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Two-dimensional (2D) materials exhibit massive potential in research and development in the scientific world due to their unique electrical, optical, thermal and mechanical properties. Graphene is an earliest found two-dimensional material, which has many excellent properties, such as high carrier mobility and large surface area. However, single layer graphene has a zero band gap, which limits its response in electronic devices. Unlike graphene, the transition metal sulfides (TMDs) have various band structures and chemical compositions, which greatly compensate for the defect of zero gap in graphene. The WS2 is one of the 2D TMDs exhibiting a series of unique properties, such as strong spin-orbit coupling, band splitting and high nonlinear susceptibility, which make it possess many applications in semiconducting optoelectronics and micro/nano-electronics. The 2D semiconductors along with semimetallic graphene are seen as basic building blocks for a new generation of nanoelectronic devices. In this way, the artificially designed TMD heterostructure is a promising option for ultrathin photodetectors. There are few reports on the physical mechanism of carrier mobility and charge distribution at the interface of WS2/graphene heterostructure, by varying the interfacial distance of WS2/graphene heterostructure to investigate the effect on the electronic properties. Here in this work, the corresponding effects of interface cohesive interaction and electronic properties of WS2/graphene heterostructure are studied by first-principles method. The calculation results indicate that the lattice mismatch between monolayer WS2 and graphene is low, the equilibrium layer distance d of about 3.42 Å for the WS2/graphene heterostructure and a weak van der Waals interaction forms in interface. Further, by analyzing the energy band structures and the three-dimensional charge density difference of WS2/graphene, we can identify that at the interface of the WS2 layer there appears an obvious electron accumulation: positive charges are accumulated near to the graphene layer, showing that WS2 is an n-type semiconductor due to the combination with graphene. Furthermore, the total density of states and corresponding partial density of states of WS2/graphene heterostructure are investigated, and the results show that the valence band is composed of hybrid orbitals of W 5d and C 2p, whereas the conduction band is comprised of W 5d and S 3p orbitals, the orbital hybridization between W 5d and S 3p will cause photogenerated electrons to transfer easily from the internal W atoms to the external S atoms, thereby forming a build-in internal electric field from graphene to WS2. Finally, by varying the interfacial distance for analyzing the Schottky barrier transition, as the interfacial distance is changed greatly from 2.4 Å to 4.2 Å, the shape of the band changes slightly, however, the Fermi level descends relatively gradually, which can achieve the transition from a p-type Schottky contact to an n-type Schottky contact in the WS2/graphene. The plane-averaged charge density difference proves that the interfacial charge transfer and the Fermi level shift are the reasons for determining the Schottky barrier transition in the WS2/graphene heterostructure. Our studies may prove to be instrumental in the future design and fabrication of van der Waals based field effect transistors.

Calpains are the key proteases involved in muscle growth, protein transformation and meat tenderization. In this study, CAPN7 cDNA of Wild boar was cloned by RT-PCR, its sequence analysis, expression characterization and polymorphism analysis were performed. The results showed that the full-length coding sequence of Wild boar CAPN7 is 2442 bp long, and encodes a protein of 813 amino acids with the catalytic site of calpain family, whose catalytic triad residues is located at amino acids 290, 458 and 478, respectively. RT-PCR expression analysis indicated that CAPN7 mRNA was ubiquitously expressed in the 12 tissues examined, but the relative abundance was unevenly distributed in tissues. The CAPN7 mRNA levels in muscle of 6 and 9-month-old crossbred pigs were higher than those of Yorkshire pigs at the same ages. In addition, a missense mutation was identified by PCR-SSCP and its distribution in wild boar, Min pig and Duroc was significantly different. The results lay the foundation for further studying the function of CAPN7 gene.

The expression of the YUCAA1 gene and the amount of endogenous indole acetic acid (IAA) in rice (Oryza sativa subsp. japonica) plants and rice suspension cells infected by Rice stripe virus (RSV) were investigated by real-time reverse transcriptase–polymerase chain reaction (RT-PCR) and high-performance liquid chromatography, respectively. The results showed that the expression of the YUCAA1 gene and the amount of endogenous IAA increased at various times (16, 32, 48 and 64 h) after infection of rice suspension cells by RSV. In rice plants infected with RSV, the expression of the YUCAA1 gene and the amount of endogenous IAA increased, in comparison with healthy rice plants, at 4–8 days after infection, and decreased at 12 and 16 days. These results indicated that RSV infection could regulate auxin biosynthesis in rice. Additionally, the expression of the RSV gene CP increased 2.9 times in rice plants after they were treated with a KPSC buffer to deplete the endogenous auxins, and decreased 45% after treatment with 30 μmol/l IAA. All of these results suggest that auxin may play a role in RSV replication in rice plants.