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

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

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

This Review focuses on noncovalent functionalization of graphene and graphene oxide with various species involving biomolecules, polymers, drugs, metals and metal oxide-based nanoparticles, quantum dots, magnetic nanostructures, other carbon allotropes (fullerenes, nanodiamonds, and carbon nanotubes), and graphene analogues (MoS2, WS2). A brief description of π–π interactions, van der Waals forces, ionic interactions, and hydrogen bonding allowing noncovalent modification of graphene and graphene oxide is first given. The main part of this Review is devoted to tailored functionalization for applications in drug delivery, energy materials, solar cells, water splitting, biosensing, bioimaging, environmental, catalytic, photocatalytic, and biomedical technologies. A significant part of this Review explores the possibilities of graphene/graphene oxide-based 3D superstructures and their use in lithium-ion batteries. This Review ends with a look at challenges and future prospects of noncovalently modified graph...

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Noncovalent Functionalization of Graphene and Graphene Oxide for Energy Materials, Biosensing, Catalytic, and Biomedical Applications

Fluorescent Chemosensors Based on Spiroring-Opening of Xanthenes and Related Derivatives Xiaoqiang Chen, Tuhin Pradhan, Fang Wang, Jong Seung Kim,* and Juyoung Yoon* Departments of Chemistry and Nano Science and of Bioinspired Science (WCU), Ewha Womans University, Seoul 120-750, Korea State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009, China Department of Chemistry, Korea University, Seoul 136-701, Korea

Fluorescent chemosensors based on spiroring-opening of xanthenes and related derivatives.

Synthesis, crystal structure, DNA interaction and antioxidant activities of two novel water-soluble Cu(2+) complexes derivated from 2-oxo-quinoline-3-carbaldehyde Schiff-bases

Synthesis, crystal structure and DNA-binding studies of the Ln(III) complex with 6-hydroxychromone-3-carbaldehyde benzoyl hydrazone.

The highly selective and sensitive detection of metal ions in aqueous solution is of great importance in tracking and studying the physiological functions of these ions in living organisms. Fe is a biologically important metal ion and plays an essential role in oxygen uptake, oxygen metabolism, and electron transfer. However, the presence of Fe in biological systems has to be efficiently moderated as both its deficiency and overloading can induce various biological disorders. Currently, the detection of Fe relies on small organic molecules, but these organic molecules are poorly soluble in water and cannot provide the necessary selectivity and sensitivity for Fe detection in biological environments. Recently, we reported that magnetic Fe3O4 nanoparticles (NPs) that were modified with polyethylene glycol (PEG) derivatives were highly soluble and stable in physiological solutions. These properties indicate that the problems related to the low solubility of small organic molecules in biological solutions can be resolved by coupling these molecules to PEG-Fe3O4 NPs. The increased solubility should thus greatly improve the detection sensitivity. The presence of magnetic Fe3O4 NPs in the sensor-PEG-Fe3O4 NP conjugate should also facilitate the magnetic separation of the Fe-sensor-PEG-Fe3O4 from biological solutions, leading to the selective detection of Fe at ultralow concentrations. Herein, we report that a rhodamine 6G derivative, N(rhodamine-6G)lactam-ethylenediamine (Rh6G-LEDA) (1a), can be coupled to the PEG-Fe3O4 NPs (1b) and act as an Fe-selective fluorescent sensor (1c ; Scheme 1). Rhodamine-based sensors have received ever-increasing interest in sensing Pb, Cu, Hg, Fe, Cr, NO, and OCl ions. Their detection is based on the on/off switch of the spirocyclic moiety, mediated by the metal ion. For example, the spirocyclic form of Rh6G-LEDA (1a) is nearly nonfluorescent and colorless. But once bound to a metal ion, it is converted into the open-cyclic form with much better intramolecular conjugation. As a result, the complex is strongly fluorescent. Unfortunately, most of the reported rhodamine-based sensors that were intended for the detection of metal ions suffer from poor water solubility, thus preventing them from having practical applications in biological systems. We demonstrate that in the presence of various metal ions in water, 1b can selectively bind to Fe (1c), thereby leading to the sensitive detection of Fe with the detection limit reaching below 2 ppb. Such a sensitive Fe probe could also be applied to intracellular Fe detection using the enhanced fluorescence from 1 c. Fe3O4 NPs were synthesized from the thermal decomposition of [Fe(acac)3] (acac = acetylacetonate) in benzyl ether in the presence of oleylamine. The oleylamine-coated 12 nm Fe3O4 NPs, as shown by transmission electron microscopy (TEM; see the Supporting Information, Figure S1 A), were functionalized by replacing oleylamine with dopaminePEG, which had been synthesized from the acylation of PEG (MW = 2000) with bromoacetyl chloride, followed by a nucleophilic substitution reaction in which a bromo substituent was displaced by the dopamine NH2. The bromo-PEGFe3O4 reacted with 1a by a nucleophilic substitution reaction between the bromide and amine groups to give 1b (see the Supporting Information, Scheme S1). 1b was readily dispersed in water, with its solubility reaching 1.23 mgmL , and it stayed in the dispersion state for at least half a month. TEM Scheme 1. Structural illustration of Rh6G-LEDA (1a), its coupling with PEG-Fe3O4 NP (1b), and its complex with Fe III (1c) along with the structural change that enhances its fluorescence property.

Selective Detection of Iron(III) by Rhodamine‐Modified Fe3O4 Nanoparticles

Synthesis, characterization, antioxidant activity and DNA-binding studies of two rare earth(III) complexes with naringenin-2-hydroxy benzoyl hydrazone ligand.

Baodui Wang

Papers

Synthesis, crystal structure, DNA interaction and antioxidant activities of two novel water-soluble Cu(2+) complexes derivated from 2-oxo-quinoline-3-carbaldehyde Schiff-bases

Synthesis, crystal structure and DNA-binding studies of the Ln(III) complex with 6-hydroxychromone-3-carbaldehyde benzoyl hydrazone.

Selective Detection of Iron(III) by Rhodamine‐Modified Fe3O4 Nanoparticles

Synthesis, characterization, antioxidant activity and DNA-binding studies of two rare earth(III) complexes with naringenin-2-hydroxy benzoyl hydrazone ligand.

Crystal structures, DNA-binding and cytotoxic activities studies of Cu(II) complexes with 2-oxo-quinoline-3-carbaldehyde Schiff-bases.