| 1. |
- Cema, G., et al.
(författare)
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Deammonification in an aerobic Rotating Biological Contactor (RBC)
- 2008
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Ingår i: Int. Workshop Manage. Pollut. Emiss. Landfills Sludge. - 9780415433372 ; , s. 211-218
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Konferensbidrag (refereegranskat)abstract
- Leachate from landfills is a highly complex polluted wastewater. Landfill leachate with a high concentration of ammonium nitrogen is generally difficult to treat, efficiently. Furthermore, it can be very expensive when there is lack of an easily biodegradable carbon source. Combination of the nitrification/denitrification with the Anammox process can be a very attractive alternative. For the purpose of this study, a Rotating Biological Contactor (RBC) was used. The main objective of the research was to investigate the performance of the Anammox process that occurs together with heterotrophic denitrification in the same RBC. During the operation period the acclimation of biofilm to the Anammox process was successful at temperature not exceeding 20°C. Apparently, the process was not affected by a high concentration of nitrite up to 100 g NO2-N m-3 Additionally, it was shown that the Stover-Kincannon model could be used for description of the ammonium and nitrite removal rates.
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| 2. |
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| 3. |
- Cema, Grzegorz, et al.
(författare)
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Simultaneous nitrification, anammox and denitrification in aerobic rotating biological contactor (RBC) treating landfill leachate
- 2008
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Ingår i: Management of Pollutant Emission from Landfills and Sludge. - London : Taylor & Francis Group. - 9780415433372 ; , s. 211-218
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Bokkapitel (refereegranskat)abstract
- Leachate from landfills is a highly complex polluted wastewater. Landfill leachate with a high concentration of ammonium nitrogen is generally difficult to treat efficiently. Furthermore, it can be very expensive when there is a lack of an easily biodegradable carbon source. Combination of the nitrification/denitrification with the Anammox process can be a very attractive alternative. For the purpose of this study, a Rotating Biological Contactor (RBC) was used. The main objective of the research was to investigate the performance of the Anammox process that occurs together with heterotrophic denitrication in the same RBC. During the operation period, the acclimation of biofilm to the Anammox process was successful at temperature not exceeding 20C. Apparently, the process was not affected by a high concentration of nitrite up to 100 g NO2 Nm3. Additionally, it was shown that the Stover-Kineannon model could be used for description of the ammonium and nitrite removal rates. Leachate from landfills is a highly complex polluted wastewater. Landfill leachate with a high concentration of ammonium nitrogen is generally difficult to treat efficiently. Furthermore, it can be very expensive when there is a lack of an easily biodegradable carbon source. Combination of the nitrification/denitrification with the Anammox process can be a very attractive alternative. For the purpose of this study, a Rotating Biological Contactor (RBC) was used. The main objective of the research was to investigate the performance of the Anammox process that occurs together with heterotrophic denitrication in the same RBC. During the operation period, the acclimation of biofilm to the Anammox process was successful at temperature not exceeding 20C. Apparently, the process was not affected by a high concentration of nitrite up to 100 g NO2 Nm³. Additionally, it was shown that the Stover-Kineannon model could be used for description of the ammonium and nitrite removal rates.
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| 6. |
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| 7. |
- Plaza-Menacho, Iván, et al.
(författare)
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Ras/ERK1/2-mediated STAT3 Ser727 phosphorylation by familial medullary thyroid carcinoma-associated RET mutants induces full activation of STAT3 and is required for c-fos promoter activation, cell mitogenicity, and transformation.
- 2007
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Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 282:9, s. 6415-24
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Tidskriftsartikel (refereegranskat)abstract
- The precise role of STAT3 Ser(727) phosphorylation in RET-mediated cell transformation and oncogenesis is not well understood. In this study, we have shown that familial medullary thyroid carcinoma (FMTC) mutants RET(Y791F) and RET(S891A) induced, in addition to Tyr(705) phosphorylation, constitutive STAT3 Ser(727) phosphorylation. Using inhibitors and dominant negative constructs, we have demonstrated that RET(Y791F) and RET(S891A) induce STAT3 Ser(727) phosphorylation via a canonical Ras/ERK1/2 pathway and that integration of the Ras/ERK1/2/ELK-1 and STAT3 pathways was required for up-regulation of the c-fos promoter by FMTC-RET. Moreover, inhibition of ERK1/2 had a more severe effect on cell proliferation and cell phenotype in HEK293 cells expressing RET(S891A) compared with control and RET(WT)-transfected cells. The transforming activity of RET(Y791F) and RET(S891A) in NIH-3T3 cells was also inhibited by U0126, indicating a role of the ERK1/2 pathway in RET-mediated transformation. To investigate the biological significance of Ras/ERK1/2-induced STAT3 Ser(727) phosphorylation for cell proliferation and transformation, N-Ras-transformed NIH-3T3 cells were employed. These cells displayed elevated levels of activated ERK1/2 and Ser(727)-phosphorylated STAT3, which were inhibited by treatment with U0126. Importantly, overexpression of STAT3, in which the Ser(727) was mutated into Ala (STAT3(S727A)), rescued the transformed phenotype of N-Ras-transformed cells. Immunohistochemistry in tumor samples from FMTC patients showed strong nuclear staining of phosphorylated ERK1/2 and Ser(727) STAT3. These data show that FMTC-RET mutants activate a Ras/ERK1/2/STAT3 Ser(727) pathway, which plays an important role in cell mitogenicity and transformation.
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