Stability of Concentrated Olive Oil‐in‐water Emulsion

The stability of olive oil-in-water (o/w) emulsion stabilized with sucrose fatty acid ester (SFAE) was evaluated through an accelerated ageing test. The stability of the emulsion in this study was examined by the appearance of any phase separation in the emulsion, mean droplet size and rheological properties over one month. The effect of accelerated ageing at 45 ℃ on the emulsion rheological properties was investigated using an amplitude sweep test, a frequency sweep test and a viscometry test. The rheological properties of the emulsion were examined at the one day, one week and one month of storage time. Among the series of emulsions prepared, the emulsion with 2∶8 of water to oil ratio (by weight) is the most stable one, which did not show any of phase separation. The amplitude sweep result shows that there was no significant change of the critical strain of the emulsion throughout one month of storage time. The dynamic properties as well as the steady flow behavior of the emulsion also show no significant changes for over one month of storage time. The mean droplet size of the emulsion remained stable around 2.5 μm within the period of investigation.     

Determination of inorganic selenium species by neutron activation analysis in aquatic species after preconcentration with ammonium pyrrolidinecarbodithionate

Inorganic selenium species were determined in several parts of a freshwater fish of the speciesTilapia nilotica found breeding in disused tin-mining pools. The inorganic selenium species in the monazite-rich ores can enter the human food chain through the consumption of the fish. The Se(IV) and Se(VI) species were preconcentrated by solvent extraction with APCDT-CHCl₃ before irradiation in a TRIGA Mk.II reactor. Total inorganic selenium species separation was done using Chelex-100 chelating resin. Quantitative interpretations of the distribution of inorganic selenium species in the fish are discussed with particular reference to the Se(IV)/Se(VI) ratio.     

Microencapsulation Preservation of the Stability and Efficacy of Citrus Grandis Oil-Based Repellent Formulation against Aedes aegypti during Storage

Essential oils have been widely used as an active ingredient in mosquito repellent products. However, essential oils are highly unstable and prone to degradation when exposed to the environment during storage. Microencapsulation techniques help to maintain the stability of molecules in essential oils that are sensitive to environmental stress, and therefore improve shelf life. In this study, the physical stability and efficacy of a repellent formulation consisting of encapsulated Citrus grandis essential oil (CGEO) were evaluated under different storage conditions over a 12-month period by comparing the formulation with a non-encapsulated formulation. The formulations were both stored under two different storage conditions, i.e., 25 ± 2 °C/60% ± 5% relative humidity (RH) and 40 ± 2 °C/75% RH ± 5%, for 12 months. Droplet size, zeta potential, and pH value were measured after 1, 6, and 12 months of storage to determine their stability. For the study of efficacy, each formulation was tested against Aedes aegypti under laboratory conditions. We found that the microencapsulated formulation’s physical characteristics showed insignificant changes as compared with the non-encapsulated formulation during storage. The microencapsulated formulation demonstrated better repellent effects, sustaining high protection (>80%) for 4 more hours of exposure after 12 months of storage as compared with the non-encapsulated formulation that demonstrated high protection for only an hour post application. Microencapsulation helped to preserve the stability of the formulation, which resulted in high protection being maintained for over 12 months of storage.     

SAR reduction in a muscle cube with metamaterial attachment

The aim of this paper is to evaluate the specific absorption rate (SAR) reduction in a muscle cube by using metamaterial. To evaluate the SAR in a realistic anatomically based model of the muscle cube, the finite-difference time-domain (FDTD) method has been utilized. The effective medium parameter is obtained to be negative at 900 MHz and 1800 MHz band by designing structural parameter of split ring resonators. The reduction is about 44.73% for 900 MHz, and about 48.27% for 1800 MHz was observed in this paper.     

Systematic Review on Biosynthesis of Silver Nanoparticles and Antibacterial Activities: Application and Theoretical Perspectives

The biosynthesis of silver nanoparticles and the antibacterial activities has provided enormous data on populations, geographical areas, and experiments with bio silver nanoparticles’ antibacterial operation. Several peer-reviewed publications have discussed various aspects of this subject field over the last generation. However, there is an absence of a detailed and structured framework that can represent the research domain on this topic. This paper attempts to evaluate current articles mainly on the biosynthesis of nanoparticles or antibacterial activities utilizing the scientific methodology of big data analytics. A comprehensive study was done using multiple databases—Medline, Scopus, and Web of Sciences through PRISMA (i.e., Preferred Reporting Items for Systematic Reviews and Meta-Analyses). The keywords used included ‘biosynthesis silver nano particles’ OR ‘silver nanoparticles’ OR ‘biosynthesis’ AND ‘antibacterial behavior’ OR ‘anti-microbial opposition’ AND ‘systematic analysis,’ by using MeSH (Medical Subject Headings) terms, Boolean operator’s parenthesis, or truncations as required. Since their effectiveness is dependent on particle size or initial concentration, it necessitates more research. Understanding the field of silver nanoparticle biosynthesis and antibacterial activity in Gulf areas and most Asian countries also necessitates its use of human-generated data. Furthermore, the need for this work has been highlighted by the lack of predictive modeling in this field and a need to combine specific domain expertise. Studies eligible for such a review were determined by certain inclusion and exclusion criteria. This study contributes to the existence of theoretical and analytical studies in this domain. After testing as per inclusion criteria, seven in vitro studies were selected out of 28 studies. Findings reveal that silver nanoparticles have different degrees of antimicrobial activity based on numerous factors. Limitations of the study include studies with low to moderate risks of bias and antimicrobial effects of silver nanoparticles. The study also reveals the possible use of silver nanoparticles as antibacterial irrigants using various methods, including a qualitative evaluation of knowledge and a comprehensive collection and interpretation of scientific studies.     

Optimization of Microwave-Assisted Pectin Extraction from Cocoa Pod Husk

Optimization of pectin extraction from cocoa pod husk was carried out to examine independent variables that affect the quality of pectin obtained and determine the best conditions for the extraction process. In this study, three independent variables thought to contribute to microwave-assisted pectin extraction were used, namely, extraction time (20, 25, and 30 min), microwave power (180, 300, and 450 W), and citric acid concentration (2.5%, 5%, and 10%). Response surface methodology was applied using central composite design (CCD) to examine the effect of independent variables on the parameter measured. Among the seven parameters measured, namely, yield, temperature, moisture content, ash content, equivalent weight, methoxyl content, and galacturonic acid content, the statistical analysis test showed that the model equations that were suitable for predicting response values were temperature, moisture content, and ash content. Therefore, the optimization of conditions was only reviewed for these three parameters. Optimization results concluded that the factors that had the most significant effect on temperature, moisture content, and ash content were extraction time and microwave power. Optimal conditions for pectin extraction were at 30 min extraction time, 450 W microwave power, and 10% solvent concentration, resulting in a temperature of 104 °C, moisture content of 6%, and ash content of 8%. Other parameter values measured under these conditions were a yield of 21.10%, equivalent weight of 602.40 mg/mol, methoxyl content of 6.07%, and galacturonic acid content of 72.86%. Pectin extracted from cocoa pod husk using this method has the potential to be further applied, especially in the food and pharmaceutical industries.     

Adsorption characteristics of organosilica based mesoporous materials

Hybrid organosilica mesoporous materials with pores of ordered three-dimensional hexagonal structure were prepared by the hydrolysis and co-condensation of 1,2-bis(triethoxysilyl)ethane with various concentrations of a surfactant as structure directing agents. The materials had high pore volume of 1-1.5 mL/g and high surface area from 1057 to 1445 m(2)/g. Adsorption measurement and adsorption calorimetry revealed that the prepared materials exhibited high hydrophobicity and high affinity toward nonpolar organic vapor such as n-hexane. The dynamic adsorption properties of the materials for n-hexane in the presence of water vapor showed that these hybrid organosilica materials preferentially adsorbed n-hexane vapor and were stable in the presence of water compared to the siliceous MCM48.     

A new double L-shaped multiband patch antenna on a polymer resin material substrate

The design and prototyping of a new double L-shaped patch antenna on substrate of available low cost polymer resin composite material is presented. The designed microstrip line fed compact antenna consists of a planar double L-shaped slotted radiating patch, 1.6 mm thick substrate and ground plane. The proposed small antenna was designed and analyzed using a finite-element method-based, commercially available, high frequency structure simulator, and fabricated on a printed circuit board. The measured ?10 dB return loss bandwidths were 220 MHz and 650 MHz at 4.85 GHz and 8.10 GHz center frequencies. The corresponding symmetric and almost steady radiation patterns have peak gains of 7.6 dBi and 4.1 dBi, making the proposed antenna suitable for C and × band wireless applications, especially for WLANs, mobiles and satellites. The radiation efficiency, input impedance and current distribution of the proposed antenna were also analyzed.     

Energetic mixing of anti‐SNAP25 on lipid monolayers: degree of saturation of C18 fatty acids

In our study, various mixtures of C18 fatty acids with different degrees of saturation in their hydrocarbon chain, namely stearic acid (SA), oleic acid (L1), linoleic acid (L2), and linolenic acid (L3), and a polyclonal antibody, anti‐synaptosome‐associated protein of 25 kDa (SNAP25) (AS25), have been investigated using the Langmuir–Blodgett (LB) technique accompanied by atomic force microscopy (AFM) imaging. The cis‐double bonds in unsaturated lipids (L1, L2, and L3) have kinks in their molecular conformation and thus could not pack as tightly and uniformly as SA. The bends and kinks in the molecular structure may interfere with the packing of the lipid monolayer which will promote fluidity as shown in the analyzed compressibility modulus (C_s^?1 ) data. The negative values of Gibbs free energy of mixing (ΔG _mix ) of C18 fatty acids/AS25 confirm the spontaneity interaction of AS25 molecules on the monolayers. The amount of AS25 incorporated into the monolayer strongly affected the thermodynamic properties of the lipid monolayers. AFM surface roughness analyses also indicate that AS25 molecules are strongly bounded on the surface membrane as predicted by the obtained energetic data. In comparison to all C18 fatty acids studied, the strongest intermolecular interaction is observed in L1 at the investigated ranges. In particular, at mole ratio of 26:1, the most negative ΔG _mix is observed at L1. Thus, we can draw the conclusion that AS25 is best mixed with L1. This L1/AS25 ratio mimicking a half bilayer membrane serves as a very useful reference in preparing fatty‐acid nanoimmunoliposomes as the targeted drug‐delivery vehicles for cancer therapy. Copyright © 2016 John Wiley & Sons, Ltd.     

Thermoresponsive Gel Mixture Carboxymethyl Cellulose and <Emphasis Type="Italic">iota</Emphasis>-Carrageenan for Topical Delivery of Hydroquinone

Property of a gel that responses to heat change contributes many advantages in topical application where the rheological properties illustrate stability of gel during storage and its spreadability upon application. In this work, a gel mixture consists of carboxymethyl cellulose (CMC) and iota-carrageenan (ι-C) was prepared and its rheological properties under temperature and Ca²⁺ ions effect were evaluated. Subsequently, hydroquinone was incorporated into the optimized gel formulation to study its in vitro release at 30 and 37°C. Higher concentration of cation Ca²⁺ was proven to increase the gel strength, however there was a limit where the concentration of cation does not affect the viscosity η and storage modulus G' of the system anymore. The phase transition of the gel mixture from solid-like to liquid-like was thermally activated and reversible. The gel mixture with gelling point in the vicinity of body temperature was selected as the optimized formulation. In vitro release revealed the effect of thermoresponsive behavior of gel on delivery of active ingredient. The formulation showed flowing behavior at 37°C where it provided enhanced release of hydroquinone. These results suggested that gel mixture of CMC and ι-C is a good candidate to be developed as a thermoresponsive gel for topical delivery of hydroquinone.