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41.
42.
David Lloyd Suzie Morrell Helle N. Carlsen Hans Degn Phillip E. James Christopher C. Rowlands 《Yeast (Chichester, England)》1993,9(8):825-833
Saccharomyces cerevisiae HSc was grown with ethanol at concentrations up to 10% (v/v). The immediate effects of additions of externally added ethanol on CO2 production and O2 consumption of washed organisms were studied by stopped-flow membrane inlet quadrupole mass spectrometry. Fermentative activities of organisms grown with ethanol (0–5% v/v) showed similar sensitivities to inhibition by ethanol, whereas those grown with 10% (v/v) ethanol had become protected and were markedly less sensitive. The fluidity of subcellular membrane fractions was measured by determination of the temperature dependence of the rotational order parameter of the spin label 5-doxyl stearic acid (free radical) by electron spin resonance. Mitochondria prepared from yeasts grown with 0, 7 and 9% (v/v) ethanol showed similar overall fluidity, although differences in temperature-dependent behaviour indicate altered lipid composition or lateral phase separations. On the other hand the microsomal fraction from organisms grown with 9% ethanol showed a remarkable increase in fluidity. These data suggest that the protective effects of growth with ethanol near the limit of tolerance on fermentative activities may arise from altered plasma membrane fluidity properties. 相似文献
43.
Marie L. Borum Kathleen L. Shehan Hans Fromm Saleem Jahangeer Marianne K. Floor Oliver Alabaster 《Lipids》1992,27(12):999-1004
The effect and possible interactive influence of different dietary amounts of wheat bran, fat and calcium on the fecal excretion,
concentration and composition of bile acids was studied in Fischer-344 rats. The fecal bile acids were analyzed using gas-liquid
chromatography. Dietary wheat bran increased both total bile acid excretion and fecal weight without changes in fecal bile
acid concentration. The proportion of fecal hyodeoxycholic acid decreased with increasing dietary fiber, whereas that of lithocholic
and deoxycholic acids increased significantly with fiber intake. The percent content of fecal chenodeoxycholic acid did not
change. Increasing dietary fat led to an increase in bile acid excretion without changes in either fecal weight or bile acid
concentration. In contrast, the level of dietary calcium did not affect the total excretion of bile acids. However, since
calcium increased the fecal weight, it consequently diluted bile acids and decreased their fecal concentration. Dietary fat
and calcium had no influence on fecal bile acid composition. There were no interactive effects of wheat bran, fat and calcium
on fecal bile acids. The finding in this study that dietary fiber, fat and calcium induce significant changes in fecal bile
acids may be of relevance to the potential of bile acids to promote carcinogenesis. 相似文献
44.
Jung‐Hyun Cho Michael Bass Hans P. Jenssen 《Journal of the Society for Information Display》2007,15(12):1029-1036
Abstract— Several rare‐earth‐doped fluoride crystals that are excited to emit visible light by sequential two‐photon absorption have been investigated as display‐medium candidates for static volumetric three‐dimensional displays. Dispersion of powders of these materials in a refractive‐index‐matched polymer is reported because such a medium may result in a scalable display. The scattering problem in such a medium is greatly reduced by index‐matching the polymer to the crystalline particles. An index‐matching condition that optimizes the performance is identified. 相似文献
45.
Reverse ray-tracing model for the performance evaluation of stationary solar concentrators 总被引:1,自引:0,他引:1
The yearly energy collection efficiency of stationary solar concentrators can be evaluated using reverse ray-tracing, and a solar radiation model. In reverse ray-tracing, rays originating at the receiver of the concentrator are traced towards the surrounding hemisphere. The method allows for the evaluation of the absolute energy collection: new concentrators may be optimized for location and tilt, requiring one-time ray-tracing. The tilt of existing concentrators is optimized. Only possible solar incidence is considered by our model. The method is fast and realistic; it can be modified for concentrators in tilt operation. 相似文献
46.
Obermaier H Mohring J Deines E Hering-Bertram M Hagen H 《IEEE transactions on visualization and computer graphics》2012,18(2):270-282
Crease surfaces describe extremal structures of 3D scalar fields. We present a new region-growing-based approach to the meshless extraction of adaptive nonmanifold valley and ridge surfaces that overcomes limitations of previous approaches by decoupling point seeding and triangulation of the surface. Our method is capable of extracting valley surface skeletons as connected minimum structures. As our algorithm is inherently mesh-free and curvature adaptive, it is suitable for surface construction in fields with an arbitrary neighborhood structure. As an application for insightful visualization with valley surfaces, we choose a low frequency acoustics simulation. We use our valley surface construction approach to visualize the resulting complex-valued scalar pressure field for arbitrary frequencies to identify regions of sound cancellation. This provides an expressive visualization of the topology of wave node and antinode structures in simulated acoustics. 相似文献
47.
Hans Michael Egon Pabst Franz Ledl und Hans-Dieter Belitz 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1985,181(5):386-390
Summary In addition to the mono- and dipyrrolidinohexosereductones described recently (Z Lebensm Unters Forsch (1984) 178:356) two further bittertasting compounds were isolated from heated mixtures of proline and sucrose (molar ratio 3: 1, 190 °C, 30 min) and also synthesized, namely 2,3-bis-(1-pyrrolidinyl)2-cyclopenten-l-one and 2,3-bis(1-pyrrolidinyl)-5methyliden-2-cyclopenten-l-one. The recognition thresholds (mmol/1) are 0.15–0.25 and 0.06–0.12 respectively. Both compounds have a burning bitter taste character. From a maltose-proline reaction mixture 2--glucosyl-5-hydroxy-5-methyl-4-piperidinyl-2-cyclopenten-1-one was isolated. When the dihydroxypyranone VI was heated with proline, 2,5-dihydroxy-5-methyl-4-prohnyl-2-cyclopenten-1-one and the cyclopent(b)azepinones XI and XII were among the compounds formed. These compounds also have a bitter taste character.Zusammenfassung Zusätzlich zu den kürzlich beschriebenen Mono- and Dipyrrolidinohexosereduktionen (Z Lebensm Unters Forsch (1984) 178:356) wurden zwei weitere bittere Verbindungen aus erhitzten Mischungen von Prolin and Saccharose (Molverhältnis 3:1, 190 °C, 30 min) isoliert and synthetisiert. Es handelt sich um 2,3-Bis-(1-Pyrrolidinyl)-2-cyclopenten-1-on und 2,3-Bis-(1-Pyrrolidinyl)-5-methyliden-2-cyclopenten-1-on. Die Erkennungsschwellenwerte (mmol/1) sind 0,15-0,25 and 0,06-0,12. Beide Verbindungen haben einen brennend-bitteren Geschmack. Aus einem Maltose-Prolin-Umsetzungsgemisch gelang die Isolierung des 2--Glucosyl-5-hydroxy-5-methyl-4-piperidinyl-2-cyclopenten-1-ons. Bei der Reaktion des Dihydropyranons VI mit Prolin wurden u. a. das 2,5-Dihydroxy-5-methyl-4-prolinyl2-cyclopenten-1-on sowie die Cyclopent(b)azepinone XI and XII gebildet. Diese Verbindungen sind ebenfalls mehr oder weniger stark bitter. 相似文献
48.
Andreas Brodehl Alexey Meshkov Roman Myasnikov Anna Kiseleva Olga Kulikova Brbel Klauke Evgeniia Sotnikova Caroline Stanasiuk Mikhail Divashuk Greta Marie Pohl Maria Kudryavtseva Karin Klingel Brenda Gerull Anastasia Zharikova Jan Gummert Sergey Koretskiy Stephan Schubert Elena Mershina Anna Grtner Polina Pilus Kai Thorsten Laser Valentin Sinitsyn Sergey Boytsov Oxana Drapkina Hendrik Milting 《International journal of molecular sciences》2021,22(7)
About 50% of patients with arrhythmogenic cardiomyopathy (ACM) carry a pathogenic or likely pathogenic mutation in the desmosomal genes. However, there is a significant number of patients without positive familial anamnesis. Therefore, the molecular reasons for ACM in these patients are frequently unknown and a genetic contribution might be underestimated. Here, we used a next-generation sequencing (NGS) approach and in addition single nucleotide polymor-phism (SNP) arrays for the genetic analysis of two independent index patients without familial medical history. Of note, this genetic strategy revealed a homozygous splice site mutation (DSG2–c.378+1G>T) in the first patient and a nonsense mutation (DSG2–p.L772X) in combination with a large deletion in DSG2 in the second one. In conclusion, a recessive inheritance pattern is likely for both cases, which might contribute to the hidden medical history in both families. This is the first report about these novel loss-of-function mutations in DSG2 that have not been previously identi-fied. Therefore, we suggest performing deep genetic analyses using NGS in combination with SNP arrays also for ACM index patients without obvious familial medical history. In the future, this finding might has relevance for the genetic counseling of similar cases. 相似文献
49.
Hui Gu Rowland M. Cannon Hans J. Seifert Michael J. Hoffmann Isao Tanaka 《Journal of the American Ceramic Society》2002,85(1):25-32
The nitrogen solubility in the SiO2 -rich liquid in the metastable binary SiO2 -Si3 N4 system has been determined by analytical TEM to be 1%–4% of N/(O + N) at 1973–2223 K. Analysis of the near edge structure of the electron energy loss peak indicates that nitrogen is incorporated into the silicate network rather than being present as molecular N2 . A regular solution model with a positive enthalpy of mixing for the liquid was used to match the data for the metastable solubility of N in the presence of crystalline Si3 N4 and to adjust the computed phase diagram. The solubility of Si3 N4 in fused SiO2 is far less than reported in liquid silicates also containing Al, Mg, and/or Y. Apparently, these cations act as modifiers that break anion bridges in the silicate network and, thereby, allow further incorporation of Si3 N4 without prohibitive amounts of network cross-linking. Finally, indications emerged regarding the diffuse nature of the Si3 N4 -SiO2 interface that leads to amorphous regions of higher N content. 相似文献
50.
Summary Dynamic mechanical measurements on polystyrene — poly(vinylmethylether) blends are demonstrating that the relaxation processes in the blends are mainly connected with the motions of the poly(vinylmethylether) chain.Concerning the effect of mixing on topological properties of the blends, an increase of the polydispersity of the relaxation processes is detected in blends with high molecular weight polystyrene while low molecular weight polystyrene exerts an effect of dilution upon the relaxation of the high molecular poly(vinylmethylether) chains.From these measurements as well as from thermoanalytical data it results that the energetic interaction is more pronounced in the blends with oligomeric than with high molecular weight polystyrene. The glass transition temperature shows a larger deviation from additivity for blends with high molecular polystyrene than for those with oligomeric polystyrene.Herrn Prof. Dr. M. Kryszewski zum 60. Geburtstag herzlichst gewidmet 相似文献