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71.
Paolo Dessì Estefania Porca Luigi Frunzo Aino–Maija Lakaniemi Gavin Collins Giovanni Esposito Piet N.L. Lens 《International Journal of Hydrogen Energy》2018,43(19):9233-9245
The influence of different inoculum pretreatments (pH and temperature shocks) on mesophilic (37 °C) and thermophilic (55 °C) dark fermentative H2 production from xylose (50 mM) and, for the first time, on the composition of the active microbial community was evaluated. At 37 °C, an acidic shock (pH 3, 24 h) resulted in the highest yield of 0.8 mol H2 mol?1 xylose. The H2 and butyrate yield correlated with the relative abundance of Clostridiaceae in the mesophilic active microbial community, whereas Lactobacillaceae were the most abundant non-hydrogenic competitors according to RNA-based analysis. At 55 °C, Clostridium and Thermoanaerobacterium were linked to H2 production, but only an alkaline shock (pH 10, 24 h) repressed lactate production, resulting in the highest yield of 1.2 mol H2 mol?1 xylose. This study showed that pretreatments differentially affect the structure and productivity of the active mesophilic and thermophilic microbial community developed from an inoculum. 相似文献
72.
73.
Marjukka M?kinen Afaf Kamal‐Eldin Anna‐Maija Lampi Anu Hopia 《European Journal of Lipid Science and Technology》2001,103(5):286-291
The effects of α‐, γ‐ and δ‐tocopherols on the stability and decomposition reactions of lipid hydroperoxides were studied. Isomerization and decomposition of cis,trans methyl linoleate hydroperoxides (cis,trans ML‐OOH) in hexadecane at 40 °C were followed by high‐performance liquid chromatography. Due to its higher hydrogen donating ability, α‐tocopherol was more efficient than γ‐ and δ‐tocopherols in inhibiting the isomerization of cis,trans ML‐OOH to trans,trans ML‐OOH. α‐Tocopherol stabilized hydroperoxides into the cis,trans configuration, whereas γ‐ and δ‐tocopherols allowed hydroperoxides to convert into trans,trans isomers. Thus, the biological importance of α‐tocopherol as compared to other tocopherols may be partly due to its better efficacy in protecting the cis,trans configuration of hydroperoxides formed, for example, in the enzymatic oxidation of polyunsaturated fatty acids. The isomeric configuration of hydroperoxides has an impact on biological activities of further oxidation products of polyunsaturated fatty acids. Paradoxically, the order of activity of tocopherols with regard to hydroperoxide decomposition was different from that obtained for hydroperoxide isomerization. γ‐ and δ‐tocopherols were more efficient inhibitors of ML‐OOH decomposition when compared to α‐tocopherol. A loss of antioxidant efficiency, observed as the tocopherol concentration increased from 2 to 20 mM, was highest for α‐tocopherol but was also evident for γ‐ and δ‐tocopherols. Thus, the differences in the relative effects of tocopherols at differing concentrations seem to result from a compromise between their radical scavenging efficiency and participation in side reactions of peroxidizing nature. 相似文献
74.
Anna‐Maija Lampi Lena H Dimberg Afaf Kamal‐Eldin 《Journal of the science of food and agriculture》1999,79(4):573-579
Δ5‐Avenasterol, an ethylidene side‐chain phytosterol, was described as an antipolymerisation agent for thermooxidised oils. This paper investigates the potential of its commercially available geometrical isomer, fucosterol, as an antipolymerisation agent for high oleic sunflower oil (HOSO). Purified triacylglycerols were prepared from HOSO and incubated in an oven, at 180°C, with or without fucosterol, sitosterol and stigmasterol. Analysis of polymers and dimers (by high‐performance size exclusion chromatography) showed that fucosterol did not affect the rate of polymerisation of purified HOSO triacylglycerols in our model. Comparison with α‐tocopherol, showed that this tocol inhibited the polymerisation of the oil while fucosterol did not. © 1999 Society of Chemical Industry 相似文献
75.
Zsuzsa Sárossy Maija Tenkanen Leena Pitkänen Anne-Belinda Bjerre David Plackett 《Food Hydrocolloids》2013
Water-extractable hemicellulose (WEH) fractions, containing approximately 65% arabinoxylans (WE-AX) and 20% mixed-linkage β-glucans were isolated from rye bran. In addition, water-extractable mixed-linkage β-glucans (BG) were isolated from oat bran as a reference material. The β-glucan content of the rye hemicellulose isolate was reduced to less than 5% by a selective lichenase treatment. Rye hemicelluloses, WEH and WE-AX had arabinose-to-xylose ratios of 0.54 and 0.57 and weight-average molecular weights (Mw) of 270 000 and 232 000 g/mol respectively. The Mw of BG was higher at 386 000 g/mol. The material properties of films prepared from the rye hemicellulose isolate and WE-AX as such, or with varying amounts of added BG (20:80; 50:50; 80:20 ratios) were studied. Prior removal of β-glucan from the isolate decreased the tensile strength of the films significantly as well as the elongation at break. Addition of BG to the purified WE-AX resulted in an increase in the tensile strength and elongation at break of the films. In contrast, the presence of BG had no clear effect on the oxygen permeability of the films. Both pure rye WE-AX and pure BG films showed excellent oxygen barrier properties (between 0.9 and 1.0 cm3 μm/m2 d kPa). However, the water vapor permeability increased with addition of increasing amounts of BG to WE-AX. To our knowledge, this is the first study on the effect of β-glucans on the material and permeability properties of arabinoxylan-based films. 相似文献
76.
Reinis Vilskersts Dana Kigitovica Stanislava Korzh Melita Videja Karlis Vilks Helena Cirule Andris Skride Marina Makrecka-Kuka Edgars Liepinsh Maija Dambrova 《International journal of molecular sciences》2022,23(1)
Right ventricular (RV) and left ventricular (LV) dysfunction is common in a significant number of hospitalized coronavirus disease 2019 (COVID-19) patients. This study was conducted to assess whether the improved mitochondrial bioenergetics by cardiometabolic drug meldonium can attenuate the development of ventricular dysfunction in experimental RV and LV dysfunction models, which resemble ventricular dysfunction in COVID-19 patients. Effects of meldonium were assessed in rats with pulmonary hypertension-induced RV failure and in mice with inflammation-induced LV dysfunction. Rats with RV failure showed decreased RV fractional area change (RVFAC) and hypertrophy. Treatment with meldonium attenuated the development of RV hypertrophy and increased RVFAC by 50%. Mice with inflammation-induced LV dysfunction had decreased LV ejection fraction (LVEF) by 30%. Treatment with meldonium prevented the decrease in LVEF. A decrease in the mitochondrial fatty acid oxidation with a concomitant increase in pyruvate metabolism was noted in the cardiac fibers of the rats and mice with RV and LV failure, respectively. Meldonium treatment in both models restored mitochondrial bioenergetics. The results show that meldonium treatment prevents the development of RV and LV systolic dysfunction by enhancing mitochondrial function in experimental models of ventricular dysfunction that resembles cardiovascular complications in COVID-19 patients. 相似文献
77.
Maija Hoikkanen Mari Honkanen Minnamari Vippola Toivo Lepistö Jyrki Vuorinen 《Progress in Organic Coatings》2011,72(4):716-723
Enhancing adhesion is of primary importance in preparation of insert injection molded plastic–metal hybrids. Here, the combination of coupling agent application parameters and steel oxide microstructure effects on the adhesion in thermoplastic urethane–stainless steel hybrids was studied. The stainless steel oxide structure was first modified by electrolytical polishing and subsequent oxidation treatment, then the steel was coated with N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (γ-AEAPS) prior to overmolding with thermoplastic urethane. The properties of formed silane coatings and ultimately the thermoplastic urethane–stainless steel hybrids were determined by several microscopical methods, infrared spectroscopy and mechanical testing. The bond strength of hybrids depended on the silane layer thickness. Also the stainless steel surface oxide structure had a remarkable influence on the coating formation and the resulting hybrid bond strength. 相似文献
78.
Kaisu Mtt Anna‐Maija Lampi Jan Petterson Birgitta M Fogelfors Vieno Piironen Afaf Kamal‐Eldin 《Journal of the science of food and agriculture》1999,79(7):1021-1027
The total and individual sterol content in 21 oat samples (seven cultivars grown at three different locations in Sweden) were analysed by gas chromatography after acid hydrolysis. The total sterol content in these oat cultivars varied between 350–491 µg g−1 of dry weight of kernel. The most abundant phytosterol was β‐sitosterol (237–321 µg g−1) followed by campesterol (32–46 µg g−1), Δ5‐avenasterol (15–47 µg g−1) and stigmasterol (11–21 µg g−1). There was a statistically significant difference in total sterol content between cultivars (p < 0.05) but no effect was found for cultivation location. Furthermore when contents of Δ5‐avenasterol in hexane‐extracted oat oil and acid‐hydrolysed oat samples were compared, it was noticed that the content of Δ5‐avenasterol was lowered due to acid hydrolysis. © 1999 Society of Chemical Industry 相似文献
79.
Acute anti‐hyperglycaemic effects of an unripe apple preparation containing phlorizin in healthy volunteers: a preliminary study 下载免费PDF全文
80.
Mari Honkanen Maija Hoikkanen Minnamari Vippola Jyrki Vuorinen Toivo Lepistö 《Journal of Materials Science》2011,46(20):6618-6626
The aim of this study was to characterize two different copper grades, oxygen-free copper, and phosphorous deoxidized copper,
with aminofunctional silane layers on them and to study these silane layers as coupling agents in the injection-molded thermoplastic
urethane–copper hybrids. The copper surfaces were as-received and modified, i.e., polished and oxidized. The copper surfaces
and silane layers which were grown from solution concentrations of 0.25 and 0.5 vol% were studied with reflection absorption
infrared spectroscopy (RAIRS), atomic force microscope (AFM), scanning electron microscope (SEM), and transmission electron
microscope (TEM). The adhesive strengths of the copper–polymer joints were measured with peel tests and peeled surfaces were
further studied with RAIRS, AFM, and FESEM. On the as-received copper surface, the silane layer was irregular and existed
mainly in the surface roughness sites. This was the reason why hybrids manufactured with the as-received copper failed mostly
in the silane layer. Hybrids manufactured with the oxidized copper sheets had a uniform silane layer and the hybrids failed
mostly cohesively in thermoplastic urethane and had excellent peel strength values. In all silane-treated copper samples,
Si–O–Si groups were formed confirming the cross-linking in the silane layer. 相似文献