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Silver nanoparticles (AgNPs) are widely used in many commercial and medical products. Serious concerns are paid on their adverse potentials to the environment and human health. In this study, toxic effects and oxidative stress induced by AgNPs with different sizes and coatings (20 nm AgNPs, 20 nm polyvinylpyrrolidone (PVP) -AgNPs and 50 nm AgNPs) in Caenorhabditis elegans (C. elegans) were investigated. The toxic effects including the shortened lifespan and decreased frequency of head thrashes and body bends of C. elegans were induced in a dose-dependent manner by AgNPs. The reactive oxygen species (ROS) production and the oxidative stress-related indicators including malondialdehyde (MDA) and glutathione (GSH) in nematodes were changed after exposure to three kinds of AgNPs. These effects were the most obvious in a 20 nm PVP-AgNPs exposure group. AgNPs could also induce the expression of genes related to oxidative stress in nematodes. In addition, the up-regulation of mtl-1 and mtl-2 in nematodes might reduce the oxidative damage caused by AgNPs, by using transgenic strains CF2222 and CL2120 nematodes. Metallothionein (MT), an antioxidant, could relieve the oxidative damage caused by AgNPs. These results suggested that 20 nm PVP-AgNPs with a smaller particle size and better dispersion have stronger toxic effects and the oxidative damage to nematodes. Mtl-1 and mtl-2 might be involved in alleviating the oxidative damage caused by AgNPs. Our findings provide clues for the safety evaluation and mechanism information of metal nanoparticles. Graphical Abstract [ABSTRACT FROM AUTHOR]

Under the background of civil military integration, military civilian joint training of space sergeants is the specific practice of implementing the national military civilian integration strategy. In view of the fact that there are some shortcomings in the training of aerospace sergeants' innovative ability at the present stage, through investigation, we can understand the current situation of the army's demand, education reform and talent training effect, and take the army's demand as the basis. Based on the practical problems, this paper summarizes and analyzes the problems existing in the cultivation of innovative ability of aerospace sergeants and their causes. Based on the practical experience of innovative training of military cadets in recent years, this paper discusses the ways and Countermeasures of cultivating innovative ability from the perspectives of innovative personality, innovative environment, innovative consciousness, innovative thinking and innovative ability, the research results have important reference significance for improving the innovative quality of aerospace cadets. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) have become widespread in the environment with increasing industrial applications. But the studies about their potential health risks are far from enough, especially in neurotoxic effects. This study aimed to investigate the neurotoxic effects of longer‐term exposure (prolonged exposure for 48 h and chronic exposure for 6 days) of 20nm AgNPs with/without polyvinylpyrrolidone (PVP) coating at low concentrations (0.01–10 mg·L−1) to Caenorhabditis elegans. The results suggested that exposure to AgNPs induced damage to nematode survival, with the longest and relative average life span reduced. Exposure to AgNPs caused neurotoxicity on locomotion behaviors (head thrashes, body bends, pharyngeal pumping frequency, and defecation interval) and sensory perception behaviors (chemotaxis assay and thermotaxis assay), as well as impaired dopaminergic, GABAergic, and cholinergic neurons, except for glutamatergic, based on the alters fluorescence intensity, in a dose‐ and time‐dependent manner. Further investigations suggested that the low‐dose AgNPs (0.01–0.1 mg·L−1) exposure raises receptors of GABAergic and dopamine in C. elegans at the genetic level, whereas opposite results were observed at higher doses (1–10 mg·L−1), which implied that AgNPs could cause neurotoxicity by impairing neurotransmitter delivery. The PVP‐AgNPs could cause a higher fatality rate and neurotoxicity at the same dose. Notably, AgNPs did not cause any deleterious effect on nematodes at the lowest dose of 0.01 mg·L−1. In general, these results suggested that AgNPs possess the neurotoxic potential in C. elegans and provided useful information to understand the neurotoxicity of AgNPs, which would offer an inspiring perspective on the safe application. In this study, C. elegans was used as a model to evaluate the neurotoxicity of longer‐term exposure of 20nm AgNPs with/without PVP coating at low concentrations. The decreased survival rate and damaged neurobehavior, as well as impaired neurons and neurotransmitters in C. elegans, were observed. The PVP‐AgNPs caused a higher fatality rate and neurotoxicity. The results indicated that AgNPs caused neurotoxicity on nematodes at the doses over 0.1 mg·L−1, which provided clues for the safe application of AgNPs. [ABSTRACT FROM AUTHOR]

With the development of nanotechnology, metal‐containing nanoparticles are used widely in the diagnosis, monitoring and treatment of central nervous system (CNS) diseases. The neurotoxicity of these nanoparticles has drawn attention. Glial cells (particularly microglial cells and astrocytes) have important functions in the CNS. Neural disorders are related to functional/histologic damage to glial cells. Dysfunctions of microglial cells or astrocytes injure the brain, and cause the neurodegeneration seen in Alzheimer's disease and Parkinson's disease. We have summarized the route of access of metal‐containing nanoparticles to the CNS, as well as their neurotoxicity and potential molecular mechanisms involved in glial cells. Metal‐containing nanoparticles cross or bypass the blood‐brain barrier, access the CNS and cause neurotoxicity. The potential mechanisms are related to inflammation, oxidative stress, DNA and/or mitochondrial damage and cell death, all of which are mediated by microglial cell activation, inflammatory factor release, generation of reactive oxygen species, apoptosis and/or autophagy in glial cells. Moreover, these processes increase the burden of the CNS and even accelerate the occurrence or development of neurodegenerative diseases. Some important signaling pathways involved in the mechanism of neurotoxicity in glial cells caused by nanoparticles are also discussed. We summarized the route of metal‐containing NPs to the CNS, their neurotoxicity and molecular mechanisms in glial cells. After entry, these NPs can induce BBB damage or dysfunction of cognition, learning and memory. The potential mechanisms involved in neuroinflammation are oxidative stress, DNA and/or mitochondrial damage and cell death. These mechanisms are mediated by activation of microglial cells, release of inflammatory factors, ROS generation, and apoptosis or autophagy in glial cells. [ABSTRACT FROM AUTHOR]

Micro‐ and nanoplastics are generated from plastics and have negative impacts on the environment due to their high level of fragmentation. They can originate from various sources such as fragments, fibers and foams. The large proportion of the waste and resistance to degradation means micro‐ and nanoplastics have become a serious global environmental problem, but there are few studies on their potential toxicity for human health. In this review, we discussed routes of exposure and the potential effects of micro‐ and nanoplastics to human health. Human beings could mainly be exposed to micro‐ and nanoplastics orally and by inhalation. The possible toxic effects of plastic particles are due to the potential toxicity of plastics themselves, and their combined toxicity with leachable additives and adsorbed contaminants. The potential risks for human health focused on their gastrointestinal toxicity and liver toxicity. The toxic mechanisms could involve oxidative stress, inflammatory reactions and metabolism disorders. More studies are needed to carry out and explore the potential toxicological mechanisms of micro‐ and nanoplastics and evaluate the combined toxicity of their adsorbed contaminants. Micro‐ and nanoplastics pollution has become a serious global environmental problem, whereas there are few studies on their potential toxicity for human health. In thish review, we summarized the sources, production of microplastics and possible routes of human exposure and potential toxicity on human health. Oral intake is the main route for human exposure to microplastics, and the potential toxicity is focused on their gastrointestinal toxicity, liver toxicity, neurotoxicity and reproductive toxicity. [ABSTRACT FROM AUTHOR]