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排序方式: 共有157条查询结果,搜索用时 214 毫秒
151.
M. Englert J. Kowalski F. Mayer R. Neumann S. Noehte R. Schwarzwald H. Suhr K. Winkler G. zu Putlitz Ch. J. Bordé S. Avrillier A. van Lerberghe Ch. Salomon Ch. Breant D. Bassi G. Scoles J. Helmcke D. Zevgolis B. Ü. Yen W. Gawlik F. Träger M. Vollmer E. Gustafson R. L. Byer J. H. M. Neijzen A. Donszelmann G. Leuchs J. Rerf H. Walther M. Inguscio A. Moretti F. Strumia J. L. Picqué J. L. Le Gouët F. Wuilleumier J. M. Bizau P. Dhez P. Koch D. Ederer O. Poulsen U. Nielsen N. I. Winstrup P. S. Ramanujam J. V. James X. Tang C. C. Wang 《Applied physics. B, Lasers and optics》1982,28(2-3):81-91
152.
Gawlik BM Martens D Schramm KW Kettrup A Lamberty A Muntau H 《Fresenius' Journal of Analytical Chemistry》2000,368(4):407-411
The second generation of the European Reference Soil-Set, the so-called EUROSOILS, has been introduced recently. The presence of organic micro-pollutants in this new type of reference materials has already been studied for polycyclic aromatic hydrocarbons, triazines, phenylureas and other pesticides. The already large amount of data concerning the level of different contaminants, the elemental composition and matrix properties is completed by a survey by means of GC/MS on the polychlorinated dibenzodioxins/furans (PCDD/Fs) and other chlorinated hydrocarbons. Higher concentrations for 4,4'-DDT in EUROSOIL 2 (10.57 +/- 0.02 ng/g), for dieldrin in EUROSOIL 3 (8.85 +/- 0.87 ng/g) and for heptachlor-epoxide in EUROSOIL 4 (5.86 +/- 0.16 ng/g) could be detected. Sum concentrations for PCDD/Fs were 15.02 ng/kg (EUROSOIL 1), 214.29 ng/kg (EUROSOIL 2), 873.32 ng/kg (EUROSOIL 3), 54.47 ng/kg (EUROSOIL 4) and 119.61 ng/kg (EUROSOIL 5). 相似文献
153.
ukasz opusiewicz Emilia Drozowska Paulina Trocer Pawe Kwiatkowski Artur Bartkowiak Annett Gefrom Monika Sienkiewicz 《Molecules (Basel, Switzerland)》2020,25(24)
Plant derived fermented beverages have recently gained consumers’ interest, particularly due to their intrinsic functional properties and presence of beneficial microorganisms. Three variants containing 5%, 10%, and 15% (w/w) of sweet blue lupin (Lupinus angustifolius L. cv. “Boregine”) seeds were inoculated with kefir grains and incubated at 25 °C for 24 h. After processing, beverages were stored in refrigerated conditions (6 °C) for 21 days. Changes in microbial population, pH, bioactive compounds (polyphenolics, flavonoids, ascorbic acid), reducing sugars, and free amino acids were estimated. Additionally, viscosity, firmness, color, and free radicals scavenging properties were determined. Results showed that lactic acid bacteria as well as yeast were capable of growing well in the lupin matrix without any supplementation. During the process of refrigeration, the viability of the microorganisms was over the recommended minimum level for kefir products. Hydrolysis of polysaccharides as well as increase of free amino acids was observed. As a result of fermentation, the beverages showed excellent DPPH, ABTS+·, ·OH, and O2− radicals scavenging activities with a potential when considering diseases associated with oxidative stress. This beverages could be used as a new, non-dairy vehicle for beneficial microflora consumption, especially by vegans and lactose-intolerant consumers. 相似文献
154.
155.
Edwin Weber Annett Zaumüller Wilhelm Seichter Mátyás Czugler 《Supramolecular chemistry》2013,25(4):351-359
Abstract Four new host compounds 1–3 (a, b) derived from malic acid as different optical species and having particular lateral substituents were synthesized. Their properties in crystalline inclusion formation were studied and discussed. Crystal structures of a free host compound 1 and its ethanol inclusion complex [1·EtOH (1:1)] have been determined by X-ray analysis [1: orthorhombic, P212121, a = 9.304(3), b = 14.950(3), c = 15.712(3) Å, Dc = 1.248 Mg·m?3, Z = 4, R = 0.039 for 2474 reflexions; 1·EtOH (1:1): triclinic, P 1; a = 11.945(3), b = 14.080(3), c = 16.029(4) Å, α = 106.82(2), β = 97.74(2), γ = 89.93(2)°, Dc = 1.187 Mg·m3, Z = 4, R = 0.096 for 10404 data]. Spontaneous resolution occurs during crystallization in crystals of 1. An interesting H-bonding pattern develops that probably is responsible for the inclusion formation with ethanol in the associate crystal. 相似文献
156.
Kate?ina Barková Matthias Kinne René UllrichLothar Hennig Annett FuchsMartin Hofrichter 《Tetrahedron》2011,67(26):4874-4878
Aromatic peroxygenases are extracellular fungal biocatalysts that selectively oxidize a variety of organic compounds. We found that the peroxygenase of the fungus Agrocybe aegerita (AaeAPO) catalyzes the H2O2-dependent hydroxylation of diverse flavonoids. The reactions proceeded rapidly and regioselectively yielding preferentially monohydroxylated products, e.g., from flavanone, apigenin, luteolin, flavone as well as daidzein, quercetin, kaempferol, and genistein. In addition to hydroxylation, O-demethylation of fully methoxylated tangeretin was catalyzed by AaeAPO. The enzyme was merely lacking activity on the quercetin glycoside rutin, maybe due to sterical hindrance by the bulky sugar substituents. Mechanistic studies indicated the presence of epoxide intermediates during hydroxylation and incorporation of H2O2-derived oxygen into the reaction products. Our results raise the possibility that fungal peroxygenases may be useful for versatile, cost-effective, and scalable syntheses of flavonoid metabolites. 相似文献
157.
Stefan Spange Annett Graeser Petra Rehak Christian Jger Marcus Schulz 《Macromolecular rapid communications》2000,21(3):146-150
Cationic polymerization of cyclohexyl vinyl ether (CHVE) within mesoporous, siliceous molecular sieves (MCM‐41) yields novel MCM‐41‐polyCHVE host‐guest hybrid materials. Initiation within the channel can be achieved by triphenylmethylium or bis(4‐methoxyphenyl)methylium silanolate ion pairs, as well as by mobile acidic silanols to a certain extent. Generation of the carbenium ions on MCM‐41 is investigated by a special UV/VIS technique. The structure of poly(vinyl ether) generated within the channels of MCM‐41 depends on the mechanism of initiation as shown by means of solid state 13C{1H} and 29Si{1H} CP MAS NMR spectroscopy. 相似文献