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Oxide dispersion strengthened (ODS) nickel (Ni)‐based superalloys are advanced materials known for their outstanding tensile and creep performance at temperatures exceeding 1000 °C. Nevertheless, their conventional synthesis presents a longstanding challenge in cost‐effectively producing intricate components for critical applications. In this work, electrostatic self‐assembly (ESA) of powders with the laser powder bed fusion (LPBF) process are successfully combined to produce yttria ODS Inconel 718 (IN718) alloy for the first time. This approach demonstrates a significant contribution of yttria to the strength of IN718 after the solid solution heat treatment, as evidenced by ≈50% improvement in room temperature yield strength with a 0.5 wt.% yttria addition. The addition of yttria by this process leads to a heterogeneous microstructure. This heterogeneous microstructure comprises two distinct grain areas with varying amounts of yttria nanoparticles and dislocation storage. The results show that the yield strength increase can be predicted by the combination of both Y2O3 dispersion strengthening and dislocation strengthening mechanisms. These findings offer an effective approach to tailor heterogeneous microstructures, unlocking new opportunities for cost‐effectively producing high‐performance ODS Ni‐based superalloy products with excellent mechanical properties. [ABSTRACT FROM AUTHOR]

A Laser Powder Bed Fusion Inconel 718 produced with intentionally non‐optimized parameters is investigated to understand the role of defects and microstructure on the high‐cycle fatigue life. Samples from three built directions and three heat treatments were used for fatigue tests at room and 650°C under R=0.1. Printing orientation has a minor effect on fatigue life at both temperatures. Most samples failed from lack of fusion defects, carefully analyzed by scanning electron microscope (SEM) observations. Surface defect leads to transgranular fracture surface, while subsurface initiation leads to crystallographic fracture surface. S−N curves related to hot isostatic pressure condition shown that defects have higher influence at 20°C than at 650°C. Kitagawa diagrams are plotted for both temperatures to quantify the influence of defect size on fatigue limit. Natural cracks are observed at the surface in order to discuss the relative part of initiation life in the whole fatigue life. Highlights: Fatigue is governed by lack of fusion (LoF) ranging from 200 to 600 μmThe fatigue limit is higher at high temperature compared with ambient temperatureHot isostatic pressure (HIP) treatment improves the fatigue resistanceNatural crack initiated from LoF propagates in a very similar way compared with long crack [ABSTRACT FROM AUTHOR]

Transition metal Fe, Co, Ni and Cu doped strontium titanate‐rich SrTiO3@TiO2 (STO@T) materials were prepared by hydrothermal method. The prepared doped materials exhibit better photocatalytic CO2 reduction to CH4 ability under visible light conditions. Among them, Fe‐doped and undoped SrTiO3@TiO2 under visible light conditions CO2 reduction products only CO, while M‐STO@T (M=Co, Ni, Cu) samples converted CO2 to CH4. The average methane yield of Ni‐doped STO@T samples are as high as 73.85 μmol g−1 h−1. The production of methane is mainly due to the increase in the response of the doped samples to visible light. And the increase in the separation rate of photogenerated electrons and holes and the efficiency of electron transport caused by the generation of impurity levels. The impurity level caused by Ti3+ plays an important role in the production of methane by CO2 visible light reduction. Ni doping effectively improves the photocatalytic performance of STO@T and CO2 reduction mechanism were explained. [ABSTRACT FROM AUTHOR]

The chemical vapor infiltration (CVI) SiC/SiC composites are porous materials, and the porosity affects the molten salt infiltration and may affect the mechanical properties. Therefore, the internal microstructures of the 2D and 3D silicon carbide composites are studied by synchrotron radiation micro‐computed tomography (micro‐CT) technology. The cross‐sectional slice and 3D volume image of the composite are reconstructed, then the pores of the composites are visualized in three dimensions, and the porosity is quantitatively analyzed. The results indicate that most of small pores (micrometer) exist between filaments and larger pores (millimeter) occur between fiber bundles, and the internal pores of 2D and 3D composites are greatly influenced by the fabric structure. In contrast, the 3D braided composites have lower porosity, smaller pore distribution fluctuations, and more stable internal structure. [ABSTRACT FROM AUTHOR]

The regulation of inflammation is pivotal for preventing the development or reoccurrence of multiple sclerosis ( MS). A biased ratio of high-M1 versus low-M2 polarized microglia is a major pathological feature of MS. Here, using microarray screening, we identify the long noncoding RNA (lnc RNA) GAS5 as an epigenetic regulator of microglial polarization. Gain- and loss-of-function studies reveal that GAS5 suppresses microglial M2 polarization. Interference with GAS5 in transplanted microglia attenuates the progression of experimental autoimmune encephalomyelitis ( EAE) and promotes remyelination in a lysolecithin-induced demyelination model. In agreement, higher levels of GAS5 are found in amoeboid-shaped microglia in MS patients. Further, functional studies demonstrate that GAS5 suppresses transcription of TRF4, a key factor controlling M2 macrophage polarization, by recruiting the polycomb repressive complex 2 ( PRC2), thereby inhibiting M2 polarization. Thus, GAS5 may be a promising target for the treatment of demyelinating diseases. [ABSTRACT FROM AUTHOR]

Aim To investigate the association between red cell distribution width ( RDW) and the severity of hepatitis B virus ( HBV)-related liver diseases. Methods Sixty-nine patients with chronic hepatitis B ( CHB) and 61 patients with HBV-related liver cirrhosis were enrolled in the present study. Forty-one healthy individuals were included as controls. Hematological parameters, hepatitis B e-antigen ( HBe Ag) status, HBV DNA levels and liver biochemistry were analyzed. Child- Pugh scores and Model for End- Stage Liver Disease ( MELD) scores of the patients with HBV-related liver cirrhosis were calculated. Results The RDW was significantly higher in patients with HBV-related liver cirrhosis as compared with CHB patients and healthy controls. RDW was slightly higher in CHB patients as compared with healthy controls. An increasing correlation of RDW with Child- Pugh grades was found. RDW was positively correlated with Child- Pugh scores and MELD scores. In patients with HBV-related liver cirrhosis, RDW was also positively correlated with total bilirubin and negatively correlated with hemoglobin and serum albumin concentration. However, no significant difference was found between HBe Ag positive and negative patients and no significant correlation between RDW and HBV DNA levels was found. Conclusion The RDW was elevated in CHB patients and patients with HBV-related liver cirrhosis and was positively correlated with the severity of HBV-related liver cirrhosis. RDW is a potential index to assess the severity of HBV-related liver diseases. [ABSTRACT FROM AUTHOR]

Diarrhetic shellfish poisoning (DSP) is a gastrointestinal illness with symptoms such as diarrhea, nausea, vomiting, headache, chills and moderate to severe abdominal pain. DSP has been recognized as a worldwide public health problem, causing great concern to the shellfish industry. Accumulation of DSP in shellfish is an unpredictable phenomenon that necessitates the implementation of a widespread collection and thorough monitoring program for mollusk toxicity. Therefore, development of accurate analytical protocols for the rapid determination of toxicity levels would be necessary. In this study we investigated cytoskeletal changes induced by okadaic acid in HL-7702 Liver Cells and developed a new cytotoxicity assay for detection and quantitation of DSP. This assay is based on fluorometric of F-actin depolymerization induced by okadaic acid (OA) compounds in HL-7702 liver cell line. The measurable range of OA was 2.5 ∼ 40 nmol/L. The detection limit of the F-actin assay for OA was 2.01 μg/100 g muscles in shellfish extracts. The performance of this assay has been evaluated by comparative analysis of shellfish samples by the fluorescent assay, mouse bioassay, and ELISA assay. Comparison of the results by all three methods revealed excellent consistency, the results of fluorescent assay were in significant correlation with ELISA assay ( R2 = 0.830). Examination of F-actin assay is very convenient, rapid, and sensitive, which can be used to quantify the amount of OA in shellfish samples. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2013. [ABSTRACT FROM AUTHOR]