| 1. |
|
|
| 2. |
- Thörn, Ingrid, 1957-, et al.
(författare)
-
Minimal residual disease assessment in childhood acute lymphoblastic leukemia : Results of a Swedish multi-centre study comparing real-time PCR and multi-colour flow cytometry
- 2009
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this Swedish multi-center study of early treatment response in childhood acute lymphoblastic leukemia (ALL), we evaluated the concordance between multicolour flow cytometry (FCM) and real-time quantitative polymerase chain reaction (RQ-PCR) for assessment of minimal residual disease (MRD). Multiple time points (i.e. day 15, 29, 50 and 106) were evaluated with the NOPHO (Nordic Society of Pediatric Hematology and Oncology) ALL 2000 treatment protocol as backbone. During 2002-2006, 334 children were diagnosed with ALL, where 228 had paired samples taken at any of the four time points. With the detection level of 0.1%, the concordance between RQ-PCR and FCM was 90% in the 726 paired samples analyzed. At day 29, the correlation between the methods was greater with MRD levels >0.1% (rs=0.7, p<0.001) than below (rs=0.2, p=0.024). MRD levels higher than 0.1% at day 29 was a significant predictor of higher risk of having a bone marrow relapse. This was true both for BCP ALL and T-ALL analysed with either FCM or RQ-PCR, although RQ-PCR was a better discriminator than FCM in T-ALL. However, using the NOPHO ALL 2000 protocol, our data indicate that a higher cut-off value (0.2%) should be applied in BCP ALL when using RQ-PCR as MRD method. In contrast, MRD levels ≥ 0.1%, analysed with either method late during induction therapy, was not a predictor of isolated extramedullary relapse. We therefore conclude that MRD assessment by RQ-PCR based IG/TCR rearrangement and multicolour FCM monitoring can be used as a clinical tool if the aim is to find childhood ALL cases with increased risk of having bone marrow relapses.
|
|
| 3. |
- Thörnerup, Ingrid, et al.
(författare)
-
Minimal residual disease assessment in childhood acute lymphoblastic leukaemia: a Swedish multi-centre study comparing real-time polymerase chain reaction and multicolour flow cytometry.
- 2011
-
Ingår i: British Journal of Haematology. - : Wiley. - 0007-1048 .- 1365-2141. ; 152:6, s. 743-753
-
Tidskriftsartikel (refereegranskat)abstract
- Minimal residual disease (MRD) assessment is a powerful prognostic factor for determining the risk of relapse in childhood acute lymphoblastic leukaemia (ALL). In this Swedish multi-centre study of childhood ALL diagnosed between 2002 and 2006, the MRD levels were analysed in 726 follow-up samples in 228 children using real-time quantitative polymerase chain reaction (RQ-PCR) of rearranged immunoglobulin/T-cell receptor genes and multicolour flow cytometry (FCM). Using an MRD threshold of 0·1%, which was the sensitivity level reached in all analyses, the concordance between RQ-PCR and FCM MRD values at day 29 was 84%. In B-cell precursor ALL, an MRD level of ≥0·1% at day 29 predicted a higher risk of bone marrow relapse (BMR) with both methods, although FCM was a better discriminator. However, considering the higher median MRD values achieved with RQ-PCR, a higher MRD cut-off (≥0·2%) improved the predictive capacity of RQ-PCR. In T-ALL, RQ-PCR was notably superior to FCM in predicting risk of BMR. That notwithstanding, MRD levels of ≥0·1%, detected by either method at day 29, could not predict isolated extramedullary relapse. In conclusion, the concordance between RQ-PCR and FCM was high and hence both methods are valuable clinical tools for identifying childhood ALL cases with increased risk of BMR.
|
|
| 4. |
- Abdel-Fattah, Wael R., et al.
(författare)
-
Growth-regulated co-occupancy of Mediator and Lsm3 at intronic ribosomal protein genes
- 2024
-
Ingår i: Nucleic Acids Research. - : Oxford University Press. - 0305-1048 .- 1362-4962. ; 52:11, s. 6220-6233
-
Tidskriftsartikel (refereegranskat)abstract
- Mediator is a well-known transcriptional co-regulator and serves as an adaptor between gene-specific regulatory proteins and RNA polymerase II. Studies on the chromatin-bound form of Mediator revealed interactions with additional protein complexes involved in various transcription-related processes, such as the Lsm2–8 complex that is part of the spliceosomal U6 small nuclear ribonucleoprotein complex. Here, we employ Chromatin Immunoprecipitation sequencing (ChIP-seq) of chromatin associated with the Lsm3 protein and the Med1 or Med15 Mediator subunits. We identify 86 genes co-occupied by both Lsm3 and Mediator, of which 73 were intron-containing ribosomal protein genes. In logarithmically growing cells, Mediator primarily binds to their promoter regions but also shows a second, less pronounced occupancy at their 3́-exons. During the late exponential phase, we observe a near-complete transition of Mediator from these promoters to a position in their 3́-ends, overlapping the Lsm3 binding sites ∼250 bp downstream of their last intron–exon boundaries. Using an unbiased RNA sequencing approach, we show that transition of Mediator from promoters to the last exon of these genes correlates to reduction of both their messenger RNA levels and splicing ratios, indicating that the Mediator and Lsm complexes cooperate to control growth-regulated expression of intron-containing ribosomal protein genes at the levels of transcription and splicing.
|
|
| 5. |
- Adli, Erik, et al.
(författare)
-
Progress Of The Ess Proton Beam Imaging Systems
- 2022
-
Ingår i: LINAC2022. - : ACoW Publishing. ; , s. 395-398
-
Konferensbidrag (refereegranskat)abstract
- The ESS Target Proton Beam Imaging Systems has the objective to image the 5 MW ESS proton beam as it entersthe spallation target. The imaging systems has to operate in a harsh radiation environment, leading to a number of challenges : development of radiation hard photon sources, long and aperture-restricted optical paths and fast electronics required to provide rapid information in case of beam anomalies. This paper outlines how main challenges of the imaging systems have been addressed, and the status of deployment as ESS gets closer to beam.
|
|
| 6. |
- Aguilar, Ximena, 1978-
(författare)
-
Folding and interaction studies of subunits in protein complexes
- 2014
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Proteins function as worker molecules in the cell and their natural environment is crowded. How they fold in a cell-like environment and how they recognize their interacting partners in such conditions, are questions that underlie the work of this thesis.Two distinct subjects were investigated using a combination of biochemical- and biophysical methods. First, the unfolding/dissociation of a heptameric protein (cpn10) in the presence of the crowding agent Ficoll 70. Ficoll 70 was used to mimic the crowded environment in the cell and it has been used previously to study macromolecular crowding effects, or excluded volume effects, in protein folding studies. Second, the conformational changes upon interaction between the Mediator subunit Med25 and the transcription factor Dreb2a from Arabidopsis thaliana. Mediator is a transcriptional co-regulator complex which is conserved from yeast to humans. The molecular mechanisms of its action are however not entirely understood. It has been proposed that the Mediator complex conveys regulatory signals from promoter-bound transcription factors (activators/repressors) to the RNA polymerase II machinery through conformational rearrangements.The results from the folding study showed that cpn10 was stabilized in the presence of Ficoll 70 during thermal- and chemical induced unfolding (GuHCl). The thermal transition midpoint increased by 4°C, and the chemical midpoint by 0.5 M GuHCl as compared to buffer conditions. Also the heptamer-monomer dissociation was affected in the presence of Ficoll 70, the transition midpoint was lower in Ficoll 70 (3.1 μM) compared to in buffer (8.1 μM) thus indicating tighter binding in crowded conditions. The coupled unfolding/dissociation free energy for the heptamer increased by about 36 kJ/mol in Ficoll. Altogether, the results revealed that the stability effect on cpn10 due to macromolecular crowding was larger in the individual monomers (33%) than at the monomer-monomer interfaces (8%).The results from the interaction study indicated conformational changes upon interaction between the A. thaliana Med25 ACtivator Interaction Domain (ACID) and Dreb2a. Structural changes were probed to originate from unstructured Dreb2a and not from the Med25-ACID. Human Med25-ACID was also found to interact with the plant-specific Dreb2a, even though the ACIDs from human and A. thaliana share low sequence homology. Moreover, the human Med25-interacting transcription factor VP16 was found to interact with A. thaliana Med25. Finally, NMR, ITC and pull-down experiments showed that the unrelated transcription factors Dreb2a andVP16 interact with overlapping regions in the ACIDs of A. thaliana and human Med25.The results presented in this thesis contribute to previous reports in two different aspects. Firstly, they lend support to the findings that the intracellular environment affects the biophysical properties of proteins. It will therefore be important to continue comparing results between in vitro and cell-like conditions to measure the magnitude of such effects and to improve the understanding of protein folding and thereby misfolding of proteins in cells. Better knowledge of protein misfolding mechanisms is critical since they are associated to several neurodegenerative diseases such as Alzheimer’s and Parkinson's. Secondly, our results substantiate the notion that transcription factors are able to bind multiple targets and that they gain structure upon binding. They also show that subunits of the conserved Mediator complex, despite low sequence homologies, retain a conserved structure and function when comparing evolutionary diverged species.
|
|
| 7. |
- Aguilar, Ximena, 1978-, et al.
(författare)
-
Interaction Studies of the Human and Arabidopsis thaliana Med25-ACID Proteins with the Herpes Simplex Virus VP16-and Plant-Specific Dreb2a Transcription Factors
- 2014
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:5, s. e98575-
-
Tidskriftsartikel (refereegranskat)abstract
- Mediator is an evolutionary conserved multi-protein complex present in all eukaryotes. It functions as a transcriptional coregulator by conveying signals from activators and repressors to the RNA polymerase II transcription machinery. The Arabidopsis thaliana Med25 (aMed25) ACtivation Interaction Domain (ACID) interacts with the Dreb2a activator which is involved in plant stress response pathways, while Human Med25-ACID (hMed25) interacts with the herpes simplex virus VP16 activator. Despite low sequence similarity, hMed25-ACID also interacts with the plant-specific Dreb2a transcriptional activator protein. We have used GST pull-down-, surface plasmon resonance-, isothermal titration calorimetry and NMR chemical shift experiments to characterize interactions between Dreb2a and VP16, with the hMed25 and aMed25-ACIDs. We found that VP16 interacts with aMed25-ACID with similar affinity as with hMed25-ACID and that the binding surface on aMed25-ACID overlaps with the binding site for Dreb2a. We also show that the Dreb2a interaction region in hMed25-ACID overlaps with the earlier reported VP16 binding site. In addition, we show that hMed25-ACID/Dreb2a and aMed25-ACID/Dreb2a display similar binding affinities but different binding energetics. Our results therefore indicate that interaction between transcriptional regulators and their target proteins in Mediator are less dependent on the primary sequences in the interaction domains but that these domains fold into similar structures upon interaction.
|
|
| 8. |
- Aid, Graham, 1980-
(författare)
-
Operationalizing Industrial Ecology in the Waste Sector : Roles and tactics for circular value innovation
- 2017
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The take-make-waste approach to resource management in human production and consumption systems is contributing to a variety of environmental and social problems worldwide. Additionally, as the world’s population and affluence increase, so do the negative impacts of poor resource management. Lifting the waste management (WM) sector into a new phase of development, which takes its lead from the ideals of Industrial Ecology and circular economy, is seen by many scholars and practitioners as one potential to assist in alleviating these impacts. While there are many studies on how more efficient inter-organizational resource management is (or could be) constructed, there are relatively few business development studies which have explored novel approaches (from roles to tactics) that WM organizations might operationalize toward more efficient resource management.The aim of this thesis is to contribute to the development of knowledge and understanding of how the waste management sector can operationalize more effective and efficient resource management. In approaching this aim, two research questions guided the exploration of: 1) novel roles for WM and 2) support tactics for such roles. Grounded in the broader context of Industrial Ecology (IE) and Business Development, five studies were performed. Two studies, focused on the novel roles of inter-organizational resource management and high value secondary resource extraction, were performed through literature review and interviews, and market driver analysis respectively. In exploring support tactics, two design and proof of concept studies were carried out to investigate data analysis tools for inter-organizational resource management, and one long-term action research engagement project was coordinated to study hands-on inter-organizational collaboration tactics.The studies highlighted that the Swedish WM sector holds some key capacities for operationalizing (and in some cases, is already developing) the novel resource management roles identified: industrial symbiosis facilitator, eco-industrial park manager, holistic facility management, and high value resource extractor. However, depending on the portfolio of services to be performed in such roles, several capacities may need to be developed or strengthened. Main opportunities seen for these roles were – staying ahead of market developments, and aligning activities with organizational goals. The main general risk related to these roles was insufficient returns on investment. Looking forward, the main enablers identified were policy leadership for more balanced market mechanisms, increasing use of external knowledge, developing long term partnerships, lobbying, stockpiling resources, and carefully crafting new business models.The tools developed for strategically applying external information toward the identification of opportunities within new roles showed tactical potential. However, their implementation in broader development processes has yet to be fully validated. The hands-on exploration of change oriented collaboration, highlighted collective system framing and goal setting and face-to-face interaction as key activities for inter-organizational approaches within roles such as industrial symbiosis facilitator.Throughout the studies, several novel roles were investigated. Each of these roles will need to be individually evaluated by directing bodies of WM organizations, and evaluated from the organization’s vision and strategy. If certain roles are chosen to be explored in more detail, they will need to be developed within full business models - addressing issues such as income structure, internal processes and capacities to be developed, and key customers. Through applying IE and business development concepts and findings, WM organizations have possibilities to translate ambitious visions into novel offerings.
|
|
| 9. |
|
|
| 10. |
- Andersson, Martin
(författare)
-
Churning losses and efficiency in gearboxes
- 2014
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Efficient transmissions systems are key to producing competitive motor vehicles that have a smaller environmental impact. Gears are the main components in vehicle transmissions and although they are already highly efficient, there is still room for improvement. In this study, the focus falls on the lubricant used to create separating films between gears and todissipate heat. When driving, the gears churn this lubricant, giving rise to power losses that are related to the amount and properties of the lubricant. However, any attempt to reduce these losses must not compromise the required lubrication and heat dissipation. Paper A reports on the use of an FZG gear test rig to investigate power losses and heat generation for different gear immersion depths, surface roughness and coatings. The results show that lower gear roughness reduces gear mesh losses and heat generation. A polishing affect was obtained when a non-coated gear ran against a coated gear.The aim of the research reported in paper B was to increase the accuracy of efficiency testing. It investigated how and whether repeated disassembly and re-assembly of the same test equipment, as well as test performance and rig conditions, affect the measured torque loss in an FZG gear test rig. It was shown that the measured torque loss changes between one assembly and another. Repeatability between tests is crucial for accurate conclusions.The aim of the research reported in paper C was to study whether gear efficiency could be increased by a running-in procedure, which would reduce the need for a coolant. A back-to-back gear test rig was used to test two running-in loads. Higher gear mesh efficiency was seen when a higher running-in load was used.
|
|
| 11. |
- Andersson, Nils-Eric, et al.
(författare)
-
Face milling of AA7010 at high cutting speeds
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Face milling using different commercial tools and inserts at varying cutting speeds on a high strength aluminium alloy has been performed. The surface integrity of the machined samples has been investigated in terms of surface roughness, residual stresses, hardness and peak broadening from x-ray diffraction at grazing angle incidence. Some fatigue testing of the machined surfaces has been done. The cutting chips from the different machining parameters are investigated and compared to one another. The results show a strong influence of tool insert on surface roughness, residual stress, peak broadening, and hardness profile and fatigue properties. The influence of cutting speed on the surface integrity is much smaller. The cutting speed does however influence the size and shape of the cutting chips. There is also a general decrease in peak broadening from x-ray diffraction very near the machined surface after high cutting speeds. This could be explained by a higher local heating of the work piece at very high cutting speeds.
|
|
| 12. |
|
|
| 13. |
- Andersson, Sören, et al.
(författare)
-
Frictions models for sliding dry, boundary and mixed lubricated contacts
- 2007
-
Ingår i: Tribology International. - : Elsevier BV. - 0301-679X .- 1879-2464. ; 40, s. 580-587
-
Tidskriftsartikel (refereegranskat)abstract
- Friction, lubrication, and wear have a strong influence on the performance and behavior of mechanical systems. This paper deals with different friction models for sliding contacts running under different conditions. The models presented are suited to different situations, depending on the type of contact, running conditions, and the behavior of interest. The models will be discussed from simulation and tribological points of view. The different types of friction models considered are:center dot friction models for transient sliding under dry, boundary and mixed lubrication conditions,center dot friction models for micro-displacements of engineering surfaces subjected to transient sliding,center dot friction models often used in the simulation and control of technical systems,center dot combined friction models that represent physical behaviors fairly well but are also suitable for use in simulating systems,center dot friction models that take into account the stochastic nature of interacting surface asperities
|
|
| 14. |
- Baiamonte, Lidia, et al.
(författare)
-
Carbide-laden coatings deposited using a hand-held high-velocity air-fuel (HVAF) spray gun
- 2021
-
Ingår i: Surface & Coatings Technology. - : Elsevier BV. - 0257-8972 .- 1879-3347. ; 406
-
Tidskriftsartikel (refereegranskat)abstract
- Driven by sustainability and cost considerations, there is growing interest in power generation utilizing renewable sources, especially biomass and waste. While premature degradation of power plant components due to corrosion is well-known, erosion can be a dominant damage mechanism in plants that use “pure” biomass with less corrosive elements like Cl, K, etc. Circulating fluidized bed (CFB) parts are prone to erosion-driven damage and demand periodic re-protection or replacement. In response to the above, this preliminary study evaluates a selection of complex carbide-based coatings to enhance protection against erosion to prolong service life of boiler components. Recognizing on-site coating requirements of real boiler applications, a specific focus is on evaluating performance of a hand-held high-velocity air-fuel (HVAF) spray gun and compare it with the current state-of-the-art high-velocity oxy-fuel (HVOF) deposition. Coatings developed by the above routes have been characterized with microstructural analyses, and their performance evaluated and ranked in an air-jet erosion rig at various impact angles.
|
|
| 15. |
- Balciunas, Darius, et al.
(författare)
-
Functional interactions within yeast mediator and evidence of differential subunit modifications
- 2003
-
Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 278:6, s. 3831-3839
-
Tidskriftsartikel (refereegranskat)abstract
- It is possible to recruit RNA polymerase II to a target promoter and, thus, activate transcription by fusing Mediator subunits to a DNA binding domain. To investigate functional interactions within Mediator, we have tested such fusions of the lexA DNA binding domain to Med1, Med2, Gal11, Srb7, and Srb10 in wild type, med1, med2, gal11, sin4, srb8, srb10, and srb11 strains. We found that lexA-Med2 and lexA-Gal11 are strong activators that are independent of all Mediator subunits tested. lexA-Srb10 is a weak activator that depends on Srb8 and Srb11. lexA-Med1 and lexA-Srb7 are both cryptic activators that become active in the absence of Srb8, Srb10, Srb11, or Sin4. An unexpected finding was that lexA-VP16 differs from Gal4-VP16 in that it is independent of the activator binding Mediator module. Both lexA-Med1 and lexA-Srb7 are stably associated with Med4 and Med8, which suggests that they are incorporated into Mediator. Med4 and Med8 exist in two mobility forms that differ in their association with lexA-Med1 and lexA-Srb7. Within purified Mediator, Med4 is present as a phosphorylated lower mobility form. Taken together, these results suggest that assembly of Mediator is a multistep process that involves conversion of both Med4 and Med8 to their low mobility forms.
|
|
| 16. |
- Balciunas, Darius, et al.
(författare)
-
The Med1 subunit of the yeast mediator complex is involved in both transcriptional activation and repression
- 1999
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences (PNAS). - 0027-8424 .- 1091-6490. ; 96:2, s. 376-381
-
Tidskriftsartikel (refereegranskat)abstract
- The mediator complex is essential for regulated transcription in vitro. In the yeast Saccharomyces cerevisiae, mediator comprises >15 subunits and interacts with the C-terminal domain of the largest subunit of RNA polymerase II, thus forming an RNA polymerase II holoenzyme. Here we describe the molecular cloning of the MED1 cDNA encoding the 70-kDa subunit of the mediator complex. Yeast cells lacking the MED1 gene are viable but show a complex phenotype including partial defects in both repression and induction of the GAL genes. Together with results on other mediator subunits, this implies that the mediator is involved in both transcriptional activation and repression. Similar to mutations in the SRB10 and SRB11 genes encoding cyclin C and the cyclin C-dependent kinase, a disruption of the MED1 gene can partially suppress loss of the Snf1 protein kinase. We further found that a lexA-Med1 fusion protein is a strong activator in srb11 cells, which suggests a functional link between Med1 and the Srb10/11 complex. Finally, we show that the Med2 protein is lost from the mediator on purification from Med1-deficient cells, indicating a physical interaction between Med1 and Med2.
|
|
| 17. |
- Bellippady, Madhura, et al.
(författare)
-
Characteristics and performance of suspension plasma sprayed thermal barrier coatings on additively manufactured superalloy substrates
- 2023
-
Ingår i: Surface and Coatings Technology. - : Elsevier. - 0257-8972. ; 472
-
Tidskriftsartikel (refereegranskat)abstract
- The complex-shaped hot-section parts of new-generation turbine engines demand unique design solutions. Additive Manufacturing (AM) is an emergent production method that can produce metallic parts with complex geometries and minimal material wastage. In this work, the characteristics and performance behavior of Thermal Barrier Coatings (TBCs) deposited on forged and AM-built HAYNES®282® superalloy substrates were studied and compared. The bond coats were produced by High-Velocity Air-Fuel (HVAF) spraying using NiCoCrAlY powder feedstock and TBC top-coats by Suspension Plasma Spraying (SPS) using water- and ethanol-based suspensions of Yttria-Stabilized Zirconia (YSZ). The microstructural features, adhesion, Thermal Cycling Fatigue (TCF) lifetime, and thermal shock lifetimes of the TBCs were comprehensively investigated. The results showed that the deposition of bond coats reduced the roughness and asperities of the AM-built substrates. Depending on the type of suspension used and the spray parameters employed, the TBCs exhibited vertically cracked and columnar microstructures. However, no significant differences in TCF and thermal shock lifetimes of TBCs on AM and forged substrates were observed. It is demonstrated that TBC systems can be produced on AM-built metallic substrates, and the resulting TBCs can have similar microstructures and properties as TBCs deposited on conventional substrates.
|
|
| 18. |
- Bellippady, Madhura, et al.
(författare)
-
Performance of Atmospheric Plasma-Sprayed Thermal Barrier Coatings on Additively Manufactured Super Alloy Substrates
- 2024
-
Ingår i: Coatings. - : MDPI. - 2079-6412. ; 14:5
-
Tidskriftsartikel (refereegranskat)abstract
- This work represents a preliminary study of atmospheric plasma-sprayed (APS) YttriaStabilized Zirconia (YSZ)-based thermal barrier coatings (TBCs) deposited on forged and additivemanufactured (AM) HAYNES®282® (H282) superalloy substrates. The effect of different feedstockmorphologies and spray gun designs with radial and axial injection on APS-deposited YSZ layercharacteristics such as microstructure, porosity content, roughness, etc., has been investigated. Theperformance of TBCs in terms of thermal cycling fatigue (TCF) lifetime and erosion behaviour werealso comprehensively investigated. In view of the high surface roughness of as-built AM surfacescompared to forged substrates, two different types of NiCoCrAlY bond coats were examined: oneinvolved high-velocity air fuel (HVAF) spraying of a finer powder, and the other involved APSdeposition of a coarser feedstock. Despite the process and feedstock differences, the above two routesyielded comparable bond coat surface roughness on both types of substrates. Variation in porositylevel in the APS topcoat was observed when deposited using different YSZ feedstock powdersemploying axial or radial injection. However, the resultant TBCs on AM-derived substrates wereobserved to possess similar microstructures and functional properties as TBCs deposited on reference(forged) substrates for any given YSZ deposition process and feedstock.
|
|
| 19. |
- Bellippady, Madhura, et al.
(författare)
-
Process Parameter Impact on Axial Plasma Sprayed Ytterbium Disilicate Coatings for Environment Barrier Coating Applications
- 2024
-
Ingår i: Sustainable Production through Advanced Manufacturing, Intelligent Automation and Work Integrated Learning. - : IOS Press. - 9781643685106 - 9781643685113 ; , s. 101-110
-
Bokkapitel (refereegranskat)abstract
- In future generation aviation, light weight, and thermally stable SiC/SiC ceramic matrix composites (CMCs) are considered the most promising structural materials to replace traditionally used Ni-based superalloys. However, in the presence of steam (a common combustion reaction product) and corrosive species (from ingestion of debris along with the intake air during take-off and landing), accelerated degradation of CMCs compromising its structural integrity is inevitable. Environmental Barrier Coatings (EBCs) are protective ceramic coatings consisting of rare earth (RE) silicates as a topcoat with silicon as a bond coat, and are widely used on CMCs, to impede their surface recession.Thermal spray techniques are commonly employed to deposit EBCs, with highly crystalline, dense, and crack free coatings being desired for robust performance. In general, the high particle velocity and efficient energy transfer in axial feeding systems can result in coatings with higher density, reduced oxide content, and improved mechanical properties. In the present study, axial plasma sprayed ytterbium disilicate (YbDS) coatings deposited on silicon carbide (SiC) substrates using varying plasma spray parameters have been comprehensively characterized. Microstructure, porosity, and hardness have been studied for YbDS coatings deposited by varying nozzle diameter, carrier gas flow rate and stand of distance (SOD) during plasma spraying. Erosion and thermal cyclic fatigue performance of these coatings has also been investigated.
|
|
| 20. |
- Bergseth, Ellen, et al.
(författare)
-
Influence of real surface topography on the contact area ratio in differently manufactured spur gears
- 2012
-
Ingår i: Tribology International. - : Elsevier BV. - 0301-679X .- 1879-2464. ; 56, s. 72-80
-
Tidskriftsartikel (refereegranskat)abstract
- Surface topography measurements from spur gears produced using four different manufacturing methods were used as input to a contact analysis programme. All test gears were case-hardened, two gears were machined in the hardened state using honing and grinding respectively, and two gears were machined in the non-hardened state using hobbing and hobbing followed by green-shaving respectively. The results show that the surface topography caused by the manufacturing methods has a large influence on the real contact area in the early life of the gear. The green-shaved gear surfaces and the honed gear surfaces have the highest contact area ratio after manufacturing (as-manufactured), which could be advantageous for future gear life with respect to e.g. the running-in process.
|
|
| 21. |
- Bergseth, Ellen, et al.
(författare)
-
Logarithmical Crowning for Spur Gears
- 2010
-
Ingår i: Strojniski vestnik. - 0039-2480. ; 56:4, s. 239-244
-
Tidskriftsartikel (refereegranskat)abstract
- Gear tooth modifications, such as lead crowning, are often recommended to compensate for misalignment (e.g. assembly deviations). Lead crowning means that the tooth centre is slightly thicker than the tooth edges and is usually described as a circular arc profile. The use of crowning shifts the peak load from the tooth flank edges and, therefore, reduces the risk for high contact pressures at the edges, which can otherwise result in a shortened service life. In this study a logarithmical lead profile was compared with traditional lead profile modifications for gears. The profiles were applied on a spur gear pair and a numerical method for contact analysis was used to calculate the contact pressure distribution at the pitch diameter. All lead profiles were optimised with respect to low contact pressure at a specific normal load, a specified maximum misalignment in the plane of action and a tooth flank edge contact criteria. The results show that the logarithmical profile responds differently to misalignments compared to the traditional lead profile modifications. The logarithmical profile resulted in lower maximum contact pressures for small misalignments and is, therefore, of further interest in terms of achieving a robust gear design. (C) 2010 Journal of Mechanical Engineering. All rights reserved.
|
|
| 22. |
|
|
| 23. |
- Björklund, Ann-Christin, et al.
(författare)
-
Using ICF to Describe Problems With Functioning in Everyday Life for Children Who Completed Treatment for Brain Tumor : An Analysis Based on Professionals' Documentation
- 2021
-
Ingår i: Frontiers in Rehabilitation Sciences. - : Frontiers Media S.A.. - 2673-6861. ; 2
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Children treated for brain tumors often experience persistent problems affecting their activity performance and participation in everyday life, especially in school. Linking these problems to the International Classification of Functioning, Disability and Health (ICF) classification system can be described as affecting body function, activity performance, and/or participation. Services involved in the everyday life of the child have different focus and goals when meeting the child in context, which advantage the use of ICF to overcome this impediment to follow-up and provide comprehensive support for children who have completed treatment for a brain tumor.Aim: The aim of the study was to use the ICF classification system to describe how professionals in healthcare, habilitation, and school document problems with everyday life functioning at body, activity, and participation levels for children who completed treatment for a brain tumor.Materials and Methods: A retrospective review of records from healthcare, habilitation, and school concerning nine children completed treatment for brain tumor was implemented. Identified problems in everyday life were linked to ICF codes. Descriptive statistics of ICF-linked code frequency supplemented by network visualization diagrams viewing the co-occurrence between codes within the body, activity participation, and environmental components were performed.Results: Most documented problems were found in healthcare records, whereas the documentation in habilitation and school was sparse. The frequently occurring codes, independent of record source, were linked to the body function component, and ICF-linked problems in habilitation and school were salient in the activity and participation component. To gain a holistic picture of relations between ICF codes and problems, network visualization diagrams were used to illustrate clusters of problems.Conclusion: Code prevalence likely reflects where healthcare professionals and educators focus their attention when meeting the needs of children treated for a brain tumor in context. To maximize the comprehensive view of functioning and participation of children in everyday life, the full range of difficulties regarding body impairments, activity limitations, and participation restrictions must be identified and linked to each other in patterns of co-occurrence, which the ICF facilitate. However, ICF provides no guidance on how to identify networks of problems within the body, activity, and participation. Identifying such networks is important for building comprehensive interventions for children.
|
|
| 24. |
- Björklund, Catarina, 1981-, et al.
(författare)
-
Design and synthesis of potent and selective BACE-1 inhibitors
- 2010
-
Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society. - 0022-2623 .- 1520-4804. ; 53:4, s. 1458-1464
-
Tidskriftsartikel (refereegranskat)abstract
- Several highly potent BACE-1 protease inhibitors have been developed from an inhibitor series containing a novel hydroxyethylene (HE) core structure displaying aryloxymethyl or benzyloxymethyl P1 side chains and a methoxy P1’ side chain. The target molecules were readily synthesized from chiral carbohydrate starting materials, furnishing the inhibitor compounds in good overall yields. The inhibitors show both high BACE-1 potency and good selectivity against cathepsin D, where the most potent inhibitor furnish a BACE-1 IC50 value of 0.32 nM and displays > 3000 fold selectivity over cathepsin D.
|
|
| 25. |
- Björklund, Camilla, et al.
(författare)
-
Matematikkundervisning
- 2013
-
Bok (övrigt vetenskapligt/konstnärligt)abstract
- Denna boken är skriven av en grupp erfarna norska och svenska lärarutbildare i matematik. Boken bygger på utprövad erfarenhet - såväl egen som andras - och på aktuell, relevant forskning i matematikdidaktik. Texten väver samman matematik och matematikdidaktik, det vill säga ämnet som det undervisas i och frågor om hur ämnet kan läras och undervisas. Boken innehåller det som är absolut viktigast att få med sig i den grundläggande lärarutbildningen i matmatik.
|
|
| 26. |
- Björklund, Elisabet, et al.
(författare)
-
Quality control of flow cytometry data analysis for evaluation of minimal residual disease in bone marrow from acute leukemia patients during treatment.
- 2009
-
Ingår i: Journal of pediatric hematology/oncology : official journal of the American Society of Pediatric Hematology/Oncology. - : Lippincott Williams & Wilkins. - 1536-3678 .- 1077-4114. ; 31:6, s. 406-15
-
Tidskriftsartikel (refereegranskat)abstract
- Low levels of leukemia cells in the bone marrow, minimal residual disease (MRD), are considered to be a powerful indicator of treatment response in acute lymphatic leukemia (ALL). A Nordic quality assurance program, aimed on standardization of the flow cytometry MRD analysis, has been established before implementation of MRD at cutoff level 10 as one of stratifying parameters in next Nordic Society of Pediatric Hematology and Oncology (NOPHO) treatment program for ALL. In 4 quality control (QC) rounds 15 laboratories determined the MRD levels in 48 follow-up samples from 12 ALL patients treated according to NOPHO 2000. Analysis procedures were standardized. For each QC round a compact disc containing data in list-mode files was sent out and results were submitted to a central laboratory. At cutoff level 10, which will be applied for clinical decisions, laboratories obtained a high concordance (91.6%). If cutoff level 10 was applied, the concordance would be lower (85.3%). The continuing standardization resulted in better concordance in QC3 and QC4 compared with QC1 and QC2. The concordance was higher in precursor B as compared with T-cell ALL. We conclude that after standardization, flow cytometry MRD detection can be reliably applied in international, multicenter treatment protocols.
|
|
| 27. |
- Björklund, Johan, et al.
(författare)
-
Postoperative mortality 90 days after robot-assisted laparoscopic prostatectomy and retropubic radical prostatectomy : a nationwide population-based study
- 2016
-
Ingår i: BJU International. - : Wiley. - 1464-4096 .- 1464-410X. ; 118:2, s. 302-306
-
Tidskriftsartikel (refereegranskat)abstract
- Objective To assess 90-day postoperative mortality after robot-assisted laparoscopic radical prostatectomy (RARP) and retropubic radical prostatectomy (RRP) using nationwide population-based registry data. Patients and Methods We conducted a cohort study using the National Prostate Cancer Register of Sweden, including 22 344 men with localized prostate cancer of clinical stage T1-T3, whose prostate-specific antigen levels were <50 mu g/mL and who had undergone primary radical prostatectomy in the period 1998-2012. Vital status was ascertained through the Total Population Register. The rates for 90-day postoperative mortality were analysed using logistic regression analysis, and comparisons of 90-day mortality with the background population were made using standardized mortality ratios (SMRs). Results Of the 14 820 men who underwent RRP, 29 (0.20%) died, and of the 7 524 men who underwent RARP, 10 (0.13%) died. Mortality in the cohort during the 90-day postoperative period was lower than in an age-matched background population: SMR 0.57 (95% confidence interval [CI] 0.39-0.75). There was no statistically significant difference in 90-day mortality according to surgical method: RARP vs RRP odds ratio (OR) 1.14; 95% CI 0.46-2.81. Postoperative 90-day mortality decreased over time: 2008-2012 vs 1998-2007 OR 0.44; 95% CI 0.21-0.95, mainly because of lower mortality after RARP. Conclusion The 90-day postoperative mortality rates were low after RARP and RRP and there was no statistically significant difference between the methods. Given the long life expectancy among men with low-and intermediate-risk prostate cancer, very low postoperative mortality is a prerequisite for RP, which was fulfilled by both RRP and RARP. The selection of healthy men for RP is highlighted by the lower 90-day mortality after RP compared with the background population.
|
|
| 28. |
- Björklund, Stefan, et al.
(författare)
-
An S-phase specific release from a transcriptional block regulates the expression of mouse ribonucleotide reductase R2 subunit
- 1992
-
Ingår i: EMBO Journal. - 0261-4189 .- 1460-2075. ; 11:13, s. 4953-4959
-
Tidskriftsartikel (refereegranskat)abstract
- Ribonucleotide reductase (RR) activity in mammalian cells is closely linked to DNA synthesis. The RR enzyme is composed of two non-identical subunits, proteins R1 and R2. Both proteins are required for holoenzyme activity, which is regulated by S-phase specific de novo synthesis and breakdown of the R2 subunit. In quiescent cells stimulated to proliferate and in elutriated cell populations enriched in the various cell cycle phases the R2 protein levels are correlated to R2 mRNA levels that are low in G0/G1-phase cells but increase dramatically at the G1/S border. Using an R2 promoter-luciferase reporter gene construct we demonstrate an unexpected early activation of the R2 promoter as cells pass from quiescence to proliferation. However, due to a transcriptional block, this promoter activation only results in very short R2 transcripts until cells enter the S-phase, when full-length R2 transcripts start to appear. The position for the transcriptional block was localized to a nucleotide sequence approximately 87 bp downstream from the first exon/intron boundary by S1 nuclease mapping of R2 transcripts from modified in vitro nuclear run-on experiments. These results identify blocking of transcription as a mechanism to control cell cycle regulated gene expression.
|
|
| 29. |
- Björklund, Stefan, et al.
(författare)
-
Compensation of systematic errors in five-axis high-speed machining
- 2002
-
Ingår i: International Journal of Production Research. - : Informa UK Limited. - 0020-7543 .- 1366-588X. ; 40:15 SPEC., s. 3765-3778
-
Tidskriftsartikel (refereegranskat)abstract
- A method is described for the compensation of errors associated with tool path generation, particularly during five-axis high-speed machining (HSM). Information on machine tool performance and its dynamic features is used to calculate possible errors and convenient modifications of the NC program, thereby avoiding errors when parts are actually being machined. This 'preprocess method' by means of postprocessing with NC software is presented. The errors dealt with are mainly servo lag errors, but the explored approach can support most systematic errors associated with machine tool performance. These are briefly summarized. Research so far has largely been aimed at the implementation of compensation routines in the CNC controller and at corrections in real time. The problem is that most applications are only available for three-axis milling. The presented approach (compensation before machining by using software routines in a specially designed postprocessor) is based on a fuzzy logic expert system. The benefits can be summarized as data reduction, data improvement, precontrol of feed, and improved component accuracy. The applied procedure is also convenient for implementation in an industrial environment by retrofitting existing equipment. The suggested method provides improved control over machine dynamics, permitting high-speed machining centres to maintain a maximum or near-maximum feed rate despite axis reversals and tool path changes, even at corners. Two categories of results are presented, namely the management of NC data related to expected performance of the machine tool and improvements of the machine tool performance in terms of productivity and accuracy of the machined test components.
|
|
| 30. |
|
|
| 31. |
|
|
| 32. |
- Björklund, Stefan, 1969-, et al.
(författare)
-
Function-dependent coating architectures by hybrid powder-suspension plasma spraying : Injector design, processing and concept validation
- 2018
-
Ingår i: Materials & design. - : Elsevier BV. - 0264-1275 .- 1873-4197. ; 142, s. 56-65
-
Tidskriftsartikel (refereegranskat)abstract
- The attractive properties achieved by Suspension Plasma Spraying (SPS), combined with the availability of high throughput capable plasma spray systems that permit axial feeding, provide encouragement to explore use of suspensions for next generation functional applications. This paper deals with realization of coatings with various pre-determined function-dependent architectures by employing a hybrid powder-suspension feedstock. Some illustrative application-relevant coating architecture designs are discussed, along with the specific benefits that can accrue by deploying a multi-scale powder-suspension feedstock combination. An elegant feedstock delivery arrangement to enable either simultaneous or sequential feeding of powders and suspensions to enable convenient processing of coatings with desired architectures is presented. As proof-of-concept, deposition of layered, composite and functionally graded coatings using the above system is also demonstrated using appropriate case studies
|
|
| 33. |
|
|
| 34. |
- Björklund, Stefan, et al.
(författare)
-
Mediator of transcriptional regulation.
- 1996
-
Ingår i: TIBS -Trends in Biochemical Sciences. Regular ed.. - 0968-0004 .- 1362-4326. ; 21:9, s. 335-7
-
Tidskriftsartikel (refereegranskat)abstract
- A multi-protein complex, termed mediator, has been isolated from yeast, based on its requirement for transcriptional activation in a system reconstituted from pure RNA polymerase II and general transcription factors. Mediator polypeptides include the products of many genes previously recovered from screens for mutations affecting transcription. This connection between biochemical and genetic studies reveals that mediator is important for both activation and repression of transcription, and that mediator plays a role in transcriptional regulation in vivo as well as in vitro. Mediator binds the carboxy-terminal domain of RNA polymerase II, forming a polymerase holoenzyme, whose possible association with additional proteins is a subject of some controversy.
|
|
| 35. |
|
|
| 36. |
- Björklund, Stefan
(författare)
-
Reformismens anatomi : Erasmus versus Luther
- 2009
-
Bok (övrigt vetenskapligt/konstnärligt)abstract
- The author analyses the sharp philosophical debates between Erasmus Rotterdamus and Martin Luther, revolutionary and determinist, and takes that as a ground for discussion of the concept of "reformism". Ha proposes that "reformism" should [sic] used for a "step-by-step" method of political change, irrespective of the content of policies. He also tries to list some characteristics of the "reformistic" attitude.
|
|
| 37. |
- Björklund, Stefan, et al.
(författare)
-
S-phase-specific expression of mammalian ribonucleotide reductase R1 and R2 subunit mRNAs
- 1990
-
Ingår i: Biochemistry. - : American Chemical Society (ACS). - 0006-2960 .- 1520-4995. ; 29:23, s. 5452-5458
-
Tidskriftsartikel (refereegranskat)abstract
- Ribonucleotide reductase in mammalian cells is composed of two nonidentical subunits, proteins R1 and R2, each inactive alone. The R1 protein is present in excess in proliferating cells, and its levels are constant during the cell cycle. Expression of the R2 protein, which is limiting for enzyme activity, is strictly S-phase-correlated. In this paper, we have used antisense RNA probes in a solution hybridization assay to measure the levels of R1 and R2 mRNA during the cell cycle in centrifugally elutriated cells and in cells synchronized by isoleucine or serum starvation. The levels of both transcripts were very low or undetectable in G0/G1-phase cells, showed a pronounced increase as cells progressed into S phase, and then declined when cells progressed into G2 + M phase. The R1 and R2 transcripts increased in parallel, starting slightly before the rise in S-phase cells, and reached the same levels. The relative lack of cell cycle dependent variation in R1 protein levels, obtained previously, may therefore simply be a consequence of the long half-life of the R1 protein. Hydroxyurea-resistant, R2-overproducing mouse TA3 cells showed the same regulation of the R1 and R2 transcripts as the parental cells, but with R2 mRNA at a 40-fold higher level.
|
|
| 38. |
|
|
| 39. |
|
|
| 40. |
- Björklund, Stefan
(författare)
-
The influence of surface roughness in elliptical contacts
- 2001
-
Ingår i: Tribology International. - 0301-679X .- 1879-2464. ; 34:12, s. 841-845
-
Tidskriftsartikel (refereegranskat)abstract
- The influence of surface roughness on contact behaviour is of great importance in many tribological situations. In the last decade several methods to calculate the pressure distribution and the real contact area in contacts between rough surfaces have been described. A problem arising for slender elliptical contacts, such as between gear teeth, roller and raceway, cam and follower, etc., is that the size of the contact is much greater than the size of the asperities. Accordingly the number of contact nodes necessary for an accurate solution to the problem becomes excessively large. This paper describes a method to calculate the influence of three-dimensional surface roughness in contacts that are very long in one direction. The method is based on restricting the calculations to a subpart of the real contact area, while the rest of the contact is taken into account by mirroring techniques. The results show that the real contact area is very sensitive to the amplitude of the roughness, while the waviness is less important. An equation is suggested from which the real area can be calculated if the smooth case contact parameters and two roughness parameters are known.
|
|
| 41. |
- Björklund, Stefan, et al.
(författare)
-
The mediator complex
- 2004
-
Ingår i: Advances in protein chemistry. - 0065-3233 .- 1557-8941. ; 67, s. 43-65
-
Tidskriftsartikel (refereegranskat)
|
|
| 42. |
|
|
| 43. |
- Blomberg, Jeanette, et al.
(författare)
-
Interactions between DNA, transcriptional regulator Dreb2a and the Med25 mediator subunit from Arabidopsis thaliana involve conformational changes
- 2012
-
Ingår i: Nucleic Acids Research. - Oxford : Oxford University Press. - 0305-1048 .- 1362-4962. ; 40:13, s. 5938-5950
-
Tidskriftsartikel (refereegranskat)abstract
- Mediator is a multiprotein coregulatory complex that conveys signals from DNA-bound transcriptional regulators to the RNA polymerase II transcription machinery in eukaryotes. The molecular mechanisms for how these signals are transmitted are still elusive. By using purified transcription factor Dreb2a, mediator subunit Med25 from Arabidopsis thaliana, and a combination of biochemical and biophysical methods, we show that binding of Dreb2a to its canonical DNA sequence leads to an increase in secondary structure of the transcription factor. Similarly, interaction between the Dreb2a and Med25 in the absence of DNA results in conformational changes. However, the presence of the canonical Dreb2a DNA-binding site reduces the affinity between Dreb2a and Med25. We conclude that transcription regulation is facilitated by small but distinct changes in energetic and structural parameters of the involved proteins.
|
|
| 44. |
- Blomberg, Jeanette, et al.
(författare)
-
Pseudomonas syringae infectivity correlates to altered transcript and metabolite levels of Arabidopsis mediator mutants
- 2024
-
Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 14:1
-
Tidskriftsartikel (refereegranskat)abstract
- Rapid metabolic responses to pathogens are essential for plant survival and depend on numerous transcription factors. Mediator is the major transcriptional co-regulator for integration and transmission of signals from transcriptional regulators to RNA polymerase II. Using four Arabidopsis Mediator mutants, med16, med18, med25 and cdk8, we studied how differences in regulation of their transcript and metabolite levels correlate to their responses to Pseudomonas syringae infection. We found that med16 and cdk8 were susceptible, while med25 showed increased resistance. Glucosinolate, phytoalexin and carbohydrate levels were reduced already before infection in med16 and cdk8, but increased in med25, which also displayed increased benzenoids levels. Early after infection, wild type plants showed reduced glucosinolate and nucleoside levels, but increases in amino acids, benzenoids, oxylipins and the phytoalexin camalexin. The Mediator mutants showed altered levels of these metabolites and in regulation of genes encoding key enzymes for their metabolism. At later stage, mutants displayed defective levels of specific amino acids, carbohydrates, lipids and jasmonates which correlated to their infection response phenotypes. Our results reveal that MED16, MED25 and CDK8 are required for a proper, coordinated transcriptional response of genes which encode enzymes involved in important metabolic pathways for Arabidopsis responses to Pseudomonas syringae infections.
|
|
| 45. |
|
|
| 46. |
- Broach, James R, et al.
(författare)
-
The Msn2 mediated stress response : Survival based on "hedging your bet" and a dynamic interplay of transcription factor binding and nucleosome occupancy
- 2015
-
Ingår i: Yeast. - : Wiley-Blackwell. - 0749-503X .- 1097-0061. ; 32:Suppl. 1, s. S221-S222
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Yeast cell subjected to many different stresses elicit an acute transcriptional stress response mediated by the Msn2 transcription factor, which alters expression of both a stress specific-cohort of genes as well as a common cohort of genes that changes expression in a stereotypic fashion upon exposure to any of a wide variety of stresses. We have shown by dynamic single cell analysis that stresses regulate Msn2 activity through cytoplasm to nuclear relocalization but do so in an unusual way: stresses induce increased frequency of bursts of short-lived, recurrent periods of Msn2 nuclear localization with different stresses eliciting different patterns of bursts. Moreover, genetically identical cells subject to an identical stress can behave quite differently, with some cells mounting a robust nuclear occupancy of Msn2 while others show no nuclear localization at all. We have proposed that this idiosyncratic behavior allows populations of cells to “hedge their bet” as to what will be the optimum strategy for surviving the ensuing stress. We have used computational modeling and single cell analysis to determine that bursting is a consequence of noise in the stress signaling pathways amplified by the small number of Msn2 molecules in the cell. Moreover, we have applied genome wide chromatin immunoprecipitation and nucleosome profiling to address how different stresses determine where Msn2 binds under a particular stressful conditions, and thus what genes are regulated by that stress, and how that binding affects, and is affected by, nucleosome positioning and other transcription factor binding. These results provide in vivo validation of Widon's model of indirect cooperativity of transcription factor binding, mediated by partial unwinding of nucleosomes by one transcription factor to allow access for a second transcription factor to a previously occluded binding site. Finally, we have addressed the “bet hedging” hypothesis by showing that persistence of the Msn2-mediated stress response yields cell growth arrest and have identified the targets responsible for that growth arrest. We have applied experimental evolution paradigms to address the relative fitness of cells exhibiting stochastic stress responses versus those with a uniform response. In short, our results indicate that the stress response is complex and that complexity is critical for cell survival.
|
|
| 47. |
|
|
| 48. |
|
|
| 49. |
- Chereji, Razvan V., et al.
(författare)
-
Mediator binds to boundaries of chromosomal interaction domains and to proteins involved in DNA looping, RNA metabolism, chromatin remodeling, and actin assembly
- 2017
-
Ingår i: Nucleic Acids Research. - : Oxford University Press. - 0305-1048 .- 1362-4962. ; 45:15, s. 8806-8821
-
Tidskriftsartikel (refereegranskat)abstract
- Mediator is a multi-unit molecular complex that plays a key role in transferring signals from transcriptional regulators to RNA polymerase II in eukaryotes. We have combined biochemical purification of the Sac-charomyces cerevisiae Mediator from chromatin with chromatin immunoprecipitation in order to reveal Mediator occupancy on DNA genome-wide, and to identify proteins interacting specifically with Mediator on the chromatin template. Tandem mass spectrometry of proteins in immunoprecipitates of mediator complexes revealed specific interactions between Mediator and the RSC, Arp2/Arp3, CPF, CF 1A and Lsm complexes in chromatin. These factors are primarily involved in chromatin remodeling, actin assembly, mRNA 3'-end processing, gene looping and mRNA decay, but they have also been shown to enter the nucleus and participate in Pol II transcription. Moreover, we have found that Mediator, in addition to binding Pol II promoters, occupies chromosomal interacting domain (CID) boundaries and that Mediator in chromatin associates with proteins that have been shown to interact with CID boundaries, such as Sth1, Ssu72 and histone H4. This suggests that Mediator plays a significant role in higher-order genome organization.
|
|
| 50. |
- Choquet, Isabelle, 1965-, et al.
(författare)
-
Clogging and lump formation during atmospheric plasma spraying with powder injection downstream the plasma gun
- 2007
-
Ingår i: Journal of thermal spray technology (Print). - : Springer Science and Business Media LLC. - 1059-9630 .- 1544-1016. ; 16:4, s. 512-523
-
Tidskriftsartikel (refereegranskat)abstract
- This study aimed to numerically and experimentally investigate lump formation during atmospheric plasma spraying with powder injection downstream the plasma gun exit. A first set of investigations was focused on the location and orientation of the powder port injector. It turned out impossible to keep the coating quality while avoiding lumps by simply moving the powder injector. A new geometry of the powder port ring holder was designed and optimized to prevent nozzle clogging, and lump formation using a gas screen. This solution was successfully tested for applications with Ni-5wt.%Al and ZrO2-7wt.%Y2O3 powders used in production. The possible secondary effect of plasma jet shrouding by the gas screen, and its consequence on powder particles prior to impact was also studied.
|
|
