Re-emergence of the important role of radionuclide generators to provide diagnostic and therapeutic radionuclides to meet future research and clinical demands

Radionuclide generators have been the main stay of diagnostic nuclear medicine and it is no exaggeration to state that the growth of nuclear medicine would not have happened to the present levels but for the availability of ⁹⁹Mo/^99mTc generator. This article provides a brief account of the various radionuclide generators currently in clinical use or which have made substantial progress or likely to be materialized in the foreseeable future to bring evolutional progress in nuclear medicine. Further, a brief outline on the regulatory challenges and impact on radionuclide generator technology with the emergence of professionally run central radiopharmacies have been provided.     

Validation of an extraction paper chromatography (EPC) technique for estimation of trace levels of 90Sr in 90Y solutions obtained from 90Sr/90Y generator systems

While the extraction paper chromatography (EPC) technique constitutes a novel paradigm for the determination of few Becquerels of ⁹⁰Sr in MBq quantities of ⁹⁰Y obtained from ⁹⁰Sr/⁹⁰Y generator, validation of the technique is essential to ensure its usefulness as a real time analytical tool. With a view to explore the relevance and applicability of EPC technique as a real time quality control (QC) technique for the routine estimation of ⁹⁰Sr content in generator produced ⁹⁰Y, a systematic validation study was carried out diligently not only to establish its worthiness but also to broaden its horizon. The ability of the EPC technique to separate trace amounts of Sr²⁺ in the presence of large amounts of Y³⁺ was verified. The specificity of the technique for Y³⁺ was demonstrated with ⁹⁰Y obtained by neutron irradiation. The method was validated under real experimental conditions and compared with a QC method described in US Pharmacopeia for detection of ⁹⁰Sr levels in ⁹⁰Y radiopharmaceuticals.     

Kinetics of oxidation of glutathione by an octahedral cobalt(III) complex with phenolate–amide–amine coordination

The reduction of the octahedral cobalt(III) complex Co^III(HL)·9H₂O, H₄L = 1,8-bis(2-hydroxybenzamido)-3,6-diazaoctane by glutathione (GSH) has been studied by conventional spectrophotometry at 25.0 ≤ t/°C ≤ 45.0, 0.02 ≤ [H⁺]/mol dm^?3 ≤ 0.20 and I = 0.3 mol dm^?3 (NaClO₄). The reaction is biphasic. The fast initial phase is attributed to the H⁺-induced formation of the mixed ligand complex, [Co^III(H₂L)GSH]⁺, for which the rate-limiting step is the chelate ring opening via Co^III–NH (amide–N) bond cleavage of the protonated species, [Co^III(H₂L)]⁺. Outer-sphere association equilibria between GSH/GSH₂ ⁺ and [Co^III(H₂L)]⁺ substantially retard the ring opening process and consequently the mixed ligand complex formation. This is then followed by a slow phase involving reduction of [Co^III(H₂L)GSH]⁺ by both GSH and GSH₂ ⁺. The final products are the corresponding Co(II) complex and the oxidized form of GSH, GS–SG. The kinetic data and activation parameters for the redox process are interpreted in terms of an outer-sphere electron transfer mechanism.     

OSCILLATION THEOREMS FOR DELAY AND NEUTRAL DELAY DIFFERENTIAL EQUATIONS

Oscillation criteria for the delay differential equationx′(t)+p(t)x(t-т(t))=0,where p, т are non-negative real-valued continuous functions are investigated inthe case when the numbers k=integral from n=t-т(t) to t(p(s)ds),L=integral from n=t-т(t) to t(p(s)ds)satisfy 0≤k<1/e and 1/e≤L<1. The present result improves almost allresults of the literature concerning it. Furthermore, it is established that allsolutions of the odd-order neutral delay differential equation(x(t)-px(t-т))~(n)+Q(t)x(t-σ)=0,where 0≤p<1,т,σ∈(0,∞)and Q(t)≥0,are oscillatory ifintegral from n=t-σ to t ((t-s)~(n-1)Q(s)ds>(1/e)(1-p)(n-1))!.This result generalizes a theorem of Gopalsamy et. al (Czech. Math. J., 42(1992),313-323)and also extends a very well-known result of Ladas (ApplicableAnalysls, 9(1979),93-98).     

A new solution method for fuzzy chance constrained programming problem

This paper deals with an optimization model, where both fuzziness and randomness occur under one roof. The concept of fuzzy random variable (FRV), mean and variance of FRV is used in the model. In particular, the methodology is developed in the presence of FRV in the constraint. The methodology is verified through numerical examples.     

Soliton dynamics in a modified Yakushevich model

We study a modified Yakushevich model with different disc diameters representing different bases and find two new in-phase solitonic solutions. We also discuss here the effect of helical structure which acts as perturbation on soliton centre of mass.     

Quantitative determination of saroglitazar,a predominantly PPAR alpha agonist,in human plasma by a LC–MS/MS method utilizing electrospray ionization in a positive mode

A sensitive LC–MS/MS method was developed and validated for quantitation of saroglitazar using turboion spray interface with positive ion mode. A liquid–liquid extraction, with a mixture of dichloromethane and diethyl ether, was employed for the extraction of saroglitazar and glimepiride (IS) from human plasma. The chromatographic separation was achieved using an ACE‐5, C₁₈ (4.6 × 100 mm) column with a gradient mobile phase comprising acetonitrile and ammonium acetate buffer with trifluoracetic acid in purified water. Both analytes were separated within 10 min with retention times of 4.52 and 2.57 min for saroglitazar and IS, respectively. Saroglitazar quantitation was achieved by the summation of two MRM transition pairs (m/z 440.2 to m/z 366.0 and m/z 440.2 to m/z 183.1), while that of IS was achieved using transition pair m/z 491.3 to m/z 352.0. The calibration standards of saroglitazar showed linearity from 0.2 to 500 ng/mL, with a lower limit of quantitation of 0.2 ng/mL. The biases for inter‐ and intra‐batch assays were ?7.51–1.15% and ?11.21 to ?3.25%, respectively, while the corresponding precisions were 5.04–8.06% and 1.53–7.68%, respectively. The developed method was used to monitor the plasma concentrations of saroglitazar in clinical samples.     

Rapid Access to Substituted Indenones through Grignard Reaction and Its Application in the Synthesis of Fluorenones Using Ring Closing Metathesis

An efficient, one-step method has been used to access a variety of substituted indenones in a regiospecific manner by Grignard addition to indene-1,3-dione. This method provides straightforward access to natural products such as neo-lignans and isoampelopsin D analogues. Moreover, diallyl indenones have been synthesized and employed as ring-closing metathesis (RCM) precursors for the facile synthesis of substituted fluorenone derivatives through an RCM-aromatization sequence.     

Iodine as a mild, efficient, and cost-effective catalyst for the synthesis of thiiranes from oxiranes

We developed an efficient protocol for the synthesis of thiiranes from oxiranes using a catalytic amount of molecular iodine. The notable features of this procedure are mild reaction conditions, high conversions, short reaction times, economic viability of the reagents, compatibility with various functionalities, and simple experimental/product isolation procedures which make it a useful and attractive process for the synthesis of a range of thiiranes.