Analysis of some allowed beta-transitions

Sakai’s method of analysing logft values has been extended to higher excited states in even-even nuclei. Within the context of the rather limited data an enhancement in the matrix element is observed for transitions to 2″⁺, 2?⁺ and 4′⁺ and 4″⁺ levels.     

Active nematics are intrinsically phase separated

Two-dimensional nonequilibrium nematic steady states, as found in agitated granular-rod monolayers or films of orientable amoeboid cells, were predicted [Europhys. Lett. 62, 196 (2003)10.1209/epl/i2003-00346-7] to have giant number fluctuations, with the standard deviation proportional to the mean. We show numerically that the steady state of such systems is macroscopically phase separated, yet dominated by fluctuations, as in the Das-Barma model [Phys. Rev. Lett. 85, 1602 (2000)10.1103/PhysRevLett.85.1602]. We suggest experimental tests of our findings in granular and living-cell systems.     

Biocatalytically oligomerized epicatechin with potent and specific anti-proliferative activity for human breast cancer cells

Catechins, naturally occurring flavonoids derived from wine and green tea, are known to exhibit multiple health benefits. Epigallocatechin gallate (EGCG) is one of the most widely investigated catechins, but its efficacy in cancer therapy is still inconsistent and limited. The poor stability of EGCG has contributed to the disparity in the reported anti-cancer activity and other beneficial properties. Here we report an innovative enzymatic strategy for the oligomerization of catechins (specifically epicatechin) that yields stable, water-soluble oligomerized epicatechins with enhanced and highly specific anti-proliferative activity for human breast cancer cells. This one-pot oxidative oligomerization is carried out in ambient conditions using Horseradish Peroxidase (HRP) as a catalyst yielding water-soluble oligo(epicatechins). The oligomerized epicatechins obtained exhibit excellent growth inhibitory effects against human breast cancer cells with greater specificity towards growth-inhibiting cancer cells as opposed to normal cells, achieving a high therapeutic differential. Our studies indicate that water-soluble oligomeric epicatechins surpass EGCG in stability, selectivity and efficacy at lower doses.     

Assembling metal phosphonates in the presence of monodentate-terminal and bidentate-bridging pyridine ligands. Use of non-covalent and covalent-coordinate interactions to build polymeric metal-phosphonate architectures

The cubic transition metal phosphonates [(t)BuPO3M(2-apy)]4 (M= Zn (1), Co (2)), whose core resembles the D4R SBU of zeolites, have been synthesized from a reaction between the corresponding metal acetate, tert-butylphosphonic acid and 2-aminopyridine (2-apy) at room temperature. X-Ray structure determination reveals that the molecules of 1 and 2, which crystallize in the tetragonal I4(1)/a space group with crystallographically imposed 4 symmetry, form a 3-D supramolecular assembly aided by N-H...O hydrogen bonding. When the same reaction was carried out by using a bridging bidentate Lewis base such as 4,4'-bipyridine, insoluble precipitate is obtained for both zinc and cobalt. In the case of other metal salts such as copper, manganese and nickel, however, one-dimensional polymeric compounds such as [M((t)BuPO3H)2(4,4'-bipy)(H2O)2]n (M= Cu (3), Mn (4)), [(Ni(4,4'-bipy)(H2O)4)((t)BuPO3H)2(H2O)]n (5) have been isolated. The solid-state structures of 3-5 have been determined by single crystal X-ray diffraction studies. Compounds 3 and 4 are isostructural and crystallize in the triclinic P1 space group with two phosphonate ligands coordinated to the metal centers in a [1.100] fashion, whereas in the case of compound 5, the polymeric backbone is formed by Ni-4,4'-bipy units and the phosphonate anions show no bonding interaction to the metal. The 1-D polymeric chains of 3-5 organize in the solid-state as 3-D supramolecular assemblies with the aid of extensive hydrogen bonding interaction between coordinated water molecules and P-OH or P=O groups of the phosphonate ligands.     

Conformationally locked bridged bicyclic diselenides: synthesis, structure, Se...O interaction, and theoretical studies

A general synthetic methodology has been developed for the synthesis of a conformationally locked, bridged diselena-bicyclo[3.2.1]octane skeleton by regio- and stereospecific tandem nucleophilic ring opening of cis-1,4-aziridino-epoxides with tetraethylammonium tetraselenotungstate [Et4N]2WSe4, 1, in a one-pot synthesis. Some correlations have been made on the physicochemical characteristics of the diselenides with a change in the dihedral angles.