다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Over the past few decades, researchers have established artificial enzymes as highly stable and low-cost alternatives to natural enzymes in a wide range of applications. A variety of materials including cyclodextrins, metal complexes, porphyrins, polymers, dendrimers and biomolecules have been extensively explored to mimic the structures and functions of naturally occurring enzymes. Recently, some nanomaterials have been found to exhibit unexpected enzyme-like activities, and great advances have been made in this area due to the tremendous progress in nano-research and the unique characteristics of nanomaterials. To highlight the progress in the field of nanomaterial-based artificial enzymes (nanozymes), this review discusses various nanomaterials that have been explored to mimic different kinds of enzymes. We cover their kinetics, mechanisms and applications in numerous fields, from biosensing and immunoassays, to stem cell growth and pollutant removal. We also summarize several approaches to tune the activities of nanozymes. Finally, we make comparisons between nanozymes and other catalytic materials (other artificial enzymes, natural enzymes, organic catalysts and nanomaterial-based catalysts) and address the current challenges and future directions (302 references).

Nanomaterials with enzyme-like characteristics (nanozymes): next-generation artificial enzymes

Hollow micro-/nanostructures are of great interest in many current and emerging areas of technology. Perhaps the best-known example of the former is the use of fly-ash hollow particles generated from coal power plants as partial replacement for Portland cement, to produce concrete with enhanced strength and durability. This review is devoted to the progress made in the last decade in synthesis and applications of hollow micro-/nanostructures. We present a comprehensive overview of synthetic strategies for hollow structures. These strategies are broadly categorized into four themes, which include well-established approaches, such as conventional hard-templating and soft-templating methods, as well as newly emerging methods based on sacrificial templating and template-free synthesis. Success in each has inspired multiple variations that continue to drive the rapid evolution of the field. The Review therefore focuses on the fundamentals of each process, pointing out advantages and disadvantages where appropriate. Strategies for generating more complex hollow structures, such as rattle-type and nonspherical hollow structures, are also discussed. Applications of hollow structures in lithium batteries, catalysis and sensing, and biomedical applications are reviewed.

Hollow Micro-/Nanostructures: Synthesis and Applications**

Supercapacitors have drawn considerable attention in recent years due to their high specific power, long cycle life, and ability to bridge the power/energy gap between conventional capacitors and batteries/fuel cells. Nanostructured electrode materials have demonstrated superior electrochemical properties in producing high-performance supercapacitors. In this review article, we describe the recent progress and advances in designing nanostructured supercapacitor electrode materials based on various dimensions ranging from zero to three. We highlight the effect of nanostructures on the properties of supercapacitors including specific capacitance, rate capability and cycle stability, which may serve as a guideline for the next generation of supercapacitor electrode design.

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Supercapacitor electrode materials: nanostructures from 0 to 3 dimensions

1: Magnetic Particles: Preparation, Properties and Applications: M. Ozaki. 2: Maghemite (gamma-Fe2O3): A Versatile Magnetic Colloidal Material C.J. Serna, M.P. Morales. 3: Dynamics of Adsorption and Oxidation of Organic Molecules on Illuminated Titanium Dioxide Particles Immersed in Water M.A. Blesa, R.J. Candal, S.A. Bilmes. 4: Colloidal Aggregation in Two-Dimensions A. Moncho-Jorda, F. Martinez-Lopez, M.A. Cabrerizo-Vilchez, R. Hidalgo Alvarez, M. Quesada-PMerez. 5: Kinetics of Particle and Protein Adsorption Z. Adamczyk.

Surface and Colloid Science

We have demonstrated that poly(2-aminothiophenol)-stablized gold nanoparticles with proper gold size and polymer thickness are active catalysts for Suzuki−Miyaura cross-coupling reaction of aryl halides with arylboronic acids in water and air for the first time. High yields can be obtained with aryl halides or arylboronic acids bearing a variety of substituents. This new finding will undoubtedly broaden the application of gold nanoparticles in organic catalytic reactions.

Facile Synthesis of Highly Stable Gold Nanoparticles and Their Unexpected Excellent Catalytic Activity for Suzuki−Miyaura Cross-Coupling Reaction in Water

A facile and effective route has been proposed to synthesize gold nanoparticles with controllable size that uniformly deposited on surfaces of polyaniline (PANI) nanofibers, where PANI nanofibers themselves act as both supporter and reductant. Effects of reagent concentration, reaction time, and temperature on size and uniformity of gold nanoparticles are investigated. Furthermore, a functional doping acid of typical thioglycolic acid (TA) that introduced in PANI nanofibers shows good potential for improvement in uniformity of composites and control over gold nanoparticle size. Fourier transform infrared (FTIR), X-ray diffraction (XRD), and ultraviolet−visible (UV−vis) spectra are used to characterize PANI nanofiber/gold nanoparticle composites. Adaptability of this approach for making PANI nanofiber composites with other noble metal nanoparticles, such as platinum, silver, and palladium nanoparticles, is also studied. A possible formation mechanism involved has been then proposed. Furthermore, PANI nanof...

Novel Approach to Controllable Synthesis of Gold Nanoparticles Supported on Polyaniline Nanofibers

Mesoporous hybrid shells of TiO2/NiO were prepared by sequential coating of TiO2 and NiO on SiO2 nanospheres through a combined sol–gel and hydrothermal process followed by calcination and template removal. Evaluation of visible light photocatalytic activities in dye degradation and H2 production demonstrated their superior performance, which could be attributed to the porous nature of the hybrid shells and the enhanced charge separation and visible-light absorption associated with the introduction of NiO.

TiO2/NiO hybrid shells: p–n junction photocatalysts with enhanced activity under visible light

A novel method has been developed to synthesize gold nanoparticles with tunable size and morphology supported on both inner and outer surfaces of poly(o-phenylenediamine) (PoPD) hollow microspheres, which act as both reductant and template/stabilizer. The size of gold nanoparticles supported on shells of PoPD hollow microspheres can be tuned from 3 to 15 nm by changing the concentration of the gold source, HAuCl4. Gold nanorods supported on shells of PoPD hollow microspheres can also be fabricated by introducing a well-known seed-growth strategy. In addition, silver nanoparticles supported on shells of PoPD hollow microspheres can also be successfully fabricated using the same strategy, which indicates the diversity of this proposed method for polymer hollow microspheres supporting noble metal nanoparticles. The products are characterized by X-ray diffraction and contact angle analysis. Furthermore, the catalytic activity of the obtained PoPD-microsphere-supported gold nanoparticles for aerobic alcohol oxidation is investigated. The results demonstrate that such polymer-supported gold nanoparticles can be used as reusable catalysts with high catalytic activity for aerobic alcohol oxidation in water.

Reactive Template Method to Synthesize Gold Nanoparticles with Controllable Size and Morphology Supported on Shells of Polymer Hollow Microspheres and Their Application for Aerobic Alcohol Oxidation in Water

Monodisperse carbon nanoparticles encapsulated in hollow NiO nanostructures (C@NiO) have been successfully synthesized by calcination from a Ni(OH)2 covered carbon (C@Ni(OH)2) precursor. The as-prepared products at each stage were extensively characterized and carefully discussed. The electrochemical properties of the carbon encapsulated in hollow NiO nanostructures were investigated using cycling voltammetry and charge–discharge techniques. The specific capacitance of the obtained C@NiO electrode was about 988.7 F g−1 at a current density of 0.5 A g−1. It shows better performance than hollow NiO spheres obtained in oxygen atmosphere. Furthermore, the C@NiO electrode shows a good capacitive retention of ca. 90.7% after 1000 charge–discharge cycles.

/pdf/carbon-nanoparticles-encapsulated-in-hollow-nickel-oxides-1j6luyvtjk.pdf

Rong Guo

Papers

Facile Synthesis of Highly Stable Gold Nanoparticles and Their Unexpected Excellent Catalytic Activity for Suzuki−Miyaura Cross-Coupling Reaction in Water

Novel Approach to Controllable Synthesis of Gold Nanoparticles Supported on Polyaniline Nanofibers

TiO2/NiO hybrid shells: p–n junction photocatalysts with enhanced activity under visible light

Reactive Template Method to Synthesize Gold Nanoparticles with Controllable Size and Morphology Supported on Shells of Polymer Hollow Microspheres and Their Application for Aerobic Alcohol Oxidation in Water

Carbon-nanoparticles encapsulated in hollow nickel oxides for supercapacitor application