Microplastics (MPs) are a new kind of environmental pollutant that has attracted extensive attention in recent years. MPs can be ingested by multiple organisms and mainly accumulate in the intestine. ...However, there is still little known about the toxic effects of MPs on humans. Here, we chose the male adult mice as the research model, which were exposed to 2 µm polyvinyl chloride (PVC) MPs at a concentration of 100 mg/kg for consecutive 60 days, to study the toxicity of PVC-MPs. The changes in gut histology, enzymatic biomarkers, the intestinal microbiome, and metabolomic responses were monitored in mice. The results displayed that the PVC-MPs reduced intestinal mucus secretion and increased intestinal permeability. Moreover, PVC-MPs exposure decreased mRNA expression levels of colonic mucus secretion-related genes, indicating dysfunction of intestinal mucus secretion after exposure to PVC-MPs. With regard to the gut microbiota, high throughput sequencing of the full-length 16S rRNA gene sequencing indicated 15 and 17 kinds of gut microbes changed markedly after PVC-MPs exposure at the genus and species level, respectively. Furthermore, marked alterations in the gut microbiome and fecal metabolic profiles were observed, most of which were related to intestinal injury and barrier dysfunction. These results show that exposure to PVC-MPs leads to intestinal injury and changes gut microbiome composition and metabolome profiles, thus the health risk of PVC-MPs to animals needs more concern. This study helps to provide a new idea about the health risk of PVC-MPs to humans.
Triclosan (TCS), a broad-spectrum, lipophilic, and antibacterial agent, has been commonly used in cosmetics, medical devices, and household products. The toxicity of TCS has recently become a ...research hotspot. Emerging evidence has shown that TCS can easily migrate to humans and animals and cause adverse effects on various target organs. However, the effects of TCS exposure on nephrotoxicity and underlying mechanisms remain unknown. The aim of the present study was to explore TCS-induced nephrotoxicity. Therefore, we establish a mouse model based on adult male mice to explore the effects of 10-week TCS exposure (50 mg/kg) on kidney. After mice were sacrificed, their blood, feces, and renal tissues were harvested for further analysis. We found that TCS treatment dramatically caused kidney structural damage, and increased blood urea nitrogen (BUN) and creatinine (Cr) expression levels, which indicated renal dysfunction. In addition, TCS exposure increased the malondialdehyde (MDA) and decreased superoxide dismutase (SOD) and total cholesterol (TCHO) expression levels, which indicated oxidative stress and lipid metabolism changes. The RNA sequencing (RNA-seq) of kidney tissue identified 221 differentially expressed genes (DEGs) enriched in 50 pathways, including drug metabolism-other enzymes, oxidative phosphorylation, glutathione metabolism, and inflammatory mediator regulation of TRP channels signaling pathways. The full-length 16S rRNA gene sequencing results showed that TCS exposure altered the community of gut microbiota, which was closely related to renal function damage. The above findings provide new insights into the mechanism of TCS-induced nephrotoxicity.
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•Adult mice exposed to Triclosan (50 mg/kg/day) for 10 weeks were found to have renal injury.•More than 221 DEGs enriched in 50 signaling pathways were identified by RNA-seq in the kidneys of Triclosan-treated mice.•Triclosan exposure for 10 weeks changed the gut microbiota structure in adult mice.
Plastics have been proven to be a potential threat to the ecosystem, and their toxicity mechanism is still uncertain. In the ecological environment, plastics can be degraded into microplastics (MPs) ...and nanoplastics (NPs), which can be contaminated and ingested through the food chain. MPs and NPs are associated with severe intestinal injury, intestinal microbiota disorder, and neurotoxicity, but it is still unclear whether MPs- and NPs-induced intestinal microbiota dysbiosis will affect the brain through the gut-brain axis. In the current study, we determined the effects of exposure to polystyrene (PS)-MPs and PS-NPs on anxiety-like behaviors and explored the underlying mechanisms. This study explored the behavioral effects of 30-day and 60-day exposure to PS-NPs and PS-MPs using the open field test (OFT) and elevated plus maze (EPM) test. Behavioral tests showed PS-NPs and PS-MPs treatment remarkedly induced anxiety-like behaviors compared with the control group. Using 16 S rRNA gene sequencing and untargeted metabolomics analyses, we observed that PS-MPs and PS-NPs exposure reduced the beneficial gut microbiota expression level, such as Lachnoclostridium and Lactobacillus, and increased the conditionally pathogenic bacteria expressions level, such as Proteobacteria, Actinobacteria, and Desulfovibrio. In addition, PS-NPs and PS-MPs reduce intestinal mucus secretion and increase intestinal permeability. The results of serum metabonomics suggested that the metabolic pathways, such as ABC transporter pathways, aminoacyl-tRNA biosynthesis, biosynthesis of amino acids, and bile secretion were enriched after PS-NPs and PS-MPs treatment. Besides, neurotransmitter metabolites were also altered by PS-NPs and PS-MPs. It is noteworthy that the correlation analysis showed that the disorder of intestinal microbiota was related to anxiety-like behaviors and neurotransmitter metabolites disorder. The regulation of intestinal microbiota may be a promising treatment strategy for PS-MPs- and PS-NPs-induced anxiety disorder.
•PS-MPs and PS-NPs induced anxiety-like behaviors in adult mice.•PS-MPs and PS-NPs induced gut microbiota dysbiosis and intestinal barrier dysfunction.•PS-MPs and PS-NPs changed serum metabolic profiles, especially in neurotransmitter metabolites.
The aim of this study is to analysis the tensile deformation behavior of 3D printed unidirectional continuous fiber reinforced thermos-plastic composites (UD-CFRTP). Tensile experiments were ...performed to obtain the deformation curves and tensile properties of composites specimens. It is found that the reinforcement fiber bundles of specimens bearing the load non-synchronously. Meanwhile, with the fiber content change, the deformation form could be different. An improved micromechanical model was proposed to investigate the influence of non-synchronous phenomenon and fiber content on the deformation behavior. The fiber content is measured by the number of reinforcement fiber bundles instead of fiber volume fraction in this model. Based on this model, the deformation behavior and tensile properties of test specimens with different fiber bundles number were analyzed in detail. The analytical results about deformation behavior and tensile properties show a good agreement with experiment results.
Spinal cord injury (SCI) can have a significant impact on an individual's life. Herein, we discuss how resveratrol improves SCI by inhibiting nuclear factor kappa-light-chain-enhancer of activated B ...cells (NF-κB) signaling pathway. Evidences show resveratrol suppresses NF-κB signaling pathway to exert its beneficial effects on various diseases. NF-κB signaling pathway plays a significant role in the pathophysiological mechanisms of SCI including increase in inflammation, augmentation of damage caused by free radicals and lipid peroxidation as well as facilitation of apoptosis and axonal demyelination. We also discuss mechanisms between resveratrol and NF-κB signaling pathway in the wake of SCI, which can be potential targets for resveratrol to treat SCI.
Under the overarching principle of sustainability, the reliance solely on expanding the landmass to meet the demand for high-quality economic growth is unsustainable. To address the need for ...harmonious ecological–economic development, this paper examines the influence of carbon emissions trading (CET) policies on the urban land green utilization efficiency (LGUE) from an environmental regulation perspective. Harnessing municipal panel data from 278 cities across China between 2011 and 2020, the study initially employs a super-efficient SBM model to estimate the urban LGUE. Further, a progressive difference-in-differences methodology is utilized to delve into CET’s impact on the LGUE. The main results are as follows. (1) Through the visual analysis of the time–space evolution trend, the LGUE displays pronounced spatial agglomeration, with the LGUE values being higher in the central and western regions compared to the east, and in the south versus the north. Over time, it follows a “U-shaped” change pattern. (2) The CET policy exerts a statistically significant positive influence on the LGUE, although this effect is accompanied by a temporal lag. Following a number of approaches to validate the results, the impact remains significant. (3) Regarding the heterogenous effects, the CET policy appears to have a greater impact on resource-based cities and those in the eastern part of China relative to non-resource-based and central–western cities. This research offers empirical evidence and countermeasure recommendations for the further refinement of the CET policy to enhance the urban LGUE.
Place attachment has been extensively studied in the field of tourism. However, it is important to recognize that place attachment alone may not fully capture the emotional expression of tourists' ...spiritual beliefs and their sense of belonging to a destination. Therefore, a more comprehensive attachment theory is needed to encompass higher dimensions. This article focuses on the ancient Chinese villages of Yantou, Cangpo, and Furong from a tourist perspective, and introduces genius loci in architectural phenomenology. We set out to expand the study of spiritual dimensions of place attachment on the basis of local attachment, redefining tourists' place connection and putting forward the new concept of place conversion. A qualitative analysis of online text using Rooting theory was conducted to condense 22 categories into 6 main categories and establish a model. The study shows that the mechanism of place conversion is composed of situational perception (place perception and place identity), physical and mental immersion (spatio-temporal immersion and place conversion), and behavioral willingness (tourists intention and conversion behavior). The study has implications for the conservation and development of traditional villages and future research on the spiritual experiences of tourists.
Abstract
Background
Orbital apex syndrome (OAS) is a rare disease with a noticeable mortality rate. Although its etiology has been repeatedly assessed, few reports have concentrated on odontogenic ...infection. We presented a rare case of OAS secondary to apical periodontitis.
Case presentation
A 61-year-old male was admitted to our hospital for a 3-day history of left orbital and head pain, along with diplopia for 1-day. He also had toothache symptoms before his admission. Due to the atypical early symptoms of orbital apex and cranial nerve injury, no timely and effective diagnosis and treatment were initially provided. However, as the disease progressed and complications occurred, we timely adjusted the diagnosis and successfully controlled the infection. During the one-year follow-up, no recurrence of inflammation was observed; nevertheless, the ptosis and ophthalmoplegia persisted.
Conclusions
OAS is a rare, while severe complication of odontogenic infection. This case had various symptoms and nerve injury in the orbital apical area. When disease is atypical in its early stages, treatment is easily overlooked. Early detection and suspicion of orbital apex-related complications should be heightened.
Methamphetamine (METH) is an amphetamine-type stimulant that is highly toxic to the central nervous system (CNS). Repeated intake of METH can lead to addiction, which has become a globalized problem, ...resulting in multiple public health and safety problems. Recently, the non-coding RNA (ncRNA) has been certified to play an essential role in METH addiction through various mechanisms. Herein, we mainly focused on three kinds of ncRNAs including long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs), which are involved in neurotoxicity effects such as cognitive impairment, behavioral abnormalities, and psychiatric disorders due to METH abuse. In addition, differential expression (DE) ncRNAs also suggest that specific responses and sensitivity to METH neurotoxicity exist in different brain regions and cells. We summarized the relationships between the ncRNAs and METH-induced neurotoxicity and psychiatric disturbances, respectively, hoping to provide new perspectives and strategies for the prevention and treatment of METH abuse.
Graphical Abstract
Schematic diagram of the non-coding RNAs (ncRNAs) was involved in methamphetamine (METH)-induced neurotoxicity. The ncRNAs were involved in METH-induced blood–brain barrier disruption, neuronal, astrocyte, and microglial damage, and synaptic neurotransmission impairment. The study of ncRNAs is a hot spot in the future to further understand the neurotoxicity of METH and provide more favorable scientific support for clinical diagnosis and innovation of related treatments.
•Define the thermodynamics and kinetics of mechano-electrochemical interaction for pipeline corrosion.•Quantitatively determine the effects of elastic and plastic deformations on pipeline ...corrosion.•Develop a mechano-electrochemical interaction based multiple physics field coupling model for pipeline corrosion prediction.•Review the state-of-the-arts of pipeline corrosion under stressing conditions.•Identify further research topics in mechano-electrochemical interaction during corrosion.
Engineering structures such as pipelines usually operate under stressing conditions. When corrosion occurs on the structures in service environments, the stress and corrosion reactions synergistically result in a so-called mechano-electrochemical (M-E) interaction, adversely affecting the structural integrity. This work reviewed the fundamentals of the M-E interaction for pipeline corrosion, where both corrosion thermodynamics and kinetics were derived by incorporating the effect of stress and strain applied on the pipelines. Under an elastic deformation, the M-E interaction for pipeline corrosion is usually negligible, while a dynamic elastic stress can degrade the integrity of corrosion scale on the steel and slightly accelerates the steel corrosion. However, plastic deformation results in an appreciable M-E interaction, remarkably changing both corrosion potential and corrosion rate of pipeline steels. Based on the M-E interaction theory, a multi-physics field coupling model with finite element analysis was developed to assess corrosion defects on pipelines for failure prediction. Perspectives of the M-E interaction in pipeline corrosion research and preventive management were analyzed.
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