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This study focused on describing the bioavailability of ursolic/oleanolic acids (UA/OA) and the methods to increase it, so that these 2 bioactive compounds can have therapeutic and preventive effects in chronic diseases and cancer. Ursolic/oleanolic acids are natural compounds that have been known since the 19th century. They are very widespread and offer special benefits for human health - especially that their high absorbability makes them suitable for use in therapeutic and preventive treatment. One of the important aspects of their bioavailability is related to their interaction with other bioactive compounds or drugs. In chronic diseases and cancer, UA/OA may affect the absorption of other nutrients and interact with bioactive compounds. By increasing the bioavailability of UA/OA with various technical processes, especially using nanocarriers and nanoparticles, these compounds can affect collagen production, contributing to maintaining skin elasticity and preventing the appearance of wrinkles. Today, UA/OA are frequently used to treat many conditions, ranging from chronic to metabolic. [ABSTRACT FROM AUTHOR]

Ca- and Cu-decorated TiO2 microparticles are titanium dioxide nanoparticles that have been decorated with calcium and copper ions. TiO2, CaO, and CuO are low-cost, non-toxic, and non-hazardous materials. The aim of the present study was the physicochemical characterization of Ca- and Cu-decorated TiO2 microparticles and the evaluation of their antimicrobial activity. Thus, Ca2+ and Cu2+ species were incorporated onto TiO2 surfaces by a two-step wet method. The obtained TiO2-CaO-CuO composites were characterized by several experimental techniques. The electronic structure and charge properties of the composites were investigated by density functional theory calculations. Furthermore, the composites were successfully tested for inhibitory effects on Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans standard strains. The zeta potential data indicate that the physiological condition of investigated microbial strains was strongly affected in presence of a dispersion of 10 μg/L of composites in a saline phosphate buffer also, the recorded SEM images show a damaged microbial cell surface in the presence of composites. [ABSTRACT FROM AUTHOR]

Plastics, once regarded as a revolutionary material shaping modern society, now pose an unprecedented threat to our environment. Household solid waste sorting stations produce several fractions, one of which contains a high concentration of Low-Density Polyethylene (LDPE) film waste (packaging, sunscreen film, etc.). This fraction is difficult to recycle because it contains quite a lot of impurities. Usually, it is sent to cement factories that burn it together with other fuels. However, with some processing techniques such as catalytic pyrolysis, this fraction could be valorized. In this paper, experiments were carried out in batches at a laboratory-scale installation, with a processing capacity of 1–3 kg of waste. A pyrolysis reactor was connected to a distillation column, enabling separation of the fractions. The gaseous and liquid fractions were characterized by GC-FID-TCD (gases) and GC-MS (liquids) analysis. Natural catalysts such as bentonite or clinoptilolite were studied and used in the melting of plastic mass to simplify the process as much as possible. To test the activity of the catalysts, the pyrolysis of LDPE granules was initially studied. It was found that natural zeolites are much more active than bentonite and that a minimum concentration of 5–10% is needed to have a positive effect on the composition of the fractions (increasing the weight of the light fractions (C1–C6, C6–C10, and C11–C13) in relation to the heavy fractions (C13–C20 and C20+). Catalytic pyrolysis gives a completely different distribution of light hydrocarbons. The best catalyst selected from LDPE lab experiments was then tested upon the pyrolysis of plastic film waste obtained by a waste treatment plant. The research objective reported in this paper was to obtain a fraction of combustible gases in the largest possible proportion, which can be much more easily exploited by burning in an engine that drives an electric generator. [ABSTRACT FROM AUTHOR]

Oak bark is a by-product known for its richness in polyphenols, with tanning substances being particularly interesting for their application in different fields. Vegetable tannins are mostly utilized in the leather sector, but are also widely used as adhesives, in cement plasticizers and for medical and agrochemical applications owing to their natural antimicrobial activity. This study aimed to develop a green and efficient pilot-scale technique for extracting polyphenols from oak bark by ultrasound-assisted extraction (UAE) using a modified Dual-Frequency Reactor (DFR). Different parameters, such as extraction time, temperature, and solvent type (water, sodium hydroxide or sodium sulfite and bisulfite solutions) were investigated for their influence on the total phenolic content (TPC) and the quantity of dry extract. Control experiments by conventional methods were also performed. UAE at 50 °C yielded the highest TPC and dry extract (confirmed by ANOVA analysis, p < 0.05) in just 10 min, suggesting that UAE can be considered an energy- and cost-effective alternative to conventional techniques. The most suitable solvent was found to be a 0.5% sodium hydroxide solution. The molecular profile of the extracts was assessed by FTIR-ATR spectroscopy, revealing typical signals of tannins in all extracts. Furthermore, antimicrobial activity tests demonstrated the complete absence of Gram-positive and Gram-negative bacteria in the extracts, ensuring the suitability of the product for different kinds of application. [ABSTRACT FROM AUTHOR]

As a renewable and sustainable resource, lignocellulosic biomass serves as a crucial raw material for the production of biofuels, biochemicals, and various value-added products. This paper aims to develop and optimize a mild alkaline treatment of sawdust assisted by ultrasound, along with enzymatic hydrolysis of the pretreated material. The alkaline sonochemical pretreatment emerged as the optimal approach to enhance the susceptibility of cellulose to subsequent enzymatic hydrolysis to improve the yield of reducing sugars. A comparative study was performed using various ultrasonic applicators (horn and bath) and conventional assisted alkaline pretreatment. The ultrasonic-assisted pretreatment revealed a higher delignification of 68% (horn) and 57% (bath) compared with conventional pretreatment. Processes were optimized using a statistical analysis based on a 23 factorial design. The ratios between sawdust and alkaline solution (RSL = 0.5–1.5 g/100 mL), US amplitude (A = 20–60%), and working temperature (t = 30–50 °C) were selected as process factors. The optimal operating conditions to maximize the reducing sugar yield (138.15 mg GE/gsubstrate) were found as follows: a solid/liquid ratio of RSL,opt = 1.25 g/100 mL, US amplitude of Aopt = 60%, and pretreatment temperature of topt = 50 °C. The overall outcomes clearly confirmed the intensification of delignification by ultrasound-assisted alkaline pretreatment. [ABSTRACT FROM AUTHOR]

Ultrasonic technology (US) can be considered a very sustainable and efficient method to remove bisphenol A (BPA) from water. Compared with other methods, the proposed method has some advantages: a simple implementation on existing water treatment and purification facilities, it does not generate residual compounds that produce sludge, a relatively fast time is required for degradation (1–2 h), and high degradation efficiencies. In this work, we present the results regarding BPA degradation efficiency using the ultrasonic technique. The influence of frequency and of some additional compounds, such as carbon tetrachloride (CCl4), FeSO4 7H2O (FS), and ethyl anthraquinone (EAC), were studied. Three different frequencies were used: 1146 kHz, 864 kHz, and 580 kHz, at 50 W. The sampling, performed every 15 min, revealed that the highest BPA degradation was achieved after 60 min. Using the liquid chromatography tandem mass spectrometry (LC-MS/MS) technique, the degradation compounds were identified. Pathways of BPA degradation were also proposed. The use of additives such as CCl4, FS, and EAC proved to have a positive effect on the BPA degradation process assisted by ultrasound. After 60 min of exposure, the degradation capacities reached values of between 50% and 75%, while the mineralization capacities were situated between 20% and 35%. CCl4 and EAC had a more pronounced stimulating action than FS, with the EAC having the highest mineralization capacity, representing around 75% of the degradation capacity. [ABSTRACT FROM AUTHOR]

The Nickel ferrite (NiFe2O4) nanoparticle size was successfully prepared using the sol-gel method, while, the conducting polymer (PANI-PTSA) the chemical oxidative method was used. The nanocomposite {NiFe2O4/PANI-PTSA} is an excellent shielding material that reduces the cross-sectional area by absorbing radar waves at X-band, then offers protection from risky microwave radiation. The specimens NF, PNF1, PNF2 and PNF3 were characterised using some techniques, for instance, X-ray diffraction (XRD), Fourier transforms infrared (FTIR) and vector network analyser (VNA). Results showed that the specimen PNF3, which mixed by ratio (3:1) and 2.1 mm thickness, got better reflection loss (R.L); { – 19.5, – 25.19, – 59.08} dB, at frequency band {8.3, 9.5, 10.7} GHz, respectively, while the power absorption was (99 %), (>99.68%), (99.99 %) in that order. Here the nanocomposite {NiFe2O4/PANI-PTSA} adds new outcomes to the electromagnetic interference (EMI) for shielding and microwave absorption in various advanced military applications at frequency band (8–12 GHz). [ABSTRACT FROM AUTHOR]

Chemical methods for the synthesis of esters require the use of high temperatures in the presence of chemical catalysts resulting in undesirable by-products. To avoid these problems the use of biocatalysis can lead to greener products. The aim of this papar is to study the synergism of enzyme catalysis with unconventional techniques suc as microwave or ultrasound assited processes. The effect of different reaction parameters, such as temperature, enzyme loading, ultrasonic amplitude and duty cycle, on the enzymatic synthesis of isoamyl acetate has been evaluated. To highlight the efficiency of unconventional techniques, experiments using conventional methods were also performed. The concetrations of isoamyl acetate obtained by unconventional methods were higher than those achieved under conventional heating, as 478 mgester/gmixture was obtained with ultrasounds in 1 h using 25g/L of enzyme loading, at 50°C as compared to 387 mgester/gmixture by conventional methods. Mild process conditions and using green techniques (microwaves and ultrasounds) make the biocatalytic procedure a useful way to synthetise esters with application on food, pharmaceutical and cosmetic industries. [ABSTRACT FROM AUTHOR]