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  • Author: Xiao-Chun Ma x
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Ran Zhu and Xiao-Chun Ma

Abstract

Pulmonary embolism (PE) is a clinical emergency that will increase the mortality if complicated with unstable hemodynamics. Because of its nonspecific clinical symptoms, it’s a great challenge to make a PE diagnosis. The golden standard to diagnose PE is computed tomography of pulmonary artery (CTPA), but a diagnosis of PE also composed of evaluation of PE risk factors, possibilities, and risk stratification. Ultrasonography may detect right ventricle strain related to hemodynamic change, intravascular thrombosis, thrombosis in right heart or pulmonary arteries, pulmonary infarction, and local pleural effusion. Combination of ultrasound and traditional PE possibility evaluation score may further improve the pretest probability of CTPA. A comprehensive ultrasonography may sometimes rule out PE and may disclose other causes for the clinical situations. A heart-lung-vessel-integrated multiorgan ultrasonography can help with the diagnosis of PE and so should be a necessary weapon for the physicians.

Open access

Y.C. Lin, Dao-Guang He, Ming-Song Chen, Xiao-Min Chen, Chun-Yang Zhao and Xiang Ma

Abstract

The flow softening behaviors of a nickel-based superalloy with δ phase are investigated by hot compression tests over wide ranges of deformation temperature and strain rate. Electron backscattered diffraction (EBSD), optical microscopy (OM), and scanning electron microscopy (SEM) are employed to study the flow softening mechanisms of the studied superalloy. It is found that the flow softening behaviors of the studied superalloy are sensitive to deformation temperature and strain rate. At high strain rate and low deformation temperature, the obvious flow softening behaviors occur. With the increase of deformation temperature or decrease of strain rate, the flow softening degree becomes weaken. At high strain rate (1s−1), the flow softening is mostly induced by the plastic deformation heating and flow localization. However, at low strain rate domains (0.001-0.01s−1), the effects of deformation heating on flow softening are slight. Moreover, the flow softening at low strain rates is mainly induced by the discontinuous dynamic recrystallization and the dissolution of δ phase (Ni3Nb).