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771.
Timo Stressler Thomas Eisele Johanna Rost Eva‐Maria Haunschild Prof. Dr. Andreas Kuhn Prof. Dr. Lutz Fischer 《化学,工程师,技术》2013,85(3):318-322
A new isolate of Mortierella alpina, > 98 % identical with M. alpina ATCC 16266, was cultivated in a defined glucose‐based medium with three organic nitrogen sources (glycine, urea and Na‐L‐glutamate) at three different concentrations in shaking flasks at 20 °C. The results were compared to the cultivation in complex medium with yeast extract as nitrogen source. In the defined media, high yields of polyunsaturated fatty acids (PUFAs) and arachidonic acid (ARA), respectively, were obtained with Na‐L‐glutamate. However, the absolute highest yields of PUFA and ARA were measured with the yeast extract medium. An optimized yeast extract complex medium was used for a submerse bioreactor cultivation in a 45‐L scale. Furthermore, M. alpina was cultivated in a solid state fermenter, using an oat bran water mixture as substrate. 相似文献
772.
In Part I of the paper ((1999), Trib. Trans., 42, pp. 851–859) we investigated the effect of the polyethylene concentration on the film forming properties in a rolling bearing. This second part presents the influence of the polymer additive concentration on the traction behavior experienced using a two-disk machine at different temperatures and contact pressures. By using the traction data, a semi-empirical approach for determining the effective lubricant theological parameters in EHL contacts was performed. Using this approach, the effect of polymer concentration upon rheological parameters that appear in the Johnson and Tevaarwerk model with Eyring stress was quantified. 相似文献
773.
Maria D. Salazar-Villalpando David A. BerryAnthony Cugini 《International Journal of Hydrogen Energy》2010
Isotopic tracer and nuclear reaction analysis (NRA) are used to probe the identity of oxygen for CO formation during the catalytic partial oxidation (CPOX) of methane to synthesis gas on 18O2 labeled Rh (1 wt.%)/(Ce0.56Zr0.44)O2−x. Results reveal that methane is selectively oxidized by lattice oxygen ions from the catalyst to form carbon monoxide. 18O2 isotopic exchange experiments, as a function of temperature in the 0–850 °C range, were performed on Rh (1 wt.%)/(Ce0.56Zr0.44)O2−x, and (Ce0.56Zr0.44)O2−x. It was observed that the presence of rhodium considerably accelerates the oxygen exchange with the support; the maximal exchange rates could be observed at lower temperatures, 250 °C. This may be due to oxygen spillover from the metal particles to the oxide. Comparing results from the isotopic exchange experiments on Rh/γ-alumina and Rh (1 wt.%)/(Ce0.56Zr0.44)O2−x. It was revealed that oxygen conducting materials have a much higher oxygen storage capacity and isotopic exchange rate than non-oxygen conducting materials. 相似文献
774.
A biodegradable polyester, poly(tetramethylene dodecanedioate), was injection molded in a rectangular cavity. Thin sections were sliced from molded samples starting from the skin. The morphology distribution inside the molded samples was studied by X‐ray analysis. The diffusion and solubility coefficient of water vapor were then measured using the microgravimetric method at the temperature of 30°C. Results show that morphology developed during the process influences the diffusion of water molecules through the polymer matrix. In particular, a direct influence of crystalline degree on the sorption and diffusion parameters was identified. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
775.
Sara Salucci Sabrina Burattini Michela Battistelli Valentina Baldassarri Maria Cristina Maltarello Elisabetta Falcieri 《International journal of molecular sciences》2013,14(1):532-546
Ultraviolet B (UVB) radiation acts as a strong apoptotic trigger in many cell types, in tumor and normal cells. Several studies have demonstrated that UVB-induced cell death occurs through the generation of reactive oxygen species. The consequent oxidative stress includes the impairment of cellular antioxidants, the induction of DNA damage and the occurrence of apoptosis. In this review, we investigated UVB apoptotic action in various cell models by using ultrastructural, molecular and cytofluorimetric techniques. Myeloid leukemia HL-60, T-lymphoblastoid Molt-4 and myelomonocytic U937 human cells, generally affected by apoptotic stimuli, were studied. Human chondrocytes and C2C12 skeletal muscle cells, known to be more resistant to damage, were also considered. All of them, when exposed to UVB radiation, revealed a number of characteristic apoptotic markers. Membrane blebbing, cytoplasm shrinkage and chromatin condensation were detected by means of electron microscopy. DNA cleavage, investigated by using agarose gel electrophoresis and TUNEL reaction, was observed in suspended cells. Differently, in chondrocytes and in skeletal muscle cells, oligonucleosomic DNA fragmentation did not appear, even if a certain TUNEL positivity was detected. These findings demonstrate that UVB radiation appears to be an ideal tool to study the apoptotic behavior. 相似文献
776.
Bond Kenneth; Ospina Maria B.; Hooton Nicola; Bialy Liza; Dryden Donna M.; Buscemi Nina; Shannahoff-Khalsa David; Dusek Jeffrey; Carlson Linda E. 《Canadian Metallurgical Quarterly》2009,1(2):129
The authors used a 5-round Delphi study with a panel of 7 experts in meditation research to achieve agreement on a set of criteria for a working definition of “meditation” for use in a comprehensive systematic review of the therapeutic use of meditation. Participants agreed that essential to a meditation practice is its use of (a) a defined technique, (b) logic relaxation, and (c) a self-induced state. Participants also agreed that a meditation practice may (d) involve a state of psychophysical relaxation somewhere in the process; (e) use a self-focus skill or anchor; (f) involve an altered state/mode of consciousness, mystic experience, enlightenment or suspension of logical thought processes; (g) be embedded in a religious/spiritual/philosophical context; or (h) involve an experience of mental silence. The results of this study provide insight into the challenges faced by researchers who want to demarcate meditative practices from nonmeditative practices, and they describe an approach to this problem that may prove useful for researchers trying to operationalize meditation in the context of comparative research. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
777.
Snoeren Natalie D.; Gaskell M. Gareth; Di Betta Anna Maria 《Canadian Metallurgical Quarterly》2009,35(2):542
The present study investigated the mechanisms underlying perceptual compensation for assimilation in novel words. During training, participants learned canonical versions of novel spoken words (e.g., decibot) presented in isolation. Following exposure to a second set of novel words the next day, participants carried out a phoneme monitoring task. Here, the novel words were presented with final alternations (e.g., decibop) in carrier sentences that either licensed assimilation (viable context: Our decibop behaved badly) or did not (unviable context: Our decibop does very well). Listeners had to monitor for the underlying form of the assimilated consonant (e.g., /t/ in decibop). Results showed more responses corresponding to the underlying form in viable than in unviable contexts. This viability effect was equivalent for novel words learned on the same day and on the previous day but was absent for unexposed control items. The processing difference between exposed and control novel words supports the idea that compensation for assimilation interacts with newly acquired phonological information and suggests that contextual compensation for assimilation is enhanced by lexical knowledge. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
778.
Beatriz Abad-García Sergio Garmón-Lobato María Belén Sánchez-Ilárduya Luis A. Berrueta Blanca Gallo Francisca Vicente Rosa Maria Alonso-Salces 《European Food Research and Technology》2014,238(5):803-818
The contents of 49 polyphenols in sweet orange, tangerine, lemon and grapefruit juices from 18 cultivars grown in Spain were determined by reversed-phase high-performance liquid chromatography with photodiode array detection. Citrus polyphenolic profiles consist of 81–97 % of flavanones, 0.3–13.6 % of flavones, 0.1–6.0 % of flavonols, 0.6–9.6 % of hydroxycinnamic acids and 0.2–0.4 % of coumarins (only found in grapefruit juices). Several markers that allow to distinguish with practical certainty grapefruit and lemon juices between them and from the other Citrus species are reported. Each of these markers is a reliable and useful tool to detect juice adulteration. Grapefruit juice markers were naringenin-7-O-neohesperidoside, naringenin-7-O-neohesperidoside-4′-O-glucose, naringenin-O-hexosylhexoside, hesperetin-7-O-neohesperidoside, naringenin-O-rhamnosylmalonylhexoside, isosakuranetin-7-O-neohesperidoside, hesperetin-7-O-rutinoside, apigenin-6-C-hexoside-O-hexoside, apigenin-7-O-neohesperidoside and scopoletin-O-hexoside. Lemon juice markers were eriodictyol-7-O-rutinoside-4′-O-glucoside, eriodictyol-7-O-rutinoside, diosmetin-6,8-di-C-glucoside, diosmetin-8-C-glucoside, luteolin-7-O-rutinoside, diosmetin-6-C-glucoside and diosmetin-6,8-di-C-hexosideacylhexoside. The markers naringenin-O-hexosylhexoside, apigenin-6-C-hexoside-O-hexoside, scopoletin-O-hexoside, diosmetin-8-C-glucoside and diosmetin-6,8-di-C-hexosideacylhexoside were detected, characterized and quantitatively determined in grapefruit and lemon juices for the first time by our research group, as far as the authors know. Classification models provided by LDA and PLS-DA correctly identify all sweet orange and tangerine juices. Moreover, PLS regression model determines the percentage (10–70 %) of tangerine juice used to adulterate sweet orange juice with a suitable confidence interval (RMSEP = 7 %). 相似文献
779.
Ana Paula Rodrigues Brasil Sebastio Tavares de Rezende Maria do Carmo Gouveia Pelúzio Valria Monteze Guimares 《Food chemistry》2010,118(2):251-255
The objectives of this work were to establish a safe and economically viable process for the removal of raffinose oligosaccharides (RO) from soy flour and compare the effects of RO elimination from diets with regard to nutritional parameters by testing in Wistar rats. Debaryomyces hansenii UFV-1 was cultivated in suspension of defatted soy flour (1:10 w/v). An increase in α-galactosidase activity was observed in the medium, with a consequent decrease in the RO concentration. A total reduction of RO was achieved at 36 h of incubation. The diet containing soy flour free of RO presented higher digestibility, 91.28%, in relation to the diet containing soy flour with RO, 87.14%. However, the removal of the oligosaccharides from the diet did not promote a significant improvement in the values of weight gain, and other nutritional parameters tested on rats, during the experimental period of 14 days. 相似文献
780.
Maria Grazia Calabrese Gianfranco Mamone Simonetta Caira Pasquale Ferranti Francesco Addeo 《Food chemistry》2009
The unnatural amino acid lysinoalanine (LAL) has been identified in milk and cheese products by liquid chromatography mass spectrometry (LC/ESI/MS) with selective ion monitoring (SIM) of the 9-fluorenyl-methylchloro-formate (FMOC) derivative. LAL is not present in raw milk or derived from Mozzarella cheese; however, high amounts of LAL are found in calcium caseinate and milk powder. As expected, milk fortified with caseinate or whey protein powder produces cheese with higher LAL content. Our analytical procedure is based on the simultaneous detection of specific ion masses of the FMOC–LAL derivative and the N-ε-methyl-lysine internal standard. A linear relationship was observed within the 0.2–20 ppm concentration range, in addition to a high correlation coefficient and ∼3% relative standard deviation. 相似文献