Based on the data from the fatigue test of Epoxy Molding Compound (EMC), firstly with a focus on the application problem of the instability between fitting and prediction error of BP neural network (BPNN), the prediction model of fatigue life for EMC materials is established. In this approach, the network structure is improved with initiative way by reducing input from the perspective of nodes with principal component analysis (PCA). Secondly, in order to deal with the problem of the bottleneck in local flow minimum of BPNN, this study tries to find out the global minimum and improves the convergence performance of the BPNN combining genetic algorithm (GA). The stability and practicality of the GABPNN model is analyzed after training and verifying, and the effect of the input factors on the output factor is studied in turn. Finally, this paper makes use of well-trained GABPNN prediction model to analyze optimum design methods of parameters to predict the fatigue life. The prediction and optimization results show that the well-trained GABPNN model can be used in the forecasting and optimizing design of the fatigue and fracture reliability of the epoxy molding compounds, and is of much practical value.

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Rationale: To describe the clinical effects of human umbilical cord mesenchymal stem cells (UCMSCs) combined with allogenic platelet-rich fibrin (PRF) for the treatment of lower limb ischemia in an elderly patient. Patient concerns: The patient was a 93-year-old Chinese woman with bilateral foot gangrene and ulcers lasting for 6 months. She had a prior history of Behcet's disease. Diagnoses: The admitting diagnosis for this episode was atherosclerosis bilateral limb ischemia. Interventions: First, treatment consisting of immunosuppressants, anticoagulation, antiplatelets, and anti-microbials were instituted. A UCMSC suspension was administered intravenously and injected into the lower limbs twice. An allogenic PRF membrane was externally applied 15 times over the lower limbs. Outcomes: The patient's pain improved and the 6 ulcers healed. Lessons: The combination of UCMSCs with a PRF membrane for the treatment of lower limb ischemia in an elderly patient is effective and safe. More and larger trials are needed before incorporating this therapy into mainstream treatment.

Terahertz waves have unique penetrability, safety, spectral resolution, and many other useful properties. Therefore, terahertz waves are widely employed in medical treatment, detection, imaging, security, and spectroscopy. They also possess great development prospects in photoconductive antennas (PCAs) for telecommunication and other devices. However, terahertz PCAs are still limited by the weak photocurrents and small light absorption rates, making the development of PCAs with improved conversion efficiencies highly desirable. In this study, a new type of plasmonic PCAs with high photoelectric conversion efficiency was proposed. The interaction between the 800 nm fs laser and staggered nanorods was studied by the finite difference time domain (FDTD) method. The geometric parameters of the nanorods arrays were optimized. Compared to conventional photoconductive antennas without nanostructures, the PCAs with optimized nano-plasmonic structure I showed threefold higher electric field radiations under 800 nm fs laser irradiation. Optimized plasmonic nanostructure II increases photocurrent up to 335.553 nA that indicates 10 times enhancement in comparison with conventional structure. Hence, the developed structures greatly enhanced the light absorption of the photosensitive layer based on low-temperature-grown gallium arsenide. In sum, the proposed staggered hexagonal plasmonic structures (structure II) could effectively improve the light-terahertz conversion efficiencies of PCAs.