Fluorescence of D-Glucose-Derived Carbon Dots: Effect of Process Parameters.

The aim of this study was to synthesize highly fluorescent carbon dots (CDs) from glucose using a microwave hydrothermal method. It explored the impact of glucose concentration, process time, molar ratio of KH2PO4 to glucose, and homogenization time on the resulting CDs, employing a fractional plan 3(k-1) with four independent parameters for twenty-seven synthesis. Results showed that longer process times at 200°C increased the fluorescence intensity of the CDs. The molar ratio of KH2PO4 to glucose, glucose concentration, and process time significantly influenced fluorescence. Homogenization was crucial for obtaining small particles, though an anti-aggregation agent might still be needed. UV-vis spectroscopy, spectrofluorimetry, and DLS were used to analyze the synthesized CDs. The UV-vis absorption maxima were observed around 230 nm and 282 nm, with peak shifts at different excitation wavelengths. Out of the twenty-seven samples, six CDs samples were identified to be below 10 nm and a total of twelve below 50 nm. Analyzing the results, the study concluded that the CDs possess strong fluorescence and are suitable for diverse applications. For enhanced fluorescence, longer process times at 200°C and the use of KH2PO4 were recommended, while shorter processes were preferred for obtaining smaller particles. Hierarchical clustering, the k-means method, Pareto charts, and profiles for predicted values and desirability were used to analyze the results. It was confirmed that higher fluorescence is favored by longer process time at 200°C and the use of KH2PO4. In order to obtain smaller particles, shorter processes should be used.

Nanohybrids of oxides nanoparticles-chitosan and their antimicrobial properties.

Growing international problem with pathogens acquiring resistance to antibiotics is the reason for the search for bactericidal substances against which microorganisms cannot become resistant. The aim of this study was to synthesize inorganic-organic nanohybrids and obtain materials with antimicrobial effects. Chitosan (CS) was deposited on nanocomposite carriers such as calcium oxide with titanium dioxide (CaO-TiO2), magnesium oxide with titanium dioxide (MgO-TiO2) and copper(II) oxide with titanium dioxide (CuO-TiO2). The efficiency of the process was examined at varying concentrations of chitosan and temperature. The parameters for nanohybrids synthesis were selected based on the highest amount of nano-chitosan deposited on the nanohybrids-for each carrier, the process conditions were as follows: chitosan solution at 5 g l-1and 20 °C. The materials were obtained using these parameters and were used for microbiological tests againstE. coliATCC 25922,S. aureusATCC 25923 andC. albicansATCC 10231. The growth inhibitory activity of the obtained materials was qualitatively defined. These results suggest that the synthesized nanohybrids and nanocomposites exhibit biostatic action. The material with the broadest effect was the CuO-TiO2-CS hybrid, which had biostatic properties against all tested strains at a minimal concentration of 1250µg ml-1. Further research is required to find eco-friendly, non-toxic, and more effective antimicrobials with a broad action to prevent the acquisition of resistance.

Synthesis and antimicrobial properties of CaCO3-nAg and nAg-CaCO3 nanocomposites.

The nanocomposites of nAg-CaCO3 and CaCO3-nAg with different mass content of silver nanoparticles were obtained in a two-stage continuous microwave process. The nanocomposites were characterized by XRD, TEM, UV-vis, and FTIR spectroscopy. The effects of microwave radiation, silver nanoparticles content in the composite and the molar ratio of tannic acid to silver on the size of salt crystallites were studied. The effectiveness of combining silver nanoparticles with CaCO3 was confirmed to exceed 99%. Depending on the input parameters applied, the size of salt crystals in nAg/CaCO3 nanocomposites ranged from 25 to 45 nm, while the size of salt crystals in CaCO3/nAg nanocomposites ranged from 26 to 41 nm. In addition, some of the compositions were tested for their antimicrobial activity on selected yeast and bacterial microorganisms. The prepared materials present a biocidal effect, which makes them suitable for use in antimicrobial preparations.

Preparation and of PVA-based compositions with embedded silver, copper and zinc oxide nanoparticles and assessment of their antibacterial properties.

A series of poly(vinyl alcohol) (PVA) based liquid compositions with addition of zinc oxide, silver and copper nanoparticles has been prepared. The compositions also contained other consistency-forming organic components. The physico-chemical properties of the products have been determined. Their pH and density have been assessed. Also, the size of nanoparticles has been defined with using a dynamic light scattering technique. The compositions were subjected to XRD, FT-IR and microscopic analysis as well. Thanks to the incorporation of both metal oxide and metallic nanoparticles, it was possible to enrich the products with antibacterial properties. Their inhibiting properties in the growth of microorganisms have been confirmed against both Gram-negative and Gram-positive strains such as E. coli, S. aureus and P. aeruginosa. Thanks to the ability for solidification, the compositions may be applied on a bacterially contaminated surface, and after destroying the microorganisms and its solidification, it may be peeled off along with the dead bacterial film.

Analysis of the physicochemical properties of antimicrobial compositions with zinc oxide nanoparticles.

In this study, an antimicrobial composition based on polyvinyl alcohol (PVA) and zinc oxide (ZnO) was developed. The aim of the work was to obtain a film-forming product for antimicrobial treatment of surfaces. To improve the physical, mechanical, and film-forming properties of the compositions, three natural stabilizing agents were added to the formulation: gelatine, guar gum and hydroxyethyl cellulose. Formulations with different concentrations of each stabilizer were tested, and the physicochemical properties of the obtained products were measured. The size of zinc oxide particles in obtained compositions varied from 232 to 692 nm. The compositions had a slight acidic nature. Their pH ranged from 6.84 to 6.99. The average density of products was equal to 1.37 × 103 (kg/m3). It was confirmed that zinc oxide nanoparticles do not penetrate through a model dermal membrane which is a desired effect concerning their toxicity. The antimicrobial activity of the obtained compositions was assessed against Aspergillus niger strain. After 24 h of studying, the growth inhibition was in 71% greater than in reference material. After statistical analysis of the results, it was concluded in order to achieve the most desirable physicochemical and utilitarian properties, the concentrations of gelatine, guar gum and hydroxyethylcellulose should be equal to 0.5%, 0.03% and 0.055%, respectively.

Statistical Analysis of Optimal Ultrasound Emulsification Parameters in Thistle-Oil Nanoemulsions.

Thistle oil (INCI: Silybum marianum seed oil) is known as an anti-oxidant, moisturizing and skin regenerating cosmetic raw material. Nanoemulsions are a new form of cosmetic product showing very good user properties (ease of spreading over the skin with no greasy feeling). Moreover, due to their structure, they can also transport both hydrophilic and hydrophobic active substances to the skin. The aim of this work was the preparation and characterization of nanoemulsions, based on thistle oil. The non-ionic surfactants polysorbate 80 (PEG-20 sorbitan monooleate), decyl glucoside, and a polyglyceryl-4 ester blend were applied to stabilize the nanosystems. All formulations were obtained by a high energy method, using an ultrasonic device (Labsonic U, an ultrasound homogenizer). Variations in the emulsification parameters were tested, including surfactants concentration, pre-emulsification time, ultrasound power and sonication time. On the basis of statistical analysis (experimental design, cluster analysis, classification and regression trees) the best emulsification process parameters were determined. In order to verify the results of statistical analysis, once more an experimental study was conducted. The results obtained confirmed that statistical analysis can be a useful method in determining the conditions for obtaining stable nanoemulsions with desired properties. Formulations obtained with the use of Silybum marianum seed oil were characterized by long-term stability, a low polydispersity index, low viscosity and an average droplet size less than 200 nm.

Assessment of the Environmental Impact of Solid Oil Materials Based on Pyrolysis Oil.

One method of managing used car tires is decomposition by thermochemical conversion methods. By conducting the process at temperatures of 450-750 °C, three fractions are obtained from tires: oil, gas, and solid. The liquid product of the pyrolysis of used car tires is pyrolysis oil, which consists of aromatic, polyaromatic, and aliphatic hydrocarbons. Unconventional building materials were obtained from tire pyrolysis oil and the environmental impact was evaluated. Blocks made from pyrolysis oil showed mechanical strength of up to about 1700 N. No heavy metals or polycyclic aromatic hydrocarbons, which were found in the crude heavy-PO fraction, were detected in the filtrates after incubation of the block obtained from the heavy-PO fraction at 240 °C. The highest inhibition of Sorghum saccharatum shoot (74.4%) and root (57.5%) growth was observed for solid materials from the medium-PO fraction obtained at 240 °C. The most favorable values of the parameters for the process of obtaining blocks based on post-PO were an annealing temperature of 180 °C, time of 20 h, and mass ratio of catalyst to catalyzed oil of 0.045.

Inorganic Nanomaterials Used in Anti-Cancer Therapies:Further Developments.

In this article, we provide an overview of the progress of scientists working to improve the quality of life of cancer patients. Among the known methods, cancer treatment methods focusing on the synergistic action of nanoparticles and nanocomposites have been proposed and described. The application of composite systems will allow precise delivery of therapeutic agents to cancer cells without systemic toxicity. The nanosystems described could be used as a high-efficiency photothermal therapy system by exploiting the properties of the individual nanoparticle components, including their magnetic, photothermal, complex, and bioactive properties. By combining the advantages of the individual components, it is possible to obtain a product that would be effective in cancer treatment. The use of nanomaterials to produce both drug carriers and those active substances with a direct anti-cancer effect has been extensively discussed. In this section, attention is paid to metallic nanoparticles, metal oxides, magnetic nanoparticles, and others. The use of complex compounds in biomedicine is also described. A group of compounds showing significant potential in anti-cancer therapies are natural compounds, which have also been discussed.

Synergistic effect of sorption and photocatalysis on the degree of dye removal in single and multicomponent systems on ZnO-SnO2.

The paper presents the photodegradation process of one-, two- and three-component dye mixtures by ZnO-SnO2 nanoparticles. After 60 min of running the processes, the dye removal efficiencies of 76.44, 72.69, 62.43, 77.00 and 92.46% for MB, RB, TB, MO and YQ degradation, respectively, were obtained. For binary and ternary systems, dye removal efficiencies for all cases exceeded 70%. When the binary and ternary dye mixtures were tested, the photodegradation efficiencies of ZnO-SnO2 were similar to those of the single mixtures, indicating that this material could be used in industrial applications in the future. The focus of the study was to investigate the effect of sorption on photodegradation efficiency and the presence of both cationic and anionic dyes on their degradation efficiency under UV light. The significance of the effect of sorption on the degradation efficiency allowing the interaction of the catalyst with the dyes removed was confirmed. The main factor influencing sorption and consequently photocatalysis was the nature of the dye. It was confirmed that the positively charged ZnO-SnO2 surface effectively sorbs the dyes and causes their degradation.

Assessment of waste management technology using BATNEEC options, technology quality method and multi-criteria analysis.

Best Available Techniques Not Entailing Excessive Costs (BATNEEC) options, technology quality method and multi-criteria analysis were proposed as means of developing indices for evaluating municipal waste management systems. The proposed indices can be treated as a tool for ranking the system taking into account technical, environmental, economic, social and other objectives, bearing in mind specific features of the area involved. The analysis was made for three different incineration plants (Spittelau in Vienna, Warsaw and Tarnobrzeg) together with alternative waste disposal versions (with or without biogas burning and with MBP Mechanical-Biological Process) and the waste management infrastructure. The results showed that incineration of waste is much more beneficial than disposal. These results conform to the waste hierarchy identified in EU Directive 2008/98, but the indices created are easy to interpret and useful as a tool for communicating with the public, which is often a crucial factor in determining the location of investment.

Optimisation of the co-combustion of meat-bone meal and sewage sludge in terms of the quality produced ashes used as substitute of phosphorites.

To obtain a high-quality phosphorus raw material comparable in quality to the best phosphorites used in the fertiliser industry, an analysis was carried out to determine the optimal mass proportions of a meat-bone meal and sewage sludge mixture to be used in a co-combustion process. The ashes obtained contained hydroxyapatite that could be considered a high-quality substitute for phosphorites, with an average P2O5 content of 33.5%. These ashes do not contain fluorine compounds, cadmium content is at trace levels and they do not contain the radioactive compounds that are present in trace amounts in all phosphates. The developed process is an example of a production complex using cleaner technologies and circular economy principles on a microeconomic scale.

Metal and bimetallic nanoparticles: Flow synthesis, bioactivity and toxicity.

HYPOTHESIS: Metal nanoparticles are used as additives in commercial products due to their antimicrobial properties. Apart from their high biocidal activity, it is widely observed that silver nanoparticles are toxic. Simultaneously, copper nanoparticles show fungicidal properties, but with limited effectiveness. Hence, it is suggested that a combination of Ag nanoparticles with Cu nanoparticles may decrease the toxic effects of silver while maintaining their high bioactivity. EXPERIMENTS: This paper presents the properties of Ag and Cu metal nanoparticles, and Ag-Cu and Cu-Ag bimetallic nanoparticles, synthesised in a continuous microwave reactor. The size of the metal nanoparticles obtained was in the range of 27-97 nm, and the size of the bimetallic nanoparticles was in the range of 32-184 nm, depending on the microwave irradiation, residence time, pH of the solution and concentrations of the reagents. FINDINGS: Silver nanoparticles of particle size 97 nm revealed the highest antimicrobial activity (MIC = 10 mg/dm3). Simultaneously, silver nanoparticles did not show viral properties, compared to the copper and bimetallic nanoparticles, for which the virus titre was 1.06-1.50 log TCID50/cm3. In contrast to pure metal nanoparticles, the combination of silver and copper in bimetallic systems generated nanoparticles with no genotoxicity (rac(-)/rac(+) < 1.2).

Sorption behavior of Arachis hypogaea shells against Ag+ ions and assessment of antimicrobial properties of the product.

The paper presents sorption behavior of Arachis hypogaea shells towards silver ions and possibility of their use as antimicrobial product. During the modification process of the natural sorbent, equilibrium tests were carried out. Moreover, the possibility of obtaining biocomposite Arachis hypogaea shells/nAg has been determined, and its antimicrobial properties have been evaluated. Additionally, sorption kinetics has been calculated. In the last step, silver ions were desorbed. The conducted equilibrium tests allowed to adjust the sorption isotherm model and determine the sorption capacity of tested material. This process is best described by Freudlich's isotherm, and the sorption capacity is equal to 12.33 mg/g. On the basis of kinetic studies, the chemical nature of this process has been proved (by choosing a pseudo-second order model for the sorption process). It has been confirmed that the obtained peanut shells modified with silver ions have antimicrobial properties. The tests allowed to obtain 100% inhibition of Aspergillus niger and ~ 98% Escherichia coli.

Analysis of the Exposure of Organisms to the Action of Nanomaterials.

The rapid development of the production of materials containing metal nanoparticles and metal oxides is a potential risk to the environment. The degree of exposure of organisms to nanoparticles increases from year to year, and its effects are not fully known. This is due to the fact that the range of nanoparticle interactions on cells, tissues and the environment requires careful analysis. It is necessary to develop methods for testing the properties of nanomaterials and the mechanisms of their impact on individual cells as well as on entire organisms. The particular need to raise public awareness of the main sources of exposure to nanoparticles should also be highlighted. This paper presents the main sources and possible routes of exposure to metal nanoparticles and metal oxides. Key elements of research on the impact of nanoparticles on organisms, that is, in vitro tests, in vivo tests and methods of detection of nanoparticles in organisms, are presented.

Obtaining of oil blocks as a way to manage hazardous asbestos.

In the second half of the 20th century, asbestos extraction was up to 4 Mt/year. Due to its high strength and insulation properties, this mineral was used as an additive in building materials. Over time these materials were destroyed by the process of weathering and leaching. Asbestos fibers in dust form penetrate the respiratory system causing diseases. This article proposes the binding of hazardous asbestos fibers in a polymer matrix formed from waste cooking oil. Compact materials were produced by heating catalyzed waste cooking oil and asbestos waste, and the process of obtaining these materials was optimized and their physicochemical and strength properties were determined. Oil-asbestos blocks contained sulfuric acid in a mass ratio of 0.05-0.30, being the mass of waste cooking oil, invariable mass of filling and 20% of waste cooking oil to the mass of the whole mixture. The materials were characterized by a compact structure and high hardness. The best mechanical strength above 140 N/mm was obtained for blocks with low acid to oil mass ratio ranging from 0.05 to 0.1125.

Methods for Reducing the Toxicity of Metal and Metal Oxide NPs as Biomedicine.

The rapid development of medicine has forced equally rapid progress in the field of pharmaceuticals. In connection with the expensive and time-consuming process of finding new drugs, great emphasis is put on the design and use of metal and metal oxides nanoparticles in nanomedicine. The main focus is on comprehensive presentation of both physicochemical properties and the possibilities of using, in particular, silver (Ag) and gold (Au) nanoparticles, as well as zinc oxide (ZnO) and titanium oxide (TiO2) nanoparticles as drug carriers and in the treatment of cancer. An important element of this subject is the possibility of occurrence of toxic effects of these nanoparticles. For this reason, possible mechanisms of toxic actions are presented, as well as methods used to reduce their toxicity to ensure the safety of drug carriers based on these nanostructures.

Silver nanoparticles based on blackcurrant extract show potent anti-inflammatory effect in vitro and in DSS-induced colitis in mice.

Silver nanoparticles have been used in a range of applications and although they are already employed in medicine, there are new, promising possibilities for their utilization. We investigated the potential of silver nanoparticles obtained with the use of blackcurrant extract in vitro in the LPS-stimulated RAW264.7 macrophages and in vivo in the murine DSS-induced colitis model. The examined formulations contained particles of 95 nm (Ag95) and 213 nm (Ag213) diameter. In vitro, both formulations inhibited nitric oxide (NO) release. In vivo, the preparations alleviated colitis as evidenced by a decreased macroscopic score and myeloperoxidase activity (indicative of neutrophil infiltration). In both cases, the nanoparticles of larger diameter showed better anti-inflammatory properties. Although further tests are required, our results indicate a plausible new use of silver nanoparticles in inflammatory bowel diseases.

Studies on CWL with glycerol for combustion process.

Findings of more efficient energy recovery methods are focused on composite fuels consisting of coal, water, and waste materials. The use of such slurry fuels has enormous environmental benefits due to the potential for waste utilization and low emissions of harmful oxides to the atmosphere during the combustion process. In this study, we report the effect of waste glycerol on the rheological properties of coal-water fuel (CWS). The addition of glycerol to CWS increases the viscosity (from 45.5 to 184.2 mPa·s at a shear rate of 100 rpm) and density (from 1.08 to 1.11 g/cm3) of these suspensions. The utility of choice of the most favorable parameters is equal to 0.85 for both CWS and CWS with added glycerol. Due to the fact that CWS is dosed to heated chamber, its modification with glycerol results in easier nebulization into the combustion chamber, lowering of the solidification temperature and increasing the calorific value of the resulting fuel. During combustion of CWS with glycerol, the amount of SO2 and NOx emitted is reduced by half as compared to the emission of these gases during hard coal combustion.

Safety of the application of nanosilver and nanogold in topical cosmetic preparations.

The safety of the use of cosmetic preparations with silver or gold nanoparticles was assessed. This study describes the methodology and results of research involving the generation of suspensions of silver and gold nanoparticles and creams with added silver or gold at concentrations of 20, 65, 110, 155, and 200 mg/kg. The silver nanoparticles ranged from 8 to 140 nm, and the gold nanoparticles, measured 13-99 nm. The sizes were determined using dynamic light scattering. The presence of metallic nanoparticles in the obtained oil-in-water emulsions was confirmed with UV-vis spectroscopy and transmission electron microscopy with an X-ray scattering spectrometer (TEM-EDX). Additionally, based on the TEM-EDX results, it was possible to analyse the distributions of the silver nanoparticles in the tested cosmetic emulsions. Microbiological tests showed that both the silver and gold nanoparticle emulsion possessed satisfactory fungicidal properties. Based on viscosity curves, the lowest estimated yield limits were achieved by the reference cream and the creams with the gold and silver nanoparticles at concentrations of 20 and 65 mg/kg, respectively, which improved their consistencies and distributions on the skin. The best appraisals from the respondents in terms of consistency, absorption, oiling, colour, and smell were received for the emulsion containing 200 mg/kg gold nanoparticles. The worst assessment in terms of uniformity, colour, and smell were obtained for the emulsion with 200 mg/kg silver nanoparticles. However, the most important aspect of this study was the assessment of the permeabilities of the metallic nanoparticles through imitation skin in the form of dermal membranes. The highest permeabilities were confirmed for the creams with metallic nanoparticles present at 110--200 mg/kg. This permeability is an issue of concern given the toxic properties of metallic nanoparticles for living organisms.

Synthesis and evaluation of anti-inflammatory properties of silver nanoparticle suspensions in experimental colitis in mice.

The aim of our study was to investigate the effect of newly developed silver nanoparticle aqueous suspensions NanoAg1 and NanoAg2 in the mouse models mimicking ulcerative colitis and Crohn's disease. NanoAg1 and NanoAg2 were synthesized in aqueous medium with the involvement of tannic acid. To elucidate their anti-inflammatory activity, semi-chronic mouse models of inflammation induced by dextrane sulfate sodium addition to drinking water and intracolonic (i.c.) administration of 2,4,6-trinitrobenzenesulfonic acid were used. NanoAg1 and NanoAg2 (500 mg/dm3, 100 µl/animal, i.c., once daily) significantly ameliorated colitis in dextrane sulfate sodium- and 2,4,6-trinitrobenzenesulfonic acid-induced mouse models of colonic inflammation, as indicated by reduced macroscopic, ulcer and microscopic scores. The anti-inflammatory effect was dependent on the shape and diameter of silver nanoparticles, as indicated by weaker effect of NanoAg1 than NanoAg2. In addition, administration of NanoAg2, but not NanoAg1, modulated colonic microbiota, as indicated by reduced number of Escherichia coli and Clostridium perfringens, and increased number of Lactobacillus sp. Summarizing, NanoAg1 and NanoAg2 after administered i.c. effectively alleviate colitis in experimental models of ulcerative colitis and Crohn's disease in mice. Therefore, NanoAg1 and NanoAg2 administered i.c. have the potential to become valuable agents for the treatment of inflammatory bowel diseases.