The relationship between calcium ions and the differentiation of human promyelocytic leukemia HL-60 cells was investigated. Proliferation of HL-60 cells incubated in calcium-free medium was inhibited without cell differentiation. On the other hand, incubation with 100 /¿Mverapamil markedly inhibited cell proliferation and caused slight cell differentiation into monocytes. Both calcium-free med...

Phthalic acid esters (PAEs) are compounds that used in the bottle as main plasticizers. Therefore, possibility of releasing phthalate into beverages is very high and there a concern to consumer health monitoring organizations. The aim this research was assess phthalic (di-n-octyl (DNOP), butyl benzyl (BBP), dimethyl (DMP), diethyl (DEP) dibutyl (DBP), bis(di-ethylhexyl) (DEHP), total PAEs) bott...

In the title compound, C(14)H(18)N(3)OP, a crystallographic mirror plane bis-ects the mol-ecule (the C,N,C atoms of the dimethyl-amido moiety and the P=O unit lie on the mirror plane). The P atom has a distorted tetra-hedral geometry; the bond angles at P are in the range 98.98 (11)-115.28 (7)°. In the crystal, the O atom of the P=O group acts as a double hydrogen-bond acceptor for two symmetry...

We present here the synthesis of a highly O-carboxymethylated chitosan derivative. First, an improvedprotocol for the two-step synthesis of N-trimethyl chitosan (TMC) from chitosan was developed, yield-ing a maximum degree of quaternization (DQ) of up to 46.6%. Successively, the chitosan derivativeO-carboxymethyl-N-trimethyl chitosan (CMTMC) was synthesized from the TMC obtained by applyingan o...

n-oxidation of 1,4-dihydro-2,6-dimethyl-1- phenyliminopyridine (7) with several peracids was attempted. the main compound obtained was l-phenyl- 2,6-dimethyl-4-pyridone (8), instead of the expected n-oxide (2). the reaction of phenylhydroxylamine with dimthylrnethoxypyroxonium perchlorate, however, successfully gave the n-oxide (3), which belongs to a class of nitrones in which the diazomethine...

the amphiphilic graft copolymer using chitosan (cs) as hydrophilic segment and poly (l-lactic acid) (plla) as hydrophobic segment, was prepared through a protection-graft-de protection route. chitosan is a polysaccharide comprising of copolymers of glucosamine and n-acetyl glucosamine. chitosan is the deacetylated derivative of chitin, which is one of the most abundant natural polysaccharides c...

methoxymethylation of a variety of alcohols was performed using formaldehyde dimethyl acetal in the presence of 1,3-dichloro-5,5-dimethyl hydantoin [dcdmh] and poly n,n′-dibromo-n-ethyl naphthyl-2,7-disulfonamide [pbns] as catalysts at room temperature and under solvent-free conditions. our experiments show that primary and secondary alcohols can be smoothly converted into the corresponding mom...

This study was designed to determine the effect of interconnective pore size on chondrocyte proliferation and function within chitosan sponges, and compare the potential of chitosan and polyglycolic acid (PGA) matrices for chondrogenesis. Six million porcine chondrocytes were seeded on each of 52 prewetted scaffolds consisting of chitosan sponges with (1) pores 10 microm in diameter (n=10, wher...