Objective The stress variations during the wear process of an artificial knee joint were studied.Then,a signal acquisition system was designed to capture the vibration signals induced by the wear of knee joint prosthesis.The aim was to provide new technical means for online wear monitoring of the artificial knee joint.Methods To effectively collect vibration signals,the optimal installation position of the vibration sensors was determined by analyzing the dynamic model of the knee joint prosthesis during motion and identifying the main distribution areas of the tibial insert contact stress.The dynamic model of the femoral prosthesis was solved using Lagrangian equations.The torque variation curve of the femoral prosthesis was obtained to validate the effectiveness of finite element analysis.The signals collected by the vibration sensors installed at different positions in the friction wear experiments and the surface morphology in different areas were compared to verify the effectiveness of the acquisition system design and finite element analysis results.Results The stress concentration regions of the tibial pad under four degrees of freedom(flexion,internal and external rotation,anterior-posterior displacement,and up-and-down displacement)were obtained based on a dynamic simulation.A stress concentration was evident in the middle and posterior regions of the tibial pad.A vibration signal with a higher amplitude was collected when the vibration sensor was installed at the rear end of the tibial pad.This aided the vibration feature extraction of the knee joint prosthesis.Conclusions The vibration signal acquisition system designed based on the dynamic simulation analysis effectively collected the vibration signals generated by the artificial knee joint during the wear process.This study provides an important means for evaluating the wear mechanisms of artificial knee joints and monitoring their full-life health status.

Objective The stress variations during the wear process of an artificial knee joint were studied.Then,a signal acquisition system was designed to capture the vibration signals induced by the wear of knee joint prosthesis.The aim was to provide new technical means for online wear monitoring of the artificial knee joint.Methods To effectively collect vibration signals,the optimal installation position of the vibration sensors was determined by analyzing the dynamic model of the knee joint prosthesis during motion and identifying the main distribution areas of the tibial insert contact stress.The dynamic model of the femoral prosthesis was solved using Lagrangian equations.The torque variation curve of the femoral prosthesis was obtained to validate the effectiveness of finite element analysis.The signals collected by the vibration sensors installed at different positions in the friction wear experiments and the surface morphology in different areas were compared to verify the effectiveness of the acquisition system design and finite element analysis results.Results The stress concentration regions of the tibial pad under four degrees of freedom(flexion,internal and external rotation,anterior-posterior displacement,and up-and-down displacement)were obtained based on a dynamic simulation.A stress concentration was evident in the middle and posterior regions of the tibial pad.A vibration signal with a higher amplitude was collected when the vibration sensor was installed at the rear end of the tibial pad.This aided the vibration feature extraction of the knee joint prosthesis.Conclusions The vibration signal acquisition system designed based on the dynamic simulation analysis effectively collected the vibration signals generated by the artificial knee joint during the wear process.This study provides an important means for evaluating the wear mechanisms of artificial knee joints and monitoring their full-life health status.

Objective:The study was planned to evaluate the clinical utility of microcytic anemia factor (MAF) and low hemoglobin density (LHD%) in the screening of iron deficiency in blood donors.Methods:A total of 400 blood donors, 200 male and 200 female, were randomly admitted to Fujian Blood Center from January1, 2022 to February 28, 2022 by the way of stratified sampling. According to the fourth edition of Diagnostic and therapeutic criteria for hematological diseases, the patients were divided into three groups: normal group (N=299), iron depletion group (ID, n=54) and iron deficient erythropoiesis group (IDE, n=47), Blood routine indexes including hemoglobin (HGB), mean corpuscular volume hemoglobin (MCV), mean corpuscular hemoglobin content (MCH), mean corpuscular hemoglobin concentration (MCHC) and iron metabolism indexes including serum ferritin (SF), serum iron (SI), total iron binding capacity (TIBC), transferrin saturation (TS) and unsaturated iron binding capacity (UIBC) were measured, MAF and LHD% were calculated by formula.One-way ANOVA or Kruskal-Wallis H tests were used to analyze the differences among three groups. Spearman correlation analysis was used to analyze the correlation between MAF and LHD% and iron metabolism indexes.The Receiver Operating Characteristic (ROC) curve was used to evaluated the diagnostic value of MCH, MCHC, MAF and LHD% for iron deficiency in blood donors. Results:MAF in ID group which was 11.81±0.81 were higher than the IDE group which was 10.69±0.95 and lower than the healthy group which was 13.17±1.24, the total difference among the three groups was statistically significant ( F=110.784, P<0.001), the difference between two groups was statistically significant ( P<0.01); LHD% in ID group which was 2.61 (1.87, 3.91)% were lower than the IDE group which was5.60(2.99, 8.02)% and higher than the healthy group which was1.74 (1.22, 2.73)%, the total difference among the three groups was statistically significant ( H=62.166, P<0.001), the difference between two groups was statistically significant ( P<0.01).In 101 iron deficiency blood donors, Spearman correlation analysis showed that MAF was positively correlated with SF, SI and TS ( r=0.426, P<0.01; r=0.547, P<0.01; r=0.566, P<0.01);contrarily, LHD% was negatively correlated with SF, SI and TS ( r=-0.397, P<0.01; r=-0.400, P<0.01; r=-0.479, P<0.01).The areas under the ROC curve of MCH, MCHC, MAF and LHD% diagnostic ID were 0.745, 0.646, 0.819 and 0.646, respectively;the cut-off value of MAF was 12.56, with a sensitivity of 67.90% and a specificity of 83.30%.While the areas under the ROC curve of MCH, MCHC, MAF and LHD% diagnostic IDE were 0.901, 0.834, 0.941 and 0.834, respectively; the cut-off value of MAF was 11.73, with a sensitivity of 87.60% and a specificity of 87.20%. Conclusions:MAF performed a high diagnostic value of iron deficiency, especially IDE, and can be used as a marker in the diagnosis of iron deficiency in blood donors.

Objective:To summarize the evidence of cold therapy for patients after knee joint replacement, so as to provide theoretical support for the practical implementation of cold therapy in patients after knee joint replacement in clinical practice.Methods:The literature on cold therapy for patients after knee joint replacement was systematically searched in relevant databases and websites at home and abroad. The search period was from database establishment to September 2022. The evaluation of literature quality and evidence extraction were independently completed by two researchers.Results:A total of 17 articles were included, including two clinical practice guidelines, five systematic reviews, six randomized controlled trials, and four expert consensuses. After independent evaluation and evidence extraction by two researchers, a total of 19 pieces of evidence were collected from 5 aspects: evaluation and education, observation of cold therapy, cold therapy tools, cold therapy parameters, and cold therapy effects. Among them, 8 pieces of A-level recommended evidence and 11 pieces of B-level recommended evidence.Conclusions:Cold therapy for patients after knee joint replacement is widely accepted and applied. Medical and nursing personnel should prioritize patient safety and formulate scientific cold therapy plans based on various factors such as individual differences, patient preferences, actual clinical scenarios, differences in medical equipment, medical and nursing personnel technical level, and cost-effectiveness, in order to maximize patient benefits.

BACKGROUND: Osteoporosis (OP) has become a major public health issue, threatening the bone health of middle-aged and elderly people from all around the world. Changes in the gut microbiota (GM) are correlated with the maintenance of bone mass and bone quality. However, research results in this field remain highly controversial, and no systematic review or meta-analysis of the relationship between GM and OP has been conducted. This paper addresses this shortcoming, focusing on the difference in the GM abundance between OP patients and healthy controls based on previous 16S ribosomal RNA (rRNA) gene sequencing results, in order to provide new clinical reference information for future customized prevention and treatment options of OP. METHODS: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), we comprehensively searched the databases of PubMed, Web of Science, Embase, Cochrane Library, and China National Knowledge Infrastructure (CNKI). In addition, we applied the R programming language version 4.0.3 and Stata 15.1 software for data analysis. We also implemented the Newcastle-Ottawa Scale (NOS), funnel plot analysis, sensitivity analysis, Egger's test, and Begg's test to assess the risk of bias. RESULTS: This research ultimately considered 12 studies, which included the fecal GM data of 2033 people (604 with OP and 1429 healthy controls). In the included research papers, it was observed that the relative abundance of Lactobacillus and Ruminococcus increased in the OP group, while the relative abundance for Bacteroides of Bacteroidetes increased (except for Ireland). Meanwhile, Firmicutes, Blautia, Alistipes, Megamonas, and Anaerostipes showed reduced relative abundance in Chinese studies. In the linear discriminant analysis Effect Size (LEfSe) analysis, certain bacteria showed statistically significant results consistently across different studies. CONCLUSIONS: This observational meta-analysis revealed that changes in the GM were correlated with OP, and variations in some advantageous GM might involve regional differences.
Middle Aged ; Aged ; Humans ; Gastrointestinal Microbiome/genetics* ; RNA, Ribosomal, 16S/genetics* ; Genes, rRNA ; Osteoporosis ; Feces

Objective:To construct a core competence evaluation index system for Anesthesia Intensive Care Unit (AICU) nurses, and to provide reference for the career orientation, training and management of AICU nurses.Methods:The first draft of the core competence evaluation index system of AICU nurses was developed by literature evaluation, semi-structured interview and group discussion. Using the purposive sampling method, 26 experts were selected for 2 rounds of expert consultation from August to September 2021 to determine the evaluation index system of core competence of AICU nurses, and the weights of indicators at all levels were determined by analytic hierarchy process.Results:The effective recovery rates of the 2 rounds of expert letter consultation questionnaire were respectively 92.31% (24/26) and 91.67% (22/24) , the expert authority coefficients were respectively 0.93 and 0.93, and the Kendall's harmony coefficients were respectively 0.28 and 0.19 (all P<0.01) . The final evaluation index system of AICU nurses' core competence included 4 first-level indicators (theoretical knowledge, nursing practice, comprehensive ability, personal characteristics) , 14 second-level indicators and 52 third-level indicators. Conclusions:The constructed evaluation index system of core competence of AICU nurses is scientific and reliable, which can provide a reference for the career orientation, training and management of AICU nurses.

Objective: To analyze the Oxford classification (MESTC) and the International Study of Kidney Disease in Children (ISKDC) classification for evaluating the clinical manifestations, histological lesion and short-term prognosis of children with Henoch-Schönlein purpura nephritis (HSPN). Methods: According to the Oxford classification and ISKDC classification, the histological lesions of children with HSPN diagnosed by renal biopsy from Beijing Children's Hospital affiliated to Capital Medical University from January 2018 to December 2018 were re-evaluated. The renal biopsy specimens of the selected subjects were scored according to the Oxford classification and the ISKDC classification. According to whether the first symptom was combined with renal performance, MESTC score and ISKDC classification, children were grouped. The differences in clinicopathological manifestations between the groups were compared. Correlation between MESTC and ISKDC grades was analyzed by nonparametric test rank correlation. Kaplan-Meier survival curve and Log-rank test were used to compare the difference of proteinuria remission rate between the two groups. Univariate and multivariate Cox regression equations were used to analyze the influencing factors of the proteinuria remission rate. Results: A total of 78 children with HSPN were enrolled. There were 37 male patients (47.4%) with age of (10.4±2.9) years. When the patients were divided according to MESTC scores and ISKDC classification, the results showed that the proportion of children with nephrotic-range proteinuria in the group of endocapillary hypercellularity (E1, P=0.008), segmental glomerulosclerosis (S1, P=0.015) and ISKDCⅢ(P=0.041) was higher than that of E0, S0 and ISKDCⅡ groups. The proportion of children with E1 (P=0.015), crescents (C1&C2, P=0.025) or ISKDCⅢ(P=0.017) that had been treated with high-dose methylprednisolone was higher. The result of Kaplan-Meier survival curve showed more difficult for proteinuria remission in children with C2 are than C0&C1 group (P=0.026), while no difference were found when children were grouped by M, E, S, T and ISKDC. Multivariate Cox regression analysis showed that the C2 (HR=0.143, 95%CI 0.020-1.046, P=0.055) might be a risk factor for proteinuria remission, while the P value was close to 0.05. Conclusions Children with HSPN scored as ISKDCⅢ, E1 and S1 are more likely to show nephrotic-range proteinuria. C2 may indicate that patients are more difficult to achieve proteinuria remission.

Abstract During the yellow fever epidemic in Angola in 2016, cases of yellow fever were reported in China for the first time. The 11 cases, all Chinese nationals returning from Angola, were identified in March and April 2016, one to two weeks after the peak of the Angolan epidemic. One patient died; the other 10 cases recovered after treatment. This paper reviews the epidemiological characteristics of the 11 yellow fever cases imported into China. It examines case detection and disease control and surveillance, and presents recommendations for further action to prevent additional importation of yellow fever into China.

Objective To understand the clinical characteristics, treatment effect and prognosis of children with methylmalonic acidemia (MMA) combined with renal damage, and to provide experiences about how to improve the level of diagnosis and treatment.Methods The medical records of children with MMA were collected from January of 2007 to December of 2013 in Beijing Children's Hospital Affiliated to Capital University of Medical Sciences,while the clinical manifestations,laboratory findings, imaging material, inspection results were analyzed, and the renal pathological gene analysis, treatment effect, and prognosis of MMA children with renal damage were studied, and follow-up was carried out for 3 months up to 7 years.Results Among the two hundred and ninety-six cases of MMA,28 cases (9.5％) with renal damage,including 19 boys and 9 girls, 18 patients with hyperhomocysteinemia.Their ages varied from 2 days to 13 years old when confirmed.The first symptoms of 16 cases were proteinuria, hematuria, and edema, 9 cases were complicated with acute renal failure,5 cases were diagnosed as hemolytic uremic syndrome,6 patients were diagnosed as nephrotic syndrome, receiving enough glucocorticoids treatment without improvement.The routine examination of the urine showed that proteinuria (241-3 060 mg/d), methylmalonic acid levels and urinary protein were positively correlated (r =0.982, P =0.003), as urinary β2-microglobulin [(360.386 ± 231.496) μg/L], retinol binding protein [(338.537 ± 243.293) μg/L] increased.Extrarenal clinical manifestations were the spiritual, mental and physical development retardations, seizures, anemia etc.Two cases had a positive family history.Renal pathology showed mesangial cells and mesangial matrix proliferation broadening, no electron dense deposits in mesangial area, renal tubular epithelial cell swelling degeneration, and immunofluorescence was negative.Gene analysis of 3 cases showed exon1:c.80A ＞ G,p.Q27R and exon1 :c.365A ＞ T,p.H122L/c.609 G ＞ A,p.W203X.Children with MMA were treated with vitamin B12 treatment.Two cases of multiple organ failure died during hospitalization, and 2 cases died after leaving hospital.After treatment, the level of urinary methylmalonic acid was significantly decreased, while nervous system symptoms improved significantly, and the mental state and the renal function were improved.Conclusions MMA may be associated with kidney damage,usually with severe renal tubular and glomerular impairment.Early diagnosis is the key,and timely treatment can effectively control the disease, improve the prognosis.

Objective To explore the clinical feature of spontaneous bacterial peritonitis (SBP) in children with nephrotic syndrome (NS).Methods Eleven cases of SBP in children with NS from Department of Nephrology,Beijing Children's Hospital Affiliated to Capital University of Medical Science between January 2010 and June 2014 were analyzed retrospectively.The clinical features,laboratory data and efficacy of therapy were reviewed.Results In this study,12 episodes of primary peritonitis were detected in 11 patients.One patient had 2 attacks.There were 11 cases including 9 boys and 2 girls.The age of the patients ranged from 2 years and 11months to 14 years and 11 months.Nine cases of them received steroid therapy and/or cytotoxic drugs.Peritonitis was characterized by abdominal pain,mild abdominal pain occurred in 7 cases with slow onset.Ten cases had fever of varying degrees,8 cases had abdominal distention,5 cases had diarrhea and 4 cases had nausea and vomiting.Shock signs were present suddenly in 2 cases before therapy of antibiotics.Apparent edema and severe ascites were present in all cases.Five of them were presented with increasingly rapid severe ascites and showed no response to diuretic drugs.Blood investigation showed leukocytosis and high C-reactive protein.Serum albumin levels and IgG and CD4 ratio were very low in all cases.Ascites were like cloudy pus with raised neutrophil cells.Streptococcus pneumonia was positive in both blood culture and ascites culture in 2 cases.Cephalosporin was used empirically to all cases for 7 to 10 days in 9 cases and 4 weeks in 2 cases with positive blood culture.Paracentesis to release ascites fluid was performed in 5 cases with constant ascites.Eleven cases recovered from peritonitis completely.The proteinuria was negative in 2 cases after they recovered from peritonitis.Conclusions SBP was atypical in children with NS and sometimes patients might have to abdominal pain and rebound tenderness,which may be ignored and may induce deterioration suddenly and clinicians should be aware of it clearly.SBP could lead to relapse of NS and the cure of SBP by treatment could help the children recover from NS.