Effects of nano zinc oxide and nano chitosan on the taste masking paracetamol granules.

OBJECTIVE: The purpose of this study is to investigate the taste masking of Paracetamol granules in the range of 250-850 µm, coated by two nanocomposites prepared from Eudragit® E100, nanozinc oxide, and nanochitosan, respectively, from 1 to 5% by the weight of the granules. METHODS: In this study, Paracetamol granules were coated in several formulas with two different types of nanocomposites (polymeric and mineral) on two sizes of granules to reduce bitter taste and with the FBC method and pH-sensitive polymers (Eudragit® E100). RESULTS: The effect of nanoparticles (Nano zinc oxide and Nanochitosan) on taste-masking Paracetamol was studied with dissolution-coated granules in vitro by simulating in the oral (pH 6.8) range. Based on the results of the studies, the rate of drug release was confirmed by the taste test, and the formulated granule with 5% nano-chitosan (F14) had the best bitter taste mask function of all samples. These results were also confirmed by scanning electron microscopy (SEM) analysis, which showed a smoother and more stable surface than the samples obtained from other formulations. CONCLUSION: In the comparison of the release of two types of nanocomposites in the dissolution test, it was shown that the type B granules of Paracetamol's 5% nano-chitosan-coated granule (F14) were released 99% less than Paracetamol's 5% nano-ZnO-coated granule (F11). and Paracetamol's 1% nano-chitosan-coated granule (F12) was released 91% less than Paracetamol's 1% nano-ZnO-coated granule (F9). The results showed that nano-chitosan-coated granules have better coverage of bitter taste instead of nano-ZnO.

How Nano-ZnO Affect Tomato Fruits (Solanum lycopersicum L.)? Analysis of Selected Fruit Parameters.

Tomato (Solanum lycopersicum L.), as one of the most valuable horticulture crops, was chosen to investigate the effect of nanoparticles (NPs) in the form of nano-ZnO combined with conventional fertilizer on the quality of tomato fruits, including their antioxidant potential (total antioxidant activity, lycopene and ß-carotene content), sugars content and allergenic potential (profilin and Bet v 1 content). Nano-ZnO was implemented during plant cultivation, applied by foliar spraying or directly via soil, at three different concentrations (50, 150 and 250 mg/L). The obtained results suggest that the usage of NPs during tomato plant cultivation had minor impacts on parameters such as total antioxidant activity or the content of selected allergens. Even though the total antioxidant activity was not affected by nano-ZnO, the malondialdehyde activity (MDA) content was notably decreased in fruits under nano-ZnO treatment. The content of lycopene and ß-carotene was significantly affected by the use of nano-ZnO. Moreover, the usage of nano-ZnO significantly increased the total sugar content in fruits treated with nanoparticles via foliar spraying. Based on the obtained results, it can be stated that nano-ZnO, regardless of the method of application, significantly affected tomato fruits which can be beneficial for fruit production.

The Antioxidant Potential of Tomato Plants (Solanum lycopersicum L.) under Nano-ZnO Treatment.

Tomato (Solanum lycopersicum L.) is one of the most valuable horticulture crops, consumed in both its raw and processed forms. To increase yield and efficiency, conventional and organic fertilizers are utilized in modern agriculture. Traditional fertilizers increase crop yield but are harmful to the environment. These circumstances motivate the pursuit of an alternate solution. The purpose of this research was to investigate how the application of nanoparticles (nano-ZnO) combined with conventional fertilizer influence tomato plants' development, including the antioxidant potential of cultivated plants. Three factors such as different types of cultivars, dosage of applied nano-ZnO solution and the method of nanoparticles application were implemented. Multiple analysis of selected antioxidants content and their activities such as malondialdehyde (MDA), flavonoids, polyphenols, ascorbic acid, peroxidase (POX), superoxide dismutase (SOD) or catalase (CAT) were analyzed. The obtained data exhibited that all examined parameters were strongly dependent on three implemented factors: concentration of nano-ZnO suspension, the type of cultivated tomato and the method of nanoparticles application. For instance, the accumulation of MDA in cultivated plants was different among plants under nanoparticles treatment, but in one specific case (Malinowy Bossman cultivar treated with 50 mg/L nano-ZnO suspension) the content of this marker was decreased by 34% in comparison to the corresponding control. Nevertheless, the results presented in this study showed that the usage of certain doses of nano-ZnO suspension may increase the antioxidant potential of tomato plants.

Dietary carbon loaded with nano-ZnO alters the gut microbiota community to mediate bile acid metabolism and potentiate intestinal immune function in fattening beef cattle.

BACKGROUND: To our knowledge, carbon loaded with nano-ZnO (NZnOC) represents a new nutritional additive for the animal husbandry industry. However, the mechanism by which NZnOC mediates beef cattle growth and intestinal health is not fully understood. This study aimed to investigate the effects of carbon loaded with nano-ZnO (NZnOC) supplementation on growth performance, gut microbiota, bile acid (BAs) metabolism and intestinal immunity in fattening cattle. Twenty cattle (16 ± 0.95 months) were randomly assigned to two dietary groups: CON (control, without feed additive) and NZnOC (diet supplemented with 80 mg NZnOC/kg diet dry matter basic) for 60 d. The colon digesta microbiota composition and BAs concentration were determined by microbiota metagenomics and gas chromatography methods, respectively. RESULTS: The results showed that the NZnOC-supplemented cattle had greater final weight, average daily gain and gain-to-feed ratio than those in the CON group. Cattle fed the NZnOC diet had a higher relative abundance of the secondary BAs synthesizing phyla Firmicutes, Tenericutes and Actinobacteria than those fed the CON diet. Dietary supplementation with NZnOC increased the relative abundance of the secondary BAs synthesis microbiota genera Clostridium, Ruminococcus, Eubacterium, and Brevibacillus in colon digesta. Cattle fed the NZnOC diet had increased activities of 3α-hydroxysteroid dehydrogenase (EC: 1.1.1.52) and bile acid-CoA ligase BaiB (EC: 6.2.1.7) in the colon digesta compared with those fed the CON diet. The primary BAs taurocholic acid, taurochenodeoxycholic acid and taurodeoxycholate acid were significantly decreased by dietary NZnOC supplementation, while the secondary BAs deoxycholic acid, taurolithocholic acid, beta-muricholic acid, 12-ketolithocholic acid and ursodeoxycholic acid were significantly increased. Dietary supplementation with NZnOC increased the mRNA abundance of G protein-coupled bile acid receptor 1, protein kinase cAMP-activated catalytic subunit alpha, cyclic-AMP response element binding protein 1 and interleukin (IL)-10 in the colon mucosa of cattle, while the mRNA abundance of tumor necrosis factor and IL-1ß were significantly decreased. CONCLUSIONS: In summary, dietary supplementation with NZnOC can facilitate the growth performance and intestinal immune function of cattle by improving BAs metabolism. NZnOC can be supplemented in the diet as a safe regulator of gut microbiota and as a feed additive in the ruminants industry.

The Effect of Nano-ZnO on Seeds Germination Parameters of Different Tomatoes (Solanum lycopersicum L.) Cultivars.

The agriculture sector faces numerous problems. One of the beforementioned problems relates to the proper crop plants' fertilization. The conventional bulk fertilizers are becoming less effective and have a negative impact on the environment. Nanomaterials such as zinc oxide nanoparticles (ZnO NPs) are widely used in various sectors such as medicine or electronics. Several studies indicate that nano-ZnO may likewise be considered as a potential nanofertilizer. In present research, an attempt was made to study the influence of two different sized ZnO NPs (<50 nm and <100 nm) on the seed germination of chosen tomato (Solanum lycopersicum) cultivars. The seeds of three cherry tomato cultivars were placed on a Petri dish with the NPs suspensions (0, 50, 150, and 250 mg/L) in order to examine the influence on germination parameters at a certain size of NPs and at a chosen concentration. In addition, within this study, we verified that the implicated conditions have the exact impact on all three cultivars. The obtained results indicate that all the factors affect the seed sprouting, however, this process mainly depends on the type of tomato cultivar and the size of the used nanoparticles. The parameter of the germination percentage (GP) was the only of the assumed factors that did not influence it significantly. Nevertheless, the values of other examined parameters such as the MGT, GRI, CVG, or VI depend strongly on all assumed features including the type of chosen cultivar. The obtained results vary significantly between all cultivars which indicates that the plants from the same family may require different conditions for optimal growth. In this research the <50 nm ZnO nanoparticles had more beneficial influence on sprouting parameters then parallelly used <100 nm ZnO nanoparticles.

Yolk-Shell Nano ZnO@Co-Doped NiO with Efficient Polarization Adsorption and Catalysis Performance for Superior Lithium-Sulfur Batteries.

Achieving strong adsorption and catalytic ability toward polar lithium polysulfide species (LiPSs) of the sulfur host in lithium-sulfur (Li-S) batteries is essential for their electrochemical cyclic stability. Herein, a strategy of "self-termination of ion exchange" is put forward to synthesize the novel yolk-shell sulfur host composed of ZnO nanoparticles confined in Co-doped NiO (CDN) polyhedron (ZCCDN). After sulfur infiltration, the obtained S/ZCCDN cathode achieves excellent performance of 738.56 mAh g-1 after 500 cycles at 0.5 C with a very low capacity decay rate of only 0.048% per cycle. Even at 1 C, 501.05 mAh g-1 could be retained after 500 cycles, suggesting a capacity decay ratio of only 0.076% per cycle. The good cycle performance is attributed to the improved LiPSs' conversion kinetics, which originates from ZCCDN's sturdy chemical affinity and strong catalytic ability to polar LiPSs. For the first time, by electron holography, the local interfacial polarization electric field is clarified to be existed in the material which is conducive to the capture of LiPSs and the migration of electrons and Li+ from the mesopores. This work provides a rational way for the use of zeolitic imidazolate frameworks (ZIFs) and development of cathode materials for Li-S batteries.

NanoZnO-modified titanium implants for enhanced anti-bacterial activity, osteogenesis and corrosion resistance.

Titanium (Ti) implants are widely used in dentistry and orthopedics owing to their excellent corrosion resistance, biocompatibility, and mechanical properties, which have gained increasing attention from the viewpoints of fundamental research and practical applications. Also, numerous studies have been carried out to fine-tune the micro/nanostructures of Ti and/or incorporate chemical elements to improve overall implant performance. Zinc oxide nanoparticles (nano-ZnO) are well-known for their good antibacterial properties and low cytotoxicity along with their ability to synergize with a variety of substances, which have received increasingly widespread attention as biomodification materials for implants. In this review, we summarize recent research progress on nano-ZnO modified Ti-implants. Their preparation methods of nano-ZnO modified Ti-implants are introduced, followed by a further presentation of the antibacterial, osteogenic, and anti-corrosion properties of these implants. Finally, challenges and future opportunities for nano-ZnO modified Ti-implants are proposed.

Preparation and characterization of chitosan/Nano-ZnO composite film with antimicrobial activity.

Chitosan is promising material for making food packaging film with antimicrobial activity. However, chitosan film usually has limited mechanical and antimicrobial properties and higher water solubility. To improve the performance of chitosan film, in this work, chitosan composite films were prepared by incorporating different sizes of zinc oxide particles of 5 µm, 100 nm, and 50 nm. The films were characterized by scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, and mechanical analysis. Antimicrobial assay of the chitosan and CTS/nano-ZnO composite films against Escherichia coli and Staphylococcus aureus show that the composite chitosan films have better antibacterial activity. The film containing 0.3% of 50 nm zinc oxide particles showed the best inhibition rate, suggesting that smaller sizes of nano-ZnO particles have better bacteriostatic activity and potent application as an antibacterial additive ingredient.

Dietary Nano-ZnO Is Absorbed via Endocytosis and ZIP Pathways, Upregulates Lipogenesis, and Induces Lipotoxicity in the Intestine of Yellow Catfish.

Nano-sized zinc oxide (nano-ZnO) affects lipid deposition, but its absorption patterns and mechanisms affecting lipid metabolism are still unclear. This study was undertaken to investigate the molecular mechanism of nano-ZnO absorption and its effects on lipid metabolism in the intestinal tissues of a widely distributed freshwater teleost yellow catfish Pelteobagrus fulvidraco. We found that 100 mg/kg dietary nano-ZnO (H-Zn group) significantly increased intestinal Zn contents. The zip6 and zip10 mRNA expression levels were higher in the H-Zn group than those in the control (0 mg/kg nano-ZnO), and zip4 mRNA abundances were higher in the control than those in the L-Zn (50 mg/kg nano-ZnO) and H-Zn groups. Eps15, dynamin1, dynamin2, caveolin1, and caveolin2 mRNA expression levels tended to reduce with dietary nano-ZnO addition. Dietary nano-ZnO increased triglyceride (TG) content and the activities of the lipogenic enzymes glucose 6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGD), and isocitrate dehydrogenase (ICDH), upregulated the mRNA abundances of lipogenic genes 6pgd, fatty acid synthase (fas), and sterol regulatory element binding protein 1 (srebp1), and reduced the mRNA expression of farnesoid X receptor (fxr) and small heterodimer partner (shp). The SHP protein level in the H-Zn group was lower than that in the control and the L-Zn group markedly. Our in vitro study indicated that the intestinal epithelial cells (IECs) absorbed nano-ZnO via endocytosis, and nano-Zn-induced TG deposition and lipogenesis were partially attributable to the endocytosis of nano-ZnO in IECs. Mechanistically, nano-ZnO-induced TG deposition was closely related to the metal responsive transcription factor 1 (MTF-1)-SHP pathway. Thus, for the first time, we found that the lipogenesis effects of nano-ZnO probably depended on the key gene shp, which is potentially regulated by MTF1 and/or FXR. This novel signaling pathway of MTF-1 through SHP may be relevant to explain the toxic effects and lipotoxicity ascribed to dietary nano-ZnO addition.

Effect of ultrahigh-pressure treatment on the functional properties of poly(lactic acid)/ZnO nanocomposite food packaging film.

BACKGROUND: Our living environment is being increasingly polluted by petroleum-based plastics and there is an increasing demand for biodegradable food packaging. In this study, the effect of various ultrahigh-pressure (UHP) treatments (0, 200 and 400 MPa) on the microstructure and thermal, barrier and mechanical properties of poly(lactic acid) (PLA)/ZnO nanocomposite films was studied. RESULTS: The film-forming solution was processed using UHP technology. The crystallinity, strength and stiffness of the composite film after UHP treatment increased. In addition, barrier property analysis showed that the UHP treatment significantly (P < 0.05) reduced the oxygen permeability and water vapor permeability (WVP) coefficient of the PLA/ZnO nanocomposite film. Furthermore, the WVP value of the film treated at 400 MPa (50 g kg-1 nano-ZnO content) was the lowest and reduced by 47.3% compared with that of pure PLA film. The improvement in these properties might be due to the interaction between nano-ZnO and PLA matrix promoted by UHP treatment. CONCLUSIONS: Therefore, the application of UHP technology on the film-forming solution could improve the crystallinity and functional properties of the nanocomposite film, and has great potential in the production of food packaging films with ideal functions. © 2021 Society of Chemical Industry.

Effects of different concentrations of coated nano zinc oxide material on fecal bacterial composition and intestinal barrier in weaned piglets.

BACKGROUND: Coated nano zinc oxide (Cnz) is a new feed or food additive, which is a potential replacement for a pharmacological dose level of ZnO. This study evaluated the positive effects of different concentrations of Cnz on the intestinal bacterial core, enterobacterial composition and mucosal barrier function in a pig model. RESULTS: Microbiota sequencing results showed that Cnz could significantly alter the intestinal microbiota composition and metabolism. Besides increasing the richness indices (ACE and Chao1), 10% Cnz could protect the intestinal mucosal barrier through increasing the expression of occludin and zonula occludens-1 in the small intestine, increase the abundance of Lachnospiraceae UCG-004 and decrease the abundance of Ruminococcus flavefaciens compared to high ZnO diet and 5% Cnz material. CONCLUSIONS: Cnz material at 10% supplementation is more effective than a level of 5% Cnz in increasing intestinal barrier through affecting gut microbiota. © 2020 Society of Chemical Industry.

TRPC6-Mediated Ca2+ Entry Essential for the Regulation of Nano-ZnO Induced Autophagy in SH-SY5Y Cells.

Recently, possible applications of zinc oxide nanoparticles (nano-ZnO) have been extensively studied owing to their ease of synthesis. However, the effect of nano-ZnO on the nervous system remains unclear. This study investigates the action of nano-ZnO on SH-SY5Y neuroblastoma cells. We found that nano-ZnO (0-50 µg/mL) induced a significant decrease in cell survival rate in a dose-dependent manner, and increased LC3 puncta formation. However, the apoptosis was not affected by nano-ZnO, because the protein levels of cytochrome c, caspase-3, Bcl-xL, and BAX were not varied by the nano-ZnO treatment. Nano-ZnO increased Ca2+ entry and the expression of TRPC6.The results suggested that nano-ZnO increased [Ca2+] through the TRPC-dependent Ca2+ influx, since Ca2+ influx can be prevented by the TRPC inhibitor. Furthermore, cells on nano-ZnO-treatment groups displayed loss of F-actin in a dose dependent manner, which also could be prevented by TRPC inhibitor. Herein, we demonstrated that the nano-ZnO activated TRPC6 channel, thereby increasing the Ca2+ flux and resulting in increased autophagy. Nano-ZnO could have possible anticancer effects in neuroblastoma by inhibiting the proliferation of tumor cells. However, we should also pay attention toward the biosecurity of nano materials.

Preparation and Anti-Mold Properties of Nano-ZnO/Poly(N-isopropylacrylamide) Composite Hydrogels.

The aim of this study was to overcome drawbacks of the inhomogeneous dispersion and facile agglomeration of nano-ZnO/poly(N-isopropylacrylamide) composite hydrogels (nano-ZnO/PNIPAm composite hydrogels) during synthesis and improve the anti-mold property of the nano-ZnO/PNIPAm composite hydrogels. Here, nano-ZnO/PNIPAm composite hydrogels were prepared by the radical polymerization method. Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), differential scanning calorimeter (DSC), and dynamic light scattering (DLS) were used to characterize the effects of different dispersants on the particle sizes, dispersions, and phase transition characteristics of the nano-ZnO/PNIPAm composite hydrogels. The anti-mold properties of nano-ZnO/PNIPAm composite hydrogels were studied. Results revealed that the nano-ZnO/PNIPAm composite hydrogel prepared by the addition of nano-ZnO dispersion liquid exhibited the smallest particle size, the most homogeneous dispersion, and the highest stability. The addition of the dispersant did not change the phase transition characteristics of nano-ZnO/PNIPAm, and the nano-ZnO/PNIPAm composite hydrogels (Pf) exhibited good anti-mold properties to the bamboo mold.

Highly Sensitive Impact Sensor Based on PVDF-TrFE/Nano-ZnO Composite Thin Film.

A thin film of polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) has good flexibility and simple preparation process. More importantly, compared with PVDF, its piezoelectric ß-phase can be easily formed without mechanical stretching. However, its piezoelectricity is relatively lower. Therefore, at present, PVDF-TrFE is always compounded with other kinds of piezoelectric materials to solve this problem. The effect of nano-ZnO doping amount on the sensing characteristics of the piezoelectric films was studied. PVDF-TrFE/nano-ZnO films with different nano-ZnO contents were prepared by spin coating process and packaged. The dispersion of nano-ZnO dopants and the crystallinity of ß-phase in piezoelectric films with different nano-ZnO contents were observed by scanning electron microscopy and X-ray diffraction, and the piezoelectric strain constants and dielectric constants were measured, respectively. The effect of different nano-ZnO contents on the output performance of the piezoelectric sensor was obtained by a series of impact experiments. The results show that the piezoelectric strain constant and dielectric constant can be increased by doping nano-ZnO in PVDF-TrFE. Moreover, the doping amount of nano-ZnO in PVDF-TrFE is of great significance for improving the piezoelectric properties of PVDF-TrFE/nano-ZnO thin films. Among the prepared piezoelectric films, the output voltage of PVDF-TrFE/nano-ZnO piezoelectric sensor with 7.5% nano-ZnO doping amount is about 5.5 times that of pure PVDF-TrFE. Thus, the optimal range of the doping amount for nano-ZnO is about 4⁻10%.

Ti and Zn Content in Moss Shoots After Exposure to TiO2 and ZnO Nanoparticles: Biomonitoring Possibilities.

To assess the uptake of nanoparticles by moss shoots and the possibility of biomonitoring the moss of nanoparticle pollution, two moss species frequently used in biomonitoring surveys [Hylocomium splendens (Hedw.) Schimp. and Pleurozium schreberi (Brid.) Mitt.] were repeatedly exposed to known concentrations of either nano-TiO2 or nano-ZnO suspensions. The interspecies differences were assessed by exposing both the species to 1 g L-1 nano-ZnO suspension, H. splendens samples were also exposed to either 0.1 g L-1 or 1 g L-1 suspension of nano TiO2. The exposed samples were analysed for Zn or Ti content using Inductively Coupled Plasma-Atomic Emission Spectroscopy. Both species showed a similar accumulation pattern, H. splendens being a slightly better accumulator. The washing suggests that Ti successfully penetrated the interior of the gametophyte. Since the relationship between the exposure and accumulation is linear, moss biomonitoring is, hereby, considered to be a viable, novel technique in nanoparticle pollution assessment.

Parental transfer of perfluorooctane sulfonate and ZnO nanoparticles chronic co-exposure and inhibition of growth in F1 offspring.

Perfluorooctane sulfonate (PFOS) and ZnO nanoparticles (Nano-ZnO) are two kinds of environmental contaminants that have been frequently detected in natural waters. The potential joint toxicity of PFOS and nano-ZnO remains to be fully elucidated. The objective of this study was to evaluate co-exposure effects of PFOS and nano-ZnO on growth in initial generation (F0) zebrafish after chronic exposure and to examine possible parental transfer of PFOS and nano-ZnO transgenerational effects on the growth of first generation (F1) larvae. When zebrafish (2 h after incubation) were exposed to single- and co-exposure groups for 120 days, bioconcentration resulted in significantly less growth as measured by body length and body weight, higher mortality, and less spawning in the F0 generation. These effects were possibly due to the down-regulation of the expression of Vtg1 genes along with a sex hormone (T/E2) involved in the hypothalamus-pituitary-gonad (HPG) axis. Furthermore, after long-term exposure, less fertilization, less hatching, greater mortality and more malformation were found in the F1 generation. The down-regulation of genes and hormones might be responsible for transgenerational toxicity. This study suggested that chronic exposure to PFOS and nano-ZnO adversely impacts development, reproduction in the F0 generation, and offspring embryonic growth.

Toxicity assessment and histopathological analysis of nano-ZnO against marine fish (Mugilogobius chulae) embryos.

The toxicity of nano-materials has received increasing attention in recent years. Nevertheless, relatively few studies have focused on their oceanic distributions and toxicities. In this study, we assessed nano-ZnO toxicity in marine organisms using the yellowstriped goby (Mugilogobius chulae). The relative differences in nano-ZnO dissolution and dispersal in seawater and fresh water were also investigated. The effects of nano-ZnO on embryonic development, deformity, hatching, mortality, and histopathology were analyzed. In addition, the effects of the Zn2+ concentration on M. chulae hatching and mortality were compared. The results showed that nano-ZnO had higher solubility in seawater than in fresh water. Nano-ZnO significantly inhibited hatching. By the fifth day of exposure, the LC50 of nano-ZnO was 45.40mg/L, and the mortality rate spiked. Hatching inhibition and lethality were dose-dependent over a range of 1-25mg/L nano-ZnO. Zn2+ inhibited hatching and increased lethality, but its effects were weaker than those of nano-ZnO at the same concentrations. Nano-ZnO also induced spinal bending, oedema, hypoplasia, and other deformities in M. chulae embryos and larvae. Histopathology revealed vacuolar degeneration, hepatocyte and enterocyte enlargement, and morphological abnormalities of the vertebrae. Therefore, nano-ZnO caused malformations in M. chulae by affecting embryonic growth and development. We conclude that nano-ZnO toxicity in seawater was significantly positively correlated with the associated Zn2+ concentration and sedimentary behaviour. The toxicity of nano-ZnO was cumulative and showed a critical point, beyond which embryonic and developmental toxicity in marine fish was observed.

Does seed size and surface anatomy play role in combating phytotoxicity of nanoparticles?

Rapid utilization of nano-based products will inevitably release nanoparticles into the environment with unidentified consequences. Plants, being an integral part of ecosystem play a vital role in the incorporation of nanoparticles in food chain and thus, need to be critically assessed. The present study assesses the comparative phytotoxicity of nanoparticle, bulk and ionic forms of zinc at different concentrations on selected plant species with varying seed size and surface anatomy. ZnO nanoparticles were chosen in view of their wide spread use in cosmetics and health care products, which allow their direct release in the environment. The impact on germination rate, shoot & root length and vigour index were evaluated. A concentration dependent inhibition of seed germination as well as seedling length was observed in all the tested plants. Due to the presence of thick cuticle on testa and root, pearl millet (xerophytic plant) was found to be relatively less sensitive to ZnO nanoparticles as compared to wheat and tomato (mesophytic plants) with normal cuticle layer. No correlation was observed between nanoparticles toxicity and seed size. The results indicated that variations in surface anatomy of seeds play a crucial role in determining the phytotoxicity of nanoparticles. The present findings significantly contribute to assess potential consequences of nanoparticle release in environment particularly with major emphasis on plant systems. It is the first report which suggests that variations observed in phytotoxicity of nanoparticles is mainly due to the predominant differences in size and surface anatomy of tested plant seeds and root architecture. Effect of various concentrations of nano ZnO, bulk ZnO and zinc sulphate on the growth of pearl millet (A), tomato (B) and wheat (C) seedlings.

Subcritical water oxidation of 6-aminopenicillanic acid and cloxacillin using H2O2, K2S2O8, and O2.

This study was undertaken to investigate the degradation of 6-aminopenicillanic acid (6-APA) and cloxacillin in aqueous solution by the combined effect of subcritical water and the oxidising agents O2, H2O2, and K2S2O8. Nano ZnO was used as a solid catalyst. Response surface methodology was used to determine the optimum experimental parameters (temperature, treatment time, and concentration of oxidising agent). For 6-APA, the maximum organic carbon (TOC) removal rates of 83.54%, 81.11% and 42.42% were obtained using H2O2, K2S2O8, and O2, respectively. For cloxacillin, the maximum TOC removal rates of 67.69%, 76.02% and 14.45% were obtained using H2O2, K2S2O8, and O2, respectively. Additionally, the impact of nano and commercial ZnO on TOC removal rates was determined. Secondary ions produced during the degradation process-such as nitrite, nitrate, sulphate and chloride-were determined using ion chromatography.

Enhanced ozonation degradation of atrazine in the presence of nano-ZnO: Performance, kinetics and effects.

Enhanced ozonation degradation of atrazine (ATZ) with nano-ZnO (nZnO) as catalyst and the influences of the operational parameters have been investigated through semi-continuous experiments in this study. The results demonstrated that the combination of ozone (O3) and nZnO showed an obvious synergetic effect and the ATZ degradation conformed to pseudo-first-order kinetics. An improvement of ATZ degradation efficiency by 41.8% and pseudo-first-order rate constant by more than a factor of four was obtained in the O3/nZnO process after 5min of reaction compared to O3 alone. Meanwhile, the degradation efficiency of ATZ was gradually enhanced with increasing nZnO dosage and initial pH in the range from 3.0 to 8.0, and a higher amount of ATZ was degraded when the initial concentration of ATZ rose from 0.5 to 5mg/L. Additionally, sulfate ion, chloride ion, nitrate ion and low concentrations of humic acid substances led to enhancement of the ATZ degradation. The notable decrease of ATZ removal efficiency observed in the presence of radical scavengers and the results of free radical tests indicated that OH is the dominant active radical species. The mechanism investigation demonstrated that the enhancement effect could be attributed to the introduction of nZnO, which could promote the utilization of O3, enhance the formation of superoxide radical, and further accelerate the production of hydrogen peroxide and the generation of OH/O2-.