Iron NPs Research Articles

Preparation of iron nanoparticles mediated by Punica granatum and its application for the treatment of denture stomatitis

Denture stomatitis affects around 50% of denture wearers in certain populations as a prevalent oral mucosal lesion. There has been a high interest in utilizing natural antibacterial composites, such as medicinal plants extracts. Punica granatum, a popular medicinal plant, has various pharmacological applications. In this particular research, iron NPs were formulated by the Punica granatum aqueous extract, following the principles of green chemistry. The study objective was to assess the effectiveness of FeNPs on denture stomatitis. The usual analytical examinations were applied for FeNPs. The FE-SEM results confirmed that the nanoparticles exhibited a spherical morphology, with sizes ranging from 21.6 to 65.8 nm. This clinical trial involved 30 patients who received FeNPs. Over a period of two weeks, the patients were instructed to consume the mouthwash four times per day, with 15–20 drops each time, for a duration of 2–3 minutes. Following the mouthwash, they were advised to refrain from eating or drinking for 0.5 hour. The patients in both classes were instructed to consume the medication at particular times. The erythema and inflammation levels were recorded and assessed at each session using a 6-point scale and a graded blade. Additionally, palatal mucosa mycological samples were collected for culture during each visit. The data revealed a notable reduction in the palatal erythema surface compared to the initial condition in the follow-up visits. This study suggests that FeNPs can effectively reduce the Candida colonies number and the area affected by erythema in the denture stomatitis management.

High magnetization composite magnetic fluid: structure, magnetorheology and new sealing mechanism in rotating seals.

The sealing capacity of magnetofluidic (MF) rotating seals is limited by the highest magnetization of the sealing ferrofluids (FFs) of about 1000 G (80 kA m-1). A sharp, almost an order of magnitude, increase in the supported pressure drop is possible by using a magnetorheological (MR) suspension as sealing fluid, owing to the much higher saturation magnetization of MR fluids compared to FFs. However, rotating seals with MR fluids have several shortcomings, such as a significant increase of the friction torque due to the growth of shear stress in the strong magnetic field specific to MF seals and leakage of the non-magnetic carrier liquid. At least partly, these issues can be avoided by using ferrofluid based extremely bidisperse MR suspensions of micrometer-sized iron (Fe) particles dispersed in a ferrofluid, as sealing fluid. The composite Fe3O4-Fe magnetic fluid used in this study consisted of hundreds of nanometers up to few microns size structures of interconnected (welded) Fe nanoparticles (FeMNPs) dispersed in a high colloidal stability ferrofluid with 500 G (40 kA m-1) saturation magnetization. The volume fraction of iron NPs varies from 0.5 to 15% in the ferrofluid carrier which significantly increases the magnetization and simultaneously produces important changes of flow properties in magnetic field of the resulting composite fluid, from Newtonian to strongly non-Newtonian behavior. The evaluation of the magnetic and magnetorheological behavior includes the dependence of magnetization, effective viscosity, magnetoviscous effect and dynamic yield stress on the volume fraction of Fe nanoparticles dispersed in the ferrofluid carrier. The seal gap filled with interconnected Fe nanospheres consists in randomly distributed microregions with a high intensity and high gradient magnetic field that captures the ferrofluid and provides a new sealing mechanism. Already a small amount of interconnected Fe nanospheres additive (2.5-5.0% volume fraction) produces four times increase of the rotating seal burst pressure, a much higher increase than what can be obtained from using a conventional magnetic fluid with the same magnetization. The nano-composite sealing magnetic fluid proved to be a cost-effective solution to significantly increase the performance of multi-stage rotating MF seals.

Assessment of the cytotoxicity, antioxidant, and anti-lung carcinoma effects of Fe nanoparticles green-formulated by Silybum marianum leaf aqueous extract

Silybum marianum has many therapeutic uses in pharmacology. Recently, the medicinal plants green-mediated iron nanoparticles (FeNPs) have been applied as new chemotherapeutic supplements for cancer treatment in pre-clinical trial studies. In the current research, iron nanoparticles were formulated based on green formulation rules by the S. marianum. The current iron NPs may be administrated as an anti-lung cancer material in humans after performing clinical research. The properties of iron NPs on lung cancer cells were assessed. The green-formulated iron NPs were characterized by chemical techniques mean transmission electron microscopes (TEM), field emission scanning electron microscope (FE-SEM), and UV–Vis spectroscopy. The FE-SEM findings prove the morphology of spherical NPs with a size of 14.1 to 54.8 nm. The absorbance presence at the wavelength of 271 nm indicated the Fe nanoparticles green synthesis in the UV–Vis spectrometer. The IC50 of the iron nanoparticles was 188, 211, 250, and 280 against NCI-H661, NCI-H1975, NCI-H1573, and NCI-H1563 cancer cells, respectively. The best result of the anti-lung cancer effects was seen against NCI-H661. The findings revealed that the NPs prevented lung carcinoma cells higher than normal cells.

Comparison study of iron and iron-oxide nanoparticles for thermoplasmonic applications

The plasmonic nanoparticles have the properties of surface plasmon resonance (SPR) that can be used to heat up the surrounding by absorbing maximum light from an irradiated beam. Therefore, the present study reveals the photothermal effect of iron and iron-oxide nanosphere in different ambient environments with varying radii from 20 nm to 60 nm. Based on Mie’s theory, PyMieLab_V1.0 software is used to calculate the size-dependent absorption cross-section of spherical nanoparticles. The absorption spectra at λmax have been tuned from the UV to Infrared region of Fe nanoparticles in different surrounding environments while for Fe2O3 NPs, it reveals in the UV region. As the nanoparticle size increases, the absorption peak position of Fe and Fe2O3 NPs shifts towards the longer wavelength regime on the electromagnetic spectrum. It has been observed that the heat generation rate and the maximum temperature gradually increase with particle sizes and a 60 nm particle’s size has maximum heat generated as well as a maximum temperature increase further, iron NPs are more dominant than iron oxide NPs. At the resonance wavelength, the near-field enhancement is observed with the nanosphere's radii, but with variation in the value of refractive indices, it decreases. Thus, this simulated work opens potential applications in a newly emerging field like thermo-plasmonic and thermo-optic.

Biosynthesis and Mathematical Interpretation of Zero-Valent Iron NPs Using Nigella sativa Seed Tincture for Indemnification of Carcinogenic Metals Present in Industrial Effluents.

Zero-valent iron nanoparticles (ZVI-NPs) are utilized for the indemnification of a wide range of environmental pollutants. Among the pollutants, heavy metal contamination is the major environmental concern due to their increasing prevalence and durability. In this study, heavy metal remediation capabilities are determined by the green synthesis of ZVI-NPs using aqueous seed extract of Nigella sativa which is a convenient, environmentally friendly, efficient, and cost-effective technique. The seed extract of Nigella sativa was utilized as a capping and reducing agent for the generation of ZVI-NPs. UV-visible spectrophotometry (UV-vis), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDX), and Fourier transform infrared spectroscopy (FTIR) was used to investigate the ZVI-NP composition, shape, elemental constitution, and perspective functional groups, respectively. The biosynthesized ZVI-NPs displayed a peak of plasmon resonance spectra at 340 nm. The synthesized NPs were cylindrical in shape, with a size of 2 nm and (-OH) hydroxyl, (C-H) alkanes and alkynes N-C, N=C, C-O, =CH functional groups attached to the surface of ZVI-NPs. Heavy metals were successfully remediated from industrial wastewater collected from the various tanneries of Kasur. During the reaction duration of 24 h, different concentrations of ZVI-NPs (10 μg, 20 μg and 30 μg) per 100 mL were utilized for the removal of heavy metals from industrial wastewater. The 30 μg/100 mL of ZVI-NPs proved the pre-eminent concentration of NPs as it removed >90% of heavy metals. The synthesized ZVI-NPs were analyzed for compatibility with the biological system resulting in 87.7% free radical scavenging, 96.16% inhibition of protein denaturation, 60.29% and 46.13% anti-cancerism against U87-MG and HEK 293 cell lines, respectively. The physiochemical and exposure mathematical models of ZVI-NPs represented them as stable and ecofriendly NPs. It proved that biologically synthesized NPs from a seed tincture of Nigella sativa have a strong potential to indemnify heavy metals found in industrial effluent samples.

STUDYING THE EFFICIENCY OF SOME NANOPARTICLES ON SOME PLANT PATHOGENIC FUNGI AND THEIR EFFECTS ON HYPHAL MORPHOLOGY

This study was investigated the effect of iron NPs and essential oils of clove in normal and nanoemulsion forms for controlling Fusarium oxysporum, Fusarium solani, and Alternaria solani compared with Azoxystrobin fungicide under laboratory conditions. Data revealed that all tested compounds are capable of inhibiting the growth of mycelial of F. oxysporum F. solani, and A. solani from 0 to 84.4%, 0 to 88.9 %, and 0 to 61.1 %, respectively. There is relationship was found between the tested concentration of all treatments and their percentages of inhibition of mycelium. In addition, the use of Azoxystrobin, iron NPs and essential oils of clove in normal and nanoemulsion increased the activity of polyphenol oxidase (PPO). The fungal hyphae morphology was investigated by using scanning electron microscopy (SEM). The fungi hyphae without treatments are regular branching, linearly and normal morphology shaped, the surface of the hyphae is smooth and apical tapered. Treatments caused loss of linearity, irregular branching of the terminal hyphae, deformations of the hyphal shape, and the lysis cytoplasm of the hyphal.

Nanoparticles – a novel theranostic approach to treat alzheimer’s disease

The incidence of Alzheimer’s disease (AD) is increasing day by day worldwide, which results in a poor quality of life. Early diagnosis and treatment of AD is necessary to suppress the progression of the disease. Conventional treatments have several limitations due to the protective blood-brain barrier. In this review, we described a nanoparticle-based approach to crossing the blood-brain barrier for AD detection and treatment. Nanoparticles encapsulate the anti-AD drug and are directed to the target tissues where controlled release of the drug takes place. There are various types of nanoparticles that are used to encapsulate drugs, including solid-based nanoparticles, liposomes, nanoemulsions, iron NPs, cerium NPs, selenium NPs, and gold NPs. In this review, we have described the use of different nanoparticles as nanomedicine. Nanoparticles are also coated with proteins and antibodies for efficient release of drugs. This review aims to provide clinical insights and the importance of nanotechnology in theranostics and describes how nanomedicine has revolutionized the drug delivery approach for AD treatment

Impacts of engineered iron nanoparticles on oxidative stress, fatty acid composition, and histo-architecture of the smooth scallop Flexopecten glaber.

Engineered iron nanoparticles are widely used in environmental remediation, yet their potential toxic effects on marine biota remain poorly elucidated. This study aimed to gain insight into the nanoscale zero-valent iron (NZVI) toxicity mechanisms for marine invertebrates. Aside from the effect on oxidative status and histopathology, the effect of NZVI on lipid metabolism in bivalves was studied for the first time. To this end, specimens of Flexopecten glaber were exposed to ascending concentrations (0.5, 1, and 1.5 mg/L) of NZVI for 96 h. Results illustrate differential patterns of iron accumulation in the gills and the digestive gland. By increasing NZVI concentrations, the total iron level tended to markedly increase in the gills and decrease in the digestive gland, reaching 132 and 37.6 μg/g DW, respectively, in the specimens exposed to 1.5 mg/L. Biochemical and cellular biomarkers highlighted that NZVI caused oxidative stress (measured as hydrogen peroxide, malondialdehyde, and advanced oxidation protein product levels) and alterations of antioxidant defense systems, including reduced glutathione, non-protein thiol, glutathione peroxidase, superoxide dismutase, and catalase. Modulation of lipid metabolism with changed fatty acid compositions (mainly an increase in the saturation and a decrease in unsaturation levels) was also observed in both gills and digestive gland. Moreover, several histological damages, including lipofuscin accumulation, infiltrative inflammations, and digestive tubule alterations, were observed in the two studied organs, providing supplementary evidence regarding the toxic effect of NZVI. This study adds to the growing body of evidence pointing to the hazardous impacts of iron NPs on aquatic ecosystems.

Chemo-Blended Ag & Fe Nanoparticles Effect on Growth, Physiochemical and Yield Traits of Wheat (Triticum aestivum)

The application profile of nanotechnology is increasing due to its influential effects on the environment. Recently, this field has gained tremendous magnitude in the agriculture sector as a potential improving agent for plant growth, slow-release fertilizer, and targeted delivery of agrochemicals for sustainable crop productions. A study was designed with the aim to explore the potential effects of nanoparticles mixed with organic chemicals on the growth and physiochemical properties of wheat. Synthesized silver NPs and iron NPs were characterized through SEM and a particle analyzer, which confirmed the fine particles of a size < 20 nm. The application of chemo-blended NPs enhanced plant height, shoot and root biomass and leaf area. Chlorophyll (a, b) and total chlorophyll contents were promoted with an application of blended NPs. Chemo-blended nanoparticles promoted total soluble sugars, total free amino acid contents and total protein contents of wheat. Antioxidant enzyme activities, such as superoxide dismutase, peroxidase and catalase were significantly promoted with blended NPs. Yield related attributes were also promoted in response to nanoparticles blended with organic chemicals. These results suggest that the application of chemo-blended NPs may increase plant growth and development through the improvement of the physiochemical properties of wheat.

Kinetic Study on the Effect of Substrate and Micronutrient Inhibition during Anaerobic Fermentation of Biohydrogen

There are several factors that influence the production of biohydrogen by dark fermentation including inoculum seeds, type and concentration of substrate, pH, temperature, presence of micronutrient and reactor configuration. Previous research has proven that the concentration of substrate and the presence of micronutrient will influence the yield and productivity of biohydrogen production. However, improvement of yield and productivity of the process can only be achieved once the system is under the optimum amount of substrate and micronutrient. Therefore, the best way to determine the effect of substrate concentration and presence of micronutrient is through kinetic study that was done using Monod model along with Andrews model. Besides that, the substrate inhibition effect also will be evaluated to determine the maximum substrate that needs to be supplied for maximum hydrogen production, and thus supplied the information for economic feasibility for fermentation process. In the meantime, the inhibition effect of adding the iron nanoparticles also had been evaluated in order to understand the interaction effect between iron nanoparticles and bacteria in term of catabolism reaction. It was found that increasing the substrate concentration more than 10 g/l will cause the inhibition to the system, in which it will slow down the reaction process and reduced the production of hydrogen. While the presence of iron NPs more than its optimum value (200 mg/l) will inhibit the bacterial growth and hence, affect the hydrogen production. For both cases, when the inhibition occurred at the respective concentration, it was found that the metabolic pathway was shifted to produce more hydrogen-consuming metabolite such as propionate acid, and thus, dropped the hydrogen production.

Atomically dispersed Fe-N-C catalyst displaying ultra-high stability and recyclability for efficient electroreduction of CO2 to CO.

To avoid the agglomeration of iron NPs and improve the dispersion of Fe SAs, we employed a mixed-ligand strategy to regulate the iron content in PCN-224(ZnxFey) and PCN-222(ZnxFey). Thanks to the sublimation of Zn and the Kirkendall effect, uniform dispersions of Fe SAs with 1.04-1.06 wt% were obtained in the pyrolysis products Zn0.5Fe0.5-N-C-224 and Zn0.5Fe0.5-N-C-222 with excellent CO2 → CO activity, super-stability, and recyclability.

Treatment of HT29 Human Colorectal Cancer Cell Line with Nanocarrier-Encapsulated Camptothecin Reveals Histone Modifier Genes in the Wnt Signaling Pathway as Important Molecular Cues for Colon Cancer Targeting.

Cancer cells are able to proliferate in an unregulated manner. There are several mechanisms involved that propel such neoplastic transformations. One of these processes involves bypassing cell death through changes in gene expression and, consequently, cell growth. This involves a complex epigenetic interaction within the cell, which drives it towards oncogenic transformations. These epigenetic events augment cellular growth by potentially altering chromatin structures and influencing key gene expressions. Therapeutic mechanisms have been developed to combat this by taking advantage of the underlying oncogenic mechanisms through chemical modulation. Camptothecin (CPT) is an example of this type of drug. It is a selective topoisomerase I inhibitor that is effective against many cancers, such as colorectal cancer. Previously, we successfully formulated a magnetic nanocarrier-conjugated CPT with β-cyclodextrin and iron NPs (Fe3O4) cross-linked using EDTA (CPT-CEF). Compared to CPT alone, it boasts higher efficacy due to its selective targeting and increased solubility. In this study, we treated HT29 colon cancer cells with CPT-CEF and attempted to investigate the cytotoxic effects of the formulation through an epigenetic perspective. By using RNA-Seq, several differentially expressed genes were obtained (p < 0.05). Enrichr was then used for the over-representation analysis, and the genes were compared to the epigenetic roadmap and histone modification database. The results showed that the DEGs had a high correlation with epigenetic modifications involving histone H3 acetylation. Furthermore, a subset of these genes was shown to be associated with the Wnt/β-catenin signaling pathway, which is highly upregulated in a large number of cancer cells. These genes could be investigated as downstream therapeutic targets against the uncontrolled proliferation of cancer cells. Further interaction analysis of the identified genes with the key genes of the Wnt/β-catenin signaling pathway in colorectal cancer identified the direct interactors and a few transcription regulators. Further analysis in cBioPortal confirmed their genetic alterations and their distribution across patient samples. Thus, the findings of this study reveal that colorectal cancer could be reversed by treatment with the CPT-CEF nanoparticle-conjugated nanocarrier through an epigenetic mechanism.

Functionalization with bio-molecules derived from oyster mushroom (Pleurotus florida) diminished the antibacterial potential of the mycogenic metal oxide nanoparticles (nps)

Mushrooms are mostly decomposers and possess the ability to digest food extracellularly by secreting specific enzymes. These enzymes and other bio-molecules present in the mycelium extracts of the P. florida have been used to produce zinc, copper and iron NPs extracellularly using metal salts as precursors. This work includes synthesis of metal oxide NPs by use of different concentrations (0.1to 0.9 mM) of three metal salts viz., zinc, copper and iron which were formed by incubating the salts with mycelium extracts of P. florida up to 96 hours under shaking conditions at 25±2°C in BOD incubator. The synthesis of the NPs was identified by performing the UV-Vis spectroscopy analysis at regular intervals to observe the time-dependent NPs synthesis. The visual color change in the reaction mixture was recorded and development of white, green and brown colors in zinc, copper andiron salt precursor containing sols respectively was recorded. The shape and formation of NPs was identified through TEM analysis. Incubation of the ferric chloride salt precursor with mycelial extract produced cubic shaped NPs. The antibacterial activity studies of the developed NPs using different concentrations (0.1 to 0.9 mM) along with the antibiotic standards (penicillin and gentamycin at the rate of 200 and 20 mg L-1 respectively) were performed against both gram positive and gram-negative bacteria. The results revealed formation of no inhibition zone by the biogenic NPs as compared to inhibition zones formed by the standard antibiotics (maximum 17 mm for E . coli in gentamycin).

Fertility and Iron Bioaccumulation in Drosophila melanogaster Fed with Magnetite Nanoparticles Using a Validated Method

Research on nanomaterial exposure-related health risks is still quite limited; this includes standardizing methods for measuring metals in living organisms. Thus, this study validated an atomic absorption spectrophotometry method to determine fertility and bioaccumulated iron content in Drosophila melanogaster flies after feeding them magnetite nanoparticles (Fe3O4NPs) dosed in a culture medium (100, 250, 500, and 1000 mg kg−1). Some NPs were also coated with chitosan to compare iron assimilation. Considering both accuracy and precision, results showed the method was optimal for concentrations greater than 20 mg L−1. Recovery values were considered optimum within the 95–105% range. Regarding fertility, offspring for each coated and non-coated NPs concentration decreased in relation to the control group. Flies exposed to 100 mg L−1 of coated NPs presented the lowest fertility level and highest bioaccumulation factor. Despite an association between iron bioaccumulation and NPs concentration, the 500 mg L−1 dose of coated and non-coated NPs showed similar iron concentrations to those of the control group. Thus, Drosophila flies’ fertility decreased after NPs exposure, while iron bioaccumulation was related to NPs concentration and coating. We determined this method can overcome sample limitations and biological matrix-associated heterogeneity, thus allowing for bioaccumulated iron detection regardless of exposure to coated or non-coated magnetite NPs, meaning this protocol could be applicable with any type of iron NPs.

Nanocatalytic Medicine of Iron-Based Nanocatalysts

Iron can be found in all mammalian cells and is of critical significance to diverse cellular activities within human bodies. Widespread applications and the underlying chemical and biological funda...

Zero valent nickel nanoparticles decorated polyaniline nanotubes for the efficient removal of Pb(II) from aqueous solution: Synthesis, characterization and mechanism investigation

Zero valent nickel nanoparticles (Ni0 NPs) have exhibited potential applicability in various fields including, chemical cells, fuel cells and catalysis. Alike zero valent iron NPs, Ni0 NPs and their composite nanostructures would have great prospect in remediating heavy metal pollutants from water bodies. To establish this fact composite nanotubes (CNs) of naphthalene sulfonic acid doped polyaniline (PANI-NSA) and Ni0 NPs ([email protected]0 CNs) were synthesized by immobilization of Ni0 NPs onto the PANI-NSA surface and effectively used for the removal of Pb(II) ions from aqueous solution. Morphological and structural characterization established that aggregation of ferromagnetic Ni0 NPs was greatly diminished by immobilization onto the matrix of PANI-NSA. Improved specific surface area and greater reactivity of the [email protected]0 CNs enabled superior removal performance towards Pb(II) ions in comparison with its constituents. The highest removal efficiency (90.9%) was observed using 0.5 g/L CNs at pH 5.0. Pb(II) sorption kinetics was very rapid and equilibrium was reached within 30–90 min for 50–150 mg/L concentrations at pH 5.0. The Langmuir isotherm model provided the best description of the isotherm data, with a deduced maximum Pb(II) removal capacity of 414.6 mg/g at 25 °C. Thermodynamic analysis revealed exothermic and spontaneous adsorption onto the adsorbent surface. Co-existing heavy metal ions had slight impacts on Pb(II) removal performance of the [email protected]0 with associated implications for the treatment of industrial wastewater. XRD and XPS analyses allude that Pb(II) adsorption onto deprotonated surface sites followed by reduction to Pb0 were the leading removal mechanism associated with the current CNs structure.

The first evidence of accumulation and avoidance behavior of macroinvertebrates in a forest soil spiked with human-made iron nanoparticles: A field experiment

Both earthworms and terrestrial isopods have been used to evaluate the quality of contaminated soil by NPs. However, most experiments have been conducted in the laboratory and under greenhouse conditions. Besides, little is known of Fe accumulation in earthworms from iron NPs (Fe NPs) under natural conditions. Therefore, the objective of this research was to evaluate the effect of manufactured NPs on the accumulation of Fe in macroinvertebrates from forest soil. Our results revealed that earthworms consume low amounts of Fe in a concentration of 1000 mg Fe NPs kg−1 of dry soil, with a behavior constant over time. Besides, we observed that earthworms could not detect Fe at low concentrations (1 or 10 mg Fe NPs kg−1), so they do not limit soil consumption, which translates into high amounts of Fe in their bodies. By contrast, the content of Fe in organisms is inversely proportional to increasing concentrations in the soil (R2 = -0.41, p < 0.05). Therefore, although studies are needed, in addition to considering environmental factors and the physicochemical properties of the soil, endogenous worms in the evaluated area could, under natural conditions, be useful to inform us of contamination of NP manufactured from Faith. Besides, for future research, a novel methodology should be considered to demonstrate more realistic avoidance behavior under field conditions.

Implications of iron nanoparticles in spontaneous coal combustion and the effects on climatic variables

Atmosphere, water, and soil contamination with toxic compounds is a recurrent issue due to environmental disasters, coal burning, urbanization, and industrialization, allf of which have contributed to soil contamination over the decades. Consequently, understanding of the nanomineralogy and potential hazardous elements (PHEs) in coal area soil are always a vital topic since contaminated soil can affect the environment, agricultural safety, and human health. Colombian coal mining in the La Guajira zone has been usually been related with important health and ecological effects. Coalmine rejects from active and/or abandoned operations are causes of high intensities of potential hazardous elements (PHEs) and nanoparticles (NPs, minerals and/or amorphous compounds). Although these pollutants can be reduced by sorption to NPs, in this study was recognized an analytical procedure for understand distribution of PHEs and their relationship to iron NPs(Fe-NPs) was recognized. Non and poorrly crystalline Fe-NPs performances as the major PHEs association. This complex interaction is constant and efficient in resolving PHEs in proportions above monitoring quantities. The indefinite basis of PHEs in Colombian (La Guajira area) coalmine rejects sources results in years-long leaching of PHEs into rivers and drainages. The iron-clays and their great geomobility interfere the mitigating character that Fe hydr/oxides alone show through adsorption of PHEs and their control in spontaneous coal combustion (SCC) zones. This can have significant consequences to the probable availability of several pollutants (e.g. drinking water). The new results presented in this study add novel viewpoints into the description of Fe-NPs and its incidence in SCC areas. The methodology utilized in this work can be applied as a supplementary technique to evaluate the influence of coalmining actions on ecological and human health.

Evolutions of antibiotic resistance genes (ARGs), class 1 integron-integrase (intI1) and potential hosts of ARGs during sludge anaerobic digestion with the iron nanoparticles addition

In this work, we investigated the impact of iron nanoparticle, including magnetite nanoparticles (Fe3O4 NPs) and nanoscale zero-valent iron (nZVI), on the anaerobic digestion (AD) performance. Moreover, the evolutions of antibiotic resistance genes (ARGs), class 1 integrons-integrase (intI1) and potential hosts of ARGs were also investigated. The optimal addition of Fe3O4 NPs and nZVI to promote methane production was 0.5 g/L and 1 g/L, which led to 22.07% and 23.02% increase in methane yield, respectively. The degradation rate of organic matter was also enhanced with the addition of Fe3O4 NPs or nZVI. The results of high-throughput sequencing showed that the reactors with iron NPs exhibited significant differences in microbial community structure, compared to the reactors with the non‑iron NPs. Iron NPs have caused the relative abundance of the dominant bacteria (Proteobacteria, Firmicutes and Actinobacteria) generally decreased, while the dominant archaea (Euryarchaeota) increased in AD sludge. Quantitative PCR results revealed that iron NPs accelerated the reductions in total absolute abundance of ARGs, especially a beta-lactamase resistance encoded gene (blaOXA). Network analysis displayed that the attenuation of ARGs was mainly attributed to the decline of potential hosts (Proteobacteria, Firmicutes and Actinobacteria). Meanwhile, environmental factors (such as pH, soluble chemical oxygen demand and heavy metals) were also strongly correlated with ARGs.

Reduced graphene oxide-immobilized iron nanoparticles Fe(0)@rGO as heterogeneous catalyst for one-pot synthesis of series of propargylamines

Iron nanoparticles immobilized on reduced graphene oxide (rGO), nanocomposite Fe(0)@rGO 1, were prepared in situ by reduction of GO and FeCl3·6H2O using sodium borohydride under nitrogen atmosphere. The nanocomposite 1 was isolated as a black powder having iron NPs of size ~ 41 nm. The nanocomposite 1 exhibited good catalytic activity in one-pot A3-coupling reactions of aldehyde, amines and terminal alkynes to afford propargylamines in very high yields (72–86%) at a low loading of 0.7 mol%, without any additive or a cocatalyst. The catalyst 1 can be magnetically separated, retrieved and recycled up to four times without noticeable changes in the morphology and catalytic activity.