1,004 results on '"Magnus Andersson"'
Search Results
2. Added predictive value of prehospital measurement of point-of-care lactate in an adult general EMS population in Sweden: a multi-centre observational study
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Carl Magnusson, Johan Herlitz, Christer Axelsson, Robert Höglind, Elin Lökholm, Thea Hillberg Hörnfeldt, Agnes Olander, Joakim Björås, Magnus Andersson Hagiwara, and Pär Wennberg
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Prehospital ,Point-of-care ,Patient assessment ,Emergency medical service ,Lactate ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Abstract Background Emergency medical services (EMS) personnel must rapidly assess and transport patients with time-sensitive conditions to optimise patient outcomes. Serum lactate, a valuable in-hospital biomarker, has become more accessible in EMS settings through point-of-care (POC) testing. Although POC lactate levels are valuable in specific patient groups, its broader application in EMS remains unclear. This study assessed the additional predictive value of POC lactate levels in a general adult EMS population. Methods This prospective observational study (March 2018 to September 2019) involved two EMS organisations in Västra Götaland, Sweden. Patients were triaged using the Rapid Triage and Treatment System (RETTS). POC lactate levels were measured using StatStrip Xpress devices. Non-consecutive patients who received EMS and were aged 18 years and above were available for inclusion if triaged into RETTS levels: red, orange, yellow, or green if respiratory rate of ≥ 22 breaths/min. Outcomes were adverse outcomes, including a time-sensitive diagnosis, sequential organ failure assessment (SOFA) score ≥ 2, and 30-day mortality. Statistical analyses included descriptive statistics, imputation, and regression models to assess the impact of the addition of POC lactate levels to a base model (comprising patient age, sex, presence of past medical conditions, vital signs, pain, EMS response time, assessed triage condition, and triage level) and a RETTS triage model. Results Of 4,546 patients (median age 75 [57, 84] years; 49% male), 32.4% had time-sensitive conditions, 12.5% met the SOFA criteria, and 7.4% experienced 30-day mortality. The median POC lactate level was 1.7 (1.2, 2.5) mmol/L. Patients with time-sensitive conditions had higher lactate levels (1.9 mmol/L) than those with non-time-sensitive conditions (1.6 mmol/L). The probability of a time-sensitive condition increased with increasing lactate level. The addition of POC lactate marginally enhanced the predictive models, with a 1.5% and 4% increase for the base and RETTS triage models, respectively. POC lactate level as a sole predictor showed chance-only level predictive performance. Conclusions Prehospital POC lactate assessment provided limited additional predictive value in a general adult EMS population. However, it may be beneficial in specific patient subgroups, emphasizing the need for its judicious use in prehospital settings.
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- 2024
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3. Segmentation and characterization of macerated fibers and vessels using deep learning
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Saqib Qamar, Abu Imran Baba, Stéphane Verger, and Magnus Andersson
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Instance segmentation ,YOLO ,Wood ,Fibers ,Optical microscopy ,Plant culture ,SB1-1110 ,Biology (General) ,QH301-705.5 - Abstract
Abstract Purpose Wood comprises different cell types, such as fibers, tracheids and vessels, defining its properties. Studying cells’ shape, size, and arrangement in microscopy images is crucial for understanding wood characteristics. Typically, this involves macerating (soaking) samples in a solution to separate cells, then spreading them on slides for imaging with a microscope that covers a wide area, capturing thousands of cells. However, these cells often cluster and overlap in images, making the segmentation difficult and time-consuming using standard image-processing methods. Results In this work, we developed an automatic deep learning segmentation approach that utilizes the one-stage YOLOv8 model for fast and accurate segmentation and characterization of macerated fiber and vessel form aspen trees in microscopy images. The model can analyze 32,640 x 25,920 pixels images and demonstrate effective cell detection and segmentation, achieving a $$\hbox {mAP}_{0.5-0.95}$$ mAP 0.5 - 0.95 of 78 %. To assess the model’s robustness, we examined fibers from a genetically modified tree line known for longer fibers. The outcomes were comparable to previous manual measurements. Additionally, we created a user-friendly web application for image analysis and provided the code for use on Google Colab. Conclusion By leveraging YOLOv8’s advances, this work provides a deep learning solution to enable efficient quantification and analysis of wood cells suitable for practical applications.
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- 2024
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4. Pediatric trauma patients in Swedish ambulance services -a retrospective observational study of assessments, interventions, and clinical outcomes
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Glenn Larsson, Sanna Larsson, Viktoria Strand, Carl Magnusson, and Magnus Andersson Hagiwara
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Pediatric trauma ,Prehospital assessment ,Interventions ,Prehospital care ,Emergency medical services ,Clinical outcomes ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Abstract Background Pediatric trauma patients constitute a significant portion of the trauma population treated by Swedish Emergency Medical Services (EMS), and trauma remains a notable cause of death among Swedish children. Previous research has identified potential challenges in prehospital assessments and interventions for pediatric patients. In Sweden, there is limited information available regarding pediatric trauma patients in the EMS. The aim of this study was to investigate the prevalence of pediatric trauma patients within the Swedish EMS and describe the prehospital assessments, interventions, and clinical outcomes. Methods This retrospective observational study was conducted in a region of Southwestern Sweden. A random sample from ambulance and hospital records from the year 2019 was selected. Inclusion criteria were children aged 0–16 years who were involved in trauma and assessed by EMS clinicians. Results A total of 440 children were included in the study, representing 8.4% of the overall trauma cases. The median age was 9 years (IQR 3–12), and 60.5% were male. The leading causes of injury were low (34.8%) and high energy falls (21%), followed by traffic accidents. The children were assessed as severely injured in 4.5% of cases. A quarter of the children remained at the scene after assessment. Complete vital signs were assessed in 29.3% of children, and 81.8% of children were assessed according to the ABCDE structure. The most common intervention performed by prehospital professionals was the administration of medication. The mortality rate was 0.2%. Conclusions Pediatric trauma cases accounted for 8.4% of the overall trauma population with a variations in injury mechanisms and types. Vital sign assessments were incomplete for a significant proportion of children. The adherence to the ABCDE structure, however, was higher. The children remained at the scene after assessment requires further investigation for patient safety.
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- 2024
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5. Video support for prehospital stroke consultation: implications for system design and clinical implementation from prehospital simulations
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Stefan Candefjord, Magnus Andersson Hagiwara, Bengt Arne Sjöqvist, Jan-Erik Karlsson, Annika Nordanstig, Lars Rosengren, and Hanna Maurin Söderholm
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Stroke ,Prehospital care ,Simulations ,Video ,Decision support ,Digital health ,Computer applications to medicine. Medical informatics ,R858-859.7 - Abstract
Abstract Background Video consultations between hospital-based neurologists and Emergency Medical Services (EMS) have potential to increase precision of decisions regarding stroke patient assessment, management and transport. In this study we explored the use of real-time video streaming for neurologist–EMS consultation from the ambulance, using highly realistic full-scale prehospital simulations including role-play between on-scene EMS teams, simulated patients (actors), and neurologists specialized in stroke and reperfusion located at the remote regional stroke center. Methods Video streams from three angles were used for collaborative assessment of stroke using the National Institutes of Health Stroke Scale (NIHSS) to assess symptoms affecting patient’s legs, arms, language, and facial expressions. The aim of the assessment was to determine appropriate management and transport destination based on the combination of geographical location and severity of stroke symptoms. Two realistic patient scenarios were created, with severe and moderate stroke symptoms, respectively. Each scenario was simulated using a neurologist acting as stroke patient and an ambulance team performing patient assessment. Four ambulance teams with two nurses each all performed both scenarios, for a total of eight cases. All scenarios were video recorded using handheld and fixed cameras. The audio from the video consultations was transcribed. Each team participated in a semi-structured interview, and neurologists and actors were also interviewed. Interviews were audio recorded and transcribed. Results Analysis of video-recordings and post-interviews (n = 7) show a more thorough prehospital patient assessment, but longer total on-scene time, compared to a baseline scenario not using video consultation. Both ambulance nurses and neurologists deem that video consultation has potential to provide improved precision of assessment of stroke patients. Interviews verify the system design effectiveness and suggest minor modifications. Conclusions The results indicate potential patient benefit based on a more effective assessment of the patient’s condition, which could lead to increased precision in decisions and more patients receiving optimal care. The findings outline requirements for pilot implementation and future clinical tests.
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- 2024
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6. Development of a trigger tool to identify harmful incidents, no harm incidents, and near misses in prehospital emergency care
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Niclas Packendorff, Carl Magnusson, Kristoffer Wibring, Christer Axelsson, and Magnus Andersson Hagiwara
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Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Abstract Background Emergency Medical Services (EMS) are a unique setting because care for the chief complaint is given across all ages in a complex and high-risk environment that may pose a threat to patient safety. Traditionally, a reporting system is commonly used to raise awareness of adverse events (AEs); however, it could fail to detect an AE. Several methods are needed to evaluate patient safety in EMS. In this light, this study was conducted to (1) develop a national ambulance trigger tool (ATT) with a guide containing descriptions of triggers, examples of use, and categorization of near misses (NMs), no harm incidents (NHIs), and harmful incidents (HIs) and (2) use the ATT on randomly selected ambulance records. Methods The ambulance trigger tool was developed in a stepwise manner through (1) a literature review; (2) three sessions of structured group discussions with an expert panel having knowledge of emergency medical service, patient safety, and development of trigger tools; (3) a retrospective record review of 900 randomly selected journals with three review teams from different geographical locations; and (4) inter-rater reliability testing between reviewers. Results From the literature review, 34 triggers were derived. After removing clinically irrelevant ones and combining others through three sessions of structured discussions, 19 remained. The most common triggers identified in the 900 randomly selected records were deviation from treatment guidelines (30.4%), the patient is non conveyed after EMS assessment (20.8%), and incomplete documentation (14.4%). The positive triggers were categorized as a near miss (40.9%), no harm (3.7%), and harmful incident (0.2%). Inter-rater reliability testing showed good agreement in both sessions. Conclusion This study shows that a trigger tool together with a retrospective record review can be used as a method to measure the frequency of harmful incidents, no harm incidents, and near misses in the EMS, thus complementing the traditional reporting system to realize increased patient safety.
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- 2024
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7. Diverse roles of the metal binding domains and transport mechanism of copper transporting P-type ATPases
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Zongxin Guo, Fredrik Orädd, Viktoria Bågenholm, Christina Grønberg, Jian Feng Ma, Peter Ott, Yong Wang, Magnus Andersson, Per Amstrup Pedersen, Kaituo Wang, and Pontus Gourdon
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Science - Abstract
Abstract Copper transporting P-type (P1B-1-) ATPases are essential for cellular homeostasis. Nonetheless, the E1-E1P-E2P-E2 states mechanism of P1B-1-ATPases remains poorly understood. In particular, the role of the intrinsic metal binding domains (MBDs) is enigmatic. Here, four cryo-EM structures and molecular dynamics simulations of a P1B-1-ATPase are combined to reveal that in many eukaryotes the MBD immediately prior to the ATPase core, MBD−1, serves a structural role, remodeling the ion-uptake region. In contrast, the MBD prior to MBD−1, MBD−2, likely assists in copper delivery to the ATPase core. Invariant Tyr, Asn and Ser residues in the transmembrane domain assist in positioning sulfur-providing copper-binding amino acids, allowing for copper uptake, binding and release. As such, our findings unify previously conflicting data on the transport and regulation of P1B-1-ATPases. The results are critical for a fundamental understanding of cellular copper homeostasis and for comprehension of the molecular bases of P1B-1-disorders and ongoing clinical trials.
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- 2024
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8. The non-conveyance of trauma patients in Swedish emergency medical services: a retrospective observational study of the trauma population not transported to an emergency department
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Glenn Larsson, Jana Eldh, Elisabeth Hagman, and Magnus Andersson Hagiwara
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Emergency medical services ,Triage ,Non-conveyance ,Trauma patient ,Ambulance ,Special situations and conditions ,RC952-1245 ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Abstract Introduction Due to a systemic modification in Swedish emergency medical services (EMS) staffing in recent years, the nature of the Swedish EMS has changed. Transport to an emergency department (ED) is no longer the only option. Referrals and non-conveyance form a growing part of EMS assignments. Trauma is one of the most common causes of death and accounts for 17% of Swedish EMS assignments. The aim of this study was to describe the characteristics and clinical outcomes of non-conveyed trauma patients who were assessed, treated and triaged by the EMS to gain a better understanding of, and to optimise, transport and treatment decisions. Methods The study had a descriptive, retrospective and epidemiologic design and was conducted by reviewing EMS and hospital records for 837 non-conveyed trauma patients in the southwest of Sweden in 2019. Results Three in four non-conveyed trauma patients did not seek further medical care within 72 h following EMS assessment. The patients who were admitted to hospital later were often older, had suffered a fall and had a medical history. Half of all the incidents occurred in a domestic environment, and head trauma was the major complaint. Less than 1% of the studied patients died. Conclusion Most of the non-conveyed trauma patients did not seek further medical care after being discharged at the scene. Falling was the most common trauma event, and for the older population, this meant a higher risk of hospital admission. The reasons for falls should therefore be investigated thoroughly prior to non-conveyance decisions. Future studies should focus on the reasons for non-conveyance and measure the morbidity and invalidity outcomes rather than mortality.
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- 2024
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9. Ambulance nurses’ experiences as the sole caregiver with critical patients during long ambulance transports: an interview study
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Jenny Wästerhed, Erika Ekenberg, and Magnus Andersson Hagiwara
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Ambulance services ,Critical patient care ,Rural areas ,Prehospital emergency care ,Nursing ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Abstract Background Working in rural areas involves tackling long distances and occasional lack of supportive resources. Ambulance nurses are faced with the responsibility of making immediate autonomous decisions and providing extended care to critically ill patients during prolonged ambulance transport to reach emergency medical facilities. This study aims to expose the experiences of ambulance nurses acting as primary caregivers for critically ill patients during lengthy ambulance transfers in rural regions. Method Fifteen nurses employed in an ambulance service within sparsely populated rural areas were subjected to semi-structured interviews. The collected data underwent qualitative content analysis. Result The analysis resulted in one overarching theme with two categories. The theme is ‘Safety in the Professional Role,’ and the two categories are ‘Working in sparsely populated areas presents challenges’ and ‘Rare events: when routine cannot be established.’ The findings suggest that working as an ambulance nurse in a rural setting poses various challenges that can be highly stressful. Delivering care to critically ill patients during extended ambulance transports requires the knowledge, experience, and careful planning of the healthcare provider in charge. Conclusions The findings underscore the necessity for thorough planning and adaptable thinking when attending to critically ill patients during extended transport scenarios. The absence of supporting resources can render the task demanding. Nevertheless, participants reported an inherent tranquility that aids them in maintaining focus amid their responsibilities.
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- 2024
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10. Epidemiology of patients assessed for trauma by Swedish ambulance services: a retrospective registry study
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Glenn Larsson, Christer Axelsson, Magnus Andersson Hagiwara, Johan Herlitz, Håkan Klementsson, Thomas Troëng, and Carl Magnusson
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Trauma ,Injury ,Emergency medical services ,Ambulance services ,Patient ,Severity ,Special situations and conditions ,RC952-1245 ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Abstract Background There is a lack of knowledge regarding the epidemiology of severe trauma assessed by Swedish emergency medical services (EMS). Aim To investigate the prevalence of trauma in Sweden assessed by EMS from a national perspective and describe patient demography, aetiology, trauma type, prehospital triage and clinical outcomes. Methods Data from two national quality registries, the Swedish Ambulance Registry and the Swedish Trauma Registry (SweTrau) were collected from January 1 to December 31, 2019. Inclusion criteria were an Emergency Symptoms and Signs code equivalent to trauma in the Swedish Ambulance Registry and criteria fulfilled for SweTrau inclusion. Exclusion criteria were patients 15. 12% required invasive treatment, 11% were discharged with severe disability and the 30-day mortality rate was 3.6%. Conclusion In this cross-sectional study, 14% of the primary EMS missions for one year were caused by trauma. However, only a small proportion of these cases are severe injuries, and the risk of severe disabilities and death appears to be limited. The most frequent aetiology of a severe trauma is injury caused by a car, and most severe traumas are blunt. Severe traumas are given the highest priority at the dispatch centre in the vast majority of cases, but nearly one-third of these cases are considered a low priority by the EMS nurse. The latter leaves room for improvement.
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- 2024
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11. Spontaneous spinal cord infarction: a systematic review
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Pascal Jabbour, Alexander Fletcher-Sandersjöö, Erik Edström, Adrian Elmi-Terander, Claes Hultling, Magnus Andersson, Victor Gabriel El-Hajj, Vasilios Stenimahitis, Maria Gharios, and Omar Ali Mahdi
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Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Background and objectives Spontaneous spinal cord infarction (SCInf) is a rare condition resulting in acute neurological impairment. Consensus on diagnostic criteria is lacking, which may present a challenge for the physician. This review aims to analyse the current literature on spontaneous SCInf, focusing on epidemiology, the diagnostic process, treatment strategies and neurological outcomes.Methods The study was performed in accordance with a previously published protocol. PubMed, Web of Science and Embase were searched using the keywords ‘spontaneous’, ‘spinal cord’, ‘infarction’ and ‘ischaemic’. The eligibility of studies was evaluated in two steps by multiple reviewers. Data from eligible studies were extracted and systematically analysed.Results 440 patients from 33 studies were included in this systematic review. Analysis of vascular risk factors showed that hypertension was present in 40%, followed by smoking in 30%, dyslipidaemia in 29% and diabetes in 16%. The severity of symptoms at admission according to the American Spinal Injury Association (ASIA) Impairment Scale was score A 19%, score B14%, score C36% and score D32%. The mean follow-up period was 34.8 (±12.2) months. ASIA score at follow-up showed score A 11%, score B 3%, score C 16%, score D 67% and score E 2%. The overall mortality during the follow-up period was 5%. When used, MRI with diffusion-weighted imaging (DWI) supported the diagnosis in 81% of cases. At follow-up, 71% of the patients were able to walk with or without walking aids.Conclusion The findings suggest a significant role for vascular risk factors in the pathophysiology of spontaneous SCInf. In the diagnostic workup, the use of DWI along with an MRI may help in confirming the diagnosis. The findings at follow-up suggest that neurological recovery is to be expected, with the majority of patients regaining ambulation. This systematic review highlights gaps in the literature and underscores the necessity for further research to establish diagnostic criteria and treatment guidelines.
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- 2024
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12. A hybrid CNN-Random Forest algorithm for bacterial spore segmentation and classification in TEM images
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Saqib Qamar, Rasmus Öberg, Dmitry Malyshev, and Magnus Andersson
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Medicine ,Science - Abstract
Abstract We present a new approach to segment and classify bacterial spore layers from Transmission Electron Microscopy (TEM) images using a hybrid Convolutional Neural Network (CNN) and Random Forest (RF) classifier algorithm. This approach utilizes deep learning, with the CNN extracting features from images, and the RF classifier using those features for classification. The proposed model achieved 73% accuracy, 64% precision, 46% sensitivity, and 47% F1-score with test data. Compared to other classifiers such as AdaBoost, XGBoost, and SVM, our proposed model demonstrates greater robustness and higher generalization ability for non-linear segmentation. Our model is also able to identify spores with a damaged core as verified using TEMs of chemically exposed spores. Therefore, the proposed method will be valuable for identifying and characterizing spore features in TEM images, reducing labor-intensive work as well as human bias.
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- 2023
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13. On Scene Injury Severity Prediction (OSISP) model for trauma developed using the Swedish Trauma Registry
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Anna Bakidou, Eva-Corina Caragounis, Magnus Andersson Hagiwara, Anders Jonsson, Bengt Arne Sjöqvist, and Stefan Candefjord
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Artificial Intelligence (AI) ,Clinical Decision Support System (CDSS) ,On Scene Injury Severity Prediction (OSISP) ,Prehospital care ,Trauma ,Field triage ,Computer applications to medicine. Medical informatics ,R858-859.7 - Abstract
Abstract Background Providing optimal care for trauma, the leading cause of death for young adults, remains a challenge e.g., due to field triage limitations in assessing a patient’s condition and deciding on transport destination. Data-driven On Scene Injury Severity Prediction (OSISP) models for motor vehicle crashes have shown potential for providing real-time decision support. The objective of this study is therefore to evaluate if an Artificial Intelligence (AI) based clinical decision support system can identify severely injured trauma patients in the prehospital setting. Methods The Swedish Trauma Registry was used to train and validate five models – Logistic Regression, Random Forest, XGBoost, Support Vector Machine and Artificial Neural Network – in a stratified 10-fold cross validation setting and hold-out analysis. The models performed binary classification of the New Injury Severity Score and were evaluated using accuracy metrics, area under the receiver operating characteristic curve (AUC) and Precision-Recall curve (AUCPR), and under- and overtriage rates. Results There were 75,602 registrations between 2013–2020 and 47,357 (62.6%) remained after eligibility criteria were applied. Models were based on 21 predictors, including injury location. From the clinical outcome, about 40% of patients were undertriaged and 46% were overtriaged. Models demonstrated potential for improved triaging and yielded AUC between 0.80–0.89 and AUCPR between 0.43–0.62. Conclusions AI based OSISP models have potential to provide support during assessment of injury severity. The findings may be used for developing tools to complement field triage protocols, with potential to improve prehospital trauma care and thereby reduce morbidity and mortality for a large patient population.
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- 2023
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14. O10 Ischemic stroke subtypes in SLE-associations with a STAT4 risk genotype
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Elisabet Svenungsson, Iva Gunnarsson, Johanna T Gustafsson, Agneta Zickert, Lars Rönnblom, Andreas Jönsen, Dag Leonard, Ann-Christine Syvänen, Johanna K Sandling, Gunnel Nordmark, Anders A Bengtsson, Magnus Andersson, Kerstin Elvin, Liisa Hopia, and Anna Laveskog
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Immunologic diseases. Allergy ,RC581-607 - Published
- 2024
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15. Characteristics of a trauma population in an ambulance organisation in Sweden: results from an observational study
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Glenn Larsson, Christer Axelsson, Magnus Andersson Hagiwara, Johan Herlitz, and Carl Magnusson
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Trauma ,Injury ,Emergency medical service ,Ambulance services ,Patient triage ,Mortality ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Abstract Background Globally, injuries are a major health problem, and in Sweden, injuries are the second most common reason for ambulance dispatch. However, there is a knowledge gap regarding the epidemiology of injuries requiring assessment by emergency medical services (EMS) in Sweden. The aim of the present study was to describe the prehospital population with injuries that have been assessed and treated by EMS. Methods A randomly selected retrospective sample was collected from 1 January through 31 December 2019 in a region in southwestern Sweden. Data were collected from ambulance and hospital medical records. Results Among 153,724 primary assignments, 26,697 (17.4%) were caused by injuries. The study cohort consisted of 5,235 patients, of whom 50.5% were men, and the median age was 63 years. The most common cause of injury was low-energy fall (51.4%), and this was the cause in 77.8% of those aged > 63 years and in 26.7% of those aged ≤ 63 years. The injury mechanism was a motor vehicle in 8.0%, a motorcycle in 2.1% and a bicycle in 4.0%. The most common trauma location was the residential area (55.5% overall; 77.9% in the elderly and 34.0% in the younger group). In the prehospital setting, the most frequent clinical sign was a wound (33.2%), a closed fracture were seen in 18.9% and an open fracture in 1.0%. Pain was reported in 74.9% and 42.9% reported severe pain. Medication was given to 42.4% of patients before arrival in the hospital. The most frequent triage colour according to the RETTS was orange (46.7%), whereas only 4.4% were triaged red. Among all patients, 83.6% were transported to the hospital, and 27.8% received fracture treatment after hospital admission. The overall 30-day mortality rate was 3.4%. Conclusion Among EMS assignments in southwestern Sweden, 17% were caused by injury equally distributed between women and men. More than half of these cases were caused by low-energy falls, and the most common trauma location was a residential area. The majority of the victims had pain upon arrival of the EMS, and a large proportion appeared to have severe pain.
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- 2023
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16. Fabricating a dielectrophoretic microfluidic device using 3D-printed moulds and silver conductive paint
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Shayan Valijam, Daniel P. G. Nilsson, Dmitry Malyshev, Rasmus Öberg, Alireza Salehi, and Magnus Andersson
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Medicine ,Science - Abstract
Abstract Dielectrophoresis is an electric field-based technique for moving neutral particles through a fluid. When used for particle separation, dielectrophoresis has many advantages compared to other methods, like providing label-free operation with greater control of the separation forces. In this paper, we design, build, and test a low-voltage dielectrophoretic device using a 3D printing approach. This lab-on-a-chip device fits on a microscope glass slide and incorporates microfluidic channels for particle separation. First, we use multiphysics simulations to evaluate the separation efficiency of the prospective device and guide the design process. Second, we fabricate the device in PDMS (polydimethylsiloxane) by using 3D-printed moulds that contain patterns of the channels and electrodes. The imprint of the electrodes is then filled with silver conductive paint, making a 9-pole comb electrode. Lastly, we evaluate the separation efficiency of our device by introducing a mixture of 3 μm and 10 μm polystyrene particles and tracking their progression. Our device is able to efficiently separate these particles when the electrodes are energized with ±12 V at 75 kHz. Overall, our method allows the fabrication of cheap and effective dielectrophoretic microfluidic devices using commercial off-the-shelf equipment.
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- 2023
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17. The F-pilus biomechanical adaptability accelerates conjugative dissemination of antimicrobial resistance and biofilm formation
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Jonasz B. Patkowski, Tobias Dahlberg, Himani Amin, Dharmender K. Gahlot, Sukhithasri Vijayrajratnam, Joseph P. Vogel, Matthew S. Francis, Joseph L. Baker, Magnus Andersson, and Tiago R. D. Costa
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Science - Abstract
Enteropathogenic bacteria use extracellular appendages, known as F-pili, to share plasmids carrying antibiotic resistance genes. Here, the authors show that F-pili are highly flexible but robust at the same time, and this is important for plasmid transfer and formation of biofilms that protect against the action of antibiotics.
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- 2023
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18. Hypervirulent R20291 Clostridioides difficile spores show disinfection resilience to sodium hypochlorite despite structural changes
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Dmitry Malyshev, Imogen Anne Jones, Matthew McKracken, Rasmus Öberg, Glenn M. Harper, Lovleen Tina Joshi, and Magnus Andersson
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Bacterial spores ,Laser tweezers Raman spectroscopy ,Raman spectroscopy ,LTRS ,C. difficile ,Terbium ,Microbiology ,QR1-502 - Abstract
Abstract Background Clostridioides difficile is a spore forming bacterial species and the major causative agent of nosocomial gastrointestinal infections. C. difficile spores are highly resilient to disinfection methods and to prevent infection, common cleaning protocols use sodium hypochlorite solutions to decontaminate hospital surfaces and equipment. However, there is a balance between minimising the use of harmful chemicals to the environment and patients as well as the need to eliminate spores, which can have varying resistance properties between strains. In this work, we employ TEM imaging and Raman spectroscopy to analyse changes in spore physiology in response to sodium hypochlorite. We characterize different C. difficile clinical isolates and assess the chemical’s impact on spores’ biochemical composition. Changes in the biochemical composition can, in turn, change spores’ vibrational spectroscopic fingerprints, which can impact the possibility of detecting spores in a hospital using Raman based methods. Results We found that the isolates show significantly different susceptibility to hypochlorite, with the R20291 strain, in particular, showing less than 1 log reduction in viability for a 0.5% hypochlorite treatment, far below typically reported values for C. difficile. While TEM and Raman spectra analysis of hypochlorite-treated spores revealed that some hypochlorite-exposed spores remained intact and not distinguishable from controls, most spores showed structural changes. These changes were prominent in B. thuringiensis spores than C. difficile spores. Conclusion This study highlights the ability of certain C. difficile spores to survive practical disinfection exposure and the related changes in spore Raman spectra that can be seen after exposure. These findings are important to consider when designing practical disinfection protocols and vibrational-based detection methods to avoid a false-positive response when screening decontaminated areas. Graphical Abstract
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- 2023
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19. Structural basis of ion uptake in copper-transporting P1B-type ATPases
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Nina Salustros, Christina Grønberg, Nisansala S. Abeyrathna, Pin Lyu, Fredrik Orädd, Kaituo Wang, Magnus Andersson, Gabriele Meloni, and Pontus Gourdon
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Science - Abstract
P1B-type ATPases export excess transition metals from cells. Here, the authors report a molecular structure of CopA, a coppertransporting P1B-ATPase from A. fulgidus, in an inward-facing E1 conformation.
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- 2022
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20. Prehospital assessment of patients with abdominal pain triaged to self-care at home: an observation study
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Glenn Larsson, Peter Hansson, Emelie Olsson, Johan Herlitz, and Magnus Andersson Hagiwara
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Prehospital ,EMS ,Assessment ,Triage ,Self-care ,Special situations and conditions ,RC952-1245 ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Abstract Background Patients who call for emergency medical services (EMS) due to abdominal pain suffer from a broad spectrum of diseases, some of which are time sensitive. As a result of the introduction of the concept of ‘optimal level of care‘, some patients with abdominal pain are triaged to other levels of care than in an emergency department (ED). We hypothesised that it could be challenging in a patient safety perspective. Aim This study aims to describe consecutive patients who call for EMS due to abdominal pain and are triaged to self-care by EMS clinicians. Methods This was an observational study performed in an EMS organisation in Western Sweden during 2020. The triage tool Rapid Emergency Triage and Treatment System (RETTS), which included Emergency Signs and Symptom (ESS) codes, was used to find medical records where patients with abdominal pain have been triaged to self-care and 194 patients was included in the study. Results Of total 48,311 ambulance missions, A total of 1747 patients were labelled with ESS code six (abdominal pain), including 223 (12.8%) who were given the code for self-care and 194 who were further assessed by the research group. Of these patients, 32 (16.3%) had a return visit within 96 hours due to the same symptoms and 11 (5.6%) were hospitalised. In six of these patients, the EMS triage was evaluated retrospectively and assessed as inappropriate. These patients had a final diagnosis of ruptured abdominal aneurysm (n = 1), acute appendicitis with peritonitis (n = 2) and acute pancreatitis (n = 3). All these patients required extensive evaluation and different treatments, including acute surgery, antibiotics and fluid therapy. Conclusion Amongst the 1747 patients assessed by EMS due to abdominal pain, 223 (12.8%) were triaged to self-care. Of the 194 patients who were further assessed, 16.3% required a return visit to the ED within 96 hours and 5.6% were hospitalised. Six patients had obvious time-sensitive conditions. Our study highlights the difficulties in the early assessment of abdominal pain and the requirement for an accurate decision support tool.
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- 2022
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21. Outcomes in patients not conveyed by emergency medical services (EMS): a one-year prospective study
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Erik Höglund, Agneta Schröder, Magnus Andersson-Hagiwara, Margareta Möller, and Emma Ohlsson-Nevo
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Ambulance ,Emergency medical services ,Non-conveyance ,Non-transport ,Outcome measures ,Triage ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Abstract Background The decision to not convey patients has become common in emergency medical services worldwide. A substantial proportion (12–51%) of the patients seen by emergency medical services are not conveyed by those services. The practice of non-conveyance is a result of the increasing and changing demands on the acute care system. Research focusing on the outcomes of the decision by emergency medical services to not convey patients is needed. Aim The aim was to describe outcomes (emergency department visits, admission to in-hospital intensive care units and mortality, all within seven days) and their association with the variables (sex, age, day of week, time of day, emergency signs and symptoms codes, triage level colour, and destination) for non-conveyed patients. Methods This was a prospective analytical study with consecutive inclusion of all patients not conveyed by emergency medical services. Patients were included between February 2016 and January 2017. The study was conducted in Region Örebro county, Sweden. The region consists of both rural and urban areas and has a population of approximately 295,000. The region had three ambulance departments that received approximately 30,000 assignments per year. Results The result showed that no patient received intensive care, and 18 (0.7%) patients died within seven days after the non-conveyance decision. Older age was associated with a higher risk of hospitalisation and death within seven days after a non-conveyance decision. Conclusions Based on the results of this one-year follow-up study, few patients compared to previous studies were admitted to the hospital, received intensive care or died within seven days. This study contributes insights that can be used to improve non-conveyance guidelines and minimise the risk of patient harm.
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- 2022
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22. Patient-specific brain arteries molded as a flexible phantom model using 3D printed water-soluble resin
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Daniel P. G. Nilsson, Madelene Holmgren, Petter Holmlund, Anders Wåhlin, Anders Eklund, Tobias Dahlberg, Krister Wiklund, and Magnus Andersson
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Medicine ,Science - Abstract
Abstract Visualizing medical images from patients as physical 3D models (phantom models) have many roles in the medical field, from education to preclinical preparation and clinical research. However, current phantom models are generally generic, expensive, and time-consuming to fabricate. Thus, there is a need for a cost- and time-efficient pipeline from medical imaging to patient-specific phantom models. In this work, we present a method for creating complex 3D sacrificial molds using an off-the-shelf water-soluble resin and a low-cost desktop 3D printer. This enables us to recreate parts of the cerebral arterial tree as a full-scale phantom model ( $$10\times 6\times 4$$ 10 × 6 × 4 cm) in transparent silicone rubber (polydimethylsiloxane, PDMS) from computed tomography angiography images (CTA). We analyzed the model with magnetic resonance imaging (MRI) and compared it with the patient data. The results show good agreement and smooth surfaces for the arteries. We also evaluate our method by looking at its capability to reproduce 1 mm channels and sharp corners. We found that round shapes are well reproduced, whereas sharp features show some divergence. Our method can fabricate a patient-specific phantom model with less than 2 h of total labor time and at a low fabrication cost.
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- 2022
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23. Suboptimal prehospital decision- making for referral to alternative levels of care – frequency, measurement, acceptance rate and room for improvement
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Carl Magnusson, Magnus Andersson Hagiwara, Gabriella Norberg-Boysen, Wivica Kauppi, Johan Herlitz, Christer Axelsson, Niclas Packendorff, Glenn Larsson, and Kristoffer Wibring
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Patient safety ,Prehospital care ,Time-sensitive conditions ,Decision support ,Special situations and conditions ,RC952-1245 ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Abstract Background The emergency medical services (EMS) have undergone dramatic changes during the past few decades. Increased utilisation, changes in care-seeking behaviour and competence among EMS clinicians have given rise to a shift in EMS strategies in many countries. From transport to the emergency department to at the scene deciding on the most appropriate level of care and mode of transport. Among the non-conveyed patients some may suffer from “time-sensitive conditions” delaying diagnosis and treatment. Thus, four questions arise: 1) How often are time-sensitive cases referred to primary care or self-care advice? 2) How can we measure and define the level of inappropriate clinical decision-making? 3) What is acceptable? 4) How to increase patient safety? Main text To what extent time-sensitive cases are non-conveyed varies. About 5–25% of referred patients visit the emergency department within 72 hours, 5% are hospitalised, 1–3% are reported to have a time-sensitive condition and seven-day mortality rates range from 0 .3 to 6%. The level of inappropriate clinical decision-making can be measured using surrogate measures such as emergency department attendances, hospitalisation and short-term mortality. These measures do not reveal time-sensitive conditions. Defining a scoring system may be one alternative, where misclassifications of time-sensitive cases are rated based on how severely they affected patient outcome. In terms of what is acceptable there is no general agreement. Although a zero-vision approach does not seem to be realistic unless under-triage is split into different levels of severity with zero-vision in the most severe categories. There are several ways to reduce the risk of misclassifications. Implementation of support systems for decision-making using machine learning to improve the initial assessment is one approach. Using a trigger tool to identify adverse events is another. Conclusion A substantial number of patients are non-conveyed, including a small portion with time-sensitive conditions. This poses a threat to patient safety. No general agreement on how to define and measure the extent of such EMS referrals and no agreement of what is acceptable exists, but we conclude an overall zero-vision is not realistic. Developing specific tools supporting decision making regarding EMS referral may be one way to reduce misclassification rates.
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- 2022
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24. Reasons for bias in ambulance clinicians’ assessments of non-conveyed patients: a mixed-methods study
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Helena Johansson, Kristin Lundgren, and Magnus Andersson Hagiwara
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Ambulance nurse ,Non-conveyance ,Patient safety ,See and treat ,Special situations and conditions ,RC952-1245 ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Abstract Background The number of ambulance assignments and the influx of patients to the emergency departments (EDs) in Sweden have increased in recent years. This is one reason the protocol for prehospital emergency care was developed around referring patients for non-conveyance, either through the see-and-convey elsewhere approach or through the see-and-treat approach. However, this protocol has led to challenges in patient assessments. This study aimed to investigate the underlying causes of patient harm among those referred for the see-and-treat approach by the emergency medical services. Methods This three-phase study involved a mixed-methods design. Cases of injuries, internal investigations and incident analyses of referrals for the see-and-treat approach in two regions in south eastern Sweden from 2015 to 2020 were examined using qualitative content analysis. This qualitative analysis was the basis for the quantitative analysis of the ambulance records. After the qualitative analysis was completed, a review protocol was developed; 34 variables were used to review 240 randomly selected ambulance records logged in 2020, wherein patients were referred for the see-and-treat approach. Finally, the review results were synthesised. Results The qualitative analysis revealed three common themes: ‘assessment of patients’, ‘guidelines’ and ‘environment and organisation’. These results were confirmed by a medical journal review. Shortcomings were found in the anamnesis and in the number of targeted examinations performed. The checklist for referring patients for the see-and-treat approach and the information sheet to be provided to the patients were not used. In 34% of the ambulance records examined, the EMS clinicians deviated from the current guidelines for a see-and-treat referral. Conclusions The results indicated that the low adherence to guidelines and the patient assessment deviating from the protocol put patients at risk of being harmed during a see-and-treat referral. Measures are needed to guarantee a safe assessment of an increasing number of patients who are referred for the see-and-treat approach, especially the multi-sick elderly patients.
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- 2022
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25. A study of factors that predict novice nurses’ perceived ability to provide care in acute situations
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Anders Sterner, Nerrolyn Ramstrand, Lina Palmér, and Magnus Andersson Hagiwara
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acute care ,clinical judgement ,experience ,graduate nurse ,novice nurse ,Nursing ,RT1-120 - Abstract
Abstract Aims To explore factors that predict novice nurses’ trust in their ability to provide care in acute situations and identify factors that are related to their perceived ability to make clinical judgements in acute situations. Design Exploratory cross‐sectional study. Methods Novice nurses employed within somatic care in Swedish hospitals completed an online survey. Univariate analysis facilitated exploration of the data and identification of predictor variables with the greatest association with: (1) trust in their own ability (one item) and (2) ability to make clinical judgements (four items). Multivariate binary logistic regression modelling was used to model the likelihood of outcomes based on each predictor variable. Results The two most important predictors related to trust in ability to provide care were duration of work experience and participation in acute situations during nursing education. For clinical judgement, duration of work experience was significant in all four models and experience of acute situations post‐graduation was significant in two models.
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- 2021
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26. Copper binding leads to increased dynamics in the regulatory N-terminal domain of full-length human copper transporter ATP7B.
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Fredrik Orädd, Jonas Hyld Steffen, Pontus Gourdon, and Magnus Andersson
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Biology (General) ,QH301-705.5 - Abstract
ATP7B is a human copper-transporting P1B-type ATPase that is involved in copper homeostasis and resistance to platinum drugs in cancer cells. ATP7B consists of a copper-transporting core and a regulatory N-terminal tail that contains six metal-binding domains (MBD1-6) connected by linker regions. The MBDs can bind copper, which changes the dynamics of the regulatory domain and activates the protein, but the underlying mechanism remains unknown. To identify possible copper-specific structural dynamics involved in transport regulation, we constructed a model of ATP7B spanning the N-terminal tail and core catalytic domains and performed molecular dynamics (MD) simulations with (holo) and without (apo) copper ions bound to the MBDs. In the holo protein, MBD2, MBD3 and MBD5 showed enhanced mobilities, which resulted in a more extended N-terminal regulatory region. The observed separation of MBD2 and MBD3 from the core protein supports a mechanism where copper binding activates the ATP7B protein by reducing interactions among MBD1-3 and between MBD1-3 and the core protein. We also observed an increased interaction between MBD5 and the core protein that brought the copper-binding site of MBD5 closer to the high-affinity internal copper-binding site in the core protein. The simulation results assign specific, mechanistic roles to the metal-binding domains involved in ATP7B regulation that are testable in experimental settings.
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- 2022
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27. Assessment of patients with suspected sepsis in ambulance services: a qualitative interview study
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Agnes Olander, Anders Bremer, Annelie J. Sundler, Magnus Andersson Hagiwara, and Henrik Andersson
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Ambulance clinicians ,Ambulance services ,Assessment ,Interviews ,Sepsis ,Special situations and conditions ,RC952-1245 ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Abstract Background The initial care of patients with sepsis is commonly performed by ambulance clinicians (ACs). Early identification, care and treatment are vital for patients with sepsis to avoid adverse outcomes. However, knowledge about how patients with sepsis are assessed in ambulance services (AS) by AC is limited. Therefore, the aim of this study was to explore the meaning of ACs’ lived experiences in assessing patients suspected of having sepsis. Methods A descriptive design with a qualitative approach was used. Fourteen ACs from three Swedish ambulance organizations participated in dyadic and individual semistructured interviews. A thematic analysis based on descriptive phenomenology was performed. Results AC experiences were grouped into four themes: (1) being influenced by previous experience; (2) searching for clues to the severity of the patient’s condition; (3) feeling confident when signs and symptoms were obvious; and (4) needing health-care professionals for support and consultation. Conclusions This study indicates that several factors are important to assessments. ACs needed to engage in an ongoing search for information, discuss the cases with colleagues and reconsider the assessment throughout the entire ambulance mission. A reflective and open stance based on professional knowledge could contribute to recognizing patients with sepsis.
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- 2021
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28. Bioprinted Schwann and Mesenchymal Stem Cell Co-Cultures for Enhanced Spatial Control of Neurite Outgrowth
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Enateri V. Alakpa, Anton Bahrd, Krister Wiklund, Magnus Andersson, Lev N. Novikov, Christina Ljungberg, and Peyman Kelk
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3D bioprinting ,biosynthetic conduit ,dorsal root ganglion ,mesenchymal stem cells ,nerve regeneration ,Schwann cells ,Science ,Chemistry ,QD1-999 ,Inorganic chemistry ,QD146-197 ,General. Including alchemy ,QD1-65 - Abstract
Bioprinting nerve conduits supplemented with glial or stem cells is a promising approach to promote axonal regeneration in the injured nervous system. In this study, we examined the effects of different compositions of bioprinted fibrin hydrogels supplemented with Schwann cells and mesenchymal stem cells (MSCs) on cell viability, production of neurotrophic factors, and neurite outgrowth from adult sensory neurons. To reduce cell damage during bioprinting, we analyzed and optimized the shear stress magnitude and exposure time. The results demonstrated that fibrin hydrogel made from 9 mg/mL of fibrinogen and 50IE/mL of thrombin maintained the gel’s highest stability and cell viability. Gene transcription levels for neurotrophic factors were significantly higher in cultures containing Schwann cells. However, the amount of the secreted neurotrophic factors was similar in all co-cultures with the different ratios of Schwann cells and MSCs. By testing various co-culture combinations, we found that the number of Schwann cells can feasibly be reduced by half and still stimulate guided neurite outgrowth in a 3D-printed fibrin matrix. This study demonstrates that bioprinting can be used to develop nerve conduits with optimized cell compositions to guide axonal regeneration.
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- 2023
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29. F@ce: a team-based, person-centred intervention for rehabilitation after stroke supported by information and communication technology – a feasibility study
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Susanne Guidetti, Martha Gustavsson, Kerstin Tham, Magnus Andersson, Uno Fors, and Charlotte Ytterberg
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ADL ,Disability ,eHealth ,Mobile phone ,Occupational therapy ,Participation in everyday life ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Background Globally, there is a growing use of Information and Communication Technology (ICT), including mobile phones, tablets and computers, which are being integrated into people’s daily activities. An ICT-based intervention called F@ce was developed in order to provide a structure for the process in stroke rehabilitation and facilitate change by integrating a global problem-solving strategy using SMS alerts. The aim of the study was to evaluate the feasibility of i) F@ce within in-patient and primary care rehabilitation after stroke, ii) the study design and outcome measures used, and iii) the fidelity, adherence and acceptability of the intervention. Methods Three teams comprising occupational therapists and physiotherapists who work in neurological rehabilitation participated in a preparatory workshop on F@ce and then enrolled 10 persons with stroke to participate in the intervention. Goals were set using the Canadian Occupational Performance Measure (COPM) and the participants with stroke rated their performance and satisfaction with the activities associated with the three goals every day for 8 weeks. Data were collected at inclusion, at four and 8 weeks, using the COPM, Stroke Impact Scale, Frenchay Activities Index, Life Satisfaction Checklist, Self-Efficacy Scale, Hospital Anxiety and Depression Scale, Fatigue Severity Scale, follow-up survey, daily ratings on the web platform and logbooks. Results All of the participants showed increased scores in the primary outcome (COPM) and a clinically meaningful improvement of ≥2 points was found in four participants regarding performance and in six participants regarding satisfaction. Overall fidelity to the components of F@ce was good. The response rates to the F@ce web platform were 44–100% (mean 78%). All of the participants stated that F@ce had supported their rehabilitation. Conclusion The results indicate that the most beneficial part of F@ce was the person-centred, goal-setting process and SMS alerts. All participants were satisfied with F@ce and highlighted the benefits of receiving daily alerts about their goals. This encouraged them to be more active. The only downside mentioned was that they felt under an obligation to practice, although this was described as “a positive obligation”.
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- 2020
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30. Characteristics of non-conveyed patients in emergency medical services (EMS): a one-year prospective descriptive and comparative study in a region of Sweden
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Erik Höglund, Magnus Andersson-Hagiwara, Agneta Schröder, Margareta Möller, and Emma Ohlsson-Nevo
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Ambulance ,Emergency medical services ,Non-conveyance ,Non-transport ,Triage ,Special situations and conditions ,RC952-1245 ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Abstract Background There has been an increasing demand for emergency medical services (EMS), and a growing number of patients are not conveyed; i.e., they are referred to levels of care other than ambulance conveyance to the emergency department. Patient safety issues have been raised regarding the ability of EMS to decide not to convey patients. To improve non-conveyance guidelines, information is needed about patients who are not conveyed by EMS. Therefore, the purpose of this study was to describe and compare the proportion and characteristics of non-conveyed EMS patients, together with assignment data. Methods A descriptive and comparative consecutive cohort design was undertaken. The decision of whether to convey patients was made by EMS according to a region-specific non-conveyance guideline. Non-conveyed patients’ medical record data were prospectively gathered from February 2016 to January 2017. Analyses was conducted using the chi-squared test, two-sample t test, proportion test and Mann-Whitneys U-test. Results Out of the 23,250 patients served during the study period, 2691 (12%) were not conveyed. For non-conveyed adults, the most commonly used Emergency Signs and Symptoms (ESS) codes were unspecific symptoms/malaise, abdomen/flank/groin pain, and breathing difficulties. For non-conveyed children, the most common ESS codes were breathing difficulties and fever of unclear origin. Most of the non-conveyed patients had normal vital signs. Half of all patients with a designated non-conveyance level of care were referred to self-care. There were statistically significant differences between men and women. Conclusions Fewer patients were non-conveyed in the studied region compared to national and international non-conveyance rates. The differences seen between men and women were not of clinical significance. Follow-up studies are needed to understand what effect patient outcome so that guidelines might improve.
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- 2020
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31. Development and initial validation of an instrument to measure novice nurses’ perceived ability to provide care in acute situations – PCAS
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Anders Sterner, Emma Säfström, Lina Palmér, Nerrolyn Ramstrand, and Magnus Andersson Hagiwara
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Nursing ,Education ,Educational measurement ,Psychometrics ,Self report ,Acute ,RT1-120 - Abstract
Abstract Background Novice nurses need to be better prepared to provide care in acute situations. There is currently no validated scale specifically measuring nurses’ perception of their ability to provide care in acute situations. The aim of this study was to develop and examine the psychometric properties of a scale that measures novice nurses self-reported perception of ability to provide care in acute situations. Method Development and test of the psychometric properties of the Perception to Care in Acute Situations (PCAS) scale. Items were generated from interviews with novice nurses (n = 17) and validated using opinions of an expert panel and cognitive interviews with the target group. Two hundred nine novice nurses tested the final scale. Exploratory factor analysis (EFA) was used to test construct validity, item reduction and underlying dimensions between the measured variables and the latent construct. Result The PCAS scale contains 17 items grouped into three factors. EFA demonstrated a clean three factor logic construct solution with no cross-loadings, high correlation for the total scale in both Cronbach’s alfa 0.90 and ordinal alpha 0.92. Conclusions The PCAS scale has proven to have acceptable validity. The factors,” confidence in provision of care”, “communication” and “patient perspective” are likely to be important aspects of providing care in acute situations. Additional testing of the PCAS is needed to conclude if it is sensitive enough to evaluate interventions aimed at improving novice nurses competence and suitable as a guide for reflection for novice nurses.
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- 2020
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32. Structure and ion-release mechanism of PIB-4-type ATPases
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Christina Grønberg, Qiaoxia Hu, Dhani Ram Mahato, Elena Longhin, Nina Salustros, Annette Duelli, Pin Lyu, Viktoria Bågenholm, Jonas Eriksson, Komal Umashankar Rao, Domhnall Iain Henderson, Gabriele Meloni, Magnus Andersson, Tristan Croll, Gabriela Godaly, Kaituo Wang, and Pontus Gourdon
- Subjects
P-type ATPase ,x-ray crystallography ,sulfitobacter sp. NAS14-1 ,transition metals ,PIB-4-ATPase ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
Transition metals, such as zinc, are essential micronutrients in all organisms, but also highly toxic in excessive amounts. Heavy-metal transporting P-type (PIB) ATPases are crucial for homeostasis, conferring cellular detoxification and redistribution through transport of these ions across cellular membranes. No structural information is available for the PIB-4-ATPases, the subclass with the broadest cargo scope, and hence even their topology remains elusive. Here, we present structures and complementary functional analyses of an archetypal PIB-4-ATPase, sCoaT from Sulfitobacter sp. NAS14-1. The data disclose the architecture, devoid of classical so-called heavy-metal-binding domains (HMBDs), and provide fundamentally new insights into the mechanism and diversity of heavy-metal transporters. We reveal several novel P-type ATPase features, including a dual role in heavy-metal release and as an internal counter ion of an invariant histidine. We also establish that the turnover of PIB-ATPases is potassium independent, contrasting to many other P-type ATPases. Combined with new inhibitory compounds, our results open up for efforts in for example drug discovery, since PIB-4-ATPases function as virulence factors in many pathogens.
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- 2021
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33. Towards definitions of time-sensitive conditions in prehospital care
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Kristoffer Wibring, Carl Magnusson, Christer Axelsson, Peter Lundgren, Johan Herlitz, and Magnus Andersson Hagiwara
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Prehospital care ,Time-sensitive conditions ,Decision support ,Early recognition ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Abstract Background Prehospital care has changed in recent decades. Advanced assessments and decisions are made early in the care chain. Patient assessments form the basis of a decision relating to prehospital treatment and the level of care. This development imposes heavy demands on the ability of emergency medical service (EMS) clinicians properly to assess the patient. EMS clinicians have a number of assessment instruments and triage systems available to support their decisions. Many of these instruments are based on vital signs and can sometimes miss time-sensitive conditions. With this commentary, we would like to start a discussion to agree on definitions of temporal states in the prehospital setting and ways of recognising patients with time-sensitive conditions in the most optimal way. Main body There are several articles discussing the identification and management of time-sensitive conditions. In these articles, neither definitions nor terminology have been uniform. There are a number of problems associated with the definition of time-sensitive conditions. For example, intoxication can be minor but also life threatening, depending on the type of poison and dose. Similarly, diseases like stroke and myocardial infarction can differ markedly in terms of severity and the risk of life-threatening complications. Another problem is how to support EMS clinicians in the early recognition of these conditions. It is well known that many of them can present without a deviation from normal in vital signs. It will most probably be impossible to introduce specific decision support tools for every individual time-sensitive condition. However, there may be information in the type and intensity of the symptoms patients present. In future, biochemical markers and machine learning support tools may help to identify patients with time-sensitive conditions and predict mortality at an earlier stage. Conclusion It may be of great value for prehospital clinicians to be able to describe time-sensitive conditions. Today, neither definitions nor terminology are uniform. Our hope is that this commentary will initiate a discussion on the issue aiming at definitions of time-sensitive conditions in prehospital care and how they should be recognised in the most optimal fashion.
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- 2020
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34. Cryo-EM structure of the CFA/I pilus rod
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Weili Zheng, Magnus Andersson, Narges Mortezaei, Esther Bullitt, and Edward Egelman
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fimbriae ,bacterial adhesion ,helical reconstruction ,force spectroscopy ,electron cryomicroscopy ,3D reconstruction ,3D image processing ,integrative structural biology ,Crystallography ,QD901-999 - Abstract
Enterotoxigenic Escherichia coli (ETEC) are common agents of diarrhea for travelers and a major cause of mortality in children in developing countries. To attach to intestinal cells ETEC express colonization factors, among them CFA/I, which are the most prevalent factors and are the archetypical representative of class 5 pili. The helical quaternary structure of CFA/I can be unwound under tensile force and it has been shown that this mechanical property helps bacteria to withstand shear forces from fluid motion. We report in this work the CFA/I pilus structure at 4.3 Å resolution from electron cryomicroscopy (cryo-EM) data, and report details of the donor strand complementation. The CfaB pilins modeled into the cryo-EM map allow us to identify the buried surface area between subunits, and these regions are correlated to quaternary structural stability in class 5 and chaperone–usher pili. In addition, from the model built using the EM structure we also predicted that residue 13 (proline) of the N-terminal β-strand could have a major impact on the filament's structural stability. Therefore, we used optical tweezers to measure and compare the stability of the quaternary structure of wild type CFA/I and a point-mutated CFA/I with a propensity for unwinding. We found that pili with this mutated CFA/I require a lower force to unwind, supporting our hypothesis that Pro13 is important for structural stability. The high-resolution CFA/I pilus structure presented in this work and the analysis of structural stability will be useful for the development of novel antimicrobial drugs that target adhesion pili needed for initial attachment and sustained adhesion of ETEC.
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- 2019
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35. Clinical reasoning in the emergency medical services: an integrative review
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Ulf Andersson, Hanna Maurin Söderholm, Birgitta Wireklint Sundström, Magnus Andersson Hagiwara, and Henrik Andersson
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Clinical reasoning ,Decision-making ,Emergency medical services ,Ambulances ,Clinicians ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Abstract Clinical reasoning is the process of gathering and understanding information conducted by clinicians in the emergency medical services (EMS) so as to make informed decisions. Research on clinical reasoning spans several disciplines, but a comprehensive view of the process is lacking. To our knowledge, no review of clinical reasoning in the EMS has been conducted. Aim The aim was to investigate the nature, deployment, and factors influencing EMS clinicians’ clinical reasoning by means of a review. Method Data was collected through searches in electronic databases, networking among research teams, colleagues and friends, “grey literature,” and through ancestry searches. A total of 38 articles were deemed eligible for inclusion and were analyzed using descriptive thematic analysis. The analysis resulted in an overarching finding - namely, the importance for EMS clinicians to adjust for perceived control in unpredictable situations. Within this finding, 3 themes emerged in terms of EMS clinicians’ clinical reasoning: (1) maintaining a holistic view of the patient; (2) keeping an open mind; and (3) improving through criticism. Seven subthemes subsequently emerged from these three themes. Results This review showed that EMS clinicians’ clinical reasoning begins with the information that they are given about a patient. Based on this information, clinicians calculate the best route to the patient and which equipment to use, and they also assess potential risks. They need to be constantly aware of what is happening on the scene and with the patient and strive to control the situation. This striving also enables EMS clinicians to work safely and effectively in relation to the patient, their relatives, other clinicians, associated organizations, and the wider community. A lack of contextually appropriate guidelines results in the need for creativity and forces EMS clinicians to use “workarounds” to solve issues beyond the scope of the guidelines available. In addition, they often lack organizational support and fear repercussions such as litigation, unemployment, or blame by their EMS or healthcare organization or by patients and relatives. Conclusion Clinical reasoning is influenced by several factors. Further research is needed to determine which influencing factors can be addressed through interventions to minimize their impact on patient outcomes.
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- 2019
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36. Prehospital characteristics among patients with sepsis: a comparison between patients with or without adverse outcome
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Agnes Olander, Henrik Andersson, Annelie J. Sundler, Anders Bremer, Lars Ljungström, and Magnus Andersson Hagiwara
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Emergency medical services ,Characteristics ,Prehospital ,Sepsis ,Symptoms ,Vital signs ,Special situations and conditions ,RC952-1245 ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Abstract Background The prehospital care of patients with sepsis are commonly performed by the emergency medical services. These patients may be critically ill and have high in-hospital mortality rates. Unfortunately, few patients with sepsis are identified by the emergency medical services, which can lead to delayed treatment and a worse prognosis. Therefore, early identification of patients with sepsis is important, and more information about the prehospital characteristics that can be used to identify these patients is needed. Based on this lack of information, the objectives of this study were to investigate the prehospital characteristics that are identified while patients with sepsis are being transported to the hospital by the emergency medical services, and to compare these values to those of the patients with and without adverse outcomes during their hospital stays. Methods This was a retrospective observational study. The patients’ electronic health records were reviewed and selected consecutively based on the following: retrospectively diagnosed with sepsis and transported to an emergency department by the emergency medical services. Data were collected on demographics, prehospital characteristics and adverse outcomes, defined as the in-hospital mortality or treatment in the intensive care unit, and analysed by independent sample t-test and chi-square. Sensitivity, specificity and likelihood ratio, of prehospital characteristics for predicting or development of adverse outcome were analysed. Results In total, 327 patients were included. Of these, 50 patients had adverse outcomes. When comparing patients with or without an adverse outcome, decreased oxygen saturation and body temperature, increased serum glucose level and altered mental status during prehospital care were found to be associated with an adverse outcome. Conclusions The findings suggests that patients having a decreased oxygen saturation and body temperature, increased serum glucose level and altered mental status during prehospital care are at risk of a poorer patient prognosis and adverse outcome. Recognizing these prehospital characteristics may help to identify patients with sepsis early and improve their long-term outcomes. However further research is required to predict limit values of saturation and serum glucose and to validate the use of prehospital characteristics for adverse outcome in patients with sepsis.
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- 2019
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37. A splice donor variant in CCDC189 is associated with asthenospermia in Nordic Red dairy cattle
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Terhi Iso-Touru, Christine Wurmser, Heli Venhoranta, Maya Hiltpold, Tujia Savolainen, Anu Sironen, Konrad Fischer, Krzysztof Flisikowski, Ruedi Fries, Alejandro Vicente-Carrillo, Manuel Alvarez-Rodriguez, Szabolcs Nagy, Mervi Mutikainen, Jaana Peippo, Juhani Taponen, Goutam Sahana, Bernt Guldbrandtsen, Henri Simonen, Heriberto Rodriguez-Martinez, Magnus Andersson, and Hubert Pausch
- Subjects
Male infertility ,Sterility ,Immotile sperm ,Cattle ,CCDC189 ,Biotechnology ,TP248.13-248.65 ,Genetics ,QH426-470 - Abstract
Abstract Background Cattle populations are highly amenable to the genetic mapping of male reproductive traits because longitudinal data on ejaculate quality and dense microarray-derived genotypes are available for thousands of artificial insemination bulls. Two young Nordic Red bulls delivered sperm with low progressive motility (i.e., asthenospermia) during a semen collection period of more than four months. The bulls were related through a common ancestor on both their paternal and maternal ancestry. Thus, a recessive mode of inheritance of asthenospermia was suspected. Results Both bulls were genotyped at 54,001 SNPs using the Illumina BovineSNP50 Bead chip. A scan for autozygosity revealed that they were identical by descent for a 2.98 Mb segment located on bovine chromosome 25. This haplotype was not found in the homozygous state in 8557 fertile bulls although five homozygous haplotype carriers were expected (P = 0.018). Whole genome-sequencing uncovered that both asthenospermic bulls were homozygous for a mutation that disrupts a canonical 5′ splice donor site of CCDC189 encoding the coiled-coil domain containing protein 189. Transcription analysis showed that the derived allele activates a cryptic splice site resulting in a frameshift and premature termination of translation. The mutated CCDC189 protein is truncated by more than 40%, thus lacking the flagellar C1a complex subunit C1a-32 that is supposed to modulate the physiological movement of the sperm flagella. The mutant allele occurs at a frequency of 2.5% in Nordic Red cattle. Conclusions Our study in cattle uncovered that CCDC189 is required for physiological movement of sperm flagella thus enabling active progression of spermatozoa and fertilization. A direct gene test may be implemented to monitor the asthenospermia-associated allele and prevent the birth of homozygous bulls that are infertile. Our results have been integrated in the Online Mendelian Inheritance in Animals (OMIA) database (https://omia.org/OMIA002167/9913/).
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- 2019
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38. Research challenges in prehospital care: the need for a simulation-based prehospital research laboratory
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Hanna Maurin Söderholm, Henrik Andersson, Magnus Andersson Hagiwara, Per Backlund, Johanna Bergman, Lars Lundberg, and Bengt Arne Sjöqvist
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Simulation ,Laboratory ,Prehospital ,Computer applications to medicine. Medical informatics ,R858-859.7 - Abstract
Abstract There is a need for improved research in the field of prehospital care. At the same time, there are many barriers in prehospital research due to the complex context, posing unique challenges for research, development, and evaluation. The present paper argues for the potential of simulation for prehospital research, e.g., through the development of an advanced simulation-based prehospital research laboratory. However, the prehospital context is different from other healthcare areas, which implies special requirements for the design of this type of laboratory, in terms of simulation width (including the entire prehospital work process) and depth (level of scenario detail). A set of features pertaining to simulation width, scenario depth, equipment, and personnel and competence are proposed. Close tailoring between these features and the prehospital research problems and context presents great potential to improve and further prehospital research.
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- 2019
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39. Adverse events in prehospital emergency care: a trigger tool study
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Magnus Andersson Hagiwara, Carl Magnusson, Johan Herlitz, Elin Seffel, Christer Axelsson, Monica Munters, Anneli Strömsöe, and Lena Nilsson
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Emergency medical service ,Adverse events ,Patient safety ,Trigger tool ,Prehospital ,Special situations and conditions ,RC952-1245 ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Abstract Background Prehospital emergency care has developed rapidly during the past decades. The care is given in a complex context which makes prehospital care a potential high-risk activity when it comes to patient safety. Patient safety in the prehospital setting has been only sparsely investigated. The aims of the present study were 1) To investigate the incidence of adverse events (AEs) in prehospital care and 2) To investigate the factors contributing to AEs in prehospital care. Methods We used a retrospective study design where 30 randomly selected prehospital medical records were screened for AEs each month in three prehospital organizations in Sweden during a period of one year. A total of 1080 prehospital medical records were included. The record review was based on the use of 11 screening criteria. Results The reviewers identified 46 AEs in 46 of 1080 (4.3%) prehospital medical records. Of the 46 AEs, 43 were classified as potential for harm (AE1) (4.0, 95% CI = 2.9–5.4) and three as harm identified (AE2) (0.3, 95% CI = 0.1–0.9). However, among patients with a life-threatening condition (priority 1), the risk of AE was higher (16.5%). The most common factors contributing to AEs were deviations from standard of care and missing, incomplete, or unclear documentation. The most common cause of AEs was the result of action(s) or inaction(s) by the emergency medical service (EMS) crew. Conclusions There were 4.3 AEs per 100 ambulance missions in Swedish prehospital care. The majority of AEs originated from deviations from standard of care and incomplete documentation. There was an increase in the risk of AE among patients who the EMS team assessed as having a life-threatening condition. Most AEs were possible to avoid.
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- 2019
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40. Carbide Precipitation during Processing of Two Low-Alloyed Martensitic Tool Steels with 0.11 and 0.17 V/Mo Ratios Studied by Neutron Scattering, Electron Microscopy and Atom Probe
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Erik Claesson, Hans Magnusson, Joachim Kohlbrecher, Mattias Thuvander, Fredrik Lindberg, Magnus Andersson, and Peter Hedström
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tool steel ,precipitation ,carbides ,martensite ,tempering ,STEM ,Mining engineering. Metallurgy ,TN1-997 - Abstract
Two industrially processed low-alloyed martensitic tool steel alloys with compositions Fe-0.3C-1.1Si-0.81Mn-1.5Cr-1.4Ni-1.1Mo-0.13V and Fe-0.3C-1.1Si-0.81Mn-1.4Cr-0.7Ni-0.8Mo-0.14V (wt.%) were characterized using small-angle neutron scattering (SANS), scanning electron microscopy (SEM), Scanning transmission electron microscopy (STEM), and atom probe tomography (APT). The combination of methods enables an understanding of the complex precipitation sequences that occur in these materials during the processing. Nb-rich primary carbides form at hot working, while Fe-rich auto-tempering carbides precipitate upon quenching, and cementite carbides grow during tempering when Mo-rich secondary carbides also nucleate and grow. The number density of Mo-rich carbides increases with tempering time, and after 24 h, it is two to three orders of magnitude higher than the Fe-rich carbides. A high number density of Mo-rich carbides is important to strengthen these low-alloyed tool steels through precipitation hardening. The results indicate that the Mo-rich secondary carbide precipitates are initially of MC character, whilst later they start to appear as M2C. This change of the secondary carbides is diffusion driven and is therefore mainly seen for longer tempering times at the higher tempering temperature of 600 °C.
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- 2022
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41. The final assessment and its association with field assessment in patients who were transported by the emergency medical service
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Carl Magnusson, Christer Axelsson, Lena Nilsson, Anneli Strömsöe, Monica Munters, Johan Herlitz, and Magnus Andersson Hagiwara
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Prehospital ,Assessment ,Diagnose ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Abstract Background In patients who call for the emergency medical service (EMS), there is a knowledge gap with regard to the final assessment after arriving at hospital and its association with field assessment. Aim In a representative population of patients who call for the EMS, to describe a) the final assessment at hospital discharge and b) the association between the assessment in the field and the assessment at hospital discharge. Methods Thirty randomly selected patients reached by a dispatched ambulance each month between 1 Jan and 31 Dec 2016 in one urban, one rural and one mixed ambulance organisation in Sweden took part in the study. The exclusion criteria were age
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- 2018
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42. High-Speed Imaging of Water Hammer Cavitation in Oil–Hydraulic Pipe Flow
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Marcus Jansson, Magnus Andersson, and Matts Karlsson
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hydraulic transients ,column separation ,cavitation erosion ,Thermodynamics ,QC310.15-319 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
A pipe water hammer with column separation was studied in a range of flow rates (Re=465 to 2239) in a test rig with an acrylic glass observation section. Pressure transients were measured with piezoresistive pressure sensors, while the gas evaporation and condensation were captured by high-speed recording with a Photron SA-Z at a frame rate of 75,000 fps. Separation lengths were estimated by a threshold value in the images. The results did not show a sharp gas–oil interface but consisted of small, dispersed bubbles mixed with larger vapor structures, where the bubbles seemed to become smaller after each collapse. These findings differ from the transient cavitating characteristics commonly reported in nonhydraulic piping systems governed by different fluid properties and time scales. Good repeatability, both in terms of pressure transients and bubble distribution, was observed. The column separation was quantified as a metric of separation length, which was consistent between the tests. Combined with pressure measurements, these results may assist in obtaining a better understanding of the transient cavitation dynamics within oil–hydraulic systems as well as be used to improve modelling strategies towards more accurate cavitation erosion predictions.
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- 2022
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43. Simulation strategies for the Food and Drug Administration nozzle using Nek5000
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Nour Sánchez Abad, Ricardo Vinuesa, Philipp Schlatter, Magnus Andersson, and Matts Karlsson
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Physics ,QC1-999 - Abstract
Computational fluid dynamics (CFD) is currently a versatile tool used for flow characterization in diverse areas of industry and research; however, its application in medical devices is less developed due to high regulatory standards for safety purposes. In this context, the development of a rigorous and standardized CFD methodology is essential in order to improve the accuracy and ensure the reliability of biomedical applications. To that end, the Food and Drug Administration (FDA) proposed a benchmark model of an idealized medical device to provide a common ground for verification and validation processes. Previous studies have evaluated the potential of conventional turbulence models to predict the relevant flow features in the FDA nozzle but have also been deemed inaccurate or exhibited high dependency on the numerical scheme. Furthermore, validation of computational results relied on previous experiments performed with particle image velocimetry (PIV), which also exhibited noticeable uncertainties. Here, we perform direct numerical simulations (DNSs) of the flow through the FDA nozzle configuration, at Reynolds numbers based on the throat diameter Ret = 500, 2000, 3500, and 5000, using the spectral-element code Nek5000. The predictive capabilities of the synthetic-eddy method and parabolic-inflow conditions at the inlet were tested, and the results were compared with PIV data. Our results highlight the very high sensitivity of this flow case to the inflow conditions and the disturbances at the throat, particularly when predicting the laminar–turbulent jet breakdown. Due to this extreme sensitivity, any benchmark data of this geometry need to include a very detailed characterization of both the conditions at the inflow and the throat, in order to enable relevant comparisons.
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- 2020
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44. Ejaculated boar spermatozoa displaying a rare multivesicular defect
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Szabolcs Nagy, Tuire Tamminen, Magnus Andersson, and Heriberto Rodriguez-Martinez
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CLSM ,Exosomes ,Pig ,Semen morphology ,TEM ,Veterinary medicine ,SF600-1100 - Abstract
Abstract Two cases of a previously unreported sperm defect appearing in boar studs in Finland are presented. Spermatozoa showed small particles scattered on their surface with a prevalence decreasing with boar age. Semen samples, either stained with eosin-nigrosin or examined with phase contrast optics on formaldehyde-fixed spermatozoa, revealed the presence of multiple particles attached to the surface of spermatozoa counted as dead cells at fixation. Transmission electron microscopy revealed these were multivesicular and multilamellar vesicles, built up by phospholipid membranes. The case is classified as a post-epididymal multivesicular sperm defect with a favorable prognosis.
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- 2018
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45. Permeability and ammonia selectivity in aquaporin TIP2;1: linking structure to function
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Viveca Lindahl, Pontus Gourdon, Magnus Andersson, and Berk Hess
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Medicine ,Science - Abstract
Abstract Aquaporin TIP2;1 is a protein channel permeable to both water and ammonia. The structural origin of ammonia selectivity remains obscure, but experiments have revealed that a double mutation renders it impermeable to ammonia without affecting water permeability. Here, we aim to reproduce and explain these observations by performing an extensive mutational study using microsecond long molecular dynamics simulations, applying the two popular force fields CHARMM36 and Amber ff99SB-ILDN. We calculate permeabilities and free energies along the channel axis for ammonia and water. For one force field, the permeability of the double mutant decreases by a factor of 2.5 for water and 4 for ammonia, increasing water selectivity by a factor of 1.6. We attribute this effect to decreased entropy of water in the pore, due to the observed increase in pore–water interactions and narrower pore. Additionally, we observe spontaneous opening and closing of the pore on the cytosolic side, which suggests a gating mechanism for the pore. Our results show that sampling methods and simulation times are sufficient to delineate even subtle effects of mutations on structure and function and to capture important long-timescale events, but also underline the importance of improving models further.
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- 2018
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46. Integrated ovarian mRNA and miRNA transcriptome profiling characterizes the genetic basis of prolificacy traits in sheep (Ovis aries)
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Kisun Pokharel, Jaana Peippo, Mervi Honkatukia, Arja Seppälä, Johanna Rautiainen, Nasser Ghanem, Tuula-Marjatta Hamama, Mark A. Crowe, Magnus Andersson, Meng-Hua Li, and Juha Kantanen
- Subjects
Finnsheep ,Texel ,F1 cross ,Flushing diet ,Ovulation rate ,GDF9 ,Biotechnology ,TP248.13-248.65 ,Genetics ,QH426-470 - Abstract
Abstract Background The highly prolific breeds of domestic sheep (Ovis aries) are globally valuable genetic resources for sheep industry. Genetic, nutritional and other environmental factors affect prolificacy traits in sheep. To improve our knowledge of the sheep prolificacy traits, we conducted mRNA-miRNA integrated profiling of ovarian tissues from two pure breeds with large (Finnsheep) vs. small (Texel) litter sizes and their F1 crosses, half of which were fed a flushing diet. Results Among the samples, 16,402 genes (60.6% known ovine genes) were expressed, 79 novel miRNAs were found, and a cluster of miRNAs on chromosome 18 was detected. The majority of the differentially expressed genes between breeds were upregulated in the Texel with low prolificacy, owing to the flushing diet effect, whereas a similar pattern was not detected in the Finnsheep. F1 ewes responded similarly to Finnsheep rather than displaying a performance intermediate between the two pure breeds. Conclusions The identification and characterization of differentially expressed genes and miRNAs in the ovaries of sheep provided insights into genetic and environmental factors affecting prolificacy traits. The three genes (CST6, MEPE and HBB) that were differentially expressed between the group of Finnsheep and Texel ewes kept in normal diet appeared to be candidate genes of prolificacy traits and will require further validation.
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- 2018
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47. ToxId: an efficient algorithm to solve occlusions when tracking multiple animals
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Alvaro Rodriguez, Hanqing Zhang, Jonatan Klaminder, Tomas Brodin, and Magnus Andersson
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Medicine ,Science - Abstract
Abstract Video analysis of animal behaviour is widely used in fields such as ecology, ecotoxicology, and evolutionary research. However, when tracking multiple animals, occlusion and crossing are problematic, especially when the identity of each individual needs to be preserved. We present a new algorithm, ToxId, which preserves the identity of multiple animals by linking trajectory segments using their intensity histogram and Hu-moments. We verify the performance and accuracy of our algorithm using video sequences with different animals and experimental conditions. The results show that our algorithm achieves state-of-the-art accuracy using an efficient approach without the need of learning processes, complex feature maps or knowledge of the animal shape. ToxId is also computationally efficient, has low memory requirements, and operates without accessing future or past frames.
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- 2017
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48. Synthetic NAC 71-82 Peptides Designed to Produce Fibrils with Different Protofilament Interface Contacts
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Thomas Näsström, Tobias Dahlberg, Dmitry Malyshev, Jörgen Ådén, Per Ola Andersson, Magnus Andersson, and Björn C. G. Karlsson
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α-synuclein ,NAC 71-82 peptides ,fibril polymorphs ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Alpha-synucleinopathies are featured by fibrillar inclusions in brain cells. Although α-synuclein fibrils display structural diversity, the origin of this diversity is not fully understood. We used molecular dynamics simulations to design synthetic peptides, based on the NAC 71-82 amino acid fragment of α-synuclein, that govern protofilament contacts and generation of twisted fibrillar polymorphs. Four peptides with structures based on either single or double fragments and capped or non-capped ends were selected for further analysis. We determined the fibrillar yield and the structures from these peptides found in the solution after fibrillisation using protein concentration determination assay and circular dichroism spectroscopy. In addition, we characterised secondary structures formed by individual fibrillar complexes using laser-tweezers Raman spectroscopy. Results suggest less mature fibrils, based on the lower relative β-sheet content for double- than single-fragment peptide fibrils. We confirmed this structural difference by TEM analysis which revealed, in addition to short protofibrils, more elongated, twisted and rod-like fibril structures in non-capped and capped double-fragment peptide systems, respectively. Finally, time-correlated single-photon counting demonstrated a difference in the Thioflavin T fluorescence lifetime profiles upon fibril binding. It could be proposed that this difference originated from morphological differences in the fibril samples. Altogether, these results highlight the potential of using peptide models for the generation of fibrils that share morphological features relevant for disease, e.g., twisted and rod-like polymorphs.
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- 2021
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49. Structure of the human ClC-1 chloride channel.
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Kaituo Wang, Sarah Spruce Preisler, Liying Zhang, Yanxiang Cui, Julie Winkel Missel, Christina Grønberg, Kamil Gotfryd, Erik Lindahl, Magnus Andersson, Kirstine Calloe, Pascal F Egea, Dan Arne Klaerke, Michael Pusch, Per Amstrup Pedersen, Z Hong Zhou, and Pontus Gourdon
- Subjects
Biology (General) ,QH301-705.5 - Abstract
ClC-1 protein channels facilitate rapid passage of chloride ions across cellular membranes, thereby orchestrating skeletal muscle excitability. Malfunction of ClC-1 is associated with myotonia congenita, a disease impairing muscle relaxation. Here, we present the cryo-electron microscopy (cryo-EM) structure of human ClC-1, uncovering an architecture reminiscent of that of bovine ClC-K and CLC transporters. The chloride conducting pathway exhibits distinct features, including a central glutamate residue ("fast gate") known to confer voltage-dependence (a mechanistic feature not present in ClC-K), linked to a somewhat rearranged central tyrosine and a narrower aperture of the pore toward the extracellular vestibule. These characteristics agree with the lower chloride flux of ClC-1 compared with ClC-K and enable us to propose a model for chloride passage in voltage-dependent CLC channels. Comparison of structures derived from protein studied in different experimental conditions supports the notion that pH and adenine nucleotides regulate ClC-1 through interactions between the so-called cystathionine-β-synthase (CBS) domains and the intracellular vestibule ("slow gating"). The structure also provides a framework for analysis of mutations causing myotonia congenita and reveals a striking correlation between mutated residues and the phenotypic effect on voltage gating, opening avenues for rational design of therapies against ClC-1-related diseases.
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- 2019
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50. Model Verification and Error Sensitivity of Turbulence-Related Tensor Characteristics in Pulsatile Blood Flow Simulations
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Magnus Andersson and Matts Karlsson
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barycentric anisotropy invariant map ,turbulence componentality ,epistemic modeling errors ,patient-specific computational hemodynamics ,large eddy simulations ,image-based cardiovascular flow modeling ,Thermodynamics ,QC310.15-319 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
Model verification, validation, and uncertainty quantification are essential procedures to estimate errors within cardiovascular flow modeling, where acceptable confidence levels are needed for clinical reliability. While more turbulent-like studies are frequently observed within the biofluid community, practical modeling guidelines are scarce. Verification procedures determine the agreement between the conceptual model and its numerical solution by comparing for example, discretization and phase-averaging-related errors of specific output parameters. This computational fluid dynamics (CFD) study presents a comprehensive and practical verification approach for pulsatile turbulent-like blood flow predictions by considering the amplitude and shape of the turbulence-related tensor field using anisotropic invariant mapping. These procedures were demonstrated by investigating the Reynolds stress tensor characteristics in a patient-specific aortic coarctation model, focusing on modeling-related errors associated with the spatiotemporal resolution and phase-averaging sampling size. Findings in this work suggest that attention should also be put on reducing phase-averaging related errors, as these could easily outweigh the errors associated with the spatiotemporal resolution when including too few cardiac cycles. Also, substantially more cycles are likely needed than typically reported for these flow regimes to sufficiently converge the phase-instant tensor characteristics. Here, higher degrees of active fluctuating directions, especially of lower amplitudes, appeared to be the most sensitive turbulence characteristics.
- Published
- 2020
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