Recent advances in nucleic acid signal amplification-based aptasensors for sensing mycotoxins.

Mycotoxin contamination in food products may cause serious health hazards and economic losses. The effective control and accurate detection of mycotoxins have become a global concern. Even though a variety of methods have been developed for mycotoxin detection, most conventional methods suffer from complicated operation procedures, low sensitivity, high cost, and long assay time.

Elongation and Ligation-Mediated Differential Coding for Label-Free and Locus-Specific Analysis of 8-Oxo-7,8-dihydroguanine in DNA.

Oxidative DNA damage is closely associated with the occurrence of numerous human diseases and cancers. 8-Oxo-7,8-dihydroguanine (8-oxoG) is the most prevalent form of DNA damage, and it has become not only an oxidative stress biomarker but also a new epigenetic-like biomarker. However, few approaches are available for the locus-specific detection of 8-oxoG because of the low abundance of 8-oxoG damage in DNA and the limited sensitivity of existing assays.

Ligase detection reaction amplification-activated CRISPR-Cas12a for single-molecule counting of FEN1 in breast cancer tissues.

We construct a simple fluorescent biosensor for single-molecule counting of flap endonuclease 1 (FEN1) based on ligase detection reaction (LDR) amplification-activated CRISPR-Cas12a. This biosensor exhibits excellent selectivity and high sensitivity with a detection limit (LOD) of 1.31 × 10 U.

Construction of a label-free fluorescent biosensor for homogeneous detection of mA eraser FTO in breast cancer tissues.

Fat mass and obesity-associated protein (FTO) is a crucial eraser of RNA N- methyladenosine (mA) modification, and abnormal FTO expression level is implicated in pathogenesis of numerous cancers. Herein, we demonstrate the construction of a label-free fluorescent biosensor for homogeneous detection of mA eraser FTO in breast cancer tissues. When FTO is present, it specifically erases the methyl group in mA, inducing the cleavage of demethylated DNA by endonuclease DpnII and the generation of a single-stranded DNA (ssDNA) with a 3'-hydroxyl group.

Near-room temperature ferromagnetism and a tunable anomalous Hall effect in atomically thin FeCoGeTe.

Itinerant ferromagnetism at room temperature is a key factor for spin transport and manipulation. Here, we report the realization of near-room temperature itinerant ferromagnetism in Co doped FeGeTe thin flakes. The ferromagnetic transition temperature (∼323 K-337 K) is almost unchanged when the thickness is as low as 12 nm and is still about 284 K at 2 nm (bilayer thickness).

Demethylation-activated light-up dual-color RNA aptamersensor for label-free detection of multiple demethylases in lung tissues.

Methylation is one of the most prevalent epigenetic modifications in natural organisms, and the processes of methylation and demethylation are closely associated with cell growth, differentiation, gene transcription and expression. Abnormal methylation may lead to various human diseases including cancers. Simultaneous analysis of multiple DNA demethylases remains a huge challenge due to the requirement of diverse substrate probes and scarcity of proper signal transduction strategies.

Construction of a Dual-Mode Biosensor with Ferrocene as Both a Signal Enhancer and a Signal Tracer for Electrochemiluminescent and Electrochemical Enantioselective Recognition.

We demonstrate for the first time the construction of a dual-mode biosensor for electrochemiluminescent (ECL) and electrochemical chiral recognition of l- and d-isomers of amino acids, with ferrocene (Fc) as both a signal enhancer and a signal tracer. With the dissolved oxygen as a coreactant, ZnInS acts as the ECL emitter to generate a weak cathodic ECL signal. Fc can enter into the β-cyclodextrin (β-CD) cavity on ZnInS-modified electrode as a result of host-guest interaction.

Construction of Multiple DNAzymes Driven by Single Base Elongation and Ligation for Single-Molecule Monitoring of FTO in Cancer Tissues.

Fat mass and obesity-associated proteins (FTO) play an essential role in the reversible regulation of N-methyladenosine (mA) epigenetic modification, and the overexpression of FTO is closely associated with the occurrence of diverse human diseases (e.g., obesity and cancers).

Development of a chiral electrochemical sensor based on copper-amino acid mercaptide nanorods for enantioselective discrimination of tryptophan enantiomers.

Chirality is an important property of nature and it regulates fundamental phenomena in nature and organisms. Here, we develop a chiral electrochemical sensor based on copper-amino acid mercaptide nanorods (L-CuCys NRs) to discriminate tryptophan (Trp) isomers. The chiral L-CuCys NRs are prepared in alkaline solution based on the facile coordination reaction between the sulfhydryl groups of L-Cys and copper ions.

Target-activated T7 transcription circuit-mediated multiple cycling signal amplification for monitoring of flap endonuclease 1 activity in cancer cells.

The structure-specific endonuclease flap endonuclease 1 (FEN1) is an essential functional protein in DNA replication and genome stability, and it has been identified as a promising biomarker and drug target for multiple cancers. Herein, we develop a target-activated T7 transcription circuit-mediated multiple cycling signal amplification platform for monitoring FEN1 activity in cancer cells. In the presence of FEN1, the flapped dumbbell probe is cleaved to generate a free 5' flap single-stranded DNA (ssDNA) with the 3'-OH terminus.

Construction of Genetically Encoded Light-Up RNA Aptamers for Label-free and Ultrasensitive Detection of CircRNAs in Cancer Cells and Tissues.

Circular RNAs (circRNAs) as endogenous non-coding RNAs are characterized by covalently closed circular structures, and they widely exist in mammalian cells. The aberrant expression of circRNAs may result in various diseases. Herein, we demonstrate the construction of genetically encoded light-up RNA aptamers for ultrasensitive and label-free detection of circRNA mitochondrial tRNA translation optimization 1 (circMTO1) in cancer cells and tissues.

CRISPR/Cas12a-enhanced single-molecule counting for sensitive detection of flap endonuclease 1 activity at the single-cell level.

We develop a new fluorescent biosensor for flap endonuclease 1 (FEN1) assay based on CRISPR/Cas12-enhanced single-molecule counting. This biosensor is simple, selective, and sensitive with a detection limit of 2.325 × 10 U and it is applicable for inhibitor screening, kinetic parameter analysis, and quantifying cellular FEN1 with single-cell sensitivity.

Controllable assembly of dendritic DNA nanostructures for ultrasensitive detection of METTL3-METTL14 mA methyltransferase activity in cancer cells and human breast tissues.

N-Methyladenosine (mA) is a reversible chemical modification in eukaryotic messenger RNAs and long noncoding RNAs. The aberrant expression of RNA methyltransferase METTL3-METTL14 complex may change the mA methylation level and cause multiple diseases including cancers. The conventional METTL3-METTL14 assays commonly suffer from time-consuming procedures and poor sensitivity.

Mix-and-Detection Assay with Multiple Cyclic Enzymatic Repairing Amplification for Rapid and Ultrasensitive Detection of Long Noncoding RNAs in Breast Tissues.

Long noncoding RNAs (lncRNAs) are valuable biomarkers and therapeutic targets, and they play essential roles in various pathological and biological processes. So far, the reported lncRNA assays usually suffer from unsatisfactory sensitivity and time-consuming procedures. Herein, we develop a mix-and-read assay based on multiple cyclic enzymatic repairing amplification (ERA) for sensitive and rapid detection of mammalian metastasis-associated lung adenocarcinoma transcript 1 (lncRNA MALAT1).

Target-activated cascade transcription amplification lights up RNA aptamers for label-free detection of metalloproteinase-2 activity.

We demonstrate that target-activated cascade transcription amplification lights up RNA aptamers for label-free detection of metalloproteinase-2 (MMP-2) activity with zero background. This assay exhibits good specificity and high sensitivity with a limit of detection (LOD) of 0.6 fM.

Single-Molecule Biosensing of Alkaline Phosphatase in Cells and Serum Based on Dephosphorylation-Triggered Catalytic Assembly and Disassembly of the Fluorescent DNA Chain.

Alkaline phosphatase (ALP) is a valuable biomarker and effective therapeutic target for the diagnosis and treatment of diverse human diseases, including bone disorder, cardiovascular disease, and cancers. The reported ALP assays often suffer from laborious procedures, costly reagents, inadequate sensitivity, and large sample consumption. Herein, we report a new single-molecule fluorescent biosensor for the simple and ultrasensitive detection of ALP.

[Remediation Performance via the Passivation of a Porous Biomorph Genetic Composite of -FeO/FeO/C Using a Bamboo Template on As(Ⅴ) Contaminated Soils].

Red soil from Guangxi, China was selected as the background soil, and a porous biomorphic genetic composite of -FeO/FeO/C comprising a bamboo template (PBGC-Fe/C) was used as a passivator to remediate As(Ⅴ) contaminated soils. The performance of PBGC-Fe/C was characterized by Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FT-IR). The results showed that PBGC-Fe/C could improve the passivation effect of As(Ⅴ) from the contaminated soils compared with a single passivation material.

[Passivation and Remediation Effects and Mechanisms of Plant Residual Modified Materials on Lead-Contaminated Soils].

The specific characteristics and mechanism of passivation of Pb in soil were studied using HAP/C composite (PBGC-HAP/C) as passivation, and using proportion of PBGC-HAP/C, particle size and type of passivator, soil moisture content, soil pH value of Pb, and particle size of the material as influencing factors. The results showed that with an increase in dosage of the passivator and passivation time, the passivation effect increases gradually. Reducing the particle size of the passivator is beneficial to improving the passivation effect.

FTO gene polymorphisms and obesity risk in Chinese population: a meta-analysis.

Background: There is tremendous increase in obesity worldwide. Many factors including diet, life style, genetic, and epigenetic changes contribute to obesity. The fat mass and obesity-associated (FTO) gene polymorphisms are strongly associated with obesity.

Mesenchymal stem cell-mediated suppression of hypertrophic scarring is p53 dependent in a rabbit ear model.

Introduction: Mesenchymal stem cells (MSCs) are considered to play important roles in wound repair and tissue remodeling. Hypertrophic scar (HTS) is a cutaneous condition characterized by deposits of excessive amount of collagen after an acute skin injury. However, currently there is little knowledge about the direct relationship between MSCs and HTS.

3,3-Dinitro-azetidinium chloride.

In the title gem-dinitro-azetidinium chloride salt, C3H6N3O4(+)·Cl(-), the cations and anions lie on a mirror plane. The azetidine ring is virtually planar, with a mean deviation from the plane of 0.0569 Å.

[Identification of the meiotic events in grasshopper spermatogenesis].

The grasshoppers are ideal materials to study various meiotic stages of spermatogenesis due to their easy availability, fairly large chromosomes, and fewer numbers of chromosomes. It is easy to make temporary squash preparation of grasshopper testes; however, it is usually difficult for the beginners to differentiate between stages of meiosis. In view of this, we demonstrated the method of identification of meiotic stages by chromosome number and chromosome conformation, taking spermatogonial meiosis of Locusta migratoria manilensis as an example.

[Indication of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa B ligand (RANKL) in gingival crevicular fluid to remodeling of alveolar bone during retention].

Objective: To investigate the level of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa B ligand (RANKL) in gingival crevicular fluid (GCF) during orthodontic retention and corresponding expression of OPG and RANKL in periodontal tissues.

Methods: Fifteen male Wistar rats (age, 6 weeks) were divided into three groups with 5 rats for each. GCF samples were collected at the baseline, 14 days after orthodontic force application, and 14 days after orthodontic force removal.