Additional file 1 of Association between body mass index and myopia in the United States population in the National Health and Nutrition Examination Surveys 1999 to 2008: a cross-sectional study

Additional file 1: Table S1. Frequency and proportion of missing values for all variables

Encapsulating N‑Doped Carbon Nanorod Bundles/MoO₂ Nanoparticles via Surface Growth of Ultrathin MoS₂ Nanosheets for Ultrafast and Ultralong Cycling Sodium Storage

Conversion-type anode materials possess high theoretical capacity for sodium-ion batteries (SIBs), owing to multi-electron transmission (2–6 electrons). Mo-based chalcogenides are a class of great promise, high-capacity host materials, but their development still undergoes serious volume changes and low transport kinetics during the cycling process. Here, MoO2 nanoparticles anchored on N-doped carbon nanorod bundles (N-CNRBs/MoO2) are synthesized by a facile self-polymerized route and a following annealing. After hydrothermal sulfuration, N-CNRBs/MoO2 composites are encapsulated by surface growth of ultrathin MoS2 nanosheets, acquiring hierarchical N-CNRBs/MoO2@MoS2 composites. Serving as the SIB anode, the N-CNRBs/MoO2@MoS2 electrode exhibits significantly improved sodium-ion storage properties. The reversible capacity is up to 554.4 mA h g–1 at 0.05 A g–1 and maintains 249.3 mA h g–1 even at 10.0 A g–1. During 5000 cycles, no obvious capacity decay is observed and the reversible capacities retain 334.8 mA h g–1 at 3.0 A g–1 and 301.4 mA h g–1 at 5.0 A g–1. These properties could be ascribed to the vertical encapsulation of MoS2 nanosheets on high-crystalline N-CNRBs/MoO2 substrates. The hierarchical architecture and unique heterostructure between MoO2 and MoS2 synergistically facilitate sodium-ion diffusion, relieve volume changes, and boost pseudocapacitive charge storage of N-CNRBs/MoO2@MoS2 electrode. Therefore, the rational growth of nanosheets on complex substrates shows promising potential to construct anode materials for high-performance batteries

<i>In Situ</i> Growth of Mo₂C Crystals Stimulating Sodium-Ion Storage Properties of MoO₂ Particles on N‑Doped Carbon Nanobundles

Sodium-ion batteries (SIBs) are considered as the candidate for the upcoming large-scale energy storage systems. However, transition-metal oxides still have the problem of insufficient utilization of active sites, mainly signified by the low practical capacity in long cycles. Here, the composite (MoO2@Mo2C/C) of Mo2C crystals in situ grown in N-doped carbon nanobundles (N-CNBs) with MoO2 particles on their surface is designed by self-polymerization and two-step calcination. Through a series of characterizations and tests, it is found that the N-CNBs endow the composite with improved conductivity and reinforced structural stability and effectively alleviates the volume expansion and structural collapse of MoO2 particles. The high integration of Mo2C crystals with MoO2 particles/N-CNBs (Mo2C/C) further enhances the charge-transfer ability and structural stability for the composite. Importantly, the storage sites of MoO2 particles and Mo2C crystals are gradually activated during sodium-ion storage, significantly improving the effective capacity in the long cycles. After 8000 cycles at 5.0 A g–1, the reversible capacity of MoO2@Mo2C/C as a SIB anode gradually increases from 126.2 to 419.1 mAh g–1, with a capacity retention of up to 332.4%. This study fully demonstrates the potential advantages of metal carbides in energy storage and can provide a good reference for the development of metal ion batteries

Interface Electronic Modulation of Monodispersed Co Metal-Co₇Fe₃ Alloy Heterostructures for Rechargeable Zn–Air Battery

Engineering heterointerfaces between metal and alloy to facilitate charge transfer would be an attractive strategy for superefficient electrocatalysis. Herein, a simple xerogel-pyrolysis strategy has been designed to prepare an advanced bifunctional electrocatalyst, Co/Co7Fe3 confined by a porous N-doped carbon nanosheets/CNTs composite (Co/Co7Fe3@PNCC). The formative Co/Co7Fe3 heterostructure promoted the charge transfers from metal Co to active alloy Co7Fe3, thus reducing the energy barrier of the oxygen reduction reaction and improving the catalytic kinetics and active surface area for the oxygen evolution reaction. The PNCC provided monodispersed confined space for Co/Co7Fe3 particles, which also owned a high specific surface area for ions/gases diffusion. Therefore, Co/Co7Fe3@PNCC exhibited excellent bifunctional oxygen catalysis activities and durability with an ultralow polarization gap (ΔE) of only 0.64 V. When practically adopted as an air electrode in ZAB, a large open-circuit voltage of 1.534 V, a maximum power density of 211.82 mW cm–2, an ultrahigh specific capacity of 807.33 mAh g–1, and superior durability over 800 h were obtained. This catalyst design concept offers a facile strategy toward modulating electronic structure to achieve efficient bifunctional electrocatalysts for ZAB

Novel Metal–Organic Framework-Assisted Synthesis of ZnO Nanoparticle-Decorated {221} SnO₂ Octahedrons for Improved Triethylamine Gas Sensing

The construction of composites based on metal oxides with exposed high-energy facets is very significant in a wide range of applications including gas detection, catalysis, and energy storage. However, the synthesis of such composites is always hindered by the smooth exposed surface of metal oxides, which is difficult to nucleate and grow a second component. To solve this problem, a novel metal–organic framework-assisted method was proposed to anchor ZnO nanoparticles on {221} facets of SnO2 octahedrons simply by a coating and oxidation process of ZIF-8 on the smooth {221} surface. It was found that a high nucleation energy results from an appropriate ratio of Zn2+ and 2-methylimidazole, giving priority to the heterogeneous nucleation and growth process for ZIF-8 on the surface of SnO2 octahedral nanoparticles. The coverage of ZnO on the smooth surface can also be modulated by the ZIF-8 film. Thanks to the newly designed composites with special structure, the gas-sensing performances of {221} SnO2 were improved extensively, whose response toward 100 ppm triethylamine (TEA) can be increased more than triple times from 5.68 to 18.37 (Ra/Rg) by the combination of ZnO nanoparticles. This intensively improved gas-sensing performance was attributed to the special structure with extra sensitive depletion layers at the heterojunction as well as the single-crystalline feature of SnO2 octahedral nanoparticles. These composites are thus promising gas-sensing materials for TEA detection with excellent performances. More significantly, it can also pave a new way to combine metal oxides with exposed high-energy facets, providing a unique and effective means for enhancing the properties and functionality of materials in a range of fields

Hierarchical Porous and Sandwich-like Sulfur-Doped Carbon Nanosheets as High-Performance Anodes for Sodium-Ion Batteries

The development of high-performance carbon-based anodes for Na-ion batteries is highly desired but still remains challenging because of carbon materials with a low reversible capacity and poor cyclic performance. Herein, novel S-doped carbon nanosheets (SCNs) were prepared by a hydrothermal self-assembly process in the presence of graphene oxide (GO) as the matrix, starch as the carbon source, and dibenzyl disulfide as the sulfur source. The obtained SCNs with hierarchical pores and a sandwich-like structure were utilized as anode materials for Na-ion batteries, exhibiting a high reversible discharging capacity of 207.3 mAh g–1 after 100 cycles at 50 mA g–1. When the current density is up to 1 A g–1, a reversible discharge capacity of 118.8 mAh g–1 can also be acquired. Moreover, the prominent long-term cycling stability of more than 500 cycles can be obtained at 200 mA g–1. The outstanding electrochemical property (high reversible capacity, high rate performance, and long-term cycling stability) of the SCN electrode may be due to the synergistic effect of S doping, hierarchical pores, and the sandwich-like structure. Furthermore, electrochemical kinetic analysis also confirmed that the sodium storage mechanism of the SCN electrode reinforced pseudocapacitive-control behavior. The present study not only shows a high-performance anode material for Na-ion batteries but also provides a new method to prepare S-doped carbon materials for various applications