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排序方式: 共有339条查询结果,搜索用时 15 毫秒
1.
A Triton X-100-4.0G-D (4.0G-D refers to a 4.0-generation dendrimer) was brought forward as a new phosphorescence labeling reagent. Two types of specific affinity adsorption (AA) reactions (direct method and sandwich method) were carried out between the labeling product of Triton X-100-4:0G-D-Wheat germ agglutinin (WGA) and alkaline phosphatase (ALP), the product of AA reaction preserved the good characteristics of room temperature phosphorescence (RTP) of 4.0G-D and △Ip of the product was proportional to the content of ALP. According to the fact stated above, a new method for the determination of trace ALP by affinity adsorption solid substrate-room temperature phosphorimetry (AA-SS-RTP) was established on the basis of WGA labeled with the Triton X-100-4.0G-D. The detection limits were 0.20 ag·spot^-1 (corresponding concentration: 5.0×10^-16 g·mL^-1, namely 5.0×10^-18 mol·L^-1) for a direct method and 0.14 ag·spot^-1 (corresponding concentration: 3.5×10^-16 g·mL^-1, namely 3.5×10^-18 mol·L^-1) for a sandwich method, respectively. For their high sensitivity, good repeatability and high accuracy, the direct method and sandwich method have been successfully appfied to determine the content of ALP in human serum, and the results were coincided with the clinical detection results of the enzyme-linked immunosorbent assay method by the Zhangzhou Hospital of Traditional Chinese Medicine. Meanwhile, the mechanism for the determination of trace ALP by AA-SS-RTP was discussed. 相似文献
2.
《Arabian Journal of Chemistry》2022,15(1):103472
As a representative of traditionally fermented Chinese medicine, Massa Medicata Fermentata (MMF) shows the functions of invigorating the spleen and stomach and promoting digestion, which plays an important role in the treatment of gastrointestinal diseases. The fermentation mechanism and the key factors that affect the quality of MMF have not been revealed yet, which has become an urgent issue that limits its clinical application. This article aims to systematically and comprehensively reveal the transformation of physical properties and the dynamic trend of chemical components including substrate components, volatile components, and lactic acid as anaerobic fermentation product during MMF fermentation. Along with obvious hyphae growth observed for MMF, the weight of MMF decreased, and the moisture and temperature increased. Through the quantified 14 components from substrate, ferulic acid increased from 45.53 ± 6.94 to 141.89 ± 78.40 μg/g, while glycosides and phenolic acids declined except caffeic acid. Also, within the 66 volatile components analyzed, alcohols and acids increased, while aldehydes and ketones decreased. Lactic acid was not detected in the fermentation substrate, but an apparent increase in lactic acid content was observed along with the increased fermentation days, resulting in 2.54 ± 0.15 mg/g on day 8. Based on the tested components, the fermentation process of MMF was discriminated into three distinct stages by principal component analysis, and an optimal fermentation time of four days was proposed. The results of this study will be of great significance to clarify the characteristics of fermentation and conduce to improving quality standards of MMF. 相似文献
3.
Protoplasts were isolated from embryogenic calli derived from immature embryos ofwheat (Triticum aestivum L. cv. Jinan 177). The protoplasts were cultured in NMB mediumsupplemented with 1mg/L 2,4- D and 500mg/l casein hydrolysate (CH). The regenerated cellsfrom protoplasts divided to form somatic embryos directly. The somatic embryos grown to1.5- 2 mm in size directly developed into complete plants on solid MB medium without hor-mones. 相似文献
4.
The procedure and method for the transfer of two sets of 14 pairs of wheatgrass (Agropyron interrnedium) chromosomes into common wheat to establish two sets of wheat-wheatgrass alien addition lines are reported. Meanwhile, observations and analyses have been made on the phenotypicaI characters of all the 14 alien addition lines established. It is determined that wheatgrass chromosomes in some of the established addition lines carry the rustresistant genes. In addition, questions concerning the location and distribution of certain agriculturally important genes of wheatgrass chromosomes have been discussed. 相似文献
5.
A kinetic method for the determination of selenium(IV) traces is proposed, based on its inhibitory action on the oxidation of Nile Blue A by hydrogen peroxide in phosphate buffer (pH 10.5). A linear dependence was established between the rate of the proposed indicator reaction and selenium concentration in the range 9.5 × 10–2-1.58 ng cm–3. The experimental conditions of maximal selenium effect were established. Selenium, determined by the tangent method, was determined at concentrations over the range 0.22–1.26 ng cm–3, with relative standard deviations up to 4.5%. The reaction rate was followed spectrophotometrically. The effect of foreign ions on the accuracy of this method was also investigated. The method was applied to the determination of selenium in pharmaceutical preparations and wheat flour. 相似文献
6.
铕对小麦根细胞钙调素及NAD激酶的影响研究 总被引:2,自引:0,他引:2
研究了Eu对小麦根细胞内钙调素的含量和活性以及对受钙调素调控的专一性酶NAD激酶的影响。结果表明,Eu^3+有类似Ca^2+的作用,影响受Ca^2+浓度调控的信号系统关键蛋白——钙调素的活性和含量变化。从而引起钙调素调控酶NAD激酶的活性改变,最终影响细胞内生理生化过程。认为稀土离子对生物体的Hormesis效应町能与稀土离子对细胞信号传递系统的影响有关,稀土离子可能通过影响细胞信号系统来调节细胞内的各种生理生化变化,形成稀土元素生物效应的多样性特征。 相似文献
7.
Persson A Garde A Jönsson AS Jonsson G Zacchi G 《Applied biochemistry and biotechnology》2001,94(3):197-211
The conversion of sodium lactate to lactic acid with water-splitting electrodialysis was investigated. One way of reducing
the power consumption is to add a conductive layer to the acid compartment. Doing this reduced the power consumption by almost
50% in a two-compartment cell, whereas the electric current efficiency was not affected at all. Three different solutions
were treated in the electrodialysis unit: a model solution with 70 g/L of sodium lactate and a fermentation broth that had
been prefiltered two different ways. The fermentation broth was either filtered in an open ultrafiltration membrane (cut-off
of 100,000 Dalton) in order to remove the microorganisms or first filtered in the open ultrafiltration membrane and then in
an ultrafiltration membrane with a cut-off of 2000 Dalton to remove most of the proteins. The concentration of sodium lactate
in the fermentation broth was 70 g/L, as well. Organic molecules present in the broth (peptides and similar organic material)
fouled the membranes and, therefore, increased power consumption. Power consumption increased more when permeate from the
more open ultrafiltration membrane was treated in the electrodialysis unit than when permeate from the membrane with the lower
cut-off was treated, since there was a higher amount of foulants in the former permeate. However, the electrodialysis membranes
could be cleaned efficiently with a 0.1 M sodium hydroxide solution. 相似文献
8.
优质农产品溯源系统的引入,既能提升有效供给、缩短流通时间,又能降低流通中的数量损耗和价值损失,由此带来了双渠道供应链系统在投资、销售、定价等方面的系列决策问题。考虑制造商开辟电子渠道、从溯源系统降低流通损耗和提高质量出发,分别构建制造商主导型的双渠道供应链决策模型。通过对比分析应用前后各成员在投资、定价及销售方面的最优策略,得到相关的核心边界值。数值仿真结果表明:核心边界值主要与双重损耗的改善程度及其他参数相关,各成员及系统接受溯源系统的应用成本不同,应用成本对各渠道销量的影响程度亦不相同,但各成员调整定价的应用成本边界值是一致的。 相似文献
9.
Priyabrata Das Suvra Mandal Sudeshna Gangopadhyay Kalipada Das Arpita Ghosh Mitra Swati Dasgupta 《Natural product research》2016,30(4):474-477
Methylphophorbide a (MPa) has been isolated from the ethanol extract of the wheat grass plant. Its antioxidative efficacy is evaluated by hydroxyl radical scavenging activities and reducing capacity which are significantly up regulated in comparison with aqueous extract of the plant. The compound shows iron-binding capacity where the Fe2+ binds with MPa by two types of binding patterns with dissociation constants 157.17 and 27.89. It has antioxidative and cytotoxic effects on HeLa and Hep G2 cells. The cancerous cell survivability decreases with increasing concentration of MPa. These findings have provided evidence for the traditional use of the wheat grass plant in the treatment of cancers, oxidative stress and iron overloaded disorders. 相似文献
10.
以核心期刊《化学教育》2018-2021年高中化学教学设计及实施类文献为研究对象,在较完备的教材分析视角指引下,采用内容分析法研究优质教学案例中教材分析的现状及特点,在此基础上构建教材分析模型,探索优质教学案例的设计路径。 相似文献