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Background: miR-20b has been shown to be aberrantly expressed in several tumor types. However, the clinical significance of miR-20b in the prognosis of patients with gastric cancer (GC) is poorly understood, and the exact role of miR-20b in GC remains unclear., Materials and Methods: The expression of miR-20b was detected in 102 patients with GC by a SYBR Green assay and was compared with the expression in matched adjacent normal tissue specimens. The aim of the present study was to investigate the association of the expression of miR-20b with the clinicopathological characteristics and the overall survival of patients with GC as analyzed by Kaplan-Meier analysis and Cox proportional hazards regression models., Results: Our results showed that miR-20b expression was upregulated in GC tissue compared with normal mucosa (P=0.00). Furthermore, miR-20b expression was positively correlated with advanced lymph node metastasis (P=0.041), tumor node metastasis stage (P=0.000), and deeper and distant metastasis (P=0.031). The overall survival rate of patients with GC was significantly lower in those whose tumors expressed high levels of miR-20b mRNA compared with those whose tumors expressed low levels of miR-20b mRNA (P=0.019)., Conclusion: miR-20b may serve as a potential molecular marker for the prognosis of GC.

The ASD FieldSpec portable spectrometer was adopted to collect canopy reflectance spectrum data of the 9 main tree species in study area by a long-term observation to get the data of the four seasons Then the smoothed reflectance curve and the first derivation curve from 350 to 1400 nm and several commonly used vegetation spectral characteristic parameters were generated to analyse seasonal change characteristics and variation of the 9 tree species in visible and near-infrared band and to explore the best band characteristics and period for species identification. The results showed that different trees had different and rather unique spectral features during the four seasons. The spectral characteristics of the deciduous trees have regular changes with the cycle of the seasons, whereas those of the evergreen tree species have no significant changes in one year. As well changes in the spectral characteristics could effectively reflect forest phenology changes, and it is proposed that the optimal strategy for tree species classification may be the integration and analysis of multi-seasonal spectral data. Evergreen trees and deciduous trees in the winter have obvious differences in the canopy spectral characteristics and the best single-season remote sensing data for tree species recognition is in summer.

Lewis-acid-catalyzed reactions of arylvinylidenecyclopropanes having three substituents at the corresponding cyclopropyl rings have been investigated thoroughly. The reaction products are highly dependent on the substituents at the corresponding cyclopropyl rings and the electronic nature of the aryl groups. For arylvinylidenecyclopropanes bearing two alkyl groups at the C-1 position (R1, R2, R3=aryl; R4=H; R5, R6=alkyl), naphthalene derivatives were formed in the presence of Lewis-acid Eu(OTf)3 in DCE at 40 degrees C. For arylvinylidenecyclopropanes in which R1, R2, R3=aryl and R4, R5=alkyl (syn/anti isomeric mixtures), the corresponding 6aH-benzo[c]fluorine derivatives were formed in the syn-configuration via a double intramolecular Friedel-Crafts reaction when all of the aryl groups do not have electron-withdrawing groups or the corresponding indene derivatives were obtained via an intramolecular Friedel-Crafts reaction as long as one electron-deficient aryl group was attached. For arylvinylidenecyclopropanes in which R1, R2, R3, R4=aryl and R5=alkyl or H, the corresponding indene derivatives were obtained exclusively via a sterically demanding intramolecular Friedel-Crafts reaction. Lewis-acid effects and mechanistic insights have been discussed on the basis of experimental investigations.