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- Bergemalm, Daniel, 1977-, et al.
(author)
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Markers of systemic inflammation in preclinical ulcerative colitis
- 2019
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In: United European Gastroenterology journal. - : Sage Publications. - 2050-6406 .- 2050-6414. ; 7:8_suppl, s. 111-111
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Journal article (peer-reviewed)abstract
- Introduction: Data on the preclinical stage of ulcerative colitis (UC) are sparse. At diagnosis, UC often shows a modest increase in systemic inflammatory markers like C-reactive protein (CRP). However, a subclinical inflammation with elevated levels of CRP and interleukin-6 (IL6) in serum have been observed several years before diagnosis [1]. First-degree relatives, including healthy twin siblings, also display elevated levels of some inflammatory markers as a consequence of shared genetic and environmental risk factors [2]. It is reasonable to believe that the preclinical inflammation, reflecting early pathogenic mechanisms, ultimately leads to a diagnosis of UC.Aim and Method: We aimed to deeper examine the systemic preclinical inflammation in UC using a comprehensive set of protein markers. Cases with UC were identified at clinical follow-up of a prospectively collected population-based cohort of healthy individuals from northern Sweden. Plasma samples from cases and controls were subjected to proximity extension assay for relative quantification of 92 protein markers of inflammation. Results were validated in an inception cohort of treatment naïve, newly diagnosed patients with UC (n=101) vs. healthy controls (n=50). In addition, to examine the impact of shared genetic and environmental factors, a cohort of healthy mono- and dizygotic twin siblings of twins with UC (n=41) and matched healthy controls (n=37) were explored.Results: Pre-diagnostic plasma samples from 72 cases who later in life developed UC and 140 controls, matched for gender, age, year of health survey and area of residence, were identified (table 1). Six proteins were significantly upregulated (p<0.05) in pre-diagnostic UC compared to matched healthy controls. A receiver-operating curve based prediction model using the six protein markers combined with sex, age, smoking status and time to diagnose was set up for validation. The model discriminated newly diagnosed, treatment naïve UC cases from healthy controls (AUC=0.96; CI 0.93-0.98). An AUC of 0.73 (CI 0.62-0.84) was observed when the model was applied to healthy twin siblings vs. healthy controls and four out of six proteins were upregulated similarly as in the pre-diagnostic samples. The relative levels of the six proteins showed an intermediate upregulation in pre-diagnostic samples and samples from healthy twin siblings compared to samples at diagnosis of UC. Only one protein showed a significant correlation with time to diagnosis in the pre-diagnostic samples. Using pathway analysis, the six protein upregulations pointed towards subclinical inflammation in UC being caused by dysregulation of four immune pathways.Conclusions: This is the first comprehensive characterisation of preclinical systemic inflammation in UC. Inflammatory proteins were upregulated several years prior to diagnosis of UC and to some extent these alterations were also seen in healthy twin siblings of UC patients. Characterisation of the preclinical stage of UC could pave the way for identification of predictive biomarkers and preventive strategies.
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| 2. |
- Forstner, O., et al.
(author)
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The ILIAS project for selective isobar suppression by laser photodetachment
- 2015
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In: Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 361, s. 217-221
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Journal article (peer-reviewed)abstract
- Laser photodetachment is the process when the extra electron of a negative ion is removed by means of laser radiation. This can happen only if the photon energy is larger than the electron affinity of the ion. The process can be used in mass spectrometry to selectively suppress unwanted isobars, provided that the electron affinity of the unwanted isobar is lower than that of the isobar under investigation.At the Ion Laser InterAction Setup (ILIAS) at the University of Vienna laser photodetachment of negative atomic and molecular ions is studied and its applicability for selective isobar suppression in accelerator mass spectrometry (AMS) is evaluated. The setup provides mass separated beams of negative ions with energies up to 30 keV. Negative ions are produced in a Middleton type cesium sputter ion source, mass selected and overlapped with a strong continuous wave laser beam. In order to extend the interaction time of ions and laser, the ion beam is decelerated to thermal energies in a gas-filled radio frequency quadrupole cooler. For an appropriate choice of the photon energy, unwanted isobars are neutralized while the isobar of interest is unaffected and remains negatively charged.A description of the ILIAS setup and results from the commissioning phase of the RFQ cooler are presented. Up to 8% ion beam transmission could be achieved after a recent redesign of the extraction system. Furthermore first results of photodetachment experiments of 63Cu− within the RFQ cooler are presented.
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| 3. |
- Mellqvist, Johan, 1965, et al.
(author)
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Measurements of fugitive emissions of vocs from stationary sources using the SOF method - Standardization efforts and results from recent studies in California
- 2019
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In: AQM 2019 - Air Quality Measurement Methods and Technology Conference 2019.
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Conference paper (peer-reviewed)abstract
- The Solar Occultation Flux (SOF) method is used to screen and quantify VOC emissions from industrial conglomerates down to sub-areas in individual plants, such as a few tank process area or water treatment areas. The SOF method has been applied in several larger campaigns in both Europe and in the US (Mexico City 2006, Texas 2006/2009/2011/2012; Le Havre 2008, Rotterdam 2008/2010 and Antwerp 2010/2016, California 2013/20T5, Tianjin China 2016) and in more than 100 individual plant surveys over the world. The technique has been validated by comparison to other methods and tracer gas releases and it typically has an uncertainty of 30%, mostly due to uncertainties in the wind field. In the various campaign studies it has been found that the measured emissions obtained with SOF are 3–10 times higher than the reported emission obtained by calculations. The SOF method is Best Available Technology in Europe for quantitative measurements of diffuse emissions from refineries and the chemical sector. The technique is presently being standardized by the European CEN.
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| 4. |
- Mellqvist, Johan, 1965, et al.
(author)
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Mobile optical measurements of emissions and fenceline concentrations from oil and gas production
- 2019
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In: AQM 2019 - Air Quality Measurement Methods and Technology Conference 2019.
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Conference paper (peer-reviewed)abstract
- The mobile measurement platform and optical methods used in the SQAMD project1 allowed for mapping concentrations and measuring fluxes from a large number of sources and source types, and provided very useful information on the relative contribution of small stationary sources to alkane and BTEX emissions in the SCAB. Sources ranged from single oil wells to large tank farms, refineries, and off shore installations. Note that these sources are not subjected to the same regulatory requirements as larger industrial facilities. Future studies aimed at improving the emission estimates in SCAB should include a larger subset of units from all major source categories, and a better characterization of their spatial and temporal variability.
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| 5. |
- Mellqvist, Johan, 1965, et al.
(author)
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Quantification of Gas Emissions from Refineries, Gas Stations, Oil Wells and Agriculture using Optical Solar Occultation Flux and Tracer Correlation Methods
- 2016
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In: AGU Fall meeting San Francisco Dec 2016.
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Conference paper (other academic/artistic)abstract
- Industrial volatile organic compound (VOC) emissions may contribute significantly to ozone formation. In order to investigate how much small sources contribute to the VOC concentrations in the Los Angeles metropolitan area a comprehensive emission study has been carried out on behalf of the South Coast Air Quality Management District (SCAQMD). VOC emissions from major sources such as refineries, oil wells, petrol stations oil depots and oil platforms were measured during September and October 2015 using several unique optical methods, including the Solar Occultation Flux method (SOF) and tracer correlation technique based on extractive FTIR and DOAS combined with an open path multi reflection cell. In addition, measurements of ammonia emissions from farming in Chino were demonstrated. The measurements in this study were quality assured by carrying out a controlled source gas release study and side by side measurements with several other techniques. The results from the field campaign show that the emissions from the above mentioned sources are largely underestimated in inventories with potential impact on the air quality in the Los Angeles metropolitan area. The results show that oil and gas production is a very significant VOC emission source. In this presentation the techniques will be discussed together with the main results from the campaign including the quality assurance work.
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| 8. |
- Samuelsson, Jerker, 1972, et al.
(author)
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Quantification of VOC emissions using tracer dispersion, Mobile Extractive FTIR (MEFTIR) and Mobile Whitecell-DOAS (MWDOAS)
- 2015
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In: Proceedings of the Air and Waste Management Association's Annual Conference and Exhibition, AWMA. - 1052-6102. - 9781510815582 ; 3, s. 2310-2317
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Conference paper (peer-reviewed)abstract
- The application of Mobile Extractive FTIR and Mobile Whitecell Differential Optical Absorption Spectroscopy to establish VOC emission factors for tank filling operations and for discharge of petroleum products to trucks and vessels is described. An example of VOC emissions related to discharge of gasoline to trucks at a depot, which was connected to vapor recovery unit, is presented. Discharge of gasoline to ships was found to have an alkane (CH4 emission factor of about 5x10-5 kg emitted VOC/kg discharged product, comparable to the corresponding for trucks. This is an abstract of a paper presented at the 108th AWMA Annual Conference and Exhibition (Raleigh, NC 6/22-25/2015).
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