Zinc Salts Research Articles

Study of the Influence of Anionic Composition of Salts on Synthesis of Zinc Orthostannate by the Sol-Gel Method

The effect of anionic composition of zinc salts upon interaction with tin (IV) chloride on preparation of zinc orthostannate by the sol-gel method was studied. It was determined that the minimum temperature for the synthesis of zinc orthostannate was 800 °C. It was revealed that when zinc chloride was used, tetraaminezinc chloride was formed, which decomposed during firing. When zinc acetate or zinc sulfate was used, the synthesis of zinc orthostannate was not fully completed up to 1100 °C.

Pleurotus spp. Mycelia Enriched in Magnesium and Zinc Salts as a Potential Functional Food.

Worldwide, mushrooms belonging to the Pleurotus spp. such as P. citrinopileatus, P. djamor, and P. pulmonarius are highly valued not only for their taste and aroma but also for their health-promoting properties. These species are rich in bioelements, vitamins, and above all, compounds that exhibit immunostimulatory activity. Therefore, in this study, we aimed to determine the effect of the supplementation of culture media using inorganic Mg and Zn salts. This is the first study to establish the bioavailability of the selected elements (Mg and Zn) and anions (Cl−, SO42−) from the enriched biomass by means of the extraction of lyophilized mycelium into artificial digestive juices. The following salts were added to the liquid Oddoux medium: ZnSO4·7H2O, ZnCl2, MgSO4·7H2O or MgCl2·6H2O. The bioelements, anions and organic compounds in the obtained biomass were determined. The addition of Zn and Mg salts to the media increased the production of biomass by 30% and increased the bioaccumulation of the inorganic salts. Maintaining in vitro cultures under optimized and controlled conditions produced mycelium with a better composition and health properties than otherwise. Such enriched biomass may be classified as potential functional foods, aiding in overcoming deficiencies of elements and organic compounds with biological activity in humans.

Usage of Oral Rehydration Salts and Other Treatments in Management of Diarrhoea Among Children Under-Five Years Attending Primary Health Care Facilities in Dar es Salaam

Background Diarrhoeal disease is highly preventable and easily manageable, yet remains a significant cause of childhood mortality in Tanzania. Since dehydration caused by acute diarrhoea is the main contributor to mortality, key measures to treat diarrhoea include rehydration using oral rehydration salts (ORS) and zinc supplements. Therefore, this study aimed to assess ORS use, pediatric zinc and antibiotics in the management of diarrhoea in children under-five years attended at the primary health care facilities in Dar es salaam, Tanzania. Also, factors associated with antibiotics usage were determined. Methods A cross-sectional study was conducted from March to September 2019. Ten dispensaries were selected from five Dar es salaam municipalities in Tanzania. A total of 301 children under-five years with diarrhoea were enrolled. Information on socio-demographic characteristics was obtained by asking the parents/guardians, whereas clinical characteristics, laboratory results, diagnosis, and treatment were extracted from children’s files. The information obtained was recorded in the structured questionnaire. Data were analyzed using statistical package for social science software, version 22.0. Descriptive statistics were used to summarize the information collected. The multivariable logistic regression was used to determine factors associated with antibiotics use in diarrhoea management, whereby p<0.05 was considered statistically significant. Results Of 301 children enrolled, 85.7% had acute watery diarrhoea. ORS and pediatric zinc were prescribed to 75.1% and 48.8% of children, respectively. At least one antibiotic was prescribed to more than half (66.8%) of the enrolled children. The odds that antibiotics were prescribed in the management of children with acute watery diarrhoea was less compared to those with bloody or persistent diarrhoea (AOR 0.1 (95% CI 0.02 – 0.3) p< 0.01). Also, children attending health facilities in Ilala municipality had 2.1 (AOR (95%CI 1.2 – 3.8) p = 0.014) times odds of being given antibiotics compared to those attended at other health facilities in other municipalities. Conclusion ORS usage in managing diarrhoea among children under-five years is higher than the use of pediatric zinc. A high incidence of antibiotics use in acute watery diarrhoea management was observed, which is against recommended guidelines. The study recommends continuing education to health care providers and the community on proper management of diarrhoea in children under-five years. Keywords: Diarrhoea; children under-five, pediatric zinc and oral dehydration salts.

Virucidal Action Mechanism of Alcohol and Divalent Cations Against Human Adenovirus.

Hygiene and disinfection practices play an important role at preventing spread of viral infections in household, industrial and clinical settings. Although formulations based on >70% ethanol are virucidal, there is a currently a need to reformulate products with much lower alcohol concentrations. It has been reported that zinc can increase the virucidal activity of alcohols, although the reasons for such potentiation is unclear. One approach in developing virucidal formulations is to understand the mechanisms of action of active ingredients and formulation excipients. Here, we investigated the virucidal activity of alcohol (40% w/v) and zinc sulfate (0.1% w/v) combinations and their impact on a human adenovirus (HAdV) using, nucleic acid integrity assays, atomic force microscopy (AFM) and transmission electron microscopy (TEM). We observed no difference in virucidal activity (5 log10 reduction in 60 min) against between an ethanol only based formulation and a formulation combining ethanol and zinc salt. Furthermore, TEM imaging showed that the ethanol only formulation produced gross capsid damage, whilst zinc-based formulation or formulation combining both ethanol and zinc did not affect HAdV DNA. Unexpectedly, the addition of nickel salt (5 mM NiCl2) to the ethanol-zinc formulation contributed to a weakening of the capsid and alteration of the capsid mechanics exemplified by AFM imaging, together with structural capsid damage. The addition of zinc sulfate to the ethanol formulation did not add the formulation efficacy, but the unexpected mechanistic synergy between NiCl2 and the ethanol formulation opens an interesting perspective for the possible potentiation of an alcohol-based formulation. Furthermore, we show that AFM can be an important tool for understanding the mechanistic impact of virucidal formulation.

The Associated Regulatory Mechanisms of Zinc Lactate in Redox Balance and Mitochondrial Function of Intestinal Porcine Epithelial Cells.

Zinc lactate (ZnLA) is a new organic zinc salt which has antioxidant properties in mammals and can improve intestinal function. This study explored the effects of ZnLA and ZnSO4 on cell proliferation, Zn transport, antioxidant capacity, mitochondrial function, and their underlying molecular mechanisms in intestinal porcine epithelial cells (IPEC-J2). The results showed that addition of ZnLA promoted cell proliferation, inhibited cell apoptosis and IL-6 secretion, and upregulated the mRNA expression and concentration of MT-2B, ZNT-1, and CRIP, as well as affected the gene expression and activity of oxidation or antioxidant enzymes (e.g., CuZnSOD, CAT, and Gpx1, GSH-PX, LDH, and MDA), compared to ZnSO4 or control. Compared with the control, ZnLA treatment had no significant effect on mitochondrial membrane potential, whereas it markedly increased the mitochondrial basal OCR, nonmitochondrial respiratory capacity, and mitochondrial proton leakage and reduced spare respiratory capacity and mitochondrial reactive oxygen (ROS) production in IPEC-J2 cells. Furthermore, ZnLA treatment increased the protein expression of Nrf2 and phosphorylated AMPK, but reduced Keap1 and p62 protein expression and autophagy-related genes LC3B-1 and Beclin mRNA abundance. Under H2O2-induced oxidative stress conditions, ZnLA supplementation markedly reduced cell apoptosis and mitochondrial ROS levels in IPEC-J2 cells. Moreover, ZnLA administration increased the protein expression of Nrf2 and decreased the protein expression of caspase-3, Keap1, and p62 in H2O2-induced IPEC-J2 cells. In addition, when the activity of AMPK was inhibited by Compound C, ZnLA supplementation did not increase the protein expression of nuclear Nrf2, but when Compound C was removed, the activities of AMPK and Nfr2 were both increased by ZnLA treatment. Our results indicated that ZnLA could improve the antioxidant capacity and mitochondrial function in IPEC-J2 cells by activating the AMPK-Nrf2-p62 pathway under normal or oxidative stress conditions. Our novel finding also suggested that ZnLA, as a new feed additive for piglets, has the potential to be an alternative for ZnSO4.

Electrodialysis enhanced with disodium EDTA as an innovative method for separating Cu(II) ions from zinc salts in wastewater

In recent years, interest in developing methods for hazardous metal recovery from wastewater has grown steadily within the scientific community. This report describes a method based on electrodialysis enhanced with metal-complex formation to separate cupric ions from zinc sulfate present in a model zinc plating bath. The investigated method can be applied for resource (zinc sulfate) recovery, or to reduce the amount of hazardous galvanic wastes. In this work, the disodium salt of ethylenediaminetetraacetic acid (Na2EDTA) is employed as a complexing agent. The effects of the membrane and current density on the separation efficiency are evaluated and discussed. Finally, the optimal conditions for selective removal of Cu(II) ions from a zinc salt bath are identified, and the effectiveness of the examined method is demonstrated in a batch test. It was determined that, by using thick heterogeneous AM(H)-CM(H) ion-exchange membranes an approximately 13-fold reduction in Cu(II) content, relative to Zn(II), can be achieved at high Zn(II) recovery (94.6%) and current density (220 A/m2). The possibility of applying the described method for concentration of zinc salts in the plating bath was also evaluated. It was shown that Zn(II) content can be increased of up to 1.5 times.

In-situ growth of ultrafine ZnO on g-C3N4 layer for highly active and selective CO2 photoreduction to CH4 under visible light

Photocatalytic CO2 reduction to solar fuels is considered as a promising strategy to address the global warming and energy shortages. Herein, a novel method is proposed to prepare g-C3N4/ZnO nanocomposites via refluxing zinc salt methanol solution containing pre-formed g-C3N4 with KOH methanol solution as precipitating agent. Some in-situ grown ultrafine ZnO nanoparticles are decorated on ultrathin g-C3N4 layers with well-defined interface, which not only causes efficient charge transfer and separation, but also creates more active sites for CO2 adsorption and activation. The resultant g-C3N4/ZnO composites demonstrate significant enhanced CO2 photoreduction activity and selectivity for CH4 production under visible light irradiation, and the optimal g-C3N4/ZnO composite delivers the best overall photoactivity (158.4 μmol g−1 h−1) with CH4/CO production rates of 19.8/0.37 μmol g−1 h−1, which is 9.42 times higher than that of g-C3N4 alone. This work provides an ideal synthetic strategy for g-C3N4-based hybrid materials with highly efficient CO2 photoreduction.

Solvation Structure and Electrochemical Properties of a New Weakly Coordinating Aluminate Salt as a Nonaqueous Electrolyte for Zinc Batteries

In continuation of our interest in developing multivalent electrolytes for energy storage, we report a new zinc salt with a weakly coordinating anion, tetrakis(perfluoro-tert-butoxy) aluminate (TPFA), as a stable electrolyte for nonaqueous systems. We examined the electrochemical and structural properties of this nonaqueous electrolyte in various solvents. ZnTPFA2 supports highly reversible Zn deposition and stripping behavior in acetonitrile and ethereal solvents, with up to 91% Coulombic efficiency. A variety of analytical techniques were used to identify the local coordination structure around Zn2+ in both the crystal phase and the solution phase, providing clear evidence of solvent coordination around the cation.

Nanostructured zinc: properties and applications in functional alimentary products

The paper presents the properties of nanostructured zinc salts and their application for the production of functional food for preventive purposes on the example of marmalade, kefir, ice cream and bakery products. The size of nanostructured zinc sulfate was determined by the NTA method. As it turned out, the size of nanoparticles is 145 nm, and the polydispersity coefficient has a value of 1.34, which indicates its ellipsoid shape. These data allow using the synthesized product for functional purposes.

A Maturation Process or Binders Based on Coordination Chemistry to Boost the Mechanical Strength and Cyclability of Si-Based Electrodes

Silicon is attractive as negative electrode material for Li-ion batteries (LIBs) to increase their energy density [1]. The main challenge is to deal with the large silicon volume expansion induced by its lithiation, which damages the mechanical integrity of the electrode, and produces an unstable solid electrolyte interphase (SEI).Recently, we have discovered a post-processing treatment, called maturation, which very significantly improves the mechanical and electrochemical stabilities of silicon-based electrodes made with polycarboxylic acid binders [2-4]. It consists of storing the electrode in a humid atmosphere for a few days before drying and cell assembly. We found that during maturation, the atmospheric-induced corrosion of the current collector releases oxidized copper species that migrate into the electrode to physically crosslink the binder phase, substantially modifying its resiliency to the silicon volume variation as shown by various in situ and operando characterizations. The pre-addition of a small amount of copper or zinc salt in the electrode slurry allows to reach similar improvement of electrochemical performance than maturation [5]. This reveals that there is great potential to explore coordination chemistry to design new, more efficient binders through the medium strength and dynamic nature of coordination bonds [6]. Acknowledgments The authors thank the Natural Sciences and Engineering Research Council of Canada (NSERC) (grant RGPIN-2016-04524) and Transition Énergétique Québec (TEQ) (grant Techno-0040-0001) for financial support of this work.

Recent Advances in Zinc Oxide Nanostructures with Antimicrobial Activities.

This article reviews the recent developments in the synthesis, antibacterial activity, and visible-light photocatalytic bacterial inactivation of nano-zinc oxide. Polycrystalline wurtzite ZnO nanostructures with a hexagonal lattice having different shapes can be synthesized by means of vapor-, liquid-, and solid-phase processing techniques. Among these, ZnO hierarchical nanostructures prepared from the liquid phase route are commonly used for antimicrobial activity. In particular, plant extract-mediated biosynthesis is a single step process for preparing nano-ZnO without using surfactants and toxic chemicals. The phytochemical molecules of natural plant extracts are attractive agents for reducing and stabilizing zinc ions of zinc salt precursors to form green ZnO nanostructures. The peel extracts of certain citrus fruits like grapefruits, lemons and oranges, acting as excellent chelating agents for zinc ions. Furthermore, phytochemicals of the plant extracts capped on ZnO nanomaterials are very effective for killing various bacterial strains, leading to low minimum inhibitory concentration (MIC) values. Bioactive phytocompounds from green ZnO also inhibit hemolysis of Staphylococcus aureus infected red blood cells and inflammatory activity of mammalian immune system. In general, three mechanisms have been adopted to explain bactericidal activity of ZnO nanomaterials, including direct contact killing, reactive oxygen species (ROS) production, and released zinc ion inactivation. These toxic effects lead to the destruction of bacterial membrane, denaturation of enzyme, inhibition of cellular respiration and deoxyribonucleic acid replication, causing leakage of the cytoplasmic content and eventual cell death. Meanwhile, antimicrobial activity of doped and modified ZnO nanomaterials under visible light can be attributed to photogeneration of ROS on their surfaces. Thus particular attention is paid to the design and synthesis of visible light-activated ZnO photocatalysts with antibacterial properties

Precursor Dependent Tailoring of Morphology and Crystallite Size of Biogenic ZnO Nanostructures with Enhanced Antimicrobial Activity- a Novel Green Chemistry Approach

During recent years, there has been a growing pursuit in researching and developing new therapeutic antimicrobial agents from several sources to combat microbial resistance. Therefore, a greater attention has been paid in screening of antimicrobial activity and evaluating methods. The objective of the present study was to synthesize, characterize, and explore nanosized biogenic zinc oxide (ZnO) NPs and evaluate its performance for the antimicrobial activity. Biogenic zinc oxide nanoparticles (ZnO NPs) were fabricated with the two different zinc salts (zinc acetate and zinc nitrate) from aqueous Achyranthes aspera leaf extract and characterized using modern methods and tools, such as X-ray diffraction, Fourier transform infrared spectroscopy, and UV-vis spectroscopy, which indicated the formation of very pure ZnO NPs. The scanning electron microscopic analysis (SEM) explored the formation of flower-like morphology in the sample of zinc acetate precursor and spherical morphology in the sample of zinc nitrate precursor. Further, the elemental composition of both samples was analyzed by energy dispersive spectroscopy (EDS). The antibacterial of ZnO NPs was evaluated by disk diffusion method on Gram-negative pathogen Escherichia coli and Gram-positive pathogen Staphylococcus aureus. ZnO nanoparticles exhibited a higher zone of inhibition (29 mm) because of having a larger specific surface area. Minimum inhibitory concentration (MIC) values of biogenic ZnO NPs were observed in the range of 40–60 μg/mL against selected oral pathogens. Overall, the green synthesized ZnO NPs demonstrated the astounding potential for the antimicrobial activity as an alternative clean-green therapeutic solution.

One-pot synthesis of core–shell ZIF-8@ZnO porous nanospheres with improved ethanol gas sensing

Rational design and synthesis of hollow core–shell hetero-structures with high complexity still remains challenging for high gas-sensing performances. Here, ZIF-8@ZnO (zeolite imidazolate framework-8) core–shell material was synthesized using an easy-to-use hydrothermal reaction. ZnO is a kind of homologous metal oxide of ZIF-8 material. Therefore, without adding other zinc salts, the formation of ZIF-8@ZnO was completed in a one-pot reaction. Then a series of morphology and structure analysis including XRD, BET, SEM, EDX, etc. were carried out to study the positive effect of ZIF-8 film on the sensing performance of ZnO nanospheres. The results show that the ZIF-8 film uniformly covers the surface of porous ZnO nanospheres with a diameter of about 400 nm, forming a core–shell structure. Compared to the other volatile organic compounds (VOCs), ZIF-8@ZnO shows a higher sensitivity and selectivity to 50 ppm ethanol gas at an operating temperature of 220 °C, which can achieve 13.8. This is almost 2.7 times that of pure ZnO nanospheres (5.1). The obtained results show that ZIF-8@ZnO core–shell material not only greatly improves the sensitivity of the sensor, but also enhance the selectivity of ethanol gas sensing.

Chemical Recycling of End-of-Life Poly(lactide) via Zinc-Catalyzed Depolymerization and Polymerization.

The chemical recycling of poly(lactide) was investigated based on depolymerization and polymerization processes. Using methanol as depolymerization reagent and zinc salts as catalyst, poly(lactide) was depolymerized to methyl lactate applying microwave heating. An excellent performance was observed for zinc(II) acetate with turnover frequencies of up to 45000 h−1. In a second step the monomer methyl lactate was converted to (pre)poly(lactide) in the presence of catalytic amounts of zinc salts. Here zinc(II) triflate revealed excellent performance for the polymerization process (yield: 91 %, Mn ∼8970 g/mol). Moreover, the (pre)poly(lactide) was depolymerized to lactide, the industrial relevant molecule for accessing high molecular weight poly(lactide), using zinc(II) acetate as catalyst.

Влияние технологической добавки ЦД-12 на свойства термоагрессивостойкой резины для уплотнительных элементов

The article presents the results of a study of the effect of the technological active additive СD-12, which is a combination of zinc salts of fatty acids, on the physical and mechanical properties and resistance to aggressive media of rubber for sealing elements of packer-anchor equipment. The rubber mixture was prepared on the basis of hydrogenated nitrile-butadiene rubber Therban 3406, vulcanizing agent Novoperox BP-40, coagents for vulcanization of zinc monomethacrylate and oligoester acrylates MGF-9 and TGM-3, antioxidants Naugard 445 and agidol-2, fillers of technical carbon P 514 and T 900, filler dispersant stearic acid, rosin softener and other ingredients. To stabilize the physical and mechanical properties of vulcanizates, uniform dispersion of rubber components, reduce viscosity and improve vulcanization properties, a technological additive CD-12 was also introduced into the rubber mixture. The rubber mixture was prepared in a laboratory SKI-3L rubber mixer at a temperature not exceeding 70 °C for 7 min. The resulting mixture was vulcanized on a PV-100-2RT-2-PCD vulcanization press at a temperature of 150 °C for 60 minutes and then further vulcanized in a thermostat at a temperature of 160 °C for 6 hours. For the obtained vulcanizates, the physical and mechanical properties and resistance to the action of aggressive media were determined according to the standards existing in the rubber industry. On the basis of a rubber mixture heat-aggressive persistent sealing elements with a hardness of 70±5 Shore A units were made. These sealing elements as part of two sets of packer-anchor equipment were tested for tightness in a casing string simulator. The tests were carried out in an environment of PMS-200 polymethylsiloxane fluid at a temperature of 150 °C, an axial load of 6 tons and a pressure of 70 MPa. It is shown that both sets of packers have passed the tests and meet the requirements. The developed rubber mixture with a hardness of 70±5 Shore A units, containing the process additive СD-12, can be used for the manufacture of sealing elements for packers used in the oil and gas industry.

Synthesis of a multi-functional zinc-centered nitrogen-rich graphene-like thin film from natural sources on the steel surface for achieving superior anti-corrosion properties

Novel zinc-centered graphene-like compounds were developed on the metal surface using nature-based phytochemicals based on Papaver somniferum extract and zinc salt. Through the FTIR, UV–vis, GIXRD, and Raman analyses, the deposited film composition on the substrate was investigated. Outcomes from the EIS indicated an inhibition degree of 99 % on the protected samples after 11 days of exposure, expressing the high corrosion retardation durability of the deposited film. Polarization test evidenced mixed inhibition with anodic inhibition dominancy. The formation of a dense graphene-like based film composed of Zn-poppy complexes over the metal surface was affirmed by AFM, SEM/EDS, and contact-angle techniques.

Reducing Chlorothalonil Use in Fungicide Spray Programs for Powdery Mildew, Anthracnose, and Gummy Stem Blight in Melons.

Fungicides are applied to nearly 80% of U.S. melon acreage to manage the numerous foliar and fruit diseases that threaten yield. Chlorothalonil is the most widely used fungicide but has been associated with negative effects on human and bee health. We designed alternative fungicide programs to examine the impact of reducing chlorothalonil use (Bravo Weather Stik) on watermelon, cantaloupe, and honeydew melon in 2016, 2017, and 2018 in Maryland. Chlorothalonil was replaced in the tank mix of weekly sprays of targeted fungicides with either polyoxin D zinc salt (Oso) or an extract of Reynoutria sachalinensis (Regalia). Powdery mildew (PM; Podosphaera xanthii), gummy stem blight (GSB; Stagonosporopsis spp.), and anthracnose (Colletotrichum orbiculare) were the most prevalent diseases to occur in the 3 years. Replacing chlorothalonil with the biopesticides as the tank-mix component of the fungicide spray program was successful in reducing GSB and PM severity in cantaloupe, honeydew melon, and watermelon compared with the untreated control, with the exception of GSB in 2017 in cantaloupe, and similar to the program including chlorothalonil in all cases, except anthracnose in watermelon. Anthracnose disease severity was not significantly reduced compared with the untreated control when chlorothalonil was replaced with the biopesticides and yields were not improved over the chlorothalonil-alone treatment in any of the trials. Therefore, replacement of chlorothalonil may not fully address its loss as a fungicide resistance management tool but efficacy can be maintained when polyoxin D is alternated with R. sachalinensis as a tank mix with targeted fungicides to manage PM and GSB.

Toxic Impact of Zinc Salt (ZnSO4) on Some Haematological Parameters in a Freshwater Mud Eel Amphipnous cuchia (Hamilton, 1822)

Background: Zinc (Zn), a heavy metal present in aquatic environment, has toxic effect on fishes. Present study was to assess toxicity of Zinc salt (ZnSO4) on total erythrocyte count (TEC), haemoglobin (Hb) content (g/dl) and haematocrit value (PCV%) of blood of freshwater mud eel Amphipnous cuchia. Methods: Live fishes collected from ponds were acclimatized in laboratory. TEC, Hb content and PCV% of blood samples collected after 15, 30, 60 and 90 days, of control fishes and fishes exposed to low (0.5mg/l) and high (1mg/l) concentrations of ZnSO4, were determined by standard methods. Result: TEC, Hb content and PCV% varied respectively from 2.48 x 106/mm3 to 2.70 x 106/mm3, 12.02 g/dl to 12.30 g/dl and 28.50 % to 33.60 % in fishes in low and from 2.36 x 106/mm3 to 2.60 x 106/mm3, 11.82 g/dl to 12.20 g/dl and 26.20 % to 31.50 % in fishes in high concentration of ZnSO4 solution, showing decreasing trend in all three blood parameters vis-a-vis their control values viz. TEC (2.74 x 106/mm3), Hb content (12.60 g/dl) and PCV% (34.50 %), decrease being more prominent in fishes exposed to high than those to low concentration. The depletion in these blood parameters may be attributed to the haemotoxic characteristics of Zinc (Zn).

Simple and effective synthesis of zinc ferrite nanoparticle immobilized by reduced graphene oxide as anode for lithium-ion batteries

In this work, a simple and effective method is developed to synthesize zinc ferrite nanoparticles (ZnFe2O4) in a redox coprecipitation reaction system containing only ferrous and zinc salt followed by a solid-state reaction. On this foundation, ZnFe2O4 nanoparticles with reduced size are further immobilized by reduced graphene oxide (RGO) to engineer a ZnFe2O4/RGO composite by simply introducing graphene oxide (GO) in the above reaction system. The ZnFe2O4/RGO composite electrode exhibits attractive lithium-ion storage capability with a reversible capacity of about 760 mAh·g−1 for 200 charge/discharge cycles and 603 mAh·g−1 for 700 cycles under a current rate of 1.0 A·g−1. The robust and porous RGO supporting framework, well immobilized ZnFe2O4 nanoparticles with controlled size and pseudocapacitive behavior of the composite jointly ensure the good battery performance. Moreover, the synthetic route for ZnFe2O4 nanoparticles and ZnFe2O4/RGO composite is simple and economic, which may be further developed for massive production and applied in other fields.

ZnO and TiO2 nanoparticles alter the ability of Bacillus subtilis to fight against a stress.

Due to the physicochemical properties of nanoparticles, the use of nanomaterials increases over time in industrial and medical processes. We herein report the negative impact of nanoparticles, using solid growth conditions mimicking a biofilm, on the ability of Bacillus subtilis to fight against a stress. Bacteria have been exposed to sublethal doses of nanoparticles corresponding to conditions that bacteria may meet in their natural biotopes, the upper layer of soil or the gut microbiome. The analysis of the proteomic data obtained by shotgun mass spectrometry have shown that several metabolic pathways are affected in response to nanoparticles, n-ZnO or n-TiO2, or zinc salt: the methyglyoxal and thiol metabolisms, the oxidative stress and the stringent responses. Nanoparticles being embedded in the agar medium, these impacts are the consequence of a physiological adaptation rather than a physical cell injury. Overall, these results show that nanoparticles, by altering bacterial physiology and especially the ability to resist to a stress, may have profound influences on a “good bacteria”, Bacillus subtilis, in its natural biotope and moreover, on the global equilibrium of this biotope.