| 1. |
- Engel, C., et al.
(author)
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Association of the variants CASP8 D302H and CASP10 V410I with breast and ovarian cancer risk in BRCA1 and BRCA2 mutation carriers
- 2010
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In: Cancer Epidemiology, Biomarkers and Prevention. - : American Association for Cancer Research. - 1055-9965 .- 1538-7755. ; 19:11, s. 2859-2868
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Journal article (peer-reviewed)abstract
- Background: The genes caspase-8 (CASP8) and caspase-10 (CASP10) functionally cooperate and play a key role in the initiation of apoptosis. Suppression of apoptosis is one of the major mechanisms underlying the origin and progression of cancer. Previous case-control studies have indicated that the polymorphisms CASP8 D302H and CASP10 V410I are associated with a reduced risk of breast cancer in the general population.Methods: To evaluate whether the CASP8 D302H (CASP10 V410I) polymorphisms modify breast or ovarian cancer risk in BRCA1 and BRCA2 mutation carriers, we analyzed 7,353 (7,227) subjects of white European origin provided by 19 (18) study groups that participate in the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). A weighted cohort approach was used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI).Results: The minor allele of CASP8 D302H was significantly associated with a reduced risk of breast cancer (per-allele HR, 0.85; 95% CI, 0.76-0.97; Ptrend = 0.011) and ovarian cancer (per-allele HR, 0.69; 95% CI, 0.53-0.89; Ptrend = 0.004) for BRCA1 but not for BRCA2 mutation carriers. The CASP10 V410I polymorphism was not associated with breast or ovarian cancer risk for BRCA1 or BRCA2 mutation carriers.Conclusions: CASP8 D302H decreases breast and ovarian cancer risk for BRCA1 mutation carriers but not for BRCA2 mutation carriers.Impact: The combined application of these and other recently identified genetic riskmodifiers could in the future allow better individual risk calculation and could aid in the individualized counseling and decision making with respect to preventive options in BRCA1 mutation carriers.
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| 2. |
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| 3. |
- De Abreu Goes, Jesus, 1989, et al.
(author)
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Correlation between Vehicle- and Rapid- Aged Commercial Lean NOx Trap Catalysts
- 2017
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In: SAE International Journal of Engines. - : SAE International. - 1946-3944 .- 1946-3936. ; 10:4, s. 1613-1626
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Conference paper (other academic/artistic)abstract
- Even though substantial improvements have been made for the lean NOx trap (LNT) catalyst in recent years, the durability still remains problematic because of the sulfur poisoning and sintering of the precious metals at high operating temperatures. Hence, commercial LNT catalysts were aged and tested in order to investigate their performance and activity degradation compared to the fresh catalyst, and establish a proper correlation between the aging methods used. The target of this study is to provide useful information for regeneration strategies and optimize the catalyst management for better performance and durability. With this goal in mind, two different aging procedures were implemented in this investigation. A catalyst was vehicle-aged in the vehicle chassis dynamometer for 100000 km, thus exposed to real conditions. Whereas, an accelerated aging method was used by subjecting a fresh LNT catalyst at 800 °C for 24 hours in an oven under controlled conditions. Engine dynamometer studies were performed with a Volvo mid-sized diesel engine with the purpose of testing the NOx storage and reduction performance, as well as the THC and CO conversion activity of the catalysts under controlled conditions. The aged catalysts activity was shown to be significantly degraded, mainly at low working temperatures compared to the fresh LNT, and one reason for this could be limited NO oxidation. In addition, the oven-aged sample was found to be well correlated to the vehicle-aged catalyst. On top of that, several vehicle emission cycles were carried out in the vehicle chassis dynamometer with a 2.0 l Volvo XC90 diesel vehicle in order to study the catalysts performance under real driving conditions and monitor the gradual deterioration of the vehicle-aged catalyst during the vehicle aging testing.
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| 4. |
- De Abreu Goes, Jesus, 1989, et al.
(author)
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Detailed Characterization Studies of Vehicle and Rapid Aged Commercial Lean NOx Trap Catalysts
- 2018
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In: Industrial & Engineering Chemistry Research. - : American Chemical Society (ACS). - 1520-5045 .- 0888-5885. ; 57:29, s. 9362-9373
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Journal article (peer-reviewed)abstract
- Commercial lean NOxtrap (LNT) catalysts were aged and characterized to elucidate the effect of aging on their performances and examine the deactivation of a rapid-aged catalyst toward an improved correlation with respect to a vehicle-aged catalyst. Detailed characterization studies were carried out on the flow reactor with small cylindrical cores extracted from the commercial LNT catalysts. Physicochemical characterization techniques were also implemented. The catalyst evaluation revealed that aging resulted in a significant deterioration of NOxstorage and reduction functions as a consequence of precious metal sintering, loss of surface area of the NOxstorage and support materials, phase transitions of the adsorber compounds, and large accumulation of poison species. Among the aged samples examined, the middle (lengthwise) vehicle-aged sample showed the highest NOxconversion, while the oven-aged catalyst was the most active of the aged samples for water gas shift reaction and oxygen storage.
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| 5. |
- De Abreu Goes, Jesus, 1989, et al.
(author)
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Sulfur Poisoning Effects on Modern Lean NOx Trap Catalysts Components
- 2019
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In: Catalysts. - : MDPI AG. - 2073-4344. ; 9:6
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Journal article (peer-reviewed)abstract
- In the present work, a series of different materials was investigated in order to enhance the understanding of the role of modern lean NOx trap (LNT) components on the sulfur poisoning and regeneration characteristics. Nine different types of model catalysts were prepared, which mainly consisted of three compounds: (i) Al2O3, (ii) Mg/Al2O3, and (iii) Mg/Ce/Al2O3 mixed with Pt, Pd, and Pt-Pd. A micro flow reactor and a diffuse reflectance infrared Fourier transform spectrometer (DRIFTS) were employed in order to investigate the evolution and stability of the species formed during SO2 poisoning. The results showed that the addition of palladium and magnesium into the LNT formulation can be beneficial for the catalyst desulfation due mainly to the ability to release the sulfur trapped at relatively low temperatures. This was especially evident for Pd/Mg/Al2O3 model catalyst, which demonstrated an efficient LNT desulfation with low H-2 consumption. In contrast, the addition of ceria was found to increase the formation of bulk sulfate species during SO2 poisoning, which requires higher temperatures for the sulfur removal. The noble metal nature was also observed to play an important role on the SOx storage and release properties. Monometallic Pd-based catalysts exhibited the formation of surface palladium sulfate species during SO2 exposure, whereas Pt-Pd bimetallic formulations presented higher stability of the sulfur species formed compared to the corresponding Pt- and Pd-monometallic samples.
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| 6. |
- Ding, Yuan C, et al.
(author)
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A nonsynonymous polymorphism in IRS1 modifies risk of developing breast and ovarian cancers in BRCA1 and ovarian cancer in BRCA2 mutation carriers
- 2012
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In: Cancer Epidemiology, Biomarkers and Prevention. - : American Association for Cancer Research. - 1055-9965 .- 1538-7755. ; 21:8, s. 1362-1370
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Journal article (peer-reviewed)abstract
- BACKGROUND: We previously reported significant associations between genetic variants in insulin receptor substrate 1 (IRS1) and breast cancer risk in women carrying BRCA1 mutations. The objectives of this study were to investigate whether the IRS1 variants modified ovarian cancer risk and were associated with breast cancer risk in a larger cohort of BRCA1 and BRCA2 mutation carriers.METHODS: IRS1 rs1801123, rs1330645, and rs1801278 were genotyped in samples from 36 centers in the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). Data were analyzed by a retrospective cohort approach modeling the associations with breast and ovarian cancer risks simultaneously. Analyses were stratified by BRCA1 and BRCA2 status and mutation class in BRCA1 carriers.RESULTS: Rs1801278 (Gly972Arg) was associated with ovarian cancer risk for both BRCA1 (HR, 1.43; 95% confidence interval (CI), 1.06-1.92; P = 0.019) and BRCA2 mutation carriers (HR, 2.21; 95% CI, 1.39-3.52, P = 0.0008). For BRCA1 mutation carriers, the breast cancer risk was higher in carriers with class II mutations than class I mutations (class II HR, 1.86; 95% CI, 1.28-2.70; class I HR, 0.86; 95%CI, 0.69-1.09; P(difference), 0.0006). Rs13306465 was associated with ovarian cancer risk in BRCA1 class II mutation carriers (HR, 2.42; P = 0.03).CONCLUSION: The IRS1 Gly972Arg single-nucleotide polymorphism, which affects insulin-like growth factor and insulin signaling, modifies ovarian cancer risk in BRCA1 and BRCA2 mutation carriers and breast cancer risk in BRCA1 class II mutation carriers.Impact: These findings may prove useful for risk prediction for breast and ovarian cancers in BRCA1 and BRCA2 mutation carriers.
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| 7. |
- Fathali, A., et al.
(author)
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A comparison of fuel-cut ageing during retardation and fuel-cut during acceleration
- 2014
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In: SAE Technical Papers. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191 .- 2688-3627. ; 1
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Journal article (peer-reviewed)abstract
- The effect of various fuel-cut agings, on a Volvo Cars 4-cylinder gasoline engine, with bimetallic three-way catalysts (TWCs) was examined. Deactivation during retardation fuel-cut (low load) and acceleration fuel-cut (high load, e.g. gearshift or traction control) was compared to aging at =1. Three-way catalysts were aged on an engine bench comparing two fuel-cut strategies and their impact on of the life and performance of the catalysts. In greater detail, the catalytic activity, stability and selectivity were studied. Furthermore, the catalysts were thoroughly analyzed using light-off and oxygen storage capacity measurements. The emission conversion as a function of various lambda values and loads was also determined. Fresh and 40-hour aged samples showed that the acceleration fuel-cut was the strategy that had the highest contribution towards the total deactivation of the catalyst system. Also, the retardation fuel-cut was found to be detrimental to the catalyst system but not to the same extent as an acceleration fuel-cut. During the aging procedure, exotherms were observed at the fuel-cut and the intensity of these exotherms was increasing with the length of aging time. The growing exotherms could be explained by the decomposition of HC into C and H2 and their subsequent oxidation at lean conditions. Also, the fuel-cut-off temperature measurements demonstrated that the magnitude of those exotherms was related to the total number as opposed to the total length of the fuel-cut. Copyright © 2014 SAE International.
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| 8. |
- Kristoffersson, Annika, 1963
(author)
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Water-based Tape Casting of Ceramics and Fabrication of Ceramic Laminates
- 1999
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Doctoral thesis (other academic/artistic)abstract
- The objective of the work presented in this dissertation has been twofold: to develop a water-based system for tape casting and to build laminar structures from the tapes. A set of requirements on the binder was specified and latexes were identified as suitable for water-based tape casting, mainly owing to their low viscosity and high polymeric content. A systematic approach was used to evaluate different formulations throughout the processing chain to find possibilities and limitations. Rheological measurements were used to characterise stability and flow behaviour of the suspensions and to study interactions between constituents in the suspension. The effect of the dispersant concentration was studied. It was found that, below optimum dosage, i.e. monolayer coverage, bridging flocculation can occur and the dispersant can adsorb onto latex particles. Tape casting experiments were done to investigate possible casting rates, resulting thickness and the thickness at which spontaneous cracking occurs. The cast tapes were then evaluated with regard to their quality, green density and homogeneity. It has been shown in this work that very high solids loading (> 55 vol%) can be reached in alumina systems thanks to efficient dispersants and latex binders with a high polymeric content. This in combination with an efficient drying system of the tape caster enabled high casting rates to be reached. The lowest viscous formulations also gave tapes thicker than 0.5 mm without cracking. Significant differences between binders were observed in this work. For example, in a comparison between anionic and nonionic latexes, the nonionic latex gave a more homogeneous packing of the green tape and higher final density. In the anionically stabilised latexes, phase separation between surfactant and polymer occurred, creating pore channels in the tape. The work on laminar structures focused mainly on ceramic laminates with crack deflecting ability. These types of structures have been shown to be more damage tolerant and to have superior thermal shock resistance. Examples of laminates of this type are SiC/graphite and dense/porous laminates of alumina or SiC using fugitive particles. A technique for fabricating the latter type of laminates was developed in this work. The composite is a laminate of alternating porous and dense layers of the same material. To be able to co-sinter these types of layers, it is necessary that the added fugitive particles do not affect the stability of the suspension, i.e. the packing of the ceramic matrix in the layers should be the same. Hereby the dense and porous layers sinter with the same total shrinkage, and the fugitive particles (mainly starch particles) leave voids too large to sinter themselves and will shrink only by the same amount as the surrounding matrix, leaving porosity. The advantage of such a composite is that no chemical reaction or thermal mismatch is present between the layers. During casting, when the suspension passes under the casting blade, the shearing can cause particles and polymer to be oriented in the direction of the flow. This can be used deliberately to enhance mechanical, electrical or thermal properties. However, it can also cause sintering anisotropy, making close dimensional tolerances difficult to control. The conditions that give rise to shrinkage anisotropy were studied. Water-based systems were shown to be on a par with or better than organic solvent-based systems. A desirable particle orientation benefits from a high volume fraction, elongated or plate-like particles and a high shear rate. This was exploited in making a laminate structure with alternating porous and dense layers from a coarse low sinterability powder and a fine plate-like powder for the respective layers.
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| 9. |
- Kristoffersson, E., et al.
(author)
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Communication ability and communication methods in children with cerebral palsy
- 2020
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In: Developmental Medicine and Child Neurology. - : Wiley. - 0012-1622 .- 1469-8749. ; 62:8, s. 933-938
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Journal article (peer-reviewed)abstract
- Aim To investigate if communication ability and method were related to each other and to age, sex, gross motor function, or manual ability in children with cerebral palsy. Method This cross-sectional study used data registered in the Swedish Cerebral Palsy Surveillance Program registry, involving 3000 children aged 0 to 18 years. Pearson's chi(2) test and Spearman's correlation were used to test associations between variables. Results Communication ability and method were related to each other and to age, gross motor function, and manual ability. Aided communication methods were more frequently used among older children. The more functional the communication was, the less use of unaided communication occurred. Different communication methods were used across all Communication Function Classification System (CFCS) levels. Speech was most common in more functional levels, used by 72% of the children. Forty-five per cent were considered effective communicators in all environments. For classification of communication level and method, some recurring registration errors were made by the raters. Interpretation Some raters may need clarification on interpretations of CFCS instructions. Results indicate that children should be presented to aided augmentative and alternative communication and manual signs earlier and to a greater extent.
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| 10. |
- Liu, Chengxi, 1987-, et al.
(author)
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Skattning av ruttvalsmodell för cykel för svenska förhållanden (RUCY)
- 2023
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Reports (other academic/artistic)abstract
- Avgörande för ökat hållbart resande är tillgängligheten till hållbara färdmedel. Planering för cykeltrafik blir därför ett allt viktigare område. Därmed behöver våra transportmodeller förbättras i hur de modellerar cykelresor och specifikt hur cyklisters ruttval bör modelleras. Under 2019 har rapporten ”Behovsanalys för cykeltrafikmodeller” levererats till Trafikverket och Sveriges Kommuner och Regioner. Rapporten sammanfattar behov av att vidareutveckla makroskopiska trafikmodeller bland annat för att utvärdera effekter av cykelinvesteringar/åtgärder. I projektet RUCY adresserar vi denna fråga. Många investeringsåtgärder handlar om att bredda befintliga cykelbanor vilket inte kan utvärderas med det befintliga samhällsekonomiska analysverktyget. Även internationellt har nästan inga studier fångat upp hur cykelbanans bredd har påverkat ruttvalet. Det finns därmed ett värde i att öka kunskapsmängden inom området och jämföra resultat mellan olika länder/städer.RUCY använder GPS-data från ca 13 000 cykelresor från projektet ”Bike data – Crowd sourced Big Data för cykling” för att skatta en ruttvalsmodell för cykel för Göteborg. En modell baserad på HIdden-Markovs kartmatchningsalgoritm används för att identifiera rutter utifrån GPS-spår. Möjliga alternativa rutter genereras via upprepade ruttsökningsmetoder samt observerade rutter med samma start- och målpunkt. En Path-size-logit-modell har skattats med relativa effekter för exempelvis cykelbana med olika breddkategorier, belysning och lutning.Resultaten visar att osäkerhet i kartmatchning, som inte har fått uppmärksamhet i de flesta tidigare studierna, har en stor påverkan på modellskattningsresultaten. Studien lyckas fånga resenärernas skillnad i upplevd resuppoffring mellan cykelbana med bredd mindre än 2 meter och de med bredd större än 2 meter. Studien fångar också effekter av lutning, korsningsfördröjning, belysning samt typ av beläggning. Effekterna jämförs med internationella studier. Fångade effekter av bredd av cykelbana möjliggör utvärdering av infrastrukturinvesteringar som breddar befintliga cykelbanor. Dock noterar vi att fler känslighetsanalyser med avseende på effekter av cykelbanans bredd behövs. Studien illustrerar hur resultat av ruttvalsmodeller kan integreras i en transportmodell som möjliggör utvärdering av relevanta policyåtgärder för cykel.
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