The thermal annealing effects on the photocarrier dynamics in thin films of [6,6]-phenyl C61 butyric acid methyl ester (PCBM) on quartz substrates are investigated. Both the photocarrier generation via charge-transfer state and the charge transport in PCBM films are studied by time-resolved photoconductance (PC) measurement. More than 90% of external photocarrier generation efficiency relative to the non-annealed film is reduced upon annealing of the PCBM film at high temperatures. Excitation light power dependence of PC indicates that the photocarrier in the non-annealed film is generated by a one-photon process, while photons of more than one are required in highly annealed films. The multiphotonic process for carrier generation and the substantial reduction of carrier density caused by the thermal treatment are associated with trap formation. The density of photoinjected carrier is also affected by applying external magnetic field. The observed positive magnetophotoconductance (MPC) in non-annealed film is understood in terms of the incoherent spin conversion in nongeminate electron–hole (e–h) pairs with a selective recombination from singlet e–h pairs. In highly annealed film, the broad magnetic field dependence of MPC with negative phase is suggested to originate from the detrapping of trapped carrier assisted by collision with the triplet exciton.

The microtubule-binding protein tau has been the center of researches concerning Alzheimer’s disease (AD) due to several clinical trials of β-amyloid therapies failing recently. The availability of the tau fibril structure from AD brain enables computational modeling studies to calculate binding affinities with different ligands. In this study, the tau paired helical filaments (PHF-Tau) (PDB ID: 5O3L) was used as receptor and interactions with the lipids: 3-alpha-cholesterol; 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine; and C18:1 sphingomyelin, were explored with molecular docking, molecular dynamics, and natural bond orbital analysis. Docking sites upon solvation of the protein with transferable interatomic potential-3 points reveal the amphipathic nature of PHF-Tau and molecular dynamics simulations show that the embedded phosphocholine at the tail side gives high potential energy values with some amino acids forming H-bond interactions.