Strengthening Erdös–Pósa property for minor‐closed graph classes

Let ?? and ?? be graph classes. We say that ?? has the Erd?s–Pósa property for ?? if for any graph G ∈??, the minimum vertex covering of all ??‐subgraphs of G is bounded by a function f of the maximum packing of ??‐subgraphs in G (by ??‐subgraph of G we mean any subgraph of G that belongs to ??). Robertson and Seymour [J Combin Theory Ser B 41 (1986), 92–114] proved that if ?? is the class of all graphs that can be contracted to a fixed planar graph H, then ?? has the Erd?s–Pósa property for the class of all graphs with an exponential bounding function. In this note, we prove that this function becomes linear when ?? is any non‐trivial minor‐closed graph class. © 2010 Wiley Periodicals, Inc. J Graph Theory 66:235‐240, 2011     

Nasal in situ gel containing hydroxy propyl ��-cyclodextrin inclusion complex of artemether: development and in vitro evaluation

The objective of the present investigation was to explore the formulation and evaluation of in situ gel for the nasal delivery of artemether (ARM), a poorly water-soluble antimalarial agent using temperature induced gelation technique using Pluronic with mucoadhesive polymer Hydroxy Propyl Methyl Cellulose (HPMC) K4M in different ratios. Initially, due to low water solubility, an inclusion complex of the antimalarial artemether (ARM) in hydroxypropyl-??-cyclodextrin (HP??CD) was prepared and characterized. The in situ gels so prepared were characterized for its gelation properties, viscosity, gel strength, mucoadhesion, drug content, drug release rate and for its histopathological studies. Pluronic and HPMC based in situ gel (PLH2) showed the effective gelation, viscosity, gel strength and drug release properties along with good mucoadhesive strength, it is further subjected for stability studies carried out at 30 ± 2 °C and 60 ± 5% RH for 90 days in order to know the influence of temperature and relative humidity on drug content and on drug release profile. Histological examination of formulations did not show any remarkable damage to nasal mucosa. The formulation also retained the good stability at accelerated conditions over the period of 90 days. Owing to these properties it can be used as an effective delivery system for the nasal route. These in situ gelling systems would be definitely useful for cerebral malaria.     

Perspectives on ab initio molecular simulation of excited-state properties of organic dye molecules in dye-sensitised solar cells

In this mini-review, we summarise and critique the emerging field of quantum-based molecular simulation of dye-sensitised solar cells (DSSCs), with particular focus on the deployment of organic-based dyes therein. We assess the underlying methodologies, including developments, pitfalls and challenges, whilst gauging predictive performance vis-à-vis experimental performance. The predictive capabilities of simulation methods with respect to elucidation of underlying methods is considered in the light of progress towards the ultimate goal of predictive in silico design of DSSCs, to complement hand-in-hand experimental approaches in the development of state-of-the-art DSSC devices.     

Spin‐1 Bose Hubbard Model with Nearest Neighbour Extended Interaction

A spinor () Bose gas is studied in presence of a density‐density interaction through a mean field approach and a perturbation theory for either sign of the spin dependent interaction, namely the antiferromagnetic (AF) and the ferromagnetic cases. In the AF case, the charge density wave (CDW) phase appears to be sandwiched between the Mott insulating (MI) and the supersolid phases for small values of the extended interaction strength. But the CDW phase completely occupies the MI lobe when the extended interaction strength is larger than a certain critical value related to the width of the MI lobes and hence opens up the possibilities of spin singlet and nematic CDW insulating phases. In the ferromagnetic case, the phase diagram shows similar features as that of the AF case and are in complete agreement with a spin‐0 Bose gas. The perturbation expansion calculations nicely corroborate the mean field phase results in both these cases. Further, we extend our calculations in presence of a harmonic confinement and obtained the momentum distribution profile that is related to the absorption spectra in order to distinguish between different phases.     

Tunneling conductance study of a metal-superconductor junction in the presence of Rashba spin orbit coupling

The tunneling conductance for a junction device consisting of a normal metal and a singlet superconductor is studied with Rashba spin orbit coupling (RSOC) being present in the metallic lead and the interface separating the two regions via an extended Blonder-Tinkham-Klapwijk (BTK) formalism. Interesting interplay between the RSOC and a number of parameters that have experimental significance, and characterize either the junction or the superconducting leads, such as the barrier transparency, quasiparticle lifetime, Fermi wavevector mismatch, an in-plane magnetic field and their effects on the tunneling conductance are investigated in details for both a s-wave and a d-wave superconductor. In an opaque barrier, in presence of a quasiparticle lifetime, a Fermi wavevector mismatch or an external in-plane magnetic field, RSOC enhances the conductance corresponding to low biasing energies, that is, at energies lesser than the superconducting gap, while the reverse is noted for energies exceeding the magnitude of the gap. Further, there are exciting anomalies noted in the conductance spectrum for the d-wave gap which can be understood by incorporating the interplay between the superconducting gap and the angle of incident of the charge carriers.     

Alkaloidal Phytoconstituents for Diabetes Management: Exploring the Unrevealed Potential

The main characteristic feature of diabetes mellitus is the disturbance of carbohydrate, lipid, and protein metabolism, which results in insulin insufficiency and can also lead to insulin resistance. Both the acute and chronic diabetic cases are increasing at an exponential rate, which is also flagged by the World Health Organization (WHO) and the International Diabetes Federation (IDF). Treatment of diabetes mellitus with synthetic drugs often fails to provide desired results and limits its use to symptomatic treatment only. This has resulted in the exploration of alternative medicine, of which herbal treatment is gaining popularity these days. Owing to their safety benefits, treatment compliance, and ability to exhibit effects without disturbing internal homeostasis, research in the field of herbal and ayurvedic treatments has gained importance. Medicinal phytoconstituents include micronutrients, amino acids, proteins, mucilage, critical oils, triterpenoids, saponins, carotenoids, alkaloids, flavonoids, phenolic acids, tannins, and coumarins, which play a dynamic function in the prevention and treatment of diabetes mellitus. Alkaloids found in medicinal plants represent an intriguing potential for the inception of novel approaches to diabetes mellitus therapies. Thus, this review article highlights detailed information on alkaloidal phytoconstituents, which includes sources and structures of alkaloids along with the associated mechanism involved in the management of diabetes mellitus. From the available literature and data presented, it can be concluded that these compounds hold tremendous potential for use as monotherapies or in combination with current treatments, which can result in the development of better efficacy and safety profiles.