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Wearable electronics based on conductive hydrogels (CHs) easily suffer from prolonged response times, reduced wearing comfort, shortened service lives, and impaired signal accuracy in cold environments, because conventional CHs tend to freeze at subzero temperatures and lose their flexibility, adhesion, transparency, and conductivity, which will limit their applications in extreme environments. Inspired by the way psychrotolerant creatures and superabsorbent materials interfere with the hydrogen bonding networks of water, a freeze‐resistant conductive organohydrogel (COH) is facilely fabricated. The synergy effect between charged polar terminal groups and a binary solvent system of water–ethylene glycol weakens the hydrogen bonding between water molecules and endows the COH with remarkable freezing tolerance (−78 °C). Additionally, the obtained COH is ultra‐stretchable (≈6185%), tough (9.2 MJ m−3), highly transparent (≈99%), self‐adhesive (10.2–27.8 kPa), and biocompatible. This versatile COH is assembled into a strain sensor and a well‐designed bracelet electrocardiogram sensor. Benefiting from the exceptional low‐temperature tolerance of the prepared COH, these devices exhibit fast response with delay‐free signals even at −40 °C. Overall, this work proposes a strategy to develop multifunctional COHs for supporting human health in cold environments. [ABSTRACT FROM AUTHOR]

Based on the irresistible inherent trade‐off between the mechanical and self‐healing performances of cross‐linked polyurethane materials, there is still an intractable challenge to design efficient self‐healing and tough elastomers, especially in flexible sensors. Herein, a tough, efficient self‐healing, and recyclable cross‐linked polyurethane elastomer (DTPU) was prepared by integrating oxime‐carbamate bonds and thiourethane bonds into the network. The extraordinary mechanical properties and self‐healing performances of DTPU elastomers were related to the synergistic effect of oxime‐carbamate bonds in the main chain and thiourethane bonds in the chemical cross‐linked sites. The existence of dynamic cross‐linked points not only optimized the mechanical properties of DTPU but also provided support for the reversible cleavage and formation of oxime carbamate bond, thus endowing DTPU with efficient self‐healing performance and recyclability. After self‐healing at mild temperatures for 6 h, the self‐healed DTPU elastomers had a tensile strength of 30.27 MPa and a self‐healing efficiency of 95.5%. After multiple hot‐pressing, the original mechanical strength of DTPU was restored to over 100%, exhibiting excellent recyclable characteristics. Additionally, strain sensors based on self‐healing flexible elastomers were fabricated by introducing conductive carbon nanotubes. The strain sensors maintained their electrical conductivity after 3 times self‐healing, demonstrating great potential in healable flexible electronics. [ABSTRACT FROM AUTHOR]

Graphite is a thermally conductive filler. However, when dispersed into high density poly(ethylene) (HDPE) resin, graphite particles tend to agglomerate and requires a compatibilizer to achieve desired thermal/physical properties. In this study, oleic acid (OA), a bio‐based additive and polyethylene‐polyamines (PEPA) were used to synthesize a new compatibilizer, PEPA‐g‐OA, containing numerous NR2 groups. The experimental results showed that PEPA‐g‐OA can significantly improve the compatibility between graphite particles and the HDPE matrix due to uniform dispersion of graphite in the HDPE matrix. When the graphite content was 25 wt%, the thermal conductivity of the composite recorded 1.2 W m−1 K−1 (three times that of neat HDPE) and the volume resistivity was 1.8 × 109 Ω cm, indicating excellent electrical insulation. Compared to the composites with no graphite content, the properties of the composites with 25 wt% graphite content exhibited narrower melting and crystallization peaks, more stable mechanical properties, and higher ultraviolet aging resistance. Synthesized new bio‐based compatibilizer and thermally conductive and electrically insulating composites developed in this study can be useful in different industrial fields for the preparation of the next generation composites. [ABSTRACT FROM AUTHOR]

Nowadays, polyurethanes with multifunctional and multiple shape memory effects, especially those without the use of toxic phosgene and isocyanate, have attracted significant attention. In this work, to prepare a kind of non‐isocyanate polyurethane (NIPU) with triple shape memory effect, we introduced the behenic acid (BA) with good crystallinity into the NIPUs network, which combines glass transition of the cross‐linked network and crystallization‐melting of behenic acid, endowing the NIPUs with two independent transition temperatures: the glass transition temperature (Tg) and crystallization melting temperature (Tm). Specifically, the NIPUs were synthesized by the addition reaction of bi‐functional cyclic carbonate and semi‐crystalline curing agent. The bi‐functional cyclic carbonate was prepared by thiol‐ene click reaction, and the BA was grafted onto polyethyleneimine to prepare semi‐crystalline curing agent. By adjusting the ratio of BA to PEI and curing temperature, the crystallinity of NIPU can be tuned in a wide range, so that the NIPUs has tunable and superior triple shape memory performance, and the shape recovery rate is almost 100%. [ABSTRACT FROM AUTHOR]

In this study, green composites were prepared using natural rubber (NR) as the matrix and the sisal microcrystalline cellulose (MCC) as the filler. Three modifying agents oleic acid (OA), γ‐aminopropyltriethoxylsilane (KH550), and bis‐γ‐(triethoxysilylpropyl)‐tetrasulfide (Si69) were individually tested to modify the MCC to improve the interfacial compatibility of the NR and MCC. Combined with modern instrumental analysis technology and molecular dynamics simulation, the reinforcing effect and microscopic mechanism of modified MCC on NR were analyzed. The structure–activity relationship of NR and MCC composites was further revealed, and the interaction between the two components was clarified. At the same time, the reinforcing and compatibilizing effect of three kinds of modified MCC in NR matrix were also revealed. The results showed that the properties of NR/Mod‐MCC composites were better than those of NR/MCC composites, where NR/OA‐MCC presented the highest tensile strength, followed by NR/Si69‐MCC. In addition, NR/Si69‐MCC exhibited higher elongation at break and NR/KH550‐MCC exhibited higher vulcanization characteristics. Molecular model systems were constructed through molecular dynamics simulation to investigate the interactions between the three modified cellulose molecules and the NR molecules. OA‐cellulose has a better interaction with NR than KH550‐cellulose and Si69‐cellulose, The simulation results were consistent with the experimental results. [ABSTRACT FROM AUTHOR]

The low tensile strength of ethylene/α‐octene co‐polymer (POE) limits its application as high‐strength materials. In this study, 3‐amino‐1,2,4‐triazole (ATA) was grafted onto maleic anhydride functionalized POE (PM) by melt reaction to obtain side chains capable of forming hydrogen bonding and metal coordination bonding, and then ferric chloride hexahydrate and POE are blended with them to obtain composite materials with high strength and fracture energy. The introduction of iron‐based coordination bonding and hydrogen bonding double dynamic crosslinking network endow thermoplastic elastomers with excellent mechanical strength and high toughness. Fourier transform infrared spectroscopy, rheological tests, and X‐ray photoelectron spectroscopy reveal the existence of non‐covalent crosslinking networks. Based on the strengthening and toughening of non‐covalent dynamic crosslinking network, the tensile strength of the modified POE elastomer composites achieves 12.5 MPa along with the elongation at break of 3540%. In addition, the modified POE elastomer composites exhibit improved melt elasticity and thermal stability. [ABSTRACT FROM AUTHOR]

Nanostructures made entirely of DNAs display great potential as chemotherapeutic drug carriers but so far cannot achieve sufficient clinic therapy outcomes due to off‐target toxicity. In this contribution, an aptamer‐embedded hierarchical DNA nanocluster (Apt‐eNC) is constructed as an intelligent carrier for cancer‐targeted drug delivery. Specifically, Apt‐eNC is designed to have a built‐in reserve pool in the interior cavity from which aptamers may move outward to function as needed. When surface aptamers are degraded, ones in reserve pool can move outward to offer the compensation, thereby magically preserving tumor‐targeting performance in vivo. Even if withstanding extensive aptamer depletion, Apt‐eNC displays a 115‐fold enhanced cell targeting compared with traditional counterparts and at least 60‐fold improved tumor accumulation. Moreover, one Apt‐eNC accommodates 5670 chemotherapeutic agents. As such, when systemically administrated into HeLa tumor‐bearing BALB/c nude mouse model, drug‐loaded Apt‐eNC significantly inhibits tumor growth without systemic toxicity, holding great promise for high precision therapy. [ABSTRACT FROM AUTHOR]

Thermoplastic elastomer ethylene/α‐octene co‐polymer (POE) is a special polymer material with both elasticity and thermoplasticity. However, the nonpolarity and low‐tensile strength of POE limit its application in polar materials and high‐strength materials fields. In this study, we synthesized a specific molecule with C═C bonds and NH bonds, which was introduced into POE to construct hydrogen bonding network, and the prepared modified POE is further blended with carboxyl terminated polystyrene nanospheres as toughening agent to prepare modified POE elastomer composites. Based on such dual toughening strategy containing chemical modification and physical toughening, the modified POE elastomer composites possess improved mechanical properties. The composites achieve a tensile strength of 21.4 MPa, elongation at break of 1268%, fracture energy of 109.6 MJ∙m−3 and exhibit improved thermal stability. Impressively, the tensile strength of reprocessed composites is restored to more than 90% of their original tensile strength even after four times of reprocessing steps, demonstrating excellent reusability. [ABSTRACT FROM AUTHOR]

This special issue focuses on all aspects of parallel programming on multicore and manycore architectures such as programming models and systems, applications algorithms, performance analysis, and debugging and performance tools. In "Code Generation for Energy-Efficient Execution of Dynamic Streaming Task Graphs on Parallel and Heterogeneous Platforms", Litzinger et al. enhance the programming model of streaming applications by introducing dynamic elements into the task graphs so that the runtime system can remap tasks and adapt the change of streaming-in task structures at runtime. [Extracted from the article]

The rapidly growing demand for accident-free driving in intelligent transportation makes reliable broadcast a critical factor for vehicular ad hoc networks. Existing solutions always try to improve the broadcast reliability by retransmitting lost packets. However, the excessive retransmissions can easily cause unpredictable time delay and even broadcast storms, rendering the reliable broadcast problem unsolved. In this paper, a novel reliable broadcast scheme is proposed by exploring the advantages of lost data piggybacking. Our scheme allows all the vehicles to piggyback some received packets cooperatively to help other vehicles to recover the lost packets. We formulate the cooperative piggybacking problem as a cooperative offloading game and present a decentralized solution to compute the optimal data piggybacking solutions based on only partial network information. A reward-penalty scheme is designed for the offloading process to impel all the vehicles' decisions that converge to the Nash equilibrium, which is proved to be the global optimal solution to the decentralized offloading scheme. Simulation results show that the proposed cooperative offloading scheme can achieve much higher broadcast reliability and lower propagation delay, in comparison with existing solutions. In a small vehicle network, all lost cooperative awareness messages can be successfully recovered within 25 ms after the initial broadcast by using the data traces generated by GEMV2. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]