| 1. |
- Lehtipalo, Katrianne, et al.
(författare)
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Multicomponent new particle formation from sulfuric acid, ammonia, and biogenic vapors
- 2018
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 4:12
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Tidskriftsartikel (refereegranskat)abstract
- A major fraction of atmospheric aerosol particles, which affect both air quality and climate, form from gaseous precursors in the atmosphere. Highly oxygenated organic molecules (HOMs), formed by oxidation of biogenic volatile organic compounds, are known to participate in particle formation and growth. However, it is not well understood how they interact with atmospheric pollutants, such as nitrogen oxides (NOx) and sulfur oxides (SOx) from fossil fuel combustion, as well as ammonia (NH3) from livestock and fertilizers. Here, we show how NOx suppresses particle formation, while HOMs, sulfuric acid, and NH3 have a synergistic enhancing effect on particle formation. We postulate a novel mechanism, involving HOMs, sulfuric acid, and ammonia, which is able to closely reproduce observations of particle formation and growth in daytime boreal forest and similar environments. The findings elucidate the complex interactions between biogenic and anthropogenic vapors in the atmospheric aerosol system.
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| 2. |
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| 3. |
- Wagner, Robert, et al.
(författare)
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The role of ions in new particle formation in the CLOUD chamber
- 2017
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 17:24, s. 15181-15197
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Tidskriftsartikel (refereegranskat)abstract
- The formation of secondary particles in the atmosphere accounts for more than half of global cloud condensation nuclei. Experiments at the CERN CLOUD (Cosmics Leaving OUtdoor Droplets) chamber have underlined the importance of ions for new particle formation, but quantifying their effect in the atmosphere remains challenging. By using a novel instrument setup consisting of two nanoparticle counters, one of them equipped with an ion filter, we were able to further investigate the ion-related mechanisms of new particle formation. In autumn 2015, we carried out experiments at CLOUD on four systems of different chemical compositions involving monoterpenes, sulfuric acid, nitrogen oxides, and ammonia. We measured the influence of ions on the nucleation rates under precisely controlled and atmospherically relevant conditions. Our results indicate that ions enhance the nucleation process when the charge is necessary to stabilize newly formed clusters, i.e., in conditions in which neutral clusters are unstable. For charged clusters that were formed by ion-induced nucleation, we were able to measure, for the first time, their progressive neutralization due to recombination with oppositely charged ions. A large fraction of the clusters carried a charge at 1.5 nm diameter. However, depending on particle growth rates and ion concentrations, charged clusters were largely neutralized by ion-ion recombination before they grew to 2.5 nm. At this size, more than 90% of particles were neutral. In other words, particles may originate from ion-induced nucleation, although they are neutral upon detection at diameters larger than 2.5 nm. Observations at Hyytiala, Finland, showed lower ion concentrations and a lower contribution of ion-induced nucleation than measured at CLOUD under similar conditions. Although this can be partly explained by the observation that ion-induced fractions decrease towards lower ion concentrations, further investigations are needed to resolve the origin of the discrepancy.
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| 4. |
- Ahonen, Matti, et al.
(författare)
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Back Pain and Quality of Life 10 Years After Segmental Pedicle Screw Instrumentation for Adolescent Idiopathic Scoliosis
- 2023
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Ingår i: Spine. - : Ovid Technologies (Wolters Kluwer Health). - 0362-2436 .- 1528-1159. ; 48:10, s. 665-671
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Tidskriftsartikel (refereegranskat)abstract
- Study Design.Comparative cohort study. Objective.The aim of the present study was to evaluate pain and health-related quality of life (HRQoL) in surgically managed patients with a minimum follow-up of 10 years compared with patients with untreated adolescent idiopathic scoliosis (AIS) and a healthy control group. Summary of Background Data.Posterior spinal fusion with pedicle screws is the standard treatment for AIS, although it remains unclear whether this procedure results in improved long-term HRQoL compared with untreated patients with AIS. Patients and Methods.Sixty-four consecutive patients at a minimum follow-up of 10 years, who underwent posterior pedicle screw instrumentation for AIS were prospectively enrolled. Fifty-three (83%) of these patients completed Scoliosis Research Society (SRS) 24 questionnaires, clinical examination, and standing spinal radiographs. Pain and HRQoL were compared with age and sex-matched patients with untreated AIS and healthy individuals. Results.The mean major curve was 57 degrees preoperatively and 15 degrees at the 10-year follow-up. SRS-24 self-image domain score showed a significant improvement from preoperative to 2 years and remained significantly better at the 10-year follow-up (P < 0.001). Patients fused to L3 or below had lower pain, satisfaction, and total score than patients fused to L2 or above (P < 0.05), but self-image, function, and activity scores did not differ between groups at 10-year follow-up. Pain, self-image, general activity, and total SRS domains were significantly better at 10-year follow-up in the surgically treated patients as compared with untreated patients (all P < 0.05). Healthy controls had significantly higher total scores than those surgically treated at 10-year follow-ups (P < 0.001). Conclusion.Patients undergoing segmental pedicle screw instrumentation for AIS maintain high-level HRQoL during a 10-year follow-up. Their HRQoL was significantly better than in the untreated patients with AIS, except for the function domain. However, HRQoL remained at a lower level than in healthy controls.
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| 5. |
- Alriksson-Schmidt, Ann I, et al.
(författare)
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CP-North: living life in the Nordic countries? : A retrospective register research protocol on individuals with cerebral palsy and their parents living in Sweden, Norway, Denmark, Finland and Iceland
- 2019
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Ingår i: BMJ Open. - : BMJ. - 2044-6055. ; 9:10
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Cerebral palsy (CP) is one of the most common neurodevelopmental disabilities. Yet, most individuals with CP are adults. How individuals with CP fare in terms of health, quality of life (QoL), education, employment and income is largely unknown. Further, little is known about the effects of having a child with CP on the parents. The Nordic countries are known for their strong welfare systems, yet it is unknown to what extent the added burden related to disability is actually compensated for. We will explore how living with CP affects health, QoL, healthcare utilisation, education, labour market outcomes, socioeconomic status and mortality throughout the lifespan of individuals with CP and their parents. We will also investigate if these effects differ between subgroups, within and across the Nordic countries. METHODS AND ANALYSES: CP-North is a multidisciplinary 4-year (1 August 2017 to 31 July 2021) register research project. The research consortium comprises researchers and users from Sweden, Norway, Denmark, Iceland and Finland. Data from CP registries and follow-up programmes, or cohorts of individuals with CP, will be merged with general national registries. All individual studies are structured under three themes: medical outcomes, social and public health outcomes, and health economics. Both case-control and cohort designs will be included depending on the particular research question. Data will be analysed in the individual countries and later merged across nations.ETHICS AND DISSEMINATION: The ethics approval processes in each individual country are followed. Findings will be published (open access) in international peer-reviewed journals in related fields. Updates on CP-North will be published online at http://rdi.arcada.fi/cpnorth/en/.
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| 6. |
- Beck, Lisa J., et al.
(författare)
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Differing Mechanisms of New Particle Formation at Two Arctic Sites
- 2021
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Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 48:4
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Tidskriftsartikel (refereegranskat)abstract
- New particle formation in the Arctic atmosphere is an important source of aerosol particles. Understanding the processes of Arctic secondary aerosol formation is crucial due to their significant impact on cloud properties and therefore Arctic amplification. We observed the molecular formation of new particles from low-volatility vapors at two Arctic sites with differing surroundings. In Svalbard, sulfuric acid (SA) and methane sulfonic acid (MSA) contribute to the formation of secondary aerosol and to some extent to cloud condensation nuclei (CCN). This occurs via ion-induced nucleation of SA and NH3 and subsequent growth by mainly SA and MSA condensation during springtime and highly oxygenated organic molecules during summertime. By contrast, in an ice-covered region around Villum, we observed new particle formation driven by iodic acid but its concentration was insufficient to grow nucleated particles to CCN sizes. Our results provide new insight about sources and precursors of Arctic secondary aerosol particles.
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| 7. |
- Grahn, Petra, et al.
(författare)
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Early disc degeneration in radiotherapy-treated childhood brain tumor survivors
- 2023
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Ingår i: BMC Musculoskeletal Disorders. - : BioMed Central (BMC). - 1471-2474. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundChildhood brain tumor (BT) survivors have an increased risk of treatment-related late effects, which can reduce health-related quality of life and increase morbidity. This study aimed to investigate lumbar disc degeneration in magnetic resonance imaging (MRI) in adult survivors of radiotherapy-treated childhood BT compared to age and sex-matched population controls.MethodsIn this cross-sectional comparative study, 127 survivors were identified from hospital registries. After a mean follow-up of 20.7 years (range 5-33.1), 67 survivors (mean age 28.4, range 16.2-43.5) were investigated with MRI and compared to 75 sex-matched population-based controls. Evaluated MRI phenotypes included Pfirrmann grading, , intervertebral disc protrusions, extrusions, and high-intensity-zone-lesions (HIZ). Groups were also compared for known risk factors of lumbar intervertebral disc (IVD) degeneration.ResultsChildhood BT survivors had higher Pfirrmann grades than controls at all lumbar levels (all p < 0.001). Lumbar disc protrusions at L4-5 (p = 0.02) and extrusions at L3-4 (p = 0.04), L4-5 (p = 0.004), and L5-S1 (p = 0.01) were significantly more common in the BT group compared to the control. The survivor cohort also had significantly more HIZ-lesons than the controls (n=13 and n=1, p=0.003). Age at diagnosis was associated with lower degree of IVD degeneration (p < 0.01). Blood pressure correlated with IVD degeneration (P < 0.05).ConclusionsSigns of early disc degeneration related to tumor treatment can be seen in the IVDs of survivors. Disc degeneration was more severe in children treated in adolescence.
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| 8. |
- Haapala, Hermanni, et al.
(författare)
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Surgical and Health-related Quality of life Outcomes in Children With Congenital Scoliosis During 5-year Follow-up. Comparison to Age and Sex-matched Healthy Controls
- 2023
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Ingår i: Journal of Pediatric Orthopaedics. - : Ovid Technologies (Wolters Kluwer Health). - 0271-6798 .- 1539-2570. ; 43:6, s. E451-E457
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Tidskriftsartikel (refereegranskat)abstract
- Background:Congenital spinal anomalies represent a heterogeneous group of spinal deformities, of which only progressive or severe curves warrant surgical management. Only a limited number of studies have investigated the impact of surgery on the health-related quality of life and very limited data exists comparing these outcomes to healthy controls.Methods:A single surgeon series of 67 consecutive children with congenital scoliosis (mean age at surgery 8.0 y, range: 1.0 to 18.3 y, 28 girls) undergoing hemivertebrectomy (n = 34), instrumented spinal fusion (n = 20), or vertical expandable prosthetic titanium rib procedure (n = 13) with a mean follow-up of 5.8 years (range: 2 to 13 y). The comparison was made to age and sex-matched healthy controls. Outcome measures included the Scoliosis Research Society questionnaire both pre and postoperatively, radiographic outcomes, and complications.Results:The average major curve correction was significantly better in the hemivertebrectomy (60%) and instrumented spinal fusion (51%) than in the vertical expandable prosthetic titanium rib group (24%), respectively (P < 0.001). Complications were noted in 8 of 67 (12%) children, but all patients recovered fully during follow-up. Pain, self-image, and function domains improved numerically from preoperative to final follow-up, but the pain score was the only one with a statistically significant change (P = 0.033). The Scoliosis Research Society pain, self-image, and function domain scores remained at a significantly lower level at the final follow-up than in the healthy controls (P <= 0.05), while activity scores improved to a similar level.Conclusions:Surgery for congenital scoliosis improved angular spinal deformities with a reasonable risk of complications. Health-related quality of life outcomes improved from preoperative to final follow-up, but especially pain and function domains remained at a significantly lower level than in the age and sex-matched healthy controls.
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| 9. |
- Helenius, Linda, et al.
(författare)
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Postoperative outcomes of pedicle screw instrumentation for adolescent idiopathic scoliosis with and without a subfascial wound drain: a multicentre randomized controlled trial
- 2022
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Ingår i: The Bone & Joint Journal. - : British Editorial Society of Bone & Joint Surgery. - 2049-4394 .- 2049-4408. ; 104-B:9, s. 1067-1072
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Tidskriftsartikel (refereegranskat)abstract
- AimsThe aim of this study was to evaluate whether, after correction of an adolescent idiopathic scoliosis (AIS), leaving out the subfascial drain gives results that are no worse than using a drain in terms of total blood loss, drop in haemoglobin level, and opioid consumption.MethodsAdolescents (aged between 10 and 21 years) with an idiopathic scoliosis (major curve ≥ 45°) were eligible for inclusion in this randomized controlled noninferiority trial (n = 125). A total of 90 adolescents who had undergone segmental pedicle screw instrumentation were randomized into no-drain or drain groups at the time of wound closure using the sealed envelope technique (1:1). The primary outcome was a drop in the haemoglobin level during first three postoperative days. Secondary outcomes were 48-hour postoperative oxycodone consumption and surgical complications.ResultsAll 90 patients were included in the primary outcome analysis (no drain = 43; drain = 47). The mean total postoperative blood loss (intraoperative and drain output) was significantly higher in the group with a subfascial drain than in the no-drain group (1,008 ml (SD 520) vs 631 ml (SD 518); p < 0.001). The drop in haemoglobin level did not differ between the study groups over the postoperative timepoints (p = 0.290). The 48-hour opioid consumption was significantly higher in the no-drain group (2.0 mg/kg (SD 0.9) vs 1.4 (SD 0.6); p = 0.005). Two patients in the no-drain and one patient in the drain group developed a surgical site infection.ConclusionLeaving the subfascial drain out after pedicle screw instrumentation for AIS is not associated with higher postoperative haemoglobin levels. Patients treated without a subfascial drain needed 30% more opioids during the first 48 hours than those who had a drain.
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| 10. |
- Henningsson, Johan, 1965-
(författare)
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Fund Managers as Cultured Observers
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- During the last few decades, Intellectual Capital (IC) has been recognized as an important resource in firms. In order to improve IC reporting, a number of guidelines have been initiated in Europe and in Japan. The capital market has been one important target group for these initiatives. However, actors on the capital market seem to be ambivalent towards IC information. They both demand and find such information useful, and at the same time, they seem to lack interest in it. This thesis contains five papers that aim to explore how actors on the capital market deal with IC information. A qualitative research approach is applied involving interviews with 14 fund managers in Stockholm. In the analysis of the data, fund managers are seen as ‘cultured observers’, meaning they are influenced by social forces when they observe IC information. Three social forces were identified as being imposed on the respondents. These forces represent social logics that are created in the relationship between the fund managers and · the organization in which they work · the market price and rationale · the agendas around certain companies The seemingly increased complexity of IC information does not always bother fund managers. The rationale of interacting social networks reduces this complexity in order for the information to make sense in their meaning-based reproduction. With respect to ethical funds, this thesis suggests that the rationales of the three social forces above do not seem to have changed in order to include social aspects. Instead, these aspects are taken care of elsewhere in organizations, leaving fund managers outside of their potential for compromising market rationales. Furthermore, fund managers tend to reduce the complexity of information concerning personnel and the working environment by depending on having the right management in organisations. This thesis contributes by increasing our understanding of how the social environment influences fund managers when they observe IC information. By regarding fund managers as ‘cultured observers’ it explores how complexity is dealt with, an approach that contrasts with assumptions within finance theory about profit maximizing actors. Here, the market price and rationale represent one social force among many.
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