An insight on human skin penetration of diflunisal: lipogel versus hydrogel microemulsion

Diflunisal is a NSAID used in acute and long term management of pain and inflammation associated with osteoarthritis, rheumatoid arthritis and symptoms of primary dysmenorrhea. However, its oral use is associated with side effects such as peptic ulceration, dyspepsia, gastrointestinal disturbances and bleeding. The aim of this work was to develop lecithin organogels (LO) transdermal delivery system for diflunisal and to study its human skin penetration ability in comparison with an optimized microemulsion-based hydrogel. Ternary phase diagrams were constructed using butyl lactate as an organic solvent and two commercial grades of lecithin. The formation of gel phase was lecithin concentration dependent with Phosholipion 85?G being capable of forming organogels at lower lecithin concentration than Lipoid S75. The gels prepared using butyl lactate were able to tolerate higher amounts of water than could be incorporated in the lipogels prepared with other organic solvents. All the investigated gels possessed acceptable physical properties and were able to deliver diflunisal through human skin. The lipogels delivered higher total drug amount through the skin than the hydrogel. The composition of lecithin seemed to have some effect on the skin permeability enhancement ability of the lipogel. Lecithin containing higher amount of phosphatidyl ethanolamine could provide better transdermal delivery. The elaborated lecithin organogels are potential carriers that create a good opportunity for transdermal delivery of diflunisal overcoming the side effects associating its oral route.     

Integer programming models for logical layout design of modular machining lines

The preliminary design or reconfiguration of modular manufacturing lines is addressed. The modules are multi-spindle units. Each unit executes a subset of operations. The set of all available spindle units and their costs are known. The problem is to select the right spindle units and to arrange them into linear workstations. The objective is to design such a line respecting technological constraints and minimizing the investment cost. In this paper, some efficient formulations of linear integer programming (IP) models and specific techniques to reduce the calculation time are proposed. Experiments were carried out which highlight the performance of the models.     

Coiled-coil molecular recognition: directed solution assembly of receptor ectodomains

The high affinity interleukin-2 (IL-2) receptor is composedof at least three cell surface proteins (, ß and subunits), each of which is independently capable of ligandbinding. Physiologically, these subunits cooperate to form dimericand trimeric complexes that efficiently capture IL-2 and transmitthe signal across the membrane. The knowledge of how each subunitfunctions with respect to ligand capture, signal transmissionand internalization is essential for the development of ligand-basedIL-2 agonists and antagonists, as well as receptor-related therapeuticand diagnostic reagents. Only one of the subunits (p55 or chain)is capable of interacting with ligand in solution in a mannerthat resembles cell surface binding. To generate soluble multhnerkcomplexes of the IL-2 receptor subunits that may bind ligandin solution in a fashion that mimics the same receptor complexeson the cell surface, we have added recognition sequences (coiled-coilheptad repeats) to the ectodomains of the individual receptors.Here we describe the expression and characterization of a prototypeIL-2ß receptor ectodomain-coiled-coil fusion proteinand demonstrate that this is a feasible approach to the preparationof cytokine receptor solution complexes.     

Intelligent reversible watermarking in integer wavelet domain for medical images

The prime requirement of reversible watermarking scheme is that the system should be able to restore the cover work to its original state after extracting the hidden information. Reversible watermarking approaches, therefore, have wide applications in medical and defense imagery. In this paper, an intelligent reversible watermarking approach GA-RevWM for medical images is proposed. GA-RevWM is based on the concept of block-based embedding using genetic algorithm (GA) and integer wavelet transform (IWT). GA based intelligent threshold selection scheme is applied to improve the imperceptibility for a fixed payload or vice versa. The experimental results show that GA-RevWM provides significant improvement in terms of imperceptibility for a desired level of payload against the existing approaches.     

Studies on thermal degradation kinetics and dielectric properties of polyether imide foam/nanosilica-based nanocomposites

ABSTRACT

In this paper, polyether imide (PEI) having properties such as a high glass transition temperature of 216°C, high heat resistance, high flame resistance, low smoke generation and a high melting point within the range of 400°C, having low thermal conductivity and low dielectric constant was chosen to be a polymeric foam. Water vapor-induced phase separation method was used to prepare PEI foams. PEI foams were reinforced with nano-silica (weight 1, 3 and 5%) in order to alter the dielectric properties, thermal conductivity and degradation kinetics of foamed polymer. The tested samples showed a reduction in dielectric constant than that of solid PEI but at a higher loading, it showed a higher value due to threshold percolation and a reduction in thermal conductivity was observed for foamed PEI. From thermogravimetric analysis, we can conclude that PEI with 3% filler loading showed better thermal stability compared to other PEI foam compositions.     

Methemoglobin Is an Endogenous Toll-Like Receptor 4 Ligand—Relevance to Subarachnoid Hemorrhage

Neuroinflammation is a well-recognized consequence of subarachnoid hemorrhage (SAH), and may be responsible for important complications of SAH. Signaling by Toll-like receptor 4 (TLR4)-mediated nuclear factor κB (NFκB) in microglia plays a critical role in neuronal damage after SAH. Three molecules derived from erythrocyte breakdown have been postulated to be endogenous TLR4 ligands: methemoglobin (metHgb), heme and hemin. However, poor water solubility of heme and hemin, and lipopolysaccharide (LPS) contamination have confounded our understanding of these molecules as endogenous TLR4 ligands. We used a 5-step process to obtain highly purified LPS-free metHgb, as confirmed by Fourier Transform Ion Cyclotron Resonance mass spectrometry and by the Limulus amebocyte lysate assay. Using this preparation, we show that metHgb is a TLR4 ligand at physiologically relevant concentrations. metHgb caused time- and dose-dependent secretion of the proinflammatory cytokine, tumor necrosis factor α (TNFα), from microglial and macrophage cell lines, with secretion inhibited by siRNA directed against TLR4, by the TLR4-specific inhibitors, Rs-LPS and TAK-242, and by anti-CD14 antibodies. Injection of purified LPS-free metHgb into the rat subarachnoid space induced microglial activation and TNFα upregulation. Together, our findings support the hypothesis that, following SAH, metHgb in the subarachnoid space can promote widespread TLR4-mediated neuroinflammation.     

A novel and effective PECVD SiO2/SiN antireflectioncoating for Si solar cells

It is shown that sequential plasma-enhanced chemical vapor deposition (PECVD) of SiN and SiO₂ can produce a very effective double-layer antireflection (AR) coating. This AR coating is compared with the frequently used and highly efficient MgF₂/ZnS double layer coating. The SiO₂/SiN coating improves the short-circuit current (J_SC) by 47%, open-circuit voltage (V_OC) by 3.7%, and efficiency (Eff) by 55% for silicon cells with oxide surface passivation. The counterpart MgF₂/ZnS coating gives similar but slightly smaller improvement in V_OC and Eff. However, if silicon cells do not have the oxide passivation, the PECVD SiO₂/SiN gives much greater improvement in the cell parameters, 57% in J_SC, 8% in V_OC, and 66% in efficiency, compared to the MgF₂/ZnS coating which improves J_SC by 50%, V_OC by 2%, and cell efficiency by 54%. This significant additional improvement results from the PECVD deposition-induced surface/defect passivation. The internal quantum efficiency (IQE) measurements showed that the PECVD SiO₂/SiN coating a absorbs fair amount of photons in the short-wavelength range (<500 nm); however, the improved surface/defect passivation more than compensates for the loss in J_SC and gives higher improvement in the cell efficiency compared to the MgF₂/ZnS coating     

Modeling and Simulation of a PMSG-based Marine Current Turbine System under Faulty Rectifier Conditions

This paper deals with the modeling and simulation of a permanent magnet synchronous generator (PMSG)-based marine current turbine (MCT) under faulty rectifier conditions. The modeling of the generator is established in the synchronous rotating d-q reference frame. The control of the speed, the d-axis current, and the q-axis current are achieved using proportional integral (PI) correctors. The faulty mode deals with the study of single and multiple open-switch damages appearing in the pulse width modulation (PWM) power rectifier. Simulations are carried out to highlight the proposed PMSG-based MCT performance in both cases using MATLAB/Simulink environment.