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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.

To the gas system of multi-coalbeds overlay in Zhina coalfield, the initial proposals about coalbed methane (CBM) exploitation, based on a large number of coalfield geological exploration data and the results obtained in coalbed methane exploration recently, was proposed through the analysis of coal reservoir's flexibility energy on horizontal and that of different gas systems on vertical, respectively. The study revealed that Zhongzhai exploration area is the independent gas system of multi-coalbeds overlay. The relation of methane flexibility energy and burial depth of a coalbed show intense fluctuations among the four gas systems, however, methane flexibility energy is increasing with burial depth of coalbed in every different gas system. Adopting subsection fracturing and drainage pattern, the first gas system was the best fit for CBM exploitation. Zhi-2 well, a unified gas system of multi-coalbeds overlay, is located in Zhuzang syncline, of which coal reservoir's flexibility energy is increasing with...

Coal reservoir permeability is an important parameter to used to evaluate coalbed methane resource potential and select favorable zones. This article presents a research on Gemudi syncline. The coal reservoir permeability was largely studied by a considerable amount of geological data obtained from mercury injection experiments, scanning electron microscope observation, and gas/water phase permeability tests. The results revealed that the macro-fractures are especially developed in Gemudi syncline. The micro-fractures and micro-pores of Gemudi syncline are also well developed. The pores, of which the diameters are less than 0.10 μm, occupy the biggest proportion, above 70%. Most pores are open. The measured permeability of the samples varies from 0.33 to 6.69 mD, although most are higher than 0.5 mD. Considering the Mopan mountain mine, which has similar conditions with Gemudi syncline, it is thought that the permeability of coal seams in Gemudi syncline is comparatively high. But the large amount of micr...

Comparative pharmacokinetic profiles of diaveridine following single intravenous and oral dose of 10 mg/kg body weight in healthy pigs and chickens were investigated, respectively. Concentrations of diaveridine in plasma samples were determined using a validated high-performance liquid chromatography-ultraviolet (HPLC-UV) method. The concentration-time data were subjected to noncompartmental kinetic analysis by WinNonlin program. The corresponding pharmacokinetic parameters in pigs or chickens after single intravenous administration were as follows, respectively: t1/2β (elimination half-life) 0.74 ± 0.28 and 3.44 ± 1.07 h; Vd (apparent volume of distribution) 2.70 ± 0.99 and 3.86 ± 0.92 L/kg; ClB (body clearance) 2.59 ± 0.62 and 0.80 ± 0.14 L/h/kg; and AUC0-∞ (area under the blood concentration vs. time curve) 4.11 ± 1.13 and 12.87 ± 2.60 μg∙h/mL. The corresponding pharmacokinetic parameters in pigs or chickens after oral administration were as follows, respectively: t1/2β 1.78 ± 0.41 and 2.91 ± 0.57 h; Cmax (maximum concentration) 0.43 ± 0.24 and 1.45 ± 0.57 μg/mL; Tmax (time to reach Cmax ) 1.04 ± 0.67 and 3.25 ± 0.71 h; and AUC0-∞ 1.33 ± 0.55 and 9.28 ± 2.69 μg∙h/mL. The oral bioavailability (F) of diaveridine in pigs or chickens was determined to be 34.6% and 72.2%, respectively. There were significant differences between the pharmacokinetics profiles in these two species.

In the view of supply chain finance, the default risk of the enterprise not only exists within the enterprise, but also gets along with between two enterprises, which makes it more essential to evaluate the default risk of the whole supply chain. This paper addresses on the contagion of the risk between two enterprises, selecting the financing enterprises as the research object and taking two enterprises which in the same supply chain of Chinese auto industry as sample. Then establish the Logit model based on the financial data of enterprises. Taking the probability as basis, it is possible to get the enterprise combination default probability using Copula function. Then compare it with single enterprise default probability to enhance the accuracy of supply chain financial default risk assessment. At last, provide a basis for improving the accuracy of supply chain enterprise default risk assessment.

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.

Molecular dynamics simulations have been performed to study the mechanical properties of armchair-type single-walled and multiple-walled carbon nanotubes under tensile loading with and without hydrogen storage. Advanced bond order potentials were used in the simulations. Hydrogen molecules stored inside or outside nanotubes reduced the fracture strength of nanotubes. During the deformation, some C-C bonds were broken and reconstructed. If hydrogen. molecules were around, hydrogen atoms would compete with the carbon atoms, to form the H-C bonds, which reduces the mechanical strength of nanotubes. Such detrimental effect of hydrogen is enhanced if the curvature of the tubes is increased, or if hydrogen is stored in a multiple-walled carbon nanotube.

This letter reports a mechanism of chemistry-mediated two-dimensional to three-dimensional (2D–3D) transition during In thin film deposition, and the corresponding evolution of nanoscale islands. Using magnetron sputtering technique, we deposit In on Au substrate. Despite the fact that In wets on Au, In islands prevail over the uniform film soon after the deposition starts. The 2D–3D transition is found to be a result of the formation of Au3In on the Au substrate. The alloy formation leads to nonwetting of In, thereby the high mobility of In atoms and In clusters, and eventually well-separated In islands. The structures of In and Au are characterized by scanning electron microscopy, transmission electron microscopy, and electron diffraction.

This letter addresses the issue of surface softening versus stiffening during elastic deformation. Using a combination of molecular statics and ab initio calculations, we show that a solid surface can be either softer or stiffer elastically than the corresponding bulk. Whether a particular surface is softer or stiffer depends on the competition between atomic coordination and electron redistribution (which sometimes is referred as bond saturation) on the surface. Taking Cu as an example, we demonstrate that the Young’s modulus along 〈110〉 direction on {100} surface is larger than its bulk counterpart; meanwhile, it is smaller along 〈100〉 direction on {100} surface.

A Stone–Wales (SW) defect is a dipole of 5–7 ring pair in a hexagonal network, which is one of the most important defective structures in carbon nanotubes (CNTs) that will affect mechanical, chemical, and electronic properties of CNTs. Using the extended Huckel method, we calculated the formation energy of SW defects in carbon nanotubes. The formation energy of SW defects was then fitted to a simple formula as a function of the tube radius and the orientation of a SW defect in the tube. This result provides a convenient tool for the study of thermodynamics and kinetics of SW defects, as well as the interaction of SW defects with other types of defects in CNTs.

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.

This Letter proposes a characteristic length scale on surfaces and demonstrates its impact on nanorod growth. The proposed length scale is the dimension of a surface segment bounded by multiple-layer steps. Lattice kinetic Monte Carlo simulations, taking Cu as the prototype of nanorods, show that the proposed length scale (i) exists as the result of a diffusion barrier of adatoms down multiple-layer steps, (ii) dictates that the diameter of metallic nanorods is on the order of several hundred nanometers, and (iii) sets the upper limit of the facet dimension.

This paper describes atomistic determinations of the Young's modulus of free standing thin films, or nanoplates. Using a combination of analytical formulation and molecular statics simulations, we show that the Young's modulus of a nanoplate may either increase or decrease with the thickness. It is the competition of bond saturation and bond loss on surfaces that dictates the increase or decrease. Taking Cu as an example, we demonstrate that the Young's modulus is larger than its bulk counterparts for nanoplates having some surfaces and loading directions, and smaller for others.

In catalysis applications, it is desirable to have nanorods of smaller diameter. However, if the separation of nanorods is smaller than their diameter, nanorods will merge to become dense films. The separation of nanorods derives from the separation of nucleating clusters on the substrate. This letter reports a theory of the smallest separation of nanorods. This theory is in closed form and is verified by accompanying lattice kinetic Monte Carlo simulations. The theoretical prediction of transition from nanorods to dense films—when the separation of nanorods is smaller than their diameter—is in good agreement with in-house experimental observation.

Five main saponins were separated from the cell cultures of Panax notoginseng (Burk) F. H. Chen. They were sanchinoside Rb1, Re, R1, Rg1 and Rh1 identified by TLC, HPLC, IR, M. P., 13CNMR and EI-MS. Saponin components of the cell cultures were almost the same as those of the cultivated plants. But the content of saponins was different between the cell cultures and the cultivated plants. Saponin extraction and separation procedure suitable for the cell cultures has to be different from that for the cultivated plants.

By omitting the component NH4NO3 and doubling the amount of KNO3 in MS medium, the Panax quinque folium cells cultured in such medium grew more rapidly and their saponin content was much higher than that cultured in regular MS medium. The growth rate and saponin content of the cells cultured in such medium (KNO33300 mg/l) increased 65.1% and 166.2% respectively as compared with that cultured in the regular medium. The application of oligosaccharins from Panax ginseng and Dendrobium candidum also increased their saponin content and growth rate. Especially, the content of Rg group saponins was apparently raised. It took more than 25 days for the cell suspension cultures to produce saponins in large amounts. The curve of saponin formation lagged slightly behind the growth curve in cell suspension culture and fermentation culture. The cell fermentation culture with a stabilized pH value was better than the culture with the pH value changing spontaneously on saponin content, growth rate and biomass. Finally, the culture patterns of P. quinque folium cells were compared and discussed.

Using classical molecular statics simulations, we show that nanoplate elasticity strongly depends on surface reconstruction and alignment of bond chains. Because of its well-established surface reconstructions and the readily available interatomic potential, diamond-cubic silicon is the prototype of this study. We focus on silicon nanoplates of high-symmetry surfaces, {111} and {100}; with 7×7 and 2×1 reconstructions. Nanoplates with unreconstructed {111} surfaces are elastically stiffer than bulk. In contrast, the same nanoplates with 7×7 reconstructed {111} surfaces are elastically softer than bulk. On {100} surfaces, the 2×1 surface reconstruction has little impact. The bond chains are along one of the two ⟨110⟩ directions, making the two ⟨110⟩ directions nonequivalent. The alignment of the bond chains on the opposite surfaces of a nanoplate dictates its elastic anisotropy. The sensitivity of nanoplate elasticity on details of surface atomic arrangements may impact the application of nanoplates (or nan...