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Gemechu Zeleke Siegrid De Baere Sultan Suleman Mathias Devreese 《Molecules (Basel, Switzerland)》2022,27(3)
A fast, accurate and reliable ultra-high performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS) method was developed for simultaneous quantification of ivermectin (IVER), doramectin (DORA), and moxidectin (MOXI) in bovine plasma. A priority for sample preparation was the eradication of possible infectious diseases to avoid travel restrictions. The sample preparation was based on protein precipitation using 1% formic acid in acetonitrile, followed by Ostro® 96-well plate pass-through sample clean-up. The simple and straightforward procedure, along with the short analysis time, makes the current method unique and suitable for a large set of sample analyses per day for PK studies. Chromatographic separation was performed using an Acquity UPLC HSS-T3 column, with 0.01% acetic acid in water and methanol, on an Acquity H-Class ultra-high performance liquid chromatograph (UHPLC) system. The MS/MS instrument was a Xevo TQ-S® mass spectrometer, operating in the positive electrospray ionization mode and two multiple reaction monitoring (MRM) transitions were monitored per component. The MRM transitions of m/z 897.50 > 753.4 for IVER, m/z 921.70 > 777.40 for DORA and m/z 640.40 > 123.10 for MOXI were used for quantification. The method validation was performed using matrix-matched calibration curves in a concentration range of 1 to 500 ng/mL. Calibration curves fitted a quadratic regression model with 1/x2 weighting (r ≥ 0.998 and GoF ≤ 4.85%). Limits of quantification (LOQ) values of 1 ng/mL were obtained for all the analytes, while the limits of detection (LOD) were 0.02 ng/mL for IVER, 0.03 ng/mL for DORA, and 0.58 ng/mL for MOXI. The results of within-day (RSD < 6.50%) and between-day (RSD < 8.10%) precision and accuracies fell within acceptance ranges. No carry-over and no peak were detected in the UHPLC-MS/MS chromatogram of blank samples showing good specificity of the method. The applicability of the developed method was proved by an analysis of the field PK samples. 相似文献
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Akalu Tefera Aklilu Zeleke 《International Journal of Mathematical Education in Science & Technology》2013,44(8):1091-1096
In this note we present a class of functions (f, g) that satisfy ‘freshman rules’ in calculus. 相似文献
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Adam A. Y. Oumer A. N. Najafi G. Ishak M. Firdaus M. Aklilu T. B. 《Journal of Thermal Analysis and Calorimetry》2020,139(4):2739-2768
Journal of Thermal Analysis and Calorimetry - The need for better thermal–hydraulic performance of heat exchangers remains the primary reason for further improving the design of heat... 相似文献
4.
Akilu Suleiman Baheta Aklilu Tesfamichael Sharma K. V. 《Journal of Thermal Analysis and Calorimetry》2020,140(4):1999-2010
Journal of Thermal Analysis and Calorimetry - Thermal conductivity, dynamic viscosity, and density of TiN nanofluids (NFs) with different base mediums have been characterized for the prospect of... 相似文献
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In this paper a simple and highly sensitive electroanalytical method for the determination of caffeine content using 1,4-benzoquinone modified carbon paste electrode is presented. The method is based on suppression of 1,4-benzoquinone peak current on addition of caffeine. Square-wave and cyclic voltammetric techniques were utilised for the investigation. The 1,4-benzoquinone modified electrode exhibited a well-defined peak with reproducible peak current values for repetitive measurements; and showed a decrease in peak current value with an increase in caffeine content. The result revealed two linear range regions between 0 mmol L−1 and 0.5 mmol L−1 and 0.5 mmol L−1 and 8.0 mmol L−1, with detection limits of 0.3 μmol L−1 and 5.1 μmol L−1, respectively. The method was then successfully applied to the determination of caffeine content in coffee samples. The effects of pH, electrode composition, step potential, pulse amplitude and square-wave frequency on the voltammetric responses were also investigated. 相似文献
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In this paper, we compute the Möbius function of pointed integer partition and pointed ordered set partition using topological and analytic methods. We show that the associated order complex is a wedge of spheres and compute the associated reduced homology group for each subposet. In addition, we compute the Möbius function of pointed graded lattice and use our method to compute the Möbius function of pointed direct sum decomposition of vector spaces. 相似文献
7.
Christopher J. Smith Aklilu Zeleke 《International Journal of Mathematical Education in Science & Technology》2013,44(8):1067-1077
The use of computer algebra systems such as Maple and Mathematica is becoming increasingly important and widespread in mathematics learning, teaching and research. In this article, we present computerized proof techniques of Gosper, Wilf–Zeilberger and Zeilberger that can be used for enhancing the teaching and learning of topics in discrete mathematics. We demonstrate by examples how one can use these computerized proof techniques to raise students' interests in the discovery and proof of mathematical identities and enhance their problem-solving skills. 相似文献
8.
Thomas Franke Ronald H. W. Hoppe Christopher Linsenmann Kidist Zeleke 《Central European Journal of Mathematics》2013,11(4):760-778
We consider the mathematical modeling and numerical simulation of high throughput sorting of two different types of biological cells (type I and type II) by a biomedical micro-electro-mechanical system (BioMEMS) whose operating behavior relies on surface acoustic wave (SAW) manipulated fluid flow in a microchannel. The BioMEMS consists of a separation channel with three inflow channels for injection of the carrier fluid and the cells, two outflow channels for separation, and an interdigital transducer (IDT) close to the lateral wall of the separation channel for generation of the SAWs. The cells can be distinguished by fluorescence. The inflow velocities are tuned so that without SAW actuation a cell of type I leaves the device through a designated outflow channel. However, if a cell of type II is detected, the IDT is switched on and the SAWs modify the fluid flow so that the cell leaves the separation channel through the other outflow boundary. The motion of a cell in the carrier fluid is modeled by the Finite Element Immersed Boundary method (FE-IB). Numerical results are presented that illustrate the feasibility of the surface acoustic wave actuated cell sorting approach. 相似文献
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Giovanni Porru Aklilu Zeleke 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1993,44(5):923-928
We define some functionals involvingu(x) andx'u
i
, whereu(x) is a classical solution of the equation (q
p-2
u
i
)
i
+k(u)q
p
=0,p > 1, and prove that such functionals satisfy a second order elliptic differential equation. By a suitable choice of such functionals we investigate an overdetermined problem.Partially supported by Regione Autonoma della Sardegna. 相似文献
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