The evaluation of active transcriptional repressor domain for CRISPRi in plants.

With the development of clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (CRISPR/Cas9) system in gene editing, the catalytic site in Cas9 has been mutated to dead Cas9 (dCas9) to regulate target gene's expression with the guidance of single guide RNA (sgRNA) in many organisms. When dCas9 was navigated to the region close to the transcription start site, duo to sterical hindrance, it could downregulate the expression level of target gene specifically without genomic alteration. Furthermore, the fusion of synthetic transcriptional repressor domain (TRD) to dCas9 could improve the gene silencing efficiency dramatically, the above all was also known as CRISPR interference system (CRISPRi). Till now, SRDX repressor domain was the most frequently used TRD in plant. Nevertheless, its incomplete repression limited the application of CRISPRi system. Hereafter, in this study, we identified three more effective TRDs, DLN144, DLS and MIX in plant. To dissect the transcriptional repressing activity of DLN144, DLS and MIX in plant, first and foremost, we proved their transcriptional repression efficiency in transient transformed Nicotiana benthamiana leaves. Then, their intrinsic transcriptional repressing activity was corroborated in stable transgenic wheat and N. benthamiana. These three functional TRDs, DLN144, DLS and MIX, provide more options for the application of CRISPRi in plant and shed new light on the advancement of more robust TRDs by combining different individual effective repressor domain in plant which will facilitate the application of CRISPRi when higher repression efficiency is required.

Effects of thickness reduction in cold rolling process on the formability of sheet metals using ANFIS.

Cold rolling has detrimental effect on the formability of sheet metals. It is, however, inevitable in producing sheet high quality surfaces. The effects of cold rolling on the forming limits of stretch sheets are not investigated comprehensively in the literature. In this study, a through experimental study is conducted to observe the effect of different cold rolling thickness reduction on the formability of sheet metals. Since the experimental procedure of such tests are costly, an artificial intelligence is also adopted to predict effects of cold thickness reduction on the formability of the sheet metals. In this regard, St14 sheets are examined using tensile, metallography, cold rolling and Nakazima's hemi-sphere punch experiments. The obtained data are further utilized to train and test an adaptive neural network fuzzy inference system (ANFIS) model. The results indicate that cold rolling reduces the formability of the sheet metals under stretch loading condition. Moreover, the tensile behavior of the sheet alters considerably due to cold thickness reduction of the same sheet metal. The trained ANFIS model also successfully trained and tested in prediction of forming limits diagrams. This model could be used to determine forming limit strains in other thickness reduction conditions. It is discussed that determination of forming limit diagrams is not an intrinsic property of a chemical composition of the sheet metals and many other factors must be taken into account.

Transcriptional regulation by CRISPR/dCas9 in common wheat.

The application of CRISPR/Cas9 system for gene editing, as a technical coup for biotechnology, is worldwide and encompasses multiple of species. The inactivation of catalytical site in Cas9 (dCas9) has been reprogrammed as an effective approach to regulate the transcriptional level of target genes, especially for the functionally essential genes and redundant genes. Here, we exploited the CRISPR/dCas9 system to manipulate the transcriptional level of target genes in common wheat. To improve target gene's expression, we generated transcriptional activator by fusing 6×TAL-VP128 activation domain to the C-terminus of dCas9 in frame. For target gene's repressing expression transcriptionally, 3×SRDX repression domain was conjugated to the C-terminus of dCas9 in frame. Our results showed that dCas9 fused activation or repression domain could increase or decrease the transcriptional level of target gene effectively in stable transgenic lines of wheat. The study on the tRNA-processing system in CRISPR/dCas9 based transcriptional regulation system demonstrated that this robust multiplex targeted tool can be incorporated to the CRISPR/dCas9 system to facilitate the target regulation of several genes' transcriptional level. Our data broaden the application of CRISPR/dCas9 based transcriptional regulation and provide great opportunities to investigate the function of essential genes in common wheat.

[Clinical effects of micro-implant and traditional anchorage in orthodontic treatments].

PURPOSE: To analyze the value of micro-implant and traditional anchorage in the treatment of malocclusion. METHODS: From Jan 2015 to Jan 2016, 20 cases with malocclusion were randomly divided into control group(10) and experimental group (10). A comparison was conducted between the control group, in which traditional anchorage was used and the experimental group, in which micro-implant anchorage was adopted. The data were analyzed with SPSS 17.0 software package. RESULTS: There was significant difference of U1-NA, L1-NB, U1-APg, U6-PtPNS between the 2 groups(P<0.05). Adverse reaction was not found in the control group, but 8% in the experimental group(P<0.05). CONCLUSIONS: Micro-implant anchorage can improve overjet relation of the anterior teeth and effect of orthodontic treatment.