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The spread of the COVID-19 had profoundly affected the development of the air transportation. In order to determine the changes in air transportation volume associated with the development of the epidemic, this paper takes Southwest China as the study area. Monthly data and methods, such as the coefficient of variation, rank-size analysis and spatial matching index, were applied. The results found that: (1) during 2020–2022, there was a positive relationship between passenger volume and epidemic development, while freight volume increased for most airports in the first quarter of 2020–2022, particularly in the eastern region; (2) From the perspective of changes in air transportation volume under the development of the COVID-19, among various types of airports, the changes in transportation volume of main trunk airports were more significant than those of regional feeder airports in remote areas; (3) however, under the influence of the epidemic, main trunk airports still exhibited stronger attraction in passenger volume. That is to say, the passengers who chose to travel by air still tended to choose the main trunk airports and formed the agglomeration distribution pattern which around high-level airports in the provincial capital. Whereas the freight volume had a tendency of equalization among airports in Southwest China; (4) Over the course of time, the consistency of the spatial distribution of the number of cases and the passenger or freight volume in southwest China gradually increased. Among them, the spatial matching rate of the passenger volume and the number of COVID-19 cases was always higher than that of the cases and freight volume, which might indicate that there was a stronger correlation relationship. Therefore, it is proposed that the construction of multi-center airport system should be strengthened, the resilience of the route network for passenger transportation should be moderately enhanced, and the risk-resistant capacity of mainline airports and airports in tourist cities should be upgraded, so as to provide references for the orderly recovery of civil aviation and regional development. [ABSTRACT FROM AUTHOR]

With the deterioration of underground coal quality, hundreds of millions of tons of coal slime in China need to be treated using flotation methods every year. However, the design and selection of coal slurry flotation collectors lack theoretical guidance. In this paper, the quantitative structure–activity relationship (QSAR) model between the molecular structure descriptors of collectors and the flotation recovery and selectivity index is established by using pure kaolinite/clean coal flotation experiments and molecular simulation techniques. Flotation results showed that the flotation recovery rate of kaolinite by collectors with larger head group size, such as DDMAC, DDP, and DTAC, is higher than that of the other collectors with smaller head group size. DDA, DDP, and DD have similar flotation capabilities for clean coal, and their selectivity was slightly better than others. The QSAR model between the molecular structure descriptor and the selectivity index was successfully constructed by combining flotation experiments and molecular simulation results. The reliability of this model has been proven through theoretical analysis and flotation experiments. The molecular simulation results indicate that all eight collectors can advertise on 001 (−) surface of kaolinite, but the final advertisement configuration is different. DDA has less coverage on the surface of kaolinite. When the collector is DDA, the concentration of water molecules near the 001 (−) surface of kaolinite is the highest, indicating that the collector DDA has the weakest effect on improving the hydrophobicity of the 001 (−) surface of kaolinite. DDMAC and DDBAC have the best facilitation to the surface hydrophobicity of kaolinite 001 (−). The research results have theoretical guidance significance for the selection and design of mineral flotation collectors. [ABSTRACT FROM AUTHOR]

Eucommia ulmoides staminate flowers (EUF), a newly approved functional food in China, have great potential for hormonal regulation. Herein, we aim to demonstrate the chemical composition and pharmacological activity of EUF in testosterone production and hormonal regulation. EUF extract and its components, kaempferol and geniposidic acid, exhibited a strong stimulating effect by increasing testosterone secretion, reducing ROS production, or promoting viability in Leydig cells. Meanwhile, the increased testosterone production was related to the upregulation of mRNA and protein expression of the steroidogenic pathway, such as steroidogenic acute-regulatory protein (StAR), 3β -hydroxysteroid dehydrogenase type 1 (HSD3B1), 17α-hydroxylase/17,20-lyase (CYP17A1), and nuclear receptor subfamily 5 group A member 1 (NR5A1). However, PKA inhibitor H89 or adenylyl cyclase inhibitor SQ22536 could block their effect. The results of transgenic yeast models showed the androgenic agonistic effects of kaempferol and naringenin and the estrogenic agonistic effects of rutin. These results indicated that the testosterone promotional effect of EUF was related to the activation of the steroidogenic pathway and potential hormonal regulation. Kaempferol and geniposidic acid might be the key active ingredients. [ABSTRACT FROM AUTHOR]

The third author's name is spelled incorrectly. The correct name is: Yi Miao.The affiliation 1 for all the authors is incorrect. The correct affiliation 1 is: College of Geography and Environment, Shandong Normal University, Jinan, Shandong, China.The correct citation is: Li Z, Deng X, Miao Y, Duan J (2024) Study on the temporal and spatial relationship between public health events and the development of air transport scale: A case of the Southwest China. PLoS ONE 19(4): e0301461. https://doi.org/10.1371/journal.pone.0301461.By Zihan Li; Xiwen Deng; Yi Miao and Jinglong DuanReported by Author; Author; Author; Author [Extracted from the article]

A decrease in population is an emerging challenge in China's urbanization trajectory. This study utilizes data from the Sixth and Seventh Population Censuses to identify Chinese cities experiencing population decline, focusing on prefecture-level cities. It employs 30 indicators relevant to nine Sustainable Development Goals (SDGs) concerning urban areas and populations to evaluate the progress of these shrinking cities in 2010 and 2020. A novel metric, "SDG population elasticity", is introduced to quantify the association between population reduction and SDG indexes. The study employs K-means++ clustering for 130 shrinking cities. The findings reveal that out of the 130 cities, 63 exhibit a downward trend in SDG index scores, predominantly in China's northeast and western regions. The Northeast region has negative SDG population elasticity, indicating a lag in sustainable development compared to that in other areas. Additionally, the research categorizes China's shrinking cities into four groups: cities with strong population elasticity feedback-significantly declining SDGs, cities with weak population elasticity feedback-slightly regressing SDGs, cities with high population loss-negative SDGs in decline, and cities with smart population decline-steady SDGs growth. These findings offer a foundation for crafting bespoke policies in shrinking cities to ensure a balanced approach to sustainable development and monitor advancement toward achieving the SDGs. [ABSTRACT FROM AUTHOR]

• Machine learning algorithms, particularly the stacked ensemble model, proved to be a valuable tool in predicting the risk of functional dependency among middle-aged and elderly Chinese adults. • A compact model was developed using a smaller set of predictors. It maintained both discrimination and accuracy, making it practical for routine clinical practice. • For ADL dependency, arthritis, age, self-report health, and waist circumference were identified as highly significant predictors. Conversely, cognitive function, age, living in rural areas, and performance in chair stand test emerged as highly ranked predictors for IADL dependency. To develop prediction models for assessing functional dependency in a middle-aged and older Chinese population. Adults ≥45 years old from the China Health and Retirement Longitudinal Study (CHARLS) and without functional dependency at baseline were included. Functional dependency was defined as needing any help in any basic activities of daily living (ADL) or instrumental activities of daily living (IADL). The outcomes were overall functional dependency, ADL and IADL dependency. Stacked ensemble models were constructed based on five selected machine learning models. Models were trained and tested in the 2011–2015 cohort, and were externally validated in the 2015–2018 cohort. SHapley Additive exPlanations (SHAP) was utilized to quantify the significance of predictors. In the training cohort, a total of 6,297 participants were included at baseline, 1,893 developed functional dependency during the follow-up period. The stacked ensemble model achieved the best performance in terms of discrimination ability for predicting overall functional dependency, ADL and IADL dependency, with AUCs of 0.750, 0.690 and 0.748, respectively; in external validation cohort, the corresponding AUCs were 0.725, 0.719 and 0.727, respectively. A compact model was further developed and maintained similar predictive performance. The stacked ensemble approach can serve as a useful tool for identifying the risk of functional dependency in a large Chinese population. For ADL dependency, arthritis, age, self-report health, and waist circumference were identified as highly significant predictors. Conversely, cognitive function, age, living in rural areas, and performance in chair stand test emerged as highly ranked predictors for IADL dependency. [ABSTRACT FROM AUTHOR]

Purpose: Several model studies suggested the implementation of latent tuberculosis infection (LTBI) testing and treatment could greatly reduce the incidence of tuberculosis (TB) and achieve the 2035 target of the "End TB" Strategy in China. The present study aimed to evaluate the cost-effectiveness of LTBI testing and TB preventive treatment among key population (≥ 50 years old) susceptible to TB at community level in China. Methods: A Markov model was developed to investigate the cost-effectiveness of LTBI testing using interferon gamma release assay (IGRA) and subsequent treatment with 6-month daily isoniazid regimen (6H) (as a standard regimen for comparison) or 6-week twice-weekly rifapentine and isoniazid regimen (6-week H2P2) in a cohort of 10,000 adults with an average initial age of 50 years. Results: In the base-case analysis, LTBI testing and treatment with 6H was dominated (i.e., more expensive with a lower quality-adjusted life year (QALY)) by LTBI testing and treatment with 6-week H2P2. LTBI testing and treatment with 6-week H2P2 was more effective than no intervention at a cost of $20,943.81 per QALY gained, which was below the willingness-to-pay (WTP) threshold of $24,211.84 per QALY gained in China. The one-way sensitivity analysis showed the change of LTBI prevalence was the parameter that most influenced the results of the incremental cost-effectiveness ratios (ICERs). Conclusion: As estimated by a Markov model, LTBI testing and treatment with 6-week H2P2 was cost-saving compared with LTBI testing and treatment with 6H, and it was considered to be a cost-effective option for TB control in rural China. [ABSTRACT FROM AUTHOR]

The study of intercity network structure from the perspective of flow space can effectively reveal the connection patterns, hierarchical laws, and spatial organization of cities. However, current studies mostly focus on a single real or virtual space, neglecting the comprehensive perspective. Furthermore, the research subject of network relationships is usually the complex original aligned network rather than the spatially cohesive network structure. In this study, spatial network structures are constructed and extracted based on the migration flow and attention flow, which represent people's objective behavior and subjective will, respectively. This study then reveals the association between virtual and real networks from three aspects: node location, node attributes, and local network structure characteristics. Results indicate that compared with the real network structure, the virtual network structure has a strong same-level node agglomeration and a significant node size difference. Spatial dislocations are observed in the high association of the various measures of China's real and virtual network structures. The degree of differences in network structures between virtual and real spaces varies spatially. This paper reveals the dynamics of urban development in different spaces, helping build a human-centered, high-quality space governance system for virtual and real spaces. • Spatial network structure considering the geographical proximity and interaction strength among cities is extracted. • Location, attribution, and structure-based association analysis method for non-aligned intercity networks is proposed. • The degree of differences in network structures between virtual and real spaces varies spatially. • The association pattern between real and virtual networks is spatially dislocated in different indicators. [ABSTRACT FROM AUTHOR]

Municipal solid waste incineration (MSWI) fly ash contains large amounts of Ca, Si, and other elements, giving it the potential to be used as a raw material for cement production. However, fly ash often contains a high content of salts, which greatly limits its blending ratio during cement production. These salts are commonly removed via water washing, but this process is affected by the nature and characteristics of fly ash. To clarify the influence of the ash characteristics on salt removal, a total of 60 fly ash samples from 13 incineration plants were collected, characterized, and washed. The ash characterization and cluster analysis showed that the incinerator type and flue gas purification technology/process significantly influenced the ash characteristics. Washing removed a high percentage of salts from fly ash, but the removal efficiencies varied significantly from each other, with the chlorine removal efficiency ranging from 73.76% to 96.48%, while the sulfate removal efficiency ranged from 6.92% to 51.47%. Significance analysis further revealed that the salt removal efficiency varied not only between the ash samples from different incinerators, but also between samples collected at different times from the same incinerator. The high variance of the 60 ash samples during salt removal was primarily ascribed to their different mineralogical and chemical characteristics. Mineralogical analysis of the raw and washed ash samples showed that the mineralogical forms and proportion of these salts in each ash sample greatly influenced their removal. The presence of less-soluble and insoluble chloride salts (e.g., CaClOH, Ca 2 Al(OH) 6 (H 2 O) 2 Cl etc.) in fly ash significantly affected the chlorine removal efficiency. This study also found that Fe, Mn, and Al in fly ash were negatively correlated with the dechlorination efficiency of fly ash. In summary, the different physical and chemical properties of fly ash caused great discrepancies in salt removal. Consequently, it is suggested to consider the potential impact of the ash source and ash generation time on salt removal to ensure a reliable treatment efficiency for engineering applications. • Incinerator type and gas purification process considerably affect ash property. • Water washing could remove 73.76–96.48% of chlorine from MSWI fly ash. • Fly ash characteristics pose a significant influence on chlorine removal. • Ash blending ratio in cement kiln increased from 0.14–0.23% to 0.31–2.69% after washing. [ABSTRACT FROM AUTHOR]

This study utilized a quasi-experimental design to investigate the impact of different scaffoldings and inner speech on learning motivation, flexible thinking, and individual academic achievement in a technology-enhanced learning environment. The sample consisted of 181 college students in China who were randomly assigned to one of four groups: the procedural-scaffolding group, the conceptual-scaffolding group, the conceptual-and-procedural scaffolding group, and the control group. The data were analysed using a two-way ANCOVA and planned comparisons. The findings revealed that the conceptual-and-procedural scaffolding group exhibited higher scores in learning motivation, flexible thinking, and academic achievement than the conceptual or procedural scaffolding groups. No interaction effect was observed between the types of scaffolding and the level of inner speech on learning motivation. The reasons for the superior performance of the conceptual scaffolding group compared to the procedural scaffolding group and the absence of an interaction effect between the two independent variables have been thoroughly discussed. These findings have important implications for future studies aimed at enhancing education and research. • An experimental study exploring students' learning motivation, flexible thinking, and academic achievement was done by the effect of scaffolding. • The 181 samples were analyzed. • Several data analyses,such as descriptive analyses, two-way ANCOVA, and planned comparison, were analysed. • Possible research issues in the future and educational implications of scaffolding on students' cognitive behaviours were proposed. • The effects of conceptual scaffolding and procedural scaffolding on students' behaviors were reported. [ABSTRACT FROM AUTHOR]

Molecular analyses help to better understand the overall picture of characteristics, meteorological effects, sources, and secondary transformations of organic aerosols (OA). A two-year observation campaign was conducted in polluted central China during 2019–2021, and 130 compounds of molecular OA (quantified organic compounds, QOCs) were quantified. The average concentration of QOCs was 1971 ng/m3, showing the highest normalized QOCs in PM 2.5 (31 ng/μg) compared to others. Among the QOCs, the polar category contributed 84%, with the dominated abundant fatty acids observed. The enhanced acid ratios of malonic/succinic and octadecanoic/oleic in summer indicated higher aerosol age, significantly promoted by temperature. Three benzenetricarboxylic acids, mostly from secondary formation, also exhibited quite high concentrations in summer. The noticeable presence of carcinogenic polycyclic aromatic hydrocarbons (PAHs) (45% of ∑28PAHs) highlighted severe health risks associated with human exposure, particularly in winter (56 ng/m3, approximately 7 times that in summer). According to the random forest model assessments, meteorological conditions in summer were most conducive to eliminating pollutants, while that in winter contributed 19% of QOC concentration. The Positive Matrix Factorization analysis revealed that anthropogenic secondary organic aerosols (ASOA) and biogenic SOA (BSOA) jointly accounted for 32% of QOCs, followed by biomass burning (20%), coal combustion (17%), vehicle emissions (16%), and cooking (15%). ASOA was positively correlated with O 3 (r = 0.58) and aerosol acidity facilitated ASOA production at 40% < relative humidity <80%. On polluted days, BSOA increased as NO 2 and PM 2.5 increased, contributing to worsened aerosol pollution. In spring and summer, gas-phase oxidation contributed more saturated dicarboxylic acids (52 and 55%), while aqueous-phase conversion predominated in autumn and winter (59 and 66%). This study provides new information on particulate molecular organic compounds as well as the secondary transformation, which is of great significance for formulating the prevention and control measures of aerosol pollution. [Display omitted] • A total of 130 compounds were measured, covering 8 types of polar and 5 types of non-polar molecules. • Winter meteorological conditions were estimated to contribute 19% to organic components. • Anthropogenic SOA was significantly promoted by aerosol acidity (40% < RH < 80%) and O 3. • Aqueous-phase oxidation predominated in the formation of saturated dicarboxylic acids (55%). [ABSTRACT FROM AUTHOR]

Neonicotinoid insecticides can selectively interact with the unique nicotinic acetylcholine receptor subtypes in insects and are considered to be low toxic to mammals. However, there is still insufficient knowledge on human exposure to neonicotinoid insecticides, especially for children. This study aimed to investigate urinary concentrations and profiles of neonicotinoid insecticides in South China children and to analyze potential influencing factors. Six neonicotinoid insecticides, including imidacloprid (IMI), thiamethoxam (THM), acetamiprid (ACE), clothianidin (CLO), thiacloprid (THD) and dinotefuran (DIN), exhibited high detection frequencies (>90%) in urine samples collected from 305 children, suggesting broad exposure in South China children. The median concentrations were determined to be 0.13, 0.21, 0.01, 0.19, 0.002 and 1.64 μg/L, respectively. Among the target neonicotinoids, urinary concentrations of CLO and THM exhibited a significant and positive correlation between each other (p < 0.05), suggesting similar sources of these two chemicals. [Display omitted] • Neonicotinoid insecticides were frequently detected in urine samples from South China children. • DIN was the most abundant neonicotinoid insecticide in urine samples. • Urinary CLO positively correlated with THM, indicating similar exposure sources. [ABSTRACT FROM AUTHOR]

Neonicotinoid insecticides can selectively interact with the unique nicotinic acetylcholine receptor subtypes in insects and are considered to be low toxic to mammals. However, there is still insufficient knowledge on human exposure to neonicotinoid insecticides, especially for children. This study aimed to investigate urinary concentrations and profiles of neonicotinoid insecticides in South China children and to analyze potential influencing factors. Six neonicotinoid insecticides, including imidacloprid (IMI), thiamethoxam (THM), acetamiprid (ACE), clothianidin (CLO), thiacloprid (THD) and dinotefuran (DIN), exhibited high detection frequencies (>90%) in urine samples collected from 305 children, suggesting broad exposure in South China children. The median concentrations were determined to be 0.13, 0.21, 0.01, 0.19, 0.002 and 1.64 μg/L, respectively. Among the target neonicotinoids, urinary concentrations of CLO and THM exhibited a significant and positive correlation between each other (p < 0.05), suggesting similar sources of these two chemicals. [Display omitted] • Neonicotinoid insecticides were frequently detected in urine samples from South China children. • DIN was the most abundant neonicotinoid insecticide in urine samples. • Urinary CLO positively correlated with THM, indicating similar exposure sources. [ABSTRACT FROM AUTHOR]