Solvophobically Driven Complexation of Adamantyl Mannoside with β-Cyclodextrin in Water and Structured Organic Solvents

The effects of solvent and temperature on the complexation of adamantyl mannoside with β-cyclodextrin and 6-O-monotosyl-6-deoxy-β-cyclodextrin were explored experimentally and by means of molecular dynamics simulations. Efficient binding was observed only in hydrogen-bonded solvents, which indicated solvophobically driven complexation. The stability of the inclusion complex was considerably higher in aqueous media. A pronounced temperature dependence of Δ_rH^○ and Δ_rS^○, resulting in perfect enthalpy–entropy compensation, was observed in water. The complexation thermodynamics was in line with classical rationale for the hydrophobic effect at lower temperatures and the nonclassical explanation at higher temperatures. This finding linked cyclodextrin complexation thermodynamics with insights regarding the effect of temperature on the hydration water structure. The complexation enthalpies and entropies were weakly dependent on temperature in organic media. The signs of Δ_rH^○ and Δ_rS^○ were in accordance with the nonclassical hydrophobic (solvophobic) effect. The structures of the optimized product corresponded to those deduced spectroscopically, and the calculated and experimentally obtained values of Δ_rG^○ were in very good agreement. This investigation clearly demonstrated that solvophobically driven formation of cyclodextrin complexes could be anticipated in structured solvents in general. However, unlike in water, adamantane and the host cavity behaved solely as structure breakers in the organic media explored so far.     

Dark consequences from light neutrino condensations

In this Letter we discuss light neutrino dipole moments, computed in the neutrino-mass extended Standard Model, as a possible source for neutrino condensates which may cause cosmological constant observed today.     

A multivariate extension of an inequality of Brenner–Alzer

In this paper, we present a more general and extended form in a multivariate setting of an inequality of Brenner and Alzer.     

One‐dimensional approximations of the eigenvalue problem of curved rods

In this work we analyse the asymptotic behaviour of eigenvalues and eigenfunctions of the linearized elasticity eigenvalue problem of curved rod‐like bodies with respect to the small thickness ? of the rod. We show that the eigenfunctions and scaled eigenvalues converge, as ? tends to zero, toward eigenpairs of the eigenvalue problem associated to the one‐dimensional curved rod model which is posed on the middle curve of the rod. Because of the auxiliary function appearing in the model, describing the rotation angle of the cross‐sections, the limit eigenvalue problem is non‐classical. This problem is transformed into a classical eigenvalue problem with eigenfunctions being inextensible displacements, but the corresponding linear operator is not a differential operator. Copyright © 2001 John Wiley & Sons, Ltd.     

Some remarks on the Chebyshev functional

Identities are provided for the Chebyshev functional defined on a real linear space equipped with a bilinear form. In addition, some inequalities for the functional are discussed.     

The argument principle and holomorphic extendibility to finite Riemann surfaces

Let M be a finite Riemann surface and let A(M) be the algebra of all continuous functions on M∪bM which are holomorphic on M. We prove that a continuous function Φ on bM extends to a function in A(M) if and only if for every f,g in A(M) such that fΦ+g≠0 on bM, the change of argument of fΦ+g is nonnegative.     

The modulus of Rudin-Carleson extensions

We prove the followingTheorem. LetF be a closed subset of the unit circleT which has Lebesgue measure zero. Suppose thatp is a smooth positive function onT. GivenfC(F) which satisfies|f(s)|p(s) (sF) and a neighbourhoodU ofF there is an extension off in the disc algebra such that and .     

Novel variational definition of diabatic states

The requirement that diabatic states be dominated by a single electronic configuration is transformed into a variational principle. A very simple algorithm for the adiabatic—diabatic transformation is found. It is equally applicable to avoided and to true potential crossing situations.     

Massless and massive quanta resulting from a mediumlike metric tensor

We formulate a simple model of the primordial scalar field theory in which the metric tensor is a generalization of the metric tensor from electrodynamics in a medium. The radiation signal corresponding to the scalar field propagates with a velocity that is generally less thanc. This signal can be associated simultaneously with imaginary and real effective (momentum-dependent) masses. The requirement that the imaginary effective mass vanishes, which we take to be the prerequisite for the vacuumlike signal propagation, leads to the spontaneous splitting of the metric tensor into two distinct metric tensors: one metric tensor gives rise to masslesslike radiation and the other to a massive particle.