7,426 research outputs found

    Fourier-DeepONet: Fourier-enhanced deep operator networks for full waveform inversion with improved accuracy, generalizability, and robustness

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    Full waveform inversion (FWI) infers the subsurface structure information from seismic waveform data by solving a non-convex optimization problem. Data-driven FWI has been increasingly studied with various neural network architectures to improve accuracy and computational efficiency. Nevertheless, the applicability of pre-trained neural networks is severely restricted by potential discrepancies between the source function used in the field survey and the one utilized during training. Here, we develop a Fourier-enhanced deep operator network (Fourier-DeepONet) for FWI with the generalization of seismic sources, including the frequencies and locations of sources. Specifically, we employ the Fourier neural operator as the decoder of DeepONet, and we utilize source parameters as one input of Fourier-DeepONet, facilitating the resolution of FWI with variable sources. To test Fourier-DeepONet, we develop two new and realistic FWI benchmark datasets (FWI-F and FWI-L) with varying source frequencies and locations. Our experiments demonstrate that compared with existing data-driven FWI methods, Fourier-DeepONet obtains more accurate predictions of subsurface structures in a wide range of source parameters. Moreover, the proposed Fourier-DeepONet exhibits superior robustness when dealing with noisy inputs or inputs with missing traces, paving the way for more reliable and accurate subsurface imaging across diverse real conditions

    Expression profiling of miR-96, miR-584 and miR-422a in colon cancer and their potential involvement in colon cancer pathogenesis

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    Purpose: To determine the correlation between miRNAs; miR-96, miR-422a and miR584, and colon cancer, and also to test whether any of these miRNAs can act as non-invasive biomarkers in colon cancerMethods: The tumor samples and the corresponding normal mucosa used in this study were collected from 60 patients diagnosed with colon cancer. HT-29, HCT-116 and SW-620 cell lines were used for miRNA expression profiling. Total RNA was extracted using kit-based methods with minor modifications, and specific miRNAs were detected and quantified by quantitative real-time polymerase chain reaction [RT-PCR].Results: The results indicate down-regulation of miR-96, miR-584 and miR-422a in colon cancer tissue and decreased expression levels in the three colon cancer cell lines (all p < 0.01). Lower miRNA expression levels are correlated with increased tumor size.Conclusion: This study shows that miR-96, miR-584 and miR-422a are down-regulated in colon cancer and are associated with tumor size. Thus, the ratio of miR-96/miR-638 in plasma is a potential noninvasive biomarker in colon cancer.Keywords: Colon cancer, miR-96, miR-422a, miR-584, Expression profiling, Biomarke

    Propofol causes neuronal degeneration in neonatal mice and long-term neurocognitive consequences in adult mice

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    Purpose: To investigate the effect of propofol on brain development in neonatal mice and long-term neurocognitive impact in adult mice.Method: The offspring of female C57Bl/6 and male CD-1 mice were administered propofol at concentrations of 2.5 and 5.0 mg/kg (treatment group) or normal saline (control) on postnatal day 7. Thereafter, histological and immunohistochemical examinations were performed on the mice brain. Apoptotic assay, neuronal nuclei antigen immunohistochemistry (to assess neuron density), and behavioral and neurocognitive tests were conducted on the adult mice.Results: Propofol induced cellular degeneration and apoptosis in the brains of neonatal mice. It also modulated physiological parameters (pH, PO2, glucose and lactate), among which decreased blood glucose might be associated with cellular degeneration in the brain. Propofol also caused long-term neuronal deficits in adults, which showed impaired neurocognitive functions. Upon reaching adulthood, propofol-treated mice showed slow learning response and poor memory compared to controls.Conclusion: Propofol causes neurodegeneration in neonatal mice and has long-term neurocognitive consequences in adults, indicating that the use of propofol anesthetics in neonates requires careful consideration.Keywords: Anesthesia, Apoptosis, Brain injury, Neonate, Neurodegeneration, Propofo
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