An extract from the apical portion of etiolated seedlings of Pisum sativum L. was used as a test system to examine the action of ethylene on DNA polymerase activity. The extract catalyzed the polymerization of labeled deoxyribonucleoside triphosphates into a trichloroacetic acid-insoluble product. The system required Mg(2+), nicked DNA, and all four deoxyribonucleoside triphosphates for maximum...

At low pressure, ethylene gas consists of single translating and rotating molecules and behaves as an ideal gas. With decrease of free volume by compression, various rotating supramolecular particles are formed, which require less space for the movement: molecular pairs, bimolecules and oligomolecules. The appearance of a new kind of particles is manifested as a phase transition of the second o...

The objective of this study was to synthesize and characterize particles as a drug-delivery platform for gliomas, a highly advanced and invasive stage of brain tumor with poor prognosis. Poly(aminoethyl methacrylate-co-methyl methacrylate) particles were prepared by suspension polymerization and poly(aminoethyl methacrylate-co-poly(ethylene glycol) methacrylate) particles were prepared by emuls...

0

Pectin is an anionic, water-soluble polymer predominantly consisting of covalently 1,4-linked α-D-galacturonic acid units. This naturally occurring, renewable and biodegradable polymer is underutilized in polymer science due to its insolubility in organic solvents, which renders conventional polymerization methods impractical. To circumvent this problem, cerium-initiated radical polymerization ...

Novel complexation hydrogel nanospheres of poly(methacrylic acid-grafted-poly(ethylene glycol)) (P(MAA-gEG)) were prepared by dispersion polymerization to be used for protein delivery applications. Polymerization was conducted in solvents such as deionized water, ethanol/water, sodium hydroxide, hydrochloric acid, and acetic acid solutions. When polymerizing in deionized water we produced nanos...

A class of new biodegradable hydrogels based on poly(ethylene glycol) methacrylate-graft-poly(glutamic acid) and poly(ethylene glycol) dimethacrylate was synthesized by photoinduced polymerization. Because all the polymeric constituents were highly hydrophilic, crosslinking could be performed in aqueous solutions. This type of crosslinked hydrogel was prepared by modifying a select number of ac...

Novel ionizable polymer networks were prepared from oligo(ethylene glycol) (OEG) multiacrylates and acrylic acid (AA), employing bulk radical photopolymerization techniques. The properties of these materials exhibit a complex dependence on the network structure and composition. Dynamic mechanical analysis and penetrant sorption experiments demonstrated that the cross-linked structure of the mat...

Microparticles or nanospheres of hydrogels of crosslinked poly(methacrylic acid) grafted with poly(ethylene glycol) as well as crosslinked poly(acrylic acid) grafted with poly(ethylene glycol) were prepared for use as oral insulin delivery carriers. The copolymer carriers were synthesized by precipitation/dispersion polymerization that led to gel nanospheres or by bulk polymerization and subseq...