Development,method validation and simultaneous quantification of eleven bioactive natural products from high-altitude medicinal plant by high-performance liquid chromatography

Herein, a novel, rapid, reliable, simple method validation and simultaneous quantification of 11 bioactive compounds (mostly xanthones) have been described. International Conference on Harmonization guidelines were used for the analytical method validation. Good linearity, repeatability, intra- and inter-day precision, accuracy and reliability were well-illuminated in the method validation procedure. The calibration curves showed a good linear relationship (r > 0.999) within test range. Precision was evaluated by intra- and inter-day tests with relative standard deviation <2.79% and accuracy validation recovery of 74.16%–91.84%. On quantification study, the validated method described the high content of bioactive xanthone derivatives, including 1-hydroxy-3, 5-dimethoxyxanthone ( 7 ), 2-(allyloxy)-8-hydroxy-1, 6-dimethoxyxanthone ( 6 ) 1, 7, 8-trihydroxy-3-methoxyxanthone ( 9 ) and Coxanthone E ( 5 ) in Codonopsis ovata, which is advantageous given the numerous pharmacological and biological effects associated with these compounds, which mostly exhibit anti-cancerous, antioxidant, anti-inflammatory, anti-mutagenic and anti-obesity effects. The bulk abundance of these compounds can also be used for further modification to produce better lead molecules for drug discovery with low toxicity and high potency. The proposed method makes it possible to simultaneously determine all bioactive compounds in one run and can be extended to marker-based standardization of herbal formulations in medicinal and pharmaceutical industries.     

Performance analysis of synchronous coherent optical systems in the presence of multiple in-line amplifiers

The performance of synchronous binary and M-ary coherent optical systems with cascaded optical amplifiers are analysed. From the relative performance of the various demodulation techniques that are compared in terms of power penalties due to amplifier input power, noise accumulation and bit rate, it is predicted that binary homodyne PSK and M-ary FSK schemes not only accommodate more noise accumulation due to multiple amplifiers but also facilitate improvement in dynamic range. The results on the performance of systems in the 1–10Gb/s range show that total system lengths of the order of 5000km can be achieved at 10Gb/s for 16-FSK and homodyne PSK for a bit error rate of 10−9 and 1 dB power penalty, whereas it is reduced by a factor of about two for DPSK which was the best of the direct detection and asynchronous coherent schemes that have been previously analysed. This revised version was published online in November 2006 with corrections to the Cover Date.     

The 0+ → 0+ positron double- β decay with emission of two neutrinos in the nuclei 96Ru, 102Pd, 106Cd and 108Cd

Theoretical results for two neutrinos in the nuclei ⁹⁶Ru, ¹⁰²Pd, ¹⁰⁶Cd and ¹⁰⁸Cd are presented. The study employs the Hartree-Fock-Bogoliubov model to obtain the wave functions of the parent and daughter nuclei, in conjunction with the summation method to estimate the double-beta decay nuclear matrix elements. The reliability of the intrinsic wave functions of ^{96, 102}Ru, ⁹⁶Mo, ^{102, 106, 108}Pd and ^{106, 108}Cd nuclei is tested by comparing the theoretically calculated spectroscopic properties with the available experimental data. The calculated half-lives T_1/2^2ν of ⁹⁶Ru, ¹⁰²Pd, ¹⁰⁶Cd and ¹⁰⁸Cd nuclei for 2ν β⁺β⁺, 2ν β⁺EC and 2ν ECEC modes are presented. The effect of deformation on the nuclear transition matrix element M_2ν is also studied.     

A subordination result involving Ruscheweyh derivatives and Hadamard product of certain classes of analytic functions

In the present paper we obtain an interesting subordination relation for a generalized subclass of analytic functions by using both the Hadamard product and Ruscheweyh derivatives. Some corollaries are also deduced as special cases of our main result.     

Ductile failure with gradient plasticity coupled to the phase-field fracture at finite strains

Most metals fail in a ductile fashion, i.e, fracture is preceded by significant plastic deformation. The modeling of failure in ductile metals must account for complex phenomena at micro-scale, such as nucleation, growth and coalescence of micro-voids. In this work, we start with von-Mises plasticity model without considering void generation. The modeling of macroscopic cracks can be achieved in a convenient way by the continuum phase field approaches to fracture, which are based on the regularization of sharp crack discontinuities [1]. This avoids the use of complex discretization methods for crack discontinuities and can account for complex crack patterns. The key aspect of this work is the extension of the energetic and the stress-based phase field driving force function in brittle fracture to account for a coupled elasto-plastic response in line with our recent work [3]. We develop a new theoretical and computational framework for the phase field modeling of ductile fracture in elastic-plastic solids. To account for large strains, the constitutive model is constructed in the logarithmic strain space, which simplify the model equations and results in a formulation similar to small strains. We demonstrate the modeling capabilities and algorithmic performance of the proposed formulation by representative simulations of ductile failure mechanisms in metals. (© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Sequence Analysis of KpnI Repeat Sequences to Revisit the Phylogeny of the Genus Carthamus L.

Repetitive DNA sequences constitute a significant proportion of eukaryotic genomes. Knowledge about the distribution of repetitive DNA sequences is necessary in order to gain insights into the organization, evolution and behavior of eukaryotic genomes. Therefore, we used two repetitive DNA sequences pCtKpnI-I and pCtKpnI-II, earlier reported in Carthamus tinctorius L. to study the phylogeny and to revise the taxonomic status of the taxa belonging to the genus. The study unraveled two major lines within the genus Carthamus; one line included all the diploid taxa (2n?=?24) and the other line comprised the taxa with 2n?=?20 and the polyploid taxa (2n?=?44 and 64). The results of the present study will prove useful in molecular breeding for improving some targeted agronomic traits in genus Carthamus.     

Effect of transition metal salt additive on the structural packing and thermal stability of the non-aqueous lyotropic mesophases

The present study demonstrates the interfacial interplay between transition metal salt (TMS) additive and range of non-aqueous lyotropic mesophases. Structural aspect reveals the substantial influence of the additive addition on the self-assembly and packing of micelles as intense growth of hexagonal planes was seen in the vicinity of the pre-existed lamellar mesophase (as the surfactant concentration loomed to the higher value in the parent binary mixture). Such structural modulations certainly resulted from reduction in optimal surface area of head group and packing parameter under the influence of interfacial interactions amid charged counter ions and metal salt additive. The origin and thermal stability of hexagonal ordering have been addressed and discussed.     

Structural and dielectric behaviour of non-aqueous lyotropic mixtures: influence of amphiphile chain lengths and counter ions

This study highlights the effects of amphiphile chain length and counter ions on the self-assembly and dielectric behaviour of non-aqueous lyotropic liquid crystals. Two-dimensional hexagonal mesophase is seen for short-chain length sodium dodecyl sulphate, while lamellar and multiwall lamellar mesophases are noticed for long-chain length cetyltrimethylammonium bromide and polyoxyethylene (20) sorbitan monolaurate amphiphiles in the non-aqueous domains of ethylene glycol. A strong influence of amphiphile counter ions is seen on static dielectric constant, loss factor, relaxation frequency and relaxation time of these lyotropic mixtures. Refractive indices of these lyotropic phases are also highlighted.     

Effect of solvent polarity on the self-assembly and dielectric dynamics of non-aqueous lyotropic liquid crystalline phases

Binary mixtures comprising cetylpyridinium chloride and non-aqueous solvents of varying polarity [ethylene glycol (ε ~ 37.2) and formamide (ε ~ 109)] were studied via X-ray diffraction, polarisation optical microscopy, differential scanning calorimetry and dielectric spectroscopy. Layered lamellar mesophase was observed in both mixtures. Formamide-based mesophase was found more ordered and stable up to higher temperature (140°C). Ordering and stability of the mesophase was explained considering the higher polarity and dipolar–dipolar interactions of formamide. Dielectric spectroscopy demonstrates the large magnitudes of capacitance and permittivity (Cp ≈ 9 µF and ε ≈ 2428) for mesophase derived from formamide. Dynamical relaxation parameters of both mixtures were discussed and correlated with their structural aspects.