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The less improvement of ambient visibility suspects the government’s efforts on alleviating PM 2.5 pollution. The COVID-19 lockdown reduced PM 2.5 and increased visibility in Wuhan. Compared to pre-lockdown period, the PM 2.5 concentration decreased by 39.0 μg m −3 , dominated by NH 4 NO 3 mass reduction (24.8 μg m −3 ) during lockdown period. The PM 2.5 threshold corresponding to visibility of 10 km (PTV 10 ) varied in 54–175 μg m −3 and an hourly PM 2.5 of 54 μg m −3 was recommended to prevent haze occurrence. The lockdown measures elevated PTV 10 by 9–58 μg m −3 as the decreases in PM 2.5 mass scattering efficiency and optical hygroscopicity. The visibility increased by 107%, resulted from NH 4 NO 3 extinction reduction. The NH 4 NO 3 mass reduction weakened its mutual promotion with aerosol water and increased PM 2.5 deliquescence humidity. Controlling TNO 3 (HNO 3  + NO 3 − ) was more effective to reduce PM 2.5 and improve visibility than NH x (NH 3  + NH 4 + ) unless the NH x reduction exceeded 11.7–17.5 μg m −3 .

The transboundary health impacts of air pollution associated with the international trade of goods and services are greater than those associated with long-distance atmospheric pollutant transport. The international air pollution trade Air quality and mortality are affected by local air pollution, but not all local air pollution comes from local emissions. It is also fed by atmospheric transport of pollutants from distant sources, and some of the pollution in one region is due to the production of goods for consumption in another. This study investigates the effect of these two remote pollution sources on premature mortality linked to fine particulate matter pollution. Qiang Zhang et al . find that, in 2007, about 12 per cent of premature deaths related to fine particulate matter were attributed to air pollutants from distant sources and about 22 per cent were associated with goods and services produced in one region for consumption in another. The findings suggest that the health impacts of pollution associated with international trade are greater than those associated with long-distance atmospheric pollutant transport. Millions of people die every year from diseases caused by exposure to outdoor air pollution 1 , 2 , 3 , 4 , 5 . Some studies have estimated premature mortality related to local sources of air pollution 6 , 7 , but local air quality can also be affected by atmospheric transport of pollution from distant sources 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 . International trade is contributing to the globalization of emission and pollution as a result of the production of goods (and their associated emissions) in one region for consumption in another region 14 , 19 , 20 , 21 , 22 . The effects of international trade on air pollutant emissions 23 , air quality 14 and health 24 have been investigated regionally, but a combined, global assessment of the health impacts related to international trade and the transport of atmospheric air pollution is lacking. Here we combine four global models to estimate premature mortality caused by fine particulate matter (PM 2.5 ) pollution as a result of atmospheric transport and the production and consumption of goods and services in different world regions. We find that, of the 3.45 million premature deaths related to PM 2.5 pollution in 2007 worldwide, about 12 per cent (411,100 deaths) were related to air pollutants emitted in a region of the world other than that in which the death occurred, and about 22 per cent (762,400 deaths) were associated with goods and services produced in one region for consumption in another. For example, PM 2.5 pollution produced in China in 2007 is linked to more than 64,800 premature deaths in regions other than China, including more than 3,100 premature deaths in western Europe and the USA; on the other hand, consumption in western Europe and the USA is linked to more than 108,600 premature deaths in China. Our results reveal that the transboundary health impacts of PM 2.5 pollution associated with international trade are greater than those associated with long-distance atmospheric pollutant transport.

The result of Aethalometer model to black carbon (BC) source apportionment is highly determined by the absorption Ångström exponent ( α ) of aerosols from fossil fuel combustion ( α ff ) and wood burning ( α wb ). A method using hourly measured potassium to calculate the α ff and α wb values was developed in this study. Results showed that the optimal α ff and α wb were 1.09 and 1.79 for the whole dataset. The optimal α values in the diurnal resolution were also calculated with α ff and α wb varied in 1.02 –1.19 and 1.71–1.90, respectively. Using the dynamic α values, the Pearson correlation coefficient between BC and potassium from wood burning substantially improved compared to the results derived from the fixed α values. The method developed in this study is expected to provide more reasonable BC source identification results, which are helpful for air quality, climate, and human health modeling studies.

With the widespread use of tigecycline, especially in elderly people infected with multidrug-resistant bacteria, the associated coagulation disorders are attracting the attention of clinicians. The risk factors of tigecycline-associated hypofibrinogenemia are still controversial. The aims of our study were to explore the related factors of hypofibrinogenemia caused by tigecycline, and to establish the risk assessment criteria for tigecycline-associated hypofibrinogenemia. This was an observational retrospective cohort study of patients treated for at least 3 days with tigecycline. Hypofibrinogenemia was defined as plasma fibrinogen <2.0 g/L. Risk factors were determined using logistic regression analysis, and the risk assessment criteria were identified by using receiver operating characteristic curves. In total, 148 patients were included in the analysis, mean age was 77.09±15.11 years old. Ninety patients who developed hypofibrinogenemia during tigecycline treatment with mean plasma fibrinogen of 1.42 g/L were included in the hypofibrinogenemia group, the other 58 patients with mean plasma fibrinogen of 2.68 g/L were included in the normal group. In the multivariate analysis, age ( = 0.035), tigecycline treatment duration ( = 0.044), and baseline fibrinogen level ( = 0.002) were independently associated with hypofibrinogenemia. An age of ≥82 years, ≥9 days of medication, and a baseline fibrinogen level of ≤3.5 g/L were selected for predicting hypofibrinogenemia. Hypofibrinogenemia was independently associated with bleeding (OR 8.96, 95% CI [1.132-70.946], = 0.038). Hypofibrinogenemia is a common adverse effect of tigecycline in our study. Elderly patients are more prone to developing hypofibrinogenemia after the administration of tigecycline. It is independently associated with bleeding but not death. The risk assessment criteria can help in the identification of patients with high risk of hypofibrinogenemia.

Hot extremes, ultraviolet (UV) radiation, and surface ozone all have prominent effects on human health and ecosystems. Here we show evidence that both hot extremes and high surface UV radiation at noon time occur concurrently in summer over the Yangtze Plain. Composite analysis suggests that hot extremes in summer are primarily caused by the westward extension of the Western Pacific Subtropical High, which leads to less clouds and consequently more downward solar radiation on the surface over the Yangtze Plain. It is found that surface UV radiation may be dominated by cloud variations, instead of stratospheric ozone during the hot extremes. Further analysis indicates that the hot extremes and high UV radiation, which play important roles in photochemistry in the troposphere, may result in more surface ozone. The concurrent hot extremes, strong UV radiation, and severe ozone pollutions over the Yangtze Plain in summer are likely to have dramatical influences on human health, which should be paid more attention.

The significant bidirectional comorbidity risk and extensive subclinical involvement observed between chronic obstructive pulmonary disease (COPD) and inflammatory bowel disease (IBD) underscore the pivotal role of the \"gut-lung axis\" in cross-organ pathological crosstalk. Here, we comprehensively review the molecular and immunological mechanisms driving this comorbidity. Genome-wide association studies (GWAS) have substantiated genetic pleiotropy that underpins a shared susceptibility to mucosal defense deficits. The \"common mucosal immune system\" (CMIS), rooted in embryonic homology, constitutes the anatomical basis for this pathological interplay, wherein aberrant immune cell homing, Th17/Treg imbalance, and the cross-organ trafficking of innate lymphoid cells (ILCs) mediate the distal dissemination of inflammation. Furthermore, gut dysbiosis-induced depletion of short-chain fatty acids (SCFAs), acting in concert with systemic hypoxia and the IL-23/IL-17 axis, potentiates synergistic injury to the gut-lung barriers. We highlight the reciprocal, bidirectional causality of this \"hypoxic loop\" and its testable mechanistic predictions for barrier dysfunction. Furthermore, we evaluate pharmacological evidence from drug repositioning, alongside a critical examination of the \"hidden axis\" of clinical therapies as profound iatrogenic confounders. Elucidating these mechanisms is critical for establishing systemic diagnostic and therapeutic strategies; interventions targeting shared molecular targets and the microbiota hold promise for achieving a simultaneous treatment approach for these distinct pathologies.

Western China has experienced rapid industrialization and urbanization since the implementation of the National Western Development Strategies (the \"Go West\" movement) in 1999. This transition has affected the spatial and temporal characteristics of nitrogen dioxide (NO2) pollution. In this study, we analyze the trends and variability of tropospheric NO2 vertical column densities (VCDs) from 2005 to 2013 over Western China, based on a wavelet analysis on monthly mean NO2 data derived from the Ozone Monitoring Instrument (OMI) measurements. We focus on the anthropogenic NO2 by subtracting region-specific \"background\" values dominated by natural sources. After removing the background influences, we find significant anthropogenic NO2 growth over Western China between 2005 and 2013 (8.6 ± 0.9 % yr−1 on average, relative to 2005), with the largest increments (15 % yr−1 or more) over parts of several city clusters. The NO2 pollution in most provincial-level regions rose rapidly from 2005 to 2011 but stabilized or declined afterwards. The NO2 trends were driven mainly by changes in anthropogenic emissions, as confirmed by a nested GEOS-Chem model simulation and a comparison with Chinese official emission statistics. The rate of NO2 growth during 2005–2013 reaches 11.3 ± 1.0 % yr−1 over Northwestern China, exceeding the rates over Southwestern China (5.9 ± 0.6 % yr−1) and the three well-known polluted regions in the east (5.3 ± 0.8 % yr−1 over Beijing-Tianjin-Hebei, 4.0 ± 0.6 % yr−1 over the Yangtze River Delta, and −3.3 ± 0.3 % yr−1 over the Pearl River Delta). Subsequent socioeconomic analyses suggest that the rapid NO2 growth over Northwestern China is likely related to the fast developing resource- and pollution-intensive industries along with the \"Go West\" movement as well as relatively weak emission controls. Further efforts should be made to alleviate NOx pollution to achieve sustainable development in Western China.

Small-scale nonlinear chemical and physical processes over pollution source regions affect the tropospheric ozone (O3), but these processes are not captured by current global chemical transport models (CTMs) and chemistry–climate models that are limited by coarse horizontal resolutions (100–500 km, typically 200 km). These models tend to contain large (and mostly positive) tropospheric O3 biases in the Northern Hemisphere. Here we use the recently built two-way coupling system of the GEOS-Chem CTM to simulate the regional and global tropospheric O3 in 2009. The system couples the global model (at 2.5° long.  ×  2° lat.) and its three nested models (at 0.667° long.  ×  0.5° lat.) covering Asia, North America and Europe, respectively. Specifically, the nested models take lateral boundary conditions (LBCs) from the global model, better capture small-scale processes and feed back to modify the global model simulation within the nested domains, with a subsequent effect on their LBCs. Compared to the global model alone, the two-way coupled system better simulates the tropospheric O3 both within and outside the nested domains, as found by evaluation against a suite of ground (1420 sites from the World Data Centre for Greenhouse Gases (WDCGG), the United States National Oceanic and Atmospheric Administration (NOAA) Earth System Research Laboratory Global Monitoring Division (GMD), the Chemical Coordination Centre of European Monitoring and Evaluation Programme (EMEP), and the United States Environmental Protection Agency Air Quality System (AQS)), aircraft (the High-performance Instrumented Airborne Platform for Environmental Research (HIAPER) Pole-to-Pole Observations (HIPPO) and Measurement of Ozone and Water Vapor by Airbus In- Service Aircraft (MOZAIC)) and satellite measurements (two Ozone Monitoring Instrument (OMI) products). The two-way coupled simulation enhances the correlation in day-to-day variation of afternoon mean surface O3 with the ground measurements from 0.53 to 0.68, and it reduces the mean model bias from 10.8 to 6.7 ppb. Regionally, the coupled system reduces the bias by 4.6 ppb over Europe, 3.9 ppb over North America and 3.1 ppb over other regions. The two-way coupling brings O3 vertical profiles much closer to the HIPPO (for remote areas) and MOZAIC (for polluted regions) data, reducing the tropospheric (0–9 km) mean bias by 3–10 ppb at most MOZAIC sites and by 5.3 ppb for HIPPO profiles. The two-way coupled simulation also reduces the global tropospheric column ozone by 3.0 DU (9.5 %, annual mean), bringing them closer to the OMI data in all seasons. Additionally, the two-way coupled simulation also reduces the global tropospheric mean hydroxyl radical by 5 % with improved estimates of methyl chloroform and methane lifetimes. Simulation improvements are more significant in the Northern Hemisphere, and are mainly driven by improved representation of spatial inhomogeneity in chemistry/emissions. Within the nested domains, the two-way coupled simulation reduces surface ozone biases relative to typical GEOS-Chem one-way nested simulations, due to much improved LBCs. The bias reduction is 1–7 times the bias reduction from the global to the one-way nested simulation. Improving model representations of small-scale processes is important for understanding the global and regional tropospheric chemistry.

The development of next-generation lithium-based batteries is accompanied by the intention to suppress the formation of dendritic lithium on the electrode, and is dominated by the picture that dendrites start to grow at the electrodes. Shifting from liquid to solid-state electrolytes, a high transference number is a quantity that promises the restraint of such parasitic side reactions. In this study, nanofocus X-ray wide-angle scattering is used to detect possible lithium-based crystallites in the polymer-based electrolyte. We perform operando scanning nanofocus wide-angle X-ray scattering on a composite gel-type polymer consisting of poly(vinylidene fluoride-co-hexafluoropropylene) and the single-ion conducting polymer poly((trifluoromethane) sulfonimide lithium styrene) in a lithium symmetric cell. We observe the occurrence and kinetics of lithium carbonate crystallites inside the electrolyte over a depth of 16 µm during three half-cycles. Furthermore, we prove the existence of lithium hydroxide crystallites near the lithium electrode and their absence in the bulk. Importantly, we identify the growth of pure metallic lithium inside the electrolyte as a sign of lithium dendrite growth happening inside the polymer-based electrolyte and not at the electrodes. Thus, nanofocus wide-angle X-ray scattering visualizes local structure changes such as dendrite formation inside the polymer-based electrolyte despite an unchanged electrochemical performance. Polymer electrolytes are promising candidates as separators in lithium metal batteries. Here, authors reveal the existence of local lithium-based crystallites inside the polymer electrolyte in a lithium symmetric cell. A combination of unique operando wide-angle X-ray scattering with a nano-sized beam and complementary spectroscopic techniques identifies these crystallites as lithium carbonate, lithium hydroxide, and even metallic lithium. It is shown that these crystallites lower the ionic conductivity and the transference number.

Nitrogen oxides (NOX = NO + NO2) are a major air pollutant under stringent emission regulation in China. The nation has effectively cut its total anthropogenic emission since the peaking around 2012, with cities at the forefront of implementing mitigation measures. However, the city-level emission changes and cross-city contrast remains poorly understood, due to inaccuracies in existing emission data. Using the satellite-based high-resolution PHLET inversion, we derived city-level NOX emissions in China from 2012 to 2020. We found much weaker emission declines in small cities (by 14.7% from 2012–2014 mean to 2018–2020 mean, for the bottom one-third of cities ordered by economic volumes) and medium cities (by 21.3%, for the middle one-third), compared to those in large cities (by 30.6%, for the top one-third) and provincial capital cities in the North Region of China (by 54.2%). Emissions even grew in 43.0% of small cities, compared to 17.4% for large cities. Cross-city emission differences both within each province and among the provinces decreased substantially over time, resulting in a relative shift of emission burdens towards small and medium cities. Such a tendency is hardly resolved by bottom–up emission inventories, highlighting the value of satellite-based high-resolution inversion for tracking city-level emissions to support targeted emission control.