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61.
Robert Socha Lesław Juszczak Sławomir Pietrzyk Dorota Gałkowska Teresa Fortuna Teresa Witczak 《International Journal of Food Science & Technology》2011,46(3):528-534
The phenolic components of honeys have great participation in their nutritional value and antioxidant activity. Moreover, phenolic components are promising markers for the determination of botanical and geographical origin of honey. The purpose of the present work was to study the antioxidant activity and profiles of phenolic acids and flavonoids of honeys of various origins. The total phenolic content of honeys varied from 4.46 to 15.04 mg of gallic acid equivalents per 100 g of product and the total phenolic acid content determined chromatographically varied from 201.05 to 2089.08 μg per 100 g of product. Buckwheat honey exhibited the highest antioxidant activity and contained the highest total phenolic amount, whereas rape honey exhibited the lowest values in this respect. Moreover, the buckwheat honey contained the highest amount of phenolic acids. There were significant linear correlations between total phenolic content and antioxidant activity of honey extracts in the reaction with DPPH? (1,1‐diphenyl‐2‐picrylhydrazyl) and ABTS? + (2,2′‐azinobis‐(3‐ethylbenzothiazoline‐6‐sulfonic acid)) free radicals. In most samples, p‐coumaric acid was the dominant phenolic acid (39.1–677.2 μg per 100 g). The honeys also contained considerable amount of gallic acid (6.0–913.8 μg per 100 g). Among flavonoids naringenin was predominant in the most studied honey samples. 相似文献
62.
Analog circuit testing is considered to be a very difficult task. This difficulty is mainly due to the lack of fault models and accessibility to internal nodes. To overcome this problem, an approach is presented for analog circuit modeling and testing. The circuit modeling is based on first-order sensitivity computation. The testability of the circuit is analyzed by the multiple-fault model and by functional testing. Component deviations are deduced by measuring a number of output parameters, and through sensitivity analysis and tolerance computation. Using this approach, adequate tests are identified for testing catastrophic and soft faults. Some experimental results are presented for simple models as well as multiple-fault models. 相似文献
63.
The application of new materials to produce forged connecting parts is presented in this work. Particular attention is put on modern bainitic steels due to their increased ductile and strength properties, which influence the behaviour of final products under further exploitation conditions. Bainitic steels do not require a series of thermo‐mechanical operations to obtain these elevated properties, which is one of the advantages of this material. Experimental analysis and numerical simulations of steel behaviour during multi‐step cold forging operations are described in this paper. Since it is one of the possible fracture initiation mechanisms, strain localization development during cold forging is investigated in detail. Conventional constitutive models used in finite element programs have limitations in modeling stochastic and discontinuous phenomena that are responsible for strain localization. The cellular automata model is used as constitutive law in this work to overcome these difficulties and investigate material flow during multi‐stage cold forging operations. Connection of the cellular automata (CA) and finite element (FE) methods creates a so‐called multi‐scale CAFE model. The main aspects of the model are described briefly in this paper. The experimental part of this work supports the numerical investigation. Comparison of the parameters measured and predicted by the CAFE model is presented and discussed as well. 相似文献
64.
Discordant twins with Parkinson''s disease: positron emission tomography and early signs of impaired cognitive circuits 总被引:1,自引:0,他引:1
VA Holthoff P Vieregge J Kessler U Pietrzyk K Herholz J B?nner R Wagner K Wienhard G Pawlik WD Heiss 《Canadian Metallurgical Quarterly》1994,36(2):176-182
Anti-neutrophil cytoplasmic antibodies (ANCA) in sera from 52 patients with rheumatoid arthritis (RA), including 9 patients with malignant RA (MRA) and 20 healthy controls were examined by indirect immunofluorescence technique (IIF). Nine out of 52 RA patients showed positive ANCA staining. None of MRA patients had, however, ANCA in sera. The staining pattern for ANCA was either perinuclear for 4 sera or non-specific for 5 sera, but not cytoplasmic. Furthermore, anti-nuclear antibodies (ANA) in 9 ANCA positive RA sera were tested by IIF, using Hep-2 cells. Six sera had positive ANA. Three sera showed as nucleolar and 1 serum as centromere in ANA staining pattern. The incidence of these ANA staining pattern in ANCA positive sera (4 out of 9) was higher than in ANCA negative sera (1 out of 19). The clinical profiles and laboratory findings of 9 RA patients with positive ANCA revealed that they had suffered and treated for more than 10 years and had still active joint inflammation, like intractable RA. These results indicate that ANCA in RA are not associated with vasculitis. 相似文献
65.
Lis J Pasieczna A Karbowska B Zembrzuski W Lukaszewski Z 《Environmental science & technology》2003,37(20):4569-4572
Thallium was determined in 120 samples of soil and 30 samples of stream sediments from the southeastern part of the Silesian-Cracowian zinc-lead ore deposits. Soil samples were taken from topsoils (0.0-0.2 m) and bottom soils (0.8 and 1.0 m). Thallium was determined by flow-injection-differential-pulse anodic stripping voltammetry. The samples were decomposed sequentially with 73% hydrofluoric acid and a mixture of nitric acid and hydrogen peroxide. The results showed that zinc-lead ore mining as well as their processing and smelting leads to a significant increase of thallium in the top layer of soil and in stream sediments. The highest recorded concentration was 150 ppm Tl for stream sediment and 35 ppm for a soil sample. Thallium concentration in small rivers from the investigated area was by 2 orders of magnitude higher than in the reference area. The highest recorded concentration being 3.24 microg L(-1). 相似文献
66.
Passive sampling is a very attractive alternative to active sampling due to its simplicity and low cost. Among the passive samplers used in air analysis, permeation passive samplers are the least affected by ambient conditions, including humidity, air currents, and temperature changes. The biggest drawback of permeation passive samplers is the need to calibrate them experimentally for each individual target analyte. The paper presents the results of research on the calibration of permeation passive samplers based on physicochemical properties of the analytes. Strong correlations were found between the calibration constants of the samplers and the number of carbon atoms among families of compounds (R2 ranging from 0.8507 for alcohols to 0.9995 for aromatic hydrocarbons), the molecular weights of the compounds (R2 = 0.8742), their boiling points (R2 = 0.8911), and linear temperature-programmed retention indexes (R2 = 0.9225). The last correlation makes it possible to estimate the calibration constants for unidentified analytes, which is impossible when the conventional procedure is used. This makes it possible to deploy permeation passive samplers in the same way in which active sampling is deployed. 相似文献
67.
The aim of this study was to assess the influence of bioflavonoids from the radix of Scurellaria baicalensis on the level of lipids, via the determination of the concentrations of triglycerides, total cholesterol and high-density lipoprotein (HDL) cholesterol in the plasma of laboratory rats fed high-fat and high-cholesterol diets, and via the calculation of their atherogenic index. We also studied the influence of bioflavonoids on their physical development by measuring the increase in their body mass and liver mass. The rats were fed a diet with a 15% content of fresh or oxidized lard or sunflower oil, along with 0.5% added cholesterol. 0.05% S. baicalensis radix extract was added to the diet of half of the rats as the source of bioflavonoids. In the group of rats fed a diet containing oxidized oil we observed a significantly lower increase in body mass (15.5 +/- 7.6 g/4 weeks/rat) than that observed for the control rats (77.0 +/- 15.7 g/4 weeks/rat). The addition of S. baicalensis radix extract to the diet raised the increase in body mass in the groups receiving oil as the source of fat; those receiving fresh oil had a 40% increase, and those receiving oxidized oil showed a 300% increase relative to the appropriate controls. In all the groups of rats fed a diet with bioflavonoids added, a beneficial decrease in the plasma triglyceride content was observed relative to the appropriate controls. In the plasma of rats on a diet containing the extract and fresh or oxidized oil or fresh lard, we observed a beneficial reduction in the total cholesterol level relative to the appropriate controls. The atherogenic index was higher for the group of animals fed with fresh lard than for those fed with fresh oil, and higher for those fed with oxidized oil than for those fed with oxidized lard. The addition of bioflavonoids to the diet beneficially reduced the atherogenic index value in the group fed with fresh oil, and increased its value in the group fed with oxidized lard. 相似文献
68.
The aim of this study was to examine the changes which occur under the influence of different heating methods in the compositions of fatty acids and selected fat quality indicators in fillets of herring. The results that are compared herein were obtained via conventional culinary techniques and using microwave radiation. Culinary processes like boiling, grilling and frying, whether done conventionally or with a microwave oven, did not lead to a reduction in the n-3 polyunsaturated fatty acids (PUFAs) fraction of the total fatty acids, indicating that these fatty acids have a high durability and a low susceptibility to thermal oxidative processes. The culinary processes used in this study also had an insignificant influence on the fat quality indicators--the peroxide and anisidine value. The fat quality indicators in herring, both after conventional and microwave heating, differ little, and indicate a low content of primary and secondary products of oxidation. 相似文献
69.
70.