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Background: To date, over 150 genetically modified (GM) crops are widely cultivated. To comply with regulations developed for genetically modified organisms (GMOs), including labeling policies, many detection methods for GMO identification and quantification have been developed., Results: To detect the entrance and exit of unauthorized GM crop events in China, we developed a novel quadruplex real-time PCR method for simultaneous detection and quantification of GM cotton events GHB119 and T304-40 in cotton-derived products (based on the 5'-flanking sequence) and the insect-resistance gene Cry2Ae. The limit of detection was 10 copies for GHB119 and Cry2Ae and 25 copies for T304-40. The limit of quantification was 25 copies for GHB119 and Cry2Ae and 50 copies for T304-40. Moreover, low bias and acceptable standard deviation and relative standard deviation values were obtained in quantification analysis of six blind samples containing different GHB119 and T304-40 ingredients., Conclusions: The developed quadruplex quantitative method could be used for quantitative detection of two GM cotton events (GHB119 and T304-40) and Cry2Ae gene ingredient in cotton derived products.

Alzheimer's disease (AD) is an age-related and progressive neurodegenerative disease. Beta-amyloid (Aβ) plays an important role in the pathogenesis of AD. Autophagy is a self-degradative process and its related protein Beclin-1 is involved in the initiation of autophagy. However, the role of Beclin-1 in the pathogenesis of AD is rarely reported. In this study, we examined cell viability and medium levels of neuron-specific enolase (NSE) in PC12 cells incubated with gradient concentrations of Aβ(1-42) (0.625, 1.25, 2.5, 5, 10 μM) for 6, 12, 24, 48, and 72 h, drew the index changes curves, and investigated the correlation between them. The result showed that cell viability was negatively correlated with NSE levels. Based on this study, Beclin-1 expression was quantitatively detected in Aβ1-42-treated PC12 cells and the dynamic changes curve of Beclin-1 was drawn from 3 to 72 h. Beclin-1 expression was positively correlated with cell viability. Furthermore, both autophagy inhibitor 3-methyladenine (3-MA) and autophagy activator rapamycin were used to investigate the effect of autophagy on Aβ(1-42)-induced cell injury. Aβ(1-42)-induced Beclin-1 expression was further upregulated by rapamycin but was downregulated by 3-MA. Moreover, cell viability was increased by rapamycin but was decreased by 3-MA, and NSE was decreased by rapamycin but was increased by 3-MA, suggesting that activation of Beclin-1-dependent autophagy before the damage occurred can prevent neuronal cell death, while inhibition of Beclin-1-dependent autophagy can hastened cell death. These findings indicate that increasing Beclin-1-dependent autophagy may have a preventive effect before the AD occurred.

Autophagy is usually up-regulated to provide more ATP in response to starvation or OGD (oxygen-glucose deprivation), but the relationship between autophagy and ATP, [Ca2+]i (intracellular free Ca2+ concentration) or MMP (mitochondrial membrane potential) during reoxygenation is not yet fully clear. The role of autophagy is unknown in PC12 cells subjected to 2 h OGD with different time points of reoxygenation. In the present study, we showed that Beclin-1 was up-regulated beginning at 0 h reoxygenation peaking at 24 h and lasting for 48 h. Cell viability was decreased from 0 to 48 h reoxygenation, reaching its minimum at 10 h reoxygenation. ATP was decreased from 0 to 10 h reoxygenation, reaching its minimum at 4 h reoxygenation. A significant negative correlation was observed between ATP and Beclin-1 (r = -0.61, P<0.05) at 0 h reoxygenation, but ATP was not significant related (r = 0.24, P>0.05) to Beclin-1 at 24 h reoxygenation. Besides, Nimodipine, a calcium antagonist, significantly reduced [Ca2+]i and Beclin-1, but increased MMP in OGD/R-treated cells. At 24 h reoxygenation, Beclin-1 expression reached its maximum, cell viability continued to increase, and ATP was higher than that before OGD. These results suggest that energy metabolism dysfunction can induce autophagy during OGD in PC12 cells. Increased [Ca2+]i and decreased MMP may induce autophagy during reoxygenation in PC12 cells. Autophagy may be a protective effect on PC12 cells treated with different time points of reoxygenation after 2 h OGD.

Vanadium-doped magnesium nanostructures are fabricated by an oblique angle co-deposition method and hydrogenated/dehydrogenated for 21 cycles. The effective thermal conductivity and density of the MgH2 nanostructures is measured by using a photothermal system. A multilayer physical model is used to fit the experimental data. Our results show that the effective thermal conductivity of the hydrogenated V-doped Mg nanostructures is in the range of 1.16-2.40 W m(-1) K(-1) and the density falls in the range of 878-1320 kg m(-3). The measured density agrees well with the estimation from electron micrograph observation. Variation in the measurements indicates strong nonuniformity of the sample structure and thickness. Based on the measured density and effective thermal conductivity, the thermal conductivity of bulk V-doped Mg hydrides is also evaluated using Maxwell's correlation.

A unique diffusion barrier structure, consisting of layers of a Ti nanorod array and Ti film, has been fabricated on Si substrate for a subsequent 2 at.% Ti-doped Mg film deposition using a combinational technique of multilayer growth, co-deposition and dynamic shadowing growth. The hydrogenation of the Ti-doped Mg film on such a barrier structure shows that the barrier can prevent direct Mg-Si contact and suppress the formation of Mg(2)Si alloy in a high-temperature process. When this film has been hydrogenated at temperatures T≤300 °C for approximately 150 h, tetragonal single-crystal MgH(2) nanowires are formed on the surface of the Ti-doped Mg film. The hydrogenation time and temperature are the two main factors for the nanowire formation. The doping of Ti also plays a significant role. This result reveals that complicated dynamic processes could occur during the hydrogenation of Ti-doped Mg film when Mg(2)Si formation can be eliminated by an effective diffusion barrier layer.