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Visar resultat 21 - 25 av 337 avhandlingar som matchar ovanstående sökkriterier.

1. 21. Quantum Chemistry for Large Systems

   Författare :Elias Rudberg; Pawel Salek; Christian Ochsenfeld; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum chemistry; fast multipole method; density matrix purification; sparse matrices; Theoretical chemistry; Teoretisk kemi;

   Sammanfattning : This thesis deals with quantum chemistry methods for large systems. In particular, the thesis focuses on the efficient construction of the Coulomb and exchange matrices which are important parts of the Fock matrix in Hartree-Fock calculations. LÄS MER

3. 22. Computational chemistry studies of UV induced processes in human skin

   Författare :Jonas Danielsson; Aatto Laaksonen; Villy Sundström; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Photochemistry; Theoretical chemistry; Density functional theory; UV effects; TD-DFT; enzyme catalysis; DNA damage; Molecular dynamics; Physical chemistry; Fysikalisk kemi;

   Sammanfattning : This thesis presents and uses the techniques of computational chemistry to explore two different processes induced in human skin by ultraviolet light. The first is the transformation of urocanic acid into a immunosuppressing agent, and the other is the enzymatic action of the 8-oxoguanine glycosylase enzyme. LÄS MER

4. 23. Theoretical modeling of metal- and enzyme catalyzed transformations

   Författare :Jonas Nyhlén; Jan-Erling Bäckvall; Timofei Privalov; Walter Thiel; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; density functinal theory; computational chemistry; directed evolution; enzyme; mechanistic studies; catalysis; ruthenium; hydrogen transfer; racemization; artificial photosynthesis; frustrated lewis pairs; hydrogen storage; Organic chemistry; Organisk kemi; organisk kemi; Organic Chemistry;

   Sammanfattning : This thesis is focused on describing and predicting catalytic reactions. The major part of the work is based on density functional theory (DFT). In some cases where the size of the investigated system precluded the use of more accurate methods molecular dynamics was employed. LÄS MER

5. 24. Computational studies of photodynamic drugs, phototoxic reactions and drug design

   Författare :Klefah Abrahem Klefah Musa; Leif Eriksson; Nino Russo; Örebro universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NSAIDs; fluoroquinolone; photodegradation; phototoxicity; drug design; DFT; TD-DFT; Biophysical chemistry; Biofysikalisk kemi; Chemistry; Kemi;

   Sammanfattning : The most important criterion when designing new drugs or improving old ones in order to prevent side effects or at least diminish them is drug safety. Treatment of all diseases generally needs use of either topical application or systemic medications (transported in the blood) during a certain period of time. LÄS MER

7. 25. Modified Glycopeptides Targeting Rheumatoid Arthritis : Exploring molecular interactions in class II MHC/glycopeptide/T-cell receptor complexes

   Författare :Ida E. Andersson; Jan Kihlberg; Anna Linusson Jonsson; Craig Crews; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Major histocompatibility complex; class II MHC; T-cell receptor; rheumatoid arthritis; collagen-induced arthritis; glycopeptide; amide bond isostere; comparative modeling; rational design; molecular docking; molecular dynamics simulation; statistical molecular design; Bioorganic chemistry; Bioorganisk kemi; organisk kemi; Organic Chemistry; Biorganic Chemistry; bioorganisk kemi; datorlingvistik; computational linguistics;

   Sammanfattning : Rheumatoid arthritis (RA) is an autoimmune inflammatory disease that leads to degradation of cartilage and bone mainly in peripheral joints. In collagen-induced arthritis (CIA), a mouse model for RA, activation of autoimmune CD4+ T cells depends on a molecular recognition system where T-cell receptors (TCRs) recognize a complex between the class II MHC Aq protein and CII259-273, a glycopeptide epitope from type II collagen (CII). LÄS MER