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91.
In this paper, the evolution equations with nonlinear term describing the resonance interaction between the long wave and
the short wave are studied. The semi-discrete and fully discrete Crank-Nicholson Fourier spectral schemes are given. An energy
estimation method is used to obtain error estimates for the approximate solutions. The numerical results obtained are compared
with exact solution and found to be in good agreement. 相似文献
92.
Measurement of the length of DNA fragments plays a pivotal role in genetic mapping, disease diagnostics, human identification and forensic applications. PCR followed by electrophoresis is used for DNA length measurement of STRs, a process that requires labeled primers and allelic ladders as standards to avoid machine error. Sequencing‐based approaches can be used for STR analysis to eliminate the requirement of labeled primers and allelic ladder. However, the limiting factor with this approach is unsynchronized polymerization in heterozygous sample analysis, in which alleles with different lengths can lead to imbalanced heterozygote peak height ratios. We have developed a rapid DNA length measurement method using peptide nucleic acid and dideoxy dNTPs to “tailor” DNA templates for accurate sequencing to overcome this hurdle. We also devised an accelerated “dyad” pyrosequencing strategy, such that the combined approach can be used as a faster, more accurate alternative to de novo sequencing. Dyad sequencing interrogates two bases at a time by allowing the polymerase to incorporate two nucleotides to DNA template, cutting the analysis time in half. In addition, for the first time, we show the effect of peptide nucleic acid as a blocking probe to stop polymerization, which is essential to analyze the heterozygous samples by sequencing. This approach provides a new platform for rapid and cost‐effective DNA length measurement for STRs and resequencing of small DNA fragments. 相似文献
93.
Akram M. El-Didamony Alaa S. Amin Ahmed K. Ghoneim Ayman M. Telebany 《Central European Journal of Chemistry》2006,4(4):708-722
Four simple, accurate, sensitive and economical procedures (A–D) for the estimation of gentamicin sulphate and vancomycin
hydrochloride, both in pure form and in pharmaceutical formulations have been developed. The methods are based on the oxidation
of the studied drugs by a known excess of potassium permanganate in sulphuric acid medium and subsequent determination of
unreacted oxidant by reacting it with amaranth dye (method A), acid orange II (method B), indigocarmine (method C) and methylene
blue (method D), in the same acid medium at a suitable λmax=521, 485, 610 and 664 nm, respectively. The reacted oxidant corresponds to the drug content. Regression analysis of Beer-Lambert
plots showed good correlations in the concentration ranges 4–8, 3–8, 4–9 and 5–9 μg ml−1 with gentamicin and 4–8, 1.5–4, 1.5–4 and 3.5–5.5 μg ml−1 with vancomycin for methods A, B, C, and D, respectively. The molar absorptivity, sandell sensitivity, detection and quantification
limits were calculated. The stoichiometric ratios for the cited drugs were studied. The optimum reaction conditions and other
analytical parameters were evaluated. The influence of the substance commonly employed as excipients with these drugs were
studied. The proposed methods were applied to the determination of these drugs in pharmaceutical formulations. The results
have demonstrated that the methods are equally accurate and reproducible as the official methods. 相似文献
94.
Muhammad Ali Inam Rizwan Khan Kang Hoon Lee Muhammad Akram Zameer Ahmed Ki Gang Lee Young Min Wie 《Molecules (Basel, Switzerland)》2021,26(22)
Arsenic (As)-laden wastewater may pose a threat to biodiversity when released into soil and water bodies without treatment. The current study investigated the sorption properties of both As(III, V) oxyanions onto iron hydroxide (FHO) by chemical coagulation. The potential mechanisms were identified using the adsorption models, ζ-potential, X-ray diffraction (XRD) and Fourier Transform Infrared Spectrometry (FT-IR) analysis. The results indicate that the sorption kinetics of pentavalent and trivalent As species closely followed the pseudo-second-order model, and the adsorption rates of both toxicants were remarkably governed by pH as well as the quantity of FHO in suspension. Notably, the FHO formation was directly related to the amount of ferric chloride (FC) coagulant added in the solution. The sorption isotherm results show a better maximum sorption capacity for pentavalent As ions than trivalent species, with the same amount of FHO in the suspensions. The thermodynamic study suggests that the sorption process was spontaneously exothermic with increased randomness. The ζ-potential, FT-IR and XRD analyses confirm that a strong Fe-O bond with As(V) and the closeness of the surface potential of the bonded complex to the point of zero charge (pHzpc) resulted in the higher adsorption affinity of pentavalent As species than trivalent ions in most aquatic conditions. Moreover, the presence of sulfates, phosphates, and humic and salicylic acid significantly affected the As(III, V) sorption performance by altering the surface properties of Fe precipitates. The combined effect of charge neutralization, complexation, oxidation and multilayer chemisorption was identified as a major removal mechanism. These findings may provide some understanding regarding the fate, transport and adsorption properties onto FHO of As oxyanions in a complex water environment. 相似文献
95.
The kinetics of formation of N‐diketohydrindylidenehistidinatocopper(II) complex has been investigated in the presence of cationic cetyltrimethylammonium bromide (CTAB) surfactant in aqueous medium (pH = 5.0). Similarly in aqueous solution, the reaction followed irreversible first‐order kinetics with respect to [Ninhydrin]. Although the reaction mechanism remained unaltered by micelles, a typical kψ‐[CTAB] profile was observed, that is, with a progressive increase in [CTAB], the reaction rate increased, reached a maximum value, and then decreased. The results are treated quantitatively in terms of the kinetic pseudo‐phase model. Activation parameters were also evaluated and a large decrease in ΔS# shows the formation of a well‐structured activated complex. It was found that anionic sodium dodecyl sulphate (SDS) and non‐ionic Triton X‐100 (TX‐100) surfactants have no effect on the reaction. © 1999 John Wiley & Sons, Inc. Int J Chem Kinet 31: 729–736, 1999 相似文献
96.
Kinetics of the interaction of histidine and histidine methyl ester with ninhydrin under varying concentrations of reactants, anionic (sodium dodecyl sulphate, SDS), cationic (cetyltrimethylammonium bromide, CTAB) and non‐ionic (Triton X‐100, TX‐100) micelles have been carried out. Rate of the reaction was found to be independent of the initial concentration of histidine (and histidine methyl ester) but was dependent on [Ninhydrin]. The SDS micelles had no effect on the rate of the reaction. In the presence of the CTAB micelles a small enhancement in the rate was observed. The rate − [CTAB] profile showed that the increase in [CTAB] increased the rate up to a maximum value and a further increase had a decreasing effect on the rate. The rate was enhanced by TX‐100 also but, unlike CTAB micelles, TX‐100 possessed a curve without peak for the rate − [TX‐100] profile. The following rate equation was obeyed by the reaction in CTAB and TX‐100 micelles: Values of kw, km, and KS were evaluated and are reported herein. ©1999 John Wiley & Sons, Inc. Int J Chem Kinet 31: 103–111, 1999 相似文献
97.
98.
In this article we investigate the frame properties and closedness for the shift invariant space Vp(F) = { ?i=1r ?j ? \Zd di(j) fi (·-j): ( di(j) )j ? \Zd ? lp }, \q 1 £ p £ ¥ . \displaystyle V_p(\Phi) = \left\{ \sum_{i=1}^r \sum_{j\in \Zd} d_i(j) \phi_i (\cdot-j): \ \left( d_i(j) \right)_{j\in \Zd}\in \ell^p \right\}, \q 1\le p \le \infty~. We derive necessary and sufficient conditions for an indexed family {fi(·-j): 1 £ i £ r, j ? \Zd}\{\phi_i(\cdot-j):\ 1\le i\le r, j\in \Zd\} to constitute a pp-frame for Vp(F)V_p(\Phi), and to generate a closed shift invariant subspace of LpL^p. A function in the LpL^p-closure of Vp(F)V_p(\Phi) is not necessarily generated by lp\ell^p coefficients. Hence we often hope that Vp(F)V_p(\Phi) itself is closed, i.e., a Banach space. For p 1 2p\ne 2, this issue is complicated, but we show that under the appropriate conditions on the frame vectors, there is an equivalence between the concept of pp-frames, Banach frames, and the closedness of the space they generate. The relation between a function f ? Vp(F)f \in V_p(\Phi) and the coefficients of its representations is neither obvious, nor unique, in general. For the case of pp-frames, we are in the context of normed linear spaces, but we are still able to give a characterization of pp-frames in terms of the equivalence between the norm of ff and an lp\ell^p-norm related to its representations. A Banach frame does not have a dual Banach frame in general, however, for the shift invariant spaces Vp(F)V_p(\Phi), dual Banach frames exist and can be constructed. 相似文献
99.
A. A. Qureshi N. U. Khattak M. Sardar M. Tufail M. Akram T. Iqbal H. A. Khan 《Radiation measurements》2001,34(1-6):355-359
Some times high uranium contents are present in the phosphate rocks used for the manufacturing of fertilizer. In view of the harmful effects on human health due to the processing and use of such fertilizers in agriculture, it is important to analyse phosphate rocks for uranium content determination. Ten representative rock samples from Kakul phosphate deposit exposed near Abbotabad, Pakistan which are used for the manufacturing of fertilizers were studied for uranium content determination with the help of fission track and neutron activation analysis techniques. Each sample was split into three parts. The first and second parts (solid slabs and pellets) were subjected to fission track analysis, while the third part was analysed using neutron activation analysis technique for comparison. On the average a uranium content of 37 ppm was found in the phosphate rocks. The results of uranium content determinations with the help of fission track and neutron activation analysis techniques show a remarked resemblance up to ±0.1%. This indicates that the fission track analysis technique of uranium content determination is a reliable method inspite of its simplicity. The uranium content in the Kakul deposits is within the permissible limit allowed for the mining and processing of the phosphate rocks for the manufacturing of fertilizers. 相似文献
100.
The high prevalence of cancer has been increased the rate of studying about the new formulation of chemotherapeutic drugs. In this regards, one of the suitable options is the use of metal nanoparticles for formulating these drugs. In the recent study, Lens culinaris seed aqueous extract conjugated gold nanoparticles (AuNPs) are reported for the first time to exert a dietary therapeutic potential compared to mitoxantrone in an animal model of acute myeloid leukemia. The synthesized AuNPs were characterized using different techniques including UV–Vis., FT-IR, XRD, FE-SEM, and TEM. DPPH free radical scavenging test was done to evaluate the antioxidant potentials of HAuCl4, L. culinaris, AuNPs, and mitoxantrone. For the analyzing of cytotoxicity effects of HAuCl4, L. culinaris, AuNPs, and mitoxantrone, MTT assay was used on HUVEC, 32D-FLT3-ITD, Human HL-60/vcr, and Murine C1498 cell lines. In vivo assay, induction of acute myeloid leukemia was done by 7,12-Dimethylbenz[a]anthracene (DMBA) in 75 mice. Then, the animals were randomly divided into six subgroups, including control, untreated, HAuCl4, L. culinaris, AuNPs, and mitoxantrone. SEM and TEM images showed uniform spherical morphology and average diameters of 10–40 nm for the nanoparticles. DPPH test revealed similar antioxidant potentials for mitoxantrone and AuNPs. Similar to mitoxantrone, AuNPs had low cell viability dose-dependently against 32D-FLT3-ITD, Human HL-60/vcr, and Murine C1498 cell lines without any cytotoxicity on HUVEC cell line. AuNPs and mitoxantrone significantly (p ≤ 0.05) reduced the weight and volume of liver and spleen, the pro-inflammatory cytokines, and the total WBC, blast, neutrophil, monocyte, eosinophil, and basophil counts and increased the mRNA expression of Sphingosine-1-phosphate receptor-1 and Sphingosine-1-phosphate receptor-5, the anti-inflammatory cytokines, and the lymphocyte, platelet, and RBC parameters as compared to the untreated mice. It looks that AuNPs can be administrated as a chemotherapeutic supplement or drug for the treatment of acute myeloid leukemia in the clinical trial. 相似文献