Evaluation of antifungal effect of iron‐oxide nanoparticles against different Candida species

Iron‐oxide nanoparticles (IONPs) have been widely favoured due to their biodegradable, low cytotoxic effects and having reactive surface which can be altered with biocompatible coatings. Considering various medical applications of IONPs, the authors were encouraged to study whether IONPs could be effective against fungal infections caused by Candida species. In this study, IONPs were characterised by scanning electron microscopy, X‐ray diffraction, Fourier transform infrared spectroscopy and vibrating sample magnetometer. The goal of this study was to evaluate the antifungal activity of IONPs against different Candida spp. compared with fluconazole (FLC). IONPs were spherical with the size of 30–40 nm. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values of IONPs ranged from 62.5 to 500 µg/ml and 500 to 1000 μg/ml, respectively. The MIC and MFC of FLC were in range of 16–128 μg/ml and 64–512 μg/ml, respectively. The growth inhibition value indicated that Candida tropicalis, Candida albicans and Candida glabrata spp. were most susceptible to IONPs. The finding showed that the IONPs possessed antifungal potential against pathogenic Candida spp. and could inhibit the growth of all the tested Candida spp. Further studies, both in vitro and in vivo (including susceptibility, toxicity, Probability of kill (PK) and efficacy studies) are needed to determine whether IONPs are suitable for medicinal purposes.Inspec keywords: iron compounds, nanoparticles, nanomedicine, biomedical materials, microorganisms, cellular biophysics, toxicology, drugs, scanning electron microscopy, X‐ray diffraction, Fourier transform infrared spectraOther keywords: antifungal effect, iron‐oxide nanoparticles, Candida species, biodegradable effects, cytotoxic effects, reactive surface, biocompatible coatings, medical applications, IONP, fungal infections, Candidiasis, immunocompromised hosts, antifungal drugs, resistant organisms, antifungal properties, side effects, chemical drugs, scanning electron microscopy, X‐ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometer, antifungal activity, disc diffusion, broth microdilution, minimal inhibitory concentration, minimum fungicidal concentration, Candida tropicalis, Candida Albicans, Candida glabrata, antifungal potential, Fe₃ O₄      

Electrical Resistance Tomography (ERT) applications to Chemical Engineering

Electrical Resistance Tomography (ERT) has the capability of offering time-evolving multidimensional comprehensive process knowledge, enrichment of fundamental process understanding and enhancement of the design and operation of process equipment by measuring the conductivity distribution within a process-plant of interest. This paper reviews the wide variety of previous work on ERT applications to Chemical Engineering. The applications are categorized based on the unit operations ERT has been applied to, the media under investigation, the purpose of ERT measurements and also other technologies used in conjunction with ERT. The aim of this taxonomy is to provide the reader with a general understanding of the current situation of ERT related research and proven applications in the Chemical Engineering field and to facilitate the recognition of research gaps for future investigation. Based on this detailed taxonomy and review the potential application of ERT to the milk powder processing industry was identified. Some results of the application of ERT to milk mixing/holding tanks and milk flow pipelines for the purpose of concentration and composition measurements, detection of abnormalities and faults, and multidimensional flow and velocity profile measurements have also been presented as a case study of using this taxonomy.     

Synthesis of a Series of PEG-Based ABA Triblock Copolymers and Their Influence on Rheology of Cement Slurries

A series of water-soluble ABA triblock copolymers consisting of a polyethylene glycol central block joined to two blocks of six different homopolymers have been synthesized via simple solvent-free and ecofriendly routes and characterized by FTIR and ¹HNMR spectroscopy. Dispersing and slump-retaining abilities of the copolymers in cement slurries were evaluated by mini-slump spread method. Rheological measurements of samples with the best performance were carried out using a rate-controlled coaxial cylinder viscometer. The test results indicate that the dispersing power of the copolymers in cement pastes is strongly affected by the structure and degree of polymerization of the monomers.     

New high permeable polysulfone/ionic liquid membrane for gas separation

In this study, the effects of 1-Ethyl-3-methylimidazolium tetrafluoroborate ionic liquid on CO₂/CH₄ separation performance of symmetric polysulfone membranes are investigated. Pure polysulfone membrane and ionic liquid-containing membranes are characterized. Field emission scanning electron microscopy (FE-SEM) is used to analyze surface morphology and thickness of the fabricated membranes. Energy dispersive spectroscopy (EDS) and elemental mapping, Fourier transform infrared (FTIR), thermal gravimetric (TGA), X-ray diffraction (XRD) and Tensile strength analyses are also conducted to characterize the prepared membranes. CO₂/CH₄ separation performance of the membranes are measured twice at 0.3 MPa and room temperature (25 °C). Permeability measurements confirm that increasing ionic liquid content in polymer-ionic liquid membranes leads to a growth in CO₂ permeation and CO₂/CH₄ selectivity due to high affinity of the ionic liquid to carbon dioxide. CO₂ permeation significantly increases from 4.3 Barrer (1 Barrer=10^-10 cm³(STP)·cm·cm^-2·s^-1·cmHg^-1, 1cmHg=1.333kPa) for the pure polymer membrane to 601.9 Barrer for the 30 wt% ionic liquid membrane. Also, selectivity of this membrane is improved from 8.2 to 25.8. mixed gas tests are implemented to investigate gases interaction. The results showed, the disruptive effect of CH₄ molecules for CO₂ permeation lead to selectivity decrement compare to pure gas test. The fabricated membranes with high ionic liquid content in this study are promising materials for industrial CO₂/CH₄ separation membranes.     

Perfect forward secrecy in VoIP networks through design a lightweight and secure authenticated communication scheme

With the growth of the internet, development of IP based services has increased. Voice over IP (VoIP) technology is one of the services which works based on the internet and packet switching networks and uses this structure to transfer the multimedia data e.g. voices and images. Recently, Chaudhry et al., Zhang et al. and Nikooghadam et al. have presented three authentication and key agreement protocols, separately. However, in this paper, it is proved that the presented protocols by Chaudhry et al. and also Nikooghadam et al. do not provide the perfect forward secrecy, and the presented protocol by Zhang et al. not only is vulnerable to replay attack, and known session-specific temporary information attack, but also does not provide user anonymity, re-registration and revocation, and violation of fast error detection. Therefore, a secure and efficient two-factor authentication and key agreement protocol is presented. The security analysis proves that our proposed protocol is secure against various attacks. Furthermore, security of proposed scheme is formally analyzed using BAN logic and simulated by means of the AVISPA tool. The simulation results demonstrate security of presented protocol against active and passive attacks. The communication and computation cost of the proposed scheme is compared with previously proposed authentication schemes and results confirm superiority of the proposed scheme.

     

Synthesis of new electromagnetic nanocomposite based on modified Fe3O4 nanoparticles with enhanced magnetic,conductive, and catalytic properties

A new method for the fabrication of an electromagnetic nanocomposite based on Fe₃O₄ and polyaniline (PANI) is offered. The authors focused on improvement of the physical and electromagnetic properties of the nanocomposite using a new synthetic method. Supermagnetic Fe₃O₄ nanoparticles were synthesized through coprecipitation method. As a chemical modification, the third generation of poly (amidoamine) dendrimer was grafted on the surface of the nanoparticles. PANI was grafted from –NH₂ functional groups of dendrimer via in situ polymerization of aniline. Finally, Au nanoparticles were loaded on the nanocomposite and its catalytic activity for reduction reactions was studied.     

Investigation of Fuel Energy Gain for Tritium-Poor Fuels in Fast Ignition Fusion Approach

One of the most fascinating ignition schemes for the inertial fusion energy that might be feasible is fast ignition.Its targets are ignited on the outside surface so there is no need to low density and high temperature center is required by central hot spot ignition.Fast ignition concept is noteworthy for a simple but fundamental reason:In principle it requires less total energy input to achieve ignition.In this paper,fuel energy and fuel energy gain of nearly pure deuterium capsule are calculated.This capsule is ignited by a deuterium-tritium seed,which would reduce the tritium inventory to a few percentages.The variations of fuel energy gain versus fuel density have been studied and submitted.On the basis of different physical parameters the following results of the investigation are presented and discussed.The energy gain curves for different tritium concentrations are found and limiting gain curves are derived.Finally,tritium-poor fast ignitor is compared to equimolar deuterium-tritium fast ignitor.     

A hybrid metaheuristic approach for the capacitated p-median problem

The capacitated p-median problem (CPMP) seeks to obtain the optimal location of p medians considering distances and capacities for the services to be given by each median. This paper presents an efficient hybrid metaheuristic algorithm by combining a proposed cutting-plane neighborhood structure and a tabu search metaheuristic for the CPMP. In the proposed neighborhood structure to move from the current solution to a neighbor solution, an open median is selected and closed. Then, a linear programming (LP) model is generated by relaxing binary constraints and adding new constraints. The generated LP solution is improved using cutting-plane inequalities. The solution of this strong LP is considered as a new neighbor solution. In order to select an open median to be closed, several strategies are proposed. The neighborhood structure is combined with a tabu search algorithm in the proposed approach. The parameters of the proposed hybrid algorithm are tuned using design of experiments approach. The proposed algorithm is tested on several sets of benchmark instances. The statistical analysis shows efficiency and effectiveness of the hybrid algorithm in comparison with the best approach found in the literature.