A novel extraction method for three ochratoxins in human urine based on polystyrene/polyethersulfone electrospun nanofibers coated with copper nanoparticles.

In this study, four types of nanofibers were prepared via electrospinning and characterized through SEM, TEM, EDS, FTIR, TG, XPS and water contact angle analyses, and the novel polystyrene/polyethersulfone nanofibers coated with copper nanoparticles (PS/PES-CuNPs nanofibers) were developed as an ideal adsorbent for the extraction of three ochratoxins from human urine. The solid-phase extractant of sample pretreatment displayed preferable sensitivity and an extraction effect, and the analytical method based on the novel packed-fiber solid-phase extraction strategy followed by high performance liquid chromatography-fluorescence detection (PFSPE-HPLC-FLD) achieved an exceedingly low limit of detection (LOD) and limit of quantification (LOQ) of 0.108-0.162 µg L-1 and 0.658-0.701 µg L-1, respectively; a high spiked recovery of 71.3-92.0% and a lower adsorption time of 7 min, thus demonstrating excellent results compared with other reported adsorbents for ochratoxins from various samples. With the application of this method for the detection of ochratoxins in human urine samples, six in thirty samples were tested positive. This study confirmed that the PS/PES-CuNP nanofibers and PFSPE showed promising potential as a sensitive method for simultaneous extraction and detection of ochratoxins in complex samples.

The roles of circular RNAs in nerve injury and repair.

Nerve injuries significantly impact the quality of life for patients, with severe cases posing life-threatening risks. A comprehensive understanding of the pathophysiological mechanisms underlying nerve injury is crucial to the development of effective strategies to promote nerve regeneration. Circular RNAs (circRNAs), a recently characterized class of RNAs distinguished by their covalently closed-loop structures, have been shown to play an important role in various biological processes. Numerous studies have highlighted the pivotal role of circRNAs in nerve regeneration, identifying them as potential therapeutic targets. This review aims to succinctly outline the latest advances in the role of circRNAs related to nerve injury repair and the underlying mechanisms, including peripheral nerve injury, traumatic brain injury, spinal cord injury, and neuropathic pain. Finally, we discuss the potential applications of circRNAs in drug development and consider the potential directions for future research in this field to provide insights into circRNAs in nerve injury repair.

[Phosphate and tension homology-induced kinase 1/Parkin signaling mediates cognitive dysfunction in sepsis-associated encephalopathy through activation of hippocampal mitochondrial autophagy].

OBJECTIVE: To investigate the effects of gene of phosphate and tension homology (PTEN)-induced putative kinase 1 (PINK1)/Parkin pathway on hippocampal mitophagy and cognitive function in mice with sepsis-associated encephalopathy (SAE) and its possible mechanism. METHODS: A total of 80 male C57BL/6J mice were randomly divided into Sham group, cecal ligation puncture (CLP) group, PINK1 plasmid transfection pretreatment groups (p-PINK1+Sham group, p-PINK1+CLP group), empty vector plasmid transfection control group (p-vector+CLP group), with 16 mice in each group. The mice in CLP groups were treated with CLP to reproduce SAE models. The mice in the Sham groups were performed laparotomy only. Animals in the p-PINK1+Sham and p-PINK1+CLP groups were transfected with PINK1 plasmid through the lateral ventricle at 24 hours before surgery, while mice in the p-vector+CLP group were transfected with the empty plasmid. Morris water maze experiment was performed 7 days after CLP. The hippocampal tissues were collected, the pathological changes were observed under a light microscope after hematoxylin-eosin (HE) staining, and the mitochondrial autophagy was observed under a transmission electron microscopy after uranyl acetate and lead citrate staining. The expressions of PINK1, Parkin, Beclin1, interleukins (IL-6, IL-1ß) and microtubule-associated protein 1 light chain 3 (LC3) were detected by Western blotting. RESULTS: Compared with the Sham group, CLP group mice in Morris water maze experiment had longer escape latency, shorter target quadrant residence time, and fewer times of crossing the platform at 1-4 days. Under the light microscope, the hippocampal structure of the mouse was injured, the neuronal cells were arranged in disorder, and the nuclei were pyknotic. Under the electron microscope, the mitochondria appeared swollen, round, and wrapped by bilayer or multilayer membrane structures. Compared with the Sham group, CLP group had higher expressions of PINK1, Parkin, Beclin1, LC3II/LC3I ratio, IL-6 and IL-1ß in hippocampus, indicating that sepsis induced by CLP could activated inflammatory response and caused PINK1/Parkin-mediated mitophagy. Compared with the CLP group, p-PINK1+CLP group had shorter escape latencies, spent more time in the target quadrant and had more number of crossings in the target quadrant at 1-4 days. Under the light microscope, the hippocampal structures of mice was destroyed, the neurons were arranged disorderly, and the nuclei were pyknotic. Under transmission electron microscope, swollen and rounded mitochondria and mitochondrial structure wrapped by double membrane or multilayer membrane structure were observed. Compared with the CLP group, the levels of PINK1, Parkin, Beclin1 and LC3II/LC3 ratio in the p-PINK1+CLP group were significantly increased [PINK1 protein (PINK1/ß-actin): 1.95±0.17 vs. 1.74±0.15, Parkin protein (Parkin/ß-actin): 2.06±0.11 vs. 1.78±0.12, Beclin1 protein (Beclin1/ß-actin): 2.11±0.12 vs. 1.67±0.10, LC3II/LC3I ratio: 3.63±0.12 vs. 2.27±0.10, all P < 0.05], while the levels of IL-6 and IL-1ß were significantly decreased [IL-6 protein (IL-6/ß-actin): 1.69±0.09 vs. 2.00±0.11, IL-1ß protein (IL-1ß/ß-actin): 1.11±0.12 vs. 1.65±0.12, both P < 0.05], suggesting that overexpression of PINK1 protein could further activate mitophagy and reduce the inflammatory response caused by sepsis. There was no statistically significant difference in the above pathological changes and related indicators between Sham group and p-PINK1+Sham group, CLP group and p-vector+CLP group. CONCLUSIONS: PINK1 overexpression can further activate CLP-induced mitophagy by upregulating Parkin, thereby inhibiting inflammation response and alleviate cognitive function impairment in SAE mice.

Insight into protein synthesis in axon regeneration.

Successful axon regeneration is crucial for the treatment of numerous nerve injuries and neurodegenerative diseases, which requires adequate and accurate protein synthesis, including mRNA translation, both in the neuron somas and locally in the axons. Recent studies have shed light on novel functions and mechanisms of protein synthesis that are relevant for axon regeneration, with a particular focus on local translation. Here, we review the new developed technologies and approaches for investigating local translation, discuss the roles of local translation in axon regeneration, and summarize the key signaling molecules and pathways that regulate local translation during axon regeneration. Additionally, we give an overview of local translation in the peripheral and central nervous systems neurons and the latest progress in protein synthesis in neuron somas respectively. Finally, we consider the potential directions for future research in this field to provide insights into protein synthesis in axon regeneration.

Determination of aflatoxin B1 by novel nanofiber-packed solid-phase extraction coupled with a high performance liquid chromatography-fluorescence detector.

A novel analytical proposal based on nanofiber-packed solid-phase extraction coupled with high performance liquid chromatography-fluorescence detector (HPLC-FLD) has been successfully developed for determining aflatoxin B1 (AFB1) in foods. Four types of nanofibers, including polystyrene (PS) nanofibers, polypyrrole (PPY) nanofibers, polystyrene-acrylic resin (PS-AR) nanofibers, and polystyrene-polyvinyl pyrrolidone (PS-PVP) nanofibers, were fabricated by electrospinning and utilized to prepare a home-made extraction device. In this study, the factors of different fibers, namely, fiber dosage, pH of extraction solution, type of salt ion, concentration of salt ion, and volume of the eluent were optimized. Under optimized conditions, the method showed good linearity in the range of 0.1-40 ng mL-1 with a correlation coefficient greater than 0.999 and good inter-day accuracy (90.8-112.7% recovery) and precision (1.8-3.6% intra-day RSDs, 2.6% inter-day RSD), and the limit of detection (LOD) was 0.05 ng mL-1. Due to its cost-effective, time-saving, environmentally friendly, and simple performance, it has the potential to be utilized to determine aflatoxins in complicated matrices.

Visual saliency guided perceptual adaptive quantization based on HEVC intra-coding for planetary images.

Due to the limited storage space of spacecraft and downlink bandwidth in the data delivery during planetary exploration, an efficient way for image compression onboard is essential to reduce the volume of acquired data. Applicable for planetary images, this study proposes a perceptual adaptive quantization technique based on Convolutional Neural Network (CNN) and High Efficiency Video Coding (HEVC). This technique is used for bitrate reduction while maintaining the subjective visual quality. The proposed algorithm adaptively determines the Coding Tree Unit (CTU) level Quantization Parameter (QP) values in HEVC intra-coding using the high-level features extracted by CNN. A modified model based on the residual network is exploited to extract the saliency map for a given image automatically. Furthermore, based on the saliency map, a CTU level QP adjustment technique combining global saliency contrast and local saliency perception is exploited to realize a flexible and adaptive bit allocation. Several quantitative performance metrics that efficiently correlate with human perception are used for evaluating image quality. The experimental results reveal that the proposed algorithm achieves better visual quality along with a maximum of 7.17% reduction in the bitrate as compared to the standard HEVC coding.

Genomic Characterization of ESBL/AmpC-Producing Escherichia coli in Stray Dogs Sheltered in Yangzhou, China.

Purpose: Limited data are available on the prevalence and antimicrobial resistance of extended spectrum ß-lactamase- (ESBL) and AmpC ß-lactamase-producing Escherichia coli in stray dogs. We aimed to investigate the genomic characteristics of ESBL/AmpC-producing E. coli isolated from stray dogs sheltered in Yangzhou, China. Methods: We collected 156 samples including 115 fecal swabs, 35 kennel floor swabs, two breeder hand and shoe sole swabs, and four feed samples. The isolates were tested for resistance by antimicrobial susceptibility testing and further analyzed for cefotaxime-resistant E. coli isolates by whole genome sequencing. Results: We identified 80 cefotaxime-resistant E. coli isolates (51.3%), 59 isolates (73.8%) from feces and 21 (26.2%) from the environment. Whole-genome sequencing analysis showed that bla CTX-M-15 (n=30) and bla CTX-M-55 (n=29) were the most prevalent genotypes. Two isolates only carried the AmpC ß-lactamase gene bla CMY-2; one isolate had a combination of AmpC ß-lactamase gene bla DHA-1 and ESBL ß-lactamase gene bla CTX-M-14. Other important resistance genes such as bla OXA-10, bla TEM-1B, bla TEM-135, bla TEM-106, tet(A), qnrS1, qnrB4, and oqxAB were also detected. The serotype combination was highly abundant, with O10:H25 predominating (n=12). Most cefotaxime-resistant E. coli isolates belonged to phylogroup A (62.5%, n=50), followed by phylogroup B1 (26.3%, n=21). Thirty different sequence types (STs) and 27 distinct plasmid replicons were identified, among which ST2325 (n=12) and IncFII (n=38) was the most frequent ST and plasmid, respectively. ESBL/AmpC-producing isolates were divided into four major clades; clade IV was the primary lineage containing 37 isolates from feces and 13 from the environment. Three high-risk E. coli clone ST23 strains and one ST10 strain belonged to clades III and IV, respectively. Conclusion: Our study provides a comprehensive overview of resistance profiles and genomic characteristics in ESBL/AmpC-producing E. coli and highlights the possible role of stray dogs as an antibiotic resistance gene reservoir.