Development and validation of an RP‐HPLC method for the quantitation of odanacatib in rat and human plasma and its application to a pharmacokinetic study

A simple, specific, sensitive and reproducible high‐performance liquid chromatography (HPLC) assay method has been developed and validated for the estimation of odanacatib in rat and human plasma. The bioanalytical procedure involves extraction of odanacatib and itraconazole (internal standard, IS) from a 200 μL plasma aliquot with simple liquid–liquid extraction process. Chromatographic separation was achieved on a Symmetry Shield RP₁₈ using an isocratic mobile phase at a flow rate of 0.7 mL/min. The UV detection wave length was 268 nm. Odanacatib and IS eluted at 5.5 and 8.6 min, respectively with a total run time of 10 min. Method validation was performed as per US Food and Drug Administration guidelines and the results met the acceptance criteria. The calibration curve was linear over a concentration range of 50.9–2037 ng/mL (r² = 0.994). The intra‐ and inter‐day precisions were in the range of 2.06–5.11 and 5.84–13.1%, respectively, in rat plasma and 2.38–7.90 and 6.39–10.2%, respectively, in human plasma. The validated HPLC method was successfully applied to a pharmacokinetic study in rats. Copyright © 2015 John Wiley & Sons, Ltd.     

High Surface Area Flexible Chemiresistive Biosensor by Oxidative Chemical Vapor Deposition

Fabrication of a chemiresistive biosensor for detection of biomolecules is demonstrated on a high surface area, flexible electro‐spun nylon fiber mat. For the first time, the –OH functionalized conducting copolymer of 3,4‐ethylenedioxythiophene (EDOT) and 3‐thiopheneethanol (3‐TE) is synthesized and conformally deposited on the electro‐spun mats by oxidative chemical vapor deposition (oCVD). The free –OH functional groups of the copolymer are available for immobilization of analyte specific biomolecules. Here, avidin and biotin molecules are employed as the analyte‐specific molecule and analyte respectively for their high specificity to each other. The sensitivities of avidin immobilized conducting copolymer on electro‐spun mats are tested against micro‐molar to nano‐molar concentrations of biotin in aqueous solutions. Application of electro‐spun fiber mat in this case enhances the sensor response 6 times when compared to a flat substrate and also significantly lowers the response time. In addition to the experimental studies, current work also includes modeling of the kinetics of the change of response for the biotin‐avidin interactions as a function of time. Most importantly, this fabrication technique promises an extremely sensitive and field deployable method for the detection of other biomolecules, for example, food pathogens.     

Development and validation of a RP‐HPLC method for the quantitation of tofacitinib in rat plasma and its application to a pharmacokinetic study

A novel, simple, specific, sensitive and reproducible high‐performance liquid chromatography (HPLC) assay method has been developed and validated for the estimation of tofacitinib in rat plasma. The bioanalytical procedure involves extraction of tofacitinib and itraconazole (internal standard, IS) from rat plasma with a simple liquid–liquid extraction process. The chromatographic analysis was performed on a Waters Alliance system using a gradient mobile phase conditions at a flow rate of 1.0 mL/min and C₁₈ column maintained at 40 ± 1 °C. The eluate was monitored using an UV detector set at 287 nm. Tofacitinib and IS eluted at 6.5 and 8.3 min, respectively and the total run time was 10 min. Method validation was performed as per US Food and Drug Administration guidelines and the results met the acceptance criteria. The calibration curve was linear over a concentration range of 182–5035 ng/mL (r² = 0.995). The intra‐ and inter‐day precisions were in the range of 1.41–11.2 and 3.66–8.81%, respectively, in rat plasma. The validated HPLC method was successfully applied to a pharmacokinetic study in rats. Copyright © 2015 John Wiley & Sons, Ltd.     

Hypergeometrically Represented Responsive and Reliable Cloud Service Model for Personal and Private Clouds

Wireless Personal Communications - Last two decades have witnessed a tremendous evolution and growth of cloud computing paradigm and reliability estimation techniques. In spite of recent...     

Adder design using 5-input majority gate in a novel “Multilayer Gate Design Paradigm” for Quantum Dot Cellular Automata Circuits

This paper proposes a novel design paradigm for circuits designed in quantum dot cellular automata (QCA) technology. Previously reported QCA circuits in the literature have generally been designed in a single layer which is the main logical block in which the inverter and majority gate are on the base layer, except for the parts where multilayer wire crossing was used. In this paper the concept of multilayer wire crossing has been extended to design logic gates in multilayers. Using a 5-input majority gate in a multilayer, a 1-bit and 2-bit adder have been designed in the proposed multilayer gate design paradigm. A comparison has been made with some adders reported previously in the literature and it has been shown that circuits designed in the proposed design paradigm are much more efficient in terms of area, the requirement of QCA cells in the design and the input-output delay of the circuit. Over all, the availability of one additional spatial dimension makes the design process much more flexible and there is scope for the customizability of logic gate designs to make the circuit compact.     

In-Situ Monitoring of Chromium Uptake in Different Parts of the Wheat Seedling (Triticum aestivum) using Laser-Induced Breakdown Spectroscopy

The present work is a methodological study to investigate the effect of chromium (VI) stress on wheat seedlings. Point detection capability of laser-induced breakdown spectroscopy (LIBS) was utilized for the monitoring of in-situ chromium uptake in wheat (Triticum aestivum) seedlings. Chromium accumulation and its effects on other elements in wheat seedling were investigated by comparing the intensities of spectral lines of chromium and other minerals present in the LIBS spectra. In-situ LIBS spectra of the different parts of the wheat seedlings were recorded by directly focusing the laser beam on the surface of root, stem, and leaf of the seedlings grown with and without chromium-containing solutions. The spectra obtained from the different parts (root, stem, and leaf) of the wheat plant were analyzed to determine the distribution pattern/accumulation of chromium. Effect of the chromium uptake on the distribution pattern of other elements like calcium (Ca), magnesium (Mg), sodium (Na), and potassium (K) was also investigated. It was observed that chromium concentrations in plant organs decreased in the following order: roots > leaves > stems.     

A strategy to access fused triazoloquinoline and related nucleoside analogues

Fused triazoloquinolines have been prepared starting from (E)-3-(2-nitrophenyl)-1-aryl-prop-2-en-1-ones and sugar or benzyl azides in a sequential [3+2] cycloaddition reaction, followed by one pot Pd–C assisted reduction, cyclization and aromatization. The triazolyl fused quinolines with N¹-glycosyl substituents as unnatural nucleosides have inherent potential to generate a library of compounds for bioevaluations.