A
bstract
The Rényi entropies as a generalization of the entanglement entropy imply much more information. We analytically calculate the Rényi entropies (with a spherical entangling surface) by means ...of a class of neutral hyperbolic black holes with scalar hair as a one-parameter generalization of the MTZ black hole. The zeroth-order and third-order phase transitions of black holes lead to discontinuity of the Rényi entropies and their second derivatives, respectively. From the Rényi entropies that are analytic at
n
= ∞, we can express the entanglement spectrum as an infinite sum in terms of the Bell polynomials. We show that the analytic treatment is in agreement with numerical calculations for the low-lying entanglement spectrum in a wide range of parameters.
Severe hazes occurred during 2016–2017 winter manifested winter haze was still a tough challenge in Beijing since the unprecedented haze in January 2013. Three haze episodes were identified from ...December 15, 2016 to January 15, 2017 in Beijing: the Red-Alert episode, the mixed haze-dust episode and the longest and heaviest Cross 2017 New Year's Haze episode. We analyzed the chemical components (water-soluble inorganic ions, carbonaceous components and trace elements) of multi-size airborne particles (PM1, PM2.5, PM10) samples, as well as the associated gaseous pollutants and meteorological parameters. Compared with the well-documented severe haze in January 2013, 2016–2017 winter haze was characterized by more stagnant synoptic conditions, sustained accumulation growth of PM enhanced by secondary reactions and regional contribution, as well as prominent fine particles mainly constituted by high concentrations of carbonaceous aerosol, secondary inorganic ions and anthropogenic elements. With strict pollution control measures since the enacting of Clean Air Action Plan in 2013, ambient concentrations of SO2, as well as SO42− and most anthropogenic elements in PM2.5 have decreased, whereas NO3− and NH4+ concentration in PM2.5 increased by as high as 77.9% and 47.3% respectively compared with January 2013. The ratios of NO3− /SO42− in PM1, PM2.5, PM10 were higher than 1.0 no matter during normal period or haze period, totally different with the results in January 2013, which suggested the increased relative contribution from mobile sources and decreased contribution from coal combustion in Beijing. Nitrate and its precursors had become major concerns during winter haze in Beijing, although the rapid growth of sulfate still played an important role in the formation and evolution of extremely heavy haze events. Under ammonium-rich and high relative humidity conditions, NO3− was thought to mainly be produced by enhanced heterogeneous reactions. To prevent Beijing winter haze effectively, it's quite crucial to cut NOx, NH3, SO2 and VOCs emissions simultaneously and strengthen regional cooperation on air pollution control.
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•Characteristics, precursors and sources of PM2.5 have changed obviously since the enacting of Clean Air Action Plan in 2013.•Compared with January 2013, SO2, SO42− and trace elements in PM2.5 decreased, whereas NO3− and NH4+ increased significantly.•2016–2017 winter haze is featured with more stagnant meteorology and sustained accumulation of PM2.5 enhanced by regional transport and secondary reactions.•Carbonaceous aerosol (OC, EC) and secondary inorganic aerosol (SO42−, NO3− and NH4+) were two major parts in PM with fine-mode size distributions.
In order to probe the seasonal variation, formation mechanisms as well as geographical origins of fine particles and its chemical components in two cities (Zhengzhou, ZZ and Xinxiang, XX) in Central ...Plains Urban Agglomeration, daily PM2.5 aerosol samples were collected for four consecutive seasons during 2017–2018. The annual average concentrations of PM2.5 (particulate matter with an aerodynamic diameter smaller than 2.5 μm) were calculated at 70.5 ± 50.8 and 69.0 ± 46.3 μg m−3 at ZZ and XX, respectively. Daily ambient PM2.5 concentrations ranged from 18.2 to 303.0 μg m−3, among which >81% of the total sampling days exceeded the National Ambient Air Quality Standard of China (NAAQS, 35 μg m−3 as an annual average). Additionally, concentrations of PM2.5 and its major chemical components were seasonally dependent, usually with the highest mass concentration in winter. Compared with previous studies, higher NO3−/SO42− were observed in this study depicted that air pollution caused by motor vehicle exhaust cannot be ignored. OC concentration was higher at ZZ than XX during sampling campaign likely partially caused by larger number of motor vehicles, chemical pesticide and solvent used in ZZ. Both homogeneous and heterogeneous reactions played an important role in the formation of nitrate, while heterogeneous reactions dominated the formation of sulfate. We also found a faster increase in nitrate than in sulfate during the evolution of haze. The characteristics of long-range transportation of PM2.5 and its major chemical components and gaseous precursors were observed at both sites through back trajectories and WPSCF analysis, suggesting the complexity of air pollution and the multi-influence among cities.
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•Seasonal variation characteristics of PM2.5 and its chemical components are explored.•A faster increase in nitrate than in sulfate during the evolution of haze periods.•Severe pollution in winter has alleviated obviously compared with previous years.•Discrepancies of individual compositions of PM2.5 at both sites are significant.•Long-range transportation of PM2.5 is observed at both sites with WPSCF analysis.
Carbonaceous constituents have various adverse impacts on human health, visibility, and climate change. Although comprehensive studies on the characteristics of carbonaceous constituents have been ...conducted recently, systematic studies covering both the mass characteristics and light-absorption properties of carbonaceous constituents on a regional scale in China are quite limited. In this study, current seasonal measurements of organic carbon (OC) and elemental carbon (EC) in PM2.5 were investigated during autumn and winter (1–30 October 2017 and December 18, 2017 to January 17, 2018) in six selected cities located at the eastern foot of the Taihang Mountains: Beijing, Baoding, Shijiazhuang, Handan, Xinxiang, and Zhengzhou. Seasonal variations were similar when Beijing was excluded. The lowest concentrations of OC (18.33 ± 9.39 μg/m3) and EC (7.66 ± 5.64 μg/m3) were observed in Xinxiang (autumn) and Beijing (winter), respectively, while the highest concentrations of OC (38.43 ± 62.10 μg/m3) and EC (12.24 ± 24.67 μg/m3) occurred in Baoding during winter mainly due to elevated fuel combustion for space heating. The results of the potential source contribution function (PSCF) analysis suggested that border zones between several provinces in North China should be highlighted in order to strengthen pollution control. Moreover, by separating the optical properties of brown carbon from those of black carbon, we were able to estimate the contributions of brown carbon to the PM2.5 total light-absorption coefficient. The results show that the brown carbon absorption coefficient (at 405 nm) in winter at six sites accounted for 21.2%, 33.3%, 34.7%, 39.1%, 48.6%, and 23.3% of the PM2.5 light absorption, which are values that are comparable to the contribution of black carbon in Xinxiang. These results provide a more comprehensive understanding of carbonaceous constituents on a regional scale.
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•Significant seasonal variations of PM2.5 and its carbonaceous components were observed.•Seasonal variations of OC/EC and brown carbon highly relied on fuel used for heating.•Beijing showed the opposite seasonal characteristics compared with other cities.•Light absorption of brown carbon was comparable to black carbon in Xinxiang winter.
Natural antioxidants represented by quercetin have been documented to be effective against atherosclerosis. However, the related mechanisms remain largely unclear. In this study, we identified a ...novel anti-atherosclerotic mechanism of quercetin inhibiting macrophage pyroptosis by activating NRF2 through binding to the Arg483 site of KEAP1 competitively. In ApoE−/− mice fed with high fat diet, quercetin administration attenuated atherosclerosis progression by reducing oxidative stress level and suppressing macrophage pyroptosis. At the cellular level, quercetin suppressed THP-1 macrophage pyroptosis induced by ox-LDL, demonstrated by inhibiting NLRP3 inflammasome activation and reducing ROS level, while these effects were reversed by the specific NRF2 inhibitor (ML385). Mechanistically, quercetin promoted NRF2 to dissociate from KEAP1, enhanced NRF2 nuclear translocation as well as transcription of downstream antioxidant protein. Molecular docking results suggested that quercetin could bind with KEAP1 at Arg415 and Arg483. In order to verify the binding sites, KEAP1 mutated at Arg415 and Arg483 to Ser (R415S and R483S) was transfected into THP-1 macrophages, and the anti-pyroptotic effect of quercetin was abrogated by Arg483 mutation, but not Arg415 mutation. Furthermore, after administration of adeno associated viral vector (AAV) with AAV-KEAP1-R483S, the anti-atherosclerotic effects of quercetin were almost abolished in ApoE−/− mice. These findings proved quercetins suppressed macrophage pyroptosis by targeting KEAP1/NRF2 interaction, and provided reliable data on the underlying mechanism of natural antioxidants to protect against atherosclerosis.
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•A novel mechanism of quercetin protects against atherosclerosis by inhibiting macrophage pyroptosis has been elucidated.•Quercetin inhibits macrophage pyroptosis by suppressing oxidative stress levels through the activation of NRF2 pathway.•Quercetin affects NRF2-KEAP1 interaction by competitively binding to KEAP1 at Arg483 site.•This study provides a new insight into the mechanisms by which natural antioxidants intervene in atherosclerosis.
Elevated plasma homocysteine levels, known as hyperhomocysteinemia, have been identified as an independent risk factor for atherosclerosis and related cardiovascular diseases. Macrophage ...pyroptosis-mediated inflammation is crucial in the development of atherosclerosis, but the underlying mechanisms remain unclear.
A hyperhomocysteinemia atherosclerotic model with ApoE
mice fed with a high-methionine diet was constructed to investigate the role of plasma homocysteine in atherosclerosis. THP-1-derived macrophages were used to investigate the mechanisms by which Hcy regulates pyroptosis.
We found that hyperhomocysteinemia resulted in larger atherosclerotic plaques and more secretion of inflammatory cytokines, while these effects were attenuated in Caspase-1 knockdown mice. Likewise, in vitro experiments demonstrated that treatment of macrophages with homocysteine resulted in NLRP3 inflammasome activation and pyroptosis, as evidenced by cleavage of Caspase-1, production of downstream IL-1β, elevation of lactate dehydrogenase activity, and extensive propidium iodide-positive staining of cells. These were all inhibited by Caspase-1 inhibitor. In addition, excessive generation of reactive oxygen species was associated with mitochondrial dysfunction, characterized by loss of mitochondrial membrane potential and ATP synthesis. Moreover, further experiments revealed that homocysteine induced endoplasmic reticulum stress, enhanced communication between the endoplasmic reticulum and mitochondria, and consequently contributed to calcium disorder. Furthermore, the endoplasmic reticulum stress inhibitor, 4PBA, the calcium chelator, BAPTA, and calcium channel inhibitor, 2-APB significantly improved macrophage pyroptosis.
Homocysteine accelerates atherosclerosis progression by enhancing macrophages pyroptosis via promoting endoplasmic reticulum stress, endoplasmic reticulum-mitochondria coupling, and disturbing of calcium disorder.
Endophytic fungi have the potential to enhance plant resistance to various stresses and promote the ecological adaptation of the hosts. To evaluate the effects of the riparian endophytes on rice ...seedlings to flooding tolerance, here we screened out two fungi from the plant
Myricaria laxiflora
growing in the Yangtze River zone. Through morphological characteristics and rDNA ITS (internal transcriber region) sequence, the two strains were, respectively, identified as
Aspergillus fumigatus
and
Chaetomium globosum
. Metabolites derived from both fungi were capable of increasing tolerance of rice to flooding. Systematic separation and purification coupled to bioassays revealed that two natural antioxidants, Z-
N
-4-hydroxystyryl formamide (NFA) and chaetoglobosin A (CheA), were effective for alleviating flooding stress. Both NFA and CheA can reverse the decline trend of oxidative parameters caused by long-term flooding, such as malondialdehyde, superoxide dismutase, ethanol dehydrogenase, and NADPH oxidase. Gene expression analyses of NADPH oxidase families indicated that
OsRbohB
could be involved in conferring flooding tolerance mediated by the two natural antioxidants. These findings contribute to understanding the role of the natural antioxidants in riparian endophytic fungi and providing a basis for improvement of flooding tolerance of rice and other crop plants.
High-temporal resolution and timely emission estimates are essential for developing refined air quality management policies. Considering the advantages of extensive coverage, high reliability, and ...near real-time capabilities, in this work, electric power big data (EPBD) was first employed to obtain accurate hourly resolved facility-level air pollutant emissions information from the cement industries in Tangshan City, China. Then, the simulation optimization was elucidated by coupling the data with the weather research and forecasting (WRF)-community multiscale air quality (CMAQ) model. Simulation results based on estimated emissions effectively captured the hourly variation, with the NMB within ±50% for NO2 and PM2.5 and R greater than 0.6 for SO2. Hourly PM2.5 emissions from clinker production enterprises exhibited a relatively smooth pattern, whereas those from separate cement grinding stations displayed a distinct diurnal variation. Despite the remaining underestimation and/or overestimation of the simulation concentration, the emission inventory based on EPBD demonstrates an enhancement in simulation results, with RMSE, NMB, and NME decreasing by 9.6%, 15.8%, and 11.2%, respectively. Thus, the exploitation of the vast application potential of EPBD in the field of environmental protection could help to support the precise prevention and control of air pollution, with the possibility of the early achievement of carbon peaking and carbon neutrality targets in China and other developing countries.
Natural sources, such as soil and wind-erosion dust (SWD), biomass open burning (BOB), sea salt spray (SSAS) and biogenic source (BIO), are major contributors to atmospheric emissions of trace ...elements (TEs) globally. In this study, we used a comprehensive approach to account for area-, production- and biofuel consumption-based emission factor calculation methods, and thus developed an integrated high-resolution emission inventory for 15 types of TEs (As, B, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Sb, Se, V and Zn) originated from natural sources in China for the year 2015. The results show that national emissions of TEs in 2015 range from 7.45 tons (Hg) to 1, 400 tons (Zn) except for the extremely high emissions of Mn (10, 677 tons). SWD and BIO are identified as the top two source contributors, accounting for approximately 67.7% and 26.1% of the total emissions, respectively. Absolute emissions of TEs from natural sources are high in the Xinjiang, Inner Mongolia and Tibet autonomous regions with large areas of bare soil and desert. However, emission intensity of TEs per unit area in the Southern provinces of China is higher than those in Northern China and Southwestern China, with the Yunnan and Sichuan provinces displaying the highest emission intensity. Our results suggest that controlling SWD can play a significant role in reducing fugitive particulate matter and the associated emissions of TEs from natural sources in China; and desertification control is particularly critical in the Northwest provinces where the majority of deserts are located.
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•Emission of Mn (10, 677t) from natural sources ranks 1st in 15 trace elements in China.•Emissions of other elements in 2015 range from 7.45 tons (Hg) to 1, 400 tons (Zn).•Soil & wind-erosion dust and biogenic are identified as the two biggest contributors.•Soil & wind-erosion dust shared over 95% of total emission of Cr, Co, As, Mn and V.•Emission intensity per unit land is higher in Southern than that in Northern provinces.
Micheliolide (MCL), which is the active metabolite of parthenolide, has demonstrated promising clinical application potential. However, the effects and underlying mechanisms of MCL on atherosclerosis ...are still unclear.
ApoE−/− mice were fed with high fat diet, with or without MCL oral administration, then the plaque area, lipid deposition and collagen content were determined. In vitro, MCL was used to pretreat macrophages combined by ox-LDL, the levels of ferroptosis related proteins, NRF2 activation, mitochondrial function and oxidative stress were detected.
MCL administration significantly attenuated atherosclerotic plaque progress, which characteristics with decreased plaque area, less lipid deposition and increased collagen. Compared with HD group, the level of GPX4 and xCT in atherosclerotic root macrophages were increased in MCL group obviously. In vitro experiment demonstrated that MCL increased GPX4 and xCT level, improved mitochondrial function, attenuated oxidative stress and inhibited lipid peroxidation to suppress macrophage ferroptosis induced with ox-LDL. Moreover, MCL inhibited KEAP1/NRF2 complex formation and enhanced NRF2 nucleus translocation, while the protective effect of MCL on macrophage ferroptosis was abolished by NRF2 inhibition. Additionally, molecular docking suggests that MCL may bind to the Arg483 site of KEAP1, which also contributes to KEAP1/NRF2 binding. Furthermore, Transfection Arg483 (KEAP1-R483S) mutant plasmid can abrogate the anti-ferroptosis and anti-oxidative effects of MC in macrophages. KEAP1-R483S mutation also limited the protective effect of MCL on atherosclerosis progress and macrophage ferroptosis in ApoE−/− mice.
MCL suppressed atherosclerosis by inhibiting macrophage ferroptosis via activating NRF2 pathway, the related mechanism is through binding to the Arg483 site of KEAP1 competitively.
•MCL attenuated AS development, decreased inflammatory response and improved oxidative stress.•MCL inhibited macrophage ferroptosis and mitochondrial function to attenuate the progress of AS.•MCL suppressed ferroptosis by increasing GPX4 and xCT via activating NRF2 pathway.•MCL promotes KEAP1/NRF2 dissociation by competing with NRF2 to bind the Arg483 site of KEAP1.
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