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How well does XAD resin extraction recover halogenated disinfection byproducts for comprehensive identification and toxicity testing?

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Journal of Environmental Sciences 2022年第7期34卷 264-275页

作者： Xiaobin Liao joshua m.allen Caroline O.Granger Susan D.Richardson Department of Chemistry and Biochemistry University of South CarolinaColumbiaSouth Carolina 29208USA Institute of municipal and Environmental Engineering College of Civil EngineeringHuaqiao UniversityFujian 361021China Currently at LanzaTech 535 Commerce DriveSopertonGeorgia 30457USA

Halogenated disinfection byproducts(DBPs) are an unintended consequence of drinking water disinfection, and can have significant toxicity. XAD resins are commonly used to extract and enrich trace levels of DBPs for comprehensive, nontarget identification of DBPs and also for in vitro toxicity studies. However, XAD resin recoveries for complete classes of halogenated DBPs have not been evaluated, particularly for low, environmentally relevant levels(ng/L to low μg/L). Thus, it is not known whether levels of DBPs or the toxicity of drinking water might be underestimated. In this study, DAX-8/XAD-2 layered resins were evaluated, considering both adsorption and elution from the resins, for extracting 66 DBPs from water. Results demonstrate that among the 7 classes of DBPs investigated, trihalomethanes(THms), including iodo-THms, were the most efficiently adsorbed, with recovery of most THms ranging from 50%-96%, followed by halonitromethanes(40%-90%). The adsorption ability of XAD resins for haloacetonitriles, haloacetamides, and haloacetaldehydes was highly dependent on the individual species. The adsorption capacity of XAD resins for haloacetic acids was lower(5%-48%), even after adjusting to p H 1 before extraction. Recovery efficiency for most DBPs was comparable with their adsorption, as most were eluted effectively from XAD resins by ethyl acetate. DBP polarity and molecular weight were the two most important factors that determine their recovery. Recovery of trichloromethane, iodoacetic acid, chloro-and iodo-acetonitrile, and chloroacetamide were among the lowest, which could lead to underestimation of toxicity, particularly for iodoacetic acid and iodo-acetonitrile, which are highly toxic.

关键词： XAD resins Disinfection byproducts DBPs Recovery Toxicity

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Total organic halogen(TOX) in human urine: A halogen-specific method for human exposure studies

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Journal of Environmental Sciences 2017年第8期29卷 285-295页

作者： Susana Y.Kimura Weiwei Zheng Taylor N.Hipp joshua m.allen Susan D.Richardson Department of Chemistry and Biochemistry University of South Carolina Key Laboratory of Public Health Safety Ministry of Education Department of Environmental Health School of Public Health Fudan University

Disinfection by-products（DBPs） are a complex mixture of compounds unintentionally formed as a result of disinfection processes used to treat drinking water. Effects of long-term exposure to DBPs are mostly unknown and were the subject of recent epidemiological studies. However,most bioanalytical methods focus on a select few DBPs. In this study, a new comprehensive bioanalytical method has been developed that can quantify mixtures of organic halogenated compounds, including DBPs, in human urine as total organic chlorine（TOCl）, total organic bromine（TOBr）, and total organic iodine（TOI）. The optimized method consists of urine dilution, adsorption to activated carbon, pyrolysis of activated carbon, absorption of gases in an aqueous solution, and halide analysis with ion chromatography and inductively coupled plasma-mass spectrometry. Spike recoveries for TOCl, TOBr, and TOI measurements ranged between 78% and 99%. Average TOCl, TOBr, and TOI concentrations in five urine samples from volunteers who consumed tap water were 1850, 82, and 21.0 μg/L as X^-, *** who consumed spring water（control） had TOCl, TOBr, and TOI average concentrations in urine of 1090, 88, and 10.3 μg/L as X^-, respectively. TOCl and TOI in the urine samples from tap water consumers were higher than the control. However, TOBr was slightly lower in tap water urine samples compared to mineral water urine samples, indicating other sources of environmental exposure other than drinking water. A larger sample population that consumes tap water from different cities and mineral water is needed to determine TOCl, TOBr, and TOI exposure from drinking water.

关键词： Adsorbable organic halogen(AOX) Total organic halogen(TOX) Disinfection by-products(DBPs) Total organic chlorine(TOCl) Total organic bromine(TOBr) Total organic iodine(TOI) Urine Drinking water

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Relationships between regulated DBPs and emerging DBPs of health concern in U.S. drinking water

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Journal of Environmental Sciences 2022年第7期34卷 161-172页

作者： Stuart W.Krasner Ai Jia Chih-Fen T.Lee Raha Shirkhani joshua m.allen Susan D.Richardson michael J.Plewa metropolitan Water District of Southern California Water Quality LaboratoryCA 91750USA Department of Chemistry and Biochemistry University of South CarolinaSC 29208USA Department of Crop Sciences University of Illinois at Urbana-ChampaignIL 61801USA Safe Global Water Institute University of Illinois at Urbana-ChampaignIL 61801USA

A survey was conducted at eight U.S. drinking water plants, that spanned a wide range of water qualities and treatment/disinfection practices. Plants that treated heavily-wastewaterimpacted source waters had lower trihalomethane to dihaloacetonitrile ratios due to the presence of more organic nitrogen and HAN precursors. As the bromide to total organic carbon ratio increased, there was more bromine incorporation into DBPs. This has been shown in other studies for THms and selected emerging DBPs(HANs), whereas this study examined bromine incorporation for a wider group of emerging DBPs(haloacetaldehydes, halonitromethanes). moreover, bromine incorporation into the emerging DBPs was, in general, similar to that of the THms. Epidemiology studies that show an association between adverse health effects and brominated THms may be due to the formation of brominated emerging DBPs of heath concern. Plants with higher free chlorine contact times before ammonia addition to form chloramines had less iodinated DBP formation in chloraminated distribution systems, where there was more oxidation of the iodide to iodate(a sink for the iodide) by the chlorine. This has been shown in many bench-scale studies(primarily for iodinated THms), but seldom in full-scale studies(where this study also showed the impact on total organic iodine. Collectively, the THms, haloacetic acids, and emerging DBPs accounted for a significant portion of the TOCl, TOBr, and TOI;however, ~50% of the TOCl and TOBr is still unknown. The correlation of the sum of detected DBPs with the TOCl and TOBr suggests that they can be used as reliable surrogates.

关键词： Disinfection by-products Total organic bromine Total organic iodine Trihalomethanes Haloacetonitriles Haloacetaldehydes Iodo-trihalomethanes Iodoacetic acids

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Showering in Flint, mI: Is there a DBP problem?

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Journal of Environmental Sciences 2017年第8期29卷 271-284页

作者： joshua m.allen Amy A.Cuthbertson Hannah K.Liberatore Susana Y.Kimura Anurag mantha marc A.Edwards Susan D.Richardson Department of Chemistry and Biochemistry University of South Carolina the Department of Chemistry University of Calgary Civil and Environmental Engineering Virginia Tech

Lead contamination in the City of Flint, mI has been well documented over the past two years, with lead levels above the EPA Action Level until summer 2016. This resulted from an ill-fated decision to switch from Detroit water（Lake Huron） with corrosion control, to Flint River water without corrosion control. Although lead levels are now closer to normal,reports of skin rashes have sparked questions surrounding tap water in some Flint *** study investigated the presence of contaminants, including disinfection by-products（DBPs）, in the hot tap water used for showering in the homes of residents in Flint. Extensive quantitative analysis of 61 regulated and priority unregulated DBPs was conducted in Flint hot and cold tap water, along with the analysis of 50 volatile organic compounds and a nontarget comprehensive, broadscreen analysis, to identify a possible source for the reported skin rashes. For comparison, chlorinated hot and cold waters from three other cities were also sampled, including Detroit, which also uses Lake Huron as its source *** showed that hot water samples generally contained elevated levels of regulated and priority unregulated DBPs compared to cold water samples, but trihalomethanes were still within regulatory limits. Overall, hot shower water from Flint was similar to waters sampled from the three other cities and did not have unusually high levels of DBPs or other organic chemicals that could be responsible for the skin rashes observed by residents. It is possible that an inorganic chemical or microbial contaminant may be responsible.

关键词： Disinfection by-products Disinfection byproducts DBPs Flint Hot water Showering Bathing Drinking water

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microstructure segmentation with deep learning encoders pre-trained on a large microscopy dataset

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npj Computational materials 2022年第1期8卷 1905-1916页

作者： joshua Stuckner Bryan Harder Timothy m.Smith materials and Structures Division NASA Glenn Research Center21000 Brookpark RdClevelandOH44135USA

This study examined the improvement of microscopy segmentation intersection over union accuracy by transfer learning from a large dataset of microscopy images called *** neural network encoder architectures were trained on over 100,000 labeled microscopy images from 54 material *** pre-trained encoders were then embedded into multiple segmentation architectures including UNet and DeepLabV3+to evaluate segmentation performance on created benchmark microscopy *** to ImageNet pre-training,models pre-trained on microNet generalized better to out-of-distribution micrographs taken under different imaging and sample conditions and were more accurate with less training *** training with only a single Ni-superalloy image,pre-training on microNet produced a 72.2%reduction in relative intersection over union *** results suggest that transfer learning from large in-domain datasets generate models with learned feature representations that are more useful for downstream tasks and will likely improve any microscopy image analysis technique that can leverage pre-trained encoders.

关键词： union intersection image

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Same Concept Different Outcomes:Sugars Determine Circadian Clock Protein Fate in Animals and Plants

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molecular Plant 2020年第3期13卷 360-362页

作者： Wei Liu joshua m.Gendron Department of molecular Cellular and Developmental BiologyYale UniversityNew HavenCT 06511USA

most eukaryotes have a self-sustaining circadian clock that senses environmental cues and the internal metabolic state and then imposes daily temporal organization of the *** clock,by nature,regulates the daily creation and destruction of a large quantity of RNA and proteins,including those at the core of the oscillator *** a transcriptional-translational feedback loop maintains the rhythmicity of the oscillator,various post-translational modifications(PTms)of clock proteins play fundamental roles in keeping the pace of the circadian clock near 24 *** maintain circadian clock pacing,PTms act to ensure the rapid,efficient,and precise activation,inactivation,and finally destruction of core clock proteins(Hirano et al.,2016).

关键词： maintain oscillator precise

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Exotic parrots breeding in urban tree cavities: nesting requirements, geographic distribution, and potential impacts on cavity nesting birds in southeast Florida

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Avian Research 2019年第4期10卷 459-468页

作者： joshua m.Diamond michael S.Ross Florida International University Earth & Environment

Background:Exotic parrots have established breeding populations in southeast Florida,including several species that nest in tree *** aimed to determine the species identity,nest site requirements,relative nest abundance,geographic distribution,and interactions of parrots with native cavity-nesting bird ***:We searched miami-Dade County,Florida,and nearby areas for natural cavities and holes excavated by woodpeckers,recording attributes of potential nest *** inspected all cavities with an elevated video inspection system to determine occupancy by parrots or other *** mapped nearly 4000 citizen science observations of parrots in our study area corresponding to our study period,and used these to construct range maps,comparing them to our nesting ***:Not all parrots reported or observed in our study area were actively *** parrots were observed at tree cavities,which previous studies have suggested is evidence of reproduction,but our inspections with an elevated video inspection system suggest they never initiated nesting *** parrot species did successfully nest in tree cavities,Red-masked Parakeets(Psittacara erythrogenys)and Orange-winged Parrots(Amazona amazonica)being the most common(n=7 and 6 nests,respectively).These two parrots had similar nesting requirements,but Orange-winged Parrots use nests with larger entrance holes,which they often *** analysis of nests combined with citizen science data indicate that parrots are limited to developed *** most common parrots were less abundant cavity nesters than the native birds which persist in miami’s urban areas,and far less abundant than the invasive European Starling(Sturnus vulgaris).Conclusions:Exotic parrots breeding elsewhere in the world have harmed native cavity-nesting birds through interference competition,but competitive interference in southeast Florida is minimized by the urban affinities of parrots in this ***

关键词： Amazona Cavity nest webs Invasive species Parakeets Psittacara Urban ecology

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Cost-Effectiveness of Interventions for Alternate Food to Address Agricultural Catastrophes Globally

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International Journal of Disaster Risk Science 2016年第3期7卷 205-215页

作者： David C.Denkenberger joshua m.Pearce Global Catastrophic Risk Institute Department of Civil and Architectural Engineering Tennessee State University Department of materials Science and Engineering Michigan Technological University Department of Electrical and Computer Engineering Michigan Technological University

The literature suggests there is about a 1 % risk per year of a 10 % global agricultural shortfall due to catastrophes such as a large volcanic eruption, a medium asteroid or comet impact, regional nuclear war, abrupt climate change, and extreme weather causing multiple breadbasket failures. This shortfall has an expected mortality of about 500 million people. To prevent such mass starvation, alternate foods can be deployed that utilize stored biomass. This study developed a model with literature values for variables and, where no values existed,used large error bounds to recognize uncertainty. Then monte Carlo analysis was performed on three interventions: planning, research, and development. The results show that even the upper bound of USD 400 per life saved by these interventions is far lower than what is typically paid to save a life in a less-developed country. Furthermore, every day of delay on the implementation of these interventions costs 100–40,000 expected lives(number of lives saved multiplied by the probability that alternate foods would be required). These interventions plus training would save 1–300 million expected lives. In general, these solutions would reduce the possibility of civilization collapse, could assist in providing food outside of catastrophic situations, and would result in billions of dollars per year of return.

关键词： Agricultural catastrophe Alternate food Global catastrophic risk Intervention cost-effectiveness

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Coronavirus Disease 2019 and Liver Injury:A Retrospective Analysis of Hospitalized Patients in New York City

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Journal of Clinical and Translational Hepatology 2021年第4期9卷 551-558页

作者： joshua m.Bender Howard J.Worman Department of medicine Vagelos College of Physicians&SurgeonsColumbia UniversityNew YorkNYUSA Department of Pathology and Cell Biology Vagelos College of Physicians&SurgeonsColumbia UniversityNew YorkNYUSA

Background and Aims:Coronavirus disease 2019(COVID-19)is a global threat,affecting more than 100 million people and causing over 2 million *** laboratory test abnormalities are an extrapulmonary manifestation of COVID-19,yet characterization of hepatic injury is *** objective was to further characterize and identify causes of liver injury in patients with ***:We conducted a retrospective cohort study of 551 patients hospitalized with COVID-19 at NewYork-Presbyterian Hospital/Columbia University Irving medical Center between march 1,2020 and may 31,*** analyzed patient demographics,liver laboratory test results,vital signs,other relevant test results,and clinical outcomes(mortality and intensive care unit admission).Results:Abnormal liver laboratory tests were common on hospital admission for COVID-19 and the incidence increased during *** those with elevated serum alanine aminotransferase and/or alkaline phosphatase activities on admission,58.2%had a cholestatic injury pattern,35.2%mixed,and 6.6%*** liver disease was not associated with outcome;however,abnormal direct bilirubin or albumin on admission were associated with intensive care unit stay and *** average,patients who died had greater magnitudes of abnormalities in all liver laboratory tests than those who *** hepatitis was a mechanism of severe hepatocellular injury in some ***:Liver laboratory test abnormalities are common in hospitalized patients with COVID-19,and some are associated with increased odds of intensive care unit stay or *** hepatocellular injury is likely attributable to secondary effects such as systemic inflammatory response syndrome,sepsis,and ischemic hepatitis.

关键词： Aminotransferase Bilirubin Ischemic hepatitis SARS-CoV-2

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Probing Electrocatalytic CO_(2) Reduction at Individual Cu Nanostructures via Optically Targeted Electrochemical Cell microscopy

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Journal of Analysis and Testing 2019年第2期3卷 140-149页

作者： joshua D.Walmsley joshua W.Hill Partha Saha Caleb m.Hill Department of Chemistry University of WyomingLaramieWY 82071USA

Optically targeted electrochemical cell microscopy(OTECCm)was applied to measure electrocatalytic rates at individual Cu nanoparticles(NPs)under electrolyte conditions relevant to CO_(2) *** electrocatalytic responses from individual NPs were found to exhibit a wide variation in behavior,with significant NP-to-NP variations in the magnitude of electrocata-lytic currents and necessary overpotentials being *** of these quantities with metrics of NP size suggest no significant variations in the inherent electrocatalytic activity of the NPs with *** element simulations of diffusion in this system demonstrate the observed diffusion-limited currents are significantly smaller than expected,attributable to the presence of a significant amount of residual ligand on the surface of the Cu NPs,which were prepared via an organic phase *** results presented here further demonstrate the promise of techniques which employ correlated optical and electrochemical measurements,such as OTECCm,for studying electrocatalysis at individual NPs.

关键词： Electrochemistry Electrochemical microscopy Nanoparticles CO_(2)reduction

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