排序方式: 共有12条查询结果,搜索用时 15 毫秒
1.
2.
O. Paredes-López F. Guevara-Lara M. L. Schevenin-Pinedo R. Montes-Rivera 《Plant foods for human nutrition (Dordrecht, Netherlands)》1989,39(2):137-148
Micro-Kjeldahl, Lowry and Bradford procedures were compared for determining the protein content ofPhaseolus vulgaris seeds during their development. Micro-Kjeldahl and biuret techniques were also compared with mature seeds of a normal and a genetically-improved bean cultivar. The protein contents of casein and soy protein isolate were as well estimated by these four methods. For many samples of both bean and food protein products large disagreements were found between micro-Kjeldahl and the other three procedures. 相似文献
3.
The Bradford protein quantification assay is based on an absorbance shift in Coomassie brilliant blue G-250 (CBB). Samples extracted for glomalin, a protein produced by arbuscular mycorrhizal (AM) fungi, are quantified using the Bradford assay. CBB is known to react with polyphenolic substances, and co-extraction of glomalin and humic substances is known to occur. The effects of increasing concentrations polyphenolic compounds were measured. The addition of any amount of polyphenolic compounds increased the Bradford reactive fraction (BRF) of soil extract. Caution is required when interpreting BRF data, as comparison of BRF data from different studies or different field sites is problematic. The BRF may represent recalcitrant organic material in soil, though its relationship to AM fungi remains unclear. 相似文献
4.
5.
6.
介绍了布拉德福定律及测算模型构造,并对西昌学院图书馆农学(S)类文献核心出版社进行了测算,得到核心出版社为:中国农业出版社、金盾出版社、化学工业出版社、中国林业出版社。对西昌学院图书馆农学类核心文献采访发现,2011年的农学类图书采访仅限为核心出版社,应增加对布氏重要点区域的10家农学类重点出版社的采访。 相似文献
7.
核心期刊的确定需要借鉴本校教师的学科背景和研究领域。对教师论文的引文来源做分析,得出写论文时获取参考文献的特点和需求,并分别用布拉德福区域法和计算法确定引文源期刊的布拉德福离散系数和核心期刊数,综合比较得出核心区期刊。这样得到的核心区期刊更加有针对性,更加符合学校和读者的需求。 相似文献
8.
9.
对布拉德福定律合理性的思考 总被引:1,自引:0,他引:1
易祖民 《农业图书情报学刊》2011,23(1):146-148,179
学科复杂化发展趋势给布拉德福定律适用范围带来挑战,通过总结近年来对布拉德福定律本身及其合理性的一些研究,定性地分析说明布拉德福定律值得商榷,并提出布拉德福定律作为一个"经验定律"在实际研究与应用中应注意的问题,以期为今后对布拉德福定律乃至其他科学经验定律的研究与应用提供参考。 相似文献
10.
Carl L. Rosier 《Soil biology & biochemistry》2006,38(8):2205-2211
Despite the widely acknowledged importance of arbuscular mycorrhizal fungi (AMF) in soil ecology, quantifying their biomass and presence in field soils is hindered by tedious techniques. Hence biochemical markers may be useful, among which glomalin-related soil protein (GRSP) could show a particular promise. Presently GRSP is operationally defined, its identification resting solely on the methods used to extract it from soil (citric acid buffer and autoclaving) and the assays (Bradford/enzyme-linked immunosorbent assay (ELISA) with a monoclonal antibody) utilized to detect it. The current assumption is that most non-heat stable soil proteins except glomalin are destroyed during the harsh extraction procedure. However, this critical assumption has not been tested. The purpose of this research was to challenge the GRSP extraction process to determine the accuracy of the Bradford method as a measure of glomalin; and to provide some assessment of the specificity of the ELISA monoclonal antibody. In two studies we spiked soil samples either with known quantities of a glycoprotein (BSA: bovine serum albumin) or with leaf litter from specific sources. After extraction 41-84% of the added BSA was detected with the Bradford method. This suggests that the currently used extraction procedure does not eliminate all non-glomalin proteins. Also, ELISA cross-reactivity against BSA was limited, ranging from 3% to 14%. Additions of leaf litter also significantly influenced GRSP extraction and quantification suggesting that plant-derived proteins, as would occur in the field, had a similar effect as BSA. Litter additions decreased the immunoreactive protein values, suggesting interference with antibody recognition. We conclude that the use of GRSP, especially Bradford-based detection, in the assessment of AMF-derived substances within field soils is problematic, it may be inappropriate in situations of significant organic matter additions. 相似文献