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1.
J Environ Manage ; 359: 121071, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38718608

RESUMO

Particulate matter with an aerodynamic diameter of less than 1 µm (PM1.0) can be extremely hazardous to human health, so it is imperative to accurately estimate the spatial and temporal distribution of PM1.0 and analyze the impact of related policies on it. In this study, a stacking generalization model was trained based on aerosol optical depth (AOD) data from satellite observations, combined with related data affecting aerosol concentration such as meteorological data and geographic data. Using this model, the PM1.0 concentration distribution in China during 2016-2019 was estimated, and verified by comparison with ground-based stations. The coefficient of determination (R2) of the model is 0.94, and the root-mean-square error (RMSE) is 8.49 µg/m3, mean absolute error (MAE) is 4.10 µg/m3, proving that the model has a very high performance. Based on the model, this study analyzed the PM1.0 concentration changes during the heating period (November and December) in the regions where the "coal-to-gas" policy was implemented in China, and found that the proposed "coal-to-gas" policy did reduce the PM1.0 concentration in the implemented regions. However, the lack of natural gas due to the unreasonable deployment of the policy in the early stage caused the increase of PM1.0 concentration. This study can provide a reference for the next step of urban air pollution policy development.


Assuntos
Poluentes Atmosféricos , Material Particulado , Material Particulado/análise , China , Poluentes Atmosféricos/análise , Carvão Mineral , Monitoramento Ambiental , Poluição do Ar/análise , Aerossóis/análise
2.
ACS Appl Mater Interfaces ; 11(15): 14150-14158, 2019 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-30908006

RESUMO

A series of coaxial fibers with poly(ethylene terephthalate) (PET) as sheath and poly(tetradecyl acrylate) (PTA) comb-like polymeric phase change material as core have been prepared via an electrospinning technology with carbon nanotube (CNT) dispersed into a core component, denoted as PET/PTA- x CNT, where x is the mass fraction of CNT. The morphology, structure, and thermal performance of coaxial fibers are characterized. Good thermal stability below 300 °C is shown due to the sheath-core structure for PET/PTA- x CNT coaxial fibers. Light-to-thermal conversion effect is contributed from the wide UV-vis light absorbance of CNT and phase change of PTA, and PET/PTA-2% CNT reaches 60 °C after 600 s illumination under 100 mW/cm2. Furthermore, a comparable temperature variation is proved for the covered bottle with PET composite membrane containing PET/PTA-2% CNT coaxial fibers, and after 900 s illumination, the inner temperature of the bottle gets to 38 °C, which is 3 °C higher than that of the PET-covered one. The investigations of light-to-thermal conversion and thermoregulated ability of fibers guide an approach to thermal management material and greenhouse film application.

3.
Huan Jing Ke Xue ; 40(1): 33-43, 2019 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-30628257

RESUMO

To analyze the spatial and temporal variation characteristics of PM2.5 in Beijing-Tianjin-Hebei and its surrounding regions, a 1 km resolution AOT product was retrieved from MODIS data and the remote sensing inversion of the PM2.5 concentration in Beijing-Tianjin-Hebei and its surrounding regions was realized using the geographically weighted regression model. On this basis, the synthesis results of multi-timescale PM2.5 concentrations were verified and analyzed. Finally, the spatial and temporal variation characteristics of PM2.5 in Beijing-Tianjin-Hebei and its surrounding regions between 2016 and 2017 were compared and analyzed using different time scales. The results show that the verification of the PM2.5 concentration products of the average daily, monthly, and annual averages are in general good. The larger the time scale is, the better is the PM2.5 effect of the remote sensing estimation. The relative accuracy of the annual average PM2.5 products is higher than 80%. However, the precision of the PM2.5 remote sensing results for 2016 and 2017 is relatively close (at the same time scales). The PM2.5 distribution in Beijing-Tianjin-Hebei and its surrounding regions shows a seasonal variation (winter > autum ≈ spring > summer). The spatial distribution is high in the southern but low in the northern part. Compared with 2016, the average PM2.5 concentration decreased by~9.2% in 2017. The area with high values was significantly reduced. High PM2.5 concentrations occurred in November and December and low concentrations were observed in August. The PM2.5 concentration change between 2017 and 2016 is closely related to the comprehensive control crucial action and specific inspection activities of air pollution in 2017, which indirectly account for the effect of the reduction of the atmospheric pollution.

4.
Int J Oncol ; 53(2): 567-578, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29901191

RESUMO

Colorectal cancer (CRC) is a type of cancer with a mortality rate among the highest worldwide owing to its high rate of metastasis. Therefore, inflammation-associated metastasis in the development of CRC is currently a topic of considerable interest. In the present study, the pro-inflammatory cytokine interleukin-4 (IL-4) was identified to promote the epithelial-mesenchymal transition (EMT) of CRC cells. However, the enhancing effect of IL-4 was more evident in HCT116 cells compared with in RKO cells. Accordingly, an increased expression level of STAT6 was observed in HCT116 cells compared with RKO cells. Further investigations identified that E2F1 was required for maintaining the level of signal transducer and activator of transcription 6 (STAT6) in HCT116 cells. Mechanistically, E2F1 induced specificity protein 3 (SP3) directly by binding to the promoter of the STAT6 gene and activating its transcription in CRC cells. As a result, phosphorylation-activated STAT6 increased the expression of several EMT drivers, including zinc finger E-box-binding homeobox (Zeb)1 and Zeb2, which serve a critical function in IL-4-induced EMT. Rescue experiments further confirmed that IL-4-induced EMT relied on an intact E2F1/SP3/STAT6 axis in CRC cells. Finally, analysis of clinical CRC specimens revealed a positive correlation between E2F1, SP3 and STAT6. The ectopically expressed E2F1/SP3/STAT6 axis indicated a poor prognosis in patients with CRC. In conclusion, the E2F1/SP3/STAT6 pathway was identified to be essential for IL-4 signaling-induced EMT and aggressiveness of CRC cells.


Assuntos
Neoplasias Colorretais/metabolismo , Fator de Transcrição E2F1/metabolismo , Interleucina-4/metabolismo , Fator de Transcrição STAT6/genética , Fator de Transcrição Sp3/metabolismo , Animais , Proliferação de Células , Neoplasias Colorretais/genética , Transição Epitelial-Mesenquimal , Feminino , Regulação Neoplásica da Expressão Gênica , Células HCT116 , Células HT29 , Humanos , Masculino , Camundongos , Transplante de Neoplasias , Regiões Promotoras Genéticas , Fator de Transcrição STAT6/metabolismo , Transdução de Sinais
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