168 research outputs found

    Intelligent automatic sleep staging model based on CNN and LSTM

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    Since electroencephalogram (EEG) is a significant basis to treat and diagnose somnipathy, sleep electroencephalogram automatic staging methods play important role in the treatment and diagnosis of sleep disorders. Due to the characteristics of weak signals, EEG needs accurate and efficient algorithms to extract feature information before applying it in the sleep stages. Conventional feature extraction methods have low efficiency and are difficult to meet the time validity of fast staging. In addition, it can easily lead to the omission of key features owing to insufficient a priori knowledge. Deep learning networks, such as convolutional neural networks (CNNs), have powerful processing capabilities in data analysis and data mining. In this study, a deep learning network is introduced into the study of the sleep stage. In this study, the feature fusion method is presented, and long-term and short-term memory (LSTM) is selected as the classification network to improve the accuracy of sleep stage recognition. First, based on EEG and deep learning network, an automatic sleep phase method based on a multi-channel EGG is proposed. Second, CNN-LSTM is used to monitor EEG and EOG samples during sleep. In addition, without any signal preprocessing or feature extraction, data expansion (DA) can be realized for unbalanced data, and special data and non-general data can be deleted. Finally, the MIT-BIH dataset is used to train and evaluate the proposed model. The experimental results show that the EEG-based sleep phase method proposed in this paper provides an effective method for the diagnosis and treatment of sleep disorders, and hence has a practical application value

    Design and research of hydraulic cylinder precise control test system

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    The position deviation after the continuous action of the hydraulic support in the fully-mechanized mining face affects the mining efficiency of the shearer. In view of the above problems, the mechanism of the hydraulic system of the fully-mechanized mining face is analyzed, the coupling relationship between the system pressure, flow and the displacement of the hydraulic cylinder is established, and a hydraulic cylinder precise displacement test platform with emulsion/pure water as the transmission medium is designed and built, which can carry out eccentric load and lateral load experiments of the test hydraulic cylinder. The test platform is composed of hydraulic test system, oil pressure regulation system, electrical control system, data acquisition system, upper computer software system, loading test bench, etc. The oil pressure regulation mechanism adjusts the working attitude of the hydraulic cylinder, the data acquisition system monitors and tests the pressure, flow, displacement, temperature and other data of the hydraulic cylinder in real time, and the loading test bench equates the hydraulic support, scraper conveyor and shearer as adjustable weight. Data acquisition frequency of the hydraulic cylinder precise control test system is 2 000 Hz, the nominal pressure is 31.5 MPa, the nominal flow is 400 L / min, the test hydraulic cylinder has a cylinder diameter of 100-240 mm, a stroke of 400-1 800 mm, and the working resistance is larger than 100 kN, which can achieve the working mechanism of the hydraulic cylinder under variable working conditions. When the system flow is 126 L/min, the displacement control error of the tested hydraulic cylinder is close to 20%; when the system flow is 50 L/min, the displacement control error of the tested hydraulic cylinder is stable within 7%. The experimental results show that the transient action of hydraulic cylinder extension and retraction can be ignored in the working process, and the displacement control error is mainly caused by the response delay of valve control components, and the control error increases linearly with the increase of system flow, which verifies the feasibility of the high flow rapid action and small flow precise regulation control scheme of the two speed pressure regulating valve. The hydraulic cylinder precise control test system is applicable to the research on the precise control of hydraulic cylinder and the coordinated control of hydraulic cylinder cluster, and provides an experimental method for realizing the precise control of hydraulic support in high-pressure and large flow fully-mechanized mining face

    The Local Brain Abnormalities in Patients With Transient Ischemic Attack: A Resting-State fMRI Study

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    Background: Transient ischemic attack (TIA) is an important risk factor for stroke. Despite the transient episodes of clinical symptoms, brain alterations are still observed in patients with TIA. However, the functional mechanism of transient ischemia is still unclear. Here, we employed resting-state functional magnetic resonance imaging (rs-fMRI) to explore the functional abnormalities in patients with TIA.Methods: 48 TIA patients and 41 age- and sex-matched healthy controls (HCs) were enrolled in the study. For each participant, we collected rs-fMRI data and clinical/physiological/biochemical data. Amplitude of low frequency fluctuation (ALFF), regional homogeneity (ReHo), and degree centrality (DC) were then calculated. Two sample t-tests were performed to compare the ALFF, ReHo, and DC maps between the two groups. Furthermore, a correlation analysis was performed to explore the relationship between local brain abnormalities and clinical/physiological/biochemical characteristics tests in TIA patients.Results: Compared with the HCs, the TIA patients exhibited decreased ALFF in the left middle temporal gyrus, decreased DC in the triangular part of right inferior frontal gyrus, and no significant statistical difference in ReHo. No correlation was found between local abnormalities and clinical/physiological/biochemical scores in the patients with TIA.Conclusion: Collectively, we found decreased ALFF and DC in patients with TIA which provide evidence for local brain dysfunctions and may help to understand the pathological mechanism for the disease

    INHIBITORY EFFECT OF SAPONINS AND POLYSACCHARIDES FROM RADIX RANUNCULI TERNATI ON HUMAN GASTRIC CANCER BGC823 CELLS

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    The effects of different Radix ranunculi ternati extracts on human gastric cancer BGC823 cells were investigated, different methods were used to extract the saponins and polysaccharides from Radix ranunculi ternati, and MTT assay and colony formation assay were used to observe the effects of saponins and polysaccharides from Radix ranunculi ternati on in-vitro cultured human gastric cancer BGC823 cells. The results found that the saponins and polysaccharides from Radix Ranunculi Ternati had certain effects on both the growth and colony formation of human gastric cancer BGC823 cells, while improving the immune function of normal mice, of which saponins had more significant effects than polysaccharides

    Scutellarin Ameliorates Renal Injury via Increasing CCN1 Expression and Suppressing NLRP3 Inflammasome Activation in Hyperuricemic Mice

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    Considerable evidences have indicated that elevated uric acid (UA) was involved in renal tubular injury leading to hyperuricemic nephropathy (HN). Scutellarin is a biologically active flavonoid derived from the Chinese traditional herb Erigeron breviscapus Hand-Mazz, which has been widely used in the treatment of cardiovascular and cerebrovascular diseases. In the present study, we analyzed the effect of scutellarin on HN, by using C57BL/6 mice and human renal tubular epithelial cell line HK-2 which was subjected to adenine/potassium oxonate and UA to mimic a HN injury. The HN mice showed a significant decrease in renal function with the increased SCr and blood urea nitrogen (BUN) (p < 0.05). Hematoxylin-eosin staining results showed a histological injury in HN mice kidney tissues with severe tubular damage. Scutellarin dose dependently alleviated the renal injury of the HN model (p < 0.05), and a dose of 20 mg/kg/day remarkably reduced the Scr level (26.10 +/- 3.23 mu mol/ml vs. 48.39 +/- 7.51 mu mol/ml, p < 0.05) and BUN (151.12 +/- 30.24 mmol/L vs. 210.43 +/- 45.67 mmol/L, p < 0.05) compared with the HN model group. Similarly, scutellarin decreased NGAL, Kim-1, cystatin C, and IL-18 protein expression levels in HN mouse (p < 0.05). Overexpressed CCN1 could not induce NLRP3 inflammasome activation, with no change of mRNA and protein expression levels of NLRP3, ASC, and pro-caspase-1 compared with the control HK-2. However, HK-2 showed a significant NLRP3 inflammasome activation and apoptosis. Importantly, knockdown of CCN1 not only aggravated NLRP3 inflammasome activation and apoptosis but also abrogated the protective effect of scutellarin in UA-induced HK-2 injury. Thus, scutellarin might alleviate HN progression via a mechanism involved in CCN1 regulation on NLRP3 inflammasome activation

    Hypermethylation of miR-338-3p and Impact of its Suppression on Cell Metastasis Through N-Cadherin Accumulation at the Cell -Cell Junction and Degradation of MMP in Gastric Cancer

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    Background/Aims: MicroRNAs (miRNAs) have been well studied in human carcinogenesis and cancer progression. Our previous study showed the down-regulation of miR-338-3p expression in human gastric cancer (GC). However, the reasons of this dysregulation remain largely unclear. Methods: Bisulfite sequence analysis was performed to explore the methylation status of the promoter region of miR-338-3p. Cell wound-healing and transwell assays were performed to examine the capacity of cell migration and cell interaction. A dual-luciferase reporter was used to validate the bioinformatics-predicted target gene of miR-338-3p. Western blotting, RNA interference, and immunofluorescence (IF) were used to evaluate the expression of MMPs and the location of N-cadherin to determine the mechanism underlying miR-338-3p-induced anti-tumor effects. Results: miR-338-3p was epigenetically silenced, and this loss of expression was significantly correlated with the Borrmann Stage in GC. Restoring miR-338-3p expression in BGC-823 cells inhibited cell migration and invasion. Moreover, Ras-related protein (Rab-14) and Hedgehog acyltransferase (Hhat) were identified as direct targets of miR-338-3p. Both enforced expression of miR-338-3p and small interfering RNA induced Rab14-mediated accumulation of N-cadherin in the cell -cell junctions or Hhat-associated matrix metalloproteinase (MMP) degradation, which may underline the metastasis defects caused by loss of miR-338-3p in GC. Conclusion: These data indicate that miR-338-3p functions as a tumor suppressor in GC, and that the hypermethylation status of its CpG island might be a novel potential strategy for treating GC
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