| 1. |
- Bendtsen, Katja Maria, et al.
(author)
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Particle characterization and toxicity in C57BL/6 mice following instillation of five different diesel exhaust particles designed to differ in physicochemical properties
- 2020
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In: Particle and Fibre Toxicology. - : Springer Science and Business Media LLC. - 1743-8977. ; 17:1
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Journal article (peer-reviewed)abstract
- BACKGROUND: Diesel exhaust is carcinogenic and exposure to diesel particles cause health effects. We investigated the toxicity of diesel exhaust particles designed to have varying physicochemical properties in order to attribute health effects to specific particle characteristics. Particles from three fuel types were compared at 13% engine intake O2 concentration: MK1 ultra low sulfur diesel (DEP13) and the two renewable diesel fuels hydrotreated vegetable oil (HVO13) and rapeseed methyl ester (RME13). Additionally, diesel particles from MK1 ultra low sulfur diesel were generated at 9.7% (DEP9.7) and 17% (DEP17) intake O2 concentration. We evaluated physicochemical properties and histopathological, inflammatory and genotoxic responses on day 1, 28, and 90 after single intratracheal instillation in mice compared to reference diesel particles and carbon black. RESULTS: Moderate variations were seen in physical properties for the five particles: primary particle diameter: 15-22 nm, specific surface area: 152-222 m2/g, and count median mobility diameter: 55-103 nm. Larger differences were found in chemical composition: organic carbon/total carbon ratio (0.12-0.60), polycyclic aromatic hydrocarbon content (1-27 μg/mg) and acid-extractable metal content (0.9-16 μg/mg). Intratracheal exposure to all five particles induced similar toxicological responses, with different potency. Lung particle retention was observed in DEP13 and HVO13 exposed mice on day 28 post-exposure, with less retention for the other fuel types. RME exposure induced limited response whereas the remaining particles induced dose-dependent inflammation and acute phase response on day 1. DEP13 induced acute phase response on day 28 and inflammation on day 90. DNA strand break levels were not increased as compared to vehicle, but were increased in lung and liver compared to blank filter extraction control. Neutrophil influx on day 1 correlated best with estimated deposited surface area, but also with elemental carbon, organic carbon and PAHs. DNA strand break levels in lung on day 28 and in liver on day 90 correlated with acellular particle-induced ROS. CONCLUSIONS: We studied diesel exhaust particles designed to differ in physicochemical properties. Our study highlights specific surface area, elemental carbon content, PAHs and ROS-generating potential as physicochemical predictors of diesel particle toxicity.
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| 2. |
- Berthing, Trine, et al.
(author)
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Pulmonary toxicity and translocation of gallium phosphide nanowires to secondary organs following pulmonary exposure in mice
- 2023
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In: Journal of Nanobiotechnology. - 1477-3155. ; 21:1
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Journal article (peer-reviewed)abstract
- Background: III-V semiconductor nanowires are envisioned as being integrated in optoelectronic devices in the near future. However, the perspective of mass production of these nanowires raises concern for human safety due to their asbestos- and carbon nanotube-like properties, including their high aspect ratio shape. Indeed, III-V nanowires have similar dimensions as Mitsui-7 multi-walled carbon nanotubes, which induce lung cancer by inhalation in rats. It is therefore urgent to investigate the toxicological effects following lung exposure to III-V nanowires prior to their use in industrial production, which entails risk of human exposure. Here, female C57BL/6J mice were exposed to 2, 6, and 18 µg (0.12, 0.35 and 1.1 mg/kg bw) of gallium phosphide (III-V) nanowires (99 nm diameter, 3.7 μm length) by intratracheal instillation and the toxicity was investigated 1, 3, 28 days and 3 months after exposure. Mitsui-7 multi-walled carbon nanotubes and carbon black Printex 90 nanoparticles were used as benchmark nanomaterials. Results: Gallium phosphide nanowires induced genotoxicity in bronchoalveolar lavage cells and acute inflammation with eosinophilia observable both in bronchoalveolar lavage and lung tissue (1 and 3 days post-exposure). The inflammatory response was comparable to the response following exposure to Mitsui-7 multi-walled carbon nanotubes at similar dose levels. The nanowires underwent partial dissolution in the lung resulting in thinner nanowires, with an estimated in vivo half-life of 3 months. Despite the partial dissolution, nanowires were detected in lung, liver, spleen, kidney, uterus and brain 3 months after exposure. Conclusion: Pulmonary exposure to gallium phosphide nanowires caused similar toxicological effects as the multi-walled carbon nanotube Mitsui-7. Graphical Abstract: [Figure not available: see fulltext.]
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| 3. |
- Gren, Louise, et al.
(author)
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Effect of renewable fuels and intake O2 concentration on diesel engine emission characteristics and reactive oxygen species (ROS) formation
- 2020
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In: Atmosphere. - : MDPI AG. - 2073-4433. ; 11:6
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Journal article (peer-reviewed)abstract
- Renewable diesel fuels have the potential to reduce net CO2 emissions, and simultaneously decrease particulate matter (PM) emissions. This study characterized engine-out PM emissions and PM-induced reactive oxygen species (ROS) formation potential. Emissions from a modern heavy-duty diesel engine without external aftertreatment devices, and fueled with petroleum diesel, hydrotreated vegetable oil (HVO) or rapeseed methyl ester (RME) biodiesel were studied. Exhaust gas recirculation (EGR) allowed us to probe the effect of air intake O2 concentration, and thereby combustion temperature, on emissions and ROS formation potential. An increasing level of EGR (decreasing O2 concentration) resulted in a general increase of equivalent black carbon (eBC) emissions and decrease of NOx emissions. At a medium level of EGR (13% intake O2), eBC emissions were reduced for HVO and RME by 30 and 54% respectively compared to petroleum diesel. In general, substantially lower emissions of polycyclic aromatic hydrocarbons (PAHs), including nitro and oxy-PAHs, were observed for RME compared to both HVO and diesel. At low-temperature combustion (LTC, O2 < 10%), CO and hydrocarbon gas emissions increased and an increased fraction of refractory organic carbon and PAHs were found in the particle phase. These altered soot properties have implications for the design of aftertreatment systems and diesel PM measurements with optical techniques. The ROS formation potential per mass of particles increased with increasing engine O2 concentration intake. We hypothesize that this is because soot surface properties evolve with the combustion temperature and become more active as the soot matures into refractory BC, and secondly as the soot surface becomes altered by surface oxidation. At 13% intake O2, the ROS-producing ability was high and of similar magnitude per mass for all fuels. When normalizing by energy output, the lowered emissions for the renewable fuels led to a reduced ROS formation potential.
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| 4. |
- Jiang, Zheshun, et al.
(author)
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Hexavalent chromium still a concern in Sweden : Evidence from a cross-sectional study within the SafeChrom project
- 2024
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In: International journal of hygiene and environmental health (Print). - : Elsevier. - 1438-4639 .- 1618-131X. ; 256
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Journal article (peer-reviewed)abstract
- ObjectivesHexavalent chromium (Cr(VI)) is classified as a human carcinogen. Occupational Cr(VI) exposure can occur during different work processes, but the current exposure to Cr(VI) at Swedish workplaces is unknown.MethodsThis cross-sectional study (SafeChrom) recruited non-smoking men and women from 14 companies with potential Cr(VI) exposure (n = 113) and controls from 6 companies without Cr(VI) exposure (n = 72). Inhalable Cr(VI) was measured by personal air sampling (outside of respiratory protection) in exposed workers. Total Cr was measured in urine (pre- and post-shift, density-adjusted) and red blood cells (RBC) (reflecting Cr(VI)) in exposed workers and controls. The Bayesian tool Expostats was used to assess risk and evaluate occupational exposure limit (OEL) compliance.ResultsThe exposed workers performed processing of metal products, steel production, welding, plating, and various chemical processes. The geometric mean concentration of inhalable Cr(VI) in exposed workers was 0.15 μg/m3 (95% confidence interval: 0.11–0.21). Eight of the 113 exposed workers (7%) exceeded the Swedish OEL of 5 μg/m3, and the Bayesian analysis estimated the share of OEL exceedances up to 19.6% for stainless steel welders. Median post-shift urinary (0.60 μg/L, 5th-95th percentile 0.10–3.20) and RBC concentrations (0.73 μg/L, 0.51–2.33) of Cr were significantly higher in the exposed group compared with the controls (urinary 0.10 μg/L, 0.06–0.56 and RBC 0.53 μg/L, 0.42–0.72). Inhalable Cr(VI) correlated with urinary Cr (rS = 0.64) and RBC-Cr (rS = 0.53). Workers within steel production showed the highest concentrations of inhalable, urinary and RBC Cr. Workers with inferred non-acceptable local exhaustion ventilation showed significantly higher inhalable Cr(VI), urinary and RBC Cr concentrations compared with those with inferred acceptable ventilation. Furthermore, workers with inferred correct use of respiratory protection were exposed to significantly higher concentrations of Cr(VI) in air and had higher levels of Cr in urine and RBC than those assessed with incorrect or no use. Based on the Swedish job-exposure-matrix, approximately 17 900 workers were estimated to be occupationally exposed to Cr(VI) today.ConclusionsOur study demonstrates that some workers in Sweden are exposed to high levels of the non-threshold carcinogen Cr(VI). Employers and workers seem aware of Cr(VI) exposure, but more efficient exposure control strategies are required. National strategies aligned with the European strategies are needed in order to eliminate this cause of occupational cancer.
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| 5. |
- Kokot, Hana, et al.
(author)
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Prediction of Chronic Inflammation for Inhaled Particles : the Impact of Material Cycling and Quarantining in the Lung Epithelium
- 2020
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In: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 32:47
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Journal article (peer-reviewed)abstract
- On a daily basis, people are exposed to a multitude of health-hazardous airborne particulate matter with notable deposition in the fragile alveolar region of the lungs. Hence, there is a great need for identification and prediction of material-associated diseases, currently hindered due to the lack of in-depth understanding of causal relationships, in particular between acute exposures and chronic symptoms. By applying advanced microscopies and omics to in vitro and in vivo systems, together with in silico molecular modeling, it is determined herein that the long-lasting response to a single exposure can originate from the interplay between the newly discovered nanomaterial quarantining and nanomaterial cycling between different lung cell types. This new insight finally allows prediction of the spectrum of lung inflammation associated with materials of interest using only in vitro measurements and in silico modeling, potentially relating outcomes to material properties for a large number of materials, and thus boosting safe-by-design-based material development. Because of its profound implications for animal-free predictive toxicology, this work paves the way to a more efficient and hazard-free introduction of numerous new advanced materials into our lives.
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| 6. |
- Vogel, Gisela, et al.
(author)
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Shifting focus : A grounded theory of how family members to critically ill patients manage their situation
- 2023
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In: Intensive & Critical Care Nursing. - : Elsevier. - 0964-3397 .- 1532-4036. ; 78
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Journal article (peer-reviewed)abstract
- Objectives: Critical illness is a life-threatening condition for the patient, which affects their family members as a traumatic experience. Well-known long-term consequences include impact on mental health and health-related quality of life. This study aims to develop a grounded theory to explain pattern of behaviours in family members of critically ill patients cared for in an intensive care unit, addressing the period from when the patient becomes critically ill until recovery at home.Research methodology/design: We used a classic grounded theory to explore the main concern for family members of intensive care patients. Fourteen interviews and seven observations with a total of 21 participants were analysed. Data were collected from February 2019 to June 2021.Setting: Three general intensive care units in Sweden, consisting of a university hospital and two county hospitals.Findings: The theory Shifting focus explains how family members' main concern, living on hold, is managed. This theory involves different strategies: decoding, sheltering and emotional processing. The theory has three different outcomes: adjusting focus, emotional resigning or remaining in focus.Conclusion: Family members could stand in the shadow of the patients' critical illness and needs. This emotional adversity is processed through shifting focus from one's own needs and well-being to the patient's survival, needs and well-being. This theory can raise awareness of how family members of critically ill patients manage the process from critical illness until return to everyday life at home. Future research focusing on family members' need for support and information, to reduce stress in everyday life, is needed.Implications for Clinical Practice: Healthcare professionals should support family members in shifting focus by interaction, clear and honest communication, and through mediating hope.
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| 7. |
- Vogel, Gisela, et al.
(author)
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Stabilizing life : A grounded theory of surviving critical illness
- 2021
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In: Intensive & Critical Care Nursing. - : Elsevier. - 0964-3397 .- 1532-4036. ; 67
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Journal article (peer-reviewed)abstract
- OBJECTIVES: The experience of critical illness among patients is both complex and multifaceted. It can make patients vulnerable to long-term consequences such as impairment in cognition, mental health and physical functional ability which affects health related quality of life. This study aims to explore patients' patterns of behaviour during the process from becoming critical ill to recovery at home.DESIGN: We used a classic grounded theory methodology to explore the main concern for intensive care patients. Thirteen participants were interviewed and seven different participants were observed.SETTING: Three general intensive care units in Sweden, consisting of a university hospital, a county hospital and a district hospital.FINDINGS: The theory Stabilizing life explains how patients' main concern, being out of control, can be resolved. This theory involves two processes, recapturing life and recoding life, and one underlying strategy, emotional balancing that is used during the whole process.CONCLUSION: The process from becoming critically ill until recovery home is perceived as a constant fight in actions and mind to achieve control and stabilize life. This theory can form the basis for further qualitative and quantitative research about interventions that promotes wellbeing during the whole process.
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| 8. |
- Vogel, Gisela, et al.
(author)
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The distorted memories of patients treated in the intensive care unit during the COVID-19 pandemic : A qualitative study
- 2023
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In: Intensive & Critical Care Nursing. - : Elsevier. - 0964-3397 .- 1532-4036. ; 79
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Journal article (peer-reviewed)abstract
- Background: During the COVID-19 pandemic, patients cared for in the intensive care unit were exposed to many risk factors for developing delirium and subsequent distorted memories. Further, seeing healthcare professionals who have been dressed in personal protective equipment and face masks could have affected the patients ' memories. Therefore, the aim of this study was to explore memories and how they are experienced and managed by former patients who have been treated for COVID-19 in an intensive care unit. Methods: Sixteen former patients treated for COVID-19 at a large emergency hospital in Sweden were interviewed 3-8 months after discharge from the intensive care unit. The data were interpreted using thematic analysis. The Consolidated Criteria for Reporting Qualitative Research checklist was followed in the reporting of the study. Findings: Participants ' descriptions of their memories of treatment in the intensive care unit for COVID-19 generated three themes: ' Distorted truth ' the content in the memories which implied facing death in an unreal distorted environment. ' Captive,' was the experience and feelings linked to memories with a feeling of being exposed and alone, and ' Coping with memories ' explained how participants managed the implications of the memories using a mixture of strategies. Conclusions: For former patients who were admitted to an intensive care unit after a diagnosis of COVID-19, memories caused considerable distress, which were similar to other intensive care patients ' experiences, before the pandemic. Emotion-focused and problem-focused strategies could be used to cope with these memories. Healthcare professionals wearing protective equipment gave the patient a distant feeling, but more important was to be treated with attention/care and respect. Implications for clinical practice: Awareness of the impact of distorted memories on patients who are severely ill and their needs and strategies to cope with these memories can form the basis for early interventions that promotes well-being during care and recovery. Healthcare professionals have an important task to inform patients and their family members about the existence of distorted memories, and talk about the patients ' experience of them, to facilitate their recovery.
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