We report a direct determination of the time dependent mean-squared segment displacement of a polymer chain in the melt covering the transition from free to constraint Rouse relaxation along the virtual tube of the reptation model. This has been achieved by a neutron spin-echo (NSE) measurement of the segmental self-correlation function as conveyed by the spin-incoherent scattering from two ful...

Polyethylene glycols (PEG 200-7(0) are used as solvents in various pharmaceutical preparations meant for both internal and external use (1,2). PEGs are incompatible with iodine, potassium iodide, sorbitol, tannic acid, metallic salts like bismuth, mercury and silver salts (2). Their systemic absorption in certain conditions may result in renal failure and CNS depression (3). Morbidity has been ...

Polyethylene glycols (PEGs) are products of condensed ethylene oxide and water that can have various derivatives and functions. Since many PEG types are hydrophilic, they are favorably used as penetration enhancers, especially in topical dermatological preparations. PEGs, together with their typically nonionic derivatives, are broadly utilized in cosmetic products as surfactants, emulsifiers, c...

A rapid method for determining diethylene glycol (DEG) in toothpaste based on the use of ultra-performance liquid chromatography (UPLC) coupled to time-of-flight mass spectrometry (TOF-MS) has been developed. The method has been validated in toothpaste samples spiked at different levels, 0.005, 0.1 and 5%, obtaining satisfactory recoveries (74-98%) and relative standard deviations (<4%). Quanti...

We have studied the generation of reactive oxygen species during the metabolism of a carcinogen, benzo[a]pyrene, by human mammary epithelial cells. We have quantitated the production of one type of oxidative DNA damage, thymine glycols, by using a monoclonal antibody specific to this base modification. Thymine glycols were produced in DNA in a dose-dependent manner after exposure of human mamma...

The C12•`C36 sym. ƒ¿-glycols were prepared from acyloins by catalytic hydrogenation with Raney nickel. The properties of ƒ¿-glycols were studied. Melting point of the ƒ¿-glycol is higher than that of the corresponding acyloin or ƒ¿-diketone and decreases with chain length. Two hydroxyl groups can be quantitatively acetylated by acetic anhydride, and reacted with 3, 5-dinitrobenzoyl chloride to ...

A new class of hydrogels utilizing DNA (DNA quadruplex gel) has been constructed by directly and symmetrically coupling deoxynucleotide phosphoramidite monomers to the ends of polyethylene glycols (PEGs) in liquid phase, and using the resulting DNA-PEG-DNA triblock copolymers as macromonomers. Elongation of merely four deoxyguanosine residues on PEG, which produces typically ≈10 grams of desire...

Polyethylene glycols (PEGs) are believed to be chemically inert agents, but larger PEG polymers could have immunogenicity. A 39-year-old man was referred to emergency room for loss of consciousness and dyspnea after taking of PEG-3350 (Colyte®). In laboratory findings, the initial serum tryptase level was increased to 91.9 mg/L (normal range: 0.00-11.40 mg/L) without any other laboratory abnorm...

Gas-phase ion mobility studies of mixtures containing polyethylene glycols (PEG) and an active pharmaceutical ingredient (API), lamivudine, have been carried out using electrospray ionization-ion mobility spectrometry-quadrupole-time-of-flight mass spectrometry (ESI-IMS-Q-TOF). In addition to protonated and cationized PEG oligomers, a series of high molecular weight ions were observed and ident...