Small-Molecule Organic Cathodes with Carbon Coating for Highly Efficient Potassium-ion Batteries.

Small-molecule organic cathodes face dissolution in potassium-ion batteries (PIBs). For the first time, an interesting and effective strategy is unveiled to resolve this issue by designing a new soluble small-molecule organic compound namely [N,N'-bis(2-anthraquinone)]-1,4,5,8-naphthalenetetracarboxdiimide (NTCDI-DAQ, 237 mAh g-1 ): Through the precise manipulation of carbonization temperature and time, the molecules on the surface of NTCDI-DAQ particles can be transformed into amorphous carbon with controllable thickness. This strategy called surface self-carbonization can form a carbon protective layer on organic cathodes and significantly increase their insolubility against liquid electrolytes without affecting the electrochemical behavior of bulk particles. As a result, the as-obtained NTCDI-DAQ@C sample displays significantly improved cathode performance in PIBs. In half cells, NTCDI-DAQ@C shows superior capacity stability of 84 % compared to 35 % of NTCDI-DAQ during 30 cycles under the same conditions. In full cells with a KC8 anode, NTCDI-DAQ@C delivers a peak discharge capacity of 236 mAh g-1 cathode and a high energy density of 255 Wh kg-1 cathode in 0.1-2.8 V, with 40 % capacity retention during 3000 cycles at 1 A g-1 . To the best of our knowledge, the integrated performance of NTCDI-DAQ@C is among the best of soluble organic cathodes reported in PIBs.

Design of Cooperative Output Regulators for Heterogeneous Uncertain Nonlinear Multiagent Systems.

Cooperative output regulation (COR) of multiagent systems having heterogeneous uncertain nonlinear dynamics is often challenging because of the complex system dynamics and the coupling among agents. This article develops an adaptive internal model-based distributed regulator such that the outputs of a network of nonlinear agents are all regulated to a reference despite external disturbances. Specifically, we consider heterogeneous agents having nonlinear strict-feedback forms, with nonidentical unknown control directions, and subject to an unknown linear exosystem. Addressing the nonlinear COR problem shows the capability and flexibility of the proposed output regulator. The simulation results of output synchronization of Lorenz systems and cooperative tracking control of multiple ships are presented to show the capability of the proposed regulator.

Novel application of multispectral refraction topography in the observation of myopic control effect by orthokeratology lens in adolescents.

BACKGROUND: Myopia, as one of the common ocular diseases, often occurs in adolescence. In addition to the harm from itself, it may also lead to serious complications. Thus, prevention and control of myopia are attracting more and more attention. Previous research revealed that single-focal glasses and orthokeratology lenses (OK lenses) played an important part in slowing down myopia and preventing high myopia. AIM: To compare the clinical effects of OK lenses and frame glasses against the increase of diopter in adolescent myopia and further explore the mechanism of the OK lens. METHODS: Changes in diopter and axial length were collected among 70 adolescent myopia patients (124 eyes) wearing OK lenses for 1 year (group A) and 59 adolescent myopia patients (113 eyes) wearing frame glasses (group B). Refractive states of their retina were inspected through multispectral refraction topography. The obtained hyperopic defocus was analyzed for the mechanism of OK lenses on slowing down the increase of myopic diopter by delaying the increase of ocular axis length and reducing the near hyperopia defocus. RESULTS: Teenagers in groups A and B were divided into low myopia (0D - -3.00 D) and moderate myopia (-3.25D - -6.00 D), without statistical differences among gender and age. After 1-year treatment, the increase of diopter and axis length and changes of retinal hyperopic defocus amount of group A were significantly less than those of group B. According to the multiple linear analysis, the retinal defocus in the upper, lower, nasal, and temporal directions had almost the same effect on the total defocus. The amount of peripheral retinal defocus (15°-53°) in group A was significantly lower than that in group B. CONCLUSION: Multispectral refraction topography is progressive and instructive in clinical prevention and control of myopia.

A novel cascade strategy using a nanonized targeted prodrug for enhanced oral delivery efficiency.

It is a great challenge to improve the oral bioavailability for BCS class IV drugs because they have low solubility and poor permeability. However, nanonization and intestinal transporter-targeted prodrugs can increase the solubility and permeability, respectively. Hence, an "increased solubility and improved permeability" cascade strategy was proposed to enhance the dissolution rate and permeability for BCS class IV drugs. In this study, acyclovir glutarate (AG), a prodrug of acyclovir, was synthesized to improve intestinal permeability by targeting monocarboxylate transporter 1 (MCT 1), an intestinal influx transporter. Then, AG was formulated as AG nanoneedles (AGNNs) to improve dissolution behavior. AG was demonstrated to exhibit greatly higher cellular uptake efficiency and permeability than acyclovir due to the MCT 1-mediated active transport. Furthermore, intact AGNNs were also demonstrated to be endocytosed by enterocytes and to be transcytosed potentially. In addition, oral pharmacokinetics showed that the AUC0-24h of AGNNs was 1.89-fold to that of acyclovir. Collectively, these results confirmed that nanonized MCT 1-targeted prodrugs enhanced the oral bioavailability of acyclovir in a cascade manner. Our findings propose a promising strategy to develop BCS class IV drugs and have significant implications for a wide range of such drugs for high oral delivery efficiency.

A new approach to developing diagnostics and therapeutics: Aggregation-induced emission-based fluorescence turn-on.

Fluorescence imaging is a promising visualization tool and possesses the advantages of in situ response and facile operation; thus, it is widely exploited for bioassays. However, traditional fluorophores suffer from concentration limits because they are always quenched when they aggregate, which impedes applications, especially for trace analysis and real-time monitoring. Recently, novel molecules with aggregation-induced emission (AIE) characteristics were developed to solve the problems encountered when using traditional organic dyes, because these new molecules exhibit weak or even no fluorescence when they are in free movement states but emit intensely upon the restriction of intramolecular motions. Inspired by the excellent performances of AIE molecules, a substantial number of AIE-based probes have been designed, synthesized, and applied to various fields to fulfill diverse detection tasks. According to numerous experiments, AIE probes are more practical than traditional fluorescent probes, especially when used in bioassays. To bridge bioimaging and materials engineering, this review provides a comprehensive understanding of the development of AIE bioprobes. It begins with a summary of mechanisms of the AIE phenomenon. Then, the strategies to realize accurate detection using AIE probes are discussed. In addition, typical examples of AIE-active materials applied in diagnosis, treatment, and nanocarrier tracking are presented. In addition, some challenges are put forward to inspire more ideas in the promising field of AIE-active materials.

Impacts of particle shapes on the oral delivery of drug nanocrystals: Mucus permeation, transepithelial transport and bioavailability.

For drug nanocrystals (NCs), particle shapes can affect aqueous solubility, dissolution rate and oral bioavailability. However, the effects of particle shapes on the transport of NCs across the intestinal barriers remain unclear. In the present study, spherical, rod-shaped and flaky NCs (SNCs, RNCs, and FNCs) were prepared and characterized. Meanwhile, fluorescence resonance energy transfer molecules were used to track the fate of intact NCs. Results showed that particle shapes had great influences on the mucus permeation, cellular uptake and transmembrane transport of NCs, and RNCs exhibited the best absorption efficiency. Besides, we found that endoplasmic reticulum/Golgi and Golgi/plasma membrane pathways might be involved in the transcytosis and exocytosis of NCs. Moreover, the oral bioavailability study showed that AUC0-24h of RNCs was 1.44-fold and 1.8-fold higher than that of SNCs and FNCs, respectively. Collectively, these results provided compelling evidences that RNCs could potentially improve the absoption efficacy of NCs in oral delivery. Our findings give deep insights into the impacts of particle shapes on the oral absoption of NCs and provide valuable knowledge for rational design of optimized NCs for oral drug delivery.

One-step synthesis of wire-in-plate nanostructured materials made of CoFe-LDH nanoplates coupled with Co(OH)2 nanowires grown on a Ni foam for a high-efficiency oxygen evolution reaction.

Developing high-performance, robust and cost-effective oxygen evolution reaction (OER) catalysts for electrochemical water splitting is a promising way to produce energy-saving electrolytic hydrogen fuels. Herein, a series of rational wire-in-plate nanostructured CoFe LDH electrocatalysts grown on a Ni foam were developed via a one-step hydrothermal method. In this series of catalysts, Co4Fe2-LDHs/Co(OH)2-NWs exhibit excellent OER performance which is attributed to the most rational wire-in-plate nanostructure: the overpotentials of only 220 and 231 mV to drive current densities of 50 mA cm-2 and 100 mA cm-2, respectively, with a small Tafel slope of 51 mV dec-1. Our study opens up a new horizon for the design of hierarchical structures with the coexistence of multidimensional nanounits for electrocatalysts.

Targeted deposition of ZnO2 on brookite TiO2 nanorods towards high photocatalytic activity.

A novel heterostructure was first synthesized by directly depositing photocatalytic inert ZnO2 onto facet {201} of brookite nanorods. The heterostructure thus obtained was found to show a superior photocatalytic activity under UV-light irradiation. The exceptional photocatalytic performance was due to the band-structure match between ZnO2 and brookite as well as synergic charge accumulation by different facets of the brookite nanorods.