| 1. |
- Bryois, J., et al.
(författare)
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Genetic identification of cell types underlying brain complex traits yields insights into the etiology of Parkinson’s disease
- 2020
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 52:5, s. 482-493
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies have discovered hundreds of loci associated with complex brain disorders, but it remains unclear in which cell types these loci are active. Here we integrate genome-wide association study results with single-cell transcriptomic data from the entire mouse nervous system to systematically identify cell types underlying brain complex traits. We show that psychiatric disorders are predominantly associated with projecting excitatory and inhibitory neurons. Neurological diseases were associated with different cell types, which is consistent with other lines of evidence. Notably, Parkinson’s disease was genetically associated not only with cholinergic and monoaminergic neurons (which include dopaminergic neurons) but also with enteric neurons and oligodendrocytes. Using post-mortem brain transcriptomic data, we confirmed alterations in these cells, even at the earliest stages of disease progression. Our study provides an important framework for understanding the cellular basis of complex brain maladies, and reveals an unexpected role of oligodendrocytes in Parkinson’s disease. © 2020, The Author(s), under exclusive licence to Springer Nature America, Inc.
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| 5. |
- Sikora, M., et al.
(författare)
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The population history of northeastern Siberia since the Pleistocene
- 2019
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 570:7760
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Tidskriftsartikel (refereegranskat)abstract
- Northeastern Siberia has been inhabited by humans for more than 40,000 years but its deep population history remains poorly understood. Here we investigate the late Pleistocene population history of northeastern Siberia through analyses of 34 newly recovered ancient genomes that date to between 31,000 and 600 years ago. We document complex population dynamics during this period, including at least three major migration events: an initial peopling by a previously unknown Palaeolithic population of 'Ancient North Siberians' who are distantly related to early West Eurasian hunter-gatherers; the arrival of East Asian-related peoples, which gave rise to 'Ancient Palaeo-Siberians' who are closely related to contemporary communities from far-northeastern Siberia (such as the Koryaks), as well as Native Americans; and a Holocene migration of other East Asian-related peoples, who we name 'Neo-Siberians', and from whom many contemporary Siberians are descended. Each of these population expansions largely replaced the earlier inhabitants, and ultimately generated the mosaic genetic make-up of contemporary peoples who inhabit a vast area across northern Eurasia and the Americas.
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| 6. |
- Hardarson, Johann P. P., et al.
(författare)
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Appraisals of Social Trauma and Their Role in the Development of Post-Traumatic Stress Disorder and Social Anxiety Disorder
- 2023
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Ingår i: Behavioral Sciences. - : MDPI. - 2076-328X. ; 13:7
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Tidskriftsartikel (refereegranskat)abstract
- Cognitive theories of post-traumatic stress disorder (PTSD) feature appraisal of trauma as a critical factor in the development and maintenance of the disorder. Here we explored appraisals of social trauma (severe rejection or humiliation). Participants were outpatients with social anxiety disorder (SAD) and clinically significant PTSD symptoms (PTSS) after social trauma (n = 15); two clinical control groups of either SAD (n = 32) or obsessive-compulsive disorder (OCD; n = 13); and a control group with no diagnoses (n = 38). Measures included a clinical interview to assess social trauma and related open-ended appraisals and the Posttraumatic Cognitions Inventory (PTCI). Raters blind to group assignment performed content analyses of appraisals. Results showed that the PTSS group scored significantly higher than either clinical group on the PTCI SELF subscale. Only the SELF subscale predicted a diagnosis of both PTSS and SAD. All but one PTSS participant reported primarily negative beliefs about their social trauma, and the most common categories were flawed self and others are critical or cruel. Post-traumatic appraisals implicated in the course of PTSD are significant in how individuals respond to social trauma, with negative self-cognitions linked to both PTSS and SAD.
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| 7. |
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| 8. |
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| 9. |
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| 10. |
- Maya-Gonzalez, C., et al.
(författare)
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Register-based and genetic studies of Prader-Willi syndrome show a high frequency of gonadal tumors and a possible mechanism for tumorigenesis through imprinting relaxation
- 2023
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Ingår i: Frontiers in medicine. - : Frontiers Media S.A.. - 2296-858X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Prader-Willi syndrome (PWS) is a rare disease caused by a lack of expression of inherited imprinted genes in the paternally derived Prader-Willi critical region on chromosome 15q11.2-q13. It is characterized by poor feeding and hypotonia in infancy, intellectual disability, behavioral abnormalities, dysmorphic features, short stature, obesity, and hypogonadism. PWS is not a known cancer predisposition syndrome, but previous investigations regarding the prevalence of cancer in these patients suggest an increased risk of developing specific cancer types such as myeloid leukemia and testicular cancer. We present the results from a Swedish national population-based cohort study of 360 individuals with PWS and 18,000 matched comparisons. The overall frequency of cancer was not increased in our PWS cohort, but we found a high frequency of pediatric cancers. We also performed whole-genome sequencing of blood- and tumor-derived DNAs from a unilateral dysgerminoma in a 13-year-old girl with PWS who also developed bilateral ovarian sex cord tumors with annular tubules. In germline analysis, there were no additional findings apart from the 15q11.2-q13 deletion of the paternal allele, while a pathogenic activating KIT mutation was identified in the tumor. Additionally, methylation-specific multiplex ligation-dependent probe amplification revealed reduced methylation at the PWS locus in the dysgerminoma but not in the blood. In conclusion, our register-based study suggests an increased risk of cancer at a young age, especially testicular and ovarian tumors. We found no evidence of a general increase in cancer risk in patients with PWS. However, given our limited observational time, further studies with longer follow-up times are needed to clarify the lifetime cancer risk in PWS. We have also described the second case of locus-specific loss-of-imprinting in a germ cell tumor in PWS, suggesting a possible mechanism of carcinogenesis.
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| 11. |
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| 13. |
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| 14. |
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| 15. |
- Das, Yadunandan, et al.
(författare)
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Quantitative Nanostructure and Hardness Evolution in Duplex Stainless Steels : Under Real Low-Temperature Service Conditions
- 2022
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Ingår i: Metallurgical and Materials Transactions. A. - : Springer Nature. - 1073-5623 .- 1543-1940. ; 53:2, s. 723-735
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Tidskriftsartikel (refereegranskat)abstract
- Duplex stainless steels are a group of widely used stainless steels, because of their attractive combination of strength and corrosion resistance. However, these steels embrittle because of a phase separation phenomenon in the ferrite phase when exposed to temperatures within the miscibility gap. This manuscript investigates the phase separation in two commercial stainless steels, the duplex stainless steel (DSS) 22Cr-5Ni (2205 or UNS S32205), and the super-duplex stainless steel (SDSS) 25Cr-7Ni (2507 or UNS S32750), and its subsequent effect on mechanical property evolution. Long-term isothermal aging heat treatments were carried out at industrially relevant temperatures between 250 °C and 350 °C for up to 48,000 hours, and quantitative measurements of the amplitude and wavelength of the phase separated nanostructure were obtained using Small-Angle Neutron Scattering (SANS). These quantifications were used as input parameters in hardness models to predict the hardness evolution. It is concluded that the quantitative information from SANS combined with these hardness models enables the prediction of hardness evolution in DSS at low temperatures, which in turn correlates with the embrittlement of the DSS.
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| 16. |
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| 17. |
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| 18. |
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| 19. |
- Hertzman, S., et al.
(författare)
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Nitrogen Solubility in Alloy Systems Relevant to Stainless Steels
- 2021
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Ingår i: Metallurgical and Materials Transactions. A. - : Springer Nature. - 1073-5623 .- 1543-1940. ; 52:9, s. 3811-3820
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Tidskriftsartikel (refereegranskat)abstract
- High-performance stainless steels are alloyed with nitrogen for several different reasons. For the austenitic grades, the kinetics of deleterious phase transformations are delayed, the strength is increased, and the corrosion resistance is improved. For duplex steels, the weldability and corrosion resistance depend directly on their nitrogen contents. Reliable databases are crucial for the development of new stainless steels and their processing. In order to calibrate the existing thermodynamic data, a series of experiments was undertaken. Several laboratory alloys in Fe–Cr–X systems, where X = Ni, Mn, Cu, were reacted with nitrogen gas at nitrogen activities 0.5 and 1 in the temperature range from 1050 °C to 1350 °C and subsequently analyzed for nitrogen solubility and phase constitution. A novel, simplified experimental technique was used, providing a dew point that is low enough to allow for fast nitrogen transport through the specimen surface, ensuring equilibrium conditions. The results are compared to thermodynamic equilibrium calculations.
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| 20. |
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| 21. |
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| 22. |
- Nilsson, Hanna, et al.
(författare)
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Risk of hernia formation after radical prostatectomy : a comparison between open and robot-assisted laparoscopic radical prostatectomy within the prospectively controlled LAPPRO trial
- 2022
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Ingår i: Hernia. - : Springer Science and Business Media LLC. - 1265-4906 .- 1248-9204. ; 26, s. 157-164
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: In addition to incisional hernia, inguinal hernia is a recognized complication to radical retropubic prostatectomy. To compare the risk of developing inguinal and incisional hernias after open radical prostatectomy compared to robot-assisted laparoscopic prostatectomy. Method: Patients planned for prostatectomy were enrolled in the prospective, controlled LAPPRO trial between September 2008 and November 2011 at 14 hospitals in Sweden. Information regarding patient characteristics, operative techniques and occurrence of postoperative inguinal and incisional hernia were retrieved using six clinical record forms and four validated questionnaires. Results: 3447 patients operated with radical prostatectomy were analyzed. Within 24 months, 262 patients developed an inguinal hernia, 189 (7.3%) after robot-assisted laparoscopic prostatectomy and 73 (8.4%) after open radical prostatectomy. The relative risk of having an inguinal hernia after robot-assisted laparoscopic prostatectomy was 18% lower compared to open radical retropubic prostatectomy, a non-significant difference. Risk factors for developing an inguinal hernia after prostatectomy were increased age, low BMI and previous hernia repair. The incidence of incisional hernia was low regardless of surgical technique. Limitations are the non-randomised setting. Conclusions: We found no difference in incidence of inguinal hernia after open retropubic and robot-assisted laparoscopic radical prostatectomy. The low incidence of incisional hernia after both procedures did not allow for statistical analysis. Risk factors for developing an inguinal hernia after prostatectomy were increased age and BMI.
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| 23. |
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| 24. |
- Ponten, E, et al.
(författare)
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A complex DICER1 syndrome phenotype associated with a germline pathogenic variant affecting the RNase IIIa domain of DICER1
- 2022
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Ingår i: Journal of medical genetics. - : BMJ. - 1468-6244 .- 0022-2593. ; 59:2, s. 141-146
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Tidskriftsartikel (refereegranskat)abstract
- Germline pathogenic variants in DICER1 cause DICER1 syndrome, an autosomal dominant, pleiotropic tumour predisposition syndrome with variable expressivity and reduced penetrance for specific dysplastic and neoplastic lesions. Recently, a syndrome with the acronym GLOW (Global developmental delay, Lung cysts, Overgrowth, Wilms tumour) was described in two children with mosaic missense mutations in hotspot residues of the DICER1 RNase IIIb domain.MethodsWhole genome sequencing, exome sequencing, Sanger sequencing, digital PCR and a review of Wilms tumours with DICER1 RNase III domain mutations were performed.ResultsA de novo heterozygous c.4031C>T (p.S1344L) variant in the sequence encoding the RNase IIIa domain of DICER1 was detected. Clinical investigations revealed a phenotype that resembles the GLOW subphenotype of DICER1 syndrome.ConclusionThe phenotypic overlap between patients with p.S1344L mutation and GLOW syndrome provide clinical support for recent discoveries that RNase IIIa-Ser1344 site mutations impede miRNA-5p biogenesis analogous to DICER1 hotspot mutations in the RNase IIIb domain. We show that an individual with a heterozygous germline p.S1344L mutation has a severe form of DICER1 syndrome (‘DICER1 syndrome plus’), with notable features of intellectual disability, macrocephaly, physical abnormalities, Wilms tumour and a well-differentiated fetal adenocarcinoma of the lung.
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| 25. |
- Wahlander, K., et al.
(författare)
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Risk of recurrent venous thromboembolism or bleeding in relation to thrombophilic risk factors in patients receiving ximelagatran or placebo for long-term secondary prevention of venous thromboembolism
- 2006
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Ingår i: Br J Haematol. - : Wiley. - 0007-1048 .- 1365-2141. ; 133:1, s. 68-77
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Tidskriftsartikel (refereegranskat)abstract
- The impact of prothrombotic abnormalities on the risk of recurrent venous thromboembolism (VTE) and bleeding in patients receiving long-term anticoagulation remains unclear. This analysis evaluated the influence of potential prothrombotic risk factors (antithrombin, protein C, protein S, factor V Leiden mutation, prothrombin gene G20210A mutation, cardiolipin antibodies, number of risk factors) on the risk of recurrent VTE or bleeding during treatment with oral ximelagatran (24 mg twice daily) or placebo for 18 months [THRombin Inhibitor in Venous thromboEmbolism (THRIVE) III trial]. Of the 1223 patients in the intention-to-treat population, prothrombotic state was analysed in 559 patients receiving ximelagatran and 540 patients receiving placebo. It is possible that patients at a high risk of recurrent VTE were poorly represented in this analysis because of selection bias. Prothrombotic risk factors were reported in 41% of patients (8% had > or = 2 factors). No significant interactions were found between ximelagatran treatment and potential prothrombotic risk factors for the risk of recurrent VTE or bleeding by Cox proportionate hazard modelling. There was no clear evidence for a higher risk of recurrent VTE or bleeding across subgroups according to the potential prothrombotic factors analysed in this study.
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| 26. |
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| 27. |
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| 28. |
- Andersson, L-O, et al.
(författare)
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A new neutron beam facility
- 2004
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Ingår i: Proc. of the 9th European Particle Accelerator Conference.
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Konferensbidrag (refereegranskat)
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| 29. |
- Baghdadchi, Amir, et al.
(författare)
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Effect of Ni content on 475°C embrittlement of directed energy deposited duplex stainless steel using a laser beam and wire feedstock
- 2024
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Ingår i: Materialia. - 2589-1529. ; 36
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Tidskriftsartikel (refereegranskat)abstract
- Duplex stainless steel (DSS), specifically the 2209 grade, is increasingly employed in additive manufacturing, particularly in processes like directed energy deposition using a laser beam with wire (DED-LB/w). However, a significant challenge arises when DSS faces brittleness within the temperature range of 250–500 °C. This study employs advanced characterization techniques, including atom probe tomography (APT) and transmission electron microscopy (TEM), to investigate DSS embrittlement after aging at 400 °C for up to 1000 h. The hardness analysis revealed that the higher Ni content in DED-LB/w-fabricated DSS cylinder promotes the age hardening compared to 2205 wrought DSS plate. Furthermore, APT and TEM demonstrated that, alongside the decomposition of ferrite into Fe-rich (α) and Cr-rich (αʹ) phases, clustering of Ni, Mn, and Si atoms contributes to the embrittlement. Although the Ni-Mn-Si-rich clusters could suggest nucleation of G-phase, the G-phase crystal structure was not observed by TEM. This might be attributed to the short aging time or limitations in the characterization technique. This work underscores the impact of characterization techniques on the measurement of spinodal decomposition, with APT providing capability of detecting nanometer sized clusters. By elucidating the complexities of 475 °C-embrittlement in DED-LB/w DSS, this study offers valuable insights for industrial applications and a deeper understanding of age hardening in duplex DSSs under specific manufacturing conditions.
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| 30. |
- Djos, Anna, 1983, et al.
(författare)
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Multifocal Neuroblastoma and Central Hypoventilation in An Infant with Germline ALK F1174I Mutation
- 2022
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Ingår i: Diagnostics. - : MDPI AG. - 2075-4418. ; 12:9
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Tidskriftsartikel (refereegranskat)abstract
- A preterm infant with central hypoventilation was diagnosed with multifocal neuroblastoma. Congenital anomalies of the autonomic nervous system in association with neuroblastoma are commonly associated with germline mutations in PHOX2B. Further, the ALK gene is frequently mutated in both familial and sporadic neuroblastoma. Sanger sequencing of ALK and PHOX2B, SNP microarray of three tumor samples and whole genome sequencing of tumor and blood were performed. Genetic testing revealed a germline ALK F11741 mutation that was present in all tumor samples as well as in normal tissue samples from the patient. Neither of the patient's parents presented the ALK variant. Array profiling of the three tumor samples showed that two of them had only numerical aberrations, whereas one sample displayed segmental alterations, including a gain at chromosome 2p, resulting in two copies of the ALK-mutated allele. Whole genome sequencing confirmed the presence of the ALK variant and did not detect any aberrations in the coding or promotor region of PHOX2B. This study is to our knowledge the first to report a de novo ALK F11741 germline mutation. This may not only predispose to congenital multifocal neuroblastoma but may also contribute to the respiratory dysfunction seen in this patient.
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| 31. |
- Hautakangas, H, et al.
(författare)
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Genome-wide analysis of 102,084 migraine cases identifies 123 risk loci and subtype-specific risk alleles
- 2022
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Ingår i: Nature genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 54:2, s. 152-
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Tidskriftsartikel (refereegranskat)abstract
- Migraine affects over a billion individuals worldwide but its genetic underpinning remains largely unknown. Here, we performed a genome-wide association study of 102,084 migraine cases and 771,257 controls and identified 123 loci, of which 86 are previously unknown. These loci provide an opportunity to evaluate shared and distinct genetic components in the two main migraine subtypes: migraine with aura and migraine without aura. Stratification of the risk loci using 29,679 cases with subtype information indicated three risk variants that seem specific for migraine with aura (in HMOX2, CACNA1A and MPPED2), two that seem specific for migraine without aura (near SPINK2 and near FECH) and nine that increase susceptibility for migraine regardless of subtype. The new risk loci include genes encoding recent migraine-specific drug targets, namely calcitonin gene-related peptide (CALCA/CALCB) and serotonin 1F receptor (HTR1F). Overall, genomic annotations among migraine-associated variants were enriched in both vascular and central nervous system tissue/cell types, supporting unequivocally that neurovascular mechanisms underlie migraine pathophysiology.
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| 32. |
- Laine, Christine M., et al.
(författare)
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A Novel Splice Mutation in PLS3 Causes X-linked Early Onset Low-Turnover Osteoporosis
- 2015
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Ingår i: Journal of Bone and Mineral Research. - : Wiley. - 0884-0431. ; 30:3, s. 437-445
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Tidskriftsartikel (refereegranskat)abstract
- Genetic factors play an important role in the development of osteoporosis. Several monogenic forms of osteoporosis have been recognized, most recently an X-chromosomal form resulting from mutations in the gene encoding plastin 3 (PLS3). PLS3 is a protein involved in actin bundle formation in the cytoskeleton. We present a large family with early onset osteoporosis and X-linked inheritance. Phenotyping was performed on 19 family members and whole-exome sequencing on 7 family members (5 with a diagnosis of early onset osteoporosis and 2 with normal bone parameters). Osteoporosis had its onset in childhood and was characterized by recurrent peripheral fractures, low bone mineral density (BMD), vertebral compression fractures, and significant height loss in adulthood. Males were in general more severely affected than females. Bone histomorphometry findings in 4 males and 1 female showed severe trabecular osteoporosis, low amount of osteoid, and decreased mineral apposition rate, indicating impaired bone formation; resorption parameters were increased in some. All affected subjects shared a single base substitution (c.73-24T>A) in intron 2 of PLS3 on Xq23. The mutation, confirmed by Sanger sequencing, segregated according to the skeletal phenotype. The mutation introduces a new acceptor splice site with a predicted splice score of 0.99 and, thereby, as confirmed by cDNA sequencing, induces the insertion of 22 bases between exons 2 and 3, causing a frameshift and premature termination of mRNA translation (p.Asp25Alafs(not asymptotic to)17). The mutation affects the first N-terminal calcium-binding EF-hand domain and abolishes all calcium-and actinbinding domains of the protein. Our results confirm the role of PLS3 mutations in early onset osteoporosis. The mechanism whereby PLS3 affects bone health is unclear, but it may be linked to osteocyte dendrite function and skeletal mechanosensing. Future studies are needed to elucidate the role of PLS3 in osteoporosis and to define optimal treatment. (C) 2014 American Society for Bone and Mineral Research.
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| 33. |
- Laine, Christine M., et al.
(författare)
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WNT1 Mutations in Early-Onset Osteoporosis and Osteogenesis Imperfecta
- 2013
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Ingår i: New England Journal of Medicine. - 0028-4793 .- 1533-4406. ; 368:19, s. 1809-1816
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Tidskriftsartikel (refereegranskat)abstract
- This report identifies human skeletal diseases associated with mutations in WNT1. In 10 family members with dominantly inherited, early-onset osteoporosis, we identified a heterozygous missense mutation in WNT1, c.652T -> G (p.Cys218Gly). In a separate family with 2 siblings affected by recessive osteogenesis imperfecta, we identified a homozygous nonsense mutation, c.884C -> A, p.Ser295(star). In vitro, aberrant forms of the WNT1 protein showed impaired capacity to induce canonical WNT signaling, their target genes, and mineralization. In mice, Wnt1 was clearly expressed in bone marrow, especially in B-cell lineage and hematopoietic progenitors; lineage tracing identified the expression of the gene in a subset of osteocytes, suggesting the presence of altered cross-talk in WNT signaling between the hematopoietic and osteoblastic lineage cells in these diseases.
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| 34. |
- Olsson, Bertil, et al.
(författare)
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Safety and tolerability of an immediate-release formulation of theoral direct thrombin inhibitor AZD0837 in the prevention of stroke and systemic embolism in patients with atrial fibrillation.
- 2010
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Ingår i: Thrombosis and Haemostasis. - 0340-6245. ; 103:Jan 13, s. 604-612
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Tidskriftsartikel (refereegranskat)abstract
- AZD0837 is an investigational oral anticoagulant which is converted to the active form, ARH067637, a selective direct thrombin inhibitor. The present study, a multicentre, randomised, parallel-group, dose-guiding study, assessed the safety and tolerability of an immediate-release formulation of AZD0837 compared with dose-adjusted warfarin in the prevention of stroke and systemic embolic events in atrial fibrillation (AF) patients. Two hundred fifty AF patients with at least one additional risk factor for stroke were randomised to receive either immediate-release AZD0837 (150mg twice daily [bid] or 350mg bid, blinded treatment) or dose-adjusted warfarin (international normalised ratio 2.0-3.0, open treatment) for three months. The safety and tolerability of 150mg bid AZD0837 appeared to be as good as that of warfarin. Total bleeding events were six with 150mg bid AZD0837, 15 with 350mg bid AZD0837, and eight with warfarin. Alanine aminotransferase elevations (>3xupper limit of normal) were infrequent, without apparent differences between treatment groups. A numerically higher incidence of serious adverse events was observed with 350mg bid AZD0837 compared with 150mg bid, with six of 13 being cardiac related, all with different diagnoses. An increase in mean serum creatinine of approximately 10% was observed in both AZD0837 groups, which returned to baseline after completion of therapy. There were no strokes, transient ischaemic attacks or cerebral haemorrhages with any of the treatments. In conclusion, the safety and tolerability of 150mg bid immediate-release AZD0837 appeared to be as good as that of dose-adjusted warfarin. However, larger studies will be needed to define the safety profile of AZD0837.
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| 35. |
- Pettersson, N., et al.
(författare)
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Nanostructure evolution and mechanical property changes during aging of a super duplex stainless steel at 300°C
- 2015
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Ingår i: Materials Science & Engineering. - : Elsevier. - 0921-5093 .- 1873-4936. ; 647, s. 241-248
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Tidskriftsartikel (refereegranskat)abstract
- The nanostructure evolution and the corresponding changes in mechanical properties of a super duplex stainless steel 2507 (UNS S32750) during aging at 300. °C up to 12,000. h have been investigated. Microstructural studies using transmission electron microscopy and atom probe tomography show that subtle Cr concentration fluctuations develop during aging. The amplitude of the concentration fluctuations is proportional to the hardness of the ferrite phase, and it is also proportional to the decrease in room temperature impact toughness during aging. The fracture behaviour of the alloy changes gradually from ductile to cleavage fracture, upon aging. The cracks were found to propagate through the ferrite phase, partly along deformation twin interfaces, and delamination between the austenite and ferrite phases was observed.
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| 36. |
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| 37. |
- Prokofiev, A. V, et al.
(författare)
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A new neutron beam facility at TSL
- 2006
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Ingår i: International workshop on Fast Neutron Detectors and Applications,Cape Town, South Africa, April 3-6. ; , s. 016-
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Konferensbidrag (refereegranskat)
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| 38. |
- Prokofiev, A.V, et al.
(författare)
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A new neutron facility for SEE testing
- 2005
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Ingår i: 8th European Conference on Radiation and its Effects on Components and systems, 2005, (in press).
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Konferensbidrag (refereegranskat)
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| 39. |
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| 40. |
- Prokofiev, A.V, et al.
(författare)
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A new neutron facility for single-event testing
- 2005
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Ingår i: IEEE International Reliability Physics Symposium (IRPS2005): San José, California, USA, April 17-21, 2005, (in press).
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Konferensbidrag (populärvet., debatt m.m.)
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| 41. |
- Romlin, Birgitta S, et al.
(författare)
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Perioperative monitoring of platelet function in paediatric cardiac surgery by thromboelastometry, or platelet aggregometry?
- 2016
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Ingår i: British Journal of Anaesthesia. - : Elsevier BV. - 0007-0912 .- 1471-6771. ; 116:6, s. 822-828
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Tidskriftsartikel (refereegranskat)abstract
- Background Impaired platelet function increases the risk of bleeding complications in cardiac surgery. Reliable assessment of platelet function can improve treatment. We investigated whether thromboelastometry detects clinically significant preoperative, perioperative, and postoperative adenosine diphosphate (ADP)-dependent platelet dysfunction in paediatric cardiac surgery patients. Methods Fifty-seven children were included in a single-centre prospective observational study. Clot formation (modified rotational thromboelastometry with heparinase, HEPTEM) and platelet aggregation (multiple electrode aggregometry) were analysed at five time points before, during, and after surgery. The accuracy of thromboelastometric indices of platelet function [maximal clot firmness (MCF) and clot formation time (CFT)] to detect ADP-dependent platelet dysfunction (defined as ADP-induced aggregation ≤30 units) was calculated with receiver operating characteristics analysis, which also identified optimal cut-off levels. Positive and negative predictive values for the identified cut-off levels (CFT≥166 s; MCF≤43 mm) to detect platelet function were determined. Results The MCF and CFT were highly accurate in predicting platelet dysfunction during cardiopulmonary bypass [CPB; area under the aggregation curve 0.89 (95% confidence interval 0.80–0.97) and 0.86 (0.77–0.96), respectively] but not immediately after CPB [0.64 (0.48–0.79) and 0.67 (0.52–0.82), respectively] or on arrival at the intensive care unit [0.53 (0.37–0.69) and 0.60 (0.44–0.77), respectively]. The positive and negative predictive values were acceptable during CPB (87 and 67%, respectively, for MCF≤43 mm; 80 and 100% for CFT≥166 s) but markedly lower after surgery. Conclusion In paediatric cardiac surgery, thromboelastometry has acceptable ability to detect ADP-dependent platelet dysfunction during, but not after, CPB.
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| 42. |
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| 44. |
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| 45. |
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| 46. |
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| 47. |
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| 48. |
- Wessman, S., et al.
(författare)
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Evaluation of Austenite Reformation in Duplex Stainless Steel Weld Metal using Computational Thermodynamics
- 2014
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Ingår i: Welding in the World. - : Springer Science and Business Media LLC. - 0043-2288 .- 1878-6669. ; 58:2, s. 217-224
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Tidskriftsartikel (refereegranskat)abstract
- This paper provides a theoretical study of austenite reformation during cooling of duplex stainless weld metal using computational thermodynamics and kinetics. Model alloys of the superduplex 2509 weld metal and 2205 base material were used for the study and austenite reformation was calculated at equilibrium conditions and at cooling rates from 0.01 to 2,000 K/s. The calculations also provided the possibility to study the distribution of the alloying elements at ferrite and austenite phase boundaries. The importance of nitrogen for austenite reformation at rapid cooling was studied by comparing with simulations for a low-nitrogen alloy. The results were also compared with experimental and model results from the literature providing good correlation and the unique possibility to study the distribution of alloying elements between the growing austenite and the shrinking ferrite.
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| 49. |
- Wessman, S
(författare)
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Evaluation of the WRC 1992 diagram using computational thermodynamics
- 2013
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Ingår i: Welding in the World. - : Springer Science and Business Media LLC. - 0043-2288 .- 1878-6669. ; 57:3, s. 305-314
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Tidskriftsartikel (refereegranskat)abstract
- Ferrite content of a stainless steel weld metal is a vital parameter for ensuring that the microstructure and thus also corrosion and mechanical properties are adequate. A rapid way of estimating ferrite content and thus microstructure is by using weld metal composition and a Welding Research Council (WRC)-1992 diagram. The ferrite-forming alloying elements are estimated to a chromium equivalent, the austenitic to a nickel equivalent and the ferrite content is estimated by help of isoferrite lines. This diagram was derived by empirical work on a large number of commercial and laboratory stainless weld metals covering a wide alloy span. The present paper uses computational thermodynamics, i.e. Thermo-Calc, to evaluate the influence of temperature and key stainless alloying elements. The alloying range for duplex stainless weld metal was studied and the WRC 1992 diagram was compared with results from calculations. The chromium and nickel equivalents were evaluated and coefficients for Mo, Nb, C, N and Cu assessed. The results showed that while the coefficients for Mo and N proved accurate, the values for Nb, C and Cu would require an adjustment. Alternative diagrams with adjusted chromium and nickel equivalents and iso-ferrite lines in both ferrite numbers and volume percent were suggested.
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- Wessman, Sten, et al.
(författare)
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On Phase Equilibria in Duplex Stainless Steels
- 2010
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Ingår i: STEEL RES INT. - : Wiley. - 1611-3683 .- 1869-344X. ; 81:5, s. 337-346
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Tidskriftsartikel (refereegranskat)abstract
- The equilibrium conditions of four duplex stainless steels; Fe-23Cr-4.5Ni-0.1N, Fe-22Cr-5.5Ni-3Mo-0.17N, Fe-25Cr-7Ni-4Mo-0.27N and Fe-25Cr-7Ni-4Mo-1W-1.5Cu-0.27N were studied in the temperature region from 700 to 1000 degrees C. Phase compositions were determined with SEM EDS and the phase fractions using image analysis on backscattered SEM images. The results showed that below 1000 degrees C the steels develop an inverse duplex structure with austenite and sigma phase, of which the former is the matrix phase. With decreasing temperature, the microstructure will be more and more complex and finely dispersed. The ferrite is, for the higher alloyed steels, only stable above 1000 degrees C and at lower temperatures disappears in favour of intermetallic phases. The major intermetallic phase is sigma phase with small amounts of chi phase, the latter primarily in high Mo and W grades. Nitrides, not a focus in this investigation, were present as rounded particles and acicular precipitates at lower temperatures. The results were compared to theoretical predictions using the TCFE5 and TCFE6 databases.
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