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Chan SL, Chiang CL, Chok KSH, Lee AS, Tang RSY, Lim FMY, Lee KF, Tai AYP, Lee SWM, Lo RCL, Chan AWH, Mok FPT. Hong Kong consensus recommendations on the management of pancreatic ductal adenocarcinoma. Hong Kong Med J 2024; 30:147-162. [PMID: 38590158 DOI: 10.12809/hkmj2210476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024] Open
Abstract
This project was undertaken to develop the first set of consensus statements regarding the management of pancreatic ductal adenocarcinoma (PDAC) in Hong Kong, with the goal of providing guidance to local clinicians. A multidisciplinary panel of experts discussed issues surrounding current PDAC management and reviewed evidence gathered in the local context to propose treatment recommendations. The experts used the Delphi approach to finalise management recommendations. Consensus was defined as ≥80% acceptance among all expert panel members. Thirty-nine consensus statements were established. These statements cover all aspects of PDAC management, including diagnosis, resectability criteria, treatment modalities according to resectability, personalised management based on molecular profiling, palliative care, and supportive care. This project fulfils the need for guidance regarding PDAC management in Hong Kong. To assist clinicians with treatment decisions based on varying levels of evidence and clinical experience, treatment options are listed in several consensus statements.
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Affiliation(s)
- S L Chan
- Department of Clinical Oncology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - C L Chiang
- Department of Clinical Oncology, Queen Mary Hospital, Hong Kong SAR, China
| | - K S H Chok
- Department of Surgery, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - A S Lee
- Department of Clinical Oncology, Tuen Mun Hospital, Hong Kong SAR, China
| | - R S Y Tang
- Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - F M Y Lim
- Department of Oncology, Princess Margaret Hospital, Hong Kong SAR, China
- Department of Pathology, School of Clinical Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - K F Lee
- Department of Surgery, Prince of Wales Hospital, Hong Kong SAR, China
| | - A Y P Tai
- Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong SAR, China
| | - S W M Lee
- Department of Pathology, School of Clinical Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - R C L Lo
- Department of Pathology, School of Clinical Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - A W H Chan
- Department of Anatomical and Cellular Pathology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - F P T Mok
- Department of Surgery and Combined Endoscopy Unit, Caritas Medical Centre, Hong Kong SAR, China
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2
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Wang X, Chan AWH. Particulate Matter and Volatile Organic Compound Emissions Generated from a Domestic Air Fryer. Environ Sci Technol 2023; 57:17384-17392. [PMID: 37927234 DOI: 10.1021/acs.est.3c04639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2023]
Abstract
Air frying has become a popular cooking method for domestic cooking, but the level of released indoor air pollutants is poorly understood. In this work, we compared particle and gas phase emission factors (EF) and particle size distributions between cooking with a domestic air fryer and a pan for a variety of foods. The PM10 EFs of air frying chicken wings and breast were higher than pan cooking by a factor of 2.1 and 5.4, respectively. On the other hand, a higher PM10 emission factor from air frying can be achieved by increasing the amount of oil to levels similar to or above those from pan-frying for French fries and asparagus. We propose that higher temperature and greater turbulence lead to higher PM10 EFs for cooking with the air fryer compared with the pan for the same mass of oil added. EFs of volatile organic compounds (VOCs) are also generally higher for cooking with the air fryer compared with the pan: 2.5 times higher for French fries and 4.8 times higher for chicken breast. Our study highlights the potential risk of higher indoor PM10 levels associated with domestic air frying under certain cases and proposes possible mitigation measures.
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Affiliation(s)
- Xing Wang
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Arthur W H Chan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
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3
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Yao M, Zhao Y, Chang C, Wang S, Li Z, Li C, Chan AWH, Xiao H. Multiphase Reactions between Organic Peroxides and Sulfur Dioxide in Internally Mixed Inorganic and Organic Particles: Key Roles of Particle Phase Separation and Acidity. Environ Sci Technol 2023; 57:15558-15570. [PMID: 37797208 DOI: 10.1021/acs.est.3c04975] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/07/2023]
Abstract
Organic peroxides (POs) are ubiquitous in the atmosphere and particularly reactive toward dissolved sulfur dioxide (SO2), yet the reaction kinetics between POs and SO2, especially in complex inorganic-organic mixed particles, remain poorly constrained. Here, we report the first investigation of the multiphase reactions between SO2 and POs in monoterpene-derived secondary organic aerosol internally mixed with different inorganic salts (ammonium sulfate, ammonium bisulfate, or sodium nitrate). We find that when the particles are phase-separated, the PO-S(IV) reactivity is consistent with that measured in pure SOA and depends markedly on the water content in the organic shell. However, when the organic and inorganic phases are miscible, the PO-S(IV) reactivity varies substantially among different aerosol systems, mainly driven by their distinct acidities (not by ionic strength). The second-order PO-S(IV) rate constant decreases monotonically from 5 × 105 to 75 M-1 s-1 in the pH range of 0.1-5.6. Both proton catalysis and general acid catalysis contribute to S(IV) oxidation, with their corresponding third-order rate constants determined to be (6.4 ± 0.7) × 106 and (6.9 ± 4.6) × 104 M-2 s-1 at pH 2-6, respectively. The measured kinetics imply that the PO-S(IV) reaction in aerosol is an important sulfate formation pathway, with the reaction kinetics dominated by general acid catalysis at pH > 3 under typical continental atmospheric conditions.
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Affiliation(s)
- Min Yao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
- School of Environmental & Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China
| | - Yue Zhao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Chongxuan Chang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Shunyao Wang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Ziyue Li
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Chenxi Li
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Arthur W H Chan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Huayun Xiao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
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4
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Ditto JC, Crilley LR, Lao M, VandenBoer TC, Abbatt JPD, Chan AWH. Indoor and outdoor air quality impacts of cooking and cleaning emissions from a commercial kitchen. Environ Sci Process Impacts 2023; 25:964-979. [PMID: 37102581 DOI: 10.1039/d2em00484d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Gas and particulate emissions from commercial kitchens are important contributors to urban air quality. Not only are these emissions important for occupational exposure of kitchen staff, but they can also be vented to outdoors, causing uncertain health and environmental impacts. In this study, we chemically speciated volatile organic compounds and measured particulate matter mass concentrations in a well-ventilated commercial kitchen for two weeks, including during typical cooking and cleaning operations. From cooking, we observed a complex mixture of volatile organic gases dominated by oxygenated compounds commonly associated with the thermal degradation of cooking oils. Gas-phase chemicals existed at concentrations 2-7 orders of magnitude lower than their exposure limits, due to the high ventilation in the room (mean air change rate of 28 h-1 during operating hours). During evening kitchen cleaning, we observed an increase in the signal of chlorinated gases from 1.1-9.0 times their values during daytime cooking. Particulate matter mass loadings tripled at these times. While exposure to cooking emissions in this indoor environment was reduced effectively by the high ventilation rate, exposure to particulate matter and chlorinated gases was elevated during evening cleaning periods. This emphasizes the need for careful consideration of ventilation rates and methods in commercial kitchen environments during all hours of kitchen operation.
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Affiliation(s)
- Jenna C Ditto
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Canada.
- Department of Chemistry, University of Toronto, Toronto, Canada.
| | | | - Melodie Lao
- Department of Chemistry, York University, Toronto, Canada
| | | | | | - Arthur W H Chan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Canada.
- Department of Chemistry, University of Toronto, Toronto, Canada.
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5
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Abstract
Cooking emissions account for a major fraction of urban volatile organic compounds and organic aerosol. Aldehyde species, in particular, are important exposure hazards in indoor residential and occupational environments, and precursors to particulate matter and ozone formation in outdoor air. Formation pathways of aldehydes from oils that lead to their emissions are not well understood. In this work, we investigate the underlying mechanisms involved in the formation of aldehydes from heated cooking oil emissions, through studying how antioxidants and oil composition modulate oxidation chemistry. Our results demonstrate that gaseous emissions are driven by radical-mediated autoxidation reactions in cooking oil, and the composition of cooking oils strongly influences the reaction mechanisms. Antioxidants have a dual effect on aldehyde emissions depending on the rates of radical propagation reactions. We propose a mechanistic framework that can be used to understand and predict cooking emissions under different cooking conditions. Our results highlight the need to understand the rates and mechanisms of autoxidation and other reactions in cooking oils in order to accurately predict the gas- and particle-phase emissions from food cooking in urban atmospheres.
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Affiliation(s)
- Manpreet Takhar
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, M5S 3E5, Canada
| | - Yunchun Li
- College of Science, Sichuan Agricultural University, Ya'an, 625014, China
| | - Jenna C Ditto
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, M5S 3E5, Canada
| | - Arthur W H Chan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, M5S 3E5, Canada
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Wang S, Zhao Y, Chan AWH, Yao M, Chen Z, Abbatt JPD. Organic Peroxides in Aerosol: Key Reactive Intermediates for Multiphase Processes in the Atmosphere. Chem Rev 2023; 123:1635-1679. [PMID: 36630720 DOI: 10.1021/acs.chemrev.2c00430] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Organic peroxides (POs) are organic molecules with one or more peroxide (-O-O-) functional groups. POs are commonly regarded as chemically labile termination products from gas-phase radical chemistry and therefore serve as temporary reservoirs for oxidative radicals (HOx and ROx) in the atmosphere. Owing to their ubiquity, active gas-particle partitioning behavior, and reactivity, POs are key reactive intermediates in atmospheric multiphase processes determining the life cycle (formation, growth, and aging), climate, and health impacts of aerosol. However, there remain substantial gaps in the origin, molecular diversity, and fate of POs due to their complex nature and dynamic behavior. Here, we summarize the current understanding on atmospheric POs, with a focus on their identification and quantification, state-of-the-art analytical developments, molecular-level formation mechanisms, multiphase chemical transformation pathways, as well as environmental and health impacts. We find that interactions with SO2 and transition metal ions are generally the fast PO transformation pathways in atmospheric liquid water, with lifetimes estimated to be minutes to hours, while hydrolysis is particularly important for α-substituted hydroperoxides. Meanwhile, photolysis and thermolysis are likely minor sinks for POs. These multiphase PO transformation pathways are distinctly different from their gas-phase fates, such as photolysis and reaction with OH radicals, which highlights the need to understand the multiphase partitioning of POs. By summarizing the current advances and remaining challenges for the investigation of POs, we propose future research priorities regarding their origin, fate, and impacts in the atmosphere.
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Affiliation(s)
- Shunyao Wang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai200240, China
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai200444, China
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, OntarioM5S 3E5, Canada
| | - Yue Zhao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Arthur W H Chan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, OntarioM5S 3E5, Canada
- School of the Environment, University of Toronto, Toronto, OntarioM5S 3E8, Canada
| | - Min Yao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Zhongming Chen
- State Key Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing100871, China
| | - Jonathan P D Abbatt
- Department of Chemistry, University of Toronto, Toronto, OntarioM5S 3H6, Canada
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7
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Wang S, Gallimore PJ, Liu-Kang C, Yeung K, Campbell SJ, Utinger B, Liu T, Peng H, Kalberer M, Chan AWH, Abbatt JPD. Dynamic Wood Smoke Aerosol Toxicity during Oxidative Atmospheric Aging. Environ Sci Technol 2023; 57:1246-1256. [PMID: 36630690 DOI: 10.1021/acs.est.2c05929] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Wildfires are a major source of biomass burning aerosol to the atmosphere, with their incidence and intensity expected to increase in a warmer future climate. However, the toxicity evolution of biomass burning organic aerosol (BBOA) during atmospheric aging remains poorly understood. In this study, we report a unique set of chemical and toxicological metrics of BBOA from pine wood smoldering during multiphase aging by gas-phase hydroxyl radicals (OH). Both the fresh and OH-aged BBOA show activity relevant to adverse health outcomes. The results from two acellular assays (DTT and DCFH) show significant oxidative potential (OP) and reactive oxygen species (ROS) formation in OH-aged BBOA. Also, radical concentrations in the aerosol assessed by electron paramagnetic resonance (EPR) spectroscopy increased by 50% following heterogeneous aging. This enhancement was accompanied by a transition from predominantly carbon-centered radicals (85%) in the fresh aerosol to predominantly oxygen-centered radicals (76%) following aging. Both the fresh and aged biomass burning aerosols trigger prominent antioxidant defense during the in vitro exposure, indicating the induction of oxidative stress by BBOA in the atmosphere. By connecting chemical composition and toxicity using an integrated approach, we show that short-term aging initiated by OH radicals can produce biomass burning particles with a higher particle-bound ROS generation capacity, which are therefore a more relevant exposure hazard for residents in large population centers close to wildfire regions than previously studied fresh biomass burning emissions.
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Affiliation(s)
- Shunyao Wang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Peter J Gallimore
- Department of Earth and Environmental Sciences, University of Manchester, Manchester M13 9PL, United Kingdom
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Carolyn Liu-Kang
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Kirsten Yeung
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Steven J Campbell
- Centre for Atmospheric Science, Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
- Department of Environmental Sciences, University of Basel, 4056 Basel, Switzerland
| | - Battist Utinger
- Department of Environmental Sciences, University of Basel, 4056 Basel, Switzerland
| | - Tengyu Liu
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
- Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, Nanjing 210023, China
| | - Hui Peng
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
- School of the Environment, University of Toronto, Toronto, Ontario M5S 3E8, Canada
| | - Markus Kalberer
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
- Centre for Atmospheric Science, Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | - Arthur W H Chan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
- School of the Environment, University of Toronto, Toronto, Ontario M5S 3E8, Canada
| | - Jonathan P D Abbatt
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
- School of the Environment, University of Toronto, Toronto, Ontario M5S 3E8, Canada
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Montesanti S, Walker I, Chan AWH. Editorial: Improving disaster health outcomes and resilience through rapid research: Implications for public health policy and practice. Front Public Health 2022; 10:989573. [PMID: 35983355 PMCID: PMC9379345 DOI: 10.3389/fpubh.2022.989573] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 07/15/2022] [Indexed: 11/19/2022] Open
Affiliation(s)
- Stephanie Montesanti
- School of Public Health, University of Alberta, Edmonton, AB, Canada
- Centre for Healthy Communities, School of Public Health, University of Alberta, Edmonton, AB, Canada
- *Correspondence: Stephanie Montesanti
| | - Iain Walker
- Research School of Psychology, Australian National University, Canberra, ACT, Australia
| | - Arthur W. H. Chan
- Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
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Abstract
The high-temperature cooking of protein-rich foods represents an important but poorly constrained source of nitrogen-containing gases and particles to indoor and outdoor atmospheres. For example, panfrying meat may form and emit these nitrogen-containing compounds through complex chemistry occurring between heated proteins and cooking oils. Here, we simulate this cooking process by heating amino acids together with triglycerides. We explore their interactions across different temperatures, triglyceride types, and amino acid precursors to form amide-containing products. Ammonia, arising from the thermal degradation of amino acids, may react with a triglyceride's ester linkages, forming amides and promoting de-esterification reactions that break the triglyceride into volatilizable products. Additionally, triglycerides may thermally oxidize and fragment as they are heated, and the resulting oxygenated breakdown products may react with ammonia to form amides. We observed evidence for amide formation through both of these pathways, including gas-phase emissions of C2-11H5-23NO species, whose emission factors ranged from 33 to 813 μg total gas-phase amides per gram of amino acid precursor. Comparable quantities of particle-phase oleamide (C18H35NO) were emitted, ranging from 45 to 218 μg/g. The observed amide products had variable predicted toxicities, highlighting the importance of understanding their emissions from cooking and their ultimate inhalation exposure risks.
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Affiliation(s)
- Jenna C Ditto
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada
- Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada
| | | | - Arthur W H Chan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada
- Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada
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10
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Ho SSK, Hon SSF, Hung E, Lee JFY, Mo F, Tong M, So C, Chu S, Ng DCK, Lam D, Cho C, Mak TWC, Ng SSM, Futaba K, Suen J, To KF, Chan AWH, Yeung WWK, Ma BBY. Prognostic implication of the neoadjuvant rectal score and other biomarkers of clinical outcome in Hong Kong Chinese patients with locally advanced rectal cancer undergoing neoadjuvant chemoradiotherapy. Hong Kong Med J 2022; 28:230-238. [PMID: 35667869 DOI: 10.12809/hkmj208969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND Neoadjuvant chemoradiotherapy is a standard treatment for locally advanced rectal cancer, for which pathological complete response is typically used as a surrogate survival endpoint. Neoadjuvant rectal score is a new biomarker that has been shown to correlate with survival. The main objectives of this study were to investigate factors contributing to pathological complete response, to validate the prognostic significance of neoadjuvant rectal score, and to investigate factors associated with a lower neoadjuvant rectal score in a cohort of Hong Kong Chinese. METHODS Data of patients with locally advanced rectal cancer who received neoadjuvant chemoradiotherapy from August 2006 to October 2018 were retrieved from hospital records and retrospectively analysed. RESULTS Of 193 patients who had optimal response to neoadjuvant chemoradiotherapy and surgery, tumour down-staging was the only independent prognostic factor that predicted pathological complete response (P<0.0001). Neoadjuvant rectal score was associated with overall survival (hazard ratio [HR]=1.042, 95% confidence interval [CI]=1.021-1.064; P<0.0001), disease-free survival (HR=1.042, 95% CI=1.022-1.062; P<0.0001), locoregional recurrence-free survival (HR=1.070, 95% CI=1.039-1.102; P<0.0001) and distant recurrence-free survival (HR=1.034, 95% CI=1.012-1.056; P=0.002). Patients who had pathological complete response were associated with a lower neoadjuvant rectal score (P<0.0001), but pathological complete response was not associated with survival. For patients with intermediate neoadjuvant rectal scores, late recurrences beyond 72 months from diagnosis were observed. CONCLUSION Neoadjuvant rectal score is an independent prognostic marker of survival and disease recurrence in a cohort of Hong Kong Chinese patients who received neoadjuvant chemoradiotherapy for locally advanced rectal cancer.
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Affiliation(s)
- S S K Ho
- Department of Medicine and Geriatrics, Princess Margaret Hospital, Hong Kong
| | - S S F Hon
- Department of Surgery, Alice Ho Miu Ling Nethersole Hospital, Hong Kong
| | - E Hung
- Department of Imaging and Interventional Radiology, Prince of Wales Hospital, Hong Kong
| | - J F Y Lee
- Department of Surgery, Prince of Wales Hospital, Hong Kong
| | - F Mo
- State Key Laboratory in Translational Oncology in South China, Sir YK Pao Centre for Cancer, Department of Clinical Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong
| | - M Tong
- State Key Laboratory in Translational Oncology in South China, Sir YK Pao Centre for Cancer, Department of Clinical Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong
| | - C So
- State Key Laboratory in Translational Oncology in South China, Sir YK Pao Centre for Cancer, Department of Clinical Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong
| | - S Chu
- Department of Surgery, Prince of Wales Hospital, Hong Kong
| | - D C K Ng
- Department of Surgery, North District Hospital, Hong Kong
| | - D Lam
- Department of Clinical Oncology, Prince of Wales Hospital, Hong Kong
| | - C Cho
- Department of Imaging and Interventional Radiology, Prince of Wales Hospital, Hong Kong
| | - T W C Mak
- Department of Surgery, Prince of Wales Hospital, Hong Kong
| | - S S M Ng
- Department of Surgery, Prince of Wales Hospital, Hong Kong
| | - K Futaba
- Department of Surgery, Prince of Wales Hospital, Hong Kong
| | - J Suen
- Department of Clinical Oncology, Prince of Wales Hospital, Hong Kong
| | - K F To
- Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Hong Kong
| | - A W H Chan
- Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Hong Kong
| | | | - B B Y Ma
- State Key Laboratory in Translational Oncology in South China, Sir YK Pao Centre for Cancer, Department of Clinical Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong
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11
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Yao M, Li Z, Li C, Xiao H, Wang S, Chan AWH, Zhao Y. Isomer-Resolved Reactivity of Organic Peroxides in Monoterpene-Derived Secondary Organic Aerosol. Environ Sci Technol 2022; 56:4882-4893. [PMID: 35357822 DOI: 10.1021/acs.est.2c01297] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Organic peroxides play a vital role in the formation, evolution, and health impacts of atmospheric aerosols, yet their molecular composition and fate in the particle phase remain poorly understood. Here, we identified, using iodometry-assisted liquid chromatography mass spectrometry, a large suite of isomer-resolved peroxide monomers (C8-10H12-18O5-8) and dimers (C15-20H22-34O5-14) in secondary organic aerosol formed from ozonolysis of the most abundant monoterpene (α-pinene). Combining aerosol isothermal evaporation experiments and multilayer kinetic modeling, bulk peroxides were found to undergo rapid particle-phase chemical transformation with an average lifetime of several hours under humid conditions, while the individual peroxides decompose on timescales of half an hour to a few days. Meanwhile, the majority of isomeric peroxides exhibit distinct particle-phase behaviors, highlighting the importance of the characterization of isomer-resolved peroxide reactivity. Furthermore, the reactivity of most peroxides increases with aerosol water content faster in a low relative humidity (RH) range than in a high RH range. Such non-uniform water effects imply a more important role of water as a plasticizer than as a reactant in influencing the peroxide reactivity. The high particle-phase reactivity of organic peroxides and its striking dependence on RH should be considered in atmospheric modeling of their fate and impacts on aerosol chemistry and health effects.
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Affiliation(s)
- Min Yao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ziyue Li
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Chenxi Li
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Huayun Xiao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Shunyao Wang
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto Ontario M5S 3E5, Canada
| | - Arthur W H Chan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto Ontario M5S 3E5, Canada
| | - Yue Zhao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
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12
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Dingle JH, Kohl L, Khan N, Meng M, Shi YA, Pedroza-Brambila M, Chow CW, Chan AWH. Sources and composition of metals in indoor house dust in a mid-size Canadian city. Environ Pollut 2021; 289:117867. [PMID: 34375850 DOI: 10.1016/j.envpol.2021.117867] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 05/28/2023]
Abstract
House dust is an important medium for exposure to persistent pollutants, such as metals. Detailed characterization of metal composition is needed to identify sources and potential health impacts of exposure. In this study we show that specific metals in dust dominate in different locations within residential homes in a mid-size Canadian city (Fort McMurray, Alberta), up to two years after a major wildfire event in 2016. Dust samples were collected in high-traffic (e.g. bedroom, N = 186), low-traffic (e.g. basement, N = 158), and entranceway areas (N = 171) of residential homes (N = 125), and analyzed for 25 trace metal elements using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The profile of metal concentrations in the entranceway resembled that of outdoor soils, especially for crustal elements. On the other hand, Cu, Zn, and Pb concentrations in dust sampled in indoor living areas were on average three to six times higher than in other indoor locations indicating indoor sources for these elements. In general, Pb concentrations were similar or lower than in an average Canadian residence, but a substantial fraction showed anomalously high concentrations in the low-traffic areas, particularly on concrete surfaces in basements. Notably, the 2016 wildfires showed limited influence on metal concentrations in indoor dust, despite the widespread concerns in the community about long term exposure. Enrichment factor ratio calculations and principal component analysis showed two classes of sources of metals in dust that represent geogenic-outdoor sources and anthropogenic-indoor sources. Overall, we demonstrate that outdoor and indoor sources of dust impact its composition, and these influences are reflected in the different areas of a home.
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Affiliation(s)
- Justin H Dingle
- University of Toronto, Department of Chemical Engineering and Applied Chemistry, 200 College Street, Toronto, ON, M5S 3E5, Canada
| | - Lukas Kohl
- University of Toronto, Department of Chemical Engineering and Applied Chemistry, 200 College Street, Toronto, ON, M5S 3E5, Canada
| | - Nadiha Khan
- University of Toronto, Department of Chemical Engineering and Applied Chemistry, 200 College Street, Toronto, ON, M5S 3E5, Canada
| | - Meng Meng
- University of Toronto, Department of Chemical Engineering and Applied Chemistry, 200 College Street, Toronto, ON, M5S 3E5, Canada
| | - Yuelun A Shi
- University of Toronto, Department of Chemical Engineering and Applied Chemistry, 200 College Street, Toronto, ON, M5S 3E5, Canada
| | - Marcia Pedroza-Brambila
- University of Toronto, Department of Chemical Engineering and Applied Chemistry, 200 College Street, Toronto, ON, M5S 3E5, Canada
| | - Chung-Wai Chow
- University of Toronto, Department of Chemical Engineering and Applied Chemistry, 200 College Street, Toronto, ON, M5S 3E5, Canada; University of Toronto, Faculty of Medicine, 1 King's College Cir, Toronto, ON, M5S 1A8, Canada; University of Toronto, Dalla Lana School of Public Health, 155 College St, Toronto, ON, M5T 3M7, Canada
| | - Arthur W H Chan
- University of Toronto, Department of Chemical Engineering and Applied Chemistry, 200 College Street, Toronto, ON, M5S 3E5, Canada.
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13
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Liu T, Chan AWH, Abbatt JPD. Multiphase Oxidation of Sulfur Dioxide in Aerosol Particles: Implications for Sulfate Formation in Polluted Environments. Environ Sci Technol 2021; 55:4227-4242. [PMID: 33760581 DOI: 10.1021/acs.est.0c06496] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Atmospheric oxidation of sulfur dioxide (SO2) forms sulfate-containing aerosol particles that impact air quality, climate, and human and ecosystem health. It is well-known that in-cloud oxidation of SO2 frequently dominates over gas-phase oxidation on regional and global scales. Multiphase oxidation involving aerosol particles, fog, and cloud droplets has been generally thought to scale with liquid water content (LWC) so multiphase oxidation would be negligible for aerosol particles due to their low aerosol LWC. However, recent field evidence, particularly from East Asia, shows that fast sulfate formation prevails in cloud-free environments that are characterized by high aerosol loadings. By assuming that the kinetics of cloud water chemistry prevails for aerosol particles, most atmospheric models do not capture this phenomenon. Therefore, the field of aerosol SO2 multiphase chemistry has blossomed in the past decade, with many oxidation processes proposed to bridge the difference between modeled and observed sulfate mass loadings. This review summarizes recent advances in the fundamental understanding of the aerosol multiphase oxidation of SO2, with a focus on environmental conditions that affect the oxidation rate, experimental challenges, mechanisms and kinetics results for individual reaction pathways, and future research directions. Compared to dilute cloud water conditions, this paper highlights the differences that arise at the molecular level with the extremely high solute strengths present in aerosol particles.
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Affiliation(s)
- Tengyu Liu
- Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, Nanjing, 210023, China
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Arthur W H Chan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Jonathan P D Abbatt
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
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14
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Mahdavi A, Dingle J, Chan AWH, Siegel JA. HVAC filtration of particles and trace metals: Airborne measurements and the evaluation of quantitative filter forensics. Environ Pollut 2021; 271:116388. [PMID: 33388682 DOI: 10.1016/j.envpol.2020.116388] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 12/12/2020] [Accepted: 12/23/2020] [Indexed: 06/12/2023]
Abstract
Filters installed in the heating, ventilation, and air-conditioning (HVAC) systems can serve as air-cleaning and sampling devices for indoor particles. The purpose of this article is to evaluate these dual roles. An occupied home with a central HVAC system equipped with a Minimum Efficiency Reporting Value (MERV, from ASHRAE Standard 52.2) 11 filter was monitored for six weeks. Weekly airborne gravimetric and real-time sampling was performed to measure the particle size distribution and the concentration of total suspended particles (TSP), PM10, PM2.5, PM1, and 12 trace metals. The weekly system runtimes were intentionally changed to provide a wide range of weekly filtration volumes. The quantitative filter forensics (QFF) concentrations of particulate matter (PM) and trace metals were calculated using the analysis of the dust collected on the HVAC filter, the filtration volume, and filter in-situ efficiency. The results indicated that filtration was not influential to remove PM and trace metals as the concentrations during the weeks with continuous HVAC operation were not consistently lower than those during the other weeks. This suggests the dominance of other particle and trace metal source and loss mechanisms weakens the influence of filtration in this home. The QFF evaluation results indicated that the concentration of TSP and over half of the tested trace metals (e.g., Pb, Cd, Ni, V, Sb, K, and Sr) could be estimated by QFF within a factor of two when compared to airborne sampling results. PM10, PM2.5, and PM1 concentrations were significantly underestimated by QFF potentially due to the limitations of size distribution analysis by a laser diffraction particle sizer (LDPS) for the detection of <1 μm particles. Overall, while QFF was promising for TSP and some trace metals, improvement in size distribution analysis could extend the application of QFF for airborne sampling.
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Affiliation(s)
- Alireza Mahdavi
- Department of Civil and Mineral Engineering, University of Toronto, Toronto, Canada
| | - Justin Dingle
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Canada
| | - Arthur W H Chan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Canada
| | - Jeffrey A Siegel
- Department of Civil and Mineral Engineering, University of Toronto, Toronto, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, Canada.
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15
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Wang S, Zhou S, Tao Y, Tsui WG, Ye J, Yu JZ, Murphy JG, McNeill VF, Abbatt JPD, Chan AWH. Organic Peroxides and Sulfur Dioxide in Aerosol: Source of Particulate Sulfate. Environ Sci Technol 2019; 53:10695-10704. [PMID: 31418552 DOI: 10.1021/acs.est.9b02591] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Sulfur oxides (SOx) are important atmospheric trace species in both gas and particulate phases, and sulfate is a major component of atmospheric aerosol. One potentially important source of particulate sulfate formation is the oxidation of dissolved SO2 by organic peroxides, which comprises a major fraction of secondary organic aerosol (SOA). In this study, we investigated the reaction kinetics and mechanisms between SO2 and condensed-phase peroxides. pH-dependent aqueous phase reaction rate constants between S(IV) and organic peroxide standards were measured. Highly oxygenated organic peroxides with O/C > 0.6 in α-pinene SOA react rapidly with S(IV) species in the aqueous phase. The reactions between organic peroxides and S(IV) yield both inorganic sulfate and organosulfates (OS), as observed by electrospray ionization ion mobility mass spectrometry. For the first time, 34S-labeling experiments in this study revealed that dissolved SO2 forms OS via direct reactions without forming inorganic sulfate as a reactive intermediate. Kinetics of OS formation was estimated semiquantitatively, and such reaction was found to account for 30-60% of sulfur reacted. The photochemical box model GAMMA was applied to assess the implications of the measured SO2 consumption and OS formation rates. Our findings indicate that this novel pathway of SO2-peroxide reaction is important for sulfate formation in submicron aerosol.
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Affiliation(s)
- Shunyao Wang
- Department of Chemical Engineering and Applied Chemistry , University of Toronto , Toronto , Ontario M5S 3E5 , Canada
| | - Shouming Zhou
- Department of Chemistry , University of Toronto , Toronto , Ontario M5S 3H6 , Canada
| | - Ye Tao
- Department of Physical and Environmental Sciences , University of Toronto Scarborough , Toronto , Ontario M1C 1A4 , Canada
| | - William G Tsui
- Department of Chemical Engineering , University of Columbia , New York , New York 10027 , United States
| | - Jianhuai Ye
- Department of Chemical Engineering and Applied Chemistry , University of Toronto , Toronto , Ontario M5S 3E5 , Canada
- School of Engineering and Applied Sciences , Harvard University , Cambridge , Massachusetts 02138 , United States
| | - Jian Zhen Yu
- Department of Chemistry , Hong Kong University of Science and Technology , Hong Kong , China
| | - Jennifer G Murphy
- Department of Chemistry , University of Toronto , Toronto , Ontario M5S 3H6 , Canada
| | - V Faye McNeill
- Department of Chemical Engineering , University of Columbia , New York , New York 10027 , United States
| | - Jonathan P D Abbatt
- Department of Chemistry , University of Toronto , Toronto , Ontario M5S 3H6 , Canada
| | - Arthur W H Chan
- Department of Chemical Engineering and Applied Chemistry , University of Toronto , Toronto , Ontario M5S 3E5 , Canada
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16
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Zeglinski MR, Turner CT, Zeng R, Schwartz C, Santacruz S, Pawluk MA, Zhao H, Chan AWH, Carlsten C, Granville DJ. Soluble Wood Smoke Extract Promotes Barrier Dysfunction in Alveolar Epithelial Cells through a MAPK Signaling Pathway. Sci Rep 2019; 9:10027. [PMID: 31296909 PMCID: PMC6624307 DOI: 10.1038/s41598-019-46400-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 06/07/2019] [Indexed: 02/07/2023] Open
Abstract
Wildfire smoke induces acute pulmonary distress and is of particular concern to risk groups such as the sick and elderly. Wood smoke (WS) contains many of the same toxic compounds as those found in cigarette smoke (CS) including polycyclic aromatic hydrocarbons, carbon monoxide, and free radicals. CS is a well-established risk factor for respiratory diseases such as asthma and COPD. Limited studies investigating the biological effects of WS on the airway epithelium have been performed. Using a cell culture-based model, we assessed the effects of a WS-infused solution on alveolar epithelial barrier function, cell migration, and survival. The average geometric mean of particles in the WS was 178 nm. GC/MS analysis of the WS solution identified phenolic and cellulosic compounds. WS exposure resulted in a significant reduction in barrier function, which peaked after 24 hours of continuous exposure. The junctional protein E-cadherin showed a prominent reduction in response to increasing concentrations of WS. Furthermore, WS significantly repressed cell migration following injury to the cell monolayer. There was no difference in cell viability following WS exposure. Mechanistically, WS exposure induced activation of the p44/42, but not p38, MAPK signaling pathway, and inhibition of p44/42 phosphorylation prevented the disruption of barrier function and loss of E-cadherin staining. Thus, WS may contribute to the breakdown of alveolar structure and function through a p44/42 MAPK-dependent pathway and may lead to the development and/or exacerbation of respiratory pathologies with chronic exposure.
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Affiliation(s)
- Matthew R Zeglinski
- International Collaboration on Repair Discoveries (ICORD), Vancouver Coastal Health Research Institute, University of British Columbia (UBC), Vancouver, BC, Canada.,Department of Pathology and Laboratory Medicine, UBC, Vancouver, BC, Canada.,UBC Centre for Heart Lung Innovation, St. Paul's Hospital, UBC, Vancouver, BC, Canada.,British Columbia Professional Firefighters' Burn and Wound Healing Group, Vancouver, BC, Canada
| | - Christopher T Turner
- International Collaboration on Repair Discoveries (ICORD), Vancouver Coastal Health Research Institute, University of British Columbia (UBC), Vancouver, BC, Canada.,Department of Pathology and Laboratory Medicine, UBC, Vancouver, BC, Canada.,UBC Centre for Heart Lung Innovation, St. Paul's Hospital, UBC, Vancouver, BC, Canada.,British Columbia Professional Firefighters' Burn and Wound Healing Group, Vancouver, BC, Canada
| | - Rui Zeng
- Department of Chemical Engineering & Applied Chemistry, University of Toronto, Toronto, ON, Canada
| | - Carley Schwartz
- UBC Centre for Heart Lung Innovation, St. Paul's Hospital, UBC, Vancouver, BC, Canada.,Department of Medicine, Division of Respiratory Medicine, Chan-Yeung Centre for Occupational and Environmental Respiratory Disease, Vancouver Coastal Health Research Institute, UBC, Vancouver, BC, Canada
| | - Stephanie Santacruz
- International Collaboration on Repair Discoveries (ICORD), Vancouver Coastal Health Research Institute, University of British Columbia (UBC), Vancouver, BC, Canada.,Department of Pathology and Laboratory Medicine, UBC, Vancouver, BC, Canada.,UBC Centre for Heart Lung Innovation, St. Paul's Hospital, UBC, Vancouver, BC, Canada.,British Columbia Professional Firefighters' Burn and Wound Healing Group, Vancouver, BC, Canada
| | - Megan A Pawluk
- International Collaboration on Repair Discoveries (ICORD), Vancouver Coastal Health Research Institute, University of British Columbia (UBC), Vancouver, BC, Canada
| | - Hongyan Zhao
- International Collaboration on Repair Discoveries (ICORD), Vancouver Coastal Health Research Institute, University of British Columbia (UBC), Vancouver, BC, Canada.,Department of Pathology and Laboratory Medicine, UBC, Vancouver, BC, Canada.,UBC Centre for Heart Lung Innovation, St. Paul's Hospital, UBC, Vancouver, BC, Canada.,British Columbia Professional Firefighters' Burn and Wound Healing Group, Vancouver, BC, Canada
| | - Arthur W H Chan
- Department of Chemical Engineering & Applied Chemistry, University of Toronto, Toronto, ON, Canada
| | - Christopher Carlsten
- UBC Centre for Heart Lung Innovation, St. Paul's Hospital, UBC, Vancouver, BC, Canada.,Department of Medicine, Division of Respiratory Medicine, Chan-Yeung Centre for Occupational and Environmental Respiratory Disease, Vancouver Coastal Health Research Institute, UBC, Vancouver, BC, Canada
| | - David J Granville
- International Collaboration on Repair Discoveries (ICORD), Vancouver Coastal Health Research Institute, University of British Columbia (UBC), Vancouver, BC, Canada. .,Department of Pathology and Laboratory Medicine, UBC, Vancouver, BC, Canada. .,UBC Centre for Heart Lung Innovation, St. Paul's Hospital, UBC, Vancouver, BC, Canada. .,British Columbia Professional Firefighters' Burn and Wound Healing Group, Vancouver, BC, Canada.
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17
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Yuen BTY, Hung EHY, Cho CCM, Hon SSF, Chan AWH, Chau HHL. Magnetic Resonance Imaging for Rectal Submucosal Tumours. Hong Kong J Radiol 2017. [DOI: 10.12809/hkjr1716935] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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18
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Worton DR, Decker M, Isaacman-VanWertz G, Chan AWH, Wilson KR, Goldstein AH. Improved molecular level identification of organic compounds using comprehensive two-dimensional chromatography, dual ionization energies and high resolution mass spectrometry. Analyst 2017; 142:2395-2403. [PMID: 28555694 DOI: 10.1039/c7an00625j] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A new analytical methodology combining comprehensive two-dimensional gas chromatography (GC×GC), dual ionization energies and high resolution time of flight mass spectrometry has been developed that improves molecular level identification of organic compounds in complex environmental samples. GC×GC maximizes compound separation providing cleaner mass spectra by minimizing erroneous fragments from interferences and co-eluting peaks. Traditional electron ionization (EI, 70 eV) provides MS fragmentation patterns that can be matched to published EI MS libraries while vacuum ultraviolet photoionization (VUV, 10.5 eV) yields MS with reduced fragmentation enhancing the abundance of the molecular ion providing molecular formulas when combined with high resolution mass spectrometry. We demonstrate this new approach by applying it to a sample of organic aerosol. In this sample, 238 peaks were matched to EI MS library data with FM ≥ 800 but a fifth (42 compounds) were determined to be incorrectly identified because the molecular formula was not confirmed by the VUV MS data. This highlights the importance of using a complementary technique to confirm compound identifications even for peaks with very good matching statistics. In total, 171 compounds were identified by EI MS matching to library spectra with confirmation of the molecular formula from the high resolution VUV MS data and were not dependent on the matching statistics being above a threshold value. A large number of unidentified peaks were still observed with FM < 800, which in routine analysis would typically be neglected. Where possible, these peaks were assigned molecular formulas from the VUV MS data (211 in total). In total, the combination of EI and VUV MS data provides more than twice as much molecular level peak information than traditional approaches and improves confidence in the identification of individual organic compounds. The molecular formula data from the VUV MS data was used, in conjunction with GC×GC retention times and the observed EI MS, to generate a new, searchable EI MS library compatible with the standard NIST MS search program. This library is deliberately dynamic and editable so that other end users can add new entries and update existing entries as new information becomes available.
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Affiliation(s)
- David R Worton
- Department of Environmental Sciences Policy and Management, University of California, Berkeley, CA 94720, USA.
| | - Monika Decker
- Department of Environmental Sciences Policy and Management, University of California, Berkeley, CA 94720, USA.
| | - Gabriel Isaacman-VanWertz
- Department of Environmental Sciences Policy and Management, University of California, Berkeley, CA 94720, USA.
| | - Arthur W H Chan
- Department of Environmental Sciences Policy and Management, University of California, Berkeley, CA 94720, USA.
| | - Kevin R Wilson
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Allen H Goldstein
- Department of Environmental Sciences Policy and Management, University of California, Berkeley, CA 94720, USA. and Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720, USA
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19
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Sitt JCM, Chan AWH, Mou J, Abrigo J, Tam YH, To KF, Chu WCW. Sonographic Features and Diagnostic Algorithm of Common Scrotal Masses in Children: with Pathological Correlations. Hong Kong J Radiol 2016. [DOI: 10.12809/hkjr1614245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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20
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Sitt JCM, Lee RKL, Chan AWH, Hui M, Wong KT, Yu SCH. Clinical Application, Performance, and Common Pitfalls of Ultrasound-guided Pleural Biopsy: Our Local Experience. Hong Kong J Radiol 2016. [DOI: 10.12809/hkjr1615368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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21
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Ye J, Gordon CA, Chan AWH. Enhancement in Secondary Organic Aerosol Formation in the Presence of Preexisting Organic Particle. Environ Sci Technol 2016; 50:3572-9. [PMID: 26963686 DOI: 10.1021/acs.est.5b05512] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Atmospheric models of secondary organic aerosol (SOA) typically assume organic species form a well-mixed phase. As a result, partitioning of semivolatile oxidation products into the particle phase to form SOA is thought to be enhanced by preexisting organic particles. In this work, the physicochemical properties that govern such enhancement in SOA yield were examined. SOA yields from α-pinene ozonolysis were measured in the presence of a variety of organic seeds which were chosen based on polarity and phase state at room temperature. Yield enhancement was only observed with seeds of medium polarities (tetraethylene glycol and citric acid). Solid hexadecanol seed was observed to enhance SOA yields only in chamber experiments with longer mixing time scales, suggesting that the mixing process for SOA and hexadecanol may be kinetically limited at shorter time scales. Our observations indicate that, in addition to kinetic limitations, intermolecular interactions also play a significant role in determining SOA yields. Here we propose for the first time to use the Hansen solubility framework to determine aerosol miscibility and predict SOA yield enhancement. These results highlight that current models may overestimate SOA formation, and parametrization of intermolecular forces is needed for accurate predictions of SOA formation.
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Affiliation(s)
- Jianhuai Ye
- Department of Chemical Engineering and Applied Chemistry, University of Toronto , Toronto, Ontario M5S 3E5, Canada
| | - Catherine A Gordon
- Department of Chemical Engineering and Applied Chemistry, University of Toronto , Toronto, Ontario M5S 3E5, Canada
| | - Arthur W H Chan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto , Toronto, Ontario M5S 3E5, Canada
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22
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Worton DR, Zhang H, Isaacman-VanWertz G, Chan AWH, Wilson KR, Goldstein AH. Comprehensive Chemical Characterization of Hydrocarbons in NIST Standard Reference Material 2779 Gulf of Mexico Crude Oil. Environ Sci Technol 2015; 49:13130-13138. [PMID: 26460682 DOI: 10.1021/acs.est.5b03472] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Comprehensive chemical information is needed to understand the environmental fate and impact of hydrocarbons released during oil spills. However, chemical information remains incomplete because of the limitations of current analytical techniques and the inherent chemical complexity of crude oils. In this work, gas chromatography (GC)-amenable C9-C33 hydrocarbons were comprehensively characterized from the National Institute of Standards and Technology Standard Reference Material (NIST SRM) 2779 Gulf of Mexico crude oil by GC coupled to vacuum ultraviolet photoionization mass spectrometry (GC/VUV-MS), with a mass balance of 68 ± 22%. This technique overcomes one important limitation faced by traditional GC and even comprehensive 2D gas chromatography (GC×GC): the necessity for individual compounds to be chromatographically resolved from one another in order to be characterized. VUV photoionization minimizes fragmentation of the molecular ions, facilitating the characterization of the observed hydrocarbons as a function of molecular weight (carbon number, NC), structure (number of double bond equivalents, NDBE), and mass fraction (mg kg(-1)), which represent important metrics for understanding their fate and environmental impacts. Linear alkanes (8 ± 1%), branched alkanes (11 ± 2%), and cycloalkanes (37 ± 12%) dominated the mass with the largest contribution from cycloalkanes containing one or two rings and one or more alkyl side chains (27 ± 9%). Linearity and good agreement with previous work for a subset of >100 components and for the sum of compound classes provided confidence in our measurements and represents the first independent assessment of our analytical approach and calibration methodology. Another crude oil collected from the Marlin platform (35 km northeast of the Macondo well) was shown to be chemically identical within experimental errors to NIST SRM 2779, demonstrating that Marlin crude is an appropriate surrogate oil for researchers conducting laboratory research into impacts of the DeepWater Horizon disaster.
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Affiliation(s)
- David R Worton
- Aerosol Dynamics, Inc. , Berkeley, California 94710, United States
| | | | | | | | - Kevin R Wilson
- Chemical Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
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23
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Ng SC, Ching JYL, Chan VCW, Wong MCS, Tang R, Wong S, Luk AKC, Lam TYT, Gao Q, Chan AWH, Wu JCY, Chan FKL, Lau JYW, Sung JJY. Association between serrated polyps and the risk of synchronous advanced colorectal neoplasia in average-risk individuals. Aliment Pharmacol Ther 2015; 41:108-15. [PMID: 25339583 DOI: 10.1111/apt.13003] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 09/12/2014] [Accepted: 10/06/2014] [Indexed: 12/16/2022]
Abstract
BACKGROUND Serrated polyps of the colorectum have distinct histological features and malignant potential. AIM To assess the association between the presence of serrated polyps and synchronous advanced colorectal neoplasia. METHODS Among 4989 asymptomatic Chinese individuals aged 50-70 years who underwent screening colonoscopy, 281 cases with advanced neoplasia (adenoma ≥1 cm, with tubulovillous/villous histology, with high-grade dysplasia, or invasive adenocarcinoma) were compared with 4708 controls without advanced neoplasia for age, sex, smoking history, body mass index, family history of colorectal cancer and the presence of serrated polyps. Independent predictors of advanced neoplasia were determined by multivariate logistic regression analysis. RESULTS The prevalence of advanced neoplasia and serrated polyps (excluding small distal hyperplastic polyps) was 5.7% and 5.6%, respectively. 3.7% and 0.4% subjects had proximal and large (≥10 mm) serrated polyps, respectively. Independent predictors of synchronous advanced colorectal neoplasia were the presence of sessile serrated adenomas (OR: 4.52; 95% CI: 2.40-8.49), proximal serrated polyps (OR: 2.23, 95% CI: 1.38-3.60), large serrated polyps (OR: 59.25; 95% CI: 18.85-186.21), hyperplastic polyps (OR: 1.66; 95% CI: 1.03-2.67), three or more serrated polyps (OR: 4.86; 95% CI: 1.24-19.15) and one or more non-advanced tubular adenomas (OR: 3.58, 95% CI: 2.59-4.96). CONCLUSION Detection of proximal, sessile and/or large serrated polyps at screening colonoscopy is independently associated with an increased risk for synchronous advanced neoplasia.
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Affiliation(s)
- S C Ng
- Department of Medicine and Therapeutics, Institute of Digestive Disease, Li Ka Shing Institute of Health Science, State Key Laboratory of Digestive Diseases, Chinese University of Hong Kong, Shatin, Hong Kong, China
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24
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Worton DR, Isaacman G, Gentner DR, Dallmann TR, Chan AWH, Ruehl C, Kirchstetter TW, Wilson KR, Harley RA, Goldstein AH. Lubricating oil dominates primary organic aerosol emissions from motor vehicles. Environ Sci Technol 2014; 48:3698-3706. [PMID: 24621254 DOI: 10.1021/es405375j] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Motor vehicles are major sources of primary organic aerosol (POA), which is a mixture of a large number of organic compounds that have not been comprehensively characterized. In this work, we apply a recently developed gas chromatography mass spectrometry approach utilizing "soft" vacuum ultraviolet photoionization to achieve unprecedented chemical characterization of motor vehicle POA emissions in a roadway tunnel with a mass closure of >60%. The observed POA was characterized by number of carbon atoms (NC), number of double bond equivalents (NDBE) and degree of molecular branching. Vehicular POA was observed to predominantly contain cycloalkanes with one or more rings and one or more branched alkyl side chains (≥80%) with low abundances of n-alkanes and aromatics (<5%), similar to "fresh" lubricating oil. The gas chromatography retention time data indicates that the cycloalkane ring structures are most likely dominated by cyclohexane and cyclopentane rings and not larger cycloalkanes. High molecular weight combustion byproducts, that is, alkenes, oxygenates, and aromatics, were not present in significant amounts. The observed carbon number and chemical composition of motor vehicle POA was consistent with lubricating oil being the dominant source from both gasoline and diesel-powered vehicles, with an additional smaller contribution from unburned diesel fuel and a negligible contribution from unburned gasoline.
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Affiliation(s)
- David R Worton
- Department of Environmental Science, Policy and Management, University of California , Berkeley, California 94720, United States
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25
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Zhang H, Ruehl CR, Chan AWH, Nah T, Worton DR, Isaacman G, Goldstein AH, Wilson KR. OH-Initiated Heterogeneous Oxidation of Cholestane: A Model System for Understanding the Photochemical Aging of Cyclic Alkane Aerosols. J Phys Chem A 2013; 117:12449-58. [DOI: 10.1021/jp407994m] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Haofei Zhang
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department
of Environmental Sciences, Policy, and Management, University of California, Berkeley, California 94720, United States
| | - Christopher R. Ruehl
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Arthur W. H. Chan
- Department
of Environmental Sciences, Policy, and Management, University of California, Berkeley, California 94720, United States
| | - Theodora Nah
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - David R. Worton
- Department
of Environmental Sciences, Policy, and Management, University of California, Berkeley, California 94720, United States
- Aerosol
Dynamics Inc., Berkeley, California 94720, United States
| | - Gabriel Isaacman
- Department
of Environmental Sciences, Policy, and Management, University of California, Berkeley, California 94720, United States
| | - Allen H. Goldstein
- Department
of Environmental Sciences, Policy, and Management, University of California, Berkeley, California 94720, United States
- Environmental
and Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department
of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
| | - Kevin R. Wilson
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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26
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Worton DR, Surratt JD, Lafranchi BW, Chan AWH, Zhao Y, Weber RJ, Park JH, Gilman JB, de Gouw J, Park C, Schade G, Beaver M, Clair JMS, Crounse J, Wennberg P, Wolfe GM, Harrold S, Thornton JA, Farmer DK, Docherty KS, Cubison MJ, Jimenez JL, Frossard AA, Russell LM, Kristensen K, Glasius M, Mao J, Ren X, Brune W, Browne EC, Pusede SE, Cohen RC, Seinfeld JH, Goldstein AH. Observational insights into aerosol formation from isoprene. Environ Sci Technol 2013; 47:11403-11413. [PMID: 24004194 DOI: 10.1021/es4011064] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Atmospheric photooxidation of isoprene is an important source of secondary organic aerosol (SOA) and there is increasing evidence that anthropogenic oxidant emissions can enhance this SOA formation. In this work, we use ambient observations of organosulfates formed from isoprene epoxydiols (IEPOX) and methacrylic acid epoxide (MAE) and a broad suite of chemical measurements to investigate the relative importance of nitrogen oxide (NO/NO2) and hydroperoxyl (HO2) SOA formation pathways from isoprene at a forested site in California. In contrast to IEPOX, the calculated production rate of MAE was observed to be independent of temperature. This is the result of the very fast thermolysis of MPAN at high temperatures that affects the distribution of the MPAN reservoir (MPAN / MPA radical) reducing the fraction that can react with OH to form MAE and subsequently SOA (F(MAE formation)). The strong temperature dependence of F(MAE formation) helps to explain our observations of similar concentrations of IEPOX-derived organosulfates (IEPOX-OS; ~1 ng m(-3)) and MAE-derived organosulfates (MAE-OS; ~1 ng m(-3)) under cooler conditions (lower isoprene concentrations) and much higher IEPOX-OS (~20 ng m(-3)) relative to MAE-OS (<0.0005 ng m(-3)) at higher temperatures (higher isoprene concentrations). A kinetic model of IEPOX and MAE loss showed that MAE forms 10-100 times more ring-opening products than IEPOX and that both are strongly dependent on aerosol water content when aerosol pH is constant. However, the higher fraction of MAE ring opening products does not compensate for the lower MAE production under warmer conditions (higher isoprene concentrations) resulting in lower formation of MAE-derived products relative to IEPOX at the surface. In regions of high NOx, high isoprene emissions and strong vertical mixing the slower MPAN thermolysis rate aloft could increase the fraction of MPAN that forms MAE resulting in a vertically varying isoprene SOA source.
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Affiliation(s)
- David R Worton
- Department of Environmental Science, Policy and Management, ∥Department of Chemistry, University of California , Berkeley, California 94720, United States
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27
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Ruehl CR, Nah T, Isaacman G, Worton DR, Chan AWH, Kolesar KR, Cappa CD, Goldstein AH, Wilson KR. The Influence of Molecular Structure and Aerosol Phase on the Heterogeneous Oxidation of Normal and Branched Alkanes by OH. J Phys Chem A 2013; 117:3990-4000. [DOI: 10.1021/jp401888q] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Christopher R. Ruehl
- Chemical Sciences Division,
Lawrence Berkeley National Laboratory, Berkeley, California 94720,
United States
- Department of Environmental Sciences, Policy, & Management, University of California, Berkeley, California 94720, United States
| | - Theodora Nah
- Chemical Sciences Division,
Lawrence Berkeley National Laboratory, Berkeley, California 94720,
United States
- Department of Chemistry, University
of California, Berkeley, California 94720, United States
| | - Gabriel Isaacman
- Department of Environmental Sciences, Policy, & Management, University of California, Berkeley, California 94720, United States
| | - David R. Worton
- Department of Environmental Sciences, Policy, & Management, University of California, Berkeley, California 94720, United States
- Aerosol Dynamics Inc., Berkeley,
California 94710, United States
| | - Arthur W. H. Chan
- Department of Environmental Sciences, Policy, & Management, University of California, Berkeley, California 94720, United States
| | - Katheryn R. Kolesar
- Department of Civil & Environmental Engineering, University of California, Davis, California 95616, United States
| | - Christopher D. Cappa
- Department of Civil & Environmental Engineering, University of California, Davis, California 95616, United States
| | - Allen H. Goldstein
- Department of Environmental Sciences, Policy, & Management, University of California, Berkeley, California 94720, United States
- Department of Civil & Environmental Engineering, University of California, Berkeley, California 94720, United States
- Environmental
Energy Technologies
Division, Lawrence Berkeley National Laboratory, Berkeley, California
94720, United States
| | - Kevin R. Wilson
- Chemical Sciences Division,
Lawrence Berkeley National Laboratory, Berkeley, California 94720,
United States
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28
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Gentner DR, Isaacman G, Worton DR, Chan AWH, Dallmann TR, Davis L, Liu S, Day DA, Russell LM, Wilson KR, Weber R, Guha A, Harley RA, Goldstein AH. Elucidating secondary organic aerosol from diesel and gasoline vehicles through detailed characterization of organic carbon emissions. Proc Natl Acad Sci U S A 2012; 109:18318-23. [PMID: 23091031 PMCID: PMC3494959 DOI: 10.1073/pnas.1212272109] [Citation(s) in RCA: 170] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Emissions from gasoline and diesel vehicles are predominant anthropogenic sources of reactive gas-phase organic carbon and key precursors to secondary organic aerosol (SOA) in urban areas. Their relative importance for aerosol formation is a controversial issue with implications for air quality control policy and public health. We characterize the chemical composition, mass distribution, and organic aerosol formation potential of emissions from gasoline and diesel vehicles, and find diesel exhaust is seven times more efficient at forming aerosol than gasoline exhaust. However, both sources are important for air quality; depending on a region's fuel use, diesel is responsible for 65% to 90% of vehicular-derived SOA, with substantial contributions from aromatic and aliphatic hydrocarbons. Including these insights on source characterization and SOA formation will improve regional pollution control policies, fuel regulations, and methodologies for future measurement, laboratory, and modeling studies.
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Affiliation(s)
- Drew R. Gentner
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720
| | - Gabriel Isaacman
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720
| | - David R. Worton
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720
- Aerosol Dynamics, Berkeley, CA 94710
| | - Arthur W. H. Chan
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720
| | - Timothy R. Dallmann
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720
| | - Laura Davis
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720
| | - Shang Liu
- Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA 92093; and
| | - Douglas A. Day
- Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA 92093; and
| | - Lynn M. Russell
- Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA 92093; and
| | - Kevin R. Wilson
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Robin Weber
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720
| | - Abhinav Guha
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720
| | - Robert A. Harley
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720
| | - Allen H. Goldstein
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720
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Isaacman G, Chan AWH, Nah T, Worton DR, Ruehl CR, Wilson KR, Goldstein AH. Heterogeneous OH oxidation of motor oil particles causes selective depletion of branched and less cyclic hydrocarbons. Environ Sci Technol 2012; 46:10632-10640. [PMID: 22947099 DOI: 10.1021/es302768a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Motor oil serves as a useful model system for atmospheric oxidation of hydrocarbon mixtures typical of anthropogenic atmospheric particulate matter, but its complexity often prevents comprehensive chemical speciation. In this work we fully characterize this formerly "unresolved complex mixture" at the molecular level using recently developed soft ionization gas chromatography techniques. Nucleated motor oil particles are oxidized in a flow tube reactor to investigate the relative reaction rates of observed hydrocarbon classes: alkanes, cycloalkanes, bicycloalkanes, tricycloalkanes, and steranes. Oxidation of hydrocarbons in a complex aerosol is found to be efficient, with approximately three-quarters (0.72 ± 0.06) of OH collisions yielding a reaction. Reaction rates of individual hydrocarbons are structurally dependent: compared to normal alkanes, reaction rates increased by 20-50% with branching, while rates decreased ∼20% per nonaromatic ring present. These differences in rates are expected to alter particle composition as a function of oxidation, with depletion of branched and enrichment of cyclic hydrocarbons. Due to this expected shift toward ring-opening reactions heterogeneous oxidation of the unreacted hydrocarbon mixture is less likely to proceed through fragmentation pathways in more oxidized particles. Based on the observed oxidation-induced changes in composition, isomer-resolved analysis has potential utility for determining the photochemical age of atmospheric particulate matter with respect to heterogeneous oxidation.
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Affiliation(s)
- Gabriel Isaacman
- Environmental Science, Policy, and Management, University of California, Berkeley, California, United States.
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30
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Isaacman G, Wilson KR, Chan AWH, Worton DR, Kimmel JR, Nah T, Hohaus T, Gonin M, Kroll JH, Worsnop DR, Goldstein AH. Improved Resolution of Hydrocarbon Structures and Constitutional Isomers in Complex Mixtures Using Gas Chromatography-Vacuum Ultraviolet-Mass Spectrometry. Anal Chem 2012; 84:2335-42. [DOI: 10.1021/ac2030464] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Gabriel Isaacman
- Environmental Science, Policy,
and Management, University of California, Berkeley, California, United States
| | - Kevin R. Wilson
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California,
United States
| | - Arthur W. H. Chan
- Environmental Science, Policy,
and Management, University of California, Berkeley, California, United States
| | - David R. Worton
- Environmental Science, Policy,
and Management, University of California, Berkeley, California, United States
- Aerosol Dynamics Inc., Berkeley, California, United States
| | - Joel R. Kimmel
- Center for Aerosol and Cloud
Chemistry, Aerodyne Research, Inc., Billerica,
Massachusetts, United States
- Cooperative Institute for Research
in the Environmental Sciences and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado, United States
- Tofwerk AG, Thun, Switzerland
| | - Theodora Nah
- Chemistry, University of California, Berkeley, California, United States
| | - Thorsten Hohaus
- Center for Aerosol and Cloud
Chemistry, Aerodyne Research, Inc., Billerica,
Massachusetts, United States
| | | | - Jesse H. Kroll
- Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts,
United States
- Chemical
Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts,
United States
| | - Douglas R. Worsnop
- Center for Aerosol and Cloud
Chemistry, Aerodyne Research, Inc., Billerica,
Massachusetts, United States
| | - Allen H. Goldstein
- Environmental Science, Policy,
and Management, University of California, Berkeley, California, United States
- Environmental
and Energy Technologies
Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States
- Civil and Environmental Engineering, University of California, Berkeley, California, United
States
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31
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Li WH, Lau TCF, Wong KK, Chan AWH, Cheung MT. Colorectal cancer surgery of octogenarians in Hong Kong: who will survive? Hong Kong Med J 2011; 17:358-364. [PMID: 21979471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
OBJECTIVE. To assess the accuracy of the Association of Coloproctology of Great Britain and Ireland scoring system in predicting the 30-day mortality after surgery for colorectal cancer in Hong Kong elderly (aged 80 years or more) patients. DESIGN. Early mortality outcome audit in a historical cohort. SETTING. Queen Elizabeth Hospital, Hong Kong. PATIENTS. All Chinese patients (aged 80 years or more) who underwent elective or emergency surgery for colorectal cancer in the Department of Surgery between January 2005 and December 2009. MAIN OUTCOME MEASURES. Receiver operating characteristic curve analyses were used to estimate the predictive ability of the score. RESULTS. In all, 180 patients with colorectal cancer were included in this review. The overall 30-day and hospital mortality rates were 29/180 (16%) and 31/180 (17%), respectively. The Association of Coloproctology of Great Britain and Ireland score was significantly higher among patients who died within 30 days (4.2 vs 3.1, P=0.0001), and was the only independent predictor for 30-day mortality by logistic regression (P=0.009; odds ratio=2.555; 95% confidence interval, 1.277-4.932). The mean score of this study population was 3.22 (median, 3.10), giving a predicted 30-day mortality rate of 16.0 to 17.4%, which corresponded with an observed 30-day mortality of 16.1% encountered in this study. The score had a significantly larger area under the curve for the 30-day mortality rates (odds ratio=0.811; 95% confidence interval, 0.722-0.849) as compared to the American Society of Anesthesiologists score (0.664; 0.589-0.735) [P=0.0001]. CONCLUSION. The Association of Coloproctology of Great Britain and Ireland scoring system can accurately predict the 30-day mortality rate of elderly Hong Kong Chinese patients (aged 80 years or more) operated on for colorectal cancer.
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Affiliation(s)
- W H Li
- Department of Surgery, Queen Elizabeth Hospital, 30 Gascoigne Road, Hong Kong.
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32
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Yasmeen F, Szmigielski R, Vermeylen R, Gómez-González Y, Surratt JD, Chan AWH, Seinfeld JH, Maenhaut W, Claeys M. Mass spectrometric characterization of isomeric terpenoic acids from the oxidation of α-pinene, β-pinene, d-limonene, and Δ3-carene in fine forest aerosol. J Mass Spectrom 2011; 46:425-442. [PMID: 21438093 DOI: 10.1002/jms.1911] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In this study, we present liquid chromatographic and mass spectral data for predominant terpenoic acids formed through oxidation of α-pinene, β-pinene, d-limonene, and Δ(3)-carene that occur in fine forest aerosol from K-puszta, Hungary, a rural site with coniferous vegetation. Characterization of these secondary organic aerosol tracers in fine ambient aerosol is important because it allows one to gain information on monoterpene precursors and source processes such as oxidation and aging processes. The mass spectral data were obtained using electrospray ionization in the negative ion mode, accurate mass measurements, and linear ion trap tandem mass spectrometric experiments. Emphasis is given to the mass spectrometric differentiation of isobaric terpenoic acids, such as, e.g. the molecular weight (MW) 186 terpenoic acids, cis-pinic, cis-caric, homoterpenylic, ketolimononic, and limonic acids. Other targeted isobaric terpenoic acids are the MW 184 terpenoic acids, cis-pinonic and cis-caronic acids, and the MW 204 tricarboxylic acids, 3-methyl-1,2,3-butanetricarboxylic and 3-carboxyheptanedioic acids. Fragmentation pathways are proposed to provide a rational explanation for the observed isomeric differences and/or to support the suggested tentative structures. For the completeness of the data set, data obtained for recently reported lactone-containing terpenoic acids (i.e. terpenylic and terebic acids), related or isobaric compounds (i.e. norpinic acid, diaterpenylic acid acetate, and unknown MW 188 compounds) are also included, the rationale being that other groups working on this topic could use this data compilation as a reference.
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Affiliation(s)
- Farhat Yasmeen
- Department of Pharmaceutical Sciences, University of Antwerp, BE-2610 Antwerp, Belgium
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33
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Ng MCY, Lam VKL, Tam CHT, Chan AWH, So WY, Ma RCW, Zee BCY, Waye MMY, Mak WW, Hu C, Wang CR, Tong PCY, Jia WP, Chan JCN. Association of the POU class 2 homeobox 1 gene (POU2F1) with susceptibility to Type 2 diabetes in Chinese populations. Diabet Med 2010; 27:1443-9. [PMID: 21059098 DOI: 10.1111/j.1464-5491.2010.03124.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
AIMS POU class 2 homeobox 1 (POU2F1), also known as octamer-binding transcription factor-1 (OCT-1), is a ubiquitous transcription factor that plays a key role in the regulation of genes related to inflammation and cell cycles. POU2F1 is located on chromosome 1q24, a region with linkage for Type 2 diabetes in Chinese and other populations. We examined the association of POU2F1 genetic variants with Type 2 diabetes in Hong Kong Chinese using two independent cohorts. METHODS We genotyped five haplotype-tagging single nucleotide polymorphisms at POU2F1 in 1378 clinic-based patients with Type 2 diabetes and 601 control subjects, as well as 707 members from 179 families with diabetes. RESULTS We found significant associations of rs4657652, rs7532692, rs10918682 and rs3767434 (OR = 1.26-1.59, 0.0003 < P(unadjusted) < 0.035) with Type 2 diabetes in the clinic-based case-control cohorts. Rs3767434 was also associated with Type 2 diabetes (OR = 1.55, P(unadjusted) = 0.013) in the family-based cohort. Meta-analysis revealed similar associations. In addition, the risk G allele of rs10918682 showed increased usage of insulin treatment during a mean follow-up period of 7 years [hazard ratio = 1.50 (1.05-2.14), P = 0.025]. CONCLUSIONS Using separate cohorts, we observed consistent results showing the contribution of multiple variants at POU2F1 to the risk of Type 2 diabetes.
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Affiliation(s)
- M C Y Ng
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, China.
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Loza CL, Chan AWH, Galloway MM, Keutsch FN, Flagan RC, Seinfeld JH. Characterization of vapor wall loss in laboratory chambers. Environ Sci Technol 2010; 44:5074-8. [PMID: 20527767 DOI: 10.1021/es100727v] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Laboratory chambers used to study atmospheric chemistry and aerosol formation are subject to wall loss of vapors and particles that must be accounted for in calculating aerosol yields. While particle wall loss in chambers is relatively well-understood and routinely accounted for, that of vapor is less so. Here we address experimental measurement and modeling of vapor losses in environmental chambers. We identify two compounds that exhibit wall loss: 2,3-epoxy-1,4-butanediol (BEPOX), an analog of an important isoprene oxidation product; and glyoxal, a common volatile organic compound oxidation product. Dilution experiments show that BEPOX wall loss is irreversible on short time scales but is reversible on long time scales, and glyoxal wall loss is reversible for all time scales. BEPOX exhibits minimal uptake onto clean chamber walls under dry conditions, with increasing rates of uptake over the life of an in-use chamber. By performing periodic BEPOX wall loss experiments, it is possible to assess quantitatively the aging of chamber walls.
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Affiliation(s)
- Christine L Loza
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
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35
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Wong GLH, Wong VWS, Choi PCL, Chan AWH, Chan HLY. Development of a non-invasive algorithm with transient elastography (Fibroscan) and serum test formula for advanced liver fibrosis in chronic hepatitis B. Aliment Pharmacol Ther 2010; 31:1095-103. [PMID: 20180785 DOI: 10.1111/j.1365-2036.2010.04276.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Non-invasive assessments of liver fibrosis in chronic hepatitis B were well established. AIM To develop a combined algorithm of liver stiffness measurement (LSM) and serum test formula to predict advanced liver fibrosis in chronic hepatitis B. METHODS We reported an alanine aminotransferase (AST)-based LSM algorithm for liver fibrosis in 156 chronic hepatitis B patients, which formed the training cohort to evaluate the performance of APRI (AST-to-platelet-ratio-index), Forns index, FIB-4 and Fibroindex against liver histology. The best combined LSM-serum formula algorithm would be validated in another cohort of 82 chronic hepatitis B patients. RESULTS In the training cohort, LSM has the best performance of diagnosing advanced (> or =F3) fibrosis [area under the receiver operating characteristics curve (AUROC) 0.88, 95% confidence interval (CI) 0.85-0.91], while Forns index has the best performance among the various serum test formulae (AUROC 0.70, 95% CI 0.62-0.78). In the combined algorithm, low LSM or low Forns index could be used to exclude advanced fibrosis as both of them had high sensitivity (>90%). To confirm advanced fibrosis, agreement between high LSM and high Forns index could improve the specificity (from 99% to 100% and from 87% to 98% in the training and validation cohorts respectively). CONCLUSION A combined LSM-Forns algorithm can improve the accuracy to predict advanced liver fibrosis in chronic hepatitis B.
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Affiliation(s)
- G L H Wong
- Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong SAR, China
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36
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Surratt JD, Chan AWH, Eddingsaas NC, Chan M, Loza CL, Kwan AJ, Hersey SP, Flagan RC, Wennberg PO, Seinfeld JH. Reactive intermediates revealed in secondary organic aerosol formation from isoprene. Proc Natl Acad Sci U S A 2010; 107:6640-5. [PMID: 20080572 PMCID: PMC2872383 DOI: 10.1073/pnas.0911114107] [Citation(s) in RCA: 315] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Isoprene is a significant source of atmospheric organic aerosol; however, the oxidation pathways that lead to secondary organic aerosol (SOA) have remained elusive. Here, we identify the role of two key reactive intermediates, epoxydiols of isoprene (IEPOX = beta-IEPOX + delta-IEPOX) and methacryloylperoxynitrate (MPAN), which are formed during isoprene oxidation under low- and high-NO(x) conditions, respectively. Isoprene low-NO(x) SOA is enhanced in the presence of acidified sulfate seed aerosol (mass yield 28.6%) over that in the presence of neutral aerosol (mass yield 1.3%). Increased uptake of IEPOX by acid-catalyzed particle-phase reactions is shown to explain this enhancement. Under high-NO(x) conditions, isoprene SOA formation occurs through oxidation of its second-generation product, MPAN. The similarity of the composition of SOA formed from the photooxidation of MPAN to that formed from isoprene and methacrolein demonstrates the role of MPAN in the formation of isoprene high-NO(x) SOA. Reactions of IEPOX and MPAN in the presence of anthropogenic pollutants (i.e., acidic aerosol produced from the oxidation of SO(2) and NO(2), respectively) could be a substantial source of "missing urban SOA" not included in current atmospheric models.
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Affiliation(s)
- Jason D. Surratt
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Arthur W. H. Chan
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Nathan C. Eddingsaas
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - ManNin Chan
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125
| | - Christine L. Loza
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Alan J. Kwan
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125
| | - Scott P. Hersey
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125
| | - Richard C. Flagan
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125
| | - Paul O. Wennberg
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125
| | - John H. Seinfeld
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125
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37
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Wong GLH, Wong VWS, Choi PCL, Chan AWH, Chan HLY. Development of a non-invasive algorithm with transient elastography (Fibroscan) and serum test formula for advanced liver fibrosis in chronic hepatitis B. Aliment Pharmacol Ther 2010. [PMID: 20180785 DOI: 10.1111/j.13652036.2010.04276.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/13/2023]
Abstract
BACKGROUND Non-invasive assessments of liver fibrosis in chronic hepatitis B were well established. AIM To develop a combined algorithm of liver stiffness measurement (LSM) and serum test formula to predict advanced liver fibrosis in chronic hepatitis B. METHODS We reported an alanine aminotransferase (AST)-based LSM algorithm for liver fibrosis in 156 chronic hepatitis B patients, which formed the training cohort to evaluate the performance of APRI (AST-to-platelet-ratio-index), Forns index, FIB-4 and Fibroindex against liver histology. The best combined LSM-serum formula algorithm would be validated in another cohort of 82 chronic hepatitis B patients. RESULTS In the training cohort, LSM has the best performance of diagnosing advanced (> or =F3) fibrosis [area under the receiver operating characteristics curve (AUROC) 0.88, 95% confidence interval (CI) 0.85-0.91], while Forns index has the best performance among the various serum test formulae (AUROC 0.70, 95% CI 0.62-0.78). In the combined algorithm, low LSM or low Forns index could be used to exclude advanced fibrosis as both of them had high sensitivity (>90%). To confirm advanced fibrosis, agreement between high LSM and high Forns index could improve the specificity (from 99% to 100% and from 87% to 98% in the training and validation cohorts respectively). CONCLUSION A combined LSM-Forns algorithm can improve the accuracy to predict advanced liver fibrosis in chronic hepatitis B.
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Affiliation(s)
- G L H Wong
- Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong SAR, China
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Claeys M, Iinuma Y, Szmigielski R, Surratt JD, Blockhuys F, Van Alsenoy C, Böge O, Sierau B, Gómez-González Y, Vermeylen R, Van der Veken P, Shahgholi M, Chan AWH, Herrmann H, Seinfeld JH, Maenhaut W. Terpenylic acid and related compounds from the oxidation of alpha-pinene: implications for new particle formation and growth above forests. Environ Sci Technol 2009; 43:6976-82. [PMID: 19806730 DOI: 10.1021/es9007596] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Novel secondary organic aerosol (SOA) products from the monoterpene alpha-pinene with unique dimer-forming properties have been identified as lactone-containing terpenoic acids, i.e., terpenylic and 2-hydroxyterpenylic acid, and diaterpenylic acid acetate. The structural characterizations were based on the synthesis of reference compounds and detailed interpretation of mass spectral data. Terpenylic acid and diaterpenylic acid acetate are early oxidation products generated upon both photooxidation and ozonolysis, while 2-hydroxyterpenylic acid is an abundant SOA tracer in ambient fine aerosol that can be explained by further oxidation of terpenylic acid. Quantum chemical calculations support that noncovalent dimer formation involving double hydrogen bonding interactions between carboxyl groups of the monomers is energetically favorable. The molecular properties allow us to explain initial particle formation in laboratory chamber experiments and are suggested to play a role in new particle formation and growth above forests, a natural phenomenon that has fascinated scientists for more than a century.
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Affiliation(s)
- Magda Claeys
- Department of Pharmaceutical Sciences, University of Antwerp, BE-2610 Antwerp, Belgium.
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Chan AWH, Galloway MM, Kwan AJ, Chhabra PS, Keutsch FN, Wennberg PO, Flagan RC, Seinfeld JH. Photooxidation of 2-methyl-3-Buten-2-ol (MBO) as a potential source of secondary organic aerosol. Environ Sci Technol 2009; 43:4647-4652. [PMID: 19673246 DOI: 10.1021/es802560w] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
2-Methyl-3-buten-2-ol (MBO) is an important biogenic hydrocarbon emitted in large quantities by pine forests. Atmospheric photooxidation of MBO is known to lead to oxygenated compounds, such as glycolaldehyde, which is the precursor to glyoxal. Recent studies have shown that the reactive uptake of glyoxal onto aqueous particles can lead to formation of secondary organic aerosol (SOA). In this work, MBO photooxidation under high- and low-NO(x) conditions was performed in dual laboratory chambers to quantify the yield of glyoxal and investigate the potential for SOA formation. The yields of glycolaldehyde and 2-hydroxy-2-methylpropanal (HMPR), fragmentation products of MBO photooxidation, were observed to be lower at lower NO(x) concentrations. Overall, the glyoxal yield from MBO photooxidation was 25% under high-NO(x) and 4% under low-NO(x) conditions. In the presence of wet ammonium sulfate seed and under high-NO(x) conditions, glyoxal uptake and SOA formation were not observed conclusively, due to relatively low (< 30 ppb) glyoxal concentrations. Slight aerosol formation was observed under low-NO(x) and dry conditions, with aerosol mass yields on the order of 0.1%. The small amount of SOA was not related to glyoxal uptake, but is likely a result of reactions similar to those that generate isoprene SOA under low-NO(x) conditions. The difference in aerosol yields between MBO and isoprene photooxidation under low-NO(x) conditions is consistent with the difference in vapor pressures between triols (from MBO) and tetrols (from isoprene). Despite its structural similarity to isoprene, photooxidation of MBO is not expected to make a significant contribution to SOA formation.
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Affiliation(s)
- Arthur W H Chan
- Department of Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
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Surratt JD, Gómez-González Y, Chan AWH, Vermeylen R, Shahgholi M, Kleindienst TE, Edney EO, Offenberg JH, Lewandowski M, Jaoui M, Maenhaut W, Claeys M, Flagan RC, Seinfeld JH. Organosulfate Formation in Biogenic Secondary Organic Aerosol. J Phys Chem A 2008; 112:8345-78. [DOI: 10.1021/jp802310p] [Citation(s) in RCA: 478] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jason D. Surratt
- Department of Chemistry, California Institute of Technology,
Pasadena, California 91125, Department of Pharmaceutical Sciences,
University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610
Antwerp, Belgium, Department of Chemical Engineering, California Institute
of Technology, Pasadena, California 91125, National Exposure Laboratory,
Office of Research and Development, Environmental Protection Agency,
Research Triangle Park, North Carolina 27711, Alion Science and Technology,
P.O. Box 1231,
| | - Yadian Gómez-González
- Department of Chemistry, California Institute of Technology,
Pasadena, California 91125, Department of Pharmaceutical Sciences,
University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610
Antwerp, Belgium, Department of Chemical Engineering, California Institute
of Technology, Pasadena, California 91125, National Exposure Laboratory,
Office of Research and Development, Environmental Protection Agency,
Research Triangle Park, North Carolina 27711, Alion Science and Technology,
P.O. Box 1231,
| | - Arthur W. H. Chan
- Department of Chemistry, California Institute of Technology,
Pasadena, California 91125, Department of Pharmaceutical Sciences,
University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610
Antwerp, Belgium, Department of Chemical Engineering, California Institute
of Technology, Pasadena, California 91125, National Exposure Laboratory,
Office of Research and Development, Environmental Protection Agency,
Research Triangle Park, North Carolina 27711, Alion Science and Technology,
P.O. Box 1231,
| | - Reinhilde Vermeylen
- Department of Chemistry, California Institute of Technology,
Pasadena, California 91125, Department of Pharmaceutical Sciences,
University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610
Antwerp, Belgium, Department of Chemical Engineering, California Institute
of Technology, Pasadena, California 91125, National Exposure Laboratory,
Office of Research and Development, Environmental Protection Agency,
Research Triangle Park, North Carolina 27711, Alion Science and Technology,
P.O. Box 1231,
| | - Mona Shahgholi
- Department of Chemistry, California Institute of Technology,
Pasadena, California 91125, Department of Pharmaceutical Sciences,
University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610
Antwerp, Belgium, Department of Chemical Engineering, California Institute
of Technology, Pasadena, California 91125, National Exposure Laboratory,
Office of Research and Development, Environmental Protection Agency,
Research Triangle Park, North Carolina 27711, Alion Science and Technology,
P.O. Box 1231,
| | - Tadeusz E. Kleindienst
- Department of Chemistry, California Institute of Technology,
Pasadena, California 91125, Department of Pharmaceutical Sciences,
University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610
Antwerp, Belgium, Department of Chemical Engineering, California Institute
of Technology, Pasadena, California 91125, National Exposure Laboratory,
Office of Research and Development, Environmental Protection Agency,
Research Triangle Park, North Carolina 27711, Alion Science and Technology,
P.O. Box 1231,
| | - Edward O. Edney
- Department of Chemistry, California Institute of Technology,
Pasadena, California 91125, Department of Pharmaceutical Sciences,
University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610
Antwerp, Belgium, Department of Chemical Engineering, California Institute
of Technology, Pasadena, California 91125, National Exposure Laboratory,
Office of Research and Development, Environmental Protection Agency,
Research Triangle Park, North Carolina 27711, Alion Science and Technology,
P.O. Box 1231,
| | - John H. Offenberg
- Department of Chemistry, California Institute of Technology,
Pasadena, California 91125, Department of Pharmaceutical Sciences,
University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610
Antwerp, Belgium, Department of Chemical Engineering, California Institute
of Technology, Pasadena, California 91125, National Exposure Laboratory,
Office of Research and Development, Environmental Protection Agency,
Research Triangle Park, North Carolina 27711, Alion Science and Technology,
P.O. Box 1231,
| | - Michael Lewandowski
- Department of Chemistry, California Institute of Technology,
Pasadena, California 91125, Department of Pharmaceutical Sciences,
University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610
Antwerp, Belgium, Department of Chemical Engineering, California Institute
of Technology, Pasadena, California 91125, National Exposure Laboratory,
Office of Research and Development, Environmental Protection Agency,
Research Triangle Park, North Carolina 27711, Alion Science and Technology,
P.O. Box 1231,
| | - Mohammed Jaoui
- Department of Chemistry, California Institute of Technology,
Pasadena, California 91125, Department of Pharmaceutical Sciences,
University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610
Antwerp, Belgium, Department of Chemical Engineering, California Institute
of Technology, Pasadena, California 91125, National Exposure Laboratory,
Office of Research and Development, Environmental Protection Agency,
Research Triangle Park, North Carolina 27711, Alion Science and Technology,
P.O. Box 1231,
| | - Willy Maenhaut
- Department of Chemistry, California Institute of Technology,
Pasadena, California 91125, Department of Pharmaceutical Sciences,
University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610
Antwerp, Belgium, Department of Chemical Engineering, California Institute
of Technology, Pasadena, California 91125, National Exposure Laboratory,
Office of Research and Development, Environmental Protection Agency,
Research Triangle Park, North Carolina 27711, Alion Science and Technology,
P.O. Box 1231,
| | - Magda Claeys
- Department of Chemistry, California Institute of Technology,
Pasadena, California 91125, Department of Pharmaceutical Sciences,
University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610
Antwerp, Belgium, Department of Chemical Engineering, California Institute
of Technology, Pasadena, California 91125, National Exposure Laboratory,
Office of Research and Development, Environmental Protection Agency,
Research Triangle Park, North Carolina 27711, Alion Science and Technology,
P.O. Box 1231,
| | - Richard C. Flagan
- Department of Chemistry, California Institute of Technology,
Pasadena, California 91125, Department of Pharmaceutical Sciences,
University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610
Antwerp, Belgium, Department of Chemical Engineering, California Institute
of Technology, Pasadena, California 91125, National Exposure Laboratory,
Office of Research and Development, Environmental Protection Agency,
Research Triangle Park, North Carolina 27711, Alion Science and Technology,
P.O. Box 1231,
| | - John H. Seinfeld
- Department of Chemistry, California Institute of Technology,
Pasadena, California 91125, Department of Pharmaceutical Sciences,
University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610
Antwerp, Belgium, Department of Chemical Engineering, California Institute
of Technology, Pasadena, California 91125, National Exposure Laboratory,
Office of Research and Development, Environmental Protection Agency,
Research Triangle Park, North Carolina 27711, Alion Science and Technology,
P.O. Box 1231,
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Sorooshian A, Ng NL, Chan AWH, Feingold G, Flagan RC, Seinfeld JH. Particulate organic acids and overall water‐soluble aerosol composition measurements from the 2006 Gulf of Mexico Atmospheric Composition and Climate Study (GoMACCS). ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2007jd008537] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Armin Sorooshian
- Department of Chemical Engineering California Institute of Technology Pasadena California USA
| | - Nga L. Ng
- Department of Chemical Engineering California Institute of Technology Pasadena California USA
| | - Arthur W. H. Chan
- Department of Chemical Engineering California Institute of Technology Pasadena California USA
| | - Graham Feingold
- Chemical Sciences Division, Earth System Research Laboratory NOAA Boulder Colorado USA
| | - Richard C. Flagan
- Department of Chemical Engineering California Institute of Technology Pasadena California USA
| | - John H. Seinfeld
- Department of Chemical Engineering California Institute of Technology Pasadena California USA
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42
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Kroll JH, Chan AWH, Ng NL, Flagan RC, Seinfeld JH. Reactions of semivolatile organics and their effects on secondary organic aerosol formation. Environ Sci Technol 2007; 41:3545-50. [PMID: 17547176 DOI: 10.1021/es062059x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Secondary organic aerosol (SOA) constitutes a significant fraction of total atmospheric particulate loading, but there is evidence that SOA yields based on laboratory studies may underestimate atmospheric SOA. Here we present chamber data on SOA growth from the photooxidation of aromatic hydrocarbons, finding that SOA yields are systematically lower when inorganic seed particles are not initially present. This indicates that concentrations of semivolatile oxidation products are influenced by processes beyond gas-particle partitioning, such as chemical reactions and/or loss to chamber walls. Predictions of a kinetic model in which semivolatile compounds may undergo reactions in both the gas and particle phases in addition to partitioning are qualitatively consistent with the observed seed effect, as well as with a number of other recently observed features of SOA formation chemistry. The behavior arises from a kinetic competition between uptake to the particle phase and reactive loss of the semivolatile product. It is shown that when hydrocarbons react in the absence of preexisting organic aerosol, such loss processes may lead to measured SOA yields lower than would occur under atmospheric conditions. These results underscore the need to conduct studies of SOA formation in the presence of atmospherically relevant aerosol loadings.
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Affiliation(s)
- Jesse H Kroll
- Department of Environmental Science and Engineering, California Institute of Technology, Pasadena, California 91125, USA
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Wong VWS, Hui AY, Tsang SWC, Chan JLY, Wong GLH, Chan AWH, So WY, Cheng AYS, Tong PCY, Chan FKL, Sung JJY, Chan HLY. Prevalence of undiagnosed diabetes and postchallenge hyperglycaemia in Chinese patients with non-alcoholic fatty liver disease. Aliment Pharmacol Ther 2006; 24:1215-22. [PMID: 17014580 DOI: 10.1111/j.1365-2036.2006.03112.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Non-alcoholic fatty liver disease is prevalent in affluent countries and is strongly associated with metabolic syndrome. AIM To study the prevalence of undiagnosed diabetes and postchallenge hyperglycaemia in Chinese patients with non-alcoholic fatty liver disease. METHODS 73 consecutive patients with biopsy-proven non-alcoholic fatty liver disease and no history of diabetes underwent comprehensive metabolic screening. Diagnosis of diabetes and impaired glucose regulation was based on the 2006 American Diabetes Association criteria. RESULTS The prevalence of undiagnosed diabetes and impaired glucose tolerance in non-alcoholic fatty liver disease patients was 33% and 29%, respectively. Among patients with 2-h plasma glucose above 7.8 mm, 47% had normal fasting glucose (below 5.6 mm). Impaired glucose tolerance was more common in patients with non-alcoholic steatohepatitis than those with simple hepatic steatosis (P = 0.036), and 2-h plasma glucose correlated with fibrosis stage (Spearman coefficient: 0.25, P = 0.046). In a binary logistic regression analysis, high fasting glucose and low high-density lipoprotein cholesterol were independent factors associated with diabetes. Nevertheless, if oral glucose tolerance test was only performed in non-alcoholic fatty liver disease patients with impaired fasting glucose, 20.8% of diabetes cases would be missed. CONCLUSIONS Isolated postchallenge hyperglycaemia is common among Chinese non-alcoholic fatty liver disease patients without history of diabetes. It is associated with histological severe disease, and cannot be accurately predicted by any fasting glucose cut-off.
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Affiliation(s)
- V W S Wong
- Institute of Digestive Diseases, The Chinese University of Hong Kong, Prince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, Hong Kong SAR
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