In recent years, the development of electronic skin and smart wearable body sensors has put forward high requirements for flexible pressure sensors with high sensitivity and large linear measuring range. However, it turns out to be difficult to increase both of them simultaneously. In this paper, a flexible capacitive pressure sensor based on a porous carbon conductive pastepolydimethylsiloxane composite is reported, the sensitivity and the linear measuring range of which were developed using multiple methods including adjusting the stiffness of the dielectric layer material, fabricating a microstructure and increasing the dielectric permittivity of the dielectric layer. The capacitive pressure sensor reported here has a relatively high sensitivity of 1.1 kPa −1 and a large linear measuring range of 10 kPa, making the product of the sensitivity and linear measuring range 11, which is higher than that of the most reported capacitive pressure sensors to our best knowledge. The sensor has a detection of limit of 4 Pa, response time of 60 ms and great stability. Some potential applications of the sensor were demonstrated, such as arterial pulse wave measuring and breath measuring, which shows it as a promising candidate for wearable biomedical devices. In addition, a pressure sensor array based on the material was also fabricated and it could identify objects in the shape of different letters clearly, which shows promising application in future electronic skins.

Electronic skin (e‐skin) integrating pressure sensors and strain sensors has shown great potential applications in smart robotics and healthcare monitoring for their flexibility and wearability. However, making the sensor low cost and highly durable for industrialization and commercialization is still a problem to be addressed. An embedded 3D printing technology is developed based on novel thermosetting printing ink which is prepared using the Ecoflex and carbon nanoparticles. The properties of the printing ink including printability and electrical conductivity are first studied and then optimized. By using this technology, a glove‐shaped e‐skin integrating both strain sensors and pressure sensors is fabricated, and the properties of the sensors are studied. Both types of sensors have excellent stability and reliability which are verified by multiple long‐term measurements (10 000 testing cycles). Specifically, the sensors possess a great shock resistance and high durability which are significant for application in real life. Furthermore, some applications for human activity monitoring and personal healthcare are demonstrated, including complex gesture recognition using 15 strain sensors, hardness sensing using pressure sensors coupled with strain sensors, and arterial pulse measurement using pressure sensors, which are promising for smart robotic sensing and wearable biomedical devices.

This paper reports a novel microarray chip for in-situ, real-time and selective electroporation on individual cells integrated with cell positioning and impedance monitoring. An array of quadrupole-electrode units (termed positioning electrodes) and pairs of planar center electrodes located at the centers of each quadrupole-electrode unit were fabricated on the chip. The positioning electrodes are used to trap and position living cells onto the center electrodes based on negative dielectrophoresis (nDEP). The center electrodes are used for in-situ cell electroporation, and also used to measure cell impedance for monitoring cellular dynamics in real time. Controllably selective electroporation and electrical measurement on the cells in array are realized. We present an evidence of selective electroporation through use of fluorescent dyes. Subsequently we use in-situ and real-time impedance measurement to monitor the process, which demonstrates the dynamic behavior of the cell electroporation. Finally, we show the use of this device to perform successful transfection onto individual HeLa cells with vector DNA encoding a green fluorescent.

This paper presents a novel microarray chip integrating cell positioning with in situ, real-time and long-time impedance measurement on a single cell. The microchip integrates a plurality of quadrupole-electrode units (termed positioning electrodes) patterned into an array with pairs of planar electrodes (termed measuring electrodes) located at the centers of each quadrupole-electrode unit. The positioning electrodes are utilized to trap and position living cells onto the measuring electrodes based on negative dielectrophoresis (nDEP), while the measuring electrodes are used to measure impedances of the trapped single cells. Each measuring electrode has a small footprint area of 7 × 7 μm(2) to ensure inhabiting only one single cell on it. However, the electrode with a small surface area has a low double-layer capacitance when it is immersed in a liquid solution, thus generating a large double-layer impedance, which reduces the sensitivity for impedance measurement on the single cell. To enlarge the effective surface areas of the measuring electrodes, a novel surface-modification process is proposed to controllably construct gold nanostructures on the surfaces of the measuring electrodes while the positioning electrodes are unstained. The double layer capacitances of the modified electrodes are increased by about one order after surface-modification. The developed microchip is used to monitor the adhering behavior of a single HeLa cell by measuring its impedance spectra in real time. The measured impedance is analyzed and used to extract cellular electrical parameters, which demonstrated that the cell compresses the electrical double layer in the process of adherence and adheres onto the measuring electrodes after 4-5 hours.

Developing low-cost, high performance, stable non-noble bifunctional electrocatalysts for overall water splitting is of great importance for future energy supplement. Despite recent advances in the synthesis of transition metal selenide nanostructures, the fabrication of porous nanosheet based binder-free electrode with more active sites remains a major challenge. Herein, the self-templating construction of a porous CoSe2 nanosheet array on carbon cloth (p-CoSe2/CC) has been reported by vapor selenizing the preprepared α-Co­(OH)2 nanosheet array precursor. Arising from large active surface area, fast diffusion of generated gas and strong structural stability, the as-obtained p-CoSe2/CC can serve as an efficient bifunctional electrocatalyst for both OER and HER in alkaline electrolyte, with a current density of 10 mA cm–2 at overpotential of 243 mV for OER and 138 mV for HER, respectively. Moreover, when p-CoSe2/CC is assembled as an alkaline electrolyzor, it only needs a cell voltage of 1.62 V at 10 mA cm–2 and shows excellent long-term stability of 20 h. The versatile fabrication strategy with self-templated porous structure proves a new way to construct other advanced metal selenide for energy conversion and storage.

Organic–inorganic two-dimensional (2D) perovskite is an optoelectronic material, with quantum-well structure and improved moisture stabilities, which has been widely used in various optoelectronic devices recently. In this review, the structure and properties of organic–inorganic 2D perovskite materials are first briefly introduced. After that, according to the different photoelectron coupling mechanisms, the recent progress of typical 2D perovskite-based optoelectronic devices is described in detail: including photodetectors, light-emitting diodes, solar cells, and lasers, as well as some optoelectronic devices (e.g., optical memory and optical synapses). We analyzed the influence of structure, manufacturing process, and material selection on device performance and showed promising progress in different applications. Subsequently, we proposed the possible breakthrough development direction of 2D perovskite-based optoelectronic devices in the coming years. This work points out the way for future progress of 2D perovskite-based optoelectronic devices, which is conducive to further improving device performance and inspiring designs of high-performance organic–inorganic 2D perovskite-based optoelectronic devices.

Depression and related mood disorders are among the world's greatest public health problems. Previous studies have demonstrated that astilbin (AST) has broad pharmacological functions which may modulate numerous pathways, such as antioxidant, scavenging free radicals, anti-inflammatory and so on, similarly to some of other flavonoids. In this study, the antidepressant-like effect of AST was investigated using chronic unpredictable mild stress ( Key words depression; astilbin; chronic unpredictable mild stress; serotonin; dopamine; brain-derived neurotrophic factor Depression is a serious medical illness that characterized by affective disorder. According to the World Health Organization (WHO), by the year 2030, depression will result in more years of life lost to disability than any other illness.1) At present, most antidepressants used clinically with low efficacy and many side effects can not meet the clinical needs. Therefore, with the increased prevalence of depression and social burden every year, the development of new antidepressants is becoming a top priority.Despite the fact that the molecular and cellular mechanisms remain unclear, a leading hypothesis of depression recently suggests that neurotrophic factors and adult neurogenesis play critical roles in mediating the behavioural responses to antidepressants.2) The brain-derived neurotrophic factor (BDNF) is closely related to neuronal survival and neurogenesis and plays an important role in animal models of depression. Various stress procedures including chronic unpredictable mild stress (CUMS) result in obviously decreases of BDNF expression in the brain, while chronic administration of almost all kinds of antidepressants including imipramine regulates BDNF levels. [3][4][5] The extracellular signal-regulated kinases (ERK) and AKT pathways are the two important downstream signaling pathways of BDNF. It has been reported that some of new antidepressants under development upregulate the expression of BDNF in different brain regions of stress mice via promoting the phosphorylation of ERK1/2 and AKT and thus activating the ERK, AKT pathways to produce antidepressant effects. [6][7][8] In recent studies, natural flavonoids especially resveratrol, tea polyphenols and curcumin show attractive prospect in the field of neural protection research.7,9,10) There is growing evidence indicated that flavonoids ameliorate the symptoms of depression via upregulating the levels of monoaminergic neurotransmitters 11) and promoting the expression of neurotrophic factors. 12,13)

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