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151.
The potential of peptidase-containing bran extracts from germinated cereals (wheat, emmer, barley) and a peptidase preparation from Aspergillus niger (AN-PEP) to degrade gluten in wheat starch below the threshold for gluten-free foods of 20 mg/kg was compared. The gluten-specific peptidase activity of the peptidases was determined by using gliadin as a protein-based substrate as well as the two celiac-active peptides PQPQLPYPQPQLPY (α-gliadin) and SQQQFPQPQQPFPQQP (γ-hordein). The peptidase activity of AN-PEP exceeded the activities of bran from germinated cereals by a factor up to 690,000. Three wheat starches with initial gluten contents of 110, 1679, and 2070 mg/kg, respectively, were incubated with bran extracts and AN-PEP, lyophilized, and residual gluten was quantitated by a competitive ELISA. Unlike peptidases from bran extracts, AN-PEP was capable of degrading gluten below 20 mg/kg in all starches. The absence of gluten in AN-PEP-treated starches was confirmed by liquid-chromatography-mass spectrometry. The properties of gluten-free starches were comparable to the native starches with the exception of a reduced viscosity after AN-PEP treatment. This problem could be overcome by using higher enzyme concentrations and shorter incubation times or by optimizing AN-PEP production for lower residual α-amylase activity. 相似文献
152.
Bruno B. Chomel Jennifer B. Henn Rickie W. Kasten Nathan C. Nieto Janet Foley Sophia Papageorgiou Claire Allen Jane E. Koehler 《Veterinary research》2009,40(4)
Bartonella rochalimae was first isolated from the blood of a human who traveled to Peru and was exposed to multiple insect bites. Foxes and dogs are likely natural reservoirs for this bacterium. We report the results of experimental inoculation of two dogs, five cats and six guinea pigs with the only human isolate of this new Bartonella species. Both dogs became bacteremic for 5–7 weeks, with a peak of 103–104 colony forming units (CFU)/mL blood. Three cats had low bacteremia levels (< 200 CFU/mL) of 6–8 weeks’ duration. One cat that remained seronegative had two bacterial colonies isolated at a single culture time point. A fifth cat never became bacteremic, but seroconverted. None of the guinea pigs became bacteremic, but five seroconverted. These results suggest that dogs could be a reservoir of this strain of B. rochalimae, in contrast to cats and guinea pigs. 相似文献
153.
西藏草地资源价值及退化损失评估 总被引:3,自引:0,他引:3
用4类共13个指标评估了西藏草地资源的价值,并根据草地资源退化速率评估了草地价值年损失量.结果表明,西藏草地资源的价值为1080.33×108元·a-1,包括:调节功能价值884.4989×108元·a-1(81.87%);实物提供价值173.2957×108元·a-1(16.04%);支持功能价值18.6253×108元·a-1(1.72%);旅游功能价值3.91×108元·a-1(0.36%).其中,调节功能的价值由6项组成(空气质量调节未计算),依大小次序排列为土壤碳累积、蓄水、营养物质循环、土壤保持、废弃物降解和养分归还.总体来看,草地资源的文化功能和支持功能有待进一步发展.西藏草地资源的总价值(现值)为11883.63亿元,退化损失的价值为2376.726亿元,年草地资源退化损失价值为297.091亿元. 相似文献
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157.
Koehler A 《Science (New York, N.Y.)》1924,60(1562):525-526
158.
Data for 85 soil profiles, located at random within 17 physiographic units in a 1,000 km2 area near Oxford, and each characterized by 37 properties, were analysed by two sets of multivariate techniques. Principal component analysis yielded two components accounting for 44 per cent of the total variation, and the distribution of the profiles along these components is plotted as a scatter diagram (ordination). Similarity analysis and hierarchical grouping (classification) were performed using three different similarity indices, two different standardization techniques, and three different sorting strategies. Before analysis the profiles were classified by two pedologists, independently using their judgement. For the Brown Earths there was moderately good agreement between the results of the two prior classifications and between them and those produced by the several numerical procedures. The degree of clustering was slight and much less than imagined prior to analysis. For the Gleys there was no evident clustering. Different numerical procedures gave different results, as also did the two prior classifications. Pedologists faced with difficult classificatory decisions cannot look to any hierarchical clustering strategy as arbiter, though they should get guidance from a principal component plot. 相似文献
159.
Fibrous radial aragonite nodules occur in a toposequence developed in the Triassic (Keuper) in a subhumid mediterranean climate (Soria, Spain). Neoformation in situ of the nodules in these soils is proposed, on micromorphological and physico-chemical grounds, such as their fragility, the inclusion of material from the groundmass, their occurrence along cracks and their high Mg: Ca ratio. 相似文献
160.