As an emerging material, nanomaterials have attracted extensive attention due to their small size, surface effect and quantum tunneling effect, as well as potential applications in traditional ...materials, medical devices, electronic devices, coatings and other industries. Herein, the influence of nanoparticle selection, production process, grain size, and grain boundary structures on the mechanical properties of nanomaterials is introduced. The current research progress and application range of nano-materials are presented. The unique properties of nano-materials make them superior over traditional materials. Therefore, nanomaterials will have a broader application prospect in the future. Research on nanomaterials is significant for the development and application of materials science.
Nonlinear optical switches that reversibly convert between on/off states by thermal stimuli are promising for applications in the fields of photoelectronics and photonics. Currently one main drawback ...for practical application lies in the control of their switch temperature, especially for the temperature range near room temperature. By mixed melting treatment, here we describe an alloy-like nonlinear optical switch with tunable switch temperature via a dual solid solution approach within the coordination polymer system. We initially prepare a coordination polymer (i-PrNHMe
)Cd(SCN)
, which functions as a high-contrast thermoresponsive nonlinear optical switch originating from a phase transition at around 328 K. Furthermore, by taking advantage of a synergistic dual solid solution effect, the melt mixing of it with its analogue (MeNHEt
)Cd(SCN)
, which features an unequal anionic chain templated by an isomeric ammonium, can afford coordination polymer solid solutions with switch temperatures that are tunable in a range of 273-328 K merely by varying the component ratio.
We reported herein the development of heterobimetallic NiFe molecular platform to understand NiFe synergistic effect in water oxidation catalysis. Compared to homonuclear bimetallic compounds (NiNi ...and FeFe), NiFe complex possesses more remarkable catalytic water oxidation performance. Mechanistic studies suggest that this remarkable difference is attributed to the fact that NiFe synergy can effectively promote O−O bond formation. The generated NiIII(μ‐O)FeIV=O is the key intermediate and O−O bond was formed via intramolecular oxyl‐oxo coupling between bridged O radical and terminal FeIV=O moiety.
A family of structurally well‐defined bimetallic complexes (FeFe, NiFe, NiNi, ZnFe, NiZn) was used as a molecular platform to understand Ni/Fe cooperative water oxidation mechanism. The results disclosed that O−O bond formed via intramolecular oxyl‐oxo coupling between bridged O radical and terminal FeIV=O moiety in NiIII(μ‐O)FeIV=O species, which provides a helpful guidance for rational design of heterobimetallic catalysts.
infection is mostly a family-based infectious disease. To facilitate its prevention and management, a national consensus meeting was held to review current evidence and propose strategies for ...population-wide and family-based
infection control and management to reduce the related disease burden.
Fifty-seven experts from 41 major universities and institutions in 20 provinces/regions of mainland China were invited to review evidence and modify statements using Delphi process and grading of recommendations assessment, development and evaluation system. The consensus level was defined as ≥80% for agreement on the proposed statements.
Experts discussed and modified the original 23 statements on family-based
infection transmission, control and management, and reached consensus on 16 statements. The final report consists of three parts: (1)
infection and transmission among family members, (2) prevention and management of
infection in children and elderly people within households, and (3) strategies for prevention and management of
infection for family members. In addition to the 'test-and-treat' and 'screen-and-treat' strategies, this consensus also introduced a novel third 'family-based
infection control and management' strategy to prevent its intrafamilial transmission and development of related diseases.
is transmissible from person to person, and among family members. A family-based
prevention and eradication strategy would be a suitable approach to prevent its intra-familial transmission and related diseases. The notion and practice would be beneficial not only for Chinese residents but also valuable as a reference for other highly infected areas.
Dielectric switches that can be converted between high and low dielectric states by thermal stimuli have attracted much interest owing to their many potential applications. Currently one main ...drawback for practical application lies in the non‐tunability of their switch temperatures (TS). We report here an ionic co‐crystal (Me3NH)4Ni(NCS)6 that contains a multiply rotatable Me3NH+ ion and a solely rotatable one due to a more spacious supramolecular cage for the former one. This compound undergoes an isostructural order–disorder phase transition and it can function as a frequency‐tuned dielectric switch with highly adjustable TS, which is further revealed by the variable‐temperature structure analyses and molecular dynamics simulations. In addition, the distinct arrangements and molecular dynamics of two coexisting Me3NH+ ions confined in different lattice spaces as well as the notable offset effect on the promoting/hindering of dipolar reorientation after dielectric transition provide a rarely observed but fairly good model for understanding and modulating the dipole motion in crystalline environment.
Dipole motion in a crystal: The ionic co‐crystal (Me3NH)4Ni(NCS)6 undergoes an order–disorder phase transition and functions as a frequency‐tuned dielectric switch with a highly adjustable switching temperature. The distinct arrangements and molecular dynamics of two coexisting Me3NH+ ions provide a model for understanding/modulating the dipole motion in a crystalline environment.
Acne vulgaris is a chronic inflammatory dermatosis affecting approximately 85% of adolescents. There are many factors contributing to the development of this ailment. A recent study indicated that ...gut microbiota takes part in the pathogenesis of acne. We aimed to investigate the link between acne vulgaris and gut microbiota. A total of 31 moderate to severe acne vulgaris patients and 31 healthy controls were enrolled. We collected their feces, and gut microbiota was evaluated by the hypervariable regions of 16S rRNA genes through high-throughput sequencing. We identified links between acne vulgaris and changes of gut microbiota. At the phylum level, Actinobacteria (0.89% in acne patients and 2.84% in normal controls, P = 0.004) was decreased and Proteobacteria (8.35% in acne patients and 7.01% in normal controls, P = 0.031) was increased. At the genus level, Bifidobacterium, Butyricicoccus, Coprobacillus, Lactobacillus and Allobaculum were all decreased. The observed difference in genera between acne patients and healthy controls provides a new insight into the link between gut microbiota changes and acne vulgaris risk.
A new perovskite‐like coordination polymer (CH3)2NH2Cd(N3)3 is reported which undergoes a reversible ferroelastic phase transition. This transition is due to varied modes of motion of the (CH3)2NH2+ ...guest accompanied by a synergistic deformation of the Cd(N3)3− framework. The unusual two‐staged switchable dielectric relaxation reveals the molecular dynamics of the polar cation guest, which are well controlled by the variable confined space of the host framework. As the material switches from the ferroelastic phase to the paraelastic phase, a remarkable increase of the rotational energy barrier is detected. As a result, upon heating at low temperature, this compound shows a notable change from a low to a high dielectric state in the ferroelastic phase. This thermoresponsive host–guest system may serve as a model compound for the development of sensitive thermoresponsive dielectric materials and may be key to understanding and modulating molecular/ionic dynamics of guest molecules in confined space.
Flexible frameworks: A perovskite‐like coordination polymer (CH3)2NH2Cd(N3)3 undergoes a ferroelastic‐to‐paraelastic phase transition as a result of the motion of the guest cation within the host framework (see picture), which itself undergoes a simultaneous deformation. This material acts as a thermoresponsive dielectric system owing to the well‐controlled guest molecular dynamics in the confined space.
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