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61.
Juliana Q. Mollica Denise C. Cara Mirna D’Auriol Verena B. Oliveira Isabela C. Cesar Maria G.L. Brandão 《Journal of Functional Foods》2013,5(4):1975-1984
Tropical ecosystems are particularly rich in edible plant species with different bioactive substances. Among the plants with promising benefits for health are species from the genus Dioscorea (Dioscoreaceae), especially those named yam. Recent studies have shown the beneficial effects of different species of Dioscorea, and its main constituent, diosgenine, in the treatment of food allergy. In this study we evaluated the potential of D. trifida, the only yam native from South America, in the treatment of ovalbumin (OVA) induced food allergy in Balb/c mice. HPLC/DAD analysis showed the presence of three very distinctive groups of natural products in extracts and fractions: (I) very polar substances, including allantoin, (II) phenolic substances as flavonoids and phenolic acids and (III) diosgenin and derivatives. Sensitive mice received casein feed with supplementation of crude extract (CE) and fractions. The supplementation with all products from D. trifida reduced IGE, intestinal oedema and mucus production, parameters observed in OVA allergic mice. The results showed the potential of this food to prevent or treat this disease and the necessity to be better explored. 相似文献
62.
The catalytic activity of single‐wall carbon nanohorns (SWNH) as counter electrodes (CE) of dye‐sensitized solar cells (DSC) was studied for the iodide/triiodide redox reaction. The catalytic activities of SWNH and high surface SWNH (HS‐SWNH) obtained by partial oxidation of SWNH were assessed based on charge‐transfer resistances (Rct) and current–voltage curves. A half‐cell configuration was used, and CE performances were compared to CEs made of carbon black (CB) and Pt. A CE assembled with HS‐SWNH and mixed with 10 wt.% of hydroxyethyl cellulose (HEC) ‐ HS‐SWNH/HEC was found to have the highest electrocatalytic activity (lowest Rct) among all the carbon‐based CEs tested when annealed at 180 °C (Rct = 141 Ω cm2); however, a very thick film (several tens of µm) would be required in order to perform comparably to a Pt CE. The annealing of such CE at higher temperatures (above 400 °C) did not improve its catalytic activity, contrary to the other studied carbonaceous CEs. The redox catalytic activity of SWNH and HS‐SWNH decorated with Pt was also studied on a half‐cell configuration and compared to that of Pt/CB and pristine Pt. The Pt/SWNH/HEC CE showed the highest electrocatalytic activity per mass of Pt, needing just 50% of Pt load to yield the same electrocatalytic activity of a DSC equipped with a Pt CE, but having half of its transparency. Additionally, applications in temperature‐sensitive substrates are envisioned for the Pt/SWNH/HEC CE due to the use of lower annealing temperatures. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
63.
Magnetic microactuators based on polymer magnets 总被引:5,自引:0,他引:5
Integrated permanent magnet microactuators have been fabricated using micromachined polymer magnets. The hard magnetic material utilized is a polymer composite, consisting of magnetically hard ceramic ferrite powder imbedded in a commercial epoxy resin to a volume loading of 80%. The magnets have the form of thin disks approximately 4 mm in diameter and 90 μm in thickness. These disks have been magnetized in the thickness direction, and even in this geometrically unfavorable direction showed typical permanent magnet behavior with an intrinsic coercivity Hci of 4000 Oe (320 kA/m) and a residual induction Br of 600 Gauss (60 mT). Cantilever beam-type magnetic actuators carrying a screen-printed disk magnet on their free ends have been fabricated on an epoxy board. A planar coil on the opposite side of the substrate is used to drive the beams vertically. The actuators exhibit hard magnetic behavior allowing both attraction and repulsion by reversing the current direction. Static and dynamic testing of the magnetic actuators have been performed. The experimental data are compared with theoretical results obtained from both finite element simulations and analytical models. Good agreement is obtained between simulation and experiment 相似文献
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Microfabrication techniques for chemical/biosensors 总被引:1,自引:0,他引:1
Hierlemann A. Brand O. Hagleitner C. Baltes H. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》2003,91(6):839-863
Microfabrication processes for chemical and biochemical sensors are reviewed. Standard processing steps originating from semiconductor technology are detailed, and specific micromachining steps to fabricate three-dimensional mechanical structures are described. Fundamental chemical sensor principles are briefly abstracted and corresponding state-of-the-art examples of microfabricated chemical sensors and biosensors are given. The advantages and disadvantages of either fabricating devices in IC fabrication technology with additional microfabrication steps, or of using custom-designed nonstandard microfabrication process flows are debated. Finally, monolithic integrated chemical and biological microsensor systems are presented, which include transducer structures and operation circuitry on a single chip. 相似文献
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C. A. Neufeld H. Will und J. Brand 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1907,13(4):206-210
Ohne Zusammenfassung 相似文献
70.
Mechanoreceptors in joint function 总被引:1,自引:0,他引:1