Production and characterization of surface-active compounds from Gordonia amicalis

Two methods were used to make crude preparations of surface-active compounds (SACs) produced by Gordonia amicalis grown on the medium containing 1% diesel oil. Using a 2:1 (v/v) solution of chloroform:methanol for extraction, Type I SACs were isolated and shown to produce oil in water (O/W) emulsions. Type II SACs were isolated by precipitation with ammonium sulfate and produced predominantly water in oil emulsions (W/O). The crude Type I and II preparations were able to produce a significant reduction in the surface tension of water; however, the crude Type II preparation had 10-25 fold higher emulsification activity than the Type I preparation. Both SAC preparations were analyzed by the TLC and each produced two distinct bands with Rf 0.44 and 0.62 and Rf 0.52 and 0.62, respectively. The partially purified SACs were characterized by the ESI(+)-MS, FT-IR and NMR. In each one of these fractions, a mixture of 10 oligomers was found consisting of a series of compounds, with masses from 502 to 899, differing in molecular mass by a repeating unit of 44 Daltons. The mass spectra of these compounds did not appear to match other known biosurfactants and could represent a novel class of these compounds.

Threats of toxic warfare / 军事医学

In 2002, a research report about toxic warfare launched by the United States Air Force attracted the attentionof the U.S.military and civilian disaster emergency rescue organizations .By reviewing historical events related to the malicioususe of toxic industrial chemicals in the war , this report proposed the concept of Toxic Warfare , and discussed itsimpact on the United States military and homeland security .In this paper, the concept and history of toxic warfare and itsinfluence on American military and homeland security are reviewed , the threats of toxic warfare facing China and counter -measures against toxic warfare are analyzed.

Management situation and using industrial chemicals at some productive manufacturer in Vietnam

The investigation was performed on employees and workers who contact with chemicals at 9 institutions using various substances in the process of production of paint, rubber, shoe and wood articles in Ha Noi, Hai Phong and Da Nang. Results showed that the current regulations were not complied preserve and use of chemical substance, without emergency equipments available for working staff and environment. A high rate of workers had not been educate on chemical safety and a high rate of work place and facilities had not guideline for using chemical substances.