Clinical trials are usually long term studies and it seems impossible to reach all required subjects at the same time. Performing interim analyses and monitoring results may provide early termination of trial after obtaining significant results. The aim of this study is comparing group sequential tests in respect to advantage of sample size reduction and early termination. In this study, 4 test...

To incorporate formal assessments of potential efficacy into feasibility and pilot studies of complex interventions, appropriate methods for sample size determination are required. In particular, the implications of clustered patient outcomes resulting from cluster randomisation or treatment provision must be addressed. In this paper we will show how small-sample methods used to design phase II...

Background The ethical significance of sample size is enshrined in principles of Good Clinical Practice and in quality standards for reporting trial results, yet sample size is often one of the most ill-considered aspects of a grant application. Researchers are also battling with an increasing complexity in study design. With some adaptive trial designs, for example, analytical solutions to sam...

semiconductor nanoparticles exhibit size dependent properties due to quantum confinement effect that arenot present in their bulk counterparts. in this work, extremely fine and pure sno2 nanoparticles of ~1.1nm size were synthesized by a solution process, in which amorphous precipitate of sno2 was crystallizedby microwave heating. the particles sizes varied from ~1.1 to ~2.7 nm. by xrd analysis...

this paper discusses about preparation of biodegradable polymer /clay nanocomposites based on organically modified montmorillonite clay; i.e. cloisite 10a and biodegradable polymer chitosan by solution mixing technique and their characterization. the nanocomposites were successfully prepared and their structures were characterized by powder x-ray diffraction (xrd), particle size analyzer (beckm...