In the present study, based on the mimic oxidase catalytic character of nucleic-acid-stabilized silver nanoclusters (DNA/AgNCs) and hybridization chain reactions for signal amplification, the ...fabrication of a label-free sensitive "turn-on" electrochemical aptasensor for the amplified determination of lysozyme was demonstrated. First, the designed DNA duplex was modified on the electrode. With the specific binding of the target, lysozyme and its aptamer, the lysozyme-binding DNA sequence was liberated, exposing the induced DNA sequence, which in turn triggered the formation of the supersandwich DNA structure. Because the cytosine-rich sequence was designed ingeniously on the DNA sequence, DNA/AgNCs were formed on the supersandwich DNA structure. The peroxidase-like character of DNA/AgNCs produced detectable electrochemical signals for the lysozyme aptasensor, which showed a satisfying sensitive detection of lysozyme with a low detection limit of 42 pM and a wide linear range of 10(-10) M to 10(-5) M.
Tetrodotoxin (TTX) is a highly toxic compound detected in various edible marine animals even in European waters. To characterize the hazard by oral exposure to TTX, its tissue distribution was ...evaluated after single (75 μg/kg) or 7-day (25–125 μg/kg) oral administration in mice. Moreover, TTX liver and renal toxicity was evaluated after 7-day oral administration. The elimination cycle of a single oral dose of TTX (75 µg/kg) was found to be approximately 168 h (7 days). Daily oral administration of TTX at doses of 25, 75, and 125 µg/kg for 7 consecutive days revealed dose-dependent toxic effects on the liver and kidney. Histopathological examination showed increased inflammatory cell infiltration in the liver and kidney with higher TTX doses, along with disorganization of the hepatic cord and renal tubular cell arrangement. The study results indicated that TTX had more hepatotoxicity than nephrotoxicity in mice. These findings provide insights into the unintentional ingestion of a low dose of TTX in mammals, including humans, and emphasize the importance of food safety.
Heat tolerance is increasingly becoming a crucial trait for aquaculture species in the face of rapidly changing climate conditions. Alternative splicing (AS) is a vital mechanism within cells that ...modulates gene abundance and functional diversity, enabling organisms to effectively respond to diverse stressful conditions, including thermal stress. However, it is still uncertain whether AS contributes to heat tolerance in shrimp. In this study, we conducted an extensive transcriptome analysis on the Pacific white shrimp,
, revealing a total of 1267, 987, and 130 differential AS events (DAS) in the gill, hepatopancreas, and muscle, respectively, following exposure to heat stress. Among all of the DAS events, exon skipping (ES) was the predominant form of splicing modification observed. Interestingly, a minor portion of DAS genes exhibited overlap across the three tissues, implying that heat stress exerts unique effects on various tissue types. Moreover, the functional enrichment analysis demonstrated that commonly identified DAS genes were primarily associated with the "spliceosome" pathway, indicating that the AS of splicing-related genes played a crucial role in the response to heat stress. Our findings also revealed that heat stress tended to induce longer mRNA isoforms through differential alternative 3' splice site (A3SS) events. Notably, A3SS events exhibited the highest proportion of maintained open reading frames (ORFs) under heat stress. Interestingly, we observed a limited overlap between the genes exhibiting DAS and those showing differential gene expression (DEG), indicating that AS may function as a distinct regulatory mechanism independent of transcriptional regulation in response to heat stress. This is the first comprehensive study on AS in crustacea species under heat stress, which broadens our understanding of the regulatory mechanisms governing the crustaceans' response to environmental stress, providing valuable insights for the aquaculture breeding of shrimp and other aquatic animals.
Penaeid shrimp (family Penaeidae) represents one of the most economically and ecologically important groups of crustaceans. However, their genome sequencing and assembly have encountered extreme ...difficulties during the last 20 years. In this study, based on our previous genomic data, we investigated the genomic characteristics of four penaeid shrimp species and identified potential factors that result in their poor genome assembly, including heterozygosity, polyploidization, and repeats. Genome sequencing and comparison of somatic cells (diploid) of the four shrimp species and a single sperm cell (haploid) of
identified a common bimodal distribution of K-mer depths, suggesting either high heterozygosity or abundant homo-duplicated sequences present in their genomes. However, penaeids have not undergone whole-genome duplication as indicated by a series of approaches. Besides, the remarkable expansion of simple sequence repeats was another outstanding character of penaeid genomes, which also made the genome assembly highly fragmented. Due to this situation, we tried to assemble the genome of penaeid shrimp using various genome sequencing and assembly strategies and compared the quality. Therefore, this study provides new insights about the genomic characteristics of penaeid shrimps while improving their genome assemblies.
Deltamethrin (DM) is a synthetic pyrethroid used for agricultural purposes to control insects. However, its extensive use contaminates the aquatic environment and results in serious health problems ...in aquatic organisms. Knowledge about the toxic effect of DM in freshwater prawns is limited; therefore, this study aims to assess the toxicity of DM in Macrobrachium rosenbergii based on multiple biomarkers. Four-day acute toxicity tests showed that DM was highly toxic to M. rosenbergii with the 24 h, 48 h, 72 h and 96 h LC50 values to be 1.919, 0.603, 0.539, and 0.449 μg/L, respectively. According to 96 h LC50, prawns were exposed to DM at three concentrations (0.02, 0.08, and 0.32 μg/L) for 4 days, and then moved into fresh water for decontamination to investigate the toxic effect of DM in M. rosenbergii. At low concentration (0.02 μg/L and 0.08 μg/L), DM did not cause obvious histopathological damage to hepatopancreas and gill tissue, while at high concentration (0.32 μg/L), the histopathological harm was serious and the damage did not recover to the initial level after 7-day decontamination. 0.02 μg/L DM exposure did not induce significant changes in most of the biomarkers except the increased lactate dehydrogenase (LDH) activity, lactic acid (LD) level, and the first increased then decreased mRNA expression of immune-related genes, indicating the stimulation of DM on energy production and immunity. 0.08 μg/L and 0.32 μg/L DM exposure resulted in varying degrees of damage on prawns, but overall, their toxic effects showed similar trends based on the biomarkers. Increase in malonaldehyde (MDA) and hydrogen peroxide (H2O2) content and decrease in superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity after DM exposure demonstrated the oxidative stress caused by DM. The significantly increased acid phosphatase (ACP), alkaline phosphatase (AKP), LDH activity and LD level indicated hepatopancreatic dysfunction and respiration disruption. The first increased and then decreased expression pattern of immune-related genes indicated the immunosuppression caused by DM. After 7-day decontamination in freshwater, the activity/level of the biomarkers partly recovered. This study revealed the severe toxic effect of DM on Macrobrachium rosenbergii based on multiple biomarkers, providing fundamental knowledge for the establishment of DM toxicity assessment system with proper parameters in freshwater crustaceans.
•Knowledge of DM’s toxic effect on freshwater prawns is limited.•DM was highly toxic to M. rosenbergii, with the 96 h LC50 values to be 0.449 μg/L.•0.02 μg/L DM stimulated energy production and immune system in M. rosenbergii.•0.08 μg/L DM caused oxidative stress and immunosuppression in M. rosenbergii.•0.32 μg/L DM caused irreversible damage to hepatopancreas and gill in M. rosenbergii.
To study the influence of multi-factors, such as long sunshine, sand erosion, and so on, in southern Xinjiang, we selected two kinds of composite insulators for the transmission lines in southern ...Xinjiang to study the aging characteristics of the umbrella skirt surface. The results of scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) show that the surface roughness of the umbrella skirt is high and there are a large number of micron inorganic particles. The skirt has the characteristics of low C/O element ratio and high Al element content. The results of thermogravimetric analysis and micro infrared test show that the aging depth of the Myli Line skirt after 19 years of operation is 160~190 µm and that of Yuhe Line 1 after 14 years of operation is greater than 180 µm. The plasma discharge method was used to simulate the corona discharge in the actual operation to accelerate the aging of the surface of the umbrella skirt and the hydrophobic recovery of the umbrella skirt was investigated. The results show that the temperature has a great influence on the surface hydrophobic recovery performance after plasma treatment. These results may provide some theoretical guidance and technical support for the selection, operation, and maintenance of composite insulators in Xinjiang.
Platelet-derived growth factor-BB (PDGF-BB) is often overexpressed in human malignant tumors as an indicator for tumor angiogenesis. Here by the photoinduced electron transfer (PET) between DNA-Ag ...fluorescent nanoclusters (NCs) and G-quadruplex/hemin complexes, we present a sensitive label-free fluorescent sensor for PDGF-BB. In the presence of PDGF-BB, the specific conjugation with its aptamer induced the conformational change of the duplex-like DNA sequence, releasing the G-quadruplex sequence part. Then in the presence of hemin and K+, the horseradish peroxidase mimicking DNAzyme (HRP-DNAzyme) was formed. With the electron transfer between the DNA-Ag NCs to the hemin Fe (III) center of HRP-DNAzyme, the PET occurred with a decrease in the fluorescence intensity of the DNA-Ag NCs. The detection performance such as selectivity, linear dynamic range, sensitivity, and the quenching capability of HRP-DNAzyme were estimated. The detection range for PDGF-BB is from 5×10−13 to 1×10−8M and the detection limit is 1×10−13M. The experimental results confirmed that the novel fluorescent aptasensor possessed a good sensitivity and high selectivity for PDGF-BB. In addition, the developed probe is nontoxic, label-free only involving one-step hybridization without sophisticated fabrication process. Furthermore, based on this quenching mode occurred by PDGF-BB and hemin, using PDGF-BB and hemin as inputs and the fluorescence signal as an output, a logic gate has been fabricated.
•Photoinduced electron transferred between Ag nanoclusters and HRP-DNAzyme.•A label-free fluorescent aptasensor was fabricated for PDGF-BB.•A logic gate of hemin and PDGF-BB also shows satisfying result.•The process only involved one-step incubation.
Sweet potato, a hexaploid species lacking a reference genome, is one of the most important crops in many developing countries, where abiotic stresses are a primary cause of reduction of crop yield. ...Glutathione S-transferases (GSTs) are multifunctional enzymes that play important roles in oxidative stress tolerance and cellular detoxification.
A total of 42 putative full-length GST genes were identified from two local transcriptome databases and validated by molecular cloning and Sanger sequencing. Sequence and intraspecific phylogenetic analyses revealed extensive differentiation in their coding sequences and divided them into eight subfamilies. Interspecific phylogenetic and comparative analyses indicated that most examined GST paralogs might originate and diverge before the speciation of sweet potato. Results from large-scale RNA-seq and quantitative real-time PCR experiments exhibited extensive variation in gene-expression profiles across different tissues and varieties, which implied strong evolutionary divergence in their gene-expression regulation. Moreover, we performed five manipulated stress experiments and uncovered highly divergent stress-response patterns of sweet potato GST genes in aboveground and underground tissues.
Our study identified a large number of sweet potato GST genes, systematically investigated their evolutionary diversification, and provides new insights into the GST-mediated stress-response mechanisms in this worldwide crop.
The monitoring of synthetic colourants in foods is very important due to their potential toxicity and pathogenicity. Herein, an electrochemical sensor for rapid and simple detection of Ponceau 4R and ...Allura Red was constructed using multi-wall carbon nanotube (MWNT) sensing film. In pH 7.0 phosphate buffer, two oxidation peaks are observed at 0.56 and 0.68
V for Ponceau 4R and Allura Red. Because of its large surface area and high accumulation efficiency, the MWNT film sensor remarkably enhances the oxidation signals of Ponceau 4R and Allura Red. The detection parameters such as pH value, amount of MWNT, accumulation potential and time were optimised. The MWNT film sensor possesses high sensitivity to Ponceau 4R and Allura Red, and the limits of detection are as low as 15 and 25
μg
L
−1. Finally, the MWNT sensor was successfully used to detect Ponceau 4R and Allura Red in different soft drinks.
In view of identification of strong mine quake and rock burst, the mine geology, structural mechanics, mining production data and acoustic emission monitoring process data are infused to build two ...fuzzy process neural network models based on fuzzy set theory. The model integrates fuzzy logic inference mechanism with process neural network process signal analysis and learning capacity. It presents domain knowledge based on fuzzy set and membership function, and adaptively establishes computational logic and fuzzy decision rules based on process signal distribution features, which can effectively infuse multi-source information and prior knowledge, demonstrating good ability to comprehensively analyze various quantitative and qualitative mixed information and identify microquake features, as well as small sample modeling capacity. It has good adaptability for predictive analysis of strong mine quake and rock burst with uncertainty.
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