Physiochemical and cytotoxicity study of TPGS stabilized nanoemulsion designed by ultrasonication method

The main aim of the present work was to prepare TPGS stabilized D-α-Tocopherol, lemon oil, tween-80, and water nanoemulsion by low cost and highly effective sonication method. The prepared nanoemulsion showed good stability for 60 days at variable temperature conditions i.e. 4, 25 and 37 °C. The tolerance of the prepared nanoemulsion to salt (50 mM–500 mM) and pH (pH 2–pH 7.4) was also studied. The morphology and droplet size of pure and quinine loaded nanoemulsion was characterized with transmission electron microscopy. The prepared formulation was transparent and the obtained average particle size ranged between 25 nm and 35 nm. The nanoemulsion was found to be non toxic. The cell viability study of pure nanoemulsion carried out on Hep G2 cells revealed that the cell viability was 100%. The formulation further exhibited high quinine loading and release capacity with cumulative release up to 76 ± 2% and 65 ± 2% at pH 7.4 and pH 5.5 respectively. The interaction between quinine and vitamins (riboflavin, thiamine and biotin) was also carried out (aqueous medium). The study revealed that riboflavin had strong interaction with quinine and vitamins vis-à-vis thiamine and biotin.     

Ultrasound processed nanoemulsion: A comparative approach between resveratrol and resveratrol cyclodextrin inclusion complex to study its binding interactions,antioxidant activity and UV light stability

Resveratrol is a naturally occurring therapeutic molecule used for treatment of diseases caused by oxidative stress. This investigation elucidates the advantages of fabrication of size controlled resveratrol inclusion complex. This has been done by encapsulating resveratrol-cyclodextrin inclusion complex in a phospholipid stabilized nanoemulsion formulated by ultrasonication emulsification method. The prepared nanoemulsion has been compared with resveratrol encapsulated nanoemulsion system. The morphology of the resveratrol nanoemulsion and inclusion complex nanoemulsion have been observed using transmission electron microscopy with average size 20.41 ± 3.41 and 24.48 ± 5.70 nm respectively. The nanoemulsion showed good loading and release efficiency. The radical diminishing potential of resveratrol and its inclusion complex has been compared in nanoemulsion. The effect of UV irradiation (365 nm) on resveratrol in different solvent systems (ethanol, water and nanoemulsion) indicated that nanoemulsion prevents degradation of resveratrol. Efforts have also been made to explore the interactions between bovine serum albumin and resveratrol in nanoemulsion.     

Tea saponin additive to extract eleutheroside B and E from Eleutherococcus senticosus by ultrasonic mediation and its application in a semi-pilot scale

The safety of ethanol in operations and its effects on human health are gradually being questioned. Under this premise, we attempted to use the natural surfactant tea saponin, which originates from the processing residues of camellia oil, as the additive of the extraction solvent and to extract eleutheroside B and eleutheroside E in the roots and rhizomes of E. senticosus by ultrasonic mediation. After a single-factor experiment, extraction kinetics at different powers and reaction temperatures, and Box–Behnken design optimization, the optimal conditions obtained were 0.3% tea saponin solution as the extraction solvent, 20 mL/g liquid–solid ratio, 250 W ultrasonic irradiation power (43.4 mW/g ultrasonic power density) and 40 min ultrasonic irradiation time. Under optimal conditions, satisfactory yields of eleutheroside B (1.06 ± 0.04 mg/g) and eleutheroside E (2.65 ± 0.12 mg/g) were obtained with semi pilot scale ultrasonic extraction equipment. The experiments showed that compared with the traditional thermal extraction process, the extraction time is significantly reduced at lower operating temperatures.     

Ultrasonic effects on the degradation kinetics,preliminary characterization and antioxidant activities of polysaccharides from Phellinus linteus mycelia

In this study, a high-molecular-weight polysaccharide PL-N isolated from the alkaline extract of Phellinus linteus mycelia was degraded by ultrasound. Results showed that ultrasound treatment at different ultrasonic intensities decreased the intrinsic viscosity and molecular weight of PL-N, as well as narrowed the molecular weight distribution. A larger reduction in intrinsic viscosity and molecular weight was caused by a higher ultrasonic intensity. The degradation kinetics model was fitted to (1/M_t − 1/M₀) = k·t, and the reaction rate constant (k) increased with increasing ultrasonic intensity. Ultrasound degradation did not change the primary structure of PL-N, and scanning electron microscopy analysis indicated that the morphology of the original PL-N was different from that of degraded PL-N fractions. Antioxidant activity assays in vitro indicated that the degraded PL-N fraction with low molecular weight had stronger hydroxyl radical scavenging capacity and higher TEAC and FRAP values.     

Preparation of continuous TiO2 fibers by sol-gel method and its photocatalytic degradation on formaldehyde

The continuous TiO₂ fibers were prepared by sol-gel method using the tetrabutyl orthotitanate as the precursor. The sol-formation process is studied by FT-IR spectroscopy. The synthesized continuous TiO₂ fibers were characterized using SEM, HRTEM and XRD. Results demonstrate that the titanate sol has good spinnability when R ≤ 2 (R = H₂O:Ti(OC₄H₉)₄, molar ratio). The fibers have the length of several meters and the diameter of about 30 μm. The fibers are a radial close-packed product of nano-particles with high crystallinity. The continuous TiO₂ fibers are co-crystal including anatase phase and rutile phase. The formaldehyde degradation ratio of continuous TiO₂ fiber was 98.6%.     

Improved ultrasonic degradation of hydrophilic and hydrophobic aldehydes in water by combined use of atomization and UV irradiation onto the mist surface

Ultrasonic irradiation of 430 kHz, which induces both the chemical effect of pyrolysis and the physical effect of atomization, was carried out to achieve highly effective decomposition of organic substances in water with UV₂₅₄ irradiation and H₂O₂ addition. To investigate the influence of physicochemical properties of the substrate on the degradation rate, three different aldehydes, namely, formaldehyde, acetaldehyde, and benzaldehyde, were selected as model substrates. Upon ultrasonic irradiation alone, the removal ratio of the hydrophobic substrate benzaldehyde reached 100% after 120 min, whereas the removal ratios of the hydrophilic substrates formaldehyde and acetaldehyde were only 21.1% and 53.0%, respectively. By combining ultrasonic atomization and UV₂₅₄ irradiation, formaldehyde and acetaldehyde underwent effective gas-phase decomposition on the surfaces of the mist particles. Photolysis by UV₂₅₄ irradiation mainly affected for the decomposition of aldehydes on the mist surface rather than the reaction of hydroxyl radicals derived from H₂O₂ made by water sonolysis. However, the addition of H₂O₂ effectively improved the decomposition and mineralization rates for both hydrophilic and hydrophobic aldehydes owing to the generation of hydroxyl radicals on the surfaces of the mist particles, which greatly contributed to the gas-phase decomposition. Consequently, the effective decomposition of organic pollutants was achieved regardless of their physicochemical properties in aqueous media.     

Effects of ultrasonic assisted high-temperature cooking method on the physicochemical structure characteristics and in vitro antioxidant capacities of dietary fiber from Dendrocalamus brandisii Munro shoots

In this study, the ultrasonic assisted high-temperature cooking extraction method of soluble dietary fiber from bamboo shoots was optimized by response surface methodology, and the effects of ultrasonic assisted high-temperature cooking extraction on the structural characteristics, physicochemical properties and antioxidant activity of soluble dietary fiber (SDF) from bamboo shoots were evaluated. The yield of modified UH-SDF¹ was significantly higher than that of untreated D-SDF². FTIR and XRD confirmed that UH-SDF had more hydrophilic groups and higher crystallinity (28.73 %), resulting in better thermal stability. SEM observation showed that UH-SDF exhibited a more loose microstructure, and the particle size of UH-SDF (601.52 μm) was significantly smaller than that of D-SDF (242.59 μm), so UH-SDF had a larger specific surface area. In addition, UH-SDF has stronger water holding capacity, water swelling capacity and oil holding capacity than D-SDF. The DPPH radical and hydroxyl radical scavenging rates of UH-SDF were 8.91 % and 7.49 % higher than those of D-SDF. In addition, the reducing ability of UH-SDF was higher than that of D-SDF, which had better antioxidant activity. In summary, UH-SDF has the potential to be developed as an anti-inflammatory functional food.     

Green extraction of lutein from marigold flower petals,process optimization and its potential to improve the oxidative stability of sunflower oil

Marigold flower petals are considered the richest source of lutein which possesses immense applications in the food and health sector. The study was undertaken to improve the stability of sunflower oil by enriching it with lutein extracted from marigold flower petals using safe and green technology. The extraction of lutein was optimized using Box-Behnken design by ultrasound-assisted extraction (UAE) employing sunflower oil as a solvent. The impact of three independent variables i.e., ultrasonic intensity, solid to solvent ratio, and extraction time were evaluated on the amount of lutein extracted and its antioxidant activity. Highest amount of lutein (21.23 mg/g) was extracted by employing ultrasonic intensity of 70 W/m2, extraction time of 12.5 min, and solid to solvent ratio of 15.75%. FT-IR spectra of lutein extracted by ultrasound and conventional extraction show similar peaks depicting that ultrasound does not have any impact on the functionality of lutein. Sunflower oil incorporated with lutein at 1000 PPM and the synthetic antioxidant (TBHQ) showed good oxidative stability than oil with 500 PPM lutein and no lutein during accelerated storage for a month. The oxidative stability was shown by different oil samples in the following order: TBHQ = 1000PPM lutein˃500PPM lutein ˃control oil. It was concluded that the ultrasound technique extracts lutein efficiently from marigold flowers and this lutein was effective in improving the oxidative stability of sunflower oil under accelerated storage conditions.     

Soft X-ray enhancement from porous target irradiated by high power sub-nanosecond laser beam and the effect of plasma opacity

In this paper, we investigate numerically the enhancement of the soft continuum X-ray yield emitted from porous aluminum targets irradiated by sub-nanosecond high power pulsed laser beam. The calculations were conducted for two different conditions: (i) ignoring plasma opacity, and (ii) including it in the calculations; and finally the results were compared. In the calculations, the main emission mechanisms were assumed to be the free–bound and free–free (bremsstrahlung) transitions at water windows wavelengths ranges 2.3–4.4 nm and also 12.6–14.6 nm, which is useful for lithography applications. The free–free and bound–free transitions were also considered for calculating the opacity. The results show that for both conditions, the X-ray yield rises with increasing the porosity and the increase rate is almost equal in both cases; however, the calculations are not appropriate for estimating the absolute values of the X-ray yield when the plasma opacity is ignored.     

Quenching of fluorescence by light: A new method to control the excited-state lifetimes and orientations of fluorophores

We report steady-state and time-resolved studies of quenching of fluorescence by light i.e. light quenching. The dyes rhodamine B (RhB) and 4-dicyanomethylene-2-methyl-6(p-dimethamino)-4H-pyrane (DCM) were excited in the anti-Stokes region from 560 to 615 nm. At a high illumination power the intensities of DCM and RhB were sublinear with incident power, an effect we believe is due to stimulated emission, andnot ground-state depopulation. The extent of light quenching was proportional to the amplitude of the emission spectrum at the incident wavelength, as expected for light-stimulated decay from the excited state. Control measurements at a decreased average illumination power, and in solvents of various viscosities, indicated that the effect was not due to undesired photochemical processes. Importantly, the frequency-domain intensity decays remained single exponentials, and the lifetimes were unchanged with light quenching, which suggests that the effect was not due to heating or other photochemical effects. These results are consistent with a quenching process which occurs within the quenching pulse. Importantly, as expected for light quenching with a single pulsed laser beam, the time 0 anisotropies of RhB and DCM were decreased due to orientation-dependent quenching of the excited-state population. In closing we discuss some possible future applications of light quenching to studies of dynamic processes.This report is partially based on the experimental data published previously [1,2].     

Correction to: Generation of amplitude- and phase-modulated signal beam with a phase-only spatial light modulator and its detection by the transport of intensity equation method for holographic data storage

This study evaluates a novel holographic data storage (HDS) that uses a phase-only spatial light modulator (SLM) for the multilevel complex amplitude modulation of a signal beam and the transport of intensity equation (TIE) method to detect the signal beam without interferometry, to increase the capacity of the HDS, simplifying its optical system, and improving the stability of the signal beam modulation and detection. Both the amplitude and phase of the signal beam were modulated by a computer-generated hologram displayed in a phase-only SLM, a 4-f optical system, and a pinhole placed in the Fourier plane. The complex amplitude-modulated signal beam generated by this scheme does not always perfectly match the target complex amplitude, and deviations from the amplitude and phase of the target complex amplitude may exist. It is unclear whether the TIE method, which is sensitive to the state of the beam intensity and the phase distributions to be detected (such as zero-intensity points and phase discontinuities), can accurately detect a signal beam whose complex amplitude is modulated by the modulation scheme with a phase-only SLM. Here, we demonstrate via numerical simulations and experiments that several methods of complex amplitude generation using a phase-only SLM can achieve multilevel modulation of the amplitude and phase of a signal beam and are suitable for detection by the TIE method in HDS.

     

A study of the solid state-gaseous phase equilibrium in CdSe and its application to the growing of single crystals from the gaseous phase by Frerich's method

The equilibrium between the solid state and the gaseous phase of the semi-conducting compound CdSe is investigated. This is a study of two equilibrium reactions CdSe(s)Cd(g) + + (1/2) Se₂(g) and Se₆(g)3 Se₂(g) as a function of the temperature. The results were used to estimate the optimum conditions for the growing of CdSe single crystals from the gaseous phase by Frerichs' method. The basic electrical and optical properties were then measured on the crystals. In conclusion the results of the experiments are evaluated and compared with those of other authors.In conclusion, the authors thank Dr. E. Klier and other members of the department for much valuable advice and remarks, and laboratory assistants O. Kundrátová and J. Rejna for help in the work.     

On the synthesis of AlPO4-21 molecular sieve by vapor phase transport method and its phase transformation to AlPO4-15 molecular sieve

An experimental design was applied to the synthesis of AlPO₄-21 molecular sieve (AWO structure) by vapor phase transport (VPT) method, using tetramethylguanidine (TMG) as the template. In this study, the effects of crystallization time, crystallization temperature, phosphor content, template content and water content in the synthesis gel were investigated. The materials obtained were characterized by X-ray diffraction, scanning electron microscopy and fourier transform infrared spectroscopy (FT-IR). Microstructural analysis of the crystal growth in vapor synthetic conditions revealed a revised crystal growth route from zeolite AlPO₄-21 to AlPO₄-15 in the presence of the TMG. Homogenous hexagonal prism AlPO₄-21 crystals with size of 7 × 3 μm were synthesized at a lower temperature (120 °C), which were completely different from the typical tabular parallelogram crystallization microstructure of AlPO₄-21 phase. The crystals were transformed into AlPO₄-21 phase with higher crystallization temperature, longer crystallization time, higher P₂O₅/Al₂O₃ ratio and higher TMG/Al₂O₃ ratio.