| 1. |
- André, Benny
(författare)
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Nanocomposites for Use in Sliding Electrical Contacts
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis nanocomposite materials for use in high performance electrical contacts are tested. Self mating silver as coatings on cupper substrates are the most used material combination in power connectors today. In this work two new concepts were tested. The first one was to change one of the mating surfaces to a hard thin coating and keep the other surface made of silver. Tested coatings were nanocomposites with hard carbides in a matrix of amorphous carbon. TiC/a-C and Ti-Ni-C/a-C were tested both electrically and tribologically. The total amount of carbon and the amount of carbon matrix was important, both for the electrical and the tribological properties. The Ti-Ni-C coating also showed that substituting Ti in TiC with the weak carbide former Ni changed the stability of the carbides. The substitution resulted in more a-C matrix and less C in the carbides. Thin coatings of nc-TiC/a-C and Ti-Ni-C/a-C showed high potential as material candidates for use in electrical contacts. The other tested concept was to modify the used silver instead of replacing it. This was done by embedding nanoparticles of solid lubricant IF-WS2 in the silver. The results from reciprocating sliding displayed low friction and high wear resistance. The modified silver surfaces lasted for 8000 strokes with a friction of about 0.3 while at the same time allowing for a low contact resistance. The results for surfaces of pure silver coating displayed a friction of 0.8-1.2 and that the silver was worn through already after 300 strokes. A new method to investigate inherent hardness and residual stress of thin coatings, on complex geometries or in small areas, was also developed. An ion beam was used to create stress free coating as free standing micro pillars. Hardness measured on the pillars and on as-deposited coating were then used to calculate the residual stress in the coatings.
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| 2. |
- Arnaiz, Aitor, et al.
(författare)
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A New Integrated E-maintenance Concept
- 2010. - 1
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Ingår i: E-maintenance. - London : Springer. - 9781849962049 - 9781849962056 ; , s. 61-82
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Bokkapitel (refereegranskat)abstract
- This chapter outlines the work done in Dynamite project (http://DYNAMITE.vtt.fi), as well as the resulting concept nicknamed as DynaWeb. DynaWeb represents the link between Dynamite and the e-maintenance technologies described in previous chapters and results in a global framework where all technologies can participate within an advanced maintenance solution.This chapter serves as an introduction to the rest of the chapters dealing with specific technologies that have been converted into ‘capabilities’, such as intelligent sensors, wireless communications, intelligent web services or smart PDAs, as well as to the final demonstrations
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| 3. |
- Beral, Valerie, et al.
(författare)
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The number of women who would need to be screened regularly by mammography to prevent one death from breast cancer
- 2011
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Ingår i: Journal of medical screening. - : SAGE Publications. - 1475-5793 .- 0969-1413. ; 18:4, s. 210-212
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Tidskriftsartikel (refereegranskat)abstract
- The number of women who would need to be screened regularly by mammography to prevent one death from breast cancer depends strongly on several factors, including the age at which regular screening starts, the period over which it continues, and the duration of follow-up after screening. Furthermore, more women would need to be INVITED for screening than would need to be SCREENED to prevent one death, since not all women invited attend for screening or are screened regularly. Failure to consider these important factors accounts for many of the major discrepancies between different published estimates. The randomised evidence indicates that, in high income countries, around one breast cancer death would be prevented in the long term for every 400 women aged 50-70 years regularly screened over a ten-year period.
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| 4. |
- Bjerg, Anders, 1982, et al.
(författare)
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Increase in pollen sensitization in Swedish adults and protective effect of keeping animals in childhood
- 2016
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Ingår i: Clinical and Experimental Allergy. - : Wiley. - 0954-7894 .- 1365-2222. ; 46:10, s. 1328-1336
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: To date, most studies of the "allergy epidemic" have been based on self-reported data. There is still limited knowledge on time trends in allergic sensitization, especially among adults.OBJECTIVE: To study allergic sensitization, its risk factors, and time trends in prevalence.METHODS: Within West Sweden Asthma Study (WSAS) a population-based sample of 788 adults (17-60y) underwent skin prick tests (SPT) for 11 aeroallergens 2009-2012. Specific IgE was analyzed in 750 of the participants. Those aged 20-46y (n=379) were compared with the European Community Respiratory Health Survey sample aged 20-46y from the same area (n=591) in 1991-1992.RESULTS: Among those aged 20-46y the prevalence of positive SPT to pollen increased; timothy from 17.1% to 29.0% (p<0.001) and birch from 15.6% to 23.7% (p=0.002) between 1991-1992 and 2009-2012. Measurements of specific IgE confirmed these increases. Prevalence of sensitization to all other tested allergens was unchanged. In the full WSAS sample aged 17-60y any positive SPT was seen in 41.9%, and the dominating sensitizers were pollen (34.3%), animals (22.8%) and mites (12.6%). Pollen sensitization was strongly associated with rhinitis, whereas indoor allergens were more associated with asthma. Growing up with livestock or furred pets decreased the risk of sensitization, adjusted odds ratio 0.53 (0.28-0.995) and 0.68 (0.47-0.98) respectively.CONCLUSION: Pollen sensitization has increased in Swedish adults since the early 1990's, while the prevalence of sensitization to other allergens has remained unchanged. This is one plausible explanation for the increase in rhinitis 1990-2008 in Swedish adults, during which time the prevalence of asthma, which is more associated with perennial allergens, was stable. Contact with animals in childhood seems to reduce the risk of sensitization well into adulthood. One major factor contributing to the rise in pollen allergy is a significant increase in levels of birch and grass pollen over the past three decades.
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| 5. |
- Bohman, Anton, et al.
(författare)
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Heredity of nasal polyps.
- 2015
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Ingår i: Rhinology. - 0300-0729. ; 53:1, s. 25-8
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Tidskriftsartikel (refereegranskat)abstract
- Nasal polyps is a common disease but little is known about its` pathogenesis. Our hypothesis was that there are genetic factors involved in the development of this disease. The aim of this study was to examine close relatives of patients with nasal polyps and comparing them with a general population with regard to prevalence of polyps.
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| 6. |
- Bohman, Anton, et al.
(författare)
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Heredity of nasal polyps
- 2015
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Ingår i: Rhinology. - 0300-0729 .- 1996-8604. ; 53:1, s. 25-28
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Tidskriftsartikel (refereegranskat)abstract
- Background: Nasal polyps is a common disease but little is known about its' pathogenesis. Our hypothesis was that there are genetic factors involved in the development of this disease. The aim of this study was to examine close relatives of patients with nasal polyps and comparing them with a general population with regard to prevalence of polyps. Methodology: Patients with nasal polyps who attended the clinic were recruited to the study and were asked whether they had any close adult relatives (siblings, parents or children). We intended to recruit two relatives per patient, one of each gender, for nasal endoscopy. The prevalence of nasal polyps in these relatives was compared with the prevalence of nasal polyps in a general population. Results: During a 4-year period, 368 patients and 410 relatives were recruited to the study. Although we were unable to recruit two close relatives for every patient, we were able to calculate nasal polyp prevalence within families as being 19.2%. Compared with the prevalence of nasal polyps among individuals in a general Swedish population from the same geographical area, the relative risk for polyps among relatives was almost five times higher. Conclusion: This study strongly indicates that heredity is a factor of importance for development of nasal polyps.
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| 7. |
- Bohman, Anton, et al.
(författare)
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Relative frequencies of symptoms and risk factors among patients with chronic rhinosinusitis with nasal polyps using a case-control study
- 2018
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Ingår i: Acta Oto-Laryngologica. - : TAYLOR & FRANCIS LTD. - 0001-6489 .- 1651-2251. ; 138:1, s. 46-49
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The aim of this study was to investigate the relative frequency of important symptoms of chronic rhinosinusitis with nasal polyps (CRSwNP), the link between CRSwNP and the lower airways and the importance of smoking in CRSwNP.Method: Three hundred and sixty-eight patients with CRSwNP and 1349 controls were recruited to the study and underwent a structured interview about symptoms from the upper and lower airways, and about smoking habits. Furthermore, all participants were clinically examined using nasal endoscopy.Results: Due to interactions between the outcome variables, a multiple logistic regression model was fitted to the data. Nasal secretions, nasal blockage and impaired sense of smell were symptoms associated with CRSwNP. Furthermore, male gender, increasing age and asthma were also associated with the disease. Current smoking was less frequent among patients with CRSwNP.Conclusion: By comparing symptoms and risk factors of patients with CRSwNP with those of a large population-based control group and testing them in a multiple logistic regression model, we have been able to generate data that address key research interests in CRSwNP.
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| 8. |
- Collins, Ruairi, et al.
(författare)
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Biochemical discrimination between selenium and sulfur 1 : a single residue provides selenium specificity to human selenocysteine lyase
- 2012
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Ingår i: PLoS One. - Stockholm : Karolinska Institutet, Dept of Medical Biochemistry and Biophysics. - 1932-6203.
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Tidskriftsartikel (refereegranskat)abstract
- Selenium and sulfur are two closely related basic elements utilized in nature for a vast array of biochemical reactions. While toxic at higher concentrations, selenium is an essential trace element incorporated into selenoproteins as selenocysteine (Sec), the selenium analogue of cysteine (Cys). Sec lyases (SCLs) and Cys desulfurases (CDs) catalyze the removal of selenium or sulfur from Sec or Cys and generally act on both substrates. In contrast, human SCL (hSCL) is specific for Sec although the only difference between Sec and Cys is the identity of a single atom. The chemical basis of this selenium-over-sulfur discrimination is not understood. Here we describe the X-ray crystal structure of hSCL and identify Asp146 as the key residue that provides the Sec specificity. A D146K variant resulted in loss of Sec specificity and appearance of CD activity. A dynamic active site segment also provides the structural prerequisites for direct product delivery of selenide produced by Sec cleavage, thus avoiding release of reactive selenide species into the cell. We thus here define a molecular determinant for enzymatic specificity discrimination between a single selenium versus sulfur atom, elements with very similar chemical properties. Our findings thus provide molecular insights into a key level of control in human selenium and selenoprotein turnover and metabolism.
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| 9. |
- Cornell, Robert F, et al.
(författare)
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Maintenance versus Induction Therapy Choice on Outcomes after Autologous Transplantation for Multiple Myeloma
- 2017
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Ingår i: Biology of blood and marrow transplantation. - : Elsevier BV. - 1083-8791 .- 1523-6536. ; 23:2, s. 269-277
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Tidskriftsartikel (refereegranskat)abstract
- Bortezomib (V), lenalidomide (R), cyclophosphamide (C), and dexamethasone (D) are components of the most commonly used modern doublet (RD, VD) or triplet (VRD, CVD) initial induction regimens before autologous hematopoietic cell transplantation (AHCT) for multiple myeloma (MM) in the United States. In this study we evaluated 693 patients receiving "upfront" AHCT after initial induction therapy with modern doublet or triplet regimens using data reported to the Center for International Blood and Marrow Transplant Research from 2008 to 2013. Analysis was limited to those receiving a single AHCT after 1 line of induction therapy within 12 months from treatment initiation for MM. In multivariate analysis, progression-free survival (PFS) and overall survival were similar irrespective of induction regimen. However, high-risk cytogenetics and nonreceipt of post-transplant maintenance/consolidation therapy were associated with higher risk of relapse. Patients receiving post-transplant therapy had significantly improved 3-year PFS versus no post-transplant therapy (55% versus 39%, P = .0001). This benefit was most evident in patients not achieving at least a complete response post-AHCT (P = .005). In patients receiving upfront AHCT, the choice of induction regimen (doublet or triplet therapies) appears to be of lower impact than use of post-transplant therapy.
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| 10. |
- Dhakal, Binod, et al.
(författare)
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Hematopoietic cell transplantation utilization and outcomes for primary plasma cell leukemia in the current era
- 2020
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Ingår i: Leukemia. - : SPRINGERNATURE. - 0887-6924 .- 1476-5551. ; 34:12, s. 3338-3347
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Tidskriftsartikel (refereegranskat)abstract
- The outcomes of patients with primary plasma cell leukemia (pPCL) after undergoing hematopoietic cell transplantation (HCT) in the novel agent era are unknown. We report outcomes of 348 patients with pPCL receiving autologous (auto-) HCT (n = 277) and allogeneic (allo-) HCT (n = 71) between 2008 and 2015. Median age was 60 years and 56 years for auto- and allo-HCT respectively. For auto-HCT, the 4-year outcomes were: non-relapse mortality (NRM) 7% (4-11%), relapse (REL) 76% (69-82%), progression-free survival (PFS) 17% (13-23%), and overall survival (OS) 28% (22-35%). Karnofsky performance status (KPS) > 90 and >= very good partial response (VGPR) predicted superior OS in multi-variate analysis for auto-HCT. For allo-HCT, the 4-year outcomes were: NRM 12% (5-21%), REL 69% (56-81%), PFS 19% (10-31%), and OS 31% (19-44%). Compared with prior CIBMTR pPCL patients (1995-2006), inferior survival was noted in the current cohort (3-year OS, 39% vs. 38% in allo-HCT, and 62% vs. 35% in auto-HCT) respectively. However, we noted an increased HCT utilization, from 12% (7-21%) in 1995 to 46% (34-64%) in 2009 using SEER data (available till 2009). Despite modern induction translating to higher proportion receiving HCT, the outcomes remain poor in pPCL patients, mainly derived by high relapse rates post-HCT.
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