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61.
Morteza Hosseini Freshteh Khaki Ehsan Shokri Hossein Khabbaz Mehdi Dadmehr Mohammad Reza Ganjali Mina Feizabadi Davood Ajloo 《Journal of fluorescence》2017,27(6):2059-2068
A novel sensitive method for detection of DNA methylation was developed with thioglycollic acid (TGA)-capped CdTe quantum dots (QDs) as fluorescence probes. Recognition of methylated DNA sites would be useful strategy due to the important roles of methylation in disease occurrence and developmental processes. DNA methylation occurs most often at cytosine-guanine sites (CpG dinucleotides) of gene promoters. The QDs significantly interacted with hybridized unmethylated and methylated DNA. The interaction of CpG rich methylated and unmethylated DNA hybrid with quantum dots as an optical probe has been investigated by fluorescence spectroscopy and electrophoresis assay. The fluorescence intensity of QDs was highly dependent to unmethylated and methylated DNA. Specific site of CpG islands of Adenomatous polyposis coli (APC), a well-studied tumor suppressor gene, was used as the detection target. Under optimum conditions, upon the addition of unmethylated dsDNA, the fluorescence intensity increased in linear range from 1.0?×?10??10 to 1.0?×?10??6M with detection limit of 6.2?×?10??11 M and on the other hand, the intensity of QDs showed no changes with addition of methylated dsDNA. We also demonstrated that the unmethylated and methylated DNA and QDs complexes showed different mobility in electrophoresis assay. This easy and reliable method could distinguish between methylated and unmethylated DNA sequences. 相似文献
62.
Mehrorang Ghaedi Morteza Montazerozohori Mehdi Nejati Biyareh Kianoosh Mortazavi Mostafa Soylak 《International journal of environmental analytical chemistry》2013,93(5):528-542
Multiwalled carbon nanotubes chemically functionalized with 2-((3-silylpropylimino) methyl) phenol (SPIMP-MWCNT) and successfully applied for the solid phase extraction (SPE) of some metal ions in food samples. The influences of the analytical parameters including pH, amounts of solid phase, eluent conditions (type, volume and concentrations), sample volume and interference of some metal ions on the recoveries of ions Cu2+, Pb2+, Fe2+, Ni2+ and Zn2+ ion were investigated. The metal ions retained on SPIMP-MWCNT was eluted using 6?mL of 4?mol?L?1 HNO3 solution and their content was determined by flame atomic absorption spectrometry (FAAS) with recoveries more than 95% and relative standard deviations (n?=?5) between 2.4–3.4% for both reproducibility and repeatability. The detection limit of this metal ions was between 1.0–2.6?ng?mL?1 (3S b , n?=?10) and their preconcentration factor was 100, while their loading capacity was above 32.9?mg?g?1 of SPIMP-MWCNT. The proposed method was successfully applied for the preconcentration and determination of analytes in different samples. 相似文献
63.
Morteza Moniri 《Archive for Mathematical Logic》2002,41(1):101-105
For a classical theory T, ℋ(T) denotes the intuitionistic theory of T-normal (i.e. locally T) Kripke structures. S. Buss has asked for a characterization of the theories in the range of ℋ and raised the particular
question of whether HA is an ℋ-theory. We show that T
i
∈ range(ℋ) iff T
i
= ℋ(T). As a corollary, no fragment of HA extending iΠ
1 belongs to the range of ℋ. A. Visser has already proved that HA is not in the range of H by different methods. We provide more examples of theories not in the range of ℋ. We show PA-normality of once-branching Kripke models of HA + MP, where it is not known whether the same holds if MP is dropped.
Received: 15 August 1999 / Published online: 3 October 2001 相似文献
64.
Oxidative deprotection of a variety of trimethylsilyl ethers were performed by Fe(NO3)3.9H2O in the presence of H3PMo12O40.xH2O as catalyst at room temperature in good to high yields under solvent‐free conditions. 相似文献
65.
The effect of calcination temperature on the activity and some properties of low temperature water gas shift reaction catalysts
has been investigated. The activities of catalysts have been determined using a fixed bed catalytic reactor. The following
results may be deduced from the present study. 1. The catalysts' total surface area decreased with increasing calcination
temperature, presumably due to the partial sintering of the catalysts particles. 2. The presence of an amorphous CuO phase
within the structure of some catalysts may be related to the desirable conditions prevailing during synthesis of the latter.
3. Observation of a similar trend between the increase in copper crystallite particle size and enhancement of catalyst activities
with increasing calcination temperature demonstrates the important contribution made by the copper crystallite phase to the
overall activities of water gas shift reaction catalysts.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
66.
Intraelemental relative photoelectron line intensities for 20 pure elements obtained under ultrahigh vacuum (5·10?9 torr) and high resolution with cleaned surfaces are presented. Theoretical and experimental aspects of relative photoelectron line intensities as well as other characteristics of significance to quantitative analysis are discussed. Experimental data are related to theoretical results and compared with other recent work. 相似文献
67.
Oxidative electrochemical detection is used for liquid chromatographic separation of polynuclear aromatic hydrocarbons (PAH's). The amperometric response is shown to be dependent on the working potential, ionic strength, flow rate, pH, temperature and pretreatment of the glassy carbon electrode surface. These experimental factors were optimized by choosing the maximum signal-to-noise ratio for anthracene and benz(a)-anthracene. The figures of merit (sensitivity, limit of detection and linear dynamic range) of six PAH's are reported and compared with ultraviolet absorption detection. Varying the applied potential gives the capability for selective detection. 相似文献
68.
Tungstate sulfuric acid (TSA)/KMnO4 as a novel heterogeneous system for rapid deoximation 总被引:1,自引:0,他引:1
Neat chlorosulfonic acid reacts with anhydrous sodium tungstate to give tungstate sulfuric acid (TSA), a new dibasic inorganic solid acid in which two sulfuric acid molecules connect to a tungstate moiety via a covalent bond. A variety of oximes were oxidized to their parent carbonyl compounds under mild conditions with excellent yields in short times by a heterogeneous wet TSA/KMnO4 in dichloromethane system. 相似文献
69.
Morteza Moniri 《Archive for Mathematical Logic》2010,49(3):291-300
In this paper we prove conservation theorems for theories of classical first-order arithmetic over their intuitionistic version.
We also prove generalized conservation results for intuitionistic theories when certain weak forms of the principle of excluded
middle are added to them. Members of two families of subsystems of Heyting arithmetic and Buss-Harnik’s theories of intuitionistic
bounded arithmetic are the intuitionistic theories we consider. For the first group, we use a method described by Leivant
based on the negative translation combined with a variant of Friedman’s translation. For the second group, we use Avigad’s
forcing method. 相似文献
70.
Morteza Sadeghi Homayoon Moadel Somaieh Khatti Behnam Ghalei 《Journal of Macromolecular Science: Physics》2013,52(6):1128-1135
The sorption behaviors of sulfuric, perchloric, and phosphoric acids in polybenzimidazole membranes have been investigated. The results of sorption isotherms are consistent with the general form of a dual-mode sorption isotherm. The dual-mode sorption parameters were found using a least-squares program by fitting experimental data to a dual-mode equation. Results indicate a correlation between permeant properties like acidity, size, and the affinity constant in Langmuir-mode sorption species. Moreover, the results show that the size of the permeants has the dominant effect on Henry's constant. The obtained results for , site saturation constant, in Langmuir-mode sorption in the case of perchloric and phosphoric acids, reveals that the two acid molecules interact with two N?H basic groups in the polybenzimidazole repeat units. But in the case of sulfuric acid, it is shown that sulfuric acid neutralizes some of the basic groups in the polymer by its strong second hydrogen and the obtained value for was 1.25. 相似文献