ObjectiveTo investigate the mechanism of modified Si Junzitang and Shashen Maidong Tang ［Yiqi Yangyin Jiedu prescription （YQYYJD）］ in enhancing the sensitivity of cisplatin in epidermal growth factor receptor tyrosine kinase inhibitor （EGFR-TKI）-resistant lung adenocarcinoma cells based on aerobic glycolysis. MethodsThe effects of different concentrations of YQYYJD （0， 2， 3， 4， 5， 6， 7， 8 g·L^-1） and cisplatin （0， 3， 6， 9， 12， 15， 18， 21， 24， 27 mg·L^-1） on the proliferation and activity of PC9/GR cells were detected by the cell counting kit-8 （CCK-8） assay after 24 hours of intervention. The half-maximal inhibitory concentration （IC₅₀） for PC9/GR cells was calculated to determine the concentrations used in subsequent experiments. PC9/GR cells were divided into blank group （complete medium）， YQYYJD group （5 g·L^-1）， cisplatin group （12 mg·L^-1）， and combined group （YQYYJD 5 g·L^-1 + cisplatin 12 mg·L^-1）. After 24 hours of intervention， cell viability was measured using CCK-8 assay. Cell proliferation was assessed by colony formation assay， and cell migration was evaluated by scratch and Transwell assays. Glucose consumption， lactate production， and adenosine triphosphate （ATP） levels were measured by colorimetric assays. The expression levels of glycolysis-related proteins， including hexokinase 2 （HK2）， phosphofructokinase P （PFKP）， pyruvate kinase M2 （PKM2）， lactate dehydrogenase A （LDHA）， glucose transporter 1 （GLUT1）， and monocarboxylate transporter 4 （MCT4）， were determined by Western blot. ResultsBoth YQYYJD and cisplatin inhibited the viability of PC9/GR cells in a concentration-dependent manner. The IC₅₀ of PC9/GR cells for YQYYJD and cisplatin were 5.15 g·L^-1 and 12.91 mg·L^-1， respectively. In terms of cell proliferation， compared with the blank group， the cell survival rate and the number of colonies formed in the YQYYJD group， cisplatin group， and combined group were significantly decreased （P<0.01）. Compared with the YQYYJD and cisplatin groups， the combined group showed a further significant reduction in cell survival rate and colony formation （P<0.01）. In terms of cell migration， compared with the blank group， the cell migration rate and the number of cells passing through the Transwell membrane in the YQYYJD group， cisplatin group， and combined group were significantly decreased （P<0.01）. Compared with the YQYYJD and cisplatin groups， the combined group exhibited a further significant reduction in cell migration rate and the number of cells passing through the Transwell membrane （P<0.01）. In terms of glycolysis， compared with the blank group， glucose consumption， lactate production， and ATP levels in the YQYYJD group， cisplatin group， and combined group were significantly decreased （P<0.01）. Compared with the YQYYJD and cisplatin groups， the combined group showed a further significant reduction in glucose consumption， lactate production， and ATP levels （P<0.05）. Compared with the blank group， the protein expression levels of HK2， PFKP， PKM2， and LDHA in the YQYYJD， cisplatin， and combined groups were significantly decreased （P<0.01）. The combined group showed a further significant reduction in the expression levels of these proteins compared with the YQYYJD and cisplatin groups （P<0.01）. No significant differences were observed in the protein expression levels of GLUT1 and MCT4 among the groups. ConclusionYQYYJD can synergistically inhibit the proliferation and migration of PC9/GR cells and enhance their sensitivity to cisplatin. The mechanism may be related to the downregulation of the expression of glycolysis-related rate-limiting enzymes， including HK2， PFKP， PKM2， and LDHA， thereby inhibiting glycolysis.

ObjectiveTo observe the prognosis effect of soluble programmed death ligand-1（sPD-L1） in treating patients with advanced lung adenocarcinoma treated with epidermal growth factor receptor-tyrosine kinase inhibitors（EGFR-TKIs） and the influence of Yiqi Yangyin Jiedu prescription. MethodA prospective cohort-controlled study was conducted to enroll patients treated with EGFR-TKIs in the first line of treatment，who were admitted to the Oncology Department of Longhua Hospital and Shanghai Chest Hospital from May 1^st， 2021 to June 30^th， 2023， and they were evaluated as non-progressive and identified with deficiency of Qi and Yin after one month of treatment. The patients were divided into an exposed group （EGFR-TKIs combined with Yiqi Yangyin Jiedu prescription） and a non-exposed group （EGFR-TKIs alone）according to whether or not they were treated with Yiqi Yangyin Jiedu prescription and were treated until disease progression， or death and intolerable adverse reactions occurred. The enzyme-linked immunosorbent assay （ELISA） was applied to detect the level of sPD-L1 in patients at the time of enrollment and disease progression，and Cox risk proportionality model was used to analyze the independent prognostic factors affecting disease progression of patients treated with EGFR-TKIs. ResultA total of 90 patients （39 in the exposed group and 51 in the non-exposed group） undergoing disease progression after EGFR-TKI treatment were enrolled. At the time of enrolment and after disease progression，the levels of serum sPD-L1 in the 90 patients were 12.06 （27.54） ng·L^-1 and 41.99 （62.93） ng·L^-1，respectively. Compared with that at the time of enrollment， the serum sPD-L1 level in the 90 patients was significantly increased after disease progression （P<0.01）. The serum sPD-L1 level in patients in the exposed group was 12.27 （24.78） ng·L^-1 and 29.57 （61.12）ng·L^-1 respectively at the time of enrolment and after disease progression. In the non-exposed group， patients had serum sPD-L1 levels of 11.81 （28.46） ng·L^-1 and 49.54 （74.12） ng·L^-1 respectively at the time of enrolment and after disease progression. Compared with that at the time of enrollment， the serum sPD-L1 level in the two groups of patients was significantly increased after disease progression （P<0.01）. In addition， compared with that in the non-exposed group， the sPD-L1 level in the exposed group was greatly reduced after disease progression（P<0.01）. Cox multifactorial analysis showed that sPD-L1 level and age at the time of enrolment were associated with patients' progression-free survival（PFS），and that low levels of sPD-L1 （<12.06 ng·L^-1） prolonged the PFS and reduced the risk of disease progression in patients treated with EGFR-TKIs compared with high levels of sPD-L1. ConclusionElevated sPD-L1 level is a poor prognostic factor for the long-term efficacy of EGFR-TKIs，and treatment with Yiqi Yangiin Jiedu prescription can down-regulate sPD-L1 level of patients treated with EGFR-TKIs.

Diabetic retinopathy（DR）， as one of the most common and serious microvascular complications of diabetes mellitus， seriously threatens human health， and belongs to "Xiaoke eye diseases" in traditional Chinese medicine（TCM）， which has been richly experienced by medical practitioners through the ages， but is mostly recorded in a piecemeal manner and has not been systematically researched. This disease is featured by long course and repeated attack， and is refractory， which belongs to the research category of "persistent illness entering collaterals". Systematic establishment of TCM collateral disease theory for guiding prevention and treatment of DR has important clinical value. On the basis of close correlation between tertiary collaterals at the terminal of collaterals and capillaries and microcirculation， the concept of "tertiary collaterals-microvascular" is proposed. It is pointed out that DR falls within the scope of "tertiary collaterals-microvascular" diseases， and presents four types of micro-pathological characteristics， including stasis， insufficiency， growth and bleeding of tertiary collaterals. It is concluded that "deficiency of both Qi and Yin" is the basic pathogenesis of DR， and "blood stasis and collateral obstruction" is the important pathogenesis and key factor. Thus， the treatment method of "dispersing blood stasis， dredging collateral， tonifying Qi and Yin， stopping hemorrhage and improving eyesight" is determined， and the formula of Tongluo Mingmu capsules is developed. The article tightly focuses on the pathological changes such as stasis， growth， insufficiency and bleeding of collaterals， addresses both symptoms and root causes， and plays a synergistic role of both dispersing stasis and stopping bleeding. In this way， it can realize the purpose of tonifying Qi and Yin to replenish the essence， dispersing stasis and dredging collaterals to meet the requirement， as well as stopping hemorrhage and improving eyesight to deal with changes. Fundamental researches demonstrate that Tongluo Mingmu capsules has synergy effects of protecting both retinal capillaries and retinal cells. Phase-Ⅲ clinical trial of new drug has proven definite clinical efficacy and good safety， which provides a new drug choice for enhancing clinical effect of DR， and further supports the scientific value of Luobing theory in preventing and treating DR and other clinically significant diseases.

ObjectiveTo investigate the influence of entecavir （ETV） versus tenofovir alafenamide fumarate （TAF） on renal function in previously untreated patients with chronic hepatitis B （CHB）. MethodsA retrospective analysis was performed for the clinical data of 167 previously untreated CHB patients who received ETV or TAF treatment for at least 48 weeks at the outpatient service of Department of Infectious Diseases in The First Affiliated Hospital of Nanchang University from September 2019 to November 2023， and according to the antiviral drug used， they were divided into ETV group with 117 patients and TAF group with 50 patients. In order to balance baseline clinical data， propensity score matching （PSM） was used for matching and analysis at a ratio of 2∶1， and the two groups were compared in terms of estimated glomerular filtration rate （eGFR） and the incidence rate of abnormal renal function at week 48. According to eGFR at week 48， the patients were divided into normal renal function group and abnormal renal function group. The independent-samples t test or the Mann-Whitney U test was used for comparison of continuous data between two groups， and the chi-square test or the Fisher’s exact test was used for comparison of categorical data between two groups. The multivariate Logistic regression analysis was used to investigate the influencing factors for abnormal renal function， and the receiver operating characteristic （ROC） curve was used to assess the performance of each indicator in predicting abnormal renal function. The Kaplan-Meier method was used to analyze the cumulative incidence rate of abnormal renal function， and the log-rank test was used for comparison. The analysis of variance with repeated measures was used to compare the dynamic changes of eGFR during antiviral therapy in CHB patients. ResultsAfter PSM matching， there were 100 patients in the ETV group and 50 patients in the TAF group. There were no significant differences in baseline clinical data between the ETV group and the TAF group （all P>0.05）， with an eGFR level of 112.29±9.92 mL/min/1.73 m² in the ETV group and 114.72±12.15 mL/min/1.73 m² in the TAF group. There was a reduction in eGFR from baseline to week 48 in both groups， and compared with the TAF group at week 48， the ETV group had a significantly lower eGFR （106.42±14.12 mL/min/1.73 m² vs 112.25±13.44 mL/min/1.73 m²， t=-2.422， P=0.017） and a significantly higher incidence rate of abnormal renal function （17.00% vs 4.00%， χ²=5.092， P=0.024）. After the patients were divided into normal renal function group with 131 patients and abnormal renal function group with 19 patients， the univariate analysis showed that there were significant differences between the two groups in age （Z=-2.039， P=0.041）， treatment drug （ETV/TAF） （χ²=5.092， P=0.024）， and baseline eGFR level （t=4.023， P<0.001）， and the multivariate Logistic regression analysis showed that baseline eGFR （odds ratio ［OR］=0.896， 95% confidence interval ［CI］： 0.841 — 0.955， P<0.001） and treatment drug （OR=5.589， 95%CI： 1.136 — 27.492， P=0.034） were independent influencing factors for abnormal renal function. Baseline eGFR had an area under the ROC curve of 0.781 in predicting abnormal renal function in CHB patients， with a cut-off value of 105.24 mL/min/1.73 m²， a sensitivity of 73.68%， and a specificity of 82.44%. The Kaplan-Meier curve analysis showed that the patients with baseline eGFR≤105.24 mL/min/1.73 m² had a significantly higher cumulative incidence rate of abnormal renal function than those with baseline eGFR>105.24 mL/min/1.73 m² （χ²=22.330， P<0.001）， and the ETV group had a significantly higher cumulative incidence rate of abnormal renal function than the TAF group （χ²=4.961， P=0.026）. With the initiation of antiviral therapy， both the ETV group and the TAF group had a significant reduction in eGFR （F=5.259， P<0.001）， but the ETV group only had a significant lower level of eGFR than the TAF group at week 48 （t=-2.422， P=0.017）； both the baseline eGFR≤105.24 mL/min/1.73 m² group and the baseline eGFR>105.24 mL/min/1.73 m² group had a significant reduction in eGFR （F=5.712， P<0.001）， and there was a significant difference in eGFR between the two groups at baseline and weeks 12， 24， 36， and 48 （t=-13.927， -9.780， -8.835， -9.489， and -8.953， all P<0.001）. ConclusionFor CHB patients initially treated with ETV or TAF， ETV antiviral therapy has a higher risk of renal injury than TAF therapy at week 48.

Objective To explore the relationship between education level and the risk of all-cause mortality in the middle-aged and elderly (≥45 years old) population in China. Methods Using data from five surveys from 2011-2020, years of education, age, gender, marital status, type of household, alcohol consumption status, smoking status, physical activity, limited ability to perform activities of daily living (ADLs), chronic disease status, and body mass index were collected. According to the survival status，the study participants were divided into a survival group (n=8625) and an all-cause mortality group (n=1735). Cox proportional risk regression model was used to analyze the relationship between years of education and the risk of all-cause mortality in middle-aged and elderly people with stratified analysis. Results The survey was conducted on 10360 research subjects, including 4 983 males and 5 377 females, with an age M(Q_R) of 59(8) years old. A total of 88 187 person years (average 8.512 person years) were followed up, and a total of 1735 deaths were reported over 9 years. The all-cause mortality rate was 19.674 ‰, with an education period M(Q_R) of 5(8) years and a survival time M(Q_R) of 9 (0) years. After adjusting for confounding factors, for every 1 year increase in education, the risk of all-cause mortality decreased by 2.60% [HR=0.974, 95% CI (0.960-0.988)]. The stratified analysis results showed that in the population aged 45-59, for every 1 year increase in education, the risk of all-cause mortality decreased by 1.00% [HR=0.990, 95% CI (0.959,1.021)]; In the population aged 60-74 and over 75, for every 1 year increase in education, the risk of all-cause mortality decreased by 2.70% [HR=0.973, 95% CI (0.948, 0.999)] and 3.50% [HR=0.965, 95% CI (0.929, 1.003)], respectively. Conclusion Improving the education level of middle-aged and elderly people (≥ 45 years old) in China can reduce the risk of all-cause mortality, and elderly education should be vigorously promoted.

ObjectiveTo analyze the metabolomic characteristics of platelets in fibrinogen（FIB） overexpression rats of coronary heart disease with blood stasis syndrome（CHD-BSS）， explore potential biomarkers， and investigate the mechanism of FIB overexpression on CHD-BSS. MethodsSD rats were randomly divided into BSS group and BSS+FIB overexpression group（BSS+FIB group）， with 10 rats in each group. Both the BSS+FIB group and the BSS group were fed a high-fat diet combined with oral administration of vitamin D₃ and subcutaneous injection of isoproterenol， but rats in the BSS+FIB group were overexpressed with FIB during the initial modeling stage by transfection with adeno-associated virus（AAV）. The overexpression level of FIB in rat liver and plasma samples was detected by enzyme-linked immunosorbent assay（ELISA） and real-time fluorescence quantitative polymerase chain reaction（Real time PCR）， as well as the expression level of liver FIB A（FGA） mRNA. The characteristics of metabolites in rat platelet samples were analyzed by ultra-high performance liquid chromatography-quadrupole-electrostatic field orbital trap high-resolution mass spectrometry（UPLC-Q-Exactive Orbitrap-MS）， and the differential metabolites between groups were screened by principal component analysis（PCA） and orthogonal partial least squares-discriminant analysis（OPLS-DA）， and the enriched pathways were analyzed. The accuracy of potential biomarkers in the diagnosis of CHD-BSS was evaluated by receiver operating characteristic（ROC） curve. The expression of autophagy related proteins phosphorylated adenosine monophosphate（AMP） activated protein kinase（p-AMPK）/AMPK， phosphorylated mammalian target of rapamycin（p-mTOR）/mTOR， microtubule-associated protein 1 light chain 3（LC3） Ⅱ/Ⅰ and p62 in platelets were detected by Western blot. ResultsCompared with the BSS group， the expression levels of FIB in liver and plasma samples of the BSS+FIB group were significantly increased（P<0.05， P<0.01）， and the expression level of FIB mRNA in the liver was remarkably increased（P<0.01）， indicating successful overexpression of FIB. Platelet metabolomics results showed significant differences in metabolic profiles between the BSS+FIB group and the BSS group， and a total of 25 significantly enriched metabolic pathways and 8 metabolites involved in these metabolic pathways， among which uric acid， guanosine and ribose 1-phosphate levels were up-regulated， while adenosine diphosphate（ADP）， AMP， guanosine diphosphate（GDP）， adenylosuccinate and norepinephrine levels were down-regulated. The diagnostic ability analysis of differential metabolites showed that all 8 differential metabolites had good diagnostic ability， with an area under the curve（AUC）>0.85. Western blot results showed that compared with the BSS group， the expression levels of p-mTOR/mTOR and p62 proteins in platelets of the BSS+FIB group was significantly reduced（P<0.01）， while the expression levels of p-AMPK/AMPK and LC3Ⅱ/Ⅰ proteins were increased， but the difference was not statistically significant. ConclusionOverexpression of FIB can change the metabolic characteristics of CHD-BSS rat model， involving multiple aspects such as vascular endothelial injury， platelet activation and myocardial function damage. Among them， overexpression of FIB may enhance the occurrence of platelet autophagy， thereby inducing platelet activation and promoting thrombus formation.

Objective : To explore the role of lysophosphatidylcholine acyltransferase 3(LPCAT3) in Erastin-induced ferroptosis of acute myeloid leukemia(AML) cells and its related molecular regulatory mechanisms. Methods : Tetrazolium salt(MTS) method was used to detect the sensitivity of different AML cells to the classic ferroptosis inducer Erastin, real time quantitative polymerase chain reaction(qPCR) was used to detect the basal expression level ofLPCAT3mRNA, and the correlation between them was analyzed. Lentivirus-mediatedLPCAT3overexpression AML cell lines(OE group) and negative control lines(NC group) were constructed. After Erastin intervention, MTS, flow cytometry, and micromethods were used to detect cell viability, lipid reactive oxygen species(ROS), and Malondialdehyde(MDA), respectively. qPCR and Western blot were used to detect unfolded protein response(UPR) classic pathway signaling molecules(PERK, ATF4, GRP78, etc.) expression levels. The above ferroptosis-related indicators were detected after combined intervention with the UPR inhibitor 4-phenylbutyric acid(4-PBA), and the regulatory relationship was analyzed. Results : Four different types of AML cells had different sensitivities to ferroptosis, among which K562 cells were relatively insensitive. The IC50of the four types of AML cells to Erastin was negatively correlated with the expression level ofLPCAT3(r=-0.919,P<0.001). After Erastin intervention, the cell viability of K562 cells in the OE group was significantly inhibited by Erastin compared with the NC group(P<0.001), and the levels of lipid ROS and MDA increased(P<0.001). The results of qPCR and Western blot showed that, compared with the NC group, the mRNA and protein expression of UPR classic pathway moleculesPERK,ATF4, andGRP78mRNA and protein increased in the OE group(P<0.01). After inhibiting the UPR pathway by 4-PBA, the viability of K562 cells decreased(P<0.01), and lipid ROS and MDA levels increased(P<0.01) compared with the uninhibited state. Conclusion Overexpression ofLPCAT3can promote ferroptosis in K562 cells, and this process is negatively regulated by the classical UPR pathway PERK/ATF.

Background As a pillar industry in China, the manufacturing sector has a high incidence of non-fatal occupational injuries. The factors influencing non-fatal occupational injuries in this industry are closely related at various levels, including individual, equipment, environment, and management, making the analysis of these influencing factors complex. Objective To identify influencing factors of non-fatal occupational injuries among manufacturing workers, providing a basis for targeted interventions and surveillance. Methods A total of 2243 frontline workers from cable and shipbuilding enterprises were selected as study subjects to investigate the incidence of non-fatal occupational injuries and collect information at four levels: individual, equipment, management, and environment in past 12 months. Data balancing was performed using resampling, and LASSO regression was used to select factors of non-fatal occupational injuries. The influence degree and type of variables were judged based on the magnitude of the estimated coefficients of each variable, where variables with estimated coefficients > 0 are risk factors, and those <0 are protective factors. The area under the receiver operating characteristic (ROC)curve (AUC) was used to test the performance of the model, with an AUC value > 0.7 indicating good model performance. Results Among the 2243 frontline workers, males accounted for 77.7% (1742 out of 2243), with the main age range being 40-49 years old, representing 29.5% (661 out of 2243), 82.7% of the workers (1854 out of 2243) were married, and 55.6% (1248 out of 2243) had a junior middle school education level. The average monthly income for 51.0% (1144 out of 2243) of the workers was between 5000 and 6999 Chinese Yuan. The incidence of non-fatal occupational injuries among the manufacturing workers was 8.4% (189/2243) in the past 12 months. Among the 22 factors associated with the occurrence of non-fatal occupational injuries (P<0.05), 10 were individual-level factors, including gender, smoking, alcohol consumption, colleague relationships, average exercise duration, job burnout, work fatigue, musculoskeletal disorders, cardiovascular diseases, and neurological and sensory organ diseases; 3 were equipment-level factors, including equipment operability, hazardous workpieces, and safety hazards; 5 were environmental-level factors, including low temperatures, special operations, noise, workspace size, and dirty and disorderly environment; and 4 were management-level factors, including daily working hours, weekly working days, overtime, and pre-job technical training. The AUC value of the LASSO regression model was 0.704 and the final model retained a total of 10 variables. Among them, there were 7 risk factors for non-fatal occupational injuries (coefficient > 0), including safety hazards, musculoskeletal disorders, dangerous workpieces, job burnout, dirty and disorderly environment, smoking, and male gender; and 3 protective factors (coefficient < 0), including pre-job technical training, good colleague relationship, and long working days per week. Conclusion Manufacturing enterprises need to focus on the incidence of non-fatal occupational injuries and conduct targeted interventions for non-fatal occupational injuries by controlling potential safety hazards, providing pre-job technical training, reducing dangerous workpieces, rectifying working environment, and reasonably arranging working hours.

[Objective] To explore the feasibility of using whole blood as a source of NK cells for allogeneic CAR NK cell therapy and activated NK cell reinfusion therapy, and initially construct a technical system for the separation and purification of NK cells from whole blood. [Methods] All peripheral blood mononuclear cells (PBMCs) were enriched from 400 mL of whole blood by manual separation and machine separation, respectively. The erythrocyte loss rate, PBMCs number, NK cell purity of the two methods were compared. NK cells were sorted from PBMCs by three separation and enrichment methods as immunomagnetic bead negative selection method, platelet lysate culture expansion and PERCOLL density gradient separation method, and the purity and yield of NK cells, the activity of NK cells and the tumor-killing ability of the three separation and enrichment methods were compared. [Results] The proportion of NK cells in the lymphocyte population was higher in the manual separation method than in the machine separation method[(13.16±5.16)% vs (8.56±3.92)%, P<0.05]; the number PBMCs was lower in the manual separation method than in the machine separation method[(4.09±1.80)×10⁸vs (6.49±2.16)×10⁸, P<0.05], and there was no difference in the red blood cell loss between the two methods (P>0.05). The purity of NK cells isolated and enriched from PBMCs by manual separation method using immunomagnetic was (96.77±2.31)%; the yield was (56.27±10.47)%; the inhibition of tumor proliferation was (38.67±14.05)%; and the tumor killing rate was (19.90±8.05)%. The purity of NK cells isolated and enriched from PBMCs by manual separation method using platelet lysis culture expansion method was the highest at day 7, which was (54.84±15.80)%; the cell expansion multiple could reach 16.92±6.28 at day 7; the in vitro tumor killing rate of NK cells was (15.83±5.5)%; the tumor inhibition rate was (44.33±13.5)%; and there was no difference in the toxicity and activity of NK cells between the two methods (P>0.05). The purity of NK cells isolated and enriched by PERCOLL density gradient separation method was (15.83±5.82)%, and the yield was (14±6.25)%, which was significantly lower than the other two methods. [Conclusion] PBMCs isolated from whole blood by manual separation and NK cells enriched by negative selection with immunomagnetic beads have the potential to provide NK cell materials for CAR-NK cell therapy, and NK cells enriched by platelet lysate-conditioned medium have the potential to provide NK cells for large-scale NK cell activation reinfusion therapy.

BACKGROUND:The micro/nanostructured gradient biomimetic surface of implant materials can simulate the structure of the extracellular environment in human bone tissue,thereby achieving perfect bone integration function.However,further research is needed on the mechanisms by which the surface microstructure of bone implant materials regulates cell function and promotes osteogenesis. OBJECTIVE:To analyze the effect of titanium sheet microstructure surface on osteogenic differentiation of MC3T3-E1 osteoblasts. METHODS:(1)At a constant voltage of 5 V or 20 V,nanotube arrays of different diameters were prepared on the surface of titanium sheets by acid etching and anodic oxidation techniques,and were recorded as group R5 and group R20,respectively.The surface morphology,roughness,and hydrophilicity of pure titanium sheet(without acid etching or anodizing treatment)were measured in group R5 and group R20.(2)MC3T3-E1 osteoblasts of logarithmic growth stage were inoculated on the surface of pure titanium sheets,R5 group and R20 group respectively.After 24 hours of osteogenic induction culture,the expression of mechanical sensitive channel protein 1 was analyzed by RT-PCR and immunofluorescence staining.Osteoblast inducible base with or without the mechanosensitive channel protein 1 activator Yada1 was added,and alkaline phosphatase staining was performed after 7 days of culture.Alizarin red staining was performed after 14 days of culture. RESULTS AND CONCLUSION:(1)The surface of pure titanium sheets was smooth under scanning electron microscope.Relatively uniform and orderly nanotube arrays with average diameters of about 30 nm and 100 nm were observed on the surface of titanium sheets of groups R5 and R20,respectively.The results of scanning electron microscope were further verified by atomic force microscopy.The surface roughness of titanium sheet of group R5 was higher than that of pure titanium(P<0.05),and the water contact angle was lower than that of pure titanium(P<0.05).The surface roughness of titanium sheet in group R20 was higher than that in group R5(P<0.05),and the water contact angle was lower than that in group R5(P<0.05).(2)RT-PCR and immunofluorescence staining showed that the expression of mechanosensitive channel protein 1 in group R5 was higher than that in pure titanium group(P<0.05),and the expression of mechanosensitive channel protein 1 in group R20 was higher than that in group R5(P<0.05).Under the osteogenic induction,compared with the condition without Yada1,there were no significant changes in the activity of alkaline phosphatase and the deposition of calcified nodules in pure titanium group after Yada1 addition,while the activity of alkaline phosphatase and the deposition of calcified nodules in groups R5 and R20 after Yada1 addition were significantly increased(P<0.05).With or without Yada1,the alkaline phosphatase activity and calcified nodule deposition in group R5 were higher than those in pure titanium group(P<0.05),and the alkaline phosphatase activity and calcified nodule deposition in group R20 were higher than those in group R5(P<0.05).(3)The results show that the surface microstructure of titanium sheet can promote the osteogenic differentiation of osteoblast MC3T3-E1 by activating mechanosensitive channel protein 1.