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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]

The move towards environmentally friendly processing has been a driving force for research into green methods for the extraction of bioactive compounds from plant materials. In this study, a green and efficient process for the extraction of β-carotene from sea buckthorn berries through the simultaneous use of ultrasound and microwave, using a novel green solvent, fatty acid ethyl esters (FAEE), is described. For the same extraction time (45 min), the β-carotene content in the extract was significantly increased (according to ANOVA analysis—p < 0.05) by the simultaneous use of ultrasound and microwave, compared with the separate use of these technologies—an increase of 15 and 89% compared with ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE), respectively. The resulting extract can be used directly, without further purification, as a food supplement because the solvent itself is safe for consumption. Furthermore, FAEE contains omega-3 and omega-6 fatty acids which add to the health benefits of the extract. When β-carotene is extracted from the plant matrix, it is subjected to degradation due to oxidation, but the addition of the antioxidant vitamin E (13 mg/mL of extract) to the extract extends its stability to more than 90 days at room temperature even when exposed to light. The addition of vitamin E also enhances the health benefits of the extract. [ABSTRACT FROM AUTHOR]

Hedera helix L. contains phytochemicals with good biological properties which are beneficial to human health and can be used to protect plants against different diseases. The aim of this research was to find the most suitable extraction method and the most favorable parameters for the extraction of different bioactive compounds from ivy leaves. Different extraction methods, namely microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), and conventional heating extraction (CHE), were used. The most suitable method for the extraction of saponins is MAE with an extraction efficiency of 58%, while for carbohydrates and polyphenols, the best results were achieved via UAE with an extraction efficiency of 61.7% and 63.5%, respectively. The antioxidant activity (AA) of the extracts was also determined. The highest AA was obtained via UAE (368.98 ± 9.01 µmol TR/gDM). Better results were achieved at 50 °C for 10 min of extraction, using 80% ethanol in water as solvent. In order to evaluate their in vitro cytotoxicity, the extracts richest in bioactive compounds were tested on NCTC fibroblasts. Their influence on the DNA content of RAW 264.7 murine macrophages was also tested. Until 200 µg/mL, the extracts obtained via UAE and MAE were cytocompatible with NCTC fibroblasts at 48 h of treatment. Summarizing the above, both MAE and UAE can be employed as green and efficient methods for producing extracts rich in bioactive compounds, exhibiting strong antioxidant properties and good noncytotoxic activity. [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 influence of ultrasound irradiation on the algal biomass productivity as well as its oil content and fatty acids profile, grown in a modified Zarrouk medium, i.e., deproteinized whey waste solution, was investigated. The algal samples (Nannochloris sp. 424-1 microalgae) were grown for 7 days in a thermostated incubator at 28 °C, shaken under continuous light. During this period, the algal biomass was subjected to induced stress by ultrasonic irradiation at different powers and sonication time. The obtained results demonstrate that ultrasound stressing of algae biomass has a positive effect on both the quantity of biomass and the oil obtained, also causing a shift in fatty acid composition by increasing the proportion of C16 and C18 polyunsaturated fatty acids. A low dosage level of exposure to the ultrasound led to algal biomass increase as well as lipid accumulation. For both types of irradiation modes which were investigated, daily and only initial irradiation, the beneficial effect of the ultrasound decreases as the exposure time increases and the excessive sonication becomes detrimental to microalgae growth. [ABSTRACT FROM AUTHOR]

The aim of this study was to establish the best ultrasound assisted extraction (UAE) conditions of saponins from Hedera helix L. leaves and to evaluate the in vitro biocompatibility of the extracts richest in saponins. Different parameters, such as extraction time, temperature, ultrasound power, solvent to plant material ratio, and solvent concentration, were investigated. The most efficient extraction conditions were a temperature of 50 °C, an ultrasound amplitude of 40%, an extraction time of 60 min, a plant material to solvent ratio of 1:20 (w:v), and 80% ethanol as solvent. In vitro cytotoxicity of the extracts richest in saponins and their influence on the DNA content of L929 (NCTC) fibroblasts were tested. Until 200 µg/mL, the studied extracts were cytocompatible with L929 fibroblast cell lines at 48 h of treatment. These in vitro cell culture results provide useful information for further applications of Hedera helix extracts in a pharmaceutical field. [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]

In this study, three of the saponins present in leaves of Hedera helix L., α-hederin, hederagenin, and hederacoside C were studied for their antiproliferative activity. The three saponins were analyzed in different concentrations by in vitro tests on normal fibroblasts cells and cervix ephitelial tumor cells. Determination of cytotoxicity and antitumor effects was performed using the MTT method. From the tested saponins, α-hederin was biocompatible in normal fibroblasts cells at concentrations between 2–10 μg/mL. Its antiproliferative activity was exerted in the concentration range of 10–400 μg/mL in cervix ephitelial tumor cells. Similarly, hederagenin presented antiproliferative activity at concentrations between 25–400 μg/mL. In turn, hederacoside C was shown to be noncytotoxic in normal fibroblasts and cervix ephitelial tumor cell culture at all the tested concentrations. The obtained experimental results were analyzed by "Mixture design", a specialized form of the response surface method (RSM) provided by the Design Expert 11 software, and the optimal composition of obtained saponins mixture was selected and verified in vitro for antiproliferative activity. The results showed that an optimal saponins mixture has the potential to be used in pharmacological applications. [ABSTRACT FROM AUTHOR]

A solvent free in situ microwave hydro-distillation method for extraction of essential oil from fresh ginger root it presented. Extraction was conducted in a TE10n single-mode microwave cavity and variable power 2 kW generator operating at 2.45GHz. The main extracted components identified by gas chromatography (GC) were Zingiberene, α-Curcumene, β-Sesquiphellandrene and α-Selinene. At energy inputs of 0.40 kWh/kg higher powers and shorter exposure times, crucially did not degrade the highly volatile components (α-Pinene and Camphene) despite providing the highest essential oil yields. Optimum processing conditions were found to be 1000W (0.40kWh/kg) for 5 min, for whole ginger root, where 0.35g oil/100g plant was obtained. This was compared to a yield of 0.2g/100g plant in 150 in using conventional hydro-distillation and 0.3g/100g plant in 90 min using a multi-mode microwave cavity-based hydro-distillation. [ABSTRACT FROM AUTHOR]

The extraction of essential oils (EOs) and polyphenols from rosemary and thyme has been done using an integrated process: microwave hydro-diffusion and gravity (MHG) for EOs and microwave-assisted extraction (MAE) for polyphenols. The innovative installation based on the MHG principle allows uniform microwave irradiation field due to a mechanical stirring and experiments done at low pressure. The results of quantitative analysis of the EOs extracted by MHG after 10 min were similar with those obtained by traditional methods (conventional hydro-distillation (CHD) and microwave-assisted hydro-distillation (MHD)) after 150 and 105 min, respectively. The specific energy for MHG was 5-15 times lower compared with these classical methods. The MHG extraction of EOs is also an effective method for plant material pretreatment before polyphenol extraction. Total phenolic content increased from 35 to 55 mg GAE/g DM for rosemary and from 23 to 38 mg GAE/g DM for thyme. [ABSTRACT FROM AUTHOR]

Extraction of polyphenols from sea buckthorn leaves using microwave-assisted extraction (MAE) is described. The influence of different parameters on the extraction process (reactor type, stirring rate, extraction time, temperature, ethanol/water ratio) was studied. The polyphenolic extracts were analyzed in order to determine the total phenolic content (TPC) either by the Folin-Ciocalteu method or by differential pulse voltammetry (DPV), and the concentration of the main polyphenolic compounds by high-performance liquid chromatography (HPLC). The specific microwave energy was also determined. MAE resulted in a shorter extraction time (7.5 versus 30 min for the conventional method). The best results for MAE were obtained at a temperature of 90°C, using a solvent/plant ratio of 20/1 and 50% ethanol in the extraction solvent. The highest values of antioxidant capacity were obtained for polyphenolic extracts resulted from microwave extraction. [ABSTRACT FROM AUTHOR]

The aim of this research is to study the synthesis of light olefins via Fischer-Tropsch process while using a Fe-Ni based catalyst. The catalyst consists of several types of alumino-silicate support that has been impregnated with a solution of Fe and Ni nitrate of a molar ratio of 4:6. The impregnated supports have been dried, after which they have been calcinated at a temperature of around 550°C and activated under a continuous flow of Nitrogen and Hydrogen at a molar ratio of 1:1 and a molar flow rate of 30 mL/min for each catalyst. The supports used consisted of γAl2O3, ZSM 5, MCM 41, SBA 15. Each catalyst was tested under various temperatures (250°C, 300°C, 350°C, 400°C) at a Gas Hourly Space Velocity (GHSV) of 950 h-1 at 1 atm. For each temperature samples were taken on 30 minute intervals roughly to determine the composition of reaction gases. [ABSTRACT FROM AUTHOR]

Biocatalysts with microorganisms immobilized on solid carriers could provide the solution for development of continuous industrial processes for ethanol obtaining by fermentation of sugars. In this study, modified polyacrylamide hydrogels and marrow stem sunflower are used as supports for Saccharomyces cerevisiae yeast immobilization. The obtained structures are used for fermentation of molasses in batch systems. The free yeast cells are used as reference. The modification of polyacrilamide matrix with (2-hydroxyethyl)methacrylate has a positive effect on structure pore uniformity and fermentation performance. The mechanical properties of the obtained biocatalysts are compared. The novel natural matrix has net superior compression strength. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

In this study, microwave assisted a hydrodistillation process (MWHD) of essential oils from lavender ( Lavandula angustifolia Miller) was investigated. In order to examine any potential differences in essential oil extraction, the lavender flowers underwent enzymatic pretreatment. A 2 factorial design of experiments, combined with statistical methods of data analysis were used to optimize enzymatic pretreatment and to evaluate the influence of major variables (enzyme concentration, temperature and pH) on the performance of the microwave assisted extraction. Under optimal conditions, an extraction yield of 24 mg oil g substrate was achieved (an increase by approximately 25% in comparison with the classic extraction conditions of conventional hydrodistillation). The main compounds of the essential oils obtained were analyzed and identified by gas chromatography coupled to mass spectrometry (GC-MS). Analyzing the data obtained indicated that the content of main compounds (linalool and linalyl acetate − 73%) was greater than that obtained by conventional extraction (67%). [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

In this study, twenty-four amperometric dot microsensors based on carbon materials, (e.g., graphite (G) and graphene (GR) and carbon nanopowder (CN)). unmodified and modified with TiO2, and phthalocyanines: basic phtalocyanine (Pc), FeIIIphthalocyanine (FeIIIPc) and FeIIphthalocyanine (FeIIPc) are evaluated and tested for their ability for the analysis of serotonin (5-HT) in biological fluids (e.g. urine samples), using differential pulse voltammetry (DPV). Cyclic voltammetry (CV) was used to optimize the working conditions, e.g., pH, and electrolyte for the amperometric dot microsensors revealing (0.1 mol L-1) KCl and pH = 3.0 phosphate buffer as the optimum electrolyte and pH conditions for the assay of serotonin. The selected amperometric dot microsensors with preference to the G-FeIIIPc followed by the GR-FeIIIPc modified microsensors were used for the reliable analysis of serotonin in urine samples, with recoveries higher than 94.00%. [ABSTRACT FROM AUTHOR]

In this study, new amperometric dot microsensors based on graphene and phthalocyanines: basic phtalocyanine, FeIII phthalocyanine and CoII phthalocyanine are proposed for the assay of adenine. guanine and epinephrine in real biological fluids (e.g. urine samples), using differential pulse voltammetry (DPV). Cyclic voltammetry (CV) was used to optimize the working conditions, e.g., pH, and electrolyte for the proposed dot microsensors obtaining an optimum of 0.1 mol L-1 KCl or 0.1 mol L-1 KNO3 in a phosphate buffer solution at a pH = 4.0. The lowest limits of detection obtained for adenine (2.5 x 10-6 mol L-1), guanine (1.4 x 10-5 mol L-1), and epinephrine (1 x 10-6 mol L-1), as well as the selectivity coefficients made possible their assay in urine samples with high reliability (RSD < 1.0%). Adenine, guanine and epinephrine were recovered reliably from urine samples in percentages higher than 90.00%. [ABSTRACT FROM AUTHOR]

Immobilized yeast in natural supports was evaluated for the production of ethanol using molasses as carbon source in a fixed bed reactor. This paper will focus on marrow stem sunflower and volcanic rock supports. The activation of the supported yeast before use is of great importance. The natural supports were tested to investigate the immobilization, growth and proliferation of Saccharomyces cerevisiae yeast cells for different periods of activation. For this study gravimetric and scanning electron microscopy methods were used. The activity of the immobilized yeast was tested in a fermentation reactor with recirculation to underline the influence of the molasses concentration over the fermentation process. [ABSTRACT FROM AUTHOR]

A new method based on microwave (MW) energy addition to accelerated electron beam (ER) energy for material processing was developed. In order to investigate this method, several specially designed facilities which permit separate, successive, and simultaneous MW and EB irradiation were carried out. These facilities as well as the associated MW and EB injection systems are described. In comparison with separate EB or MW irradiation, the simultaneous EB and MW irradiation of the acrylamide-acrylic acid aqueous solution leads to the highest molecular weight values simultaneously with the smallest Huggins' constant values. Also, the absorbed dose is reduced from 0.8 kGy in the separate EB irradiation case to 0.4 kGy in the simultaneous EB and MW irradiation applied to acrylamide-acrylic acid co-polymerization. Significant higher vulcanization degrees are obtained only for higher EB irradiation doses, especially in terms of the values of the 300% modulus and tensile strength. By using simultaneous EB and MW irradiation, compared to separate EB irradiation, the same maximum value of 300% modulus is obtained for EB absorbed dose and irradiation time of 2.5 times lower at 60-W MW power and five times lower at 100-W MW power. Also, the same maximum value of tensile strength is obtained for EB absorbed dose and irradiation time of four times lower at 60-W MW power and 5.33 times lower at 100-W MW power. The combined EB and MW irradiation applied to the SO2 and NOx removal from the simulated flue gases demonstrated that for the same removal efficiency of 98% for SO2 and 76% for NOx at separate EB irradiation of 40 kGy, the required absorbed dose is about two times smaller for simultaneous EB and MW irradiation. [ABSTRACT FROM AUTHOR]