Background/Aim
There are no epidemiological reports focused on the oral and maxillofacial surgery emergency department in the West China Hospital of Stomatology. The aim of this study was to analyse the epidemiological characteristics of emergency patients admitted for Trauma and Plastic Surgery Department of the West China Hospital of Stomatology from 2016–2019.
Materials and Methods
In this retrospective study, 5220 patients with complete medical records were evaluated. The following data were collected: gender, age, etiology, disease type distribution, anatomic injury site and treatment modality.
Results
There were 3046 males and 2174 females (ratio 1.40:1), with an average age of 16.2 years. The largest group was children aged between 3 and 6 years old (28.3%). Maxillofacial injuries were the most common condition (87.3%), which mostly occurred on the forehead (29.7%), followed by the lips (27.8%). A fall was the leading cause of injury (59.9%), especially in patients younger than 6 years old. There were 327 cases of maxillofacial space infections (MSI), and the mandibular third molars were the most common tooth associated with odontogenic infections (36.2%). Univariable analysis identified that multiple‐space infection, visit time and systemic conditions were the risk factors for being admitted to the hospital for treatment. There were 116 patients (2.2%) with bleeding as the main complaint, and most of the maxillofacial bleeding patients could be stopped by compression (52.6%).
Conclusion
Males and children aged younger than 6 years were the highest risk populations. Trauma accounted for the majority of emergency patients in maxillofacial surgery. Most maxillofacial injuries involved the forehead and were mainly caused by accidental falls. The proportion of MSI was not high, but serious cases may be life‐threatening. The causes of bleeding were diverse, and the bleeding was easy to control.
At Present, stress corrosion and corrosion fatigue causing durability degradation of concrete structure in the field of civil engineering become an important problem,and thus become a hot topic to study. But the research on it at home and abroad is still in stage of theoretical exploration. This paper using self-designed corrosion fatigue loading test device, studied in magnesium nitrate solution of concrete under the action of erosion strength increasing regularity, results show that the concrete strength by corrosion fatigue than fatigue specimen attenuation extent.
The micro-mechanical properties and micro-structural characteristics of the interfacial transition zones of recycled concrete with graphene oxide were studied by using nanoindentor. The results showed that the average elastic modulus and width of the interfacial transition zone of recycled concrete with graphene oxide between new paste matrix and natural aggregate were about 20GPa and 30-35μm, respectively; The mean elastic modulus and transition zone width of the interfacial transition zone between new paste matrix and old paste matrix was about 35GPa and 25-30μm, respectively. By analyzing and calculating the probability distribution of hydration products, it was found that the graphene oxide template increased the proportion of calcium silicate hydrate in the hydrate and enhanced the content of calcium hydroxide crystal group. Compared with ordinary recycled concrete, the elastic modulus distribution in the interfacial transition zone was more uniform and the microstructure was more stable. It can be concluded that graphene oxide can enhance the mechanical properties and microstructure of the interfacial transition zone of recycled concrete so as to improve the macroscopic mechanical properties of recycled concrete.
Children are the hope of building a powerful, modern-socialist state. In recent years, all social classes have paid more and more attention to children’s enlightenment education, and the country began to implement the double reduction policy. As the main place for children to live and grow, the community has the responsibility and obligation to conduct the education of children. Work and effective development and utilization of community education resources can greatly meet the needs of children’s growth, help children develop good behavior habits, and lay a solid foundation for future education. Through the experimental survey results, this paper discusses the theoretical basis for the development and utilization of community children’s education resources under the dual emission reduction policy, puts forward the corresponding development principles, and analyzes the main strategies to improve the efficiency of social education.
Considering the actual factors such as axial compression ratio, constraint conditions and so on, We design 10 beam-column joints of different parameters under the condition of the same reinforcement ratio and use the monotonic loading type to study the influences of dosage of recycled aggregates and waste fibers, waste fiber length on beam-ends load-displacement relationships of beam-column nodes. Experimental research shows that when the dosage of recycled aggregates is 50% , waste fiber content is 0.12%, waste fiber length is 19 mm, beam-end bearing behaviour of node area is best.
At present, green energy saving idea, aimed at protecting environment and saving energy, now has become the guiding philosophy of modern architecture. Based on this, recycled carpet waste fibers for textile mechanical properties of concrete were discussed in this paper. The application of polypropylene fiber concrete abroad has been widely used, which is becoming more and more popularly in China recent years. Meanwhile, research on the application of recycled polypropylene fiber concrete is still scarce. The experiment of this paper adopt waste polypropylene fibers as reinforcing fiber, and we make the standard specimen which size is . We use the specimen to do the research of mechanical properties of compressive strength and observing the variation of compressive strength of concrete specimen in different fiber volume. We discovered that when we add volume of 0.12% recycled polypropylene fiber and the length is 19mm, the compressive strength of concrete increases greatly. We draw the conclusion that the compressive strength of recycled fiber concrete is better than ordinary one from the experiment. In addition, if such concrete was used widely, we may reach the goals of conserving resources and protecting the environment.
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