Investigation on the crystal structure and mechanical properties of the ternary compound Mg_(11-x)Zn_(x)Sr combined with experimental measurements and first-principles calculations

A new ternary compound,Mg_(11-x)Zn_(x)Sr in the Mg-Zn-Sr system was observed and studied using Scanning Electron Microscopy(SEM),Energy-Dispersive Spectroscope(EDS),X-Ray Diffraction(XRD)and Transmission Electron Microscopy(TEM).The XRD patterns were refined by the Rietveld refinement method and the results revealed that the crystallized Mg_(11-x)Zn_(x)Sr phase belonged to tetragonal I41/amd space group and had the Cd_(11)Ba prototype.The Mg atoms were successfully doped into Zn_(11)Sr crystal lattice by occupying Zn atomic sites.Moreover,the Rietveld refinement and computational results demonstrated a gradual decrease in the a-axis and c-axis lattice parameters with decreasing concentration levels of Mg coordination substitution in the lattice of Mg_(11-x)Zn_(x)Sr compound.The elastic constants and modulus of the Mg_(11-x)Zn_(x)Sr compounds calculated by first-principles calculations(FPC)indicated they were increased with the increasing of Zn content.The variation of hardness,D-band widths and the total density of states for Mg_(11-x)Zn_(x)Sr compounds with Zn content was discussed.

Emerging role of miRNAs,lncRNAs,and circRNAs in pregnancy-associated diseases

Accumulating studies have demonstrated that non-coding RNAs(ncRNAs),functioning as important regulators of transcription and translation,are involved in the establishment and maintenance of pregnancy,especially the maternal immune adaptation process.The endometrial stromal cells(ESCs),trophoblast cells,and decidua immune cells that reside at the maternal-fetal interface are thought to play significant roles in normal pregnancy and pregnancy-associated diseases.Here,we reviewed the up-to-date evidence on how microRNA,long non-coding RNA,and circular RNA regulate ESCs,trophoblast cells,and immune cells and discussed the potential applications of these ncRNAs as diagnostic and therapeutic markers in pregnancy complications.

Dual response of graphene-based ultra-small molecular junctions to defect engineering

It has been reported that N and B doping induce a quasi-bound state that suppresses the conduction in graphene nanoribbon （GNR）-based junctions, while an H defect or a pyridine-like N-atom （PN） substitution at the edge of the GNR does not affect the transmission close to the Fermi energy. However, these results may vary when the size of the functional unit of the GNR junction decreases to a molecular level. In this study, a defect is introduced to a test-bed architecture consisting of a polyacene bridging two zigzag GNR electrodes, which changes the molecular state alignment and coupling to the electrode states, and varies the equivalence between two eigen-channels at the Fermi level. It is revealed that B and N atom substitution, and H defects play a dual role in the molecular conductance, whereas the PN substitution acts as an ineffective dopant. The results obtained from density functional theory combined with the non-equilibrium Green＇s function method aid in determining the optimal design for the GNR-based ultra-small molecular devices via defect engineering.