Some aliphatic long-chain quaternary ammonium compounds and choline derivatives have been examined for their ability to induce pseudopodia from Amoeba proteus. The reaction involved in pseudopodium induction is believed to be between the quaternary nitrogen cations and polysaccharides on the cell surface. Not all of the carboxyl groups of the polysaccharide are involved in this reaction. The me...

Quaternary pyridinium salts with chains ranging from C8 to C20 belong in the large group of cationic surfactants. In this paper, the preparation of such cationic surface active agents based on the pyridinium moiety and differing in the length of the N-alkyl chain is described. Additionally, HPLC technique was established to distinguish each prepared pyridinium analogue. This study represents un...

New dimeric, trimeric and tetrameric quaternary ammonium salts were accomplished by reaction of tertiary alkyldimethyl amines with appropriate bromomethylbenzene derivatives. A series of new cationic surfactants contain different alkyl chain lengths (C4-C18), aromatic spacers and different numbers of quaternary nitrogen atoms. The structure of the products was confirmed by spectral analysis (FT...

Bacterial cellulose (BC) has attracted attention for preparing advanced materials due to its microfibrous structure. In this study, quaternary ammonium bacterial cellulose (QABC) as well as quaternary ammonium plant cellulose (QAPC) as adsorbents for proteins have been prepared. Introduction of the quaternary ammonium group was conducted under different conditions to determine the best conditio...

Ternary and quaternary metal chelates of some biologically important bivalent transition metal ions viz. Co(II), Ni(II), Cu(II) and Zn(II) formed with biologically significant ligands, viz. Asparagine (A) and Uracil (B) have been investigated. The relevant stability constants and complexation equilibria of quaternary metal chelates in solution at 30±1 oC and at constant ionic strength (I=0.1M N...

In modern communication systems, modulation is a key function that embeds the baseband signal (information) into a carrier wave so that it can be successfully broadcasted through a medium such as air or cables. Here we report a flexible all-graphene modulator circuit with the capability of encoding a carrier signal with quaternary digital information. By exploiting the ambipolarity and the nonl...

Salmonella serovars sampled from meat products in Southern Spain (Andalucía) during the period 2002-2007 were analyzed in this study. The serovars most frequently detected (in order) were Typhimurium, Enteritidis, Derby, Anatum and Rissen. Isolates (n = 43) were tested for sensitivity to biocides, including the quaternary ammonium compounds benzalkonium chloride (BC), cetrimide (CT) and hexadec...

In this study, a variety of 3, 4-dihydropyrimidin-2(1H)-ones derivatives were synthesized via three-component Biginelli reaction. The quaternary ammonium- treated clay -catalyzed process proved to be simple, efficient, and environmentally friendly.

In the title compound, C21H20N2O3, the lactone ring adopts an envelope conformation with the quaternary C atom bonded to two other C atoms as the flap. The fused pyrrolidine ring adopts a twisted conformation about the Cq-N (q = quaternary) bond. In the crystal, inversion dimers linked by pairs of N-H⋯O hydrogen bonds generate R 2 (2)(8) loops. The dimers are linked into [110] chains by pairs o...

A new quaternary linear code of length 19, codimension 5, and covering radius 2 is found in a computer search using tabu search, a local search heuristic. Starting from this code, which has some useful partitioning properties, di!erent lengthening constructions are applied to get an in"nite family of new, record-breaking quaternary codes of covering radius 2 and odd codimension. An algebraic co...