Simultaneous bioanalysis and pharmacokinetic interaction study of acebrophylline,levocetirizine and pranlukast in Sprague–Dawley rats

The combination of acebrophylline (ABP), levocetirizine (LCZ) and pranlukast (PRN) is used to treat allergic rhinitis, asthma, hay‐fever and other conditions where patients experience difficulty in breathing. This study was carried out with the aim of developing and validating a reverse‐phase high‐performance liquid chromatographic bioanalytical method to simultaneously quantitate ABP, LCZ and PRN in rat plasma. The objective also includes determination of the pharmacokinetic interaction of these three drugs after administration via the oral route after individual and combination treatment in rat. Optimum resolution between the analytes was observed with a C₁₈ Kinetex column (250 mm × 4.6 mm × 5 μm). The chromatography was performed in a gradient elution mode with a 1 mL/min flow rate. The calibration curves were linear over the concentration range of 100–1600 ng/mL. The intra‐ and inter‐day precision and accuracy were found to be within acceptable limits as specified in US Food and Drug Administration guideline for bioanalytical method validation. The analytes were stable on the bench‐top (8 h), after three freeze–thaw cycles, in the autosampler (8 h) and as a dry extract (?80°C for 48 h). The statistical results of the pharmacokinetic study in Sprague–Dawley rats showed a significant change in pharmacokinetic parameters for PRN upon co‐administration of the three drugs.     

2-Isopropylbenzimidazole and 2-methylbenzimidazole as bulky proton sources: Stereoselective protonation and application to the synthesis of γ- and δ-lactones

2-Isopropylbenzimidazole and 2-methylbenzimidazole have been found to be effective bulky proton sources for stereoselective protonation of chiral enolate anions. 2-Isopropylbenzimidazole worked in the stereoselective protonation of the Birch reduction of chiral α,β-unsaturated imides. On the other hand, 2-methylbenzimidazole was found to be the best protonation reagent in the isomerization reaction of α,β-unsaturated imide into β,γ-unsaturated imide. The Birch reduction using 2-isopropylbenzimidazole realized a concise and stereoselective synthesis of δ-lactone 14, a sex pheromone of Macrocentrus grandii, while the isomerization reaction using 2-methylbenzimidazole was employed in the highly stereoselective synthesis of the γ-lactone intermediate in the synthesis of depsipeptide antibiotics. These bulky proton sources would be powerful tools to achieve a concise synthesis of natural products.     

Cost Optimization Technique for Quantum Circuits

In this paper, an attempt is made to present a method of quantum cost minimization or optimization technique for quantum reversible circuits using proposed merger rules in Exclusive Sum of Product (ESOP) method. These modified ESOP methods are used to minimize the quantum circuits. We found that the quantum cost is drastically decreased than the previous ESOP method. It will be easy to find the quantum cost and quantum gate optimized quantum circuits implementation. It will also reduce quantum error while the quantum circuit is executed in real quantum processor.

     

Study on some aspects of the “singer's formant” in north indian classical singing

This article deals with a spectrographic analysis of the singer's formant as occurred during singing of the vowels /a/, /i/, and /o/ in North Indian classical vocal music. The resonance balance, center frequency, and band-width are shown as a function of fundamental frequency for eight singers.Two new parameters have been defined viz. asymmetry parameter (A) and spectral energy balance (W). Their variation with fundamental frequency is shown.     

A preliminary assessment of microstructural and compositional characteristics of two variants of precarbonated and postcarbonated concrete mixes

The hydration, precarbonation, and postcarbonation microstructural and compositional attributes of 2 variants of concrete were studied using scanning electron microscope, energy dispersive spectroscopy, and X‐ray diffraction techniques. Results obtained showed presence of large number of diffraction peaks indicative of SiO₂ as major phase. Higher pH, alkalinity, and absence of effects of carbonation were suggested from the presence of portlandite peaks. Evidence of effect of carbonation was studied through the analysis of the experimental diffraction peaks obtained postexposure to accelerated carbonation in a controlled environment. Presence of all the 3 polymorphs of calcium carbonate (CaCO₃) such as aragonite, vaterite, and calcite depending upon the moisture content and the material constituting the concrete sample were envisaged signifying carbonation. Precipitation of these CaCO₃ crystals was responsible for depletion of CH as well as calcium–silicate–hydrate, ettringite with the progress of carbonation as suggested by their absence in the X‐ray diffraction diffractograms of the carbonated samples. The crystal structure of the newly formed minerals in both the variants of concrete sample was highly controlled by the stages of carbonation, with development of amorphous CaCO₃ (amalgamated with that of calcium hydrates) in early stages of carbonation as well as fully developed rhombohedral CaCO₃ crystals in later stages.     

Magnetic field effect on indole exciplexes: an anomalous dielectric dependence

Individual exciplex formation between various aromatic hydrocarbons, anthracene, pyrene, all-s-trans-1,4-diphenylbuta-1,3-diene and a heteroaromatic amine, 1,2-dimethylindole, was investigated by steady-state fluorescence and magnetic field effect (MFE). A comparative study was carried out with two other exciplex systems 9-cyanophenanthrene-1,2-dimethylindole and 9-cyanophenanthrene-N-methylindole. The extent of charge transfer and dielectric dependence of MFE reveals the potential role of specific interactions related to exciplex geometry.     

Switching of one beam by another in a Kerr type nonlinear Mach–Zehnder interferometer

This paper investigates switching of one beam by another in a Kerr type nonlinear Mach–Zehnder interferometer (NMZI) with two input ports and one output port. The present investigation has been carried out using the beam propagation method (BPM). The paper presents a detailed account on the procedures used to choose the parameters of the NMZI to make it behave like a NOT gate (inverter), an AND gate, an amplifier and a wavelength converter. The paper also gives details on the manipulation of the operating inputs of the NMZI to desired values. It is shown that the operating values of both the inputs of the NMZI can simultaneously be increased/decreased by decreasing/increasing the nonlinearity coefficient of nonlinear arm of the NMZI. Variation of NMZI length varies the operating value of only the first input, keeping the second unchanged, while variation of NMZI offset varies the operating value of only the second, keeping the first unchanged. The paper also gives a detailed account on amplification of the NMZI amplifier/wavelength converter. The present investigation is useful from the scientific as well as engineering point of view.     

Steady State of Stochastic Sandpile Models

We study the steady state of the Abelian sandpile models with stochastic toppling rules. The particle addition operators commute with each other, but in general these operators need not be diagonalizable. We use their Abelian algebra to determine their eigenvalues, and the Jordan block structure. These are then used to determine the probability of different configurations in the steady state. We illustrate this procedure by explicitly determining the numerically exact steady state for a one dimensional example, for systems of size ≤12, and also study the density profile in the steady state.     

Black holes in brane worlds

A Kerr metric describing a rotating black hole is obtained on the three brane in a five-dimensional Randall-Sundrum brane world by considering a rotating five-dimensional black string in the bulk. We examine the causal structure of this space-time through the geodesic equations.     

Synthesis of 2-deamino- and 2-deamino-2-nitroactinomycin D

A single step synthesis of 2-deaminoactinomycin D ( 3a ) and 2-deamino-2-nitroactinomycin D ( 2a ) arising from actinomycin D ( 1a, AMD ) is reported. Structural confirmation was made by nmr, ir and chemical conversion to known materials.