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721.
Scanning electron microscopy of Fusarium damaged kernels of spring wheat   总被引:1,自引:0,他引:1  
Kernels of five wheat cultivars (Triticum aestivum) of different bread-making quality were examined. Grown under field conditions, heads of wheat were inoculated in the flowering stage with an aqueous suspension of Fusarium culmorum conidia. Wheat heads were collected from the control and inoculated plots at full maturity. Control (non-inoculated) kernels without any symptoms of disease and Fusarium damaged kernels (FDK) were examined under scanning electron microscopy (SEM). Examination of the FDK fraction confirmed localisation of Fusarium hyphae on the surface and inside the tissues of kernels. Observations of the endosperm from Fusarium infected kernels revealed presence of fungal hyphae in the endosperm and some characteristic structural changes in many of its regions, such as partial or complete lack of the protein matrix, damage to large and small starch granules caused by fungal amylolytic enzymes, disappearance of small starch granules as the colonisation progressed, complete disappearance of the starchy endosperm under severe infection. Fungal colonisation of the endosperm and structural changes in its area were highly variable traits within the FDK fraction of a given cultivar.  相似文献   
722.
We investigated the influence of the protruding domain of Norwalk virus-like particles (NVLP) on its overall structural and mechanical stability. Deletion of the protruding domain yields smooth mutant particles and our AFM nanoindentation measurements show a surprisingly altered indentation response of these particles. Notably, the brittle behavior of the NVLP as compared to the plastic behavior of the mutant reveals that the protruding domain drastically changes the capsid's material properties. We conclude that the protruding domain introduces prestress, thereby increasing the stiffness of the NVLP and effectively stabilizing the viral nanoparticles. Our results exemplify the variety of methods that nature has explored to improve the mechanical properties of viral capsids, which in turn provides new insights for developing rationally designed, self-assembled nanodevices.  相似文献   
723.
Asthma oxidative stress disturbances seem to enable supplementary proinflammatory pathways, thus contributing to disease development and severity. The current study analyzed the impact of two types of oral vitamin D (VD) supplementation regimens on the redox balance using a murine model of acute ovalbumin-induced (OVA-induced) asthmatic inflammation. The experimental prevention group received a long-term daily dose of 50 µg/kg (total dose of 1300 µg/kg), whereas the rescue group underwent a short-term daily dose of 100 µg/kg (total dose of 400 µg/kg). The following oxidative stress parameters were analyzed in serum, bronchoalveolar lavage fluid (BALF) and lung tissue homogenate (LTH): total oxidative status, total antioxidant response, oxidative stress index, malondialdehyde and total thiols. Results showed that VD significantly reduced oxidative forces and increased the antioxidant capacity in the serum and LTH of treated mice. There was no statistically significant difference between the two types of VD supplementation. VD also exhibited an anti-inflammatory effect in all treated mice, reducing nitric oxide formation in serum and the expression of nuclear factor kappa B p65 in the lung. In conclusion, VD supplementation seems to exhibit a protective role in oxidative stress processes related to OVA-induced acute airway inflammation.  相似文献   
724.
725.
Wireless Networks - In this paper, an extended continuous class-F power amplifier (PA) is investigated, designed, and fabricated. The new auxiliary parameter $$left(beta +alpha...  相似文献   
726.
Bulletin of Engineering Geology and the Environment - Engineering structures in the geological environment of loess sediments face a number of problems. An emphasis is placed on the surface runoff...  相似文献   
727.
728.
Metallurgical wastes landfills in Poland significantly grew during last four decades. Landfilled wastes are characterised by iron content at range 30–50% and zinc content about 2–3%. Therefore wastes are not interesting for the zinc smelter, on the other hand, even such low zinc content in ironmaking burden causes problem with a shaft furnace operation. So, the wastes are valuable for ironmaking due to the high iron content, provided that zinc will be removed from them. The article describes the general ways of dealing with zinc containing metallurgical wastes. In detail, the semi-industrial research conducted on sinter pot set of Stanislaw Staszic Institute for Ferrous Metallurgy is presented. The study determined the conditions under which obtained three benefits: landfilled sludge utilisation, raw materials substitution and zinc recovery.  相似文献   
729.
Blood pumps and ventricular assist devices are increasingly used for therapy in patients suffering from acute heart failure. Especially rotary blood pumps provide various benefits, due to their robust and simple construction. To ensure an optimal blood supply for the patient, the control of the blood flow through the pump is indispensable. In this work, a nonlinear controller for a rotary blood pump type Medos DeltaStream DP1, with a diagonally streamed impeller, was developed. This controller is able to regulate constant as well as dynamic blood flow trajectories in parallel to the beating heart of the patient. The Local Linear Model Tree algorithm (LOLIMOT) was used for the static, non-linear system identification of the blood pump. Based on this identification method, the system was linearised in several operating points and a dynamic grey-box-modelling of the system was executed. For the subsequent control of the system, an operating point-dependent controller and, furthermore, a gain scheduled PID controller were designed and extended by a feedforward controller. As a conclusion, the developed controllers revealed good servo control behaviour with the tested flow trajectories.  相似文献   
730.
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