How Hydraulic Properties of Organic Matter Control Effective Liquid Permeability of Mudrocks

Transport in Porous Media - In organic-rich Mudrocks, porous organic matter embedded within mineral matrix along with inorganic pores forms a dual porosity–permeability (ϕ–k)...     

Effect of polysorbate plasticizer on the structural and ion conduction properties of PEO–NH<Subscript>4</Subscript>PF<Subscript>6</Subscript> solid polymer electrolyte

Effects of a new plasticizer, polysorbate 80, on the structural and electrochemical properties of PEO–NH₄PF₆ polymer electrolyte system have been investigated. X-ray diffraction studies show significant increase in amorphicity of the solid polymer electrolyte on introduction of the plasticizer, which is also supported by lesser-dense spherulites observed in the SEM micrographs. The room temperature ionic conductivity of the electrolyte shows an increase of about two orders of magnitude (σ_max～10^?5 S/cm) on plasticization. The frequency dependence of the conductivity has been found to obey the Jonscher’s power law and slower backward ion hopping on plasticization. The polymer electrolyte shows protonic conduction as confirmed using cyclic voltammetry study. The studies show that polysorbate 80 is a promising plasticizer for semicrystalline polymer electrolytes.     

Neuroprotective Ability of Apocynin Loaded Nanoparticles (APO-NPs) as NADPH Oxidase (NOX)-Mediated ROS Modulator for Hydrogen Peroxide-Induced Oxidative Neuronal Injuries

Apocynin (APO) is a known multi-enzymatic complexed compound, employed as a viable NADPH oxidase (NOX) inhibitor, extensively used in both traditional and modern-day therapeutic strategies to combat neuronal disorders. However, its therapeutic efficacy is limited by lower solubility and lesser bioavailability; thus, a suitable nanocarrier system to overcome such limitations is needed. The present study is designed to fabricate APO-loaded polymeric nanoparticles (APO-NPs) to enhance its therapeutic efficacy and sustainability in the biological system. The optimized APO NPs in the study exhibited 103.6 ± 6.8 nm and −13.7 ± 0.43 mV of particle size and zeta potential, respectively, along with further confirmation by TEM. In addition, the antioxidant (AO) abilities quantified by DPPH and nitric oxide scavenging assays exhibited comparatively higher AO potential of APO-NPs than APO alone. An in-vitro release profile displayed a linear diffusion pattern of zero order kinetics for APO from the NPs, followed by its cytotoxicity evaluation on the PC12 cell line, which revealed minimal toxicity with higher cell viability, even after treatment with a stress inducer (H₂O₂). The stability of APO-NPs after six months showed minimal AO decline in comparison to APO only, indicating that the designed nano-formulation enhanced therapeutic efficacy for modulating NOX-mediated ROS generation.     

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.     

New analytical solutions for modified polarization saturation models in piezoelectric materials

Meccanica - In this paper, we present new analytical solutions for modified polarization saturation (PS) models for arbitrary polarized and semipermeable 2-D piezoelectric media. The PS model is...     

Ion transport studies in nanocomposite polymer electrolyte membrane of PVA–[C<Subscript>4</Subscript>C<Subscript>1</Subscript>Im][HSO<Subscript>4</Subscript>]–SiO<Subscript>2</Subscript>

The paper reports the effect of SiO₂ nano-filler on structural, thermal, and ion transport properties of polymer electrolyte system comprising polyvinyl alcohol (PVA) and 1-butyl-3-methylimidazolium hydrogen sulfate [C₄C₁Im][HSO₄] ionic liquid. The addition of SiO₂ nano-filler results into enhancement in amorphicity and thermal stability and lowering of glass transition temperature of the membranes. A detailed investigation of possible interactions among the constituents PVA, [C₄C₁Im][HSO₄] and SiO₂, and cation–anion and anion–anion pairs of [C₄C₁Im][HSO₄] in the polymer electrolyte and their dissociation due to SiO₂ filler has been carried out in the membranes using Fourier transform infra-red (FTIR) and Raman spectroscopy. The membranes show maximum room temperature ionic conductivity as 9.9?×?10^?3 S cm^?1 for 6 wt.% of the nano-filler which is about four times higher than the membrane without nano-filler and an order higher than pure [C₄C₁Im][HSO₄]. With temperature, the ionic conductivity shows VTF behavior in the temperature range 40–120 °C. On the basis of FTIR and ion transport results, a model for ion transport in the membranes is proposed.

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Graphical abstract Schematic model of ion transport in nanocomposite polymer electrolyte membrane of PVA-[C₄C₁Im][HSO₄]-SiO₂

     

On the convolution of Mittag–Leffler distributions and its applications to fractional point processes

We obtain the distribution of the sum of independent Mittag–Leffler (ML) random variables which are not necessarily identically distributed. Firstly we discuss the corresponding known result for independent and identically distributed ML random variables which follows as a special case of our result. Some applications of the obtained result to fractional point processes are also discussed.     

Structural phase transition and elastic properties of thorium pnictides at high pressure

In the present paper we have pointed out the weaknesses of the approach by Aynyas et al [1] to study the structural phase transition and elastic properties of thorium pnictides. The calculated values of phase transition pressure and other elastic properties using the realistic and actual approach are also given and compared with the experimental and previous theoretical work.      

Theoretical study of relative width of photonic band gap for the 3-D dielectric structure

Calculations for the relative width (Δω/ω₀) as a function of refractive index and relative radius of the photonic band gap for the fcc closed packed 3-D dielectric microstructure are reported and comparison of experimental observations and theoretical predictions are given. This work is useful for the understanding of photonic crystals and occurrence of the photonic band gap.