Non-toxic Substances Research Articles

Study of the acute toxicity of an antibacterial agent for pigs and poultry based on amoxicillin on white rats

The article presents the results of a study of the acute toxicity of the veterinary drug “Amoksidev 60” in white rats. The drug “Amoksidev 60” is a powder for the preparation of an oral solution. 1 g of the drug contains the active ingredient: amoxicillin – 500 mg (as amoxicillin trihydrate – 573 mg); excipients: anhydrous citric acid – up to 1 g. The veterinary medicinal product is used to treat pigs, diseases of the digestive tract, and respiratory organs caused by microorganisms that are sensitive to amoxicillin. The acute toxicity of an antibacterial agent based on amoxicillin for pigs and poultry was studied. Safety at low doses: administration of the drug at a dose of 2000 mg/kg body weight did not cause clinical signs of acute poisoning, and no animal in this group died within 14 days. The median lethal dose (LD50) of the drug is 6899.69 ± 1119.51 mg/kg of body weight, which allows it to be classified as a practically non-toxic substance (V toxicity class). Clinical manifestations of intoxication: when the dose is increased to 7000–12000 mg/kg, pronounced symptoms of intoxication were observed, including impaired coordination, depression, clinical convulsions, and mortality, which increased depending on the dose. Hazard classification: by toxicity, it can be attributed to class V – practically non-toxic substances (LD50 5001–15000 mg/kg), and by the degree of danger to class IV – low-hazard substances (LD50 > 5000 mg/kg), which ensures the prospect of its use in veterinary practice, provided that the recommended dosages are observed. The study results of the acute toxicity of an antibacterial agent based on amoxicillin on white rats open new directions for further scientific Research. Further studies will be aimed at studying subchronic and chronic toxicity, namely, assessing the impact of long-term use of the drug on the physiological state and function of organs and systems of the body and identifying cumulative effects of the drug.

Colloidal quantum dots as solution-based nanomaterials for infrared technologies.

This review focuses on recent progress of wet-chemistry-based synthesis methods for infrared (IR) colloidal quantum dots (CQD), semiconductor nanocrystals with a narrow energy bandgap that absorbs and/or emits IR photos covering from 0.7 to 25 micrometers. The sections of the review are colloidal synthesis, precursor reactivity, cation exchange, doping and de-doping, surface passivation and ligand exchange, intraband transitions, quenching and purification, and future directions. The colloidal synthesis section is organized based on precursors employed: toxic substances as mercury- and lead-based metals and non-toxic substances as indium- and silver-based metal precursors. CQDs are prepared by wet-chemical methods that offer advantages such as precise spectral tunability by adjusting particle size or particle composition, easy fabrication and integration of solution-based CQDs (as inks) with complementary metal-oxide-semiconductors, reduced cost of material manufacturing, and good performances of IR CQD-made optoelectronic devices for non-military applications. These advantages may allow facile and materials' cost-reduced device fabrications that make CQD based IR technologies accessible compared to optoelectronic devices utilizing epitaxially grown semiconductors. However, precursor libraries should be advanced to improve colloidal IR quantum dot synthesis, enabling CQD based IR technologies available to consumer electronics. As the attention of academia and industry to CQDs continue to proliferate, the progress of precursor chemistry for IR CQDs could be rapid.

Study of anti-inflammatory activity and acute toxicity indicators of new silver salt of pyrazole-3-carboxamide

Objective. To study the anti-inflammatory activity and some toxicological indicators of the new derivative of pyrazole-3-carboxamide SSP. Materials and methods. To assess the biological activity of the compound, its anti-inflammatory effect was studied in the model of acute inflammatory edema caused by sub-plantar injection of carrageenan solution into a rat`s hind leg. The duration effect was assessed by the intensity of suppression of the inflammatory response in relation to the control level. In order to study the safety of the substance, the local irritant effect was determined when applied cutaneously in the experiments on rats. The severity of the irritant effect was assessed by the erythema degree, the amount of edema and the increase in local skin temperature. In addition, acute toxicity of the substance under study was determined. The test compound and reference drugs were applied to the skin. Results. The study of acute toxicity of the compound SSP and the reference drug nystatin when applied cutaneously to rats showed that LD50 of both substances was more than 2500,0 mg/kg. Indicators of the degree of local irritating effect of the drugs demonstrate its absence. At the same time, the studied SSP compound has no anti-inflammatory effect administered either orally or cutaneously. Conclusions. The data obtained allow us to classify the new silver salt of pyrazol-3-carboxamide SSP as a class 5 non-toxic substance. The studied SSP compound has no local irritant effect and does not demonstrate anti-inflammatory activity in the carrageenan inflammation model.

Oudemansiella radicata polysaccharides alleviated LPS-induced liver damage via regulating TLR4/NF-κB and Bax/Bcl-2 signaling pathways

The study was aimed to develop natural non-toxic substances to prevent LPS-induced liver damages and its complications. In present work, a pyranose polysaccharide of Oudemansiella radicata polysaccharides (ORP) with typical characteristics of α-type glycosidic linkage was isolated from the O. radicata fruiting body by physico-chemical analysis, and the potential impact against LPS-induced liver damage were performed in mice model. The results demonstrated that ORP showed significant hepatoprotective effects through its potential anti-oxidative, anti-inflammatory and anti-apoptosis activities via regulating the TLR4/NF-κB and Bax/Bcl-2 signaling pathway, independently or synergistically. These findings had established a robust theoretical framework for promoting the comprehensive utilization of ORP as supplements in the development of functional foods or drugs targeting LPS-induced liver damage and its associated complications.

The study of the toxicological profile of dry extracts of narrow-leaved lavender herb

Aim. To study the acute toxicity of narrow-leaved lavender (Lavandula angustifolia) herb dry extracts of Ukrainian origin. Materials and methods. The study objects were experimental test samples: test sample No. 1 ‒ a dry extract of narrow-leaved lavender herb obtained by extraction with purified water; test sample No. 2 ‒ a dry extract of narrow-leaved lavender herb obtained by extraction with a water‒ethanol solution (40 % ethanol); test sample No. 3 ‒ a dry extract of narrow-leaved lavender herb obtained by extraction with a water‒ethanol solution (70 % ethanol). To reproduce the clinic of acute poisoning and determine LD50, the acute toxicity of test samples was studied on sexually mature white mice weighing 19-21 g under the conditions of a single intragastric administration. The animals were observed for 2 weeks, which made it possible to assess the toxic effect of the lavender extracts studied on the body of experimental animals. The weight (initial data, 3, 7 and 14 days), the behavior of animals after the introduction of test samples (appearance, respiration, salivation, urination, excreta, feed consumption by animals) were monitored by daily feed and water consumption ‒ on days 7 and 14. The macroscopic examination included the external examination of animals, the examination of internal organs of the chest (heart, lungs, thymus) and abdominal cavities (liver, spleen, kidneys, adrenal glands, testes/ovaries). For statistical processing of the data obtained (body weight), the arithmetic average value and its standard error were used; the reliability of discrepancies between samples was assessed using ANOVA RM and the Dunnet criterion. Comparisons were made with the negative control group. Indicators of the mass coefficients of internal organs were presented in the form of the median, upper and lower quartiles. The reliability of discrepancies between samples was assessed using the Kruskal-Wallis test and the Mann-Whitney test compared to the negative control group. Results and discussion. It was experimentally proven that intragastric administration of dry extracts from lavender herb in the dose of 5000 mg/kg did not lead to lethality and did not affect the general trophic processes of animals. The macroscopic examination of internal organs and analysis of their mass coefficients confirmed that a single intragastric administration of test samples of lavender extracts did not lead to pathological changes in both males and females. The organ mass coefficients were within the normal range and had no statistically significant differences compared to animals in the negative control group. Conclusions. The results of the study have demonstrated that a single intragastric administration of test samples of lavender in the dose of 5000 mg/kg does not lead to pathological changes in the physiological state of mice, which allows to attribute the extracts studied to class V of practically non-toxic substances (LD50 > 5000 mg/kg).

Current insights into yeast application for reduction of patulin contamination in foods: A comprehensive review.

Patulin, a fungal secondary metabolite with multiple toxicities, is widely existed in a variety of fruits and their products. This not only causes significant economic losses to the agricultural and food industries but also poses a serious threat to human health. Conventional techniques mainly involved physical and chemical methods present several challenges include incomplete patulin degradation, high technical cost, and fruit quality decline. In comparison, removal of mycotoxin through biodegradation is regarded as a greener and safer strategy which has become popular research. Among them, yeast has a unique advantage in detoxification effect and application, which has attracted our attention. Therefore, this review provides a comprehensive account of the yeast species that can degrade patulin, degradation mechanism, current application status, and future challenges. Yeasts can efficiently convert patulin into nontoxic or low-toxic substances through biodegradation. Alternatively, it can use physical adsorption, which has the advantages of safety, high efficiency, and environmental friendliness. Nevertheless, due to the inherent complexity of the production environment, the sole utilization of yeast as a control agent remains inherently unstable and challenging to implement on a large scale in a practical manner. Integration control, enhancement of yeast resilience, improvement of yeast cell wall adsorption capacity, and research on additional patulin-degrading enzymes will facilitate the practical application of this approach. Furthermore, we analyzed the feasibility of the yeast commercial application in patulin reduction and provided suggestions on how to enhance its commercial value, which is of great significance for the control of mycotoxins in food products.

NiFe2O4 Nanoparticles: An Efficient Catalyst for One-Pot Three Component Synthesis of Acridinediones Derivatives

A nickel ferrite nanocatalyst was synthesized in the presence of simple and cost-effective polysorbates assisted sol gel method as an effective catalyst has been successfully used for one pot multicomponent Hantzsch condensation reaction of different aromatic aldehydes, dimedone and ammonium acetate under solvent-free condition at 110 °C-120 °C. The highlights feature for the synthesis of acridinediones are the recyclability of catalyst, solvent-free reaction condition, use of inexpensive catalyst, highly efficient, facile product isolation, clean reaction, nontoxic substances and great yields in short reaction time. The recovered catalyst can run four times without loss its activity.

Improving supercapacitor performance with novel potato starch-PVA solid polymer electrolyte blend modified by sodium perchlorate-glycerol additives

The synthesis and analysis of Solid Polymer Electrolytes (SPEs) derived from a blend of Potato Starch and Poly Vinyl Alcohol (PS-PVA), enhanced with Sodium perchlorate salt (NaClO4) and Glycerol (GCL) are explored in this work. Our focus is on their suitability for Electrical Double-Layer Capacitor (EDLC) devices. GCL, a non-toxic substance, served as the plasticizer, and sodium perchlorate was incorporated to enhance the ionic conductivity of the SPE film. The conductivity at room temperature for pure PS-PVA blend, in the absence of salt and GCL, was found to be 4.16 × 10−8 S cm−1. Upon adding an optimized quantity of NaClO4 salt, the conductivity increased to 1.02 × 10−5 S cm−1. Subsequent plasticization of the salt-polymer blend with GCL induced NaClO4 dissociation, further augmenting the conductivity by one order of magnitude. A conductivity value of 10.35 × 10−5 S cm−1 was achieved for the film with 30 wt% GCL. Morphological, electrical, and structural analyses revealed that synthesized polymer films exhibited favorable characteristics. The suitability of these electrolytes for Electric Double-Layer Capacitors (EDLC) was studied using electrochemical characterizations and cycling tests for 2000 cycles. The findings demonstrate their potential for use in energy storage devices, showcasing excellent performance in specific capacitance, energy, and power densities.

Betaine Induces Apoptosis and Inhibits Invasion in OSCC Cell Lines.

Betaine, known as trimethylglycine, is a non-toxic natural substance reported to affect cancer cell responses. This study delves into the impact of betaine on the survival, proliferation, and invasion of oral squamous cell carcinoma (OSCC) cells in vitro. Human OSCC cells (HSC-4 and HSC-7) were subjected to varying concentrations of betaine, and their viability and proliferation were assessed through colourimetric MTT and colony-forming unit assays. Cell cycle progression and cell apoptosis were also investigated using flow cytometry, while cell migration and invasion were examined using a transwell migration assay, and the mRNA expression was evaluated by a quantitative polymerase chain reaction. Finally, proteomic analysis was conducted through liquid chromatography-tandem mass spectrometry on the extracted protein component of the cells. Results indicate that betaine effectively suppressed OSCC proliferation and colony formation. It triggered early apoptosis without disrupting cell cycle progression, reduced cell migration, and inhibited invasion. Betaine exposure led to significantly decreased mRNA levels of MMP1, MMP2, and MMP9 while downregulating FN1, a gene linked to epithelial-to-mesenchymal transition. Proteomic analysis revealed 9240 differentially expressed up/downregulated proteins in cells treated with betaine. The significantly upregulated proteins were associated with ATP-binding cassette (ABC) transporters, while the down-regulated proteins were associated with G protein-coupled receptors (GPCR) ligand binding. In conclusion, betaine exhibits potent anti-cancer properties by attenuating OSCC cell proliferation and mitigating invasion. Exploring this natural product as an adjunct for managing oral squamous cell carcinoma shows promise, although further investigations are needed to fully elucidate its functionality.

Characterization and Application of Cyrene as a Biomass-Based Solvent for Homogeneous Heck-Coupling Reaction.

Cyrene, a renewable, non-toxic substance having negligible vapor pressure, even at high temperatures, was proposed as a reaction medium for homogeneous Pd-catalyzed Heck-coupling reactions. It was first characterized by its temperature-dependent physicochemical properties, i.e., vapor pressure, density, surface tension, heat capacity, and viscosity, the key parameters of its reaction and process chemistry. Its refractive indices in the function of temperature were also determined. Hereafter, the effect of reaction parameters (Pd source, nature of the base, the water content of the reaction mixture, leaving group (-I, -Br, -Cl, and -OTf of aromatic substrates) on Pd-catalyzed Heck-coupling reaction was investigated using iodobenzene and styrene as model substrates. Subsequently, 4-substituted iodobenzene and styrene derivatives were applied to investigate the effect of electronic parameters on the reaction efficiency and functional group tolerance. To demonstrate the applicability of the system, thirteen stilbene derivatives were isolated with good to high yields and purity (> 95%) using 0.2 mol% of Pd, 1.5 eq. of Et3N as a base, in 1 mL of Cyrene for 2 h at 100 °C.

Development of Biocompatible and Water-Soluble Reduced Graphene Oxide Using Non-Toxic Reducing Agents for Biomedical Applications

Graphene's appeal in various applications stems from its unique properties like remarkable electrical conductivity, impressive mechanical strength, expansive surface area, minimal thermal expansion, and a high aspect ratio. However, its insolubility in water poses challenges for its use in the biomedical sector. This research focuses on developing a method to produce water-soluble and biocompatible graphene suitable for biomedical uses. The study successfully created a stable solution of graphene oxide (GO) in water using a non-ionic Pluronic copolymer. This GO-tripolymer solution maintained its solubility in phosphate buffered saline (PBS) and displayed similar UV absorption characteristics to standard GO. Given the toxicity concerns with traditional reducing agents like hydrazine, this study opted for safer alternatives. Non-toxic substances such as ascorbic acid, galactose, and bovine serum albumin were employed to reduce GO, resulting in a reduced GO (RGO) -tripolymer solution that also showed excellent solubility in PBS. The final phase of the study involved assessing the cytotoxicity of these RGO-tripolymers. The results indicated that these novel RGO-tripolymers exhibit low levels of cytotoxicity, making them potentially suitable for biomedical applications.Keywords: Graphene Oxide (GO), Biocompatibility, Non-Toxic Reducing Agents, Water Solubility and Biomedical Applications

Study of the adjuvant properties of beta-glucans from <i>Saccharomyces Cerevisiae</i> yeast

To increase the effectiveness and immunogenicity of modern vaccines, especially subunit ones, it is required to use adjuvants. Polysaccharides, due to their safety and biocompatibility, are desirable candidates for the creation of vaccine adjuvants. The aim of our study was to develop a method for obtaining beta-Glucans from the yeast Saccharomyces cerevisiae cell wall, and evaluate their adjuvant properties. The high purity and non-toxicity of the resulting preparation was achieved by using enzyme complexes of cellulase and protease in combination with ultrasound (22 kHz) at the purification stage. The developed scheme allows for the yield of beta-Glucans up to 2 g from 100 g of the biomass of wet cells. The adjuvant properties of beta-Glucans were studied in 50 male BALB/c mice, weighing 16–18 g. Immunization was performed twice, with a 14-day interval, intramuscularly, 200 μl per animal. The recombinant receptor-binding domain (RBD) of the surface S protein of the SARS-CoV-2 virus (Wuhan-Hu-1 and B.1.617.2 (Delta)) was used as an antigen, at a dose of 50 μg per animal. A positive control group was administered with the antigen combined with aluminum hydroxide. As a negative control, mice injected with the saline solution were used. The titers of specific antibodies in the blood sera were determined by ELISA assays. RBD (Wuhan-Hu-1 and Delta), and S protein (Wuhan-Hu-1, Delta and Omicron) were used as antigens. The titers of virus-neutralizing antibodies were measured in neutralization tests using SARS-CoV-2 virus strains Wuhan-Hu-1, Delta (B.1.617.2) and Omicron (B.1.1.529). The results of the study have shown that beta-Glucans have the ability to enhance the production of specific and virus-neutralizing antibodies in mice immunized with RBD. The titers of specific and virus neutralizing antibodies are comparable to their levels in the group immunized with RBD and Al(OH)₃. It has been found in the experiments in white outbred ICR mice that the preparation belongs to practically non-toxic substances. Therefore, it can be concluded that the use of beta-Glucans could become a preferable alternative to the conventional adjuvants based on aluminum salts, being biocompatible, biodegradable and non-toxic substances of low labor-intensive production.

Changes of wood surfaces treated with natural-based products – Structural and properties investigation

Preservative systems based on vegetable seed oils and natural waxes from renewable sources may confer protection to wood under exposure to various environmental conditions. These, as non-toxic substances, can form an environmentally friendly and efficient protective layer on the wood surfaces, with beneficial effects on their water resistance and dimensional stability. Thus, these natural coatings may hinder biodegradation of wood products to a certain degree. In present paper, softwood samples (from Abies alba fir tree species), prepared as dried discs (25 to 30 mm diameter, 8 to 10 mm thickness), were surface impregnated by dipping using vegetable oils, namely Asclepias syriaca seed oil, and soybean oil, respectively. Beeswax treatment was also applied for comparison purposes. Surface chemistry and morphology, biodegradation process under controlled and simulated natural conditions, and water sorption behavior of wood samples were investigated. Fourier Transform Infrared spectroscopy, X-ray diffraction, and scanning electron microscopy methods were used for investigation of surface changes in wood samples before and after impregnation with natural based products, as well as under biodegradation conditions in soil burial tests.

Adsorption and dissociation of NO on gold–palladium alloy clusters: A density functional theory study

Alloy nanoclusters often exhibit distinctive and exceptional performance, making them especially appealing as catalysts. In this study, the adsorption and dissociation of NO on AumPdn (m + n = 8) clusters was studied using density functional theory (DFT). The most stable structures of AumPdn (m + n = 8) clusters were reported by the CALYPSO search screening program and DFT geometric optimization. The binding energy and bond critical point (BCP) analysis show that alloying could lead to a more compact structure and relatively stronger stability. Molecular electrostatic potential (MESP) analysis revealed that the optimal site for the adsorption of the NO molecule on AumPdn (m + n = 8) clusters was at the top site, with Pd atoms being the preferred choice. Projected density of states (PDOS) calculations demonstrate that the d-band center of the Au5Pd3 cluster was closest to the Fermi level, enhancing the interaction between the cluster surface and adsorbed molecules. The activation energy of NO dissociation on the Au5Pd3 surface is the lowest at 0.48 eV. These findings indicate that the Au5Pd3 nano-alloy cluster shows promise as an effective catalyst in the direct transformation of NO into non-toxic substances.

Application of Cations, Acids, and Antioxidants on Mitigating Acrylamide Formation in Food with a Special Focus on Potato and Cereal Based Foods - A Review

Acrylamide is a toxic substance that formsin food during high-temperature processing methods such as deep-frying, baking, and roasting, through the Maillard reaction or the acrolein pathway. Since acrylamide has been identified for its carcinogenicity, genotoxicity, and neurotoxicity, global food authorities have established benchmark levels for different food categories. Consequently, researchers have proposed various mitigation strategies, focusing on agronomical, chemical, physical, and microbial approaches. However, most of these approaches are associated with high cost, technology, extended time, and poor sensory and nutritional quality. In this context, application of various additives such as metal cations, organic and inorganic acids, and antioxidants in optimum amounts have been effective in reducing acrylamide formation. Additives contribute to reducing acrylamide either by interacting with its precursors and/or intermediate products or by breaking down acrylamide into other non-toxic substances. Since cations can form thermostable asparagine/matrix intermediates through chelation reaction between asparagine and metal cations, asparagine will be unavailable to react with carbonyl compounds to form the Schiff base. Lower pH conditions inhibit the acrylamide formation by blocking the protonation of the α-amino group of asparagine and reducing any possibility for nucleophilic addition reactions with carbonyl groups. Toxicity associated with Maillard products can be reduced by using antioxidants in the frying oil or the food. Polyphenols are capable of reducing the acrylamide formation by directly trapping acrylamide at elevated temperature. It is essential to identify the most appropriate additive, its concentration and the optimum process conditions when applying additives to get an optimal acrylamide inhibition. This review article highlights the effect of various additive applications, their effectiveness and possible future advances in food to control acrylamide formation within the accepted level.Keywords: Acrylamide, Antioxidant, Carcinogenicity, Deep-frying, Maillard reaction

EXPERIMENTAL ASSESSMENT OF THE ACUTE TOXICITY OF "KUBAZOL" – SOLUTION FOR EXTERNAL APPLICATION BASED ON BIRCH TAR

Laboratory studies were conducted to determine the acute toxicity of the veterinary drug "Kubazol" on white rats. The drug "Kubazol" - a veterinary drug (spray for external use, solution) contains birch tar in its composition. Intended for the treatment and prevention of lesions of the skin (wounds, dermatitis, eczema), claws (injuries, superficial panaritium), hooves and hooves (foot rot, etc.) in dogs, wild pigs, wild birds and sports horses. According to the results of determining the parameters of the acute toxicity of the drug "Kubazol" (spray for external use, solution), in the case of a single intragastric administration, the LD50 for male rats is 7328.87±878.80 mg/kg of body weight, which allows us to classify it as toxic up to V class - practically non-toxic substances (LD50 5001-15000 mg/kg), and according to the degree of danger - up to IV class - low-hazard substances (LD50 > 5000 mg/kg). According to the results of toxicological studies of the veterinary drug "Kubazol" (spray for external use, solution), the LD50 indicator could not be calculated, since the death of laboratory animals was not detected within 14 days after application to the skin of rats. At the same time, the maximum dose of the drug "Kubazol (spray for external use, solution) applied to the skin of rats (based on the absolute weight of the drug) was 15,000.0 mg/kg of body weight, which allows the drug to be classified according to the degree of danger to the IV class - low-hazardous substances (LD50Сut>2500.0 mg/kg of body weight). Further studies will be the next stage of pre-registration tests aimed at studying the chronic toxicity of "Kubazol", which is mandatory material in the section "Studies on safety and residues" of the dossier for this drug.

The study on in vitro antioxidant properties, cellular immune activities and mice anti-fatigue effects of Sanghuangporus vanninii mycelium polysaccharides

Sanghuang mycelial polysaccharides (SVMPs) were studied using poplar sanghuang as raw material (sanghuangporus vanninii, SV). The bioactivity of SVMPs was evaluated through in vitro antioxidant and cellular immunity activity assays, and the acute oral toxicity and anti-fatigue ability of SVMPs in mice were determined using mice as an experimental animal model. The results showed that SVMPs have a good scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, and 2,2′-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS+) radicals, with a slightly weaker reducing power. SVMPs promote, to some extent, the secretion of cytokines Tumor Necrosis Factor-α (TNF-α), Interleukin-1β (IL-1β), and Interleukin-6 (IL-6), and the release of NO from mouse macrophage RAW264.7. In mouse experiments, the mouse tolerance of SVMPs was more greater than 18.2 g/kg BW, which was 2724 times the daily dosage of humans, and it was a non-toxic substance; the high dose group of SVMPs could significantly prolong the swimming time of weight-bearing mice. Thus, the results of this study clearly demonstrate the biological activity of SVMPs and provide a valuable basis for the potential application of SVMPs as antioxidants, immunomodulators, and functional foods.

Efficient removal of fluoride from water: Adsorption performance of MgO-x adsorbents derived from Mg-MOF-74 and insights from DFT calculations

Magnesium oxide (MgO), an inexpensive and non-toxic substance, is considered an excellent and environmentally friendly fluoride adsorbent. In this study, a series of MgO-x materials (MgO-300, MgO-500, MgO-700 and MgO-800) were obtained by calcination with Mg-MOF-74 as a precursor, and they were used for efficient fluoride removal from wastewater. Both MgO-500 and MgO-700 exhibit excellent fluoride adsorption capacity in the pH range of 3.00–10.00. Specifically, their maximum adsorption capacities are 151.11 mg g−1 and 173.30 mg g−1, respectively. By analyzing the adsorption isotherm and kinetic data, it is confirmed that the adsorption of F− by MgO-x is more in line with the Langmuir isotherm model and the pseudo-second-order kinetic model. Interestingly, the adsorption rate of MgO-500 was significantly faster than that of MgO-700. MgO-x exhibited excellent repeat application performance, with MgO-500 maintaining 75.5 % fluoride ion removal efficiency and 81.5 % regeneration efficiency after five adsorption/desorption cycles. FTIR and XPS analyses show that the adsorption mechanism of fluorine on MgO-x is mainly the result of ligand exchange and electrostatic attraction. Density functional theory calculations show that the adsorption of fluorine on the MgO (110) plane is more favorable than on the (100) plane. This study demonstrates that magnesium oxide derived from Mg-MOF-74, as an economical and environmentally friendly material, has great potential to remove excess fluoride from water.

Evaluation on the traditional safe use of Kochiae Fructus oriented by antioxidant properties and oral safety of its ethanolic extract

Kochiae Fructus (KF) is a traditional Chinese medicine, which has been used to delay aging and treat inflammation, such as rubella, eczema, cutaneous pruritus, etc. In order to fully understand the traditional medicinal value of KF, we evaluated the antioxidant properties and oral safety of its ethanolic extract. Considering flavonoids and phenolics in medicinal plants generally have strong antioxidant activity, we firstly detected the total flavonoids and phenolics contents of KFEE and its fractions. Secondly, we evaluated the antioxidant activities of KFEE and its fractions. Finally, we evaluated the oral safety of KFEE by the acute and 28-day subacute toxicities. The n-butanol fraction (ENBF) possessed the highest phenolics and flavonoids with values of 77.30 ± 3.17 mg gallic acid equivalents/g and 228.81 ± 7.56 mg rutin equivalents/g, respectively. The results of antioxidant tests showed that ENBF possessed potent antioxidant ability. Among them, the high antioxidation capacity observed in ENBF could be attributed to its rich content of flavonoids and phenolics. The results of toxicological studies showed that the LD50 value of KFEE was 6000 mg/kg BW, and the no observed adverse effect level (NOAEL) of KFEE was 600 mg/kg BW. According to the standards of the American Academy of Sciences for the classification of toxic substances, KFEE can be classified as practically non-toxic substance, which provided valuable evidence for the oral safety of KF as a natural aging delay medicine.

The effects of nontoxic bio-based substances (egg white) on the performance and passivation of ZnO nanorods arrays-based light emitting devices

An innovative approach is proposed to passivate the existing defects from metal oxide semiconductors by functionalizing nontoxic bio-based substances. As a demonstration, we synthesized zinc oxide nanorods (ZnO NRs) using a hydrothermal method and incorporated chicken egg white (albumen) as a passivator to the defects. X-ray diffraction analysis of ZnO NRs shows enhanced quality and crystallinity features after incorporating albumen. XPS measurements were performed not only to introduce the chemical bonding between the albumen and the bare ZnO NRs but also specifically provide evidence of successful capping and defect passivation to the surface layer of ZnO NRs. It was observed that when the albumen was annealed, it formed sulfhydryl groups and disulfide bonds (which created disulfide bridges) from the chemical reaction in irreversible thermal denaturation. Steady-state photoluminescence of ZnO NRs showed two emission bands, i.e. near band-edge emission (NBE) and deep-level emission (DL). The NBE is significantly improved as compared to DL emission after capping and annealing the albumen, while the quenching of DL emission confirmed the reduced defects arising from the surface of ZnO NRs. The advantages and enhanced characteristics of the albumen-capped ZnO NRs led to fabricating a stable and highly efficient light-emitting device. This work opens the great potential of utilizing nontoxic and low-cost biomaterials in passivating the defects of metal oxide nanomaterials for the development of bio-inspired and stable optoelectronic devices.