Evaluation of sesamum gum as an excipient in matrix tablets

In developing countries modern medicines are often beyond the affordability of the majority of the population. This is due to the reliance on expensive imported raw materials despite the abundance of natural resources which could provide an equivalent or even an improved function. The aim of this study was to investigate the potential of sesamum gum (SG) extracted from the leaves of Sesamum radiatum (readily cultivated in sub-Saharan Africa) as a matrix former. Directly compressed matrix tablets were prepared from the extract and compared with similar matrices of HPMC (K4M) using theophylline as a model water soluble drug. The compaction, swelling, erosion and drug release from the matrices were studied in deionized water, 0.1 N HCl (pH 1.2) and phosphate buffer (pH 6.8) using USP apparatus II. The data from the swelling, erosion and drug release studies were also fitted into the respective mathematical models. Results showed that the matrices underwent a combination of swelling and erosion, with the swelling action being controlled by the rate of hydration in the medium. SG also controlled the release of theophylline similar to the HPMC and therefore may have use as an alternative excipient in regions where Sesamum radiatum can be easily cultivated

Search for Gravitational Waves from Intermediate Mass Binary Black Holes

We present the results of a weakly modeled burst search for gravitational waves from mergers of non-spinning intermediate mass black holes (IMBH) in the total mass range 100--450 solar masses and with the component mass ratios between 1:1 and 4:1. The search was conducted on data collected by the LIGO and Virgo detectors between November of 2005 and October of 2007. No plausible signals were observed by the search which constrains the astrophysical rates of the IMBH mergers as a function of the component masses. In the most efficiently detected bin centered on 88+88 solar masses, for non-spinning sources, the rate density upper limit is 0.13 per Mpc^3 per Myr at the 90% confidence level.Comment: 13 pages, 4 figures: data for plots and archived public version at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=62326, see also the public announcement at http://www.ligo.org/science/Publication-S5IMBH

Immunity and cross-protection to nephritis produced by Australian infectious bronchitis viruses used as vaccines

Four series of viruses were generated by passage through eggs incubated at 31°C. Initial evaluation of these viruses in SPF chickens showed that they had been successfully attenuated with regard to nephritis following between five and 25 egg passages. In addition, within each series viruses could be selected that minimised deaths from nephritis whilst optimising protective immunity against virulent challenge. Eight viruses were selected and used to vaccinate birds with maternal antibodies to IB. The viruses produced minimal mortalities and protected birds from subsequent challenge. Three viruses were selected from the latter trial and subjected to a cross protection experiment with three serologically distinct virulent challenge viruses: Ql/73, Nl/62 and N9/74. All the vaccine viruses protected birds from challenge while 2032/10 protected birds better than Vac 3/10 or Vac G/15. Finally, 2032/10 and Vac A3 were used in a similar experiment. Both proved to be mild, in terms of pathogenicity to the kidneys, and produced high levels of protective immunity against the three serologically distinct challenge viruses