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Epiphytic bryophytes can maintain water, recycle nutrients, and provide habitats for many other organisms in the forest ecosystem. Describing the spatial change of epiphytic bryophytes plays an important role in understanding the potential factors of diversity distribution. The study aimed to determine the influence of environmental factors on their diversity and assemblage in the alpine forest ecosystem of Sygera Mountain. We considered 72 trees, taking into account 1152 quadrats to research the study. Our results showed bryophyte richness first exhibited a hump-shaped pattern and then increased along elevation, reaching a peak at 3500 m. The richness of the eastern aspect was higher than that of the west. Diversity of Quercus semecarpifolia was the highest. There was significant variation among elevations of bryophytes assemblages, especially for the biotopes at 3900 m and 4100 m. The differences among bryophytes assemblages on aspects and tree species were less apparent. Diameter at breast height and elevation influenced assemblage composition. Elevation, tree species, and tree properties drive the diversity of epiphytic bryophytes, and tree species were significantly related to the variation in the diversity of bryophytes. These results are helpful for understanding the relationship between the spatial distribution pattern of bryophytes and the environment.

The aim of the present study was to assess the expression of microRNA (miRNA)-4784 in the chondrocytes of early osteoarthritis (OA) and to determine the effect of double-stranded (ds)-miRNA-4784 transfection on chondrocyte function. Following the construction of an OA rabbit model, normal chondrocytes (normal control group), OA chondrocytes obtained 4 weeks after modeling (OA at week 4 group) and 8 weeks after modeling (OA at week 8 group) were used. The relative expression of miRNA-4784 in each group was detected using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Western blotting was performed to measure the expression of type II collagen (Col2a1) and matrix metalloproteinase (MMP)-3 in each group with or without ds-miRNA-4784 transfection. The results revealed that the levels of miR-4784 in groups OA at week 4 and 8 were significantly lower than that of normal control group (P<0.05). It was also demonstrated that Col2a1 mRNA expression levels in groups OA at week 4 and 8 were 49 and 38% of that in the normal control group, respectively. Furthermore, MMP-3 mRNA expression levels increased by 3.12- and 3.95-fold in groups OA at week 4 and 8, respectively, compared with those in the normal control group (P<0.01). Following transfection with ds-miRNA-4784, Col2a1 mRNA expression levels increased by 63 and 126% compared with the levels prior to treatment in groups OA at week 4 and 8, respectively (P<0.01). The expression levels of MMP-3 mRNA in groups OA at week 4 and 8 decreased following transfection compared with the levels prior to treatment. Col2a1 and MMP-3 protein expression exhibited similar patterns to the mRNA expression. In summary, the results of the present study suggest that miRNA-4784 expression is significantly reduced in early stage OA chondrocytes. Transfection with ds-miRNA-4784 promotes the expression of Col2a1 and inhibits the MMP-3 expression in chondrocytes.

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A new type of precision flow valve is designed by used the combination of piezoelectric ceramic and metal rubber, the mathematical model that possesses flow characteristics at the valve outlet is established based on Darcy's law and Newton's first law, the influence of different driving voltage and different parameters of metal rubber ring on flow characteristics is analyzed through using MATLAB software, and the effects of metal rubber ring on the flow stability of fluid in the valve outlet is analyzed on simulation by means of FLUENT software. The results show that: the flow characteristics of valve are related to the driving voltage of the piezoelectric ceramic and the parameters of metal rubber ring After the metal rubber ring is installed at the valve outlet, the fluid flow at the valve exit is gentler. The flow direction of fluid tends to be consistent, which is approximate to the laminar flow. To a certain extent, it improves the stability of the valve output flow (pressure).