BACKGROUND:Polylactic acid(PLA)has good biocompatibility and a controllable degradation rate and is currently widely used in biomedical engineering.However,PLA has shortcomings such as low mechanical strength and insufficient biological activity,which limits its further application in bone tissue engineering. OBJECTIVE:To construct polylactic acid/polydopamine/tantalum(PLA/PDA/Ta)bone tissue engineering scaffolds,and explore their biosafety and in vitro osteogenesis. METHODS:A PLA scaffold with a porous structure was prepared through liquid crystal display light-curing technology.PLA/PDA scaffolds and PLA/PDA/Ta scaffolds were prepared by soaking PLA scaffolds in dopamine solution and dopamine-tantalum nanoparticle solution,respectively.The microstructure and water contact angle of scaffolds were characterized.MC3T3-E1 cells were co-cultured with PLA,PLA/PDA,and PLA/PDA/Ta scaffolds,respectively,and CCK-8 assay and live/dead cell staining were performed.After osteogenic differentiation,alkaline phosphatase,alizarin red staining,and osteogenic gene detection were performed. RESULTS AND CONCLUSION:(1)The scanning electron microscope results exhibited that the three kinds of prepared scaffolds had an interconnected porous three-dimensional structure,and the average pore diameter was 200 μm.The water contact angle of PLA/PDA/Ta scaffolds was lower than that of PLA and PLA/PDA scaffolds(P<0.05).(2)CCK-8 assay showed that compared with PLA and PLA/PDA scaffolds,PLA/PDA/Ta scaffolds could promote cell proliferation(P<0.05).Live/dead cell staining showed good cell proliferation in the three groups.(3)Alkaline phosphatase and alizarin red staining showed that compared with PLA and PLA/PDA scaffolds,PLA/PDA/Ta scaffolds could promote the expression of alkaline phosphatase and the formation of mineralized nodules.RT-qPCR showed that compared with PLA and PLA/PDA scaffolds,PLA/PDA/Ta scaffolds could enhance the mRNA expression of cell bone morphogenetic protein,Runx-2,and type I collagen(P<0.05,P<0.01).(4)The results showed that the PLA/PDA/Ta scaffold had excellent osteogenic activity and the ability to promote cell proliferation.

Objective:To construct core medical skill index system for helicopter medical rescue personnel by Delphi expert consensus method.Methods:This study combined literature review and two rounds of Delphi expert correspondence to construct the core skill index system. Total of 22 experts from relevant disciplines were selected purposively to conduct Delphi expert consultation.Results:The effective questionnaire recovery rates of the two rounds of Delphi expert correspondence was 100%; the authority coefficient of experts was 0.87; the Kendall coordination coefficients of the importance of the first and second level indexes were 0.380 and 0.338 in the first round of correspondence, and then 0.415 and 0.357 in the second round. the Kendall coordination coefficients of the feasibility of the second level indexes were 0.347 in the first round of correspondence and 0.354 in the second round. The final core skill index system for helicopter medical rescue personnel includes 4 primary indicators: core medical skill for diseases or trauma in respiratory system, circulatory system, sports system and other system, and 32 secondary indicators.Conclusions:The core medical skill index system for helicopter medical rescue personnel constructed through two rounds of Delphi expert correspondence is scientific and reasonable, which can provide a scientific basis to accurately understand, describe, analyze, and evaluate the competence level of helicopter medical rescue personnel, as well as serve as a content framework for training programs.

ObjectiveTo investigate the molecular mechanism by which Si Junzitang in intervening in the development of hepatocellular carcinoma （HCC） by regulating the O-linked β-N-acetylglucosamine modification （O-GlcNAcylation） of nuclear factor kappa-B （NF-κB） p65 in the paracancerous tissues. MethodThe orthotopic liver cancer mouse model was established. Twenty-four C57BL/6 mice were randomly divided into four groups： Normal group， model group， Si Junzitang low-dose group （10 g·kg^-1）， and Si Junzitang high-dose group （25 g·kg^-1）， with 6 mice in each group. The O-GlcNAcylation level and phosphorylation modification level of p65 in the paracancerous tissues were detected using Western blot. The O-GlcNAcylation of p65 was assessed using immunoprecipitation （IP）. The mRNA expression of interleukin-6 （IL-6）， tumor necrosis factor-α （TNF-α）， transforming growth factor-β₁ （TGF-β₁）， vascular endothelial growth factor A （VEGFA）， matrix metalloproteinase-2 （MMP-2）， matrix metalloproteinase-9 （MMP-9） in the paracancerous tissues was detected using real-time quantitative polymerase chain reaction （Real-time PCR）. The tumor number， liver weight， locomotor activity， grip strength， and Qi status of the mice were observed and analyzed. ResultCompared with the normal group， the model group showed a significant decrease in O-GlcNAcylation in the paracancerous tissues （P<0.01）， a significant decrease in p65 O-GlcNAcylation （P<0.01）， a significant increase in p65 phosphorylation （P<0.01）， significantly elevated mRNA levels of cytokines IL-6， TNF-α， TGF-β₁， VEGFA， MMP-2， and MMP-9 （P<0.01）， significantly increased liver weight （P<0.01）， significantly declined grip strength， number of grid crossings， and number of vertical stand-ups （P<0.01）， and significantly dwindled Qi status （P<0.01）. Compared with model group， the Si Junzitang low-dose and high-dose groups showed significantly increased levels of O-GlcNAcylation in the paracancerous tissues （P<0.05， P<0.01）， significantly upregulated p65 O-GlcNAcylation levels （P<0.05， P<0.01）， and significantly decreased p65 phosphorylation levels （P<0.01）. In the Si Junzitang low-dose group， the mRNA levels of IL-6， TGF-β₁， and VEGFA significantly decreased （P<0.05， P<0.01）. In the Si Junzitang high-dose group， the mRNA levels of IL-6， TNF-α， TGF-β₁， VEGFA， MMP-2， and MMP-9 significantly decreased （P<0.01）， the number of tumors larger than 3 mm in diameter significantly decreased （P<0.01）， and liver weight significantly decreased （P<0.05）. Additionally， grip strength， number of grid crossings， and number of vertical stand-ups significantly increased （P<0.05， P<0.01）， along with a significant increase in qi status （P<0.01）. ConclusionSi Junzitang can inhibit the progression of orthotopic HCC in mice， which may be achieved by increasing the O-GlcNAcylation level in the paracancerous tissues， enhancing the O-GlcNAcylation of p65， inhibiting the phosphorylation modification of p65， and ultimately suppressing the expression of downstream IL-6， TNF-α， TGF-β₁， VEGFA， MMP-2， and MMP-9.

BACKGROUND:Gait is one of the optimal indicators of functional status in older adults.Gait parameters are associated with adverse health outcomes in older adults. OBJECTIVE:To summarize and compare the practical value of gait parameters,and to review the progress of research on spatio-temporal parameters and the risk of adverse health outcomes in older adults. METHODS:PubMed,Web of Science,and CNKI were searched for relevant literature published from January 2010 to June 2023 using the search terms of"gait speed,walking speed,step length,cadence,step frequency,step time,walking base,aged and elderly"in English and Chinese,respectively.A total of 52 papers were finally included for the systematic review. RESULTS AND CONCLUSION:Currently,researchers have focused on three basic temporal-spatial parameters,namely,step speed,step length and step frequency,to explore their association with adverse health outcomes in older adults.Reduced gait speed in older adults may increase the risk of falls,all-cause mortality,and may be an independent predictor of all-cause mortality.Older adults with slow gait speed are at higher risk of cognitive decline,and may be the preferred gait parameter in assessing cognitive impairment in older adults.Older adults with slow gait speed are more likely to have debilitating or common chronic illnesses,and are at higher risk of hospitalization and public care.Step length is positively correlated with individual height and lower limb length,but age-induced shortening of step length is not related to height or lower limb length,and shortening of step length reflects reduced physical function in older adults,and shortening of step length is a risk factor for falls and cognitive decline in older adults.Stride frequency is often used as a measure of exercise intensity,and a stride frequency of≥100 steps/minute is predictive of all-cause mortality,and slowing of step frequency may lead to a higher risk of falls,hospitalization and all-cause mortality in older adults.Changes in gait parameters are closely related to the level of physical fitness in older adults,and there may be a bidirectional relationship between the two.The results of the study will provide a theoretical basis for further improving risk screening in clinical populations,refining health risk assessment in the elderly,improving health protection and promoting active health in the elderly.

Objective:To establish right middle cerebral artery occlusion(MCAO)model in rats and to investigate the mechanism underlying motor function regulation by transcranial alternating current stimulation(tACS)intervention.Furthermore,to dynamically observe the effects of electroacupuncture combined with tACS on neurological defi-cit scores(NDS),cerebral blood flow,inflammatory-cell apoptosis gene of MCAO model rats and to explore the mechanism of cerebral and neural regulation on motor function rehabilitation after cerebral ischemia reperfusion. Method:Forty SD rats were randomly divided into sham-operation group(S group),model group(M group),electroacupuncture group(EA group),transcranial alternating current stimulation group(T group)and electroacupuncture combined with transcranial alternating current stimulation group(EA+T group).After 2 h ischemia-reperfusion,EA group was given bilateral Qu chi(LI 11)and Zu san li(ST 36)electroacupuncture under anesthesia.Right Ml was selected for tACS in T group.EA+T group was treated with EA and tACS to-gether.S and M group were treated with anesthesia for 30min per time,for 7 days.The data from before modling(B)to after modling(D7)were recorded,including neurological deficit score and blood flow of the right middle cerebral artery by laser doppler flowmetry.RT-PCR was used to analyze inflammation-cell apopto-sis gene expression at D7. Result:Neurological deficit score:at 2h,D1,M group,EA group,T group and EA+T group increased signifi-cantly compared with other time(P＜0.05).At D3,D5,D7,S group decreased significantly compared with oth-er time(P＜0.05),while M group increased significantly compared with other group(P＜0.05).EA group,T group and EA+T group were significantly different in all times(P＜0.05).At 2h,D1,D3,D5,D7,M group increased significantly compared with B.At D1,D3,D5,D7,NDS decreased significantly compared with that at 2h(P＜0.05).Blood flow:EA+T group and S group decreased at 2h,increased at D1 and decreased at D3.EA group increased at D3.However,M group decreased significantly compared with other group at D1,D3 and D5(P＜0.05).RT-PCR:motor cortex △Ct analysis:Caspase 12 in EA+T group decreased significantly compared with T group(P＜0.05),IL-1β and NLRPla in EA group and T group decreased significantly com-pared with those in S group(P＜0.05).2-△△Ct analysis in ischemic region:ATF4 in M group increased significant-ly compared with that in other groups(P＜0.05);Bcl 2 in M group increased significantly compared with that in S group,EA group and EA+T group(P＜0.05);Bax,Caspase 12,C-fos in M group increased significantly compared with those in S Group(P＜0.05). Conclusion:Electroacupuncture combined with tACS can modulate the inflammatory response and inhibit cell apoptosis through regulating ATF4、Bcl-2、Bax、Caspase 12、C-fos and can be a new strategy for the treatment of ischemic stroke.

Objective Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is the leading cause of hospitalization and death in patients with chronic obstructive pulmonary disease (COPD). Exploring the prognostic factors of AECOPD patients will assist in optimizing treatment strategies and standardizing disease management. Methods This study retrospectively collected the clinical data of 664 patients with AECOPD admitted to the Respiratory Department of Dongzhimen Hospital of Beijing University of Chinese Medicine from January 2013 to September 2019. The 3-year survival rate and treatment of the patients were investigated. According to whether the patients died,they were divided into a non-survivors group and a survivors group,and clinical data such as basic information,comorbidities,and auxiliary examination results were compared between the two groups. Incorporating clinical experience of researchers and previous research evidence,a secondary screening of variables was conducted to ultimately determine the covariates to be included in the multifactorial Cox proportional hazards regression model,and the factors affecting the 3-year survival rate of the patients were analyzed. Results A total of 664 cases were included in this study,including 362 males and 302 females,with an average age of (77.25±6.89) years old. The 3-year all-cause mortality rate of older hospitalized patients with AECOPD was 20.48％(136 patients). Older age (HR:1.071,95％CI:1.040-1.102,P<0.001);smoking history (HR:1.788,95％CI:1.173-2.723,P=0.007);Charlson comorbidity index (HR:1.209,95％CI:1.029-1.421,P=0.022);lower arterial partial pressure of oxygen (HR:1.014,95％CI:1.006-1.022,P<0.001);higher brain natriuretic peptide(HR:1.001,95％CI:1.000-1.001,P=0.025);cor pulmonale(HR:1.896,95％CI:1.235-2.908,P=0.004);respiratory failure (HR:2.437,95％CI:1.378-4.311,P=0.003);TCM syndrome differentiation elements,including kidney (HR:1.639,95％CI:1.055-2.546,P=0.028) and fluid retention (HR:2.512,95％CI:1.653-3.816,P<0.001),were independent risk factors for 3-year all-cause death of older hospitalized patients with AECOPD. Long-term regular use of bronchiectasis (HR:0.474,95％CI:0.324-0.695,P<0.001) was an independent protective factor for 3-year all-cause death. Conclusion The 3-year survival rate of elderly hospitalized patients with AECOPD is relatively low,with the TCM syndrome elements manifested as lung-kidney qi deficiency,yang deficiency with water retention,and blood stasis obstruction. Patients with moderate to severe impairment of lung function due to COPD have an increased risk of death within 3 years. Therefore,for such patients,nourishing lung-kidney qi,resolving phlegm and water retention,activating blood circulation to remove blood stasis and dredging collaterals,combined with regular use of bronchodilators,may help improve their 3-year survival rate.

[Objective]To investigate the efficacy of a blended instruction model which incorporated preceptorship into the clinical anatomy course at Sun Yat-sen University and improve satisfaction and performance of medical students.[Methods]The study recruited participants including 375 Chinese students aged 20-24 years old,2 anatomy professors,49 surgeons and 7 lab technicians. The students were divided into 10 teams and each team was tutored by 1 anatomy professor,2 surgeons and 1 lab technician. After the course ended,the Course Experience Questionnaire (CEQ) and Student Experience in Education Questionnaire (SEEQ) were used in the survey to measure the quality of teaching and students' overall educational experience. Students' performance scores were collected and analyzed.[Results]The response rates for CEQ and SEEQ were 60.3％ (226/375) and 54.6％ (200/375),respectively. CEQ indicated a moderate level of overall satisfaction with 7.12 out of 10. Subscales like Clear Goals,Good Teaching and Generic Skills showed moderately positive reception of the course,while subscales like Appropriate Workload and Appropriate Assessment revealed students' concerns about heavy workload and difficult exam. There was no statistically significant difference in perceptions between male and female students. The students who are more satisfied with the quality of the course are also more satisfied with the way it is taught (P<0.01). SEEQ further confirmed the universal appeal of the course,with high scores in dimensions like Learning,Enthusiasm and Individual Rapport among the students. Qualitative responses highlighted areas of improvement,such as consistent teaching methods,practical hands-on experience for the students and alignment between what was taught and tested.The students after the preceptorship introduction achieved better academic performance than before.[Conclusions]The blended instruction model incorporating preceptorship enhances the student satisfaction and performance in clinical anatomy course,and also stimulates students' learning enthusiasm and group interaction. We need further improvement in the teaching quality control,syllabus contents and course assessment for teaching of clinical anatomy.

Objective:To investigate the therapeutic effect and safety of recombinant human thrombopoietin (rhTPO) combined with low-dose eltrombopag in the treatment of persistent thrombocytopenia after allogeneic hematopoietic stem cell transplantation (allo-HSCT).Methods:A retrospective case series study was conducted. The retrospective analysis was conducted on the clinical data of 20 patients diagnosed with post-allo-HSCT thrombocytopenia at Blood Diseases Hospital of Chinese Academy of Medical Sciences from January 2018 to June 2021. All patients didn't meet the platelet implantation criteria [without the platelet count (Plt) ≥20×10 9/L for a consecutive period of 7 days and discontinuation of platelet transfusion] after transplantation, and they received subcutaneous injections of rhTPO (15 000 U) once daily and oral administration of eltrombopag (50 mg) once. Treatment efficacy was defined as maintaining Plt≥20×10 9/L for a consecutive period of 7 days after treatment and discontinuation of platelet transfusion; treatment inefficacy was defined as Plt<20×10 9/L after treatment or continuation of platelet transfusion. The therapeutic effect of rhTPO combined with low-dose eltrombopag was analyzed; the adverse reactions were evaluated; the clinical characteristics were compared between the effective treatment group and ineffective treatment group; the overall survival (OS) and disease-free survival (DFS) were analyzed using Kaplan-Meier method between the effective treatment group and ineffective treatment group. Results:Among the 20 patients, 9 were diagnosed with acute myeloid leukemia (AML), 5 with acute lymphoblastic leukemia (ALL), 4 with myelodysplastic syndromes (MDS), and 2 with severe aplastic anemia (SAA); 10 cases were primary failure of platelet recovery (PFPR), and 10 cases were secondary failure of platelet recovery (SFPR). The median time [ M ( Q1, Q3)] from transplantation to initiation of treatment was 79 days (50 days, 89 days), and the median duration of treatment was 19.5 days (15 days, 30 days). Of the total cohort, treatment was effective in 13 cases (65.0%, 8 cases of PFPR, 5 cases of SFPR), while 7 patients (35.0%) showed no response to treatment. The median time to achieve the therapeutic response among responders was 10 days (7 days, 19 days). During the combination treatment, 5 patients experienced elevated transaminase levels exceeding more than 2.5 times the upper limit of normal or bilirubin levels surpassing twice that limit. No instances of adverse reaction-related arterial thrombosis, myelofibrosis, or primary disease relapse occurred within this patient cohort. Megakaryocyte counts in the effective treatment group before combination treatment were higher than that in the ineffective treatment group, and the difference was statistically significant [14 (10, 20) vs. 2.5 (2, 4); Z = -2.33, P = 0.017]; Notably, no statistically significant differences were identified when comparing the compositions of gender, type of underlying diseases, human leukocyte antigen matching degree, blood type of donor and recipient, conditioning regimen use of antithymocyte globulin, quantity of CD34 + cells transfused, type of thrombocytopenia, acute graft-versus-host disease, fungal or bacterial infections, and viral infections between the two groups (all P > 0.05). The 1-year OS rates for the effective and ineffective treatment groups were 100.0% and 42.9%, respectively, and the difference in OS between the two groups was statistically significant ( P = 0.001). The 1-year DFS rates for the effective and ineffective treatment groups were 92.3% and 28.6%, respectively, and the difference in DFS between the two groups was statistically significant ( P = 0.003). Conclusions:The combination of rhTPO and low-dose eltrombopag has demonstrated certain therapeutic efficacy and good safety in the treatment of persistent thrombocytopenia after allo-HSCT.

Zi goose is a small local variety with high fecundity,good meat quality,roughage resist-ance,strong adaptability and excellent down quality.It is an excellent female parent for cross breeding among varieties.With the rapid development of goose industry,the variety of Zi goose has not been well protected,the variety is hybrid and degraded seriously,and the number of pure Zi goose is decreasing day by day.This paper reviewed the research progress on the breeding distribu-tion and preservation status of Zi goose and the variety characteristics of Zi goose,in order to pro-vide reference for the research,protection and utilization of germplasm resources of Zi goose and the stable development of goose industry.

Objective:To explore the characteristics of 24-hour movement in preschoolers and its relationship with executive function.Methods:The study subjects consisted of 555 preschoolers in Zhuhai City. An objective measurement approach was employed, physical activity level was assessed by utilizing accelerometers and executive function was evaluated by computerized behavioral tests.The characteristics of 24-hour movement in children were described.Data were analyzed using SPSS 26.0 software, independent samples t-test was used to compare differences in 24-hour activity behaviors across genders, and multivariate linear regression was used to explore the effect of preschoolers' achievement of activity behaviors on executive functioning. Results:According to the physical activity guideline for Chinese preschoolers aged 3-6 years recommendations for children's daily moderate to vigorous-intensity physical activity, sedentary screen time, and sleep duration, among the study participants, the compliance rate of moderate to vigorous-intensity physical activity (≥60 min/d) was 33.9 %(188/555), sedentary screen time (≤1 h/d) was 43.4%(241/555), and sleep duration (10-13 h/d) was 83.4 %(463/555). Only 13.3 %(74/555) of the participants met the recommended guidelines for all three behaviors. The correct score of the working memory test was (60.6±20.3) and the reaction time of the inhibitory control test was (695.1±135.8) ms. In male preschoolers, moderate to vigorous-intensity physical activity (≥60 min/d) positively predicted working memory( β=0.121, P=0.037), while sedentary screen time (≤1 h/d) negatively predicted inhibitory control ( β=-0.122, P=0.036). Conclusions:The daily compliance rate of moderate to vigorous-intensity physical activity and sedentary screen time is low among preschooler. The former is positively correlated with working memory in preschool boys, while the latter is negatively correlated with inhibitory control.