Efavirenz oral delivery via lipid nanocapsules: formulation,optimisation, and ex‐vivo gut permeation study

Present investigation aimed to prepare, optimise, and characterise lipid nanocapsules (LNCs) for improving the solubility and bioavailability of efavirenz (EFV). EFV‐loaded LNCs were prepared by the phase‐inversion temperature method and the influence of various formulation variables was assessed using Box–Behnken design. The prepared formulations were characterised for particle size, polydispersity index (PdI), zeta potential, encapsulation efficiency (EE), and release efficiency (RE). The biocompatibility of optimised formulation on Caco‐2 cells was determined using 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyltetrazolium bromide assay. Then, it was subjected to ex‐vivo permeation using rat intestine. EFV‐loaded LNCs were found to be spherical shape in the range of 20–100 nm with EE of 82–97%. The best results obtained from LNCs prepared by 17.5% labrafac and 10% solutol HS15 when the volume ratio of the diluting aqueous phase to the initial emulsion was 3.5. The mean particle size, zeta potential, PdI, EE, drug loading%, and RE during 144 h of optimised formulation were confirmed to 60.71 nm, −35.93 mV, 0.09, 92.60, 7.39 and 55.96%, respectively. Optimised LNCs increased the ex vivo intestinal permeation of EFV when compared with drug suspension. Thus, LNCs could be promising for improved oral delivery of EFV.Inspec keywords: biomedical materials, solubility, drugs, encapsulation, emulsions, nanoparticles, particle size, nanofabrication, suspensions, toxicology, nanomedicine, cellular biophysics, lipid bilayers, electrokinetic effects, drug delivery systems, molecular biophysicsOther keywords: ex‐vivo permeation, diluting aqueous phase, mean particle size, zeta potential, drug loading, optimised formulation, ex vivo intestinal permeation, improved oral delivery, efavirenz oral delivery, optimisation, ex‐vivo gut permeation study, solubility, bioavailability, phase‐inversion temperature method, formulation variables, Box–Behnken design, polydispersity index, encapsulation efficiency, Caco‐2 cells, lipid nanocapsules, 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyltetrazolium bromide assay, EFV‐loaded LNC, drug suspension, size 20.0 nm to 100.0 nm, time 144.0 hour, size 60.71 nm, voltage ‐35.93 mV     

Comparison of response for three different composite pavement sections to environmental loads

Composite pavement structures are constructed mainly either as Portland cement concrete (PCC)-over-PCC or hot mix asphalt (HMA)-over-PCC. Several successful in-service projects have been reported in Europe. The design and construction of these sections in the United States, however, still require effort. The current study includes the analysis of the response of three different composite pavement sections to the environmental loads. These sections were constructed in May of 2010 at the Minnesota Road Research Facility. The sections are constructed in three individual cells, Cell 70, a HMA-over-PCC with recycled concrete aggregate (RCA), Cell 71, exposed aggregate concrete (EAC)-over-RCA and Cell 72, EAC-over-economical concrete. All cells were heavily instrumented with thermocouples, moisture sensors, and static and dynamic strain gauges. This study characterises the structural response of HMA-over-PCC pavements and also PCC-over-PCC to the environmental loads.     

A Crest Factor Reduction Scheme with Optimum Spacing Peak Cancellation for Intra-band Non-contiguous Carrier Aggregated OFDM Signals

Wireless Personal Communications - Recent development in communications have increased the demand of internet protocol (IP)-based multimedia conferencing services. Session initiation protocol (SIP)...     

Thermal stability of additively manufactured austenitic 304L ODS alloy

Thermal stability and high-temperature mechanical properties of a 304L austenitic oxide dispersion strengthened(ODS)alloy manufactured via laser powder bed fusion(LPBF)are examined in this work.Additively manufactured 304LODS alloy samples were aged at temperatures of 1000,1100,and 1200℃for 100h in an argon atmosphere.Microstructure characterization of LPBF 304L ODS alloy before and after the thermal stability experiments revealed that despite the annihilation of dislocations,induced cellular substructure by the LPBF process was partially retained in the ODS alloy even after aging at 1200℃.The size of Y-Si-O nanoparticles after aging at 1200℃increased from 25 to 50 nm.EBSD analysis revealed that nanoparticles retained the microstructure of LPBF 304L ODS and hindered recrystallization and further grain growth.At 600℃and 800℃,the yield stress of the 290 and 145 MPa were measured,respectively,which are substantially higher than 113 MPa,and 68 MPa for 304L at the same temperatures.Furthermore,the creep properties of LPBF 304L ODS alloy were evaluated at a temperature of 700℃under three applied stresses of 70,85,and 100 MPa yielding a stress exponent(n)of～7.7;the minimum creep rate at 100 MPa was found to be about two orders of magnitude lower than found in the literature for wrought 304L stainless steel.     

A new model for discovering process trees from event logs

Process mining techniques aim at extracting knowledge from event logs. One of the most important tasks in process mining is process model discovery. In discovering process models, an algorithm is designed to build a process model from a given event log. In this paper, a new model to discover process models has been proposed. A combination of Genetic Algorithm and Simulated Annealing has been used in this model. Genetic Algorithms has previously been used in this context. Previous approaches had drawbacks in fitness evaluation that misguided the algorithm. Another problem was that the quality of the candidates, in the population, was low such that it reduced the chance of finding a perfect answer. In this paper, a new fitness measure has been proposed to evaluate process models based on event logs. Moreover SA has been used to improve the quality of candidates in the population. It has been demonstrated that the proposed model outperformed in terms of rediscovering process models, compared to other approaches which are proposed in the literature, which was the result of better fitness evaluation and increased quality of individuals,. It came to conclusion that using GA and SA in combination with each other can be effective in this context.     

A grid workflow Quality-of-Service estimation based on resource availability prediction

Accurate estimation of workflow Quality of Service (QoS) enhances the efficiency of scheduling algorithms. The availability and performance variations of Grid computing resources have made this estimation a great challenge. Most workflow QoS estimation algorithms are based on static performance of resources. In this paper, based on resources availability prediction, we propose an algorithm called WQE for estimating the QoS of a Grid workflow. WQE consists of two phases: resource monitoring and analysis and workflow QoS computation. In the first phase, two prediction algorithms are proposed to stochastically predict the availability state of resources. In the second phase, the QoS of each activity is estimated based on the host availability prediction result. The QoS of basic structures is computed by aggregating the QoS of their operands. Using a tree structure corresponding to the workflow, the QoS of basic structures is used to compute the total QoS of the workflow. The simulation results on Notre Dame University trace showed that the proposed method has higher estimation accuracy in comparison with HEFT.     

Hybrid silane-treated glass fabric/epoxy composites: tensile properties by micromechanical approach

The effect of interface modification on the interfacial adhesion and tensile properties of glass fabric/epoxy composites was evaluated in two directions of 0° and +45°. Herein, the glass fabric surface was modified by colloidal nanosilica particles and by a new blend of silane-coupling agents including both reactive and non-reactive silanes. Composite samples with high strength and toughness were obtained. A simultaneous improvement of tensile strength and toughness was observed for an epoxy composite reinforced with a hybrid-sized glass fabric including silane mixture and nanosilica. In fact, the incorporation of colloidal silica into the hybrid sizing dramatically modified the fiber surface texture and created mechanical interlocking between the glass fabric and resin. The results were analyzed by the rule of mixtures (ROM), Halpin–Tsai (H–T), and Chamis equations. It was found that the ROM equations provided approximate upper bound values for all investigated composite samples. In the samples containing nanosilica, the shear and elastic moduli values calculated by the Chamis and ROM equations showed good agreement with those obtained from experiments. However, in other samples, the values calculated by the H–T equation showed a better agreement with the experimental data. The analysis of fracture surfaces indicated that both silane and nanosilica particles had influence on the mode of failures at the interface.     

Achieving maximum bit rate in a cognitive radio network with physical layer network coding

In this paper, the power allocation problem in a relay‐assisted cognitive radio network (CRN) is considered where the secondary users exchange information in an interweave mode on the basis of physical layer network coding. In order to enhance the capacity of CRN, using multiple‐input multiple‐output and orthogonal frequency division multiplexing has become very popular in the literature. This paper goes one step further to improve the throughput of secondary users using physical layer network coding by drawing off the transmission time. The main goal is to maximize the capacity of CRN, while keeping the total interference imposed on the primary users under a certain threshold. An optimal solution to this power allocation problem with limited relay power constraint, due to the limited budget, is derived; however, because of the high complexity of this method, an efficient suboptimal solution is also proposed.