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Black carbon (BC) in the Tibetan Plateau (TP) region has distinct climate effects that strongly depend on its mixing state. The aging processes of BC in the TP are subject to emissions from various regions, resulting in considerable variability of its mixing state and physicochemical properties. However, the mechanism and magnitude of this effect are not yet clear. In this study, field observations on physicochemical properties of BC-containing particles (PM BC) were conducted in the northeast (Xihai) and southeast (Lulang) regions of the TP to investigate the impacts of transported emissions from lower-altitude areas on BC characteristics in the TP. Large spatial discrepancies were found in the chemical composition of PM BC. Both sites showed higher concentrations of PM BC when they were affected by transported air masses outside the TP but with diverse chemical composition. Source apportionment for organic aerosol (OA) suggested that primary OA in the northeastern TP was attributed to hydrocarbon OA (HOA) from anthropogenic emissions, while it was dominated by biomass burning OA (BBOA) in the southeastern TP. Regarding secondary aerosol, a marked enhancement in nitrate fraction was observed on aged BC coating in Xihai when the air masses were brought by updrafts and easterly winds from lower-altitude areas. With the development of boundary layer, the enhanced turbulent mixing promoted the elevation of anthropogenic pollutants. In contrast to Xihai, the thickly coated BC in Lulang was mainly caused by elevation and transportation of biomass burning plumes from south Asia, showing a large contribution of secondary organic aerosol (SOA). The distinct transported emissions lead to substantial variations of both chemical composition and light absorption ability of BC across the TP. The thicker coating and higher mass absorption cross-section (MAC) of PM BC in air masses elevated from lower-altitude regions reveal the promoted BC aging processes and their impacts on the mixing state and light absorption of BC in the TP. These findings emphasize the vulnerability of plateau regions to influences of elevated emissions, leading to significant changes in BC concentration, mixing states and light absorption across the TP, all of which need to be considered in the evaluation of BC radiative effects for the TP region. [ABSTRACT FROM AUTHOR]

Background: Fungal skin diseases are common skin diseases with a heterogeneous distribution worldwide. Objectives: This study aimed to analyse the spatiotemporal trends in the burden of fungal skin diseases at global, regional, and national levels from 1990 to 2021. Methods: Based on the data obtained from the Global Burden of Disease Study (GBD) 2021, we described the incident cases, prevalent cases, number of disability‐adjusted life years (DALYs), and corresponding age‐standardised rates (ASRs) for fungal skin diseases in 1990 and 2021 by sex, age, socio‐demographic index (SDI), 21 GBD regions, and 204 countries and territories. We used Joinpoint regression analysis to assess the temporal trends in burden of fungal skin diseases during 1990 to 2021. Spearman's rank test was used to analyse the relationship between disease burden and potential factors. Results: From 1990 to 2021, the incident cases, prevalent cases, and DALYs for fungal skin diseases worldwide increased by 67.93%, 67.73%, and 66.77%, respectively. Globally, the age‐standardised incidence rate (ASIR), age‐standardised prevalence rate (ASPR), and age‐standardised DALYs rate (ASDR) for fungal skin diseases in 2021 were 21668.40 per 100,000 population (95% UI: 19601.19–23729.17), 7789.55 per 100,000 population (95% UI: 7059.28–8583.54), and 43.39 per 100,000 population (95% UI: 17.79–89.10), respectively. Between 1990 and 2021, the ASIR, ASPR, and ASDR for fungal skin diseases have modestly increased, with AAPC of 11.71% (95% confidence interval [CI]: 11.03%–12.39%), 19.24% (95% CI: 18.12%–20.36%), and 20.25% (95% CI: 19.33%–21.18%), respectively. Males experienced a higher burden of fungal skin diseases than females. The incident cases, prevalent cases, and DALYs for fungal skin diseases were highest at the age of 5–9, while the ASRs were highest among the elderly. At national level, the highest ASRs were observed in Nigeria, Ethiopia, and Mali. Overall, SDI was negatively correlated with the ASRs, whereas Global Land‐Ocean Temperature Index (GLOTI) was remarkably positively correlated with the burden of fungal skin diseases. Conclusions: Between 1990 and 2021, the global burden of fungal skin diseases has increased, causing a high disease burden worldwide, particularly in underdeveloped regions and among vulnerable population such as children and the elderly. With global warming and aging of the population, the burden of fungal skin diseases may continue to increase in the future. Targeted and specific measures should be taken to address these disparities and the ongoing burden of fungal skin diseases. [ABSTRACT FROM AUTHOR]

Atmospheric aerosols not only cause severe haze pollution, but also affect climate through changes in cloud properties. However, during the haze pollution, aerosol‐cloud interactions are not well understood due to a lack of in situ observations. In this study, we conducted simultaneous observations of cloud droplet and particle number size distribution, together with supporting atmospheric parameters, from ground to cloud base in East China using a high‐payload tethered airship. We found that high concentrations of aerosols and cloud condensation nuclei were constrained below cloud, leading to the pronounced "Twomey effect" near the cloud base. The cloud inhibited the pollutants dispersion by reducing surface heat flux and thus deteriorated the near‐surface haze pollution. Satellite retrievals matched well with the in situ observations for low stratus clouds, while were insufficient to quantify aerosol‐cloud interactions for other cases. Our results highlight the importance to combine in situ vertical and satellite observations to quantify the aerosol‐cloud interactions. Plain Language Summary: Atmospheric aerosols, one of the major pollutants contributing to air pollution, also play an important role in climate through their interactions with clouds. The impact of aerosols on cloud properties remains the largest uncertainty in climate projections, partly due to a lack of in situ observations. Here, we conducted simultaneous observations on atmospheric aerosols and clouds from ground to 1,200 m above ground level in East China using a high‐payload tethered airship. We found aerosols number concentration was high below the clouds, which increased the cloud droplet concentration and decreased the cloud droplet diameter near cloud base. The clouds deteriorated the near‐surface air pollution, thus increasing exposure to hazardous levels. For low stratiform clouds, the satellite retrievals matched well with the observations, suggesting the satellite observation is a powerful tool to investigate clouds. However, the aerosol‐cloud interactions can still be underestimated by satellite measurements as the satellites record cloud properties near cloud top. We emphasize the need for direct in situ observations from the ground to high altitudes to quantify the effects of aerosols on cloud properties. Key Points: The pronounced Twomey effect near the cloud base was directly observed during the haze pollution by the tethered airship measurementThe observed Twomey effect at the cloud base in East China contradicts the satellite‐detected anti‐Twomey effect at the top of cloudsSatellite retrieved cloud effective radius is comparable to observation near cloud base of low stratus clouds, while is biased for others [ABSTRACT FROM AUTHOR]

Black carbon (BC) in the Tibetan Plateau (TP) region has distinct climate effect, which strongly depends on its mixing state. The aging processes of BC in TP are subject to emissions from various regions, resulting in considerable variability of its mixing state and physicochemical properties. However, the mechanism and magnitude of this effect are not yet clear. In this study, filed observations on physicochemical properties of BC-containing particles (PMBC) were conducted in the northeast (Xihai) and southeast (Lulang) regions of the TP to investigate the impacts of transported emissions from lower-altitude areas on BC characteristics in the TP. Large spatial discrepancies were found in the chemical composition of PMBC. Both sites showed higher concentrations of PMBC when they were affected by transported airmasses outside the TP, but with diverse chemical composition. Source apportionment for organic aerosol (OA) suggested that primary OA in the northeastern TP was attributed to hydrocarbon OA (HOA) from anthropogenic emissions, while it was dominated by biomass burning OA (BBOA) in the southeastern TP. Regarding secondary aerosol, a marked enhancement in nitrate fraction was observed on aged BC coating in Xihai when the airmasses were brought by updrafts and easterly winds from lower-altitude areas. With the development of boundary layer, the enhanced turbulent mixing promoted the elevation of anthropogenic pollutants. In contrast to Xihai, the thickly coated BC in Lulang was mainly caused by self-elevated biomass burning plume from the South Asia, showing a large contribution of secondary organic aerosol (SOA). The distinct transported emissions lead to substantial variations of both chemical composition and light absorption ability of BC across the TP. The thicker coating and higher mass absorption cross-section (MAC) of PMBC in airmasses elevated from lower-altitude regions reveals the promoted BC aging processes and their impacts on the mixing state and light absorption of BC in TP. These findings emphasize the vulnerability of plateau regions to influences of elevated emissions, leading to significant changes in BC concentration, mixing states and light absorption across the TP, which needs to be considered in the evaluation of BC radiative effects for the TP region. [ABSTRACT FROM AUTHOR]

New particle formation (NPF) plays a crucial role in the atmospheric aerosol population and has significant implications on climate dynamics, particularly in climate-sensitive zones such as the Tibetan Plateau (TP). However, our understanding of NPF on the TP is still limited due to a lack of comprehensive measurements and verified model simulations. To fill this knowledge gap, we conducted an integrated study combining comprehensive field measurements and chemical transport modeling to investigate NPF events on the southeastern TP during the pre-monsoon season. NPF was observed to occur frequently on clear-sky days on the southeastern TP, contributing significantly to the cloud condensation nuclei (CCN) budget in this region. The observational evidence suggests that highly oxygenated organic molecules (HOMs) from monoterpene oxidation participate in the nucleation on the southeastern TP. After updating the monoterpene oxidation chemistry and nucleation schemes in the meteorology–chemistry model, the model well reproduces observed NPF and reveals an extensive occurrence of NPF across the southeastern TP. The dominant nucleation mechanism is the synergistic nucleation of sulfuric acid, ammonia, and HOMs, driven by the transport of anthropogenic precursors from South Asia and the presence of abundant biogenic gases. By investigating the vertical distribution of NPF, we find a significant influence of vertical transport on the southeastern TP. More specifically, strong nucleation near the surface leads to an intense formation of small particles, which are subsequently transported upward. These particles experience enhanced growth to larger sizes in the upper planetary boundary layer (PBL) due to favorable conditions such as lower temperatures and a reduced condensation sink. As the PBL evolves, the particles in larger sizes are brought back to the ground, resulting in a pronounced increase in near-surface particle concentrations. This study highlights the important roles of anthropogenic–biogenic interactions and meteorological dynamics in NPF on the southeastern TP. [ABSTRACT FROM AUTHOR]

New particle formation (NPF) plays a crucial role in the atmospheric aerosol population and has significant implications on climate dynamics, particularly in climate-sensitive zone such as the Tibetan Plateau (TP). However, our understanding of NPF in the TP is still limited due to a lack of comprehensive measurements and verified model simulations. To fill this knowledge gap, we conducted an integrated study combining comprehensive field measurements and chemical transport modeling to investigate NPF events in the southeastern TP during the pre-monsoon season. NPF was observed to occur frequently on clear-sky days in the southeastern TP, contributing significantly to the cloud condensation nuclei (CCN) budget in this region. The observational evidence suggests that highly oxygenated organic molecules (HOMs) from monoterpene oxidation participate in the nucleation in southeastern TP. After updating the monoterpene oxidation chemistry and nucleation schemes in the meteorology-chemistry model, the model well reproduces observed NPF and reveals an extensive occurrence of NPF across the southeastern TP. The dominant nucleation mechanism is the synergistic nucleation of sulfuric acid, ammonia and HOMs, driven by the transport of anthropogenic precursors from South Asia and the presence of abundant biogenic gases. By investigating the vertical distribution of NPF, we find a significant influence of vertical transport in the southeastern TP. More specifically, strong nucleation near the surface leads to an intense formation of small particles, which are subsequently transported upward. These particles experience enhanced growth to larger sizes in the upper planetary boundary layer (PBL) due to favorable conditions such as lower temperatures and reduced condensation sink. As the PBL evolves, the particles in larger sizes are brought back to the ground, resulting in a pronounced increase in near-surface particle concentrations. This study highlights the important roles of anthropogenic-biogenic interactions and meteorological dynamics in NPF in the southeastern TP. [ABSTRACT FROM AUTHOR]

Below-cloud wet scavenging is an important pathway to remove atmospheric aerosols. The below-cloud wet-scavenging coefficient (BWSC) is the value to describe the ability of rainfall to remove aerosols. The reported BWSCs obtained from the field measurements are much higher than the theory, but the reason for this remains unclear. Based on the long-term field measurements in the Yangtze River Delta of eastern China, we find that 28 % of the rainfall events are high-BWSC events. The high-BWSC events show the sudden decrease in the particle number concentration in all size bins near the end of rainfall. By investigating the simultaneously observed changes in carbon monoxide and aerosol chemical compositions during rainfall events, the circulation patterns, and backward trajectories, we find the cause of the high-BWSC events is the air mass changing but not the wet scavenging. The change in air masses is always followed by the rainfall processes and cannot be screened out by the traditional meteorological criteria, which would cause the overestimation of BWSC. After excluding the high-BWSC events, the observed BWSC is close to the theory and is correlated with the rainfall intensity and particle number concentrations prior to rainfall. This study highlights that the discrepancy between the observed BWSC and the theoretical value may not be as large as is currently believed. To obtain reasonable BWSCs and parameterization from field measurements, the effect of air mass changing during rainfall needs to be carefully considered. [ABSTRACT FROM AUTHOR]

Below-cloud wet scavenging is an important pathway to remove atmospheric aerosols. The below-cloud wet scavenging coefficient (BWSC) is the value to describe the ability of rainfall to remove aerosols. The reported BWSCs obtained from the field measurements are much higher than the theory, but the reason for this remains unclear. In this study, based on the long-term field measurements in the Yangtze River Delta of eastern China, we find 28 % of the rainfall events are high BWSC events. The high BWSC events show the sudden decrease of particle number concentration in all size bins near the end of rainfall. By investigating the circulation patterns, backward trajectories and the variations of simultaneously observed atmospheric components, we find the cause of the high BWSC events is the air masses changing but not the wet scavenging. The change of air masses is always followed by the rainfall processes and cannot be screened out by the traditional meteorological criteria, which would cause the overestimation of BWSC. After excluding the high BWSC events, the observed BWSC is close to the theory and is correlated with the rainfall intensity and particle number concentrations prior to rainfall. This study highlights the discrepancy between the observed BWSC and the theoretical value may not be as large as it is currently believed. To obtain reasonable BWSCs and parameterization from field measurements, the effect of air masses changing during rainfall needs to be carefully considered. [ABSTRACT FROM AUTHOR]

Introduction. Cytomegalovirus ( CMV ) is a widely disseminated betaherpesvirus that typically induces latant infections. In immunocompromised populations, especially transplant and HIV-infected patients, CMV infection increases in-hospital mortality. Gap statement. Although machine learning models have been widely used in clinical diagnosis and prognosis prediction, reports on machine learning model predictions for the in-hospital mortality of HIV/AIDS patients with CMV infection have not been reported. Aim. Analyze the general gemographic and clinical characteristics of HIV/AIDS patients with CMV infection and identify the factors affecting the prognosis of this population, which will help to reduce their in-hospital mortality. Methods. Hospitalized HIV/AIDS patients with CMV infection were recruited from the Fourth People's Hospital of Nanning, Guangxi, from 2012 to 2019. After dividing them into survival and death groups based on their in-hospital survival status, their general and clinical profiles were described. Following 1 : 3 propensity score matching to equalize baseline characteristics, three machine-learning models (Random Forest, Support Vector Machine and eXtreme Gradient Boosting) were deployed to forecast factors influencing prognosis. The SHapley Additive exPlanations tool explained the models. Results. A total of 1102 HIV/AIDS patients with CMV infection were analysed. There was no statistical difference in the general condition of the study subjects ( P ＞0.05). Prevalent complications/coinfections included pneumonia (63.6%), tuberculosis (47.2%) and oral fungal infections (44.6%). There were significant differences between the groups in pneumonia, cryptococcosis and hypoproteinaemia ( P <0.05). The differences in laboratory indicators between patients were also statistically significant ( P <0.05). The three machine learning models demonstrated good performance, identifying primary predictors of mortality. Pneumonia, urea, indirect bilirubin and platelet distribution width exhibited positive associations with death, with higher levels correlating with an increased mortality risk. Conversely, CD4 T-cell count, CD8 T-cell count and platelet displayed negative correlations with mortality. Conclusions. HIV/AIDS patients with CMV infection exhibit distinctive clinical features impacting survival outcomes. Machine learning models accurately identify key influencing factors and predict mortality risk in this population, which appears to be essential to reducing in-hospital mortality.