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排序方式: 共有323条查询结果,搜索用时 453 毫秒
151.
Anamarija I. Mandic Sonja M. Đilas Gordana S. Ćetković Jasna M. Čanadanović-Brunet Vesna T. Tumbas 《International Journal of Food Properties》2013,16(4):713-726
Grape seed extracts (GSEs,) obtained from Italian and Rhine Rieslings, were examined for polyphenolic composition and antioxidant activities using HPLC and ESR spectrometry. The seed extraction was carried out with ethyl acetate and ethanol. The contents of polyphenols, flavan-3-ols and antioxidant activities were found to be higher in ethyl acetate than in ethanolic extracts. IC50 values were 0.1045 mg/mL and 0.0599 mg/mL for the stable DPPH radical in ethanolic and ethyl acetate extracts, respectively. The values for the short-lived OH radical were 0.1989 mg/mL and 0.0362 mg/mL, in the given order. The significant correlations between the antioxidant activities of GSEs and polyphenols were established (P < 0.05). Owing to their antioxidant activities, the cultivars could be used as a source to produce a GSE. 相似文献
152.
In this paper, we study the problem of resource allocation between users in next-generation networks. The starting assumption is that the service provider tries to come up with convincing offers of service level to subscribers, based on demand responsive pricing scheme, while trying to maximize its profit. We developed two algorithms with different usage-based pricing strategies. Both algorithms solve pricing optimization problem using Stackelberg game with service provider acting as a leader and users behaving as followers. We developed the bandwidth management server to perform automatic optimal bandwidth allocation to each user's session and maximize its expected utility while maximizing the overall service provider's revenue. For both algorithms, we also performed the procedure for optimization of the capacity offered to users. 相似文献
153.
Marija V. Vučković Vesna V. Antić Milutin N. Govedarica Jasna Djonlagić 《应用聚合物科学杂志》2010,115(6):3205-3216
A series of thermoplastic elastomers based on ethylene oxide‐poly(dimethylsiloxane)‐ethylene oxide (EO‐PDMS‐EO), as the soft segment, and poly(butylene terephthalate) (PBT), as the hard segment, were synthesized by catalyzed two‐step, melt transesterification reaction of dimethyl terephthalate (DMT) with 1,4‐butanediol (BD) and α,ω‐dihydroxy‐(EO‐PDMS‐EO). Copolymers with a content of hard PBT segments between 40 and 90 mass % and a constant length of the soft EO‐PDMS‐EO segments were prepared. The siloxane prepolymer with hydrophilic terminal EO units was used to improve the miscibility between the polar comonomers, DMT and BD, and the nonpolar PDMS. The molecular structure and composition of the copolymers were determined by 1H‐NMR spectroscopy, whereas the effectiveness of the incorporation of α,ω‐dihydroxy‐(EO‐PDMS‐EO) into the copolymer chains was verified by chloroform extraction. The effects of the structure and composition of the copolymers on the melting temperatures and the degree of crystallinity, as well as on the thermal degradation stability and some rheological properties, were studied. It was demonstrated that the degree of crystallinity, the melting and crystallization temperatures of the copolymers increased with increasing mass fraction of the PBT segments. The thermal stability of the copolymers was lower than that of PBT homopolymer, because of the presence of thermoliable ether bonds in the soft segments. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
154.
Václav Valeš Václav HolýMaja Buljan Vesna JanickiSigrid Bernstorff 《Thin solid films》2012,520(14):4800-4802
We report on structural, morphological and ordering properties of Fe2O3/TiO2 nanoparticles embedded in SiO2-based multilayers. We investigated the structure of these systems by X-ray diffraction and grazing incidence small angle X-ray scattering after post-growth annealing. We found that the presence of TiO2 promotes the growth and crystallization of the nanocrystals of Fe2O3. In multilayers containing both Fe2O3 and TiO2, crystalline nanoparticles create partially ordered three-dimensional arrays. 相似文献
155.
Tikhonravov AV Amotchkina TV Trubetskov MK Francis RJ Janicki V Sancho-Parramon J Zorc H Pervak V 《Applied optics》2012,51(2):245-254
We perform characterization of thin films and reverse engineering of multilayer coatings on the basis of multiangle spectral photometric data provided by a new advanced spectrophotometer accessory. Experimental samples of single thin films and multilayer coatings are produced by magnetron sputtering and electron-beam evaporation. Reflectance and transmittance data at two polarization states are measured at incidence angles from 7 to 40 deg. We demonstrate that multiangle reflectance and transmittance data provide reliable characterization and reverse-engineering results. 相似文献
156.
Vesna Stani Alain C. Pierre Thomas H. Etsell Randy J. Mikula 《Journal of the American Ceramic Society》2000,83(7):1790-1796
A GeS2 gel was prepared by sol–gel processing of Ge(OEt)4 and H2 S in toluene solution. The effects of H2 S and germanium ethoxide concentrations, concentration ratio, and temperature on the microstructure of the prepared GeS2 gels were studied. It was found that the concentrations of the reactants had the most significant influence on primary particle size and gel morphology. The microstructure of the dried gels was characterized by nitrogen BET analysis, SEM, powder XRD analysis, and infrared spectroscopy. Results indicate that the GeS2 gels are amorphous colloidal xerogels regardless of the reaction conditions and length of aging. 相似文献
157.
Vesna Cerkvenik Darinka Z. Doganoc Valentin Skubic Wim M. Beek Henk J. Keukens 《European Food Research and Technology》2001,213(1):72-76
The stability of ivermectin residues in sheep milk under conditions of pasteurization (74 °C, 40 s), high pasteurization (80 °C, 1 min), and boiling (100 °C, 10 s) based on residue content (at a level of concentration of about 2 µg/kg and 30 µg/kg of H2B1a) and sort of ingestion (in vitro, in vivo) was studied. None of these factors influenced concentrations of ivermectin in the matrix investigated. Residues of ivermectin were also stable in milk after one year of freezing at -20 °C. After two years of freezing they had diminished by approximately one quarter. The concentration of the H2B1a component was analyzed using a combined HPLC method with fluorescence detection. Samples were extracted with acetonitrile and cleaned-up using a solid phase extraction on C8 minicolumns. Eluate was concentrated under stream of nitrogen and dry extracts were pre-column derivatized with trifluoroacetic anhydride and N-methylimidazole. The method used was extensively validated. 相似文献
158.
Kutlesic Vesna; Williamson Donald A.; Gleaves David H.; Barbin Jane M.; Murphy-Eberenz Kathleen P. 《Canadian Metallurgical Quarterly》1998,10(1):41
The authors describe the psychometric development of the fourth revision of the Interview for Diagnosis of Eating Disorders (IDED–IV). The IDED–IV was tested for the purpose of differential diagnosis of eating disorders, that is, anorexia nervosa, bulimia nervosa, and binge eating disorder. Evidence for internal consistency was found for symptom ratings relevant to anorexia nervosa, bulimia nervosa, and binge eating disorder. Support was found for the content validity as well as the concurrent and discriminant validity of the IDED–IV. Finally, tests of the interrater agreement for differential diagnosis of eating disorders found the IDED–IV to yield very reliable data. The authors conclude that the IDED–IV yields sufficiently reliable and valid data to be used for determining diagnoses in research studies and clinics specializing in the treatment of eating disorders. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
159.
Vesna Kadelburg 《Dynamical Systems: An International Journal》2001,16(2):157-171
Analytically explicit estimates are found for the bounds for continuation of discrete breathers on a one-dimensional nearest-neighbour chain of Hamiltonian oscillators, for a particular example of external potential, based on the proof of existence of breathers of MacKay and Aubry. 相似文献
160.
Tadeja Kuret Katja Lakota Saa u
nik Vesna Jur
i
Oliver Distler
iga Rotar Alojzija Ho
evar Snena Sodin-emrl Mojca Frank-Bertoncelj 《International journal of molecular sciences》2021,22(12)
In this study, we explored expression of microRNA (miR), miR-target genes and matrix remodelling molecules in temporal artery biopsies (TABs) from treatment-naïve patients with giant cell arteritis (GCA, n = 41) and integrated these analyses with clinical, laboratory, ultrasound and histological manifestations of GCA. NonGCA patients (n = 4) served as controls. GCA TABs exhibited deregulated expression of several miRs (miR-21-5p, -145-5p, -146a-5p, -146b-5p, -155-5p, 424-3p, -424-5p, -503-5p), putative miR-target genes (YAP1, PELI1, FGF2, VEGFA, KLF4) and matrix remodelling factors (MMP2, MMP9, TIMP1, TIPM2) with key roles in Toll-like receptor signaling, mechanotransduction and extracellular matrix biology. MiR-424-3p, -503-5p, KLF4, PELI1 and YAP1 were identified as new deregulated molecular factors in GCA TABs. Quantities of miR-146a-5p, YAP1, PELI1, FGF2, TIMP2 and MMP9 were particularly high in histologically positive GCA TABs with occluded temporal artery lumen. MiR-424-5p expression in TABs and the presence of facial or carotid arteritis on ultrasound were associated with vision disturbances in GCA patients. Correlative analysis of miR-mRNA quantities demonstrated a highly interrelated expression network of deregulated miRs and mRNAs in temporal arteries and identified KLF4 as a candidate target gene of deregulated miR-21-5p, -146a-5p and -155-5p network in GCA TABs. Meanwhile, arterial miR and mRNA expression did not correlate with constitutive symptoms and signs of GCA, elevated markers of systemic inflammation nor sonographic characteristics of GCA. Our study provides new insights into GCA pathophysiology and uncovers new candidate biomarkers of vision impairment in GCA. 相似文献