BACKGROUND:Steroid-induced osteonecrosis of the femoral head (SONFH) is a common bone disease characterized as high morbidity and poor prognosis,but the pathogenesis is unclear.Oxidative stress treatment is closely related to the occurrence and development of SONFH,and has tremendous potential in the treatment of SONFH,which can be realized by Nano-Se.OBJECTIVE:To observe the protective effect of porous Se@SiO2 nanocomposite on chondrocytes by antioxidant stress,and to further explore its mechanism of protection and treatment of SONFH.METHODS:(1) In vitro experiment:The rat chondrocytes were isolated,cultured and identified.Then,the chondrocytes were cultured with porous Se@SiO2 nanocomposite to suppress the production of reactive oxygen species (ROS).(2) In vivo experiment:A total of 36 rats were randomly divided into three groups.Steroid-induced group and experimental group were treated with intraperitoneal injection of lipopolysaccharide and intramuscular injection of methylprednisolone to induce SON FH models.Seven days after modeling,the experimental group was intraperitoneally injected with porous Se@SiO2 nanocomposite.No intervention was done in control group (blank control).At 8 weeks after modeling,rat bilateral femoral heads were taken for hematoxylin-eosin staining and Micro-CT scanning.RESULTS AND CONCLUSION:Results from the ROS detection and TUNEL apoptosis tests showed that the level of ROS in the chondrocytes was significantly reduced after intervention with Se@SiO2 (P ＜ 0.05).Micro-CT scanning findings showed that the bone mineral density,bone volume,bone area/bone volume,trabecular number,trabecular thickness,and trabecular separation in the steroid-induced and experimental groups were significantly different from those in the control group (P ＜ 0.05).Hematoxylin-eosin staining results showed smooth femoral head,normal bone cells,chondrocytes and trabecular bone,as well as few empty bone lacunae and fat cells in the control group,while in the steroid-induced group,there was bone trabecular fracture,fat cell hypertrophy fusion,a large number of empty bone lacunae and obvious osteonecrosis.These manifestations were significantly improved in the experimental group.To conclude,the porous Se@SiO2 nanocomposite has good antioxidative stress ability,suppresses the ROS production and exerts therapeutic effects on SONFH.

Objective:To investigate the current risk awareness of medical online live webcasts among physicians in public hospital, so as to provide reference in promoting the peaceful development of medical online live webcast.Methods:From March 15th to 31st, 2022, the research team used the convenience sampling method to conduct a questionnaire survey on the risk awareness of medical online live webcast among doctors in public hospitals with the help of the " Physician Daily" Internet platform. All data were analyzed descriptively, and the comparison between groups was conducted by Chi square test.Results:1 015 questionnaires were recovered, of which 828 were valid, with an effective recovery rate of 81.6%. 741 doctors (89.5%) knew about the medical webcast, and 752 doctors (90.8%) thought that the medical webcast was risky. More than 50.0% of doctors believed that misleading the public, disclosing patients′ privacy and ideological risk were the risk points of live webcast; Health science popularization, doctor-patient humanistic activities and free medical activities were suitable for live webcast; Live webcast with goods and medical diagnosis were inappropriate for live webcast. There were significant differences in the cognition of doctors with different professional titles on the ideological risk, disclosure of patient privacy, health science popularization, medical and patient humanistic activities, and live webcasting with goods ( P < 0.05). 219 doctors participated in the medical network live webcast, of which 148 (67.6%) reported live webcast. Conclusions:Physicians in public hospitals are generally aware of medical webcasting and believe that there are risks in such behavior. But physicians with different professional titles have different cognitions on the risk points, suitable content, inappropriate behavior, and live webcastreporting of medical webcasting.

Objective:To analyze the operation status of official voice in Beijing municipal hospitals and explore the countermeasures to optimize the operation of official short video tiktok.Methods:The 21 Beijing municipal tertiary public hospitals were selected as the research objects. The 17 tiktok numbers which had been approved by the hospital as of December 31, 2020 were included. The data of basic accounts, fans, points, themes, contents, and number of periodicity were analyzed. The theme and the number of praise of the short video tiktok that broke through 10 thousand times were analyzed. The current situation and problems of official voice in Beijing municipal hospitals were analyzed.Results:The 17 official tiktok accounts of the hospital issued 2 059 pieces of tiktok, 1 737.5 thousand fans, and 9 231.8 thousand times of points, the average number of entries was 4.5 thousand times. The official tiktok construction of Beijing municipal hospitals was still in its infancy. The problems included: the weakening of IP image and the lack of system design, lack of content productivity and interaction, unclear positioning and lack of operation strategy.Conclusions:The optimization of hospital official tiktok operation needs to properly handle the relationship between science and interest, systematicness and efficiency. We should clarify the account positioning, improve productivity, strengthen interaction, enhance linkage, and do a good job in supervision.

RNA splicing contributes to a broad spectrum of post-transcriptional gene regulation during normal development, as well as pathological manifestation of heart diseases. However, the functional role and regulation of splicing in heart failure remain poorly understood. RNA binding protein (RBP), a major component of the splicing machinery, is a critical factor in this process. RNA binding motif protein 24 (RBM24) is a tissue-specific RBP which is highly expressed in human and mouse heart. Previous studies demonstrated the functional role of RBM24 in the embryonic heart development. However, the role of RBM24 in postnatal heart development and heart disease has not been investigated. In this paper, using conditional RBM24 knockout mice, we demonstrated that ablation of RBM24 in postnatal heart led to rapidly progressive dilated cardiomyopathy (DCM), heart failure, and postnatal lethality. Global splicing profiling revealed that RBM24 regulated a network of genes related to cardiac function and diseases. Knockout of RBM24 resulted in misregulation of these splicing transitions which contributed to the subsequent development of cardiomyopathy. Notably, our analysis identified RBM24 as a splice factor that determined the splicing switch of a subset of genes in the sacomeric Z-disc complex, including Titin, the major disease gene of DCM and heart failure. Together, this study identifies regulation of RNA splicing by RBM24 as a potent player in remodeling of heart during postnatal development, and provides novel mechanistic insights to the pathogenesis of DCM.