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排序方式: 共有458条查询结果,搜索用时 15 毫秒
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K. G. Bergner und H. R. Petri 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1960,111(4):319-333
Zusammenfassung Die vorliegende Arbeit befaßt sich mit dem Nachweis von Aminosäuren in Branntweinessig und in Essigbakterien. Zu Beginn erfolgt eine kurze Besprechung der bisher bekannten Literatur, der sich eine Darstellung unserer Untersuchungen anschließt.In einem aus genau bekannten, eiweiß- und aminosäurefreien Ausgangsstoffen hergestellten Branntweinessig konnten papierchromatographisch 18 Aminosäuren (Alanin, Arginin, Asparaginsäure,-Aminobuttersäure, Cystin, Glutaminsäure, Glykokoll, Histidin, Isoleucin, Leucin, Lysin, Methionin, Phenylalanin, Prolin, Serin, Threonin, Tyrosin und Valin) nachgewiesen werden. Der Essig wurde zur Verhinderung der Maillard-Reaktion bei < 1 mm Hg konzentriert und die Aminosäuren mittels einer Ionenaustauschermethode (Adsorption an einem Kationen-, dann an einem Anionen-Austauscher) von den in großem überschuß vorhandenen Begleitstoffen abgetrennt. Alle gefundenen Aminosäuren, mit Ausnahme der-Aminobuttersäure konnten auch in den zur Herstellung des Essigs verwendeten Submers-Essigbakterien — nachFrateur zur Xylinum- bzw. Suboxydans-Gruppe gehörend — ebenso wie in Orléans-Bakterien nachgewiesen werden. Die Entstehung der-Aminobuttersäure im Branntweinessig wird diskutiert.Bei elektrophoretischen Untersuchungen ergaben sich Hinweise auf die Natur der fluorescierenden Stoffe im Gärungsessig als Nucleinsäure-Spaltprodukte oder Flavine. 相似文献
44.
Helmut Keller Klaus Schwerdtfeger Hermann Petri Rainer Hölzle Klaus Hennesen 《Metallurgical and Materials Transactions B》1982,13(2):237-240
The tracer diffusivity of O18 was measured in CaO-SiO2 melts at 1600 °C. The capillary technique was used in the diffusion experiments. Afterwards the samples were exposed to proton
bombardment in a compact cyclotron. The O18 is transformed in this treatment to radioactive F18, and the concentration profile is determined by measuring the β+ radiation of this isotope. The diffusivities obtained decrease with increasing silica content and are of the same magnitude,
within experimental error, as those determined previously for silicon. 相似文献
45.
Petri A. Jokinen 《ISA transactions》1996,35(4):285-296
This paper presents an overview of the problems and possible solutions for automation information management and utilization in the process industries. The process plant life-cycle model is introduced and the cost structure of process automation investments is reviewed in this context. The general trends in process industry and developments in automation technologies are described and their effects are discussed. The advances in engineering CAD systems and their usability in solving the information management needs over the lifetime of process plants is assessed. This paper also presents one application of advanced engineering CAD system for automation information management in an oil refinery. 相似文献
46.
Renee Maxine Petri Matthias Münnich Qendrim Zebeli Fenja Klevenhusen 《Journal of dairy science》2019,102(6):5019-5030
High starch lactation diets not only enhance the risk of subacute ruminal acidosis but also of hindgut acidosis, which increases the risk of dysbiosis and the depression of fiber degradation. We recently showed that replacing corn with molassed sugar beet pulp (Bp) improved fiber degradation in high-producing dairy cattle, possibly because of an improvement of rumen and hindgut conditions for microbes by Bp feeding. However, little is known about the effects of high inclusion rates of Bp on hindgut microbes and fermentation. Thus fecal grab samples were taken from 18 high-yielding Simmental cows after 28 d of feeding 3 different levels of Bp (n = 6) for bacterial 16S rRNA amplicon sequencing. In addition, the reticular pH was continuously monitored with indwelling sensors and eating and ruminating behavior was evaluated with noseband sensors. The Bp inclusion rates were 0 g/kg (i.e., no Bp inclusion as control, CON), 120 g/kg (12Bp), or 240 g/kg (24Bp) replacing corn grain and limestone on a dry matter basis. The amount of time spent eating and ruminating was unaffected by Bp level, and the daily fluctuation in the reticular pH was reduced by 25% with Bp inclusion from 0.8 in the CON diet to 0.6 in 24Bp fed animals. Also, the fecal pH tended to increase with dietary Bp inclusion. Fecal acetate production showed a quadratic tendency with the lowest concentration (58.9%) of the total short-chain fatty acid in the 12Bp treatment. Inclusion of Bp up to 24% of the diet decreased the fecal butyrate proportion by 27%. The Shannon diversity index was increased from 5.50 to 8.09 with dietary Bp inclusion indicating increased species diversity. Of the 200 most abundant operational taxonomic units, 25 were increased by dietary Bp inclusion, whereas 15 were decreased and 7 were quadratically affected. The second most abundant group was proposed taxon “CF231” of the family Paraprevotellaceae. Although it accounted for only 2.52% of the operational taxonomic units in the CON diet, it was increased by 64% with dietary Bp inclusion. The largest relative change in the abundance was found for the genus Fibrobacter that increased more than 14-fold from 0.04% (CON) to 0.66% (24Bp). In conclusion, feeding molassed sugar beet pulp as partial substitution of corn up to 240 g/kg is a viable alternative that promotes ruminal and hindgut fermentation by supporting physiological pH and bacterial diversity. 相似文献
47.
The microflora of must and wine consists of yeasts, acetic acid bacteria and lactic acid bacteria (LAB). The latter group plays an important role for wine quality. The malolactic fermentation carried out by LAB leads to deacidification and stabilisation of wines. Nevertheless, LAB are often associated with wine spoilage. They are mainly responsible for the formation of biogenic amines. Furthermore, some strains produce exopolysaccharide slimes, acetic acid, diacetyl and other off-flavours. In this context a better monitoring of the vinification process is crucial to improve wine quality. Moreover, a lot of biodiversity studies would also profit from a fast and reliable identification method. 相似文献
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49.
Dedy Septiadi Aaron Lee Miguel Spuch‐Calvar Thomas Lee Moore Giovanni Spiaggia Wildan Abdussalam Laura Rodriguez‐Lorenzo Patricia Taladriz‐Blanco Barbara Rothen‐Rutishauser Alke Petri‐Fink 《Advanced functional materials》2020,30(34)
Nanoparticle adsorption to substrates pose a unique challenge to understand uptake mechanisms as it involves the organization of complex cytoskeletal components by cells to perform endocytosis/phagocytosis. In particular, it is not well‐understood from a cell mechanics perspective how the adhesion of particles on substrate will influence the ease of material clearance. By using a particle model, key contributing factors underlying cell adhesion on nonporous silica particle surfaces, migration and engulfment, are simulated and studied. Following a 24 h incubation period, monocyte‐derived macrophages and A549 epithelial cells are able to adhere and remove particles in their local vicinity through induction of adhesive pulling arise from cell traction forces and phagocytic/endocytic mechanisms, in a size‐dependent manner. It is observed that such particle‐decorated surfaces can be used to address the influence of surface topography on cell behavior. Substrates which presented 480 nm silica particles are able to induce greater development and maturation of focal adhesions, which play an important role in cellular mechanoregulation. Moreover, under a chemotactic influence, in the presence of 30% fetal bovine serum, macrophages are able to uptake the particles and be directed to translocate along a concentration gradient, indicating that local mechanical effects do not substantially impair normal physiological functions. 相似文献
50.