Postamplifying Cas12a Activation through Hybridization Chain Reaction-Triggered Fluorescent Nanocluster Formation for Ultrasensitive Nucleic Acid Detection.

CRISPR/Cas12a-based biosensing is advancing rapidly; however, achieving sensitive and cost-effective reporting of Cas12a activation remains a challenge. In response, we have developed a label-free system capable of postamplifying Cas12a activation by integrating hybridization chain reaction (HCR) and DNA-copper nanoclusters (DNA-CuNCs). The trans-cleavage of Cas12a triggers a silenced HCR, leading to the in situ assembly of fluorescent DNA-CuNCs, allowing for the turn-on reporting of Cas12a activation.

Visual category representations in the infant brain.

Visual categorization is a human core cognitive capacity that depends on the development of visual category representations in the infant brain. However, the exact nature of infant visual category representations and their relationship to the corresponding adult form remains unknown. Our results clarify the nature of visual category representations from electroencephalography (EEG) data in 6- to 8-month-old infants and their developmental trajectory toward adult maturity in the key characteristics of temporal dynamics, representational format, and spectral properties.

Accumulation of Heterocyclic Amines and Advanced Glycation End Products in Various Processing Stages of Plant-Based Burgers by UHPLC-MS/MS.

The accumulation of heterocyclic amines (HAs) and advanced glycation end products (AGEs) during different processing stages was investigated in commercial raw materials to plant-based hamburger meats (PBHMs). Principal component analysis (PCA) was performed to explore the difference between the samples of each processing stage. The total free HA level accumulated from 4.

A DNA-Cu nanocluster and exonuclease I integrated label-free reporting system for CRISPR/Cas12a-based SARS-CoV-2 detection with minimized background signals.

CRISPR-driven biosensing is developing rapidly, but current studies mostly adopt dye-labeled ssDNA as the signal reporter, which is costly and unstable. Herein, we developed a label-free and low-background reporter for CRISPR/Cas12a signaling by integrating DNA-templated copper nanoclusters (DNA-CuNCs) and exonuclease I (EXO I). The template of the DNA-CuNCs was rationally designed as a ds-/ss-DNA hybrid, ensuring that after a quick and nonpersistent cut of Cas12a, a majority of the template can be digested by EXO I.

Methodologies in visualizing the activation of CRISPR/Cas: The last mile in developing CRISPR-Based diagnostics and biosensing - A review.

CRISPR/Cas-based analytical procedures have revolutionized the sensing platform to fulfill the requirements of the current era in terms of sensitivity, selectivity, robustness, user-friendly feature, and cost-effectiveness for the detection of nucleic acid as well as non-nucleic acid analytes. Molecular target monitoring and transduction of the signals is a crucial prerequisite for precise molecular sensing tools. Besides, the reporting systems have become the last milestone for fabricating Cas-based molecular probes to visualize the activation of CRISPR/Cas enzymes.

Functional nucleic acids in glycobiology: A versatile tool in the analysis of disease-related carbohydrates and glycoconjugates.

As significant components of the organism, carbohydrates and glycoconjugates play indispensable roles in energy supply, cell signaling, immune modulation, and tumor cell invasion, and function as biomarkers since aberrance of them has been proved to be associated with the emergence and development of certain diseases. Functional nucleic acids (FNAs) have properties including easy-to-synthesize, good stability, good biocompatibility, low cost, and high programmability, they have attracted significant research attention and been incorporated into biosensors for detecting disease-related carbohydrates and glycoconjugates. This review summarizes the construction strategies and biosensing applications of FNAs-based biosensors in glycobiology in terms of target recognition and signal transduction.

Advancing sensing technology with CRISPR: From the detection of nucleic acids to a broad range of analytes - A review.

The CRISPR/Cas technology, derived from an adaptive immune system in bacteria, has been awarded the Nobel Prize in Chemistry in 2020 for its success in gene editing. Increasing reports reveal that CRISPR/Cas technology has a wide scope of applications and it could be incorporated into biosensors for detecting critical analytes. CRISPR-powered biosensors have attracted significant research interest due to their advantages including high accuracy, good specificity, rapid response, and superior integrity.

Signal-Amplified Detection of the Tumor Biomarker FEN1 Based on Cleavage-Induced Ligation of a Dumbbell DNA Probe and Rolling Circle Amplification.

Flap endonuclease 1 (FEN1), an endogenous nuclease with the ability to cleave the 5' overhang of branched dsDNA, is of significance in DNA replication and repair. The overexpression of FEN1 is common in cancer because of the ubiquitous upregulation of DNA replication; thus, FEN1 has been recognized as a potential biomarker in oncological investigations. However, few analytical methods targeting FEN1 with high sensitivity and simplicity have been developed.

Fluorometric detection of cancer marker FEN1 based on double-flapped dumbbell DNA nanoprobe functionalized with silver nanoclusters.

Flap endonuclease 1 (FEN1), a ubiquitous enzyme involved in DNA repair and replication, is overexpressed in highly proliferative cancer cells. FEN1 has been recognized as a promising diagnostic marker of cancers; however, very few analytical techniques have been developed for the convenient detection of FEN1. To realize the simplified quantification of FEN1, we developed a FEN1-responsive fluorescent nanoprobe based on DNA-silver nanoclusters (DNA-AgNCs).

DNA nanotechnology: A recent advancement in the monitoring of microcystin-LR.

The Microcystin-Leucine-Arginine (MC-LR) is the most toxic and widely distributed microcystin, which originates from cyanobacteria produced by water eutrophication. The MC-LR has deleterious effects on the aquatic lives and agriculture, and this highly toxic chemical could severely endanger human health when the polluted food was intaken. Therefore, the monitoring of MC-LR is of vital importance in the fields including environment, food, and public health.

Visual Imagery and Perception Share Neural Representations in the Alpha Frequency Band.

To behave adaptively with sufficient flexibility, biological organisms must cognize beyond immediate reaction to a physically present stimulus. For this, humans use visual mental imagery [1, 2], the ability to conjure up a vivid internal experience from memory that stands in for the percept of the stimulus. Visually imagined contents subjectively mimic perceived contents, suggesting that imagery and perception share common neural mechanisms.

Optical-fiber-based dynamic measurement system for 3D tip clearance of rotating blades.

This paper proposes a dynamic model for measuring the 3D tip clearance of rotating blades using an isosceles-right-triangle sensing structure consisting of three identical two-circle coaxial optical fiber bundles and a demodulation approach using the ratios of difference signals between any two bundles based on the Taylor expansion principle. The dynamic system comprising the optical fiber probe, hardware circuits, and measurement software is designed and established according to the characteristics of dynamic sensing signals. Finally, the feasibility of the system for the dynamic measurement of 3D tip clearance is experimentally verified using the simulated blades of a rotor test bench.

Demodulation technique for 3-D tip clearance measurements based on output signals from optical fiber probe with three two-circle coaxial optical fiber bundles.

In this work, we propose a new demodulation technique for three-dimensional (3-D) tip clearance measurements using the output signals acquired from three two-circle coaxial optical fiber bundles. This technique is based on the ratio of the difference in the signal intensities between any two sensing units of the optical fiber probe, and we derived the demodulation equations using the second-order Taylor expansion for a three-variable function. We verified the feasibility of the demodulation technique by experiments and demodulation error curves, which indicates that the method is viable for 3-D tip clearance measurements.

Output characteristics of two-circle coaxial optical fiber bundle with regard to three-dimensional tip clearance.

A two-circle coaxial optical fiber bundle is a type of optical sensor which has been widely used in non-contact radial displacement measurement applications. This paper has focused on output characteristics of a two-circle coaxial optical fiber bundle used as a measurement unit in a probe designed to measure a three-dimensional tip clearance. First, a model that could calculate intensity point-by-point on each receiving fiber with a simplified algorithm of overlap area was established, an aperture angle compensation algorithm was then proposed to improve the performance of the model.

Intelligent Mesoporous Materials for Selective Adsorption and Mechanical Release of Organic Pollutants from Water.

Despite recent advances in the porous materials for efficient removal of dissolved organic pollutants from water, the regeneration of porous characteristics for reuse with preventing secondary contamination remains a challenge. Here, novel supramolecular absorbents with hydrophobic pore are prepared by the self-assembly of propeller-shaped aromatic amphiphiles. The assembly of folded propeller provides a mesoporous environment within aromatic segments, which is suitable for the removal of organic pollutants from waste water.

Supramolecular Nanotubules as a Catalytic Regulator for Palladium Cations: Applications in Selective Catalysis.

Despite the recent development of highly efficient and stable metal catalysts, conferral of regulatory characteristics to the catalytic reaction in heterogeneous systems remains a challenge. Novel supramolecular nanotubules were prepared by alternative stacking from trimeric macrocycles, which was found to be able to coordinate with Pd cations. The Pd complexes exhibited a high catalytic performance for C-C coupling reaction.