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Tropospheric ozone (O3) pollution is becoming the primary obstacle to the improvement of air quality in China, especially in the Pearl River Delta (PRD) region. Because O3 pollution episodes are closely related to synoptic weather patterns (SWPs), historical episodes (from 2006 to 2019) were classified according to SWPs using the Lamb‐Jenkinson method. Monitoring network and weather reanalysis data, emission inventories, and satellite retrievals were used to investigate the spatiotemporal characteristics and influences of O3 pollution. It was found that easterly (P_E), anticyclone (P_A), and typhoon‐related (P_NE) SWPs accounted for 75% of all O3 pollution episodes. In the PRD, the O3 formation mechanism showed clear differences under different SWPs, which were affected by local emissions under P_A, whereas regional transmission dominated under P_E and P_NE. The O3 peak concentration was strongly associated with temperature, solar radiation, and shifting of the sea‐land breeze. A delayed shift of land to sea breeze caused by SWPs often caused the O3 peak to appear in the late afternoon. Finally, stepwise regression was used to explain individual meteorological parameters contributing to O3 formation. It was found that the formation of O3 pollution under P_E and P_NE was associated with increases in temperature and radiation, while P_A was mainly affected by the increase of the overnight accumulation of O3. This study advances our knowledge of the formation mechanism of O3 pollution and provides scientific support for effective O3 pollution control. Plain Language Summary: In recent years, tropospheric ozone (O3) has become an important air pollutant hindering the improvement of air quality in the Pearl River Delta (PRD) region, China. In spite of the complicated nonlinear relationship between O3 and its precursor, the variable synoptic weather patterns (SWPs), which control O3 production and transportation, bring troubles to O3 pollution control. To explore the influence of SWPs on spatiotemporal characteristics and internal causes of O3 pollution, we objectively classified the historical episodes (from 2006 to 2019) and analyzed the meteorological factors, transmission paths of pollutants, and O3 pollution characteristics under different SWPs. It was found that easterly (P_E), anticyclone (P_A), and typhoon‐related (P_NE) SWPs were the most common O3 pollution weather systems. Generally, P_A mainly features local emission pollution, the cyclone circulation is conducive to the accumulation of ozone at night, resulting in high O3 levels on the next day. P_E and P_NE tend to cause regional transmission pollution with unfavored meteorological conditions like the increase in temperature and radiation. Based on the findings, we constructed a multivariate linear regression model which can accurately predict the MDA8 O3 in advance. This study provides a scientific support for O3 pollution control. Key Points: Historical O3 episodes in the Pearl River Delta are classified according to synoptic weather patterns (SWPs)The O3 formation mechanism shows clear differences under different SWPs and the dominant parameters are diagnosedThe anticyclone pattern is sensitive to overnight ozone accumulation, while the other patterns are sensitive to meteorological parameters [ABSTRACT FROM AUTHOR]

ABSTRACT Background Nursing-sensitive indicators are considered effective tools for improving the quality of care in hospitals. However, these have not been used in paediatric intensive care units ( PICUs) in China. Aim To develop nursing-sensitive indicators for PICUs and to assess the quality of nursing in PICUs in China based on the nursing-sensitive indicators. Design Multi-centre, cross-sectional study. Methods Structure, process and outcome indicators were developed and measured from 1 January to 31 March 2014 in seven PICUs in China. Results The structure indicators showed that one nurse cared for an average of 2·8 patients in a PICU, and 44% of nurses had a bachelor's degree. The process indicators revealed that hand-washing compliance varied across PICUs, whereas pain management and physical restraint have not been adequately addressed in China. The outcome indicators revealed that the incidence rates of ventilator-associated pneumonia and central-line-associated blood stream infections were 2·96 and 0·7, respectively, per 1000 device days. Patients were intubated for a total of 4392 mechanical ventilator days, and 32 patients (7·29‰) had an unplanned extubation. Nurses were moderately satisfied in their jobs (3·1 ± 0·3), and parents reported that nurses provide high quality of care. Conclusions This study developed and used nursing-sensitive indicators to assess the quality of nursing in PICUs in China, which provided a reference for national and international comparisons of nursing quality in PICUs. Nursing staffing levels and education should be improved. Pain management and physical restraints should be regulated in China's PICUs. Nurse managers need to explore staff attitudes towards implementation of family-centred care. The development of a national database of nursing quality indicators can contribute to quality and safety improvement. Relevance to clinical practice This study developed a set of nursing-sensitive indicators, and these indicators were used to assess and improve the quality of nursing in PICUs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Reveal the concentration characteristics of three different types of VOCs. • Explore the drivers of photochemically consumed VOCs to generate O 3. • Quantify the effect of photochemical consumed VOCs sources on O 3 formation. Ground-level ozone (O 3) pollution has received widespread attention because its rising trend and adverse ecological impacts. However, the extremely strong photochemical reactions of its precursor volatile organic compounds (VOCs) increase the difficulty of reducing VOCs emissions to alleviate O 3. Here, we carried out a one-year comprehensive observation in two representative cities, Tianjin (TJ, Northern China) and Guangzhou (GZ, Southern China). By revealing the concentration characteristics of three different types of VOCs, i.e., initial VOCs without photochemical reaction (In-VOCs), consumed VOCs (C-VOCs), and measured VOCs after the reaction (M-VOCs), we elucidated the important role of C-VOCs in the formation of O 3. Although the overall trends were similar in both cities, the average concentration level of VOCs in GZ was 8.2 ppbv higher than that in TJ, and the photochemical loss of VOCs was greater by 2.2 ppbv. In addition, various drivers affecting O 3 generation from C-VOCs were specifically explored, and it was found that most alkenes of TJ were key substances for rapid O 3 formation compared to aromatics of GZ. Meanwhile, favorable meteorological conditions such as high temperature (T > 31 °C in TJ, and T > 33 °C in GZ), low relative humidity (56% in TJ and 45% in GZ), and stable atmospheric environment (proper pressure and gentle wind speed) also contribute to the generation of O 3. More importantly, we combined chemical kinetics and receptor model to quantify the three-type VOCs source contributions and assess the potential impact of C-VOCs sources on O 3 production, thus proposing environmental abatement technologies corresponding to the three types of VOCs. The differences in the comparison results of the three-type VOCs highlight the need to reduce O 3 pollution from C-VOCs sources, which provides insights for future clean air policies development. [ABSTRACT FROM AUTHOR]

Organic nitrogen (ON) compounds play a significant role in the light absorption of brown carbon and the formation of organic aerosols, however, the mixing state, secondary formation processes, and influencing factors of ON compounds are still unclear. This paper reports on the mixing state of ON-containing particles based on measurements obtained using a high-performance single particle aerosol mass spectrometer in January 2020 in Guangzhou. The ON-containing particles accounted for 21% of the total detected single particles, and the particle count and number fraction of the ON-containing particles were two times higher at night than during the day. The prominent increase in the content of ON-containing particles with the enhancement of NO x mainly occurred at night, and accompanied by high relative humidity and nitrate, which were associated with heterogeneous reactions between organics and gaseous NO x and/or NO 3 radical. The synchronous decreases in ON-containing particles and the mass absorption coefficient of water-soluble extracts at 365 nm in the afternoon may be associated with photo-bleaching of the ON species in the particles. In addition, the positive matrix factorization analysis found five factors dominated the formation processes of ON particles, and the nitrate factor (33%) mainly contributed to the production of ON particles at night. The results of this study provide unique insights into the mixing states and secondary formation processes of the ON-containing particles., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest., (Copyright © 2023. Published by Elsevier B.V.)

The outbreak of novel coronavirus pneumonia in Wuhan, Hubei Province, in 2019 and its rapid spread across the country caused severe public panic in China. The purpose of this study was to investigate the mental health problems of children's chaperones at the emergency clinic during the coronavirus disease 2019 (COVID-19) outbreak and to analyze the related influencing factors. A total of 260 chaperones for children in the emergency department participated in this cross-sectional study through the questionnaire constellation platform. The survey period was from February to June 2021. Information collected included demographic data and mental health scales. The Self-Assessment Scale for Anxiety, the Self-Rating Scale for Depression, and the Pittsburgh Sleep Quality Index assessed anxiety, depression, and sleep quality, respectively. Logistic regression was used to analyze influential factors associated with mental health problems. The prevalence of depression, anxiety, and sleep disorders among family members accompanying children attending the emergency room was 41.54%, 20.00%, and 93.08%, respectively, with 21.54% of family members suffering from moderate sleep disorders. Univariate analysis showed that being in Wuhan or not during the city closure (X2 = 8.61, P < .01) was strongly associated with the occurrence of depression; female (X2 = 4.87, P = .03), working or not (X2 = 6.39, P = .01) and fear of going to the hospital (X2 = 7.80, P = .01) were key factors for the occurrence of anxiety symptoms; Knowledge of transmission routes and prevention of COVID-19 (X2 = 12.56, P = .03) was a key factor for sleep disorders; logistic stepwise regression analysis showed that fear of going to the hospital was a risk factor for anxiety symptoms (odds ratio = 2.51, P < .01, 95% confidence interval = 1.30-4.85). Our findings suggest that mental health problems were prevalent among family members accompanying children attending the emergency department during the COVID-19 outbreak, with a high prevalence of sleep disturbances in particular. Relevant factors included presence or absence in Wuhan during the outbreak closure, gender, work or absence, and fear of hospital visits. There is a need to focus on the mental health distress of the chaperones for children in the emergency department, and to provide timely intervention and diversion., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2023 the Author(s). Published by Wolters Kluwer Health, Inc.)

The formation processes of particulate amines are closely related to their emission sources and secondary reactions, which can be revealed through the investigation of their real-time mixing states in individual particles. The mixing states of methylamine (MA)-, trimethylamine (TMA)-, and diethylamine (DEA)-containing particles were studied using a high-performance single particle aerosol mass spectrometer (HP-SPAMS) in Guangzhou, China, in January 2020. The sharp increase in TMA particles was found to be closely associated with the increase in the ambient relative humidity (RH), while the MA- and DEA-containing particles were not similarly influenced by the changes in the RH. The prominent enrichment of secondary oxygenated organics in DEA particles during the daytime was consistent with the active period of photochemistry, implying that the sharp decrease in DEA particles in the afternoon was likely due to photo-oxidation of the DEA. The number fraction (N f ) of DEA particles, the N f of the nitrate in the DEA particles, and the abundance of nitrate increased as the NO x content all increased during the nighttime, suggesting that the formation of DEA·HNO 3 salt was the dominant pathway of particulate DEA production. These results are consistent with our previous measurements in Nanjing, confirming the general and distinct mixing states of TMA and DEA particles. Positive matrix factorization analysis revealed that the total fraction of the more oxidized organics factor and the less oxidized organics factor were much higher in the DEA particles (26.9 %) than in the TMA particles (9 %), confirming the significant enrichment of oxygenated species in the DEA particles. The different mixing states of the amines revealed the unique response of each type of amine to the same atmospheric environment, and the prominent mixing states of the DEA with secondary oxygenated species suggest the potential role of DEA in tracing the evolution of organic aerosols., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Imidazoles (IMs) are potential contributors to brown carbon; they may notably contribute to climate radiative forcing. However, only a few studies have assessed the mixing state, seasonal and spatial distributions of IMs, and influencing factors for IM formation in urban aerosols. In this study, two single-particle aerosol mass spectrometers were employed to investigate the IM-containing particles in the urban areas of Beijing and Guangzhou, China. IM-containing particles were identified in the size range (d va ) of 0.2-2.0 μm, accounting for 0.7-21.7 % of all the detected particles. The number fractions of IM-containing particles in both cities were the lowest in winter and the highest in spring, probably owing to the difference in the abundance of precursors and the particle acidity. Majority of (60-80 % by number) the IM-containing particles were mixed with organic carbon (OC), with the lowest fractions found in summer. Although the number fractions of IM-containing particles in Beijing were generally higher (~1.5-3 times) than those in Guangzhou, the mixing states of the IM-containing particles at these two sites were only slightly different. Potassium-rich (K-rich) and potassium-sodium (KNa) particles were rarely found in Guangzhou; they accounted for ~15 % of the IM-containing particles in Beijing. Additionally, our results indicate that particles with higher acidity are favorable for IM formation. These findings help improving our knowledge of the mixing state, seasonal variation, and spatial distribution of IMs in urban aerosols, and the insights in influencing factors into IM formation provide valuable information for future studies of the atmospheric chemical processes associated with IMs., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2022. Published by Elsevier B.V.)

To investigate photochemical ozone (O 3 ) formation and provide localized control strategies, an intensive sampling of O 3 and its precursors (i.e. volatile organic compounds (VOCs) and nitrogen oxides (NO x = NO + NO 2 )) were conducted at an urban site in Leshan, Sichuan province during 4-13 August 2019. The mixing ratios of O 3 , total VOCs (TVOCs) and NO x were 40.0 ± 5.3, 22.5 ± 2.6 and 14.6 ± 3.8 ppbv, respectively (±95% confidence intervals). O 3 and its precursors existed a well negative correlation, indicating intensive local O 3 formation. To further explore the O 3 -precursors relationship and observation-oriented O 3 control strategies, a photochemical box model coupled with master chemical mechanism (PBM-MCM) was adapted. The relative incremental reactivity (RIR) calculated by model results showed that Leshan was in the VOCs-limited and O 3 production was most sensitive to alkenes. Moreover, O 3 isopleth diagram was drawn using the PBM-MCM simulation results and seven reduction scenarios were evaluated in Leshan. The reduction ratio of VOCs/NO x on 3:1 was proposed to be the best solution, which can be achieved effective reduction on local O 3 formation. At last, since VOCs were the key precursors of O 3 in Leshan, VOC sources and their potential contributions to O 3 formation were investigated by using the positive matrix factorization (PMF) model. Seven sources were identified, and traffic related emissions (including vehicle exhaust and gasoline evaporation, 29.9%) and fixed combustion (27.7%) had the large contribution to ambient VOCs. Among anthropogenic sources, fixed combustion and solvent usage in painting were the large contributors to O 3 formation, accounting for 30.9% and 18.3%, respectively, which should have high priorities on source reduction. This study provides scientific advices for future O 3 pollution control strategies in Leshan, which can be extended to other cities., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: The risk factors for multi-drug resistant infection (MDRI) in the pediatric intensive care unit (PICU) remain unclear. It's necessary to evaluate the epidemiological characteristics and risk factors for MDRI in PICU, to provide insights into the prophylaxis of MDRI clinically., Methods: Clinical data of 79 PICU children with MDRI were identified, and 80 children in PICU without MDRI in the same period were selected as control group. The related children's characteristics, clinical care, microbiologic data, treatments provided, and outcomes of the patients with were reviewed and collected. Univariate and multivariate logistic regression analyses were performed to identify the potential risks of MDRI in PICU., Results: Of the diagnosed 79 cases of MDRI, there were28 cases of CR-AB, 24 cases of MRSA, 22 cases of PDR-PA,3 cases of VRE and 2 cases of CRE respectively. Univariate analyses indicated that the length of PICU stay, the duration of mechanical ventilation > 5 days, parenteral nutrition, coma, urinary catheter indwelling, invasive operation, 2 or more antibiotics use were associated with MDRIs (all p < 0.05); The logistic multiple regression analyses indicated that coma, parenteral nutrition, 2 or more antibiotics use and the duration of mechanical ventilation > 5 days were independent risk factors associated with MDRI (all p < 0.05)., Conclusions: This present study has identified several potentially modifiable risk factors for MDRI in PICU, it's conducive to take appropriate measures targeting risk factors of MDRI for health care providers to reduce MDRI.