Physicochemical characterization and dissolution enhancement of loratadine by solid dispersion technique

The purpose of this investigation was to enhance the dissolution rate of loratadine using polyethylene glycol 6000 (PEG) solid dispersions (SDs). The solubility behavior of loratadine in the presence of polyethylene glycol 4000 and polyethylene glycol 6000 in water showed linear increase with increasing concentrations of PEG, indicating A _L type solubility diagrams. SDs of loratadine with PEG 6000 were prepared at 1: 1, 1: 3, 1: 5, 1: 7 and 1: 9 ratios by the solvent evaporation method. Solid dispersions were characterized for drug content, dissolution behavior and for physicochemical characteristics. The dissolution rate of loratadine was enhanced rapidly with increasing concentrations of PEG 6000 in SDs. Fourier transform infrared (FTIR) studies showed the stability of loratadine and the absence of a well-defined loratadine — PEG 6000 interaction. Differential scanning calorimetry (DSC) and X-ray powder diffractometry (XRD) studies revealed the amorphous state of loratadine in SDs of loratadine with PEG 6000 which was further confirmed from scanning electron microscopy (SEM) studies. The flow properties of the blend, physical characteristics and disintegration time of the tablets formulated indicated that PEG 6000 SD can be used to formulate fast release loratadine tablets.     

High flux nanofibrous membranes for colored effluent treatment

In this study, polyamide 66 (PA) and polyacrylonitrile (PAN) were electrospun with various arrangements on substrate surface. Spunbond–Meltblown–Spunbond polypropylene nonwoven (SMS) and carbon foam were applied as substrate to evaluate how filtration efficiency and flux is affected. In addition to substrate, the influence of polymer concentration and layer arrangement were studied. Taghuchi design was utilized for optimum structure recognition. A vat dye was used to study the filtration efficiency. The results have revealed that substrate type plays as the most effective factor among all parameters. SMS substrate was led to finer fibers fabrication, smaller pores, and therefore, superior filtration efficiency and higher flux. Although layer arrangement showed less impression than substrate, it was more effective than polymer concentration. Furthermore study on the base of Taghuchi design showed that by applying PAN/PA/PAN composite nanofibrous membrane on SMS substrate, a high filtration efficiency can be achieved by reduction of 99.58 and 86.13% turbidity and chemical oxygen demand, respectively.     

Unraveling the Potential Role of NEDD4-like E3 Ligases in Cancer

Cancer is a deadly disease worldwide, with an anticipated 19.3 million new cases and 10.0 million deaths occurring in 2020 according to GLOBOCAN 2020. It is well established that carcinogenesis and cancer development are strongly linked to genetic changes and post-translational modifications (PTMs). An important PTM process, ubiquitination, regulates every aspect of cellular activity, and the crucial enzymes in the ubiquitination process are E3 ubiquitin ligases (E3s) that affect substrate specificity and must therefore be carefully regulated. A surfeit of studies suggests that, among the E3 ubiquitin ligases, neuronal precursor cell-expressed developmentally downregulated 4 (NEDD4)/NEDD4-like E3 ligases show key functions in cellular processes by controlling subsequent protein degradation and substrate ubiquitination. In addition, it was demonstrated that NEDD4 mainly acts as an oncogene in various cancers, but also plays a tumor-suppressive role in some cancers. In this review, to comprehend the proper function of NEDD4 in cancer development, we summarize its function, both its tumor-suppressive and oncogenic role, in multiple types of malignancies. Moreover, we briefly explain the role of NEDD4 in carcinogenesis and progression, including cell survival, cell proliferation, autophagy, cell migration, invasion, metastasis, epithelial-mesenchymal transition (EMT), chemoresistance, and multiple signaling pathways. In addition, we briefly explain the significance of NEDD4 as a possible target for cancer treatment. Therefore, we conclude that targeting NEDD4 as a therapeutic method for treating human tumors could be a practical possibility.     

AQM controller design for networks supporting TCP vegas: a control theoretical approach

In this paper, a mathematical model and control theoretical framework for designing AQM controllers in networks supporting TCP Vegas is introduced. We have emphasized on a modified TCP Vegas algorithm that can respond to congestion signals through explicit congestion notification (ECN). The overall nonlinear delayed differential equations of the dynamics model of closed loop system have been derived based on TCP Vegas model. The model is then linearized to derive a transfer function representation between the packet marking probability and the bottleneck router queue length as the input and output of the modified TCP Vegas/AQM system. The model properties have been then examined especially for the case of single bottleneck homogeneous network which is closely investigated. Finally an AQM controller based on Coefficient Diagram Method (CDM) has been designed for the system and its performance has been compared with some other AQM controllers. CDM is a new indirect pole placement method that considers the speed, stability and robustness of the closed loop system in terms of time domain specifications. In order for synthesizing the simulation scenarios, our campus router traffic has been studied experimentally for a sample period of one hour and the corresponding parameters has been extracted. The simulation results are representative of good performance of developed TCP Vegas/AQM structure for different simulated scenarios.     

Integration of GaN analog building blocks on p-GaN wafers for GaN Ics

We demonstrate the key module of comparators in GaN ICs,based on resistor-transistor logic(RTL)on E-mode wafers in this work.The fundamental inverters in the comparator consist of a p-GaN gate HEMT and a 2DEG resistor as the load.The function of the RTL comparators is finally verified by a undervoltage lockout(UVLO)circuit.The compatibility of this cir-cuit with the current p-GaN technology paves the way for integrating logic ICs together with the power devices.     

Thermal radiation and slip effects on MHD stagnation point flow of non-Newtonian nanofluid over a convective stretching surface

The present analysis examines the combine effects of thermal radiation and velocity slip along a convectively nonlinear stretching surface. Moreover, MHD effects are also considered near the stagnation point flow of Casson nanofluid. Slipped effects are considered with the porous medium to reduce the drag reduction at the surface of the sheet. Main structure of the system is based upon the system of partial differential equations attained in the form of momentum, energy, and concentration equations. To determine the similar solution system of PDEs is rehabilitated into the set of nonlinear ordinary differential equations (ODEs) by employing compatible similarity transformation. Important physical parameters are acquired through obtained differential equations. To determine the influence of emerging parameters, resulting set of ODE’s in term of unknown function of velocity, temperature, and concentration are successfully solved via Keller’s box-scheme. All the obtained unknown functions are discussed in detail after plotting the results against each physical parameter. To analyze the behavior at the surface: skin friction, local Nusselt and Sherwood numbers are also illustrated against the velocity ratio parameter A, Brownian motion Nb, thermophoresis Nt, and thermal radiation parameters R. Results obtained from the set of equations described that skin friction is decreasing function of A, and local Nusselt and Sherwood number demonstrate the significant influenced by Brownian motion Nb, thermophoresis Nt, and radiation parameters R.

     

Impact of hydrophilic binders on stability of lipid-based sustained release matrices of quetiapine fumarate by the continuous twin screw melt granulation technique

Dose dumping is the major drawback of sustained release (SR) matrices. The current research aimed to develop the stable lipid-based SR matrices of quetiapine fumarate (QTF) using Geleol^TM (glyceryl monostearate; GMS) as the lipid matrix carrier and Klucel^TM EF (HPC EF), Kollidon® VA64, and Kollidon® 12PF as hydrophilic binders. Formulations were developed using advanced twin screw melt granulation (TSMG) approach and the direct compression (DC) technique. Compared with the blends of DC, the granules of TSMG exhibited improved flow properties and tabletability. Solid-state characterization by differential scanning calorimetry of the prepared granules exhibited the crystalline nature of the lipid. Fourier transform infrared spectroscopy demonstrated no interaction between the formulation ingredients. The compressed matrices of TSMG and DC resulted in the sustained release of a drug over 16–24 h. Upon storage under accelerated conditions for 6 months, the matrices of TSMG retained their sustained release characteristics with no dose dumping in alcohol, whereas the matrices of DC resulted in the dose dumping of the drug attributing to the loss of matrix integrity and phase separation of lipid. Thus, it is concluded that the uniform distribution of a softened binder into a molten lipid carrier results in the stable matrices of TSMG.     

A robust hybrid method for image encryption based on Hopfield neural network

In this paper, a robust hybrid image encryption algorithm with permutation-diffusion structure is proposed, based on chaotic control parameters and hyper-chaotic system. In the proposed method, a chaotic logistic map is employed to generate the control parameters for the permutation stage which results in shuffling the image rows and columns to disturb the high correlation among pixels. Next, in the diffusion stage, another chaotic logistic map with different initial conditions and parameters is employed to generate the initial conditions for a hyper-chaotic Hopfield neural network to generate a keystream for image homogenization of the shuffled image. The new hybrid method has been compared with several existing methods and shows comparable or superior robustness to blind decryption.