| 1. |
- Almeida, Joao, et al.
(författare)
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Increased tolerance and conversion of inhibitors in lignocellulosic hydrolysates by Saccharomyces cerevisiae
- 2007
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Ingår i: Journal of Chemical Technology and Biotechnology. - : Wiley. - 0268-2575 .- 1097-4660. ; 82:4, s. 340-349
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Forskningsöversikt (refereegranskat)abstract
- During hydrolysis of lignocellulosic biomass, monomeric sugars and a broad range of inhibitory compounds are formed and released. These inhibitors, which can be organized around three main groups, furans, weak acids and phenolics, reduce ethanol yield and productivity by affecting the microorganism performance during the fermentation step. Among the microorganisms that have been evaluated for lignocellulosic hydrolysate ethanol fermentation, the yeast Saccharomyces cerevisiae appears to be the least sensitive. In order to overcome the effect of inhibitors, strategies that include improvement of natural tolerance of microorganism and use of fermentation control strategies have been developed. An overview of the origin, effects and mechanisms of action of known inhibitors on S. cerevisiae is given. Fermentation control strategies as well as metabolic, genetic and evolutionary engineering strategies to obtain S. cerevisiae strains with improved tolerance are discussed.
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| 2. |
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| 3. |
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| 4. |
- Johnsdotter, Sara
(creator_code:cre_t, creator_code:res_t)
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Forskarnas galleri #2 : 6 om sex
- 2017
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Konstnärligt arbeteabstract
- Utgångspunkten är en presentation av sex forskare, knutna till Centrum för sexologi och sexualitetsstudier, som berättar om sina respektive forskningsfält. Utställningen består också av en tidslinje med nedslag i den svenska sexualitetshistorien, ett tittskåp med kuriosa och en samling litteratur. I en brevlåda kan besökaren kommentera eller ställa frågor till forskarna, svaren projiceras på väggen. Två offentliga samtal arrangeras och filmas; Sex och makt och Tema erotisk litteratur. I samband med utställningen visas konstprojektet "Kyss" där prästen och konstnären Kent Wisti och författaren Maria Küchen i bild och text tolkat Höga visan.
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| 5. |
- Mannerberg, Annika, et al.
(författare)
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Faster and more accurate patient positioning with surface guided radiotherapy for ultra-hypofractionated prostate cancer patients
- 2021
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Ingår i: Technical Innovations and Patient Support in Radiation Oncology. - : Elsevier BV. - 2405-6324. ; 19, s. 41-45
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: The aim of this study was to evaluate if surface guided radiotherapy (SGRT) can decrease patient positioning time for localized prostate cancer patients compared to the conventional 3-point localization setup method. The patient setup accuracy was also compared between the two setup methods. Materials and methods: A total of 40 localized prostate cancer patients were enrolled in this study, where 20 patients were positioned with surface imaging (SI) and 20 patients were positioned with 3-point localization. The setup time was obtained from the system log files of the linear accelerator and compared between the two methods. The patient setup was verified with daily orthogonal kV images which were matched based on the implanted gold fiducial markers. Resulting setup deviations between planned and online positions were compared between SI and 3-point localization. Results: Median setup time was 2:50 min and 3:28 min for SI and 3-point localization, respectively (p < 0.001). The median vector offset was 4.7 mm (range: 0–10.4 mm) for SI and 5.2 mm for 3-point localization (range: 0.41–17.3 mm) (p = 0.01). Median setup deviation in the individual translations for SI and 3-point localization respectively was: 1.1 mm and 1.9 mm in lateral direction (p = 0.02), 1.8 and 1.6 mm in the longitudinal direction (p = 0.41) and 2.2 mm and 2.6 mm in the vertical direction (p = 0.04). Conclusions: Using SGRT for positioning of prostate cancer patients provided a faster and more accurate patient positioning compared to the conventional 3-point localization setup.
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| 6. |
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| 7. |
- Mannerberg, Annika, et al.
(författare)
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Surface guided electron FLASH radiotherapy for canine cancer patients
- 2023
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Ingår i: Medical Physics. - 0094-2405. ; 50:7, s. 4047-4054
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundDuring recent years FLASH radiotherapy (FLASH-RT) has shown promising results in radiation oncology, with the potential to spare normal tissue while maintaining the antitumor effects. The high speed of the FLASH-RT delivery increases the need for fast and precise motion monitoring to avoid underdosing the target. Surface guided radiotherapy (SGRT) uses surface imaging (SI) to render a 3D surface of the patient. SI provides real-time motion monitoring and has a large scanning field of view, covering off-isocentric positions. However, SI has so far only been used for human patients with conventional setup and treatment.PurposeThe aim of this study was to investigate the performance of SI as a motion management tool during electron FLASH-RT of canine cancer patients.MethodsTo evaluate the SI system's ability to render surfaces of fur, three fur-like blankets in white, grey, and black were used to imitate the surface of canine patients and the camera settings were optimized for each blanket. Phantom measurements using the fur blankets were carried out, simulating respiratory motion and sudden shift. Respiratory motion was simulated using the QUASAR Respiratory Motion Phantom with the fur blankets placed on the phantom platform, which moved 10 mm vertically with a simulated respiratory period of 4 s. Sudden motion was simulated with an in-house developed phantom, consisting of a platform which was moved vertically in a stepwise motion at a chosen frequency. For sudden measurements, 1, 2, 3, 4, 5, 6, 7, and 10 Hz were measured. All measurements were both carried out at the conventional source-to-surface distance (SSD) of 100 cm, and in the locally used FLASH-RT setup at SSD = 70 cm. The capability of the SI system to reproduce the simulated motion and the sampling time were evaluated. As an initial step towards clinical implementation, the feasibility of SI for surface guided FLASH-RT was evaluated for 11 canine cancer patients.ResultsThe SI camera was capable of rendering surfaces for all blankets. The deviation between simulated and measured mean peak-to-peak breathing amplitude was within 0.6 mm for all blankets. The sampling time was generally higher for the black fur than for the white and grey fur, for the measurement of both respiratory and sudden motion. The SI system could measure sudden motion within 62.5 ms and detect motion with a frequency of 10 Hz. The feasibility study of the canine patients showed that the SI system could be an important tool to ensure patient safety. By using this system we could ensure and document that 10 out of 11 canine patients had a total vector offset from the reference setup position ConclusionsWe have shown that SI can be used for surface guided FLASH-RT of canine patients. The SI system is currently not fast enough to interrupt a FLASH-RT beam while irradiating but with the short sampling time sudden motion can be detected. The beam can therefore be held just prior to irradiation, preventing treatment errors such as underdosing the target.
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| 8. |
- Palmqvist, Benny, et al.
(författare)
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Scale-up of high-solid enzymatic hydrolysis of steam-pretreated softwood : the effects of reactor flow conditions
- 2016
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Ingår i: Biomass Conversion and Biorefinery. - : Springer Science and Business Media LLC. - 2190-6815 .- 2190-6823. ; 6:2, s. 173-180
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Tidskriftsartikel (refereegranskat)abstract
- The importance of flow conditions during scale-up of high-solid enzymatic hydrolysis of steam-pretreated spruce was demonstrated by comparing hydrolysis rates between laboratory (2 L) and demonstration (4 m3) scale. A positive effect of increased agitation speed on the rate of enzymatic hydrolysis was found regardless of scale. Importantly, the hydrolysis rate was higher at the larger scale when compared at similar specific power inputs. Changes in the rheological properties of the pretreated material during the hydrolysis were followed by off-line measurements of apparent viscosity. This information was used to estimate the flow conditions in the reactors, i.e., average Reynolds numbers, which together with measured mixing power consumptions enabled a more detailed comparison between the scales. The hydrolysis yields correlated better with average Reynolds numbers than specific power input over the different scales. This indicates that mass transport limitations, caused by insufficient bulk flow, likely play a decisive role in determining the rate of enzymatic hydrolysis.
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| 9. |
- Petersson, Anneli
(författare)
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Biogas cleaning
- 2013
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Ingår i: The Biogas Handbook: Science, Production and Applications. - : Elsevier Inc.. - 9780857097415 - 9780857094988 ; , s. 329-341
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Biogas contains not only methane, carbon dioxide and water, but may also contain other compounds in small amounts. These impurities can affect the equipment for biogas utilisation, by causing corrosion and mechanical wear, but may also lead to unwanted emissions. Depending on how the biogas is going to be utilised it often needs some form of cleaning to reduce the amount of unwanted impurities. The effects that different impurities may cause when biogas is utilised and technologies to reduce their concentrations are reviewed in this chapter.
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| 10. |
- Petersson, Anneli, et al.
(författare)
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Fed-batch cultivation of Saccharomyces cerevisiae on lignocellulosic hydrolyzate
- 2007
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Ingår i: Biotechnology Letters. - : Springer Science and Business Media LLC. - 1573-6776 .- 0141-5492. ; 29:2, s. 219-225
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Tidskriftsartikel (refereegranskat)abstract
- Saccharomyces cerevisiae grows very poorly in dilute acid lignocellulosic hydrolyzate during the anaerobic fermentation for fuel ethanol production. However, yeast cells grown aerobically on the hydrolyzate have increased tolerance for the hydrolyzate. Cultivation of yeast on part of the hydrolyzate has therefore the potential of enabling increased ethanol productivity in the fermentation of the hydrolyzate. To evaluate the ability of the yeast to grow in the hydrolyzate, fed-batch cultivations were run using the ethanol concentration as input variable to control the feed-rate. The yeast then grew in an undetoxified hydrolyzate with a specific growth rate of 0.19 h(-1) by controlling the ethanol concentration at a low level during the cultivation. However, the biomass yield was lower for the cultivation on hydrolyzate compared to synthetic media: with an ethanol set-point of 0.25 g/l the yield was 0.46 g/g on the hydrolyzate, compared to 0.52 g/g for synthetic media. The main reason for the difference was not the ethanol production per se, but a significant production of glycerol at a high specific growth rate. The glycerol production may be attributed to an insufficient respiratory capacity.
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