Titanium tetra isopropoxide
(TTiPO) was found to be an effective catalyst both in esterification and polycondensation reaction, and its content was optimized based on the esterification ratio and amount of formed by-products. The complex reaction was determined to be the dominant catalytic reaction mechanism. By importing the additives of metal oxides coupled with TTiPO, the weight-average molecular weights of PBST increased sharply from 8.51 x 10(4) to 14.38 x 10(4), manifesting the additives promoted the polymerization reaction greatly. The enhancement of carbonyl polarization and provision of suitable reaction space arose from the metal oxides were the reasons for promoting the polymerization reaction. With respect to thermal properties, the same melting point and heat of fusion were found, while thermal stability increased buy Entinostat with the import of additives. The result was prone to be interpreted by the higher molecular weights of PBST in the presence of additives. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 2203-2211, 2010″
“Background: Parasite resistance to the anti-malarial drug chloroquine is common in eastern Sudan. Dynamic within-host changes in the relative abundance of both sensitive
and resistant Plasmodium falciparum GSK2126458 in vitro parasites were examined in a cohort of chloroquine-treated patients presenting selleck screening library with uncomplicated falciparum malaria, using a novel allele-specific quantitative approach.
Methods: Treatment outcomes were determined for 93 patients of all ages in a per protocol cohort using a modified 14-day WHO protocol. Parasite DNA samples at days 0, 1, 2, 3, 7 and 14 following treatment were analysed
using real-time quantitative PCR methods that distinguished resistant and sensitive genotypes at amino acids 72 -76 of the pfcrt locus.
Results: Chloroquine treatment was not efficacious, and of 93 assessable patients, only 10 individuals (10.7%; 95% C.I. 4.34 -17.2%) enjoyed an adequate clinical and parasitological response. Resistant parasites with the haplotype CVIET at codons 72-76 of the pfcrt locus were dominant in the starting population. Chloroquine sensitive parasites with the haplotype CVMNK were detected in 19 individuals prior to treatment ( 20.43%; 95% C.I. 5.14 -18.5%). In these patients, CQ treatment rapidly selected CVIET parasites, and this haplotype overwhelmingly dominated the parasite population in each individual by day 2 after treatment.
Conclusions: Such rapid intra-host selection of particular genotypes after the introduction of drug will cause frequent misidentification of parasite genotypes present in the starting population.