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To explore the regulatory mechanism of micro-ribonucleic acid (miR)-122-3p in the osteogenic differentiation of mouse adipose-derived stem cells (mADSCs).The regulatory mechanism of miR-122-3p in the osteogenic differentiation of mesenchymal stem cells was investigated through its overexpression and knockdown.The overexpression of miR-122-3p inhibited the osteogenic differentiation of mADSCs. On the contrary, its knockdown promoted the osteogenic differentiation of mADSCs. The further study on the molecular mechanism of miR-122-3p regulating mADSCs' osteogenic differentiation showed that the overexpression of miR-122-3p could activate the Wingless and int-1 (WNT)/β-catenin signaling pathway, but the knockdown of miR-122-3p could repress this signaling pathway.MiR-122-3p influences the osteogenic differentiation of mADSCs by modulating the WNT/β-catenin signaling pathway.

The purpose of this study was to explore the mechanism of micro-ribonucleic acid (miR)-214-3p in regulating fracture healing in rats with osteoporosis.A total of 30 female Sprague-Dawley rats were selected and randomly divided into 3 groups, including group A [phosphate-buffered saline (PBS), n=10], group B (AntagomiR-NC, n=10), and group C (AntagomiR-214-3p, n=10). All rats underwent ovariectomy, and the osteoporosis rat model was verified by dual-energy X-ray absorptiometry 8 weeks after the operation. Then the osteoporotic fracture was established in rats via a second operation. From the successful modeling until the 6th week, 50 μL PBS (2 nmoL) was intraperitoneally injected in group A, an equal amount of AntagomiR-NC was injected in group B, and an equal amount of AntagomiR-214-3p was injected in group C once a week. At the 6th week, fracture healing of osteoporosis rats was evaluated. At the same time, the expression of miR-214-3p in the three groups was detected via reverse Transcription-Polymerase Chain Reaction (RT-PCR). Furthermore, the protein expressions of bone morphogenetic protein 2 (BMP2) and Smad4 in the three groups were detected via Western blotting (WB).After ovariectomy, the bone mineral density in each group was significantly lower than that before ovariectomy, and the differences were statistically significant (p0.05). Imaging evaluation demonstrated that compared with group A and B, there were significantly more callus tissues in group C. Meanwhile, the fracture line healing was better and blurred, and the internal fixation had no displacement and loosening. RT-PCR results indicated that the expression level of miR-214-3p in group C was significantly lower than that of the other two groups (p0.05). WB results showed that the protein expression levels of BMP2 and Smad4 in group C were significantly higher than those of group A and group B (p0.05).MiR-214-3p delays fracture healing in rats with osteoporotic fracture by inhibiting the BMP/Smad signaling pathway.

Osmotic stress at elevated osmotic pressure was used to stimulate saponin production in Panax ginseng cell cultures. The addition of 0.3 M sorbitol to culture at the time of inoculation, raising the medium osmolality by about 75% (from 150 to 260 mmol/kg), enhanced the saponin accumulation but depressed the cell growth, resulting in no improvement of the volumetric saponin yield of culture. The feeding of sorbitol (0.2–0.3 M, 36.4–54.6 g/L) to culture during the stationary growth phase increased both the saponin content of cell (45–50%) and the volumetric yield (36–38%). With combined feeding of sorbitol (0.2 M) and growth nutrients, sucrose (30 g/L) + casein hydrolysate (0.5 g/L), about 2 days before the stationary phase, the volumetric saponin yield was increased 3.5-fold, 1130.8 mg/L versus the control culture of 251.2 mg/L. Sorbitol in the culture also induced two characteristic stress responses of plant cells, the increase in phenylalanine ammonium-lyase (PAL) activity and the production of reactive oxygen species. This suggests that the stimulated saponin accumulation was part of the cell response to the osmotic stress.

The embedded atom method (EAM) potentials are probably the most widely used interatomic potentials for metals and alloys. However, the EAM potentials impose three constraints on elastic constants that are inconsistent with experiments. At a more subtle (but more important) level, the EAM potentials often incorrectly describe the outward/inward relaxation of surface layers, and therefore will not reliably describe nanostructures. This paper reports a response EAM (R-EAM) that addresses both issues. Conceptually, the electron distribution from each atom does not respond to the atom's environment within the EAM. In reality, the electron distribution from each atom depends on the atom's environment, and this dependence is explicitly incorporated in the R-EAM. Analytical derivation shows that the R-EAM potentials do not impose these three constraints on elastic constants that EAM potentials do. Furthermore, taking hexagonal close packed (hcp) metals Ti, Mg, and Zn as the prototypes, the authors show that the R-EAM potentials correctly describe surfaces---in terms of interlayer spacing and surface reconstruction, in agreement with quantum mechanics calculations, while EAM potentials are not in agreement. In comparison to EAM potentials, the R-EAM potentials require only less than twice the computational power.

A controversy exists among literature reports of constraints on elastic constants. In particular, it has been reported that embedded atom method (EAM) potentials generally impose three constraints on elastic constants of crystals that are inconsistent with experiments. However, it can be shown that some EAM potentials do not impose such constraints at all. This paper first resolves this controversy by identifying the necessary condition when the constraints exist and demonstrating the condition is physically necessary. Furthermore, this paper reports that these three constraints are eliminated under all conditions, by using response EAM (R-EAM) potentials.