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Previous studies have developed a stable weather index (SWI) based on meteorological elements that adequately represent PM 2.5 pollution over the North China Plain (NCP). However, the SWI performs poorly over the Yangtze River Delta (YRD) region because air pollution over this region is affected not only by stagnant weather (STAG) but also by transport (TRANS). For example, air pollutants can be transported from the NCP to the YRD by cold fronts. In this study, an obliquely rotated principal component analysis in the T-model is applied to classify the synoptic patterns of winter weather over the YRD region from 2013 to 2018. Among the four identified synoptic patterns, two of which cause TRANS, one pattern is most likely to cause STAG, and one pattern can lead to either STAG or TRANS depending on the location of high pressure around Shandong province. Due to the large contribution (63%) of TRANS to the total PM 2.5 pollution events, a transport pollution index (TPI) is constructed to describe the transport features of PM 2.5 pollution over the YRD region. Our results show that, when considering the SWI alone, the correlation coefficients between the SWI and ln(PM 2.5) range from 0.50 to 0.57 in the main cities of the YRD. Excitingly, when considering both the TPI and SWI (TPI+SWI), the correlation coefficients increase significantly to 0.63–0.78, suggesting that TPI+SWI better reflects the wintertime PM 2.5 pollution level over the YRD region. In addition, satisfactory performance in validation also suggests that TPI+SWI can increase the accuracy of evaluating and forecasting of PM 2.5 pollution episodes over regions downstream of source emissions. Image 1 • Air Pollution is classified as stagnant (STAG) and transport (TRANS) over YRD. • We propose two indices (SWI and TPI) to reflect STAG pollution and TRANS pollution. • SWI and TPI combined can better represent the pollution level of PM 2.5 over YRD. [ABSTRACT FROM AUTHOR]

Mast cells play a crucial role in gastrointestinal physiology and pathophysiology. This study was conducted to investigate the role of mast cells (MCs) in the protective effect of Lactobacillus casei ATCC 393 (L. casei ATCC 393) on intestinal barrier function. The regulatory effect of L. casei ATCC 393 on intestinal barrier dysfunction and MCs activation induced by Enterotoxigenic Escherichia coli K88 (ETEC K88) were evaluated by porcine mucosal mast cells (PMMCs)-porcine jejunal epithelial cells (IPEC-J2)- L. casei ATCC 393 co-culture experiments in vitro and MCs stabilizer drug experiment in vivo. Results showed that L. casei ATCC 393 pretreatment effectively alleviated the reduction of cell viability and increase of permeability in ETEC K88-infected IPEC-J2 cells. L. casei ATCC 393 pretreatment inhibited the increase of proinflammatory cytokines and some other MCs mediators, and decrease of anti-inflammatory cytokines in ETEC K88-infected PMMCs. Cromolyn sodium or L. casei ATCC 393 prevented ETEC K88-induced increase of intestinal epithelial cell permeability in IPEC-J2 cells when co-cultivation with PMMCs. Furthermore, cromolyn sodium or L. casei ATCC 393 pretreatment attenuated ETEC K88-induced increase of MCs mediators, mast cell proteases (MCPs) and carboxypeptidase A3 (CPA3) mRNA levels, and down-regulation of tight junction proteins, Toll-like receptor 2 and 4 (TLR2 and TLR4) expression levels in mice challenged by ETEC K88. These results indicated that intestinal barrier dysfunction caused by ETEC K88 was mediated by intestinal mast cell activation which can be prevented by L. casei ATCC 393 via TLRs signaling pathway. [ABSTRACT FROM AUTHOR]

Regional transport is deemed the key physical process affecting air pollution formation. Previous studies have indicated that black carbon (BC) is abundant and unevenly distributed over eastern China, but the details of its three-dimensional (3-D) distributions and sources are still lacking. In this study, based on vertical observations and by using the Weather Research and Forecasting model coupled with chemistry (WRF-Chem) coupled with the BC-tagging technique, we explored the 3-D distributions and sources of BC under two typical winter pollution events in eastern China, namely, one induced by cold front transport (TRAN) and another induced by stagnant weather (STAG). During TRAN, cold air can transport BC from upwind (North China Plain, NCP) to downwind (Yangtze River Delta, YRD) regions, thereby making the source region components of BC more diversified over the YRD than during STAG. It also significantly increased the proportion of BC residential sources in the YRD. The higher the altitude is, the higher the ratios of BC sources originating from long-range transport are. In TRAN, except for horizontal advection, which plays a key role in the distribution of BC, a stronger vertical advection changes the BC profiles and raises the boundary layer height as the cold front moves through. In particular, high-concentration BC from regional transport arrives earlier at the upper BL of downwind regions than at the surface, thus exerting a distinct positive vertical mixing effect on the surface BC. This study implies that regional transport can significantly impact BC evolution and further affect meteorology and climate on a large scale. • Regional transport was the key process of BC's 3-D structure over eastern China. • Regional transport modulated the sectoral source distribution of BC in the downwind region. • BC from regional transport arrived earlier at the upper BL of downwind regions than at the surface. [ABSTRACT FROM AUTHOR]

Lung cancer is the most common cause of cancer-related death worldwide. The occurrence of multidrug resistance (MDR) affects the therapeutic efficacy of chemotherapeutics. Therefore, to develop new anticarcinogen which can overcome MDR is urgent. Here, the novel microtubule inhibitor 5-(4-ethoxyphenyl)-1-(3,4,5-trimethoxyphenyl)-1H-1,2,4-triazol-3-amine (YAN) exhibited strong cytotoxicity towards A549 and MDR-phenotype A549/Taxol cells. We demonstrated that YAN was a poor substrate of P-glycoprotein (P-gp) and multidrug resistance-associated protein 1 (MRP1) which were over-expressed in A549/Taxol cells, and YAN inhibited their expression and function. Moreover, YAN arrested cells at mitosis phase by inhibiting microtubule polymerization. Further, YAN induced caspase-dependent apoptosis in A549 cells via mitochondria-mediated intrinsic pathway. In contrast, the multinucleation of A549/Taxol cells after YAN-treatment indicated the occurrence of mitotic catastrophe, and the subsequent apoptosis was mediated by apoptosis-inducing factor (AIF) nuclear translocation instead of p53- and caspase-dependent manner. Moreover, the inhibitory effect of YAN on PI3K/Akt activity was involved in the regulation of P-gp, MRP1 and AIF in A549/Taxol cells. Taken together, our finding indicates that YAN is a novel microtubule inhibitor and overcomes MDR by suppressing P-gp and MRP1 function and inducing cell death independent of p53 and caspase in A549/Taxol cells. Therefore, YAN possesses great potential for future development into an effective anticarcinogen especially for drug-resistant cancer. • YAN inhibits the function and expression of P-gp and MRP1 in A549/Taxol cells. • YAN induces mitosis phase arrest by inhibiting tubulin polymerization. • YAN induces apoptosis independent of p53 and caspase in A549/Taxol cells. • AIF nuclear translocation mediates YAN-induced apoptosis in A549/Taxol cells. • The inhibition of PI3K/Akt activity is involved in YAN-induced cell death. [ABSTRACT FROM AUTHOR]

The Yangtze River Delta (YRD) is one of the regions with air pollution and high ammonia (NH 3) emission in China. A high-resolution ammonia emission inventory for the YRD region was developed based on the updated source-specific emission factor (EFs) and the county-level activity data. The 1 × 1 km gridded emissions were allocated by using the appropriate spatial surrogate. The total NH 3 emissions changed insignificantly from 2006 to 2014 and varied in the range of 981.65 kt - 1014.30 kt. The fertilizer application and livestock were the major contributors of total emission. Humans, biomass burning and vehicles were the top three contributors of non-agricultural sources, accounting for 37.24%, 31.02% and 10.85%, respectively. Vehicles were calculated to be the non-agricultural source with the fastest annual growth rate. NH 3 emissions from the nitrogen fertilizer application generally peaked in summer, corresponding to the planting schedule and relatively high temperature. High NH 3 emissions occurred in the north as opposed to low emissions in the south of the YRD. The cities of Xuzhou, Yancheng and Nantong with more agricultural activities were demonstrated to have relatively high NH 3 emissions, contributing 10.0%, 9.0 and 7.1% of total emissions, respectively. The validity of the emission estimates was further evaluated based on the uncertainty analysis by Monte Carlo simulation, comparison with previous studies, and correlation analysis between NH 3 emission density and observed ground NH 3 concentration. A detailed NH 3 emission inventory is the basis of regional-scale air quality model simulation and can provide valuable information for understanding the formation mechanism of pollutants. • The 1 km × 1 km gridded NH 3 emission inventory was developed based on county-level activity data. • The emission of ammonia in the YRD was 998.83 kt in 2014. • Uncertainty and correlation analysis were used to evaluate the inventory. [ABSTRACT FROM AUTHOR]