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Determination of selected semi-volatile organic compounds in water using automated online solid-phase extraction with large-volume injection/gas chromatography/mass spectrometry

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Frontiers of Environmental Science & Engineering 2011年第3期5卷 417-425页

作者： Yongtao LI Christina L.MCCARTY Ed j.george Drinking Water Quality Laboratory Underwriters Laboratories Inc.South BendIN 46617USA Chemical Analysis Bruker DaltonicsFremontCA 94538USA

A rapid,sensitive,and cost-effective analyticalmethod was developed for the analysis of selected semivolatileorganic compounds in *** method used anautomated online solid-phase extraction technique coupledwith programmed-temperature vaporization large-volumeinjection gas chromatography/mass *** samples were extracted by using a fully automatedmobile rack system based on x-y-z robotic techniquesusing syringes and disposable 96-well extraction *** method was validated for the analysis of 30 semivolatileanalytes in drinking water,groundwater,andsurface *** a sample volume of 10 mL,the linearcalibrations ranged from 0.01 or 0.05 to 2.5μg·L^(-1),and themethod detection limits were less than 0.1μg·L^(-1).For thereagent water samples fortified at 1.0μg·L^(-1)and2.0μg·L^(-1),the obtained mean absolute recoveries were70%-130%with relative standard deviations of less than20%for most *** the drinking water,groundwater,and surface water samples fortified at 1.0μg·L^(-1),theobtained mean absolute recoveries were 50%-130%withrelative standard deviations of less than 20%for *** new method demonstrated three advantages:1)no manipulation except the fortification of surrogatestandards prior to extraction;2)significant cost reductionassociated with sample collection,shipping,storage,andpreparation;and 3)reduced exposure to hazardous solventsand other *** a result,this new automatedmethod can be used as an effective approach for screeningand/or compliance monitoring of selected semi-volatileorganic compounds in water.

关键词： automated solid-phase extraction programmed-temperature vaporization large-volume injection gas chromatography/mass spectrometry semi-volatile organic compounds water analysis

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Subjective refractions determined by Dyop® and LogMAR chart as fixation targets

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Annals of Eye Science 2022年第4期7卷 19-26页

作者： Rita W.Sum george C.Woo School of Optometry The Hong Kong Polytechnic UniversityHong KongChina

Background:Dyop®is a dynamic optotype with a rotating and segmented visual *** can be used for visual acuity and refractive error *** objective of the study was to compare refractive error measurement using the Dyop®acuity and LogMAR E ***:Fifty subjects aged 18 or above with aided visual acuity better than 6/12 were *** error was measured by subjective refraction methods using the Dyop®acuity chart and LogMAR E charts and the duration of measurement ***’s notation was used to represent the refractive error obtained for ***:There was no significant difference in terms of spherical equivalent(M)(P=0.96)or j0(P=0.78)and j45(P=0.51)components measured using the Dyop®acuity and LogMAR E ***,subjective refraction measurement was significantly faster using the Dyop®acuity chart(t=4.46,Pjective refraction.

关键词： Dyop dynamic optotype visual acuity subjective refraction

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HARNESSING ECOLOGICAL PRINCIPLES AND PHYSIOLOGIC MECHANISMS IN DIVERSIFYING AGRICULTURAL SYSTEMS FOR SUSTAINABILITY:EXPERIENCE FROM STUDIES DEPLOYING NATUR-EBASED SOLUTIONS IN SCOTLAND

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Frontiers of Agricultural Science and Engineering 2022年第2期9卷 214-237页

作者： Timothy S.george Cathy HAWES Tracy A.VALENTINE Alison j.KARLEY Pietro P.M.IANNETTA Robin W.BROOKER Ecological Sciences Department The James Hutton InstituteInvergowrieDundeeDD25DAUK

To achieve the triple challenge of food security,reversing biodiversity declines plus mitigating and adapting to climate change,there is a drive to embed ecological principles into agricultural,value-chain practices and *** diversifying cropping systems at several scales there is potential to decrease reliance on inputs,provide resilience to abiotic and biotic stress,enhance plant,microbe and animal biodiversity,and mitigate against climate *** this review we highlight the research performed in Scotland over the past 5 years into the impact of the use of ecological principles in agriculture on sustainability,resilience and provision of ecosystem *** demonstrate that diversification of the system can enhance ecosystem *** and plant management interventions,including nature-based solutions,can also enhance soil quality and utilization of legacy ***,this is facilitated by greater reliance on soil biological processes and trophic *** highlight the example of intercropping with legumes to deliver sustainability through ecological principles and use legumes as an exemplar of the *** conclude that there are many effective interventions that can be made to deliver resilient,sustainable,and diverse agroecosystems for crop and food production,and these may be applicable in any agroecosystem.

关键词： diversification ecological principles legumes plant management soil management soil ecosystem services

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Paleoecological Response of Corals to the End-Triassic Mass Extinction： An Integrational Analysis

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journal of Earth Science 2018年第4期29卷 879-885页

作者： george D Stanley jr Hannah M E Shepherd Autumn j Robinson University of Montana Paleontology Center Missoula MT 59812 USA

The end-Triassic （also Triassic-jurassic） mass extinction severely affected life on planet Earth 200 million years ago. Paleoclimate change triggered by the volcanic eruptions of the Central Atlantic Magmatic Province （CAMP） caused a great loss of marine biodiversity, among which 96% coral genera were get lost. However, there is precious little detail on the paleoecology and growth forms lost between the latest Triassic extinction and the Early jurassic recovery. Here a new pilot study was conducted by analyzing corallite integration levels among corals from the latest Triassic and Early jurassic times. Integration levels in corals from the Late Triassic and Early jurassic were determined through both the Paleobiology Database as well as from a comprehensive museum collection of fossil corals. Results suggest that in addition to a major loss of diversity following the end-Triassic mass extinction, there also was a significant loss of highly integrated corals as clearly evidenced by the coral data from the Early jurassic. This confirms our hypothesis of paleoecological selectivity for corals following the end-Triassic mass extinction. This study highlights the importance of assigning sim- ple to advanced paleoecological characters with integration levels, which opens a useful approach to understanding of mass extinction and the dynamics of the recovery.

关键词： coral loss integration level end-Triassic mass extinction paleoecology

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Analysis of High Frequency Data in Finance:A Survey

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Frontiers of Economics in China-Selected Publications from Chinese Universities 2020年第2期15卷 141-166页

作者： george j.jiang Guanzhong Pan Department of Finance and Management Science College of BusinessWashington State UniversityPullmanWA 99164USA School of Finance Yunnan University of Finance and EconomicsKunming 650221China

This study examines the use of high frequency data in finance,including volatility estimation and jump *** frequency data allows the construction of model-free volatility measures for asset *** variance is a consistent estimator of quadratic variation under mild regularity *** variation concepts,such as power variation and bipower variation,are useful and important for analyzing high frequency data when jumps are *** frequency data can also be used to test jumps in asset *** discuss three jump tests:bipower variation test,power variation test,and variance swap test in this *** presence of market microstructure noise complicates the analysis of high frequency *** survey introduces several robust methods of volatility estimation and jump tests in the presence of market microstructure ***,some applications of jump tests in asset pricing are discussed in this article.

关键词： high frequency data quadratic variation(QV) realized variance(RV) power variation(PV) bipower variation jump tests market microstructure noise asset pricing

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Increased connectivity of hiPSC-derived neural networks in multiphase granular hydrogel scaffolds

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Bioactive Materials 2022年第3期7卷 358-372页

作者： Chia-Chen Hsu julian H.george Sharlayne Waller Cyril Besnard David A Nagel Eric j Hill Michael D.Coleman Alexander M.Korsunsky Zhanfeng Cui Hua Ye Institute of Biomedical Engineering Department of Engineering ScienceUniversity of OxfordOX37DQUK MBLEM Department of Engineering ScienceUniversity of OxfordParks RoadOxfordOX13PJUK School of Biosciences College of Health and Life SciencesAston UniversityBirminghamB47ETUK Translational Medicine Research Group Aston Medical SchoolCollege of Health and Life SciencesAston UniversityBirminghamB47ETUK

To reflect human development,it is critical to create a substrate that can support long-term cell survival,differentiation,and *** are promising materials for 3D ***,a bulk structure consisting of dense polymer networks often leads to suboptimal microenvironments that impedes nutrient exchange and cell-to-cell ***,granular hydrogel-based scaffolds were used to support 3D human induced pluripotent stem cell(hiPSC)-derived neural networks.A custom designed 3D printed toolset was developed to extrude hyaluronic acid hydrogel through a porous nylon fabric to generate hydrogel *** and hydrogel granules were combined using a weaker secondary gelation step,forming self-supporting cell laden *** three and seven days,granular scaffolds supported higher cell viability compared to bulk hydrogels,whereas granular scaffolds supported more neurite bearing cells and longer neurite extensions(65.52±11.59μm)after seven days compared to bulk hydrogels(22.90±4.70μm).Long-term(three-month)cultures of clinically relevant hiPSC-derived neural cells in granular hydrogels supported well established neuronal and astrocytic colonies and a high level of neurite extension both inside and beyond the *** approach is significant as it provides a simple,rapid and efficient way to achieve a tissue-relevant granular structure within hydrogel cultures.

关键词： Microgel Hydrogel Hyaluronan iPSC Neural tissue engineering 3D printing

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文献快报(5):社交媒体使用消极体验而非使用时长增加青少年自杀意念

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中国学校卫生 2024年第5期45卷 614-614页

作者： HAMILTON j LDALACK M BOYD S I 李琪(编译) Department of Psychology Rutgers University Piscataway NJ USA. Department of Psychology George Washington University Washington DC USA. Department of Psychiatry University of Pittsburgh Pittsburgh PA USA.

社交媒体使用与青少年自杀风险的关联受到广泛关注。匹兹堡大学David教授领衔的团队在美国各地招募了60名青少年进行了为期8周的监测,通过每日3次生态瞬时评估询问青少年社交媒体使用相关的消极体验(如感到焦虑)、积极体验(如受到鼓励)... 详细信息

社交媒体使用与青少年自杀风险的关联受到广泛关注。匹兹堡大学David教授领衔的团队在美国各地招募了60名青少年进行了为期8周的监测,通过每日3次生态瞬时评估询问青少年社交媒体使用相关的消极体验(如感到焦虑)、积极体验(如受到鼓励)及自杀意念,首次通过密集监测设计探讨青少年社交媒体体验与自杀意念间的关联,结果显示,频繁经历消极的社交媒体体验的青少年更可能报告自杀意念,而积极的社交媒体体验与自杀意念报告率降低有关。此外,未发现社交媒体的使用时间(视屏时间)与自杀意念间的显著关联。研究提示社交媒体经历可能是青少年自杀可修饰的风险因素,未来的研究应将增强青少年社交媒体的积极体验感作为改善青少年心理健康和预防自杀的目标,而不仅仅是限制视屏时间。

关键词：社交媒体匹兹堡大学自杀意念青少年自杀积极体验青少年心理健康监测设计消极体验

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Linear and non-linear pseudocapacitances with or without diffusion control

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Progress in Natural Science:Materials International 2021年第6期31卷 792-800页

作者： george Zheng Chen Department of Chemical and Environmental Engineering and Advanced Materials Research Group Faculty of Engineering University of Nottingham

Pseudocapacitance is an important reversible charge storage mechanism in many electrode materials. Although the concept was first proposed in early 1960s, it has been more widely studied following the observation of rectangular cyclic voltammograms(CVs) when testing some transition metal oxides and electronically conducting polymers, and the association with supercapacitor. However, interpretation of pseudocapacitance is inconsistent in the literature. Although all agree that materials are pseudocapacitive if they undergo Faradaic reactions and exhibit rectangular CVs, some have regarded any surface confined Faradaic reactions which may present non-rectangular or even peak-shaped CVs to be pseudocapacitive. In the case of rectangular CVs, the amount of charge stored in the electrode is a linear function of the electrode potential, whilst for non-rectangular or peakshaped CVs, the relationship is non-linear. It is shown in this article that only linear pseudocapacitance is of relevance to supercapacitor, but non-linear pseudocapacitance may find applications in rechargeable battery and supercapattery. Further, it is clarified that the equation i = kv + kvis useful in analysis of electrode kinetics in terms of surface confinement and diffusion control. However, this kinetic equation is blind to the thermodynamically determined charge storage mechanisms as shown by experimental evidence, and should not be used to differentiate non-capacitive Faradaic processes from pseudocapacitance, either linear or non-linear.

关键词： Pseudocapacitance Cyclic voltammetry Galvanostatic charging and discharging Supercapacitor Rechargeable battery Supercapattery

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Salient concerns in using analgesia for cancer pain among outpatients: A cluster analysis study

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World journal of Clinical Oncology 2017年第1期8卷 75-85页

作者： Salimah H Meghani george j Knafl Department of Biobehavioral Health Sciences New Courtland Center for Transitions and HealthLeonard Davis Institute of Health EconomicsUniversity of Pennsylvania University of North Carolina at Chapel Hill School of Nursing

AIM To identify unique clusters of patients based on their concerns in using analgesia for cancer pain and predictors of the cluster *** This was a 3-mo prospective observational study(n = 207).Patients were included if they were adults(≥ 18 years), diagnosed with solid tumors or multiple myelomas, and had at least one prescription of around the clock pain medication for cancer or cancer-treatment-related *** were recruited from two outpatient medical oncology clinics within a large health system in Philadelphia.A choice-based conjoint(CBC) analysis experiment was used to elicit analgesic treatment preferences(utilities).Patients employed trade-offs based on five analgesic attributes(percent relief from analgesics, type of analgesic, type of sideeffects, severity of side-effects, out of pocket cost).Patients were clustered based on CBC utilities using novel adaptive statistical *** logistic regression was used to identify predictors of cluster *** The analyses found 4 unique clusters: Most patients made trade-offs based on the expectation of pain relief(cluster 1, 41%).For a subset, the main underlying concern was type of analgesic prescribed, i.e., opioid vs non-opioid(cluster 2, 11%) and type of analgesic side effects(cluster 4, 21%), *** one in four made trade-offs based on multiple concerns simultaneously including pain relief, type of side effects, and severity of side effects(cluster 3, 27.5%).In multivariable analysis, to identify predictors of cluster membership, clinical and socioeconomic factors(education, health literacy, income, social support) rather than analgesic attitudes and beliefs were found important; only the belief, i.e., pain medications can mask changes in health or keep you from knowing what is going on in your body was found significant in predicting two of the four clusters [cluster 1(-); cluster 4(+)].CONCLUSION Most patients appear to be driven by a single salient concer

关键词： Cancer pain Analgesia Opioids Preferences Conjoint analysis Side-effects

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Considerations for bariatric surgery in patients with cirrhosis

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World journal of Gastroenterology 2018年第28期24卷 3112-3119页

作者： george Boon-Bee Goh Philip R Schauer Arthur j McCullough Department of Gastroenterology and Hepatology Singapore General HospitalSingapore 169608Singapore Duke-NUS Graduate Medical School Singapore 169608Singapore Bariatric and Metabolic Institute Cleveland ClinicClevelandOH 44195United States Department of Gastroenterology Cleveland ClinicClevelandOH 44195United States Department of Pathobiology Cleveland ClinicClevelandOH 44195United States

With the ever increasing global obesity pandemic, clinical burden from obesity related complications are anticipated in parallel. Bariatric surgery, a treatment approved for weight loss in morbidly obese patients, has reported to be associated with good outcomes, such as reversal of type two diabetes mellitus and reducing all-cause mortality on a long term basis. However, complications from bariatric surgery have similarly been reported. In particular, with the onslaught of non-alcoholic fatty liver disease(NAFLD) epidemic, in associated with obesity and metabolic syndrome, there is increasing prevalence of NAFLD related liver cirrhosis, which potentially connotes more risk of specific complications for surgery. Bariatric surgeons may encounter, either expectedly or unexpectedly, patients with non-alcoholic steatohepatitis(NASH) and NASH related cirrhosis more frequently. As such, the issues and considerations surrounding their medical care/surgery warrant careful deliberation to ensure the best outcomes. These considerations include severity of cirrhosis, liver synthetic function, portal hypertension and the impact of surgical factors. This review explores these considerations comprehensively and emphasizes the best approach to managing cirrhotic patients in the context of bariatric surgery.

关键词： Cirrhosis Portal hypertension Non-alcoholic fatty liver disease Bariatric surgery Complications

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