Construction of aptasensors for sensitive detection of 8-OH-dG based on a diffusion mediated electrochemiluminescence quenching effect.

A DNA immobilization-free ECL aptasensor was developed for the detection of 8-hydroxy-2'-deoxygunosine based on the diffusion mediated ECL quenching effect. This ECL aptasensor exhibited a high sensitivity and low detection limit by combining homogeneous DNA reaction with dual signal amplifications: target-induced multi-DNA release and Exo I-assisted target recycling.

[Effects of VPA on the Expression of Notch Signaling Pathway in Multiple Myeloma RPMI 8226 Cell Line].

OBJECTIVE: To investigate the effects of valproic acid(VPA) on the expression of intracellular domain of Notch1 (ICN1) and Hes1 in multiple myeloma RPMI 8226 cell line. METHODS: Experiments were divided into 4 group: blank control group and groups of cells treated with VPA of different concentration (2, 4, 8 mmol/L), the cell proliferation was detected by MTT method, RT-PCR was applied to detect the mRNA expression level of ICN1 and Hes1. Western blot was used to detect the protein expression of ICN1 and Hes1. RESULTS: The proliferation of the RPMI 8226 cell was obviously inhibited by different concentration of VPA (2, 4, 8 mmol/L) at the same time. The same concentration of VPA was used to treat RPMI8226 cell for different time (24, 48, 72 h), the cell proliferation was obviously inhibited. Compared with control group, the mRNA and protein expression of ICN1 was significantly depressed at different concentration of VPA(2, 4, 8 mmol/L) for 48 h (P<0.05). Compared with control group, the mRNA and protein expression of Hes1 was depressed at different concentration 2, 4, 8 mmol/L)of VPA for 48 h (P<0.05). CONCLUSION: VPA inhibits the proliferation of the RPMI 8226 cell in a time- and dose- dependent manner; VPA down-regulates the mRNA and protein expression level of ICN1 and Hes1 in RPMI8226 cell; thus VPA might inhibit cell proliferation possibly through the inhibition of Notch signaling pathway in multiple myeloma cells.

Asymmetric synthesis of planar chiral ferrocenes by enantioselective intramolecular C-H arylation of N-(2-haloaryl)ferrocenecarboxamides.

The palladium-catalyzed intramolecular C-H arylation reaction of N-(2-bromoaryl)ferrocenecarboxamides furnishes planar chiral ferrocene derivatives. TADDOL-derived phosphoramide ligands induce enantioselectivities ranging from 91:9 to 98:2 er.