward analytical method has been developed for the determination of glyphosate and aminomethylphosphonic acid (AMPA), its major metabolite in cereals. This method entails a rapid extraction and derivatization with 9-fluorenylmethyl chloroformate followed by separation with a conventional reversed-phase rapid chromatography used in daily routine analysis and detection by electrospray ionization tandem mass spectrometry. To overcome matrix effects and compensate for any analyte losses during sample treatment, an isotopic dilution approach was used. Since 2010, the monitoring of cereals for the widely used herbicide glyphosate is obligatory to all European Union (EU)-member states, laid down in Commission Regulation (EC) No. 1213/2008. Hence, there is definitively a need for a reliable and easy-to-handle analytical method for monitoring of this compound. The proposed method can be run without having to make time-consuming changes on the equipment used for daily routine analysis. The analytical performance of the method was evaluated according to SANCO/10684/2009 criteria and demonstrated that this method is rugged and cost-effective, therefore suitable for monitoring purposes as well as legislative enforcements within the EU. The apparent recoveries of both analytes were between 97% and 113% with relative standard deviations less than 20%. The limits of quantification of glyphosate and AMPA were 0.02 mg/kg in cereal matrices. Finally, the accuracy of the method was assessed by analyzing a proficiency test material which was available from a previous round (EUPT-C4). 相似文献
53.
Wijaya A Hermann A Abriouel H Specht I Yousif NM Holzapfel WH Franz CM 《Journal of food protection》2004,67(12):2772-2778
Enterococcus faecium strain FAIR-E 345 isolated from food was shown to possess bile salt hydrolase (Bsh) activity in a plate screening assay and by high-performance liquid chromatography analysis. The bsh gene was cloned and sequenced. DNA sequence analysis revealed that it encoded a protein of 324 amino acids, with pI 4.877. A bsh gene probe was prepared from the cloned bsh gene and was used for probing plasmid and total genomic DNA of Bsh-positive enterococci isolated from food to determine the genomic location of their bsh genes. This probe was able to detect the bsh gene among total genomic DNA preparations but not from plasmid preparations of 10 plasmid-bearing Enterococcus strains. However, the probe could detect the bsh gene from total genomic DNA preparations of 12 Enterococcus strains that did not contain detectable plasmid DNA. In no cases did the probe hybridize with plasmid DNA preparations, suggesting that the bsh gene among enterococci is probably generally chromosomally encoded. This presumptive chromosomal location of bsh genes among food enterococci suggests that transfer of this trait by conjugative plasmids is unlikely. 相似文献
54.
Andrey Frolov Kimberly Miller Jeffrey T. Billheimer Tae-Hyeon Cho Friedhelm Schroeder 《Lipids》1997,32(11):1201-1209
Although it was recently recognized that sterol carrier protein-2 (SCP-2) interacts with fatty acids, little is known regarding the specificity of SCP-2 for long-chain fatty acids or branched-chain fatty-acid-like molecules. Likewise the location of the fatty-acid binding site within SCP-2 is unresolved. A fluorescent cis-parinaric acid displacement assay was used to show that SCP-2 optimally interacted with 14–22 carbon chain lipidic molecules: polyunsaturated fatty acids > monounsaturated, saturated > branched-chain isoprenoids > branched-chain phytol-derived fatty acids. In contrast, the other major fatty-acid binding protein in liver, fatty-acid binding protein (L-FABP), displayed a much narrower carbon chain preference in general: polyunsaturated fatty acids > branched-chain phytol-derived fatty acids > 14- and 16-carbon saturated > branched-chain isoprenoids. However, both SCP-2 and l-FABP displayed a very similar unsaturated fatty-acid specificity profile. The presence and location of the SCP-2 lipid binding site were investigated by fluorescence energy transfer. The distance between the SCP-2 Trp50 and bound cis-parinaric acid was determined to be 40 Å. Thus, the SCP-2 fatty-acid binding site appeared to be located on the opposite side of the SCP-2 Trp50. These findings not only contribute to our understanding of the SCP-2 ligand binding site but also provide evidence suggesting a potential role for SCP-2 and/or L-FABP in metabolism of branched-chain fatty acids and isoprenoids. 相似文献
55.
56.
Wind turbine wakes have been recognized as a key issue causing underperformance in existing wind farms. In order to improve the performance and reduce the cost of energy from wind farms, one approach is to develop innovative methods to improve the net capacity factor by reducing wake losses. The output power and characteristics of the wake of a utility‐scale wind turbine under yawed flow is studied to explore the possibility of improving the overall performance of wind farms. Preliminary observations show that the power performance of a turbine does not degrade significantly under yaw conditions up to approximately 10°. Additionally, a yawed wind turbine may be able to deflect its wake in the near‐wake region, changing the wake trajectory downwind, with the progression of the far wake being dependent on several atmospheric factors such as wind streaks. Changes in the blade pitch angle also affect the characteristics of the turbine wake and are also examined in this paper. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
57.
Behnam Mohammadi Robert Raudner Mohsin Shafiq Edgar Ahn Hermann C. Altmeppen Markus Glatzel 《European Journal of Lipid Science and Technology》2020,122(9)
Prion‐reduction in standard biodiesel processes is caused by acidic and alkaline conditions. In the alternative RepCat biodiesel process, efficient prion‐reduction can be achieved by high‐temperature/pressure. However, a possible increase in thermostability of prions in the presence of methanol during these conditions has not previously been investigated, and is verified in this work. Samples are spiked with prions, treated with methanol, and incubated at 220 °C at 80 bar for 30 min. No traces of protease‐resistant prion protein (as proxy for prions) are detected in tallow or glycerine (as the final by‐product) after treatment. Serial dilutions of spiked prions show at least 6 log10 prion reduction. More importantly, similar effects are detected using milder conditions of 200 °C at 70 bar for 15 min, representing the worst‐case conditions of the process. In conclusion, this study shows that methanol does not increase the thermostability of prions and the RepCat process can efficiently eliminate prions and is therefore safe for the usage of category 1 tallow. Practical Applications: The study further supports the applicability of RepCat process in reducing prion‐contamination in the presence of methanol. Furthermore, the conditions leads to a considerable reduction of prions in glycerine obtained as by‐product. 相似文献
58.
Hermann Scholz Johannes Vetter Ralf Herborn Arne Ruedinger 《International Journal of Applied Ceramic Technology》2020,17(4):1636-1645
Oxide fibers preparation and manufacturing capabilities at Fraunhofer-Center HTL are introduced, showing the development and preparation of oxide ceramic fibers from lab scale to pilot scale up to near production scale. As a specific example, the development of an aluminosilicate fiber with mullite composition is discussed in more detail. Fiber development started from nonaqueous sol-gel precursors in the early lab scale. With increasing fiber spinning volume, precursors were switched to water-soluble systems. Transformation from green fiber to ceramic fiber was monitored by thermogravimetric and differential thermal analysis, X-ray diffraction, and scanning electron microscopy. The evolution of ceramic phases, microstructure formation, and the effects on tensile strength and Young's modulus were investigated. Weibull statistics and fracture analysis helped to understand the results. Next step will be the transition from large lab scale to pilot scale, demonstrating manufacturing capability. 相似文献
59.
Tobias E. Schmitzhaus Maria R. Ortega Vega Roberto Schroeder Iduvirges L. Muller Silvana Mattedi Célia de Fraga Malfatti 《工业材料与腐蚀》2020,71(11):1885-1902
The aim of the present study is to evaluate the performance of N-methyl-2-hydroxyethylammonium oleate ([m-2HEA][Ol]) as a corrosion inhibitor for mild steel in a 0.1-mol/L hydrochloric acid solution and also investigate the role of chloride in the inhibition mechanism. This protic ionic liquid (PIL) has formerly shown a high efficiency as a corrosion inhibitor in a neutral chloride medium. Electrochemical and weight loss measurements, surface contact angle determination, scanning electron microscopy, and Raman spectroscopy were used to understand the factors that influence the response of the studied inhibitor. Results revealed that [m-2HEA][Ol] behaves as a mixed-type adsorption inhibitor, by blocking cathodic sites and by modifying the activation energy of the anodic reaction, and it can reach up to 94–97% of inhibition efficiency. PIL adsorption was enhanced by the excess of positive charge of the mild steel. The effect of inhibitor molecule has been discussed to propose a mechanism that explains the inhibitory action of the corrosion inhibitor, pointing out the role of chloride in the inhibition mechanism. 相似文献