Several pulse sequences have been used to detect paramagnetic chemical exchange saturation transfer (PARACEST) contrast agents in animals to quantify the uptake over time following a bolus injection. The observed signal change is a combination of relaxation effects and PARACEST contrast. The purpose of the current study was to isolate the PARACEST effect from the changes in bulk water relaxatio...

Freeze-substitution is based on rapid freezing of tissues followed by solution ("substitution") of ice at temperatures well below O degrees C. A 1 to 3 mm. specimen was thrown into 3:1 propane-isopentane cooled by liquid nitrogen to -175 degrees C. (with precautions). The frozen tissue was placed in substituting fluid at -70 degrees C. for 1 week to dissolve ice slowly without distorting tissue...

Currently, most profile control agents would be degraded in strong alkaline condition. They could not be applied in ASP (alkaline, surfactant and partially hydrolyzed polyacrylamide) flooding. To solve this problem, a new kind of alkali-resistant gel for deep profile has been studied. Based on the profile control mechanism of profile agent and the crosslinking mechanism of the polymer, the sele...

Realistic testing of chemical and biological defense systems requires an actual warfare agent. But use of such an agent is restricted to laboratory containment chambers, which are not realistic. This state of affairs has driven the chemical and biological defense community to integrate developmental testing and operational testing. Systems are challenged with both agent and simulant in laborato...

From long time, scientists are looking for natural biomolecules in order to discover new pharmaceutical agents. Therefore polysaccharides which are natural molecules from several biotopes (microbial, plant, algae, fungi, animals, and insects) constitute a very large potential of application for medical treatment. Among them, chitosan a deacetylated form of chitin (one of the most abundant polys...

Metallic aluminum (Al) is of interest as a reducing agent because of its low standard reduction potential. However, its surface is invariably covered with a dense aluminum oxide film, which prevents its effective use as a reducing agent in wet-chemical synthesis. Pitting corrosion, known as an undesired reaction destroying Al and is enhanced by anions such as F⁻, Cl⁻, and Br⁻ in aqueous solutio...

silver is composed of a large percentage of silver oxide due to their large ratio of surface to bulk silver atoms. silver nanoparticles have been a potent antibacterial, antifungal, anti-viral and anti-inflammatory agent. a simple, eco-friendly, inexpensive biosynthetic method was employed to synthesize silver nanoparticles.  the present study aimed at the comparative study of silver nanopartic...

TiO2 nanoparticles, as a photocatalyst for oxidation of dimethyl methylphosphonate (DMMP) as an organophosphorus simulant of chemical warfare agent, were prepared by using sol-gel method. The prepared nanoparticles were then modified with transition metals in order to decrease the electron-hole recombination and increase the photocatalytic activity. Transition metal ions including Pt...