Epstein–Barr virus (EBV) is a causative agent of infectious mononucleosis and several types of cancer. Like other herpesviruses, it establishes an asymptomatic, life-long latent infection, with occasional reactivation and shedding of progeny viruses. During latency, EBV expresses a small number of viral genes, and exists as an episome in the host–cell nucleus. Expression patterns of latency genes are dependent on the cell type, time after infection, and milieu of the cell (e.g., germinal center or peripheral blood). Upon lytic induction, expression of the viral immediate-early genes, BZLF1 and BRLF1, are induced, followed by early gene expression, viral DNA replication, late gene expression, and maturation and egress of progeny virions. Furthermore, EBV reactivation involves more than just progeny production. The EBV life cycle is regulated by signal transduction, transcription factors, promoter sequences, epigenetics, and the 3D structure of the genome. In this article, the molecular basis of EBV latency establishment and reactivation is summarized.

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Sugar alcohols are one promising candidate for phase-change materials (PCMs) in energy industrial societies because of their large thermal storage capacity. In this paper, we investigate the melting point and enthalpy of fusion related to the thermal storage of six-carbon sugar alcohols (galactitol, mannitol, sorbitol, and iditol) by molecular dynamics simulations and elucidate physical principles required for new PCM design. The computational melting points and enthalpies of fusion reproduce the experimental trend qualitatively. On the basis of the energy decomposition analysis we find that their enthalpies of fusion originate mainly from the decrease in the number and strength of intermolecular hydrogen bonds upon melting. Furthermore, we examine the origin of the difference of enthalpy of fusion between the four isomers. The results show that the larger enthalpy of fusion of galactitol and mannitol comes from their stable solid phases associated with the absence of notable repulsive electrostatic interaction between oxygen atoms in the molecule. In accordance with these results and an additional statistical survey, we propose the 3-fold guideline for developing new sugar alcohol like PCMs with larger thermal storage: (1) linear elongation of a carbon backbone, (2) separated distribution of OH groups, and (3) even numbers of carbon atoms.

Proton-coupled electron transfer (PCET) and hydrogen atom transfer (HAT) reactions of the phenoxyl/phenol couple are studied theoretically by using wave function theory (WFT) as well as DFT methods. At the complete active space self-consistent field (CASSCF) level, geometry optimization is found to give two transition states (TSs); one is the PCET type with two benzene rings being nearly coplanar, and the other is the HAT type with two benzene rings taking a stacking structure. Geometry optimization at the (semilocal) DFT level, on the other hand, is found to give only one transition state (i.e., the PCET-type one) and fail to obtain the stacking TS structure. By comparing various levels of theories (including long-range corrected DFT functionals), we demonstrate that the Hartree-Fock exchange at long range plays a critical role in obtaining the sufficient stacking stabilization of the present open-shell system, and that the sole addition of empirical dispersion correction to semilocal DFT functionals may not be adequate for describing such a stacking interaction. Next, we investigate the solvent effect on the PCET and HAT TS thus obtained using the reference interaction site model self-consistent field (RISM-SCF) method. The results suggest that the free energy barrier increases with increasing polarity of the solvent, and that the solvent effects are stronger for the PCET TS than the stacking HAT TS pathway. The reason for this is discussed based on the dipole moment of different TS structures in solution.