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Objective: This three-wave longitudinal study tested the prospective relationships between college adjustment, self-esteem, and mental health status (ie, subjective well-being, anxiety, and depression). Participants: The study recruited 265 Chinese undergraduate students. Methods: Demographic, college adjustment, self-esteem, and mental health status data were collected. Results: College adjustment and self-esteem were moderate in magnitude and maintained a reasonable stability over time. College adjustment and self-esteem at Year 1 and Year 2, and mental health status at Year 3, were significantly correlated with each other. College adjustment at Year 1 and Year 2, and self-esteem at Year 1 significantly predicted mental health status at Year 3. Conclusions: Interventions to improve self-esteem and college adjustment may benefit long-term mental health outcomes.

Emerging adulthood is a pivotal period for romantic relationships, yet the specific mechanisms through which attachment anxiety influences relationship dynamics and psychological outcomes in this phase are poorly understood. Particularly, in the context of romantic dyads, understanding how partners' behaviors and emotional patterns reciprocally influence each other remains underexplored. This study utilizes the Actor-Partner Interdependence Model and Actor-Partner Interdependence Mediator Model to explore the relationship between attachment anxiety,relational aggression (both perpetration and victimization), and depressive symptoms among emerging adults. A sample of 138 mixed-sex emerging adulthood couples from China, was recruited (Mage = 21.40, SD = 2.54; 50% female, 62.6% reporting that this relationship was ongoing for more than a year). Attachment anxiety significantly predicted relational aggression in both partners, with male attachment anxiety also significantly predicted female relational aggression. Significant indirect effects of both partners' relational aggression perpetration and victimization on their own and each other's relationship between attachment anxiety and depressive symptoms. These findings contribute to understanding the intricate dynamics of attachment anxiety and relational aggression in romantic relationships during emerging adulthood, emphasizing the need for targeted interventions to mitigate these risks. [ABSTRACT FROM AUTHOR]

To enhance the proportion of domestically manufactured Chinese pellets in the furnace, it is crucial to investigate the impact of calcium flux on the metallurgical characteristics of pellets and analyze the phase evolution behavior during the reduction process of medium‐silica fluxed pellets. This study examines the metallurgical properties of medium‐silica acid pellets and low‐basicity medium‐silica fluxed pellets produced in China. The results indicate that incorporating a small amount of calcium flux significantly enhances reducibility index (RI), reduces reduction swelling index, and lowers reductive degradation index (RDI+3.15 mm) for fluxed pellets. At a basicity level of 0.6, RI for medium‐silica fluxed pellets reaches 66.86%, while RDI−0.5 mm increases to 1.62% with increasing basicity levels. As pellet basicity increases, charge pressure drop (APmax) decreases, CaO content in silicate liquid phase within slag phase increases, and softening–melting zone widens, consequently leading to reduced solid‐phase particle content within pellets and increased fluidity within slag phase. [ABSTRACT FROM AUTHOR]

While aqueous-phase processing is known to contribute to the formation of nitrogen-containing organic compounds (NOCs), the specific pathways involved remain poorly understood. In this study, we aimed to characterize the NOCs present in both pre-fog aerosols and fog water collected at a suburban site in northern China. Fourier-transform ion cyclotron resonance mass spectrometry was utilized to analyze the molecular composition of NOCs in both negative and positive modes of electrospray ionization (ESI - and ESI +). In both pre-fog aerosols and fog water samples, NOCs constituted a significant portion, accounting for over 60 % of all assigned formulas in ESI - and more than 80 % in ESI +. By comparing the molecular composition of NOCs originating from biomass burning, coal combustion, and vehicle emissions, we identified that 72.3 % of NOCs in pre-fog aerosols were attributed to primary anthropogenic sources (pNOCs), while the remaining NOCs were categorized as secondary NOCs formed within the aerosols (saNOCs). Unique NOCs found in fog water were classified as secondary NOCs formed within the fog water (sfNOCs). Through a comprehensive "precursor–product pair" screening involving 39 reaction pathways, we observed that the nitration reaction, the amine pathway, and the intramolecular N-heterocycle pathway of NH 3 addition reactions contributed 43.6 %, 22.1 %, and 11.6 % of saNOCs, respectively. In contrast, these pathways contributed 26.8 %, 28.4 %, and 29.7 % of sfNOCs, respectively. This disparity in formation pathways is likely influenced by the diverse precursors, the aqueous acidity, and the gas-phase species partitioning. Correspondingly, saNOCs were found to contain a higher abundance of carbohydrate-like and highly oxygenated compounds with two nitrogen atoms compared to pNOCs. Conversely, sfNOCs exhibited a higher content of lipid-like compounds with fewer oxygen atoms. These results underscore the distinct secondary processes contributing to the diversity of NOCs in aerosols and fog water, which may lead to their different climate effects. [ABSTRACT FROM AUTHOR]

Despite extensive research on the psychological impacts of digital technology, the nuanced dynamics between adolescent loneliness and problematic smartphone use, particularly across different educational levels and genders, remain underexplored. This study aims to fill this gap by employing a Random Intercept Cross-Lagged Panel Model to dissect the bidirectional relationship between loneliness and problematic smartphone use among adolescents, with a focus on the moderating roles of educational levels and gender. Engaging 3132 students from various educational institutions in China, the research conducted a three-wave longitudinal analysis across 2022–2023. The final number of participants included 1120 adolescents (53.5% female; age in 2022: M = 14.57 years, SD = 1.57). Results reveal that loneliness significantly predicts problematic smartphone use, but not vice versa, highlighting a unidirectional influence. The study uncovers crucial differences across educational levels and gender, emphasizing the stronger effect of loneliness on problematic smartphone use among junior high students and female adolescents. These findings underscore the complexity of adolescent loneliness and its relationship with digital behavior, suggesting a need for tailored interventions considering both gender and developmental stages. [ABSTRACT FROM AUTHOR]

Using network analysis, the current study investigated the pathways that underlie selected components of sleep health and their changes over time. Undergraduates (N = 1423; 80.60% female) completed a two-wave survey, sleep health (i.e. chronotypologies (CTs), sleep procrastination (SP), sleep quality (SQ)), psychological distress (PD), emotion regulation (ER), self-control (SC), problematic smartphone use (PSU) were measured. CTs, SP, and SQ formed a spatially contiguous pattern that remained unchanged in both waves. ER and PD node increased its strength, betweenness, and closeness in the network, while the link between the two was strengthened at T2. PSU was connected to SP, but not to CTs and SQ during both waves. In the context of the network approach, SP had the highest strength, and its associations with other dimensions of individual sleep may represent key factors in understanding the influence of exposure to the COVID-19 outbreak on sleep health. [ABSTRACT FROM AUTHOR]

The formation process of in‐cloud aqueous‐phase secondary organic matter (aqSOM) and its characteristics are unclear. Herein, water‐soluble inorganic ions, oxalate, and water‐soluble organic carbon (WSOC) were determined in cloud water and aerosol (PM2.5) samples simultaneously collected at a remote mountain site in southern China during spring 2018 and winter 2020. The molecular compositions of water‐soluble organic matter (WSOM) in cloud water and aerosols were analyzed by a Fourier transform ion cyclotron resonance mass spectrometer in negative electrospray ionization (ESI‐) mode. The results showed that the mean concentration of WSOC was 6.27–8.54 mg C L−1 in cloud water and 0.60–1.37 μg C m−3 in aerosols. The strong correlation observed between WSOM and aqueous secondary matter (e.g., NO3− and oxalate), the positive matrix factorization results, and the elevated WSOM/K+ ratios observed in cloud water suggested enhanced aqSOM formation in cloud water. According to random forest analysis, the factors related to in‐cloud WSOM variation mainly included secondary ions, K+, cloud water pH, and atmospheric NOx. Additionally, 37 characteristic in‐cloud aqSOM molecules, classified as ‐Ox, ‐NOx, ‐N2Ox, and ‐N1‐2OxS, mainly consisting of dicarboxylic acids, nitrophenols, and dinitrophenols, were identified using linear discriminant analysis effect size (LefSe). The characteristic N‐ and S‐containing molecules in in‐cloud aqSOM with carbon numbers >10 had low or extremely low volatility; therefore, they might contribute to secondary organic aerosol formation after droplet evaporation. The results revealed the modifying effects of in‐cloud processes on aerosol organic composition at the molecular level and could improve our understanding of aerosol–cloud interactions. Plain Language Summary: In this study, we determined the water‐soluble ion, water‐soluble organic matter (WSOM) and organic molecular composition of cloud water and aerosol samples collected at a remote mountain site in southern China. The results indicated the formation of secondary organic matter (SOM) in cloud water, the proportion of which in total WSOM was >50%. In addition, the characteristic molecules of SOM in cloud water were identified, some of which had low or extremely low volatility and might remain in the particulate phase after droplet evaporation. This work advanced our understanding of secondary organic aerosol formation in cloud water and its implications for the climate and the environment. Key Points: The proportion of in‐cloud aqueous‐phase secondary organic matter in WSOM was >50%Some molecules, for example, diacids and dinitrophenols, were identified as characteristic molecules of in‐cloud secondary organic matterMolecules with C numbers >10 formed by in‐cloud processes had low volatility [ABSTRACT FROM AUTHOR]

The ground surface deformation induced by shield tunnels passing through enclosure structures of existing tunnels is a particular underground construction scenario that has been encountered in Wuhan Metro Line 12 engineering cases in China. Timely ground deformation prediction is important to keep shield tunneling safe. However, the classic ground deformation theory is difficult to accurately predict for this ground deformation. This paper develops a semi-analytical method to predict ground heave considering the space effect in this engineering condition. Based on the improved ground deformation theory, a novel deformation prediction method for the ground and enclosure structure is derived and combined with Kirchhoff plate theory. Comparing with field deformation measurements, the maximum difference between the measured and calculated deformation is 14.6%, which demonstrates that the proposed method can be used to predict the ground heave induced by shield tunnels passing through the enclosure structure of existing tunnels. The parameters of the underground diaphragm wall used in Wuhan Metro Line 12 are further studied in detail. The results show that the ground heaves have a positive correlation with the embedded ratio of the diaphragm wall, but a negative correlation with its elastic modulus and thickness. However, the thickness and embedded ratio have a limited effect on ground heaves. This study provides a technical reference for optimizing the setting of enclosure structures in order to protect existing buildings. [ABSTRACT FROM AUTHOR]

Both smartphone addiction and phubbing are emerging behavioral problems. The present study investigates potential risk and protective factors of smartphone addiction and phubbing behavior, including demographic factors, personal factors, and interpersonal factors among Chinese college students. A total of 866 college students (Mage = 21.01, SD = 1.60) completed self-reported questionnaires in classroom settings. Collected data were analyzed by using Pearson's correlation and hierarchical linear regression analyses. The risk factors for smartphone addiction were phubbing behavior, depression, and social anxiety, while the protective factors were self-control and sense of security. In addition, the risk factors for phubbing behavior included female sex and smartphone addiction, while the protective factors included sense of security and interpersonal adaptability. Our findings help to enhance understanding of the general and specific risks and protective factors for smartphone addiction and phubbing behavior, which can benefit intervention development for related behavior prevention and reduction. [ABSTRACT FROM AUTHOR]

Background: Anxiety may stay with nursing students throughout their internship and even persist afterwards. Although many studies have explored the effects of perceived stress on anxiety, the relationship between pre-internship perceived stress and post-internship anxiety levels has not been clarified. In addition, none had focused on the moderating roles of career adaptability and professional commitment between perceived stress and anxiety. This study aims to investigate the influence of pre-internship perceived stress on the post-internship anxiety level of nursing college students, and to analyze the moderating effects of career adaptability and professional commitment on their relationships. Methods: A longitudinal study design was employed. Full-time nursing college students from a Chinese medical university were recruited by convenient sampling. All surveys were conducted via Wen Juan Xing (www.wjx.cn), a widely used web-based survey platform in China. Two waves of surveys were collected in the pre-internship and post-internship periods, with an interval of one year. Among 823 nursing students recruited, 692 students completed all two waves of the survey (response rate: 84.08%). Participants completed a series of questionnaires examining general demographic characteristics, perceived stress, anxiety, career adaptability, and professional commitment both before and after the internship. The bias-corrected bootstrap technique of the Hayes PROCESS macro (Model 2) was used to test the moderation effect. Results: Pre-internship perceived stress was positively associated with post-internship anxiety (β = 0.474, p < 0.001). Career adaptability would mitigate the effect of perceived stress on anxiety (β = -0.009, p < 0.01, 95% CI = [-0.013, -0.004]), and this influence became stronger for nursing college students with higher levels of career adaptability. Instead, the professional commitment would enhance the effect of perceived stress on anxiety (β = 0.004, p < 0.05, 95% CI = [0.001, 0.009]). Conclusions: Adequate career adaptability was key to alleviating anxiety among nursing interns. Nursing educators and clinical nursing managers should pay attention to cultivating the career adaptability of nursing college students in order to help them successfully achieve identity transformation and career development. Meanwhile, it is crucial to guide them to develop appropriate professional commitment. [ABSTRACT FROM AUTHOR]

The presence of water in sandstone joints affects the shear characteristics of the joints, which is of considerable importance to the stability evaluations of rock slopes or tunnels subjected to water fluctuations. A series of direct shear tests with three immersion durations (30, 180, and 360 d) in water were conducted on the sandstone joint specimens collected from the reservoir area of the Three Gorges hydropower station, China. To perform duplicate tests, three-dimensional (3D) optical scanning and 3D rigid engraving were coupled to produce sandstone joints with the same surface morphology. The shear curves of the dry and immersed sandstone joints were divided into the three stages of sliding, shear-breaking, and post-peak wearing. The damaged area of the immersed joints decreased with the increased immersion duration under the same normal loading. The immersion duration did not affect the shear mode of the joints, and the peak and residual shear strengths of the sandstone joints decreased by approximately 10–28% and 2.9–26.4%, respectively, after the 360-d immersion. Experimental results pointed to the lubricant effect as the dominant mechanism for a water-induced reduction in the shear strength of the joints, followed by the chemical dissolution effect. Given the lubricant and chemical dissolution effects, a semi-empirical shear strength criterion was proposed to predict the peak shear strength of the rock joints subjected to the immersion durations. Validation against experimental shear data obtained in this study and from related literature indicated satisfactory accuracy of the proposed criterion for predicting the peak shear strength after the immersion. An engineering example of the Jianchuandong unstable rock mass located in the Three Gorges reservoir was used to demonstrate the function of wetting in lowering its safety factor. Highlights: 3D scanning and 3D engraving were coupled to produce sandstone joints. Direct shear tests with different immersion durations were conducted on joints. A novel shear strength criterion was developed considering immersion duration. [ABSTRACT FROM AUTHOR]

Purpose: Various physiological and psychological negative situations experienced by nurses as a result of COVID-19 pandemic have been shown to increase their perception of organizational difficulty and decrease their career commitment, thereby accelerating the turnover rate of nurses. Resilience and career adaptability have important influences on career commitment, so there is a need to evaluate the relationships between them and the underlying mechanisms. Patients and methods: Using a cross-lagged design, the Career Adaptability Scale, the Chinese version of career commitment, and Davidson's Resilience Scale as research methods, we studied 692 nursing students for two consecutive years to evaluate the relationship among career adaptability, resilience, and career commitment. Results: Career adaptability at T1 substantially and positively predicts the career commitment at T2. Career adaptability and resilience are mutually predictive. No interaction is found between resilience and career commitment over time. There is a substantial difference in the cross-lagged relationship among career adaptability, resilience, and career commitment for low- and high-career interest. Conclusion: Our results show the importance of developing career commitment early on. Developing career adaptability, enhancing resilience, and increasing career interest in nursing students might help to increase career commitment. [ABSTRACT FROM AUTHOR]

This work investigated seasonal variation of aerosol iron (Fe) solubility for coarse (>1 µ m) and fine (<1 µ m) particles at Xi'an, a megacity in northwestern China impacted by anthropogenic emission and desert dust. Total Fe concentrations were lowest in summer and were similar in other seasons for coarse particles but lowest in summer and highest in spring for fine particles; for comparison, dissolved Fe concentrations were higher in fall and winter than spring and summer for coarse particles but highest in winter and lowest in spring and summer for fine particles. Desert-dust aerosol was always the major source of total Fe for both coarse and fine particles in all four seasons, but it may not be the dominant source of dissolved Fe. Fe solubility was lowest in spring for both coarse and fine particles and highest in winter for coarse particles and in fall for fine particles. In general, aerosol Fe solubility was found to be higher in air masses originating from local and nearby regions than those arriving from desert regions after long-distance transport. Compared to coarse particles, Fe solubility was similar for fine particles in spring but significantly higher in the other three seasons, and at a given aerosol pH range, Fe solubility was always higher in fine particles. Aerosol Fe solubility was well correlated with relative abundance of aerosol acidic species, implying aerosol Fe solubility enhancement by acid processing; moreover, such correlations were better for coarse particles than fine particles in all four seasons. Fe solubility was found to increase with relative humidity and acid acidity for both coarse and fine particles at Xi'an, underscoring the importance of aerosol liquid water and aerosol acidity in regulating Fe solubility via chemical processing. [ABSTRACT FROM AUTHOR]

The radiative forcing of soot is dependent on the morphology, mixing state and structure. Cloud processing has been predicted to affect their mixing properties but little is known about the resulting light absorption properties. We collected ambient particles in the pre‐cloud period, the cloud residues and interstitials in the in‐cloud period at Mt. Tianjing (southern China). The morphology parameters of soot aggregates with varying mixing materials [sulfate (S) and organics (OM)] and mixing structures were investigated by a transmission electron microscope, and their absorption cross section were calculated based on discrete dipole approximation. We found that the number contribution of soot‐S decreased from 45% in the pre‐cloud period to 32% in the in‐cloud period, and that of soot‐OM increased from 44% to 60%. Moreover, the number proportion of soot‐OM with fully embedded structure increased remarkably in the in‐cloud period (29%), compared with that in the pre‐cloud period (3%). In addition, the soot‐S aggregates became denser after in‐cloud aqueous process. However, for soot‐OM aggregates, the morphology remained relatively constant. The distinctly different change of soot‐S and soot‐OM in morphology highlights the chemically resolved reconstruction of soot morphology. Theoretical calculation further shows that the changes of soot particles in the mixing state and morphological characteristics by the cloud process resulted in the light absorption enhancement increase from 1.57 to 2.01. This study highlights that the evolution of microphysical properties upon cloud processing should also be considered in climate models to more accurately evaluate the impacts of soot particles. Plain Language Summary: While soot particles are the main component of aerosols that produce positive radiative forcing in clouds, the impact of in‐cloud processes on key factors (mixing state and microphysical property) for evaluating the optical properties of soot particles is unclear. Here, we report the detailed information on several parameters required to calculate the optical properties of soot particles, throughout the cloud events. And we found that changes in the mixing state, mixing structure, and morphology of soot particles under the influence of in‐cloud processes lead to a significant light absorption enhancement. The results also highlight the role of in‐cloud aqueous formation of secondary compositions in reshaping the soot particles, which has substantial implications for the climate impact of soot particles. Given that ∼70% of the Earth's surface is covered by clouds, taking the mixing state and microphysical properties of soot particles into account in climate models may help constrain the contribution of soot particles to global radiative forcing. Key Points: Cloud processing contributes to the increase of organic coating on soot aggregates, especially for those with fully embedded structureThe sulfate coating causes more compaction of soot aggregates than the organic coating upon cloud processingChanges in the microphysical properties of soot particles driven by one cloud event increase their absorption enhancement by 1.29 times [ABSTRACT FROM AUTHOR]

Intermediate‐volatility organic compounds (IVOCs) are among the most important precursors to secondary organic aerosol (SOA), yet their sources and contributions to SOA in ambient air are poorly constrained. In this study, IVOCs were collected with sorption tubes in a coastal city in southern China during September–October 2019 and were analyzed by gas chromatography‐mass selective detector after thermo‐desorption. The measured average concentration of IVOCs was 25.0 ± 0.95 μg m−3 (mean ± 95% C.I.), and residual unresolved complex mixtures shared 79.8% ± 1.91% of IVOCs. The estimated SOA production, even only from speciated IVOCs and unspeciated branch‐alkane IVOCs, reached 2.44 ± 1.46 μg m−3, approximately five times that from VOCs during the photochemically active period (12:00–15:00 local time). Based on the positive matrix factorization model with a photochemical‐age‐based parameterization, diesel‐related emission was the largest contributor (46.6%) of IVOCs, followed by ship emission (23.0%), gasoline exhaust (16.8%), and biomass/coal burning (13.6%). Non‐road diesel engines accounted for a dominant part in diesel‐related emission. Ship emission was found to contribute SOA formation potentials (SOAFPs) comparable to that of diesel‐related emission, while biomass/coal burning showed higher SOAFPs than gasoline exhaust. Our results revealed that non‐road sources, such as ship emission, non‐road diesel engines, and biomass/coal burning contributed substantially to IVOCs, and will be of greater importance in producing ambient SOA with the increasingly stringent control on emissions from on‐road vehicles. Plain Language Summary: Intermediate‐volatility organic compounds (IVOCs) are a class of organic compounds with effective saturated concentrations between 10³ μg m⁻³ and 10⁶ μg m⁻³, with a volatility range roughly equivalent to that of C₁₂–C₂₂ normal alkanes. Although proposed to be important precursors of secondary organic aerosols (SOAs), IVOCs occurring in ambient air are poorly constrained, especially for their sources and contributions to SOA. Here, we measured IVOCs along with volatile organic compounds (VOCs) in a coastal megacity in south China during September–October 2019 and found that estimated SOA production from IVOCs was much higher than that from VOCs, which traditionally have been regarded as the most important SOA precursors. Moreover, we found that non‐road sources, including ship emissions, non‐road diesel engines, and biomass/coal burning, contributed a larger part to IVOCs than road vehicles and an even larger part to SOA production from IVOCs. Our results highlight that, in addition to controlling VOC emissions or IVOCs from road vehicles, it is crucial to control non‐road emissions of IVOCs to reduce SOA in fine particles. Key Points: Estimated intermediate‐volatility organic compounds (IVOC)‐derived secondary organic aerosol was over five times that from volatile organic compoundsFossil fuel combustion was the major contributor to primary IVOCsNon‐road emissions were important sources of primary IVOCs [ABSTRACT FROM AUTHOR]

Recent research has identified a relationship between online gaming addiction (OGA) and depressive symptoms. However, little is known regarding the underlying mechanisms. The present study aims to test the moderating effect of flow experience in the association between OGA and depressive symptoms via affect balance. A total of 1050 game players of the Glory of the King completed measures of online gaming addiction, depressive symptoms, affect balance, and flow experience. Results showed that OGA was positively associated with depressive symptoms, and affect balance mediated that association. Flow experience exacerbated the negative relationships between OGA and affect balance while tempered the positive impact of affect balance on depressive symptoms. This study contributes to a better understanding of how OGA increases the risk of depressive symptoms, and reveals the dark side of flow experience among online game players. The importance of enhancing affect balance and reducing flow experience in preventing depressive symptoms is highlighted. [ABSTRACT FROM AUTHOR]

While the formation and evolution of nitrate in airborne particles are extensively investigated, little is known about the processing of nitrate in clouds. Here we present a detailed investigation on the in-cloud formation of nitrate, based on the size-resolved mixing state of nitrate in the individual cloud residual and cloud-free particles obtained by single particle mass spectrometry, and also the mass concentrations of nitrate in the cloud water and PM 2.5 at a mountain site (1690 m a.s.l. – above sea level) in southern China. The results show a significant enhancement of nitrate mass fraction and relative intensity of nitrate in the cloud water and the cloud residual particles, respectively, reflecting a critical role of in-cloud processing in the formation of nitrate. We first exclude the gas-phase scavenging of HNO 3 and the facilitated activation of nitrate-containing particles as the major contribution for the enhanced nitrate, according to the size distribution of nitrate in individual particles. Based on regression analysis and theoretical calculations, we then highlight the role of N 2 O 5 hydrolysis in the in-cloud formation of nitrate, even during the daytime, attributed to the diminished light in clouds. Nitrate is highly related (R2= ∼ 0.6) to the variations in [NO x ][O 3 ], temperature, and droplet surface area in clouds. Accounting for droplet surface area greatly enhances the predictability of the observed nitrate, compared with using [NO x ][O 3 ] and temperature. The substantial contribution of N 2 O 5 hydrolysis to nitrate in clouds with diminished light during the daytime can be reproduced by a multiphase chemical box model. Assuming a photolysis rate at 30 % of the default setting, the overall contribution of N 2 O 5 hydrolysis pathway to nitrate formation increases by ∼ 20 % in clouds. Given that N 2 O 5 hydrolysis acts as a major sink of NO x in the atmosphere, further model updates would improve our understanding about the processes contributing to nitrate production in cloud and the cycling of odd nitrogen. [ABSTRACT FROM AUTHOR]

Atmospheric brown carbon (BrC) makes a substantial contribution to aerosol light absorption and thus global radiative forcing. Although BrC may change the lifetime of the clouds and ultimately affect precipitation, little is known regarding the optical properties and formation of BrC in the clouds. In the present study, the light-absorption properties of cloud droplet residual (cloud RES) were measured by coupled a ground-based counterflow virtual impactor (GCVI) and an aethalometer (AE-33), in addition to the cloud interstitial (cloud INT) and ambient (cloud-free) particles by PM 2.5 inlet-AE-33 at Mt. Tianjing (1690 m a.s.l.), a remote mountain site in southern China, from November to December 2020. Meanwhile, the light-absorption and fluorescence properties of water-soluble organic carbon (WSOC) in the collected cloud water and PM 2.5 samples were also obtained, associated with the concentration of water-soluble ions. The mean light-absorption coefficient (Abs 370) of the cloud RES, cloud INT, and cloud-free particles were 0.25 ± 0.15, 1.16 ± 1.14, and 1.47 ± 1.23 Mm -1 , respectively. The Abs 365 of WSOC was 0.11 ± 0.08 Mm -1 in cloud water and 0.40 ± 0.31 Mm -1 in PM 2.5 , and the corresponding mass absorption efficiency (MAE 365) was 0.17 ± 0.07 and 0.31 ± 0.21 m 2 g -1 , respectively. A comparison of the light-absorption coefficient between BrC in cloud RES and cloud INT particles, and WSOC in cloud water and PM 2.5 indicates a considerable contribution (48 %–75 %) of water-insoluble BrC to total BrC light absorption. Secondary BrC estimated by minimum R squared (MRS) method dominated the total BrC in cloud RES (67 %–85 %), rather than in the cloud-free (11 %–16 %) and cloud INT (9 %–23 %) particles. It may indicate the formation of secondary BrC during cloud processing. Supporting evidence includes the enhanced WSOC and dominant contribution of the secondary formation and biomass burning factor (>80 %) to Abs 365 in cloud water provided by positive matrix factorization (PMF) analysis. In addition, we showed that the light absorption of BrC in cloud water was closely related to humic-like substances and tyrosine-like and/or protein-like substances (r>0.63 , p<0.01), whereas only humic-like substances for PM 2.5 , as identified by excitation-emission matrix fluorescence spectroscopy. [ABSTRACT FROM AUTHOR]

Characterizing the molecular composition of cloud water could provide unique insights into aqueous chemistry. Field measurements were conducted at Mt. Tianjing in southern China in May, 2018. There are thousands of formulas (C5–30 H4–55 O1–15 N0–2 S0–2) identified in cloud water by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). CHON formulas (formulas containing C, H, O, and N elements; the same is true for CHO and CHOS) represent the dominant component (43.6 %–65.3 % of relative abundance), followed by CHO (13.8 %–52.1%). S-containing formulas constitute ∼ 5 %–20 % of all assigned formulas. Cloud water has a relative-abundance-weighted average O/C of 0.45–0.56, and the double bond equivalent of 5.10–5.70. Most of the formulas (>85 %) are assigned as aliphatic and olefinic species. No statistical difference in the oxidation state is observed between cloud water and interstitial PM2.5. CHON with aromatic structures are abundant in cloud water, suggesting their enhanced in-cloud formation. Other organics in cloud water are mainly from biomass burning and oxidation of biogenic volatile organic compounds. The cloud water contains more abundant CHON and CHOS at night, which are primarily contributed by -N2 O5 function and organosulfates, demonstrating the enhanced formation in dark aqueous or multi-phase reactions. While more abundant CHO is observed during the daytime, likely due to the photochemical oxidation and photolysis of N- or S-containing formulas. The results provide an improved understanding of the in-cloud aqueous-phase reactions. [ABSTRACT FROM AUTHOR]

Intermediate-volatility organic compounds (IVOCs) emitted from vehicles are important precursors to secondary organic aerosols (SOAs) in urban areas, yet vehicular emission of IVOCs, particularly from on-road fleets, is poorly understood. Here we initiated a field campaign to collect IVOCs with sorption tubes at both the inlet and the outlet in a busy urban tunnel (>30000 vehicles per day) in south China for characterizing emissions of IVOCs from on-road vehicles. The average emission factor of IVOCs (EF IVOCs) was measured to be 16.77±0.89 mg km -1 (average ±95 % CI, confidence interval) for diesel and gasoline vehicles in the fleets, and based on linear regression, the average EF IVOCs was derived to be 62.79±18.37 mg km -1 for diesel vehicles and 13.95±1.13 mg km -1 for gasoline vehicles. The EF IVOCs for diesel vehicles from this study was comparable to that reported previously for non-road engines without after-treatment facilities, while the EF IVOCs for gasoline vehicles from this study was much higher than that recently tested for a China V gasoline vehicle. IVOCs from the on-road fleets did not show significant correlation with the primary organic aerosol (POA) or total non-methane hydrocarbons (NMHCs) as results from previous chassis dynamometer tests. Estimated SOA production from the vehicular IVOCs and VOCs surpassed the POA by a factor of ∼2.4 , and IVOCs dominated over VOCs in estimated SOA production by a factor of ∼7 , suggesting that controlling IVOCs is of greater importance to modulate traffic-related organic aerosol (OA) in urban areas. The results demonstrated that although on-road gasoline vehicles have much lower EF IVOCs , they contribute more IVOCs than on-road diesel vehicles due to its dominance in the on-road fleets. However, due to greater diesel than gasoline fuel consumption in China, emission of IVOCs from diesel engines would be much larger than that from gasoline engines, signaling the overwhelming contribution of IVOC emissions by non-road diesel engines in China. [ABSTRACT FROM AUTHOR]

Nitrophenols have received extensive attention due to their strong light-absorbing ability in the near-ultraviolet-visible region, which could be influenced by the atmospheric processes of nitrophenols. However, our knowledge and understanding of the formation and evolution of nitrophenols are still in the nascent stages. In the present study, the mixing states of four mononitrophenol particles (i.e., nitrophenol, methynitrophenol, nitrocatechol, and methoxynitrophenol), and one nitropolycyclic aromatic hydrocarbon particles (i.e., nitronaphthol (NN)) were investigated using a single-particle aerosol mass spectrometer (SPAMS) in November 2019 in Qingdao, China. The results showed, for the first time, that mononitrophenols and NN exhibit different mixing states and diurnal variations. Four mononitrophenols were internally mixed well with each other, and with organic acids, nitrates, potassium, and naphthalene. The diurnal variation in the number fraction of mononitrophenols presented two peaks at 07:00 to 09:00 and 18:00 to 20:00, and a valley at noon. Atmospheric environmental conditions, including NO 2 , O 3 , relative humidity, and temperature, can significantly influence the diurnal variation of mononitrophenols. Multiple linear regression and random forest regression models revealed that the main factors controlling the diurnal variation of mononitrophenols were photochemical reactions during the day and aqueous-phase reactions during the night. Unlike mononitrophenols, about 62–83% of NN were internally mixed with [NH 4 ]+ and [H(NO 3) 2 ]-, but not with organic acids and potassium. The diurnal variation of NN was also different from that of mononitrophenols, generally increased from 17:00 to 10:00 and then rapidly decreaed from 11:00 to 16:00. These results imply that NN may have sources and atmospheric processes that are different from mononitrophenols. We speculate that this is mostly controlled by photochemical reactions and mixing with [NH 4 ]+, which may influence the diurnal variation of NN in the ambient particles; however, this requires further confirmation. These findings extend our current understanding of the atmospheric formation and evolution of nitrophenols. [Display omitted] • Five nitrophenols were analyzed by a single-particle aerosol mass spectrometer. • Mononitrophenols and nitronaphthol have different mixing state and diurnal variation. • Photochemistry and aqueous-phase reactions control the diurnal variation of mononitrophenols. • [NH 4 ]+ can significantly influence the diurnal variation of nitronaphthol. [ABSTRACT FROM AUTHOR]

Hygroscopicity largely determines phase state, chemical reactivity, optical properties, and cloud nucleation activities of aerosol particles, thus significantly affecting their impacts on visibility, atmospheric chemistry, and climate. In the last 20 years, a large number of field studies have investigated the hygroscopicity of tropospheric aerosols in China under subsaturated and supersaturated conditions. Aerosol hygroscopicity measurements in China are reviewed in this paper: (1) a comprehensive summary and critical discussion of aerosol hygroscopicity measurements in China are provided; (2) available measurement data are compiled and presented under a consistent framework to enhance their accessibility and usability; and (3) current knowledge gaps are identified, and an outlook which could serve as guidelines for planning future research is also proposed. [ABSTRACT FROM AUTHOR]

Background: This 3-year longitudinal study investigated the prospective relationships between mobile phone dependence and mental health status (i.e., subjective well-being, anxiety and depression) and the mediating role of college adjustment among Chinese undergraduate students.Methods: The study recruited 265 first-year undergraduate students from a university (mean age = 18.95 years, SD = 0.72) in Wenzhou, China. A baseline survey and two follow-up surveys were conducted between November 2013 and December 2015 (the response rate was 76.4%). The validated Mobile Phone Addiction Tendency Scale (MPATS), Chinese College Student Adjustment Scale (CCSAS), Index of Well-being, Self-rating Anxiety Scale (SAS), and Self-rating Depression Scale (SDS) were used for assessments.Results: The prevalence of anxiety and depression at Year 3 was 7.5% and 9.4%, respectively. Correlation analyses showed that mobile phone dependence at Year 1, college adjustment at Year 2, and mental health status at Year 3 were significantly correlated with each other. Structural equation modeling analyses showed that mobile phone dependence at Year 1 significantly predicted poor mental health status at Year 3. College adjustment at Year 2 significantly mediated the effect of mobile phone dependence at Year 1 on mental health status at Year 3.Conclusions: Interventions both on reduction of mobile phone dependency and improvement of college adjustment (especially among those with mobile phone dependence) are possible and needed among new college students to prevent their future depression and anxiety. Such interventions should be incorporated into regular education programs in universities. [ABSTRACT FROM AUTHOR]

The effects of the chemical composition and size of sea-salt-containing particles on their cloud condensation nuclei (CCN) activity are incompletely understood. We used a ground-based counterflow virtual impactor (GCVI) coupled with a single-particle aerosol mass spectrometer (SPAMS) to characterize chemical composition of submicron (dry diameter of 0.2–1.0 µm) and supermicron (1.0–2.0 µm) sea-salt-containing cloud residues (dried cloud droplets) at Mount Nanling, southern China. Seven cut sizes (7.5–14 µm) of cloud droplets were set in the GCVI system. The highest number fraction of sea-salt-containing particles was observed at the cut size of 7.5 µm (26 %, by number), followed by 14 µm (17 %) and the other cut sizes (3 %–5 %). The submicron sea-salt-containing cloud residues contributed approximately 20 % (by number) at the cut size of 7.5 µm , which was significantly higher than the percentages at the cut sizes of 8–14 µm (below 2 %). This difference was likely involved in the change in the chemical composition. At the cut size of 7.5 µm , nitrate was internally mixed with over 90 % of the submicron sea-salt-containing cloud residues, which was higher than sulfate (20 %), ammonium (below 1 %), amines (6 %), hydrocarbon organic species (2 %), and organic acids (4 %). However, at the cut sizes of 8–14 µm , nitrate, sulfate, ammonium, amines, hydrocarbon organic species, and organic acids were internally mixed with > 90 %, > 80 %, 39 %–84 %, 71 %–86 %, 52 %–90 %, and 32 %–77 % of the submicron sea-salt-containing cloud residues. The proportion of sea-salt-containing particles in the supermicron cloud residues generally increased as a function of cut size, and their CCN activity was less influenced by chemical composition. This study provided a significant contribution towards a comprehensive understanding of sea-salt CCN activity. [ABSTRACT FROM AUTHOR]

To unravel the ecological function played by pioneer plants in the practical restoration of mine tailings, it is vital to explore changes of soil characteristics and microbial communities in rhizosphere and bulk soil following the adaptation and survival of plants. In the present study, the diversity and structure of rhizospheric bacterial communities of three pioneer plants in copper mine tailings were investigated by Illumina MiSeq sequencing, and the effects of pioneer plants on soil properties were also evaluated. Significant soil improvement was detected in rhizospheric samples, and Alnus cremastogyne showed higher total organic matter, total nitrogen, and available phosphorus than two other herbaceous plants. Microbial diversity indices in rhizosphere and bulk soil of reclaimed tailings were significantly higher than bare tailings, even the soil properties of bulk soil in reclaimed tailings were not significantly different from those of bare tailings. A detailed taxonomic composition analysis demonstrated that Alphaproteobacteria and Deltaproteobacteria, Chloroflexi, Acidobacteria, and Gemmatimonadetes showed significantly higher relative abundance in rhizosphere and bulk soil. In contrast, Gammaproteobacteria and Firmicutes were abundant in bare tailings, in which Bacillus, Pseudomonas, and Lactococcus made up the majority of the bacterial community (63.04%). Many species within known heavy metal resistance and nutrient regulatory microorganism were identified in reclaimed tailings, and were more abundant among rhizospheric microbes. Hierarchical clustering and principal coordinate analysis (PCoA) analysis demonstrated that the bacterial profiles in the rhizosphere clustered strictly together according to plant types, and were distinguishable from bulk soil. However, we also identified a large shared OTUs that occurred repeatedly and was unaffected by highly diverse soil properties in rhizosphere and bulk samples. Redundancy analysis indicated that water content and Cu and As concentrations were the main environmental regulators of microbial composition. These results suggest that the interactive effect of pioneer plants and harsh soil environmental conditions remodel the specific bacterial communities in rhizosphere and bulk soil in mine tailings. And A. cremastogyne might be approximate candidate for phytoremediation of mine tailings for better soil amelioration effect and relative higher diversity of bacterial community in rhizosphere. [ABSTRACT FROM AUTHOR]

Studies have shown that water-insoluble organic matter (WIOM) accounts for a large part of the organic components in cloud water and significantly contributes to brown carbon. However, the molecular characteristics of WIOM in cloud droplets remain unclear, hampering the understanding of their climate effects. In this study, cloud water was collected at a remote mountain site in South China during the winter of 2020, and WIOM was separated by membrane filtration, extracted by methanol, and characterized using Fourier transform ion cyclotron resonance mass spectrometry coupled with an electrospray ionization source. A total of 697–1637 molecules were identified in WIOM. WIOM is characterized by lower oxidation states of carbon atoms (−1.10 ∼ −0.84 in WIOM vs. −0.58 ∼ −0.51 in water-soluble organic matter (WSOM) on average), higher carbon number (14.12–20.59 vs. 9.87–10.56) and lower unsaturation (double-bond equivalent 4.55–4.95 vs. 4.84–5.23) relative to WSOM. More abundant lipid-like compounds (12.2–41.9% in WIOM vs. <2% in WSOM) but less highly oxygenated compounds (<7% vs. 28.6–35.3%) exist in WIOM. More than 30% of WIOM molecules in cloud water are common with interstitial particles, implying that WIOM in cloud water may originate from aerosol activation and/or collision. Some unique molecules in WIOM in cloud water are identified as aqueous-phase oligomerization products, indicating the aqueous-phase formation of WIOM. Further analysis of the intermolecular relationship shows that WIOM has the potential to transform into WSOM by partitioning into the dissolved phase, oxidation and functionalization by heteroatom-containing groups, representing a previously unidentified pathway for WSOM formation in cloud water. The results provide new insights into the in-cloud chemistry, which would assist in the understanding of the aqueous formation and evolution of WIOM. [Display omitted] • Molecular composition of water-insoluble organics in cloud water was studied. • Water-insoluble organics originate from aerosol activation and oligomerization. • Water-insoluble organics can transform into water-soluble organics in cloud. [ABSTRACT FROM AUTHOR]

Nine amine species in atmospheric particles during haze and low-pollution days with low and high relative humidity (RH) were analyzed in urban Guangzhou, China. The mean concentrations of total measured amines (Ʃamines) in fine particles were 208 ± 127, 63.7 ± 21.3, and 120 ± 20.1 ng m−3 during haze, low pollution-low RH (LP-LRH), and low pollution-high RH (LP-HRH) episodes, respectively. The dominant amine species were methylamine (MA), dimethylamine (DMA), diethylamine (DEA) and dibutylamine (DBA), which in total accounted for 82–91% of the Ʃamines during different pollution episodes. The contributions of Ʃamines-C to water-soluble organic carbon (WSOC) and Ʃamines-N to water-soluble organic nitrogen (WSON) were 1.52% and 2.49% during haze, 1.24% and 1.96% during LP-LRH, and 2.00 and 2.98% during LP-HRH days, respectively. The mass proportion of Ʃamines in fine particles was higher during LP-HRH periods (0.19%) than during haze and LP-LRH periods (0.16%). The mass proportion of DBA in Ʃamines increased from 7% during haze and LP-LRH episodes to 25% during LP-HRH episodes. Compared with other amines, DBA showed a stronger linear relationship with RH (r = 0.867, p < 0.01), which demonstrates its high sensitivity to high RH conditions. Meteorological parameters (including RH, the mixed layer depth, wind speed and temperature), the oxidizing capacity (ozone concentration), and gaseous pollutants (NO x and SO 2) correlated with amines under different pollution conditions. Under high RH, acid-base reactions were the dominant pathway for the gas-to-particle distribution of amines in urban areas, while direct dissolution dominated in the background site. To our knowledge, this study is the first attempt to conduct in situ measurements of particulate amines during different pollution conditions in China, and further research is needed to in-depth understanding of the influence of amines on haze formation. • Stagnant meteorology could cause aerosol amines accumulation. • Relative humidity (RH) was a significant factor influencing the enrichment of aerosol amines. • Acid-base reaction is dominant in amines gas-particle partitioning during high RH in urban. [ABSTRACT FROM AUTHOR]

Abstract: Trimethylamine (TMA) plays an important role in atmospheric chemistry, yet its pathway towards aerosol is not clear. We report in this study the measurement of TMA in submicron particles using a single particle aerosol mass spectrometer (SPAMS) in urban Guangzhou, China for the period of 30 April through 22 May, 2010. The number fraction of TMA-containing particles relative to total detected particle number dramatically increased within the occurrence of fogs. It changed from an average of ∼7% for clear days to ∼35% for the fog events. For particles with size larger than 0.5 μm, the fraction could even account up to ∼60%. Averaged relative intensity of TMA was correlated well with relative humidity, indicating the important role of aerosol water content in the gas-to-particle partitioning of TMA. During the fog events, number based size distribution of TMA-containing particles shifted towards larger mode, peaking at droplet mode (0.5–1.2 μm), corresponding to the build-up of aerosol mass, suggesting the significant mass transfer of TMA and other semi-volatile species from gas to aerosol. Results also reveal that most of TMA-containing particles also contained signals from ammonium, nitrate and sulfate. A much larger fraction of TMA-containing particles was found to contain nitrate during the fog events than on clear days. During the fog events, nitrate and sulfate were more strongly associated with TMA compared to ammonia, which was oppositely observed on clear days. These results indicate that gas-to-particle partitioning of TMA in urban Guangzhou occurs preferentially during fog processing. The study could help improve our understanding in fog processing and potential roles of TMA-containing particles in urban Guangzhou. [Copyright &y& Elsevier]

Abstract: Single particle aerosol mass spectrometer (SPAMS) was used to characterize the single particle size and chemical composition of submicron aerosols in the urban area of the Pearl River Delta region, China, for the period April 30 through May 22, 2010. A total of 696,465 particles were sized and chemically analyzed with both positive and negative ion spectra, in which 141,338 biomass burning particles were identified representing a significant source of submicron particles ∼20.3% by number. The results have revealed that biomass burning particles have experienced extensive atmospheric processing, finding that as much as 90.5% of the particles have internally mixed with secondary inorganic species. Biomass burning particles were clustered into six distinct particle groups, comprising of K–Ca-rich, K–Na-rich, K–organic carbon (K–OC), K–elemental carbon (K–EC), K–the mixture of OC and EC (K–OCEC) and K–Secondary. K–OC was the largest contributor with a fraction of 22.9%, followed by K–Secondary type (21.4%) and K–OCEC (19.0%). K–Na-rich type was observed in 11.9% of the particles and 90% internally mixed with EC. The fraction of nitrate in biomass burning particles was 10% higher than in the non-biomass burning particles. The sodium and potassium in biomass burning particles could exhibit high affinity for nitrate gases during neutralization reactions, facilitating the particulate nitrate formation. Meanwhile, the particulate sulfate in particles in the droplet-mode size was also enhanced. The results added appreciably to the knowledge of aerosol characteristics in the PRD region atmosphere and could be applied to the climate models. [Copyright &y& Elsevier]

Vaccination is one of the most effective ways of controlling the COVID-19 pandemic. However, vaccine hesitancy is prevalent, and relatively few studies have explored how variables related to personal and external motives have affected the intention to vaccinate. The present study investigated the association between perceived personal benefits, variables reflecting external motives (i.e., perceived social benefits, collectivism, and national pride) and intention to receive COVID-19 vaccination among university students in China. The interaction between perceived personal benefits and the three factors reflecting external motives on intention to receive COVID-19 vaccination was also examined. A total of 6922 university students from five provinces of China completed a cross-sectional survey. Results showed that adjusting for significant background variables, perceived personal benefits, perceived social benefits, collectivism, and national pride were all significant factors of intention to receive COVID-19 vaccination. Results from interaction analyses also showed that the association between perceived personal benefits and COVID-19 vaccination intention was stronger among those with lower levels of national pride. Findings highlighted the important role of self-directed interest and external motives in promoting uptake of COVID-19 vaccination. [ABSTRACT FROM AUTHOR]

Background: The COVID-19 epidemic may elevate mental distress and depressive symptoms in various populations in China. Objective: This study investigates the levels of depression and mental distress due to COVID-19, and the associations between cognitive, behavioral, and psychosocial factors, and depression and mental distress due to COVID-19 among university students in China. Methods: A large-scale online cross-sectional study (16 cities in 13 provinces) was conducted among university students from February 1 to 10, 2020, in China; 23,863 valid questionnaires were returned. The Patient Health Questionnaire-9 was used to assess depression. Structural equation modeling was performed to test mediation and suppression effects. Results: Of the 23,863 participants, 47.1% (n=11,235) reported high or very high levels of one or more types of mental distress due to COVID-19; 39.1% (n=9326) showed mild to severe depression. Mental distress due to COVID-19 was positively associated with depression. All but one factor (perceived infection risks, perceived chance of controlling the epidemic, staying at home, contacted people from Wuhan, and perceived discrimination) were significantly associated with mental distress due to COVID-19 and depression. Mental distress due to COVID-19 partially mediated and suppressed the associations between some of the studied factors and depression (effect size of 6.0%-79.5%). Conclusions: Both mental distress due to COVID-19 and depression were prevalent among university students in China; the former may have increased the prevalence of the latter. The studied cognitive, behavioral, and psychosocial factors related to COVID-19 may directly or indirectly (via mental distress due to COVID-19) affect depression. Interventions to modify such factors may reduce mental distress and depressive symptoms during the COVID-19 epidemic. JMIR Ment Health 2021;8(2):e22705 doi:10.2196/22705 [ABSTRACT FROM AUTHOR]

COVID-19 has caused a devastating impact on public health and made the development of the COVID-19 vaccination a top priority. Herd immunity through vaccination requires a sufficient number of the population to be vaccinated. Research on factors that promote intention to receive the COVID-19 vaccination is warranted. Based on Diffusion of Innovations Theory, this study examines the association between the perceived efficacy of the COVID-19 vaccination, use of social media for COVID-19 vaccine-related information, openness to experience and descriptive norm with the intention to receive the COVID-19 vaccination, and the moderating role of openness to experience among 6922 university students in mainland China. The intention to receive the free and self-paid COVID-19 vaccination is 78.9% and 60.2%, respectively. Results from path analyses show that perceived efficacy of the COVID-19 vaccination, use of social media for COVID-19 vaccine-related information, and openness to experience and descriptive norm are all positively associated with the intention to receive COVID-19 free and self-paid vaccination. The association between the perceived efficacy of the COVID-19 vaccination and descriptive norm with the intention to receive the COVID-19 vaccination is stronger among those with a lower level of openness to experience. Our findings support the usefulness of Diffusion of Innovations Theory and the moderating role of openness of experience in explaining intention to receive the COVID-19 vaccination. [ABSTRACT FROM AUTHOR]

In the present study, a ground-based counterflow virtual impactor (GCVI) was used to sample cloud droplet residual (cloud RES) particles, while a parallel PM2.5 inlet was used to sample cloud-free or cloud interstitial (cloud INT) particles. The mixing state of black carbon (BC)-containing particles and the mass concentrations of BC in the cloud-free, RES and INT particles were investigated using a single particle aerosol mass spectrometer (SPAMS) and two aethalometers, respectively, at a mountain site (1690 m a.s.l.) in southern China. The measured BC-containing particles were extensively internally mixed with sulfate, and were scavenged into cloud droplets (0.05–0.45) to a similar (or slightly lower) extent as all the measured particles (0.07–0.6) over the measured size range of 0.1–1.6 µm. The results indicate the preferential activation of larger particles and/or that the production of secondary compositions shifts the BC-containing particles towards larger sizes. BC-containing particles with an abundance of both sulfate and organics were scavenged less than those with sulfate but limited organics, implying the importance of the mixing state on the incorporation of BC-containing particles into cloud droplets. The mass scavenging efficiency of BC with an average of 33% was similar for different cloud events independent of the air mass. This is the first time that both the mixing state and cloud scavenging of BC in China have been reported. Our results would improve the knowledge on the concentration, mixing state, and cloud scavenging of BC in the free troposphere. [ABSTRACT FROM AUTHOR]

Oxalic acid is globally the most abundant dicarboxylic acid. While ground-based works suggest the significance of in-cloud production (or aqueous formation) to oxalate, direct evidence is rare. With the in situ measurements performed at a remote mountain site (1690 m a.s.l.) in southern China, we first reported the size-resolved mixing state of oxalate in the cloud droplet residual (cloud RES), the cloud interstitial (cloud INT), and ambient (cloud-free) particles by single particle mass spectrometry. The results support the growing evidence that in-cloud aqueous reactions promote the formation of oxalate. Furthermore, oxalate was predominantly internally mixed with the aged biomass burning particles, highlighting the impact of biomass burning on the formation of oxalate. It can be interpreted by the individual particle mixing state that the aged biomass burning particles contained an abundance of organic components serving as precursors for oxalate. The results further show that in-cloud aqueous reaction dramatically improved the conversion of organic acids to oxalate. The abundance of glyoxylate associated with the aged biomass burning particles is the controlling factor for the in-cloud production of oxalate. Since only limited information on oxalate is available in the free troposphere, the results also provide an important reference for future understanding of the abundance, evolution and climate impacts of oxalate. We also provided the first direct field observational evidence for the enhanced aqueous formation of oxalate associated with Fe-containing particles. It is likely that reactive oxidant species (ROS) via Fenton reactions enhanced the formation of these organic compounds and their oxidation product oxalate. Gas-particle partitioning of oxalic acid followed by coordination with Fe might also partly contribute to the enhanced oxalate. Aerosol water content likely played an important role in the enhanced oxalate formation when the relative humidity is > 60%. The study could provide a reference for model simulation to improve understanding on the formation and fate of oxalate, and the evolution and climate impacts of particulate Fe. [ABSTRACT FROM AUTHOR]

In recent years, massive interbedded sandstone and slate anti-dip slopes have been discovered in the southwest and northwest regions of China. The distinct mechanical properties of different rock layers make these slopes particularly unique. In this paper, the finite-discrete element method (FDEM) is used to study the toppling failure mechanism of soft-hard interbedded anti-dip rock slopes (SHIADRSs). Firstly, the numerical model of soft-hard interbedded anti-dip rock slope (SHIADRS) is established based on a centrifugal loading test. Then, the stress state, evolution of displacement and cracks, and progress of toppling failure in the SHIADRS are analyzed. Besides, the effect of rock structure, slope angle, dip angle, and rock mechanical properties on the toppling failure of SHIADRS is discussed. The simulation results show that the toppling failure process of SHIADRS can be divided into three stages. The stress distribution in hard rock (HR) is obviously different from that in soft rock (SR) layers. HR layers bear greater bending moments than HR layer during the toppling failure of the soft-hard interbedded anti-dip rock slopes. In addition, the stability of SHIADRS is negatively correlated with the slope angle and the dip angle of rock layer. Compared to the inclination angle of rock layers, the slope angle has a more significant impact on the stability of slopes. The internal friction angle of the rock layer has almost no effect on the toppling failure of SHIADRS. [ABSTRACT FROM AUTHOR]

Abstract Amines play an important role in the formation and transformation of atmospheric aerosols. Gaseous phase and PM 2.5 samples were collected simultaneously at Nanling Mountains, southern China during autumn 2016 and summer 2017. The site is strongly affected by long distance transport from marine and continental air masses. Five amines, methylamine (MA), dimethylamine (DMA), diethylamine (DEA), dibutylamine (DBA) and morpholine (MOR), were detected by gas chromatography-mass spectrometry (GC-MS) after derivatization. The backward trajectory analyses suggested that different origins of air masses led to seasonal variation of amines. In gaseous phase samples, the average concentrations of total measured amines (Ʃamines) were 193.4 ± 111.7 ng m−3 in autumn 2016 and 307.5 ± 196.7 ng m−3 in summer 2017. In PM 2.5 samples, the average concentrations of Ʃamines were 12.4 ± 10.8 ng m−3 in autumn 2016 and 20.7 ± 11.0 ng m−3 in summer 2017. MA and DMA were the dominant amines, together contributing approximately 70% to gaseous amines and 80% to particulate amines. A strong linear relationship was found between Ʃamines and NO 3 − in PM 2.5 , implying that amines might mainly exist in the form of aminium nitrate. Ammonium (NH 4 +) was found mostly likely in the form of ammonia sulfate. Approximately 7.4% of the gaseous total amines partitioned to PM 2.5. A good linear relationship between the fraction of total atmospheric concentration sorbed by PM 2.5 (Φ) and the concentrations of O 3 was found, suggesting that O 3 likely played an important factor in the gas-to-particle partitioning of amines. Additionally, under high relative humidity circumstances (92% ± 7.0%), direct dissolution was a crucial step for gaseous amines partitioning into particles. The ratios of amines-C to water-soluble organic carbon (WSOC) and amines-N to water-soluble organic nitrogen (WSON) were 0.21% and 1.57% in autumn 2016 and 0.54% and 2.08% in summer 2017, respectively. The results of this study provide essential information on the formation mechanism of particulate amines. Highlights • Gaseous and particulate amines were detected simultaneously at a remote mountain site in southern China. • Amines were mostly likely in the form of aminium nitrate. • Approximately 7.4% of the total gaseous amines partitioned into the particulate phase. • Direct dissolution was a crucial step for gas-to-particle partitioning under high relative humidity circumstances. [ABSTRACT FROM AUTHOR]

While aerosol plays a significant role in the formation of cloud, the in-cloud scavenging of chemically segregated particle types were still insufficiently investigated and the controlling factors remain ambiguous. Several field observations were carried out during 2018–2021 at Mt. Tianjing (1690 m a.s.l.) in southern China, based on ground-based counterflow virtual impactor (GCVI)-single particle aerosol mass spectrometer (SPAMS), to investigate the in-cloud scavenging (activation) of various particle types, including black carbon (BC), organic-containing particles (OC), mineral dust (Dust), metal-containing particles (Metal), potassium-rich particles (K-rich) and sea salt (SS). GCVI was used to sample cloud droplet residual particles (Res) while PM 2.5 inlet sampled interstitial particles (Inter) during cloud events and ambient particles (Amb) on sunny days, respectively. Different types of particles were recognized based on spectral characteristics obtained by the SPAMS. Based on the coupled GCVI-SPAMS measurements, the number-based scavenging efficiencies (NSEs) of various particle types could be quantified. Besides, the influence of liquid water content (LWC), PM 2.5 , particle size, and mixing state on the NSEs were discussed. The NSE of SS was the highest (32.4%) while OC showed the lowest NSE (9.1%). Other particle types shared similar NSEs with all the detected particles, with an average of ∼20–25%. Apart from OC, NSEs of other types of particles increased with the increase of LWC and decreased with the increase of the concentration of PM 2.5 , suggesting that numerous PM 2.5 suppressed particles entering cloud droplets via competing for water vapor. The annual variations of NSEs were generally in accordance with LWC and PM 2.5 , reflecting the certain role of these environment conditions. The NSEs typically increased with particle size in a range of 0.2–2.0 μm, reflecting the dominant nucleation mechanism during in-cloud scavenging. Particles mixed with sulfate and nitrate were easier to be scavenged than those coated with organic compounds, e.g., the discrepancy reached 11.8% for the K-rich particles. [Display omitted] • In-cloud scavenging efficiencies for six chemically segregated aerosol types are firstly reported. • SS displayed the highest NSE (32.4% on average) while OC's NSE was the lowest (9.1%). • The annual variations of NSEs were generally in accordance with LWC and PM 2.5 level. • Sulfate and nitrate enhance the NSEs of BC and K-rich particles by ∼10% compare with organics. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to examine the associations between frequent exposure to positive/negative information about vaccine efficacy/safety on social media and intention of COVID-19 vaccination, and to test if media literacy and perceived information quality would moderate such associations. Design: A multi-city cross-sectional survey. Setting: At five universities in different regions of China. Subjects: 6922 university students (a response rate of 72.3%). Measures: frequency of exposure to social media information about COVID-19 vaccination, media literacy, perceived information quality, intention of COVID-19 vaccination, and sociodemographic characteristics. Analysis: Logistic regression analysis was conducted to test main and interaction effects. Results: Higher exposure to positive information about vaccine efficacy (adjusted odds ratio [AOR] = 1.30, P <.001) and vaccine safety (AOR = 1.27, P <.001) were positively associated with vaccination intention. No significant associations were shown between exposure to negative information about vaccine efficacy/safety and vaccination intention. Higher net exposure to negative vs positive information was negatively associated with vaccination intention (AOR =.82, P <.001). High media literacy was further found to attenuate the effect of negative information exposure and strengthen that of positive information exposure. Perceived information quality was not a significant moderator. Conclusion: The valence of social media information regarding the efficacy and safety of COVID-19 vaccines and individuals' media literacy jointly shaped COVID-19 vaccination intention. The findings can inform the development of effective health promotion strategies for enhancing COVID-19 vaccination. [ABSTRACT FROM AUTHOR]

• Mother phubbing (Mphubbing) is positively related to adolescent loneliness (AL) • Attachment anxiety (AA) exacerbates the relationship between Mphubbing and AL. • AA and need to belong simultaneously moderate the link between Mphubbing and AL. Research interest in exploring the negative impacts of mother phubbing on adolescent development is growing. However, limited research has explored the association between mother phubbing and adolescent loneliness, and even less is known about the potential moderating effects within this association. Thus, this study tested the association between mother phubbing and adolescent loneliness and examined whether mother–child attachment anxiety and need to belong simultaneously moderated this relationship. Participants were 4213 high school students (52.5 % boys; M age = 16.41, SD=0.77) from five provinces in China. They completed questionnaires on demographic information, mother phubbing, loneliness, mother–child attachment anxiety, and need to belong. After controlling for demographic variables, the results revealed that mother phubbing was positively related to adolescent loneliness. Mother-child attachment anxiety exacerbated the relationship between mother phubbing and adolescent loneliness. Moreover, the three-way interaction effect of mother phubbing, mother–child attachment anxiety, and need to belong on adolescent loneliness was significant. Specifically, the relationship between mother phubbing and loneliness was non-significant only for adolescents low in both mother–child attachment anxiety and need to belong. The limitations and implications of these findings are discussed. [ABSTRACT FROM AUTHOR]

Elemental carbon (EC) aerosol represents an important fraction of aerosol particles in urban area of the Pearl River Delta (PRD) region, China. Previous studies have demonstrated that EC particles in the PRD region undergo significant amounts of aging processes. To assess the degree of aging, the real-time single particle volatility of EC-containing particles was measured in an urban area of the PRD region by a thermodiluter coupled to a single particle aerosol mass spectrometer (SPAMS). The size and chemical composition of the individual particles before and after heating to 75 °C, 150 °C and 300 °C were characterized. Of the total unheated particles examined by SPAMS, 53% of the unheated particles contained EC, and a higher number fraction (69%) was observed in the particles heated to 300 °C. No significant differences in the mass spectral patterns were found between ambient temperature and 75 °C. Nitrate evaporated at 150 °C, and most of sulfate evaporated at 300 °C. EC-containing particles were clustered into four distinct particle types based on the dominant chemical species present in the mass spectra, comprised of EC, internally mixed EC and organic carbon (OC) (ECOC), internally mixed EC and sodium/potassium salt (NaK–EC), and internally mixed EC and metal species (Metal–EC). Detail analysis show that the volatility of EC-containing particles relied on the EC particle types. Among the four types, the EC type was quite volatile. A significant fraction of sulfate and organics in the ECOC type did not volatilize at 300 °C. The volatilities of secondary ions in the four EC-containing particle types were found to be dependent on their molecular composition. Additionally, the volatility of EC-containing particles decreased during the polluted hazy days due to the generation of low volatile compounds under the atmospheric conditions with higher precursor concentrations and oxidation capacity. To our knowledge, this is the first reported real-time volatility measurements of individual ambient aerosols in the PRD region. These findings provide an improved understanding of the aging process of EC particles, and may help in the modeling of its climate impact. [ABSTRACT FROM AUTHOR]

Previous outbreaks of emerging infectious diseases (e.g., SARS) had increased the uptake of influenza vaccination (IV). It is uncertain whether such was also true for COVID-19. This study hence investigated prevalence of IV behavior/intention prior to and during the COVID-19 pandemic and associated cognitive factors. A self-administered, online, and anonymous cross-sectional survey was conducted among 6,922 university students of five provinces in China during November 1–28, 2020 (response rate: 72.3%). Of all the participants, 35.1% self-reported behavioral intention of IV (next 12 months), while 62.9% reported an increased intention of IV due to COVID-19. However, only 4.7% and 2.9% had taken up IV during the 12-month period prior to the outbreak (1/2019–12/2019) and during the COVID-19 outbreak (1–11/2020), respectively. Adjusted for the background factors, the multivariable logistic regression analysis showed that in general the COVID-19 related perceptions (perceived susceptibility, perceived severity, and perceived chance of having another wave of COVID-19 outbreak) were significantly and positively associated the IV behavior (during the COVID-19 outbreak) and intention of IV uptake in the next 12 months. The COVID-19 pandemic may have influenced actual behavior and intention of IV uptake among university students during the pandemic. Efforts are warranted to reduce the intention-behavior gap of IV uptake; modification of perceived susceptibility and perceived severity regarding COVID-19 may help. Future longitudinal and intervention studies are needed to confirm the findings of this study and explore other factors affecting IV uptake during the COVID-19 period. [ABSTRACT FROM AUTHOR]

• Suicidal ideation (SI) and sleep quality (SQ) fluctuated significantly over time. • Significant reciprocal relationships in perceived stress (PS) and SI from T1 to T3. • Reciprocal relationships in SI and SQ from T1 to T2 were significant. • T2 SI partially mediated the effect of T1 PS on T3 SQ. • T2 SI fully mediated the effect of T1 SQ on T3 PS. Sleep quality is an important indicator of quality of life. It is of importance to investigate the risk factors and potential consequences of poor sleep quality, such as perceived stress and suicidal ideation. We therefore investigated the longitudinal and reciprocal relationships among perceived stress, suicidal ideation, and sleep quality. A three-wave longitudinal survey was conducted from June 2019 to June 2020 at six-month intervals in undergraduate students (N = 197, 58.9% female) in China. The participants completed self-report questionnaires in classroom settings. While the levels of perceived stress were stable, levels of suicidal ideation and sleep quality fluctuated significantly over time. There were significant reciprocal relationships between perceived stress and suicidal ideation from T1 to T3. In addition, the reciprocal relationships between suicidal ideation and sleep quality from T1 to T2 were also significant. Suicidal ideation at T2 partially mediated the relationship between perceived stress at T1 and sleep quality at T3 (indirect effect: β =0.06, 95% CI: 0.04 to 0.10, p <0.001), and suicidal ideation at T2 fully mediated the relationship between sleep quality at T1 and perceived stress at T3 (indirect effect: β =0.48, 95% CI: 0.30, 0.70, p <0.001). The subjects' educational background is single, and the measurement method is self-report measures. Suicidal ideation may play a significant role in explaining the longitudinal relationships between perceived stress and sleep quality. And suggest the importance of early identification and treatment of suicidal ideation among Chinese undergraduates. [ABSTRACT FROM AUTHOR]

• Changes in academic pressure at T1 positively linked to adolescent social anxiety at T3. • Classmate support at T2 and PSU at T2 as chain mediators. • Chain mediator model vary by changes in leisure time. • Classmate support at T2 → PSU at T2 was stronger in increased leisure time group. • Changes in academic pressure at T1 → PSU at T2 was weaker in increased group. In response to concerns surrounding excessive homework and off-campus tutoring for students undergoing compulsory education in China, the government implemented the "double reduction" policy to alleviate these burdens. This study aims to examine the mechanisms that underlie the longitudinal relationship between changes in academic pressure and social anxiety among Chinese adolescents under the background of this policy. A total of 2,202 valid questionnaires were obtained, and the sample consisted of 1,234 students who reported having a smartphone (age: M = 14.60, SD = 1.57). They were recruited to complete the changes in leisure time and academic pressure at Time 1, classmate support at Time 1 and Time 2, problematic smartphone use at Time 1 and Time 2, and social anxiety at Time 1, Time 2, and Time 3. The findings indicate that classmate support and problematic smartphone use at Time 2 significantly mediated the association between changes in academic pressure at Time 1 and social anxiety at Time 3. Changes in leisure time at Time 1 also affected these relationships. Specifically, compared to those with decreased leisure time, the relationship between classmate support at Time 2 and problematic smartphone use at Time 2 was stronger among adolescents with increased leisure time, while the relationship between changes in academic pressure at Time 1 and problematic smartphone use at Time 2 was weaker among adolescents with increased leisure time. These results highlight the importance of promoting effective stress coping strategies and peer interactions for adolescents, and also the importance of promoting active parental participation in leisure time management and guidance towards positive coping styles. [ABSTRACT FROM AUTHOR]

Quarantine plays a key role in controlling the pandemic of 2019 coronavirus disease (COVID-19). This study investigated (a) the associations between mandatory quarantine status and negative cognitions (perceived discrimination because of COVID-19 and perceived risk of COVID-19 infection)/mental health status (emotional distress because of COVID-19, probable depression, and self-harm/suicidal ideation), (b) the associations between the negative cognitions and mental health status, and (c) potential mediations between quarantined status and probable depression and self-harm/suicidal ideation via COVID-19-related negative cognitions/emotional distress. An online cross-sectional survey was conducted among 24,378 students of 26 universities in 16 Chinese cities (February 1–10, 2020). Correlation coefficients, odds ratios (OR), structural equation modeling, and other statistics were used for data analysis. Mandatory quarantined status was significantly and positively associated with perceived discrimination (Cohen's d = 0.62), perceived high/very high risk of infection (OR = 1.61), emotional distress (Cohen's d = 0.46), probable depression (OR = 2.54), and self-harm/suicidal ideation (OR = 4.98). Perceived discrimination was moderately and positively associated with emotional distress (Spearman correlation = 0.44). Associations between perceived risk of infection and mental health variables were significant but relatively weak. Cross-sectional mediation models showed good model fit, but the overall indirect paths via COVID-19-related negative cognitions/emotional distress only accounted for 12–15% of the total effects between quarantined status and probable depression and self-harm/suicidal ideation. In conclusion, quarantined participants were more likely than others to perceive discrimination and exhibit mental distress. It is important to integrate mental health care into the planning and implementation of quarantine measures. Future longitudinal studies to explore mechanisms underlying the mental health impact of quarantines are warranted. Public Significant Statement: This study suggests that mandatorily quarantined individuals are more likely to have mental distress and negative cognitions related to COVID-19 than their nonquarantined counterparts. Attention should be paid to the heightened perceived discrimination as it was associated with both mandatory quarantine status and negative mental health status. The findings demonstrate the need to develop interventions to meet the psychological needs of people in quarantine during the COVID-19 pandemic. [ABSTRACT FROM AUTHOR]

Daytime atmospheric pollution has received wide attention, while the vertical structures of atmospheric pollutants at night play a crucial role in the photochemical process on the following day, which is still less reported. Focusing on Guangzhou, a megacity of South China, we established an unmanned aerial vehicle (UAV) equipped with micro detectors to collect consecutive high-resolution samples of fine particle (PM 2.5), submicron particle (PM 1.0), black carbon (BC) and ozone (O 3) concentrations in the atmosphere, as well as the air temperature (AT) and relative humidity (RH) within a 500 m altitude during nighttime from Oct. 24th to Nov. 6th, 2018. The measurements showed that PM 2.5 , PM 1.0 , and BC decreased with altitude and were influenced by the nighttime shallow planetary boundary layer (PBL) where BC was more accumulated and fluctuated. In contrast, O 3 was positively correlated with altitude. Backward trajectory clustering and Pasquill stability classification showed that advection and convection significantly influenced the vertical distribution of all pollutants, particularly particulate matter. External air masses carrying high concentrations of pollutants increased PM 1.0 and PM 2.5 levels by 145% and 455%, respectively, compared to unaffected periods. The ratio of BC to PM 2.5 indicated that local emissions had a minor role in nighttime particulate matter. Vertical transport caused by atmospheric instability reduced the differences in pollutant concentrations at various heights. Geodetector and generalized additive model showed that RH and BC accumulation in the PBL were significant factors influencing vertical changes of the secondary aerosol intensity as indicated by the ratio of PM 1.0 to PM 2.5. The joint explanation of RH and atmospheric stability with other variables such as BC is essential to understand the generation of secondary aerosols. These findings provide insights into regional and local measures to prevent and control night-time particulate matter pollution. [Display omitted] • PM 2.5 , PM 1.0 , BC, and O 3 are detected vertically at nighttime in Guangzhou. • The vertical decline is smooth for PM 2.5 and PM 1.0 but fluctuating for BC. • Compared to PM 2.5 and PM 1.0 , BC is more sensitive to PBL. • Higher BC and humidity near the PBL reduce the secondary aerosol intensity. [ABSTRACT FROM AUTHOR]

In order to determine the dominant factors influencing on production characteristics of coalbed methane (CBM) well, the relationships between CBM wells productivity and its various factors from the no. 3 coal seam of the Lower Permian Shanxi Formation in the Shizhuangnan block of southern Qinshui basin were studied based on geophysical log, production and experiment data. CBM wells were classified into two types according to water production curves which are related to different dewatering effects. The coal seam and its roof and floor of 75 CBM wells were identified by geophysical log data. The reservoir pressure and hydraulic-head of 55 CBM wells were estimated by working fluid level height. The calculation models of coal proximate analysis components and gas content on the study area were established using geophysical log and experiment data from 14 CBM wells. The results indicate that coal rank of no. 3 coal seam is mainly anthracite (vitrinite reflectance ranges mainly from 2.505% to 3.567%). Coal macerals is mainly vitrinite (51.0–83.1%), followed by intertinite (7.5–37.3%). The groundwater in the study area flows from east to west along the direction of the elevation decrease. The groundwater flow controls gas accumulation which resulted in high gas content in west and low gas content in east. Therefore, CBM wells with high gas production rate concentrate in west. Poor sealing ability of roof may lead to external water flowing into coal reservoir through roof. This causes high water production rate and low gas production rate in CBM wells, even if CBM wells have high gas content. The western part of study area has greater potential in CBM production than eastern part of study area. Hydrological condition and sealing ability of roof are two key factors on CBM production. [ABSTRACT FROM AUTHOR]

Aerobic spore forming bacteria are potential milk powder contaminants and are viewed as indicators of poor quality. A total of 738 bacteria, including both mesophilic and thermophilic, isolated from twenty-five powdered milk samples representative of three types of milk powders in China were analyzed based on the random amplified polymorphic DNA (RAPD) protocol to provide insight into species diversity. Bacillus licheniformis was found to be the most prevalent bacterium with greatest diversity (~ 43% of the total isolates) followed by Geobacillus stearothermophilus (~ 21% of the total isolates). Anoxybacillus flavithermus represented only 8.5% of the total profiles. Interestingly, actinomycetes represented a major group of the isolates with the predominance of Laceyella sacchari followed by Thermoactinomyces vulgaris , altogether comprising of 7.3% of the total isolates. Out of the nineteen separate bacterial species (except five unidentified groups) recovered and identified from milk powders, twelve proved to belong to novel or previously unreported species in milk powders. Assessment and characterization of the harmful effects caused by this particular micro-flora on the quality and safety of milk powders will be worth doing in the future. [ABSTRACT FROM AUTHOR]

Objective To evaluate the association between the introduction of neuraxial (epidural) labor analgesia and mode of delivery in a large urban maternity hospital in China. Methods A single-intervention impact study was conducted at Shijiazhuang Obstetrics and Gynecology Hospital in Shijiazhuang. Baseline data collection occurred between August 1 and December 31, 2009, when no analgesic method was routinely employed during labor. An intervention was then implemented, consisting of a neuraxial labor analgesia service. The service was fully operational from September 1, 2010, and data were collected to August 31, 2011. The mode of delivery was compared between the different periods. Results Neuraxial analgesia rate was used in none of the 3787 deliveries during the baseline period and 3429 (33.5%) of 10 230 in the implementation period. Cesareans were performed in 1533 (40.5%) deliveries in the baseline period and 3441 (33.6%) in the implementation period (difference –6.8%, 99.8% confidence interval [CI] –9.7% to –3.9%; P < 0.0017). The proportion of vaginal deliveries in which forceps were used was unchanged (difference –0.8%, 99.8% CI –0.7% to 2.2%; P = 0.92). Conclusion The introduction of epidural analgesia reduced the frequency of cesarean delivery, which improved obstetric and neonatal outcomes. [ABSTRACT FROM AUTHOR]

Background and Aims: The Common-Sense Model asserts that illness representations of a health threat affect coping and behavioral reactions to it. Internet gaming disorder (IGD) is a newly defined mental disorder and leads to various health consequences. Little is known about illness representations of IGD and help-seeking for IGD among young adults who are at particular risk of IGD.Objective: This study investigated the roles of illness representations in intention to seek help from professionals and important others (families and friends) for IGD in college students in China.Methods: A two-wave longitudinal study was conducted with a convenience sample of college students in China (N = 591, 57.9% females, Meanage = 19.10). Descriptive analyses and logistic regression analyses were conducted.Results: Approximately 10% of participants were classified as having probable IGD. However, over 70% endorsed self-diagnosed IGD. Less than 40% perceived resources of help-seeking, and most perceived shame for help-seeking. Less than 40% intended to seek help from professionals, and 26% from family and friends. Significant predictors of intention to seek professional help included probable IGD, perceived resources of help-seeking for IGD, consequence, timeline, and treatment. Significant predictors of intention to seek help from family and friends included probable IGD, self-diagnosed IGD, perceived resources of help-seeking for IGD, shame for help-seeking for IGD, timeline, treatment control, identity, concern, and emotional response. Females were more likely to seek both types of help.Discussion and Conclusions: Perceptions of IGD and help-seeking play significant roles in help-seeking intentions. These modifiable factors can be used to guide the development of health promotion and behavioral change programs to promote help-seeking for IGD. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes a new built single particle laser desorption/ionization time of flight mass spectrometer capable of determining the size and chemical compositions of individual aerosol particles in real-time. The instrument was compactly designed with bipolar grid reflectron mass analyzers for higher mass resolution. It measures 90cm long×70cm wide×170cm high, weights ∼170kg and has a total power consumption of less than 2000W. Standard polystyrene latex particles (PSL) and metallic solution were used to perform size and mass calibration, respectively, and the effect of inlet pressure of the aerodynamic lens on size calibration was also investigated. The instrument was first used for the ambient aerosol detection in Guangzhou City, China, and the preliminary measurements show its’ ability to characterize the atmospheric aerosol particles containing different chemical compositions with diameters ranging from 250 to 2000nm and a total hit rate above 30%. The preliminary measurements also show that the aerosol particles in Guangzhou, China can be mainly classified into five types, which are rich K, rich Na, Nark, carbonaceous, and metal containing, and their formations are also generally discussed. [Copyright &y& Elsevier]