排序方式: 共有24条查询结果,搜索用时 453 毫秒
21.
V. Barii F. Klingstedt A. Naydenov P. Stefanov P. Kilpinen M. Hupa 《Catalysis Today》2005,100(3-4):337-342
The correlation between the catalytic activity towards N2O decomposition and fuel type was studied for the bed materials sampled from the bottom bed of two industrial CFB boilers, a 12 MWth and a 550 MWth, burning biomass fuels and wastes, alone or as a mixture. It was found that the elemental composition of the surface of the bed material particles changed according to the composition of the ash from the parent fuel. The measured catalytic activity of the bed material samples increased with the amount of the catalytically active oxides (CaO, MgO, Fe2O3, Al2O3). In the case of limestone addition, the activity of the bed material was influenced by both the elemental composition of the fuel, and the ratio between lime and sulfated lime. 相似文献
22.
R. Burch J.P. Breen C.J. Hill B. Krutzsch B. Konrad E. Jobson L. Cider K. Eränen F. Klingstedt L.-E. Lindfors 《Topics in Catalysis》2004,(1):19-25
The effect of the addition of hydrogen on the SCR of NO
x
with a hydrocarbon reaction was investigated. It was found that hydrogen had a remarkable effect on the temperature range over which NO
x
could be reduced during the SCR reaction with octane. Reduction of NO
x
was initiated at as low a temperature as 100 °C and >95% NO
x
conversion was achieved over a temperature range of 200–450 °C. Hydrogen has the effect of activating octane at lower temperatures and also promotes the oxidation of NO to NO2 in the absence of hydrocarbon. Transient kinetic and in situ DRIFTS measurements indicated that hydrogen has a direct role in the reaction mechanism by either promoting the formation and storage of an organic C = N species which can then readily reduce NO
x
and/or removing a species which acts as a poison to the SCR reaction at low temperatures. 相似文献
23.
Dr. Therése Klingstedt Dr. Hamid Shirani Dr. Bernardino Ghetti Dr. Ruben Vidal Prof. K. Peter R. Nilsson 《Chembiochem : a European journal of chemical biology》2021,22(15):2568-2581
In several neurodegenerative diseases, the presence of aggregates of specific proteins in the brain is a significant pathological hallmark; thus, developing ligands able to bind to the aggregated proteins is essential for any effort related to imaging and therapeutics. Here we report the synthesis of thiophene-based ligands containing nitrogen heterocycles. The ligands selectively recognized amyloid-β (Aβ) aggregates in brain tissue from individuals diagnosed neuropathologically as having Alzheimer's disease (AD). The selectivity for Aβ was dependent on the position of nitrogen in the heterocyclic compounds, and the ability to bind Aβ was shown to be reduced when introducing anionic substituents on the thiophene backbone. Our findings provide the structural and functional basis for the development of ligands that can differentiate between aggregated proteinaceous species comprised of distinct proteins. These ligands might also be powerful tools for studying the pathogenesis of Aβ aggregation and for designing molecules for imaging of Aβ pathology. 相似文献
24.
Linnea Björk Dr. Therése Klingstedt Prof. K. Peter R. Nilsson 《Chembiochem : a European journal of chemical biology》2023,24(11):e202300044
The development of ligands for detecting protein aggregates is of great interest, as these aggregated proteinaceous species are the pathological hallmarks of several devastating diseases, including Alzheimer's disease. In this regard, thiophene-based ligands have emerged as powerful tools for fluorescent assessment of these pathological entities. The intrinsic conformationally sensitive photophysical properties of poly- and oligothiophenes have allowed optical assignment of disease-associated protein aggregates in tissue sections, as well as real-time in vivo imaging of protein deposits. Herein, we recount the chemical evolution of different generations of thiophene-based ligands, and exemplify their use for the optical distinction of polymorphic protein aggregates. Furthermore, the chemical determinants for achieving a superior fluorescent thiophene-based ligand, as well as the next generation of thiophene-based ligands targeting distinct aggregated species are described. Finally, the directions for future research into the chemical design of thiophene-based ligands that can aid in resolving the scientific challenges around protein aggregation diseases are discussed. 相似文献