A Triboelectric-Electromagnetic Hybrid Nanogenerator with Magnetic Coupling Assisted Waterproof Encapsulation for Long-Lasting Energy Harvesting.

Ocean energy harvesting based on a triboelectric nanogenerator (TENG) has great application potential, while the encapsulation of triboelectric devices in water poses a critical issue. Herein, a triboelectric-electromagnetic hybrid nanogenerator (TE-HNG) consisting of TENGs and electromagnetic generators (EMGs) is proposed to harvest water flow energy. A magnetic coupling transmission component is applied to replace traditional bearing structures, which can realize the fully enclosed packaging of the TENG devices and achieve long-lasting energy harvesting from water flow. Under the intense water impact, magnetic coupling reduces the possibility of internal gear damage due to excessive torque, indicating superior stability and robustness compared to conventional TENG. At the waterwheel rotates speed of 75 rpm, the TE-HNG can generate an output peak power of 114.83 mW, corresponding to a peak power density of 37.105 W m-3. After 5 h of continuous operation, the electrical output attenuation of TENG is less than 3%, demonstrating excellent device durability. Moreover, a self-powered temperature sensing system and a self-powered cathodic protection system based on the TE-HNG are developed and illustrated. This work provides a prospective strategy for improving the output stability of TENGs, which benefits the practical applications of the TENGs in large-scale blue energy harvesting.

Acid-Doped Pyridine-Based Polybenzimidazole as a Positive Triboelectric Material with Superior Charge Retention Capability.

The energy conversion efficiency of a triboelectric nanogenerator (TENG) is severely limited by the charge density of triboelectric materials, while drastic and unavoidable charge decay happens during contact due to the insufficient charge retention capacity of positive triboelectric materials. Here, elaborately synthesized acid-ion-doped pyridine-based polybenzimidazole processing with strong charge retention capability is demonstrated to couple with negatively corona-polarized electrets. As illustrated by thermal stimulation and an ion mass spectrometer, the formation of acid-ion chimerism processes high activation energy for stored charges, and the selective anion migration can compensate the escape of polarized charge. Accordingly, the charge density can reach up to 596 µC m-2 and the charge retention rate reaches 49.7%, which is so far the highest intrinsic charge density obtained in the open air. Thus, the ionic chimerism strategy provides an effective way to suppress the charge escaping in the open air and gives a great expandable avenue for the material challenges of TENG's practical deployment.

Improved RAkEL's Fault Diagnosis Method for High-Speed Train Traction Transformer.

The traction system is very important to ensure the safe operation of high-speed trains, and the failure of the traction transformer is the most likely fault in the traction system. Fault diagnosis in actual work relies largely on manual experience. This paper proposes an improved RAkEL (Random k-Labelsets) algorithm for the fault diagnosis of high-speed train traction transformers. Firstly, this article starts from the large amount of "sleeping" fault maintenance data accumulated by the railway department, takes a single maintenance record as an instance, uses specific monitoring values to construct an instance vector, and uses the fault phenomena corresponding to the monitoring indicators as labels. Then, this paper improves the step of selecting k-labelsets in RAkEL, and extracts associated faults using the Relief algorithm. Finally, this paper excavates and uses the association rules between data and faults to identify traction transformer faults. The results showed that the improved RAkEL diagnostic method had a significant improvement in the evaluation indicators. Compared with other multi-label classification algorithms, including BR (Binary Relevance) and CLR (Calibrated Label Ranking), this method performs well on multiple evaluation indicators. It can further help engineers perform timely maintenance work in the future.

Applications of graphene-based nanomaterials in drug design: The good, the bad and the ugly.

INTRODUCTION: Graphene-based materials (GBMs) have unique physicochemical properties that make them extremely attractive as platforms for the design of new drugs. Indeed, their bidimensional (2D) morphology, high surface area, mechanical and optical properties, associated to different possibilities for functionalization of their surface, provides opportunities for their use as nanomedicines for drug delivery and/or phototherapies. AREAS COVERED: This opinion paper provides an overview of the current status of GBMs in drug design, with a focus on their therapeutic applications, potential environmental and health risks, and some controversial results. The authors discuss the chemical modifications of GBMs for the treatment of various diseases. The potential toxicity associated with some GBMs is also presented, along with a safe-by-design approach to minimize the risks. Finally, the authors address some issues associated to the use of GBMs in the biomedical field, such as contradictory antibacterial effects, fluorescence quenching and imprecise chemical functionalization. EXPERT OPINION: GBMs are a promising and exciting area of research in drug delivery. It is however important that responsible and safe use of these materials is ensured to fully exploit their advantages and overcome their drawbacks.

In Situ Imaging of Formaldehyde in Live Mice with High Spatiotemporal Resolution Reveals Aldehyde Dehydrogenase-2 as a Potential Target for Alzheimer's Disease Treatment.

Alterations in formaldehyde (FA) homeostasis are associated with the pathology of Alzheimer's disease (AD). In vivo tracking of FA flux is important for understanding the underlying molecular mechanisms, but is challenging due to the lack of sensitive probes favoring a selective, rapid, and reversible response toward FA. In this study, we re-engineered the promiscuous and irreversible phenylhydrazines to make them selective and reversible toward FA by tuning their nucleophilicity. This effort resulted in PFM309, a selective (selectivity coefficient KFA,methylglyoxal = 0.06), rapid (t1/2 = 32 s at [FA] = 200 µM), and reversible fluorogenic probe (K = 6.24 mM-1) that tracks the FA flux in both live cells and live mice. In vivo tracking of the FA flux was realized by PFM309 imaging, which revealed the gradual accumulation of FA in the live mice brain during normal aging and its further increase in AD mice. We further identified the age-dependent loss of catabolism enzymes ALDH2 and ADH5 as the primary mechanism responsible for formaldehyde excess. Activating ALDH2 with the small molecular activator Alda1 significantly protected neurovascular cells from formaldehyde overload and consequently from impairment during AD progress both in vitro and in vivo. These findings revealed PFM309 as a robust tool to study AD pathology and highlight ALDH2 as a potential target for AD drug development.

Conformational restraint as a strategy for navigating towards lysosomes.

Using the conformational restraint strategy, we developed a hydrazonate-derived coumarin into a lysosome targeting probe for imaging native formaldehyde at the subcellular level. Using this probe, we observed the overproduction of formaldehyde in lysosomes when cells were treated with endoplasmic reticulum (ER) stress inducers, suggesting the involvement of formaldehyde in protein misfolding.