in this paper, polyacrylamide/chromium acetate gel polymer system was prepared as water shut-off system to control water production in one of the iranian oil reservoirs condition. effect of various parameters such as temperature (90 °c) and water formation from view point of salinity and divalent cations, was evaluated on the gelation kinetic and gel strength using bottle testing method. the re...

Studies on the functionality of muscle proteins in gelation mechanisms of structured meat products during the last three decades are briefly reviewed. Among muscle proteins, myosin is primarily the most important protein for gelation, whereas actin plays a complementary role in gelation when it coexists with myosin. The combined data of gelation and denaturation indicate that the gelation of my...

Ehrlich ascites tumor cell extracts form a gel when warmed to 25 degrees C at pH 7.0 in sucrose solution, and the gel rapidly becomes a sol when cooled to 0 degrees C. This gel-sol transformation was studied quantitatively by determining the volume or the total protein of pellets of gel obtained by low-speed centrifugation. The gelation depended on nucleotide triphosphates, Mg2+, KCl, and a red...

Silk fibroin (SF) is a typical fibrous protein that is secreted by silkworms and spiders. It has been used in a variety of areas, and especially for tissue-engineering scaffolds, due to its sound processability, mechanical properties, biodegradability, and biocompatibility. With respect to gelation, the SF gelation time is long in aqueous solutions, so a novel approach is needed to shorten this...

Ion channels are naturally occurring pores through the proteins that regulate the passage of ions and thus maintain the concentration of ions inside and outside the cell. The ion channels control many physiological functions and they can show selectivity for a specific ion. Ion channels are mostly observed in nerve cells and muscle cells. The influx of ions into cells can be regulated by a gate...

This preliminary work explores a technique for processing collagen gels to provide a structured matrix support for cell growth and other tissue engineering applications without using cyto-toxic photo-initiators. Collagen gels can be structured by techniques similar to those of rapid manufacturing and retain the fibril structure of native collagen. Incorporation of alpha-modified minimal essenti...

Optical methods for microfluidic flow manipulation offer a flexible, noncontact technique for both fluid actuation and valving. At present, however, such techniques are limited by their high laser power requirements, low achieved flow rates, or poor valve switching times. Here we demonstrate a microfluidic valving technique based on optothermorheological manipulation using a low-power 40 mW las...

high purity fluorapatite (fa) with rod-like and spherical-like morphology was synthesized via sol-gel method. chemical characterization of fa powders was done by xrd and ftir analyses. crystallite samples were calculated using scherer method. morphology of fa powders was investigated with tem and sem images. the results revealed that increasing the time of hydrolysis of phosphate sols significa...

in recent years, chitosan nanoparticles have been studied widely for protein delivery. in this study, hemiscorpius lepturus (hl) venom was encapsulated in chitosan nanoparticles. the aim of the present work was to carry out a systematic study for preparing biocompatible and biodegradable nanoparticles for loading hl scorpion venom and to evaluate their potential as an antigen delivery system. i...

       The present study deals with the formulation and evaluation of chitosan nanoparticles containing donepezil hydrochloride for the targeted delivery to the brain. Nanoparticles were prepared by ionic gelation method using sodium tripolyphos-phate (TPP) as a cross linking agent followed by sonication. Nanoparticles were obtained in the average size ranging from 116.8 to 227.5 nm. Particle m...