AC Conductivity and Dielectric Properties of Cu–Zn ferrites

In this work, we have studied the effects of the 2 Zn ions on the electric and the dielectric properties of the Cu spinel ferrite. The mixed Cu-Zn spinel ferrite, of chemical formula 1 s s 2 4 Cu Zn Fe O , where s stepped by 0.2 according to ( 0.0 s 1.0), were prepared from purity metal oxides using the standard ceramic preparation. The AC conductivity was determined for the ferrite samples in the applied frequency range (10 10 )Hz 4 6 . In this range of frequency, the AC conductivity increases rapidly as a function of the applied frequency. The dielectric properties for the ferrite samples were also determined at room temperature. The general trend for all samples was found to decrease continuously with increasing of the applied frequency. The measurements of the electric and the dielectric properties show that, the behavior of the ferrite samples is similar to that of the semiconductor materials. The results of the electric and dielectric properties are inadequate to previous studies for various ferrite compounds. The electric conductivity for the samples was explained using the electron hopping model.In this work, we have studied the effects of the 2 Zn ions on the electric and the dielectric properties of the Cu spinel ferrite. The mixed Cu-Zn spinel ferrite, of chemical formula 1 s s 2 4 Cu Zn Fe O , where s stepped by 0.2 according to ( 0.0 s 1.0), were prepared from purity metal oxides using the standard ceramic preparation. The AC conductivity was determined for the ferrite samples in the applied frequency range (10 10 )Hz 4 6 . In this range of frequency, the AC conductivity increases rapidly as a function of the applied frequency. The dielectric properties for the ferrite samples were also determined at room temperature. The general trend for all samples was found to decrease continuously with increasing of the applied frequency. The measurements of the electric and the dielectric properties show that, the behavior of the ferrite samples is similar to that of the semiconductor materials. The results of the electric and dielectric properties are inadequate to previous studies for various ferrite compounds. The electric conductivity for the samples was explained using the electron hopping model

Model based design flow for implementing an Anti-Collision Radar detection system

International audienceIn order to ensure and increase the safety and reliability of transport systems, these systems are becoming more and more intelligent. They integrate more and more sensors and communication systems. Each of these functionalities can be implemented on a System-on-Chip (SoC). These functionalities are carried out by massive computations. As the number of integrated functionalities increase in the transport systems, the design and implementation complexity also increases at a tremendous rate. Implementation of these functionalities can be carried out either via FPGAs or DSP (digital signal processors) platforms. FPGAs are considered the ideal choice as they accelerate the computations by executing the algorithms in a parallel manner. Actually the initial steps in existing design flows are the development of the complex algorithms; and then their manual implementation, which are daunting tasks. Change in the scale of the algorithm requires starting the implementation over from scratch which results in increase design time. Normally these steps are carried out by teams of different domains which could result in compatibility issues. We propose a high abstraction level design methodology for implementation of these algorithms in a graphical manner. The advantages offered by our approach aim to reduce time to make up or time to market. Changes in the nature of the algorithm can be easily carried out due to their graphical nature and the code can be generated automatically rapidly. Afterwards the implementation can be carried out on the target FPGA platforms

Diffusion and swelling measurements in pharmaceutical powder compacts using terahertz pulsed imaging.

Tablet dissolution is strongly affected by swelling and solvent penetration into its matrix. A terahertz-pulsed imaging (TPI) technique, in reflection mode, is introduced as a new tool to measure one-dimensional swelling and solvent ingress in flat-faced pharmaceutical compacts exposed to dissolution medium from one face of the tablet. The technique was demonstrated on three tableting excipients: hydroxypropylmethyl cellulose (HPMC), Eudragit RSPO, and lactose. Upon contact with water, HPMC initially shrinks to up to 13% of its original thickness before undergoing expansion. HPMC and lactose were shown to expand to up to 20% and 47% of their original size in 24 h and 13 min, respectively, whereas Eudragit does not undergo dimensional change. The TPI technique was used to measure the ingress of water into HPMC tablets over a period of 24 h and it was observed that water penetrates into the tablet by anomalous diffusion. X-ray microtomography was used to measure tablet porosity alongside helium pycnometry and was linked to the results obtained by TPI. Our results highlight a new application area of TPI in the pharmaceutical sciences that could be of interest in the development and quality testing of advanced drug delivery systems as well as immediate release formulations.We would like to thank Huxley Bertram Engineering Ltd.,Cambridge, UK for making time available on the compactionsimulator and Martin Bennett from Huxley Bertram for helppreparing samples. We would also like to acknowledge EvonikIndustries, Germany for providing Eudragit RSPO. S.Y. wouldlike to thank the UK Engineering and Physical Sciences Re-search Council for financial support.This is the final version of the article. It was originally published online in the Journal of Pharmaceutical Sciences, 2015, doi: 10.1002/jps.24376

The Disintegration Process in Microcrystalline Cellulose Based Tablets, Part 1: Influence of Temperature, Porosity and Superdisintegrants.

Disintegration performance was measured by analysing both water ingress and tablet swelling of pure microcrystalline cellulose (MCC) and in mixture with croscarmellose sodium using terahertz pulsed imaging (TPI). Tablets made from pure MCC with porosities of 10% and 15% showed similar swelling and transport kinetics: within the first 15 s, tablets had swollen by up to 33% of their original thickness and water had fully penetrated the tablet following Darcy flow kinetics. In contrast, MCC tablets with a porosity of 5% exhibited much slower transport kinetics, with swelling to only 17% of their original thickness and full water penetration reached after 100 s, dominated by case II transport kinetics. The effect of adding superdisintegrant to the formulation and varying the temperature of the dissolution medium between 20°C and 37°C on the swelling and transport process was quantified. We have demonstrated that TPI can be used to non-invasively analyse the complex disintegration kinetics of formulations that take place on timescales of seconds and is a promising tool to better understand the effect of dosage form microstructure on its performance. By relating immediate-release formulations to mathematical models used to describe controlled release formulations, it becomes possible to use this data for formulation design. © 2015 The Authors. Journal of Pharmaceutical Sciences published by Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:3440-3450, 2015.S.Y. would like to thank the U. K. Engineering and Physical Sciences Research Council (EPSRC) for a studentship. J.S. and J.A.Z. would like to acknowledge the EPSRC for funding (EP/J007803/1).This is the final version. It was first published by Wiley at http://onlinelibrary.wiley.com/doi/10.1002/jps.24544/abstract

Reduction of Hepato-Metabolic Changes in Rat Model of Metabolic Syndrome by Metformin and Atorvastatin Combination: submitted: Apr 18, 2018 Accepted: Jun 29, 2018 Published online: Aug 30, 2018

Metabolic syndrome (MetS) and the commonly associated nonalcoholic fatty liver disease (NAFLD) is an increasing health concern and hot topic in medical research. Together with lifestyle modification, metformin (MET) and statins are among drugs with potential therapeutic beneft. The aim of this study is to investigate the potential of synergistic combination of MET and atorvastatin (ATR) in rat model of MetS. Methods. Rats were fed on high-carbohydrate, highfat (HCHF) diet for 16 weeks and either of MET, ATR, or their combination were administered from the beginning of the 9th week to the end of the study. Body weight, insulin resistance, plasma lipids, serum transaminases, TNF-α, leptin and adiponectin as well as liver histopathology were assessed. Results. Both MET and ATR worked synergistically to reverse the biochemical and histological abnormalities of MetS and ameliorated steatohepatitis more than their individual effects. Conclusion. The present study clearly demonstrates a synergistic effect of MET an ATR combination to reverse hepato-metabolic abnormalities of MetS/NAFLD in rat model and calls for pursuing subsequent clinical studies to consolidate data at han

Morphological, Physicochemical, and Molecular Evaluation of Twenty-Three Date Palm Males Growing in Aswan Governorate

An essential element of date palm production is the pollen source. The present study was conducted during two successive seasons of 2020 and 2021 to evaluate some males of Aswan date palm. Herein, morphological, physicochemical, and molecular characteristics of 23 date palm males were evaluated to determine the most superior and promising males for pollinating the female ‘Bartamoda’ cultivar. It is obvious that ‘Male No. 22’, recorded almost the highest value for morphological characteristics, pollen viability, crude protein, total amino acids, and mineral content. In contrast, ‘Male No. 5’, showed the lowest content of crude protein, total amino acids, and mineral content compared to the other males that were grown in the rest of the locations in Aswan government. All ISSR primers were highly polymorphic, with a value of 100%, highlighting the necessity of employing such primers when investigating date palm diversification. Two unique bands were among the 43 total bands that were produced. The genetic coefficients with a mean of 61.5% and the first two primary axes were able to explain roughly 52.30% of the genetic variance across the genotypes of date palms. Those results suggested that all genotypes tested are efficient for the fertilization of ‘Bartamoda’ inflorescences and can be used as pollinizer in commercial orchards of this cultivar

Mathematical modelling of liquid transport in swelling pharmaceutical immediate release tablets

Oral dosage forms are an integral part of modern health care and account for the majority of drug delivery systems. Traditionally the analysis of the dissolution behaviour of a dosage form is used as the key parameter to assess the performance of a drug product. However, understanding the mechanisms of disintegration is of critical importance to improve the quality of drug delivery systems. The disintegration performance is primarily impacted by the hydration and subsequent swelling of the powder compact. Here we compare liquid ingress and swelling data obtained using terahertz pulsed imaging (TPI) to a set of mathematical models. The interlink between hydration kinetics and swelling is described by a model based on Darcy's law and a modified swelling model based on that of Schott. Our new model includes the evolution of porosity, pore size and permeability as a function of hydration time. Results obtained from two sets of samples prepared from pure micro-crystalline cellulose (MCC) indicate a clear difference in hydration and swelling for samples of different porosities and particle sizes, which are captured by the model. Coupling a novel imaging technique, such as TPI, and mathematical models allows better understanding of hydration and swelling and eventually tablet disintegration.D.M. and J.A.Z. would like to acknowledge the U.K. Engineering and Physical Sciences Research Council (EPSRC) for funding (EP/L019922/1). S.Y. would like to thank the EPSRC for a studentship

Characterization of heterogeneity and spatial distribution of phases in complex solid dispersions by thermal analysis by structural characterization and X-ray micro computed tomography

Purpose: This study investigated the effect of drug-excipient miscibility on the heterogeneity and spatial distribution of phase separation in pharmaceutical solid dispersions at a micron-scale using two novel and complementary characterization techniques, thermal analysis by structural characterization (TASC) and X-ray micro-computed tomography (XCT) in conjunction with conventional characterization methods. Method: Complex dispersions containing felodipine, TPGS, PEG and PEO were prepared using hot melt extrusion-injection moulding. The phase separation behavior of the samples was characterized using TASC and XCT in conjunction with conventional thermal, microscopic and spectroscopic techniques. The in vitro drug release study was performed to demonstrate the impact of phase separation on dissolution of the dispersions. Results: The conventional characterization results indicated the phase separating nature of the carrier materials in the patches and the presence of crystalline drug in the patches with the highest drug loading (30% w/w). TASC and XCT where used to provide insight into the spatial configuration of the separate phases. TASC enabled assessment of the increased heterogeneity of the dispersions with increasing the drug loading. XCT allowed the visualization of the accumulation of phase separated (crystalline) drug clusters at the interface of air pockets in the patches with highest drug loading which led to poor dissolution performance. Semi-quantitative assessment of the phase separated drug clusters in the patches were attempted using XCT. Conclusion: TASC and XμCT can provide unique information regarding the phase separation behavior of solid dispersions which can be closely associated with important product quality indicators such as heterogeneity and microstructure

Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks