Stretchable strain sensors offer great potential for diverse applications in modern electronics. However, it is still difficult to fabricate strain sensors with extreme stretchability, high stability, and superior durability because of the challenge in elastic matrix. In this work, the first example of extremely stretchable and highly stable double-networks ethylene glycol (EG) organogel is developed for the fabrication of wearable strain sensors with high performances. It is shown that the formation of hybrid physically and chemically cross-linked double-networks endows the EG organogel with an extraordinarily stretchability as high as 21 000%, which is the highest value for gels reported in the literature. Meanwhile, the low vapor pressure of EG gives the organogel high ambient stability. Benefiting from the intrinsic stretchability and stability of EG organogel, the strain sensors are fabricated easily by incorporating graphene as electrically conductive filler, which display extremely wide strain-sensing range (>10 500% fracture strain) with a gauge factor of 2.3. More importantly, the sensor can withstand >50 000 loading-unloading cycles in air, exhibiting high stability and superior durability. It is demonstrated that these sensors can track joint movements and muscle vibrations (such as human joint motions, drinking, saying, breathing, and slight cough) of human body and even distinguish the deformations of different directions and the touches of a hair. This work not only provided a new elastic matrix platform for the fabrication of extremely stretchable, stable, and durable strain sensors but also demonstrates their applications as wearable electronic devices for tracking both large and tiny motions of human body, which could be further extended to the practical applications in electronic skin, human-machine interactions, and personalized health monitoring.

Chronic renal failure is a severe clinical problem which has some significant socioeconomic impact worldwide and hemodialysis is an important way to maintain patients' health state, but it seems difficult to get better in short time. Considering these, the aim in our research is to update and evaluate the effects of exercise on the health of patients with chronic renal failure. The databases were used to search for the relevant studies in English or Chinese. And the association between physical exercise and health state of patients with chronic renal failure has been investigated. Random-effect model was used to compare the physical function and capacity in exercise and control groups. Exercise is helpful in ameliorating the situation of blood pressure in patients with renal failure and significantly reduces VO2 in patients with renal failure. The results of subgroup analyses show that, in the age >50, physical activity can significantly reduce blood pressure in patients with renal failure. The activity program containing warm-up, strength, and aerobic exercises has benefits in blood pressure among sick people and improves their maximal oxygen consumption level. These can help patients in physical function and aerobic capacity and may give them further benefits.

Stack Overflow accumulates an enormous amount of software engineering knowledge. However, as time passes, certain knowledge in answers may become obsolete. Such obsolete answers, if not identified or documented clearly, may mislead answer seekers and cause unexpected problems (e.g., using an out-dated security protocol). In this paper, we investigate how the knowledge in answers becomes obsolete and identify the characteristics of such obsolete answers. We find that: 1) More than half of the obsolete answers (58.4%) were probably already obsolete when they were first posted. 2) When an obsolete answer is observed, only a small proportion (20.5%) of such answers are ever updated. 3) Answers to questions in certain tags (e.g., node.js, ajax, android, and objective-c) are more likely to become obsolete. Our findings suggest that Stack Overflow should develop mechanisms to encourage the whole community to maintain answers (to avoid obsolete answers) and answer seekers are encouraged to carefully go through all information (e.g., comments) in answer threads.

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Artificial electronic skin (e-skin) that imitates the complex functions of human skin is able to transduce external stimuli into electronic signals. However, it remains challenging to fabricate e-skin sensing materials with extreme stretchability, self-healing, mechanical compliance, extreme temperature tolerance, and an ultrawide linear response range. Here, we demonstrate a new e-skin sensor fabricated by introducing polyvinylpyrrolidone (PVP)-capped Ag nanowires into the chemically and physically cross-linked polyacrylamide–PVP double-network ethylene glycol organogel. The resulting organogel e-skin exhibits extreme stretchability (>22 000%), autonomous self-healing, as well as mechanical compliance. Particularly, the sensor is capable of antifreezing and antiheating (−20 to 80 °C) and provides an ultrawide linear response range with a gauge factor of 0.15 for 0–430% tensile strain and 0.71 for 430–18 100% tensile strain, respectively. By dynamically accommodating to a curved surface, the e-skin sensor demonstrates comprehensive applications in real-time and in situ tracking of large body deformations, spatial gesture movements, and physiological signals for motion behaviors and health level evaluation, showing great promise in wearable electronics, biomedical devices, and soft robotics.

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BackgroundAccelerated cell cycle progression is the common feature of most cancers. MiRNAs can act as oncogenes or tumor suppressors by directly modulating cell cycle machinery. It has been shown that miR-188 is upregulated in UVB-irradiated mouse skin and human nasopharyngeal carcinoma CNE cells under hypoxic stress. However, little is known about the function of miR-188 in cell proliferation and growth control.ResultsOverexpression of miR-188 inhibits cell proliferation, tumor colony formation and G1/S cell cycle transition in human nasopharyngeal carcinoma CNE cells. Using bioinformatics approach, we identify a series of genes regulating G1/S transition as putative miR-188 targets. MiR-188 inhibits both mRNA and protein expression of CCND1, CCND3, CCNE1, CCNA2, CDK4 and CDK2, suppresses Rb phosphorylation and downregulates E2F transcriptional activity. The expression level of miR-188 also inversely correlates with the expression of miR-188 targets in human nasopharyngeal carcinoma (NPC) tissues. Moreover, studies in xenograft mouse model reveal that miR-188 is capable of inhibiting tumor initiation and progression by suppressing target genes expression and Rb phosphorylation.ConclusionsThis study demonstrates that miR-188 exerts anticancer effects, via downregulation of multiple G1/S related cyclin/CDKs and Rb/E2F signaling pathway.Electronic supplementary materialThe online version of this article (doi:10.1186/s12964-014-0066-6) contains supplementary material, which is available to authorized users.

Low-pressure chemical vapor deposition (LPCVD) technique is utilized for SiN x passivation of AlGaN/GaN high-electron-mobility transistors (HEMTs). A robust SiN x / AlGaN interface featuring high thermal stability and well-ordered crystalline structure is achieved by a processing strategy of "passivation-prior-to-ohmic" in HEMTs fabrication. Effective suppression of surface-trap-induced current collapse and lateral interface leakage current are demonstrated in the LPCVD-SiN x passivated HEMTs, as compared with conventional plasma-enhanced chemical vapor deposition-SiN x passivated ones. Energy dispersive X-ray spectroscopy mapping analysis of SiN x /AlGaN interfaces suggests the interface traps are likely to stem from amorphous oxide/oxynitride interfacial layer. Index Terms-AlGaN/GaN high-electron-mobility transistors (HEMTs), current collapse, low-pressure chemical vapor deposition (LPCVD), oxidation, SiN x passivation.