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The ω-phase in metastable β-titanium (Ti) alloys attracts great research interests owing to the metastability and the involved microstructural complexity upon straining, while the fundamental understanding on its formation mechanism is still insufficient. In this study, deformation-induced ω-plates have been systematically investigated using Ti-10 wt% Cr metastable β-Ti alloy containing athermal ω-precipitates. It is found that single-variant ω-plates form either along {332}β twin interfaces or in the twin interiors, which closely depends on twin morphologies. For the acicular β-twin, the ω-plate appears in the twin interiors accompanied by high density of parallel straight dislocations, while for the lenticular twin, the ω-plate attaches to the twin interface without the surrounding dense parallel straight dislocations. These unique formation characteristics result from local stress field induced by the twinning itself and the passive transformation of athermal ω-precipitates. It is further revealed that the passive transformation of athermal ω-precipitates dominates the formation of ω-plates inside the acicular twins, while it is the locally preferential twin thickening that promotes the ω-plates to form along the lenticular twin interfaces. These findings provide new insight into deformation-induced ω-phase transformation and the intricate deformation microstructures in metastable β-Ti alloys.

Background：Lymphogenous metastasis, one of the most common dissemination routes for ovarian carcinoma, predicts a poor prognosis and relates to most cancer-related death. Now there were no effective therapy and control methods for ovarian carcinoma. Hence, it is necessary to build an animal model of lymph node metastasis in ovarian cancer to seek for the tools to find effective treatments. Our purpose of this study was to investigate the tumor cell dissemination of ovarian carcinoma to the gradient lymph nodes of nude mice and its possible mechanism.Methods: The mice models of VEGF-D over-expressed were built, and the tumor growth and sentinel lymph nodes were evaluated weekly, while the visible lymph nodes and tumor masses were excised for histological examination using HE examination. Then Evan’s Blue was conducted to observe the unveil lymphatic network. Subsequently, immunohistochemistry (IHC) was performed to check the protein expression of relative genes. Meanwhile, microvessel counting was performed within the tumor tissues and measured using computer assisted morphometric analysis.Results: The over-expression of VEGF-D promoted the tumor growth of ovarian carcinoma, facilitated the hyperplasia of tumor lymphatic and increased the intratumoral lymphatic vessel density. Besides, the up-regulation of VEGF-D induced the expression of MMP-2, which might be the underlying mechanism of the lymph metastasis in ovarian cancer.Conclusion: It was a step-by-step progression from the inoculation of cancer cells to the proliferation of the primary tumors, and then to the lymphatic metastases, in which VEGF-D and MMP-2 played vital roles.

This study aimed to investigate the predictive and prognostic roles of circulating exosomal miRNAs in breast cancer treated with trastuzumab-based chemotherapy. Circulating exosomal miRNAs from trastuzumab-resistant (n = 4) and -sensitive (n = 4) patients were profiled using miRNA microarray. The predictive and prognostic roles of filtered miRNAs were validated in 107 early-stage and 68 metastatic patients treated with trastuzumab-based chemotherapy through receiver-operating characteristic (ROC) curve analysis, logistic regression and Cox proportional hazards regression analysis, and Kaplan–Meier survival analysis. MiRNA microarray analysis revealed miR-1246 and miR-155 were the most up-regulated miRs in trastuzumab-resistant HER2-positive breast cancer patients, which were further validated in trastuzumab-resistant patient samples (n = 32) compared with trastuzumab sensitive ones (n = 36). MiR-1246 showed a ROC curve area of 0.750 with 78.1% sensitivity and 75% specificity in discriminating resistant from sensitive patients (p

Unlike stress-induced martensitic transformation, deformation twinning as well as dislocation gliding, deformation kinking is an uncommon deformation mechanism in metastable β-titanium (Ti) alloys. In this study, the unique deformation mechanism was reported in Ti-V binary β-Ti alloys for the first time. It was found that a large number of kink bands were distributed in β-grains after cold forging at a strain rate of ~103 s−1. Microstructural characterization manifests that the appearance of kink bands is frequently accompanied by slip bands, whilst dense dislocations are accumulated around the kink bands on a microscopic scale. Such local plastic deformation is quite strong so that the pre-existing athermal ω-precipitates in the initial microstructure is completely destroyed within the kink bands and instead fresh deformation-induced single variant of ω-precipitates is produced. This deformation localization mainly originates from the impediment of dislocation activity caused by both pre-existing athermal ω-precipitates and the intrinsic slip retardation in BCC crystal structures. The deformation kinking is thus suggested to follow a dislocation-based formation mechanism, whilst the resulting Taylor axis of lattice rotation was deduced to be β on basis of extensive crystallographic analysis. These findings enrich fundamental understanding on deformation kinking, and provide helpful information for utilizing the unique deformation mechanism to tune mechanical properties of β-Ti alloys.

Metastable β-titanium (Ti) alloys have been extensively used in aerospace industry owing to the outstanding mechanical properties. Temperature arising sometimes becomes unavoidable in service and thus it is necessary to evaluate plastic behavior of the alloys at elevated temperatures prior to applications. Here, plastic stability of metastable β-titanium alloys containing the β-spinodal decomposition structures at different temperatures is investigated for the first time using Ti–6Cr–5Mo–5V–4Al alloy as prototypical material. It is found that a serrated plastic flow with little frequency accompanied by overall strain softening appears in the tensile stress-strain curves at 298 K, while the serrated plastic flow occurs much more frequently and overall strain hardening capability is recovered appropriately when the tensile temperature is increased to 573 K. Microstructural characterizations reveal that ordinary dislocation slip dominates the alloy plasticity at all the testing temperatures. Dislocations strongly interact with the β-striations and dislocation debris are left around the striation interfaces. The resulting local stress accumulation destroys the β-striations in the form of shear bands so that sudden release of an avalanche of dislocations in the soft channels leads to stress drop. Subsequent dynamic reconstruction of the β-striations with the assistance of thermal activation especially at elevated temperature hardens the prior soft channels, which results in the following stress rise. The striking difference on deformation characteristics at 298 K and 573 K is that more homogeneous plasticity conferred by dense deformation bands at the latter, which is the direct reason on high serrated frequency and overall strain hardening. These findings offer valuable insights into plastic behavior of metastable β-Ti alloys, which will have important implications for the applications.

In this article, the combustion characteristic of coal–ammonia composite is investigated. Raw coal and preheating modified coal are treated to absorb the ammonia. Four kinds of samples are made to ...