The molecular mechanisms of osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) remain to be fully elucidated. MicroRNAs (miRs) serve vital roles in the process of regulating osteogenic differentiation of BMSCs. The present study aimed to investigate the role of miR‑23a‑5p in osteogenic differentiation of human (h)BMSCs, and the underlying molecular mechanism. The results of reverse transcription‑quantitative polymerase chain reaction demonstrated that miR‑23a‑5p was significantly downregulated in the process of osteogenic differentiation. Upregulation of miR‑23a‑5p inhibited osteogenic differentiation of hBMSCs, and down‑regulated expression of miR‑23a‑5p enhanced this process, which was confirmed by alkaline phosphatase (ALP) and Alizarin Red S staining. A dual‑luciferase reporter assay confirmed that mitogen‑activated protein kinase 13 (MAPK13) was a direct target of miR‑23a‑5p. In addition, knockdown of MAPK13 inhibited osteogenic differentiation of hBMSCs, similar to the effect of upregulation of miR‑23a‑5p. Finally, the knockdown of MAPK13 also blocked the effect of miR‑23a‑5p in osteogenic differentiation of hBMSCs, which was also confirmed by ALP and Alizarin Red S staining. These results indicated that by targeting MAPK13, miR‑23a‑5p serves a vital role in osteogenic differentiation of hBMSCs, which may provide novel clinical treatments for bone injury however, further studies are required.
Impact statement
For decades, Thermus was always considered to be aerobic. However, recent studies have suggested that the denitrification abilities of Thermus species may be widely underestimated. In the present study, we used comparative genomic analysis to investigate the evolutionary history of the denitrification pathway in Thermus and other members of the phylum Deinococcota. We revealed incomplete denitrification pathways to be common in Thermus and showed they are inherited mostly vertically, which further supports the importance of Thermus as a significant denitrifier in hydrothermal environments.
Aerosol is a critical factor affecting the atmospheric hydrological cycle and climate change. Acting as cloud condensation nuclei for cloud formation, aerosols have a significant impact on regional precipitation. This study uses the fully coupled chemistry module (Weather Research and Forecasting/Chem) within the Weather Research and Forecasting model to simulate convective cloud precipitation in the Yangtze River Delta of China. To investigate the impact of on precipitation, four numerical experiments are conducted. The base case uses the full emission inventory (which we call the 100% case), and the other three cases are designed based on reduced emissions for different percentages (which we call the 50% case, the 10% case, and the 1% case). Compared to the other cases, the grid point hour maximum precipitation of the 50% case is the largest, which can reach 44.1 mm/hr and has an increase of 5% over the 100% case. The strongest precipitation is delayed by about 1 hr in the 50% case, and precipitation area is increased by 6.5%. This study indicates that the influence of aerosols on regional precipitation is a nonlinear process, with a correlation coefficient of 0.52 (p<0.01) showing a strong positive correlation between cloud condensation nuclei (>250 cm−3, height of 0.5–3 km) and precipitation. Further analysis of the dynamics and microphysical processes of this convective precipitation shows that the 50% case has an area with higher rising velocity and bigger cloud water mixing ratio than the other cases but has a relatively low convective center. The formation of precipitation is mainly influenced by the accretion of snow by rain, but the role of the snow melting into rain cannot be ignored.
A novel bi-directional circularly polarized (CP) antenna with low profile, real planar configuration and broad axial ratio (AR) bandwidth is presented for S-band satellite relay communication application. The designed antenna consists of four fan-shaped patches, a sequentially rotating feed network and ground plane with annular gaps. Four fan-shaped patches are directly integrated with the feed network on the same FR4 substrate for good impedance matching and compact size. To realize the two-way radiation characteristics and excellent AR bandwidth, one parasitic annular groove on the ground plane is designed. The sequential rotation feeding network can provide good port characteristics within the available bandwidth and good AR. The properties of designed antenna was tested to validate its simulation. The final prototype is 83 Â 83 Â 0.8 mm 3 in size and it can generate a broad impedance bandwidth for voltage standing wave ratio (VSWR) <2 of 36.6% (2.32-3.36 GHz), 3-dB AR bandwidth of 21.3% (2.6-3.22 GHz) and gain over 5.4 dB in the bi-directional direction. The miniaturization, low-cost and good CP radiation for this proposed antenna make it a better candidate for future applications in the field of spacecraft relay communication.
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