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Consider a nonzero contraction T and a bounded operator X satisfying T X = q X T for a complex number q. There are some interesting results in the literature on q -commuting dilation and q -commutant lifting of such pair (T , X) when | q | = 1. Here we improve a few of them to the class of scalars q satisfying | q | ≤ 1 ‖ T ‖. [ABSTRACT FROM AUTHOR]

Abstract TLR9 is one of the major innate immune receptors expressed in the endosomes of pDCs and B cells in humans. Aberrant TLR9 activation is implicated in several autoimmune and metabolic disorders as well as in sepsis, making this receptor an important therapeutic target, though specific TLR9 antagonists are yet to be available for clinical use. Here we elucidate the importance of specific physiochemical properties through substitution patterns in quinazoline scaffold to achieve potent hTLR9 inhibition at < 50 nM as well as > 600 fold selectivity against hTLR7, another closely related TLR that shares downstream signaling with TLR9 but plays distinct roles in physiology and pathology. Assays were performed using hPBMC and reporter cell lines. Favorable in vitro ADME profile, pharmacokinetics as well as validation in a clinically relevant in vivo TLR9-inhibition efficacy model in mice establish these novel TLR9-antagonists as candidate therapeutic agents in relevant clinical contexts. Graphical abstract Image 1 Highlights • Substitutions in quinazoline that influence potency and specificity for hTLR9. • Favourable in vitro ADME and pharmacokinetics in rodent model. • In vivo TLR9-inhibition efficacy was investigated in a rodent model. • Development of potent TLR9 antagonist with excellent selectivity against TLR7. [ABSTRACT FROM AUTHOR]

[Display omitted] • The MoS 2 -MoSe 2 lateral heterostructure is semiconducting, whereas the MoS 2 -NbS 2 lateral heterostructure is metallic. • The 2D MoS 2 -MoSe 2 and MoS 2 -NbS 2 LHS can withstand massive volume change during the charging-discharging processes. • The MoS 2 -MoSe 2 and MoS 2 -NbS 2 lateral heterostructures give high Li/Na storage capacities of 518 mAh/g and 677 mAh/g, respectively. • MoS 2 -NbS 2 LHS is more advantageous over MoS 2 -MoSe 2 LHS for anodes of LIBs/SIBs. The requirement of an efficient energy storage device has become an exclusive requisite for technological and scientific innovations. In the present work, by using the 2D monolayer semiconductor-semiconductor and semiconductor-metal lateral interface structures as the model structure, we performed periodic DFT calculations to examine the possibility of 2D MoS 2 -MoSe 2 and MoS 2 -NbS 2 lateral heterostructures (LHS) as the electrodes of a battery. The MoS 2 -MoSe 2 lateral interface is a semiconductor, whereas the MoS 2 -NbS 2 lateral interface preserves metallic character. Besides, we found that Li/Na ion adsorption is more influential on the lateral heterostructure and is exothermic, with ultrafast diffusion, and is comparable to their monolayers. Meanwhile, the calculated open-circuit voltage is enormously low, like other widely investigated pristine 2D materials. The enhanced electrical conductivity, short diffusion distances, minutely low equilibrium voltage with good stability, large theoretical capacity and ultrahigh mechanical strength offered bare 2D TMDs lateral heterostructures as a potential candidate for LIBs/SIBs applications. This work broadens the possibility of applications based on 2D TMD-based semiconductor-semiconductor and semiconductor-metal lateral heterostructures. The lateral heterostructures can give an exciting new paradigm and offer exciting opportunities for potential applications in portable electronic devices. [ABSTRACT FROM AUTHOR]

The article considers the successful implementation of relativistic equation-of-motion coupled cluster method for the electron attachment problem (EA-EOMCC) at the level of single- and double- excitation approximation. The implemented relativistic EA-EOMCC method is employed to calculate ionization potential values of alkali metal atoms (Li, Na, K, Rb, Cs, Fr) and the vertical electron affinity values of LiX (X = H, F, Cl, Br), NaY (Y = H, F, Cl) starting from their closed-shell configuration. Both four-component and exact two-component calculations are done for all the opted systems. Further, we have shown the effect of spin–orbit interaction considering the atomic systems. The results of our atomic calculations are compared with the values from the NIST database and the results are found to be very accurate (<1%). [ABSTRACT FROM AUTHOR]

Abstract: The frequency and temperature dependence of dipole-quadrupole polarizability of tetrahedral P4 and adamantane molecules have been studied using first-principle all-electron density functional theory calculation. The recently developed time-dependent auxiliary density functional theory is extended for the calculation of dynamic dipole-quadrupole polarizabilities. Temperature effects are incorporated by Born–Oppenheimer molecular dynamics (BOMD) simulations recorded up to 100ps. The dynamic dipole-quadrupole polarizabilities are calculated along these trajectories. The frequency and temperature effects can be significant for the accurate calculation of dipole-quadrupole polarizability. We have also identified the main reason for the observed discrepancy between experiment and theory in the case of adamantane. [Copyright &y& Elsevier]

Abstract: The effect of light metal ion decoration of the organic linker in metal-organic framework MOF-5 on its hydrogen adsorption with respect to its hydrogen binding energy (ΔB.E.) and gravimetric storage capacity is examined theoretically by employing models of the form MC6H6:nH2 where M = Li+, Na+, Be2+, Mg2+, and Al3+. A systematic investigation of the suitability of DFT functionals for studying such systems is also carried out. Our results show that the interaction energy (ΔE) of the metal ion M with the benzene ring, ΔB.E., and charge transfer (Qtrans) from the metal to benzene ring exhibit the same increasing order: Na+ < Li+ < Mg2+ < Be2+ < Al3+. Organic linker decoration with the above metal ions strengthened H2-MOF-5 interactions relative to its pure state. However, amongst these ions only Mg2+ ion resulted in ΔB.E. magnitudes that were optimal for allowing room temperature hydrogen storage applications of MOF-5. A much higher gravimetric storage capacity (6.15 wt.% H2) is also predicted for Mg2+-decorated MOF-5 as compared to both pure MOF-5 and Li+-decorated MOF-5. [ABSTRACT FROM AUTHOR]

Abstract: We present density functional theory (DFT) calculations using B3LYP/6-31++G∗∗ method to show relaxation in geometry of base pairs on cation radical formation. The changes in hydrogen bond length and angles show that in the cationic radical form the structure of the base pairs relaxes due to the distribution of charge. According to a recent study, it has been found that, upon excitation hole transfer from base to sugar occurs which results in sugar radical formation and leads to strand breakage [A. Kumar, M.D. Sevilla, J. Phys. Chem. B 110 (2006) 24181]. One hydrogen bond increases, while the other decreases in Adenine–Thymine (AT) base pair and in case of Guanine–Cytosine (GC) base pair, one bond increases and other two decrease. Same is the case with bond angles for both the base pairs. Analysis of the electron density map of Singly Occupied Molecular Orbital (SOMO) reveals that electron is transferred mainly from adenine and guanine bases in the cationic radical formation of AT and GC base pair, respectively. The reactive sites of bases have been analyzed using condensed Fukui functions in a relaxed and frozen core approximation. The effects of relaxation on the reactivity indices are also analyzed. [Copyright &y& Elsevier]

Abstract: We consider a series of dipolar organic molecules where the donor groups and the acceptor groups are separated by π-conjugation like phenyl ring or alkene chains. We have performed extensive quantum chemical calculations based on density functional theory (DFT) to calculate their linear and non-linear optical coefficients. We show that though DFT is known to overestimate the polarizabilities of quasi-linear systems, the results with proper inclusion of exchange correlation compare well with the experimental studies. On increasing the π-conjugation length, the coefficients increase non-linearly. We also vary the donor and the acceptor groups and study the role of chemical modifications on the response properties. Herein we suggest experimental methods by which the molecules may be arranged in non-centrosymmetric fashion in the bulk for device integration. [Copyright &y& Elsevier]

In this paper, we present linear and non-linear electric properties of BH, CO and H2O using a density functional response approach, which is a combination of numerical and analytical technique and is thus a simplification of fully analytic method. In the framework of an analytic response approach using Kohn–Sham (KS) density functional theory, the derivative of the KS operator with respect to external field is evaluated numerically, while the orbital derivatives and the subsequent energy derivatives are obtained fully analytically. The method is tested using three molecules BH, CO and H2O, which are marked by high degree of electron correlation and for which extensive ab initio benchmark results are available. Further, we have made a study of possible incorporation of non-dynamical electron correlation by studying BH at several inter-nuclear distances. [Copyright &y& Elsevier]

Aberrant activation of the endosomal Toll-like receptor 7 (TLR7) has been implicated in myriad autoimmune diseases and is an established therapeutic target in such conditions. Development of diverse TLR7 antagonists is mainly accomplished through random screening. To correlate human TLR7 (hTLR7) antagonistic activity with the structural features in different chemotypes, we derived a hypothetical binding model based on molecular docking analysis along with molecular dynamics (MD) simulations study. The binding hypothesis revealed different pockets, grooves and a central cavity where ligand-receptor interaction with specific residues through hydrophobic and hydrogen bond interactions take place, which correlate with TLR7 antagonistic activity thus paving the way for rational design using varied chemotypes. Based on the structural insight thus gained, TLR7 antagonists with quinazoline were designed to understand the effect of engagement of these pockets as well as boundaries of the chemical space associated with them. The newly synthesized most potent hTLR7 antagonist, i.e. compound 63 , showed IC 50 value of 1.03 ± 0.05 μM and was validated by performing primary assay in human plasmacytoid dendritic cells (pDC) (IC 50 pDC: 1.42 μM). The biological validation of the synthesized molecules was performed in TLR7-reporter HEK293 cells as well as in human plasmacytoid dendritic cells (pDCs). Our study provides a rational design approach thus facilitating further development of novel small molecule hTLR7 antagonists based on different chemical scaffolds. Image 1 • hTLR7 antagonist binding hypothesis based on docking analysis of known antagonists. • Significance of engaging different pockets and grooves for hTLR7 antagonism. • MD simulation showed ligand binding stability and protein conformational change. • Newly designed ligands based on binding model showed potent hTLR7 antagonism. • Interaction pattern can correlate the structural change in molecule with the activity. [ABSTRACT FROM AUTHOR]

A commuting tuple of n operators (S 1 , ... , S n − 1 , P) defined on a Hilbert space H , for which the closed symmetrized polydisc Γ n = { (∑ i = 1 n z i , ∑ 1 ≤ i < j ≤ n z i z j , ... , ∏ i = 1 n z i) : | z i | ≤ 1 , i = 1 , ... , n } is a spectral set is called a Γ n -contraction. Also a triple of commuting operators (A , B , P) for which the closed tetrablock E ‾ is a spectral set is called an E -contraction, where E = { (x 1 , x 2 , x 3) ∈ C 3 : 1 − z x 1 − w x 2 + z w x 3 ≠ 0 ∀ z , w ∈ D ‾ }. There are several decomposition theorems for contraction operators in the literature due to Sz. Nagy, Foias, Levan, Kubrusly, Foguel and few others which reveal structural information of a contraction. In this article, we obtain analogues of six such major theorems for both Γ n -contractions and E -contractions. In each of these decomposition theorems, the underlying Hilbert space admits a unique orthogonal decomposition which is provided by the last component P. The central role in determining the structure of a Γ n -contraction or an E -contraction is played by positivity of some certain operator pencils and the existence of a unique operator tuple associated with a Γ n -contraction or an E -contraction. [ABSTRACT FROM AUTHOR]

Primary H 2 adsorption sites in a zeolitic imidazolate framework, ZIF-7, are identified using ab-initio density functional theory (DFT) based molecular dynamics annealing simulations. The simulations suggest several low energy adsorption sites. The effect of light transition metal decoration on hydrogen storage properties was studied. Our ab-intio DFT calculations illustrate that decorating the ZIF with Sc increases both the number of H 2 molecules, as well as the H 2 binding energy. The binding energy (∼25 kJ/mol per H 2 ) at 8H 2 loading in the pore, suggests that Sc-ZIFs can be potential candidates for hydrogen storage. [ABSTRACT FROM AUTHOR]

A comparative study of dipole moments, polarizabilities and hyperpolarizabilities of 16 different molecules is performed employing two completely different theoretical approaches namely, density functional theory (DFT) and coupled cluster singles and doubles (CCSD). Both methods include electron correlation. The CCSD method is more accurate but highly expensive. DFT with auxiliary density allows non-iterative solutions which is computational advantage and useful for large molecules. Dipole moments and polarizability calculations from DFT are in very good agreement with CCSD calculations. However, negative hyperpolarizability values from DFT differ significantly from their CCSD counterparts, whereas positive hyperpolarizabilities show reasonable agreement between these methodologies. [ABSTRACT FROM AUTHOR]

Abstract: The effect of light metal (M=Li, Be, Mg, and Al) decoration on the stability of metal organic framework MOF-5 and its hydrogen adsorption is investigated by ab initio and periodic density functional theory (DFT) calculations by employing models of the form BDC:M2:nH2 and MOF-5:M2:nH2, where BDC stands for the benzenedicarboxylate organic linker and MOF-5 represents the primitive unit cell. The suitability of the periodic DFT method employing the GGA-PBE functional is tested against MP2/6-311+G* and MP2/cc-pVTZ molecular calculations. A correlation between the charge transfer and interaction energies is revealed. The metal-MOF-5 interactions are analyzed using the frontier molecular orbital approach. Difference charge density plots show that H2 molecules get polarized due to the charge generated on the metal atom adsorbed over the BDC linker, resulting in electrostatic guest-host interactions. Our solid state results show that amongst the four metal atoms, Mg and Be decoration does not stabilize the MOF-5 to any significant extent. Li and Al decoration strengthened the H2-MOF-5 interactions relative to the pure MOF-5 exhibited by the enhanced binding energies. The hydrogen binding energies for the Li- and Al-decorated MOF-5 were found to be sensible for allowing reversible hydrogen storage at ambient temperatures. A high hydrogen uptake of 4.3wt.% and 3.9wt.% is also predicted for the Li- and Al-decorated MOF-5, respectively. [Copyright &y& Elsevier]