Effect Of Silicon Dioxide Nanoparticles Research Articles

Effect of silicon dioxide nanoparticles on the rheology properties of fresh and mechanically degraded hydrolyzed polyacrylamide polymer solutions

AbstractPartially hydrolyzed polyacrylamide is extensively utilized in enhanced oil recovery operations. However, its efficacy is compromised by mechanical degradation during transport through injection lines, valves, and reservoir, which leads to a reduction in the average molecular weight, diminishing the solution's viscosity and viscoelastic properties, critical for efficient oil displacement. In this investigation, we characterized the degree of mechanical degradation in HPAM solutions by evaluating shear and extensional rheological parameters preand post‐degradation. Mechanical degradation was induced by subjecting them to controlled flow through a valve featuring varying degrees of constriction and flow rates. Our results demonstrate a significant reduction in zero‐shear viscosity and high‐strain extensional viscosity of mechanically degraded solutions, with reductions of up to 64%. To mitigate this issue, we explored the incorporation of silica nanoparticles as a potential remedy for mechanical degradation. These nanoparticles strengthen the network structure of HPAM, thereby reducing its susceptibility to mechanical degradation. Our findings reveal that shear and extensional viscosities of mechanically degraded NPs‐HPAM solutions experienced only minimal reductions, dropping to 12% and 0%, respectively. This underscores the effectiveness of the nanoparticle‐enhanced HPAM solutions in preserving viscosity and viscoelasticity under mechanical stress, presenting a promising avenue for improving the robustness of EOR processes.

Combined effect of silicon dioxide nanoparticles and plant-derived smoke solution on physiological and biochemical parameters of pea plant (Pisum sativum L.)

Nanomaterials exhibit distinctive advantages due to their characteristic size range falling within 1-100 nanometers, which can easily penetrate through plant cell membranes. The application of plant-derived smoke (PDS) solutions is also recognized for its beneficial impact on seed germination and growth of diverse plant species. In this context, in the present study, we investigated the effects of silicon dioxide nanoparticles (SiO2 NPs), PDS, and their combined application on pea seeds, and thereafter evaluated a spectrum of morphological and biochemical growth parameters. The results demonstrated that SiO2 NPs significantly enhanced pea seed germination, seedling length/weight, secondary root formation, as well as key biochemical indicators including photosynthetic pigments, total soluble sugars, and protein content. Notably, the PDS solution also exerted a significant positive influence on all growth parameters in comparison to that of SiO2 NPs. However, the combined application of SiO2 NPs and PDS exhibited superior effects on the morphological and biochemical growth characteristics as compared to their individual applications. From these findings, it can be concluded that both SiO2 NPs and PDS solutions, whether used independently or in combination, impart beneficial effects on the morphological and biochemical growth parameters of pea plants. This research highlights the potential of SiO2 NPs and PDS solutions as promising tools for enhancing plant growth and seedling development. Future studies could further explore the underlying mechanisms and optimize application methods for maximizing the beneficial effects of these materials, thus contributing to sustainable agricultural practices and improved crop yields.

Enhanced microstructure and mechanical properties of cementless ultra-high-performance fiber-reinforced alkali-activated concrete with silicon dioxide nanoparticles

This study investigates the effect of silicon dioxide nanoparticles (nano-SiO2) on the microstructure and mechanical properties of eco-friendly, cementless ultra-high-performance fiber-reinforced alkali-activated concrete (UHP-FRAAC). Various amounts of nano-SiO2 were adopted in a range of 0%-5% of the mass of silica fume (SF). The experimental results showed that the addition of nano-SiO2 improves the packing density of ultra-high-performance alkali-activated concrete (UHP-AAC) and generates abundant calcium (alumino)silicate hydrate (C-(A-)S-H) gels to increase its density. Therefore, the interfacial bond strength and pull-out energy of steel fibers from UHP-AAC could be enhanced. At 2% nano-SiO2 replacement, the compressive strength of UHP-FRAAC was the highest (184.2 MPa), and its total porosity was the lowest, decreasing from 9.72% to 7.53%. The highest equivalent bond strength and strain energy density of UHP-FRAAC occurred at 2% nano-SiO2 replacement, i.e., 10.9 MPa and 72.5 kJ/m3, respectively. The maximum tensile strength of 14.5 MPa was observed at a nano-SiO2 content of 3%. Higher dosages of nano-SiO2, 3% or more, negatively affected the interfacial bond and tensile properties of UHP-FRAAC due to its agglomeration, but still exhibited higher performance than that of the plain UHP-FRAAC up to the dosage of 5%. Therefore, the optimal dosage of nano-SiO2 in UHP-FRAAC was suggested to be 2% by mass of silica fume.

Effects of SiO2 nanoparticles on root structures, gas exchange, and antioxidant activities of Cunninghamia lanceolata seedlings under drought stress

Increasing evidence shows that silicon possesses important physiological functions in plants, thus, silicon fertilizers are used widely in agriculture. However, few attentions were paid on the effects of silicon dioxide nanoparticles (SiO2NPs) on plant growth and resistance to abiotic stresses. In this present study, different amount of SiO2NPs were applied in pots with Cunninghamia lanceolata seedlings, and their root development, gas exchange, and drought resistance were investigated. These results showed that SiO2NPs treatment increased total root length, root volume, and the numbers of root tips of these seedlings under drought stress. Specific root area (SRA) and specific root length (SRL) also increased. SiO2NPs treatment altered anatomical structures of the first-order lateral roots of C. lanceolata seedlings under drought stress (i.e., increase in cortex thickness and the number of cortex layers). Under drought stress, SiO2NPs treatment increased net photosynthetic rates, stomatal conductance, intercellular CO2 concentration, and transpiration. SiO2NPs treatment also led to increase in light use efficiency and instantaneous Rubisco carboxylation rate and decrease in water use efficiency under drought stress. Under drought stress, SiO2NPs treatment resulted in increased activities of antioxidant enzymes (superoxide dismutase, catase, and peroxidase) and concentrations of antioxidants (ascorbate and glutathione), decreasing oxidative damage caused by drought stress. All together, these results suggested that SiO2NPs could be used for seedling culture of forest trees.

Effect of Silicon Nanoparticles on Tomato Plants Exposed to Two Forms of Inorganic Arsenic

In the environment arsenic (As) can be found mainly as arsenite (AsIII) and arsenate (AsV), which are highly toxic and threaten food security. Currently, there is great attention on the effects of silicon dioxide nanoparticles (SiO2 NPs) on plant development, and their ability to restrict As uptake. The results show that the two forms of As negatively impacted aerial dry biomass and fruit yield. Silicon content is lower in roots than in leaves. It is observed that AsIII is the form that accumulates the most in the root; in addition, the SiO2 NPs reduce the translocation of AsV. The data show that AsIII induced a negative effect on the uptake of Ca, P, Mg, and Cu, while SiO2 NPs enhances the accumulation of Fe and Zn when exposed to AsIII. The two forms of As do not impact chlorophyll content but increases when interacting with SiO2 NPs. Antioxidant enzymes APX, CAT, and SOD are higher in roots than in leaves. Phenols, flavonoids, and glutathione increased when SiO2 NPs interacted with AsIII in roots. H2O2 increases in roots and leaves by exposure to AsV and AsIII, and its interactions with SiO2 NPs, while in the fruit, H2O2 production decreases. As for the total antioxidant capacity ABTS is observed to increase by AsIII + SiO2 NPs only in roots. The bioactive compounds of the tomato fruits are modified by the treatments and the addition of SiO2 NPs alone increase in lycopene content. Therefore, our results reveal the negative impacts of AsIII, and that SiO2 NPs can at least partially mitigate As toxicity and reduce AsV translocation in tomatoes.

Effects of silicon dioxide nanoparticles (SiO2 NPs) on total hemocyte count and hemocyte viability of Galleria mellonella

Effects of silicon dioxide nanoparticles (SiO2 NPs) on total hemocyte count and hemocyte viability of Galleria mellonella

The Effect of Silicon Dioxide Nanoparticles Combined with Entomopathogenic Bacteria or Fungus on the Survival of Colorado Potato Beetle and Cabbage Beetles.

Three types of modified silicon dioxide nanoparticles (SiO2, 10–20 nm) with additives of epoxy, silane and amino groups, used independently and in combination with the entomopathogenic bacteria Bacillus thuringiensis subsp. morrisoni and fungus Metarhizium robertsii were tested against Colorado potato beetle (Leptinotarsa decemlineata) and cabbage beetles (Phyllotreta spp.). All three nanoparticles were found to have an entomocidal effect on Colorado potato beetle larvae and crucifer flea beetles when ingested. Increased susceptibility of insects to B. thuringiensis or M. robertsii blastospores and their metabolites was shown after exposure to the modified silicon dioxide nanoparticles. The potential of modified silicon dioxide nanoparticles to enhance the efficiency of biopesticides based on the bacteria B. thuringiensis and fungi M. robertsii is considered in the paper.

Effect of Silicon Dioxide Nanoparticles on Liver Morphology of Rats in Parenteral Administration

The issue of the potential safety of silicon dioxide nanoparticles (SDNPs) remains relevant. In this connection, in order to use the unique capabilities of silicon nanostructures for biomedical purposes, as well as to level their toxic effects, a detailed study of these nanoparticles interaction with cells and tissues in vivo is required.The aim of the research is to reveal morphofunctional changes in a rat's liver after a single parenteral administration of 12 nm silicon dioxide nanoparticles for the period of six months.Material and methods. Using general histological and immunohistochemical methods to study the rats' liver after a single parenteral administration of 1 ml of silicon dioxide nanoparticles at a dose of 7 mg/kg of body weight at a concentration of 2 mg/ml. The sections of the rats' liver were studied by general histological and immunohistochemical methods after injection of 1mL of a SDNPs saline suspension at a concentration of 2 mg/mL (7mg/kg of body weight). Control animals were injected with 1 ml of saline solution. The material was collected in 21 days, 2, 4 and 6 months months after the administration of the SDNPs and it was fixed in 10% neutral formaldehyde.Results. The formation of granulomas in the liver on the 21st day of the experiment and an increase in the number of Kupfer cells were revealed. However, by the 2nd month of the experiment, the number of granulomas significantly decreases compared to the 21st day of the experiment and continues to decrease in subsequent periods. The average size of granulomas decreases during the 2nd month of the experiment and does not change during the subsequent periods of the experiment. After 6 months of the experiment, the morphofunctional state of the liver is characterized by slightly pronounced aseptic inflammation.Conclusion. A single parenteral administration of silicon dioxide nanoparticles causes pronounced aseptic inflammation of the liver, decreasing by the 6th month of the experiment. Connective tissue remodeling in the liver is not observed at all periods of the experiment.

The Effects of Silicon Dioxide Nanoparticles and Zinc Oxide Nanoparticles on Waste Land soil Bacterial and Fungal Isolates

Objective: Different bacterial and fungal isolates were collected from the wasteland municipality site, Tambaram. The antimicrobial activity of two types of nanoparticles ZnO & SiO2 [Zinc oxide and Silicon dioxide] against several types of Gram-negative bacteria and fungi was investigated in this work.
 Methods: P. aeruginosa, B. subtilis, Penicillium oxalicum and Aspergillus fumigatus were isolated from 5 soil samples taken from three sites of Tambaram Municipality wasteland (Chennai). After collecting the samples, we used culturing and biochemical tests to identify the microbes and then used a chemical approach to make ZnO and SiO2 nanoparticles with altered structure and morphological features. Minimum inhibitory concentration (MIC) was used to assess the antibacterial activity of these nanoparticles against various microorganisms.
 Results: The best inhibition zone was found in Pseudomonas sps and Bacillus sps growth at concentrations of 10 µg/ml and 5 µg /ml of nano-ZnO, respectively, whereas the lower inhibition zone was found in Penicillium oxalicum and Aspergillus fumigatus at a dosage of 2.5 µg /ml of the same nanoparticle. It was also discovered that no inhibitory zone existed in any of the bacteria and fungi at a concentration of 10 µg /ml nano-SiO2. We found that all of the bacteria and fungi we tested were completely inhibited at a concentration of 1.25 g/ml nano-ZnO (MIC), with no antibacterial activity below this concentration. When compared to data that showed that all tested bacteria were not completely inhibited even at a concentration of 0.625 g/ml of nano-SiO2.
 Conclusion: In comparison to the two nanoparticles (ZnO and SiO2), nano-ZnO outperformed nano-SiO2 in inhibiting most bacteria and fungi at the quantities tested in wasteland soil.

EFFECT OF SILICON DIOXIDE NANOPARTICLES ON MECHANICAL PROPERTIES OF CARBON FIBER/UNSATURATED POLYESTER COMPOSITE

This study deals with the effect of silicon dioxide nanoparticles (SiO2NPs) on the mechanical properties of polymer matrix composite (PMC). The nanocomposites were prepared by adding carbon fiber (CF1.5%) to the unsaturated polyester resin, and then different proportions of SiO2 NPs (1 to 4% by weight) were added using the ultrasonic bath machine dispersion method. The results showed that the tensile strength decreases with the increase in the partial weight of SiO2. Impact resistance, bending and compressive strength were improved by (50.67%, 10.2%, and 18.14%) respectively at 2% by weight, then these properties decreased with the increase in weight ratio of (SiO2), and the hardness was improved by (19.7%) at 3% by weight. The present study aims to study the effect of adding silicon dioxide nanoparticles on the mechanical properties (tensile properties, compression, hardness and bending) of carbon fiber reinforced unsaturated polyester composite.

Effect of silicon dioxide nanoparticles and Rhizobium leguminosarum alone and in combination on the growth and bacterial blight disease complex of pea caused by Meloidogyne incognita and Pseudomonas syringae pv. pisi

Effects of SiO2 NPs and Rhizobium leguminosarum alone and in combination was observed on the Meloidogyne incognita and Pseudomonas syringae pv. pisi on pea. Inoculation of plants with M. incognita and P. syringae pv. pisi alone or in combination caused a significant reduction in plant growth, chlorophyll, carotenoid and increase proline content over un-inoculated control. Application of R. leguminosarum increased plant growth over plants without R. leguminosarum. Use of NPs as seed priming with R. leguminosarum caused a greater increase in plant growth, chlorophyll and carotenoid in plants with pathogens than application of R. leguminosarum with foliar spray. High root nodulation was observed in plants with R. leguminosarum but only few without R. leguminosarum. Both pathogens had adverse effect on root nodulation. Blight disease indices, galling and multiplication of M. incognita were reduced by NPs or R. leguminosearum but higher reduction was observed with NPs seed priming plus R. leguminosearum.

Effect of Silicon Dioxide Nanoparticles on Syrian Hamsters Infected by Opisthorchis felineus: 1H MRS Study of the Brain.

In recent years, silicon dioxide nanoparticles have been widely used in medicine and the pharmaceutical industry, however, their effect on the brain has hardly been studied. We assessed the effects of long-term consumption of 5-nm amorphous silicon dioxide nanoparticles (SiO2-NPs) by Syrian hamsters infected with the trematodes Opisthorchis felineus on the hippocampus and frontal cortex. Spectroscopic determination of brain neurometabolites, performed using a horizontal Magnetic Resonance Imaging system at 11.7 Tesla magnetic field, has shown that the ratio of the excitatory neurotransmitters (glutamate + glutamine + aspartate) to the inhibitory ones (GABA + glycine) was higher in the animals infected with O. felineus. However, pre-consumption of the SiO2-NPs solution prevented this imbalance. In addition, the protective effect of SiO2-NPs on the level of myo-inositol and glycine was found. It is concluded that the use of SiO2-NPs can neutralize the negative effects of infectious factors on the brain.

Effects of silicon dioxide nanoparticles on the performance and emission features at different injection timings using water diesel emulsified fuel

In this work the investigations were conducted to examine the effects of silicon dioxide (SiO2) nanoparticle on water diesel emulsified fuel (WDEF) for diesel engine at various injection timings. The base fuel used was D94W5S1 (Diesel 94%, water 5%, and SPAN-80 1%) in which SiO2 nanoparticles were added in the varying dosages of 25, 50, 75, and 100 ppm. The test fuels of WDEF-SiO2 were prepared with the magnetic stirrer and ultrasonication technique and experiments were conducted with the constant speed of 1500 RPM, compression ratio 18 and 23°bTDC injection timing. From the experiments, the test fuel with 50 ppm dosing D94W5S1-Si50 was found to be optimal as it results in a reduction of 52.52%, 29.32%, 69.69%, and 64.28% for NOX, smoke opacity, hydrocarbon, and carbon monoxide emissions respectively as compared to neat diesel at full load condition. Further, the optimal fuel was tested for different injection timing of 19°bTDC, 21°bTDC, 23°bTDC, and 25°bTDC. The results revealed that with the advancement of injection timing to 25°bTDC, brake thermal efficiency increases by 2.61%, brake specific fuel consumption diminishes by 3.7%. Except NOX emissions, which rises by 6.63%, other emissions of smoke opacity, hydrocarbon, and carbon monoxide reduces by 7.41%, 10%, and 50% respectively as compared to 23°bTDC. Finally, it can be concluded that WDEF incorporated with optimal dosing of silicon dioxide nanoparticle at advanced injection timing remarkably reduces the emissions and enhances the performance features.

Management of bacteria Pectobacterium carotovorum, Xanthomonas campestris pv. carotae, and fungi Rhizoctonia solani, Fusarium solani and Alternaria dauci with silicon dioxide nanoparticles on carrot

ABSTRACT Diseases of carrot (Daucus carota L.) that cause yield losses include bacterial soft-rot incited by Pectobacterium carotovorum pv. carotovorum (Jones) Waldee; bacterial leaf blight incited by Xanthomonas campestris pv. carotae (Pammel) Dowson; fungal leaf blight incited by Alternaria dauci (J.G. Kühn) J.W. Groves & Skolko; rot incited by Fusarium solani (Martius) Sacc., and crown rot incited by Rhizoctonia solani Kuhn. Nanoparticles are used to increase plant growth and provide protection against plant pathogens on various crops, but their effectiveness on carrot is not well understood. Effect of silicon dioxide nanoparticles (SiO2 NPs) after seed were primed, or applied to foliage, on inhibition of P. carotovorum, X. campestris pv. carotae, A. dauci, F. solani or R. solani, on growth, chlorophyll, carotenoid and proline contents of carrot were determined. Inoculation of plants with all pathogens reduced shoot and root dry weights, and chlorophyll and carotenoid contents over uninoculated controls. Inoculation of R. solani caused the greatest reduction (65.18%) in root dry weight and X. campestris pv. carotae the least (20.13%). Seed priming or foliar application with SiO2 NPs increased plant growth, and chlorophyll and carotenoid contents in inoculated plants, and the uninoculated control. Foliar application was better than seed priming in increasing growth, and chlorophyll and carotenoid contents of inoculated plants. The least increase in root dry weight (17.09%) was when plants derived from SiO2 NPs primed seed were inoculated with P. carotovorum, and the most was with foliar-applied SiO2 NPs against R. solani (85.29%). Individual inoculation of plants with pathogens caused increased proline content over the uninoculated control. Proline contents were further increased by the application of SiO2 NPs. Soft rot and bacterial blight index was 3 of 5 when plants were inoculated with P. carotovorum and X. campestris pv. carotae, respectively. Leaf blight/crown rot and root-rot indices were 4 of 5 when inoculation was with A. dauci, F. solani, and R. solani. Application of SiO2 NPs could be useful for the control of bacteria and fungi infecting carrot.

Influence of silicon dioxide nanoparticles on the fertility of heifers in frontal insemination

Investigation of the effect of silicon dioxide nanoparticles on the processes of reproduction in cattle was performed on heifers of the breeding age of red steppe breed. Synchronization of the sexual activity by double use of the estrophan, prostaglandin drug, with addition of a releasing hormone (surfagon) to the scheme before insemination was performed in the control and experimental groups. Heifers were simultaneously injected with a solution of silicon dioxide nanoparticles with estrophan injection intramuscularly in the experimental group. All animals were inseminated in frontal, rectocervical way, with deep frozen sperm, twice. Heifers were taken the blood at estrophan injections and before insemination to study the dynamics of progesterone levels. As a result, 50.0% of the heifers were fertilized from frontal insemination in the control group, in the experimental one - 70.0%, that is, the increase in fertility with the use of silicon dioxide nanoparticles was 20.0%. Progesterone level in blood serum of the heifers on the 11th day of the experiment exceeded the initial by 23.5–69.2%, and before insemination it dropped by 38.1 to 50.0% compared with the maximum value. These changes were more significant in animals of the experimental group. Presumably, the use of silicon dioxide nanoparticles increases the hormonal activity of heifers’ ovaries, which contributes to their higher fertility during insemination.

Silicone dioxide nano-particles enhance toxicity of lead on oxidative and nitro-oxidative stress

Introduction. Nanoparticles are widely used in scientific research, industry and medicine. The established capability of nanoparticles to increase the transport of chemicals and drugs into cells and through the body barriers makes the possibility of potentiating the chemical contaminants toxicity in case of their simultaneous intake an urgent matter.The aim of the study – to learn the effect of silicon dioxide nanoparticles on the ability of chemical lead acetate toxicant to cause oxidative and nitro-oxidative stress in blood serum and liver of experimental rats.Research Methods. Experiments were conducted on 40 white outbred male rats, 150–160 g in weight, which were divided into 4 groups. Animals of the group (control) 1 were daily administered with saline solution intragastrically. The rats of the group 2 were administered with colloidal solution of silicon dioxide nanoparticles in a dose of 50 mg/kg of body weight. Animals of the group 3 were injected with lead acetate in aqueous solution in a dose of 20 mg/kg of body weight (expressed as lead), the group 4 – with solution of silicon dioxide nanoparticles with lead acetate daily during 3 weeks at the same doses. The total activity of NO-synthase, catalase, superoxide dismutase, NOx content, thiobarbituric acid reactive substances, oxidized modified proteins, reduced glutathione, ceruloplasmin and total serum antioxidant activity were determined in serum and liver. The obtained parameters were statistically processed.Results and Discussion. It was proved that silicon dioxide nanoparticles did not influence the studied parameters considerably. The administration of lead acetate to rats caused significant changes of all indices. However, the maximum changes of the parameters were evidenced in the group of animals in cases of simultaneous administration of silicon dioxide nanoparticles and lead acetate. In that case, the content of thiobarbituric acid reactive substances, NOx, oxidized modified proteins, reduced glutathione, and superoxide dismutase activity in blood serum and liver homogenate of rats varied significantly compared with the parameters of the group of animals that were administered with the chemical toxicant only.Conclusion. Silicon dioxide nanoparticles enhance the capability of the chemical lead acetate toxicant to cause oxidative and nitro-oxidative stress in blood serum and liver of the experimental rats.

Effect of Silicon Dioxide Nanoparticles on Growth Improvement of Banana Shoots In Vitro within Rooting Stage

Silicon (Si) is considered as one of the most vital elements for the plant life. Nanoparticles interact with plants causing many changes morphologically and physiologically based on the properties of NPs. Nano silicon dioxide (with diameter 20:40 nm) was synthesized from sodium metasilicate and inclusively characterized. Murashige and Skoog media were supplemented with nano SiO2 in four levels (0, 50,100 and 150 ppm) in addition to IBA in order to find the interaction mechanism between nanosilica and banana plants under control condition in vitro. The efficiency of Nano SiO2 was evaluated in terms of its impact on some morphological traits, total chlorophyll content and total phenolic compounds were also assessed. Results showed a positive effect of silicon dioxide nanoparticles on rooting rate and photosynthesis pigments. Overall, application of Silicon in the nano scale was beneficial in improving growth of banana.

Effects of Silicon Dioxide Nanoparticles on Biological and Physiological Characteristics of Medicago sativa L. nothosubsp. varia (Martyn) in Natural Agroclimatic Conditions of the Subtaiga Zone in Western Siberia

This study is aimed at investigating effects of pre-sowing seed treatment of Medicago sativa L. nothosubsp. varia (Martyn) Arcang., Sarga variety, with SiO2 nanoparticles produced by laser ablation in a liquid. The purpose of the study is to investigate effects of suspensions of silicon dioxide nanoparticles at different concentrations on biological and physiological characteristics of M. sativa L. nothosubsp. varia in natural agroclimatic conditions of the subtaiga zone in Western Siberia. The study has shown that the pre-sowing seed treatment of M. sativa L. nothosubsp. varia (Martyn) Arcang., Sarga variety, with silicon dioxide nanoparticles at different concentrations has a stimulating effect on contents of chlorophyll, carotenoids, and non-steroidal phytoestrogens in a vegetative part of the plant, as well as biometric and morphometric parameters, yield, and phytoremediation potential. It has been established that M. sativa is hypersensitive to the studied pre-sowing seed treatment with suspensions of SiO2 nanoparticles at different concentrations, which determines the specificity of changes in physiological parameters, including increase in contents of photosynthetic pigments, isoflavonoids, and hydroxycinnamic acids in the plant exposed to suspensions of SiO2 nanoparticles. A significant increase in the content of biologically active substances under the influence of SiO2 nanoparticles indicates the high sensitivity of M. sativa and the specific role of nanoparticles in stimulating the biosynthesis of biologically active substances. The findings of the study demonstrate that pre-sowing seed treatment of M. sativa L. nothosubsp. varia (Martyn) Arcang., Sarga variety, with ultrafine silicon dioxide nanoparticles at different concentrations, had a stimulating effect on biological and physiological characteristics of M. sativa L. nothosubsp. varia (Martyn) Arcang., Sarga variety.

The combined effects of silicon dioxide nanoparticles and cold air exposure on the metabolism and inflammatory responses in white adipocytes.

The potential hazard of nanoparticles (NPs) from air pollution has attracted widespread attention. Though the toxicology of NPs has been intensively studied, few works have been reported on the combined effect of silicon dioxide (SiO2) NPs and cold air exposure at the cellular level. Herein, we evaluated the combined effect of SiO2 NPs and cold exposure on metabolism and the inflammatory responses in white adipocytes by qRT-PCR in vitro. After SiO2 NP or cold exposure, there were significant changes in the expressions of adipogenic genes and proinflammatory cytokine genes in white adipocytes. The mRNA levels of IL-6, IL-8, TNF-α and IL-1β were upregulated by SiO2 NP or cold exposure, and more so in the combined group. The expressions of the proinflammatory cytokine genes IL-6, IL-8, TNF-α and IL-1β increased highly significantly (P < 0.01) in the SiO2 NP alone group and the combined group, compared with the control. The expressions of the cold group tended to be upregulated significantly compared with the control in IL-6 (P < 0.01) and IL-8 (P < 0.05). The results demonstrated that there was antagonistic effect between SiO2 NPs and cold air on the plasticity and metabolism in white adipocytes, where the main effect of cold air on the plasticity and metabolism was significant (P < 0.05). However, there was a synergistic effect between SiO2 NPs and cold air on the toxic effects in white adipocytes, in which the main effect of SiO2 NPs on the toxic effects was significant (P < 0.05). In conclusion, SiO2 NPs combined with cold exposure induced a stronger inflammatory response and influenced the plasticity and metabolism in white adipocytes, accompanied by more serious health hazards.

Effects of silicon dioxide nanoparticles and nanodiamonds on intestinal commensal bacteria

Nanomaterials and nanotechnology have been widely applied in biological and biomedical field. Recent studies reveal that many nanomaterials possess antibacterial activities. While most of these studies focus on the ability of nanomaterials to inhibit the growth of pathogenic bacteria in vitro , few of them test the effects of nanomaterials on intestinal commensal bacteria. Here, we report that SiO2 nanoparticles, but not nanodiamonds, can inhibit the growth of Drosophila intestinal commensal bacteria in vitro . Surprisingly, dietary SiO2 nanoparticles of same dosage fail to display similar effects in Drosophila larvae. These results imply that the antibacterial effect of nanomaterials differs in vitro and in vivo . Comparing to in vitro environment, intestine can provide better environment for the growth of intestinal commensal bacteria and prevent the effects from exogenous nanomaterials.