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Countries are paying increasing attention to environmental issues and are moving towards the goal of energy saving and carbon reduction. This research presents a method to analyse the effects of the use of non-thermal plasma (NTP) and water injection (WI) devices on the efficiency of internal combustion engines. The devices were installed on the intake manifold to investigate the effects of additional substances produced by electrolysis on the engine performance and exhaust emissions. According to the results, the addition of the NTP and WI devices affected the power efficiency and the rate of change of the brake-specific fuel consumption (BSFC) of the internal combustion engines. In addition, the change rate of hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOx) in the exhaust gases was affected. In conclusion, the study found that the additional substances generated by the NTP-electrolysed water mist or air influenced the fuel combustion efficiency and exhaust emissions.
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Industries' air pollution causes serious challenges to modern society, among them exhaust gases from internal combustion engines, which are currently one of the main sources. This study proposes a non-thermal plasma (NTP) system for placement in the exhaust system of internal combustion engines to reduce the toxic contaminants (HC, CO, and NOx) of exhaust gases. This NTP system generates a high-voltage discharge that not only responds to the ion chemical reaction to eliminate NOx and CO, but that also generates a combustion reaction at the local high temperature of plasma to reduce HC. The NTP system was designed on both the front and rear of the exhaust pipe to analyze the difference of different exhaust flow rates under the specified frequency. The results indicate that the NTP system can greatly reduce toxic contaminants. The NTP reactor placed in the front of exhaust pipe gave HC and CO removal efficiency of about 34.5% and 16.0%, respectively, while the NTP reactor placed in the rear of exhaust pipe gave NOx removal efficiency of about 41.3%. In addition, the voltage and material directly affect the exhaust gases obviously. In conclusion, the proposed NTP system installed in the exhaust system can significantly reduce air pollutants. These results suggest that applying NTP to the combustion engine should be a useful tool to simultaneously reduce both emissions of NOx and CO.
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Poluentes Atmosféricos/química , Gases em Plasma/química , Emissões de Veículos/análise , Poluição do Ar/análise , Gases/química , Gasolina/análise , Óxidos de Nitrogênio/química , Material Particulado/química , Fenômenos FísicosRESUMO
BACKGROUND: Compared with the precise targeting of drug-resistant mutant cancer cells, strategies for eliminating non-genetic adaptation-mediated resistance are limited. The pros and cons of the existence of inflammasomes in cancer have been reported. Nevertheless, the dynamic response of inflammasomes to therapies should be addressed. METHODS: Tumor-derived exosomes were purified by differential ultracentrifugation and validated by nanoparticle tracking analysis and transmission electron microscopy. A proximity ligation assay and interleukin-1ß (IL-1ß) level were used for detecting activation of NLRP3 inflammasomes. RNA sequencing was used to analyze the exosomal RNAs. MIR21 knocked out human monocytic THP cells and mir21 knocked out murine oral cancer MTCQ1 cells were generated for confirming the exosomal delivery of microRNA (miR)-21. Syngeneic murine models for head and neck cancer (C57BLJ/6J), breast cancer (BALB/C) and lung cancer (C57BL/6J) were applied for examining the impact of Snail-miR21 axis on inflammasome activation in vivo. Single-cell RNA sequencing was used for analyzing the tumor-infiltrated immune cells. Head and neck patient samples were used for validating the findings in clinical samples. RESULTS: We demonstrated that in cancer cells undergoing Snail-induced epithelial-mesenchymal transition (EMT), tumor cells suppress NLRP3 inflammasome activities of tumor-associated macrophages (TAMs) in response to chemotherapy through the delivery of exosomal miR-21. Mechanistically, miR-21 represses PTEN and BRCC3 to facilitate NLRP3 phosphorylation and lysine-63 ubiquitination, inhibiting NLRP3 inflammasome assembly. Furthermore, the Snail-miR-21 axis shapes the post-chemotherapy tumor microenvironment (TME) by repopulating TAMs and by activating CD8+ T cells. In patients with head and neck cancer, the Snail-high cases lacked post-chemotherapy IL-1ß surge and were correlated with a worse response. CONCLUSIONS: This finding reveals the mechanism of EMT-mediated resistance beyond cancer stemness through modulation of post-treatment inflammasome activity. It also highlights the dynamic remodeling of the TME throughout metastatic evolution.
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Neoplasias de Cabeça e Pescoço , MicroRNAs , Fatores de Transcrição da Família Snail/metabolismo , Animais , Linfócitos T CD8-Positivos , Cisplatino , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/genética , Humanos , Inflamassomos , Camundongos , MicroRNAs/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Microambiente TumoralRESUMO
Fused Deposition Modeling (FDM) can be used to manufacture any complex geometry and internal structures, and it has been widely applied in many industries, such as the biomedical, manufacturing, aerospace, automobile, industrial, and building industries. The purpose of this research is to characterize the polylactic acid (PLA) and polyethylene terephthalate glycol (PETG) materials of FDM under four loading conditions (tension, compression, bending, and thermal deformation), in order to obtain data regarding different printing temperatures and speeds. The results indicated that PLA and PETG materials exhibit an obvious tensile and compression asymmetry. It was observed that the mechanical properties (tension, compression, and bending) of PLA and PETG are increased at higher printing temperatures, and that the effect of speed on PLA and PETG shows different results. In addition, the mechanical properties of PLA are greater than those of PETG, but the thermal deformation is the opposite. The above results will be a great help for researchers who are working with polymers and FDM technology to achieve sustainability.
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ABSTRACT: Human norovirus (NoV) is the leading cause of acute gastroenteritis and the rapid transmission of NoV renders infection control problematic. Our study aimed to investigate viral shedding in gastroenteritis in children caused by variants of emerging norovirus strains infections.We used RNA-dependent RNA polymerase (RdRp) sequencing to measure NoV genome copies in stool to understand the relationship between the clinical manifestations and viral shedding in hospitalized patients. The near full-length NoV genome sequence was amplified via reverse transcription-polymerase chain reaction (RT-PCR) and NoV recombination was analyzed using the Recombination Analysis Tool (RAT).From January 2015 to March 2018, 77 fecal specimens were collected from hospitalized pediatric patients with confirmed NoV gastroenteritis. The NoV genotypes were GII.4 (nâ=â22), non-GII.4 (nâ=â14), GII.4 Sydney (nâ=â21), and GII.P16-GII.2 (nâ=â20). Viral load increased from days 2 to 9 from the illness onset, resulting in an irregular plateau without peaks. After day 9, the viral load declined gradually and most viral shedding in feces ceased by day 15. The average viral load was highest in GII.4 Sydney followed by GII.P16-GII.2 infections and lowest in non-GII.4 infections. GII.4 unclassified infections showed the longest viral shedding time, followed by GII.4 Sydney infections, GII.P16-GII.2 recombinant infection resulted in the shortest duration. NoVs evolved to form a group of GII.P16-GII.2 variants during the 2017 to 2018 period.The viral load and shedding period and was different in variants of NoV infections in children. High mutation rate of emerging and re-emerging variants was observed to an enhanced epidemic risk rendering continuous surveillance.
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Infecções por Caliciviridae/virologia , Gastroenterite/virologia , Variação Genética , Norovirus/genética , Eliminação de Partículas Virais/genética , Pré-Escolar , Fezes/virologia , Feminino , Genótipo , Humanos , Lactente , Pacientes Internados/estatística & dados numéricos , Masculino , Filogenia , Reação em Cadeia da Polimerase em Tempo Real , Recombinação Genética , Taiwan , Carga ViralRESUMO
In order to optimize the efficiency of the Fused deposition modeling (FDM) process, this study used polylactic acid (PLA) material under different parameters (the printing angle and the raster angle) to fabricate specimens and to explore its tensile properties. The effect of the ultraviolet (UV) curing process on PLA materials was also investigated. The results showed that the printing and raster angles have a high impact on the tensile properties of PLA materials. The UV curing process enhanced the brittleness and reduced the elongation of PLA material. Different effects were observed on tensile strength and modulus of specimens printed with different parameters after UV curing. The above results will be a great help for researchers who are working to achieve sustainability of PLA materials and FDM technology.
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Additive manufacturing (AM) has the advantages of providing materials with lightweight microporous structures and customized features, and being environmentally safe. It is widely used in medical sciences, the aerospace industry, biological research, engineering applications, and other fields. Among the many additive manufacturing methods, fused deposition modeling (FDM) is relatively low-cost, wastes less raw material and has a lower technical threshold. This paper presents a study on 3D printing based on FDM by changing two printing parameters, namely the printing temperature and filling percentage. The produced polylactic acid (PLA) material was analyzed through tensile and Shore D hardness tests and the differences in mechanical properties before and after the UV curing process were analyzed. The results show that increasing the filling percentage or increasing the printing temperature can effectively improve the tensile Young's modulus, ultimate tensile strength, elongation, and Shore hardness of the material. The UV curing process could enhance the rigidity and hardness of the material significantly but reduced the strength and toughness of the material. These findings could benefit researchers studying FDM with the goal of achieving sustainable manufactured materials.
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Epithelial-mesenchymal transition (EMT) is a major event during cancer progression and metastasis; however, the definitive role of EMT in remodeling tumor microenvironments (TMEs) is unclear. Tumor-associated macrophages (TAMs) are a major type of host immune cells in TMEs, and they perform a wide range of functions to regulate tumor colonization and progression by regulating tumor invasiveness, local tumor immunity, and angiogenesis. TAMs are considered to have an M2-like, i.e., alternatively activated, phenotype; however, how these EMT-undergoing cancer cells promote M2 polarization of TAMs as a crucial tumor-host interplay during cancer progression is unclear. In this study, we investigated the mechanism of EMT-mediated TAM activation. Here, we demonstrate that the EMT transcriptional factor Snail directly activates the transcription of MIR21 to produce miR-21-abundant tumor-derived exosomes (TEXs). The miR-21-containing exosomes were engulfed by CD14+ human monocytes, suppressing the expression of M1 markers and increasing that of M2 markers. Knockdown of miR-21 in Snail-expressing human head and neck cancer cells attenuated the Snail-induced M2 polarization, angiogenesis, and tumor growth. In head and neck cancer samples, a high expression of miR-21 was correlated with a higher level of SNAI1 and the M2 marker MRC1. This study elucidates the mechanism of EMT-mediated M2 polarization through delivery of the miR-21-abundant exosomes, which may serve as a candidate biomarker of tumor progression and provide a potential target for intercepting EMT-mediated TME remodeling.
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Exossomos/genética , Macrófagos/metabolismo , MicroRNAs/genética , Fatores de Transcrição da Família Snail/genética , Animais , Biomarcadores/metabolismo , Linhagem Celular Tumoral , Movimento Celular/genética , Progressão da Doença , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica/genética , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Macrófagos/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Monócitos/patologia , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Transcrição Gênica/genéticaRESUMO
Snail is primarily known as a transcriptional repressor that induces epithelial-mesenchymal transition by suppressing adherent proteins. Emerging evidence suggests that Snail can act as an activator; however, the mechanism and biological significance are unclear. Here, we found that CREB-binding protein (CBP) is the critical factor in Snail-mediated target gene transactivation. CBP interacts with Snail and acetylates Snail at lysine 146 and lysine 187, which prevents the repressor complex formation. We further identified several Snail-activated targets, including TNF-α, which is also the upstream signal for Snail acetylation, and CCL2 and CCL5, which promote the recruitment of tumor-associated macrophages. Here, we present our results on the mechanism by which Snail induces target gene transactivation to remodel the tumor microenvironment.