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Myostatin (MSTN) is a growth and differentiation factor that regulates proliferation and differentiation of myoblasts, which in turn controls skeletal muscle growth. It may regulate myoblast differentiation by influencing miRNA expression, and the present study aimed to clarify its precise mechanism of action. Here, we found that MSTN–/–pigs showed an overgrowth of skeletal muscle and upregulated miR-455-3p level. Intervention of MSTNexpression using siMSTN in C2C12 myoblasts also showed that siMSTN significantly increased the expression of miR-455-3p. It was found that miR-455-3p directly targeted the 3′-untranslated region of Smad2by dual-luciferase assay. qRT-PCR, Western blotting, and immunofluorescence analyses indicated that miR-455-3p overexpression or Smad2silencing in C2C12 myoblasts significantly promoted myoblast differentiation. Furthermore, siMSTN significantly increased the expression of GATA3. The levels of miR-455-3p were considerably reduced in C2C12 myoblasts following GATA3knockdown. Consistently, GATA3knockdown also reduced the enhanced miR-455-3p expression caused by siMSTN. Finally, we illustrated that GATA3has a role in myoblast differentiation regulation. Taken together, we identified the expression profiles of miRNAs in MSTN–/–pigs and found that miR-455-3p positively regulates myoblast differentiation. In addition, we revealed that MSTN acts through the GATA3/miR-455-3p/Smad2 cascade to regulate muscle development.

Plant growth and development are determined by complex exogenous and endogenous cues. A plant follows several temporally distinct developmental stages, including embryonic, vegetative, and reproductive. The vegetative stage, which is usually the longest stage, can be subdivided into juvenile and adult phases. The transition from the juvenile to the adult phase, also called the vegetative phase change, is characterized by anatomical, morphological, and physiological changes in the vegetative parts of the shoot. Recent studies in several systems have identified the genetic temporal mechanisms of this process, which is regulated by an endogenous age cue (i.e., microRNA156/157) and its targeted genes (i.e., Squamosa promoter binding protein-box transcription factors). This review summarizes the recent advances in the study of the underlying regulatory mechanisms of vegetative phase change. This review also describes the modes of miRNA action and the functions of their targeted genes in this highly conserved developmental process. [ABSTRACT FROM AUTHOR]

As Huston's form of Kane's equation cannot be easily applied to large deployable structures, what is needed is further development of Kane's equation as described in this paper. Fully-Cartesian-coordinate (FCC) method uses Cartesian coordinates of points and Cartesian components of unitary vectors as generalized coordinates to describe three-dimension mechanisms. This FCC method avoids the need to consider angular coordinates and the resulting solution is just the space position of the structures. The FCC form of Kane's equation derived in this study is suitable for solution by computer method and is a good base for further simulation research. A numerical example showed that it is effective.

The effects of chromite sand particle size, mixing ratio of sand and copper wire, motor speed and collision friction time on the removal of copper wire paint film and copper recovery efficiency were studied. The results show that the conditions for efficient copper recovery are: chromite sand particle size is 0.40mm, chromite sand and copper wire mixing ratio is 1:1, centrifugal motor speed is 2700r/min, collision friction time is 2min. Under these conditions, the polyester enameled copper wire film was completely removed and the copper recovery rate reached 98.75%.

At present, the study of standard requirements is still missing. Firstly, this paper constructs an evaluation index system of renewable resource standard demand from four aspects: environmental demand, resource demand, economic demand and social demand. Secondly, VIKOR method is used to construct the standard requirement evaluation model. Finally, the paper makes an empirical analysis of ten major renewable resource standards in China. It is desirable to be able to provide decision support for that relevant sector through research on the requirement for demand standards of renewable resources.