Converting biomass into value-added chemicals holds the key to sustainable long-term carbon resource management. In this context, levulinic acid, which is easily obtained from cellulose, is valuable since it can be transformed into a variety of industrially relevant fine chemicals. Here we present a simple protocol for the selective esterification of levulinic acid using solid acid catalysts. S...

background : evaluation of exposition to volatile organic compounds (voc) and compare urinary level of urinary biological exposure index in sweepers in west of iran . methods: this study was carried out on 40 street sweepers and 40 non-exposed as control group living in hamadan city, west of iran. voc was analyzed using gas chromatography equipped with a flame ionization detector (fid). the uri...

A series of sulfonic acid polymers were shown to be potent and selective inhibitors of respiratory syncytial virus (RSV) and influenza A virus. The compounds inhibit the replication of RSV and influenza A virus in HeLa and MDCK cells, at concentrations of 0.16 and 4.0 micrograms/ml, respectively, and are nontoxic to growing cells at concentrations of > 100 micrograms/ml. The mode of antiviral a...

BACKGROUND: Mathematical models describing the physical, chemical and biological processes that take place in bioremediation are necessary to design and optimise these technologies. This work models the effect of toluene as a gaseous cosubstrate in the degradation of phenanthrene in soil, considering the consumption of pollutants, the production of intermediate degradation compounds and mineral...

Toluene and benzene were eliminated using multi-walled carbon nanotubes (MWCNTs). In order to investigate influence of acid treatment on the MWCNTs adsorption capacities, the MWCNTs were functionalized by nitric acid (10 M) under reflux conditions for 2 h. Fourier transform infrared (FTIR) and Raman spectroscopy were employed to confirm the formation of functional groups on the nanotubes su...

Transfer ribonucleic acid (tRNA) nucleotidyltransferase was studied after making cells permeable to macromolecules by treatment with toluene. The conditions of toluene treatment necessary for obtaining maximal activity were defined. Toluene treatment was most efficient when carried out for 5 min at 37 C at pH 9.0 on log-phase cells. No activity could be detected if cells were treated at 0 C, or...

The introduction of sulfonic acid modified silica in Nafion nanocomposite membranes is a good method of improving the Nafion performance at high temperature and low relative humidity. Sulfonic acid-modified silica is bifunctional, with silica phase expected to offer an improvement in membranes hydration while sulfonic groups enhance proton conductivity. However, as discussed in this paper, this...