FORMULATION AND EVALUATION OF BESIFLOXACIN NON-ERODIBLE OCULAR INSERTS

Objective: Ocular inserts offer many advantages over conventional dosage forms, like increased ocular residence, the possibility of releasing a drug at a slow and constant rate, accurate dosing, exclusion of preservatives, and increased shelf life. Besifloxacin is a very important drug for the treatment of infectious conjunctivitis. The present study was aimed to formulate and evaluate Besifloxacin Non-Erodible Ocular Insert using Pullulan and polyvinyl pyrrolidone as a drug reservoir, PEG 400 as a plasticizer, and Eudragit RS-100 as a rate-controlling membrane. Methods: Central composite design was employed to study the effect of independent variables, i.e., effects of Pullulan amount (X1) and PVP (X2) on the dependent variables, i.e., % moisture absorption and In vitro diffusion rate. After evaluation of all thirteen batches of ocular insert reservoir formulation, BSF2 and BSF4 were selected as a satisfactory formulation and was sandwiched between rate-controlling membrane, which was made up of Eudragit RS-100 (3 and 5%). Results: The drug content of all formulations was found to be in the range of 95.33 to 99.89 %. In vitro diffusion of Besifloxacin from reservoir formulations (BSF1 to BSF13) was found to be 62.44 to 70.62 %. In vitro diffusion rate of an ocular insert of Besifloxacin can offer benefits such as increasing residence time, prolonging drug release in the eye for 24 h. Eudragit RS-100, as a sustained drug release polymer, showed promising sustained released action. Conclusion: The study concluded that Besifloxacin non-erodible ocular inserts can be successfully developed using Pullulan and polyvinyl pyrrolidone, which will sustain the release of the drug also reduce the frequency of administration, and thereby may help to improve patient compliance.

Effect of Two-Stage Aging on Microstructure and Properties of Al-Mg-Si Alloys

The effects of two-stage aging on the microstructures, tensile properties and intergranular corrosion (IGC) sensitivity of Al-Mg-Si alloys were studied by tensile testing and IGC experiments and transmission electron microscope (TEM). The results show that the two-stage aging (180°C, 2h+160°C, 120h) can reduce the IGC sensitivity without decrease the tensile properties. The grain is distributed with high-density β′′ phases, and the grain boundary phases are spherical and intermittently distributed. The formation of the microstructure characteristic is due to the lower re-aging temperature, which results in a decline differences in the diffusion rate between the matrix and grain boundaries. As a result, the pre-precipitated phase can maintain a better strengthening effects due to the slower growth rate. The pre-precipitated phase of the grain boundary presents a spherical and intermittent distribution due to the fast coarsening speed.

Farmers' Awareness of Agricultural Environmental Risks in Kalabshaw and Zayan Area in Dakahlia Governorate: وعي الزراع بالمخاطر البيئية الزراعية بمنطقة قلابشو وزيان بمحافظة الدقهلية

The research aimed to determine the level of farmers’ awareness about of agricultural environmental risks in new reclamation land association's in kalabshaw and zayan region, in dakahlia governorate by determining the level of farmers' awareness of causes of spread of agricultural environmental risks, as well as their awareness level of damage which caused by it, In addition to identify their awareness of spread rate agricultural environmental risks, and resulting damage from it, as well as the strengths, weaknesses, opportunities and challenges available to farmers to confront agricultural environmental risks in search area. The research was conducted on 337 farmers who were selected randomly and systematically from farmers of new reclamation landassociation's in kalabshaw and zayan region. Data were collected by using a questionnaire, pretest was done until it became valid for collected data during March and April 2021. Morgan and Krejcie equation had been used to determine the sample size. Frequencies, percentages, rang, mean, standard deviation were used to present and analysis study data. The main results are as follows 1- More than two- fifths of farmers 42.4 % Their awareness level of reasons agricultural environmental risks spread was high.. 2- Two- fifths of farmers 40.7 % Their awareness level of awareness of damage which caused by agricultural environmental risks was high. 3- Two- fifths of farmers 40.4 % Their awareness level of diffusion rate agricultural environmental risks spread was high. 4- More than one- third of farmers 38.3 % Their awareness level of extent damage caused agricultural environmental risks spread was high 5- The most important aspects of strengths of farmers to face agricultural environmental risks were: Be careful to adjust dates of cultvited some crops, especially vegetables, to reduce sides effects of climate change 89%. 6- The most important aspects of weaknesses of farmers to face agricultural environmental risks were: Climate changes led to decrease productivity of some crops and increase food prices by 88.4%. 7- The most important aspects of opportunities of farmers to face agricultural environmental risks were: attuide towards to contract farming to prevent the exploitation of traders 89%. 8- The most important aspects of the challenges faced of farmers to face agricultural environmental risks were: The difficult economic conditions such as rise in land rent and rise prices of production requirements by 90.5%.

Effects of High Magnetic Fields on the Diffusion of Biologically Active Molecules

The diffusion of biologically active molecules is a ubiquitous process, controlling many mechanisms and the characteristic time scales for pivotal processes in living cells. Here, we show how a high static magnetic field (MF) affects the diffusion of paramagnetic and diamagnetic species including oxygen, hemoglobin, and drugs. We derive and solve the equation describing diffusion of such biologically active molecules in the presence of an MF as well as reveal the underlying mechanism of the MF’s effect on diffusion. We found that a high MF accelerates diffusion of diamagnetic species while slowing the diffusion of paramagnetic molecules in cell cytoplasm. When applied to oxygen and hemoglobin diffusion in red blood cells, our results suggest that an MF may significantly alter the gas exchange in an erythrocyte and cause swelling. Our prediction that the diffusion rate and characteristic time can be controlled by an MF opens new avenues for experimental studies foreseeing numerous biomedical applications.

FABRICATION AND WEAR BEHAVIOR OF PEC/N HARDENED LAYER ON PURE IRON

In this paper, the antifriction carbonitriding (PEC/N) layers were prepared on pure iron by cathodic plasma electrolytic treatment (PET) in glycerin and carbamide aqueous solution under 360[Formula: see text]V for 1, 3 and 10[Formula: see text]min. Influence of discharge time on morphology, structure, surface roughness and microhardness of PEC/N layer was analyzed. The tribological performance of the PEC/N layer, growth mechanism and diffusion process during PEC/N treatment was investigated. The thickness of the PEC/N layer grew to 48[Formula: see text][Formula: see text]m for 10[Formula: see text]min treatment and the growth of the saturation layer met the parabolic law. The highest microhardness of the surface was up to 811 HV, which was 5 times of that of iron substrate. The PEC/N layer consisted of [Formula: see text]-Fe, Fe[Formula: see text]N, Fe4N, Fe3C, Fe5C2 phases and a little FeO phase. The wear rate of the PEC/N layer reduced by five-sixes comparing with the iron substrate and the surface of the wear track was much smoother. The temperature close to the surface during PEC/N fitted by the tested temperature values inside the sample was 801∘C (1074[Formula: see text]K), and the combination diffusion rate of C and N into pure iron during PET at 360[Formula: see text]V reached [Formula: see text][Formula: see text]m2/s. The electron temperature fluctuates between 3000[Formula: see text]K and 8000[Formula: see text]K. The antifriction PEC/N layer displayed a very good wear resistance and the higher diffusion rate makes plasma electrolytic carbonitriding a very effective technique for surface modification of pure iron.

Does eWOM influence entrepreneurial firms’ rate of diffusion of innovation?

Purpose This research aims to investigate the influence of electronic word-of-mouth (eWOM) on the diffusion rate of innovation in the context of entrepreneurial firms in emerging markets. It examines a comprehensive model for the effect of eWOM dimensions (including Content, Intensity, Positive Valence and Negative Valence) on the diffusion of innovations. Thus, it provides new insights on how entrepreneurial firms can use eWOM as a communication tool to facilitate the diffusion rate of innovations in emerging markets. Design/methodology/approach A quantitative approach was adopted, consisting of 215 responses from Jordan. Data were analysed using Linear regression analysis tools. Findings A significant relationship exists between eWOM dimensions (Content, Intensity, Positive Valence and Negative Valence) and the Diffusion Rate of Innovations. In emerging markets, eWOM content highlights critical information regarding consumers’ sentiments towards new products (including features, price, design), which consumers use in judging innovations. Especially when there is a high volume of eWOM about a new product, consumers are likely to gain reassurances regarding their purchase decisions. Specifically, the valence of eWOM (including reviews, complaints and suggestions) generate adoption/risk-aversion attitudes towards new products. Consequently, entrepreneurial firms must carefully analyse eWOM regarding their products and integrate them into their marketing strategy. 10; Originality/value This research extends the eWOM literature by developing a comprehensive model for the effect of eWOM dimensions on the diffusion of innovations. Additionally, it sheds new light on the effect of eWOM valence on consumers’ attitudes towards innovations. Finally, it provides significant theoretical and managerial implications and future research direction to deepen our understanding of the effect of eWOM on entrepreneurial firms.

FORMULATION, CHARACTERIZATION, AND DETERMINATION OF THE DIFFUSION RATE STUDY OF ANTIOXIDANT SERUM CONTAINING ASTAXANTHIN NANOEMULSION

Objective: Astaxanthin is one of the natural carotenoids with strong antioxidant characteristics which is widely used in skin care. The aim of this study was developed to formulate and characterize the antioxidant serum containing astaxanthin nanoemulsion and the diffusion rate studies using diffusion Franz method. Methods: Astaxanthin nanoemulsion (As-NE) was prepared by using the self-nanoemulsifying method, followed by incorporation into serum preparation with the using carbomer as a gelling agent. Evaluation of serum As-NE was performed by physical, chemical characterizations and diffusion assay. Stability study was carried out in both accelerated (temperature of 40±2 °C/75±5%RH) and non-accelerated (at ambient temperature) conditions. Results: These results suggest that antioxidant serum As-NE had good physical and chemical characteristics that are suitable for topical administration. Conclusion: For the study of diffusion and stability under different storage conditions, it was proven that antioxidant serum As-NE form was packed in a carbomer as a gelling agent that could enhance the stability and diffusion rate of the astaxanthin.

Mathematical Modelling of the Elliptical Vortex Ring in a Viscous Fluid with the Vortex Filament Method

The article deals with modelling an elliptical vortex ring in a viscous fluid using the Lagrangian vortex filament method. The novelty is that earlier only inviscid flows restricted vortex filament method application. The proposed viscosity model uses an analogue of the diffusion rate method, which is widely applied to simulate plane-parallel and axisymmetric flows of viscous fluid. A transfer of the formula of a diffusion rate from two-dimensional flows to the model of spatial vortex filament is due to assumption that swirling of vortex lines (helicity of vorticity) is unavailable. Despite the laxity of the diffusion rate model for general spatial flows, its application enables taking into account the effect of viscous diffusion of vorticity, which provides expansion of vortex tubes in space. The paper formulates the vortex filament method in which the filaments are broken into the vortex segments. Such discretization enables turning from the equation of vorticity evolution in partial derivatives to a system of ordinary differential equations with respect to the parameters of the segments. Formulas to calculate a filament system-induced flow rate as well as formulas to perform approximate calculation of an analogue of the diffusion rate are given.The objective is to propose the viscosity model as an application to the vortex filament method by the example of modelling the evolution of an elliptical vortex ring in viscous fluid. The calculation results obtained by the vortex method are compared with the existing experiment and with the calculation performed by the grid method in the OpenFOAM package. A feature of the problem is that there are zones of nonzero helicity of vorticity where the proposed model of viscosity, strictly speaking, is not correct. It is shown that the results of calculations are in good agreement with each other and are in complete agreement with experiment. This allows saying that the effects of swirling vortex lines do not significantly affect the results of modelling a specific example of the spatial flow of viscous fluid by the proposed modification of the vortex filament method.