Superelasticity of Geometrically Graded NiTi Shape Memory Alloys

A stress plateau with a strain of 5–8% normally occurs during the stress-induced martensite transformation (SIM) of NiTi shape memory alloys. Within the stress plateau, the correlation between the stress and strain is lost, which limits their application in certain fields which require accurate control of inelastic deformation. In order to address this limitation, a series of step-like NiTi samples with graded cross-sectional area were designed and fabricated. Multiple stress plateaus were achieved by varying the sample width and adjusting the number of steps; for instance, two and three stress plateaus were obtained in the samples with two and three steps, respectively. Also, linear force–strain response was obtained by changing gradually the width of the samples. The functional stability of the geometrically graded samples was significantly improved by incomplete recrystallization annealing (600 °C) followed by low-temperature (250 °C) aging treatment. The incompletely recrystallized specimens contained many dislocations and grain and sub-grain boundaries, which promoted the uniform precipitation of Ni4Ti3 nanoparticles during aging treatment. The homogeneously and densely dispersed Ni4Ti3 nanoparticles were able to strengthen the matrix considerably and prevent plastic activities during stress-induced martensite transformation. As a result, the functional stability of the geometrically graded NiTi samples was much improved. After aging at 250 °C for 120 h, all the samples showed a small residual strain of <1.0% after 20 loading–unloading cycles

The Key Roles of GSK-3β in Regulating Mitochondrial Activity

Glycogen synthase kinase-3β (GSK-3β), a serine/threonine protein kinase, has been reported to show essential roles in molecular pathophysiology of many diseases. Mitochondrion is a dynamic organelle for producing cellular energy and determining cell fates. Stress-induced translocated GSK-3β may interact with mitochondrial proteins, including PI3K-Akt, PGC-1α, HK II, PKCε, components of respiratory chain, and subunits of mPTP. Mitochondrial pool of GSK-3β has been implicated in mediation of mitochondrial functions. GSK-3β exhibits the regulatory effects on mitochondrial biogenesis, mitochondrial bioenergetics, mitochondrial permeability, mitochondrial motility, and mitochondrial apoptosis. The versatile functions of GSK-3β might be associated with its wide range of substrates. Accumulative evidence demonstrates that GSK-3β inactivation may be potentially developed as the promising strategy in management of many diseases, such as Alzheimer’s disease (AD) and Parkinson’s disease (PD). Intensive efforts have been made for exploring GSK-3β inhibitors. Natural products provide us a great source for screening new lead compounds in inactivation of GSK-3β. The key roles of GSK-3β in mediation of mitochondrial functions are discussed in this review

A Case of Primary Hepatic Lymphoma and Related Literature Review

Objective. Primary hepatic lymphoma is a rare disease. And the clinical manifestations of this disease are nonspecific. The objective of this paper is to improve clinicians’ understanding of this disease. Methods. We analyzed the clinical characteristics of a case of primary hepatic lymphoma in association with hepatitis B virus infection and reviewed the literature. Conclusion. The clinical manifestations of primary hepatic lymphoma are nonspecific. And it is easily misdiagnosed. Postoperative radiotherapy of patients with early stage was previously speculated to achieve favorable improvement. The application of targeted therapeutic drugs, chemotherapy, or combined local radiotherapy has become the first-line treatment strategy