Crystal structure of 4,4'-(diazenediyl)dipyridinium nitrate perchlorate.

The title compound, CHN ·NO ·ClO , was obtained unexpectedly by the reaction of Co(ClO)·6HO and cytidine-5'-monophosphate with 4,4'-azo-pyridine in an aqueous solution of nitric acid. The mol-ecular structure comprises two planar 4,4'-diazenediyldipyridinium dications lying on inversion centres and perchlorate and nitrate anions in general positions. In the crystal, N-H⋯O hydrogen bonds between dications and anions lead to the formation of [232] chains.

[An ambispective cohort study of the natural history of HIV infection among former unsafe commercial blood and plasma donors].

Objective: Discussing the natural history and the influencing factors of HIV infection among former commercial blood and plasma donors engaged in unsafe blood donation practices in China.

Methods: Using ambispective cohort study, with data obtained from ten counties (districts) from six provinces in the National AIDS Control Demonstration Area. HIV/AIDS cases were found and confirmed prior to July 24, 2006 being former commercial blood.

[Epidemiology of pediatric HIV infection in six provinces of China].

Objective: To investigate the epidemiology of pediatric human immunodeficiency virus (HIV) infection in six provinces of China.

Methods: A cross-sectional study was conducted in six provinces with the highest HIV prevalence. Surveys on demographics and HIV-related questions (transmission modes, time of diagnosis, clinical stage, laboratory test) were distributed to clinicians in these provinces.