Formamidines as α-amino carbanion precursors. The synthesis of 2-arylpiperidines, -pyrrolidines,and nicotine analogs

Metallation of the $\text{t}$-butyl formamidines of benzyl or picolinyl amines followed by alkylation with α,ω -dihaloalkanes gives the title compounds after hydrazinolysis.     

Continuous regularizations in strong coupling expansions from a generalized inverse propagator method

A strong coupling expansion is derived in terms of a generalized inverse propagator and is used to construct a regularization scheme which, for some regulators, differs from the canonical one. In particular, the Gaussian cut-off is shown to induce unbiased results, in contrast to a previous analysis using this regulator in the standard way. Several continuous and discrete regulations are then compared through a numerical example which suggests their equivalence.     

Room-temperature phosphorescence of anilinonaphthalenesulfonate “fluorescence probe” compounds

2,6-anilinonaphthalenesulfonate (2,6-ANS) and 2,6-toluidinonaphthalenesulfonate (2,6-TNS) exhibit room-temperature phosphorescence when absorbed on filter paper, but the corresponding 1,8-isomers (1,8-ANS and 1,8-TNS) do not. The phosphorescence of the 2,6-isomers and nonphosphorescence of the 1,8-isomers is also found to hold in rigid glass at 77 K. No phosphorescence was detectable from N-phenyl-1-napthylamine at room temperature or 77 K, indicating that intramolecular hydrogen bonding in the 1,8-isomers isomers is not an essential feature inhibiting phosphorescence. Very effective heavy-atom enhancement of the phosphorescences of 2,6-ANS and 2,6-TNS by sodium iodide is observed.     

Model-independent amplitude analysis for the reaction πN → ρΔ

A method is proposed for determining the amplitudes for the reaction πN → ?Δ using only those moments of the joint decay angular distribution 〈Y_L1^M₁Y_L2^M₂〉 with both L₁ and L₂ even. The solution is not unique; both continuous and discrete ambiguities exist. The conditions under which an analysis is possible are studied in detail; in addition to certain positivity conditions on the joint density matrix, a complicated inequality involving the experimental moments must be satisfied. This condition defines a non-convex domain in the space of the moments. We apply our methods to the high-statistics experimental data at 3.7 GeV/c.     

Anionic amphiphilic dendrimers as antibacterial agents

An anionic amphiphilic dendrimer is reported that possesses increased cytotoxicological potency against prokaryotic cells compared to eukaryotic cells. The half-maximal effective concentration (EC50) for the dendrimer against Bacillus subtilis, a Gram-positive bacterial strain, was measured to be 4.1 x 10(-5) M, while that against human umbilical vein endothelial cells (HUVEC) was more than 36x greater at a value of 1.5 x 10(-3) M. EC50 ratios for two commercial amphiphiles, sodium dodecyl sulfate (SDS) and Triton X-100, in addition to a similar synthesized dendritic structure were at most only 3.8x greater. Furthermore, the observed EC50 values appear to be correlated to the critical aggregation constant (CAC) in solution suggesting a mechanism of action for these anionic amphiphilic dendrimers related to their supramolecular structures.