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Observations have been obtained of the initial stage of a rocket‐and‐wire‐triggered lightning flash with a high‐resolution broadband VHF interferometer. The discharge produced 54 precursor current pulses (PCPs) over 883 ms during the rocket's ascent. The interferometer observations show that the PCPs were produced by breakdown at the ascending tip of the rocket, and that individual PCPs were produced by weak upward positive breakdown over meters‐scale distances, followed by more energetic, fast downward negative breakdown over several tens of meters distance. The average propagation speeds were ~5 × 106 m s−1 and ~3 × 107 m s−1, respectively. The sustained upward positive leader (UPL) was initiated by a rapid, repetitive burst of 14 precursor pulses. Upon initiation, the VHF radiation abruptly became continuous with time. Significantly, breakdown during the UPL appeared to extend the discharge in a similar manner to that of the precursor pulses.

Microwave has been widely used in many fields, including communication, medical treatment and military industry; however, the corresponding generated radiations have been novel hazardous sources of pollution threating human’s daily life. Therefore, designing high-performance microwave absorption materials (MAMs) has become an indispensable requirement. Recently, metal–organic frameworks (MOFs) have been considered as one of the most ideal precursor candidates of MAMs because of their tunable structure, high porosity and large specific surface area. Usually, MOF-derived MAMs exhibit excellent electrical conductivity, good magnetism and sufficient defects and interfaces, providing obvious merits in both impedance matching and microwave loss. In this review, the recent research progresses on MOF-derived MAMs were profoundly reviewed, including the categories of MOFs and MOF composites precursors, design principles, preparation methods and the relationship between mechanisms of microwave absorption and microstructures of MAMs. Finally, the current challenges and prospects for future opportunities of MOF-derived MAMs are also discussed."Image missing"

Parkinson's disease (PD) is a neurodegenerative progressive disease that mainly affects the motor systems of patients. To slow this disease deterioration, early and accurate diagnosis of PD is an effective way, which alleviates mental and physical sufferings by clinical intervention. In this paper, we propose a joint regression and classification framework for PD diagnosis via magnetic resonance and diffusion tensor imaging data. Specifically, we devise a unified multi-task feature selection model to explore multiple relationships among features, samples, and clinical scores. We regress four clinical variables of depression, sleep, olfaction, cognition scores, as well as perform the classification of PD disease from the multi-modal data. The multi-task model explores the relationships at the level of clinical scores, image features, and subjects, to select the most informative and diseased-related features for diagnosis. The proposed method is evaluated on the public Parkinson's progression markers initiative (PPMI) dataset. The extensive experimental results show that the multi-task framework can effectively boost the performance of regression and classification and outperforms other state-of-the-art methods. The computerized predictions of clinical scores and label for PD diagnosis may offer quantitative reference for decision support as well.

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BDT uniformly disperse into graphene with layer like structure, resulting in greatly improved electrochemical performance in comparison with pure BDT.

extracellular matrix properties, gives them popularity in applications ranging from drug delivery, [4,5] wound dressing, [6][7][8] and tissue repair. [9,10] Various hydrogels with extraordinary properties have been reported, like tough, [11] stimuliresponse, [12] and optical variable hydrogels. [13] For example, the combination of covalently and ionically cross-linked networks endows hydrogel's excellent mechanical properties, achieving a value of 9000 J m −2 , which is comparable to natural rubber (10 000 J m −2 ). [11] Moreover, hydrogels with "self-growing" property [14] can stand duplicated stretch without ruption but gain a gradual increase in stress instead. However, in contrast to the bulk hydrogel, existing hydrogel adhesives are far from the desired properties. [15] The adhesion energy of commercial adhesives is usually ≈10 J m −2 compared to that of cartilage, composing a robust matrix of 1000 J m −2 and the adhesive layer of 800 J m −2 , respectively. [16] It is worth noting that medical and clinic adhesives should effectively prevent blood loss, gas, and tissue fluids leakage or exposure to the infectious environment or digestive fluids. [17] Thus, adhesion failure ought to result in negative therapy. Adhesion conductive hydrogels are also required to get skinlevel sensitive sensors since any interfacial vacant space will give rise to inaccurate signals. [18,19] As a result, sensors with high resolution and excellent accuracy can not be obtained under such circumstances due to "dead" regions. [20] Therefore, tough interactions between hydrogels matrix and diverse substrate, especially for wet tissues, are vital but challenging issues. [15] Of particularly significant and ideal properties for tough adhesives under stretching, dissipative energy within hydrogel matrix and interactive energy between interfaces is desired to prevent macroscopic movement. [21] By enhancing interfacial interactions via surface chemical modification, surface structuralizing, physical interlocks, or combining the principles mentioned above, a series of adhesive patches or tough adhesives with injectable, tunable curing time, degradable properties have been obtained.Numerous synthetic or natural materials, diverse design strategies, various methods, and many potential applications have emerged. In this review, as shown in Figure 1, we will summarize the state-of-art hydrogel adhesives spanning from design principles, including physical and chemical interactions In virtue of extracellular features, hydrogels have been used in various areas such as tissue repair, artificial skins, and biological electronics, etc. Intact contact of tough hydrogels to targeted surfaces is usually required to avoid blood or body fluids leakage or inaccurate signals of sensors. The collaboration of high interactive energy between interfaces and high fracture toughness of the constituent hydrogels can effectively prevent relatively macroscopic motions of adhesives from substrates under deformation. Nevertheless, variations in surface microenvironment...

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