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Background: Tuberculosis (TB), a major cause of disease and antimicrobial resistance, is spread via aerosols. Aerosols have diagnostic potential and airborne-microbes other than Mycobacterium tuberculosis complex (MTBC) may influence transmission. We evaluated whether PneumoniaCheck (PMC), a commercial aerosol collection device, captures MTBC and the aeromicrobiome of people with TB. Methods: PMC was done in sputum culture-positive people (≥ 30 forced coughs each, n = 16) pre-treatment and PMC air reservoir (bag, corresponding to upper airways) and filter (lower airways) washes underwent Xpert MTB/RIF Ultra (Ultra) and 16S rRNA gene sequencing (sequencing also done on sputum). In a subset (n = 6), PMC microbiota (bag, filter) was compared to oral washes and bronchoalveolar lavage fluid (BALF). Findings: 54% (7/13) bags and 46% (6/14) filters were Ultra-positive. Sequencing read counts and microbial diversity did not differ across bags, filters, and sputum. However, microbial composition in bags (Sphingobium-, Corynebacterium-, Novosphingobium-enriched) and filters (Mycobacterium-, Sphingobium-, Corynebacterium-enriched) each differed vs. sputum. Furthermore, sequencing only detected Mycobacterium in bags and filters but not sputum. In the subset, bag and filter microbial diversity did not differ vs. oral washes or BALF but microbial composition differed. Bags vs. BALF were Sphingobium-enriched and Mycobacterium-, Streptococcus-, and Anaerosinus-depleted (Anaerosinus also depleted in filters vs. BALF). Compared to BALF, none of the aerosol-enriched taxa were enriched in oral washes or sputum. Interpretation: PMC captures aerosols with Ultra-detectable MTBC and MTBC is more detectable in aerosols than sputum by sequencing. The aeromicrobiome is distinct from sputum, oral washes and BALF and contains differentially-enriched lower respiratory tract microbes. [ABSTRACT FROM AUTHOR]

Previous studies have shown that aerosols invigorate deep convective systems (DCS). However, the magnitude or even the existence of aerosol invigoration of DCS remains controversial. Here, we aimed to observationally quantify the full aerosol effects on DCS by tracking their entire lifecycle and spatial extent in tropical regions. We found that fine aerosols (FA) can invigorate DCS, making them taller and longer lived, and resulting in up to ×5 increase in total area and rainfall amount. In contrast, added coarse sea salt aerosols (CSA) over the ocean can inhibit the vertical development of DCS through enhancing warm rain formation, yet resulting in longer lived and extensive DCSs. Notably, combining FA and CSA generates the strongest aerosol invigoration effect at the concentrations of ~5 and ~80 μg/m³, leading up to ×10 increase in rainfall amount. Our results indicate that aerosols significantly redistribute convective precipitation and climate effects, greatly underestimated in previous studies. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) and their composites have garnered significant attention in recent years due to their exceptional properties and diverse applications across various fields. The conventional batch synthesis methods for MOFs and their composites often suffer from challenges such as long reaction times, poor reproducibility, and limited scalability. Continuous flow synthesis has emerged as a promising alternative for overcoming these limitations. In this short review, we discuss the recent advancements, challenges, and future perspectives of continuous flow synthesis in the context of MOFs and their composites. The review delves into a brief overview of the fundamental principles of flow synthesis, highlighting its advantages over batch methods. Key benefits, including precise control over reaction parameters, improved scalability and efficiency, rapid optimization capabilities, enhanced reaction kinetics and mass transfer, and increased safety and environmental sustainability, are addressed. Additionally, the versatility and flexibility of flow synthesis techniques are discussed. The article then explores various flow synthesis methods applicable to MOF and MOF composite production. The techniques covered include continuous flow solvothermal synthesis, mechanochemical synthesis, microwave and ultrasound-assisted flow synthesis, microfluidic droplet synthesis, and aerosol synthesis. Notably, the combination of flow chemistry and aerosol synthesis with real-time characterization is also addressed. Furthermore, the impact of flow synthesis on the properties and performance of MOFs is explored. Finally, the review discusses current challenges and future perspectives in the field of continuous flow MOF synthesis, paving the way for further development and broader application of this promising technique. [ABSTRACT FROM AUTHOR]

This study explores aerosol direct, indirect, and feedback effects on meteorology and fine particulate matter during heat waves of August 2022 over eastern China by using an online coupled regional climate–chemistry–aerosol model. In this period, aerosols exerted mean direct (DRE) and indirect (IRE) radiative effects of −3.9 Wm−2 and −2.4 Wm−2 at TOA, which totally caused a decrease in average surface air temperature by 0.3 °C over east China, accompanied by decreases in PBLH (planetary boundary layer height) and precipitation and an increase in PM2.5 concentration. With the anthropogenic emission reduction from 2013 to 2022, DRE apparently decreased while IRE changed little, leading to a decrease in total aerosol radiative effect (TRE) by 27% at TOA. The weakened TRE resulted in increases in surface air temperature and precipitation by 0.14 °C and 2.7 mm, respectively, on average over east China, with the maximum warming exceeding 0.5 °C in BTH (Beijing–Tianjin–Hebei province). This study highlights a warming trend due to weakened TRE, which may exacerbate heat wave, and an increasing importance of aerosol IRE relative to DRE due to weak sensitivity of cloud properties to aerosol change during the emission reduction. [ABSTRACT FROM AUTHOR]

As the health impact of ultrafine particles is getting better understood, modelling the size distribution and the number concentration with chemistry transport models becomes an increasingly important matter. The number concentrations is strongly affected by processes linked to aerosol dynamics: coagulation, condensation and gas/particle phase partitioning, nucleation. Coagulation is usually solved using an Eulerian approach, using a fixed diameter size discretization. In opposition, condensation/evaporation is rather solved using a Lagrangian approach, requiring redistribution of particles on the fixed grid size. Here, a new analytic formulation is presented to compute efficiently coagulation partition coefficients, allowing to dynamically adjust the discretization of the coagulation operator to the Lagrangian size mesh evolution, and therefore solve all the processes linked to aerosol dynamics with a Lagrangian approach, avoiding the redistribution on the fixed size grid. This new approach has the advantage of reducing the numerical diffusion introduced by condensation. The significance of these effects on number concentrations is assessed over Greater Paris with the chemistry transport model Polyphemus/Polair3D coupled to the aerosol model SSH-aerosol, using different size resolution of the particle distribution. [ABSTRACT FROM AUTHOR]

​​​​​​​A novel ground-based radiometer, referred to as the Shortwave Array Spectroradiometer-Hemispheric (SAS-He), is introduced. This radiometer uses the shadow-band technique to report total irradiance and its direct and diffuse components frequently (every 30 s) with continuous spectral coverage (350–1700 nm) and moderate spectral (∼ 2.5 nm ultraviolet–visible and ∼ 6 nm shortwave-infrared) resolution. The SAS-He's performance is evaluated using integrated datasets collected over coastal regions during three field campaigns supported by the US Department of Energy's Atmospheric Radiation Measurement (ARM) program, namely the (1) Two-Column Aerosol Project (TCAP; Cape Cod, Massachusetts), (2) Tracking Aerosol Convection Interactions Experiment (TRACER; in and around Houston, Texas), and (3) Eastern Pacific Cloud Aerosol Precipitation Experiment (EPCAPE; La Jolla, California). We compare (i) aerosol optical depth (AOD) and total optical depth (TOD) derived from the direct irradiance, as well as (ii) the diffuse irradiance and direct-to-diffuse ratio (DDR) calculated from two components of the total irradiance. As part of the evaluation, both AOD and TOD derived from the SAS-He direct irradiance are compared to those provided by a collocated Cimel sunphotometer (CSPHOT) at five (380, 440, 500, 675, 870 nm) and two (1020, 1640 nm) wavelengths, respectively. Additionally, the SAS-He diffuse irradiance and DDR are contrasted with their counterparts offered by a collocated multifilter rotating shadowband radiometer (MFRSR) at six (415, 500, 615, 675, 870, 1625 nm) wavelengths. Overall, reasonable agreement is demonstrated between the compared products despite the challenging observational conditions associated with varying aerosol loadings and diverse types of aerosols and clouds. For example, the AOD- and TOD-related values of root mean square error remain within 0.021 at 380, 440, 500, 675, 870, 1020, and 1640 nm wavelengths during the three field campaigns. [ABSTRACT FROM AUTHOR]

The onset of ice nucleation in mixed-phase clouds determines the lifetime and microphysical properties of ice clouds. In this work, we develop a novel method that differentiates between various phases of mixed-phase clouds, such as clouds dominated by pure liquid or pure ice segments, compared with those having ice crystals surrounded by supercooled liquid water droplets or vice versa. Using this method, we examine the relationship between the macrophysical and microphysical properties of Southern Ocean mixed-phase clouds at -40 to 0 °C (e.g. stratiform and cumuliform clouds) based on the in situ aircraft-based observations during the US National Science Foundation Southern Ocean Clouds, Radiation, Aerosol Transport Experimental Study (SOCRATES) flight campaign. The results show that the exchange between supercooled liquid water and ice crystals from a macrophysical perspective, represented by the increasing spatial ratio of regions containing ice crystals relative to the total in-cloud region (defined as ice spatial ratio), is positively correlated with the phase exchange from a microphysical perspective, represented by the increasing ice water content (IWC), decreasing liquid water content (LWC), increasing ice mass fraction, and increasing ice particle number fraction (IPNF). The mass exchange between liquid and ice becomes more significant during phase 3 when pure ice cloud regions (ICRs) start to appear. Occurrence frequencies of cloud thermodynamic phases show a significant phase change from liquid to ice at a similar temperature (i.e. -17.5 °C) among three types of definitions of mixed-phase clouds based on ice spatial ratio, ice mass fraction, or IPNF. Aerosol indirect effects are quantified for different phases using number concentrations of aerosols greater than 100 or 500 nm (N>100 and N>500 , respectively). N>500 shows stronger positive correlations with ice spatial ratios compared with N>100. This result indicates that larger aerosols potentially contain ice-nucleating particles (INPs), which facilitate the formation of ice crystals in mixed-phase clouds. The impact of N>500 is also more significant in phase 2 when ice crystals just start to appear in the mixed phase compared with phase 3 when pure ICRs have formed, possibly due to the competing aerosol indirect effects on primary and secondary ice production in phase 3. The thermodynamic and dynamic conditions are quantified for each phase. The results show stronger in-cloud turbulence and higher updraughts in phases 2 and 3 when liquid and ice coexist compared with pure liquid or ice (phases 1 and 4, respectively). The highest updraughts and turbulence are seen in phase 3 when supercooled liquid droplets are surrounded by ice crystals. These results indicate both updraughts and turbulence support the maintenance of supercooled liquid water amongst ice crystals. Overall, these results illustrate the varying effects of aerosols, thermodynamics, and dynamics through various stages of mixed-phase cloud evolution based on this new method that categorizes cloud phases. [ABSTRACT FROM AUTHOR]

Assessing aerosol mixing states, which primarily depend on aerosol chemical compositions, is indispensable to estimate direct and indirect effects of aerosols. The limitations of the direct measurements of aerosol chemical composition and mixing states necessitate modeling approaches to infer the aerosol mixing states. The Optical Properties of Aerosols and Clouds (OPAC) model has been extensively utilized to construct optically equivalent aerosol chemical compositions from measured aerosol optical properties using Mie inversion. However, the representation of real atmospheric aerosol mixing scenarios in OPAC has perennially been challenged by the exclusive assumption of external mixing. A Python successor to the aerosol module of the OPAC model is developed, named AeroMix, with novel capabilities to (1) model externally and core–shell mixed aerosols, (2) simulate optical properties of aerosol mixtures constituted by any number of aerosol components, and (3) define aerosol composition and relative humidity in up to six vertical layers. Designed as a versatile open-source aerosol optical model framework, AeroMix is tailored for sophisticated inversion algorithms aimed at modeling aerosol mixing states and also their physical and chemical properties. AeroMix's performance is demonstrated by modeling the probable aerosol mixing states over Kanpur (urban) and the Bay of Bengal (marine) in south Asia. The modeled mixing states are consistent with independent measurements using a single-particle soot photometer (SP2) and transmission electron microscopy (TEM), substantiating the potential capability of AeroMix to model complex aerosol mixing scenarios involving multiple internally mixed components in diverse environments. This work contributes a valuable tool for modeling aerosol mixing states to assess their impact on cloud-nucleating properties and radiation budget. [ABSTRACT FROM AUTHOR]

Long-term ground-based lidar observations are important in estimating the contribution of different sources (mostly volcanic eruptions and wildfires) to aerosol loading of the atmosphere and in developing and improving various climate models. In this paper, we carefully analyse aerosol scattering ratio profiles and aerosol layers, observed with 532-nm lidar measurements at the Siberian Lidar Station in Tomsk (56.48°N, 85.05°E) over the period 2018–2022, and identify the layers' potential sources. To compare aerosol loading over Tomsk for the last five years (2018–2022) with that for previous years, we also present and discuss time series of integrated aerosol backscatter coefficient (IABC) for three altitude ranges. The first range (15–30 km) reveals the pure stratospheric aerosol loading provided by volcanic eruptions, the second range (11–15 km) is responsible mainly for aftereffects of wildfire smoke plumes, and the third one (11–30 km) demonstrates aerosol contribution from both sources. In particular, we found for the period 2001–2022 that the annual average IABC reached its maximal values of 2.91 × 10−4 sr−1 (15–30 km) and 8.21 × 10−4 sr−1 (11–30 km) in 2022 due to the Hunga Tonga-Hunga Ha'apai volcanic eruption. The period 2020–2022 exhibited a significant increase in the relative aerosol content at altitudes of 11–15 km in the total aerosol loading at 11–30 km over Tomsk from 54.4% in 2020 to 64.8% in 2022, which indicates a shift of the main part of aerosol loading to altitudes of 11–15 km due to the increased wildfire activity in North America and north-eastern Asia. The Arctic polar vortex is also revealed to distort the real aerosol vertical distribution over Tomsk by replacing it with the aerosol distribution inside the vortex on measurement days when the vortex is over the lidar site. [ABSTRACT FROM AUTHOR]

The Advanced Geostationary Radiation Imager (AGRI) sensor on board the geostationary satellite Fengyun-4B (FY-4B) is capable of capturing particles in different phases in the atmospheric environment and acquiring aerosol observation data with high spatial and temporal resolution. To understand the quality of the Land Aerosol (LDA) product of AGRI and its application prospects, we conducted a comprehensive evaluation of the AGRI LDA AOD. Using the 550 nm AGRI LDA AOD (550 nm) of nearly 1 year (1 October 2022 to 30 September 2023) to compare with the Aerosol Robotic Network (AERONET), MODIS MAIAC, and Himawari-9/AHI AODs. Results show the erratic algorithmic performance of AGRI LDA AOD, the correlation coefficient (R), mean error (Bias), root mean square error (RMSE), and the percentage of data with errors falling within the expected error envelope of ± (0.05 + 0.15 × AOD A E R O N E T) (within EE15) of the LDA AOD dataset are 0.55, 0.328, 0.533, and 34%, respectively. The LDA AOD appears to be overestimated easily in the southern and western regions of China and performs poorly in the offshore areas, with an R of 0.43, a Bias of 0.334, a larger RMSE of 0.597, and a global climate observing system fraction (GCOSF) percentage of 15% compared to the inland areas (R = 0.60, Bias = 0.163, RMSE = 0.509, GCOSF = 17%). Future improvements should focus on surface reflectance calculation, water vapor attenuation, and more suitable aerosol model selection to improve the algorithm's accuracy. [ABSTRACT FROM AUTHOR]

Secondhand vaping exposure is an emerging public health concern that remains understudied. In this study, saliva and exhaled emissions from ENDS users (secondhand) and non-ENDS users (baseline) were collected, firsthand emissions were generated using an automated ENDS aerosol generation system programmed to simulate puffing topography profiles collected from ENDS users. Particulate concentrations and sizes along with volatile organic compounds were characterized. We revealed puffing topography metrics as potential mediators of firsthand and secondhand particle and chemical exposures, as well as metabolic and respiratory health outcomes. Particle deposition modeling revealed that while secondhand emissions displayed smaller deposited mass, total and pulmonary particle deposition fractions were higher than firsthand deposition levels, possibly due to smaller secondhand emission particle diameters. Lastly, untargeted metabolomic profiling of salivary biomarkers of lung injury due to firsthand ENDS exposures revealed potential early indicators of respiratory distress that may also be relevant in bystanders exposed to secondhand vaping scenarios. By leveraging system toxicology, we identified 10 metabolites, including leukotriene D4, that could potentially serve as biomarkers for ENDS use, exposure estimation, and the prediction of vaping-related disease. This study highlights characterization of vaping behavior is an important exposure component in advancing our understanding of potential health effects in ENDS users and bystanders. [ABSTRACT FROM AUTHOR]

This study presents the hygroscopic properties of aerosols from the Arctic free troposphere by means of contemporary lidar and radiosonde observations only. It investigates the period from the Arctic Haze in spring towards the summer season in 2021. Therefore, a one-parameter growth curve model is applied to lidar data from the Koldewey Aerosol Raman Lidar (AWIPEV in Ny-Ålesund, Svalbard) and simultaneous radiosonde measurements. Hygroscopic growth depends on different factors like aerosol diameter and chemical composition. To detangle this dependency, three trends in hygroscopicity are additionally investigated by classifying the aerosol first by its dry color ratio, and then by its season and altitude. Generally, we found a complex altitude dependence with the least hygroscopic particles in the middle of the troposphere. The most hygroscopic aerosol is located in the upper free troposphere. A hypothesis based on prior lifting of the particles is given. The expected trend with aerosol diameter is not observed, which draws attention to the complex dependence of hygroscopic growth on geographical region and altitude, and to the development of backscatter with the aerosol size itself. In a seasonal overview, two different modes of stronger or weaker hygroscopic particles are additionally observed. Furthermore, two special days are discussed using the Mie theory. They show, on the one hand, the complexity of analyzing hygroscopic growth by means of lidar data, but on the other hand, they demonstrate that it is in fact measurable with this approach. For these two case studies, we calculated that the aerosol effective radius increased from 0.16 μ m (dry) to 0.18 μ m (wet) and from 0.28 μ m to 0.32 μ m for the second case. [ABSTRACT FROM AUTHOR]

Recently, in China, during the period of transition between spring and summer, the combination of sandstorms and ozone (O3) pollution has posed a significant challenge to the strategy of coordinated control of fine particulate matters (PM2.5) and O3. On the one hand, the dust invasion brings many primary aerosols and causes a large range of transboundary transport. On the other hand, the high concentration of aerosol causes a severe disturbance to the distribution of O3. Traditionally, high-resolution assessments of the spatial distribution of aerosols and O3 can be carried out using LiDAR technology. However, the negligence of the influence of aerosols in the process of O3 retrieval in traditional differential absorption lidar (DIAL) leads to an error in the accuracy of ozone concentration. Especially when dust transit occurs, the errors become bigger. In this study, a self-customized four-wavelength differential-absorption LiDAR system was used to synchronously obtain the accurate vertical distributions of ozone and high-concentration aerosol. The wavelength index of concentrated aerosol was inverted and applied to the differential equation framework for O3 calculation. This novel approach to retrieving the vertical profile of O3 was proposed and verified by applying it to a dust pollution event that occurred from April to May 2021 in Anyang City Henan Province, which is located in Northern China. It was found that the extinction coefficient of aerosol reached 2.5 km−1 during the dust period, and O3 was mainly distributed between 500 m and 1500 m. The O3 error exceeded over 10% arising from the high-concentration aerosol below 1.5 km during the dust storm event. By employing the inversion algorithm while considering the aerosol effects, the ozone concentration error was improved by over 10% compared with the error recorded without considering the aerosol influence especially in dust events. Through this study, it was found that the algorithm could effectively realize the synchronous and accurate inversion of high-concentration aerosols and O3 and can provide key technical support for air pollution control in China in the future. [ABSTRACT FROM AUTHOR]

Using spaceborne lidar and radar observations, this study identifies deep convection systems (DCSs), including deep convection cores (DCCs) and anvils, over the Tibetan Plateau (TP) and tropical Indian Ocean (TO) and finds that DCSs over the TP are less frequent, exhibiting narrower and thinner DCCs and anvils compared to those over the TO. The thinner DCCs over the TP exert weaker radiative cooling effects at the top of atmosphere (TOA) compared to the TO. But, the shortwave TOA cloud radiative effect (CRE) of TP anvils is stronger than that of the TO possibly due to more densely packed cloud tops over the TP. It results in a stronger TOA CRE of DCSs over the TP than that of TO. In particular, the longwave CRE of DCSs over the TP is notably greater at surface and low-level atmosphere due to the distinct lower temperature and less water vapour. The width of DCSs shows a positive correlation with wind shear and atmospheric instability, and the underlying mechanisms are discussed. We also find that the impact of aerosols on cloud top heights and precipitation displays significant discrepancies between the two regions. It is because that the aerosol invigoration effect is less efficient on the TP DCSs, mainly attributed to the significantly colder cloud base. Due to competition between invigoration and direct/semi-direct radiative effects of aerosols, the correlation between precipitation and aerosols over the TP is not obvious. However, precipitation in the TO experiences invigoration followed by suppression with increasing aerosols, due to the dominance of aerosol radiative effects and enhancement entrainment under polluted conditions. [ABSTRACT FROM AUTHOR]

​​​​​​​This study compares aerosol mixing-state parameters obtained via simultaneous measurements using DMA–CCNC, H(/V)TDMA, and DMA–SP2, shedding light on the impacts of primary aerosol emissions and secondary aerosol (SA) formation. The analysis reveals significant variations in mixing-state parameters among different techniques, with VTDMA and DMA–SP2 indicating that non-volatile particles mainly stem from black carbon (BC)-containing aerosols, while a substantial proportion of nearly hydrophobic aerosols originates from fossil fuel combustion and biomass-burning emissions. Synthesizing the results, some nearly hydrophobic BC-free particles were found to be cloud condensation nuclei (CCN)-inactive under the measured supersaturated conditions, likely from fossil fuel combustion emissions, while others were CCN-active, linked to biomass-burning emissions. Moreover, BC-containing aerosols emitted from fossil fuel combustion exhibit more external mixing with other aerosol components compared to those from biomass burning. Secondary nitrate and organic aerosol formation significantly affect aerosol mixing states, enhancing aerosol hygroscopicity and volatility while reducing heterogeneity among techniques. The study also highlights distinct physical properties of two resolved secondary organic aerosol factors, hinting at their formation through different mechanisms. These findings underscore the importance of comparing aerosol mixing states from different techniques as a tool for understanding aerosol physical properties from different sources and their responses to SA formation, as well as aiding in the exploration of SA formation mechanisms. [ABSTRACT FROM AUTHOR]

Ammonia (NH 3) has major effects on the environment and climate. In situ measurements of NH 3 concentrations taken between June 2009 and July 2020 at an urban site in Beijing were analyzed to study its long-term behavior, responses to meteorological conditions, and influences on the formation of secondary inorganic aerosols (SIAs). The 11-year average NH 3 mixing ratio was 26.9±19.3 ppb (median 23.5 ppb). The annual average NH 3 mixing ratio increased from 2009 to 2017 by 50 % and then decreased by 49 % from 2017 to 2020. Notably, the long-term trend for NH 3 at the ground level did not align with the trends derived from satellite observations and emission estimates. The NH 3 concentration exhibited a stronger correlation with the daily variation in water vapor (H 2 O) concentration than with air temperature. Thermodynamic modeling revealed the nonlinear response of SIAs to NH 3 , with increased sensitivity when its concentration was reduced to 40 % of the initial level. Although reducing NH 3 concentrations can improve air quality during winter, controlling acid gas concentrations has a greater effect than controlling NH 3 concentrations on reducing SIA concentrations, until NH 3 and acidic gas concentrations are reduced below 80 % of their current levels. Nevertheless, the increased mass proportion of ammonium salts in SIAs during the observation period indicates that future control measures for NH 3 concentrations may need to be prioritized in Beijing. [ABSTRACT FROM AUTHOR]

Clouds play a vital role in regulating Earth's energy balance and are impacted by anthropogenic aerosol concentration (Na) and sea surface temperature (SST) alterations. Traditionally, these factors, aerosols and SST, are investigated independently. This study employs cloud-resolving, radiative–convective-equilibrium (RCE) simulations to explore aerosol–cloud interactions (ACIs) under varying SSTs. ACIs are found to be SST-dependent even under RCE conditions. Notably, changes in cloud radiative effects for both longwave radiation and shortwave radiation lead to a decrease in top-of-atmosphere (TOA) energy gain with increasing Na. The changes in TOA shortwave flux exhibit greater sensitivity to underlying SST conditions compared to longwave radiation. To comprehend these trends, we perform a linear decomposition, analyzing the responses of different cloud regimes and contributions from changes in the cloud's opacity and occurrence. This breakdown reveals that ice and shallow clouds predominantly contribute to the radiative effect, mostly due to changes in the cloud's opacity and due to the Twomey effect, which is proportional to the baseline cloud fraction. Moreover, with an increase in Na , we observe an increase in latent heat release at the upper troposphere associated with heightened production of snow and graupel. We show that this trend, consistently across all SSTs, affects the anvil cloud cover by affecting the static stability at the upper troposphere via a similar mechanism to the stability iris effect, resulting in an increase in outgoing longwave radiation. In conclusion, under the ongoing climate change, studying the sensitivity of clouds to aerosols and SST should be conducted concomitantly as mutual effects are expected. [ABSTRACT FROM AUTHOR]

In this study we explore aerosol–cloud interactions in liquid-phase clouds over eastern China (EC) and its adjacent ocean (ECO) using the WRF-Chem–SBM model with four-dimensional assimilation. The results show that our simulations and analyses based on each vertical layer provide a more detailed representation of the aerosol–cloud relationship compared to the column-based analyses which have been widely conducted previously. For aerosol activation, cloud droplet number concentration (Nd) generally increases with aerosol number concentration (Naero) at low Naero and decreases with Naero at high Naero. The main difference between EC and ECO is that Nd increases faster in ECO than EC at low Naero due to abundant water vapor, whereas at high Naero , when aerosol activation in ECO is suppressed, Nd in EC shows significant fluctuation due to strong surface effects (longwave radiation cooling and terrain uplift) and intense updrafts. Cloud liquid water content (CLWC) increases with Nd , but the increase rate gradually slows down for precipitating clouds, while CLWC increases and then decreases in non-precipitating clouds. Higher Nd and CLWC can be found in EC than in ECO, and the transition-point Nd value at which CLWC in non-precipitating clouds changes from increasing to decreasing is also higher in EC. Aerosol activation is strongest at moderate Naero , but CLWC increases relatively fast at low Naero. ECO cloud processes are more limited by cooling and humidification, whereas strong and diverse surface and atmospheric processes in EC allow intense cloud processes to occur under significant warming or drying conditions. [ABSTRACT FROM AUTHOR]

Particulate organic nitrates (pON) significantly contribute to the mass of organic aerosol and influence the nitrogen oxides cycle in the atmosphere, but their evolution and lifetime remain uncertain. This study performed simultaneous measurements on the anthropogenically affected surface site and the mountain site on top of the polluted planetary boundary layer (PBL). After aging in the PBL, organic nitrate was converted from primary sources (decreased from 8.7% to 4.3%) to secondary sources (increased from 6.3% to 36.1%), spanning from the surface to the mountain. The evaporation of more volatile inorganic nitrate and the production of secondary organic nitrate during aging in the PBL contributed to the enhanced pON fraction over the top of PBL. The contribution of light absorption by brown carbon increased by 57% at the top of PBL compared to the surface, consistent with the higher fraction of nitrogenous organic aerosols over the mountain. The results provide field evidence that the nitrogenous organic aerosols (OA) may be preserved by adding into secondary OA and significantly contribute to the enhanced importance of brown carbon after aging during vertical transport in the PBL. [ABSTRACT FROM AUTHOR]

Satellite remote sensing of aerosol is largely conducted at moderate or coarse spatial resolution around 1–10 km. Nevertheless, at urban areas with high human activity, aerosol can originate from complex emission sources and may also vary strongly in space. Therefore, aerosol characterization at fine spatial resolution is essential for air quality study and assessment of anthropogenic pollution as well as climate effects. However, space‐borne instruments with high spatial resolution are usually limited in swath width or spectral coverage which result in lowering information content required for aerosol and surface retrieval. Based on the Generalized Retrieval of Atmosphere and Surface Properties (GRASP) algorithm, we propose a hybrid approach by combining fine and coarse spatial resolution measurements to retrieve aerosol and surface properties simulataneously at fine spatial resolution. The instruments with coarse spatial resolution and high revisting time can provide advanced aerosol characterization. At the same time, the instruments with fine spatial resolution are sensitive to spatial variability of aerosol nearby sources. In this study, the GRASP/Hybrid approach is demonstrated and tested based on the European Space Agency Sentinel‐5p/TROPOMI together with the Italian Space Agency PRISMA satellite data. Specifically, the detailed aerosol microphysical properties from Sentinel‐5p/TROPOMI 10 km retrievals are used as a priori information for PRISMA to derive aerosol loading and surface properties at 100 meter (m) spatial resolution. The PRISMA 100 m aerosol and surface retrieval based on the developed GRASP/Hybrid approach are evaluated using available ground‐based and satellite measurements, including AERONET, VIIRS/DB aerosol and PRISMA Level 2 surface reflectance products. Plain Language Summary: Both aerosol and surface characterization at high spatial resolution are always highly demanded especially over densely populated urban areas. However, the high spatial resolution space‐borne instruments typically have small swaths that, in general, reduce the possibility of aerosol and surface decoupling. In this paper, we develop a hybrid approach based on GRASP algorithm (GRASP/Hybrid) to retrieve aerosol and surface properties at fine spatial granularity by combining fine and coarse spatial resolution satellite data. The GRASP/Hybrid approach is demonstrated using European Space Agency (ESA) Sentinel‐5p/TROPOMI and Italian Space Agency (ASI) PRISMA (Hyperspectral Precursor of the Application Mission) measurements. Specifically, the detailed aerosol microphysical properties from Sentinel‐5p/TROPOMI 10 km retrievals are used as a priori information to derive aerosol loading and surface properties exploiting PRISMA at 100 m spatial resolution. Overall, the results obtained in this study demonstrate the big potential of the approach based on the combination of instruments for a number of climate and environment monitoring studies. Key Points: Generalized Retrieval of Atmosphere and Surface Properties (GRASP)/Hybrid approach is developed and demonstrated using Sentinel‐5p/TROPOMI and PRISMA measurementsPRISMA 100 m aerosol and surface properties are retrieved based on GRASP/Hybrid approach and evaluated using reference data setsWe demonstrate the big potential of hybrid approach based on the combination of instruments for climate and environment studies [ABSTRACT FROM AUTHOR]

In August 2017, a smoke plume from wildfires in British Columbia and the Northwest Territories recirculated and persisted over northern Canada for over two weeks. We compared a full‐factorial set of NASA Goddard Institute for Space Studies ModelE simulations of the plume to satellite retrievals of aerosol optical depth and carbon monoxide, finding that ModelE performance was dependent on the model configuration, and more so on the choice of injection height approach, aerosol scheme and biomass burning emissions estimates than to the choice of horizontal winds for nudging. In particular, ModelE simulations with free‐tropospheric smoke injection, a mass‐based aerosol scheme and comparatively high fire NOx emissions led to unrealistically high aerosol optical depth. Using paired simulations with and without fire emissions, we estimated that for 16 days over an 850,000 km2 region, the smoke decreased planetary boundary layer heights by between 253 and 547 m, decreased downward shortwave radiation by between 52 and 172 Wm−2, and decreased surface temperature by between 1.5°C and 4.9°C, the latter spanning an independent estimate from operational weather forecasts of a 3.7°C cooling. The strongest surface climate effects were for ModelE configurations with more detailed aerosol microphysics that led to a stronger first indirect effect. Plain Language Summary: Smoke from biomass burning is known to have effects on surface weather. We used the NASA GISS ModelE to estimate these effects for a large 2017 smoke plume over northern Canada that persisted for two weeks. We first found that the height of the smoke release at the source was the most important factor influencing agreement between ModelE and satellite retrievals of aerosols and carbon monoxide, and that specific, plausible configurations of the model led to unrealistically high aerosol amounts. By comparing simulations with and without fire, we estimated a 16‐day cooling over a 850,000 km2 region of between 1.5°C and 4.9°C, depending on the model configuration. Key Points: We captured the overall pattern and magnitude of a large 2017 smoke plume over Canada with the NASA GISS ModelEOf the sixteen plausible model configurations tested under a full‐factorial design, two with higher NOx emissions, free‐tropospheric smoke release and mass‐based aerosols led to unrealistically high aerosol optical depthOver an 850,000 km2 region, we estimated a 16‐day surface cooling of between 1.5°C and 4.9°C [ABSTRACT FROM AUTHOR]

Climate models commonly overestimate warm rain frequency and underestimate its intensity over the ocean, primarily due to insufficient representation of the aerosol effects. This pertains to both fine aerosols (FA) and coarse sea spray aerosols (CSA), where the latter is mostly absent in the models. Here, our observations show that adding CSA enhances vertical warm rain structure, in contrast to the effect of FA. The magnitude of the effect of CSA is larger than the opposite effect of the FA. For rain with top heights of 2–3 km, the raindrop size, concentration, and rain rate can be increased by factors of 1.03, 1.47, and 1.60, respectively. These CSA-induced changes are larger for thicker clouds, reaching a maximum by factors of 1.12, 1.85, and 2.21, respectively. Therefore, the combined FA and CSA effects should be incorporated into climate models for accurately simulated precipitation microphysical processes. [ABSTRACT FROM AUTHOR]

The contents of water-soluble major's ions (MSA, Cl−, NO3−, SO42−, Na+, NH4+, K+, Mg2+, and Ca2+) in the PM10 particle fraction were investigated thanks to detailed measurements of the main chemical constituents of PM10 in remote coastal areas in Bou-Ismail; in the South-West of the Mediterranean Sea (Algeria), during a 2-year period; from July 2011 to August 2013, under the framework of the ChArMEx project (Chemistry-Aerosol Mediterranean Experiment, http://charmex.lsce.ipsl.fr). The total water-soluble ion concentrations in PM10 at the Bou-Ismail measurement station varied from 3.3 µg/m3 (July 2011) to 49.6 µg/m3 (March 2012). The annual mean mass concentrations of ions in the PM10 particulate fraction were Cl− > Na+ > SO42− > Mg2+ > NO3− > Ca2+ > K+ > NH4+ > Oxalate. The change in potassium nss-K + concentrations in PM10 over the course of a year reveals that biomass burning (BB) has an effect on three separate seasons: the beginning of winter (February and March), the end of summer (August), and the autumn (September and October). The origin periods of biomass burning BB identified employing the mapping of hotspots and fires during periods of August and September 2011, 2012, and 2013 underlined the important fires in the surrounding areas of the Mediterranean Sea (Sardinia Islands from Italy, Corsica from France). [ABSTRACT FROM AUTHOR]

The Southern Ocean (SO) provides a unique natural laboratory for studying cloud formation and cloud-aerosol interactions with minimal anthropogenic influence. The Southern Ocean Clouds, Radiation, Aerosol Transport Experimental Study (SOCRATES), was an aircraft-based campaign conducted from January 15 to February 28, 2018, off the coast of Hobart, Tasmania. During SOCRATES, the NSF/NCAR GV research aircraft, equipped with in-situ probes and remote sensors, observed aerosol, cloud, and precipitation properties, and provided detailed vertical structure of clouds over the SO, particularly for the low-level clouds (below 3 km). The HIAPER Cloud Radar (HCR) and in-situ cloud and drizzle probes (CDP and 2DS) measurements were used to provide comprehensive statistical and phase-relevant macrophysical properties for the low-level clouds sampled by the 15 research flights during SOCRATES. A new method based on HCR reflectivity and spectrum width gradient was developed to estimate cloud boundaries (cloud-base and -top heights) and classify cloud types based on their top and base heights. Low-level clouds were found to be the most prevalent, with an almost 90 % occurrence frequency. A new phase determination method was also developed to identify the single-layered low-level clouds as liquid, ice, and mixed phases, with occurrence frequencies of 45.4 %, 32.5 %, and 22.2 %, respectively. Low-level clouds over the SO have significantly higher SLW concentrations, with liquid being most prevalent at higher temperatures, ice phase dominating at lower temperatures, and mixed-phase being least common due to its thermodynamic instability. Regarding their vertical distributions, the liquid phase occurs most frequently in the lower mid-cloud range (from 500 m to 1 km), the mixed phase dominates at cloud bases lower than 1 km but is well distributed along the vertical cloud layer, while the ice phase is prevalent from the middle to upper cloud levels (1–3 km). The higher occurrence of the mixed phase at the cloud base could be attributed to large drizzle-sized drops and/or ice particles. [ABSTRACT FROM AUTHOR]

We develop the Japan Aerospace Exploration Agency (JAXA) level 2 cloud mask and cloud type classification algorithms for the Earth Clouds, Aerosols, and Radiation Explorer (EarthCARE), a joint JAXA and European Space Agency (ESA) satellite mission. Cloud profiling radar (CPR)-only, atmospheric lidar (ATLID)-only, and combined CPR–ATLID algorithms for the cloud mask and cloud particle type are described. The algorithms are developed and evaluated using ground-based data, space-borne data from CloudSat and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) and simulation data from a Japanese global cloud-resolving model, the Non-hydrostatic Icosahedral Atmospheric Model (NICAM) with Joint simulator. The algorithms are based on our algorithms for CloudSat and CALIPSO with several improvements. The cloud particle type for ATLID is derived from an attenuation–depolarization diagram trained using 355 nm multiple-field-of-view multiple-scattering polarization lidar and changing the diagram from that developed for CALIPSO. The retrieved cloud particle phases (ice, water, and mixed phases) and those reported in the NICAM output data are compared. We found that the agreement for CPR-only, ATLID-only, and combined CPR–ATLID algorithms averaged roughly 80 %, 85 %, and 80 %, respectively, for 15 different cloud scenes corresponding to two EarthCARE orbits. [ABSTRACT FROM AUTHOR]

Purpose: Improving the deep lung delivery of aerosol surfactant therapy (AST) with a dry powder formulation may enable significant reductions in dose while providing improved efficacy. The objective of Part I of this two-part study was to present the development of a new dry powder aerosol synthetic lung surfactant (SLS) product and to characterize performance based on aerosol formation and realistic in vitro airway testing leading to aerosol delivery recommendations for subsequent in vivo animal model experiments. Methods: A new micrometer-sized SLS excipient enhanced growth (EEG) dry powder formulation was produced via spray drying and aerosolized using a positive-pressure air-jet dry powder inhaler (DPI) intended for aerosol delivery directly to intubated infants with respiratory distress syndrome (RDS) or infant-size test animals. Results: The best-case design (D2) of the air-jet DPI was capable of high emitted dose (> 80% of loaded) and formed a < 2 µm mass median aerodynamic diameter (MMAD) aerosol, but was limited to ≤ 20 mg mass loadings. Testing with a realistic in vitro rabbit model indicated that over half of the loaded dose could penetrate into the lower lung regions. Using the characterization data, a dose delivery protocol was designed in which a 60 mg total loaded dose would be administered and deliver an approximate lung dose of 14.7–17.7 mg phospholipids/kg with a total aerosol delivery period < 5 min. Conclusions: A high-efficiency aerosol SLS product was designed and tested that may enable an order of magnitude reduction in administered phospholipid dose, and provide rapid aerosol administration to infants with RDS. [ABSTRACT FROM AUTHOR]

Materials and methods used for the analysis of physicochemical properties of submicron industrial aerosols are described. These approaches can be used at research centers and enterprises, including those of Rosatom, for studying the physicochemical properties of submicron and nanometer aerosols. The dispersity of industrial α-emitting submicron aerosols in air of working premises of Mayak Production Association was studied for 239Pu using the neutron-induced measurement method. The size distribution of 239PuO2 nanoparticles in air of the oxalate precipitation department is the Pareto distribution. The result obtained can be used as a priori nanoparticle size distribution in the calculation of the 239Pu-caused internal irradiation dose load on the personnel of the oxalate precipitation department, RT Plant, Mayak Production Association, using the Bayesian method. [ABSTRACT FROM AUTHOR]

Regional climate is affected by a wide variety of aerosols which modify through their radiative effects the precipitation distribution. In this article, the effects of aerosols, mainly dust aerosols on diurnal cycle of precipitation amount, frequency and intensity are investigated over central Africa by using the latest version of the Abdu Salam ICTP regional climate model coupled with the Community Land Model 4.5 as land surface scheme. Two sets of experiments have been conducted (one with aerosols interaction with dynamics and thermodynamics processes and another without this interaction) for a 10-year study period (2002–2011) and the Fourier transformation is used to study the 24-h cycle. In order to clearly understand spatial differences in RegCM experiments over central Africa, three subregions have been considered according to their land cover and climate characteristics. Our results indicate that the pattern of simulated aerosol optical depth (AOD) is well represented particularly northward of the study region compared to AOD from moderate resolution imaging spectroradiometer (MODIS) even if some differences in terms of magnitude are reported. The aerosols' effects on diurnal cycle are generally not similar to those found in the amplitude and phase. The result pointed out that over the Sahelian region, atmospheric aerosol in general and dust in particular always induced a positive effect on diurnal cycle (increase the magnitude of the cycle) of precipitation intensities and in precipitation amount and precipitation frequency as well. But, the change is opposite in terms of amplitude and peak time over some subregions. It appears that the forcing of aerosols in solar radiation as well as in latent heat flux leads to the changes in the amplitude of the precipitation amount during the DJF and JAS seasons particularly during daytime. The changes in amplitude of the precipitation frequency are not consistent even if the corresponding phase always tends to increase by up to 5 h. [ABSTRACT FROM AUTHOR]

This article is devoted to the presentation of the MAP-IO observation program. This program, launched in early 2021, has enabled the observation of nearly 700 d of measurements over the Indian and Southern Ocean with the equipment of 17 meteorological and oceanographic scientific instruments on board the ship Marion Dufresne. Several observational techniques have been developed to respond to the difficulties of observations on board the ship, in particular for passive remote sensing data, as well as for quasi-autonomous data acquisition and transfer. The first measurements made it possible to draw up unprecedented climatological data of the Southern Ocean regarding the size distribution and optical thickness of aerosols, the concentration of trace gases and greenhouse gases, UV, and integrated water vapor. High-resolution observations of phytoplankton in surface waters have also shown a great variability in latitude in terms of abundance and community structure (diversity). The operational success of this program and these unique scientific results together establish a proof of concept and underline the need to transform this program into a permanent observatory. The multi-year rotations over the Indian Ocean will enable us to assess the trends and seasonal variability of phytoplankton, greenhouse gases, ozone, and marine aerosols in a sensitive and poorly documented climatic region. Without being exhaustive, MAP-IO should make it possible to better understand and assess the biological carbon pump, to study the variability of gases and aerosols in a region that is remote in relation to the main anthropogenic sources, and to monitor the transport of stratospheric ozone by the Brewer–Dobson circulation. The meteorological MAP-IO data set is publicly available at https://www.aeris-data.fr/catalogue-map-io/ (last access: 26 August 2024) (atmospheric data) and at 10.17882/89505 (phytoplankton data). [ABSTRACT FROM AUTHOR]

Pentasa (mesalamine/MSLM) is a widely prescribed delayed‐release capsule formulation for the treatment of inflammatory bowel disease. During dissolution study of Pentasa through ultraviolet (UV) spectroscopy, an unusual end‐release of about 110% has been observed. Initial liquid chromatography‐UV (LC‐UV) analyses of these dissolution samples confirmed three prominent peaks other than MSLM with a significant area percentage. Further systematic investigation was carried out by incubating active pharmaceutical ingredient in dissolution media for a longer duration and at elevated temperature followed by analysis through an inverse gradient LC‐charged aerosol detector (CAD). LC–high‐resolution mass spectrometry (HRMS) and online hydrogen‐deuterium exchange (HDX) mass spectrometry were also employed to identify and characterize these artifact products. The area % of prominent artifacts in LC‐UV was found to be way significant when compared to the area % obtained through inverse LC‐CAD, as CAD quantifies the peaks independent of the UV wavelength of absorbance. Inverse LC‐CAD was suitable to determine the relative response factor, whereas LC‐HRMS/MS and online HDX‐MS supported the characterization of these artifacts. These artifacts were found to be trimers, tetramers of MSLM formed due to polymerization, imparting additional pi‐bonds resulting in high UV absorptivity. These techniques when used in combinations serve complimentary to each other during such investigations. [ABSTRACT FROM AUTHOR]

The results of the "Terminator" space experiment on board the International Space Station are presented. Images of Earth's atmosphere are obtained in the near IR spectral range with the limb geometry of observations under a full moon. The calculated vertical profiles of volume emission/scattering rate point that the aerosol layer occurs within the height region of 80–100 km in Earth's atmosphere. It is proposed that this layer is meteoric in origin. Estimates show that the size spectrum of aerosol particles lies within the 1–100 nm range. [ABSTRACT FROM AUTHOR]

Clouds are crucial in regulating the Earth's energy budget. Global cloud top heights have been easily retrieved from satellite measurements, but there are few methods for determining cloud base height (CBH) from satellite measurements. The Cloud Base Altitude Spatial Extrapolator (CBASE) algorithm was proposed to derive the height of the lower-troposphere liquid cloud base by using the Cloud-Aerosol Lidar with Orthogonal polarization cloud aerosol LiDAR (CALIOP) profiles and weather observations at airports from aviation routine and special weather report (METARs and SPECIs, called METAR) observation data in the United States. A modification to the CBASE algorithm over China (CNMETAR-CBASE) is presented in this paper. In this paper, the ability of the CBASE algorithm to calculate CBH in China is evaluated, and METAR observations over China (CNMETAR) were then used to modify the CBASE algorithm. The results including CNMETAR observation data in China can better retrieve CBH over China compared with the results using the original CBASE algorithm, and the accuracy of the global CBH results has been improved. Overestimations of CBH with the original algorithm range from 500 to 800 m in China, which have been reduced to about 300 m with an improved algorithm. The deviations calculated by the algorithm also have a significant reduction, from 480 m (CBASE) to 420 m (CNMETAR-CBASE). In conclusion, the modified CBASE algorithm not only calculates the CBH more accurately in China but also improves the results of the global CBH retrieved from satellites. [ABSTRACT FROM AUTHOR]

Novel observations of aerosol and clouds by means of ground-based remote sensing have been performed in Antarctica over the Ekström Ice Shelf on the coast of Dronning Maud Land at Neumayer Station III (70.67°S, 8.27°W) from January to December 2023. The deployment of the OCEANET-Atmosphere remote sensing observatory in the framework of the Continuous Observations of Aerosol-Cloud Interaction (COALA) campaign has brought Aerosol, Clouds and Trace Gases Research Infrastructure (ACTRIS) aerosol and cloud profiling capabilities next to meteorological and air chemistry in situ observations at the Antarctic station. We present an overview of the site, the instrumental setup, and data analysis strategy and introduce 3 scientific highlights from austral fall and winter, namely, 1) observations of a persistent mixed-phase cloud embedded in a plume of marine aerosol. Remote sensing–based retrievals of cloud-relevant aerosol properties and cloud microphysical parameters confirm that the free-tropospheric mixed-phase cloud layer formed in an aerosol-limited environment. 2) Two extraordinary warm air intrusions: one with intense snowfall produced the equivalent of 10% of the yearly snow accumulation and a second one with record-breaking maximum temperatures and heavy icing due to supercooled drizzle. 3) Omnipresent aerosol layers in the stratosphere. Our profiling capabilities could show that 50% of the 500-nm aerosol optical depth of 0.06 was caused by stratospheric aerosol, while the troposphere was usually pristine. As demonstrated by these highlights, the 1-yr COALA observations will serve as a reference dataset for the vertical structure of aerosol and clouds above the region, enabling future observational and modeling studies to advance understanding of atmospheric processes in Antarctica. [ABSTRACT FROM AUTHOR]

Background: Chronic obstructive pulmonary disease (COPD) is a preventable, progressive disease and the third leading cause of death worldwide. The epidemiological data of COPD from Gulf countries are very limited, as it remains underdiagnosed and underestimated. Risk factors for COPD include tobacco cigarette smoking, water pipe smoking (Shisha), exposure to air pollutants, occupational dusts, fumes, and chemicals. Inadequate treatment of COPD leads to worsening of disease. The 2024 GOLD guidelines recommend use of inhaled bronchodilators, corticosteroids, and adjunct therapies for treatment and management of COPD patients based on an individual assessment of the severity of symptoms and risk of exacerbations. This article reviews COPD pharmacotherapy in the Gulf countries and explores the role of nebulization in the management of COPD in this region. Methods: To review the COPD pharmacotherapy in the Gulf Countries, literature search was conducted using PubMed, Medline, Cochrane Systematic Reviews, and Google Scholar databases (before December 2022), using search terms such as COPD, nebulization, inhalers/inhalation, aerosols, and Gulf countries. Relevant articles from the reference list of identified studies were reviewed. Consensus statements, expert opinion, and other published review articles were included. Results: In the Gulf countries, pressurized metered-dose inhalers (pMDIs), dry powder inhalers (DPIs), soft mist inhalers, and nebulizers are used for drug delivery to COPD patients. pMDIs and DPIs are most prone to errors in technique and other common device handling errors. Nebulization is another mode of inhalation drug delivery, which is beneficial in certain patient populations such as the elderly and patients with cognitive impairment, motor or neuromuscular disorders, and other comorbidities. Conclusion: There is no major difference between Gulf countries and rest of the world in the approach to management of COPD. Nebulizers should be considered for patients who have difficulties in accessing or using MDIs and DPIs, irrespective of geographical location. [ABSTRACT FROM AUTHOR]

Because of the increasing popularity of e-cigarettes, monitoring the e-cigarette market has become important for national health authorities to guarantee safety and quality. In the EU, the Tobacco Products Directive requires emission studies for e-cigarette products. The absence of industry guidelines for studying these emissions and the lack of proper validation in the literature led us to develop and validate a method using the total error approach for the determination of nicotine in e-cigarette aerosols. A commercial vaping device was used to generate aerosols, which were then collected on Cambridge filter pads and measured for nicotine concentration by UHPLC-DAD after extraction. The method was successfully validated by generating accuracy profiles, which show that the β-expectation tolerance intervals remained below the acceptance limits of ±20%. Within-run repeatability and intermediate precision were considered acceptable since the highest RSD value obtained was below 5%. The method was applied to 15 commercial e-liquids. A complete validation of a method for the analysis of e-cigarette emissions is presented, including several parameters that impact the accuracy and reproducibility. Similar systematic approaches for method development and validation could be used for other e-cigarette emission analysis methods to ensure the reliability of the measurements. [ABSTRACT FROM AUTHOR]

Simple Summary: Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a new surgical procedure used in the treatment of peritoneal surface malignancies (PSMs). Despite encouraging clinical results, the high costs of PIPAC and the need to repeat the treatment multiple times make the procedure difficult to sustain economically. A retrospective study was conducted in order to evaluate the cost of hospitalization for patients undergoing PIPAC treatment at a high-volume center in Italy. Currently, the Italian National Health System only partially covers the hospitals' costs. Therefore, there is an urgent need for an economical redefinition of this procedure, by creating dedicated reimbursement codes. PIPAC is a new surgical procedure and a viable treatment option for PSM patients, due to promising therapeutic outcomes, minimal invasiveness, limited surgical morbidity, and systemic toxicity side effects. However, its implementation throughout hospitals is hard to obtain due to its fragile economical sustainability. A retrospective health economic analysis was conducted in order to evaluate the cost of hospitalization for patients undergoing PIPAC treatment at Fondazione Policlinico Universitario Agostino Gemelli, IRCCS, in Rome. The average cost of a PIPAC procedure was defined based on the cost of surgery (cost of surgical material, operating room, intraperitoneal chemotherapy), hospital stay, diagnostic examinations, and drugs used during the stay. A total of 493 PIPAC procedures were performed on 222 patients with peritoneal metastases or primary peritoneal cancer from 2017 to 2023. Since the mean remuneration for each PIPAC hospitalization is €5916 and the mean expenditure per hospitalization is €6538, this results in an operating profit per PIPAC hospitalization of −€622. The reimbursement of PIPAC treatment by the Italian National Health System currently only partially covers the hospital's costs. Development of specific codes and adequate reimbursement for PIPAC by recognizing this procedure as a proper treatment for peritoneal carcinomatosis is essential. [ABSTRACT FROM AUTHOR]

Aerosol acidity is a critical factor affecting atmospheric chemistry. Here, we present a study on annual, monthly, and daily variations in PM2.5 pH in Shanghai during 2010–2020. With the effective control of SO2 emissions, the NO2/SO2 ratio increased from 1.26 in 2010 to 5.07 in 2020 and the NO3−/SO42− ratio increased from 0.68 to 1.49. Aerosol pH decreased from 3.27 in 2010 to 2.93 in 2020, regardless of great achievement in reducing industrial SO2 and NOx emissions. These findings suggest that aerosol acidity might not be significantly reduced in response to the control of SO2 and NOx emissions. The monthly variation in pH values exhibited a V-shape trend, mainly attributable to aerosol compositions and temperature. Atmospheric NH3 plays the decisive role in buffering particle acidity, whereas Ca2+ and K+ are important acidity buffers, and the distinct pH decline during 2010–2016 was associated with the reduction of Ca2+ and K+ while both temperature and SO42− were important drivers in winter. Sensitivity tests show that pH increases with the increasing relative humidity in summer while it is not sensitive to relative humidity in winter due to proportional increases in H a i r + and aerosol liquid water content (ALWC). Our results suggest that reducing NOx emissions in Shanghai will not significantly affect PM2.5 acidity in winter. [ABSTRACT FROM AUTHOR]

This paper is based on the keynote talk that I presented at the International Congress on Clouds and Precipitation (ICCP, 2021), wherein I was awarded a lifetime membership of ICCP. I focus on the invigoration of cumulus clouds by high concentrations of ice nuclei and hygroscopic aerosol. As far as ice nuclei are concerned, I discuss the hypothesized invigoration of cumulus clouds by seeding with high concentrations of ice nuclei or what has been called rainfall enhancement by means of "dynamic seeding". As to the effects of enhanced concentrations of hygroscopic aerosol on cumulus dynamics and rainfall, I discuss two mechanisms, (1) "mixed-phase invigoration" and (2) "condensational invigoration". I conclude that the concept of invigoration of convective clouds using high concentrations of hygroscopic aerosol by means of "condensational invigoration" is the dominant response of cumuli to enhanced concentrations of hygroscopic aerosol. Moreover, the invigorated cumulus clouds produce more rainfall. [ABSTRACT FROM AUTHOR]

Rationale: It is unclear if e-cigarettes have reduced abuse liability relative to traditional cigarettes, especially when considering advanced devices which deliver nicotine more efficiently. Translatable and predictive animal models are needed to addresses this question. Objectives: Our goal was to explore the subjective stimulus effects of e-cigarettes by training rats to discriminate puffs of nicotine aerosol from vehicle aerosol using an aerosol delivery system designed to model e-cigarette use patterns in humans. Methods: Rats were trained to discriminate between ten, 10 s puffs of aerosol generated from 3 mg/ml nicotine e-liquid and nicotine-free e-liquid using a food-reinforced operant procedure. Following acquisition, tests were conducted to determine the specificity of the nicotine aerosol stimulus as well as the impact to the stimulus effects of nicotine resulting from the addition of menthol to e-liquid. Results: Rats learned the nicotine aerosol puff vs vehicle puff discrimination in a mean of 25 training sessions. Injected nicotine fully substituted for the stimulus effects of nicotine aerosol. The stimulus effects of nicotine aerosol were blocked by the nicotinic receptor antagonist mecamylamine. The nicotinic receptor partial agonist, varenicline as well as the stimulant d-amphetamine substituted more robustly for nicotine aerosol puffs than did the NMDA antagonist, ketamine. Menthol enhanced the stimulus effects of nicotine aerosol without altering nicotine blood plasma levels. Conclusions: Nicotine aerosol puffs can function as a training stimulus in rats. The stimulus effects were CNS-mediated and receptor specific. Menthol appears to enhance the stimulus effects of nicotine aerosol through a pharmacodynamic rather than pharmacokinetic mechanism. [ABSTRACT FROM AUTHOR]

Recent extensive research has focused on atmospheric aerosol systems, driven by their far-reaching implications for climate and public health, with a goal to identify optimal air quality management practices. This study employs Langevin dynamics to investigate the impact of size distribution and concentration of submicrometer solid aerosol particles on Brownian agglomeration tendencies within an isothermal, hydrostatically balanced atmosphere. To accomplish this, a Langevin dynamic model is devised, and parameters are carefully determined to ensure numerical integration precision, stability, and efficiency. Using this model, we numerically simulate the average agglomeration nucleus and overall agglomeration rate within the system while considering variations in the standard deviation of size distribution and volume fraction of aerosol particles. [ABSTRACT FROM AUTHOR]

Long-term, accurate, stable, and continuous aerosol records from space are a major requirement for climate and atmospheric environment research. Due to the limited period span of the single satellite mission, solving the problem requires the combination of multiple satellite missions. In this study, a novel aerosol retrieval algorithm, named enhanced Land General Aerosol Retrieval (e-LaGA), for Visible/Infrared Imager Radiometer Suite (VIIRS) was developed to continue Moderate-resolution Imaging Spectro-radiometer (MODIS) aerosol retrieval. e-LaGA utilizes a Surface Reflectance (SR) relationship model map to more accurately estimate the SR parameter, optimizes the priori aerosol-type map, and improves the multi-band retrieval strategy using the residual-interpolation approach. Additionally, e-LaGA expands the retrieval ability of the traditional Dark Target (DT) algorithm over bright surfaces, and can more accurately retrieve Aerosol Optical Depth (AOD), Fine-mode AOD (AODF), and Fraction (FMF). The validation using global 533 AERONET sites shows that the volume of matchups of AOD (AODF) is approximately 80000, the correlation coefficient (R) is 0.902 (0.879) and the fraction of meeting the expected error envelope (±0.05 ± 0.15τ) is 0.806 (0.804). The inter-comparison indicates that the accuracy of e-LaGA AOD retrievals is comparable to seven commonly used AOD products. The validation performance and spatial distribution pattern of e-LaGA AODF and FMF are in good agreement with the POLDER (Polarization and Directionality of the Earth's Reflectances) products. e-LaGA is also applied to MODIS sensors. The VIIRS e-LaGA AOD, AODF, and FMF retrievals have high consistency with MODIS e-LaGA. Their average bias of AOD is 0.006, which is smaller than 0.024 for the Deep Blue and 0.011 for the DT. These preliminary results demonstrate the robustness of the e-LaGA algorithm and its potential for establishing a long-term climate record of total and fine-mode aerosol by combining multiple satellite missions, which is expected to reduce the uncertainty of climate change research. [ABSTRACT FROM AUTHOR]

Outpatient and inpatient rehabilitation, as a complex and multimodal treatment concept, makes significant use of methods that are assigned to conservative orthopedics, in particular the procedures of physical therapy. In contrast to physiotherapy and medical training therapy, physical therapy is a form of therapy provided with technology. The spectrum ranges from hydrotherapy, mechanotherapy and thermotherapy to balneotherapy, massage forms and electrotherapy. Climatotherapy, phototherapy and aerosol/inhalation therapy have less of an impact on the orthopaedic field. Although the forms of therapy are often referred to as passive, the effect is based on physical laws, physiological reactions and adaptation. In addition, these are predominantly forms of therapy, some of which have been in use for centuries, some for thousands of years, these efficient treatments with a good safety and tolerability profile gained by means of empiricism. [ABSTRACT FROM AUTHOR]

A new high-flow, compact aerosol concentrator, using rapid, turbulent mixing to grow aerosol particles into droplets for dry spot sample collection, has been designed and tested. The "TCAC (Turbulent-mixing, Condensation Aerosol Concentrator)" is composed of a saturator for generating hot vapor, a mixing section where the hot vapor mixes with the cold aerosol flow, a growth tube where condensational droplet growth primarily occurs, and a converging nozzle that focuses the droplets into a beam. The prototype concentrator utilizes an aerosol sample flow rate of 4 L min−1. The TCAC was optimized by varying the operating conditions, such as relative humidity of the aerosol flow, mixing flow ratio, vapor temperature, and impaction characteristics. The results showed that particles with a diameter ≥ 25 nm can be grown to a droplet diameter > 1400 nm with near 100% efficiency. Complete activation and growth were observed at relative humidity ≥ 25% of the aerosol sample flow. A consistent spot sample with a diameter of D90 = 1.4 mm (the diameter of a circle containing 90% of the deposited particles) was obtained regardless of the aerosol particle diameter (dp = 20–1900 nm). For fiber counting applications using phase contrast microscopy, the TCAC can reduce the sampling time, or counting uncertainty, by two to three orders of magnitude, compared to the 25-mm-filter collection. The study shows that the proposed mixing-flow scheme enables a compact spot sample collector suitable for handheld or portable applications, while still allowing for high flow rates. [ABSTRACT FROM AUTHOR]

The particle number size distribution (PNSD) plays a crucial role in aerosol science and related industries. The recent surge in dense PNSD monitoring networks and measurement in harsh environments necessitates low-cost Electrical Mobility Sizers/Spectrometers (EMS). A miniature charger using the radioactive source of americium-241 charger was specifically developed for the low-cost EMS, with ion sources easily obtainable at low costs from smoke alarms. The ion concentration was over 5 × 1012 m−3. The measured charging efficiency of the charger aligns with the commonly used approximation formulae, while charge distributions deviate slightly from it. To solve this deviation issue, a reported inversion method is adopted which is based on the bipolar PNSD measurement. The practical use of the charger was theoretically explored, providing insights into the particle number concentration limits at commonly employed flow rates. This charger displays the potential for providing a cost-effective method of conditioning aerosol charging in large-scale or environmentally challenging PNSD measurements. Copyright © 2024 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

Dry powder inhalers (DPIs) are commonly used devices for delivering inhalable pharmaceuticals. The overall efficacy of any inhalable pharmaceutical is a function of total and regional dose, and the bioavailability of the active pharmaceutical ingredient upon deposition in the lung. Thus, a detailed understanding of the dissolution dynamics of particles from a DPI from the point of generation through to deposition in the lung may shed additional insights into the interpretation of the pharmacokinetic effects, resulting in the design of improved formulations. We present the design and benchmarking of a novel technology that directly measures the dissolution dynamics of dry aerosol particles in situ, where the relative humidity and temperature are directly comparable to the highly humid conditions within the lungs. The rate of water uptake (mass) as well as changes in the physical structure of the particle are directly measured using a combination of electrodynamics and laser light scatter. This technique offers unique insights into the dissolution dynamics of DPI starting formulations. [ABSTRACT FROM AUTHOR]

The piezoelectric and ferroelectric properties of aerosol deposited (AD) thick ceramic films are significantly reduced in comparison to bulk materials, which is assumed to be largely related to the nanometer-sized grains (∼0.01 μm) observed in the resulting microstructures. This work, therefore, focuses on understanding the role of grain size in electromechanical properties within the range of AD films based on Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9 O 3 (BCZT). In a comprehensive compilation of the piezoelectric constant (d 33) of samples from various studies the grain size dependency of the d 33 was shown for the lead-free ferroelectrics BCZT, BaTiO 3 , and (K,Na)NbO 3. In this, it can be seen that no BCZT sample with a grain size below 0.4 μm was analyzed regarding their d 33 before, thereby leaving a gap to the grain size of AD films. In this study, the grain size of ceramic bulk samples was varied using spark plasma and conventional sintering (0.1 μm – 11 μm) and their properties compared to those of AD films. To enable the fabrication of bulk samples in the same range as AD films, a hydrothermal powder with an average particle size of 0.075 μm was synthesized. A continuous increase of the permittivity, the polarization, and the piezoelectric coefficient was observed through grain size increase. These results suggest that the grain size of AD films needs to be enhanced to improve their properties. Importantly, the insights of this multiscale analysis on the grain size can help to tailor also the properties of other BCZT films and bulk samples. [ABSTRACT FROM AUTHOR]

A new set of standalone parameterizations is presented for simulating the injection, evolution, and radiative forcing by stratospheric volcanic aerosols against an idealized Held–Suarez–Williamson (HSW) atmospheric background in the Energy Exascale Earth System Model version 2 (E3SMv2). In this model configuration (HSW with enabled volcanism, HSW-V), sulfur dioxide (SO 2) and ash are injected into the atmosphere with a specified profile in the vertical, and they proceed to follow a simple exponential decay. The SO 2 decay is modeled as a perfect conversion to a long-living sulfate aerosol which persists in the stratosphere. All three species are implemented as tracers in the model framework and are transported by the dynamical core's advection algorithm. The aerosols contribute simultaneously to local heating of the stratosphere and cooling of the surface by a simple plane-parallel Beer–Lambert law applied on two zonally symmetric radiation broadbands in the longwave and shortwave ranges. It is shown that the implementation parameters can be tuned to produce realistic temperature anomaly signatures of large volcanic events. In particular, results are shown for an ensemble of runs that mimic the volcanic eruption of Mt. Pinatubo in 1991. The design requires no coupling to microphysical subgrid-scale parameterizations and thus approaches the computational affordability of prescribed aerosol forcing strategies. The idealized simulations contain a single isolated volcanic event against a statistically uniform climate, where no background aerosols or other sources of externally forced variability are present. HSW-V represents a simpler-to-understand tool for the development of climate source-to-impact attribution methods. [ABSTRACT FROM AUTHOR]

Aerosols can cause brightening of stratocumulus clouds, thereby cooling the climate. Observations and models disagree on the magnitude of this cooling, partly because of the aerosol-induced liquid water path (LWP) adjustment, with climate models predicting an increase in the LWP and satellites observing a weak decrease in response to increasing aerosols. With higher-resolution global climate models, which allow the simulation of mesoscale circulations in which stratocumulus clouds are embedded, there is hope to start bridging this gap. In this study, we present boreal summertime simulations conducted with the ICOsahedral Non-hydrostatic (ICON) global storm-resolving model (GSRM). Compared to geostationary satellite data, ICON produces realistic cloud coverage in the stratocumulus regions; however, these clouds look cumuliform, and the sign of LWP adjustments disagrees with observations. We investigate this disagreement with a causal approach, which combines time series with knowledge of cloud processes, allowing us to diagnose the sources of observation–model discrepancies. The positive ICON LWP adjustment results from a superposition of processes, with an overestimated positive response due to (1) precipitation suppression, (2) a lack of wet scavenging, and (3) cloud deepening under a weak inversion, despite (4) small negative influences from cloud-top entrainment enhancement. We also find that precipitation suppression and entrainment enhancement occur at different intensities during the day and the night, implying that daytime satellite studies suffer from selection bias. This causal methodology can guide modelers on how to modify model parameterizations and setups to reconcile conflicting studies concerning the sign and magnitude of LWP adjustments across different data sources. [ABSTRACT FROM AUTHOR]

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This study reviews the two most important and frequently used systems of tomography used in dentistry today. These are the dental panoramic radiograph (DPR) and cone-beam computed tomography (CBCT). The importance of the DPR has been accentuated by the recent COVID-19 pandemic, as it does not produce an aerosol. Its clinical importance is derived from its panoramic display of the jaws and associated structures and should be examined for incidental findings that may portend a potentially serious outcome. An important recent spin-off of the DPR is the extra-oral bitewing, which can replace its traditional, uncomfortable and aerosol-generating intra-oral counterpart. Although much has been written about them, this paper reviews their essential attributes and limitations in clinical dentistry. Although attempts have been made to reproduce some of the attributes of CT in CBCT such as Hounsfield Units (HU) and improve the contrast resolution of the soft tissues, these remain elusive. Nevertheless, CBCT's dataset should be appropriately reconstructed to fully display the clinical feature prompting its prescription. In certain cases, more than one mode of reconstruction is required. [ABSTRACT FROM AUTHOR]