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Optical coherence tomography (OCT) is a noninvasive, radiation-free, and high-resolution imaging technology. The intraoperative classification of normal and cancerous tissue is critical for surgeons to guide surgical operations. Accurate classification of gastric cancerous OCT images is beneficial to improve the effect of surgical treatment based on the deep learning method. The OCT system was used to collect images of cancerous tissues removed from patients. An intelligent classification method of gastric cancerous tissues based on the residual network is proposed in this study and optimized with the ResNet18 model. Four residual blocks are used to reset the model structure of ResNet18 and reduce the number of network layers to identify cancerous tissues. The model performance of different residual networks is evaluated by accuracy, precision, recall, specificity, F1 value, ROC curve, and model parameters. The classification accuracies of the proposed method and ResNet18 both reach 99.90%. Also, the model parameters of the proposed method are 44% of ResNet18, which occupies fewer system resources and is more efficient. In this study, the proposed deep learning method was used to automatically recognize OCT images of gastric cancerous tissue. This artificial intelligence method could help promote the clinical application of gastric cancerous tissue classification in the future. [ABSTRACT FROM AUTHOR]

Double-roll rotary forging is an advanced partial progressive forming technology with multi-factor coupling interactive effects. To date, a few relevant researches on the double-roll rotary forging technology of large-diameter thin-walled discs have been reported, and the stable rolling conditions, stress field, velocity field, and so on are not studied in detail. Herein, a reasonable 3D rigid-plastic finite model of the double-roll hot rotary forging of a disk workpiece is established under the DEFORM software environment. Based on the valid 3D finite model, the distribution of stress field and velocity field and the influence of die preheating and initial size of workpiece on the uniformity and maximum axial load were studied. The research results can promote the application and development of rotary forging technology. [ABSTRACT FROM AUTHOR]

Double-roll rotary forging is an advanced partial progressive forming technology with multi-factor coupling interactive effects. To date, a few relevant researches on the double-roll rotary forging technology of large-diameter thin-walled discs have been reported, and the stable rolling conditions, stress field, velocity field, and so on are not studied in detail. Herein, a reasonable 3D rigid-plastic finite model of the double-roll hot rotary forging of a disk workpiece is established under the DEFORM software environment. Based on the valid 3D finite model, the distribution of stress field and velocity field and the influence of die preheating and initial size of workpiece on the uniformity and maximum axial load were studied. The research results can promote the application and development of rotary forging technology. [ABSTRACT FROM AUTHOR]

Double-roll rotary forging is an emerging plastic forming technology based on rotary forging. Owing to the advantages of labor saving, small eccentric load, low noise and vibration, good uniformity, high surface quality, and material saving, it is very promising for fabrication of large-diameter thin-walled disc. To date, a few relevant researches on the double-roll rotary forging technology of large-diameter thin-walled metal discs have been reported, and the forming mechanisms and process of disc workpieces remain uninvestigated. Herein, a 3D rigid-plastic finite element model (FEM) is established to simulate the fabrication process of large-diameter thin-walled disc; four geometric features appear in the forming process: "mushroom" shape, "upper drum" shape, "drum shape" shape, and "lower drum" shape. Equivalent stress, equivalent strain, and temperature field of these four geometric shapes are analyzed, and the forming mechanism of these four geometric shapes is revealed. The reliability and accuracy of FEM are verified through experiments, and the four geometric shape features occur in the process are consistent with the simulation. The research results provide valuable guidelines for better understanding of double-roll rotary forging for the fabrication of large-diameter thin-walled discs. [ABSTRACT FROM AUTHOR]

The objective of this study was to assess the effects of whole-body vibration (WBV) on lumbar muscle oxygenation oscillations in healthy men based on the wavelet transform of near-infrared spectroscopy signals. Twelve healthy participants were exposed to WBV at frequencies of 3, 4.5 and 6 Hz while muscle oxygenation signal was monitored before, during and recovery from WBV. With spectral analysis based on wavelet transform of NIR signal, six frequency intervals were identified (I, 0.005-0.0095 Hz; II, 0.0095-0.02 Hz; III, 0.02-0.06 Hz; IV, 0.06-0.16 Hz; V, 0.16-0.40 Hz and VI, 0.40-2.0 Hz). It was found that the muscle oxygenation oscillations at 4.5 Hz in the frequency intervals I, II and III was lower during WBV compared with that of at 3 Hz. Present results demonstrated WBV at 4.5 Hz induced lower oscillatory activities than that of at 3 Hz. The lower oscillatory activities might indicate a decrease in the efficiency of oxygen supply to the oxygenated tissue and such mechanism might contribute to the development of local muscle fatigue. [ABSTRACT FROM AUTHOR]