Construction of a D-amino acid oxidase reactor based on magnetic nanoparticles modified by a reactive polymer and its application in screening enzyme inhibitors.

Developing facile and high-throughput methods for exploring pharmacological inhibitors of D-amino acid oxidase (DAAO) has triggered increasing interest. In this work, DAAO was immobilized on the magnetic nanoparticles, which were modified by a biocompatible reactive polymer, poly(glycidyl methacrylate) (PGMA) via an atom transfer radical polymerization technique. Interestingly, the enzyme immobilization process was greatly promoted with the assistance of a lithium perchlorate catalyst.

A cresyl violet-based fluorescent off-on probe for the detection and imaging of hypoxia and nitroreductase in living organisms.

A new cresyl violet-based fluorescent off-on probe has been developed through a one-step synthesis for the detection of nitroreductase (NTR) and hypoxia. The detection mechanism is based on the NTR-catalyzed reduction of the probe to cresyl violet, accompanied with a large fluorescence enhancement at a long wavelength of 625 nm. The probe can detect NTR in aqueous solution with high selectivity and sensitivity, and the detection limit is 1 ng mL(-1) NTR.

Sensitive and selective near-infrared fluorescent off-on probe and its application to imaging different levels of β-lactamase in Staphylococcus aureus.

A highly sensitive and selective near-infrared (NIR) fluorescent probe, (E)-2-(2-(6-((2-carboxy-8-oxo-7-(2-phenylacetamido)-5-thia-1-azabicyclo[4.2.0]oct-2-en-3-yl)methoxy)-2,3-dihydro-1H-xanthen-4-yl)vinyl)-3,3-dimethyl-1-propyl-3H-indol-1-ium (1), is developed for the determination of β-lactamase.

Rational design and bioimaging applications of highly selective fluorescence probes for hydrogen polysulfides.

Reactive sulfur species have received considerable attention due to their various biological functions. Among these molecules, hydrogen polysulfides (H2S(n), n > 1) are recently suggested to be the actual signaling molecules derived from hydrogen sulfide (H2S). Hydrogen polysulfides may also have their own biosynthetic pathways.

Detection of glucose via enzyme-coupling reaction based on a DT-diaphorase fluorescence probe.

Enzyme-coupling reactions play an important role in the assay of analytes. In this manuscript, we developed a new fluorescent probe for the detection of glucose through the enzyme-coupling reaction of DT-diaphorase (DTD). The probe was synthesized through a mild and simple synthetic procedure, and showed good fluorescence response to DTD.

Facile preparation of surface-exchangeable core@shell iron oxide@gold nanoparticles for magnetic solid-phase extraction: use of gold shell as the intermediate platform for versatile adsorbents with varying self-assembled monolayers.

The core@shell Fe3O4@Au nanoparticles (NPs) functionalized with exchangeable self-assembled monolayers have been developed for mode switching magnetic solid-phase extraction (MSPE) using high performance liquid chromatography with ultraviolet detection. The adsorbents were synthesized by chemical coprecipitation to prepare magnetic cores followed by sonolysis to produce gold shells. Functionalization of Fe3O4@Au NPs surface was realized through self-assembly of commercially available low molecular weight thiol-containing ligands using gold shells as intermediate platform and the dynamic nature of Au-S chemistry allowed substituent of one thiol-containing ligand with another simply by thiol exchange process.

[Influence of electroacupuncture on indocyanine green metabolism in liver: display of in vivo fluorescence imaging].

Objective: To observe the influence of electroacupuncture (EA) on indocyanine green (ICG) metabolism in the liver and the action mechanism of acupuncture for hepatic regulation.

Methods: Forty Kunming mice were randomly divided into an EA group and a control group, 20 cases in each one. Combined with classical hepatic metabolism test of ICG, after tail vein injection of ICG, twenty mice were treated with EA at "Zusanli" (ST 36) for 20 min.

Effect of ethanol extract of Selaginella doederleinii Hieron on the proliferation of nasopharyngeal carcinoma CNE-1 and C666-1 cells.

This paper mainly studied the effect of ethanol extract of Selaginella doederleinii Hieron on the proliferation of two kinds of nasopharyngeal carcinoma cell lines, CNE-1 and C666-1, and their mechanisms of action. Extract was obtained by heat reflux extraction with ethanol, and the effect of extract on the extracellular matrix adhesion of the cells, on their proliferation process, as well as on their colony-forming ability were tested using MTT assay. The results showed that the yield of dry extract was 36.

Parallel comparative studies on the toxic effects of unmodified CdTe quantum dots, gold nanoparticles, and carbon nanodots on live cells as well as green gram sprouts.

By using confocal fluorescence microscopy and direct visualization, a parallel comparative investigation has been systematically made on the relative toxicity of three common nanomaterials, such as unmodified CdTe quantum dots (QDs), Au nanoparticles (Au NPs) and carbon nanodots (C-dots), to live cells as well as green gram sprouts. Bare CdTe QDs exert the most toxic effect on a variety of cell lines (HeLa, MCF-7, NIH/3T3 cells) as well as live plants (green gram sprouts). For cells, this toxic effect leads to the partial death of cells, the decrease of cell metabolic activity, the shrinkage of cells, the breakage of chromatin, the damage of cell membrane integrity, and the fragmentation of mitochondria; for green gram sprouts, the presence of CdTe QDs markedly inhibits their growth.

Sensitive detection of ozone by a practical resorufin-based spectroscopic probe with extremely low background signal.

Ozone (O3) has attracted much attention because of its key role in human health and disease, and its detection is of great importance for various biochemical studies as well as environmental evaluation. Here we develop a simple and practical spectroscopic off-on O3 probe based on resorufin and the specific reaction of but-3-enyl with O3. The probe shows an extremely low background spectroscopic signal, but reacts with O3 producing a distinct color and fluorescence change.

Preparation of porous polymer monolithic column using functionalized graphene oxide as a functional crosslinker for high performance liquid chromatography separation of small molecules.

A newly developed porous polymer monolith was prepared through copolymerization of 3-(trimethoxysilyl)propylmethacrylate modified graphene oxide with glycidyl methacrylate and ethylene dimethacrylate as a functional crosslinker, which was synthesized through silanization reaction of graphene oxide prepared by Hummers method with 3-(trimethoxysilyl)propylmethacrylate. The monolith was characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electron microscopy, mercury intrusion porosimetry and nitrogen adsorption measurement. The monolith column was applied as the stationary phase of high performance liquid chromatography and its chromatographic performance was evaluated by separation of small molecules in the isocratic reversed-phase mode.

Facile one-pot synthesis of L-proline-stabilized fluorescent gold nanoclusters and its application as sensing probes for serum iron.

Gold nanoclusters (Au NCs) possess outstanding physical and chemical attributes that make them excellent scaffolds for the construction of novel chemical and biological sensors. In this study, a simple one-pot synthesis method, employing l-proline as the stabilizer, was presented for preparation of fluorescent Au NCs. This strategy allowed the generation of water-soluble Au NCs within a short time of 15 min.

Distinguishing folate-receptor-positive cells from folate-receptor-negative cells using a fluorescence off-on nanoprobe.

Based on the high affinity of folic acid (FA) for folate receptor (FR) that is overexpressed on the surface of many human cancer cells, we have developed a simple fluorescence nanoprobe (1) with multiple capability (fluorescence off-on response and cell-targeting ability) for imaging of FR-positive cells by covalently linking both FA and Rhodamine B (RB) to graphene oxide (GO) through disulfide bonds. The nanoprobe shows a weak fluorescence due to the electron transfer from GO to RB. However, the specific binding of FA to FR-positive cells leads to the internalization of the nanoprobe into the cells.

7-((5-Nitrothiophen-2-yl)methoxy)-3H-phenoxazin-3-one as a spectroscopic off-on probe for highly sensitive and selective detection of nitroreductase.

A new spectroscopic off-on probe, 7-((5-nitrothiophen-2-yl)methoxy)-3H-phenoxazin-3-one, is developed and applied to real-time detection of nitroreductase produced by Escherichia coli.

A tetra-layer microfluidic system for peptide affinity screening through integrated sample injection.

A novel integrated microfluidic system was designed and fabricated for affinity peptide screening with in situ detection. A tetra-layer microfluidic hybrid chip containing two top eccentric diffluent layers, an inter-layer and a bottom screening layer, was developed as the core device of the system. The eccentric diffluent layers were ingeniously invented for the vertical sample delivery from 2 top-inlets into 12 bottom-inlets, which eliminated the use of excessive accessories and complicated pipelines currently used in other systems.

Nitroreductase detection and hypoxic tumor cell imaging by a designed sensitive and selective fluorescent probe, 7-[(5-nitrofuran-2-yl)methoxy]-3H-phenoxazin-3-one.

A highly selective and sensitive fluorescence probe, 7-[(5-nitrofuran-2-yl)methoxy]-3H-phenoxazin-3-one (1), is developed for imaging the hypoxic status of tumor cells via the indirect detection of nitroreductase. The detection mechanism is based on the fact that nitroreductase can selectively catalyze the reduction of the nitro group in 1 to a hydroxylamine or amino group in the presence of reduced nicotinamide adenine dinucleotide as an electron donor that is indispensable, followed by the 1,6-rearrangement-elimination and the release of resorufin. As a result, the reaction produces a distinct color and fluorescence change from almost colorless and nonfluorescent to pink and strong red fluorescence.

Fluorescence sensing of adenosine deaminase based on adenosine induced self-assembly of aptamer structures.

A new approach is proposed for simple detection of adenosine deaminase (ADA) based on adenosine induced self-assembly of two pieces of single-stranded DNA (ssDNA). These ssDNA are two fragments of the aptamer that has a strong affinity for adenosine and are labeled with carboxyfluorescein and black hole quencher-1, respectively. The complementarities of the bases in the two pieces of ssDNA are insufficient to form a stable structure.

[Blood perfusion in different facial acupoint areas and its changes after acupuncture stimulation of Hegu (LI 4) displayed by laser Doppler imager in healthy volunteers].

Objective: To observe the blood perfusion levels in different facial acupoint regions and changes after acupuncture stimulation of Hegu (LI 4).

Methods: Thirty healthy volunteer subjects were equally divided into control group and acupuncture group. Blood perfusion levels of different facial acupoint areas were detected using a Laser Doppler Imager.

4-(8-Quinolyl)amino-7-nitro-2,1,3-benzoxadiazole as a new colorimetric probe for rapid and visual detection of Hg2+.

4-Amino-7-nitro-2,1,3-benzoxadiazole (ANBD) usually serves as a scaffold for developing fluorescent probes. In this paper, however, ANBD has been used as a chromogenic unit to design a new colorimetric probe, 4-(8-quinolyl)amino-7-nitro-2,1,3-benzoxadiazole (1), for rapid and visual detection of Hg(2+). The reaction of 1 with Hg(2+) in NaH(2)PO(4)-Na(2)HPO(4) buffer (pH 7.

In vivo monitoring of hydrogen sulfide using a cresyl violet-based ratiometric fluorescence probe.

A new cresyl violet-based ratiometric fluorescence probe is developed and applied to fluorescence imaging of H(2)S in living cells and zebrafish in vivo.

Tumor suppressor TSLC1 is implicated in cell proliferation, invasion and apoptosis in laryngeal squamous cell carcinoma by regulating Akt signaling pathway.

Overwhelming evidence has demonstrated that TSLC1 (tumor suppressor in lung cancer 1), a novel tumor suppressor, is crucially implicated in various biological processes including progression, proliferation and apoptosis during tumorigenesis. However, the exact functions and molecular details of TSLC1 in laryngeal cancer remain ill-defined. Here, the expression of TSLC1 in laryngeal squamous cell carcinoma (LSCC) tissues and cells was detected, and the biological roles of TSLC1 in LSCC cells were investigated.

Triclosan reduces the levels of global DNA methylation in HepG2 cells.

Triclosan (TCS), an antibacterial agent, is widely used in a variety of personal care and industrial products. TCS is associated with the development of liver tumors in rodents and has become a concern to environmental and human health. This study is aimed at investigating whether TCS could modulate the levels of global DNA methylation (GDM) in human hepatocytes.

Silencing of GPNMB by siRNA inhibits the formation of melanosomes in melanocytes in a MITF-independent fashion.

Background: Melanosomes are specialized membrane-surrounded organelles, which are involved in the synthesis, storage and transport of melanin. Glycoprotein (transmembrane) non-metastatic melanoma protein b (GPNMB), a melanosome-specific structural protein, shares significant amino acid sequence homology with Pmel-17. Proteomic analysis demonstrated that GPNMB is present in all stages (I-IV) of melanosomes.