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排序方式: 共有1014条查询结果,搜索用时 218 毫秒
821.
Akkerdaas JH Schocker F Vieths S Versteeg S Zuidmeer L Hefle SL Aalberse RC Richter K Ferreira F van Ree R 《Molecular nutrition & food research》2006,50(1):18-23
The clinical presentation of non-pollen related allergy to hazelnut can be severe and systemic. So far, only a limited number of non-pollen related hazelnut allergens have been identified and characterized. The aim of this study was to identify and clone new hazelnut allergens. A lambda ZAP cDNA library of hazelnut was constructed. The library was screened with serum of six hazelnut allergic patients displaying different IgE-binding patterns on hazelnut immunoblot. Rapid amplification of cDNA ends (RACE) protocols were applied to obtain full-length clones. Expression experiments were carried out in Eschericchia coli. Expression was monitored by SDS-PAGE, protein staining and immunoblotting. A hazelnut cDNA library was constructed. IgE screening resulted in the cloning of two isoforms of a novel putative hazelnut allergen. The clones were identified as oleosins, with theoretical molecular masses of 16.7 and 14.7 kDa and pI of 10.5 and 10.0, respectively. The isoforms demonstrated only 37% amino acid sequence identity but contained the typical hydrophobic stretch in the middle of the protein (53% identity) with the characteristic oleosin proline knot region (11/12 amino acids identical). Expression in E. coli of the longer isoform resulted in a clear band on SDS-PAGE. The expressed protein was recognized on an immunodot blot by IgE from serum that was used for screening the cDNA library. Hazelnut contains multiple isoforms of oleosin. IgE binding of a hazelnut-allergic patient to a recombinant version suggest that hazelnut oleosin is an allergen, as has been described for peanut and sesame. 相似文献
822.
Maria P. Seabra Maxim Avdeev Victor M. Ferreira Rob C. Pullar Neil McN. Alford Ian M. Reaney 《Journal of the American Ceramic Society》2004,87(4):584-590
The microwave dielectric properties and microstructures of compounds in the solid solution series x BaTiO3 –(1− x )La(Mg1/2 Ti1/2 )O3 (BTLMT) have been investigated. The structural phase transitions that occur as a function of x have been studied and are related to changes in the dielectric properties. For compounds where x ≤ 0.1, X-ray diffraction (XRD) showed evidence of 1:1 ordering between Mg and Ti cations. For x ≤ 0.3, XRD and electron diffraction revealed that compounds were tilted in both antiphase and in-phase. However, for 0.3 < x < 0.7, only antiphase tilting was present. The temperature coefficient of resonant frequency (τf ) vs the relative permittivity (ɛr ) was linear until x = 0.5 at which point in the solid solution the transition to a nontilted structure resulted in nonlinear behavior. τf values close to zero (−2 ppm/°C) were achieved at x = 0.5 (ɛr ∼ 60), which had a quality factor ( Q · f o ) of 9600 GHz. 相似文献
823.
Forces operative during film formation from latex dispersions 总被引:7,自引:0,他引:7
824.
Jan Willem Veldsink Bart G. Muuse Margreet M. T. Meijer F. Petrus Cuperus Rob L. K. M. van de Sande Karel P. A. M. van Putte 《European Journal of Lipid Science and Technology》1999,101(7):244-248
We studied the effect of seed conditioning via a rapid preheating technique to destroy the activity of oil-degrading enzymes. Rape and sunflower seeds were heated via steaming, oven cooking, infrared, and microwave. After the pretreatment the oil was expelled from the seeds by a screw press and its quality was determined via the analysis of oxidative stability, peroxide value, free fatty acid content, phosphorus, and iron. From the results it was concluded that preheating of the seeds leads to the expected decreased activity of lipase, but nevertheless increased levels of phosphorus and free fatty acids were observed. However, increased levels of phenolic antioxidants markedly improved the oxidative stability of rapeseed oil. From the techniques studied for heating of the seeds, microwave and steaming appeared to be the most suitable techniques. Both methods gave markedly improved oxidative stability, whereas steaming seemed to result in less formation of free fatty acids than microwave heating. Infrared heating led to rapidly burnt seeds and off-flavours. 相似文献
825.
826.
Andr M Pots Harry Gruppen Rob van Diepenbeek Johannes J van der Lee Martinus A
J
S van Boekel Gerrit Wijngaards Alphons G
J Voragen 《Journal of the science of food and agriculture》1999,79(12):1557-1564
The content and biological activity of patatin and the protease inhibitors of molecular size 20–22 kDa present in whole potato tubers were investigated as a function of storage time. The amount of buffer-extractable protein decreased gradually during storage of whole potatoes of the cultivars Bintje and Desiree for 47 weeks whereas, for Elkana, it increased after approximately 25 weeks. The patatin proportion of the extractable protein did not decrease significantly during storage, whereas the proportion of PP20–22 protease inhibitors decreased. All cultivars contained several different patatin isoforms. Bintje and Desiree showed patatin populations with two masses whereas for Elkana, only one molar mass was found. Patatin isoforms of the three cultivars examined showed no significant differences in stability towards degradation as was concluded from capillary electrophoresis analysis. No inactivation of patatin or protease inhibitors by partial degradation of these proteins was observed using matrix-assisted laser desorption/ionisation time of flight mass spectrometry (MALDI-TOF MS), whereas enzyme-activity assays suggested that the biological activity, especially in the cultivar Bintje, decreased markedly at the break of dormancy. © 1999 Society of Chemical Industry 相似文献
827.
Md Abdur Rob Sheikh Eikaku Son Motoki Kamiyama Tohru Morioka Tatsuya Matsumoto Koji Morita 《Journal of Nuclear Science and Technology》2018,55(6):623-633
During the material relocation phase of core-disruptive accidents in sodium-cooled fast reactors, the sedimentation behavior of fragmented debris discharged from the reactor core into the lower plenum region leading to a debris-bed formation is crucial in regard to in-vessel retention and safety concerns. The height of the beds formed may influence both the cooling of the bed from the decay heat in the fuel and the neutronic characteristics. To develop an experimental database of bed formation behavior, a series of experiments using simulant materials, namely, Al2O3, ZrO2, and stainless steel, were performed under gravity-driven discharge of solid particles from a nozzle into a quiescent cylindrical water pool. The bed height was measured for particles of different size, density, and sphericity, and an injection nozzle with varying diameter, injection velocity, and injection height. From these experiments, an empirical correlation was established to predict the bed height for both homogeneous and mixed particles for the different properties. This correlation reproduces reasonably well the experimental trend in bed height with critical factors, which were identified in this and previous experiments. 相似文献
828.
变压器用于信号隔离,并且将单端信号转换成差分信号。当在高速模数转换器(ADC)前端电路中使用变压器时常常忽略的一个问题是变压器绝非理想器件。任何由变压器引起的输入失衡都会使输入的正弦信号变成非理想的正弦信号波形传送给ADC的输入端,从而导致ADC的总体性能不如其它方式耦合到ADC的性能。本文讨论了变压器的输入失衡对ADC性能造成的影响,并且提供了改进电路的实例。1变压器制造商提供的多种多样的型号给变压器选择造成混乱。规定性能的供应商所采用的不同方法将问题复杂化;它们通常在选择和定义其规定的参数方面都不相同。当选… 相似文献
829.
Additive manufacturing is gaining ground in the construction industry. The potential to improve on current construction methods is significant. One of such methods being explored currently, both in academia and in construction practice, is the additive manufacturing of concrete (AMoC). Albeit a steadily growing number of researchers and private enterprises active in this field, AMoC is still in its infancy. Different variants in this family of manufacturing methods are being developed and improved continuously. Fundamental scientific understanding of the relations between design, material, process, and product is being explored. The collective body of work in that area is still very limited. After sketching the potential of AMoC for construction, this paper introduces the variants of AMoC under development around the globe and goes on to describe one of these in detail, the 3D Concrete Printing (3DCP) facility of the Eindhoven University of Technology. It is compared to other AMoC methods as well as to 3D printing in general. Subsequently, the paper will address the characteristics of 3DCP product geometry and structure, and discuss issues on parameter relations and experimental research. Finally, it will present the primary obstacles that stand between the potential of 3DCP and large-scale application in practice, and discuss the expected evolution of AMoC in general. 相似文献
830.