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Understanding aerosol‐cloud interactions under pristine atmospheric conditions is crucial for meaningful global climate change predictions. However, ability of aerosol particles to act as cloud condensation nuclei (CCN) activity of aerosols in pristine atmosphere remains limited, mainly because of the difficulty of measuring it in pristine environments. Given the extremely low CCN number concentration under low supersaturations (SSs) and the complex impact of the kinetic limitation in CCN measurements, size‐resolved CCN activity measurements at low SSs cannot be achieved with traditional methods using differential mobility analyzers and a CCN counter (CCNC) because of the low sample efficiency and the impact of particles with multiple charges. To overcome this difficulty, we propose a new method for measuring size‐resolved CCN activity at low aerosol number concentrations. The new method is based on a combined system comprising an aerodynamic aerosol classifier (AAC) and a CCNC (AAC‐CCNC system). A control program was developed to achieve high‐resolution scans of the SS and particle size within a reasonable time frame. A data inversion scheme, including corrections for the transfer function and kinetic limitation, was developed to obtain accurate size‐resolved CCN activity. In July‐August 2022, the new method was used to measure the size‐resolved CCN activity on the Tibetan Plateau. This new method can advance the size‐resolved CCN measurements, thereby enhancing our understanding of aerosol‐cloud interactions in pristine atmosphere. Plain Language Summary: Cloud condensation nuclei (CCN) are the aerosols which can form cloud droplets. Assessing the ability of aerosols to serve as CCN (CCN activity) is fundamental for understanding the interactions between aerosol and clouds and their impacts on climate and precipitation. Particularly in regions with minimal human influence, such as polar areas and the Tibetan Plateau, the low aerosol concentration makes aerosol‐cloud interaction and its climate impact highly sensitive to aerosol CCN activity. However, traditional CCN activity measurement techniques are not applicable at conditions of extremely low aerosol concentrations, restricting the understanding of aerosol‐cloud interactions and their impacts in those regions. In this study, we developed a new system for CCN activity measurements at low aerosol concentration and corresponding data processing algorithm based on a particle size selection technique distinct from that used in traditional systems. The new system was successfully deployed in a field experiment conducted in Qinghai‐Tibet Plateau in summer 2022. Comparison with CCN concentration measurement indicates that the uncertainty of the CCN activity measurement is within a reasonable range. Notably, this marks the first instance of online measurement of particle size‐resolved CCN activity in the hinterland of the Qinghai‐Tibet Plateau. Key Points: A new aerodynamic aerosol classifier‐cloud condensation nuclei counter (AAC‐CCNC) system is developed for measureing size‐resolved cloud condensation nuclei (CCN) activity under low supersaturated conditions in pristine atmospheresUncertainty correction relating to the impact of kinetic limitations in the CCN counter and the transfer function of the AAC is developedThe AAC‐CCNC system is successfully deployed for size‐resolved CCN activity measurements in the Tibetan Plateau [ABSTRACT FROM AUTHOR]

This study introduces an innovative outdoor nephelometer system designed to monitor the dynamic hygroscopic behavior of aerosols in ambient air. Field measurements conducted in the Pearl River Delta region of China unveil significant roles of relative humidity (RH) swings on aerosol phase states. Highlighting the occurrence of aerosol crystallization in the afternoon followed by gradual deliquescence as RH increases, particularly when minimum afternoon RH drops below 35%, with no such behavior observed when it exceeds 40%. Emphasizing that aerosol phase states are shaped not only by RH and chemical composition but also by their RH history, illustrating that RH levels of 70% in the morning or evening may correspond to fully dissolved metastable or partially dissolved metastable states of ambient aerosols. These findings underscore the need to account for RH history when predicting aerosol phase states and have broader implications for comprehending aerosol behavior and its atmospheric impacts. Plain Language Summary: This research introduces a new device to study how tiny particles called atmospheric aerosols in the air behave when they encounter moisture. We tested it in a region of China and discovered that relative humidity fluctuations from morning to evening impact significantly on phase state of atmospheric aerosols. In the afternoon, some of the particles might become solid, like tiny crystals, and later turn into liquid gradually as humidity increases. This phenomenon occurs when the afternoon minimum relative humidity is low, below 35%, but does not take place when it exceeds 40%. Suggesting that relative humidity history matters for aerosol phase. For example, relative humidity of 70% in the morning or evening, particles may be in a liquid or semi‐liquid state. This study helps us understand phase changes of atmospheric particles and their effects on our environment. Key Points: Innovative outdoor nephelometer system was developed to monitor aerosol hygroscopic behavior in ambient airAerosol crystallization in the afternoon followed by gradual deliquescence observedRelative humidity history plays significant roles in determining aerosol phase state [ABSTRACT FROM AUTHOR]

Activation of biomass burning aerosols (BBA) and fossil fuel combustion aerosols (FFA) in fogs and clouds significantly impact regional air quality through aqueous chemistry and climate by affecting cloud microphysics. However, we lack direct observations of how these aerosols behave in fogs and clouds. Using a newly developed aerosol‐cloud sampling system, we conducted observations during fog events and found that BBA, despite their high organic content, effectively contributed to super‐micron interstitial aerosols and fog droplets in low supersaturation fogs. In contrast, FFA, predominantly externally mixed organic, did not grow beyond the super‐micron size in fogs due to their near‐hydrophobic nature. Measurements conducted under supersaturations relevant for cloud formation revealed that portions of FFA could serve as cloud condensation nuclei, but only when supersaturation exceeded ∼0.14%. These findings have broad implications for future investigations into the influence of BBA and FFA on fog and cloud chemistry and their interactions with clouds. Plain Language Summary: Tiny particles, known as aerosols, emitted from combustion of biomass and fossil fuels, can impact air quality and global climate by interacting with fog and clouds. However, we lack direct observational evidence of how these aerosols behave in these conditions. In our study, we developed an advanced aerosol‐cloud sampling system to observe aerosol activation during fog events. Our findings highlight a crucial factor of aerosol activation: the mixing of these aerosols. Biomass burning aerosols with an internal mixture of organic and inorganic components activate more easily, even in conditions with low supersaturation like fog. In contrast, fossil fuel combustion aerosols are often externally mixed and almost water‐repellent, requiring higher supersaturation to become cloud condensation nuclei. Understanding these distinctions has significant implications for regional air quality and the intricate interactions between aerosols and clouds. By gaining insights into how various aerosols interact with fog and clouds, we can enhance our understanding of their impact on our environment and climate. Key Points: Advanced Aerosol‐Cloud sampling system was developed to characterize aerosol activation in fogsBiomass burning aerosols efficiently form fog droplets, while fossil fuel combustion aerosols are almost hydrophobic and don't contributeFossil fuel combustion organic aerosols can serve as CCN in high supersaturation conditions (>0.14%) [ABSTRACT FROM AUTHOR]

Background: Hepatocellular carcinoma (HCC) is a primary liver cancer with high mortality. The long‐term use of sorafenib, a targeted drug for hepatocellular carcinoma, will lead to drug resistance, and patients are prone to cancer metastasis, the molecular mechanism of which is still unclear. Methods: In our study, we constructed a sorafenib‐resistant hepatocellular carcinoma cell line (HepG2/Sora) and validated the resistance in vivo and in vitro. Transwell assays confirmed the invasion and migration abilities of cells. Colorimetric assays confirmed that the level of m6A methylation modification in cells. RT‐qPCR and Western blot assays confirmed that the expression levels of KIAA1429 in HepG2/Sora cells and tissues. The EMT related proteins were detected by Western blot assay. Results: Transwell and Western blot assays confirmed that HepG2/Sora cells had higher invasion and migration abilities and showed EMT phenomena. Colorimetric assays confirmed that the level of m6A methylation modification was upregulated in HepG2/Sora cells. Transwell and Western blot assays confirmed that inhibiting m6A methylation in HepG2/Sora cells inhibited their invasion, migration ability and EMT phenomenon. RT‐qPCR and Western blot assays confirmed that the expression levels of KIAA1429 in HepG2/Sora cells and tissues was increased. Silencing KIAA1429 in HepG2/Sora cells inhibited their invasion, migration ability and EMT phenomenon. Finally, we found that the medium supernatant of sorafenib‐resistant HepG2/Sora cells induced vascular production of EA.hy926 cells, and silencing KIAA1429 inhibited this induction effect. Conclusion: We suggest that KIAA1429 promotes sorafenib‐resistant hepatocellular carcinoma invasion, migration and EMT by mediating m6A methylation. KIAA1429 with its mediated m6A methylation may be a key factor for sorafenib‐resistant patients prone to cancer cell metastasis. [ABSTRACT FROM AUTHOR]

The commercial continuous‐flow streamwise thermal‐gradient cloud condensation nuclei (CCN) counter is widely used in aerosol CCN activity measurements which are critical for investigating aerosol‐cloud interactions. In CCN measurements, a critical threshold is needed for distinguishing interstitial aerosols and activated droplets, and a default threshold of 0.75 μm was set in CCN counter. Theoretically, interstitial aerosols could also grow larger than 0.75 μm in CCN counter at low supersaturations, thus theoretical thresholds derived from the Köhler theory were suggested. Here, we report that droplet growth in the CCN counter is kinetically limited and CCN‐active droplets does not reach their theoretical diameters under low supersaturations. Neglecting the kinetic growth limitation in CCN identification would count less CCN and underestimate the aerosol hygroscopicity parameter κ $\kappa $ by up to 50% for supersaturations lower than 0.1%. We recommend that thresholds considering kinetic limitations should be used as new criteria for CCN identification under low supersaturations. Plain Language Summary: Accurate Cloud Condensation Nuclei (CCN) predictions in climate and regional models are crucial for the assessment of climate effects of aerosol‐cloud interactions. Direct measurements of CCN activity, varied by aerosol size, hygroscopicity, and supersaturation, are important for model verifications and improvements. The commercial continuous‐flow streamwise thermal‐gradient CCN counter (CCNC) is widely used in CCN activity measurements. We found that the droplet growth in the CCNC is kinetically limited under low supersaturations (<0.14%), thus not reaching the theoretical critical activation diameter, which significantly affect CCN identification. Kinetic model results revealed that the wet diameter thresholds of CCN identification that took the kinetic limitations of droplet growth into account were independent of dry aerosol size and hygroscopicity thus could be directly used as new criteria for CCN identification. Neglecting the kinetic growth limitation in CCN identification would result in significant bias in CCN activity measurements and thus supersaturated aerosol hygroscopicity retrievals. Findings of this research have significant impacts on CCN activity measurements and supersaturated aerosol hygroscopicity investigations. Key Points: Limited hygroscopic growth of cloud condensation nuclei (CCN) in CCN counter is recognized and evaluated based on model analysisKinetic limitations in CCN counter impacts significantly on size‐resolved CCN activity measurementsKinetic limitations in CCN counter impacts significantly on aerosol hygroscopicity measurements under low supersaturation [ABSTRACT FROM AUTHOR]

The hygroscopicity parameter (κ) has been widely used in studies of aerosol hygroscopic growth and cloud condensation nucleus activation, but the effect of relative humidity (RH) variations on ambient aerosol hygroscopicity is rarely discussed and is often ignored in the application of κ‐Köhler theory. In this study, an improved humidified nephelometer system was used to measure the scattering enhancement (f(RH)) of bulk aerosols and the RH‐dependent κ was derived. It was found that the κ of both pure inorganic water‐soluble electrolytes and ambient aerosols is significantly RH‐dependent. The particle size had a great influence on f(RH), but κ had no obvious size dependence. Compared with using the RH‐dependent κ, the scattering coefficient of ambient aerosols with the fixed κ value would produce a relative error of −10%–25%. Parameterization schemes of RH‐dependent κ of ambient aerosols were established, which could serve as a reference for the future research. Plain Language Summary: A large proportion of environmental aerosols is hygroscopic substances. In the case of high RH, aerosol particles will absorb liquid water and will be in a state of deliquescence. The water uptake ability of aerosol is its hygroscopicity which is a very important parameter in the studies of climate effect, environmental impact, formation, and evolution process of aerosols. The κ‐Köhler theory was established and a hygroscopicity parameter (κ) was proposed in 2007 to simplify the calculation of hygroscopic growth or liquid water content for aerosol particles. The κ is commonly treated as a constant value for a certain particle or a specific mass of bulk ambient aerosols. In this study, it is found that the κ of ambient aerosol is significantly RH‐dependent, and this feature cannot be ignored in the calculation of aerosol hygroscopic growth. Key Points: A humidified nephelometer system was improved and used to measure the aerosol hygroscopicity under different relative humidityThe hygroscopicity of ambient aerosols showed significant relative humidity dependenceThe parameterization schemes of relative humidity‐dependent κ of ambient aerosols were established [ABSTRACT FROM AUTHOR]

Background: In children, internalizing and externalizing problems impact on learning. However, there is limited research on the specific impact of such problems on spatial working memory (SWM), strongly related to cognitive ability and children's learning. Aims: We explored distinct trajectories of internalizing problems and externalizing problems (conduct problems and hyperactivity/inattention) in a large general‐population sample of children followed from age 3 to age 11 years. We then assessed their role in SWM performance at age 11 years. Sample: Data were drawn from the UK's Millennium Cohort Study. Our analytic sample was children with data on SWM at age 11 years (N = 12,589). Methods: There were two stages of data analysis. Trajectory group membership was firstly estimated by group‐based trajectory modelling for internalizing problems, conduct problems, and hyperactivity/inattention at ages 3–11 years. Multiple regression then assessed the relationship between SWM at age 11 years and trajectory group membership after accounting for confounders. Results: Trajectories of internalizing, conduct, and hyperactivity/inattention symptoms across ages 3 to 11 years were related to SWM at age 11 years, even after controlling for confounding variables. For each of the three symptom domains, poor SWM was most consistently found in children with chronically high levels of symptoms. Conclusions: In general, atypical patterns of internalizing problems, conduct problems, and hyperactivity/inattention in childhood were related to poorer SWM in early adolescence. [ABSTRACT FROM AUTHOR]

Submicron aerosol (PM1) species measured by aerosol mass spectrometers have been widely used to validate chemical transport models; however, the uncertainties due to chemical differences between PM1 and PM2.5 are poorly constrained. Here we characterized such differences in a highly polluted environment in north China in winter. Our results showed that the changes in PM1/PM2.5 ratios as a function of relative humidity (RH) were largely different for primary and secondary species. Secondary organic and inorganic aerosol (SOA and SIA) presented clear decreases in PM1/PM2.5 ratios at RH > 60% during periods with high SIA contributions (>50%), likely driven by the changes in aerosol hygroscopicity and phase states, while the traffic and coal combustion OA had limited dependence on RH. Thermodynamic modeling showed negligible impacts of PM differences on predictions of particle acidity, yet these impacts can cause a difference in aerosol water content by up to 50–70%. Plain Language Summary: Current air pollution studies rely largely upon aerosol mass spectrometers that provide real‐time measurements of submicron aerosol (PM1) species, and in many studies, PM1 aerosol species are used to validate those of PM2.5 in chemical transport models and estimate particle acidity and aerosol water content which are key parameters in studying heterogeneous reactions. However, the uncertainties in air pollution studies due to the chemical differences of PM1 and PM2.5 are poorly constrained, particularly in highly polluted environment, for example, China and India. We found that the changes in PM1/PM2.5 ratios as a function of relative humidity were largely different for primary and secondary aerosol species in highly polluted environment, which was likely driven by the changes in aerosol hygroscopicity and phase states. The chemical differences of PM1/PM2.5 ratios were also found to have negligible impacts on predictions of particle acidity, yet these impacts can cause a difference in aerosol water content by up to 50–70%. Considering the rapid increases in the deployments of aerosol mass spectrometers worldwide, the results in this study are of great importance for a better understanding of the uncertainties in both modelling and observations. Key Points: We observed large chemical differences between PM1 and PM2.5 under high relative humidity periods in highly polluted environmentThe RH dependence of PM1/PM2.5 ratios of primary and secondary species was largely different due to different hygroscopicityThe chemical differences between PM1 and PM2.5 have negligible influences on particle acidity prediction, yet have a large impact on AWC [ABSTRACT FROM AUTHOR]

Abstract: Most cancer cells perform glycolysis despite having sufficient oxygen. The specific metabolic pathways of cancer cells have become the focus of cancer treatment. Recently, accumulating evidence indicates oxidative phosphorylation (OXPHOS) and glycolysis can be regulated with each other. Thus, we suggest that the glycolysis of cancer cells is inhibited by restoring or improving OXPHOS in cancer cells. In our study, we found that oxaloacetate (OA) induced apoptosis in HepG2 cells in vivo and in vitro. Meanwhile, we found that OA induced a decrease in the energy metabolism of HepG2 cells. Further results showed that the expression and activity of glycolytic enzymes were decreased with OA treatment. Conversely, the expression and activity of enzymes involved in the TCA cycle and OXPHOS were increased with OA treatment. The results indicate that OA can inhibit glycolysis through enhancement of OXPHOS. In addition, OA‐mediated suppression of HIF1α, p‐Akt, and c‐myc led to a decrease in glycolysis level. Therefore, OA has the potential to be a novel anticancer drug. [ABSTRACT FROM AUTHOR]

Characterization of unconventional materials is essential in the field of microwave engineering. In this study, we present a method for the microwave characterization of conductive and nonconductive textile materials. Our approach is based on fitting the material parameters of a numerical microstrip transmission line model so that the simulated signal transmission properties match with the data we measure from implemented test lines. Unlike many conventional test structures, such as cavity resonators and waveguides, microstrip lines can be readily manufactured in textile technology with rather relaxed tolerances in the fabrication process. In addition, our method provides estimates for all three key material parameters: frequency‐dependent relative permittivity and loss tangent of the nonconductive line substrate and the bulk conductivity of the strip conductor. For validation, we have characterized conventional microwave laminates and compared the data with the datasheets and literature and used our parameter estimates for the textile materials to optimize fully textile‐based low‐pass filters. Overall, the results confirm the applicability of our method for microwave engineering with textile materials. [ABSTRACT FROM AUTHOR]

Water vapor supersaturation, as one of the most important environmental parameters during the formation of clouds or fogs, cannot be directly measured, and few studies have been carried out to estimate it in the ambient activation process. In this study, a new method to estimate the water vapor supersaturation based on the inverse application of κ‐Köhler theory is proposed. Aerosol hygroscopic parameter κ, dry particle size distributions, and wet droplet size distributions were employed and a comparison of predicted droplet number concentration with the measurement results was made to obtain the effective supersaturation during the activation process. Using this method, we acquired the supersaturations varying from 0.01% to 0.05% in a fog episode observed in the North China Plain. In this fog episode, both hydrated unactivated droplets and activated droplets play a part in the total detected droplet number concentrations with the unactivated droplets' ratio decreasing with size. The sensitivity study was also made to evaluate the effects of droplet and aerosol hygroscopic measurement errors on the supersaturation ratio estimation. Water vapor supersaturation obtained with this method can be regarded as an effective value and can be further applied to cloud analysis in the future. This method is only based on conventional measurements of aerosol and droplets and does not rely on any other data, which makes it flexible and easy to perform. Calculated supersaturations and critical diameters can also deepen the understanding of ambient activation process and corresponding interactions between aerosol and droplet characteristics. Key Points: Ambient water vapor supersaturation can be calculated using aerosol and cloud measurementsLow supersaturations less than 0.05% were found for a dense radiation fog in the North China PlainSignificant contribution of unactivated haze particles to the total fog droplets was found in the heavily polluted fog episode [ABSTRACT FROM AUTHOR]

Compounds (III) and (IV) are characterized by single crystal XRD, FTIR, and UV/VIS spectroscopy. [ABSTRACT FROM AUTHOR]