Influence of EDA-pi interactions in drug encapsulation using nanospheres

We have evaluated the influence of aromatic and hydrophobic interactions on the strength and selectivity of encapsulation using polymeric nanospheres.     

Distribution functions, loop formation probabilities, and force-extension relations in a model for short double-stranded DNA molecules

We obtain, using transfer-matrix methods, the distribution function P(R) of the end-to-end distance, the loop formation probability, and force-extension relations in a model for short double-stranded DNA molecules. Accounting for the appearance of "bubbles," localized regions of enhanced flexibility associated with the opening of a few base pairs of double-stranded DNA in thermal equilibrium, leads to dramatic changes in P(R) and unusual force-extension curves. An analytic formula for the loop formation probability in the presence of bubbles is proposed. For short heterogeneous chains, we demonstrate a strong dependence of loop formation probabilities on sequence.     

A novel reaction of dimethylsulfonium methylide with Michael acceptors: application to the synthesis of difficultly accessible vinyl silanes and styrenes

Rather than the usual cyclopropanation and Peterson-type olefination, conditions for a novel elimination reaction from the adduct of dimethylsulfonium methylide and 2-silylalkylidene/arylidene malonate/cyanoacetate/phosphonoacetate leading to geminally substituted vinyl silanes or styrenes, respectively, have been established.     

Index theorems and supersymmetry in the soliton sector: (II). Magnetic monopoles in 3+1 dimensions

For supersymmetric Yang-Mills theories with Bogomolny-Prasad-Sommerfield monopoles, we use an open-space trace theorem on $\text{R}{}^3$ to calculate the O(?) correction to the monopole mass. For the N = 2 theory, the unrenormalized mass correction is non-vanishing (and divergent). To the same order, we calculate the quantum corrections to the central charges, and demonstrate explicitly that the Bogomolny bound is saturated. We also show that the mass correction for the N = 4 theory vanishes to O(?). Finally we discuss the renormalization of the mass correction for the N = 2 theory. This requires the parameters of the theory to be renormalized in the monopole background-field gauge, although there is no simple way known to do this. We exhibit calculations in standard gauges to show explicitly that they give gauge-dependent answers. Physical arguments based on the Dirac quantization condition suggest that the renormalized mass correction vanishes.     

A source of nonclassical radiations exhibiting photon antibunching

We show that coherent spontaneous emission by a two-level atomic system in a Dicke state placed in a resonant cavity gives a non-classical radiation exhibiting photon-antibunching. It is assumed that the “effective” population of the ground state atoms is initially large compared to unity.     

Budding dynamics of multicomponent membranes

The budding of multicomponent membranes is studied by computer simulations and scaling arguments. The simulation algorithm combines dynamic triangulation with Kawasaki exchange dynamics. The budding process exhibits three distinct time regimes: (i) formation and growth of intramembrane domains; (ii) formation of many buds; and (iii) coalescence of small buds into larger ones. The coalescence regime (iii) is characterized by scaling laws which describe the long-time behavior. Thus, the number of buds, N(bud), decays as N(bud) approximately 1/t(theta) for large time t with theta = 1/2 and theta = 2/3 in the absence and the presence of hydrodynamic interactions, respectively.     

Plane Symmetric Inhomogeneous Cosmological Models with a Perfect Fluid in General Relativity

In this paper we investigate a class of solutions of Einstein equations for the plane- symmetric perfect fluid case with shear and vanishing acceleration. If these solutions have shear, they must necessarily be non-static. We examine the integrable cases of the field equations systematically. Among the cases with shear we find three classes of solutions. PACS No.: 04.20.-q.     

Cubicity and Bandwidth

A unit cube in ${\mathbb{R}^k}$ (or a k-cube in short) is defined as the Cartesian product R ₁ × R ₂?× ... × R _k where R _i (for 1??? i??? k) is a closed interval of the form [a _i , a _i + 1] on the real line. A k-cube representation of a graph G is a mapping of the vertices of G to k-cubes such that two vertices in G are adjacent if and only if their corresponding k-cubes have a non-empty intersection. The cubicity of G is the minimum k such that G has a k-cube representation. From a geometric embedding point of view, a k-cube representation of G?=?(V, E) yields an embedding ${f: V(G) \rightarrow \mathbb{R}^k}$ such that for any two vertices u and v, ||f(u) ? f(v)||_?? ?? 1 if and only if ${(u, v) \in E(G)}$ . We first present a randomized algorithm that constructs the cube representation of any graph on n vertices with maximum degree ?? in O(?? ln n) dimensions. This algorithm is then derandomized to obtain a polynomial time deterministic algorithm that also produces the cube representation of the input graph in the same number of dimensions. The bandwidth ordering of the graph is studied next and it is shown that our algorithm can be improved to produce a cube representation of the input graph G in O(?? ln b) dimensions, where b is the bandwidth of G, given a bandwidth ordering of G. Note that b ?? n and b is much smaller than n for many well-known graph classes. Another upper bound of b + 1 on the cubicity of any graph with bandwidth b is also shown. Together, these results imply that for any graph G with maximum degree ?? and bandwidth b, the cubicity is O(min{b, ?? ln b}). The upper bound of b?+ 1 is used to derive upper bounds for the cubicity of circular-arc graphs, cocomparability graphs and AT-free graphs in terms of the maximum degree ??.