Synthesis of 2'-deoxyguanosine from 2'-deoxyadenosine C2 nitration.

An efficient synthetic method has been developed for the synthesis of 2'-deoxyguanosine from the more commercially available 2'-deoxyadenosine late-stage C2 nitration in 48.7% total yield by a 5-step synthetic procedure. Crucially, 2'-deoxyadenosine was fully protected by bennzoyl groups and then nitrated at C2 by tetrabutylammonium nitrate/trifluoroacetic anhydride.

[Epidemic condition and biological characteristics of non-O1/non-O139 Vibrio cholerae in Haizhu District of Guangzhou].

Objective: To understand the epidemic condition, distribution and biological characteristics of non-O1/non-O139 Vibrio cholerae from 2001 to 2009 in Haizhu District, to provide a scientific basis for the prevention and control of acute diarrhea.

Methods: Referring to the detecting method written in "Cholera control handbook" in the fifth edition, 764 specimens from outside environment (including the water in the Pearl River, drinking water, water for breeding fish, aquatic products and delicatessen foods), 189 specimens of healthy population and 3398 intestinal samples of patients with diarrhea, summing up to 4351 specimens for non-O1/non-O139 Vibrio cholerae test.

Results: 4,351 specimens were detected of 101 strains of non O1/non O139 Vibrio cholerae, the total detection rate was 2.

[Multiplayer white organic light-emitting diodes with different order and thickness of emission layers].

In multilayer OLED devices, the order and thickness of the emission layers have great effect on their spectrum. Based on the three basic colours of red, blue and green, a series of white organic light-emitting diodes(WOLEDS)with the structure of ITO/CuPc(12 nm)/NPB(50 nm)/EML/LiF(1 nm)/Al(100 nm) and a variety of emission layer's orders and thicknesses were fabricated. The blue emission material: 2-t-butyl-9,10-di-(2-naphthyl)anthracene (TBADN) doped with p-bis(p-N, N-diphenyl-amono-styryl)benzene(DSA-Ph), the green emission material: tris-[8-hydroxyquinoline]aluminum(Alq3) doped with C545, and the red emission material: tris-[8-hydroxyquinoline]aluminum( Alq3) doped with 4-(dicyanomethylene)-2-t-butyl-6-(1, 1, 7, 7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) were used.