The transcription factor hypoxia inducible factor-1α (HIF-1α) mediates adaptive responses to oxidative stress by nuclear translocation and regulation of gene expression. Mitochondrial changes are critical for the adaptive response to oxidative stress. However, the transcriptional and non-transcriptional mechanisms by which HIF-1α regulates mitochondria in response to oxidative stress are poorly understood. Here, we examined the subcellular localization of HIF-1α in human cells and identified a small fraction of HIF-1α that translocated to the mitochondria after exposure to hypoxia or H2O2 treatment. Moreover, the livers of mice with CCl4-induced fibrosis showed a progressive increase in HIF-1α association with the mitochondria, indicating the clinical relevance of this finding. To probe the function of this HIF-1α population, we ectopically expressed a mitochondrial-targeted form of HIF-1α (mito-HIF-1α). Expression of mito-HIF-1α was sufficient to attenuate apoptosis induced by exposure to hypoxia or H2O2-induced oxidative stress. Moreover, mito-HIF-1α expression reduced the production of reactive oxygen species, the collapse of mitochondrial membrane potential, and the expression of mitochondrial DNA-encoded mRNA in response to hypoxia or H2O2 treatment independently of nuclear pathways. These data suggested that mitochondrial HIF-1α protects against oxidative stress induced-apoptosis independently of its well-known role as a transcription factor.

The wearable electronic skin with high sensitivity and self-power has shown increasing prospects for applications such as human health monitoring, robotic skin, and intelligent electronic products. In this work, we introduced and demonstrated a design of highly sensitive, self-powered, and wearable electronic skin based on a pressure-sensitive nanofiber woven fabric sensor fabricated by weaving PVDF electrospun yarns of nanofibers coated with PEDOT. Particularly, the nanofiber woven fabric sensor with multi-leveled hierarchical structure, which significantly induced the change in contact area under ultra-low load, showed combined superiority of high sensitivity (18.376 kPa−1, at ~100 Pa), wide pressure range (0.002–10 kPa), fast response time (15 ms) and better durability (7500 cycles). More importantly, an open-circuit voltage signal of the PPNWF pressure sensor was obtained through applying periodic pressure of 10 kPa, and the output open-circuit voltage exhibited a distinct switching behavior to the applied pressure, indicating the wearable nanofiber woven fabric sensor could be self-powered under an applied pressure. Furthermore, we demonstrated the potential application of this wearable nanofiber woven fabric sensor in electronic skin for health monitoring, human motion detection, and muscle tremor detection.

The development of flexible and stretchable electronic skins that can mimic the complex characteristics of natural skin is of great value for applications in human motion detection, healthcare, speech recognition, and robotics. In this work, we propose an efficient and low-cost fabrication strategy to construct a highly sensitive and stretchable electronic skin that enables the detection of dynamic and static pressure, strain, and flexion based on an elastic graphene oxide (GO)-doped polyurethane (PU) nanofiber membrane with an ultrathin conductive poly(3,4-ethylenedioxythiophene) (PEDOT) coating layer. The three-dimensional porous elastic GO-doped PU@PEDOT composite nanofibrous substrate and the continuous self-assembled conductive pathway in the nanofiber-based electronic skin offer more contact sites, a larger deformation space, and a reversible capacity for pressure and strain sensing, which provide multimodal mechanical sensing capabilities with high sensitivity and a wide sensing range. The nanofiber-based electronic skin sensor demonstrates a high pressure sensitivity (up to 20.6 kPa), a broad sensing range (1 Pa to 20 kPa), excellent cycling stability and repeatability (over 10,000 cycles), and a high strain sensitivity over a wide range (up to approximately 550%). We confirmed the applicability of the nanofiber-based electronic skin to pulse monitoring, expression, voice recognition, and the full range of human motion, demonstrating its potential use in wearable human-health monitoring systems.

An electronic fabric based on stretchable capacitive sensor arrays detecting tactile and multimodal mechanical stimuli is presented.

The rechargeable battery is the conventional power source for mobile devices. However, limited battery capacity and frequent recharging requires further research to find new ways to deliver power without the hassle of connecting cables. Novel wireless power supply methods, such as energy harvesting and wireless power transfer, are currently receiving considerable attention. In this article, an overview of recent advances in wireless power supply is provided, and several promising applications are presented to show the future trends. In addition, to efficiently schedule the harvested energy, an energy scheduling scheme in the EH-powered D2D relay network is proposed as a case study. To be specific, we first formulate an optimization problem for energy scheduling, and then propose a modified two stage directional water filling algorithm to resolve it.