sp. nov., a new monoraphid diatom (Bacillariophyta) from southern China.

A novel monoraphid diatom species, You, Yu, Kociolek & Wang, is examined and described from the Qingyi River and Maolan Nature Reserve of southern China. The morphological description is based on light microscopy and scanning electron microscopy observations and the new species is compared with similar taxa in this genus. The characteristics unique to include its central area extending irregularly to both sides, it having closed valvocopulae with heavily silicified fimbriate margins and poles of the valvocopulae have 'sword-shaped' siliceous extensions.

Norethindrone acetate (NA) and ethinyl estradiol (EE) related oxidative transformation products in stability samples of formulated drug product: synthesis of authentic references.

Preparative chemical methods for the synthesis of eight oxidative transformation products of ethinyl estradiol (EE) and norethindrone acetate (NA) are described. The prepared materials are useful as reference materials and standards for pharmaceutical analysis of EE and NA as bulk chemical or in formulated product. All eight products result from oxidation of the A and/or B rings of the parent compounds.