| 1. |
- Andersson, A. F., et al.
(författare)
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Comparative analysis of human gut microbiota by barcoded pyrosequencing
- 2008
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 3:7
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Tidskriftsartikel (refereegranskat)abstract
- Humans host complex microbial communities believed to contribute to health maintenance and, when in imbalance, to the development of diseases. Determining the microbial composition in patients and healthy controls may thus provide novel therapeutic targets. For this purpose, high-throughput, cost-effective methods for microbiota characterization are needed. We have employed 454-pyrosequencing of a hyper-variable region of the 16S rRNA gene in combination with sample-specific barcode sequences which enables parallel in-depth analysis of hundreds of samples with limited sample processing. In silico modeling demonstrated that the method correctly describes microbial communities down to phylotypes below the genus level. Here we applied the technique to analyze microbial communities in throat, stomach and fecal samples. Our results demonstrate the applicability of barcoded pyrosequencing as a high-throughput method for comparative microbial ecology.
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| 2. |
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| 3. |
- Andersson, Fredrik, 1973-, et al.
(författare)
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Bland småbrukare och storspioner
- 2008
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Ingår i: Provins: Norrländsk litterär tidskrift. - Piteå : Norrländska författarsällskapet. - 0280-9974. ; :1
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 4. |
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| 6. |
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| 7. |
- Andersson, Fredrik, 1973-, et al.
(författare)
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The vision thing : Actors, decision-making and lock-in effects in Swedish road safety policy since the 1990s
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This paper investigates the introduction of and consequences of the “Vision Zero” (Nollvisionen) that was part of a law passed in 1997 and called for a radical reduction of deaths caused by road traffic. We try to answer the question why the Vision Zero has failed to reach its goals for the last ten years. The introduction of the Vision Zero can be explained with a combination of changes in traffic policy and welfare policy, together with a reorganization of the transport sector that created new opportunities for old interest groups. Our main conclusion is that the strong idealistic and visionary political goals in the Vision Zero are in line with a Swedish tradition of over-arching visionary national goals for the transport sector in general. Idealistic goals suppressed critical objections, but at the same time there were insufficient resources for investments and lack of approval for the policy from actors within the sector, which can create lock-in effects and actually prevent effective policies from being implemented. This might explain the relative ineffectiveness of the policy, and the slim chances of the Vision Zero to ever being achieved.
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| 10. |
- Franke Stenport, Victoria, 1970, et al.
(författare)
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Precipitation of calcium phosphate in the presence of albumin on titanium implants with four different possibly bioactive surface preparations. An in vitro study
- 2008
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Ingår i: Journal of Materials Science: Materials in Medicine. - : Springer Science and Business Media LLC. - 0957-4530 .- 1573-4838. ; 19:12, s. 3497-3505
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to compare the nucleating behaviour on four types of bioactive surfaces by using the simulated body fluid (SBF) model with the presence albumin. Titanium discs were blasted (B) and then prepared by alkali and heat treatment (AH), anodic oxidation (AO), fluoridation (F), or hydroxyapatite coating (HA). The discs were immersed in SBF with 4.5 mg/ml albumin for 3 days, 1, 2, 3 and 4 weeks and analysed with scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDX) and X-ray photoelectron spectroscopy (XPS). Topographic surface characterisation was performed with a contact stylus profilometer. The results demonstrated that the bioactive surfaces initiated an enhanced calcium phosphate (CaP) formation and a more rapid increase of protein content was present on the bioactive surfaces compared to the blasted control surface. The observation was present on all bioactive surfaces. The fact that there was a difference between the bioactive surfaces and the blasted control surface with respect to precipitation of CaP and protein content on the surfaces support the fact that there may be biochemical advantages in vivo by using a bioactive surface.
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| 11. |
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| 14. |
- Gudjonsson, Gudjon, 1973, et al.
(författare)
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Design and Fabrication of 4H-SiC RF MOSFETs
- 2007
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Ingår i: IEEE Transactions on Electron Devices. - 1557-9646 .- 0018-9383. ; 54:12, s. 3138-3145
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Tidskriftsartikel (refereegranskat)abstract
- We present simulations, fabrication and analysis of 4H-SiC RF power MOSFETs. We obtain an extrinsic transition frequency of 11.2 GHz and an f max = 11.9 GHz, a breakdown voltage above 200 V and an output power of 1.9 W/mm at 3 GHz. The measured devices are double fingered, source-gate-draingate-source with 2 × 0.4 mm total gate width and the nominal channel length of the devices is 0.5 μm. To the authors knowledge, this is the highest transition frequency and output power density ever reported for SiC RF MOSFETs. The antipunchthrough is introduced as a way to take advantage of the SiC's material properties. A detailed description of the device processing is also given. © 2007 IEEE.
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| 15. |
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| 16. |
- Gudjonsson, Gudjon, 1973, et al.
(författare)
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High Power Density 4H-SiC RF MOSFETs
- 2006
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Ingår i: IEEE Electron Device Letters. ; 527-529, s. 1277-1280
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Tidskriftsartikel (refereegranskat)
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| 17. |
- Krohn Andersson, Fredrik, 1973-
(författare)
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"By, landskap, kraftverk" : Kärnkraftens poetik
- 2009
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Ingår i: Linköping Electronic Conference Proceedings: Kultur~Natur. - Linköping : Linköping University Electronic Press. ; , s. 51-59
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Konferensbidrag (refereegranskat)
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| 18. |
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| 19. |
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| 20. |
- Krohn Andersson, Fredrik, 1973-
(författare)
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Kärnkraftens arkitektur
- 2008
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Ingår i: Dædalus. - Stockholm : Tekniska museet. - 9789176160688 ; , s. 104-122
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Bokkapitel (populärvet., debatt m.m.)
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| 24. |
- Meirelles, Luiz, 1974, et al.
(författare)
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Bone reaction to nano hydroxyapatite modified titanium implants placed in a gap-healing model
- 2008
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Ingår i: Journal Biomedical MAterials Research - A. - : Wiley. - 1549-3296 .- 1552-4965. ; 87:3, s. 624-631
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Tidskriftsartikel (refereegranskat)abstract
- Nanohydroxyapatite materials show similar chemistry to the bone apatite and depending on the underlying topography and the method of preparation, the nanohydroxyapatite may simulate the specific arrangement of the crystals in bone. Hydroxyapatite (HA) and other CaP materials have been indicated in cases in which the optimal surgical fit is not achievable during surgery, and the HA surface properties may enhance bone filling of the defect area. In this study, very smooth electropolished titanium implants were used as substrata for nano-HA surface modification and as control. One of each implant (control and nano HA) was placed in the rabbit tibia in a surgical site 0.7 mm wider than the implant diameter, resulting in a gap of 0.35 mm on each implant side. Implant stability was ensured by a fixating plate fastened with two side screws. Topographical evaluation performed with an optical interferometer revealed the absence of microstructures on both implants and higher resolution evaluation with AFM showed similar nanoroughness parameters. Surface pores detected on the AFM measurements had similar diameter, depth, and surface porosity (%). Histological evaluation demonstrated similar bone formation for the nano HA and electropolished implants after 4 weeks of healing. These results do not support that nano-HA chemistry and nanotopography will enhance bone formation when placed in a gap-healing model. The very smooth surface may have prevented optimal activity of the material and future studies may evaluate the synergic effects of the surface chemistry, micro, and nanotopography, establishing the optimal parameters for each of them.
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