Self-nanoemulsifying drug delivery system of docosahexanoic acid: development,in vitro,in vivo characterization

Context: Docosahexanoic acid (DHA) is an essential omega-3 fatty acid for normal brain development and its use has increased considerably in recent years.

Objective: The aim of this study is to develop and evaluate self-nanoemulsifying drug delivery systems (SNEDDS) of DHA for improved palatability, dispersibility and bioavailability.

Methods: The SNEDDS were prepared and evaluated for miscibility, employing different combinations of olive oil and soyabean oil as oil phase, Span 80, Span 20, soya phosphatidylcholine, Labrafil M 1944 CS as surfactants while Tween 80, PEG 400, Cremophor RH40 and propylene glycol as cosurfactants. Thermodynamically stable SNEDDS were characterized for dispersibility, self-emulsification time, droplet size, zeta potential along with sensory analysis. The optimized formulation was subjected to ex vivo and in vivo evaluation such as intestinal permeability, memory performance test, brain concentration and histopathology studies.

Results: The optimized SNEDDS formulation showed emulsification time of 27?±?4.7?s with droplet size of 17.6?±?3.5?nm and zeta potential of??37.6?±?0.5?mV. Intestinal absorption study depicted 18.3%, 21.5%, 41.5%, 98.7% absorption of DHA with SNEDDS-based formulation in comparison to 8.2%, 15.1%, 28.8%, 46.1% absorption of DHA with oil-based marketed formulation after 0.5, 1, 2 and 4?h. DHA concentration in brain homogenate was found to be increased to 2.6-fold in comparison to DHA-marketed formulation. This could be ascribed to enhanced dispersibility and bioavailability of DHA from nanosized formulation.

Conclusion: The developed formulation led to enhanced dispersibility and bioavailability of DHA due to the formation of nanodroplets.     

Note on flash and distillation systems

Flash and distillation systems evolving on the equilibrium manifold possess stable steady states when the molar flows and the boundary conditions are fixed and a vapor and liquid phase is present at all times. The results extend the range of validity of a local stability theorem for linear, constant molar overflow systems due to Acrivos and Amundson. The approach to stability analysis is motivated by the tangent plane method developed by Gibbs to open systems as it takes advantage of the negative curvature of the entropy surface to construct a Lyapunov function. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3322–3332, 2013     

Studies for Wear Property Correlation for Carbon Fabric-Reinforced PES Composites

Polyethersulfone (PES) composites were developed with carbon fabric (CF). Cold remote nitrogen oxygen plasma (CRNOP) treatment was employed to the CF to incorporate functional groups and promote fiber–matrix adhesion. This study includes the effect of PES melt flow index (MFI) on the wettability of CF and its influence on fretting wear performance. Evaluations of fretting wear properties of composites led to the conclusion that the CRNOP treatment proved beneficial to enhance performance properties significantly. Polymer MFI and treatment to CF proved to be the decisive parameters for controlling performance of composites apart from operating parameters. Perforations on the treated carbon fiber, evidently observed by FESEM, improved the fiber–matrix adhesion, and hence the performance properties. Artificial neuron network (ANN) was used for prediction of the wear behavior of composites.     

CAMP: cluster aided multi-path routing protocol for wireless sensor networks

Wireless Networks - In this article, we propose a novel routing algorithm for wireless sensor network, which achieves uniform energy depletion across all the nodes and thus leading to prolonged...     

Electrochemical evaluation of the synergistic effect of molybdate tungstate inhibitor mixtures in chloride ion medium and effect of Cl− ion on inhibition efficiency of molybdate

It is well known to corrosion community about chromates and nitrates which are widely used as corrosion inhibitors. However, it is also well known that these inhibitors are oxidizing inhibitors of which chromates are carcinogenic also. Therefore, use of non toxic inhibitors such as molybdate and tungstate are gaining importance. AC impedance analysis of mild steel panels exposed to 3% NaCl containing 6000 ppm molybdate, 5000 ppm molybdate + 1000 ppm tungstate, 3000 ppm molybdate + 3000 ppm tungstate, 1000 ppm molybdate + 5000 ppm tungstate, 6000 ppm tungstate were evaluated. The impedance studies were carried out for different durations viz. 1 hour, 1 day and 7 days. From impedance analysis, it is clear that molybdate and tungstate are not forming any promising synergistic mixtures. The effect of chloride ion concentration viz. 0.01M, 0.05M, 0.1M, 0.3M and 0.6M on inhibition efficiency of molybdate has been discussed. Addition of small amount of tungstate along with molybdate enhances long term film stability on mild steel. It has been found that the inhibition effect is decreasing with increase in concentration up to 0.1M and on further increase in concentration viz. 0.3M and 0.6M, an increase in inhibition efficiency was observed. It has been found that deaeration negatively affected the film properties and did not form a stable film. The corrosion products formed were analyzed using Mössbauer spectroscopy and FT-IR spectroscopy, which showed the presence of oxyhydroxides.     

In situ micro/nano-hydrogel synthesis from acrylamide derivates with lecithin organogel system

Acrylamide based hydrogel particles with variable charge were synthesized in different sizes using a biocompatible surfactant. We use microemulsion polymerization to synthesize the hydrogel particles in lecithin organogel systems. The phospholipid, lecithin, is a soybean extract that exhibits a rich phase behavior depending on various factors such as amount of water, co-solvent, additives and their concentrations. By UV irradiation of water-in-oil microemulsions of lecithin, containing different monomers, phospholipid coated hydrogels were synthesized in situ. The hydrogel particle size varies from a few hundred nanometers to tens of micrometer. The response time of these micron sized hydrogel particles, as measured by swelling experiments, is very fast (∼10⁰ s) in comparison with their corresponding bulk hydrogels (∼10¹ h). The positively charged cationic hydrogel microparticles were embedded/dispersed into another hydrogel matrix to render responsive behavior to a non-responsive matrix. Besides TEM and SEM studies, fluorescein dye absorption studies were also performed in order to visualize the hydrogel microparticles. Additionally, anionic hydrogel micro/nano-particles were also synthesized in the lecithin system.     

Utility scale wind turbines on a grid-connected island: A feasibility study

This paper analyzes the technical and economic feasibility of installing utility-scale wind turbines on the Fox Islands, located 12 miles from the coast of Maine in the United States. Three locations on the islands, as well as a near offshore site, are analyzed in detail as potential sites for wind turbine installations. As discussed in this work, the logistic problems of transporting and installing wind turbines on the island require innovative solutions. These include locally available amphibious vessels, which can land turbine components at suitable shallow spots on the island, self-erecting towers, which allow use of a smaller crane for installation, and a special turbine foundation suitable for the local ground conditions. In the economic analysis, in addition to standard life-cycle parameters, renewable energy credits (REC) were also included. This work concludes that the installation of sub-megawatt wind turbines on the island is logistically possible and will lead to a reduction in the cost of electricity to the customers.     

Hill slope instability of Nainital City,Kumaun Lesser Himalaya,Uttarakhand, India

Nainital City of Kumaun Lesser Himalaya is prone to mass wasting processes during monsoon season, which mischievously triggers the hill slope instability in this region. Slate, dolomitic limestone, silty sandstone and rhythmite of the Krol Formation are the main rock types. The present study focuses on the investigation of slope stability in the region in terms of potential seismicity and landslide. Geological and geotechnical mapping indicates that the major portion of the area is characterized by slope wash materials and buildings. The combination of 3–4 joint sets with one random joint is the main structure at outcrops. The major geological structures of this area are Nainital lake fault passing from the center of the lake, Main Boundary Thrust at SW, and Khuriya Fault passing from the SE direction of Nainital City. This work finds that different types of discontinuities (e.g. joints and faults), overburden due to unplanned civil structures, and neotectonic activity in the vicinity of this area affect the stability of the city. The slate forms the base of the city, dipping slightly towards the lake side along the NW direction, thus accelerating the instability of this area. Rock mass rating (RMR), slope mass rating, factor of safety (FOS) and graphical analysis of the discontinuity for slope kinematics indicate that the study area is a landslide-prone zone. This study can facilitate reducing the risk of human life, and contribute to the ongoing construction works in the area.     

Interaction of lanthanide and actinide with BaHfO3 perovskite: A case study with cerium and uranium

Speciation of actinide (An) and lanthanide (Ln) in technologically important ceramics is very important from both fundamental as well as technological aspects. The intrinsic structural flexibility of perovskite containing AO₆ and BO₁₂ polyhedra makes them suitable and rich hosts for An and Ln. In this work, emphasis was given to deciphering information such as oxidation state, local dopant site, charge compensating defects, excited state kinetics, and so forth in BaHfO₃ (BHO) related to dopant uranium (BHO-U) and cerium (BHO-Ce). Several spectroscopic techniques namely, time-resolved photoluminescence (TRPL), positron annihilation lifetime spectra (PALS), and thermoluminescence (TL) spectroscopy coupled with density functional theory (DFT) were employed to probe the same. Ce and U though are distributed at both Ba and Hf sites, Ce prefers the former, while U prefers the latter site. Uranium on the other hand stabilizes as U⁶⁺ in the form of octahedral uranate ion giving green emission. PALS suggested the formation of defects in BHO-Ce and BHO-U with oxygen vacancies predominating in the former whereas BHO-U perovskites are loaded with cation vacancies and vacancy clusters. These cation vacancies are responsible for lower TL output in BHO-U. TL measurements also suggested cerium doping leads to a higher density of deeper traps in BHO-Ce compared to uranium doping in BHO-U which is in concurrence with DFT results and may have implications in designing afterglow phosphors based on perovskite. We believe this work would have a long-term impact on exploring the potential of perovskite for nuclear waste host and afterglow phosphors applications.     

Dynamic modeling of drainage through three-dimensional porous materials

The interplay of viscous, gravity and capillary forces determines the flow behavior of two or more phases through porous materials. In this study, a rule-based dynamic network model is developed to simulate two-phase flow in three-dimensional porous media. A cubic network analog of porous medium is used with cubic bodies and square cross-section throats. The rules for phase movement and redistribution are devised to honor the imbibition and drainage physics at pore scale. These rules are based on the pressure field within the porous medium that is solved for by applying mass conservation at each node. The pressure field governs the movement and flow rates of the fluids within the porous medium. Film flow has been incorporated in a novel way. A pseudo-percolation model is proposed for low but non-zero capillary number (ratio of viscous to capillary forces). The model is used to study primary drainage with constant inlet flow rate and constant inlet pressure boundary conditions. Non-wetting phase front dynamics, apparent wetting residuals (S_wr), and relative permeability are computed as a function of capillary number (N_ca), viscosity ratio (M), and pore-throat size distribution. The simulation results are compared with experimental results from the literature. Depending upon the flow rate and viscosity ratio, the displacement front shows three distinct flow patterns—stable, viscous fingering and capillary fingering. Capillary desaturation curves (S_wr vs. N_ca) depend on the viscosity ratio. It is shown that at high flow rates (or high N_ca), relative permeability assumes a linear dependence upon saturation. Pseudo-static capillary pressure curve is also estimated (by using an invasion percolation model) and is compared with the dynamic capillary pressure obtained from the model.