Study on Properties of Glass-Fiber-Fabric-Reinforced Microwave-Absorbing Composites.

In this paper, the glass-fiber-fabric-reinforced resin-based absorbing composites were prepared, and their microwave-absorbing properties were studied via simulation and experiment. The simulation results show that the absorption bandwidth of the absorbing material can cover the X\C\S band, respectively, at different thicknesses. The minimum reflection loss (RL) of the composite with a thickness of 2.2 mm is -27.4 dB at 5.95 GHz. However, the experiment results are quite different from those of the simulation. The metallographic results indicate that it is the change of the mass fraction of the absorbents in the composites after curing that causes the difference. According to the metallographic results, three shape approximation methods were proposed to calculate the real mass ratio of the absorbents in the composites, namely, parallelogram approximation, bows approximation, and elliptical approximation. Meanwhile, the structural parameter Kf was introduced to optimize the calculation results. The electromagnetic parameters of the material based on the calculation results were measured, and the results show that the simulation results obtained via bow approximation have a better coincidence to the experiment results, and the mass ratio of the absorbent raises by around 9.95%, which lays a foundation for the subsequent design of microwave-absorbing composites.

Development of Training Videos Based on Virtual Reality Side-Cut High-Simulation Simulator of Human Wound Technology and Sealed Sputum Suction.

The development of information technology and the advancement of the process of educational informatization have provided technical support for education and education reform. The virtual simulation teaching mode is no longer a new thing for people, and it is more and more accepted by people familiar with it. Induction and analysis of short message texts generated by students' online learning can fully understand students, make effective adjustments to the classroom, guide teachers' teaching practice, and optimize the classroom, thereby improving students' learning ability, practical ability, innovation ability, and collaboration. To study the effect of virtual simulation education on improving the skills of medical students, this paper is based on video training and education of virtual reality side-cut high-simulation simulator using case analysis and literature analysis methods. It collects data from databases and builds on online education. The model was developed, and a large number of relevant pieces of literature were read and analyzed through the literature survey method. The research results show that virtual simulation teaching can effectively improve students' technical thinking and ability. Students' technical thinking and ability are about 30% higher than traditional teaching methods, and the cooperation consciousness between students reaches 0.8 consciousness, which can solve the contradiction between popularization and improvement. And to solve the problems of polarization and transformation of underachievers, students' personalities can be fully displayed and developed, and education and teaching will be on the track of quality education. This shows that training videos based on virtual reality technology can play a very good role in improving students' technical mastery.

Can a subgroup at high risk for LRR be identified from T1-2 breast cancer with negative lymph nodes after mastectomy? A meta-analysis.

Purpose: To identify a subgroup at high risk for loco-regional recurrence (LRR) from T1-2 breast cancer with negative lymph nodes (N0) after mastectomy by using a meta-analysis.Methods and materials: Published studies on the relationship between clinical features and LRR of breast cancer were identified from public databases, including PubMed, EMBASE, and the Cochrane Library. High-risk features for LRR in this patient population were defined based on the pooled results of meta-analysis.Results: For the meta-analysis, a total of 11244 breast cancers with pT1-2N0 after mastectomy from 20 publications were included for analysis. The pooled results indicated that age (hazard ratio (HR) 1.77, P=0.001), lymphovascular invasion (LVI) (HR 2.23, P<0.001), histologic grade (HR 1.66, P<0.001), HER2 status (HR 1.65, P=0.027), menopausal status (HR 1.36, P=0.015), and surgical margins (HR 2.56, P=0.014) were associated with a significantly increased risk of developing LRR in this patient population group, but not for tumor size (HR 1.32, P=0.23), systematic therapy (HR 1.67, P=0.20), and hormonal receptor status (HR 1.04, P=0.73).Conclusion: In the current study, patients with young age, positive LVI, high histologic grade, HER-2 positive, premenopausal, and positive surgical margins have an increased risk of developing LRR. Further prospective trials are needed to clearly define the role of adjuvant postmastectomy radiotherapy in T1-2N0 breast cancer at high risk of developing LRR.