MicroRNA-212 inhibits osteosarcoma cells proliferation and invasion by down-regulation of Sox4.

BACKGROUND: Multiple MicroRNAs (miRNAs) have been identified in the development and progression of osteosarcoma. However, the expression and roles of miR-212 in osteosarcoma remain largely undefined. METHODS: Real-time PCR assays were used to detect the expression of miR-212 in human osteosarcoma tissues. MiR-212 mimics were introduced into MG63 and U2OS cells. Bioinformatic prediction was used to identify the potential targets of miR-212. Protein expression analysis, luciferase assays and rescue assays were used to confirm the substrate of miR-212. RESULTS: miR-212 was significantly down-regulated in human osteosarcoma tissues, compared with adjacent normal tissues. Introduction of miR-212 mimics into MG63 and U2OS cells inhibited cell proliferation and invasion. Besides, miR-212 overexpression could also inhibit tumor growth in the nude mice. Additionally, bioinformatic prediction suggested that the sex-determining region Y-box 4 (Sox4) is a target gene of miR-212. Sox4 inhibition phenocopied the roles of miR-212, while restored expression of Sox4 dampened miR-212-mediated suppression of tumor progression. CONCLUSION: The miR-212/Sox4 interaction plays an important role of in the osteosarcoma progression.

[Impact of heavy-duty diesel vehicles on air quality and control of their emissions].

Through an analysis of the characteristics of diesel vehicle emissions and motor vehicle emissions inventories, this paper examines the impact of heavy-duty diesel vehicles on air quality in China as well as issues related to the control of their emissions. Heavy-duty diesel vehicles emit large amounts of nitrogen oxides and particulate matter. Nitrogen oxides is one of the important precursors for the formation of secondary particles and ozone in the atmosphere, causing regional haze. Diesel particulate matter is a major toxic air pollutant with adverse effect on human health, and in particular, the ultrafine particles in 30-100 nm size range can pose great health risks because of its extremely small sizes. Motor vehicles have become a major source of air pollution in many metropolitan areas and city cluster in China, and among them the heavy-duty diesel vehicles are a dominant contributor of nitrogen oxides and particulate matter emissions. Hence, controlling heavy-duty diesel vehicle emissions should be a key component of an effective air quality management plan, and a number of issues related to heavy-duty diesel vehicle emissions need to be addressed.

[Effect of ethanol gasoline and unleaded gasoline on exhaust emissions of EFI vehicles with TWC].

The injectors' flow-rate of all test vehicles that each was fixed with a three-way catalytic converter (TWC) and Electronic Fuel Injection System (EFI) was tested including before and after vehicles operated on unleaded and ethanol gasoline respectively running for a long time on real road. The three main engine-out exhaust emissions (HC, CO and NOx) from vehicles operating on different fuels were also analyzed by exhaust testing procedure for the whole light-duty vehicle. Test results showed that comparing with unleaded gasoline and ethanol gasoline has a remarkable effect on decreasing engine-out exhaust emissions of CO and HC (both at about ten percent) and the exhaust emissions of CO, HC and NOx from vehicles with TWC respectively. When burning with unleaded gasoline the three main pollutants from vehicles with TWC have already or nearly reached Europe Exhaust First Standard, after changing to ethanol gasoline CO has drastically decreased at about thirty percent, while HC and NOx decreased at about eighteen and ten percent respectively, at this time which they were all above Europe Exhaust Standard First or nearly reached Europe Exhaust Second Standard; ethanol gasoline has also other better performance such as a slight cleaning function on injectors, a slower deteriorative trend of engine-out CO and HC and a longer operating life-span of TWC.