Diffuse ultra-high energy neutrino fluxes and physics beyond the Standard Model

We study spectral distortions of diffuse ultra-high energy (UHE) neutrino flavour fluxes resulting due to physics beyond the Standard Model (SM). Even large spectral differences between flavours at the source are massaged into a common shape at earth by SM oscillations, thus, any significant observed spectral differences are an indicator of new physics present in the oscillation probability during propagation. Lorentz symmetry violation (LV) and neutrino decay are examples, and result in significant distortion of the fluxes and of the well-known bounds on them, which may allow UHE detectors to probe LV parameters, lifetimes and the mass hierarchy over a broad range.     

How Interactions Control Molecular Transport in Channels

The motion of molecules across channels and pores is critically important for understanding mechanisms of many cellular processes. Here we investigate the mechanism of interactions in the molecular transport through nanopores by analyzing exactly solvable discrete stochastic models. According to this approach the channel transport is viewed as a set of chemical transitions between discrete states. It is shown that the strength and spatial distribution of molecule/channel interactions can strongly modify the particle current. Our analysis indicates that the most optimal transport is achieved when the binding sites are near the entrance or exit of the pore depending on the sign of interaction potential. In addition, the role of intermolecular interactions during the channel transport is studied, and it is argued that an increase in the flux can be observed for some optimal interaction strength. The mechanisms of these phenomena are discussed.     

One pot synthesis of important retinoid synthon by the catalytic regioselective bi-functionalization of acetylenes,alcohol and carbon monoxide

Base free Fe(CO)₅ catalyzed one-pot synthesis of E/Z alkyl 3-formyl-3-alkyl/aryl/ferrocenyl-2-propenoates (retinoid esters) was achieved by the photolysis of alcoholic solution of terminal acetylenes and carbon monoxide. 8–10 Mol% of ironpentacarbonyl was used as a catalyst for significant transformations of retinoid esters. During the photolysis, alkynes reduced by the simultaneous double functionalization esterification and formylation and resulted in regioselective E/Z isomers of alkyl 3-formyl-3-alkyl/aryl/ferrocenyl-2-propenoates. The bi-functionalization of acetylene is quite unusual and is not observed frequently. The highest yield of the retinoid esters was achieved with 3° alcohols (96%, for E and Z isomers) while the least yield was observed with 1° alcohols (25%, for E and Z isomers). All retinoid esters are regiospecific and have exceptional biological significance to serve as key structural motifs in drug and pharmaceutical applications.     

Stretching and collapse of neutral polymer layers under association with ionic surfactants

We provide experimental evidence for stretching and collapse of neutral polymer layers, already adsorbed at an oil-in-water interface, due to its interaction with surfactants. Upon stretching, the first interaction length (2L(0)) follows a power law dependence on surfactant concentration ( proportional, variant C(x)(s), where x approximately 0.5 for cationic surfactants) and collapses in the presence of salt, as a relatively weak power law (C(-y)(s), where y=0.17), in good agreement with brush length decay for polyelectrolyte brushes.     

Estimation of a random coefficient model under linear stochastic constraints

Summary A random coefficient model in which means of random coefficients are subject to a set of linear stochastic constraints is considered and estimators for the means of coefficients are proposed. Their asymptotic properties are presented and some remarks on efficiency are placed.     

Synthesis of 2-deamino- and 2-deamino-2-nitroactinomycin D

A single step synthesis of 2-deaminoactinomycin D ( 3a ) and 2-deamino-2-nitroactinomycin D ( 2a ) arising from actinomycin D ( 1a, AMD ) is reported. Structural confirmation was made by nmr, ir and chemical conversion to known materials.     

Synthesis and studies on dichloro iodo triphenylphosphine oxide nickel(III)

A new compound of nickel(III), [Ni(OPPh₃)Cl₂I] has been prepared by the action of nitrosyl chloride or chlorine gas on [Ni(PPh₃)₂I₂]. Various physical studies of the compound are reported.