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  • Public defence: 2019-10-25 09:15 Örebro universitet, Hörsalen, Musikhögskolan, Örebro
    Mullin, Lauren Gayle
    Örebro University, School of Science and Technology.
    Advances in Mass Spectrometry for the Analysis of Emerging Persistent Organic Pollutants2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Mass spectrometry (MS) is a technique widely implemented for the measurement of environmental pollutants. A critical tool for the analysis of persistent organic pollutants (POPs) over several decades, MS as coupled with liquid and gas chromatography (LC and GC) techniques enables the analysis of emerging POPs. The aim of this thesis was to investigate the use of alternative MS-based techniques to assist specific analytical challenges including separation of stereoisomers using supercritical fluid chromatography (SFC), reduced ionization competition with appropriate mobile phase additives, and applied rotationally averaged collision-cross section (CCS) of ions via ion mobility measurements of emerging POPs.

    Chromatographic efficiency improvements for the brominated flame retardant, hexabromocyclododecane (HBCDD), were implemented through the development of two supercritical fluid chromatography (SFC) methods. Based on the inherent qualities of supercritical fluids, separation of both predominant diastereomers and respective enantiomers was performed in a shorter time with wider chromatographic resolution using SFC than existing LC methods.

    Turning next to MS ionization considerations, the emerging perfluoroalkyl substance hexafluoropropylene oxide-dimer acid (HFPO-DA) was investigated. Following a survey of analytical methodologies for HFPO-DA, the challenge of extreme dimer formation, in-source fragmentation and very low [M-H]- production was described. Method development using alternative mobile phase additives in currently used LC-MS acquisition techniques was deployed.

    Finally, ion mobility spectrometry (IMS) was implemented in a non-targeted acquisition study of indoor dust samples. This study used IMS coupled with quadrupole time-of-flight MS to identify a wide range of contaminant classes, including emerging POPs. Identification confidence is a challenge currently facing non-targeted studies, and the use of prediction mechanisms of analyte IMS gas-phase separations was explored.

    Through applying diverse alternative techniques, increased method performance was explored for emerging POPs analyses.

    List of papers
    1. Rapid separation of hexabromocyclododecane diastereomers using a novel method combining convergence chromatography and tandem mass spectrometry
    Open this publication in new window or tab >>Rapid separation of hexabromocyclododecane diastereomers using a novel method combining convergence chromatography and tandem mass spectrometry
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    2015 (English)In: Analytical Methods, ISSN 1759-9660, E-ISSN 1759-9679, Vol. 7, no 7, p. 2950-2958Article in journal (Refereed) Published
    Abstract [en]

    Analysis of the brominated flame retardant hexabromocyclododecane (HBCDD) is characterized by the separation of its three predominant diastereomers. This analysis is typically performed using reversed phase liquid chromatography (RPLC) coupled with mass spectrometric (MS) detection with analysis times in the order of 10 minutes or greater. Here we describe a rapid method using supercritical CO2 and methanol to baseline separate the three most abundant HBCDD diastereomers within a three minute run time using a High Strength Silica (HSS) C18 1.8 mu m particle size column. A unique elution order of the alpha-, beta- and gamma-HBCDD diastereomers using supercritical CO2 was observed, and can be used as an orthogonal separation for further confidence in diastereomer identification when used in conjuction with RPLC. A tandem quadrupole mass spectrometer with negative mode electrospray ionization was used for detection, operating in multiple reaction monitoring (MRM) mode. Ionization was enhanced by the addition of a make-up flow, which was introduced to the post-column effluent. Method limit of detection (LOD) and limit of quantification (LOQ) for alpha-, beta- and gamma-HBCDD were based on peak-to-peak signal to noise ratios of greater than 3 or 10, respectively. The LOD for all HBCDD diastereomers as solvent standards was 100 fg on-column, and LOQs 500 fg on-column for alpha- and gamma-HBCDD and 250 fg on-column for beta-HBCDD. In order to test the efficiency of this method, small subsets of complex human serum and whale blubber extracts were analyzed using this method, resulting in positive detections in samples of alpha-HBCDD.

    Place, publisher, year, edition, pages
    Royal Society of Chemistry, 2015
    National Category
    Analytical Chemistry
    Research subject
    Analytical Chemistry
    Identifiers
    urn:nbn:se:oru:diva-44434 (URN)10.1039/c4ay02923b (DOI)000351931000008 ()
    Available from: 2015-04-24 Created: 2015-04-24 Last updated: 2019-10-09Bibliographically approved
    2. Enantioselective Analytical- and Preparative-Scale Separation of Hexabromocyclododecane Stereoisomers Using Packed Column Supercritical Fluid Chromatography
    Open this publication in new window or tab >>Enantioselective Analytical- and Preparative-Scale Separation of Hexabromocyclododecane Stereoisomers Using Packed Column Supercritical Fluid Chromatography
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    2016 (English)In: Molecules, ISSN 1420-3049, E-ISSN 1420-3049, Vol. 21, no 11, article id 1509Article in journal (Refereed) Published
    Abstract [en]

    Hexabromocyclododecane (HBCDD) is an additive brominated flame retardant which has been listed in Annex A of the Stockholm Convention for elimination of production and use. It has been reported to persist in the environment and has the potential for enantiomer-specific degradation, accumulation, or both, making enantioselective analyses increasingly important. The six main stereoisomers of technical HBCDD (i.e., the (+) and (-) enantiomers of α-, β-, and γ-HBCDD) were separated and isolated for the first time using enantioselective packed column supercritical fluid chromatography (pSFC) separation methods on a preparative scale. Characterization was completed using published chiral liquid chromatography (LC) methods and elution profiles, as well as X-ray crystallography, and the isolated fractions were definitively identified. Additionally, the resolution of the enantiomers, along with two minor components of the technical product (δ- and ε-HBCDD), was investigated on an analytical scale using both LC and pSFC separation techniques, and changes in elution order were highlighted. Baseline separation of all HBCDD enantiomers was achieved by pSFC on an analytical scale using a cellulose-based column. The described method emphasizes the potential associated with pSFC as a green method of isolating and analyzing environmental contaminants of concern.

    Place, publisher, year, edition, pages
    Basel, Switzerland: MDPI AG, 2016
    Keywords
    hexabromocyclododecane, enantiomeric separation, supercritical fluid chromatography
    National Category
    Analytical Chemistry
    Identifiers
    urn:nbn:se:oru:diva-53487 (URN)10.3390/molecules21111509 (DOI)000389918200091 ()27834934 (PubMedID)2-s2.0-84997428723 (Scopus ID)
    Available from: 2016-11-15 Created: 2016-11-14 Last updated: 2019-10-02Bibliographically approved
    3. Analysis of hexafluoropropylene oxide-dimer acid (HFPO-DA) by liquid chromatography-mass spectrometry (LC-MS): Review of current approaches and environmental levels
    Open this publication in new window or tab >>Analysis of hexafluoropropylene oxide-dimer acid (HFPO-DA) by liquid chromatography-mass spectrometry (LC-MS): Review of current approaches and environmental levels
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    2019 (English)In: TrAC. Trends in analytical chemistry, ISSN 0165-9936, E-ISSN 1879-3142, Vol. 118, p. 828-839Article, review/survey (Refereed) Published
    Abstract [en]

    Emerging per- and polyfluorinated compounds (PFAS) compounds are of increasing interest for environmental monitoring, one being hexafluoropropylene oxide-dimer acid (HFPO-DA), commonly referred to as GenX. The following review describes existing liquid chromatography-mass spectrometry (LC-MS) methods used to analyse HFPO-DA, including sample preparation and method sensitivity relative to other PFAS. Analytical challenges are also described, in particular the significant formation of in-source fragmentation, dimer and dimer adducts which detract from [M-H](-) signal. Lastly, detected levels of HFPO-DA in environmental and biological samples are compared across the limited number of available field exposure studies, which found several mu g/L concentrations in water samples taken near fluorochemical plant discharges.

    Place, publisher, year, edition, pages
    Elsevier, 2019
    Keywords
    HFPO-DA, GenX, Negative polarity electrospray ionisation, Liquid chromatography, Mass spectrometry
    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:oru:diva-76970 (URN)10.1016/j.trac.2019.05.015 (DOI)000486383900064 ()31501636 (PubMedID)
    Note

    Funding Agency:

    Intramural EPA  EPA999999

    Available from: 2019-10-02 Created: 2019-10-02 Last updated: 2019-10-02Bibliographically approved
    4. Ionization Enhancement of Hexafluoropropylene oxide dimer acid (HFPO-DA) Through Mobile Phase Additive Selection
    Open this publication in new window or tab >>Ionization Enhancement of Hexafluoropropylene oxide dimer acid (HFPO-DA) Through Mobile Phase Additive Selection
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    (English)Manuscript (preprint) (Other academic)
    National Category
    Other Chemistry Topics
    Identifiers
    urn:nbn:se:oru:diva-76979 (URN)
    Available from: 2019-10-02 Created: 2019-10-02 Last updated: 2019-10-02Bibliographically approved
    5. Liquid Chromatography-Ion Mobility-High Resolution Mass Spectrometry for Analysis of Pollutants in Indoor Dust: Identification and Predictive Capabilities
    Open this publication in new window or tab >>Liquid Chromatography-Ion Mobility-High Resolution Mass Spectrometry for Analysis of Pollutants in Indoor Dust: Identification and Predictive Capabilities
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    (English)Manuscript (preprint) (Other academic)
    National Category
    Other Chemistry Topics
    Identifiers
    urn:nbn:se:oru:diva-76980 (URN)
    Available from: 2019-10-02 Created: 2019-10-02 Last updated: 2019-10-02Bibliographically approved
  • Public defence: 2019-10-29 13:15 Örebro universitet, Teknikhuset, Hörsal T, Örebro
    Mielle, Malcolm
    Örebro University, School of Science and Technology.
    Helping robots help us: Using prior information for localization, navigation, and human-robot interaction2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Maps are often used to provide information and guide people. Emergency maps or floor plans are often displayed on walls and sketch maps can easily be drawn to give directions. However, robots typically assume that no knowledge of the environment is available before exploration even though making use of prior maps could enhance robotic mapping. For example, prior maps can be used to provide map data of places that the robot has not yet seen, to correct errors in robot maps, as well as to transfer information between map representations.

    I focus on two types of prior maps representing the walls of an indoor environment: layout maps and sketch maps. I study ways to relate information of sketch or layout maps with an equivalent metric map and study how to use layout maps to improve the robot’s mapping. Compared to metric maps such as sensor-built maps, layout and sketch maps can have local scale errors or miss elements of the environment, which makes matching and aligning such heterogeneous map types a hard problem.

    I aim to answer three research questions: how to interpret prior maps by finding meaningful features? How to find correspondences between the features of a prior map and a metric map representing the same environment? How to integrate prior maps in SLAM so that both the prior map and the map built by the robot are improved?

    The first contribution of this thesis is an algorithm that can find correspondences between regions of a hand-drawn sketch map and an equivalent metric map and achieves an overall accuracy that is within 10% of that of a human. The second contribution is a method that enables the integration of layout map data in SLAM and corrects errors both in the layout and the sensor map.

    These results provide ways to use prior maps with local scale errors and different levels of detail, whether they are close to metric maps, e.g. layout maps, or non-metric maps, e.g. sketch maps. The methods presented in this work were used in field tests with professional fire-fighters for search and rescue applications in low-visibility environments. A novel radar sensor was used to perform SLAM in smoke and, using a layout map as a prior map, users could indicate points of interest to the robot on the layout map, not only during and after exploration, but even before it took place.

    List of papers
    1. Using sketch-maps for robot navigation: interpretation and matching
    Open this publication in new window or tab >>Using sketch-maps for robot navigation: interpretation and matching
    2016 (English)In: 2016 IEEE International Symposium on Safety, Security, and Rescue Robotics (SSRR), New York: Institute of Electrical and Electronics Engineers (IEEE), 2016, p. 252-257Conference paper, Published paper (Refereed)
    Abstract [en]

    We present a study on sketch-map interpretationand sketch to robot map matching, where maps have nonuniform scale, different shapes or can be incomplete. For humans, sketch-maps are an intuitive way to communicate navigation information, which makes it interesting to use sketch-maps forhuman robot interaction; e.g., in emergency scenarios.

    To interpret the sketch-map, we propose to use a Voronoi diagram that is obtained from the distance image on which a thinning parameter is used to remove spurious branches. The diagram is extracted as a graph and an efficient error-tolerant graph matching algorithm is used to find correspondences, while keeping time and memory complexity low.

    A comparison against common algorithms for graph extraction shows that our method leads to twice as many good matches. For simple maps, our method gives 95% good matches even for heavily distorted sketches, and for a more complex real-world map, up to 58%. This paper is a first step toward using unconstrained sketch-maps in robot navigation.

    Place, publisher, year, edition, pages
    New York: Institute of Electrical and Electronics Engineers (IEEE), 2016
    Keywords
    sketch, sketch-map, human robot interface, HRI, graph matching
    National Category
    Computer Sciences
    Research subject
    Computer Science
    Identifiers
    urn:nbn:se:oru:diva-53826 (URN)10.1109/SSRR.2016.7784307 (DOI)000391310800039 ()2-s2.0-85009754966 (Scopus ID)978-1-5090-4349-1 (ISBN)
    Conference
    14th IEEE International Symposium on Safety, Security and Rescue Robotics (SSRR 2016), EPFL, Lausanne, Switzerland, October 23-27, 2016
    Funder
    EU, Horizon 2020, ICT-23-2014 645101 SmokeBot
    Available from: 2016-12-09 Created: 2016-12-07 Last updated: 2019-10-02Bibliographically approved
    2. A method to segment maps from different modalities using free space layout MAORIS: map of ripples segmentation
    Open this publication in new window or tab >>A method to segment maps from different modalities using free space layout MAORIS: map of ripples segmentation
    2018 (English)Conference paper, Published paper (Refereed)
    Abstract [en]

    How to divide floor plans or navigation maps into semantic representations, such as rooms and corridors, is an important research question in fields such as human-robot interaction, place categorization, or semantic mapping. While most works focus on segmenting robot built maps, those are not the only types of map a robot, or its user, can use. We present a method for segmenting maps from different modalities, focusing on robot built maps and hand-drawn sketch maps, and show better results than state of the art for both types.

    Our method segments the map by doing a convolution between the distance image of the map and a circular kernel, and grouping pixels of the same value. Segmentation is done by detecting ripple-like patterns where pixel values vary quickly, and merging neighboring regions with similar values.

    We identify a flaw in the segmentation evaluation metric used in recent works and propose a metric based on Matthews correlation coefficient (MCC). We compare our results to ground-truth segmentations of maps from a publicly available dataset, on which we obtain a better MCC than the state of the art with 0.98 compared to 0.65 for a recent Voronoi-based segmentation method and 0.70 for the DuDe segmentation method.

    We also provide a dataset of sketches of an indoor environment, with two possible sets of ground truth segmentations, on which our method obtains an MCC of 0.56 against 0.28 for the Voronoi-based segmentation method and 0.30 for DuDe.

    Place, publisher, year, edition, pages
    IEEE Computer Society, 2018
    Keywords
    map segmentation, free space, layout
    National Category
    Robotics
    Research subject
    Computer Science
    Identifiers
    urn:nbn:se:oru:diva-68421 (URN)10.1109/ICRA.2018.8461128 (DOI)000446394503114 ()
    Conference
    IEEE International Conference on Robotics and Automation (ICRA 2018), Brisbane, Australia, May 21-25, 2018
    Funder
    EU, Horizon 2020, ICT-23-2014 645101 SmokeBotKnowledge Foundation, 20140220
    Available from: 2018-08-09 Created: 2018-08-09 Last updated: 2019-10-10Bibliographically approved
    3. URSIM: Unique Regions for Sketch Map Interpretation and Matching
    Open this publication in new window or tab >>URSIM: Unique Regions for Sketch Map Interpretation and Matching
    2019 (English)In: Robotics, E-ISSN 2218-6581, Vol. 8, no 2, article id 43Article in journal (Refereed) Published
    Abstract [en]

    We present a method for matching sketch maps to a corresponding metric map, with the aim of later using the sketch as an intuitive interface for human-robot interactions. While sketch maps are not metrically accurate and many details, which are deemed unnecessary, are omitted, they represent the topology of the environment well and are typically accurate at key locations. Thus, for sketch map interpretation and matching, one cannot only rely on metric information. Our matching method first finds the most distinguishable, or unique, regions of two maps. The topology of the maps, the positions of the unique regions, and the size of all regions are used to build region descriptors. Finally, a sequential graph matching algorithm uses the region descriptors to find correspondences between regions of the sketch and metric maps. Our method obtained higher accuracy than both a state-of-the-art matching method for inaccurate map matching, and our previous work on the subject. The state of the art was unable to match sketch maps while our method performed only 10% worse than a human expert.

    Place, publisher, year, edition, pages
    MDPI, 2019
    Keywords
    Map matching, sketch, human-robot interaction, interface, graph matching, segmentation
    National Category
    Computer Vision and Robotics (Autonomous Systems)
    Identifiers
    urn:nbn:se:oru:diva-75741 (URN)10.3390/robotics8020043 (DOI)000475325600020 ()2-s2.0-85069975721 (Scopus ID)
    Funder
    Knowledge Foundation, 20140220
    Note

    Funding Agency:

    EU  ICT-26-2016 732737

    Available from: 2019-08-13 Created: 2019-08-13 Last updated: 2019-10-10Bibliographically approved
    4. SLAM auto-complete: completing a robot map using an emergency map
    Open this publication in new window or tab >>SLAM auto-complete: completing a robot map using an emergency map
    2017 (English)In: 2017 IEEE International Symposium on Safety, Security and Rescue Robotics (SSRR), IEEE conference proceedings, 2017, p. 35-40, article id 8088137Conference paper, Published paper (Refereed)
    Abstract [en]

    In search and rescue missions, time is an important factor; fast navigation and quickly acquiring situation awareness might be matters of life and death. Hence, the use of robots in such scenarios has been restricted by the time needed to explore and build a map. One way to speed up exploration and mapping is to reason about unknown parts of the environment using prior information. While previous research on using external priors for robot mapping mainly focused on accurate maps or aerial images, such data are not always possible to get, especially indoor. We focus on emergency maps as priors for robot mapping since they are easy to get and already extensively used by firemen in rescue missions. However, those maps can be outdated, information might be missing, and the scales of rooms are typically not consistent.

    We have developed a formulation of graph-based SLAM that incorporates information from an emergency map. The graph-SLAM is optimized using a combination of robust kernels, fusing the emergency map and the robot map into one map, even when faced with scale inaccuracies and inexact start poses.

    We typically have more than 50% of wrong correspondences in the settings studied in this paper, and the method we propose correctly handles them. Experiments in an office environment show that we can handle up to 70% of wrong correspondences and still get the expected result. The robot can navigate and explore while taking into account places it has not yet seen. We demonstrate this in a test scenario and also show that the emergency map is enhanced by adding information not represented such as closed doors or new walls.

    Place, publisher, year, edition, pages
    IEEE conference proceedings, 2017
    Keywords
    SLAM, robotics, graph, graph SLAM, emergency map, rescue, exploration, auto complete, SLAM, robotics, graph, graph SLAM, plan de secours, sauvetage, exploration, auto complete
    National Category
    Computer Vision and Robotics (Autonomous Systems)
    Research subject
    Computer Science
    Identifiers
    urn:nbn:se:oru:diva-62057 (URN)10.1109/SSRR.2017.8088137 (DOI)000426991900007 ()2-s2.0-85040221684 (Scopus ID)978-1-5386-3923-8 (ISBN)978-1-5386-3924-5 (ISBN)
    Conference
    15th IEEE International Symposium on Safety, Security and Rescue Robotics (SSRR 2017), ShanghaiTech University, China, October 11-13, 2017
    Projects
    EU H2020 project SmokeBot (ICT- 23-2014 645101)
    Funder
    Knowledge Foundation, 20140220
    Note

    Funding Agency:

    EU  ICT-23-2014645101

    Available from: 2017-11-08 Created: 2017-11-08 Last updated: 2019-10-02Bibliographically approved
    5. The Auto-Complete Graph: Merging and Mutual Correction of Sensor and Prior Maps for SLAM
    Open this publication in new window or tab >>The Auto-Complete Graph: Merging and Mutual Correction of Sensor and Prior Maps for SLAM
    2019 (English)In: Robotics, E-ISSN 2218-6581, Vol. 8, no 2, article id 40Article in journal (Refereed) Published
    Abstract [en]

    Simultaneous Localization And Mapping (SLAM) usually assumes the robot starts without knowledge of the environment. While prior information, such as emergency maps or layout maps, is often available, integration is not trivial since such maps are often out of date and have uncertainty in local scale. Integration of prior map information is further complicated by sensor noise, drift in the measurements, and incorrect scan registrations in the sensor map. We present the Auto-Complete Graph (ACG), a graph-based SLAM method merging elements of sensor and prior maps into one consistent representation. After optimizing the ACG, the sensor map's errors are corrected thanks to the prior map, while the sensor map corrects the local scale inaccuracies in the prior map. We provide three datasets with associated prior maps: two recorded in campus environments, and one from a fireman training facility. Our method handled up to 40% of noise in odometry, was robust to varying levels of details between the prior and the sensor map, and could correct local scale errors of the prior. In field tests with ACG, users indicated points of interest directly on the prior before exploration. We did not record failures in reaching them.

    Place, publisher, year, edition, pages
    MDPI, 2019
    Keywords
    SLAM, prior map, emergency map, layout map, graph-based SLAM, navigation, search and rescue
    National Category
    Computer Vision and Robotics (Autonomous Systems)
    Identifiers
    urn:nbn:se:oru:diva-75742 (URN)10.3390/robotics8020040 (DOI)000475325600017 ()2-s2.0-85069926702 (Scopus ID)
    Funder
    Knowledge Foundation, 20140220
    Note

    Funding Agency:

    EU  ICT-26-2016 732737  ICT-23-2014 645101

    Available from: 2019-08-13 Created: 2019-08-13 Last updated: 2019-10-02Bibliographically approved
    6. A comparative analysis of radar and lidar sensing for localization and mapping
    Open this publication in new window or tab >>A comparative analysis of radar and lidar sensing for localization and mapping
    2019 (English)Conference paper, Published paper (Refereed)
    Abstract [en]

    Lidars and cameras are the sensors most commonly used for Simultaneous Localization And Mapping (SLAM). However, they are not effective in certain scenarios, e.g. when fire and smoke are present in the environment. While radars are much less affected by such conditions, radar and lidar have rarely been compared in terms of the achievable SLAM accuracy. We present a principled comparison of the accuracy of a novel radar sensor against that of a Velodyne lidar, for localization and mapping.

    We evaluate the performance of both sensors by calculating the displacement in position and orientation relative to a ground-truth reference positioning system, over three experiments in an indoor lab environment. We use two different SLAM algorithms and found that the mean displacement in position when using the radar sensor was less than 0.037 m, compared to 0.011m for the lidar. We show that while producing slightly less accurate maps than a lidar, the radar can accurately perform SLAM and build a map of the environment, even including details such as corners and small walls.

    Place, publisher, year, edition, pages
    IEEE, 2019
    National Category
    Computer Vision and Robotics (Autonomous Systems)
    Identifiers
    urn:nbn:se:oru:diva-76976 (URN)
    Conference
    9th European Conference on Mobile Robots (ECMR 2019), Prague, Czech Republic, September 4-6, 2019
    Available from: 2019-10-02 Created: 2019-10-02 Last updated: 2019-10-02Bibliographically approved
  • Public defence: 2019-11-08 09:00 Örebro universitet, Campus USÖ, hörsal C3, Örebro
    Sadeghi, Mitra
    Örebro University, School of Medical Sciences.
    Resuscitative endovascular balloon occlusion of the aorta: Physiology and clinical aspects of an emerging technique2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Traumatic hemorrhagic shock is a major cause of death worldwide. Patients enter the fatal triad of hypothermia, acidosis and coagulopathy and die quickly due to cardiovascular collapse. Ideally, procedures should be performed at the injury scene to prevent this fatal event. Unfortunately, intervention cannot be performed as soon as is needed and time to intervention becomes the enemy of survival. Hemorrhage control until definitive repair can possibly save lives. Hemorrhage from the extremities can be controlled by external pressure but severe hemorrhage from thoracic, abdominal or pelvic cavities, called non-compressible torso hemorrhage, requires internal hemorrhage control. Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) uses an endovascular balloon that is inserted into the aorta using minimally invasive methods and is inflated to increase perfusion pressure and avoid cardiovascular collapse, providing a bridge to intervention. REBOA is hypothetised to increase central blood pressure but cause ischemia reperfusion injury below the occlusion level. The purpose of this thesis was to investigate the general impact of REBOA on physiology, metabolism, inflammatory response in normovolemia and hemorrhage. Investigation was conducted through clinical and experimental models.

    Study I was a multicentre cohort study of patients with traumatic hemorrhagic shock who received REBOA. Ninety-six patients were included, with an overall mortality of 56% and with no major complications from REBOA use. REBOA was used in a continuous and non-continuous fashion depending on the patients’ level of hypovolemia.

    Study II and the following three studies were animal experimental studies. Study II was a randomized control study in pigs to evaluate physiological, metabolic, inflammatory and end-organ function in a normovolemic state. It was demonstrated that REBOA increased central blood pressure but caused ischemic insult.

    Study III, a randomised controlled experimental model in pigs. Investigation was made to examine the possibility of titrating blood pressure with partial occlusion and investigate if partial occlusion reduced the ischemic insult. Partial REBOA could be achieved in this study and the ischemia reperfusion injury was less pronounced in partial occlusion than total. However, the difficulty regarding how to determine partial occlusion in a clinical setting remained.

    Study IV was therefore an experimental study conducted to compare the different methods of determining partial occlusion and detect the best correlation to organ perfusion. The following variables were compared to oxygen consumption: end-tidal carbon dioxide, aortic blood flow, superior mesenteric blood flow and femoral mean pressure. The study revealed that end-tidal carbon dioxide correlates best to organ perfusion.

    List of papers
    1. The use of aortic balloon occlusion in traumatic shock: first report from the ABO trauma registry
    Open this publication in new window or tab >>The use of aortic balloon occlusion in traumatic shock: first report from the ABO trauma registry
    Show others...
    2018 (English)In: European Journal of Trauma and Emergency Surgery, ISSN 1863-9933, E-ISSN 1863-9941, Vol. 44, no 4, p. 491-501Article in journal (Refereed) Published
    Abstract [en]

    PURPOSE: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a technique for temporary stabilization of patients with non-compressible torso hemorrhage. This technique has been increasingly used worldwide during the past decade. Despite the good outcomes of translational studies, clinical studies are divided. The aim of this multicenter-international study was to capture REBOA-specific data and outcomes.

    METHODS: REBOA practicing centers were invited to join this online register, which was established in September 2014. REBOA cases were reported, both retrospective and prospective. Demographics, injury patterns, hemodynamic variables, REBOA-specific data, complications and 30-days mortality were reported.

    RESULTS: Ninety-six cases from 6 different countries were reported between 2011 and 2016. Mean age was 52 ± 22 years and 88% of the cases were blunt trauma with a median injury severity score (ISS) of 41 (IQR 29-50). In the majority of the cases, Zone I REBOA was used. Median systolic blood pressure before balloon inflation was 60 mmHg (IQR 40-80), which increased to 100 mmHg (IQR 80-128) after inflation. Continuous occlusion was applied in 52% of the patients, and 48% received non-continuous occlusion. Occlusion time longer than 60 min was reported as 38 and 14% in the non-continuous and continuous groups, respectively. Complications, such as extremity compartment syndrome (n = 3), were only noted in the continuous occlusion group. The 30-day mortality for non-continuous REBOA was 48%, and 64% for continuous occlusion.

    CONCLUSIONS: This observational multicenter study presents results regarding continuous and non-continuous REBOA with favorable outcomes. However, further prospective studies are needed to be able to draw conclusions on morbidity and mortality.

    Place, publisher, year, edition, pages
    Springer Berlin/Heidelberg, 2018
    Keywords
    Aortic occlusion, Hemorrhage, IABO, REBOA, Trauma
    National Category
    Surgery
    Identifiers
    urn:nbn:se:oru:diva-61724 (URN)10.1007/s00068-017-0813-7 (DOI)000440981100002 ()28801841 (PubMedID)2-s2.0-85027305588 (Scopus ID)
    Funder
    Swedish Society for Medical Research (SSMF)
    Note

    Funding Agencies:

    Research Committee of Region Örebro County  

    Nyckelfonden at Örebro University Hospital  

    ALF Grants (Agreement concerning research and education of doctors)  

    Region Örebro County 

    Available from: 2017-11-07 Created: 2017-11-07 Last updated: 2019-10-15Bibliographically approved
    2. Total resuscitative endovascular balloon occlusion of the aorta causes inflammatory activation and organ damage within 30 minutes of occlusion in normovolemic pigs
    Open this publication in new window or tab >>Total resuscitative endovascular balloon occlusion of the aorta causes inflammatory activation and organ damage within 30 minutes of occlusion in normovolemic pigs
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Surgery
    Identifiers
    urn:nbn:se:oru:diva-77389 (URN)
    Available from: 2019-10-15 Created: 2019-10-15 Last updated: 2019-10-15Bibliographically approved
    3. Blood pressure targeting by partial REBOA is possible in severe hemorrhagic shock in pigs and produces less circulatory, metabolic and inflammatory sequelae than total REBOA
    Open this publication in new window or tab >>Blood pressure targeting by partial REBOA is possible in severe hemorrhagic shock in pigs and produces less circulatory, metabolic and inflammatory sequelae than total REBOA
    Show others...
    2018 (English)In: Injury, ISSN 0020-1383, E-ISSN 1879-0267, Vol. 49, no 12, p. 2132-2141Article in journal (Refereed) Published
    Abstract [en]

    Background: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an effective adjunct in exsanguinating torso hemorrhage, but causes ischemic injury to distal organs. The aim was to investigate whether blood pressure targeting by partial REBOA (pREBOA) is possible in porcine severe hemorrhagic shock and to compare pREBOA and total REBOA (tREBOA) regarding hemodynamic, metabolic and inflammatory effects.

    Methods: Eighteen anesthetized pigs were exposed to induced controlled hemorrhage to a systolic blood pressure (SBP) of 50 mmHg and randomized into three groups of thoracic REBOA: 30 min of pREBOA (target SBP 80-100 mmHg), tREBOA, and control. They were then resuscitated by autologous transfusion and monitored for 3 h. Hemodynamics, blood gases, mesenteric blood flow, intraperitoneal metabolites, organ damage markers, histopathology from the small bowel, and inflammatory markers were analyzed.

    Results: Severe hemorrhagic shock was induced in all groups. In pREBOA the targeted blood pressure was reached. The mesenteric blood flow was sustained in pREBOA, while it was completely obstructed in tREBOA. Arterial pH was lower, and lactate and troponin levels were significantly higher in tREBOA than in pREBOA and controls during the reperfusion period. Intraperitoneal metabolites, the cytokine response and histological analyses from the small bowel were most affected in the tREBOA compared to the pREBOA and control groups.

    Conclusion: Partial REBOA allows blood pressure titration while maintaining perfusion to distal organs, and reduces the ischemic burden in a state of severe hemorrhagic shock. Partial REBOA may lower the risks of post-resuscitation metabolic and inflammatory impacts, and organ dysfunction. (C) 2018 Published by Elsevier Ltd.

    Place, publisher, year, edition, pages
    Elsevier, 2018
    Keywords
    Hemorrhage, REBOA, Trauma, Injury, Anaerobic metabolism, Aortic balloon occlusion, Shock, Partial REBOA, Ischemia reperfusion injury, Inflammatory response
    National Category
    Anesthesiology and Intensive Care Surgery
    Identifiers
    urn:nbn:se:oru:diva-70857 (URN)10.1016/j.injury.2018.09.052 (DOI)000452313500005 ()30301556 (PubMedID)2-s2.0-85054438400 (Scopus ID)
    Funder
    Swedish Society of MedicineSwedish Society for Medical Research (SSMF)
    Note

    Funding Agencies:

    Research Committee of Region Örebro County  

    Nyckelfonden at Örebro University Hospital  

    Region Örebro County  

    ALF 

    Available from: 2019-01-07 Created: 2019-01-07 Last updated: 2019-10-15Bibliographically approved
    4. End-tidal carbon dioxide as an indicator of partial REBOA and distal organ metabolism in normovolemia and hemorrhagic shock in anesthetized pigs
    Open this publication in new window or tab >>End-tidal carbon dioxide as an indicator of partial REBOA and distal organ metabolism in normovolemia and hemorrhagic shock in anesthetized pigs
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    (English)Manuscript (preprint) (Other academic)
    National Category
    Surgery
    Identifiers
    urn:nbn:se:oru:diva-77391 (URN)
    Available from: 2019-10-15 Created: 2019-10-15 Last updated: 2019-10-15Bibliographically approved
  • Public defence: 2019-11-15 09:00 Örebro universitet, Campus USÖ, hörsal C2, Örebro
    Fernberg, Ulrika
    Örebro University, School of Medical Sciences.
    Arterial stiffness and risk factors for cardiovascular disease in young adults2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Atherosclerosis is a complex, chronic vessel wall disease that often leads to severe and acute cardiovascular diseases (CVD), such as myocardial infarction and stroke. CVD are the most common cause of death, both globally and in Sweden. Since most of the risk factors for atherosclerosis are preventable, it is of great importance to highlight the benefits of a healthy lifestyle to young adults who are about to create their own habits.

    A general concern about physical inactivity, low cardiorespiratory fitness (CRF), and high body mass are supported by reports of an increased incidence and prevalence of obesity worldwide. In addition to this, the proportion of Swedish adults with low CRF almost doubled the last 20 years and the decline in CRF is more pronounced in the youngest age group.

    The scientific work presented in this thesis was carried out to investigate the impact of different lifestyle related factors on vascular status, especially arterial stiffness, in young Swedish adults. In total 840 young adults in the age range 18-25 years were recruited to the cross-sectional Lifestyle, Biomarkers, and Atherosclerosis (LBA) study, to examine vascular status, biomarkers, and lifestyle related factors.

    In the LBA study population of young adults in Sweden, 12% were classified as being at risk of future CVD. A high CVD risk was associated with low CRF and less physical activity. In the total study population 24% had unhealthy food habits, and 24% did not spend the recommended 30 minutes per day at moderate or vigorous intensities of physical activity. Low CRF, less physical activity, and overweight and obesity, were associated with stiffer arteries.

    The results raises concerns about future CVD risk and highlights the health enhancing possibilities of high CRF and physical activity on vascular status in young Swedish adults.

    List of papers
    1. Aerobic fitness is associated with low cardiovascular disease risk: the impact of lifestyle on early risk factors for atherosclerosis in young healthy Swedish individuals - the Lifestyle, Biomarker, and Atherosclerosis study
    Open this publication in new window or tab >>Aerobic fitness is associated with low cardiovascular disease risk: the impact of lifestyle on early risk factors for atherosclerosis in young healthy Swedish individuals - the Lifestyle, Biomarker, and Atherosclerosis study
    2017 (English)In: Vascular Health and Risk Management, ISSN 1176-6344, E-ISSN 1178-2048, Vol. 13, p. 91-99Article in journal (Refereed) Published
    Abstract [en]

    Background: The progression of cardiovascular disease (CVD) and atherosclerosis is slow and develops over decades. In the cross-sectional Swedish Lifestyle, Biomarker, and Atherosclerosis study, 834 young, self-reported healthy adults aged 18.0-25.9 years have been studied to identify early risk factors for atherosclerosis.

    Purpose: The aims of this study were to 1) assess selected cardiometabolic biomarkers, carotid intima-media thickness (cIMT) as a marker of subclinical atherosclerosis, and lifestyle-related indicators (food habits, handgrip strength, and oxygen uptake, VO(2)max);2) analyze the associations between cIMT and lifestyle factors; and 3) identify subjects at risk of CVD using a risk score and to compare the characteristics of subjects with and without risk of CVD.

    Method: Blood samples were taken in a fasting state, and food habits were reported through a questionnaire. cIMT was measured by ultrasound, and VO2 max was measured by ergometer bike test. The risk score was calculated according to Wildman.

    Result: cIMT (mean +/- standard deviation) was 0.50 +/- 0.06 mm, and VO2 max values were 37.8 +/- 8.5 and 42.9 +/- 9.9 mL/kg/min, in women and men, respectively. No correlation was found between aerobic fitness expressed as VO2 max (mL/kg/min) and cIMT. Using Wildman's definition, 12% of the subjects were classified as being at risk of CVD, and 15% had homeostasis model assessment of insulin resistance. A total of 35% of women and 25% of men had lower high-density lipoprotein cholesterol than recommended. Food habits did not differ between those at risk and those not at risk. However, aerobic fitness measured as VO2 max (mL/kg/min) differed; 47% of the subjects at risk had low aerobic fitness compared to 23% of the nonrisk subjects (P<0.001).

    Conclusion: High aerobic fitness is associated with low CVD risk in Swedish young adults. The high prevalence of young adults observed with unfavorable levels of high-density lipoprotein cholesterol and homeostasis model assessment of insulin resistance raises concerns about future CVD risk.

    Place, publisher, year, edition, pages
    DOVE Medical Press Ltd., 2017
    Keywords
    cIMT, cholesterol, insulin resistance, body fat, diet, aerobic fitness
    National Category
    Cardiac and Cardiovascular Systems
    Research subject
    Cardiology
    Identifiers
    urn:nbn:se:oru:diva-56877 (URN)10.2147/VHRM.S125966 (DOI)000396188000002 ()28352184 (PubMedID)2-s2.0-85015747630 (Scopus ID)
    Note

    Funding Agency:

    AFA insurance

    Available from: 2017-03-29 Created: 2017-03-29 Last updated: 2019-10-22Bibliographically approved
    2. Arterial stiffness is associated to cardiorespiratory fitness and body mass index in young Swedish adults: The Lifestyle, Biomarkers, and Atherosclerosis study
    Open this publication in new window or tab >>Arterial stiffness is associated to cardiorespiratory fitness and body mass index in young Swedish adults: The Lifestyle, Biomarkers, and Atherosclerosis study
    2017 (English)In: European Journal of Preventive Cardiology, ISSN 2047-4873, E-ISSN 2047-4881, Vol. 24, no 17, p. 1809-1818Article in journal (Refereed) Published
    Abstract [en]

    Background: Early changes in the large muscular arteries are already associated with risk factors as hypertension and obesity in adolescence and young adulthood. The present study examines the association between arterial stiffness measurements, pulse wave velocity and augmentation index and lifestyle-related factors, body composition and cardiorespiratory fitness, in young, healthy, Swedish adults.

    Design: This study used a population-based cross-sectional sample.

    Methods: The 834 participants in the study were self-reported healthy, non-smoking, age 18-25 years. Augmentation index and pulse wave velocity were measured with applanation tonometry. Cardiorespiratory fitness was measured by ergometer bike test to estimate maximal oxygen uptake. Body mass index (kg/m(2)) was calculated and categorised according to classification by the World Health Organisation.

    Results: Young Swedish adults with obesity and low cardiorespiratory fitness have significantly higher pulse wave velocity and augmentation index than non-obese young adults with medium or high cardiorespiratory fitness. The observed U-shaped association between pulse wave velocity and body mass index categories in women indicates that it might be more beneficial to be normal weight than underweight when assessing the arterial stiffness with pulse wave velocity. The highest mean pulse wave velocity was found in overweight/obese individuals with low cardiorespiratory fitness. The lowest mean pulse wave velocity was found in normal weight individuals with high cardiorespiratory fitness. Cardiorespiratory fitness had a stronger effect than body mass index on arterial stiffness in multiple regression analyses.

    Conclusions: The inverse association between cardiorespiratory fitness and arterial stiffness is observed already in young adults. The study result highlights the importance of high cardiorespiratory fitness, but also that underweight individuals may be a possible risk group that needs to be further studied.

    Place, publisher, year, edition, pages
    Sage Publications, 2017
    Keywords
    Arterial stiffness, pulse wave analysis, cardiorespiratory fitness, body mass index, young adult, atherosclerosis
    National Category
    Cardiac and Cardiovascular Systems Public Health, Global Health, Social Medicine and Epidemiology
    Identifiers
    urn:nbn:se:oru:diva-62511 (URN)10.1177/2047487317720796 (DOI)000414856300004 ()28696134 (PubMedID)2-s2.0-85033405287 (Scopus ID)
    Funder
    AFA Insurance
    Available from: 2017-11-21 Created: 2017-11-21 Last updated: 2019-10-22Bibliographically approved
    3. Body composition is a strong predictor of local carotid stiffness in Swedish, young adults: the cross sectional Lifestyle, biomarkers, and atherosclerosis study
    Open this publication in new window or tab >>Body composition is a strong predictor of local carotid stiffness in Swedish, young adults: the cross sectional Lifestyle, biomarkers, and atherosclerosis study
    2019 (English)In: BMC Cardiovascular Disorders, ISSN 1471-2261, E-ISSN 1471-2261, Vol. 19, no 1, article id 205Article in journal (Refereed) Published
    Abstract [en]

    BACKGROUND: Obesity has nearly tripled worldwide during the last four decades, especially in young adults, and is of growing concern since it is a risk factor for cardiovascular diseases (CVD). We explored how different body composition measurements are associated with intima media thickness (cIMT) and local stiffness in the common carotid artery, in a subsample of healthy, young women and men, from the Swedish Lifestyle, Biomarkers, and Atherosclerosis (LBA) Study.

    METHODS: From the LBA study, a subsample of 220 randomly selected, self-reported healthy individuals, 18-25 years old, were collected for the automatized local stiffness measurements; arterial distensibility, Young's elastic modulus, and β stiffness index. Blood pressure and mean arterial pressure (MAP) was measured using automatic blood pressure equipment. Body mass index (BMI) was calculated, waist circumference was measured, and percentage of body fat assessed using an impedance body composition analyzer. The carotid artery was scanned by ultrasound and analyzed using B-mode edge wall tracking. cIMT was measured and local stiffness measurements were calculated with carotid blood pressure, measured with applanation tonometry.

    RESULTS: No association was found between cIMT and body composition. Local carotid stiffness was associated with body composition, and women had less stiff arteries than men (p < 0.001). Of the local stiffness measurements, arterial distensibility had the strongest associations with body composition measurements in both women and men (p < 0.05). Multiple regression analyses showed that BMI in women and BMI and percentage of body fat in men had the highest impact on arterial distensibility (p < 0.01 in both women and men).

    CONCLUSIONS: Arterial distensibility was the local stiffness measurement with the strongest associations to different body composition measurements, in both women and men. In this age group, body composition measurements seem to be stronger predictors of common carotid arterial stiffness than MAP, and is a convenient way of detecting young adults who need cardiovascular risk follow-up and lifestyle counseling.

    Place, publisher, year, edition, pages
    BioMed Central, 2019
    Keywords
    Arterial distensibility, Arterial stiffness, Body composition, Carotid artery, Cross-sectional study, Epidemiological, Intima media thickness, Young adults
    National Category
    Nutrition and Dietetics Cardiac and Cardiovascular Systems
    Identifiers
    urn:nbn:se:oru:diva-76105 (URN)10.1186/s12872-019-1180-6 (DOI)000483032600001 ()31455254 (PubMedID)2-s2.0-85071644915 (Scopus ID)
    Note

    Funding Agency:

    Asset Management Arm (AFA)  130275

    Available from: 2019-09-10 Created: 2019-09-10 Last updated: 2019-10-22Bibliographically approved
    4. Higher total physical activity is associated with lower arterial stiffness in Swedish, young adults: The Lifestyle, Biomarkers, and Atherosclerosis study
    Open this publication in new window or tab >>Higher total physical activity is associated with lower arterial stiffness in Swedish, young adults: The Lifestyle, Biomarkers, and Atherosclerosis study
    (English)Manuscript (preprint) (Other academic)
    National Category
    Other Basic Medicine
    Identifiers
    urn:nbn:se:oru:diva-77488 (URN)
    Available from: 2019-10-21 Created: 2019-10-21 Last updated: 2019-10-22Bibliographically approved
    The full text will be freely available from 2019-10-25 11:00
  • Public defence: 2019-11-15 09:15 Örebro universitet, Prismahuset, Hörsal P1, Örebro
    Boman, Tomas
    Örebro University, School of Health Sciences.
    Situation på den svenska arbetsmarknaden för personer med funktionsnedsättning: en sekundäranalys om sysselsättning, yrkesnivå, stöd och anpassning för personer med olika typer av funktionsnedsättning2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The overall aim of this thesis is to explore how the labour market situation appears to persons with different types of disabilities in Sweden. Study I (n=4 359) examined the importance of the person’s type of disability for the possibility of having a job. Study II (n=3 396) examined whether there were differences in occupational attainment between persons with different types of disabilities and between persons with and without a disability (n=19 004). Study III (n=4 359) examined perceived discrimination in the workplace among persons with different types of disabilities. Study IV (n=2 268) examined whatsupport and adaptation persons with different types of disabilities need in their actual workplace or to enter the labour market. In studies I–III the respondents were divided into six disability types, and in study IV the respondents were divided into four disability types.

    Overall, it can be concluded that a person’s type of disability is of importance for the situation in the labour market, where persons with psychological disabilities encounter barriers to a greater extent than other groups, both difficulties at the present workplace and difficulties entering the labour market. Further, they were subjected to discrimination and they expressed a great need for adaptations to acquire employment and at their actual workplace. It can also be concluded that there are discriminatory mechanisms against women, who have more difficulties than men in acquiring employment, and that men, despite lower education, can more easily progress in the labour market. It is suggested that, in order to achieve inclusion and recognition, factors in the environment, such as existing support systems, need to be changed and developed, and social prejudices vis-à-vis people with disabilities must also be addressed.

    List of papers
    1. Employment opportunities for persons with different types of disability
    Open this publication in new window or tab >>Employment opportunities for persons with different types of disability
    2015 (English)In: Alter;European Journal of Disability Research ;Journal Europeen de Recherche Sur le Handicap, ISSN 1875-0672, E-ISSN 1875-0680, Vol. 9, no 2, p. 116-129Article in journal (Refereed) Published
    Abstract [en]

    The employment status of groups with different disabilities was analysed as were potentially important moderating factors (work ability, structural and individual factors). A secondary analysis was performed on 4359 respondents with disabilities from Statistics Sweden's Labour Market Investigation. The respondents were divided into six disability groups (communicative-hearing, communicative-speech-reading, communicative-vision, psychological disability, medical disability, physical disability). Logistic regression analyses showed that the probability of being employed was highest among respondents with hearing disabilities and respondents with psychological disabilities were least likely to be employed. Being a woman (very young or old) with only primary education and with partially or very impaired work ability, reduced employment opportunities. Higher education did not increase employment opportunities for respondents with impaired workability. In summary, the type of disability is essential for employment opportunities, and differences between disability groups cannot be explained by differences in other variables. The moderating factors studied were found to be of equal importance in all groups.

    Place, publisher, year, edition, pages
    Elsevier, 2015
    Keywords
    Type of disability, Employment, Self-estimated work ability, Education level
    National Category
    General Practice
    Research subject
    Family Medicine
    Identifiers
    urn:nbn:se:oru:diva-47084 (URN)10.1016/j.alter.2014.11.003 (DOI)000365124200003 ()2-s2.0-84928769973 (Scopus ID)
    Available from: 2015-12-15 Created: 2015-12-15 Last updated: 2019-10-22Bibliographically approved
    2. Can people with disabilities gain from education?: Similarities and differences between occupational attainment among persons with and without disabilities
    Open this publication in new window or tab >>Can people with disabilities gain from education?: Similarities and differences between occupational attainment among persons with and without disabilities
    2014 (English)In: Work: A journal of Prevention, Assessment and rehabilitation, ISSN 1051-9815, E-ISSN 1875-9270, Vol. 49, no 2, p. 193-204Article in journal (Refereed) Published
    Abstract [en]

    BACKGROUND: More knowledge is needed of occupational attainment of persons with disabilities, i.e. the relationship between their educational level and their profession, and factors of importance for this relationship.

    OBJECTIVE: To compare occupational attainment among persons with and without a disability.

    METHOD: 3396 informants with disabilities and 19004 non-disabled informants participated (control group) in a survey study by Statistics Sweden. The informants with disabilities were divided into six groups.

    RESULTS: Occupational attainment did not differ between the disability groups, neither between persons with and without a disability. Follow-up analysis showed that men with disabilities with primary or secondary school had an occupation above their educational level to a significantly larger extent than women with disabilities. This pattern was even clearer in comparison with the control group. Persons without disabilities, with secondary or higher education, were more successful in the labor market than persons with disabilities. Occupational attainment increased with age in both groups.

    CONCLUSIONS: Young women with disabilities who only have primary or secondary education run a higher risk of having a job that is below their educational level than men at the same educational level. This indicates discriminating mechanisms in the society related to gender and ability.

    Place, publisher, year, edition, pages
    IOS Press, 2014
    Keywords
    Discrimination, occupational attainment, educational level, self-estimated work ability
    National Category
    Medical and Health Sciences Occupational Therapy
    Research subject
    Disability Science
    Identifiers
    urn:nbn:se:oru:diva-39248 (URN)10.3233/WOR-131718 (DOI)000344347900004 ()24004782 (PubMedID)
    Available from: 2014-12-02 Created: 2014-12-02 Last updated: 2019-10-22Bibliographically approved
    3. Disability and discrimination in the workplace context: A comparative study between persons with different types of disabilities [Invalidité et discrimination sur le lieu de travail: Une étude comparative entre les personnes ayant diverses formes de handicap]
    Open this publication in new window or tab >>Disability and discrimination in the workplace context: A comparative study between persons with different types of disabilities [Invalidité et discrimination sur le lieu de travail: Une étude comparative entre les personnes ayant diverses formes de handicap]
    (English)Manuscript (preprint) (Other academic)
    National Category
    Other Health Sciences
    Identifiers
    urn:nbn:se:oru:diva-77506 (URN)
    Available from: 2019-10-22 Created: 2019-10-22 Last updated: 2019-10-22Bibliographically approved
    4. The Need of Support and Adaptation in the Workplace for Persons with Different Types of Disabilities and Reduced Work Ability
    Open this publication in new window or tab >>The Need of Support and Adaptation in the Workplace for Persons with Different Types of Disabilities and Reduced Work Ability
    (English)Manuscript (preprint) (Other academic)
    National Category
    Other Health Sciences
    Identifiers
    urn:nbn:se:oru:diva-77508 (URN)
    Available from: 2019-10-22 Created: 2019-10-22 Last updated: 2019-10-22Bibliographically approved
  • Public defence: 2019-11-15 10:00 Örebro universitet, Campus USÖ, hörsal C1, Örebro
    Tevell, Staffan
    Örebro University, School of Medical Sciences.
    Staphylococcal prosthetic joint infections: similar, but still different2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Staphylococci constitute a major part of our commensal flora but are also the most common bacteria causing prosthetic joint infections (PJIs), a dreaded complication of arthroplasty surgery. However, not all staphylococci are the same. The virulent Staphylococcus aureus has the ability to cause severe disease such as bacteremia and infective endocarditis in previously healthy people, while the coagulase-negative staphylococci Staphylococcus epidermidis and Staphylococcus capitis rarely act as pathogens unless the patient is immunocompromised or has an implanted medical device, such as a prosthetic joint. This thesis accordingly explores similarities and differences between these three staphylococci in PJIs.

    S. capitis can cause early postinterventional and chronic PJIs, a finding that has not previously been described. Furthermore, its nosocomial NRCS-A outbreak sublineage, recently observed in neonatal intensive care units, is also present in adult PJIs. When comparing nasal and PJI isolates, the patterns differed between staphylococcal species. In S. capitis, the commensal and infecting strains were separated phylogenetically, while they clustered together for S. aureus. This may indicate diverse reservoirs and acquisition routes in PJIs caused by different staphylococcal species.

    Outcomes in early postinterventional PJIs were similar in S. capitis and S. aureus infections, with 70–80% achieving clinical cure. In S. aureus infections, no virulence genes were significantly associated with outcome. Although multidrug resistance (MDR) was rare in S. aureus, inability to use biofilm-active antibiotics was a risk factor for failure. However, in S. epidermidis and in the NRCS-A sublineage of S. capitis, MDR and glycopeptide heteroresistance were widespread, highlighting the challenge of antibiotic resistance in the treatment of PJIs.

    List of papers
    1. Heterogeneous glycopeptide intermediate Staphylococcus epidermidis isolated from prosthetic joint infections
    Open this publication in new window or tab >>Heterogeneous glycopeptide intermediate Staphylococcus epidermidis isolated from prosthetic joint infections
    Show others...
    2014 (English)In: European Journal of Clinical Microbiology and Infectious Diseases, ISSN 0934-9723, E-ISSN 1435-4373, Vol. 33, no 6, p. 911-917Article in journal (Refereed) Published
    Abstract [en]

    Methicillin-resistant Staphylococcus epidermidis (MRSE) poses a major problem in prosthetic joint infections (PJIs). Vancomycin is often considered the drug of choice in the empirical treatment of staphylococcal PJIs. As recent decades have seen reports of heterogeneous glycopeptide intermediate S. aureus (hGISA), our aim was to examine the prevalence of heterogeneous glycopeptide intermediate S. epidermidis (hGISE) in PJIs. S. epidermidis isolates (n = 122) from 119 patients in three Swedish counties between 1993 and 2012 were included. All were isolated from perioperative tissue samples from revision surgery in clinically verified PJIs. Antimicrobial susceptibility testing against staphylococcal antibiotics was performed. The macromethod Etest (MME) and glycopeptide resistance detection (GRD) Etest were used to detect hGISE. Standard minimal inhibitory concentration (MIC) determination revealed no vancomycin-resistant isolates, while teicoplanin resistance was detected in 14 out of 122 isolates (11.5 %). hGISE was found in 95 out of 122 isolates (77.9 %), 64 out of 67 of isolates with teicoplanin MIC > 2 mg/L (95.5 %) and 31 out of 55 of isolates with teicoplanin MIC a parts per thousand currency sign2 mg/L (56.4 %). Thus, the presence of hGISE cannot be ruled out by teicoplanin MIC a parts per thousand currency sign2 mg/L alone. Multidrug resistance was detected in 86 out of 95 hGISE isolates (90.5 %) and in 16 out of 27 isolates (59.3 %), where hGISE could not be detected. In conclusion, hGISE detected by MME or GRD was common in this material. However, hGISE is difficult to detect with standard laboratory diagnostic routines. Glycopeptide treatment may not be sufficient in many of these PJIs, even if standard MIC classifies the isolated S. epidermidis as susceptible.

    Place, publisher, year, edition, pages
    New York: Springer, 2014
    National Category
    Infectious Medicine Microbiology in the medical area
    Research subject
    Infectious Diseases; Microbiology
    Identifiers
    urn:nbn:se:oru:diva-35350 (URN)10.1007/s10096-013-2025-3 (DOI)000335743500004 ()24338092 (PubMedID)2-s2.0-84903820002 (Scopus ID)
    Note

    Funding Agencies:

    Research committee of Östergotland, County Council, Sweden

    Research committee of Värmland, County Council, Sweden

    Available from: 2014-06-13 Created: 2014-06-13 Last updated: 2019-10-21Bibliographically approved
    2. Genomic characterization and outcome of prosthetic joint infections caused by Staphylococcus aureus
    Open this publication in new window or tab >>Genomic characterization and outcome of prosthetic joint infections caused by Staphylococcus aureus
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Infectious Medicine
    Identifiers
    urn:nbn:se:oru:diva-77473 (URN)
    Available from: 2019-10-21 Created: 2019-10-21 Last updated: 2019-10-21Bibliographically approved
    3. Staphylococcus capitis isolated from prosthetic joint infections
    Open this publication in new window or tab >>Staphylococcus capitis isolated from prosthetic joint infections
    2017 (English)In: European Journal of Clinical Microbiology and Infectious Diseases, ISSN 0934-9723, E-ISSN 1435-4373, Vol. 36, no 1, p. 115-122Article in journal (Refereed) Published
    Abstract [en]

    Further knowledge about the clinical and microbiological characteristics of prosthetic joint infections (PJIs) caused by different coagulase-negative staphylococci (CoNS) may facilitate interpretation of microbiological findings and improve treatment algorithms. Staphylococcus capitis is a CoNS with documented potential for both human disease and nosocomial spread. As data on orthopaedic infections are scarce, our aim was to describe the clinical and microbiological characteristics of PJIs caused by S. capitis. This retrospective cohort study included three centres and 21 patients with significant growth of S. capitis during revision surgery for PJI between 2005 and 2014. Clinical data were extracted and further microbiological characterisation of the S. capitis isolates was performed. Multidrug-resistant (≥3 antibiotic groups) S. capitis was detected in 28.6 % of isolates, methicillin resistance in 38.1 % and fluoroquinolone resistance in 14.3 %; no isolates were rifampin-resistant. Heterogeneous glycopeptide-intermediate resistance was detected in 38.1 %. Biofilm-forming ability was common. All episodes were either early post-interventional or chronic, and there were no haematogenous infections. Ten patients experienced monomicrobial infections. Among patients available for evaluation, 86 % of chronic infections and 70 % of early post-interventional infections achieved clinical cure; 90 % of monomicrobial infections remained infection-free. Genetic fingerprinting with repetitive sequence-based polymerase chain reaction (rep-PCR; DiversiLab®) displayed clustering of isolates, suggesting that nosocomial spread might be present. Staphylococcus capitis has the potential to cause PJIs, with infection most likely being contracted during surgery or in the early postoperative period. As S. capitis might be an emerging nosocomial pathogen, surveillance of the prevalence of PJIs caused by S. capitis could be recommended.

    Place, publisher, year, edition, pages
    New York: Springer, 2017
    National Category
    Infectious Medicine Microbiology
    Identifiers
    urn:nbn:se:oru:diva-52726 (URN)10.1007/s10096-016-2777-7 (DOI)000391388800014 ()27680718 (PubMedID)2-s2.0-84988919555 (Scopus ID)
    Note

    Funding Agencies:

    Research committee of Värmland County Council, Sweden LIVFOU-456821  LIVFOU-457061

    Research committee of Östergötland County Council, Sweden LIO-447091

    Örebro University, Sweden ORU 1.3.1-01273/2015

    Available from: 2016-10-04 Created: 2016-10-03 Last updated: 2019-10-21Bibliographically approved
    4. Presence of the neonatal Staphylococcus capitis outbreak clone (NRCS-A) in prosthetic joint infections
    Open this publication in new window or tab >>Presence of the neonatal Staphylococcus capitis outbreak clone (NRCS-A) in prosthetic joint infections
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Infectious Medicine
    Identifiers
    urn:nbn:se:oru:diva-77474 (URN)
    Available from: 2019-10-21 Created: 2019-10-21 Last updated: 2019-10-21Bibliographically approved
    5. Same Organism, Different Phenotype: Are Phenotypic Criteria Adequate In Coagulase-Negative Staphylococcal Orthopaedic Implant-Associated Infections?
    Open this publication in new window or tab >>Same Organism, Different Phenotype: Are Phenotypic Criteria Adequate In Coagulase-Negative Staphylococcal Orthopaedic Implant-Associated Infections?
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    2019 (English)In: Journal of bone and joint infection, ISSN 2206-3552, Vol. 4, no 1, p. 16-19Article in journal (Refereed) Published
    Abstract [en]

    In current diagnostic criteria for implant-associated bone- and joint infections, phenotypically identical low-virulence bacteria in two intraoperative cultures are usually required. Using whole-genome sequencing, we have further characterized three phenotypically different Staphylococcus capitis isolated from one prosthetic joint infection, highlighting the challenges in defining microbiological criteria for low-virulence prosthetic joint infections.

    Place, publisher, year, edition, pages
    British Editorial Society of Bone and Joint Surger, 2019
    National Category
    Infectious Medicine
    Identifiers
    urn:nbn:se:oru:diva-77484 (URN)10.7150/jbji.30256 (DOI)30755843 (PubMedID)
    Available from: 2019-10-21 Created: 2019-10-21 Last updated: 2019-10-21Bibliographically approved
  • Public defence: 2019-11-22 09:00 Örebro universitet, Campus USÖ, hörsal C1, Örebro
    Fägerstad, Anida
    Örebro University, School of Health Sciences.
    No-shows in dental care: perspectives on adolescents' attendance pattern2019Doctoral thesis, comprehensive summary (Other academic)
  • Public defence: 2019-11-22 13:00 Örebro universitet, Campus USÖ, hörsal C3, Örebro
    Fischer, Per
    Örebro University, School of Medical Sciences.
    Hemi and total wrist arthroplasty2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Aim: To study implant survival and implant loosening following primary total wrist arthroplasty (TWA) using four different implants. To report outcome following wrist revision arthroplasty. To evaluate a new radial wrist hemi arthroplasty (RWHA) design clinically and biomechanically.

    Method: The studies included 136 primary TWAs and 16 revision TWAs, both studies with prospectively collected data. Six fresh frozen cadaveric wrist specimen were used for biomechanical analysis. The RHWA was evaluated clinically in a pilot series of 20 cases.

    Results: Total implant survival was 92% but with high frequency of implant loosening of surviving Re-Motion implants. None of the surviving Maestro implants were considered radiographically loose. Implant survival following revision arthroplasty was 75%, considerably lower than following primary TWAs. However, none of the patients with surviving revision implants had pain at rest and little or no pain in activity. The surgical procedure and placement of the RHWA was feasible. Overall, the kinematic and functional changes appeared acceptable compared to the native wrist. None of the patients underwent revision following RHWA but reoperation was performed in 7 patients on the indication of persistent pain. However, patients reported relief of pain and improvement of patient-reported outcome measures.

    Conclusion: High long-term implant survival and no signs of radiographic loosening was found for the Maestro implant. However, the Maestro implant is no longer available on the market and we believe there is a need for new TWA designs. Revision arthroplasty is a valid option in the management of failed TWA. However, implant survival is lower than for primary TWAs and as many as 25% require additional surgery. Promising results were found using the new RHWA design but the implant needs modification before further testing.

    List of papers
    1. Total wrist arthroplasty, a 10 year follow-up
    Open this publication in new window or tab >>Total wrist arthroplasty, a 10 year follow-up
    (English)Manuscript (preprint) (Other academic)
    National Category
    Surgery
    Identifiers
    urn:nbn:se:oru:diva-77452 (URN)
    Available from: 2019-10-18 Created: 2019-10-18 Last updated: 2019-10-18Bibliographically approved
    2. Revision Arthroplasty of the Wrist in Patients With Rheumatoid Arthritis, Mean Follow-Up 6.6 Years
    Open this publication in new window or tab >>Revision Arthroplasty of the Wrist in Patients With Rheumatoid Arthritis, Mean Follow-Up 6.6 Years
    2018 (English)In: Journal of Hand Surgery-American Volume, ISSN 0363-5023, E-ISSN 1531-6564, Vol. 43, no 5, p. 489.e1-489.e7Article in journal (Refereed) Published
    Abstract [en]

    PURPOSE: Management of failed total wrist arthroplasty (TWA) can be challenging; surgical treatment options include salvage arthrodesis, revision arthroplasty, and resection arthroplasty. There are few studies regarding salvage arthrodesis, and revision arthroplasty has been infrequently investigated. The aim of the study was to report the outcome after revision arthroplasty of the wrist.

    METHODS: A retrospective cohort of 16 revision TWAs was evaluated between 2003 and 2016. Data were collected before surgery and 1 and 5 years after surgery. The indication for revision arthroplasty was failed TWA. The primary end point was implant survival. Secondary outcome measures included visual analog scale (VAS) pain scores, range of motion, handgrip strength, and functional scoring with the Canadian Occupational Performance Measure (COPM), Patient-Rated Wrist Evaluation (PRWE), and Disabilities of the Arm, Shoulder, and Hand (DASH).

    RESULTS: Mean follow-up was 6.6 years. Synthetic bone graft was used in 9 cases, allograft corticocancellous bone graft in 1 case, and cement in 6 cases. Of the 16 revision TWAs, 4 were re-revised, 1 because of infection, and 3 cases underwent total wrist arthrodesis. In the non-re-revised cases, range of motion and grip strength was preserved compared with preoperative results. The VAS pain score in activity improved, but not significantly, at 1 (median, 1; range, 0-4.5) and 5 years after surgery (median, 0) compared with before surgery (median, 5). The COPM performance and satisfaction as well as PRWE scores improved significantly at 1 year (median COPM performance, 4.8; COPM satisfaction, 5.6; and PRWE, 24) and improved, but not significantly, at the 5-year follow (median COPM performance, 4.8; COPM satisfaction, 5.0; and PRWE, 37) in the non-re-revised cases.

    CONCLUSIONS: Revision arthroplasty of the wrist is a valid motion-preserving option to wrist arthrodesis in the management of failed TWA. However, the outcome is uncertain and as many as 25% require additional surgery.

    TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

    Place, publisher, year, edition, pages
    Elsevier, 2018
    Keywords
    Total wrist arthroplasty, osteoarthritis, rheumatoid arthritis
    National Category
    Orthopaedics Surgery
    Identifiers
    urn:nbn:se:oru:diva-67046 (URN)10.1016/j.jhsa.2017.10.038 (DOI)000432437100018 ()29224946 (PubMedID)2-s2.0-85044505797 (Scopus ID)
    Note

    Funding Agency:

    Örebro County Council Research Committee

    Available from: 2018-05-18 Created: 2018-05-18 Last updated: 2019-10-18Bibliographically approved
    3. FUNCTIONAL and KINEMATIC ANALYSIS of A WRIST RADIAL HEMIARTHROPLASTY DESIGN
    Open this publication in new window or tab >>FUNCTIONAL and KINEMATIC ANALYSIS of A WRIST RADIAL HEMIARTHROPLASTY DESIGN
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    2018 (English)In: Journal of Musculoskeletal Research, ISSN 0218-9577, Vol. 21, no 1, article id 1850005Article in journal (Refereed) Published
    Abstract [en]

    Purpose: A biomechanical functional assessment was performed on a newly designed wrist hemiarthroplasty implant with aimed to identifying differences between the native wrist and wrist following the hemiarthroplasty procedure with (Hemi+PRC) and without a proximal row carpectomy (Hemi).

    Methods: Six cadaveric wrists were mounted on a custom testing fixture and underwent a series of functional tests to investigate differences in range of motion, muscles moment arms, and axis of rotation between the intact and post-operative wrists. The tested movements included manually-driven flexion-extension, radial-ulnar deviation, dart throwers motion, and circumduction.

    Results: The only significant change in range of motion was a decrease in flexion between the intact (77.75±14.40°) and both the Hemi (65.97±17.72°) and Hemi+PRC (60.08±17.18°) conditions. Minor differences in the mean position and variability of the axis of rotation's piercing point were identified. A statistically significant decrease in the flexion moment arm of the flexor carpi radialis was identified between the intact (16.1±2.6mm) and Hemi+PRC (14.0±3.4mm) conditions. Statistically significant decreases were also identified in the radial deviation moment arms of the extensor carpi radialis brevis' between the intact (15.3±7.8mm) and Hemi+PRC (7.3±12.5mm) conditions and the flexor carpi radialis' between the intact (15.3±3.2mm) and Hemi (12.0±5.7mm) conditions as well as in the ulnar deviation moment arm of the extensor carpi ulnaris between the intact (34.9±11.3mm) and Hemi (13.2±21.9mm) conditions.

    Conclusions: While some statistically significant functional changes were identified between the native and hemiarthroplasty wrist, the findings suggest that post-operative function is equally acceptable in hemiarthroplasty with and without resection of the proximal carpal row. © 2018 World Scientific Publishing Company.

    Place, publisher, year, edition, pages
    World Scientific, 2018
    Keywords
    Functional and kinematic analysis, Wrist, Wrist radial hemiarthroplasty design, article, carpal bone, flexor carpi radialis muscle, hemiarthroplasty, human, range of motion, rotation, ulna
    National Category
    Surgery
    Identifiers
    urn:nbn:se:oru:diva-77453 (URN)10.1142/S0218957718500057 (DOI)2-s2.0-85044274774 (Scopus ID)
    Note

    Export Date: 18 October 2019; Article; CODEN: JMURF; Correspondence Address: Rizzo, M.; Mayo Clinic, Department of Orthopedic Surgery, 200 First St. SW, United States; email: Rizzo.marco@mayo.edu

    Available from: 2019-10-18 Created: 2019-10-18 Last updated: 2019-10-18Bibliographically approved
    4. Clinical, radiographic and patient-perceived outcome after radial hemi-wrist arthroplasty of the wrist with a new implant. A pilot study
    Open this publication in new window or tab >>Clinical, radiographic and patient-perceived outcome after radial hemi-wrist arthroplasty of the wrist with a new implant. A pilot study
    (English)Manuscript (preprint) (Other academic)
    National Category
    Surgery
    Identifiers
    urn:nbn:se:oru:diva-77454 (URN)
    Available from: 2019-10-18 Created: 2019-10-18 Last updated: 2019-10-18Bibliographically approved
    The full text will be freely available from 2019-10-22 13:00
  • Public defence: 2019-11-29 09:15 Örebro universitet, Långhuset, Hörsal L2, Örebro
    Grylin, Hanna
    Örebro University, School of Science and Technology.
    Passivitetsrätten vid skattetillägg2019Doctoral thesis, comprehensive summary (Other academic)
  • Public defence: 2019-12-03 13:00 Örebro universitet, Hörsalen, Musikhögskolan, Örebro
    Twizeyimana, Jean Damascene
    Örebro University, Örebro University School of Business.
    e-Government and value creation in the context of a developed country: a perspective on public value and information infrastructure2019Doctoral thesis, comprehensive summary (Other academic)
  • Public defence: 2019-12-05 13:15 Örebro universitet, Forumhuset, Biografen, Örebro
    Mukamurenzi, Solange
    Örebro University, Örebro University School of Business.
    E-government Service Evaluation in Rwanda: A Design Perspective2019Doctoral thesis, comprehensive summary (Other academic)
  • Public defence: 2019-12-06 09:00 Örebro universitet, Campus USÖ, hörsal C1, Örebro
    Månsson, Emeli
    Örebro University, School of Medical Sciences.
    Molecular epidemiology of Staphylococcus epidermidis in prosthetic joint infections2019Doctoral thesis, comprehensive summary (Other academic)
  • Public defence: 2019-12-13 13:00 Örebro universitet, Hörsalen, Musikhögskolan, Örebro
    Ullsten, Alexandra
    Örebro University, School of Music, Theatre and Art.
    Singing, sharing, soothing: Family-centred music therapy during painful procedures in neonatal care2019Doctoral thesis, comprehensive summary (Other academic)
  • Public defence: 2019-12-20 13:00 Örebro universitet, Konsertsalen, Musikhögskolan, Örebro
    Larsson, Christina
    Örebro University, School of Music, Theatre and Art.
    Att lära genom improvisation - en didaktisk studie i grundskolans musikundervisning2019Doctoral thesis, comprehensive summary (Other academic)