Magnetic random access memories based on the spin transfer torque phenomenon (STT-MRAMs) have become one of the leading candidates for next generation memory applications. Among the many attractive features of this technology are its potential for high speed and endurance, read signal margin, low power consumption, scalability, and non-volatility. In this paper, we discuss our recent results on perpendicular STT-MRAM stack designs that show STT efficiency higher than 5 kBT/μA, energy barriers higher than 100 kBT at room temperature for sub-40 nm diameter devices, and tunnel magnetoresistance higher than 150%. We use both single device data and results from 8 Mb array to demonstrate data retention sufficient for automotive applications. Moreover, we also demonstrate for the first time thermal stability up to 400 °C exceeding the requirement of Si CMOS back-end processing, thus opening the realm of non-volatile embedded memory to STT-MRAM technology.

Shape memory polymers (SMPs) are polymers with the shape memory effect. The biodegradable SMPs are candidate materials for making biomedical devices and scaffolds for tissue engineering. Superparamagnetic iron oxide nanoparticles (SPIO NPs) have recently been reported to promote the osteogenic induction of human mesenchymal stem cells (hMSCs). In this study, we synthesized water-based biodegradable shape memory polyurethane (PU) as the main component of the 3D printing ink for fabricating bone scaffolds. The 3D printing ink contained 500 ppm of SPIO NPs to promote osteogenic induction and shape fixity, and it also contained polyethylene oxide (PEO) or gelatin for the improvement of printability. Scaffolds were printed by the microextrusion-based low-temperature fuse deposition manufacturing (LFDM) platform. Both PU–PEO and PU–gelatin ink showed excellent printability. Shape memory properties were evaluated in 50 °C air and 37 °C water. PU–PEO scaffolds showed better shape fixity and recovery than PU–gelatin scaffolds, while the shape memory properties in water were better than those in air. hMSCs were seeded for evaluation of bone regeneration. The proliferation of the hMSCs in PU/gelatin and PU/gelatin/SPIO scaffolds was greater than that in PU/PEO and PU/PEO/SPIO scaffolds, confirming the better compatibility of gelatin vs PEO as the viscosity enhancer of the ink. The gradual release of SPIO NPs from the scaffolds promoted the osteogenesis of seeded hMSCs. With SPIO in the scaffolds, the osteogenesis increased 2.7 times for PU/PEO and 1.5 times for PU/gelatin scaffolds based on the collagen content. Meanwhile, SPIO release from PU/PEO/SPIO scaffolds was faster than that from PU/gelatin/SPIO scaffolds at 14 days, consistent with the better osteogenesis observed in PU/PEO/SPIO scaffolds. We concluded that 3D printed PU scaffolds with shape memory properties, biodegradability, and osteogenic effect may be employed to the minimally invasive surgical procedures as customized-bone substitutes for bone tissue engineering.

Auricular acupressure relieves menstrual pain and distress in high-school adolescents. The findings may serve as a basis for using auricular acupressure to treat dysmenorrhea in adolescents. There was pain reduction with sham as well as with true acupoint acupressure, but the latter was significantly greater. The sham acupoint may not be used as a control for auricular acupoint and qualitative evaluation of dysmenorrhea should be added to the evaluation by SF-MPQ in future studies.

Background. Dysmenorrhea and accompanying symptoms can have a negative impact on academic achievement, physical activity and functioning, and quality of life. Unfortunately, stress increases the sensitivity and severity of pain, activating sympathetic responses while inhibiting parasympathetic responses. Objective. This study used objective, physiological measurements to evaluate the effects of auricular acupressure on menstrual pain and menstrual distress in young college students with primary dysmenorrhea across two menstrual cycles. The aim was to determine if significant differences could be detected between the intervention and follow-up phases after controlling life stress. Design. A one-group experimental research design was used, and repeated measurements and followups were done. Thirty-two women completed questionnaires and physiological parameters were measured. Results. Significant differences between the intervention and follow-up phases were found for high frequency (HF) and blood pressure on day 1 and no significant differences in menstrual pain and menstrual distress, heart rate variability, low frequency (LF), LF/HF ratio, or heart rate. Conclusion. Auricular acupressure effectively increases parasympathetic activity to maintain autonomic function homeostasis in young women with primary dysmenorrhea and may have a value in alleviating menstrual pain and menstrual distress in a high-stress life. Future studies should consider stress, stimulus dose of auricular acupressure, severity of menstrual pain, and a longitudinal research design.