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Objective: To develop a machine learning diagnostic model based on MMP7 and other serological testing indicators for early and efficient diagnosis of biliary atresia (BA). Methods: A retrospective analysis was conducted on patient information from those hospitalized for pathological jaundice at Beijing Children's Hospital between January 1, 2019, and December 31, 2023. Patients with serum MMP7, liver stiffness measurements, and other routine serological tests were included in the study. Six machine learning models were constructed, including logistic regression (LR), random forest (RF), decision tree (DET), support vector machine classifier (SVC), neural network (MLP), and extreme gradient boosting (XGBoost), to diagnose BA. The area under the receiver operating characteristic curve was used to evaluate the diagnostic efficacy of the various models. Results: A total of 98 patients were included in the study, comprising 64 BA patients and 34 patients with other cholestatic liver diseases. Among the six machine learning models, the XGBoost algorithm model and RF algorithm model achieved the best predictive performance, with an AUROC of nearly 100% in both the training and validation sets. In the training set, these two algorithm models achieved an accuracy, precision, recall, F1 score, and AUROC of 1. Through model interpretation analysis, serum MMP7 levels, serum GGT levels, and acholic stools were identified as the most important indicators for diagnosing BA. The nomogram constructed based on the XGBoost algorithm model also demonstrated convenient and efficient diagnostic efficacy. Conclusion: Machine learning models, especially the XGBoost algorithm and RF algorithm models, constructed based on preoperative serum MMP7 and serological tests can diagnose BA more efficiently and accurately. The most important influencing factors for diagnosis are serum MMP7, serum GGT, and acholic stools. [ABSTRACT FROM AUTHOR]

Objective: The present study endeavored to investigate the interconnection between obstructive sleep apnea (OSA) and cognitive function, alongside the manifestations of depression and anxiety. Simultaneously, an analysis was conducted to discern the factors exerting influence upon cognitive function. Methods: A cohort of 102 patients, who had undergone polysomnography (PSG) at Binhu Hospital, Anhui Medical University, between January 2022 and June 2023, was encompassed in the study. Employing the PSG findings, these individuals were classified into two distinct categories: the grouping consisted of those with either negligible or mild OSA, and the other comprised individuals with moderate to severe OSA. Utilizing the Montreal Cognitive Assessment (MoCA-Beijing), Stroop Color and Word Test (SCWT), Digit Span Test (DST), Self-rating Depression Scale (SDS), and Self-rating Anxiety Scale (SAS), scores were recorded and analysed for each of the respective assessments. Additionally, discrepancies and associations between these groups were also scrutinized. Results: The group exhibiting moderate to severe OSA demonstrated significantly elevated measurements in parameters such as neck circumference, BMI, completion times for SCWT-A, B, C, Sleep Inefficiency Index (SIE), SAS, and SDS, in comparison to the No or Mild OSA group. Furthermore, the moderate-severe OSA group manifested notably diminished MoCA scores in areas of visual-spatial and executive function, memory, language, abstraction, delayed recall, orientation, total MoCA score, lowest oxygen saturation (LSaO2), average oxygen saturation, Digit Span Test-backward(DST-b), and Digit Span Test-forward(DST-f), as contrasted with the no-mild OSA group. These inter-group disparities exhibited statistical significance (p < 0.05). The MoCA total score portrayed inverse correlations with age, Apnea-Hypopnea Index (AHI), BMI, SIE, SAS, SDS, CT90%, AHT90%, and Hypoxic Apnea Duration (HAD) (ranging from -0.380 to -0.481, p < 0.05). Conversely, it displayed positive correlations with DST-f, DST-b, LSaO2, and average oxygen saturation (ranging from 0.414 to 0.744, p < 0.05). Neck circumference, AHI, and SAS were autonomously linked to MoCA scores (OR = 1.401, 1.028, 1.070, p < 0.05), while AHI exhibited an independent correlation with SDS and SAS scores (OR = 1.001, p = 0.003). Conclusion: Patients grappling with moderate to severe OSA frequently reveal cognitive impairment and concomitant emotional predicaments encompassing depression and anxiety. These manifestations share an intimate association with AHI, LSaO2, and average oxygen saturation. Notably, anxiety, when coupled with OSA, emerges as an autonomous influential element impinging upon cognitive impairment. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to investigate the relationship between serum immunoglobulin M (IgM) and the severity of coronary artery disease in Chinese patients who underwent coronary angiography. Methods: A total of 2,045 patients who underwent coronary angiography (CAG) from March 2017 to March 2020 at Beijing Hospital were included in this study. Serum IgM concentration and biochemical indicators were measured before coronary angiography (CAG). The triquartile IgM levels at baseline in the population were analysed. Spearman rank correlation was used to analyse the association between IgM and traditional risk factors for coronary artery disease (CAD). CAD patients were divided into subgroups by affected area, number of affected vessels, and Gensini score to analyse the relationship between IgM and CAD severity. Multivariable logistic regression analysis was used to evaluate the association between IgM and CAD severity. Results: Serum IgM levels were significantly lower in the CAD group (63.5 mg/dL) than in the non-coronary artery disease (NCAD) group (72.3 mg/dL) (P < 0.001). Serum IgM levels were significantly associated with sex. Serum IgM levels were positively correlated with traditional CAD risk factors such as TG, TC and LDL-C (P < 0.05), and negatively associated with the number of obstructed vessels, the number of affected areas, and Gensini scores. After adjusting for age, sex, smoking status, hypertension, dyslipidaemia, diabetes, stroke, and statin use history, a high IgM level was independently negatively associated with the severity of CAD expressed by the Gensini score. Conclusion: We determined that serum IgM was independently negatively associated with the severity of CAD diagnosed by angiography in Chinese adults. [ABSTRACT FROM AUTHOR]

Forests are one of the most important sources of negative oxygen ions (NAIs). NAIs have been recognized as beneficial for both physical and mental well–being, and higher concentrations of NAIs have been associated with improved health. However, the environmental factors that predominantly influence NAI concentration and their relationship with NAIs remain uncertain. This study aims to investigate the dominant factors and their impact on NAI concentration by observing NAIs and various environmental factors in two different environments (natural forest and urban forest) in the Beijing region over a one–year period. Through our investigation, we aimed to identify the key factor as well as other influential variables affecting NAI concentration. Our analysis encompassed the examination of dynamic concentration changes over multiple time scales, revealing uniform trends in both forest types. Notably, natural forests consistently demonstrated higher NAI concentration across these time scales, attributable to greater vegetation density and the stability of the forest microenvironment. By utilizing regression, correlation analysis, and structural equation analysis, we determined that relative humidity (RH) has the most significant effect on NAI concentration. Notably, both NAI concentration and RH displayed similar patterns across multiple time scales. When considering hourly average daily variation, the lowest values for both NAI concentration and RH were observed at noon, followed by an increase that persisted throughout the night. Seasonal average variation showed that both NAI concentration and RH peaked in the summer, followed by autumn. In terms of daily average annual variation, summer exhibited more days with high NAI concentration and high RH, which can be attributed to the increased rainfall during that season. Rainy weather was found to contribute to higher NAI concentration and RH levels. Furthermore, our findings revealed that on a daily scale, high RH and high NAI concentration occurred more frequently under conditions of high air temperature and low wind speed. However, the air quality index demonstrated only a minor effect in urban forest, while net radiation exhibited no significant influence on NAI concentration and RH. The fitted equations and trends of the aforementioned environmental factors with NAI concentration and RH were found to be comparable. The path analysis further corroborates these conclusions. The findings of this study indicate that RH is the primary factor driving the fluctuations in NAI concentration across various time scales, including hourly, daily, and seasonal variations. The study revealed that wind speed indirectly impacts NAI concentration by modulating RH. In contrast, air temperature influences NAI concentration both indirectly through RH and directly. The environmental factors affecting NAI concentration in the two types of forests are similar, but the degrees vary; in urban forests, wind speed, air quality index, and RH are slightly higher, while in natural forests, air temperature is slightly higher. This discovery further enhances our understanding of the underlying mechanisms and dynamic changes in NAI concentration within urban forests and natural forests. Moreover, it confirms the reliability and effectiveness of using RH as an indicator to monitor changes in NAI concentration over time. [ABSTRACT FROM AUTHOR]

Background: Dysphagia can lead to serious complications such as aspiration and aspiration pneumonia, timely and effective rehabilitation training can improve the swallowing function of patients. However, the conventional rehabilitation training methods used in clinical settings have shortcomings such as poor adherence of patients. We present the study design of a randomized controlled trial that evaluated whether video-game based swallowing rehabilitation training can effectively improve swallowing in patients with dysphagia and whether it has additional benefits compared with conventional training methods to improve swallowing function and training compliance among patients with dysphagia. Methods: A randomized controlled trial with 4 weeks of intervention and 4 weeks of follow-up will be conducted in a rehabilitation center in Beijing, China. We will enroll 78 patients aged 18–80 years with dysphagia. Participants will be randomly assigned to the experimental group (video-game based swallowing function training) and the control group (conventional swallowing function training). All participants will receive 30 min of training per day, 5 times per week, for a total of 4 weeks. The primary outcome is swallowing function. Secondary outcomes include patients' quality of life, training compliance, and training satisfaction. Outcomes are assessed at baseline (pre-treatment), 4 weeks of treatment (post-treatment), and 8 weeks (follow-up), and the assessor is not aware of the participants' grouping. Discussion: The protocol describes a new rehabilitation training method for dysphagia, which involves participant eligibility recruitment, recruitment strategies, and data analysis plan. The results of the study will inform the rehabilitation training and clinical care management of swallowing function in patients with dysphagia. Trial registration: ClinicalTrials.gov, NCT05978700. Registered on 28 July 2023. [ABSTRACT FROM AUTHOR]

Exploring the dynamics of an urban landscape pattern is significant for urban ecological environment evaluation. Previous studies on urban landscape monitoring are relatively few, making it difficult to comprehensively reflect the characteristics of urban landscape patterns. Here, we proposed a methodological framework to monitor the dynamics of the landscape pattern, vegetation coverage, and the habitat quality using the Landsat imagery obtained from 1999 to 2021 in Beijing, China. First, changes in the landscape characteristics associated with land use were explored by the transfer matrix and landscape metric analysis methods. Subsequently, the dimidiate pixel model was employed to analyze changes in regional vegetation coverage on a landscape perspective. Finally, the habitat quality was evaluated on the basis of remote sensing ecological index (RSEI) model, and the correlation between the habitat quality and the landscape index was retrieved using the gray correlation degree model. The results showed that the landscape pattern underwent fragmentation, and the edge effect was strong. A high vegetation coverage was dominant throughout the landscape, and a medium vegetation coverage was relatively scattered, especially in built-up areas. The landscape was highly fragmented in areas with a low vegetation coverage. There were significant regional differences in habitat quality, and the quality was higher in the northwest and western mountainous areas. Furthermore, there was a strong correlation between the habitat quality and the index-based landscape pattern, which demonstrated the distribution pattern of landscape types significantly impacts habits quality. Overall, these findings are significant for future urban planning and construction. [ABSTRACT FROM AUTHOR]

The observation facts of trend and variability are estimated for a century‐long timescale, as well as some possible attributions affecting temperature extremes over Beijing‐Tianjin‐Hebei region. In this paper, the new constructed daily maximum and minimum temperature series during the last 100 years in situ stations of Beijing, Tianjin and Baoding city are used, and two 30‐year baseline climatology of 1961–1990 and 1980–2010 are both used in calculating extreme temperature events. The results indicate that there are long‐lasting, frequent and serious extreme warming over Beijing‐Tianjin‐Hebei region, especially for extreme low temperature, with larger declining trends (at 5% significance) from 1981 to 2010 baseline than those from 1961 to 1990 baseline. And from a statistical perspective, El Niño decay years and surface sea temperature (SST) anomalies at some typical ocean regions of the Arabian Sea and the Bengal Bay on the northern Indian Ocean, the Western Pacific and the Mid Atlantic, Southern Indian Ocean and around 45°–85°E, 68°–82°N on the southwest Arctic Ocean can be used as the warning signals denoting extreme warming over Beijing‐Tianjin‐Hebei region. Additionally, urbanization has a significant (at 5% significance) effect on extreme warming over Beijing‐Tianjin‐Hebei region since 1979, with 24.3% warming contribution for annual minimum temperature. [ABSTRACT FROM AUTHOR]

Extreme heat events are frequent in the Beijing–Tianjin–Hebei (BTH) region due to global warming and accelerated urbanization. While previous studies have analyzed the trend of extreme heat events in the Beijing–Tianjin–Hebei (BTH) region, the interdecadal changes of these events remain unclear. Therefore, this study aims to analyze the interdecadal temporal and spatial characteristics of summer extreme heat events in the BTH region using daily mean and maximum temperature datasets from 174 stations over the period 1979–2020. The results are shown as follows: (1) From 1979 to 2020, extreme heat events showed an overall upward trend in the BTH region. There were similarities in the changes in the extreme maximum temperature (TXx) and the number of high-temperature days (Htd) between different generations, and both were low until the mid-1990s. (2) In terms of the spatial pattern, TXx and Htd both showed the spatial distribution characteristics of being high in the south and low in the north. Extreme heat events in the BTH region were mainly concentrated in Beijing City, Tianjin City, and the eastern region of Hebei, and the TXx increase in most areas reached 1.5–2.0 °C. (3) The number of high-temperature days (Htd) increased significantly in the background of global warming, especially in Beijing, Tianjin, and Shijiazhuang Cities. (4) Extreme heat events in the BTH region mainly occurred in June and July, and the interdecadal changes showed a decreasing trend in June and an increasing trend in July. A high proportion of Htd was concentrated in Northern Hebei Province in July. [ABSTRACT FROM AUTHOR]

Understanding the temporal and spatial dynamics and determinants of public transport ridership play an important role in urban planning. Previous studies have focused on exploring the determinants at the station level using global models, or a local model, geographically weighted regression (GWR), which cannot reveal spatial autocorrelation at the global level. This study explores the factors affecting bus ridership considering spatial autocorrelation using the spatial Durbin model (SDM). Taking the community in Beijing as the basic study unit, this study aims to explore the temporal and spatial dynamics of bus ridership and identify its key determinants considering neighboring effects. The results show the following: (1) The temporal dynamics are quite distinct on weekdays and weekends as well as at different time slots of the day. (2) The spatial patterns of bus ridership varied across different time slots, and the hot areas are mainly located near the central business district (CBD), transport hubs, and residential areas. (3) Key determinants of bus ridership varied across weekends and weekdays and varied at different time slots per day. (4) The spatial neighboring effects had been verified. This study provides a common analytical framework for analyzing the spatiotemporal dynamics and determinants of bus ridership at the community level. [ABSTRACT FROM AUTHOR]

With the great economic benefits that metallurgy can bring to us, serious environmental pollution can occur if metallurgical sewages and tailings are not properly disposed. This study aimed to report a real environmental pollution case that happened in Miyun, Beijing. The suspect components left after mining and the toxicity of the sewage samples were analyzed using a comprehensive forensic approach. Five sewage samples and nine soil samples were collected from the crime scene. The heavy metal and total cyanide contents in these samples were tested using inductively coupled plasma atomic emission spectrometry and ultraviolet–visible spectroscopy, respectively. The soil samples were analyzed by x-ray diffraction. Moreover, the effects of metallurgical sewage on the morphological behavior and activity inhibition rate of Daphnia magna were investigated. The results showed that the sewage samples contained small amounts of Au, large amounts of Cu, and total cyanide. The soil samples contained Mg, Fe, and many other metal elements. The biotoxicity results indicated that all of the five sewage samples caused serious deformation or other problems of D. magna. Furthermore, the study reconstructed the metallurgical process of the case according to the experimental results. In conclusion, the sewage samples contained hazardous waste, and the heavy metal content exceeded the safety standard of China. [ABSTRACT FROM AUTHOR]

Background: This study took Beijing as an example to estimate the incidence and regional inequalities of catastrophic health expenditures (CHEs) in a megacity of China. Methods: This study used data from the Health Services Survey Beijing (HSSB) 2018. Logistic regressions were used to investigate the risk factors for experiencing CHE, and concentration curves, the concentration index and its decomposition method based on probit models were used to estimate the inequalities in CHE. Results: CHE occurred in 25.51% of the households of the outer suburb villages, 6.78% of the households of the innercity area communities, 17.10% of the households of the villages of the inner-city areas, and 11.91% of the households of the communities of the outer suburbs. In areas in the outer suburbs, households with private insurance coverage were associated with a lowered risk of CHE, and lower educational attainment and lower occupational class were related to an increasing risk of CHE. This study also discovered pro-rich financing disparities in CHE in Beijing, with the outer suburbs having the highest levels of CHE disparity. When it comes to the observed contributions of disparities in CHE, a significant portion of them is connected to the sorts of occupations, educational levels, and residential status. Conclusion: The impoverishment brought on by medical expenses and CHE must still be taken into account in the postpoverty elimination era. The megacity of China was discovered to have significant regional differences in the incidence of pro-rich financing inequity in CHE. Disparities in socioeconomic status (SES), one of the controllable variables, may be a key area to address to lower the risk and minimize CHE inequality in megacities towards the path to universal health coverage (UHC). Additionally, it is important to consider the financial protection impact of inclusive supplementary medical insurance on lowering the likelihood of CHE in the periphery areas. [ABSTRACT FROM AUTHOR]

Heavy precipitation and associated flood hazards can cause enormous socioeconomic losses. The advances in atmospheric modeling enable great promise in accurately predicting precipitation. However, the representation of land‐atmosphere exchange processes in atmospheric models and its impacts on precipitation evolution remain high uncertainties. This study investigated the sensitivity of convective precipitation to land‐atmosphere exchanges and examined the improvements in precipitation simulations by a dynamic vegetation‐type‐dependent exchange scheme. We conducted 3‐km‐resolution convection‐permitting modeling for three heavy precipitation events that occurred over areas with different dominant land‐cover types. The results showed that land‐atmosphere exchange efficiency significantly altered the precipitation intensity as well as the onset and peak time of precipitation but hardly affected the precipitation pattern. Strong exchange simulations could agree better with the observed precipitation in the 21 July 2012 Beijing and the 19 June 2010 Jiangxi heavy precipitation events occurring over humid and semihumid zones, while weak exchange simulations could attain higher consistencies with the observations in the 30 July 2012 Ningxia heavy precipitation event occurring over arid and semiarid zones. As a more physical alternative, the dynamic exchange simulations could achieve the closest agreement with the field observations, especially the intensity and location of the heaviest rainfall. The dynamic scheme modifies land‐atmosphere exchange efficiency to match local land cover conditions and could provide promising applications in heavy precipitation modeling studies. Plain Language Summary: Over recent decades, the frequent occurrence of heavy precipitation events has caused devastating ecological and socioeconomic impacts, such as agriculture losses, infrastructure damage, and casualties. High‐resolution atmospheric modeling at a convection‐permitting grid spacing (≤4 km) provides valuable applications for predicting heavy precipitation. Precipitation can be strongly affected by the energy and moisture exchanges between land surface and atmosphere. However, the representation of land‐atmosphere interactions in atmospheric models and the responses of precipitation to land‐atmosphere exchange efficiency remain great uncertainties. This study performed 3‐km high‐resolution atmospheric modeling with a dynamic vegetation‐type‐dependent land‐atmosphere exchange scheme for three typical heavy precipitation events that occurred over areas with different dominant land‐cover types. The results showed that land‐atmosphere exchange efficiency mainly affected the precipitation intensity as well as the onset and peak time of precipitation. The dynamic exchange scheme modifies the efficiency of land‐atmosphere exchanges to match local land cover conditions and could reproduce well the field observations, especially the intensity and location of the heaviest rainfall which usually serve as the most concerned variable in a major rainstorm event. Our findings show that the dynamical scheme could help achieve more accurate precipitation simulations. Key Points: A dynamic vegetation‐type‐dependent land‐atmosphere exchange scheme was applied into convection‐permitting atmospheric modelsLand‐atmosphere exchange efficiency mainly affected the precipitation intensity as well as the onset and peak time of precipitationThe dynamic exchange simulations agreed well with the field observations, especially the intensity and location of the heaviest rainfall [ABSTRACT FROM AUTHOR]

The immuno-inflammatory response is a crucial early step in the development of acute coronary syndrome (ACS). In this study, we investigated whether immunoglobulin M (IgM) in the body's initial immune response can predict the prognosis of patients with ACS. This prospective cohort study enrolled 1556 ACS patients at Beijing Hospital between March 2017 and October 2020. All patients underwent coronary angiography (CAG). The serum IgM concentration and biochemical indicators were evaluated prior to CAG. The primary endpoint was the composite endpoint of major adverse cardiovascular and cerebrovascular events (MACCEs). Multivariate Cox proportional hazards models was used to explore the association between IgM levels and the endpoint. The average serum IgM levels of the population was 61.3 (42.6–88.4) mg/dL. During the median follow-up period of 55 months, 150 MACCEs occurred. Kaplan-Meier analysis showed that low serum IgM levels were associated with occurrence of MACCEs (log-rank p = 0.009). Univariate Cox proportional hazards models showed that low serum IgM (≤78.05 mg/dL) was associated with MACCEs (hazard ratio (HR) 1.648, 95 % confidence interval (CI): 1.129–2.406, p = 0.010). In patients with IgM ≤78.05 mg/dL, the HR for partially adjusted MACCEs events was 1.576 (95 % CI: 1.075–2.310) and 1.930 (95 % CI: 1.080–3.449) after adjusting for multiple covariates. The subgroup analysis showed that for patients in ≤24 BMI, never smoking and non-dyslipidemia subgroup, the lower serum IgM levels was significantly associated with the risk of MACCEs (p interaction < 0.001, p interaction = 0.037, p interaction = 0.024, respectively). Low serum IgM levels was independently associated with MACCEs in ACS patients, especially for patients without obesity, smoking and dyslipidemia. [Display omitted] • Serum IgM levels were associated with MACCEs in ACS patients. • Low serum IgM levels predicted MACCEs in ACS patients, especially for patients without obesity, smoking and dyslipidemia. • Measuring total serum IgM levels may help identify patients with ACS at an increased risk for MACCEs. [ABSTRACT FROM AUTHOR]

Mitophagy is suggested to be involved in tumor initiation and development; however, mitophagy heterogeneity in hepatocellular carcinoma (HCC) and its association with immune status and prognosis remain unclear. Differentially expressed genes (DEGs) were identified using expression profiles acquired from The Cancer Genome Atlas (TCGA). Mitophagy-related subtypes were identified using the ConsensusClusterPlus software. The differences in prognosis, clinical characteristics, and immune status, including immune cell infiltration, immune function, immune-checkpoint gene expression, and response to immunotherapy, were compared between subtypes. A mitophagy-related gene signature was constructed by applying least absolute shrinkage and selection operator regression to the TCGA cohort. The International Cancer Genome Consortium cohort and the cohort from Peking Union Medical College Hospital were utilized for validation. Carbonyl cyanide m-chlorophenylhydrazone was used to induce mitophagy in HCC cell lines to obtain our own mitophagy signature. Real-time polymerase chain reaction was used for the experimental validation of the expression of model genes. Two mitophagy-related subtypes with distinct prognoses, clinical characteristics, immune states, and biological function patterns were identified based on the mitophagy-related DEGs. The subtype that showed higher mitophagy-related DEG expression had worse survival outcomes, suppressed immune function, higher immune-checkpoint gene expression, and a better response to immunotherapy, indicating that this subpopulation in HCC may benefit from immune-checkpoint blockade therapy and other immunotherapies. A risk model consisting of nine mitophagy-related genes was constructed and its performance was confirmed in two validation cohorts. The risk score was an independent risk factor even when age, sex, and tumor stage were considered. Our study identified two distinct mitophagy subtypes and built a mitophagy signature, uncovering mitophagy heterogeneity in HCC and its association with immune status and prognosis. These findings shed light on the treatment of HCC, especially with immunotherapy. [ABSTRACT FROM AUTHOR]

In recent years, there are many reasons for the frequent safety accidents in the construction field. The most controversial and typical one that firmly correlated with China's national condition is the low-price bid winning and the general subcontracting management, which probably have a great impact on the unsafe behavior intention of workers on the construction site. In order to figure out their internal relation, a quantitative statistical analysis of the unsafe behavior intentions of construction workers in the Beijing area was conducted through the on-site questionnaire considering three main variables, namely, general subcontract management, reasonable low-cost bid winning, and construction experiences. Meanwhile, the correlation, regression, and mediating effects of different influencing factors were analyzed through a regressive model to quantify the impact of each variable on the unsafe behavior intention of construction workers. The results showed that the influence of low-price bid winning on the unsafe behavior intention of on-site workers is faint. This is mainly because, in the case of labor buyer's market, the actual salary of workers is not relevant to whether the project is awarded at a low price. However, the general subcontracting management has a great impact on the unsafe behavior intention of on-site workers. At the same time, low-price bid winning also indirectly affects the strength of general subcontracting safety management, which has an indirect impact on the unsafe behavior intention of on-site workers. Generally, it is of greater significance to enhance the strength of the general subcontracting management and to formulate relevant regulations to guarantee the safety of construction workers. [ABSTRACT FROM AUTHOR]

Protecting soil from Pb contamination has been a programme for a long time in China. However, research on lead pollution in wetlands remains rare. To understand the characteristics of Pb pollution in Beijing and the sources of contamination of different soil samples in wetlands, we collected samples during all four seasons from two soil horizons and analyzed their Pb concentrations and Pb isotope ratios. The average concentrations of Pb varied from 65.44 mg/kg in spring to 106.11 mg/kg in winter. Concentrations in autumn were significantly lower than those in spring and summer and were notably different between A and B Horizons (59.42 and 71.47 mg/kg, respectively). The Pb isotopic compositions show that Pb pollution results from a mixing of geogenic and anthropogenic materials. The ratios of 206Pb/207Pb and 206Pb/208Pb evidenced that coal combustion and vehicle exhaust are the main sources of lead contamination in the two horizons. These results will help in reducing lead contamination in soil by knowing the temporal and spatial variations and sources of lead in Beijing. [ABSTRACT FROM AUTHOR]

Purpose: The global coronavirus disease 2019 (COVID-19) epidemic has significantly impacted people's lives. This study aimed to examine the influence of the unexpected second wave of COVID-19 on sleep quality and anxiety of Chinese residents in Beijing in June 2020, compared with the initial outbreak at the beginning of 2020, and to investigate the associated factors.Methods: Using a web-based cross-sectional survey, we collected data from 1,511 participants. assessed with demographic information, sleep quality and anxiety symptoms. The participants were asked to compare their recent sleep and sleep during the first outbreak. The Zung's Self-rating Anxiety Scale (SAS) was used to assess their current insomnia severity. Multivariable logistic regression models were used to analyze the association between COVID-19 epidemic and risk of sleep disturbance and anxiety symptom.Results: The overall prevalence of sleep disturbance and anxiety symptoms were 50.8% and 15.3% respectively. People had significantly shorter sleep duration during the second wave of COVID-19(7.3 ± 1.3) h than the first outbreak (7.5 ± 1.4)h (p < 0.001). During the second outbreak, people were less concerned about infection and more concerned about financial stress and occupational inferference. Beijing residents did not have significant differences in sleep disturbance and anxiety compared with other regions, nor were occupations and nucleic acid testing associated risk factors. Home quarantine, health administrators, history of insomnia and anxiety-depression were significantly associated with sleep disturbance. Female gender, home quarantine, history of insomnia and anxiety-depression were significantly associated with anxiety.Conclusion: High prevalence of sleep disturbance and depression symptom was common during the second wave of COVID-19 crisis in Beijing. Home quarantine and previous history of insomnia and anxiety-depressive risk factors were associated with sleep disturbance and anxiety. Female gender was impacting predictor of anxiety. We need continuous assessment of the sleep quality and anxiety symptoms of this epidemic. [ABSTRACT FROM AUTHOR]

Background: To analyze the possible causes, treatment and outcomes of postoperative pneumothorax in patients with Gross type C esophageal atresia/tracheoesophageal fistula (EA/TEF).Methods: Medical records of patients with Gross type C EA/TEF who were diagnosed and treated in Beijing Children's Hospital from January 2007 to January 2020 were retrospectively collected. They were divided into 2 groups according to whether postoperative pneumothorax occurred. Univariate and multivariate logistic regression analysis were performed to identify risk factors for pneumothorax.Results: A total of 188 patients were included, including 85 (45 %) in the pneumothorax group and 103 (55 %) in the non-pneumothorax group. Multivariate logistic regression analysis showed that postoperative anastomotic leakage [P < 0.001, OR 3.516 (1.859, 6.648)] and mechanical ventilation [P = 0.012, OR 2.399 (1.210, 4.758)] were independent risk factors for pneumothorax after EA/TEF repair. Further analysis of main parameters of mechanical ventilation after surgery showed that none of them were clearly related to the occurrence of pneumothorax. Among the 85 patients with pneumothorax, 33 gave up after surgery and 52 received further treatment [conservative observation (n = 20), pleural puncture (n = 11), pleural closed drainage (n = 9), both pleural puncture and closed drainage (n = 12)]. All of the 52 patients were cured of pneumothorax at discharge.Conclusions: Anastomotic leakage and postoperative mechanical ventilation were risk factors for pneumothorax after repair of Gross type C EA/TEF, but the main parameters of mechanical ventilation had no clear correlation with pneumothorax. After symptomatic treatment, the prognosis of pneumothorax was good. [ABSTRACT FROM AUTHOR]

Background: To compare the clinical outcomes between thoracoscopic approach and thoracotomy surgery in patients with Gross type C Esophageal atresia (EA) and tracheoesophageal fistula (TEF).Methods: Patients with Gross type C EA/TEF who underwent surgery from January 2007 to January 2020 at Beijing Children's Hospital were retrospectively analyzed. The patients were divided into two groups according to surgical approaches. The perioperative factors and postoperative complications were compared among the two groups.Results: One hundred and ninety patients (132 boys and 58 girls) with a median birth weight of 2975 (2600, 3200) g were included. The primary operations were performed via thoracoscopic (n = 62) and thoracotomy (n = 128) approach. After comparison of clinical characteristics between the two groups, we found that there were statistically significant differences in associated anomalies, method of fistula closure, duration of mechanical ventilation after surgery, feeding option before discharge, management of pneumothorax, and prognosis (all P < 0.05). To a certain extent, thoracoscopic surgery reduced the incidence of anastomotic leakage and increased the incidence of anastomotic stricture in this study. However, there were no statistically significant differences between the two groups in terms of operative time, postoperative pneumothorax, anastomotic leakage, anastomotic stricture, and recurrent tracheoesophageal fistula (all P > 0.05).Conclusions: Thoracoscopy surgery for Gross type C EA/TEF is a safe and effective, minimally invasive technique with comparable operative time and incidence of postoperative complications. [ABSTRACT FROM AUTHOR]

Context: Green infrastructure (GI) has become an integral part of the process leading toward urban sustainability because it provides multiple ecosystem services that contribute to urban ecosystems and human health. Planners and managers have therefore attempted to understand and improve GI multifunctionality. Objectives: This study has characterized and mapped GI multifunctionality in the Fengtai District of Beijing based on the ecosystem services (ES) perspective and has developed an adaptive model to improve its multifunctionality. The study has aimed to: (1) assess and map GI multifunctional degree, (2) characterize GI multifunctional types, and (3) propose adaptive solutions based on characterization of GI multifunctional types. Methods: Biophysical models and social questionnaires were used to quantify and map ES, ES hotspots, and ES bundles to identify the degree of multifunctionality and characterize GI multifunctional types. An adaptive model was designed to improve GI multifunctionality for local planning and design practice. Results: Three GI multifunctional degrees were mapped, and areas with high multifunctional degree were found to account for only 5.55% of the study area. Seven GI multifunctional types were identified by the distinct heterogeneity of their compositions and function sets. These types of GI also implied different improvement strategies for GI planning and design practice. The adaptive model offers integrated solutions for preserving, restoring, and embedding levels that correspond to the characterization of GI multifunctional types. Conclusions: The ES-based framework proposed in this paper integrates multifunctionality analyses and can be helpful to urban planners and designers in adaptive GI planning. [ABSTRACT FROM AUTHOR]

Liquid water in aerosol particles has a significant effect on their optical properties, especially on light scattering, whose dependence on chemical composition is investigated here using measurements made in southern Beijing in 2019. The effect is measured by the particle light scattering enhancement f (RH), where RH denotes the relative humidity, which is found to be positively and negatively impacted by the proportions of inorganic and organic matter, respectively. Black carbon is also negatively correlated. The positive impact is more robust when the inorganic matter mass fraction was smaller than 40 % (R=0.93 , R : the Pearson's correlation coefficient), becoming weaker as the inorganic matter mass fraction gets larger (R=0.48). A similar pattern was also found for the negative impact of the organic matter mass fraction. Nitrate played a more significant role in aerosol hygroscopicity than sulfate in Beijing. However, the deliquescence point of ambient aerosols was at about RH = 80 % when the ratio of the sulfate mass concentration to the nitrate mass concentration of the aerosol was high (mostly higher than ∼ 4). Two schemes to parameterize f (RH) were developed to account for the deliquescent and non-deliquescent effects. Using only one f (RH) parameterization scheme to fit all f (RH) processes incurs large errors. A piecewise parameterization scheme is proposed, which can better describe deliquescence and reduces uncertainties in simulating aerosol hygroscopicity. [ABSTRACT FROM AUTHOR]

A comprehensive field experiment measuring aerosol chemical and physical properties at a suburban site in Beijing around the 2019 Spring Festival was carried out to investigate the impact of reduced anthropogenic emissions on aerosol formation. Sharply reduced sulfur dioxide (SO2) and nitrogen dioxide (NO2) concentrations during the festival holiday resulted in an unexpected increase in the surface ozone (O3) concentration caused by the strong O3 -titration phenomenon. Simultaneously, the reduced anthropogenic emissions resulted in massive decreases in particle number concentration at all sizes and the mass concentrations of organics and black carbon. However, the mass concentrations of inorganics (especially sulfate) decreased weakly. Detailed analyses of the sulfur oxidation ratio and the nitrogen oxidation ratio suggest that sulfate formation during the holiday could be promoted by enhanced nocturnal aqueous-phase chemical reactions between SO2 and O3 under moderate relative humidity (RH) conditions (40 % < RH < 80 %). Daytime photochemical reactions in winter in Beijing mainly controlled nitrate formation, which was enhanced a little during the holiday. A regional analysis of air pollution patterns shows that the enhanced formation of secondary aerosols occurred throughout the entire Beijing–Tianjin–Hebei (BTH) region during the holiday, partly offsetting the decrease in particle matter with an aerodynamic diameter less than 2.5 µ m. Our results highlight the necessary control of O3 formation to reduce secondary pollution in winter under current emission conditions. [ABSTRACT FROM AUTHOR]

Objective: Schizophrenia is a public concern in metropolises. Increases in city size may strengthen the correlation between prevalence of schizophrenia and indices of socioeconomic status, such as education. This study used population-based data of adults to investigate the association between education and schizophrenia in Chinese metropolises and its differences between inner city areas and outer suburbs. Methods: Data was obtained from the Second China National Sample Survey on Disability in 2006, and analysis was restricted to 189,143 participants aged 18 years or older in all counties (districts) of Beijing, Shanghai, and Tianjin. Schizophrenia diagnoses were ascertained according to the International Statistical Classification of Diseases, 10th Revision. Logistic regression models were fitted to examine the association between education and schizophrenia. Results: An inverse U-shaped pattern between education and schizophrenia was found in inner city areas of Chinese metropolises. Compared with the primary school or below group, the odds ratios of junior high school group and senior high school or above group was 2.79 (95% CI 1.96, 3.96) and 1.45(95% CI 0.99, 2.13), respectively. In outer suburbs, junior high school (OR = 0.87, 95% CI 0.63, 1.19) and senior high school or above groups (0.58, 95% CI 0.38, 0.87) were less likely to develop schizophrenia than the primary school or below group. Conclusions: This study showed an association between education and schizophrenia in Chinese metropolises. In inner city areas, the association was an inverse U-shaped pattern between education and schizophrenia, whereas in suburban areas, the association was a negative linear pattern. Our findings can help identify high-risk populations of schizophrenia in Chinese metropolises. Programs for prevention and early intervention of schizophrenia will need to consider the socioeconomic disparities between inner city and outer suburban areas. Public policies can help improve mental health by developing social security for migrants in inner city areas and promoting regional equality. [ABSTRACT FROM AUTHOR]

To understand the effect of forests and wetlands on air quality, the PM10 and PM2.5 concentration and meteorological data were collected in the forest and wetland in the Beijing Olympic Forest Park in China from May 2106 to May 2017. The blocking rates of forest and wetland to PMs were calculated under different air quality grades which were divided into six levels base on a technical regulation. And we have got three main conclusions. (1) The diurnal variations of PMs were different in the forest and wetland. It showed a first decrease and then an increase in the forest; the lowest value (PM10 = 40.00 µg/m3, PM2.5 = 5.37 µg/m3) was at approximately 12:00. In the wetlands, the lowest values were recorded at 16:00 (PM10 = 39.63 µg/m3 and PM2.5 = 15.89 µg/m3). (2) Another result showed that the blocking in the forest were significantly higher than that at the wetlands (P <.05), and the blocking effects were much better under lower air quality grades. The blocking rate of PM10 and PM2.5 was the highest when the air quality is excellent in the forest. When it comes to wetland, the highest blocking rate of PM10 appears at good air quality, and the highest of PM2.5 was at serious polluted. (3) In addition, there was negative correlation between PM concentrations and temperature, whereas the correlation between PM concentrations and relative humidity is positive. However, the correlation between blocking and meteorological parameters is weak. [ABSTRACT FROM AUTHOR]

Forests and wetlands, as two important ecosystems, play a crucial role in reducing the concentration of particulate matters. The main purpose of this study is to reveal the contribution of forest and wetland ecosystems to the reduction of particulate matter. We collected the concentration and meteorological data during the daytime in a forest and a wetland in the Olympic Park in Beijing. The main results are as follows: daily variation in the PM10 and PM2.5 concentration had the similar trend with the lowest value at midday and relatively high values in the morning and at nightfall. In the forest ecosystem, the trend of PM10 concentration at three heights followed the order: 6 m > 10 m > 1.5 m, while that of the PM2.5 followed the order 1.5 m > 10 m > 6 m. In the wetland, PM10 and PM2.5 concentrations at the three heights exhibited the same trend: 10 m > 1.5 m > 6 m. It is a comprehensive impact on concentration which may include vegetation collection rate, meteorological conditions and some kind of human activities. The PM deposition velocity of wetland was higher than that of forest, and showed the highest values in winter both in PM2.5 and PM10. The PM deposition flux in wetland was lower than forest only in autumn, and the value of deposition flux was higher than forest in other seasons. PM concentrations was positively correlated with relative humidity but negatively correlated with temperature and wind velocity. [ABSTRACT FROM AUTHOR]

In Beijing, particulate matter (PM) in the atmosphere, especially PM2.5 and PM10, have attracted public attention because of its adverse effects. A series of studies have investigated the sources and spatial–temporal variation of PM. Wetland has been reported to own the capacity of resolving air problem. To examine the characteristics of the particulate matter in wetlands, the diurnal variation of PM2.5 and PM10 concentrations with respect to two heights (i.e. 1.5 and 10 m, respectively) and three meteorological factors (i.e. wind speed, temperature, and relative humidity, respectively) was monitored in the Cuihu National Wetland Park in Beijing, and the dry deposition velocity and flux were analysed using the above-mentioned data. Results indicated that (1) As for diurnal variation, the PM concentration constantly decreased at 07:00–16:00 and gradually increased at 16:00–18:00. The maximum instantaneous concentration was observed at 07:00–10:00, while the minimum instantaneous concentration was observed at 13:00–16:00. (2) The annual concentration variation of PM followed the order of dry period > wet period > normal period. (3) The particulate concentrations at 10 m were always greater than those at 1.5 m. (4) The PM concentration was positively correlated to the relative humidity and negatively correlated to the temperature. Wind speed exhibited a complex effect on PM concentration. (5) The regulation of dry deposition efficiency followed the order of spring > winter > summer. (6) Wind speed strongly and positively affected the dry deposition velocity of PM10. The effects of temperature and relative humidity on dry deposition were uncertain. [ABSTRACT FROM AUTHOR]

Black carbon (BC) is one of the most important climate pollutants due to its strong positive radiative forcing on the climate system. However, long-term observation of BC is inadequate, and its trend remains unknown at both regional and global scales. In this study, using quality-controlled ground-based black carbon observations at 34 stations, the climatology of BC mass concentration during 2006–2017 in China was evaluated for the first time. The national annual average BC concentration was 3534 ng/m3, and the concentration exhibited large spatial variation, from a minimum of 272 ng/m3 to a maximum of 10,228 ng/m3. Significant seasonal variations were also observed. The peak BC concentration (4763 ± 3380 ng/m3) occurred during winter, followed by autumn (3752 ± 2623 ng/m3) and spring (3022 ± 2121 ng/m3). The lowest BC concentration occurred in summer (2583 ± 1780 ng/m3) due to decreased emissions, wet removal by precipitation, and diffusion induced by strong turbulent mixing. Additionally, the diurnal variability at about 80% of the stations in China showed a bimodal pattern. Daily maximum BC concentration during 0000–0600, 0600–1200, 1200–1800, and 1800–2400 local solar time accounted for 0, 41, 12, and 47% of the total, respectively. In particular, the diurnal and monthly variations in BC were explicitly analyzed at seven baseline stations. Surface BC has exhibited a significant declining trend across China, which is partly corroborated by the increase in single scattering albedo during the same period in Beijing. Also, the BC radiative forcing at the top of the atmosphere has declined at the rate of − 0.9 ± 0.1 W/m2/10 years over China, which differs from with the trend in the simulation using the CMIP6 emission. The decreasing BC has led to a larger reduction rate in atmospheric heating (− 3.7 ± 0.4 W/m2/10 years), implying a less stable atmosphere that facilitates the dispersion of air pollutants. The declining BC burden implies for both the air quality in China and regional climate change. [ABSTRACT FROM AUTHOR]

Urban parks have become a priority intervention for urban sustainability, but evidence of conducting urban park planning for public health and environmental justice is far from understood. Based on a case study in the central city of Beijing, this study estimated the area proportion of various green space types and the distribution characteristics within subdistricts, and conducted a series of multiple regression models to examine the role of urban parks in affecting health outcomes and the differences between vulnerable groups. The results indicated that urban parks had more significant health impacts than other green space types in terms of quantity, and were particularly important for older and low-income groups. For urban park distribution characteristics, accessibility was more important than availability and attractiveness in affecting health outcomes, especially for the older group. Specifically, urban park density and distance to urban parks were important for the older group, while the vegetation quality of urban parks only affected the health outcomes of the low-income group. The findings of this study suggest that urban parks should be given priority in green space planning practices, and that more accessible and free urban parks should be provided for public health and environmental justice. • Exposure metrics of urban parks and other green space types were spatially estimated. • Urban park is more important than other green space types in affecting human health. • Accessibility is more important than availability and attractiveness of urban parks. • Urban park density and distance to urban parks are important for the older group. • Vegetation quality of urban parks only affects the low-income group's health status. [ABSTRACT FROM AUTHOR]

With the rapid development of industry, studies on lead pollution in total suspended particulate matter (TSP) have received extensive attention. This paper analyzed the concentration and pollution sources of lead in the Cuihu Wetland in Beijing during the period of 2016–2017. The results show that the lead contents in TSP in the Cuihu Wetland were approximately equal in summer and spring, greater in winter, and greatest in autumn. The corresponding lead concentrations were 0.052, 0.053, 0.101, and 0.115 ng/m³, respectively. We compared the 206Pb/207Pb data with other materials to further understand the potential sources of atmospheric lead. The mean values of 206Pb/207Pb from spring to winter were 1.082, 1.098, 1.092, and 1.078, respectively. We found that the lead sources may be associated with coal burning, brake and tire wear, and vehicle exhaust emissions. We also calculated the enrichment factor values for the four seasons, and the values were all much greater than 10, indicating that the lead pollution is closely related to human activities. [ABSTRACT FROM AUTHOR]

Nitrate is a very important aerosol component, thus elucidation of its characteristics and formation mechanisms is essential and important for effective reduction of aerosol pollution. In this work, highly time-resolved submicron aerosol (PM1) data measured by Aerodyne aerosol mass spectrometers (AMS) in Nanjing, Beijing and Lanzhou during both summer and winter were integrated to investigate the nitrate behaviors in urban China air. Results showed that nitrate occupied 1/8-1/4 of PM1 mass, typically higher than those observed in rural/remote regions. Relative mass fractions of nitrate also varied significantly at different pollution levels. Nitrate mass fractions generally increased with the increase of PM1 loadings during summer, while the contributions during winter increased first and then decreased with the increase of pollution levels. We further propose that there are at least three mechanisms that likely govern the urban nitrate behaviors: Type I--thermodynamics driven, Type II--photochemistry driven, and Type III--planetary boundary layer (PBL) dynamics driven. Analyses of the ammonium-sulfate-nitrate data revealed that ammonium nitrate was able to form before sulfuric acid was fully neutralized in some urban areas. Our findings provide useful insights into the characterization and reduction of fine particulate nitrate pollution. [ABSTRACT FROM AUTHOR]

Beijing faces a serious problem of carbon emissions and the economic sectors are the main source of carbon emissions. Previous literatures have extensively focused on estimating the impact of carbon emissions of individual sector. Little attention has been paid to the multisectoral carbon emissions. In this paper, a multisectoral decomposition analysis was reported to explore the carbon emissions in Beijing. The emissions are decomposed into energy structure, energy intensity, economic structure (in industry), economic output, and population scale effects by the method of logarithmic mean Divisia index. Agricultural, industrial, construction, transportation, commercial, and other sectors are taken into consideration. The results show that population scale effect is the main factor for increasing carbon emissions in all sectors. The energy efficiency improvements are primarily responsible for the decrease in emissions in the industrial sector, while it increases emissions in construction, transportation, and commercial sectors. The economic output in agricultural and other sectors exerts a positive effect on emissions. In contrast, the energy structure effect only makes a minor contribution to the emission decrease in industrial, construction, commercial, and other sectors. [ABSTRACT FROM AUTHOR]

Travel mode identification is an essential step in travel information detection with global positioning system (GPS) survey data. This paper presents a hybrid procedure for mode identification using large-scale GPS survey data collected in Beijing in 2010. In a first step, subway trips were detected by applying a GPS/geographic information system (GIS) algorithm and a multinomial logit model. A comparison of the identification results reveals that the GPS/GIS method provides higher accuracy. Then, the modes of walking, bicycle, car and bus were determined using a nested logit model. The combined success rate of the hybrid procedure was 86%. These findings can be used to identify travel modes based on GPS survey data, which will significantly improve the efficiency and accuracy of travel surveys and data analysis. By providing crucial travel information, the results also contribute to modeling and analyzing travel behaviors and are readily applicable to a wide range of transportation practices. [ABSTRACT FROM AUTHOR]

Carbon emissions related to population factors have aroused great attention around the world. A multitude of literature mainly focused on single demographic impacts on environmental issues at the national level, and comprehensive studies concerning population-related factors at a city level are rare. This paper employed STIRPAT (Stochastic Impacts by Regression on Population, Affluence and Technology) model incorporating PLS (Partial least squares) regression method to examine the influence of population-related factors on carbon emissions in Beijing from 1984 to 2012. Empirically results manifest that urbanization is the paramount driver. Changes in population age structure have significantly positive impacts on carbon emissions, and shrinking young population, continuous expansion of working age population and aging population will keep on increasing environmental pressures. Meanwhile, shrinking household size and expanding floating population boost the discharge of carbon emissions. Besides, per capita consumption is an important contributor of carbon emissions, while industry energy intensity is the main inhibitory factor. Based upon these findings and the specific circumstances of Beijing, policies such as promoting clean and renewable energy, improving population quality and advocating low carbon lifestyles should be enhanced to achieve targeted emissions reductions. [ABSTRACT FROM AUTHOR]

Urban greenspace can provide important health benefits for urban residents, but knowledge about the potential mechanisms remains unclear, and it is challenging in promoting health behaviors through design and management practices. This study proposed a hypothetical model that assumed ecosystem services as mediating factors between urban greenspace and health behaviors. An urban park in Beijing was selected as a case area to test the hypothesis and identify the ecosystem services-mediated pathways. Results based on spatial explicit mapping and multivariate statistical analysis confirmed the hypothesis and showed that urban greenspaces contribute to health behaviors in varying degrees through the delivery of health behaviors-related ecosystem services. The promotion effect was mainly mediated by cultural services, which is much more obvious than regulating services. We identified the importance of different properties of inner urban greenspace in promoting health behaviors through ecosystem services-mediated pathways. Green elements, especially tree canopy shaded ground, were found to contribute the most to health behaviors in the pathways, and slightly higher than facilities and grey elements. To promote health benefits, the design and arrangement of facilities and grey elements in urban greenspace is suggested to be cooperated with green elements for enhancing multiple ecosystem services. The findings will enhance the understanding of potential theoretical pathways from urban greenspace to health benefits, and support health promotion-oriented design and management practices. [Display omitted] • An ecosystem services-mediated health benefits model was proposed in this study. • Urban parks promote health behaviors through the delivery of multiple ecosystem services,especially cultural services. • Green elements are basis for the delivery of health-related ecosystem services. • Facilities and grey elements in urban greenspace should be designed to be cooperated with green elements. [ABSTRACT FROM AUTHOR]

Background The Helicobacter heilmannii sensu lato ( H. heilmannii s.l.) group consists of long, spiral-shaped bacteria naturally colonizing the stomach of animals. Moreover, bacteria belonging to this group have been observed in 0.2-6% of human gastric biopsy specimens, and associations have been made with the development of chronic gastritis, peptic ulceration, and gastric MALT lymphoma in humans. Materials and Methods To gain insight into the prevalence of H. heilmannii s.l. infections in patients suffering from gastric disease in China, H. heilmannii s.l. species-specific PCRs were performed on DNA extracts from rapid urease test ( RUT)-positive gastric biopsies from 1517 patients followed by nucleotide sequencing. At the same time, Helicobacter pylori cultivation and specific PCR was performed to assess H. pylori infection in these patients. Results In total, H. heilmannii s.l. infection was detected in 11.87% (178/1499) of H. pylori-positive patients. The prevalence of H. suis, H. felis, H. bizzozeronii, H. heilmannii sensu stricto (s.s.), and H. salomonis in the patients was 6.94%, 2.20%, 0.13%, 0.07%, and 2.54%, respectively. Results revealed that all patients with H. heilmannii s.l. infection were co-infected with H. pylori, and some patients were co-infected with more than two different Helicobacter species. Conclusions Helicobacter heilmannii s.l. infections are fairly common in Chinese patients. This should be kept in mind when diagnosing the cause of gastric pathologies in patients. Helicobacter suis was shown to be by far the most prevalent H. heilmannii s.l.species. [ABSTRACT FROM AUTHOR]

Apple chlorotic leaf spot virus ( ACLSV) is one of the most economically important latent viruses infecting apple in China. This is the first report of the almost complete nucleotide sequence and the characterization of the genome of a Chinese isolate ( ACLSV- MS, GenBank Accession Number ) from apple. Based on the genome nucleotide sequence, ACLSV- MS showed the highest identity (99.4%) to isolate ACLSV-B6 (GenBank Accession Number ) from apple in Japan and the least identity (69.5%) with isolate TaTao5 (GenBank Accession Number: ) from peach in the USA. The occurrence and distribution of ACLSV in China were also recorded. Three hundred and twenty-seven apple samples (40 different cultivars) collected from 56 sites in 13 provinces of China were tested by RT- PCR. The virus was detected in all regions surveyed (the provinces of Heilongjiang, Liaoning, Hebei, Beijing, Henan, Shanxi, Shaanxi, Shandong, Gansu, Ningxia, Xinjiang, Sichuan and Yunnan), with an average incidence of 69.7%. The positive samples in Heilongjiang province were highest with an incidence of 100% followed by Henan province with an incidence of 86.7%. The positive samples in Liaoning and Shanxi were the lowest with an incidence of 50%. The occurrence of virus in five common cultivars was determined. The percentage of ACLSV was highest in cv. Gala with an incidence of 33.3%, while lowest in cv. Starking with an incidence of 18.2%. It was also found in younger (≤20 years) apple orchards the occurrence of ACLSV decreased with the increase of tree age, but when trees were more than 20 years old, the occurrence of ACLSV increased. This is the first extensive survey in the last decade in China for monitoring ACLSV, which provides important information for ACLSV control in China. [ABSTRACT FROM AUTHOR]

Due to long-term over-exploitation of groundwater in Beijing Municipality, regional groundwater funnels have formed and land subsidence has been induced. By combining a groundwater monitoring network, GPS monitoring network data, radar satellite SAR data, GIS and other new technologies, a coupled process model based on the dynamic variation of groundwater and the deformation response of land subsidence has been established. The dynamic variation of groundwater funnels and the land subsidence response process were analyzed systematically in Beijing. Study results indicate that current groundwater funnel areas are distributed mainly in the southwest of Shunyi District, the northeast of Chaoyang District and the northwest of Tongzhou District, with an average decline rate of groundwater level of 2.66 m/yr and a maximum of 3.82 m/yr in the center of the funnels. Seasonal and interannual differences exist in the response model of land subsidence to groundwater funnels with uneven spatial and temporal distribution, where the maximum land subsidence rate was about −41.08 mm/yr and the area with a subsidence rate greater than 30 mm/yr was about 1637.29 km. Although a consistency was revealed to exist between a groundwater funnel and the spatial distribution characteristics of the corresponding land subsidence funnel, this consistency was not perfect. The results showed that the response model of land subsidence to the dynamic variation of groundwater was more revealing when combining conventional technologies with InSAR, GIS, GPS, providing a new strategy for environmental and hydrogeological research and a scientific basis for regional land subsidence control. [ABSTRACT FROM AUTHOR]

This study concerns the use of personal samplers to evaluate the exposure of traffic police to polycyclic aromatic hydrocarbons (PAHs) during the winter of 2005 in Beijing. We measured the samples collected for gas and particulate phases PAHs with the same technique used for an earlier study during the summer of 2004, and evaluated exposure risk based on the calculated benzo(a)pyrene equivalent concentrations (BaPeq) of both summer and winter. The mean exposure concentrations of gaseous and particulate phase PAHs in the winter are 4300±2900 ng/m3 and 750±1000 ng/m3, respectively, significantly higher than those measured simultaneously at control sites and also considerably higher than the values measured during the summer. The exposure PAH profiles for police and the control subjects are similar with predominant naphthalene in gaseous phase and dominant fluoranthene, pyrene, anthracene and naphthalene in particulate phase. Large daily variations occur both in summer and winter, because of the changes in the weather conditions especially wind speed and relative humidity which tend to disperse and scavenge PAHs in air. In the winter, the average BaPeq value for traffic police is 82.1 ng/m3, which is significantly higher than those for the control subjects and the national standard of 10 ng/m3 for ambient air. Particulate phase PAHs contribute more than 90% of the total exposure risk in the winter. Annually, weighted-average probabilities of exceeding the national standard (10 ng/m3) are 69.3% and 20.6% for the police and the controls, respectively. [Copyright &y& Elsevier]

Urban greenspace has been highlighted as a means of offsetting carbon dioxide (CO 2) emissions and mitigating climate change in cities. However, it is still challenging to design for sustainable carbon sequestration. This study developed a transdisciplinary framework to link carbon sequestration research with planting design practices. Taking 28 urban parks in Beijing as a case, we integrated field investigation and remote sensing images to analyze the relationship between planting design indicators and carbon sequestration efficiency, and the change of carbon sequestration efficiency with the growth of plant biomass. The results showed that carbon sequestration efficiency varied over the urban parks with a mean value of 8.72 gC m−2d-1, and varied with plant growth. The difference was associated with individual plant properties and biotope structure. Medium-sized plants and biotopes with partly open structure are proved cost-effective for sustainable carbon sequestration of urban greenspace. We summarized adaptive planting design strategies for different biotope types and emphasized the benefits of nurturing growing and partly open biotopes structured with different sizes of plants. The results will be possible to produce information for landscape architects for improving sustainable carbon sequestration not only in the study area but also in other cities with similar climatic characteristic. [ABSTRACT FROM AUTHOR]

In this study, the content of chromium (Cr), arsenic (As), cadmium (Cd) and lead (Pb) in domestic and imported infant formulas from Beijing, China were analyzed using inductively coupled plasma mass spectrometry. The content of Cr, As, Cd and Pb was 2.51–83.80, 0.89–7.87, 0.13–3.58 and 0.36–5.57 μg/kg, respectively. Even though there were no significant differences in toxic elements content between domestic and imported infant formulas, Cd content was slightly lower in domestic samples. The estimated daily intake (EDI), target hazard quotient (THQ) and hazard index (HI) were calculated for infants between 0.5 and 5 y of age. The EDIs were lower than the oral reference doses. THQ of As, Cr, Cd and Pb was 0.027–0.103, 0.024–0.093, 0.0025–0.0090 and 0.0015–0.0046, respectively. HI values were 0.055–0.192 for boys and 0.056–0.209 for girls and were inversely associated with age with a threshold < 1. The non-carcinogenic risk value were in the safe range, indicating that exposure of As, Pb, Cr and Cd from infant formulas do not represent a health risk in China. [ABSTRACT FROM AUTHOR]

The accurate derivation of the proportion and absorption enhancement of black carbon (BC)-containing aerosols in the atmosphere is critical to assess their effect on air quality and climate. Here, using the field measured size-resolved volatility shrink factor, BC bulk mass concentration and the BC mass fraction in BC-containing particles in winter Beijing, we retrieved and quantified both the number and mass concentration of (1) non-BC, (2) internally mixed BC and (3) externally mixed BC of ambient fine aerosol particles. The reliability of the retrieval method has been evaluated by comparing with the simultaneously measured data. The number fraction of BC-containing particles accounts for 60–78% of ambient fine particles, with internally (both BC core and coating materials) and externally mixed BC of 51–64% and 9–23%, respectively. Only for nucleated particles on clean days, when nucleation is a major source of aerosol particles, did the non-BC component dominate (54%). A large amount of aerosols are BC-containing particles, with mass fraction of 32–52%, suggesting the dominant role of BC in elevating mass concentration of particulate matter (PM) in a polluted urban area. We also show that the BC particles are thickly coated with coating thickness (characterized by D p /D c , ratio of the BC diameter before and after heating at 300 °C) of 1.6–2.2, implying efficient aging of BC particles in polluted urban area. Our results imply a large proportion of BC-containing particles in the atmosphere, which could help towards understanding the role of BC on regional haze formation and climate forcing. Image 1 • Mixing state of BC was retrieved using a new method. • BC-containing particles account for large proportions of ambient fine aerosols. • The BC-containing particles are thickly coated. Main findings of this work: 1. BC-containing particles account for large proportion. 2. The BC-containing particles are thickly coated. [ABSTRACT FROM AUTHOR]

Clouds are significant in the global radiation budget, atmospheric circulation, and hydrological cycle. However, knowledge regarding the observed climatology of the cloud vertical structure (CVS) over Beijing is still poor. Based on high-resolution radiosonde observations at Beijing Nanjiao Weather Observatory (BNWO) during the period 2010–2017, the method for identifying CVS depending on height-resolved relative humidity thresholds is improved, and CVS estimation by radiosonde is compared with observations by millimeter-wave cloud radar and ceilometer at the same site. Good consistency is shown between the three instruments. Then, the CVS climatology, including the frequency distribution and seasonal variation, is investigated. Overall, the occurrence frequency (OF) of cloudy cases in Beijing is slightly higher than that of clear-sky cases, and the cloud OF is highest in summer and lowest in winter. Single-layer clouds and middle-level clouds are dominant in Beijing. In addition, the average cloud top height (CTH), cloud base height (CBH), and cloud thickness in Beijing are 6.2 km, 4.0 km, and 2.2 km, respectively, and show the trend of reaching peaks in spring and minimums in winter. In terms of frequency distribution, the CTH basically resides below an altitude of 16 km, and approximately 43% of the CBHs are located at altitudes of 0.5–1.5 km. The cloud OF has only one peak located at altitudes of 4–8 km in spring, whereas it shows a trimodal distribution in other seasons. The height at which the cloud OF reaches its peak is highest in summer and lowest in winter. To the best of our knowledge, the cloud properties analyzed here are the first to elucidate the distribution and temporal variation of the CVS in Beijing from a long-term sounding perspective, and these results will provide a scientific observation basis for improving the atmospheric circulation model, as well as comparisons and verifications for measurements by ground-based remote sensing equipment. [ABSTRACT FROM AUTHOR]

Particulate matter (PM) pollution in Beijing is becoming an increasingly serious problem and is thus attracting considerable scientific attention. In order to reveal the characteristics and source of PM2.5 and its components, observations of PM2.5, water-soluble ions, elemental carbon (EC), and organic carbon (OC) were conducted in the urban green belt of Beijing from April 2016 to April 2017. The annual average concentrations of PM2.5, EC, OC, SO42-, NO3-, and NH4 +were found to be 124.02, 10.21, 30.73, 36.84, 27.63, and 16.87 µg/m³, respectively. Moreover, the ratios of OC/EC, NO3 -/SO42- were 2.58 and 0.75, respectively, and calculated secondary organic carbon concentration was 9.75 µg/m³ These results indicate that: 1) PM2.5 pollution in the urban green belt of Beijing is more serious than in many other cities in China and has increased considerably over a period of five years; 2) there is a considerable variation in both the total PM2.5 concentration and composition of water-soluble ions throughout different seasons, while the forest belt width has no evident influence on the PM concentration and water-soluble ions; 3) OC and EC concentrations and the ratio of OC/EC shows that traffic emissions during summer are higher than in other seasons and that traffic emissions are the dominant carbon source in Beijing. Furthermore, the carbon contribution to total PM2.5 is greater than in other cities. [ABSTRACT FROM AUTHOR]

Forests and vegetation are known to play an important role in capturing air pollutants, whereas the role of wetland plants in this context has been poorly understood. This study focused on particle accumulation in six common wetland plant species in a wetland in Beijing, China. The aim of the study was to show the capacity of the six plants species to accumulate particulates of two different size fractions (fine particles: diameter < 2.5 μm; coarse particles: diameter ranging from 2.5 to 10 μm) over three growing seasons. This study also discussed the differences among species with respect to their ability to accumulate particles and their unique microstructures and investigated the possible associations between stoma density, stoma width, stoma length, groove width, and particle accumulation. The results showed that Phragmites australis accumulated a considerable proportion of both coarse and fine particles. The leaf surface microstructure was observed using scanning electron microscopy (SEM). Microstructures, such as trichomes, were good at capturing particles, but there was no relationship between surface roughness and particle accumulation. Regression analysis showed that the correlation between stoma density, groove width, stoma width, and particle accumulation was moderate (R 2  = 0.45, 0.30, and 0.34, respectively). Thus, wetlands in urban areas could provide an important ecosystem service: accumulation of hazardous particulate matter. The results of this study could be useful to select wetland species with a strong particle-accumulating ability. P. australis has the potential to be a good biofilter in artificial wetlands in cities. In addition, when selecting species, it is better to select those with more trichomes or hairs on their leaf surfaces. [ABSTRACT FROM AUTHOR]

The fine particular matter (PM) concentrations in China have increased considerably due to the rapid economic growth and urbanization in the last few decades, especially in the most populated and industrialized regions. Beijing-Tianjin-Hebei is one of the most polluted regions in China, so to monitor the PM2.5 concentrations over this region is quite critical for human health. By making use the new released hourly PM2.5 mass concentration from ground-based observations in Beijing-Tianjin-Hebei over China, and collocated MODIS level 2 AOD data from April 2014 to March 2015, we explored the relation between surface PM2.5 mass concentration and MODIS AOD and possibility to derive the surface PM2.5 from satellite retrieval in the region. Our study show that the relation strongly depend on the seasons due to distinct seasonal characteristics of PM2.5 and AOD, with a relatively better correlation in spring and summertime (correlation coefficient r ranging from 0.52 to 0.79) than autumn and wintertime (r can be low as to 0.23 in site Baoding). Our analysis gave evidence that worse relationship and/or smaller number of sample in wintertime is associated with the significantly high PM2.5 concentration and a lot of missing data occurring in MODIS AOD, implying that current MODIS AOD retrieval scheme does not work very well in highly polluted cases. The derived PM2.5 mass concentration from MODIS AOD in summertime can basically capture the major observed features of the time series and about 20% large bias of the derived values compared to the observation is expected to be reduced if longer time period data is available and used for analysis. [ABSTRACT FROM AUTHOR]

Lead pollution has attracted significant attention over the years. However, research on the transfer of lead between urban atmospheric particles, soils, and plants remains rare. We measured lead concentrations and lead isotope ratios in total suspended particles (TSP), soil, and plants in an urban wetland in Beijing. The study period was September 2016–August 2017- covering all four seasons. The concentrations of lead in the atmospheric particles vary from 3.13 to 6.68 mg/m3. It is significantly higher in autumn than that in spring and summer (P < 0.05). There is also a significant difference between summer and winter (P < 0.05). The soil lead concentrations range from 57 to 114 mg/kg, with the highest concentration in spring, followed by summer, winter and autumn. The lead concentrations are 1.28–7.75 mg/kg in plants. The concentration was highest in spring and significantly higher than in summer. The bioaccumulation factor of Phragmites australis was 0.064 (<0.1), indicating that lead is not easily transferred to plants. Unlike the bioaccumulation factors, translocation factors have much higher values, indicating a higher transfer within the plants. Results also indicate an interesting seasonal pattern with almost 97% of lead in plants during spring being of atmospheric origin, whereas in autumn, soilborne sources contribute almost 94%. The isotopic compositions of lead in the urban atmosphere-soil-plant system show that lead pollution results from the mixing of geogenic and anthropogenic materials. Vehicle exhaust, crustal rocks and ore deposits are likely primary sources of lead pollution within the study domain. [Display omitted] • Lead concentrations in soils are much higher than that in TSP and plant samples. • Contributions of airborne sources of lead vary from 6.5% to 97.3% in four seasons. • Contributions of soilborne sources of lead vary from 2.7% to 93.5% in four seasons. • Vehicle exhaust, crustal rocks and ore deposits are the main sources of lead pollution in Cuihu wetland in Beijing. [ABSTRACT FROM AUTHOR]

Abstract: Size-segregated aerosol samples were collected daily in Beijing from 1 Jun. to 20 Sep. during the Beijing Olympic Games in 2008 to investigate aerosol concentrations, particle size distributions, and sources as well as the effects of pollution control measures on the chemical compositions (including Water-soluble ions, trace elements, elemental carbon (EC), and organic carbon (OC)) in aerosols of different sizes. Water-soluble ions, EC, OC, and trace elements accounted for 45.0%, 1.6%, 14.7%, and 11.4% of the total particle mass (PM), respectively. Approximately 56%, 56%, 30%, 71% and 55% of the PM, water-soluble ions, trace elements, EC and OC, respectively, were associated with particles smaller than 2.1 μm. Sulfate, nitrate, and ammonium were the dominant ions, which together accounted for approximately 77% of total water-soluble ions. The crustal elements accounted for the majority of the trace elements present. Different sources showed different mass size distributions. Anthropogenic source compounds, such as sulfate, nitrate, ammonium, OC, EC, and toxic elements, were mainly present in fine mode aerosols, whereas crustal elements, such as Al, Fe, Ca, Mg and Ba, primarily occurred in the coarse mode. and concentrations were strongly correlated (r 2 = 0.90, slope = 1.63) in the fine mode, thereby indicating that was mainly present as (NH4)2SO4; in contrast, a weak correlation between and (r 2 = 0.18, slope = 0.54) was observed in the coarse mode, indicating that was associated with other ions. Similarly, and exhibited a stronger correlation in the fine mode than in the coarse mode, indicating that and were formed via the same in-cloud processes in fine particles. The OC/EC ratio and the correlations between EC and OC concentrations showed that the sources of carbonaceous species were secondary organic carbon from fine particles and the long-range transport of coarse carbonaceous particles from biomass burning. The concentrations of atmospheric pollutants declined during the 2008 Olympic Games, indicating that the pollution control measures were effective in decreasing particulate air pollution in Beijing. [Copyright &y& Elsevier]

Air samples were collected using active samplers at various heights of 8, 15, 32, 47, 65, 80, 102, 120, 140, 160, 180, 200, 240, 280 and 320m on a meteorological tower in an urban area of Beijing in two campaigns in winter 2006. Altitudinal distributions of polycyclic aromatic hydrocarbons (PAHs) in atmospheric boundary layer of Beijing in winter season were investigated. Meteorological conditions during the studied period were characterized by online measurements of four meteorological parameters as well as trajectory calculation. The mean total concentrations of 15 PAHs except naphthalene of gaseous and particulate phase were 667±450 and 331±144ngm−3 in January and 61±19 and 29±6ngm−3 in March, respectively. Domestic coal combustion and vehicle emission were the dominant PAH sources in winter. Although the composition profiles derived from the two campaigns were similar, the concentrations were different by one order of magnitude. The higher concentrations in January were partly caused by higher emission due to colder weather than March. Moreover, weak wind, passing through the city center before the sampling site, picked up more contaminants on the way and provided unfavorable dispersion condition in January. For both campaigns, PAH concentrations decreased with heights because of ground-level emission and unfavorable dispersion conditions in winter. The concentration ratio of PAHs in gas versus solid phases was temperature dependent and negatively correlated to their octanol–air partition coefficients. [Copyright &y& Elsevier]