Akkermansia muciniphila, a common colonizer in the intestinal mucus layer of humans, has gradually been considered as promising candidate for the next‐generation probiotic, given its physiological ...benefits from animal and human studies. This article comprehensively reviewed A. muciniphila from the published peer‐reviewed articles in the aspects of its role in the host physiology and commonly consumed food that can boost its abundance, which should provide useful and fundamental information for scientists and engineers and even ordinary consumers. Akkermansia muciniphila is not only a crucial biomarker that indicates the physiology of human beings but also has huge potential to become a probiotic given its physiological benefits in various clinical scenarios. Current barriers in terms of regulations, necessity for large‐scale clinical experiments and production feasibility need to be resolved before A. muciniphila can be widely applied as the next‐generation probiotic.
Bulk pure tungsten (W), W-0.5 wt%TiC (WTC05) and W-1 wt%Y2O3 (WY10) materials were prepared by a developed two-step hot-pressing (HP) sintering method. Metallographic observation, SEM and TEM ...characterization were conducted to obtain the information of material microstructures. The results indicate that a small amount of TiC or Y2O3 addition could effectively improve the sinterability and reduce the grain size of the HP sintered WTC05 and WY10 alloys. The relative density of WTC05 and WY10 reaches as high as 99%, and the average grain size of WTC05 and WY10 are 2.61 μm and 3.57 μm, respectively, which are several times smaller than that of pure W. Among the three W materials, pure W has the poor tensile performance with insufficient strength and ductility, WTC05 has the highest tensile strength with the ultimate tensile strength of 1082 MPa at 300 °C, and WY10 has the best ductility and moderate strength. The relationship between the microstructures and the tensile properties has been investigated, and suggestions on microstructure parameters have been proposed for preparing high performance W-based materials.
Bulk Cu/Ta nanolamellar multilayers with an individual layer thickness from several micrometers down to 50 nm were successfully fabricated via a combination of cross accumulative roll bonding (CARB) ...and an intermediate annealing step. This fabrication technique allowed to effectively suppress the formation of plastic instabilities and edge cracks during the repeated rolling process. A transition of the layered morphology from non-planar interfaces at the submicron level to nearly planar interfaces at the nano-scale was observed with decreasing layer thickness. High resolution transmission electron microscopy, selected area electron diffraction and X-ray diffraction were performed, and the results indicate that the Cu/Ta nanolamellar multilayers with a layer thickness of 50 nm show a {100}Ta110∥{110}Cu111 rolling texture relationship. Tensile tests revealed that the ultimate tensile strength of the composite was up to 950 MPa, which is approximately 5 times higher than that of the initial pure Cu and Ta. The hardness of the prepared multilayer maintained unchanged even after an annealing at 500 °C for 1 h. These unique properties are attributed to an atomically flat bimetal interface and the low amount of homophase grain boundaries resulted from the CARB process.
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The microstructure significantly influences the mechanical properties of metals and alloys. Herein, we present a novel approach to tailoring the mechanical properties of a CoCrNi medium-entropy alloy ...by controlling nanotwin-HCP lamellae and annealing twins. It has been observed that the dislocations, three-dimensional nanotwins and Lomer-Cottrell locks, induced by equal channel angular pressing, synergistically strengthened the CoCrNi alloy. The nanotwin-HCP composite lamellae, induced by post-deformation annealing at 500 °C, resulted in high strength of 1.5 GPa and a strain of 4.1%. A superior combination of high strength (~ 1 GPa) and excellent ductility (~ 45%) has been obtained by further decorating the microstructure through producing annealing twins in recrystallized micro-sized grains. The present study presents the strengthening mechanisms and provides a generic approach to obtain the desirable mechanical properties of the alloys via microstructural optimization.
Osteosarcoma is the most common primary malignant tumor of bone, the long-term survival of which has stagnated in the past several decades. Celastrol, a triterpene from traditional Chinese medicine, ...has been proved to possess potent anti-tumor effect on various cancers. However, the effect of celastrol on human osteosarcoma and the underlying mechanisms remains to be elucidated. We reported here that celastrol could inhibit cell proliferation by causing G2/M phase arrest. Exposure to celastrol resulted in the activation of caspase-3, -8, and -9, indicating that celastrol induced apoptosis through both extrinsic and intrinsic pathways. Autophagy occurred in celastrol-treated cells as evidenced by formation of autophagosome and accumulation of LC3B-II. The celastrol-induced cell death was remarkably restored by the combination of autophagy and apoptosis inhibitors. Furthermore, inhibition of apoptosis enhanced autophagy while suppression of autophagy diminished apoptosis. Celastrol also induced JNK activation and ROS generation. The JNK inhibitor significantly attenuated celastrol-triggered apoptosis and autophagy while ROS scavenger could completely reverse them. The ROS scavenger also prevented G2/M phase arrest and phosphorylation of JNK. Importantly, we found that celastrol had the similar effects on primary osteosarcoma cells. Finally, in vivo, celastrol suppressed tumor growth in the mouse xenograft model. Taken together, our results revealed that celastrol caused G2/M phase arrest, induced apoptosis and autophagy via the ROS/JNK signaling pathway in human osteosarcoma cells. Celastrol is therefore a promising candidate for development of antitumor drugs targeting osteosarcoma.
The refractory tungsten alloys with high ductility/strength/plasticity are highly desirable for a wide range of critical applications. Here we report an interface design strategy that achieves 8.5 mm ...thick W-0.5 wt. %ZrC alloy plates with a flexural strength of 2.5 GPa and a strain of 3% at room temperature (RT) and ductile-to-brittle transition temperature of about 100 °C. The tensile strength is about 991 MPa at RT and 582 MPa at 500 °C, as well as total elongation is about 1.1% at RT and as large as 41% at 500 °C, respectively. In addition, the W-ZrC alloy plate can sustain 3.3 MJ/m(2) thermal load without any cracks. This processing route offers the special coherent interfaces of grain/phase boundaries (GB/PBs) and the diminishing O impurity at GBs, which significantly strengthens GB/PBs and thereby enhances the ductility/strength/plasticity of W alloy. The design thought can be used in the future to prepare new alloys with higher ductility/strength.
Abstract
The feedback from the accretion of central supermassive black holes (SMBHs) is a hot topic in the coevolution of SMBHs and their host galaxies. By tracing the large-scale outflow using the ...line profile and bulk velocity shift of O
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5007, the evolutionary role of outflow is studied here on a large sample of 221 type 2 quasars (QSO2s) extracted from Reyes et al. By following our previous study on local Seyfert 2 galaxies, the current spectral analysis on the Sloan Digital Sky Survey spectroscopic database enables us to arrive at the following results: (1) by using the Lick indices, we confirm that QSO2s are, on average, more frequently associated with younger stellar populations than Seyfert galaxies; (2) QSO2s with a stronger outflow tend to be associated with a younger stellar population, which implies a coevolution between the feedback from SMBHs and the host in QSO2s; (3) although occupied at the high
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(4000) sequence established from local, less-luminous Seyfert galaxies, which suggests a decrease of the accretion activity of SMBHs and also of feedback as the circumnuclear stellar population continuously ages.
Introducing the transformation-induced plasticity (TRIP) effects into the CoCrNi medium entropy alloy (MEA) to improve the strength and ductile of the alloy is a hot issue in MEA. Herein, we ...developed two novels non-equiatomic CoCrNi (with Co content of 40 and 50 at. %) MEAs with TRIP effects by increasing the content of Co to lowering the stacking fault energy. It was found that the HCP phase is too tiny to be neglected in Co40 alloy, while in Co50 alloy the 2% HCP phase mainly precipitating at the interface between the annealing twin and the matrix can be found. The tensile test results show that Co40 alloy exhibits a simultaneously improved yield strength (YS) and ultimate tensile strength (UTS) without sacrificing plasticity, while for Co50 alloy, the sample shows significantly increased total elongation (TE) and UTS. The microstructure evolution of Co50 alloy during the deformation process was systematically studied by interrupting the tensile test under different strains. This work proposed that non-equiatomic MEA with more desirable mechanical properties than the equiatomic one can be obtained via introducing TRIP effects.
Dense pure tungsten and W–(0.1, 0.2, 0.5, 1.0) wt% Zr alloys were fabricated through spark plasma sintering method. The relative density of all the samples was about 97%. The FESEM and TEM analysis, ...tensile tests and Vickers micro-hardness measurements were exploited to characterize these samples. It is found that Zr could capture impurity oxygen in tungsten and form nanometer scaled ZrO2 particles. With the increase of Zr addition from 0 to 0.2wt%, the room-temperature fracture strength increased from 154MPa to 265MPa, and the fracture energy density elevated from 3.73×104J/m3 to 9.22×104J/m3. However, more Zr addition would increase the size of Zr–O particles and significantly decrease the fracture strength and toughness of tungsten.
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