Development and validation of an LC-MS/MS-ESI method for the determination of lorglumide, a CCK-1 antagonist in mouse plasma: application to a pharmacokinetic study

A highly sensitive, rapid assay method was developed and validated for the estimation of lorglumide in mouse plasma using liquid chromatography coupled to tandem mass spectrometry with electrospray ionization in positive‐ion mode. The assay procedure involves extraction of lorglumide and phenacetin (internal standard, IS) from mouse plasma with simple protein precipitation. Chromatographic separation was achieved using an isocratic mobile (0.2% formic acid solution–acetonitrile, 20:80, v/v) at a flow‐rate of 0.5 mL/min on an Atlantis dC₁₈ column maintained at 40 °C with a total run time of 4.0 min. The MS/MS ion transitions monitored were 459.2 → 158.4 for lorglumide and 180.1 → 110.1 for IS. Method validation was performed as per FDA guidelines and the results met the acceptance criteria. The lower limit of quantitation achieved was 0.42 ng/mL and the linearity range extended from 0.42 to 500 ng/mL. The intra‐ and inter‐day precisions were in the ranges of 1.47–10.9 and 3.56–7.53, respectively. Copyright © 2011 John Wiley & Sons, Ltd.     

Highly sensitive LC-MS/MS-ESI method for simultaneous quantitation of albendazole and ricobendazole in rat plasma and its application to a rat pharmacokinetic study

A highly sensitive and specific LC-MS/MS-ESI method was developed for simultaneous quantification of albenadazole (ABZ) and ricobendazole (RBZ) in rat plasma (50 μL) using phenacetin as an internal standard (IS). Simple protein precipitation was used to extract ABZ and RBZ from rat plasma. The chromatographic resolution of ABZ, RBZ and IS was achieved with a mobile phase consisting of 5 m m ammonium acetate (pH 6) and acetonitrile (20:80, v/v) at a flow rate of 1 mL/min on a Chromolith RP-18e column. The total chromatographic run time was 3.5 min and the elution of ABZ, RBZ and IS occurred at 1.66, 1.50 and 1.59 min, respectively. A linear response function was established for the ranges of concentrations 2.01-2007 and 6.02-6020 ng/mL for ABZ and RBZ, respectively. The intra- and inter-day precision values for ABZ and RBZ met the acceptance as per FDA guidelines. ABZ and RBZ were stable in battery of stability studies, viz. bench-top, auto-sampler and freeze-thaw cycles. The developed assay was applied to a pharmacokinetic study in rats.     

Shape evolution in odd-A 137 Pm

The odd mass nucleus ¹³⁷Pm has been studied to high spins through the ¹⁰⁹Ag(³²S, 2p2n)¹³⁷Pm reaction at an incident beam energy of 150 MeV. The de-exciting ??-rays were detected using an array of 18 Compton suppressed clover detectors. The level scheme of ¹³⁷Pm has been extended up to $J^\pi = \tfrac{{43}} {2}^ -$ and excitation energy of E _x ? 6 MeV with the observation of 42 new gamma transitions. The linear polarization (IPDCO) measurements for the ??-ray transitions have been done for the first time. The spin and parity assignments for most of the reported levels have been made using these results and the coincidence angular anisotropy (R_DCO) measurements. The nuclear shape evolution is discussed in the light of Total Routhian Surface (TRS) and Cranked Shell Model (CSM) calculations.     

Use of carbon-containing materials for efficient high-order harmonic generation of laser radiation

A systematic study of the high-order harmonic generation (HHG) of laser radiation in various carbon-containing plasma plumes (CCPPs) is presented. The materials studied are: graphite, boron carbide, C₆₀, polytetrafluoroethylene, polyethylene, carbon nanotubes, and soot. These studies show that CCPPs present the best plasma media for efficient lower order (from 9th to 19th) harmonic generation, while the harmonic cutoff restricted to the 29th order. The advantages of CCPPs for the harmonic generation are confirmed by comparison of the HHG conversion efficiency with that in Ag and In plasma plumes, where the highest conversion efficiency was reported. Use of two-color pump scheme allows further enhancement of harmonic yield from the CCPPs.     

Structural features of epitaxial NiFe2O4 thin films grown on different substrates by direct liquid injection chemical vapor deposition

NiFe₂O₄ (NFO) thin films are grown on four different substrates, i.e., Lead Zinc Niobate–Lead Titanate (PZN–PT), Lead Magnesium Niobate–Lead Titanate (PMN–PT), MgAl₂O₄ (MAO) and SrTiO₃ (STO), by a direct liquid injection chemical vapor deposition technique (DLI-CVD) under optimum growth conditions where relatively high growth rate (～20 nm/min), smooth surface morphology and high saturation magnetization values in the range of 260–290 emu/ cm³ are obtained. The NFO films with correct stoichiometry (Ni:Fe=1:2) grow epitaxially on all four substrates, as confirmed by energy dispersive X-ray spectroscopy, transmission electron microscopy and x-ray diffraction. While the films on PMN–PT and PZN–PT substrates are partially strained, essentially complete strain relaxation occurs for films grown on MAO and STO. The formations of threading dislocations along with dark diffused contrast areas related to antiphase domains having a different cation ordering are observed on all four substrates. These crystal defects are correlated with lattice mismatch between the film and substrate and result in changes in magnetic properties of the films. Atomic resolution HAADF imaging and EDX line profiles show formation of a sharp interface between the film and the substrate with no inter-diffusion of Pb or other elements across the interface. Antiphase domains are observed to originate at the film–substrate interface.     

Preparation and photocatalytic properties of hybrid core–shell reusable CoFe2O4–ZnO nanospheres

Magnetically separable and reusable core–shell CoFe₂O₄–ZnO photocatalyst nanospheres were prepared by the hydrothermal synthesis technique using glucose derived carbon nanospheres as the template. The morphology and the phase of core–shell hybrid structure of CoFe₂O₄–ZnO were assessed via TEM, SEM and XRD. The magnetic composite showed high UV photocatalytic activity for the degradation of methylene blue in water. The photocatalytic activity was found to be ZnO shell thickness dependent. Thicker ZnO shells lead to higher rate of photocatalytic activity. Hybrid nanospheres recovered using an external magnetic field demonstrated good repeatability of photocatalytic activity. These results promise the reusability of the hybrid nanospheres for photocatalytic activity.     

Observation of bulk like magnetic ordering below the blocking temperature in nanosized zinc ferrite

We investigated the magnetic behavior of nanosized zinc ferrite with the help of vibrating sample magnetometry and in-field Mössbauer spectroscopy. The nanoparticles of zinc ferrite with crystallite size ranging from 10 to 62 nm were synthesized by a nitrate method. The structure and phase were determined with the help of X-ray diffraction. Attributes of cation inversion were found with the calculated values of lattice parameter. The saturation magnetization decreases with the increase in crystallite size at room temperature, while these values are almost the same at 10 K for all the samples except the one with crystallite size of 10 nm. The thermal magnetization measurement shows a decrease in blocking temperature with increase in particle size for these samples. The synthesized samples exhibit the presence of antiferromagnetic ordering below the blocking temperature as investigated by in-field Mössbauer spectroscopy.     

One pot glucose detection by [Fe(III)(biuret-amide)] immobilized on mesoporous silica nanoparticles: an efficient HRP mimic

An [Fe(III)(biuret-amide)] complex has been immobilized onto mesoporous silica nanoparticles via Cu(I) catalyzed azide-alkyne click chemistry. This hybrid material functions as an efficient peroxidase mimic and was successfully used for the quantitative determination of hydrogen peroxide and glucose via a one-pot colorimetric assay.     

An organocatalytic direct Mannich-cyclization cascade as [3+2] annulation: asymmetric synthesis of 2,3-substituted pyrrolidines

A new method for asymmetric synthesis of 2,3-substituted pyrrolidines from N-PMP aldimines and succinaldehyde via formal [3+2] cycloaddition is reported. This reaction involves proline catalyzed direct Mannich reaction and acid catalyzed reductive cyclization with high yields (up to 78%) and excellent enantioselectivities (up to >99%).