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101.
Victor Manuel Duarte Zaragoza Rogelio Carrillo-González Maria Luisa Lozano Camargo Violeta Carrasco Hernández 《Soil & Sediment Contamination》2019,28(2):148-161
This study evaluated the effect of composted cow manure (CCM) on the chemical fractionation and retention degree of heavy metals (HMs) in mine tailings from Zimapán, México. In a greenhouse experiment, mine tailings from three deposits were incubated for 3 months; experimental units were placed in a PVC container, where increasing doses of CCM were applied. HM pseudo-total concentrations, HM extractions with ethylenediaminetetraacetic acid (EDTA, 0.05 M), and a sequential chemical extraction (SCE) were carried out. The HM concentrations were determined by atomic absorption spectrophotometry. The pseudo-total concentrations of Pb, Cu, Cd, and Ni found were up to 1506, 206, 27, and 23 mg kg?1, respectively; extractable Pb was up to 42%; 21% for Cu; 51% for Cd; and 16% of Ni of the pseudo-total concentrations of each metal. Treatment with 12% of CCM in mine tailing decreased EDTA-extractable HM concentrations, while the SCE revealed a decrease in exchangeable fraction and an increase in the organic fraction of HM. A positive correlation between CCM application and organic fractions of HMs was found, although the highest increasements were recorded in the organic fraction. 相似文献
102.
Microwave‐assisted extraction was employed to extract polyphenols from the leaf of Magnolia kwangsiensis Figlar & Noot . The yield of polyphenols was 2.44±0.02 % under the optimal conditions of RSM: acetone concentration of 70 %, ratio of solvent to material of 21 mL?g?1 and extraction time of 16 min. The antioxidant activities were evaluated in terms of total antioxidant ability, reducing power, DPPH ? and ? OH scavenging activity. Results showed the polyphenols presented potential antioxidant activities, especially the stronger scavenging activity on ? OH. In term of ? OH scavenging activity, the IC50 value of NKA‐9 purification was 0.335 mg mL?1, equivalent to 35.23 % of VC. The IC50 values of crude extract and ethyl acetate extract were 0.580 and 0.828 mg mL?1, equivalent to 60.99 % and 87.07 % of VC. Results indicated that M. kwangsiensis leaf polyphenols present potential antioxidant activities that make it beneficial for human health by preventing or reducing oxidative damage. 相似文献
103.
(S,S)‐DIOP, a common catalyst used in asymmetric reaction, was adopted as chiral extractant to separate 3‐chloro‐phenylglycine enantiomers in liquid‐liquid extraction. The factors affecting extraction efficiency were studied, including metal precursors, organic solvents, extraction temperature, chiral extractant concentration, and pH of aqueous phase. (S,S)‐DIOP‐Pd exhibited good ability to recognize 3‐chloro‐phenylglycine enantiomers, and the operational enantioselectivity (α) is 1.836. The highest performance factor (pf) was obtained under the condition of extraction temperature of 9.1°C, (S,S)‐DIOP‐Pd concentration of 1.7 mmol/L, and pH of aqueous phase of 7.0. In addition, the possible recognition mechanism of (S,S)‐DIOP‐Pd towards 3‐chloro‐phenylglycine enantiomers was discussed. 相似文献
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The abdominal hollowing technique is used for training the transversus abdominis (TrA). However, the optimal intensity of hollowing is still unclear. The objective of the present study is to verify the validity of estimating the tension of the TrA by measuring the girth of the abdomen with a tape and to determine the optimum intensity of hollowing to effectively train the TrA. Sixteen healthy males performed hollowing with an intensity of 0%, 25%, 50%, 75%, and 100%, estimated from the girth of the abdomen. The shear elastic modulus was measured for the rectus abdominis (RA), external oblique (EO), internal oblique (IO), and TrA at all intensities via ultrasonic shear wave elastography. The shear elastic modulus was considered as the index of the tension of the abdominal muscles at each intensity, and the ratio of the TrA to RA, EO, and IO respectively was calculated as the index of TrA selectivity. As the intensity of hollowing increased, the girth of abdomen decreased and tension of all the four muscles increased. The ratio of TrA to the RA, EO, and IO did not exhibit a significant variation among hollowing intensities of 25% to 100%. It is rational to estimate the tension of the TrA by measuring the girth of the abdomen. Moreover, considering both TrA contraction intensity and selectivity, abdominal hollowing performed at maximum intensity was effective for the maximum contraction training of the TrA. 相似文献
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木本植物基因组DNA提取及鉴定 总被引:13,自引:0,他引:13
采用改良后的CTAB法,对山葡萄、软枣猕猴桃、蒙古栎、核桃楸、西伯利亚红松和偃松基因组DNA进行提取。结果表明,所提基因组DNA分子量与λDNA(48 kb)接近,其紫外吸收比在1.66~1.89之间。第3次和第4次上清提取的DNA质量优于第1次和第2次。从提取产量看,每克鲜重提取DNA量最小为15 μg·g-1(核桃楸第4次上清),最高的为272 μg·g-1(山葡萄第3次上清)。西伯利亚红松和偃松第1次和第2次上清基本未提出DNA,第3次和第4次上清中得到了较高质量的DNA。经酶切鉴定和PCR扩增,所提的基因组DNA可以用于进一步研究。 相似文献
109.
适用于盐生植物的双向电泳样品制备方法 总被引:13,自引:0,他引:13
比较了三氯乙酸,丙酮沉淀法(TCA)、三氯乙酸沉淀法(E-TCA)和酚抽法(Phe)3种方法对盐生植物盐角草(Salicornia europaea L.)总蛋白的提取效果。3种方法分别得到579、343和535个蛋白点;TCA和E-TCA法所得图谱均存在严重的横向纹理,Phe法所得图谱则背景干净,基本上没有纹理。说明Phe法不仅能很好地提取盐角草蛋白,而且能有效去除样品中的盐分。对Phe法的提取液进行了改进,所得图谱背景更加清晰,蛋白点数增加。为其他盐生植物以及嗜盐微生物蛋白质的提取提供了重要参考。 相似文献
110.
利用高效液相色谱法测定尿囊素的含量,本文采用正交实验,对白刺种子尿囊素的提取工艺进行了优化.结果表明各因素对尿囊素的提取效果的影响程度为乙醇浓度>温度>料液比>提取时间>提取次数.从而确定白刺种子中尿囊素的最佳提取工艺为乙醇浓度为60%,料液比为1∶12(W/V),提取温度为80℃,提取时间为1 h,重复提取3次. 相似文献