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排序方式: 共有508条查询结果,搜索用时 62 毫秒
51.
Ivo Bendix Corina Schulze Clarissa von Haefen Alexandra Gellhaus Stefanie Endesfelder Rolf Heumann Ursula Felderhoff-Mueser Marco Sifringer 《International journal of molecular sciences》2012,13(10):12939-12951
Autophagy is a self-degradative process that involves turnover and recycling of cytoplasmic components in healthy and diseased tissue. Autophagy has been shown to be protective at the early stages of programmed cell death but it can also promote apoptosis under certain conditions. Earlier we demonstrated that oxygen contributes to the pathogenesis of neonatal brain damage, which can be ameliorated by intervention with recombinant human erythropoietin (rhEpo). Extrinsic- and intrinsic apoptotic pathways are involved in oxygen induced neurotoxicity but the role of autophagy in this model is unclear. We analyzed the expression of autophagy activity markers in the immature rodent brain after exposure to elevated oxygen concentrations. We observed a hyperoxia-exposure dependent regulation of autophagy-related gene (Atg) proteins Atg3, 5, 12, Beclin-1, microtubule-associated protein 1 light chain 3 (LC3), LC3A-II, and LC3B-II which are all key autophagy activity proteins. Interestingly, a single injection with rhEpo at the onset of hyperoxia counteracted these oxygen-mediated effects. Our results indicate that rhEpo generates its protective effect by modifying the key autophagy activity proteins. 相似文献
52.
53.
van der Schalk Job; Fischer Agneta; Doosje Bertjan; Wigboldus Dani?l; Hawk Skyler; Rotteveel Mark; Hess Ursula 《Canadian Metallurgical Quarterly》2011,11(2):286
In the present research, we test the assumption that emotional mimicry and contagion are moderated by group membership. We report two studies using facial electromyography (EMG; Study 1), Facial Action Coding System (FACS; Study 2), and self-reported emotions (Study 2) as dependent measures. As predicted, both studies show that ingroup anger and fear displays were mimicked to a greater extent than outgroup displays of these emotions. The self-report data in Study 2 further showed specific divergent reactions to outgroup anger and fear displays. Outgroup anger evoked fear, and outgroup fear evoked aversion. Interestingly, mimicry increased liking for ingroup models but not for outgroup models. The findings are discussed in terms of the social functions of emotions in group contexts. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
54.
Bernadette Peace Michael Topka Kenneth Skorenko Adam Kowalski Ursula Williams Michael Hagerman Rebecca Cortez 《Materials Letters》2011,65(21-22):3208-3211
We report on morphosynthesis techniques that have been employed to tune polyamine film nanoarchitectures and on their resulting morphologies. Specific layers discussed include films of aniline/Laponite clay and aniline solution processed with V2O5 catalyst. Synthesis approaches examined include films generated in-situ (glass templating), solution based drop casting, and mechanochemical grinding. Surface topography results suggest that these approaches provide dimensionality control of the polyaniline morphology. Surface images of the mechanochemically ground polyaniline/Laponite nanocomposite layer reveal interfacial contact which is promising for potential heterojunction solar cell designs. 相似文献
55.
M. Pischetsrieder Ursula Gro? Christiane Schoetter 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1999,209(1):172-177
Two HPLC methods with diode array detection were used to separate Maillard products from milk components. The Maillard products
4-(β-d-galactopyranosyloxy)-2-hydroxy-2-methyl-2H-pyran-3(6H)-one (2), 1-[3-(β-d-galactopyranosyloxy)-2-furanyl]-1-ethanone (4), 4-(β-d-galactopyranosyloxy)-5-(hydroxymethyl)-2-methyl-3(2H)-furanone (5), isomaltol (7), maltol (9), 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (6), and 5-hydroxymethyl-2-furfuraldehyde (8) were determined using a water-methanol gradient. Furthermore, 4,5-dihydroxy-2-(β-d-galactopyranosyloxy)-5-methyl-2-cyclopenten-1-one (3) was separated from the milk components by applying the interaction reagent octylamine. Several heated or processed milk
samples were analyzed, and formation of the Maillard products was determined and quantified. Thus it was found that 2 and 3 are early products of the Maillard reaction in milk, whereas after prolonged heating 4, 5, and particularly 9 and 6 become more important. Compounds 7 and 8 were not detected, even if the samples were heated under stringent conditions. 相似文献
56.
Olaf A.M. Fisscher Klaasjan Visscher Alan Pearson Ursula Weisenfeld 《Creativity & Innovation Management》2001,10(4):251-258
Research and development departments in industrial firms may not take it for granted anymore that they are the only preferred supplier of research and development to the company of which they are a part. The growing need to be innovative and the increasing availability of innovative competencies on the market result in a pressure on these departments to become more business–like and to reconsider their sources of competitive advantage over other (potential) suppliers of research and development. Traditionally, scientific and technological knowledge and skills concerning the product were the prime source. Nowadays, managerial competencies and the ability to work for and with your clients and suppliers are becoming more important. To become a competitive business in a business, research and development departments should create the competencies that enable them to create value for their clients. This calls for good competence management, comprising management of human resources, information technology, and internal and external interfaces. In this paper we explore what it means and what it takes for research and development departments to implement competence management, elaborating it theoretically and describing a case of competence management in the research and development department of a European car company. 相似文献
57.
Kirsti Rouvinen-Watt Anne-Mari Mustonen Rebecca Conway Catherine Pal Lora Harris Seppo Saarela Ursula Strandberg Petteri Nieminen 《Lipids》2010,45(2):111-128
Hepatic lipidosis is a common pathological finding in the American mink (Neovison vison) and can be caused by nutritional imbalance due to obesity or rapid body weight loss. The objectives of the present study
were to investigate the timeline and characterize the development of hepatic lipidosis in mink in response to 0–7 days of
food deprivation and liver recovery after 28 days of re-feeding. We report here the effects on hematological and endocrine
variables, body fat mobilization, the development of hepatic lipidosis and the alterations in the liver lipid classes and
tissue fatty acid (FA) sums. Food deprivation resulted in the rapid mobilization of body fat, most notably visceral, causing
elevated hepatosomatic index and increased liver triacylglycerol content. The increased absolute amounts of liver total phospholipids
and phosphatidylcholine suggested endoplasmic reticulum stress. The hepatic lipid infiltration and the altered liver lipid
profiles were associated with a significantly reduced proportion of n-3 polyunsaturated FA (PUFA) in the livers and the decrease
was more evident in the females. Likewise, re-feeding of the female mink resulted in a more pronounced recovery of the liver
n-3 PUFA. The rapid decrease in the n-3/n-6 PUFA ratio in response to food deprivation could trigger an inflammatory response
in the liver. This could be a key contributor to the pathophysiology of fatty liver disease in mink influencing disease progression. 相似文献
58.
Ursula Wölwer-Rieck und Hans Büning-Pfaue 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1990,191(4-5):319-321
Zusammenfassung Es wird eine HPLC-Methode vorgestellt, die es gestattet, Furazolidon (FZ) neben seinem offenkettigen Cyanometaboliten 3-(4-Cyano-2-oxobutyli-denamino)-2-oxazolidon (M1) in Forellen nachzuweisen. Im Muskel und Leber von Forellen, die 7 Tage lang mit FZ-haltigem Futter behandelt worden waren, konnten nur während der Behandlungszeit Rückstände von M1 und FZ nachgewiesen werden. Schon zu Beginn der Absetzzeit lagen die Konzentrationen an FZ und M1 unterhalb der Nachweisgrenze.
The residue behaviour of the furazolidone metabolite 3-(4-Cyano-2-oxobutylideneamino)-2-oxazolidone in trout
Summary A high-performance liquid chromatography (HPLC)-method for the determination of furazolidone (FZ) and its open-chain cyano-derivative 3-(4-cyano-2-oxobutylideneamino)-2-oxazolidone (M1) in trout is described. Only during the medication period residues of FZ and M1 were detected in the muscle and liver of the trout, which were treated with food containing FZ over a period of 7 days. After the beginning of the withdrawal period, the concentration of FZ and M1 were found to be under the limits of detection.相似文献
59.
Celeste Fernández Eduardo Lujano Ursula Macias Josseilin Marcano Pablo J. Baricelli Clementina Longo Sergio A. Moya María G. Solórzano Marisol C. Ortega Alvaro J. Pardey 《Catalysis Letters》2004,95(3-4):143-150
Rhodium(I) complexes of the type, cis-[Rh(CO)2(amine)2](PF6) where (amine = 3-picoline, 2-picoline, pyridine, 2,6-lutidina or 3,5-lutidine) dissolved in 80% aqueous amine solutions catalyzed the selective reduction of 4-nitrobenzoic acid to 4-aminobenzoic acid under CO atmosphere. The importance of these catalytic systems is their high chemo selectivity for the aromatic nitro group of the 4-nitrobenzoic acid with respect to the carboxylic group, allowing the production of the desired aromatic amine in high yields. The 4-aminobenzoic acid production depends on the nature of the coordinated amine. The Rh/3,5-lutidine system, the most active catalyst among tested, displays turnover frequencies for 4-aminobenzoic acid production of about 173 moles per mole Rh per day for [Rh] = 1 × 10?4 mol, [4-nitrobenzoic acid] = 3.82 × 10?3mol, 10 mL of 80% aqueous 3,5-lutidine, P(CO) = 0.9 atm at 100 °C. Analyses of kinetic results for the Rh/3,5-lutidine system show a first order dependence on 4-nitrobenzoic acid concentration, a non-linear dependence on CO pressure, a segmented Arrhenius plot and dependence on the nature of the reducing gas agent. These data are discussed in terms of a possible mechanism. 相似文献
60.
The adsorption and reaction of toluene on vanadyl pyrophosphate catalysts was studied by in situ infrared spectroscopy. Strongly
adsorbed benzaldehyde and physically adsorbed cyclic anhydride species were observed at temperatures above 523 K. Water formed
during reaction generates acid hydroxyl groups which cause a stronger adsorption of benzaldehyde and consecutive oxidation
reactions. By co-adsorption of pyridine the acid sites are blocked and the deeper oxidation is suppressed.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献