362 research outputs found

    Concentration of acrylamide in a polyacrylamide gel affects VP4 gene coding assignment of group A equine rotavirus strains with P[12] specificity

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    <p>Abstract</p> <p>Background</p> <p>It is universally acknowledged that genome segment 4 of group A rotavirus, the major etiologic agent of severe diarrhea in infants and neonatal farm animals, encodes outer capsid neutralization and protective antigen VP4.</p> <p>Results</p> <p>To determine which genome segment of three group A equine rotavirus strains (H-2, FI-14 and FI-23) with P[12] specificity encodes the VP4, we analyzed dsRNAs of strains H-2, FI-14 and FI-23 as well as their reassortants by polyacrylamide gel electrophoresis (PAGE) at varying concentrations of acrylamide. The relative position of the VP4 gene of the three equine P[12] strains varied (either genome segment 3 or 4) depending upon the concentration of acrylamide. The VP4 gene bearing P[3], P[4], P[6], P[7], P[8] or P[18] specificity did not exhibit this phenomenon when the PAGE running conditions were varied.</p> <p>Conclusions</p> <p>The concentration of acrylamide in a PAGE gel affected VP4 gene coding assignment of equine rotavirus strains bearing P[12] specificity.</p

    Exploratory analysis of gut microbiota differences in childhood asthma with different severity

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    Objective·To explore the characteristics and differences of gut microbiota in children with different severity of bronchial asthma, and build a prediction model of gut microbiota in severe asthma.Methods·In this study, children aged 5 to 14 diagnosed with asthma in the Department of Respiratory Medicine of Children's Hospital of Fudan University from Sep 1, 2020 to Aug 31, 2022 were selected, and children with severe asthma (SA) according to the Recommendations for Standardized Diagnosis and Management of Bronchial Asthma in Children (2020) were included. Children with mild to moderate asthma (MMA) and healthy children in the same period were matched according to age and gender. Stool samples collected from the three groups were subjected to 16S rRNA gene sequencing and the gut microbiota diversity, structure, and composition were assessed. The area under the receiver operating characteristic (ROC) curve (AUC) was applied to compare the predictive efficacy for SA.Results·Fifty children were enrolled in the SA group, 54 children matched by gender and age were in the MMA group and 39 healthy children were in the healthy control group. The α diversity of gut microbiota significantly decreased in the asthma children (P<0.05), compared with that in the healthy control group. The relative abundance of Treponema was the highest in the SA group, followed by the MMA group and healthy control group (P<0.001). The relative abundance of Lactobacillus in the MMA group and SA group was higher than that in the healthy control group (both P<0.05). The SA group had a higher relative abundance of Prevotella, Lactobacillus, Eubacterium_eligens_group, Treponema, and Fusicatenibacter. The MMA group had a higher relative abundance of Barnesiella, Holdemanella, Romboutsia and Turicibacter. The healthy control group had a higher relative abundance of the uncultured and Muribaculaceae. Among them, the relative abundance of Barnesiella decreased in the SA group, and it was found to have the highest sensitivity and specificity in predicting SA (AUC 0.713, 95%CI 0.604‒0.815).Conclusion·The diversity of gut microbiota in asthma children is lower than that in healthy children, and the composition of gut microbiota differs among childhood asthma with different severity. The abundance of Barnesiella decreases in the SA group significantly, suggesting that analysis of gut microbiota may help in the assessment of childhood asthma with different severity

    Differences in tissue distribution ability of evodiamine and dehydroevodiamine are due to the dihedral angle of the molecule stereo-structure

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    Introduction: This researcher focused at the evodiamine and dehydroevodiamine tissue distribution and structure-pharmacokinetics (PK) relationship after intravenous injection in mice.Methods: Using a transmembrane transport experiment, the permeability of evodiamine and dehydroevodiamine on Caco-2 cells was evaluated. The tissue distribution and pharmacokinetics (PK) of evodiamine and dehydroevodiamine in mice were studied. To comprehend the connection between structure and tissue distribution, physicochemical property evaluations and molecular electrostatic potential (MEP) calculations were performed.Results: Dehydroevodiamine’s Papp values in vitro were 10−5 cm/s, whereas evodiamine’s were 10−6 cm/s. At a dose of 5 mg/kg, the brain concentration of dehydroevodiamine was 6.44 times more than that of evodiamine. By MEP or physicochemical measures, the permeability difference between evodiamine and dehydroevodiamine is unaffected. The dihedral angle of the stereo-structure appears to be the main cause of the difference in tissue distribution ability between evodiamine and dehydroevodiamine.Discussion: Dehydroevodiamine has a dihedral angle of 3.71° compared to 82.34° for evodiamine. Dehydroevodiamine can more easily pass through the phospholipid bilayer than evodiamine because it has a more planar stereo-structure. Dehydroevodiamine is therefore more likely to pass cross the blood-brain barrier and enter the brain in a tissue-specific manner

    Application of FGD-BCEL loss function in segmenting temporal lobes on localized CT images for radiotherapy

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    ObjectivesThe aim of this study was to find a new loss function to automatically segment temporal lobes on localized CT images for radiotherapy with more accuracy and a solution to dealing with the classification of class-imbalanced samples in temporal lobe segmentation.MethodsLocalized CT images for radiotherapy of 70 patients with nasopharyngeal carcinoma were selected. Radiation oncologists sketched mask maps. The dataset was randomly divided into the training set (n = 49), the validation set (n = 7), and the test set (n = 14). The training set was expanded by rotation, flipping, zooming, and shearing, and the models were evaluated using Dice similarity coefficient (DSC), Jaccard similarity coefficient (JSC), positive predictive value (PPV), sensitivity (SE), and Hausdorff distance (HD). This study presented an improved loss function, focal generalized Dice-binary cross-entropy loss (FGD-BCEL), and compared it with four other loss functions, Dice loss (DL), generalized Dice loss (GDL), Tversky loss (TL), and focal Tversky loss (FTL), using the U-Net model framework.ResultsWith the U-Net model based on FGD-BCEL, the DSC, JSC, PPV, SE, and HD were 0.87 ± 0.11, 0.78 ± 0.11, 0.90 ± 0.10, 0.87 ± 0.13, and 4.11 ± 0.75, respectively. Except for the SE, all the other evaluation metric values of the temporal lobes segmented by the FGD-BCEL-based U-Net model were improved compared to the DL, GDL, TL, and FTL loss function-based U-Net models. Moreover, the FGD-BCEL-based U-Net model was morphologically more similar to the mask maps. The over- and under-segmentation was lessened, and it effectively segmented the tiny structures in the upper and lower poles of the temporal lobe with a limited number of samples.ConclusionsFor the segmentation of the temporal lobe on localized CT images for radiotherapy, the U-Net model based on the FGD-BCEL can meet the basic clinical requirements and effectively reduce the over- and under-segmentation compared with the U-Net models based on the other four loss functions. However, there still exists some over- and under-segmentation in the results, and further improvement is needed

    ScratchDet: Training Single-Shot Object Detectors from Scratch

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    Current state-of-the-art object objectors are fine-tuned from the off-the-shelf networks pretrained on large-scale classification dataset ImageNet, which incurs some additional problems: 1) The classification and detection have different degrees of sensitivity to translation, resulting in the learning objective bias; 2) The architecture is limited by the classification network, leading to the inconvenience of modification. To cope with these problems, training detectors from scratch is a feasible solution. However, the detectors trained from scratch generally perform worse than the pretrained ones, even suffer from the convergence issue in training. In this paper, we explore to train object detectors from scratch robustly. By analysing the previous work on optimization landscape, we find that one of the overlooked points in current trained-from-scratch detector is the BatchNorm. Resorting to the stable and predictable gradient brought by BatchNorm, detectors can be trained from scratch stably while keeping the favourable performance independent to the network architecture. Taking this advantage, we are able to explore various types of networks for object detection, without suffering from the poor convergence. By extensive experiments and analyses on downsampling factor, we propose the Root-ResNet backbone network, which makes full use of the information from original images. Our ScratchDet achieves the state-of-the-art accuracy on PASCAL VOC 2007, 2012 and MS COCO among all the train-from-scratch detectors and even performs better than several one-stage pretrained methods. Codes will be made publicly available at https://github.com/KimSoybean/ScratchDet.Comment: CVPR2019 Oral Presentation. Camera Ready Versio

    Study of Characteristic and Period of Communication and Electronics Industry in Chinese Securities Market

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    Purpose: This study aims to analyze the characteristics of communication and electronics industry in Chinese stock market and calculate the average periods of it. Design/methodology/approach: We use R/S analysis method to study the characteristics of communication and electronics industry in Chinese stock market, and use Matlab software and Eviews software to calculate some representative exponents of this industry. Findings: The results show that the probability distribution of the communication and electronics industry in the Chinese stock market is nearly non-normal distribution, but a partial distribution, showing a peak, thick tail, migraine and other features. Hurst exponent calculated shows that the communication and electronics industry in the Chinese stock market has obvious fractal characteristics, and does not follow a random walk assumption, but follows persistent trend. The average big circulation period is about 400 days; the average small circulation period is about 200 days. Research limitations/implications: We use R/S analysis method to study the characteristics including periods and venture.of communication and electronics industry in Chinese stock market. Practical implications: The average periods and related venture can give investors properly suggestions. Originality/Value: We use R/S analysis method and Matlab software and Eviews software to analyze the characteristics of communication and electronics industry in Chinese stock market which has barely been studied. The results unfold the characteristics of this industry and can give investors properly suggestions as well.Key words: Stock market; Fractal; R/S analysis; Hurst exponent; Periods; Communication and electronic

    The behavior of methane/hydrogen/air premixed flame in a closed channel with inhibition

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    Hydrogen enriched natural gas (HNG) is a promising alternative fuel. But the blended fuel will inevitably have different ignition and combustion characteristics as compared to natural gas. The extent of the resulting difference depends on the percentage of hydrogen addition. It may affect the compatibility of combustion systems and have safety implications. The present study was aimed at enhancing the safety of HNG through inhibition by inert gases. Laboratory tests were conducted for methane/hydrogen/air premixed flame propagating in a closed channel with either nitrogen (N2) or carbon dioxide (CO2) as the inhibitor. Mixtures with different hydrogen volumetric fractions in fuel, including 0%, 20%, 50% or 80% were investigated. The flame shape evolution and the overpressure in the channel were recorded by high-speed Schlieren photography and pressure sensor, respectively. The flame shape was found to change in various ways depending on the inhibitor and hydrogen content. The pressure wave had remarkable impacts on flame and pressure dynamics. The effect of buoyancy on the flame deformation was observed and discussed. Both N2 and CO2 were found to have considerable inhibiting effect on the flame speed and overpressure build-up in the channel while the inhibiting effect of CO2 was stronger. The inhibition mechanisms of either N2 or CO2 were revealed from thermal and kinetic aspects
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