This article provides an overview about specifically modified Mannich reactions where the process involves an ortho-quinone methide (o-QM) intermediate. The reactions are classified on the basis of the o-QM source followed by the reactant, e.g., the dienophile partner in cycloaddition reactions (C=C or C=N dienophiles) or by the formation of multicomponent Mannich adducts. Due to the important ...

Hybrid quantum mechanics/molecular mechanics (QM/MM) simulations have become a popular tool for investigating chemical reactions in condensed phases. In QM/MM methods, the region of the system in which the chemical process takes place is treated at an appropriate level of quantum chemistry theory, while the remainder is described by a molecular mechanics force field. Within this approach, chemi...

Presenilin 1 (PS1) is the causative gene for an autosomal dominant familial Alzheimer's disease (AD) mapped to chromosome 14. Here we show that QM/Jun-interacting factor (Jif)-1, a negative regulator of c-Jun, is a candidate to mediate the function of PS1 in the cell. We screened for proteins that bind to PS1 from a human embryonic brain cDNA library using the two-hybrid method and isolated one...

We present an extensible interface between the AMBER molecular dynamics (MD) software package and electronic structure software packages for quantum mechanical (QM) and mixed QM and classical molecular mechanical (MM) MD simulations within both mechanical and electronic embedding schemes. With this interface, ab initio wave function theory and density functional theory methods, as available in ...

BCH codes have been studied for over fifty years and widely employed in consumer devices, communication systems, and data storage systems. However, the dimension of BCH codes is settled only for a very small number of cases. In this paper, we study the dimensions of BCH codes over finite fields with three types of lengths n, namely n = qm − 1, n = (qm − 1)/(q− 1) and n = qm +1. For narrow-sense...

Herein we will focus on the use of quantum mechanics (QM) in drug design (DD) to solve disparate problems from scoring protein-ligand poses to building QM QSAR models. Through the variational principle of QM we know that we can obtain a more accurate representation of molecular systems than classical models, and while this is not a matter of debate, it still has not been shown that the expense ...

In the tradition of toy models of quantum mechanics in vector spaces over finite fields (e.g., Schumacher and Westmoreland’s "modal quantum theory"), one finite field stands out, Z2, since vectors over Z2 have an interpretation as natural mathematical objects, i.e., sets. This engages a sets-to-vector-spaces bridge that is part of the mathematical folklore to translate both ways between set con...

Conspectus Quantum mechanics (QM) has revolutionized our understanding of the structure and reactivity of small molecular systems. Given the tremendous impact of QM in this research area, it is attractive to believe that this could also be brought into the biological realm where systems of a few thousand atoms and beyond are routine. Applying QM methods to biological problems brings an improved...

Quadriceps myopathy (QM) is a rare form of muscle disease characterized by pathological changes predominately localized to the quadriceps. Although numerous inheritance patterns have been implicated in QM, several QM patients harbor deletions in dystrophin. Two defined deletions predicted loss of functional spectrin-like repeats 17 and 18. Spectrin-like repeat 17 participates in actin-filament ...