60 research outputs found

    MicroRNA-595 promotes osteogenic differentiation of bone marrow mesenchymal stem cells by targeting HMGA2

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    Purpose: To investigate the effect of miR-595 on osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs).Methods: Human BMSCs were osteogenically differentiated, and protein expression of alkaline phosphatase (ALP), osteocalcin (OCN), and Runt-related transcription factor 2 (RUNX2) were evaluated by western blot. Expression of miR-595 was measured by quantitative reverse transcription (qRT-PCR). The effect of miR-595 on viability of BMSCs was determined by MTT assay. Osteogenic differentiation of BMSCs was assessed by ALP and Alizarin red S (ARS) staining. The target gene of miR-595 was predicted by TargetScan analysis and validated by luciferase activity assay.Results: MiR-595 expression was higher in osteogenically differentiated BMSCs than in undifferentiated BMSCs (p < 0.01). Osteogenic ALP, OCN, and RUNX2 were also upregulated (p < 0.01). MiR-595 expression increased the viability of BMSCs, mineralized bone matrix formation, and ALP activity. High mobility group AT-hook 2 (HMGA2) expression was lower in osteogenically differentiated BMSCs and was found to be a target of miR-595. Overexpression of HMGA2 attenuated the miR-595-induced increase in cell viability, ALP activity, mineralized bone matrix formation, and osteogenic gene expression in BMSCs.Conclusion: The miR-595/HMGA2 axis is involved in osteogenic differentiation of BMSCs suggesting that it is a promising therapeutic target for osteoporosis

    Predictions of energy profile of four states in USA

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    In this paper, we calculate the value of the residual energy in 2001-2009 in four states by establishing Grey Prediction Model.  We use MATLAB software programming to predict the energy profile of each state for 2025 and 2050 in the absence of any policy changes

    Meta-analysis Followed by Replication Identifies Loci in or near CDKN1B, TET3, CD80, DRAM1, and ARID5B as Associated with Systemic Lupus Erythematosus in Asians

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    Systemic lupus erythematosus (SLE) is a prototype autoimmune disease with a strong genetic involvement and ethnic differences. Susceptibility genes identified so far only explain a small portion of the genetic heritability of SLE, suggesting that many more loci are yet to be uncovered for this disease. In this study, we performed a meta-analysis of genome-wide association studies on SLE in Chinese Han populations and followed up the findings by replication in four additional Asian cohorts with a total of 5,365 cases and 10,054 corresponding controls. We identified genetic variants in or near CDKN1B, TET3, CD80, DRAM1, and ARID5B as associated with the disease. These findings point to potential roles of cell-cycle regulation, autophagy, and DNA demethylation in SLE pathogenesis. For the region involving TET3 and that involving CDKN1B, multiple independent SNPs were identified, highlighting a phenomenon that might partially explain the missing heritability of complex diseases

    Analysis of Sealing Performance of Metal B-ring Self-Tightening Structure

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    Process industries often use B-ring self-tightening sealing structures and rely on interference assembly to meet the initial sealing requirements. Therefore, determining reasonable B-ring material, size and interference is crucial to ensure the sealing performance of the structure. In this paper, based on elastic deformation analysis, the deformation co-ordination equation of a B-ring sealing structure was established, and a sealing contact pressure calculation formula was obtained, with discussion of the main factors affecting sealing performance. With the finite element method, transient temperature field analysis was carried out for startup and shutdown load cases, and contact analysis was carried out for interference assembly, startup and shutdown. Based on the evaluation criteria of sealing performance with proposed sealing rate and leakage parameters, the effects of material properties, interference, B-ring size, etc., on sealing performance were investigated, revealing that although a B-ring with high material yield stress can meet the sealing requirements, both the B-ring and the sealing surface of a reactor body will yield plastic deformation. B-rings with a low material yield stress exhibit obvious plastic deformation during startup and leak during shutdown. However, leakage parameters can be minimized by smaller interference and moderate wave radius

    FINITE ELEMENT ANALYSIS OF A LARGE FIXED TUBESHEET HEAT EXCHANGER BASED ON SUB-MODEL TECHNIQUE

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    As enormous number of tubes in large fixed tubesheet heat exchangers, it is difficult to model all the tubes and tubesheet connections in detail for FEA. Therefore, it fails to yield an accurate stress field around the connecting region of tubes and tubesheet, which is essential for the effective stress intensity evaluation. Taking a large fixed tubesheet heat exchanger as example, the maximum stress intensity location is found for the tube layout region of the tubesheet according to the coarse model. Then the sub model is utilized in the predetermined maximum stress location. In the sub model, detailed connecting structure of the tube and the tubesheet are included, such as the weld metal and contact condition between the tube and tubesheet hole. Both stress classification and limit load analysis are preformed for the sub model structure. Although both the weld and the tube fail the evaluation based on stress classification, it is more reasonable to evaluate the connecting region with the direct route based on limit load analysis for the structure with non axisymmetric stress distribution. Limit analysis is carried out and limit load is determined by zero-curvature method. It is shown that the structure meets the strength requirement based on the relevant standards

    Fast Calculation of Transient Thermal Stress in Surge Lines with Thermal Stratification Region

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    Nuclear power plants applying for license renewal are required to undertake a fatigue assessment of various components, which demands the fast calculation of transient thermal stress of the fatigue-sensitive components such as surge lines. In this study, the strategy of Green’s function database construction for the thermal stratification region was investigated, and the thermal stress calculation was shown to be more accurate by dividing the flow cases and thermal zones. Furthermore, a method to determine the fluid temperature for the thermal zones of the thermal stratification region was studied. In addition to the temperature of the hot leg fluid and the outlet fluid from the pressurizer, seven thermocouples installed on the outside wall in the thermal stratification region were used to determine the fluid temperature of thermal zones with stratification, and the calculation result of the fluid temperature was verified with the temperature Green’s functions

    STEADY-STATE TEMPERATURE FIELD AND STRESS FIELD ANALYSIS OF AUTOCLAVE TOOTH-LOCKED QUICK OPENING STRUCTURE

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    In order to provide accurate temperature field of autoclave,and make preparation for stress analysis,temperature of autoclave tooth-locked quick opening structure was measured. Using ANSYS to simulate the temperature field,the result is compared with the measured data. It shows that the simulation result is consistent with the actual situation. The strength and fatigue life were evaluated by JB4732-1995,evaluation results meet the requirements
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