BACKGROUND:The elastic modulus of traditional bone implants is large and does not match the elastic modulus of human bone,which will cause a stress shielding effect and lead to bone resorption.The trabecular scaffold of the triply periodic minimal surface with radial gradient has elastic modulus matching with human cancellous bone,and its yield strength is greater than that of human cortical bone,which provides a new choice for the design of bone scaffold. OBJECTIVE:Triply periodic minimal surface structure with radial gradient was constructed by the implicit surface method.The sample was manufactured by laser selective melting technology,and the quasi-static compression test was carried out to obtain trabecular scaffolds with mechanical properties matching human bones. METHODS:Four types of the trabecular scaffolds of the triply periodic minimal surface with a radial gradient of G,I,P and D were established by the implicit surface method.Samples were manufactured by laser selective melting technology.We observed the surface morphology of the molded sample,evaluated the molding quality,conducted a quasi-static compression test,and evaluated the mechanical properties of the samples. RESULTS AND CONCLUSION:The quasi-static compression test results showed that compared with the four triply periodic minimal surface scaffolds,the platform stress of the G scaffold had less fluctuation and no failure or fracture,indicating that the G scaffold had the best plasticity.The mechanical properties of the G scaffolds with 45%,55%and 65%porosities were analyzed.It was found that the elastic modulus of G scaffolds with 55%porosity was within the range of elastic modulus of human cancellous bone(0.022-3.7 GPa),and the yield strength was close to the maximum yield strength of human cortical bone(187.7-222.3 MPa).In conclusion,G triply periodic minimal surface scaffold with 55%porosity can reduce the stress shielding effect,bear a higher body load,improve the stability of the implant,and prolong the service life of the implant.

BACKGROUND:Vertebral compression fracture is a common disease in the current orthopedic field.However,the occurrence of re-fracture in neighboring vertebrae after surgery is a problem that cannot be ignored,which has a serious impact on the normal life of patients. OBJECTIVE:The aim of this study is to establish four postoperative models with different recovery heights using computed tomography images.By using finite element analysis,we derived the stresses on the neighboring vertebrae at different recovery heights and further explored the importance of postoperative recovery of the height of the injured vertebrae. METHODS:A finite element model of the thoracolumbar spine(T11-L3)was established and validated,on the basis of which four postoperative finite element models of L1 with different recovery heights of 100%,80%,60%,and 40%were constructed,in which the cement capacity varied with the recovery height.The specific models are as follows:Model 1 was the postoperative model with normal recovery height,and the cement capacity was 8.3 mL.Model 2 was the postoperative model in which 20%of the anterior height of the L1 was removed and the posterior convexity angle became 10.41°,and the cement capacity was 6.9 mL.Model 3 was the postoperative model in which 40%of the anterior height of the L1 was removed and the posterior convexity angle became 20.17°,and the cement capacity was 4.7 mL.Model 4 was a postoperative model with 60%of the L1 anterior height removed and the posterior convexity angle changed to 28.85°,with a cement capacity of 3.6 mL.For evaluation of the postoperative model,we applied a moment of 7 Nm and an axial force of 500 N.The followings were recorded and analyzed:peak stresses in the L2 upper endplate and T12 lower endplate;peak stresses in the L2 and T12 cancellous bone. RESULTS AND CONCLUSION:(1)The highest peak stresses for each condition of the L2 upper endplate,T12 lower endplate,L2 cancellous bone,and T12 cancellous bone occurred in Model 1 and Model 4.In particular,the T12 lower endplate,except for the posterior extension condition,the anterior flexion,left and right lateral bending,and left and right rotation conditions all reached their highest peak stresses in Model 4,with stresses of 50.3,33.1,44.9,34.3,and 31.9 MPa.(2)Based on the peak stresses in the adjacent vertebral endplates and cancellous bone,after excluding Model 1 and Model 4,the minimum peak stresses for most of the conditions appeared in the Model 2,and the minimum peak stresses appeared in the Model 2 in 66.6%of the cases,especially in the upper endplates of the L2 and cancellous bone except for the posterior extension condition,the minimum peak stresses all appeared on the Model 2.(3)Therefore,controlling the recovery height at about 100%and 40%of the original height was a dangerous recovery height,which had a greater impact on the neighboring vertebrae.Controlling the recovery height at about 80%of the original height may be a more ideal choice.With a recovery height of about 80%of the original height,the adjacent vertebrae are subjected to less stress,thus reducing the risk of re-fracture of the adjacent vertebrae in the patient.

AIM:To investigate the role of specific long noncoding RNA SLC25a6(lncSLC25a6)in homocys-teine(Hcy)-induced cuproptosis in cardiomyocytes.METHODS:Rat cardiomyocytes were cultured in vitro and divided into control group and Hcy group.After 48 h of intervention,the expression levels of cuproptosis-related proteins,ferre-doxin 1(FDX1)and heat shock protein 70(HSP70),were detected by Western blot and immunofluorescence staining.The oxidative stress state of cardiomyocytes was assessed using fluorescence staining,and the intracellular Cu2+levels were measured using a copper ion assay kit.Furthermore,the impact of Hcy on the expression of cuproptosis-related proteins in cardiomyocytes was analyzed following overexpression of lncSLC25a6.RESULTS:Compared with the control group,80 μmol/L Hcy significantly accelerated cardiomyocyte damage,with a notable underexpression of lncSLC25a6(P<0.05).Western blot results indicated that,compared with the control group,the expression level of FDX1 in the Hcy intervention group was significantly reduced(P<0.05),while the expression level of HSP70 was significantly elevated(P<0.05),and the expression level of copper ions in cardiomyocytes of the Hcy group was increased(P<0.05).Immunofluorescence staining showed a significant reduction in FDX1 fluorescence intensity and a significant increase in HSP70 fluorescence in-tensity in the Hcy group.Further overexpression of lncSLC25a6 significantly mitigated Hcy-induced cuproptosis in cardio-myocytes,resulting in elevated expression of FDX1 and reduced expression of HSP70(P<0.05).Pearson correlation analysis demonstrated that the expression level of lncSLC25a6 was negatively correlated with FDX1 protein expression(r=-0.676,P=0.046)and positively correlated with HSP70 expression(r=0.680,P=0.044).CONCLUSION:lnc-SLC25a6 significantly mitigates Hcy-induced cuproptosis in cardiomyocytes,positioning it as a potential therapeutic target for managing Hcy-induced cardiac injury.

Objective To study the role of ubiquitin-conjugating enzyme 9(UBC9)in the pyroptosis of homocysteine-induced macrophages mediated by small ubiquitin-like modifier(SUMO)modification.Methods First,the effects of homocysteine at different concentrations(0 μmol/L,50 μ.mol/L,100 μmol/L,150 μmol/L and 200 μmol/L)on the viability and pyrodeath of mouse macrophages(RAW264.7)were detected by CCK-8 and Western blot.Western blot was used to detect the expression levels of UBC9,SUMO-1,and the inflammatory cytokine IL-1β in different groups of cells.qRT-PCR was used to detect the mRNA expression of UBC9 before and after RNA interference and the expression of UBC9,pyrogen-related protein,and SUMO-1 after RNA interference.Results After stimulation with 100 μmol/L homocysteine,the effect of macrophage activity was minimal,and NLRP3 and Caspase-1 were the proteins with the most obvious increase in expression(P＜0.05).Compared with the Control group,the Hcy group's expression of IL-1β and SUMO-1 was increased(P＜0.01).Compared with the Control group,the Hcy group's UBC9 protein and mRNA levels were increased(P＜0.05).The expression of NLRP3,Caspase-1,IL-1β,UBC9,and SUMO-1 was decreased in the si-UBC9+Hcy group compared with the si-NC+Hcy group(P＜0.01).Conclusions Homocysteine induces pyroptosis in macrophages,and its mechanism of action is related to the up-regulation of UBC9 to induce SUMO modification.

【Objective】 To analyze the basic characteristics of whole blood donors from blood stations before and after the outbreak of COVID-19. 【Methods】 After excluding invalid data, data related to the basic characteristics of whole blood donors collected from 26 blood stations in China during 2018 to 2021 were statistically analyzed, including the trend of total whole blood donors, the number of repeated blood donors, the frequency of blood donation, the average age of donors and the recruitment of first-time blood donors. 【Results】 Affected by the epidemic, 8 out of 14 indicators were with large variations, accounting for 57%. The overall growth rate of total whole blood donors during the epidemic was higher than before the epidemic (P<0.05).The number of repeated blood donors has shown an increased trend, with a higher number during the epidemic than before (P<0.05). The frequency of blood donation was lower during the epidemic than before(P<0.05).Average ages of blood donors and female blood donors fluctuated widely during the epidemic, both higher than those before the epidemic(P<0.05).The donation rate of first-time blood donors <25 years old and ≥25 years old varied widely and irregularly during the epidemic (both P<0.05). The percentage of first-time blood donors fluctuated irregularly during the epidemic, with overall percentage lower than that before the epidemic(P<0.05). 【Conclusion】 Whole blood donors from 26 blood stations increased after the outbreak of COVID-19, and some indicators in certain areas showed significant fluctuations during the epidemic.

【Objective】 To analyze the hepatitis B virus (HBV) infection data of blood donors from 18 domestic blood stations, so as to investigate the HBV infection situation of blood donors. 【Methods】 The positive rate of HBV and its distribution characteristics of regions, the percentage of HBsAg+ ELISA in first-time vs repeated blood donors, and the percentage of HBsAg-/HBV DNA+ blood donors of 18 domestic blood stations during 2017 to 2020 were collected from the Working Platform for Practice Comparison of Blood Centers, and the HBV infection among blood donors were statistically analyzed. 【Results】 From 2017 to 2020, the positive rate of HBV in blood donors among 18 domestic blood stations was 13.48/10 000-144.02/10 000, with the average HBV positive rate in eastern, central and western region at 26.14/10 000, 51.98/10 000 and 41.00/10 000, respectively. The HBsAg+ rate by ELISA among first-time and repeated blood donors was 14.55/10 000-305.39/10 000 vs 1.04/10 000-87.43/10 000 The HBsAg-/HBV DNA+ yield was 1.80/10 000-35.31/10 000. 【Conclusion】 The distribution of HBV infection in blood donors has regional characteristics, and HBV prevalence was low in repeated blood donors. HBsAg ELISA combined with HBV DNA detection can better ensure blood safety.

Objective:To explore the risk factors for death within 1 year after hip fracture surgery in the elderly.Methods:A case control study was made on the clinical data of 551 elderly patients with hip fracture treated in Second Affiliated Hospital of Soochow University from January 2019 to December 2020, including 182 males and 369 females; aged 65-100 years [80(73,86)years]. Joint replacement, cannulated screw fixation or proximal femoral nail fixation were performed. The patients were divided into survival group ( n=494) and death group ( n=57) based on the death within 1 year after surgery recorded at postoperative telephone follow-up. The gender, age, hypertension, diabetes, cardiovascular diseases, chronic respiratory diseases, neurological diseases, chronic renal failure, anemia on admission, fracture types, American anesthesiologist Association (ASA) classification, operative methods, preoperative waiting time, duration of operation and perioperative blood transfusion were recorded in two groups. Univariate Cox regression was used to analyze the correlation between the above indexes and death within 1 year after surgery. All indexes with P<0.2 in the univariate analysis were included in multivariate Cox regression analysis to clarify the independent risk factors for death within 1 year after surgery. Results:Univariate Cox regression analysis showed that death within 1 year after surgery correlated with gender, age chronic respiratory diseases, chronic renal failure and anemia on admission (all P<0.01), but not with hypertension, diabetes, cardiovascular diseases, neurological diseases, fracture types, ASA classification, operative methods, preoperative waiting time, duration of operation or perioperative blood transfusion (all P>0.05). Multivariate Cox regression analysis showed that male ( HR=2.08, 95% CI 1.20, 3.61, P<0.01), age ≥ 80 years ( HR=2.22, 95% CI 1.15, 4.28, P<0.05), chronic respiratory diseases ( HR=2.54, 95% CI 1.19, 5.40, P<0.05), chronic renal failure ( HR=4.57, 95% CI 1.27, 16.44, P<0.05), anemia on admission ( HR=2.82, 95% CI 1.38, 5.76, P<0.01) were significantly associated with death within 1 year after surgery. Conclusion:Male age≥ 80 years, chronic respiratory disease, chronic renal failure and anemia on admission are independent risk factors for death within 1 year after hip fracture surgery in the elderly.

Objective: To analyze and compare the distribution of the high-risk population of upper gastrointestinal (UGI) cancer and the factors influencing the compliance rate of endoscopic screening in urban China and rural China. Methods: From 2015 to 2017, an epidemiological survey was conducted on residents aged 40-69 in two rural areas (Luoshan county of Henan province, Sheyang county of Jiangsu province) and two urban areas (Changsha city of Hunan province, Harbin city of Heilongjiang province). As a result, high-risk individuals were recommended for endoscopic screening. Chi-square χ(2) test was used to compare the high-risk rate of UGI cancer between urban and rural residents. In addition, the multivariate logistic regression model was used to analyze the factors influencing the compliance rate of endoscopic screening. Results: A total of 48, 310 residents aged 40-69 were enrolled in this study, including 22 870 (47.34%) residents from rural areas and 25 440 (52.66%) residents from urban areas. A total of 23 532 individuals were assessed with a high risk of UGI cancer, with an overall risk rate of 48.71%. A higher proportion of participants with high risk was observed in rural China (56.17%, 12 845/22 870) than in urban China (42.01%, 10 687/25 440). A total of 10 971 high-risk individuals with UGI cancer participated in endoscopic screening, with an overall compliance rate of 46.62% (10 971/23 532), 45.15% (5 799/12 845) in rural China, and 48.40% (5 172/10 687) in urban China. In rural population, the compliance rate of endoscopic screening was higher in those of females, aged 50-69 years, primary school education or above, high income, a family history of UGI cancer, history of gastric and duodenal ulcer, history of reflux esophagitis, and history of superficial gastritis, but lower in smokers (P<0.05). Among the urban population, the compliance rate of endoscopic screening was higher in those aged 40-49 years, uneducated, low income, family history of UGI cancer, history of reflux esophagitis, history of superficial gastritis, but lower in smokers (P<0.05). Conclusions: The proportion of participants with high risk of UGI cancer in rural areas is higher than that of urban areas. The compliance rates of endoscopic screening in urban and rural areas are low, and influencing factors of endoscopic screening exhibit some differences in rural China and urban China.
China/epidemiology* ; Early Detection of Cancer ; Esophagitis, Peptic ; Female ; Gastritis ; Gastrointestinal Neoplasms/epidemiology* ; Humans ; Rural Population ; Urban Population

【Objective】 To learn the production efficient of platelet components among prefecture-level blood stations in China, to provide supporting data for those blood stations to optimize the production mode of platelet components and continuously improve production efficiency and supply capacity. 【Methods】 The data from 2017 to 2020 was obtained from 24 prefecture-level blood stations who were the members of the practice comparison network for blood institutes in China. The collection units of apheresis platelets, the number of dual-collections of apheresis platelets and plasma, the average apheresis units of one platelet apheresis procedure, the discarded rate of apheresis platelets, the amount of expired apheresis platelets and the amount of apheresis platelets issued were collected. For concentrated platelets, the prepared amount of platelet concentrates and the amount of expired platelet concentrates were collected; both the quantity of qualified and issued concentrated platelets were submitted for statistical analysis.The total output and efficiency of platelet components were calculated based on the collected data. 【Results】 The average annual growth rate of apheresis platelets collection in 24 prefecture-level blood stations was 12.23%, accounting for 99.80% of the total platelet output; the average collection unit of one platelets apheresis procedure was 1.75; from 2019 to 2020, only 5 blood stations performed dual-collection of platelet and plasma during one apheresis procedure; the discarded rate of apheresis platelets was 0.28%, of which 0.007% was due to expiration. A total of 1 621.2 therapeutic units of concentrated platelets were prepared, and 13.03% of them was discarded due to the expiration. The production efficiency of platelet components was 97.56%, of which the production efficiency of apheresis platelets was 97.61% and the production efficiency of concentrated platelets was 74.43%. 【Conclusion】 There are large regional differences in the supply capacity of platelet components in prefecture-level blood stations. Apheresis platelets are the main resource of platelet components product, and the collection capacity is increasing over the years with the characteristics of high production efficiency and low expiration scrapping rate. However, the preparation of concentrated platelets are still limited with relatively low production and high expiration discarded rate.

【Objective】 To understand the current situation of blood components distribution in domestic prefecture-level blood stations through analyzing the components distribution data of 24 prefecture-level blood stations in China. 【Methods】 The data of components distribution of 24 blood stations from 2017 to 2020 as well as the data of blood deployment of 24 blood stations from 2019 to 2020 were collected and analyzed. 【Results】 From 2017 to 2020, positive annual growth in red blood cells, plasma and cryoprecipitate was observed in 22, 19 and 15 out of the 24 blood stations, and the annual growth median rate of above three components was 5.24%, 3.80% and 3.25%, respectively. Among the 24 prefecture-level blood stations, 23 carried out the preparation of cryoprecipitate. 【Conclusion】 The distribution of red blood cells, cryoprecipitate and plasma in prefecture-level blood stations is increasing year by year. However, there is a overstock of plasma, and most blood stations need blood employment.