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短链脂肪酸(Short-Chain Fatty Acids, SCFAs)是膳食纤维在肠道中经微生物代谢后的主要终产物,是肠道微生物与宿主间重要的信息传递使者。SCFAs作为关键介质直接或间接在机体多个器官和组织中发挥着重要的生理作用,其准确定量对于研究生物体内SCFAs的产生、变化规律,对于揭示肠道微生物与人类健康之间复杂关系具有重要的意义。SCFAs在人体内分布广泛,具有分子量小、易挥发、紫外吸收弱等特点,且不同生物样品之间种类及含量相差较大,因此SCFAs分析检测方法一直是研究的难点。在系统介绍SCFAs的来源、种类及分布的基础上,对其常用的分析检测方法进行总结,以期为进一步开发高效和灵敏的SCFAs分析方法提供参考。 相似文献
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三氟乙酸的生物累积效应和持久污染性已经成为关注的热点,对其进行监测至关重要。本文综述了环境样品中三氟乙酸分析方法,讨论了样品的预处理技术和检测方法。 相似文献
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多环芳烃(PAHs)是一种广泛存在于环境中的污染物。PAHs通过分配、沉降、迁移等过程,影响其在环境中的分布特征,从而对人类健康存在很大的潜在危害。文章主要从气相色谱,高效液相色谱及酶联免疫吸附法对PAHs的分析方法进行了概述。 相似文献
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脱氢表雄酮及其代谢产物脱氢表雄酮硫酸酯是人体重要的甾体激素,准确定量检测人体生物基质中的含量对临床生理、心理疾病的诊断具有重要意义。本文介绍了近几年国内外先进的检测技术,并分析了各个方法的优缺点,指出气相色谱-质谱法适合检测物含量低的生物样品检测,而液相色谱-质谱法的应用范围最广。 相似文献
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催化极谱法测定生物样品中的微量硒 总被引:1,自引:0,他引:1
建立了测定生物样品中微量硒的催化极谱法。试验发现Se(Ⅳ)与谷胱甘肽在-0.94 V(vs.SCE)处形成一个灵敏的极谱催化波。Se(Ⅳ)浓度在4.0×10-7~8.0×10-6mol/L的范围内,峰电流与Se(Ⅳ)浓度呈线性关系。Se(Ⅳ)的检出限为2.0×10-7mol/L,相对标准偏差均小于5%。此法简便、快速、灵敏,结果准确。 相似文献
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Andrés Izquierdo M. D. Luque de Castro Miguel Valcárcel 《Journal of Automated Methods and Management in Chemistry》1993,15(4):121-125
An automatic-continuous method for the simultaneous determination of copper and lead based on flow injection analysis (FIA) and stripping voltammetry (SV) is proposed. The method affords the determination of the analytes at the ng/ml level (linear ranges 0.64 to 64.0 ng/ml and 2.1 to 62.2 ng/ml for copper and lead, respectively) with good precision (r.s.d. values smaller than 4%). The selectivity of SV allows the method to be applied to the determination of these analytes in bovine liver fresh samples and certified reference materials from the National Institute for Standards and Technology and the Community Bureau of Reference. The performance of the method was assessed by repeatability and validation statistical studies. 相似文献
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Fahmida Irin Babina Shrestha Jaclyn E. Cañas Mohammad A. Saed Micah J. Green 《Carbon》2012,50(12):4441-4449
We demonstrate a novel technique for quantitative detection of carbon nanotubes (CNTs) in biological samples by utilizing the thermal response of CNT under microwave irradiation. In particular, rapid heating of CNT due to microwave absorption is employed to quantify CNT uptake in agricultural samples with excellent sensitivity. We inject alfalfa (Medicago sativa) roots with a known quantity of CNT (single-walled and multi-walled) and expose the samples to a microwave field (30–50 W) to generate standard temperature-CNT concentration relationships; this detection method is then used to accurately determine CNT uptake by alfalfa plant roots grown in CNT-laden soil. The threshold for detectable CNT concentration is much lower (<0.1 μg) than common analytical methods such as electron microscopy and Raman spectroscopy. Considering the lack of effective detection methods for CNT uptake in plants, our concept is not only unique but also practical, as it addresses a major problem in the field of nanomaterial characterization and nanotoxicology risk assessment. 相似文献
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清洁能源对于缓解能源环境压力有重要意义,而生物电化学研究在清洁能源领域受到人们重视。生物电化学是以生物体系的研究及其控制和应用为目的,并融合了生物学、电化学和化学等多门学科交叉形成的一门独立的学科,是在分子水平上研究生物体系荷电粒子(可能包括非荷电粒子)运动过程所产生的电化学现象的科学。在能源环境领域,生物电化学研究环境有机污染物化学能回收,如微生物电解池(microbial electrolysis cells,MECs),氢能的回收同时完成污染物的处理。本文介绍了微生物电解池制氢的基本原理、电极材料产氢评价指标;MECs系统不同结构对产氢效能的影响的比较,MECs实际应用中所存在的问题;提出了今后微生物电解池在制氢方面的发展趋势和研究方向及在制氢方面的应用前景。 相似文献
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Tikole S Jaravine V Rogov VV Rozenknop A Schmöe K Löhr F Dötsch V Güntert P 《Chembiochem : a European journal of chemical biology》2012,13(7):964-967
Faster than death: NMR techniques that make use of nonlinear sampling and hyperdimensional processing enable the recording of complete NMR data sets for the automated assignment of the backbone and side-chain resonances of short-lived protein samples of cell lysates. 相似文献
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A rapid and quantitative method for total fatty acid analysis of fungi and other biological samples 总被引:3,自引:0,他引:3
A quantitative method for the one-step esterification and determination of absolute amounts of polyunsaturated fatty acids
in biotechnologically produced fungal mycelia is proposed. A system of two internal standards was used to quantify the total
fatty acid content of the samples by gas chromatography. The degree of methylation of the analyzed fatty acids was calculated
using the internal standards, and subsequently this quotient was used to validate the derivatization and extraction reactions.
By utilizing this degree of methylation, the corrected amounts of the various fatty acids in the sample can be calculated. 相似文献
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废水生物处理系统中胞外多聚物的研究进展 总被引:1,自引:0,他引:1
胞外多聚物(extracellular polymeric substances,EPS)是一类具有特殊形态和结构的高分子化合物。EPS普遍存在于生物聚集体内,是生物聚集体形成与稳定的关键性物质,对废水生物处理系统的稳定运行具有重要作用。文章归纳总结了EPS的组分、结构特性、可生物降解性及其吸附特性等方面的研究成果;重点从EPS的主要组成物质胞外蛋白(extracellular protein,PN)和胞外多糖(extracellular polysaccharide,PS)以及结构特性中紧密附着型EPS(tightly bound EPS,TB-EPS)和松散附着型EPS(loosely bound EPS,LB-EPS)的研究出发,论述了EPS对生物聚集体的影响,适当升高PN和PS的含量有助于污泥絮凝,然而过多的PS含量将可能对污泥的沉降与脱水性能起负面影响。文章还分析了其影响机理,PN和PS能够有效促进污泥絮凝可能是由于PN表面电负性和高疏水性的影响以及PS的生物凝胶特性和吸附架桥作用。 相似文献