Low-energy Method Research Articles

Single-step and low-energy method to prepare solid lipid nanoparticles and nanostructured lipid carriers using biocompatible solvents

Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLCs) are widely being explored for improving dermal/transdermal and oral delivery of drugs, neutraceuticals and cosmeceuticals. High-pressure homogenization (HPH) is the most commonly used preparation method for SLN/NLCs. SLN/NLCs preparation by the HPH requires high energy input and longer duration. Here, we describe a simple yet innovative low-energy method to prepare SLN/NLCs in a single-step using biocompatible solvents. We first show that biocompatible solvents such as Transcutol P, Soluphor P, N-methyl pyrrolidone, and glycofurol can solubilize glyceryl monostearate, glyceryl behenate, and glyceryl distearate to a variable degree. Our pre-formulation studies showed that only GMS could be transformed into SLN or NLCs despite high solubility of the lipids investigated indicating the importance of solvent-lipid interaction parameter in our preparation method. Finally, we show that SLN and NLCs of glyceryl monostearate with size < 150 nm and acceptable polydispersity index can be easily developed using Transcutol P as a biocompatible solvent and polyoxyl-40-stearate (MYS-40) as a stabilizer. As the Transcutol P has excellent acceptability for dermal/transdermal and oral route, there is no need to remove the residual Transcutol P (5% v/v) from the prepared glyceryl monostearate SLN/NLCs. Thus, our method offers a simple yet innovative way to prepare GMS SLN/NLCs suitable for dermal/transdermal and oral applications.

3D printing of poly(vinylidene fluoride-trifluoroethylene): a poling-free technique to manufacture flexible and transparent piezoelectric generators

Abstract

Increasing Energy Efficiency in Wireless Sensor Networks Using GA-ANFIS to Choose a Cluster Head and Assess Routing and Weighted Trusts to Demodulate Attacker Nodes

Demodulating harmful nodes and diminishing the energy waste in sensor nodes can prolong the lifespan of wireless sensor networks (WSNs). In this study, a genetic algorithm (GA) and an adaptive neuro fuzzy inference system were used to diminish the energy waste of sensors. Weighted trust evaluation was applied to search for harmful nodes in the network to prolong the lifespan of WSNs. A low-energy adaptive clustering hierarchy method was used to analyze the results. It was discovered that searching for harmful nodes with GA-ANFIS using weighted trust evaluation significantly increased the lifespan of WSNs. For evaluation of the proposed method we used the mean of energy of all sensors against of the round, data packets received in base station, minimum energy versus rounds and number of alive sensors versus rounds. Also, in this paper we compared the proposed method results with LEACH, LEACH-DT, Random, SIF and GA-Fuzzy methods. As results the proposed method has high life time than other methods. A representation of the overall system was implemented using MATLAB software.

Efficient nanowire-assisted electroporation and cellular inclusion release of microalgal cells achieved by a low voltage

A mild and low-energy cell disruption method with high efficiency has growing application potential in both the extraction of high-value microalgal products and the inactivation of microalgal cells. Conventional technologies available have disadvantages including high energy consumption, the use of chemicals and so on. Here, this study developed an efficient microalgal cell disruption method using the copper oxide nanowire (CuONW)-modified three-dimensional (3D) copper foam electrodes with a low applied voltage. Electrodes with nanowires synthesized at 400 °C, the optimal preparation temperature, achieved efficient microalgal cell electroporation. Microalgal cells were completely inactivated and disrupted at the voltage of 2 V with the hydraulic retention time (HRT) of 10 s. Scanning electron microscopy (SEM) images showed obvious electroporation damage on the cell surface upon electroporation-treatment (2 V, 30 s). The amount of released cellular inclusion increased significantly with prolonged HRT and the energy consumption of this technology was only 0.014 kWh/kg via the treatment of 2 V and 10 s. This study provided a novel, energy-efficient and chemical-free technique for both microalgal products extraction and cell inactivation.

Picosecond Electric-Field-Induced Switching of Antiferromagnets

Antiferromagnetic spintronics are hoped to enable ultrafast, high-density memory arrays working at picosecond time scales, but current methods to switch the antiferromagnetic order cost a lot of energy. This work proposes an ultrafast yet low-energy method for switching the N\'eel vector of an antiferromagnetic layer, by reconfiguration of the anisotropy energy when an electric field is applied. Theoretical analysis shows the possibility of switching the N\'eel vector of a 50-nm circular antiferromagnetic element with an energy dissipation of 250 aJ in less than 30 ps, without any current-induced torque.

Новые результаты по лазерному разделению изотопов с использованием низкоэнергетических методов

Новые результаты по лазерному разделению изотопов с использованием низкоэнергетических методов

Nanoemulsion containing essential oil from Xylopia ochrantha Mart. produces molluscicidal effects against different species of Biomphalaria (Schistosoma hosts).

BACKGROUND This work describes a chemical study of the essential oil from leaves of Xylopia ochrantha, an endemic Annonaceae species from Brazil, and its activity against Biomphalaria species. Considering its poor solubility in aqueous medium, the essential oil was nanoemulsified to evaluate its action on controlling some mollusc species of genus Biomphalaria, snail hosts of Schistosoma mansoni that causes schistosomiasis, which mainly affects tropical and subtropical countries.OBJECTIVES The main aims of this work were to analyse the chemical composition of essential oil from X. ochrantha, and to evaluate the effect of its nanoemulsion on molluscs of genus Biomphalaria and their oviposition.METHODS Chemical analysis was performed by gas chromatography coupled to mass spectrometry. Nanoemulsions were prepared by a low energy method and characterised by particle size and polydispersity index. Biological assays evaluating the mortality of adult species of B. glabrata, B. straminea and B. tenagophila and their ovipositions upon contact with the most stable nanoemulsion during 24 and 48 h were performed.FINDINGS Chemical analysis by mass spectrometry revealed the majority presence of bicyclogermacrene and germacrene D in the essential oil. The formulation with a hydrophilic-lipophilic balance (HLB) of 9.26 was the most suitable for the oil delivery system. This nanoemulsion caused the mortality in B. tenagophila, B. straminea and B. glabarata of different sizes at levels ranging from 50 to 100% in 48 h. Additionally, the formulation could inhibit the development of deposited eggs.CONCLUSION Thus, these results suggest the use of nanoemulsified essential oil from X. ochrantha as a possible alternative in controlling some Biomphalaria species involved in the schistosomiasis cycle.

Creating High-Density Large Square Bales by Recompression

Abstract. Creating high-density biomass bales would reduce the number of bales handled, stored, and transported to biorefineries, thereby reducing costs. Recompression of large square bales is one approach to increase bale density; however, recompression research on large bales is limited. Recompression of common biomass crops in 80 cm × 90 cm nominal cross-section bales was used to quantify pressure-density and stress relaxation relationships as well as restraining forces required to maintain compressed densities. Linear, power, and exponential models were fit to the pressure-density data, with the linear model providing the best representation of the recompression process. When bales were recompressed soon after bale formation, density increased by an average of 134%, and the target dry-basis density of 205 kg m-3 was exceeded at the end of recompression with all crops. While still compressed, bales were wrapped with four steel cables configured with load cells to measure the restraining force after release of pressure followed by bale re-expansion. Total restraining forces ranged from 18 to 40 kN. Bale density decreased by an average of 17% due to re-expansion after pressure was released. Strain relief induced by allowing the bale to re-expand by approximately 10% before placing the cables around the bales reduced the required restraining force by an average of 35%. Although the forces applied were great (>560 kN), the dry-basis specific energy requirements were comparatively low (0.18 to 0.29 kWh Mg-1) because recompression took place over a relatively long duration of approximately 20 to 25 s. Recompressing large square bales is a low-energy method to achieve bale densities that should ensure weight-limited biomass transport. Keywords: Bales, Biomass, Compression, Energy.

Incorporation of Homogenizer in Nanoemulsion Injection Scheme for Enhanced Oil Recovery

This work presents a theoretical approach of incorporating a homogenizer within a nanoemulsion injection scheme for enhanced oil recovery (EOR). Nanoemulsions are kinetically stable emulsions stabilized by surfactants with droplet sizes ranging from 20 to 500 nm and have the potential to deliver chemical agents depending on their application. For EOR, nanoemulsions have the potential to be more effective than the often used microemulsion which are thermodynamically stable and thus may break due to the heterogeneous conditions inherent in oil and gas reservoirs. There are two primary categories of nanoemulsion formulation which are high energy methods and low energy methods. High energy methods involve creating nanoemulsions using a high energy process such as high pressure homogenization. These methods can be expensive due to the energy applied to the nanoemulsion formulation process. Low energy methods involve manipulating the chemistry of the oil and surfactant formulation and are thus low cost due to the low energy input. Current technology illustrates that nanoemulsion size control is relatively straightforward using high energy methods such as high pressure homogenization. Injecting incompressible fluids into a reservoir requires substantial energy in the form of pumps. Incorporating a homogenizer in the injection scheme gives an opportunity for the homogenizer to utilize the high energy inherent in the injection process. This is illustrated using the mechanical energy balance that combines the potential, kinetic, friction, and homogenizer pressure drops inherent in the incorporation of a homogenizer in the injection of nanoemulsions. Analysis shows the relative contributions of each of these pressure effects in the overall determination of the bottom hole injection pressure. Incorporating a homogenizer into a nanoemulsion EOR process would schematically give direct control over nanoemulsion size while conserving energy by using the high energy inherent in an EOR injection process. This would be a novel direct approach of controlling the stability of nanoemulsions (by controlling the size) while not producing extra costs associated with high energy nanoemulsion creation methods. The describe procedure illustrates how to design an injection performance curve that can schematically give control of nanoemulsion size.

Bifunctional clove oil nanoparticles for anesthesia and anti-bacterial activity in Nile tilapia (Oreochromis niloticus)

Clove oil (an essential oil extracted from the flower buds of clove plant, Syzygium aromaticum) is used as an anesthetic agent in order to reduce stress and mortality rate as well as other potential negative effects on fish homeostasis. However, utilization of essential oils in aquaculture has limited practicality due to their high volatility and water insolubility. In this study, we developed and evaluated an effective, cheap, safe, and easy-to-administer form of clove oil by encapsulating the poorly water-soluble clove oil into lipid-based nanoscale carriers used for safe anesthesia and antibiotic alternatives against infectious pathogens in farmed tilapia. Clove oil nanoparticle was prepared via the phase inversion composition technique (low energy method), physicochemically and biologically characterized. Our results showed that the well-dispersed water-soluble clove oil nanoparticles had negative charge with a narrow particle size distribution, and showed sustained release of active ingredients (eugenol) over an extended period of time up to 48 h. As compared to the standard clove oil, our results clearly indicated that shorter induction time and longer recovery time in tilapia were achieved with clove oil nanoparticles, confirming its stronger anesthetic effect. Additionally, this improved version of clove oil nanoparticle exhibited good anti-bacterial activity against two important tilapia pathogens namely Streptococcus agalactiae and Flavobacterium columnare. In conclusion, the so-called bifunctional clove oil nanoparticles has been successfully developed with enhanced solubility, and improved sedation and anesthesia with a sustained release, as well as the enhanced antimicrobial activity against fish pathogens.

Ultrafine ZnS quantum dots decorated reduced graphene oxide composites derived from ZIF-8/graphene oxide hybrids as anode for sodium-ion batteries

Ultrafine ZnS quantum dots (QD) with sub-10 nm-scale decorated reduced graphene oxide composites is prepared by a very simple and low-energy two-step method. First, we prepare zeolitic imidazolate frameworks (ZIFs) and graphene oxide composites by stirring at room temperature. Then, the ZnS quantum dots and reduced graphene oxide composites (ZnS/GAs) is obtained by refluxing and annealing. Because of the smaller nanosize of ZnS and the addition of reduced graphene oxide, the composites exhibit the excellent specific capacity and the superior cycle performance for ZnS-based anodes. Meanwhile, N-doped carbon and reduced graphene oxide composites (NC/GAs) is also prepared by direct carbonization of zeolitic imidazolate frameworks and graphene composites. The ZnS/GAs is tested for SIBs; The capacity is still stable at 539 mAh/g at 100 mA/g, 512 mAh/g at 200 mA/g and 456 mAh/g at 500 mA/g after 100 cycles. Even when the current density is increased to 1 A/g, the capacity can still reach 362 mAh/g after 300 cycles. The NC/GAs is also tested for SIBs; the capacity is still stable at 283 mAh/g at 100 mA/g after 100 cycles and can still achieve 202 mAh/g at 1 A/g after 1000 cycles.

Nanoemulsions: Synthesis, Characterization, and Application in Bio-Based Active Food Packaging.

The increasing demands for foods with fresh-like characteristics, lower synthetic additive and preservative contents, and low environmental footprint, but still safe to consume, have guided researchers and industries toward the development of milder processing technologies and more eco-friendly packaging solutions. As sustainability acquires an increasingly critical relevance in food packaging, bio-based and/or biodegradable materials stand out as suitable alternatives to their synthetic counterparts. In this context, the use of nanoemulsions has represented a step forward for improving the performance of sustainable food packaging devices, especially for the successful incorporation of new compounds and functionalities into conventional films and coatings. This class of emulsions, featuring unique optical stability and rheological properties, has been developed to protect, encapsulate, and deliver hydrophobic bioactive and functional compounds, including natural preservatives (such as essential oils from plants), nutraceuticals, vitamins, colors, and flavors. This article presents the surfactants (including naturally occurring proteins and carbohydrates), dispersants, and oil-soluble functional compounds used for designing food-grade nanoemulsions intended for packaging applications. The improved kinetic stability, bioavailability, and optical transparency of nanoemulsions over conventional emulsions are discussed considering theoretical concepts and real experiments. Bottom-up and top-down approaches of nanoemulsion fabrication are described, including high-energy (such as high-pressure homogenizers, microfluidics, ultrasound, and high-speed devices) and low-energy methods (for instance, phase inversion and spontaneous emulsification). Finally, incorporation of nanoemulsions in biopolymer matrixes intended for food packaging applications is also addressed, considering current characterization techniques as well as their potential antimicrobial activity against foodborne pathogens.

Effect of Freeze-Thaw Pretreatment on Extraction Yield and Antioxidant Bioactivity of Corn Carotenoids (Lutein and Zeaxanthin)

As a green and low-energy pretreatment method, the effect of freeze-thaw (FT) pretreatment on extraction yield and antioxidant bioactivity of carotenoids of the corn gluten meal (CGM) were evaluated in this study. The CGM particles ruptured in FT treatment due to the repeated damage caused by FT to CGM particles. The carotenoid compounds of pretreated CGM were lutein, zeaxanthin, β-carotene, and cryptoxanthin. Among them, the major carotenoids are lutein and zeaxanthin. The optimized FT pretreatment conditions included freezing temperature of −20°C, moisture content of 100%, and 2 cycles. An increase in the yield of lutein and zeaxanthin was observed in the range of 2.23–16.39 µg/g and 4.66–36.3 µg/g as a result of pretreatment as against 1.17 and 2.52 µg/g of the untreated sample, respectively. Moreover, the release of lutein and zeaxanthin from CGM was facilitated by FT pretreatment and increased the antioxidant activity of the carotenoids.

CHARACTERISTICS AND TOXICITY OF NANOEMULSION FORMULATION OF PIPER RETROFRACTUM AND TAGETES ERECTA EXTRACT MIXTURES

Characteristics and Toxicity of Nanoemulsion Formulations of Piper retrofractum and Tagetes erecta Extract Mixtures. Nanotechnology has been used in the developing of botanical insecticide formulation for improving its stability and effectiveness. The research was aimed to make nanoemulsion formulations of Piper retrofractum fruits and Tagetes erecta flowers extracts and to evaluate their toxicity against brown planthopper (Nilaparvata lugens [Stål]) nymphs. The development of nanoemulsion formulaions was carried out by using the low energy method with inversion phase emulsification. The toxicity of the four formulations was tested against brown planthopper nymphs using a contact method. Four nanoemulsion formulations were obtained. The study showed that in the developing of the formulations, the type and level of emulsifier materials affected the physical characteristics of formulas, such as stability, surface tension, viscosity, particle size, and particle morphology. The nanoemulsion formulation containing 1% of the mixture of P. retrofractum fruits and T. erecta flowers extracts, 1.75% Triton X-100 emulsifier showed the highest toxic on the brown planthopper nymph, with the LC95 value was 0.15%. The study indicates that nanoemulsion formulation of P. retrofractum and T. erecta extracts are potential to be developed as botanical insecticide to control brown planthopper of rice.

Domperidone nanocrystals with boosted oral bioavailability: fabrication, evaluation and molecular insight into the polymer-domperidone nanocrystal interaction.

The aim of this study was to employ experimental and molecular modelling approaches to use molecular level interactions to rationalise the selection of suitable polymers for use in the production of stable domperidone (DOMP) nanocrystals with enhanced bioavailability. A low-energy antisolvent precipitation method was used for the preparation and screening of polymers for stable nanocrystals of DOMP. Ethyl cellulose was found to be very efficient in producing stable DOMP nanocrystals with particle size of 130 ± 3nm. Moreover, the combination of hydroxypropyl methylcellulose and polyvinyl alcohol was also shown to be better in producing DOMP nanocrystals with smaller particle size (200 ± 3.5nm). DOMP nanosuspension stored at 2-8°C and at room temperature (25°C) exhibited better stability compared to the samples stored at 40°C. Crystallinity of the unprocessed and processed DOMP was monitored by differential scanning calorimetry and powder X-ray diffraction. DOMP nanocrystals gave enhanced dissolution rate compared to the unprocessed drug substance. DOMP nanocrystals at a dose of 10mg/kg in rats showed enhanced bioavailability compared to the raw drug substance and marketed formulation. A significant increase in plasma concentration of 2.6μg/mL with a significant decrease in time (1h) to reach maximum plasma concentration was observed for DOMP nanocrystals compared to the raw DOMP. Molecular modelling studies provided underpinning knowledge at the molecular level of the DOMP-polymer nanocrystal interactions and substantiated the experimental studies. This included an understanding of the impact of polymers on the size of nanocrystals and their associated stability characteristics.

Low-energy nano-emulsification approach as a simple strategy to prepare positively charged ethylcellulose nanoparticles

Positively charged ethylcelulose nanoparticles have been obtained from alkylamidoammonium/Span 80 based nano-emulsion templates. Oil-in-water polymeric nano-emulsions form in a broad range of oil-to-surfactant ratios and water contents above 75 wt% by a low-energy method at 25 °C. Nano-emulsions with a water content of 90 wt% showed droplet sizes typically below 300 nm and high positive zeta potential values (∼55 mV). If oleylamine is added to the system, smaller droplet sizes and higher zeta potential values (∼66 mV) are obtained, but the stability of the nano-emulsions decreases. Although these nano-emulsions are destabilized by creaming, the period of stability is large enough to allow nanoparticle preparation by solvent evaporation. Polymeric nanoparticles obtained show a globular core-shell-like morphology, with mean diameters of around 250 nm. The surface charge of the nanoparticles is similar to that of the nano-emulsion template and remains positive after 24 h dialysis, suggesting slow desorption kinetics of the alkylamidoammonium from the nanoparticle surface. These results indicate that the proposed nano-emulsion approach is a good strategy for the preparation of positively charged nanoparticles from nonionic ethylcellulose polymers.

Is it possible to obtain nanodispersions with jaboticaba peel’s extract using low energy methods and absence of any high cost equipment?

Jaboticaba (Myrciaria cauliflora) is considered a "super fruit" due to its remarkable phenolic content and antioxidant capacity. Despite the great potential of its peels, to our knowledge the investigation of novel nanostructured systems with this natural raw material, still considered an industrial residue, is scarce. The present study aimed to obtain nanodispersions with its peel's extract through a low energy method. Antioxidant assays were performed, showing positive results for DPPH (IC50 = 0.89 μg/mL) and FRAP (225.53 μmol equivalent ferrous sulphate/g). The chemical characterization in terms of flavonoids (2.56%) and total monomeric anthocyanins (0.80%) contents were also performed. Overall, the nanodispersion prepared with the non-ionic surfactant polysorbate 85 and the hydroalcoholic extract standardized in ellagic acid (129 µg/mL) presented the best properties regarding particle size distribution and zeta potential. Thus, it opens perspectives for the generation of novel food-grade nanodispersions through an ecofriendly approach that is in accordance to sustainable concepts.

Self-nanoemulsifying system improves oral absorption and enhances anti-acute myeloid leukemia activity of berberine

BackgroundRecently, we found that berberine (BBR) exerts anti-acute myeloid leukemia activity, particularly toward high-risk and relapsed/refractory acute myeloid leukemia MV4-11 cells in vitro. However, the poor water solubility and low bioavailability observed with oral BBR administration has limited its clinical use. Therefore, we design and develop a novel oil-in-water self-nanoemulsifying system for BBR (BBR SNE) to improve oral bioavailability and enhance BBR efficacy against acute myeloid leukemia by greatly improving its solubility.ResultsThis system (size 23.50 ± 1.67 nm, zeta potential − 3.35 ± 0.03 mV) was prepared with RH40 (surfactant), 1,2-propanediol (co-surfactant), squalene (oil) and BBR using low-energy emulsification methods. The system loaded BBR successfully according to thermal gravimetric, differential scanning calorimetry, and Fourier transform infrared spectroscopy analyses. The release profile results showed that BBR SNE released BBR more slowly than BBR solution. The relative oral bioavailability of this novel system in rabbits was significantly enhanced by 3.41-fold over that of BBR. Furthermore, Caco-2 cell monolayer transport studies showed that this system could help enhance permeation and prevent efflux of BBR. Importantly, mice with BBR SNE treatment had significantly longer survival time than BBR-treated mice (P < 0.001) in an MV4-11 engrafted leukemia murine model.ConclusionsThese studies confirmed that BBR SNE is a promising therapy for acute myeloid leukemia.

Plasma-relevant electron scattering cross sections of propene

Propene (C3H6) is considered to be an important molecule in the field of plasma science due to it being recognized as a by-product of plasma irradiation at the diverter regions and plasma facing walls in modern fusion devices. This article reports electron scattering elastic, momentum transfer, differential and excitation cross sections of propene. The rate coefficients for the elastic and momentum transfer cross sections are also reported. The data reported in this article are considered to be important in the field of plasma physics due to their direct influence on plasma modeling applications. Two theoretical methods were used for the present study; the R-matrix method for low energy and spherical complex optical potential formalism for high energy. The R-matrix calculation was performed using the correlation-consistent polarized valence-only triple-zeta basis set and a reasonable agreement with the target properties was obtained. The scattering calculations were then performed using these parameters to compute various cross sections. The present cross sections compare reasonably well with the only available data in the literature. More experimental studies of a similar nature are encouraged for the validation of the present results.

Effect of gelation and storage conditions on the oxidative stability of microemulsion and nanoemulsion delivery systems

Increased interest in the use of microemulsion and nanoemulsion delivery systems for medical, cosmetic and food purposes, promotes the development of research on their physical and chemical stability, and the safety of use. Here, we have for the first time evaluated the oxidative stability of linseed oil dispersed in the microemulsion, nanoemulsion, and their gelled systems, stored under different conditions, and compared to the bulk oil. Oxidative stability was determined by measuring the peroxide value and p-anisidine value of the oil phase. All systems had an identical proportion of oil to surfactant mixture and were obtained by low energy methods. Carbopol 940 was used as the gelator. The influence of sunlight in ambient conditions, elevated temperature, oxygen presence and UV radiation on the oxidation of oil in emulsions was determined. The results indicate different influence of the analyzed conditions on the oxidation stages of individual emulsions. Due to the high transparency and small particle sizes, micro-, nanoemulsions, and particularly their gelled forms were the most sensitive to UV radiation. However, the gelation process inhibited the oxidation caused by temperature and the presence of oxygen. In addition, the results show a counter-intuitive result in that, under all test conditions, the oxidative stability of the oil was higher in emulsions compared to bulk oil.