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Severe haze is a major public health concern in China and India. Both countries rely heavily on coal for energy, and sulfur dioxide (SO 2 ) emitted from coal-fired power plants and industry is a major pollutant contributing to their air quality problems. Timely, accurate information on SO 2 sources is a required input to air quality models for pollution prediction and mitigation. However, such information has been difficult to obtain for these two countries, as fast-paced changes in economy and environmental regulations have often led to unforeseen emission changes. Here we use satellite observations to show that China and India are on opposite trajectories for sulfurous pollution. Since 2007, emissions in China have declined by 75% while those in India have increased by 50%. With these changes, India is now surpassing China as the world’s largest emitter of anthropogenic SO 2 . This finding, not predicted by emission scenarios, suggests effective SO 2 control in China and lack thereof in India. Despite this, haze remains severe in China, indicating the importance of reducing emissions of other pollutants. In India, ~33 million people now live in areas with substantial SO 2 pollution. Continued growth in emissions will adversely affect more people and further exacerbate morbidity and mortality.

A multi-axis differential optical absorption spectroscopy (MAX-DOAS) instrument was deployed in May and June 2016 at a monitoring station (37.18∘ N, 114.36∘ E) in the suburban area of Xingtai, which is one of the most polluted cities in the North China Plain (NCP), during the Atmosphere-Aerosol-Boundary Layer-Cloud (A2BC) experiment and Air chemistry Research In Asia (ARIAs) joint experiments to derive tropospheric vertical profiles of NO2, SO2, HONO, HCHO, CHOCHO and aerosols. Aerosol optical depths derived from MAX-DOAS were found to be consistent with collocated sun-photometer measurements. Also the derived near-surface aerosol extinction and HCHO mixing ratio agree well with the coincident visibility meter and in situ HCHO measurements, with mean HCHO near-surface mixing ratios of ∼3.5 ppb. Underestimations of MAX-DOAS results compared to in situ measurements of NO2 (∼60 %) and SO2 (∼20 %) are found expectedly due to vertical and horizontal inhomogeneity of trace gases. Vertical profiles of aerosols and NO2 and SO2 are reasonably consistent with those measured by a collocated Raman lidar and aircraft spirals over the station. The deviations can be attributed to differences in sensitivity as a function of altitude and substantial horizontal gradients of pollutants. Aerosols, HCHO and CHOCHO profiles typically extended to higher altitudes (with 75 % integrated column located below ∼1.4 km) than NO2, SO2 and HONO did (with 75 % integrated column below ∼0.5 km) under polluted conditions. Lifted layers were systematically observed for all species (except HONO), indicating accumulation, secondary formation or long-range transport of the pollutants at higher altitudes. Maximum values routinely occurred in the morning for NO2, SO2 and HONO but occurred at around noon for aerosols, HCHO and CHOCHO, mainly dominated by photochemistry, characteristic upslope–downslope circulation and planetary boundary layer (PBL) dynamics. Significant day-to-day variations are found for all species due to the effect of regional transport and changes in synoptic pattern analysed with the backward propagation approach based on HYSPLIT trajectories. Low pollution was often observed for air masses from the north-west (behind cold fronts), and high pollution was observed from the southern areas such as industrialized Wu'an. The contribution of regional transport for the pollutants measured at the site during the observation period was estimated to be about 20 % to 30 % for trace gases and about 50 % for aerosols. In addition, agricultural burning events impacted the day-to-day variations in HCHO, CHOCHO and aerosols. It needs to be noted that although several MAX-DOAS measurements of trace gases and aerosols in the NCP area have been reported in previous studies, this study is the first work to derive a comprehensive set of vertical profiles of NO2, SO2, HONO, HCHO, CHOCHO and aerosols from measurements of one MAX-DOAS instrument. Also, so far, the validation of MAX-DOAS profile results by comparison with various surface in situ measurements as well as profile measurements from lidar and aircraft is scarce. Moreover, the backward propagation approach for characterizing the contributions of regional transport of pollutants from different regions was applied to the MAX-DOAS results of trace gases and aerosols for the first time.

This study investigates the spatiotemporal variability of ambient methane (CH4) using a drone-deployable Aeris Technologies MIRA Strato LDS midwave-infrared analyzer. Laboratory calibration with NOAA-certified gas standards and Standard Reference Material (SRM) for CH4 demonstrated high measurement precision across a range of concentrations (R2 = 0.9986, slope = 0.9678). Field validation conducted during a two-week intercomparison with a Picarro G2301 in September 2023 confirmed the MIRA Strato’s reliability under ambient conditions (R2 = 0.9845; slope = 0.9438), indicating strong agreement with the reference analyzer. Diurnal patterns revealed peak CH4 concentrations (~2.2 ppm) between 04:00–08:00 LT and minima (~2.1 ppm) between 13:00–17:00 LT, consistent with nocturnal boundary-layer stability and daytime convective mixing. Across 14 midday UAV flights from October 2023 to September 2024, CH4–altitude slopes ranged from −3.05 × 10−4 to +1.41 × 10−4 ppm/m, reflecting variable stratification and uplift regimes. The highest flight concentration (2.23 ppm) was observed on 19 October under stable conditions, while the lowest (2.03 ppm) was observed on 14 August under elevated vertical mixing. These extremes reflect seasonal background accumulation and convective transport effects. Temperature was the most consistent predictor, with regression coefficients ranging from −0.021 to +0.008 ppm/°C, while ethane (C2H6) coefficients were significant but confounded due to measurements below detection limits. The analyzer maintained strong signal stability throughout (mean CV ≈ 0.0066; max = 0.0114), and remote sensing validation with TROPOMI supported observed seasonal accumulation trends. These results demonstrate the MIRA Strato’s capability to resolve near-surface CH4 dynamics and characterize convective transport in complex atmospheric environments.

Yttrium iron garnet (YIG), as a core material in microwave devices, remains a key focus in materials science for performance optimization. In this study, Y3Fe4.8Cu0.1Sn0.1O12 samples were prepared via the solid-phase method with the co-doping of low-magnetic-anisotropy Cu2+ and Sn4+, combined with hot-press sintering under different conditions. Systematic analyses revealed that hot-press sintering optimized the microstructure, reduced porosity, and improved the compactness to 5.60 g/cm3. The sample hot-pressed sintered at 1200 °C achieved a maximum ε′ of 34, the lowest dielectric loss and a minimal FMR linewidth of 21 Oe, thus holding great potential for applications in high-frequency microwave devices requiring low loss and high integration. This work provides a viable approach to regulating the microstructure, dielectric properties, and magnetic properties of YIG ferrites.

A suite of instruments was deployed to simultaneously measure nitrous acid (HONO), nitrogen oxides (NOx = NO + NO2), carbon monoxide (CO), ozone (O3), volatile organic compounds (VOCs – including formaldehyde, HCHO) and meteorological parameters near a typical industrial zone in Nanjing in the Yangtze River Delta (YRD) region of China from 1 to 31 December 2015. High levels of HONO were detected using a wet-chemistry-based method. HONO ranged from 0.03 to 7.04 ppbv with an average of 1.32±0.92 ppbv. Elevated daytime HONO was frequently observed with a minimum of several hundred parts per trillion by volume (pptv) on average, which cannot be explained by the homogeneous OH + NO reaction (POH+NO) and primary emissions (Pemission), especially during periods with high particulate matter (PM2.5) loadings. HONO chemistry and its impact on the atmospheric oxidation capacity in the study area were further investigated using a Master Chemical Mechanism (MCM) box model. The results show that the average hydroxyl radical (OH) production rate was dominated by the photolysis of HONO (7.13×106 molec. cm−3 s−1), followed by the ozonolysis of alkenes (3.94×106 molec. cm−3 s−1), the photolysis of O3 (2.46×106 molec. cm−3 s−1) and the photolysis of HCHO (1.60×106 molec. cm−3 s−1) during the campaign period, especially within plumes that originated from the industrial zone. Model simulations indicated that heterogeneous chemistry played an important role in HONO formation. The average nighttime NO2 to HONO conversion rate was determined to be ∼0.8 % h−1. A good correlation between nocturnal HONO∕NO2 and the product of particle surface area density (S∕V) and relative humidity (RH), S/V⋅RH, supports the heterogeneous NO2∕H2O reaction mechanism. The other HONO source, designated as Punknonwn, was about twice as high as POH+NO on average and displayed a diurnal profile with an evidently photo-enhanced feature, i.e., photosensitized reactions of NO2 may be an important daytime HONO source. Nevertheless, our results suggest that daytime HONO formation was mostly due to the light-induced conversion of NO2 on aerosol surfaces, whereas heterogeneous NO2 reactions on the ground surface dominated nocturnal HONO production. Our study indicated that an elevated PM2.5 level during haze events can promote the conversion of NO2 to HONO by providing more heterogeneous reaction sites, thereby increasing the atmospheric oxidation capacity, which may further promote the formation of secondary air pollutants. Highlights: High levels of HONO, with an average of 1.32±0.92 ppbv, were observed near one of the largest industrial zones in the YRD region of China. HONO photolysis and alkene ozonolyses contributed the most to OH production and, hence, the atmospheric oxidation capacity. High loading of PM2.5 provided additional reaction surfaces for HONO formation. Heterogeneous formation mechanisms were the most important daytime HONO sources and were further enhanced by sunlight.

Objective: To investigate the therapeutic effects and safety profile of Wanshi Shachong Xiaoji Pills (WSXPs) on a functional dyspepsia (FD) mouse model and to preliminarily explore its potential mechanism and impact on associated hepatic metabolism. Methods: An FD model was established in mice using L-arginine. Gastrointestinal motility was assessed by measuring gastric emptying and intestinal propulsion rates. Serum levels of gastrointestinal hormones (MTL, GAS, VIP, CCK) and gut microbiota composition were analyzed. A one-month repeated-dose toxicity study was conducted in normal mice to evaluate safety. The effects of WSXPs on lipid metabolism and inflammation were further examined in a hepatocyte steatosis model in vitro, and network pharmacology was employed to predict potential mechanisms. Results: WSXPs significantly alleviated FD symptoms by improving gastrointestinal motility, bidirectionally regulating gut hormone levels, and increasing the abundance of beneficial bacteria (Akkermansia muciniphila). Long-term administration showed no significant toxicity. In vitro, WSXPS reduced lipid accumulation and inflammation in hepatocytes. Network analysis identified the PI3K-Akt signaling pathway as a potentially central common target, providing a hypothesis for future mechanistic studies. Conclusions: WSXPs effectively improve FD symptoms, modulates gut microbiota, and exhibits potential benefits on hepatic lipid metabolism in vitro, possibly via the PI3K-Akt pathway. This hepatocyte-level finding, combined with its in vivo efficacy in FD, suggests a promising avenue for future research into its potential applications in metabolic-associated conditions. This study provides a scientific foundation for the further development and clinical application of WSXPs in treating FD.

An active lifestyle protects against cardiovascular diseases, yet its mechanisms in modulating the cardiac immune environment and preserving cardiac function remain unclear. Here, we identify a subpopulation of monocyte-derived cardiac macrophages, termed iNOS + Arg1 + macrophages, which simultaneously express pro-inflammatory and pro-reparative genes in exercised male mice. Inhibiting either pro-inflammatory iNOS or pro-reparative Arg1 in these macrophages counters the exercise-induced cardiac function preservation. Mechanistically, exercise enhances glycolysis in monocytes, increasing lactate production and driving histone lactylation at H3K18, mediated by p300 as the relevant lactyltransferase and counterbalanced by HDAC2 as deacetylase. H3K18la accelerates the transition of cardiac macrophages to a pro-reparative state, restoring immune homeostasis and preserving cardiac function. Notably, human monocytes from physically active individuals exhibit elevated levels of Pan-Kla and H3K18la compared to those from sedentary individuals. Importantly, adoptive transfer of highly histone-lactylated monocytes restores cardiac function in sepsis-induced cardiomyopathy, which might translate into a promising therapeutic strategy for cardiomyopathy. Active lifestyle has considerable cardiac health benefits, but the metabolic and immunological background need further investigation. Here the authors show that a cardiac macrophage population, characterised by simultaneous pro-inflammatory and reparative properties, accumulate upon exercise, and these cells restore cardiac health upon transfer in a mouse model of sepsis-induced cardiomyopathy.

The spectral dependence of light absorption by atmospheric particulate matter has major implications for air quality and climate forcing, but remains uncertain especially in tropical areas with extensive biomass burning. In the September-October 2007 biomass-burning season in Santa Cruz, Bolivia, we studied light absorbing (chromophoric) organic or “brown” carbon (BrC) with surface and space-based remote sensing. We found that BrC has negligible absorption at visible wavelengths, but significant absorption and strong spectral dependence at UV wavelengths. Using the ground-based inversion of column effective imaginary refractive index in the range 305–368 nm, we quantified a strong spectral dependence of absorption by BrC in the UV and diminished ultraviolet B (UV-B) radiation reaching the surface. Reduced UV-B means less erythema, plant damage, and slower photolysis rates. We use a photochemical box model to show that relative to black carbon (BC) alone, the combined optical properties of BrC and BC slow the net rate of production of ozone by up to 18% and lead to reduced concentrations of radicals OH, HO 2 , and RO 2 by up to 17%, 15%, and 14%, respectively. The optical properties of BrC aerosol change in subtle ways the generally adverse effects of smoke from biomass burning.

In this paper, multi-source observation, such as aircraft, ground-based remote sensing, and satellite-retrieved data, has been utilized to compare and analyze the vertical characteristics of aerosol optical properties and the planetary boundary layer height (HPBL) over the North China Plain (NCP) region during May–June 2016. Aircraft observations show the vertical profiles of aerosol absorption coefficients (σabs), scattering coefficients (σsca), and extinction coefficients (σext) gradually decrease with altitude, with their maximum values near HPBL. The vertical profiles of σext depended most on the vertical distribution of measured σsca, indicating a significant contribution of scattering aerosols. In addition, the prominent characteristic of the inverse relationship between σext and moisture profile could serve as a reference for predicting air quality in the NCP region. The lower layer pollution during the field experiment was likely caused by the accumulation of fine-mode aerosols, characterized by the vertical distribution of the Ångström exponent and the Aerosol Robotic Network (AERONET) products. Typically, HPBL derived from aircraft and surface Micro Pulse Lidar (MPL) was approximate, while the predicted HPBL by meteorological data indicates an underestimation of ~192 m. Aerosol optical depth (AOD) calculated from aircraft and ground-based remote sensing (such as MPL and AERONET) experienced a strong correlation, and both of them exhibited a similar tendency. However, the AOD retrieved from satellites was significantly larger than that from aircraft and ground-based remote sensing. Overall, the inversion algorithm, cloud identification algorithm, representativeness of the space, and time of the observation may lead to an overestimation or underestimation of AOD under certain circumstances. This study may serve as a re-evaluation of AOD retrieved from multi-source observations and provide a reference to uncover the actual atmospheric environment in the NCP regions.

Forest emissions of biogenic volatile organic compounds (BVOCs), such as isoprene and other terpenes, play a role in the production of tropospheric ozone and aerosols. In a northern Michigan forest, the direct measurement of total OH reactivity, which is the inverse of the OH lifetime, was significantly greater than expected. The difference between measured and expected OH reactivity, called the missing OH reactivity, increased with temperature, as did emission rates for terpenes and other BVOCs. These measurements are consistent with the hypothesis that unknown reactive BVOCs, perhaps terpenes, provide the missing OH reactivity.