Publications by authors named "Qunqun Guo"

In recent years, a disease called "Baotou" has been causing large-scale yield reductions of in China. Interestingly, , which once reported to be a probiotic or pathogen for multiple marine organisms, was strongly proved to be the pathogen causing "Baotou" disease in this study. Analysis of 16S rRNA gene profiling revealed that was the most abundant and dominant bacterium on the algal thalli suffering from "Baotou" disease, whereas its presence was scarcely detected on healthy thalli.

View Article and Find Full Text PDF

Dopamine (DA) is a widely present, calcium cholinergic neurotransmitter in the body, playing important roles in the central nervous system and cardiovascular system. Developing fast and sensitive DA detection methods is of great significance. Fluorescence-based methods have attracted much attention due to their advantages of easy operation, a fast response speed, and high sensitivity.

View Article and Find Full Text PDF

Since RNA is an important biomarker of many infectious pathogens, RNA detection of pathogenic organisms is crucial for disease diagnosis and environmental and food safety. By simulating the base mismatch during DNA replication, this study presents a novel three-way junction structure-mediated reverse transcription-free exponential amplification reaction (3WJ-RTF-EXPAR) for the rapid and sensitive detection of pathogen RNA. The target RNA served as a switch to initiate the reaction by forming a three-way junction (3WJ) structure with the ex-trigger strand and the ex-primer strand.

View Article and Find Full Text PDF

Polysaccharides have attracted immense attention as the largest source of bioactive compounds. Its bioavailability and bioactivity can be improved by utilizing degradation enzymes to reduce their molecular weight and viscosity. In this study, a 654 bp gene encoding xylanase was screened from the genome of Bacillus altitudinis JYY-02 and overexpressed in Escherichia coli Rosetta (DE3).

View Article and Find Full Text PDF

, the pine wood nematode (PWN), is the causal agent of pine wilt disease (PWD), which causes enormous economic loss annually. According to our previous research, fomepizole, as a selective inhibitor of PWN alcohol dehydrogenase (ADH), has the potential to be a preferable lead compound for developing novel nematicides. However, the underlying molecular mechanism is still unclear.

View Article and Find Full Text PDF

Polylactic acid (PLA) is a biodegradable polymer made from natural sources, and its electrospinning (e-spinning) nanofiber membrane doped with antibacterial ingredients is widely used in the field of medical dressings. In this research, 9 wt% of rosmarinic acid (RosA) and 0.04 wt% of graphite oxide (GO) with synergistic antibacterial activity were introduced into the e-spinning PLA precursor solution, and the obtained PLA nanofiber membrane showed good antibacterial properties and wound healing effects.

View Article and Find Full Text PDF

Pine wood nematode (PWN), , is a major pathogen of pine wilt disease (PWD), which is a devastating disease affecting pine trees. Eco-friendly plant-derived nematicides against PWN have been considered as promising alternatives to control PWD. In this study, the ethyl acetate extracts of fruits and roots were confirmed to have significant nematicidal activity against PWN.

View Article and Find Full Text PDF

Gardenia blue (GB) is a natural blue pigment widely used in textiles and the pharmaceutical industry. The geniposide in gardenia fruits can be hydrolyzed by β-glucosidase to form genipin, which reacts with amino acids to produce GB. In this study, a bacterial strain which secreted thermostable β-glucosidase (EC 3.

View Article and Find Full Text PDF

Pine wilt disease (PWD) caused by is considered a major threat to pine forests worldwide. Uridine diphosphate (UDP)-glycosyltransferases (UGTs) catalyze the conjugation of small lipophilic compounds with sugars and play crucial roles in the detoxification and homeostatic processes in all living organisms. We investigated the molecular characteristics and biological functions of the gene that encodes UGTs in .

View Article and Find Full Text PDF

Lycopene is an orange-red carotenoid, which confers a visual phenotype to assess genetic transformation of microorganisms. In this study, the lycopene synthesis pathway was constructed in engineered Escherichia coli BL21 (DE3) by transforming plasmid pET-15b-crtBEI, wherein crtB, crtE, and crtI could be expressed under the control of the T7 promoter and lacO operator and lycopene could be accumulated in the engineered bacteria upon induction by lactose. A good linear relationship was observed between the lycopene content in engineered bacterial culture and lactose concentration in the range of 4-52 g/L; using this relation, the lactose concentration in milk could be determined.

View Article and Find Full Text PDF

It has been widely reported that the addition of trimethylglycine (betaine) decreases osmotic pressure inhibition for cell growth, leading to increased production of amino acids. However, the underlying mechanism is unclear. To determine the global metabolic differences that occur under the addition of trimethylglycine, transcriptome analysis was performed.

View Article and Find Full Text PDF

Small extracellular vesicles (sEVs), often referred to as exosomes, are potential biomarkers for noninvasive cancer diagnosis. However, because of their phenotype heterogeneity, precise detection of tumor-derived sEVs is a great challenge. Herein, a dual-aptamer-assisted AND logic gate was fabricated for sensitive electrochemical detection of tumor-derived sEVs based on a cyclic enzymatic signal amplification strategy.

View Article and Find Full Text PDF
Article Synopsis
  • A dangerous plant pest linked to Pine Wild Disease (PWD) prompted research into the physiological effects of carbon quantum dots (CQDs) synthesized using glucose through hydrothermal reactions.
  • The properties of these CQDs varied based on the temperature and time of the reaction, and transcriptome analysis revealed their potential to stimulate detoxification and fatty acid degradation in the pest.
  • Observations showed that CQDs significantly affected the pest's locomotion, reproduction, and targeted the intestine as the main organ of influence.
View Article and Find Full Text PDF

With some indoles and azaindoles being successfully developed as anticancer drugs, the design and synthesis of indole and azaindole derivatives with remarkable antitumor activity has received increasing attention and significant progress has been made. This paper reviews the recent progress in the study of tumorigenesis, mechanism of actions and structure activity relationships about anticancer indole and azindole derivatives. Combining structure activity relationships and molecular targets-related knowledge, this review will help researchers design more effective, safe and cost-effective anticancer indoles and azindoles agents.

View Article and Find Full Text PDF
Article Synopsis
  • A new electrochemical aptasensor was developed for detecting tumor-derived extracellular vesicles (EVs) without the need for labels, using split aptamers that recognize a specific protein called PTK7.
  • When target EVs are present, the split aptamers induce a reaction that forms a DNA duplex on the sensor's electrode, which enhances the detection signal through increased current caused by the binding of a chemical reporter (Ru(NH3)63+).
  • The sensor demonstrated a sensitivity of detecting as low as 6.607 × 10^5 EVs per mL and could effectively differentiate between various tumor-derived EVs, making it promising for use in clinical diagnostics.
View Article and Find Full Text PDF

Punicalagin showed significant nematotoxic activity against pine wood nematode (PWN), , in the authors' previous research. The authors performed high-throughput transcriptomic sequencing of punicalagin-treated nematodes to generate clues for its nematotoxic mechanism of action. The authors identified 2,575 differentially expressed genes, 1,428 of which were up-regulated and 1,147 down-regulated.

View Article and Find Full Text PDF

MicroRNAs (miRNAs) in cancer cell-derived exosomes are important cancer biomarkers. Herein, a sensitive hybridization chain reaction (HCR) electrochemical assay was fabricated for the detection of exosomal microRNA-122 (miR-122). The hairpin DNA (hpDNA) probes were first immobilized on the surface of a gold electrode.

View Article and Find Full Text PDF

Exosomes are non-invasive biomarkers for cancer diagnosis. Herein, we describe an electrochemiluminescent (ECL) aptasensor for the detection of exosomes from breast tumor cells. Mercaptopropionic acid (MPA)-modified Eu-doped CdS nanocrystals (MPA-CdS:Eu NCs) and HO were used as ECL emitters and coreactant, respectively.

View Article and Find Full Text PDF

Betaine can act as a stress protectant, methyl donor, or enzyme stabilizer in vitro for the biosynthesis of structurally complex compounds. The performances of betaine type and concentration on the metabolic processes of Escherichia coli JLTHR in a 5-L fermentor were investigated. The results showed that the maximum L-threonine production of 127.

View Article and Find Full Text PDF

In this paper, a dual-signal ratiometric electrochemiluminescence (ECL) assay was developed to detect human DNA (cytosine-5)-methyltransferase1 (DNMT1) activity. Mercaptopropionic acid (MPA)-modified Eu3+-doped CdS nanocrystals (MPA-CdS:Eu NCs) and luminol were used as two different ECL emitters, which showed ECL signals at different electrochemical potentials. The resultant ECL peaks exhibited opposite trends in the DNMT1 system.

View Article and Find Full Text PDF

The ethanol extracts from the roots of Maxim. Shan Yuan was toxic against the pine wood nematode The ethyl acetate-soluble fraction derived from this extract increased its potency with a mortality of 95.25% in 72 hr at 1.

View Article and Find Full Text PDF

The ethanol extract of Punica granatum L. rind was tested to show significant nematicidal activity against pine wood nematode. Three nematicidal compounds were obtained from the ethanol extract by bioassay-guided fractionation and identified as punicalagin 1, punicalin 2, and corilagin 3 by mass and nuclear magnetic resonance spectral data analysis.

View Article and Find Full Text PDF

The ethanol extract of the Ficus carica L. leaves was tested to show strong nematicidal activity against pine wood nematode (PWN), Bursaphelenchus xylophilus, causing 90.93% corrected mortality within 72 h at 1.

View Article and Find Full Text PDF

Pine wilt disease (PWD), a destructive disease for pine trees, is caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus and additional bacteria. In this study, extracts of Zostera marina showed a high nematicidal activity against PWN and some of the bacteria that it carries. Light yellow crystals were obtained from extracts of Z.

View Article and Find Full Text PDF

Objective: To cultivate various yet-to-be cultured heterotrophs from anaerobic granule sludge, we used a selective culture medium with low concentrations of substrates supplemented a variety of antibiotics.

Methods: An obligate anaerobic, thermophilic, hydrogen-producing bacterium, strain VM20-7(T), was isolated from an upflow anaerobic sludge blanket (UASB) reactor treating high-strength organic wastewater from isomerized sugar production processes.

Results: Cells of strain VM20-7(T) are non-motile, spherical, pear or teardrop shaped, occurring singly(o)r as aggregates (0.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_session3ppsr6r28ea9lc8pc7te17tqs7u80gr9): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once