Downregulation of rho-associated protein kinase 1 by mi R-124 in colorectal cancer

AIM: To investigate the roles and interactions of rhoassociatedprotein kinase (ROCK)1 and miR-124 inhuman colorectal cancer (CRC).METHODS: Expression of ROCK1 protein wasexamined by Western blotting, and quantitativereverse transcriptase PCR was performed to measureexpression of ROCK1 mRNA and miR-124. Two cancercell lines were transfected with pre-miR-124 (mimic)and anti-miR-124 (inhibitor) and the effects onROCK1 protein and mRNA expression were observed.In addition, cell proliferation was assessed via a5-ethynyl-2′ deoxyuridine assay. Soft agar formationassay, and cell migration and invasion assays wereused to determine the effect of survivin on thetransformation and invasion activity of CRC cells.RESULTS: miR-124 was significantly downregulated inCRC compared to normal specimens (0.603 ± 0.092 vs1.147 ± 0.286, P = 0.016) and in metastatic comparedto nonmetastatic CRC specimens (0.416 ± 0.047 vs0.696 ± 0.089, P = 0.020). Expression of miR-124 wassignificantly associated with CRC metastasis, tumor Tand N stages, and tumor grade (all P < 0.05). ROCK1protein was significantly increased in CRC comparedto normal tissues (1.896 ± 0.258 vs 0.866 ± 0.136,P = 0.026), whereas ROCK1 mRNA expression wasunaltered (2.613 ± 0.251 vs 2.325 ± 0.246). miR-124and ROCK1 were inversely expressed in CRC tissuesand cell lines. ROCK1 mRNA was unaltered in cellstransfected with miR-124 mimic and miR-124 inhibitor,compared to normal controls. There was a significantreduction in ROCK1 protein in cells transfected withmiR-124 mimic and a significant increase in cells transfected with miR-124 inhibitor (P s < 0.05).Transformation and invasion of cells transfectedwith miR-124 inhibitor were significantly increasedcompared to those in normal controls (P < 0.05). Cellstransfected with miR-124 inhibitor showed increasedcell proliferation.CONCLUSION: miR-124 promotes hyperplasia andcontributes to invasion of CRC cells, but downregulatesROCK1. ROCK1 and miR-124 may play important rolesin CRC.

Microstructure and mechanical properties of ultralow carbon high-strength steel weld metals with or without Cu-Nb addition

Two types of ultralow carbon steel weld metals(with and without added Cu-Nb) were prepared using gas metal arc welding(GMAW) to investigate the correlation between the microstructure and mechanical properties of weld metals.The results of microstructure characterization showed that the weld metal without Cu-Nb was mainly composed of acicular ferrite(AF), lath bainite(LB), and granular bainite(GB).In contrast, adding Cu-Nb to the weld metal caused an evident transformation of martensite and grain coarsening.Both weld metals had a high tensile strength(more than 950 MPa) and more than 17% elongation;however, their values of toughness deviated greatly,with a difference of approximately 40 J at-50℃.Analysis of the morphologies of the fracture surfaces and secondary cracks further revealed the correlation between the microstructure and mechanical properties.The effects of adding Cu and Nb on the microstructure and mechanical properties of the weld metal are discussed;the indication is that adding Cu-Nb increases the hardenability and grain size of the weld metal and thus deteriorates the toughness.

Component SPD matrices： A low-dimensional discriminative data descriptor for image set classification

In pattern recognition,the task of image set classification has often been performed by representing data using symmetric positive definite(SPD)matrices,in conjunction with the metric of the resulting Riemannian manifold.In this paper,we propose a new data representation framework for image sets which we call component symmetric positive definite representation(CSPD).Firstly,we obtain sub-image sets by dividing the images in the set into square blocks of the same size,and use a traditional SPD model to describe them.Then,we use the Riemannian kernel to determine similarities of corresponding subimage sets.Finally,the CSPD matrix appears in the form of the kernel matrix for all the sub-image sets;its i,j-th entry measures the similarity between the i-th and j-th sub-image sets.The Riemannian kernel is shown to satisfy Mercer’s theorem,so the CSPD matrix is symmetric and positive definite,and also lies on a Riemannian manifold.Test on three benchmark datasets shows that CSPD is both lower-dimensional and more discriminative data descriptor than standard SPD for the task of image set classification.

Nanostructural thermoelectric materials and their perfor- mance

In this review, an attempt was made to introduce the traditional concepts and materials in thermo- electric application and the recent development in search- ing high-performance thermoelectric materials. Due to the use of nanostructural engineering, thermoelectric materials with a high figure of merit are designed, leading to their blooming application in the energy field. One dimensional nanotubes and nanoribbons, two-dimensional planner structures, nanocomposites, and heterostructures were summarized. In addition, the state-of-the-art theoretical calculation in the prediction of thermoelectric materials was also reviewed, including the molecular dynamics （MD）, Boltzmann transport equation, and non-equilibrium Green＇s function. The combination of experimental fabrication and first-principles prediction significantly promotes the discovery of new promising candidates in the thermoelectric field.