Targeting the LINC00324/miR-16-5p/SEPT2 Signaling Cascade is Effective to Reverse Malignant Phenotypes in Glioblastoma.

BACKGROUND: Long non-coding RNAs (LncRNAs) are identified as pivotal regulators and biomarkers for glioblastoma (GBM). However, the role of a novel LncRNA LINC00324 in regulating GBM progression has not been fully studied in the existing publications. OBJECTIVE: In this study, we evidenced LINC00324 to act as an oncogene to facilitate GBM development, and the underlying mechanisms have also been uncovered. METHODS: Clinicopathology and follow-up data of GBM patients were retrospectively studied, LINC00324 expression in clinical tissue or cell lines of GBM was measured by Real-time qPCR, and the role of LINC00324 in cell proliferation and migration was investigated by loss-of-function experiments in vitro and in vivo. The targeting genes of LINC00324 were predicted and verified by bioinformatic analysis and dual luciferase reporter gene system, respectively. RESULTS: LINC00324 was found to be significantly upregulated in GBM tissues and cells in contrast to normal counterparts, and the GBM patients with high-expressed LINC00324 tended to have a worse prognosis. Further, loss-offunction experiments showed that the silencing of LINC00324 suppressed cell proliferation, colony formation and migration, and promoted cell apoptosis in GBM cells in vitro. Consistently, the in vivo experiments supported that LINC00324 ablation also restrained tumorigenesis in nude mice models. The following mechanism studies showed that LINC00324 sponged miR-16-5p to upregulate SEPT2 in a competing endogenous RNA-dependent manner, and the inhibitory effects of LINC00324 downregulation on the malignant characteristics of GBM cells were abrogated by both miR-16-5p ablation and SEPT2 overexpression. CONCLUSION: LINC00324 promotes the malignant phenotypes in GBM via targeting the miR-16-5p/SEPT2 axis, and the study provides novel biomarkers for GBM diagnosis and therapy.

Theoretical and Experimental Investigation on the Flexural Behaviour of Prestressed NC-UHPC Composite Beams.

To investigate the normal section strength and cracking bending moment of normal concrete-ultra-high-performance concrete (NC-UHPC) composite beams, calculation formulas were established considering the tensile strength of UHPC based on the current railway bridge design code. Using the railway T-beam as a template, prestressed NC-UHPC composite beams with different NC layer heights were built. A static bending test was performed, the pressure of the steel strand and the deflection and strain of the beam were measured, and the evolution of cracks in each beam was observed. The calculation formulas of the normal section strength and cracking bending moment of NC-UHPC composite beam were verified by the test. The results showed that the type of strain was similar to load-deflection curves with increasing load; the bending failure process of the NC-UHPC composite beam showed four obvious stages: elasticity, uniform cracking, crack development, and yield. Cracks in the beam started to appear at stage II, developed rapidly at stage III, and stopped emerging at stage IV. The calculation formulas for the normal section strength and the cracking bending moment of the NC-UHPC composite beam were in good agreement with the test values. Normal concrete with a compressive strength of 80 MPa can replace UHPC for the design of NC-UHPC composite beams.

Study of Practical Analysis Method for Shear Warping Deformationof Composite Box Girder with Corrugated Steel Webs.

Shear warping deformation is an important part of the flexural and constrained torsion analysis of composite box girder with corrugated steel webs (CBG-CSWs), which is also the main reason for the complex force analysis of box girders. A new practical theory for analyzing shear warping deformations of CBG-CSWs is presented. By introducing shear warping deflection and corresponding internal forces, the flexural deformation of CBG-CSWs is decoupled to the Euler-Bernoulli beam (EBB) flexural deformation and the shear warping deflection. On this basis, a simplified method for solving shear warping deformation using the EBB theory is proposed. According to the similarity of the governing differential equations of constrained torsion and shear warping deflection, a convenient analysis method for the constrained torsion of CBG-CSWs is derived. Based on the decoupled deformation states, a beam segment element analytical model applicable to EBB flexural deformation, shear warping deflection, and constrained torsion deformation is proposed. A variable section beam segment analysis program considering the variation of section parameters is developed for CBG-CSWs. Numerical examples of constant and variable section continuous CBG-CSWs show that the stress and deformation results obtained by the proposed method are in good agreement with the 3D finite element results, verifying the effectiveness by the proposed method. Additionally, the shear warping deformation has a great influence on the cross-sections near the concentrated load and middle supports. This impact along the beam axis decays exponentially, and the decay rate is related to the shear warping coefficient of the cross-section.

Simulation Approach for Random Diffusion of Chloride in Concrete under Sustained Load with Cellular Automata.

Steel bar corrosion caused by chloride is the major reason for concrete structure durability failures in a corrosive environment. An accurate simulation of chloride ion diffusion in concrete is hence critical to durability design, maintenance, and reinforcement of concretes in erosive environments. To accurately simulate actual chloride ion diffusion in concretes, an improved three-dimensional neighborhood type is proposed according to the mechanism of chloride ion diffusion in concrete, and a three-dimensional cellular automaton model (3D CA model) for describing the diffusion process of chloride in concrete is established based on this neighborhood type. The accuracy and correctness of simulation results obtained from the 3D CA model were verified by comparison with Fick's second law analytical solutions. Based on the 3D CA model, an improved modified 3D CA model is developed (3D RTCA model) which takes into account random chloride ion distribution in concrete, the time dependence of the coefficient of chloride ion diffusion, and the structure stress level effect on chloride ion diffusion. Numerical simulation results reveal that the 3D RTCA model has higher calculation accuracy in predicting long-term concentration of chloride in concretes, and the simulation results are closer to experimental findings than analytical results obtained based on Fick's second law. Compared with Fick's second law analytical solutions, the 3D RTCA model can reflect more truly the cross-sectional stress level effect on chloride ion diffusion through simple local evolution rules. Besides, the 3D RTCA model can genuinely describe the randomness and uncertainty of the chloride diffusion process. The 3D RTCA model developed in the current study provides a novel perspective and method to investigate chloride ion diffusion in concrete from structural level.

Statistical Modelling of Carbonation Process in Reinforced Concrete Structure.

In order to quantitatively analyze the factors affecting the carbonation of reinforced concrete structures, the carbonation coefficient model is established based on 1834 groups of test data from natural carbonation and indoor accelerated tests in this paper. The main factors considered in the statistical model are the environmental temperature, the concentration of carbon dioxide, relative humidity, water-cement ratio, fly ash replacement, compressive strength of 28 days, curing time, compaction type, exposure to a salt environment, and environmental exposure classes. Based on the multiple nonlinear regression method, the carbonation coefficient model is fitted in two sections according to the different environmental exposures of the concrete structure. To analyze the applicability of the formula, the statistical formulas of relative humidity less than 70% and relative humidity higher than 70% are verified by the test data, and satisfactory results are obtained. Based on the quantitative analysis of the statistical model, the specific effects of relative humidity, strength, carbon dioxide content, fly ash, and curing time on concrete carbonation are clarified. The results show that the factors affecting carbonation are also different with different humidity values in the exposed environment of the concrete structure. When the relative humidity of the exposed environment is less than 70%, the parameters that have a great impact on concrete carbonation are fly ash replacement, compressive strength of 28 days, relative humidity, and the concentration of carbon dioxide. Among them, fly ash replacement, relative humidity, and the concentration of carbon dioxide can promote the carbonation of concrete. When the relative humidity of the exposed environment is higher than 70%, the parameters that have a great impact on concrete carbonation are the concentration of carbon dioxide, relative humidity, compressive strength of 28 days, curing time, and exposure classes. Only the concentration of carbon dioxide is conducive to the carbonation of concrete, and relative humidity has a very significant effect on concrete carbonation.

Diffusion Behavior of Chloride Ions in Concrete Box Girder under the Influence of Load and Carbonation.

In order to study the durability degradation characteristics of concrete box girder under load and carbonation and chloride ion erosion, a scale model of concrete box girder was made for experimental research. According to the test results, the diffusion characteristics of chloride ions in the concrete box girder under the coupling effect of load and carbon dioxide were analyzed. By revising the calculation formula of the existing chloride ion concentration considering multiple factors, a calculation model of chloride ion concentration considering the influence of carbonation was proposed, and the test results were verified. The results show that the chloride concentration of the box girder on the same cross section is non-uniformly distributed due to the shear lag effect and the spatial structure. After considering the effect of carbonation, the difference rate of the improved model proposed in this paper is generally within 10%. Compared with the original model, the difference rate is reduced by a maximum of 19%.