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1.
Eco‐friendly ionic liquid assisted capillary electrophoresis and α‐acid glycoprotein‐assisted liquid chromatography for simultaneous determination of anticancer drugs in human fluids
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Deia Abd El‐Hady Hassan M. Albishri Rajesh Rengarajan 《Biomedical chromatography : BMC》2015,29(6):925-934
In the current work, two eco‐friendly analytical methods based on capillary electrophoresis (CE) and reversed phase liquid chromatography (RPLC) were developed for simultaneous determination of the most commonly used anticancer drugs for Hodgkin's disease: methotrexate (MTX), vinblastine, chlorambucil and dacarbazine. A background electrolyte (BGE) of 12.5 mmol/L phosphate buffer at pH 7.4 and 0.1 µmol/L 1‐butyl‐3‐methyl imidazolium bromide (BMImBr) ionic liquid (IL) was used for CE measurements at 250 nm detection wavelength, 20 kV applied voltage and 25 °C. The rinsing protocol was significantly improved to reduce the adsorption of IL on the interior surface of capillary. Moreover, RPLC method was developed on α‐1‐acid glycoprotein (AGP) column. Mobile phase was 10 mmol/L phosphate buffer at pH 6.0 (100% v/v) and flow rate at 0.1 mL/min. As AGP is a chiral column, it was successfully separated l ‐MTX from its enantiomer impurity d ‐MTX. Good linearity of quantitative analysis was achieved with coefficients of determinations (r2) >0.995. The stability of drugs measurements was investigated with adequate recoveries up to 24 h storage time under ambient temperature. The limits of detection were <50 and 90 ng/mL by CE and RPLC, respectively. The using of short‐chain IL as an additive in BGE achieved 600‐fold sensitivity enhancement compared with conventional Capillary Zone Electrophoresis (CZE). Therefore, for the first time, the proposed methods were successfully applied to determine simultaneously the analytes in human plasma and urine samples at clinically relevant concentrations with fast and simple pretreatments. Developed IL‐assisted CE and RPLC methods were also applied to measure MTX levels in patients’ samples over time. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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3.
H.S RagabA Shehap M.S Abo EllilW.H Osman F.H Abd El-Kader 《Journal of Physics and Chemistry of Solids》2002,63(10):1839-1847
Ternary-phase ceramic system of Li2O Al2O3 4SiO2 doped with CuO, FeO and TiO2 has been prepared and subjected to dc electrical conductivity and thermally stimulated depolarization current (TSDC) measurements as a function of temperature (30-250 °C) and field strength. The electrical conductivity results are explained by assuming both ionic and electronic conduction mechanisms coexist with different contributions over the whole temperature range of experiments. TSDC spectra have been found to be characterized by a broad intense relaxation peak, which can be attributed to an ionic charge polarization. The broad relaxation transitions are apparently a result of the nonuniform nature of this process. Activation energies are calculated for both dc electrical conductivity and TSDC according to Arrhenius equation and initial rise method, respectively. 相似文献
4.
Pre—Separation Axioms in Fuzzifying Topology 总被引:1,自引:0,他引:1
K.M.AbdEl-Hakeim F.M.Zeyada 《模糊系统与数学》2003,17(1):28-36
1 IntroductionYing[5,6 ] introduced and elementally developed so called fuzzifying topology with the semanticmethod of continuous valued L ogic.Shen[7] introduced and studied T0 -,T1-,T2 (Hausdorff) -,T3(regularity) -,T4 (normality) -separation axioms in fuzzifying topology.In [3 ]the concepts of thefamily of fuzzifying pre-open sets,fuzzifying pre-neighbourhood structure of a point and fuzzifyingpre-closure are introduced and studied.It is worth to mention that pre-separation axioms are … 相似文献
5.
Abid Karim 《光学学报》2003,23(Z1)
In this paper, a new method is outlined for the estimation of coupling efficiency between a source laser and a WGPD. Internal quantum efficiencies as high as 72% (for 0.15 μm device) and 86.5% (for 0.5 μm device) are achieved. 相似文献
6.
Sonya V. Roberson Albert J. Fahey Amit Sehgal Alamgir Karim 《Applied Surface Science》2002,200(1-4):150-164
We present a simple method for chemical modification of chlorosilane self-assembled monolayers (SAMs) on Si surfaces by exposure to a gradient of UV-ozone radiation to create stable substrates with a range of contact angles (θH2O≈5–95°) and surface energies on a single substrate. These gradient energy substrates are developed to potentially generate libraries for combinatorial studies of thin film phenomenology, where a systematic variation of interfacial surface energy represents one of the significant parameters along one axis. The graded oxidation process presents a systematic variation of surface chemical composition. We have utilized contact angle measurements and time-of-flight secondary ion mass spectrometry (ToF-SIMS) to investigate this variation for a series of ions, among which are SiCH3+, SiOH+ and COOH−. We show that the macroscopic measurements of surface free energy/contact angle correlate with the detailed analysis of surface chemistry (as assessed by ToF-SIMS) on these test substrates. 相似文献
7.
Abdel Raouf F. Elhefnawy Galal M. Moatimid Abd Elmonem Khalil Elcoot 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2004,86(2):63-91
The nonlinear electrohydrodynamic stability of
cylindrical interface, supporting surface charge, among two
conducting fluids is investigated. The two fluids are subjected to
a radial electric field. The analysis based on the multiple scale
technique. It is shown that the evolution of the amplitude is
governed by two partial differential equations. These equations
are combined to yield two alternate Schrödinger equations with
cubic nonlinearity. One of which calculates the nonlinear cutoff
electric field, separating stable and unstable disturbances, while
the other is used to analyze the stability of the system. The
stability criteria are analytically discussed and numerically
confirmed. Numerical calculations resulted in set of graphs to
indicate the stability picture of the considered system. 相似文献
8.
在重力场和磁场影响下自旋刚性航天器的周期运动 总被引:1,自引:0,他引:1
考虑重力场和磁场对轴对称航天器本体的影响,研究其质心在圆形轨道上的运动,通过降低系统的运动方程数,并将它变成为一个带电粒子在电磁场作用下的平面运动.确认系统运动是稳定的,并通过Liapunov全纯积分定理,构建其近似的周期运动. 相似文献
9.
M.M. El-Nahass M.A.M. Seyam H.E.A. El-Sayed A.M. Abd El-Barry 《Applied Surface Science》2006,252(18):6218-6227
Thin films of samples of the glassy SxSe100−x system with 0 ≤ x ≤ 7.28 have been prepared by thermal evaporation technique at room temperature (300 K). X-ray investigations show that the structure of pure selenium (Se) does change seriously by the addition of small amount of sulphur S ≤7.28%. The lattice parameters were determined as a function of sulphur content. Results of differential thermal analysis (DTA) of the glassy compositions of the system SxSe100−x were discussed. The characteristic temperatures (Tg, Tc and Tm) were evaluated. Dark electrical resistivities, ρ, of SxSe100−x thin films with different thicknesses from 100 to 500 nm, were measured in the temperature range from 300 to 423 K. Two distinct linear parts with different activation energies were observed. The variation of electrical resistivity of examined compositions has been discussed as a function of the film thickness, temperature and the sulphur content. The application of Mott model for the phonon assisted hopping of small polarons gave the same two activation energies obtained from the resistivity temperature calculations. 相似文献
10.
Ong LG Abd-Aziz S Noraini S Karim MI Hassan MA 《Applied biochemistry and biotechnology》2004,118(1-3):73-79
The oil palm sector is one of the major plantation industries in Malaysia. Palm kernel cake is a byproduct of extracted palm
kernel oil. Mostly palm kernel cake is wasted or is mixed with other nutrients and used as animal feed, especially for ruminant
animals. Recently, palm kernel cake has been identified as an important ingredient for the formulation of animal feed, and
it is also exported especially to Europe, South Korea, and Japan. It can barely be consumed by nonruminant (monogastric) animals
owing to the high percentages of hemicellulose and cellulose contents. Palm kernel cake must undergo suitable pretreatment
in order to decrease the percentage of hemicellulose and cellulose. One of the methods employed in this study is fermentation
with microorganisms, particularly fungi, to partially degrade the hemicellulose and cellulose content. This work focused on
the production of enzymes by Aspergillus niger and profiling using palm kernel cake as carbon source. 相似文献