Objective:To investigate the surface characterization,cell adhension and proliferation of ultrafine grained titanium (UFG Ti) after different sand blasting and acid-etching(SLA).Methods:The billets of UFG Ti and commercially pure titanium Ti(CP Ti) were incised into cylindrical specimens with 7 mm in diameter and 2 mm in height.The specimens were sand blasted at the air pressure of 0.2,0.4,0.6 and 0.8 MPa respectively(n =10) and then acid-etched.The surface morphology,roughness and surface wettability of the specimens were examined.Rat embryo osteoblasts MC3T3-E1 were cultured on the speciments for 1 d,3 d and 5 d respectively,the cell morphology and cell density were observed.Results:The different hierarchical porous topographies were formed on the surface of UFG and CP Ti after modified by SLA.The sizes of blasted holes on the surface and the surface roughness of both materials increased with the increase of blast pressure,but the values of UFG Ti were lower than those of CP Ti correspondingly(P ＜ 0.05).The surface wettability of them was also changed with the blast pressure,but the values of UFG Ti was significantly smaller than those of CP Ti(P ＜ 0.05).When the blast pressure was 0.6 Mpa,the UFG Ti exhibited excellent wettability,the cell density was the highest,the morphology of MC3T3-E1 cells on UFG Ti was superior to that on CP Ti.Conclusion:UFG Ti exhibits proper surface morphology,roughness and excellent wettability,which is more appropriate for adhension and proliferation of MC3T3-E1 cells after modification by SLA at blast pressure of 0.6 Mpa.

Objective To explore the feasibility of 3D printed individualized applicator for the intracavitary HDR-brachytherapy for nasopharyngeal carcinoma.Methods CT scan was performed in 1 case of recurrent rT1 nasopharyngeal carcinoma and 1 case of T2 residual nasopharyngeal carcinoma and the obtained images were transmitted to 3D image processing software.The geometric contour parameters of the nasopharyngeal cavity were obtained and a pipeline was designed to make it close to the recurrent gross tumor volume (rGTV).Individualized cavity applicators were created by using 3D printer.The applicator was inserted into the patient's nasopharyngeal cavity through oral cavity.The source tube and false source were inserted into the preset pipe of the applicator.CT scan was performed again and the images were transmitted to the 3D brachytherapy planning system.Mter delineating the target volume and organ at risk,treatment plan was optimized.After completing the first treatment,the applicator was removed.Before second treatment in a few days,CT scan was reviewed to confirm whether the position was correct.Results When the applicator was inserted into the nasopharyngeal cavity,it could be fully aligned with the nasopharyngeal wall and self-fixed without additional fixation measures.Comparing the location of false source in multiple reviews of CT scan,the error was ≤ 1 mm.No significant discomfort was reported throughout the treatment.In optimized three-dimensional treatment,100％ prescription dose curve included the full rGTV,maximum dose of the brain stem and spinal cord was＜30％ prescription dose.Recurrent patients were given with a prescription dose of DT 40Gy/8 fractions/4 weeks and patients with residual tumors were given with 12Gy/2 fractions/1 week.No tumor recurrence was observed at postoperative 3 months in two cases.Conclusions The 3D printed individualized nasopharyngeal intracavitary applicator has the advantages of self-fixation,accurate location,good repeatability and good patient tolerance.The short-term outcome is effective,whereas its long-term clinical effect and adverse reactions need to be further observed.

Objective To observe the application value of enhanced recovery after surgery(ERAS)in perioperative nursing for patients undergoing percutaneous endoscopic interlaminar discec-tomy based on three-dimensional visualized virtual surgical system.Methods Eighty-six patients with lumbar spinal stenosis were randomly divided into experimental group(receiving perioperative nursing based on ERAS)and control group(receiving conventional perioperative nursing)using a random number table method,with 43 patients in each group.The postoperative recovery,pain intensity[Vis-ual Analogue Scale(VAS)score],lumbar function[Japanese Orthopaedic Association(JOA)sco-ring system for lumbar disorders],rehabilitation motivation[Pittsburgh Rehabilitation Participation Scale(PRPS)score],compliance[Adherence Rating Scale(ARS)score],quality of life[World Health Organization Quality of Life BREF(WHOQOL-BREF)score],complications,and satisfaction were compared between the two groups.Results The first ambulation time,first meal time,and hos-pital stay after surgery in the experimental group were shorter than those in the control group(P＜0.05).The total incidence of complications in the experimental group was 9.30％,which was lower than 27.91％in the control group(P＜0.05).Three days after surgery,the VAS score of the experimental group was(1.77±0.58),which was lower than(2.54±0.72)in the control group(P＜0.05).After intervention,the JOA scoring system for lumbar disorders,PRPS score,WHOQOL-BREF score,and satisfaction score in the experimental group were higher than those in the control group,while the ARS score was lower(P＜0.05).Conclusion The application of ERAS in perioperative nursing for patients undergoing percutaneous endoscopic interlaminar discectomy based on three-di-mensional visualized virtual surgical system can not only shorten the first ambulation time,first meal time,and hospital stay after surgery for patients with lumbar spinal stenosis,improve rehabilitation motivation and compliance,significantly relieve pain,but also promote the recovery of lumbar func-tion,reduce occurrence of complications,and effectively enhance quality of life and patients'satis-faction.

Objective To observe the application value of enhanced recovery after surgery(ERAS)in perioperative nursing for patients undergoing percutaneous endoscopic interlaminar discec-tomy based on three-dimensional visualized virtual surgical system.Methods Eighty-six patients with lumbar spinal stenosis were randomly divided into experimental group(receiving perioperative nursing based on ERAS)and control group(receiving conventional perioperative nursing)using a random number table method,with 43 patients in each group.The postoperative recovery,pain intensity[Vis-ual Analogue Scale(VAS)score],lumbar function[Japanese Orthopaedic Association(JOA)sco-ring system for lumbar disorders],rehabilitation motivation[Pittsburgh Rehabilitation Participation Scale(PRPS)score],compliance[Adherence Rating Scale(ARS)score],quality of life[World Health Organization Quality of Life BREF(WHOQOL-BREF)score],complications,and satisfaction were compared between the two groups.Results The first ambulation time,first meal time,and hos-pital stay after surgery in the experimental group were shorter than those in the control group(P＜0.05).The total incidence of complications in the experimental group was 9.30％,which was lower than 27.91％in the control group(P＜0.05).Three days after surgery,the VAS score of the experimental group was(1.77±0.58),which was lower than(2.54±0.72)in the control group(P＜0.05).After intervention,the JOA scoring system for lumbar disorders,PRPS score,WHOQOL-BREF score,and satisfaction score in the experimental group were higher than those in the control group,while the ARS score was lower(P＜0.05).Conclusion The application of ERAS in perioperative nursing for patients undergoing percutaneous endoscopic interlaminar discectomy based on three-di-mensional visualized virtual surgical system can not only shorten the first ambulation time,first meal time,and hospital stay after surgery for patients with lumbar spinal stenosis,improve rehabilitation motivation and compliance,significantly relieve pain,but also promote the recovery of lumbar func-tion,reduce occurrence of complications,and effectively enhance quality of life and patients'satis-faction.

Objective:To analyze the epidemiological characteristics of indigenous 2019-nCoV infection in population under 18 years old in 31 provinces of China, and provide evidence for the prevention and control of COVID-19.Method:Demographic and epidemiologic information of children and adolescents with 2019-nCoV infection reported in China between April 29, 2020 and May 31, 2022 were collected from China's Disease Prevention and Control Information System. We analyzed the epidemiological characteristics of the 2019-nCoV infection in children and adolescents and compared the epidemiological characteristics of the cases at different epidemic stages.Result:A total of 63 916 indigenous 2019-nCoV infection cases in children and adolescents were reported in China from April 29, 2020 to May 31, 2022, in which 14 777 (23.12%) were confirmed cases and 49 139 (76.88%) were asymptomatic cases. An obvious incidence peak (40 864 cases) was observed in April, 2022, and two sub-peaks were observed in January, 2020 and January, 2021, respectively. The 2019-nCoV infection cases occurred in 187 cities above prefecture level in 30 provinces, the cases reported in Shanghai (41 562 cases), Changchun (5 753 cases) and Jilin (3 888 cases) accounted for 80.11% of the total cases (51 203/63 916). The proportion of the cases in males was 54.34%. The age of the cases, M ( Q1, Q3) was 10 (5, 14) years, and 57.73% of the cases were 6 - 15 years old. The cases in students accounted for the highest proportion (56.14%). The interval between illness onset and diagnosis of confirmed cases, M ( Q1, Q3) was 1 (0, 2) days. Among the 2019-nCoV infection cases in children and adolescents, 76.88% were asymptomatic, 21.78% were mild ones, 1.32% were moderately severe ones, 0.02% were severe ones, and there were no critical cases and deaths. Compared with other age groups, the proportion of severe or critical cases was higher in children aged <1 year (0.12%). The proportion of asymptomatic infections was highest in Omicron variant epidemic (78.43%). Conclusion:The 2019-nCoV infection cases in children and adolescents aged <18 years in 31 provinces in China were mainly primary and secondary school students aged 6-15 years. Most cases were asymptomatic and mild ones with low clinical severity. It is still necessary to strengthen the surveillance for 2019-nCoV infection in children and adolescents to improve the prevention and control of COVID-19 in school age children.

Influenza imposes a significant disease burden on society and individuals annually, and influenza vaccination is considered a significant public health measure to prevent influenza and reduce influenza-related severe disease and death. The low influenza vaccination rate in China is partly due to certain factors affecting the willingness and behavior of individuals to receive them. Scientific research and targeted interventions on these factors can effectively improve the vaccination situation. Commonly used individual-level theoretical models for influenza vaccination behavior include the health belief model, protection motivation theory, and theory of planned behavior. This study reviews theoretical models commonly employed in researching influenza vaccination willingness and behavior. An overview of these practical applications and challenges models is presented to provide references for relevant research and intervention programs in China.