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51.
Carmelina Summa Fernando Cordeiro Raposo Josephine McCourt Roberto Lo Scalzo Karl-Heinz Wagner Ibrahim Elmadfa Elke Anklam 《European Food Research and Technology》2006,222(3-4):368-375
The free-radical scavenging activity of cocoa samples subjected to different roasting treatments has been determined. The
samples (raw, pre-roasted and roasted) were separated into four molecular weight fractions per sample (>30, 30–10, 10–5, and
<5 kDa). The free-radical scavenging activity was determined with the DPPH• (1,1-dipheny-2-picrylhydrazyl), and ABTS•+ [2,2’-azinobis (3-ethylbenzothiazoline-6-sulfonic acid)] free-radical scavenging assays for all samples. Both tests were
compared in terms of sensitivity and measurement precision, at different reaction times. Comparing the results from each test,
the free-radical scavenging activity trends were similar for each fraction but with notable differences in the sensitivity
of the assays. Analysis of the concentration of reducing substances, such as water soluble phenolics, melanoidins, carbohydrates,
etc, in these fractions by the photometric Folin–Ciocalteu assay, showed a similar pattern to the free-radical scavenging
activity trend. Moreover, this comparison showed that there were significantly (P < 0.05) more reducing substances and free-radical scavenging activity in the 10–5 kDa roasted cocoa bean fraction. 相似文献
52.
53.
René-Maxime Gracien Sarah C. Reitz Marlies Wagner Christoph Mayer Steffen Volz Stephanie-Michelle Hof Vinzenz Fleischer Amgad Droby Helmuth Steinmetz Sergiu Groppa Elke Hattingen Johannes C. Klein Ralf Deichmann 《Magma (New York, N.Y.)》2017,30(1):75-83
Objective
Proton density (PD) mapping requires correction for the receive profile (RP), which is frequently performed via bias-field correction. An alternative RP-mapping method utilizes a comparison of uncorrected PD-maps and a value ρ(T1) directly derived from T1-maps via the Fatouros equation. This may be problematic in multiple sclerosis (MS), if respective parameters are only valid for healthy brain tissue. We aimed to investigate whether the alternative method yields correct PD values in MS patients.Materials/methods
PD mapping was performed on 27 patients with relapsing-remitting MS and 27 healthy controls, utilizing both methods, yielding reference PD values (PDref, bias-field method) and PDalt (alternative method).Results
PDalt-values closely matched PDref, both for patients and controls. In contrast, ρ(T1) differed by up to 3 % from PDref, and the voxel-wise correlation between PDref and ρ(T1) was reduced in a patient subgroup with a higher degree of disability. Still, discrepancies between ρ(T1) and PDref were almost identical across different tissue types, thus translating into a scaling factor, which cancelled out during normalization to 100 % in CSF, yielding a good agreement between PDalt and PDref.Conclusion
RP correction utilizing the auxiliary parameter ρ(T1) derived via the Fatouros equation provides accurate PD results in MS patients, in spite of discrepancies between ρ(T1) and actual PD values.54.
Emmanuelle Dupont Jacques J.F. Commandeur Sylvain Lassarre Frits Bijleveld Heike Martensen Constantinos Antoniou Eleonora Papadimitriou George Yannis Elke Hermans Katherine Pérez Elena Santamariña-Rubio Davide Shingo Usami Gabriele Giustiniani 《Accident; analysis and prevention》2014
In this paper a unified methodology is presented for the modelling of the evolution of road safety in 30 European countries. For each country, annual data of the best available exposure indicator and of the number of fatalities were simultaneously analysed with the bivariate latent risk time series model. This model is based on the assumption that the amount of exposure and the number of fatalities are intrinsically related. It captures the dynamic evolution in the fatalities as the product of the dynamic evolution in two latent trends: the trend in the fatality risk and the trend in the exposure to that risk. Before applying the latent risk model to the different countries it was first investigated and tested whether the exposure indicator at hand and the fatalities in each country were in fact related at all. If they were, the latent risk model was applied to that country; if not, a univariate local linear trend model was applied to the fatalities series only, unless the latent risk time series model was found to yield better forecasts than the univariate local linear trend model. In either case, the temporal structure of the unobserved components of the optimal model was established, and structural breaks in the trends related to external events were identified and captured by adding intervention variables to the appropriate components of the model. As a final step, for each country the optimally modelled developments were projected into the future, thus yielding forecasts for the number of fatalities up to and including 2020. 相似文献
55.
Schirmer M Walz MM Vollnhals F Lukasczyk T Sandmann A Chen C Steinrück HP Marbach H 《Nanotechnology》2011,22(8):085301
We have investigated the lithographic generation of TiO(x) nanostructures on Si(100) via electron-beam-induced deposition (EBID) of titanium tetraisopropoxide (TTIP) in ultra-high vacuum (UHV) by scanning electron microscopy (SEM) and local Auger electron spectroscopy (AES). In addition, the fabricated nanostructures were also characterized ex situ via atomic force microscopy (AFM) under ambient conditions. In EBID, a highly focused electron beam is used to locally decompose precursor molecules and thereby to generate a deposit. A drawback of this nanofabrication technique is the unintended deposition of material in the vicinity of the impact position of the primary electron beam due to so-called proximity effects. Herein, we present a post-treatment procedure to deplete the unintended deposits by moderate sputtering after the deposition process. Moreover, we were able to observe the formation of pure titanium oxide nanocrystals (<100 nm) in situ upon heating the sample in a well-defined oxygen atmosphere. While the nanocrystal growth for the as-deposited structures also occurs in the surroundings of the irradiated area due to proximity effects, it is limited to the pre-defined regions, if the sample was sputtered before heating the sample under oxygen atmosphere. The described two-step post-treatment procedure after EBID presents a new pathway for the fabrication of clean localized nanostructures. 相似文献
56.
Schirmer M Walz MM Papp C Kronast F Gray AX Balke B Cramm S Fadley CS Steinrück HP Marbach H 《Nanotechnology》2011,22(47):475304
We report on the stepwise generation of layered nanostructures via electron beam induced deposition (EBID) using organometallic precursor molecules in ultra-high vacuum (UHV). In a first step a metallic iron line structure was produced using iron pentacarbonyl; in a second step this nanostructure was then locally capped with a 2-3 nm thin titanium oxide-containing film fabricated from titanium tetraisopropoxide. The chemical composition of the deposited layers was analyzed by spatially resolved Auger electron spectroscopy. With spatially resolved x-ray absorption spectroscopy at the Fe L? edge, it was demonstrated that the thin capping layer prevents the iron structure from oxidation upon exposure to air. 相似文献
57.
Heme-dependent and heme-independent nitrite reduction by lactic acid bacteria results in different N-containing products 总被引:1,自引:0,他引:1
Gudrun Wolf Elke K. Arendt Ute Pfhler Walter P. Hammes 《International journal of food microbiology》1990,10(3-4):323-329
Seventy strains of lactic acid bacteria were investigated for nitrite reductase activity. Two types of this activity were detected. Type I was found in Lactobacillus plantarum, L. pentosus and Pediococcus pentosaceus. This activity is heme-dependent with ammonia as the sole product. Type II mechanism is heme-independent and reduces nitrite to NO and N2O. 相似文献
58.
59.
Infection of feline immunodeficiency virus (FIV) has been shown to induce apoptosis that might be associated with the lymphocyte depletion in the infected cats. To investigate the inhibitory effect of antioxidants on FIV-induced apoptosis, we examined the effect of N-acetylcysteine (NAC) and ascorbic acid (AA) on apoptosis and virus replication in feline lymphoblastoid (Fel-039) and fibroblastoid (CRFK) cell lines infected with FIV. The treatment with NAC or AA induced a significant inhibition of viral replication and apoptosis in Fel-039 cells and tumor necrosis factor alpha (TNF-alpha)-treated CRFK cells infected with FIV. Both cell lines in the presence of noncytotoxic concentrations of NAC or AA showed in increase of intracellular glutathione (GSH) level, which might protect the cells against oxidative stresses exerted by FIV infection and TNF-alpha treatment. On the basis of these in vitro results, we suggest that antioxidant therapies aimed at restoring depleted GSH level might be effective for inhibition of viral replication and cell death associated with the development of immunodeficiency. 相似文献
60.
Long-run effects of regional policy in an economic union 总被引:2,自引:0,他引:2
Uwe Walz 《The Annals of Regional Science》1996,30(2):165-183
Regional policy in economic unions (e.g. in the European Union) is usually conducted with the objective of overcoming regional disparities. By developing a two-regional growth model with endogenous technological change, we address the long-term implications of regional policy measures. We show that regional policies aiming to support the less-developed region do not only change the location of production between the regions but also affect the overall growth performance of the union. By altering the incentive to accumulate knowledge capital, regional policies influence the steady-state growth rate. Our analysis shows that a potential trade-off between regional equity and dynamic efficiency exists. 相似文献