55 research outputs found

    Prediction of lymph node status in patients with early-stage cervical cancer based on radiomic features of magnetic resonance imaging (MRI) images

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    Abstract Background Lymph node metastasis is an important factor affecting the treatment and prognosis of patients with cervical cancer. However, the comparison of different algorithms and features to predict lymph node metastasis is not well understood. This study aimed to construct a non-invasive model for predicting lymph node metastasis in patients with cervical cancer based on clinical features combined with the radiomic features of magnetic resonance imaging (MRI) images. Methods A total of 180 cervical cancer patients were divided into the training set (n = 126) and testing set (n = 54). In this cross-sectional study, radiomic features of MRI images and clinical features of patients were collected. The least absolute shrinkage and selection operator (LASSO) regression was used to filter the features. Seven machine learning methods, including eXtreme Gradient Boosting (XGBoost), Logistic Regression, Multinomial Naive Bayes (MNB), Support Vector Machine (SVM), Decision Tree, Random Forest, and Gradient Boosting Decision Tree (GBDT) are used to build the models. Receiver operating characteristics (ROC) curve and area under the curve (AUC), accuracy, sensitivity, and specificity were calculated to assess the performance of the models. Results Of these 180 patients, 49 (27.22%) patients had lymph node metastases. Five of the 122 radiomic features and 3 clinical features were used to build predictive models. Compared with other models, the MNB model was the most robust, with its AUC, specificity, and accuracy on the testing set of 0.745 (95%CI: 0.740–0.750), 0.900 (95%CI: 0.807–0.993), and 0.778 (95%CI: 0.667–0.889), respectively. Furthermore, the AUCs of the MNB models with clinical features only, radiomic features only, and combined features were 0.698 (95%CI: 0.692–0.704), 0.632 (95%CI: 0.627–0.637), and 0.745 (95%CI: 0.740–0.750), respectively. Conclusion The MNB model, which combines the radiomic features of MRI images with the clinical features of the patient, can be used as a non-invasive tool for the preoperative assessment of lymph node metastasis

    Rna M6a Methylation Regulates Glycolysis of Beige Fat and Contributes to Systemic Metabolic Homeostasis

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    Abstract N6‐methyladenosine (m6A) modification has been implicated in the progression of obesity and metabolic diseases. However, its impact on beige fat biology is not well understood. Here, via m6A‐sequencing and RNA‐sequencing, this work reports that upon beige adipocytes activation, glycolytic genes undergo major events of m6A modification and transcriptional activation. Genetic ablation of m6A writer Mettl3 in fat tissues reveals that Mettl3 deficiency in mature beige adipocytes leads to suppressed glycolytic capability and thermogenesis, as well as reduced preadipocytes proliferation via glycolytic product lactate. In addition, specific modulation of Mettl3 in beige fat via AAV delivery demonstrates consistently Mettl3's role in glucose metabolism, thermogenesis, and beige fat hyperplasia. Mechanistically, Mettl3 and m6A reader Igf2bp2 control mRNA stability of key glycolytic genes in beige adipocytes. Overall, these findings highlight the significance of m6A on fat biology and systemic energy homeostasis

    Integral Effects of Porosity, Permeability, and Wettability on Oil–Water Displacement in Low-Permeability Sandstone Reservoirs—Insights from X-ray CT-Monitored Core Flooding Experiments

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    Porosity, permeability, and wettability are crucial factors that affect the oil–water displacement process in reservoirs. Under subsurface conditions, the integral effects of these factors are extremely difficult to document. In this paper, waterflooding experiments were carried out using a core flooding system monitored with X-ray dual-energy CT. The mesoscale, three-dimensional characteristics of water displacing oil were obtained in real time. The integral effects of porosity, permeability, and wettability on the waterflooding in the low-permeability sandstone reservoirs were investigated. It was found that if the reservoir rock is water-wet, then the residual oil saturation decreases gradually with increasing porosity and permeability, showing an increasing waterflooding efficiency. On the contrary, if the reservoir rock is oil-wet, the residual oil saturation gradually increases with improving porosity and permeability, showing a decreasing waterflooding efficiency. The porosity, permeability, and wettability characteristics of reservoirs should be comprehensively evaluated before adopting technical countermeasures of waterflooding or wettability modification during oilfield development. If the porosity and permeability of the reservoir are high, water-wet reservoirs can be directly developed with waterflooding. However, it is better to make wettability modifications first before the waterflooding for oil-wet reservoirs. If the porosity and permeability of the reservoir are poor, direct waterflooding development has a better effect on oil-wet reservoirs compared with the water-wet reservoirs

    Characterisation of forkhead box protein A3 as a key transcription factor for hepatocyte regeneration

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    Background & Aims: Liver regeneration is vital for the recovery of liver function after injury, yet the underlying mechanism remains to be elucidated. Forkhead box protein A3 (FOXA3), a member of the forkhead box family, plays important roles in endoplasmic reticulum stress sensing, and lipid and glucose homoeostasis, yet its functions in liver regeneration are unknown. Methods: Here, we explored whether Foxa3 regulates liver regeneration via acute and chronic liver injury mice models. We further characterised the molecular mechanism by chromatin immunoprecipitation sequencing and rescue experiments in vivo and in vitro. Then, we assessed the impact of Foxa3 pharmacological activation on progression and termination of liver regeneration. Finally, we confirmed the Foxa3–Cebpb axis in human liver samples. Results: Foxa3 is dominantly expressed in hepatocytes and cholangiocytes and is induced upon partial hepatectomy (PH) or carbon tetrachloride (CCl4) administration. Foxa3 deficiency in mice decreased cyclin gene levels and delayed liver regeneration after PH, or acute or chronic i.p. CCl4 injection. Conversely, hepatocyte-specific Foxa3 overexpression accelerated hepatocytes proliferation and attenuated liver damage in an CCl4-induced acute model. Mechanistically, Foxa3 directly regulates Cebpb transcription, which is involved in hepatocyte division and apoptosis both in vivo and in vitro. Of note, Cebpb overexpression in livers of Foxa3-deficient mice rescued their defects in cell proliferation and regeneration upon CCl4 treatment. In addition, pharmacological induction of Foxa3 via cardamonin speeded up hepatocyte proliferation after PH, without interfering with liver regeneration termination. Finally, Cebpb and Ki67 levels had a positive correlation with Foxa3 expression in human chronic disease livers. Conclusions: These data characterise Foxa3 as a vital regulator of liver regeneration, which may represent an essential factor to maintain liver mass after liver injury by governing Cebpb transcription. Impact and Implications: Liver regeneration is vital for the recovery of liver function after chemical insults or hepatectomy, yet the underlying mechanism remains to be elucidated. Herein, via in vitro and in vivo models and analysis, we demonstrated that Forkhead box protein A3 (FOXA3), a Forkhead box family member, maintained normal liver regeneration progression by governing Cebpb transcription and proposed cardamonin as a lead compound to induce Foxa3 and accelerate liver repair, which signified that FOXA3 may be a potential therapeutic target for further preclinical study on treating liver injury

    A comprehensive review of electrochemical hybrid power supply systems and intelligent energy managements for unmanned aerial vehicles in public services

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    The electric unmanned aerial vehicles (UAVs) are rapidly growing due to their abilities to perform some difficult or dangerous tasks as well as many public services including real-time monitoring, wireless coverage, search and rescue, wildlife surveys, and precision agriculture. However, the electrochemical power supply system of UAV is a critical issue in terms of its energy/power densities and lifetime for service endurance. In this paper, the current power supply systems used in UAVs are comprehensively reviewed and analyzed on the existing power configurations and the energy management systems. It is identified that a single type of electrochemical power source is not enough to support a UAV to achieve a long-haul flight; hence, a hybrid power system architecture is necessary. To make use of the advantages of each type of power source to increase the endurance and achieve good performance of the UAVs, the hybrid systems containing two or three types of power sources (fuel cell, battery, solar cell, and supercapacitor,) have to be developed. In this regard, the selection of an appropriate hybrid power structure with the optimized energy management system is critical for the efficient operation of a UAV. It is found that the data-driven models with artificial intelligence (AI) are promising in intelligent energy management. This paper can provide insights and guidelines for future research and development into the design and fabrication of the advanced UAV power systems.Published versionThis work is supported in part by the founding of state key laboratory of industrial control technology, Zhejiang University (ICT2021B19), the Technological Innovation and Application Demonstration in Chongqing (Major Themes of Industry: cstc2019jscx-zdztzxX0033, cstc2019jscx-fxyd0158) and the National Natural Science Foundation of China (NO. 22005026, 21908142)

    Study of degradation of fuel cell stack based on the collected high-dimensional data and clustering algorithms calculations

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    Accurate perception of the performance degradation of fuel cell is very important to detect its health state. However, inconsistent operating conditions of fuel cell vehicles in the test result in errors in the data. In order to obtain a more credible degradation rate, this study proposes a novel method to classify the experimental data collected under different working conditions into similar operating conditions by using dimensionality reduction and clustering algorithms. Firstly, the experimental data collected from fuel cell vehicles belong to high-dimensional data. Then projecting high-dimensional data into three-dimensional feature vector space via principal component analysis (PCA). The dimension-reduced three-dimensional feature vectors are input into the clustering algorithm, such as K-means and density-based noise application spatial clustering(DBSCAN). According to the clustering results, the fuel cell voltage data with similar operating conditions can be classified. Finally, the selected voltage data can be used to precisely represent the true performance degradation of an on-board fuel cell stack. The results show that the voltage using the K-means algorithm declines the fastest, followed by the DBSCAN algorithm, finally the original data, which indicates that the performance of the fuel cell actually declines faste. Early intervention can prolong its life to the greatest extent

    Influencing Factors of Shear Wave Radiation of a Dipole Source in a Fluid-Filled Borehole

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    In shear wave far detection logging, dipole-source radiation is the main factor influencing the amplitude of the reflected shear waves. In this paper, a method is derived with the far-field asymptotic solution to calculate the dipole-source radiation of shear waves in a fluid-filled borehole. Then the dipole-source radiation of the shear waves is simulated under both low and high frequencies. In addition, the influences of formation elastic parameters on the dipole-source radiation of the shear waves are analyzed and the variations of the radiation characteristics of the shear wave with source main frequency and borehole radius are compared. Results show that the density and compressional wave velocity of the formation have little effect on the dipole-source radiation of the shear waves. However, the shear wave velocity not only affects the shear wave amplitude radiated to the formation by the dipole source (radiation performance), but also affects the energy distribution of the shear wave at different locations in space (radiation direction). The dipole source has better radiation performance and radiation coverage at low frequency and the optimal excitation frequency in different formations is very close, which is good for the application of this technology under different circumstances. At low frequency, the borehole has little influence on the dipole-source radiation, no matter how large the borehole radius is. However, at high frequency, the borehole modulation of the dipole-source radiation cannot be ignored, especially at large borehole radius

    Systematic study of short circuit activation on the performance of PEM fuel cell

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    During the operation of proton exchange membrane fuel cell (PEMFC), it always suffers from reversible performance loss caused by the oxidation of platinum catalyst on its electrode, which reduces the electrochemical active surface area. Short circuit method has been found to improve the performance of fuel cells by stripping of oxides and other adsorbed species from platinum, which needs systematical understanding the effective parameters of short circuit method on fuel cell performance. In this paper, the effects of different short circuit activation parameters (duration, interval, cycles, cut-off voltage, operating current) are carefully studied and analyzed during short circuit operations. In addition, the mechanism revealing how relevant parameters influence short circuit activations is deeply analyzed. The results show that five groups of activation parameters have obvious influence on the activation of fuel cell, indicating that the short-circuit activation effect can be optimized. Among these parameters, the short-circuit duration parameter have the greatest impact on activation, because the platinum hydroxides and oxides is gradually removed during short-circuit duration and results in a larger effective surface area of the platinum catalyst for the electrochemical reaction. However, the smallest impact is short-circuit interval. Another finding is that the five activation parameters are not independent, so the optimal activation parameter value needs to be analyzed in combination with the operating conditions. Finally, according to the activation principle, selection of appropriate short circuit activation parameters for application are proposed to further improve performance and fuel utilization by considering the safety of the stack.This work was supported in part by the National Key Research and Development Program under Grant 2018YFB0105402 and Grant 2018YFB0105703, the Technological Innovation and Application Demonstration in Chongqing (Major Themes of Industry: cstc2018jszx-cyztzxX0005, cstc2019jscx-zdztzxX0033 and cstc2019jscx-fxydX0020) and by the Fundamental Research Funds for the Central Universities under Grant 2019CDXYQC0003, 244005202014, 2019, and Grant 2018CDXYTW0031

    Two Novel AGXT Mutations Cause the Infantile Form of Primary Hyperoxaluria Type I in a Chinese Family: Research on Missed Mutation

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    Primary hyperoxaluria type 1 (PH1) is a rare metabolic disorder characterized by a defect in the liver-specific peroxisomal enzyme alanine-glyoxylate and serine-pyruvate aminotransferase (AGT). This disorder results in hyperoxaluria, recurrent urolithiasis, and nephrocalcinosis. Three forms of PH1 have been reported. Data on the infantile form of PH1 are currently limited in literature. Despite the fact that China is the most populated country in the world, only a few AGXT mutations have been reported in several Chinese PH1 patients. In the present study, we investigated a Chinese family in which two siblings are affected by the infantile form of PH1. Sanger sequencing was carried out on the proband, but the results were misleading. Two novel missense mutations (c.517T > C/p.Cys173Arg and c.667A > C/p.Ser223Arg) of the AGXT gene were successfully detected through whole-exome sequencing. These two mutations occurred in the highly conserved residues of the AGT. Four software programs predicted both mutations as the cause of the disease. A postmortem examination was performed and revealed the occurrence of global nephrocalcinosis on both kidneys. The crystals were collected and analyzed as calcium oxalate monohydrate. This study extends the knowledge on the clinical phenotype–genotype correlation of the AGXT mutation. That is, (i) two novel missense mutations were identified for the infantile form of PH1 and (ii) the same AGXT genotype caused the same infantile form of PH1 within the family