Microplastics (MPs), which are new environmental pollutants with a diameter of <5 mm, have received wide attention in recent years. However, there are still very limited data regarding the risks of ...MPs to animals, especially higher mammals. In this study, we exposed male mice to 5 μm pristine and fluorescent polystyrene MP for six weeks. The results showed that the polystyrene MP was observed in the guts of mice and could reduce the intestinal mucus secretion and cause damage the intestinal barrier function. In addition, high-throughput sequencing of the V3-V4 region of the 16S rRNA gene was used to explore the change of the gut microbiota composition in the cecal content. At the phylum level, the content of Actinobacteria decreased significantly in the polystyrene MP-treated group. The PD whole-tree indexes of the alpha diversity and principal component analysis (PCA) of the beta diversity indicated that the diversity of gut microbiota was altered after polystyrene MP exposure. At the genus level, a total of 15 types of bacteria changed significantly after exposure to polystyrene MP. Furthermore, the predicted KEGG (Kyoto Encyclopedia of Genes and Genomes) metabolic pathway differences indicated that the main metabolic pathways of the functional genes in the microbial community were significantly influenced by the polystyrene MP. In addition, indexes of amino acid metabolism and bile acid metabolism in the serum were analyzed after polystyrene MP exposure. These results indicated that polystyrene MP caused metabolic disorders. In conclusion, the polystyrene MP induced gut microbiota dysbiosis, intestinal barrier dysfunction and metabolic disorders in mice. This study provided more data on the toxicity of MPs in a terrestrial organism to aid in the assessment of the health risks of polystyrene MP to animals.
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•5 μm polystyrene microplastic could be accumulated in the gut of mice.•5 μm polystyrene microplastic induced intestinal barrier dysfunction in mice.•5 μm polystyrene microplastic induced gut microbiota dysbiosis in mice.•5 μm polystyrene microplastic induced bile acids metabolism disorder in mice.
•Polystyrene microplastic decreased the secretion of mucin in gut of mice.•Polystyrene microplastic induced gut microbiota dysbiosis in mice.•Polystyrene microplastic induced hepatic lipid metabolism ...disorder in mice.
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Microplastic (MP) has become a concerning global environmental problem. It is toxic to aquatic organisms and can spread through the food chain to ultimately pose a threat to humans. In the environment, MP can interact with microbes and act as a microbial habitat. However, effects of polystyrene MP on the gut microbiota in mammals remain unclear. Here, male mice were exposed to two different sizes of polystyrene MP for 5 weeks to explore its effect. We observed that oral exposure to 1000 μg/L of 0.5 and 50 μm polystyrene MP decreased the body, liver and lipid weights in mice. Mucus secretion in the gut decreased in both sizes of polystyrene MP-treated groups. Regarding the gut microbiota, at the phylum level, polystyrene MP exposure decreased the relative abundances of Firmicutes and α-Proteobacteria in the feces. Furthermore, high throughput sequencing of the V3-V4 region of the 16S rRNA gene revealed significant changes in the richness and diversity of the gut microbiota in the cecums of polystyrene MP-treated mice. At the genus level, a total of 6 and 8 types of bacteria changed in the 0.5 and 50 μm polystyrene MP-treated groups, respectively. Furthermore, an operational taxonomic unit (OTU) analysis identified that 310 and 160 gut microbes were changed in the 0.5 and 50 μm polystyrene MP-treated groups, respectively. In addition, the hepatic triglyceride (TG) and total cholesterol (TCH) levels decreased in both 1000 μg/L 0.5 and 50 μm polystyrene MP-treated groups. Correspondingly, the relative mRNA levels of some key genes related to lipogenesis and TG synthesis decreased in the liver and epididymal fat. These results indicated that polystyrene MP could modify the gut microbiota composition and induce hepatic lipid disorder in mice; while the mouse is a common mammal model, consequently, the health risks of MP to animals should not be ignored.
The initial setting time, fluidity and rheological properties of compound paste systems containing ultra-fine GGBS (UFS) were studied. The replacement of UFS into cement results in fast setting. An ...increase in the dosage of UFS shortened the initial setting time gradually due to the shortening of the induction period. Under the same UFS dosage, the induction period and initial setting time of the pastes was shorter in proportion to the fineness of the particles. The UFS showed a negative effect on the fluidity, and increasing the dosage of UFS gradually reduced the initial fluidity of the pastes. However, an interesting phenomenon was observed: for the same dosage of polycarboxylate superplasticizer (PCE), the initial fluidity was approximately the same as the increasing dosage of UFS. These results indicate that a possible positive synergistic effect on the initial fluidity was exerted due to the combination of UFS and the PCE, indicating that the UFS benefits the dispersing efficiency of PCE and the fluidity preservation of the pastes. The cement paste with UFS showed adverse effects on the rheological behaviour. The yield stress (τ0) and the plastic viscosity (ηp) increased with the rising dosage of UFS. Under the period of steady-state shearing (1800 s), the initial shear stress (τi) and minimum shear stress (τmin) increased consistently as the UFS content increased. However, adding PCE to the cement-UFS system resulted in rheological properties opposite to those of the pastes without PCE; the τi and τmin decreased as the UFS content increased. The results also confirmed the positive synergy effects between the UFS and the PCE.
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•An increase in the dosage of UFS shortened the initial setting time.•The yield stress and plastic viscosity increase with the rising dosage of UFS.•Cement-UFS paste can get good rheological properties with a small amount of PCE.
Clinical experience plays a vital role in the development of the professional identity (PI) of nursing students. China has applied a strict zero- COVID health policy in combating the COVID-19 ...pandemic since December 2019 and studies have been conducted in different places of China to explore PI development of nursing students during the pandemic time among the intern nursing students who are on clinical practices. This review study aims to synthesize the previous studies and provide a comprehensive picture of the impacts of the pandemic on the PI development of intern nursing students. Arksey and O'Malley's five-stage scoping review framework was used. Combinations of keywords were used to search relevant articles in both Chinese and English databases published from inception of the articles until the final search date (10 March 2022). The initially included articles were also appraised for their quality, and those that passed the appraisal were left for data analysis. The analytic results were cross-checked among the reviewers. Three themes emerged from the included studies: 1) the PI levels, 2) the impacts of personal and social factors of PL, and 3) the specific impact of the COVID-19 pandemic. The levels of students' PI ranged from 66%-80% of the total scores in PI instruments, almost the same levels as in pre-pandemic time, despite the elevated social image of nurses after the COVID-19 pandemic. There is no consensus about the impacts of most personal and social factors on students' PI across the studies. The impacts of COVID-19 on PI were both positive and negative. COVID-19 epidemic exerted complicated impacts on the PI of intern nursing students. While it is necessary to address the fear of the COVID-19 pandemic among intern nursing students, the pandemic may not be an opportunistic time to enhance the students' PI.
Consideration herein is the stability issue of peaked solitary wave solution for the modified Camassa-Holm-Novikov equation, which is derived from the shallow water theory. This wave configuration ...accommodates the ordered trains of the modified Camassa-Holm-Novikov-peaked solitary solution. With the application of conservation laws and the monotonicity property of the localized energy functionals, we prove the orbital stability of this wave profile in the
energy space according to the modulation argument.
Despite the fact that antimony triselenide (Sb2Se3) thin‐film solar cells have undergone rapid development in recent years, the large open‐circuit voltage (VOC) deficit still remains as the biggest ...bottleneck, as even the world‐record device suffers from a large VOC deficit of 0.59 V. Here, an effective interface engineering approach is reported where the Sb2Se3/CdS heterojunction (HTJ) is subjected to a post‐annealing treatment using a rapid thermal process. It is found that nonradiative recombination near the Sb2Se3/CdS HTJ, including interface recombination and space charge region recombination, is greatly suppressed after the HTJ annealing treatment. Ultimately, a substrate Sb2Se3/CdS thin‐film solar cell with a competitive power conversion efficiency of 8.64% and a record VOC of 0.52 V is successfully fabricated. The device exhibits a much mitigated VOC deficit of 0.49 V, which is lower than that of any other reported efficient antimony chalcogenide solar cell.
A heterojunction post‐annealing treatment is utilized to suppress the nonradiative recombination for a highly competitive power conversion efficiency of 8.64% and a record open‐circuit voltage (VOC) of 520 mV in Sb2Se3 thin‐film solar cells. The VOC deficit of the device is lower than that of any other reported efficient antimony chalcogenide solar cells.
Chinese medicine (CM) is usually prescribed as CM formula to treat disease. The lack of effective research approach makes it difficult to elucidate the molecular mechanisms of CM formula owing to its ...complicated chemical compounds. Network pharmacology is increasingly applied in CM formula research in recent years, which is identified suitable for the study of CM formula. In this review, we summarized the methodology of network pharmacology, including network construction, network analysis and network verification. The aim of constructing a network is to achieve the interaction between the bioactive compounds and targets and the interaction between various targets, and then find out and validate the key nodes via network analysis and network verification. Besides, we reviewed the application in CM formula research, mainly including targets discovery, bioactive compounds screening, toxicity evaluation, mechanism research and quality control research. Finally, we proposed prospective in the future and limitations of network pharmacology, expecting to provide new strategy and thinking on study for CM formula.
Targeting mTOR for cancer therapy Hua, Hui; Kong, Qingbin; Zhang, Hongying ...
Journal of hematology & oncology,
07/2019, Letnik:
12, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Mechanistic target of rapamycin (mTOR) is a protein kinase regulating cell growth, survival, metabolism, and immunity. mTOR is usually assembled into several complexes such as mTOR complex 1/2 ...(mTORC1/2). In cooperation with raptor, rictor, LST8, and mSin1, key components in mTORC1 or mTORC2, mTOR catalyzes the phosphorylation of multiple targets such as ribosomal protein S6 kinase β-1 (S6K1), eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1), Akt, protein kinase C (PKC), and type-I insulin-like growth factor receptor (IGF-IR), thereby regulating protein synthesis, nutrients metabolism, growth factor signaling, cell growth, and migration. Activation of mTOR promotes tumor growth and metastasis. Many mTOR inhibitors have been developed to treat cancer. While some of the mTOR inhibitors have been approved to treat human cancer, more mTOR inhibitors are being evaluated in clinical trials. Here, we update recent advances in exploring mTOR signaling and the development of mTOR inhibitors for cancer therapy. In addition, we discuss the mechanisms underlying the resistance to mTOR inhibitors in cancer cells.
Microplastics (MPs) has gradually become a global environmental pollution problem and may harm human and animal health. In recent years, a large number of studies had shown that MPs had various ...toxicological effects on different organisms. At the same time, a number of studies had also shown that gut microbiota was closely related to host health and as a toxicity target for certain environmental pollutants including MPs. The fact is that more and more studies proved that MPs not only could interact with microorganism directly but also serve as a carrier for other pollutants and interacted with microorganism indirectly. In this review, we summarized the interactions between MPs and microorganisms as well as gut microbiota, and considered the possible impacts of MPs on environmental animal and human health, suggesting that the environmental microorganisms and the gut microbiota of animals were also the very important target for MPs. We hope that more studies pay more attention to focus on the relationship between MPs, gut microbiota, and environmental animals and human health in the future.
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•Microplastics could interact with microorganisms as well as gut microbiota.•Microplastics may affect host health through effects on gut microbiota.•Effects of microplastics on gut microbiota need more attention.
This paper is concerned with the large time behavior of solutions to the Cauchy problem for a one-dimensional compressible non-isentropic Navier-Stokes/Allen-Cahn system which is a combination of the ...classical Navier-Stokes system with an Allen-Cahn phase field description. Motivated by the relationship between Navier-Stokes/Allen-Cahn and Navier-Stokes, the author can prove that the solutions to the one dimensional compressible non-isentropic Navier-Stokes/Allen-Cahn system tend time-asymptotically to the rarefaction wave, where the strength of the rarefaction wave is not required to be small. The proof is mainly based on a basic energy method.
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