BACKGROUND:How to effectively promote bone regeneration and bone reconstruction after bone injury has always been a key issue in clinical bone repair research.The use of biological and degradable materials loaded with bioactive factors to treat bone defects has excellent application prospects in bone repair. OBJECTIVE:To investigate the effect of polylactic acid-glycolic acid copolymer(PLGA)composite scaffold modified by lysine-grafted graphene oxide nanoparticles(LGA-g-GO)on osteogenic differentiation and new bone formation. METHODS:PLGA was dissolved in dichloromethane and PLGA scaffold was prepared by solvent evaporation method.PLGA/GO composite scaffolds were prepared by dispersing graphene oxide uniformly in PLGA solution.LGA-g-GO nanoparticles were prepared by chemical grafting method,and the PLGA/LGA-g-GO composite scaffolds were constructed by blending LGA-g-GO nanoparticles at different mass ratios(1%,2%,and 3%)with PLGA.The micromorphology,hydrophilicity,and protein adsorption capacity of scaffolds of five groups were characterized.MC3T3 cells were inoculated on the surface of scaffolds of five groups to detect cell proliferation and osteogenic differentiation. RESULTS AND CONCLUSION:(1)The surface of PLGA scaffolds was smooth and flat under scanning electron microscope,while the surface of the other four scaffolds was rough.The surface roughness of the composite scaffolds increased with the increase of the addition of LGA-g-GO nanoparticles.The water contact angle of PLGA/LGA-g-GO(3%)composite scaffolds was lower than that of the other four groups(P<0.05).The protein adsorption capacity of PLGA/LGA-g-GO(1%,2%,and 3%)composite scaffolds was stronger than PLGA and PLGA/GO scaffolds(P<0.05).(2)CCK-8 assay showed that PLGA/LGA-g-GO(2%,3%)composite scaffold could promote the proliferation of MC3T3 cells.Alkaline phosphatase staining and alizarin red staining showed that the cell alkaline phosphatase activity in PLGA/LGA-g-GO(2%,3%)group was higher than that in the other three groups(P<0.05).The calcium deposition in the PLGA/GO and PLGA/LGA-g-GO(1%,2%,and 3%)groups was higher than that in the PLGA group(P<0.05).(3)In summary,PLGA/LGA-g-GO composite scaffold can promote the proliferation and osteogenic differentiation of osteoblasts,and is conducive to bone regeneration and bone reconstruction after bone injury.

Objective To assess the nutritional status of vitamin D and associated factors among adults of six ethnic minority groups native to Yunnan Province,and provide evidence for policy making.Methods Between May 2019 and August 2020,a total of 690 adults were selected from Jinuo,Bulang,Jingpo,Deang,Achang and Pumi ethnic groups according to the sex and age composition in the 6th national census.A questionnaire survey and an anthropometric examination were conducted by trained health workers,and serum 25(OH)D levels were determined with high-performance liquid chromatography-tandem mass spectrometry.Results The median of serum 25(OH)D was 28.7(P25～P75∶24.3～33.8)ng/mL,and the prevalence of vitamin D sufficiency,insufficiency and deficiency were 44.2%、47.5%and 8.3%,respectively.There were significant differences in serum 25(OH)D levels among the six ethnic groups(χ2=139.29,P<0.01).Multivariate logistic regression showed that ethnic groups living in higher latitude areas(Pumi,Jingpo,Deang,and Achang),women,and those whose BMI≥24.0 were more likely to be vitamin D insufficient or deficient.Conclusion More than half of the ethnic adults suffer from vitamin D malnutrition which also varies across ethnicities.Further surveillance and interventions among key areas and populations are needed.

The COVID-19 epidemic has spread to the whole world for three years and has had a serious impact on human life, health and economic activities. China's epidemic prevention and control has gone through the following stages: emergency unconventional stage, emergency normalization stage, and the transitional stage from the emergency normalization to the "Category B infectious disease treated as Category B" normalization, and achieved a major and decisive victory. The designated hospitals for prevention and control of COVID-19 epidemic in Tianjin has successfully completed its tasks in all stages of epidemic prevention and control, and has accumulated valuable experience. This article summarizes the experience of constructing a hospital infection prevention and control system during the "Category B infectious disease treated as Category A" period in designated hospital. The experience is summarized as the "Cluster" hospital infection prevention and control system, namely "three rings" outside, middle and inside, "three districts" of green, orange and red, "three things" before, during and after the event, "two-day pre-purification" and "two-director system", and "one zone" management. In emergency situations, we adopt a simplified version of the cluster hospital infection prevention and control system. In emergency situations, a simplified version of the "Cluster" hospital infection prevention and control system can be adopted. This system has the following characteristics: firstly, the system emphasizes the characteristics of "cluster" and the overall management of key measures to avoid any shortcomings. The second, it emphasizes the transformation of infection control concepts to maximize the safety of medical services through infection control. The third, it emphasizes the optimization of the process. The prevention and control measures should be comprehensive and focused, while also preventing excessive use. The measures emphasize the use of the least resources to achieve the best infection control effect. The fourth, it emphasizes the quality control work of infection control, pays attention to the importance of the process, and advocates the concept of "system slimming, process fattening". Fifthly, it emphasizes that the future development depends on artificial intelligence, in order to improve the quality and efficiency of prevention and control to the greatest extent. Sixth, hospitals need to strengthen continuous training and retraining. We utilize diverse training methods, including artificial intelligence, to ensure that infection control policies and procedures are simple. We have established an evaluation and feedback mechanism to ensure that medical personnel are in an emergency state at all times.

Objective To evaluate the pharmacokinetic characteristics and safety of single and multiple oral azvudine tablets in healthy young and elderly Chinese subjects.Methods This was a open-label and parallel-group study.The trial consisted of two groups:healthy young subjects group and healthy elderly subjects group,with 12 subjects in each group.Enrolled subjects were first given a single dose,fasting oral azvudine tablet 5 mg,after a 3-day cleansing period entered the multiple dose phase,fasting oral azvudine tablet 5 mg·d-1 for 7 days.Results After a single dose of azvudine 5 mg,Cmax and AUC0-∞ were(4.76±2.12)ng·mL-1,(6.53±2.20)ng·mL-1·h,and Tmax,t1/2 were 0.75,1.87 h in young subjects;Cmax and AUC0-∞ were(6.40±3.25)ng·mL-1,(9.50±3.70)ng·mL-1·h,and Tmax,t1/2 were 0.63,2.66 h in elderly subjects.After a multiple dose of azvudine 5 mg·d-1 for 7 d,Cmax and AUC0-∞ were(3.26±1.61)ng·mL-1,(5.38±2.19)ng·mL-1·h,and Tmax,ss,t1/2,ss were 0.88,2.13 h in young subjects;Cmax,ss and AUC0-∞,ss were(3.97±2.09)ng·mL-1,(6.71±3.26)ng·mL-1·h,and Tmax,ss,t1/2,ss were 0.75,2.56 h in elderly subjects.Elderly/young geometric mean ratios and 90％CIs were 128.37％(88.23％-186.76％),139.93％(105.42％-185.72％),140.03％(106.33％-184.41％)for azvudine Cmax,AUC0-t,AUC0-∞ after a single dose,and were 118.66％(80.83％-174.20％),118.41％(83.60％-167.69％),118.95％(84.78％-166.89％)for azvudine Cmax,AUC0-t,AUC0_∞ after a multiple dose of azvudine 5 mg·d-1 for 7 d.Conclusion After single and multiple oral administration of azvudine tablets,systemic exposure to azvudine was higher in healthy elderly subjects compared with healthy young subjects.After taking azvudine tablets,the types,severity and incidence of adverse events and adverse drug reactions in healthy elderly people were not significantly different from those in healthy young subjects.Azvudine was found to be safe and well tolerated in healthy elderly subjects.

Objective To investigate the risk factors for pediatric acute perforation appendicitis,and to construct a nomogram predictive model and conduct the verification.Methods A total of 426 children patients with appendectomy in this hospital from June 30,2020 to June 30,2022 were selected as the study subjects 340 children with acute appendicitis admitted to the hospital from 30 June 2020 to 28 February 2022 were the training set and 86 children patients with appendicitis hospitalized in this hospital from March 1,2022 to June 30,2022 conducted the external validation(verification set).The univariate and multivariate logistic regression models were employed to analyze the independent risk factors of pediatric acute perforation appendicitis.The nomograms predictive model was constructed.The receiver operating characteristic(ROC)curve and calibra-tion curve were used to evaluate the predictive efficiency of the model.The decision curve analysis(DCA)was used to evaluate the application value of the model.Results Of the 426 children,198 were perforated and 228 were not perforated.The univariate and multivariate logistic regression analyses revealed that elevated C-reac-tive protein(CRP),presence of stercorolith in appendiceal cavity,time of onset to visiting hospital ≥2 d and body temperature ≥37.3 ℃ were the independent risk factors for pediatric acute perforation appendicitis(P＜0.05).The Hosmer-Lemeshow test demonstrated that the nomogram predictive model had good fitting(P=0.869),and the area under the curve(AUC)for the training and validation sets were 0.808 and 0.860 respectively,showing the good predictive ability of the model.The calibration curve closely approach the ideal diagonal.The model showed good discrimination,consistency and accuracy.The DC A revealed that the curve was far away from oblique and horizontal lines,and the model had good clinical practicability.Conclusion The constructed nomogram model of pediatric acute perforation appendicitis has good predictive ability and may help clinic to identify as early as possible.

Objective To investigate the incidence rate,clinical characteristics,and prognosis of neonatal stroke in Shenzhen,China.Methods Led by Shenzhen Children's Hospital,the Shenzhen Neonatal Data Collaboration Network organized 21 institutions to collect 36 cases of neonatal stroke from January 2020 to December 2022.The incidence,clinical characteristics,treatment,and prognosis of neonatal stroke in Shenzhen were analyzed.Results The incidence rate of neonatal stroke in 21 hospitals from 2020 to 2022 was 1/15 137,1/6 060,and 1/7 704,respectively.Ischemic stroke accounted for 75％(27/36);boys accounted for 64％(23/36).Among the 36 neonates,31(86％)had disease onset within 3 days after birth,and 19(53％)had convulsion as the initial presentation.Cerebral MRI showed that 22 neonates(61％)had left cerebral infarction and 13(36％)had basal ganglia infarction.Magnetic resonance angiography was performed for 12 neonates,among whom 9(75％)had involvement of the middle cerebral artery.Electroencephalography was performed for 29 neonates,with sharp waves in 21 neonates(72％)and seizures in 10 neonates(34％).Symptomatic/supportive treatment varied across different hospitals.Neonatal Behavioral Neurological Assessment was performed for 12 neonates(33％,12/36),with a mean score of(32±4)points.The prognosis of 27 neonates was followed up to around 12 months of age,with 44％(12/27)of the neonates having a good prognosis.Conclusions Ischemic stroke is the main type of neonatal stroke,often with convulsions as the initial presentation,involvement of the middle cerebral artery,sharp waves on electroencephalography,and a relatively low neurodevelopment score.Symptomatic/supportive treatment is the main treatment method,and some neonates tend to have a poor prognosis.

Objective:To study the correlation between the number of hemophagocytes and peripheral blood cells in bone marrow of patients with fever of unknown origin.Methods:A total of 465 patients with fever of unknown origin in our hospital from January 2019 to December 2021 were selected as the research objects,which was to reviewed retrospectively the correlation between the number of hemophagocytes and peripheral blood cells in bone marrow.Results:The positive rates of hemophagocytes detected in the three lines decreased group,the two lines decreased group,the one line decreased group,normal group of the three lines and at least one of the three lines increased group were 86.4％,62.1％,38.3％,34.6％and 33.3％,respectively.The number of hemophagocytes per unit area in the three lines decreased group was significantly higher than that in the other four groups(P＜0.001).The number of hemophagocytes per unit area in the two lines decreased group was higher than that in the one line decreased group,normal group of three lines and at least one of the three lines increased group(P＜0.01).There was no significant difference in the number of hemophagocytes per unit area between the group with a decreased number of one line and the other two groups with a normal number of three lines and the group with at least one increased number of three lines(P＞0.05).The missed rates of hemophagocytes in the five groups were 15.78％,22.03％,62.22％,77.78％and 53.84％,respectively.Conclusion:For patients with fever of unknown origin,especially those with obvious decrease in the number of three lines and two lines in peripheral blood cells,which should pay attention to the detection of hemophagocytes in bone marrow.Meanwhile,if the number of three lines was normal even at least one of the three lines increased,the presence of hemophagocytes in the bone marrow slice should be also carefully observed.

Background/Aims: Low educational attainment is a well-established risk factor for nonalcoholic fatty liver disease (NAFLD) in developed areas. However, the association between educational attainment and the risk of NAFLD is less clear in China. Methods: A cross-sectional study including over 200,000 Chinese adults across mainland China was conducted. Information on education level and lifestyle factors were obtained through standard questionnaires, while NAFLD and advanced fibrosis were diagnosed using validated formulas. Outcomes included the risk of NAFLD in the general population and high probability of fibrosis among patients with NAFLD. Logistic regression analysis was employed to estimate the risk of NAFLD and fibrosis across education levels. A causal mediation model was used to explore the potential mediators. Results: Comparing with those receiving primary school education, the multi-adjusted odds ratios (95% confidence intervals) for NAFLD were 1.28 (1.16 to 1.41) for men and 0.94 (0.89 to 0.99) for women with college education after accounting for body mass index. When considering waist circumference, the odds ratios (95% CIs) were 0.94 (0.86 to 1.04) for men and 0.88 (0.80 to 0.97) for women, respectively. The proportions mediated by general and central obesity were 51.00% and 68.04% for men, while for women the proportions were 48.58% and 32.58%, respectively. Furthermore, NAFLD patients with lower educational attainment showed an incremental increased risk of advanced fibrosis in both genders. Conclusions In China, a low education level was associated with a higher risk of prevalent NAFLD in women, as well as high probability of fibrosis in both genders.

OBJECTIVES: To explore the difference in CT values between pulmonary thromboembolism and postmortem clot in postmortem CT pulmonary angiography (CTPA) to further improve the application value of virtual autopsy. METHODS: Postmortem CTPA data with the definite cause of death from 2016 to 2019 were collected and divided into pulmonary thromboembolism group (n=4), postmortem clot group (n=5), and control group (n=5). CT values of pulmonary trunk and left and right pulmonary artery contents in each group were measured and analyzed statistically. RESULTS: The average CT value in the pulmonary thromboembolism group and postmortem clot group were (168.4±53.8) Hu and (282.7±78.0) Hu, respectively, which were lower than those of the control group (1 193.0±82.9) Hu (P<0.05). The average CT value of the postmortem clot group was higher than that of the pulmonary thromboembolism group (P<0.05). CONCLUSIONS CT value is reliable and feasible as a relatively objective quantitative index to distinguish pulmonary thromboembolism and postmortem clot in postmortem CTPA. At the same time, it can provide a scientific basis to a certain extent for ruling out pulmonary thromboembolism deaths.
Humans ; Autopsy ; Thrombosis ; Pulmonary Embolism/diagnostic imaging* ; Tomography, X-Ray Computed ; Angiography ; Cadaver