The human body absorbs and loses heat largely through infrared radiation centering around a wavelength of 10 micrometers. However, neither our skin nor the textiles that make up clothing are capable of dynamically controlling this optical channel for thermal management. By coating triacetate-cellulose bimorph fibers with a thin layer of carbon nanotubes, we effectively modulated the infrared radiation by more than 35% as the relative humidity of the underlying skin changed. Both experiments and modeling suggest that this dynamic infrared gating effect mainly arises from distance-dependent electromagnetic coupling between neighboring coated fibers in the textile yarns. This effect opens a pathway for developing wearable localized thermal management systems that are autonomous and self-powered, as well as expanding our ability to adapt to demanding environments.

We combine two amazing abilities found in nature: the superhydrophobic property of lotus leaf and the adhesive ability of mussel adhesive protein. The molecular structure mimic of the single units of adhesive proteins, dopamine, was polymerized in an alkaline aqueous solution to encapsulate microparticles. The as-formed thin polydopamine walls worked as reactive templates to generate silver nanoparticles on the capsuled particles. As a result, core/shell/satellite composite particles were generated with a hierarchical structure similar to the micromorphology of lotus leaf. The composite particles exhibited extremely water repellence after fluorination. Because dopamine can deposit and adhere to all kinds of materials, this method can be applied to diverse microparticles, from organic to inorganic. In addition, particles of different sizes and matters can be modified to superhydrophobic particles in one pot. Magnetic particles have also been prepared which could be used as oil-absorbent and magnetic controlled carriers. "Oil marbles" formed underwater were achieved for the first time.

Glucocorticoids (GCs) induce apoptosis in lymphoid cells through activation of the GC receptor (GR). We have evaluated the role of p38, a MAPK, in lymphoid cell apoptosis upon treatment with the synthetic GCs dexamethasone (Dex) or deacylcortivazol (DAC). The highly conserved phosphoprotein p38 MAPK is activated by specific phosphorylation of its threonine180 and tyrosine182 residues. We show that Dex and DAC stimulate p38 MAPK phosphorylation and increase the mRNA of MAPK kinase 3, a specific immediate upstream activator of p38 MAPK. Enzymatic assays confirmed elevated activity of p38 MAPK. Pharmacological inhibition of p38 MAPK activity was protective against GC-driven apoptosis in human and mouse lymphoid cells. In contrast, inhibition of the MAPKs, ERK and cJun N-terminal kinase, enhanced apoptosis. Activated p38 MAPK phosphorylates specific downstream targets. Because phosphorylation of the GR is affected by MAPKs, we examined its phosphorylation state in our system. We found serine 211 of the human GR to be a substrate for p38 MAPK both in vitro and intracellularly. Mutation of this site to alanine greatly diminished GR-driven gene transcription and apoptosis. Our results clearly demonstrate a role for p38 MAPK signaling in the pathway of GC-induced apoptosis of lymphoid cells.

Aligned carbon nanotube sheets provide an engineered scaffold for the deposition of a silicon active material for lithium ion battery anodes. The sheets are low-density, allowing uniform deposition of silicon thin films while the alignment allows unconstrained volumetric expansion of the silicon, facilitating stable cycling performance. The flat sheet morphology is desirable for battery construction.

In this article, we report a bioinspired approach to preparing stable, functional multilayer films by the integration of mussel-inspired catechol oxidative chemistry into a layer-by-layer (LbL) assembly. A polyanion of poly(acrylic acid-g-dopamine) (PAA-dopamine) bearing catechol groups, a mussel adhesive protein-mimetic polymer, was synthesized as the building block for LbL assembly with poly(allylamine hydrochloride) (PAH). The oxidization of the incorporated catechol group under mild oxidative condition yields o-quinone, which exhibits high reactivity with amine and catechol, thus endowing the chemical covalence and retaining the assembled morphology of multilayer films. The cross-linked films showed excellent stability even in extremely acidic, basic, and highly concentrated aqueous salt solutions. The efficient chemical cross-linking allows for the production of intact free-standing films without using a sacrificial layer. Moreover, thiol-modified multilayer films with good stability were exploited by a combination of thiols-catechol addition and then oxidative cross-linking. The outstanding stability under harsh conditions and the facile functionalization of the PAA-dopamine/PAH multilayer films make them attractive for barriers, separation, and biomedical devices.

3D Multi-object tracking (MOT) is crucial to autonomous systems. Recent work uses a standard trackingby-detection pipeline, where feature extraction is first performed independently for each object in order to compute an affinity matrix. Then the affinity matrix is passed to the Hungarian algorithm for data association. A key process of this standard pipeline is to learn discriminative features for different objects in order to reduce confusion during data association. In this work, we propose two techniques to improve the discriminative feature learning for MOT: (1) instead of obtaining features for each object independently, we propose a novel feature interaction mechanism by introducing the Graph Neural Network. As a result, the feature of one object is informed of the features of other objects so that the object feature can lean towards the object with similar feature (i.e., object probably with a same ID) and deviate from objects with dissimilar features (i.e., object probably with different IDs), leading to a more discriminative feature for each object; (2) instead of obtaining the feature from either 2D or 3D space in prior work, we propose a novel joint feature extractor to learn appearance and motion features from 2D and 3D space simultaneously. As features from different modalities often have complementary information, the joint feature can be more discriminate than feature from each individual modality. To ensure that the joint feature extractor does not heavily rely on one modality, we also propose an ensemble training paradigm. Through extensive evaluation, our proposed method achieves stateof-the-art performance on KITTI and nuScenes 3D MOT benchmarks. Our code will be made available at https: //github.com/xinshuoweng/GNN3DMOT

The surprising properties of biomaterials are the results of billions of years of evolution. Generally, biomaterials are assembled under mild conditions with very limited supply of constituents available for living organism, and their amazing properties largely result from the sophisticated hierarchical structures. Following the biomimetic principles to prepare manmade materials has drawn great research interests in materials science and engineering. In this review, we summarize the recent progress in fabricating bioinspired materials with the emphasis on mimicking the structure from one to three dimensions. Selected examples are described with a focus on the relationship between the structural characters and the corresponding functions. For one-dimensional materials, spider fibers, polar bear hair, multichannel plant roots and so on have been involved. Natural structure color and color shifting surfaces, and the antifouling, antireflective coatings of biomaterials are chosen as the typical examples of the two-dimensional biomimicking. The outstanding protection performance, and the stimuli responsive and self-healing functions of biomaterials based on the sophisticated hierarchical bulk structures are the emphases of the three-dimensional mimicking. Finally, a summary and outlook are given.

Polypyrrole (PPy) nanowire networks have been synthesized in high yield (higher than 90%) by chemical oxidative polymerization of pyrrole in the presence of hexadecyltrimethylammonium bromide (HTAB) and organic diacids (oxalic acid, tartaric acid, or glutaric acid) and triacid (citric acid). The diameter of nanowire is 60−90 nm. The influence of reaction conditions, such as polymerization temperature, polymerization time, and the molar ratios of HTAB to organic acids and pyrrole, on the morphologies of the PPy nanowire networks has been systematically investigated. In addition, the interconnected PPy nanoparticles are prepared without using HTAB. The film of PPy nanowire networks and nanoparticles is superhydrophilic. A plausible formation mechanism of PPy nanowire networks is discussed.