Obscured Contribution of Oxygenated Intermediate-Volatility Organic Compounds to Secondary Organic Aerosol Formation from Gasoline Vehicle Emissions.

Secondary organic aerosol (SOA) formation from gasoline vehicles spanning a wide range of emission types was investigated using an oxidation flow reactor (OFR) by conducting chassis dynamometer tests. Aided by advanced mass spectrometric techniques, SOA precursors, including volatile organic compounds (VOCs) and intermediate/semivolatile organic compounds (I/SVOCs), were comprehensively characterized. The reconstructed SOA produced from the speciated VOCs and I/SVOCs can explain 69% of the SOA measured downstream of an OFR upon 0.

A Rat Dry Eye Model with Lacrimal Gland Dysfunction Induced by Scopolamine.

Aqueous-deficient dry eye (ADDE) is a type of dry eye disease that can result in the reduction of tear secretion quantity and quality. Prolonged abnormal tear production can lead to a disturbance in the ocular surface environment, including corneal damage and inflammation. In severe cases, ADDE can cause vision loss or even blindness.

Unambiguous Analysis and Systematic Mapping of Oxygenated Aromatic Compounds in Atmospheric Aerosols Using Ultrahigh-Resolution Mass Spectrometry.

Compositional analysis of organic aerosols (OAs) at the molecular level has been a long-standing challenge in field and laboratory studies. In this work, we applied different extraction protocols to aerosol samples collected from the ambient atmosphere and biomass burning sources, followed by Orbitrap mass spectrometric analysis with a soft electrospray ionization source operating in both positive and negative ionization modes. To systematically map the distribution of mono- and dioxygenated aromatic compounds (referred to as aromatic CHO and CHO formulas) in OA, we developed a unique two-dimensional Kendrick mass defect (2D KMD) framework.

Nitrate Radicals Suppress Biogenic New Particle Formation from Monoterpene Oxidation.

Highly oxygenated organic molecules (HOMs) are a major source of new particles that affect the Earth's climate. HOM production from the oxidation of volatile organic compounds (VOCs) occurs during both the day and night and can lead to new particle formation (NPF). However, NPF involving organic vapors has been reported much more often during the daytime than during nighttime.

[Chemical Composition and Characterization of Nitroaromatic Compounds in Urban Areas of Shanghai].

The compositional characteristics, concentration of nitroaromatic compounds(NACs) in PM in urban Shanghai, and their correlation with gaseous precursors were investigated. A total of 39 winter and 46 summer PM samples from 2020 to 2021 were collected using a high-flow sampler and analyzed via ultra-performance liquid chromatography coupled with ESI-Orbitrap high-resolution mass spectrometry(UPLC-Orbitrap-HRMS). Quantitative analysis was performed on 12 NACs compounds, combined with backward trajectory meteorological elements, molecular composition, and classification analysis of CHON substances.

[Characteristics and Cause of PM During Haze Pollution in Winter 2022 in Zhoukou, China].

The characteristics and main factors of causes of haze in Zhoukou in January 2022 were analyzed. Six air pollutants, water-soluble ions, elements, OC, EC, and other parameters in fine particulate matter were monitored and analyzed using a set of online high-time-resolution instruments in an urban area. The results showed that the secondary inorganic aerosols(SNA), carbonaceous aerosols(CA, including organic carbon OC and inorganic carbon EC), and reconstructed crustal materials(CM, such as AlO, SiO, CaO, and FeO, etc.

High serum interleukin-6 concentration upon admission is predictive of disease severity in paediatric trauma patients.

Background: Trauma is the leading cause of death among children worldwide. The inflammatory response of paediatric patients to multiple injuries can be monitored using serum interleukin-6 (IL-6) levels. This study aimed to assess the value of IL-6 levels in predicting the severity of paediatric trauma and its clinical association with disease activity.

Important Roles and Formation of Atmospheric Organosulfates in Marine Organic Aerosols: Influence of Phytoplankton Emissions and Anthropogenic Pollutants.

Organosulfates (OSs) could be potentially important compounds in marine organic aerosols, while their formation in marine atmospheres is far from clear due to a lack of cruise observations. In this work, shipboard atmospheric observations were conducted over the Yellow Sea and Bohai Sea to investigate the abundance and formation of biogenic isoprene/monoterpene-OSs in marine aerosols. The quantified OSs and NOSs accounted for 0.

Thrombocytosis and eosinophilia in 32 Chinese neonatal incontinentia pigmenti.

Introduction: Incontinentia pigmenti (IP) is a rare X-linked dominant genetic disease affecting ectodermal tissue and often misdiagnosed in the neonatal period. The aim of this study was to highlight sequential clinical features and evaluate prognosis of the 32 neonatal IP patients.

Material And Methods: A retrospective descriptive analysis was performed, using the clinical, blood analytical, pathological, radiological, genetic, and followed-up data of neonatal patients diagnosed with IP from 2010 to 2021, in Xi'an, China.

[Spatial and Temporal Distribution Characteristics of Ozone Concentration and Population Health Benefit Assessment in the Yangtze River Delta Region from 2017 to 2020].

In recent years, the ozone (O) concentration has showed a rising trend in China, becoming second only to PM as an important factor affecting air quality. To grasp the spatial-temporal variations characteristics of O and the associated health impacts during the implementation of the three-year plan on defending the blue sky in the Yangtze River Delta (YRD) region, data collected from 210 monitoring stations in the YRD from 2017 to 2020 were analyzed using the global Moran's index and Getis-Ord index methods, and the associated health benefits of reduced O exposure were evaluated using the health risk and environmental value assessment methods. The results showed that during the study period, the interquartile range (IQR) of the annual average O concentration and that of the warm season both presented a declining trend.

The interplays among meteorology, source, and chemistry in high particulate matter pollution episodes in urban Shanghai, China.

High particulate matter (PM) pollution episodes still occur occasionally in urban China, despite of improvements in recent years. Investigating the influencing factors of high-PM episodes is beneficial in the formulation of effective control measures. We herein present the effects of weather condition, emission source, and chemical conversion on the occurrence of high-PM episodes in urban Shanghai using multiple online measurements.

Investigation of a haze-to-dust and dust swing process at a coastal city in northern China part I: Chemical composition and contributions of anthropogenic and natural sources.

The long retention of dust air masses in polluted areas, especially in winter, may efficiently change the physicochemical properties of aerosols, causing additional health and ecological effects. A large-scale haze-to-dust weather event occurred in the North China Plain (NCP) region during the autumn-to-winter transition period in 2018, affecting the coastal city Qingdao several times between Nov. 27th and Dec.

Hourly organic tracers-based source apportionment of PM before and during the Covid-19 lockdown in suburban Shanghai, China: Insights into regional transport influences and response to urban emission reductions.

During the Covid-19 outbreak, strict lockdown measures led to notable reductions in transportation-related emissions and significantly altered atmospheric pollution characteristics in urban and suburban areas. In this work, we compare comprehensive online measurements of PM major components and organic molecular markers in a suburban location in Shanghai, China before lockdown (Dec. 28, 2019 to Jan.

Field Detection of Highly Oxygenated Organic Molecules in Shanghai by Chemical Ionization-Orbitrap.

Secondary organic aerosol, formed through atmospheric oxidation processes, plays an important role in affecting climate and human health. In this study, we conducted a comprehensive campaign in the megacity of Shanghai during the 2019 International Import Expo (EXPO), with the first deployment of a chemical ionization─Orbitrap mass spectrometer for ambient measurements. With the ultrahigh mass resolving power of the Orbitrap mass analyzer (up to 140,000 Th/Th) and capability in dealing with massive spectral data sets by positive matrix factorization, we were able to identify the major gas-phase oxidation processes leading to the formation of oxygenated organic molecules (OOM) in Shanghai.

[Characteristics of Nitroaromatic Compounds in PM in Urban Area of Shanghai].

Nitroaromatic compounds (NACs) are an important class of nitrogen-containing compounds in fine particles. The investigation of characteristics and seasonal variation of NACs in PM increases our knowledge about nitrogen-containing compounds and contributes to the scientific basis in formulating reduction policies of NO in urban areas. In this study, we analyzed the chemical composition of PM samples collected from March 2018 to February 2019 in an urban location in Shanghai.

Abundance of organosulfates derived from biogenic volatile organic compounds: Seasonal and spatial contrasts at four sites in China.

Atmospheric organosulfates (OSs) derived from biogenic volatile organic compounds (BVOCs) encode chemical interaction strength between anthroposphere and biosphere. We report BVOC-derived OSs in the summer of 2016 and the winter of 2017 at four locations in China (i.e.

Comparative Assessment of Cooking Emission Contributions to Urban Organic Aerosol Using Online Molecular Tracers and Aerosol Mass Spectrometry Measurements.

Cooking organic aerosol (COA) is an important source of particulate pollutants in urbanized regions. Yet, the diversity and complexity of COA components make direct identification and quantification of COA difficult. In this study, we conducted collocated OA measurements with an aerosol mass spectrometer (AMS) and a thermal desorption aerosol gas chromatography-mass spectrometer (TAG) in Shanghai.

Polycyclic aromatic hydrocarbons in leaves of Cinnamomum camphora along the urban-rural gradient of a megacity: Distribution varies in concentration and potential toxicity.

Rapid urbanization and industrialization have precipitated the significant urban-rural gradient involving various aspects of human-related activities especially in megacities. Anthropogenic activities are the main source of polycyclic aromatic hydrocarbon (PAH) contamination, and the rising awareness concerning PAH potential toxicity to human health promotes a further understanding of its spatial distribution pattern in cities. Whether the distribution of PAH concentration and potential toxicity respond to the urban-rural gradient still requires investigation.

[Exposure Levels, Sources, and Health Risks of Heavy Metal Components of PM in Housewives in Rural Shanghai].

To investigate exposure characteristics and potential health risk of PM-bound heavy metals in housewives in rural areas, 265 personal exposure samples from 143 subjects were collected in the Songjiang district, Shanghai from February 2017 to June 2018. Mass concentrations of 13 elements in PM were determined by energy-dispersive X-ray fluorescence spectrometry (ED-XRF). The sources of heavy metal components in PM were analyzed using positive matrix factorization (PMF).

Nitrite-Mediated Photooxidation of Vanillin in the Atmospheric Aqueous Phase.

Nitrite (NO) and its conjugate acid, nitrous acid (HNO), have long been recognized as a ubiquitous atmospheric pollutant as well as an important photochemical source of hydroxyl radicals (·OH) and reactive nitrogen species (·NO, ·NO, ·NO, etc.) in both the gas phase and aqueous phase. Although NO/HNO plays an important role in atmospheric chemistry, our understanding on its role in the chemical evolution of organic components in atmospheric waters is rather incomplete and is still in dispute.

Monoterpene and Sesquiterpene α-Hydroxy Organosulfates: Synthesis, MS/MS Characteristics, and Ambient Presence.

Organosulfates (OSs) derived from biogenic volatile organic compounds are important compounds signifying interactions between anthropogenic sulfur pollution and natural emission. In this work, we substantially expand the OS standard library through the chemical synthesis of 26 α-hydroxy OS standards from eight monoterpenes (i.e.

Estimating Secondary Organic Aerosol Production from Toluene Photochemistry in a Megacity of China.

The production of secondary organic aerosols (SOA) from toluene photochemistry in Shanghai, a megacity of China, was estimated by two approaches, the parametrization method and the tracer-based method. The temporal profiles of toluene, together with other fifty-six volatile organic compounds (VOCs), were characterized. Combing with the vapor wall loss corrected SOA yields derived from chamber experiments, the estimated toluene SOA by the parametrization method as embodied in the two-product model contributes up to ∼40% of the total SOA budget during summertime.

[Health Benefit Analyses of the Clean Air Action Plan Implementation in Shanghai].

To understand the public health benefits of the Clean Air Action Plan implemented in Shanghai from 2013-2017, the changes of the PM exposure levels and related health and economic benefits were quantitatively evaluated by using air quality numerical modeling, health risk assessment, and environmental valuation methods. The results show that the proportion of the population exposed to a mean annual PM concentration lower than or equal to 35 μg·m has increased from 1.62% in the base year to 34.