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991.
Peix A Rivas R Velázquez E Mateos PF Martínez-Molina E Muñoz-Herrera A Gómez-Alonso A Velázquez E 《Electrophoresis》2005,26(23):4402-4410
The random intergenic spacer analysis is a recently developed technique for the study of microbial populations. The bacterial intergenic spacer (ITS) is located between 16S rRNA and 23S rRNA genes and presents different length and sequence among bacterial species. Therefore, the amplicons can be separated by electrophoresis commonly performed at low voltage during several hours. Although this technique is especially useful for unculturable microorganisms, it has not been applied before to clinical sample analysis. As these samples have a limited number of bacterial species, the size of the gels may be reduced to facilitate their handling and to reduce the running time. To obtain maximum separation among the ITS bands, we analysed in this work different electrophoretical conditions including staircase electrophoresis, a technique based on the application of several voltage steps. The results obtained showed a different behaviour of the electrical resistance during the performance of submarine horizontal and vertical staircase electrophoresis. In the first case the resistance decreased during most of the running time whereas in the second case it increased. Here, we show that the performance of horizontal staircase electrophoresis reduces the running time more than 80% with respect to conventional electrophoresis at low voltages. This procedure was applied to the separation of ITS bands from bacterial DNA present in a tissue from a vocal cord biopsy. The sequencing of these bands allowed their identification. This new procedure may be very useful in the rapid diagnosis of bacteria present in human, animal and plant tissues. 相似文献
992.
Summary A thermodynamic criterion, Q, is suggested which permits to estimate the difference in the functional group energy of interactions for two different stationary phases. The linear dependence of Q on the homolog number m of any series Rm X can be used as the thermodynamic criterion for the identification of substances by GC analysis.Enlarged text of the paper presented at the Fourth Danube Symposium on Chromatography, Bratislava, Czechoslovakia, September 1983. 相似文献
993.
994.
The title compound [Cu(C11H29N5)](ClO4)2 was synthesized and characterized by elemental analysis,IR and X-ray single-crystal diffraction.The compound crystallizes in the monoclinic system,space group P21/n with a = 9.405(2),b = 14.495(3),c = 14.715(3)(A),β = 90.262(3)°,V =2006.1(7)(A)3,Mr = 493.83,Z= 4,F(000) = 1028,Dc= 1.635 g/cm3,T= 298(2) K,μ = 1.403 mm-1 and λ = 0.71073(A).The structure was refined to R = 0.0508 and wR = 0.1250 for 2293 observed reflections with I > 2σ(I).The Cu(Ⅱ)atom possesses a five-coordinate CuN5 environment which shows a slightly distorted square-pyramidal geometry.Antimicrobial activity study found that the complex is active against Salmonella species,Staphylococcus aureu,Bacillus pumilus and Bacillus coliforms. 相似文献
995.
996.
Spectroscopic investigations have been undertaken on the effects of lanthanide ions on the spectrum of the anticancer agent, daunomycin. The visible spectral perturbations due to the metal ions resulted in hypochromic effects in the 480 nm region and in shifts towards longer wavelength. The different metal ions investigated did not give any significant difference in the, spectral character. Data analysis according to the methods of molar ratio, continuous variation and graphical approaches based on simplex matrix theory indicated the presence of predominantly a ML2 species at metal to ligand ratios, less than one. Data also suggested the presence of ML and ML3 as well. 相似文献
997.
饮料中总砷的测定及其价态形态分析 总被引:6,自引:0,他引:6
本文采用新银盐光度法,通过对样品的全消解、改变氢化物发生的介质和酸度等方法,成功地对同一样品中砷总量、砷的价态和砷的形态进行了分析。三价砷和无机砷总量的检出限分别为0.1和0.2ppb(3S),相关系数r_1=0.9995、r_2=0.9998。样品中砷总量(无机砷和有机砷)和无机砷总量(As(Ⅲ)和As(Ⅴ))的回收率分别为95~105%和100%,适用于饮料中超痕量砷的全分析。 相似文献
998.
Elif Varhan Oral Özge Tokul-Ölmez İsmail Yener Mehmet Firat Zeki Tunay Pınar Terzioğlu 《Analytical letters》2019,52(2):320-336
Aerial parts and roots of the 12 Allium species collected from five localities of Turkey were studied for trace elements (Ag, As, Cd, Co, Cr, Cu, Ni, Pb, Se, Tl, V, and Zn) using inductively coupled plasma mass spectrometry (ICP-MS). A tomato leaves certified reference material was used to characterize the accuracy and precision of the analysis. Each Allium species contained Se (315–2740?µg/kg), Tl (2.75–71?µg/kg), V (77–6790?µg/kg), and Zn (3.73–26.6?mg/kg) which can meet the necessary daily intake of these minerals. In addition, chemometric analyses were performed using correlation analysis, principal component analysis, and hierarchical cluster analysis to determine the association of 12 trace elements in the Allium species. Using chemometrics, the distribution of elements between aerial parts and roots, and geographic collection localities of Allium species were also examined. This study is important the consumers because of the wide consumption of Allium species. This report is the first detailed characterization of the metal content of Allium species. 相似文献
999.
评述了Ge-132定性方法的文献资料。实验证明对于Ge-132的定性方法,除了用荧光酮检测Ge外,羧基的鉴定也是必要的。 相似文献
1000.
Transients of currents during the adsorption of CO on polycrystalline (pc) Pt in solutions of H2SO4 and H2SO4 + HCl are measured at a constant potential. The obtained values are compared with relevant reference data for Pt electrodes. Possible reasons for the established differences are discussed. Transient currents for the methanol adsorption on pcPt and Pt/Pt are compared. A method for correct determination of the composition of a chemisorption layer, which forms during dissociative adsorption of simple organic compounds of the type of RH
m
, is considered. Experimental data on the methanol adsorption suggest that adsorption products on pcPt are chiefly species of CO. On Pt/Pt, at low potentials, in addition to CO one should assume the adsorption of species of HCO in perceptible amounts. 相似文献