Chalcogen bonds are noncovalent interactions and increasingly coming into focus for the design of complex structures in research areas such as crystal engineering, molecular recognition catalysis. Conceptionally, chalcogen can be considered interaction between one σ-hole Lewis base center. Herein, we analyze bidentate chelating ligands having two nucleophilic centers with single a chalcogenazol...

σ-Receptors are integral membrane proteins that have been implicated in a number of biological functions, many of which involve the modulation of ion channels. A wide range of synthetic ligands activate σ-receptors, but endogenous σ-receptor ligands have proven elusive. One endogenous ligand, dimethyltryptamine (DMT), has been shown to act as a σ-receptor agonist. Progesterone and other steroid...

We introduce a one-dimensional (1D) XZ model with alternating σ i σ z i+1 and σ x i σ x i+1 interactions on even/odd bonds, interpolating between the Ising model and the quantum compass model. We present two ways of its exact solution by: (i) mapping to the quantum Ising models, and (ii) using fermions with spin 1/2. In certain cases the nearest neighbor pseudospin correlations change discontin...

We show this configuration in Figure 1. We calculate that the energy of this configuration is HΛ(σ|σ) = 0. We can calculate the energy of this configuration in a different way, using line segments separating lattice points with different spins, as follows. For an n × n square, there are 2n(n + 1) nearest neighbor interactions. Put a line segment between every two lattice points with different s...

The relative levels of different σ factors dictate the expression profile of a bacterium. Extracytoplasmic function σ factors synchronize the transcriptional profile with environmental conditions. The cellular concentration of free extracytoplasmic function σ factors is regulated by the localization of this protein in a σ/anti-σ complex. Anti-σ factors are multi-domain proteins with a receptor ...

nbo analysis and density functional theory (dft: b3lyp/6-311+g**) based method were used to study the impacts of the anomeric effects (ae) on the conformational properties of 2-methoxy-1,2,4,5-tetrahydro-benzo[d]oxepine (1), -thiepine (2) and -selenepine (3). the gibbs free energy difference (geq–gax) values (i.e. δgeq-ax) at 298.15 k and 1 atm between the axial and equatorial conformations inc...

Bacterial promoters are recognized by RNA polymerase (RNAP) σ subunit, which specifically interacts with the -10 and -35 promoter elements. Here, we provide evidence that the β' zipper, an evolutionarily conserved loop of the largest subunit of RNAP core, interacts with promoter spacer, a DNA segment that separates the -10 and -35 promoter elements, and facilitates the formation of stable close...

UAB-FT-597, UB-ECM-PF-06/03, hep-ph/0601191 We compute and analyze the Flavor-Changing Neutral Current (FCNC) interactions of Minimal Supersymmetric Standard Model Higgs bosons (h ≡ h, H, A) with heavy quarks (top and bottom), focusing on the strongly-interacting sector. We correlate the Higgs bosons production cross-section at the LHC with the FCNC decay branching ratios and find the maximum a...