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OBJECTIVE: Atherosclerosis is an inflammation-associated disease resulting in a huge health hazard. Abundance of researches showed that long non-coding RNAs (lncRNAs) played vital roles in atherosclerosis, but the molecular mechanism of nuclear-enriched abundant transcript (NEAT1) has not been fully elucidated yet. PATIENTS AND METHODS: Human umbilical vein endothelial cells (HUVECs) were treated with oxidized low-density lipoprotein (ox-LDL) for constructing the model of atherosclerosis. The detection of NEAT1, microRNA-30c-5p (miR30c-5p), and transcription factor 7 (TCF7) expression was implemented by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Cell proliferation and apoptosis were measured by 3-(4, 5-dimethylthiazol-2-y1)-2, 5-diphenyl tetrazolium bromide (MTT) and flow cytometry, respectively. The levels of apoptosis-associated proteins were examined through Western blot and the concentrations of inflammatory cytokines were determined by enzyme-linked immunosorbent assay (ELISA). The targeted relationship was analyzed by Dual-Luciferase reporter assay. RESULTS: NEAT1 was upregulated in serum of patients with atherosclerosis and HUVECs treated with ox-LDL. Knockdown of NEAT1 exerted the promotion of proliferation but suppression of apoptosis and inflammation in oxLDL-treated HUVECs. Moreover, NEAT1 targeted miR-30c-5p and the overexpression of miR30c-5p reversed the ox-LDL-induced effects in HUVECs. Furthermore, miR-30c-5p directly refrained the TCF7 level, and NEAT1 repression decreased the expression of TCF7 by upregulating miR-30c-5p. The knockdown of NEAT1 afforded the protective effect for HUVECs treated with ox-LDL through miR-30c-5p/TCF7 axis. CONCLUSIONS: The knockdown of NEAT1 overtly motivated proliferation but alleviated the apoptosis and inflammation in ox-LDLtreated HUVECs by miR-30c-5p/TCF7 axis. NEAT1 accelerated the progression of atherosclerosis therapies, functioning as an indicative element. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The aim of this study was to investigate the role of interleukin-1β (IL- 1β) in the apoptosis of synovial cells in rheumatoid arthritis (RA) rats, and to explore the underlying mechanism. MATERIALS AND METHODS: The apoptosis of the synovial cells in RA rats in the IL-1β group and the control group was analyzed by scoring under an electron microscope. The expressions of cleaved-poly (ADP-ribose) polymerase (PARP), PARP and anti-apoptosis gene products in synovial cells of IL-1β treated RA rats were explored as well. Meanwhile, the expressions of B-cell lymphoma 2 (Bcl- 2), Bcl-xL, and Active-Caspase3 in the synovial cells of RA rats with IL-1β treatment were evaluated by the Western blotting. To further clarify the relationship between IL-1β and the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway in the synovial cells of RA rats, the expressions of NF-κB regulated the gene products of matrix metalloproteinase-3 (MMP-3), MMP-9, cyclooxygenase- 2 (Cox-2), and vascular endothelial growth factor (VEGF) in synovial cells of RA rats after that we investigated the treatment with IL-1β (was investigated). In addition, the expression of NF-κB in the synovial cells of RA rats treated with IL-1β was determined. RESULTS: The results showed that, compared with the control group, IL-1β treatment significantly increased the number of apoptotic cells. This meant that IL-1β treatment could promote the apoptosis of the synovial cells (p<0.05). IL-1β treatment significantly promoted the expression level of cleaved-PARP (p<0.05). However, it remarkably reduced the expressions of Bcl-2 and Bcl-xL (p<0.05). Meanwhile, the level of the active-Caspase3 in the synovial cells of RA rats treated with IL-1β was significantly enhanced (p<0.01). In comparison with the control group, the IL-1β group exhibited significantly elevated expressions of NF-κB-regulated gene products in the synovial cells of RA rats (p<0.01). Besides, the positive markers of the activated NF-κB were detected in the synovial cells of RA rats in the IL-1β group and the control group. The results demonstrated that they were mainly located in the nucleus of the IL-1β group. CONCLUSIONS: IL-1β can promote the apoptosis of the synovial cells in RA rats via the NF- κB pathway. [ABSTRACT FROM AUTHOR]

In this paper, the variation of gamma prime precipitates along the creep specimen from the end to the fracture surface was studied, on which a necking phenomenon was observed. The morphologies and chemical compositions of gamma prime precipitates of crept DD417G alloy under the condition of 1000°C/115 MPa were studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), scanning TEM, with energy diffraction spectrum and X-ray diffraction. The results indicate that with a negative gamma/gamma prime lattice misfit the superalloy gamma prime rafted structure formed perpendicular to the tensile loading axis, but in the necked zone, the gamma prime rafts are thickened significantly and no longer perpendicular to the tensile loading axis, but tend to parallel to the tensile loading axis. Based on element diffusion and lattice rotation theories, this phenomenon was discussed. From the observation and analysis of dislocation configurations, it is evident that the tertiary creep deformation is mainly controlled by dislocation shearing mechanism. And, some γ′ particles also precipitate from the matrix during the creep test. [ABSTRACT FROM AUTHOR]

In this paper, a nickel based superalloy with good corrosion resistance is fabricated by directional solidification, and its microstructure and tensile properties were investigated. Microstructure observations reveal that besides the γ′ precipitates and γ matrix, some MC, Ni5Hf and M3B2 particles precipitate along the grain boundary. Tensile tests exhibit that the alloy has obvious anomalous yield and intermediate temperature brittleness (ITB) behaviour. The tensile properties depend on temperature significantly. Below 650°C, the yield strength decreases slightly but rises rapidly between 650 and 750°C, and after then, it decreases gradually with temperature increasing further. Examination by TEM exhibits that sharing of the γ′ by dislocation is almost the main deformation mechanism at low temperature, but the γ′ bypass dominates the deformation at high temperature and the transition temperature should be ∼800°C. In addition, the carbides and eutectic structure contribute partly to the ITB behaviours. [ABSTRACT FROM AUTHOR]

The effect of high cooling rate of approximately 102 K/s and subsequent hot isostatic pressure (HIP) and high temperature (HT) treatment on the microstructure and mechanical properties of NiAl-based intermetallic alloys was investigated. The results reveal that rapid solidification refines the microstructure of the NiAl-Cr(Mo)-0.5Hf eutectic alloy and transforms the Ni2AlHf Heusler phase, which is present in the equilibrium state to a metastable Hf(Ni, Al, Cr) solid solution phase. Simultaneously, the shape and distribution of the Hf(Ni, Al, Cr) solid solution phase were considerably improved. After the HIP treatment, the Hf(Ni, Al, Cr) solid solution phase has changed from continuous distribution along eutectic cell boundaries into semicontinuous distribution, and the primary NiAl(Cr, Mo) phase has coarsened. The HT treatment reduces the volume fraction of the primary NiAl(Cr, Mo) phase and optimizes the distribution of the Hf(Ni, Al, Cr) solid solution phase. Rapid solidification and the resulting fine-grained microstructure will significantly improve the mechanical properties of the alloy in compression tests. However, additional HIP and HT treatments enhance the high-temperature strength properties obviously. [ABSTRACT FROM AUTHOR]

The NiAl-Cr(Mo) eutectic alloy doped with Dy was prepared by suction casting technique and its microstructure and mechanical properties were investigated. It is found that with the addition of Dy, the Ni5Dy phase is formed along the NiAl/Cr(Mo) phase boundary in the intercellular region. By the suction casting method, the microstructure of the alloy get well optimisation which can be characterised by the fine interlamellar spacing, high proportion of eutectic cell area and fine homogeneous distributed Ni5Dy phase, The compression test results reveal that the room temperature and high temperature mechanical properties of the suction cast alloy improve significantly, compared with the conventionally cast alloy, [ABSTRACT FROM AUTHOR]

Microstructural stability and microstructure-property relationship during long-term thermal exposure in K452 alloy (a new Ni-base cast superalloy with -21 pet Cr, 11 pct Co, 3.5 pet W, 2.5 pet Al, 3.5 pet Ti, and others) are investigated. It is found that exposure temperature and time have significant effects on the microstructure and properties of the alloy. During exposure, the microstructure is degraded by γ' coarsening, MC carbide (M mainly represents Ti, W, and Nb) degeneration, precipitation and evolution of grain interior (GI) M[sub23]C[sub6] carbide, evolution of grain boundary (GB) microstructure, and precipitation of η phase. Among them, the γ' coarsening is the leading reason for the decrease of strength of the alloy. The GJ M[sub23]C[sub6] and the η phase have negligible influence on the properties due to their relatively small populations. Blocky, closely spaced GB M[sub23]C[sub6] particles engulfed in γ' increase the stress-rupture life, whereas the formation of a continuous GB M[sub23]C[sub6] chain has an opposite effect. A life peak occurs when the M[sub23]C[sub6]/γ' structure at the GBs is in an optimal form. The degenerated MC is the preferred initiation site of microcracks. Its presence at the GBs promotes the onset of intergranular fracture, and leads to the decrease in mechanical properties. [ABSTRACT FROM AUTHOR]

The effects of micro-Ru alloying addition on NiAl alloys were investigated by optical microscopy, SEM, X-ray diffraction and powder X-ray diffraction. The mechanical properties were characterised by Vickers microhardness measurement and compression tests at room temperature and various elevated temperatures. Micro-Ru alloying addition does not modify the crystal structure of NiAl alloys. However, local electronic structure may be modified owing to the specific site occupancy preference of Ru, smaller size difference between Ru and Al and different electronic nature of Ru and Ni. This is partially verified by the decrease of the long range order degree accurately measured via powder X-ray diffraction. As a result, a maximum softening effect occurs at 0·5 at.-%Ru addition indicated by Vickers microhardness measurement and compression testing results. [ABSTRACT FROM AUTHOR]

Precipitation behavior of Heusler phase (Ni2AlHf) in a directionally solidified (DS) NiAl- 28Cr-5Mo-1Hf (at.%) alloy was examined using scanning electron microscope (SEM) and transmission electron microscope (TEM). In the as-cast alloy, the Ni2AlHf phase generally appeared on the NiAl/Cr(Mo) interface, which degraded the NiAl/Cr(Mo) eutectic structure. In the heat-treated alloy, the density of the intercellular Ni2AlHf phase was slightly reduced. In addition, the spherical Ni2AlHf phase precipitated heterogeneously in the NiAl matrix, but the Ni2AlHf phase did not precipitate in the lamellar Cr(Mo) phase. The precipitation behavior of the Ni2AlHf phase could be explained in terms of the interfacial energy. A lattice model was also proposed to explain the NiAl↔Ni2AlHf phase transformation. [ABSTRACT FROM AUTHOR]

The mechanical behaviour of polycrystalline Ni76Al23Zr alloy was studied as a function of heat treatment, environment, and temperature. It was found that the tensile ductility was very sensitive to temperature, the alloy showing low ductility at temperatures from 700 to 1000°C both in air and vacuum. Environmental embrittlement could be alleviated for those specimens with elongated grains. The ductile transgranular fracture was explained by stress concentration at the intersection of slip bands and grain boundaries. It was also found that an oxide layer, formed during tensile testing at elevated temperature, affected the environmental embrittlement of Ni3Al(Zr) alloy. An adherent Al rich oxide film was effective in protecting the underlying alloy from oxygen penetration. [ABSTRACT FROM AUTHOR]

The mechanical behaviour and microstructural evolution in tension of NiAl - 9Mo eutectic alloy at 1100 ° C and strain rates from 10[sup -5] to 10[sup -3] s[sup -1] have been investigated. High values of strain rate sensitivity index, but relatively small elongations between 150 and 200%, have been observed. Tensile specimens with various strains were quenched in water to preserve the dislocation structures for TEM examination. The TEM results show that the dislocation configuration and density change significantly with an increase in strain rate, and therefore correspond to different deformation mechanisms. At a low strain rate (5[sup .]5 × 10[sup -5] s[sup -1]), the dislocation density is relatively low and dislocation activity is regarded as an accommodation mechanism for grain boundary sliding. In contrast, the high density of dislocations as well as clear subboundaries observed in grains at a high strain rate (5[sup .]5 × 10[sup -4] s[sup -1]) suggest that the dislocations are active directly in response to the applied stress as well as participating in the relaxation process of grain boundary sliding by subboundary formation. Thus, grain boundary sliding is mainly responsible for superplastic deformation at a low strain rate, while superlastic deformation at a high strain rate is controlled by the combined operation of both grain boundary sliding and dynamic recovery. [ABSTRACT FROM AUTHOR]

The microstructure of a multiphase NiAl-33.5Cr-0.5Zr intermetallic alloy was examined by SEM with energy dispersive spectroscopy and TEM. The tensile creep behaviour of the hot isostatically pressed NiAl-33.5Cr-0.5Zr alloy was studied. The results of the creep test indicated that all of the creep curves under the present test have similar characteristics: a short primary creep stage, a dominant tertiary creep stage, and nearly identical creep strains (~45%). The apparent stress exponent and the apparent activation energy were analysed and discussed. The mechanism of the creep deformation was also analysed by the observation of TEM. [ABSTRACT FROM AUTHOR]

The orientation relationship (OR) between α[sub 2]-Ti[sub 3]Al precipitates in the B2 phase in a Ti-47at.% Al-2at.% W-0.5at.% Si alloy was determined by transmission electron microscopy. The OR is \[2110][sub α2] //\[111][sub B2] and (0221)[sub α2] //(110)[sub B2], in which the close-packed planes of the α[sub 2] and B2 phases are not exactly parallel to each other. This OR is precisely predicted from the invariant line theory and the reciprocal lattice overlap theory. [ABSTRACT FROM AUTHOR]