The average molecular weight of the water soluble hemicelluloses (hemicellulose B) of the Avena coleoptile cell wall was determined by gel permeation chromatography (GPC) and viscometry. Analysis of the neutral sugar composition of henucellulose B eluted from a GPC column (Sepharose 4B) indicated that it consists of /J-glucan with a high molecular weight and arabinoxylan with a low molecular we...

BACKGROUND High-molecular-weight hydroxyethyl starch (HES) compromises blood coagulation more than medium-molecular-weight HES. The authors compared medium molecular weight HES (200 kd [HES200]) and low-molecular-weight HES (70 kd [HES70]). METHODS In a prospective, double-blind, randomized-sequence crossover study, 22 male volunteers received 15 ml/kg HES200 and HES70. Blood samples were tak...

background: low molecular weight heparin (lmwh) is used for the treatment and prevention of coagulative disorders. few patients receiving therapeutic doses of lmwh develop major hemorrhage. currently there are few reports in the literature on acute overdose on adults.  in this study, clinical profile, treatment and outcome of 21 patients who acutely overdosed enoxaparin are described. methods: ...

A new chemical compound is developed at Petroleum University of Technology to enhance the recovery of the free imbibition process and simultaneously hinder asphaltene precipitation. The compound is tested on heavy oil samples from Marun oil field, Bangestan reservoir. The effects of the chemical compound on viscosity, hydrocarbon composition, and average molecular weight of the heavy oil are in...

Heparin and low molecular weight heparins are polydisperse polysaccharides with a degree of polymerization ranging from 4 to approximately 40. The determination of their average molecular weights has traditionally relied on size exclusion chromatography involving the use of oligosaccharides of known size and molecular weight as standards. 13C NMR spectroscopy is applied for the first time to ob...

the degradation of poly (vinyl pyrrolidone) (pvp) by means of ultrasound irradiation and itscombination with heterogenous photocatalysis (tio2 nanoparticles) was investigated. emphasiswas given on the effect of additive on degradation rate constants. 24 khz of ultrasoundirradiation was provided by a sonicator, while an ultraviolet source of 30 w was used for uvirradiation. to increase the effic...

in the present work, a titanium-based ziegler-natta catalyst was employed to synthesize ultra molecular weight polyethylene in a slurry medium. the effect of different parameters such as ethylene pressure, temperature, catalyst composition, and hydrogen pressure was studied. as the results indicate, increasing either [al]/[ti] ratio or temperature causes polymerization rate to go through a maxi...