Search

Reaction of (P)AuOTf [P=P(t‐Bu)2o‐biphenyl] with indenyl‐ or 3‐methylindenyl lithium led to isolation of gold η1‐indenyl complexes (P)Au(η1‐inden‐1‐yl) (1 a) and (P)Au(η1‐3‐methylinden‐1‐yl) (1 b), respectively, in >65 % yield. Whereas complex 1 b is static, complex 1 a undergoes facile, degenerate 1,3‐migration of gold about the indenyl ligand (ΔG≠153K=9.1±1.1 kcal/mol). Treatment of complexes 1 a and 1 b with (P)AuNTf2 led to formation of the corresponding cationic bis(gold) indenyl complexes trans‐[(P)Au]2(η1,η1‐inden‐1,3‐yl) (2 a) and trans‐[(P)Au]2(η1,η2‐3‐methylinden‐1‐yl) (2 b), respectively, which were characterized spectroscopically and modeled computationally. Despite the absence of aurophilic stabilization in complexes 2 a and 2 b, the binding affinity of mono(gold) complex 1 a toward exogenous (P)Au+ exceed that of free indene by ~350‐fold and similarly the binding affinity of 1 b toward exogenous (P)Au+ exceed that of 3‐methylindene by ~50‐fold. The energy barrier for protodeauration of bis(gold) indenyl complex 2 a with HOAc was ≥8 kcal/mol higher than for protodeauration of mono(gold) complex 1 a. [ABSTRACT FROM AUTHOR]

Appropriately characterising the mixed space–time relations of the contagion process caused by hybrid space and time factors remains the primary challenge in COVID‐19 forecasting. However, in previous deep learning models for epidemic forecasting, spatial and temporal variations are captured separately. A unified model is developed to cover all spatio–temporal relations. However, this measure is insufficient for modelling the complex spatio–temporal relations of infectious disease transmission. A dynamic adaptive spatio–temporal graph network (DASTGN) is proposed based on attention mechanisms to improve prediction accuracy. In DASTGN, complex spatio–temporal relations are depicted by adaptively fusing the mixed space–time effects and dynamic space–time dependency structure. This dual‐scale model considers the time‐specific, space‐specific, and direct effects of the propagation process at the fine‐grained level. Furthermore, the model characterises impacts from various space–time neighbour blocks under time‐varying interventions at the coarse‐grained level. The performance comparisons on the three COVID‐19 datasets reveal that DASTGN achieves state‐of‐the‐art results with a maximum improvement of 17.092% in the root mean‐square error and 11.563% in the mean absolute error. Experimental results indicate that the mechanisms of designing DASTGN can effectively detect some spreading characteristics of COVID‐19. The spatio–temporal weight matrices learned in each proposed module reveal diffusion patterns in various scenarios. In conclusion, DASTGN has successfully captured the dynamic spatio–temporal variations of COVID‐19, and considering multiple dynamic space–time relationships is essential in epidemic forecasting. [ABSTRACT FROM AUTHOR]

Paraspinal muscle atrophy is gaining attention in spine surgery due to its link to back pain, spinal degeneration and worse postoperative outcomes. Electrical impedance myography (EIM) is a noninvasive diagnostic tool for muscle quality assessment, primarily utilized for patients with neuromuscular diseases. However, EIM's accuracy for paraspinal muscle assessment remains understudied. In this study, we investigated the correlation between EIM readings and MRI‐derived muscle parameters, as well as the influence of dermal and subcutaneous parameters on these readings. We retrospectively analyzed patients with lumbar spinal degeneration who underwent paraspinal EIM assessment between May 2023 to July 2023. Paraspinal muscle fatty infiltration (FI) and functional cross‐sectional area (fCSA), as well as the subcutaneous thickness were assessed on MRI scans. Skin ultrasound imaging was assessed for dermal thickness and the echogenicities of the dermal and subcutaneous layers. All measurements were performed on the bilaterally. The correlation between EIM readings were compared with ultrasound and MRI parameters using Spearman's correlation analyses. A total of 20 patients (65.0% female) with a median age of 69.5 years (IQR, 61.3–73.8) were analyzed. The fCSA and FI did not significantly correlate with the EIM readings, regardless of frequency. All EIM readings across frequencies correlated with subcutaneous thickness, echogenicity, or dermal thickness. With the current methodology, paraspinal EIM is not a valid alternative to MRI assessment of muscle quality, as it is strongly influenced by the dermal and subcutaneous layers. Further studies are required for refining the methodology and confirming our results. [ABSTRACT FROM AUTHOR]

Hyperbolic phonon polaritons in optically uniaxial hexagonal boron nitride (hBN) have shown considerable potential for manipulating light on the deep‐subwavelength scale, but the inherent in‐plane isotropy of hBN hinders their further application in planar polariton meta‐optics. Engineering these polaritons to achieve ultraconfined in‐plane anisotropic propagation is of scientific significance for facilitating light–matter interactions toward an extreme scale. Here, the polariton features are systematically investigated in a vertically stacked van der Waals heterostructure consisting of hBN and tellurium (Te), a highly birefringent van der Waals crystal in the mid‐infrared region. Polaritons in this heterostructure exhibit Te‐thickness‐dependent anisotropic dispersion, and the configurable in‐plane anisotropy and enhanced field confinement are experimentally demonstrated using scanning near‐field optical microscopy. It is concluded that these findings contribute to the fundamental understanding of anisotropic polaritons in hBN van der Waals heterostructures, providing a practical avenue for effectively engineering anisotropic PhPs in an intrinsically isotropic van der Waals material. [ABSTRACT FROM AUTHOR]

Nanocomposite represents the backbone of many industrial fabrication applications and exerts a substantial social impact. Among these composites, metal nanostructures are often employed as the active constituents, thanks to their various chemical and physical properties, which offer the ability to tune the application scenarios in thermal management, energy storage, and biostable materials, respectively. Nanocellulose, as an emerging polymer substrate, possesses unique properties of abundance, mechanical flexibility, environmental friendliness, and biocompatibility. Based on the combination of flexible nanocellulose with specific metal fillers, the essential parameters involving mechanical strength, flexibility, anisotropic thermal resistance, and conductivity can be enhanced. Nowadays, the approach has found extensive applications in thermal management, energy storage, biostable electronic materials, and piezoelectric devices. Therefore, it is essential to thoroughly correlate cellulose nanocomposites' properties with different metallic fillers. This review summarizes the extraction of nanocellulose and preparation of metal modified cellulose nanocomposites, including their wide and particular applications in modern advanced devices. Moreover, we also discuss the challenges in the synthesis, the emerging designs, and unique structures, promising directions for future research. We wish this review can give a valuable overview of the unique combination and inspire the research directions of the multifunctional nanocomposites using proper cellulose and metallic fillers. [ABSTRACT FROM AUTHOR]

Submarine volcanos are the most active areas in the deep sea, but the environmental consequences of frequent volcanic activity on the geophysical fields and biogeochemical processes near hydrothermal chimneys have not been fully understood yet. In particular, how continuous high‐flux thermal energy, the most typical form of energy in active submarine volcanic systems, affects electron transport and geoelectric field remains unknown. This study provides the first evidence that thermal energy can be efficiently converted to electrical energy at an extremely small spatial scale of the submarine black chimneys. The Seebeck coefficient of sulfide chimneys can reach more than 200 μV/K, with high electrical conductivity of 104 S/m and low thermal conductivity of 1.0 W/(m·K) within 300–700 K. A maximal potential gradient of 300 mV/cm under a temperature difference of 300–700 K can be generated by the thermoelectric conversion of sulfide chimneys, with a maximum energy converting efficiency up to 1%. The thermoelectric conversion effect of a global‐scale submarine volcanos could enable electroactive bacteria to fix appromaxiately 105–106 tons of carbon per year. In addition, the thermal‐electrochemical experiments indicated sulfides underwent rapid oxidation under thermoelectric effects, which may help explain the intense oxidative weathering of sulfides in some anoxic deep‐sea hydrothermal zones. Plain Language Summary: Hydrothermal vents are the most active areas for energy and material exchange in the submarine volcanic systems. The conversion of chemical and biomass energy has been considered as the major driving force for biogeochemical processes in hydrothermal vents, while the primary thermal energy has rarely been a concern. This study revealed that hydrothermal black chimneys could achieve stable thermoelectric conversion with a maximum energy conversion efficiency of 1%. The thermoelectric transport performance of sulfides is mainly influenced by crystal structure, chemical composition and substituting ions. Both the generation of natural electric field and the growth and metabolism of electroactive microorganisms in deep sea are clolsely related to the thermoelectric effects of sulfides. The rapid oxidation of sulfides under a thermoelectric potential well explains the intense weathering of minerals in anoxic seafloor regions. Key Points: Proposing a geoelectric mechanism caused by thermoelectric effects of sulfides in submarine volcanic systemsBuilding a quantitative model to estimate the efficiency of thermoelectric conversion and carbon fixationExplaining rapid oxidative weathering of hydrothermal vent sulfides by thermoelectric mechanism [ABSTRACT FROM AUTHOR]

Smart adhesives with the ability to rapidly switch, achieve high adhesion tuning ratios, and provide precise control hold tremendous potential in various fields ranging from micromanipulation to manufacturing. Despite significant progress, an efficient and robust adhesive switch remains a rarity. In this study, a design strategy for magnetically actuated adhesives that exhibit switchable adhesion between high and low levels exceeding 50 times is proposed. The non‐contact actuation of the magnetic field induces a pre‐designed deformation of the magnetic tentacles, resulting in both interface cracks at the adhesion interface and a push force on the target object. Consequently, the pull‐off force can be precisely adjusted according to the strength of the magnetic field. This proposed adhesive also exhibits ultrafast detachment (<1.0 s). Tentative experiments are conducted for transfer‐print technology and on‐demand detachment, which demonstrate the advantages of magnetically actuated adhesives in a non‐contact manner. The proposed strategy of switching adhesion may be particularly useful for practical applications that require highly precise and swiftly controlled movements. [ABSTRACT FROM AUTHOR]

Random metasurfaces have demonstrated significant potential in radar‐signature control applications, but their ability to manipulate scattering‐field reduction is limited by relying solely on the diffusion mechanism. To achieve flexible and arbitrary designs for scattering‐field reduction, a diffusion–absorption hybrid metasurface is proposed based on the Babinet principle. This hybrid metasurface adopts complementary bilayer metasurfaces to satisfy the impedance matching condition and employs a hybrid absorption and diffusion mechanism. Such complementary designs' intralayer resonances and interlayer couplings are tailored by multi‐objective optimization, achieving the precise and wideband design of absorptive elements with a specific reflection phase. By optimizing the spatial distributions of elements, diffusion is introduced and designs are achieved with a continuous scattering‐field reduction from 15.40 to 32.58 dB at 15 GHz. Three representative designed structures are fabricated and verified as proof of concept. The experimental results are consistent with the calculations and simulations, demonstrating a 12.32–24.46 dB scattering‐field reduction range. The proposed high‐freedom metasurface and the implementation multi‐objective optimization strategy collectively empower flexible wavefront manipulation, offering a viable solution for designing hybrid meta‐devices that incorporate multiple mechanisms. [ABSTRACT FROM AUTHOR]

High‐speed and highly sensitive infrared photodetectors are regarded as one of the most essential components in modern photonic devices and technology because of constantly emerging application scenarios. In this paper, an ultrafast and extremely low noise mid‐infrared (MIR) photodetector is reported at both room and cryogenic temperatures by leveraging the high‐mobility 2D electron gas (2DEG) at the polar CdTe/PbTe heterostructure interface. The detector simultaneously exhibits a peak detectivity of ≈4.2 × 1011 Jones with rapid response in the order of 10 ns, which is substantially superior to the state‐of‐the‐art 2DEG MIR detectors made of 2D layered materials. The ultrafast response with extremely low noise of the 2DEG photodetector is attributed to the unique band alignment at the interface. The practical infrared imaging application is further showcased using the 2DEG MIR detector by revealing the fine features of a MIR radiation target. This work highlights the promising prospect of utilizing the unique 2DEG interface in the field of high‐speed and highly sensitive MIR detection. [ABSTRACT FROM AUTHOR]

Quasi‐solid‐state lithium metal batteries are deemed as one of the most promising next‐generation energy storage devices due to their enhanced safety and high energy density. However, the Li/Gel polymer Electrolyte (GPE) interface deterioration induced by the side reactions, dendrite growth during Li plating, and contact loss during Li stripping will inevitably lead to the failure of the battery. Herein, a Li/Li23Sr6–Li3N/Sr2N anode structure (LSN) prepared by hot‐rolling process is designed, where Sr2N serves as an inert skeleton to retain the interfacial coupling and to avoid contact loss. At the same time, the Li3N–Li23Sr6 interphase with high Li adsorption energy and fast Li+ transfer kinetics regulate the Li plating behavior. Benefitting from the design, when coupled with the carbonate‐based GPE, the lifespan of the symmetric battery with the LSN is extended to 1300 h at 0.2 mA cm−2/0.2 mAh cm−2. Furthermore, the LSN||LiFePO4 (LFP) full cell exhibits a steady cycle with extremely low voltage polarization at 0.5 C after 200 cycles. This study provides a practical strategy to stabilize the Li/GPE interface and deepens the understanding of Li+ plating/stripping behaviors through the interphase. [ABSTRACT FROM AUTHOR]

Integrated control circuits with multiple computation functions are essential for soft robots to achieve diverse complex real tasks. However, designing compliant yet simple circuits to embed multiple computation functions in soft electronic systems above the centimeter scale is still a tough challenge. Herein, utilizing smooth cyclic motions of magnetic liquid metal droplets (MLMD) in specially designed and surface‐modified circulating channels, a soft reconfigurable circulator (SRC) consisting of three simple and reconfigurable basic modules is described. Through these modules, MLMD can utilize their conductivity and extreme deformation capabilities to transfer their simple cyclic motions as input signals to programmable electrical output signals carrying computing information. The obtained SRCs make it possible for soft robots to perform complex computing tasks, such as logic, programming, and self‐adaptive control (a combination of programming and feedback control). Following, a digital logic‐based grasping function diagnosis, a locomotion reprogrammable soft car, and a self‐adaptive control‐based soft sorting gripper are demonstrated to verify SRCs' capabilities. The unique attributes of MLMD allow complex computations based on simple configurations and inputs, which provide new ways to enhance soft robots' computing capabilities. [ABSTRACT FROM AUTHOR]

The self‐trapped excitons (STEs) in soft van der Waals (vdW) materials have aroused tremendous attention. The conventional methods to manipulate the STEs include the introduction of permanent defect or lattice distortion, which lead to the suppression of the inherent structures and properties. Developing a non‐destructive method to achieve room temperature STEs with high tunability is thus of strategic interest. Stacking 2D materials to form a vdW heterostructure will introduce many‐body interactions, which should be exploited to tailor STE emissions controllably. To this regard, the highly tunable STE emissions in vdW heterostructures composed of lead iodide, hexagonal boron nitride, or molybdenum oxide are demonstrated. It is found that the synergistic effect of the dielectric screening and interfacial many‐body interaction improve the temperature characteristic and emission properties of STEs. The strong STE emissions with highly tunable center energies in a broadband spectrum range from ≈625 to 750 nm are verified at room temperature. This work provides a non‐destructive method to manipulate the STE emissions at room temperature in rigid lattice vdW materials, which is expected to open the potential of STEs for next‐generation optoelectronics. [ABSTRACT FROM AUTHOR]

Anion doping is an efficient method for modifying the electrical property of the p‐type semiconductor CuI. However, adjustment of the hole density is still challenging. Using sputtering and spin coating techniques, well‐controlled S‐doping of CuI thin films has been realized. The spin‐coated samples present a single (111) out‐of‐plane orientation and very high crystallinity, which is comparable with previously reported epitaxial CuI thin films. The sputtered thin films have advantages in surface morphology and conductivity. Substituting S for I can achieve efficient acceptor doping of CuI for both the physical and chemical growth methods. The highest conductivity of CuI appears at 2.0 at% of S doping, and the doping efficiency is influenced by the self‐compensation effect. [ABSTRACT FROM AUTHOR]

Bone quality is increasingly being recognized in the assessment of fracture risk. Nonenzymatic collagen cross‐linking with the accumulation of advanced glycation end products stiffens and embrittles collagen fibers thus increasing bone fragility. Echogenicity is an ultrasound (US) parameter that provides information regarding the skin collagen structure. We hypothesized that both skin and bone collagen degrade in parallel fashion. Prospectively collected data of 110 patients undergoing posterior lumbar fusion was analyzed. Preoperative skin US measurements were performed in the lumbar region to assess dermal thickness and echogenicity. Intraoperative bone biopsies from the posterior superior iliac spine were obtained and analyzed with confocal fluorescence microscopy for fluorescent advanced glycation endproducts (fAGEs). Pearson's correlation was calculated to examine relationships between (1) US and fAGEs, and (2) age and fAGEs stratified by sex. Multivariable linear regression analysis with adjustments for age, sex, body mass index (BMI), diabetes mellitus, and hemoglobin A1c (HbA1c) was used to investigate associations between US and fAGEs. One hundred and ten patients (51.9% female, 61.6 years, BMI 29.8 kg/m2) were included in the analysis. In the univariate analysis cortical and trabecular fAGEs decreased with age, but only in women (cortical: r = −0.32, p = 0.031; trabecular: r = −0.32; p = 0.031). After adjusting for age, sex, BMI, diabetes mellitus, and HbA1c, lower dermal (β = 1.01; p = 0.012) and subcutaneous (β = 1.01; p = 0.021) echogenicity increased with increasing cortical fAGEs and lower dermal echogenicity increased with increasing trabecular fAGEs (β = 1.01; p = 0.021). This is the first study demonstrating significant associations between skin US measurements and in vivo bone quality parameters in lumbar fusion patients. As a noninvasive assessment tool, skin US measurements might be incorporated into future practice to investigate bone quality in spine surgery patients. [ABSTRACT FROM AUTHOR]

The effect of birefringence in anisotropic materials has been a long‐term issue for polarized Raman scattering. In this work, the polarization‐dependent Raman scattering in anisotropically birefringent materials is modeled with birefringence considered in the fundamental polarization selection rule. The birefringence‐induced polarization transformation is treated as a tensor in the calculation of Raman scattering intensity. The validity of this theory is further demonstrated in experiments by taking angle‐resolved polarized Raman measurements on the basal and cross planes of α‐MoO3—a typical biaxial van der Waals crystal with strong in‐plane and out‐of‐plane anisotropy. The anomalous angular dependency of polarized Raman scattering intensity can be well reproduced by the modified theoretical model with fitted real‐valued Raman tensors and birefringence‐related parameters. It can be concluded that this work can provide a valuable reference and guidance for quantitative analyses of anisotropic materials by using polarization‐resolved Raman scattering spectroscopy. [ABSTRACT FROM AUTHOR]

High‐performance thermal interface materials are in increasing demand because of the problems of dissipating heat from high‐power computing devices. To solve this problem, this study proposes a method of microstructural design through uniaxial compression of graphene foam along the out‐of‐plane direction. The thermal conductivity of the composites with graphene foam shows an anisotropic growth along the direction of the compressive strain. The in‐plane thermal conductivity increases significantly from 0.189 to 1.669 W m−1 K−1 at an extremely low filler content of 2.24 vol%, whereas the out‐of‐plane thermal conductivity increases slightly to 0.303 W m−1 K−1. Moreover, the samples exhibit outstanding in‐plane thermal conductivity enhanced efficiency, which reaches 415.19% at a 1.29 vol% graphene content. The mechanism of anisotropic thermal conductivity enhancement is revealed by constructing a theoretical model based on a geometrical unit cell simplified from the morphology of graphene foam. This uniaxial compression method of a 3 structure provides a novel direction for improving the thermal conductivity of polymeric matrix composites more controllably. [ABSTRACT FROM AUTHOR]

2D transition metal dichalcogenides have shown great potential for next‐generation microelectronic devices owing to their ability to prolong the life of Moore's law by mitigating the short‐channel effect. Recently, many efforts have been made on doping 2D films to create p‐n junctions, in which plasma implantation has been placed great expectations due to its CMOS process compatibility. However, ultrathin vertical 2D p‐n homostructure with excellent rectification behaviors have rarely been studied so far. Herein, MoS2 van der Waals p‐n homojunctions are fabricated by highly efficient N2 plasma implantation. Kelvin probe force microscope reveals the surface potential difference of ≈130 mV between n‐MoS2 and p‐MoS2. The fabricated field‐effect transistor (FET) presents a high rectification ratio up to 3.1 × 10–3 at the gate bias VGS = 20 V, which is over 20 times larger than that of the vertical homojunction obtained by surface chemical doping. The forward current is mainly dominated by both the interlayer recombination and band‐to‐band tunneling, while the ultra‐low reverse current in the order of 10 pA is governed by direct tunneling. The results demonstrate a new CMOS‐compatible way to fabricate vertical 2D homojunction, which is the basic structure of many low‐dimensional microelectronic devices. [ABSTRACT FROM AUTHOR]

Over the past decades, the booming development of flexible electronics in various fields, e.g., Internet of Things and epidermal electronics, requires the support of a reliable manufacturing approach, where circuit patterning is the core. Although the existing circuit patterning methods represented by photochemical etching and direct printing process have shown good performance, they still cannot satisfy today's demands on environmental friendliness and cost‐efficiency concurrently. Here, by regulating the milling force distribution on the flexible workpiece with a grooved soft template, this work presents a milling‐based patterning technique that is compatible with roll‐to‐roll technology, to achieve continuous selective removal of conductive material in one step and hence directly pattern electrical circuits on aluminum clad laminates. Without introducing any chemicals, this new approach generates no emission but recyclable aluminum scraps. Moreover, the process shows a considerable processing speed of 30 m min−1, and costs only commercial aluminum clad laminates. Examples of device fabrication include a radio frequency identification tag and a temperature sensor. Ultimately, this work can bring an eco‐friendly, economic and high‐throughput approach to flexible electronics manufacturing. [ABSTRACT FROM AUTHOR]

A Soft Reconfigurable Circulator Enabled by Magnetic Liquid Metal Droplet for Multifunctional Control of Soft Robots. Adv. Sci. 2023, 10, 2300935In the part of the "Acknowledgements" section, the text "The work was funded by the National Science Foundation of China (nos. 52188162 and U1613204)" was incorrect. This should read: "The work was funded by the National Science Foundation of China (nos. 52188102 and U1613204)"We apologize for this error.By Yi Xu; Jiaqi Zhu; Han Chen; Haochen Yong and Zhigang WuReported by Author; Author; Author; Author; Author [Extracted from the article]

Being minimally invasive and highly effective, radiofrequency ablation (RFA) is widely used for small‐sized malignant tumor treatment. However, in clinical practice, a large number of tumors are found in irregular shape, while the current RFA devices are hard to control the morphologic appearance of RFA lesions on demand, which usually ends up with unnecessarily excessive tissue ablation and subsequently often brings irreversible damage to the organs' functions. Herein, active cannulas for each of the individually controlled subelectrodes to achieve an on‐demand shape morphing and thus conformal RFA lesion are introduced. The target shape as well as the length of inserted subelectrodes can be precisely controlled by tuning the active stylets and cannulas. What's more, owing to independent movement and energy control of each subelectrodes, the electrode is shown to be not only efficient enough to accomplish accurate trajectory control to target tissue in a single insertion, but also adaptive enough to ablate target tissues with diverse morphologic appearances and locations. On‐demand conformal ablation of target tissue is demonstrated as well under the guidance of ultrasound imaging with the device. Potentially, the RFA electrode is a promising minimally invasive treatment of malignant tumors in future clinical practice. An interactive preprint version of the article can be found at: https://www.authorea.com/doi/full/10.22541/au.164019293.38729522. [ABSTRACT FROM AUTHOR]

To understand the process window of bias‐enhanced nucleation of diamond, it is important to study surface modifications of Ir substrates that occur under different conditions. Herein, various microstructures formed on Ir substrates are reported. The first microstructure contains rectangular particles with a size of several hundred nanometers obtained at a relatively high pressure of 12.5 kPa and a high temperature of 880 °C; these particles consist of epitaxially grown Ir3Si species. The second microstructure includes particles oriented along the [110] direction; these particles, however, consist of etched Ir pillars with a height of 400 nm when the substrate temperature increases to 1110 °C. Both microstructures form because of Ir sputtering due to the bombardment of energetic charged ions and the transport of Ir surface atoms. This study demonstrates two types of surface modifications under different bias‐enhanced nucleation conditions and provides a method for preparing an epitaxial Ir–Si compound that can be applied in various silicon‐based electronic devices. [ABSTRACT FROM AUTHOR]

BACKGROUND: Diatomite and biochemical fulvic acid were used as raw materials to prepare biochemical fulvic acid‐modified diatomite using by the sol–gel method. The structure and properties of samples were investigated by X‐ray diffraction, scanning electron microscopy, etc. The effects of solution pH and reaction temperature on the adsorption performance of adsorption materials were evaluated by taking tetracycline as the target pollutant. The adsorption kinetics, adsorption rate mechanism and adsorption isotherm of tetracycline were revealed. RESULTS: The results showed that the main form of diatomite is amorphous SiO2. The surface and channels of diatomite were loaded with biochemical fulvic acid, and the specific surface area of the modified material increased from 9.182 to 13.774 m2 g−1, while the average pore size decreased from 10.972 to 7.15 nm. The pH of the tetracycline solution was 5 and the initial concentration was 20 mg L−1; the adsorption capacity of the modified sample increased 1.93‐fold to 29.84 mg g−1. When the adsorption temperature was increased from 10 to 60 °C, the adsorption capacity of the modified material increased nearly fourfold, reaching 78.8 mg g−1. CONCLUSION: Quasi‐second‐order reaction kinetics has a correlation coefficient R2 of 0.993, which suggests a good fit to the adsorption process of tetracycline by the modified diatomite. Both Freundlich and Redlich–Peterson adsorption isotherm equations can elucidate the adsorption process of the composites. The adsorption is heterogeneous adsorption on the surface, mainly multi‐layer adsorption and electrostatic attraction adsorption. © 2022 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Flexible electronics attract extensive interest in academic research and commercial markets. Fabrication of electronics on flexible substrates remains a great challenge though. Mostly, components of electronics including metal electrodes and functional materials are created via physical vapor deposition (PVD) in conjunction with photolithography. Nevertheless, ultrathin polymeric substrates are susceptible to environmental shocks during PVD. In this paper, a full‐solution process for fabricating copper (Cu) electrodes of micrometer (µm) scale on polymeric substrates is realized under ambient conditions via photolithography‐patterning polymer‐assisted metal deposition (pp‐PAMD). Apart from low fabrication costs from instruments capitals and energy inputs, these flexible Cu electrodes show superior mechanical durability. As a proof‐of‐concept application, large‐quantity and high‐quality indium selenide (InSe) nanoflakes, obtained by liquid electrochemical intercalation and ultrasonic exfoliation, are deposited on top of flexible Cu electrodes to construct all‐solution‐processed flexible photodetectors. The as‐fabricated flexible InSe photodetectors demonstrate excellent operational stability during 5000 continuous laser on‐off cycles, shelf stability under ambient storage conditions without encapsulation for 20 weeks, thermal viability from 90 to 360 K, and flexible stability upon mechanical bending at a radius (r) of 2 mm for 5000 cycles. This work implies the potential of pp‐PAMD technique and prospects of solution processes in fabricating flexible electronics. [ABSTRACT FROM AUTHOR]

Background: The majority of adolescents and young adults (AYA) who use cannabis also use alcohol. Although cannabis use is increasing in the United States (US), it is not known whether the increase contributes to either increased co‐use of alcohol and cannabis (e.g., complementarity) or replacement of alcohol with cannabis (e.g., substitution). The current study estimated the prevalence of alcohol use by cannabis use status among US AYA ages 12 to 25 in 2018 and trends in alcohol use by cannabis use status from 2002 to 2018. Methods: Data were drawn from the 2002 to 2018 National Survey on Drug Use and Health public use data files. The analytic sample included AYA ages 12 to 25 (2018 sample, n = 26,924; total combined sample 2002 to 2018, n = 576,053). Linear and logistic regression models were used to estimate past‐month alcohol use, daily alcohol use, and average quantity of alcohol consumed among AYA with and without past‐month cannabis use from 2002 to 2018. Results: In 2018, any alcohol use and daily alcohol use were significantly more common among AYA who used cannabis use than those who did not use cannabis. Overall, any alcohol use, daily alcohol use, and average drinks per day declined from 2002 to 2018 among AYA irrespective of recent cannabis use. However, the decline in any alcohol use, daily alcohol use, and average alcohol drinks per day was more rapid among AYA who used cannabis (daily and nondaily) than those who did not use cannabis. The rate of decline in average alcohol drinks per day was also higher among AYA with daily compared to nondaily cannabis use. Conclusions: Even with declines in alcohol use over time, drinking is much more common among AYA who report cannabis than those without recent cannabis use, which is consistent with complementarity. Yet, because the decline in alcohol use has been more rapid among AYA who use cannabis, there is also evidence of substitution. Thus, the current data on alcohol and cannabis use are consistent with both complementarity and substitution. However, these relationships may change as cannabis legalization expands over time. [ABSTRACT FROM AUTHOR]

Background and Objective: Cementum is a part of the periodontium and anchors periodontal ligaments to the alveolar bone. Cementoblasts are responsible for the cementum formation via matrix deposition and subsequently mineralization. Thus, exploring novel mechanisms underlying the function of cementoblast contributes to the treatment of cementum damage. Recently, circRNA Lrp6 (circLRP6) has been of interest due to its active role in cell differentiation, but its potential role in cementoblast differentiation remains unclear. Herein, we attempted to elucidate the role of circLRP6 in cementoblast differentiation and clarify any associated mechanisms. Material and Methods: The mRNA expressions of circLRP6, miR‐145a‐5p, zinc finger E‐box binding homeobox 2 (Zeb2), runt‐related transcription factor 2 (Runx2), osteopontin (Opn), and bone sialoprotein (Bsp) were evaluated by qRT‐PCR. The protein levels of Zeb2 were measured by Western blot. Bioinformatic analysis and dual‐luciferase reporter assays were used to test the potential binding targets of miR‐145a‐5p. The differentiation potentials of the cementoblasts were assessed by Alkaline phosphatase (ALP) staining, ALP activity assay, Alizarin red S (ARS) staining, and quantification. Results: In this study, circLRP6 was significantly upregulated in cementoblast differentiation. Furthermore, circLRP6 knockdown inhibited ALP levels, reduced calcium nodule formation and the expression of Runx2, Opn, and Bsp. Mechanically, bioinformatic analysis and dual‐luciferase reporter assays confirmed miR‐145a‐5p was a potential binding target of circLRP6. miR‐145a‐5p can negatively regulate cementoblast differentiation. Subsequently, bioinformatic analysis and dual‐luciferase reporter assays confirmed Zeb2 was a potential miR‐145a‐5p target. miR‐145a‐5p overexpression resulted in a downregulation of Zeb2. Furthermore, Zeb2 inhibition partially reversed the effect of circLRP6 during cementoblast differentiation. Conclusion: Taken together, circLRP6 appears to modulate cementoblast differentiation by antagonizing the function of miR‐145a‐5p, thereby increasing Zeb2. This study serves as a stepping stone for the potential development of an approach to promote cementum formation. [ABSTRACT FROM AUTHOR]

The development of advanced transparent electrical devices has created an urgent demand for wide‐bandgap transparent semiconductors. Herein, a simple, low‐cost ink‐based method for preparation of LaCuOS is introduced. High transmittances of above 60% and 65% at visible (380–750 nm) and mid‐infrared (3–5 μm) wavelengths, respectively, are obtained with LaCuOS films prepared using this ink. With these films, the carrier concentration is above 1018 cm−3, while a conductivity of 5 S cm−1 is obtained, electrical properties that are both higher than those of most transparent p‐type semiconductors. From density functional theory calculations, it is surmised that the improved conductivity of the LaCuOS is a result of its high carrier concentration, and its hole effective mass, which is smaller than that of typical transparent p‐type semiconductors. [ABSTRACT FROM AUTHOR]

The rapid development of train transportation toward higher speed and heavier load requires superior wheel materials with high strength and toughness. Herein, a 20Mn2SiNiMo bainitic wheel steel is developed and bainitic wheels are produced. The quenching and tempering process of bainitic wheels is studied considering the bainitic ferrite content and stability of retained austenite (RA). The quenching process includes water spraying and air cooling. Proeutectoid ferrite can be suppressed during the water‐spraying process. During air cooling, the bainitic ferrite transformation is promoted and the stability of RA is improved with the extension of cooling time. Corresponding microstructure of as‐quenched steel at wheel rim is bainite with different morphologies, martensite, and RA. The evolution of RA at lower and higher tempering temperatures is dominated by carbon enrichment and carbon consumption, respectively. Yield strength of bainitic wheel steel mainly comes from body‐centered cubic phase (containing martensite and bainitic ferrite). The increase of dislocation density and the decrease of effective grain size are beneficial for yield strength improvement. Bainitic packets with various direction, deformation‐induced martensite transformation of RA, and plastic deformation all play an important role in enhancing the toughness of bainitic wheel steel. [ABSTRACT FROM AUTHOR]

Objectives: Acute lung injury (ALI) not only affects pulmonary function but also leads to intestinal dysfunction, which in turn contributes to ALI. Mesenchymal stem cell (MSC) transplantation can be a potential strategy in the treatment of ALI. However, the mechanisms of synergistic regulatory effects by MSCs on the lung and intestine in ALI need more in‐depth study. Materials and methods: We evaluated the therapeutic effects of MSCs on the murine model of lipopolysaccharide (LPS)‐induced ALI through survival rate, histopathology and bronchoalveolar lavage fluid. Metagenomic sequencing was performed to assess the gut microbiota. The levels of pulmonary and intestinal inflammation and immune response were assessed by analysing cytokine expression and flow cytometry. Results: Mesenchymal stem cells significantly improved the survival rate of mice with ALI, alleviated histopathological lung damage, improved intestinal barrier integrity, and reduced the levels of inflammatory cytokines in the lung and gut. Furthermore, MSCs inhibited the inflammatory response by decreasing the infiltration of CD8+ T cells in both small‐intestinal lymphocytes and Peyer's patches. The gut bacterial community diversity was significantly altered by MSC transplantation. Furthermore, depletion of intestinal bacterial communities with antibiotics resulted in more severe lung and gut damages and mortality, while MSCs significantly alleviated lung injury due to their immunosuppressive effect. Conclusions: The present research indicates that MSCs attenuate lung and gut injury partly via regulation of the immune response in the lungs and intestines and gut microbiota, providing new insights into the mechanisms underlying the therapeutic effects of MSC treatment for LPS‐induced ALI. [ABSTRACT FROM AUTHOR]

Endowed with the expected visions for future surgery, minimally invasive surgery (MIS) has become one of the most rapid developing areas in modern surgery. Soft robotics, which originates from interdisciplinary advances in materials, fabrication, and electronics, featuring better adaptability and safer interaction, holds great promises in addressing current technical challenges in MIS, which are difficult to be solved with current rigid robotic technologies. For the first time, herein, the expected characteristics of next‐generation MIS from the surgeons' perspectives are analyzed and the recent progress of soft surgical instruments from three different aspects is comprehensively summarized: engineering design, fabrication techniques, and human–robot interaction. Perspectives of next‐generation soft surgical robots are then discussed, where some exciting possibilities are emphasized. It is believed that further developments of intelligent soft robotics enable the next‐generation MIS to agilely navigate to the target and conduct dexterous diagnostic or therapeutic procedures without any trade‐offs in invasiveness and ultimately be a propitious solution for future surgery. [ABSTRACT FROM AUTHOR]

The mechanical properties of titanium nitride (TiN) and related multicomponent films have been studied for decades. However, the virtues of TiN(100) coatings themselves and of their binding ability to Si(100) substrate are to be studied to ensure the application of transition layer for upper sediment, while the synergism between various growth parameters needs a further understanding. Herein, we present the mechanical properties of TiN(100), (111) planes and binding nature of Si(100)/TiN(100) interface by first principle. Then, TiN(100) films were epitaxially grown by pulse laser deposition (PLD) method on Si wafers under different conditions, and the structures, valence states, and properties were tested. We have obtained a high‐quality deposit with the hardness of ~31 GPa, which can firmly adhere on the substrate with high structural integrity, thus can be employed for further deposition of other oxide films. In general, higher substrate temperature and laser energy will improve the quality of the film. We anticipate that this study can give some hints on the properties of different crystal faces and the relationship of preparation variables during growing process. [ABSTRACT FROM AUTHOR]

Diamond powders with high hydrophobicity are prepared by etching graphite plates using a hydrogen/argon (H2/Ar) plasma. The morphology and size of the diamond powders are found to vary with the proportion of Ar in H2 from 0% to 50%. Wettability is measured using water contact angle (WCA) measurements giving values between 129.7° and 146.9°. The high hydrophobicity can be ascribed to the aggregated structure of the as‐grown diamond powders. To check this assumption, the aggregated diamond powders are separated into individual particles by mechanical grinding; then, the WCAs of separated as‐grown diamond powders and commercial dispersed diamond powders are compared. The separated diamond surfaces show the lower WCAs of 99.68° and 96.96°. The surface of the aggregated diamond powders also exhibits high adhesion to water. The diamond surface grown in 2% Ar suspends 40 μL of water under a tilt angle of 180°. Such aggregated diamond powders are promising for no‐loss liquid transportation. [ABSTRACT FROM AUTHOR]

Two‐dimensional (2D) semiconducting boron nanosheets (few‐layer borophene) have been theoretically predicted, but their band gap tunability has not been experimentally confirmed. In this study, hydroxy‐functionalized borophene (borophene‐OH) with tunable band gap was fabricated by liquid‐phase exfoliation using 2‐butanol solvent. Surface‐energy matching between boron and 2‐butanol produced smooth borophene, and the exposed unsaturated B sites generated by B−B bond breaking during exfoliation coordinated with OH groups to form semiconducting borophene‐OH, enabling a tunable band gap of 0.65–2.10 eV by varying its thickness. Photoelectrochemical (PEC) measurements demonstrated that the use of borophene‐OH to fabricate working electrodes for PEC‐type photodetectors significantly enhanced the photocurrent density (5.0 μA cm−2) and photoresponsivity (58.5 μA W−1) compared with other 2D monoelemental materials. Thus, borophene‐OH is a promising semiconductor with great optoelectronic potential. [ABSTRACT FROM AUTHOR]

A Cu‐catalyzed enantioselective hydroamination of α,β‐unsaturated carbonyl compounds for the synthesis of β‐amino acid derivatives was achieved through ligand‐controlled reversal of the hydrocupration regioselectivity. While the hydrocupration of α,β‐unsaturated carbonyl compounds to form α‐cuprated species has been extensively investigated, we report herein that, in the presence of an appropriate ancillary chiral ligand, the opposite regiochemistry can be observed for cinnamic acid derivatives, leading to the delivery of the copper to the β‐position. This copper can react with an electrophilic aminating reagent, 1,2‐benzisoxazole, to provide enantioenriched β‐amino acid derivatives, which are important building blocks for the synthesis of natural products and bioactive small molecules. [ABSTRACT FROM AUTHOR]

The placenta and umbilical cord are pre‐eminent candidate sources of mesenchymal stem cells (MSCs). However, placenta‐derived MSCs (P‐MSCs) showed greater proliferation capacity than umbilical cord‐derived MSCs (UC‐MSCs) in our study. We investigated the drivers of this proliferation difference and elucidated the mechanisms of proliferation regulation. Proteomic profiling and Gene Ontology (GO) functional enrichment were conducted to identify candidate proteins that may influence proliferation. Using lentiviral or small interfering RNA infection, we established overexpression and knockdown models and observed changes in cell proliferation to examine whether a relationship exists between the candidate proteins and proliferation capacity. Real‐time quantitative polymerase chain reaction, western blot analysis, and immunofluorescence assays were conducted to elucidate the mechanisms underlying proliferation. Six candidate proteins were selected based on the results of proteomic profiling and GO functional enrichment. Through further validation, yes‐associated protein 1 (YAP1) and β‐catenin were confirmed to affect MSCs proliferation rates. YAP1 and β‐catenin showed increased nuclear colocalization during cell expansion. YAP1 overexpression significantly enhanced proliferation capacity and upregulated the expression of both β‐catenin and the transcriptional targets of Wnt signaling, CCND1, and c‐MYC, whereas silencing β‐catenin attenuated this influence. We found that YAP1 directly interacts with β‐catenin in the nucleus to form a transcriptional YAP/β‐catenin/TCF4 complex. Our study revealed that YAP1 and β‐catenin caused the different proliferation capacities of P‐MSCs and UC‐MSCs. Mechanism analysis showed that YAP1 stabilized the nuclear β‐catenin protein, and also triggered the Wnt/β‐catenin pathway, promoting proliferation. [ABSTRACT FROM AUTHOR]

Objective: miR‐146a is widely induced during the immune response. However, little is known about the biogenesis, function and mechanism of miR‐146a in cementoblasts during the pathogenesis of periodontitis. This study aimed to investigate the effects of miR‐146a in murine cementoblast‐derived OCCM‐30 cells following IL‐1β stimulation. Materials and methods: OCCM‐30 cells were cultured and exposed to IL‐1β. IL‐6, IL‐1β and TNF‐α, and miR‐146a‐5p expression was assessed by qRT‐PCR. Mimics/inhibitors were transiently transfected into cells to determine the function of miR‐146a‐5p. Signalling pathways including p38 MAPK, ERK1/2 and NF‐κB were studied by using specific inhibitors. The indicated proteins were measured by Western blot analysis and ELISA. Results: In IL‐1β‐stimulated OCCM‐30 cells, the expression levels of miR‐146a‐5p along with IL‐6 and IL‐1β increased in a time‐dependent manner. The ERK1/2, p38 MAPK and NF‐κB pathway were activated upon IL‐1β stimulation. Blocking the NF‐κB pathway decreased IL‐6, IL‐1β and miR‐146a‐5p expression. The overexpression of miR‐146a‐5p reduced IL‐6 and IL‐1β expression, while the inhibition of miR‐146a‐5p increased IL‐6 and IL‐1β expression in IL‐1β‐treated OCCM‐30 cells. miR‐146a‐5p attenuated IL‐6 and IL‐1β expression via the IRAK1/TRAF6 pathway. Conclusion: This study suggested that miR‐146a‐5p attenuates IL‐1β‐induced inflammatory factors in cementoblast‐derived cell line. [ABSTRACT FROM AUTHOR]

Infrared (IR) antireflective and protective coating (ARPC) is crucial for the development of IR precision guidance and detection systems for practical applications, attracting significant attention from strong military powers worldwide. Extreme application environments require functional film to have high surface hardness, excellent stability, and good adhesion. Further, multispectral optical transmission demands extremely low absorption in the visible and far‐IR bands, adjustability of optical performance parameters, and optical antireflection in particular bands, and radar stealth requires a relatively low resistance. Herein, recent experimental progress on IR ARPC is reviewed and future opportunities are discussed. Based on the application environment and window substrate, various ARPC material systems, including diamond‐like C, Ge carbide, B phosphide, and oxides, have been developed. These systems are capable of fulfilling different application demands and demonstrate exciting application prospects. To promote the development of IR ARPC material technology, the basic characteristics, fabrication techniques, microscale structures, optical properties, mechanical properties, and development and applications of typical IR ARPC materials from a comprehensive and systematic perspective are presented. [ABSTRACT FROM AUTHOR]

Objective: Irisin is a newly identified exercise‐induced myokine which can affect glucose metabolism and cortical bone mass and strength. However, the influence of irisin on cementoblasts remains largely unknown. Material and methods: An immortalized mouse cementoblast cell line OCCM‐30 was used in this study. Cementoblast differentiation markers and PGC‐1α in cells cultured with mineral induction medium were evaluated by qRT‐PCR. Cementoblast mineralization was evaluated by alizarin red staining. Differentiation markers and the activity of p38 MAPK pathway under irisin stimulation were assessed by qRT‐PCR or Western blot analysis. p38 MAPK pathway inhibitor SB203580 or p38 siRNA was used to further identify the regulatory mechanism. Cell proliferation treated with irisin was examined by CCK‐8 method. Results: The expression of Runx2, osterix, ALP, and PGC‐1α was up‐regulated consistently under mineral induction. The formation of mineralized nodules was increased by irisin. Runx2, osterix, ALP, and osteocalcin were obviously up‐regulated under irisin stimulation as well as the activity of p38 MAPK pathway. When pretreated with SB203580 or p38 siRNA before irisin stimulation, the irisin‐induced differentiation was distinctly suppressed. OCCM‐30 cell proliferation was enhanced when treated with high‐dose irisin for long time. Conclusion: Irisin can promote the differentiation of cementoblasts via p38 MAPK pathway. [ABSTRACT FROM AUTHOR]

Aims: To estimate trends in the prevalence of cannabis use and risk perceptions of cannabis use from 2005 to 2017 among United States people with and without depression. Design Linear time trends of the prevalence of any, daily and non‐daily past 30‐day cannabis use and perceived great risk associated with regular cannabis use (outcome variables) among people with and without past‐year depression were assessed using logistic regression with survey year as the predictor. All analyses were adjusted for gender, age, race/ethnicity and income; models assessing time trends of cannabis use prevalence were also adjusted for perceived risk. Setting: The United States: National Survey on Drug Use and Health, an annual cross‐sectional survey, 2005–17 public use data files. Participants: A total of 728 691 people aged ≥ 12 years. Measurements Self‐report of any, daily and non‐daily past 30‐day cannabis use and perceived great risk associated with regular cannabis use. Findings The prevalence of any, daily and non‐daily cannabis use in the past month was higher among those with depression versus those without [e.g. 2017 for any use: 18.94 versus 8.67%; adjusted odds ratio (aOR) = 2.17 (95% confidence interval (CI) = 1.92, 2.45)]. Any, daily and non‐daily cannabis use increased among people with and without depression from 2005 to 2017, yet the increase in any (aORs = 1.06 versus 1.05; P = 0.008) and daily (aORs = 1.10 versus 1.07; P = 0.021) cannabis use adjusted for socio‐demographic characteristics was more rapid among those with depression. Perception of great risk associated with regular cannabis use was significantly lower among those with depression (P < 0.001) and decreased significantly more rapidly over the study period among people with depression, compared with those without (aORs = 0.89 versus 0.92; P < 0.001). Conclusions: The prevalence of cannabis use in the United States increased from 2005 to 2017 among people with and without depression and was approximately twice as common among those with depression. People with depression experienced a more rapid decrease in perception of risk, which may be related to the more rapid increase in any and daily past‐month cannabis use in this group. [ABSTRACT FROM AUTHOR]

Natural convection heat transfer of molten salt is widely used in concentrated solar plants, such as the solar receiver, the single‐tank thermal energy storage system, and so forth. Meanwhile, adding nanoparticles into molten salts to form nanofluids can obviously improve the thermal properties of the working medium. However, the heat transfer performance of the molten salt‐based nanofluids has not been investigated extensively, and the action mechanism between base fluids and nanoparticles is still unclear. In the present work, a lattice Boltzmann model considering fluid and nanoparticles as two different phases was developed, and various interactions were taken into consideration. Meanwhile, the effects of nanoparticle concentrations, aspect ratios of the rectangular vessel, and Ra on natural convection heat transfer of solar salt‐based SiO2 nanofluids were analysed. The results show that specific heat capacity contributes substantially to heat transfer for all aspect ratios, and the maximum enhancement of natural convection heat transfer is obtained with a mass fraction of 1.0%. However, increase in Ra intensifies the effect of viscosity and weakens the heat transfer enhancement. Through interaction analysis, it indicated that nanoparticles tend to be driven to the top area of the rectangular vessel by temperature difference, driving force, and drag force. Meanwhile, a Nu enhancement contour was provided to optimize the design of a single energy storage tank. [ABSTRACT FROM AUTHOR]

Summary: Background: Hepatitis B core‐related antigen (HBcrAg) is a viral marker for the development of cirrhosis and hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB). However, the relationship between HBcrAg and HBV recurrence after liver transplantation (LT) is unclear. Aim: To investigate the correlation of serum HBcrAg level with HBV recurrence post‐LT to evaluate the prognostic role of the pre‐LT HBcrAg level. Methods: This retrospective cohort study enrolled 357 CHB patients who received LT for a median of 36.6 months. Univariate and multivariate analyses and time‐dependent receiver operating characteristic (ROC) curves for markers associated with HBV recurrence were analysed. Results: 48 patients (13.4%) had HBV recurrence after LT. HBcrAg, detectable HBV DNA, HCC and HCC recurrence were associated with HBV recurrence. In a multivariate analysis, HBcrAg level was independently associated with HBV recurrence, and the relationship between HBcrAg level and incident HBV recurrence was significant and graded (HR: 3.17 per unit; 95% CI: 1.97‐5.11; P for trend < .001). Additionally, HBcrAg level was superior to HBV DNA level in predicting HBV recurrence by time‐dependent ROC analysis. Patients with an HBcrAg ≥ 5.0 log U/mL had a significantly higher 5‐year cumulative recurrence rate than those with an HBcrAg < 5.0 log U/mL (37.6% vs 6%, P < .001); the adjusted hazard ratio was 5.27 (95% CI 2.47‐11.25, P < .001). Conclusion: An elevated serum HBcrAg level was independently associated with the risk of HBV recurrence in patients with CHB after LT. [ABSTRACT FROM AUTHOR]

Oxime, whose dynamic nature was reported to be switchable between ON/OFF by tuning the acidity, is employed in a novel type of dynamic covalent approach that is amenable to use in water for self‐assembly of purely organic molecules with complex topology. In strongly acidic conditions, the dynamic nature of oxime is turned ON, allowing occurrence of error‐checking and therefore a catenane and a macrocycle self‐assembled in high yields. In neutral conditions, oxime ceases to be dynamic, which helps to trap the self‐assembled products even when the driving forces of their formation are removed. We envision that this switchable behaviour might help, at least partially, to resolve a commonly encountered drawback of dynamic covalent chemistry, namely that the intrinsic stability of the self‐assembled products containing dynamic bonds, such as imine or hydrazone, are often jeopardized by their reversible nature. An off and on relationship: In strongly acidic aqueous solutions, the oxime bond is dynamic and allows both a catenane and a macrocycle to self‐assemble in relatively high yields. The dynamic nature of oxime linkage could be turned OFF almost fully in neutral conditions, making the self‐assembled catenane kinetically inert in both solid state and solution at elevated temperatures or during chromatography and counteranion exchange. [ABSTRACT FROM AUTHOR]

A key challenge in advancing the design of hybrid nanostructures (HNs) lies in the difficulty in mastering the principle of selected hybrid formation, which is complicated not only by the size and shape variations of nanoparticles but also by the interfacial phenomena associated with surface ligands. Here this study elaborates the formation mechanism of HNs by a combined experimental and theoretical study employing multiscale simulations and shows how molecular information encoded on particle surface can be transferred into distinct composite patterns. The emergence of different HNs is found to be not only related to ligand binding strengths affecting the reaction kinetics but also the ligand-ligand interactions responsible for phase segregation. Unexpectedly, the sulfidation of Ag nanoparticles co-stabilized by citrate/gallic acid with different molar ratios constantly produces heterodimers with faster reaction rate than the formation of core-shell structures when they are solely coated by citrate or gallic acid. The surprising result originates from the phase separation of two short surface ligands with large contrast in binding strengths as indicated by photoluminescence spectra and supported by the dissipative particle dynamics simulations. Hierarchical HNs consisting of a heterodimer shell with built-in hot spots can be further synthesized using Au@Ag core-shell particles with mixed surface layers. [ABSTRACT FROM AUTHOR]