| 1. |
- Aspholm-Hurtig, Marina, et al.
(författare)
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Functional adaptation of BabA, the H. pylori ABO blood group antigen binding adhesin.
- 2004
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Ingår i: Science (New York, N.Y.). - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 305:5683, s. 519-22
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Tidskriftsartikel (refereegranskat)abstract
- Adherence by Helicobacter pylori increases the risk of gastric disease. Here, we report that more than 95% of strains that bind fucosylated blood group antigen bind A, B, and O antigens (generalists), whereas 60% of adherent South American Amerindian strains bind blood group O antigens best (specialists). This specialization coincides with the unique predominance of blood group O in these Amerindians. Strains differed about 1500-fold in binding affinities, and diversifying selection was evident in babA sequences. We propose that cycles of selection for increased and decreased bacterial adherence contribute to babA diversity and that these cycles have led to gradual replacement of generalist binding by specialist binding in blood group O-dominant human populations.
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| 2. |
- Link, Siim, et al.
(författare)
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Atmospheric fluidized bed gasification of untreated and leached olive residue, and co-gasification of olive residue, reed, pine pellets and Douglas fir wood chips
- 2012
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 94, s. 89-97
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Tidskriftsartikel (refereegranskat)abstract
- The fluidized bed gasification of untreated and pre-treated olive residue and pre-treated olive residue mixed with reed, pine pellets and Douglas fir wood chips is studied. Leaching is used as a pre-treatment process targeted on the elimination of alkali metals such as K and Na as well as chlorine to reduce/eliminate the ash-related problems during gasification. The leaching pre-treatment process could affect the producer gas composition toward the lower or higher yield of CO and H-2 of the producer gas depending on the moisture content of parent fuels. The lower total tar yield of the producer gas in the case of leached olive residue was observed compared to untreated olive residue. At the same time, there are present wider varieties of different tar components in the producer gas of the leached olive residue compared to the untreated one. The distinctions in tar composition and content between the leached and untreated olive residue are attributed to the alkali and alkali earth metal and chorine chemistry affected by leaching pre-treatment. The addition of woody fuels and reed at elevated proportions resulted in the lower LHV value compared to the leached olive residue. The tar content of the producer gas is seen to increase adding reed and woody fuels to the leached olive residue, i.e. the producer gas contained additional variety of tar components whereas phenol becomes one of the key components determining the total tar content, apart from benzene, toluene and naphthalene. This is seen to be due to the higher cellulose, hemicelluloses, lignin as well as higher chlorine content of the reed and woody fuels compared to the leached olive residue. The olive residue is seen to be better fuel for gasification compared with woody fuels and reed. Even more, we believe that the leached olive residue is better compared to all other tested fuel/mixtures in this study. It is seen that the proportions of different fuels in the mixture play role in the composition of the producer gas.
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