ObjectiveTo investigate the effects of modified Ditan tang on genes related to the transcription-translation feedback loop （TTFL） of biorhythm in the rat model of non-alcoholic fatty liver disease （NAFLD） and its mechanism for prevention and treatment of NAFLD. MethodsSixty-five healthy SPF male SD rats were randomly assigned into blank （n=20）， model （n=15）， and low-， medium-， and high-dose （2.68， 5.36， and 10.72 g·kg^-1·d^-1， respectively） modified Ditan tang （n=10） groups. Other groups except the blank group were fed a high-fat diet for 12 weeks. The modified Ditan tang groups were treated with the decoction at corresponding doses by gavage， and the blank and model groups were treated with an equal volume of normal saline from the 9th week for 4 weeks. The levels of triglyceride （TG）， total cholesterol （TC）， low-density lipoprotein cholesterol （LDL-C）， high-density lipoprotein cholesterol （HDL-C）， aspartate aminotransferase （AST）， and alanine aminotransferase （ALT） in the serum were measured by an automatic biochemical analyzer. TG and non-esterified fatty acid （NEFA） assay kits were used to measure the levels of TG and NEFA in the liver. The pathological changes in the hypothalamus and liver were observed by hematoxylin-eosin staining， and the lipid deposition in the liver was observed by oil red O staining. The levels of brain-muscle ARNT-like protein 1 （BMAL1/ARNTL） in the hypothalamus and liver were determined by immunohistochemical staining. The mRNA and protein levels of BMAL1， circadian locomotor output cycles kaput （CLOCK）， period circadian clock 2 （PER2）， and cryptochrome1 （Cry1） in the hypothalamus and liver were determined by Real-time PCR and Western blot， respectively. ResultsCompared with the blank group， the model group showed elevated levels of TG， TC， LDL-C， AST， and ALT （P<0.01） and a lowered level of HDL-C （P<0.05） in the serum， elevated levels of TG and NEFA in the liver （P<0.01）， pyknosis and deep staining of hypothalamic neuron cells， and a large number of vacuoles in the brain area. In addition， the model group showed lipid deposition in the liver， up-regulated mRNA and protein levels of CLOCK and BMAL1 （P<0.01）， and down-regulated mRNA and protein levels of Cry1 and PER2 （P<0.01） in the hypothalamus and liver. Compared with the model group， all the three modified Ditan tang groups showed lowered levels of TG， TC， LDL-C， ALT， and AST （P<0.05， P<0.01） and an elevated level of HDL-C （P<0.05） in the serum， and lowered levels of TG and NEFA （P<0.05， P<0.01） in the liver. Furthermore， the three groups showed alleviated pyknosis and deep staining of hypothalamic neuron cells， reduced lipid deposition in the liver， down-regulated mRNA and protein levels of CLOCK and BMAL1 （P<0.05， P<0.01）， and up-regulated mRNA and protein levels of Cry1 and PER2 （P<0.05， P<0.01） in the hypothalamus and liver. ConclusionModified Ditan tang can reduce lipid deposition in the liver and regulate the expression of CLOCK， BMAL1， Cry1， and PER2 in the TTFL of NAFLD rats.

Objective To explore the severity of loneliness among the elderly in communities in Shanghai,and to identify factors associated with social and emotional loneliness respectively.Methods A cross-sectional study was conducted in older adults aged 65 years or above in Pudong New Area,Jing'an District and Huangpu District in Shanghai from Mar to Jun 2021.In Pudong New Area,multi-stage stratified random sampling was conducted based on the age and gender distribution of Shanghai,while in Huangpu District and Jing'an District convenience sampling was conducted.A total of 635 samples were included in the study.Loneliness was assessed using the De Jong Gierveld Loneliness Scale with social and emotional loneliness subscales.Logistic regression analyses were conducted to identify factors associated with social and emotional loneliness.Results Among the 635 participants,only 53 older adults(8.4%)were not lonely.Female(OR=0.46,95%CI:0.31-0.70),higher self-efficacy(OR=0.97,95%CI:0.94-1.00),more objective social support(OR=0.96,95%CI:0.93-0.99)were associated with less severe social loneliness.Meanwhile,higher level of education(secondary education,OR=0.56,95%CI:0.34-0.95;college or above,OR=0.30,95%CI:0.11-0.83)and higher self-efficacy(OR=0.96,95%CI:0.93-0.99)were associated with less severe emotional loneliness,while depression(OR=3.41,95%CI:1.76-6.60)and worse social capital(OR=2.02,95%CI:1.29-3.16)were associated with more severe emotional loneliness.Conclusion Up to 91.6%of the elderly in our study sample were moderately lonely or above.The factors associated with social loneliness include self-efficacy,gender and social support.The factors associated with emotional loneliness are self-efficacy,education level,depression,and social capital.

BACKGROUND:Multiple sclerosis is a chronic inflammatory demyelinating disease of the central nervous system mediated by T cells.The Toll-like receptors(TLRs)/myeloid differentiation factor 88(MyD88)/nuclear factor kappa-B(NF-κB)signaling pathway plays an important role in the development of the disease.Exploring the specific mechanism of the signaling pathway is essential for further treatment of the disease and improving the prognosis of patients. OBJECTIVE:To review the TLRs/MyD88/NF-κB signaling pathway and its role in multiple sclerosis/experimental autoimmune encephalomyelitis models,which provides new ideas and strategies for the treatment of multiple sclerosis by inhibiting the TLRs/MyD88/NF-κB signaling pathway. METHODS:The literature related to the topic from January 2002 to December 2022 was searched in CNKI,WanFang and PubMed databases.A total of 61 articles were finally included for analysis. RESULTS AND CONCLUSION:The TLRs/MyD88/NF-κB signaling pathway is an important pathway that triggers a pro-inflammatory immune response.The TLRs/MyD88/NF-κB signaling pathway plays an important role in the development of multiple sclerosis by regulating the antigen presentation of dendritic cells,destroying the integrity of the blood-brain barrier,and promoting the activation of T cells,B cells and microglia.By targeting TLRs,MyD88 and NF-κB molecules,inhibiting the activation or signal transduction of TLRs,MyD88 and NF-κB,and reducing the secretion of pro-inflammatory factors,multiple sclerosis can be treated.Animal studies have shown that active ingredients of traditional Chinese medicines,such as flavonoids and glycosides,and traditional Chinese medicine compound formulas,such as Buyang Huanwu Tang,can also treat experimental autoimmune encephalomyelitis by regulating the TLRs/MyD88/NF-κB signaling pathway,which points to the direction of searching for medicines targeting the TLRs/MyD88/NF-κB signaling pathway for the treatment of multiple sclerosis.

Objective:To investigate the prognosis of patients with initially resectable gastric cancer liver metastasis (GCLM) who were treated by different modalities, and analyze the influencing factors for prognosis of patients.Methods:The retrospective cohort study was conducted. The clinicopathological data of 327 patients with initially resectable GCLM who were included in the database of a nationwide multicenter retrospective cohort study on GCLM based on real-world data from January 2010 to December 2019 were collected. There were 267 males and 60 females, aged 61(54,68)years. According to the specific situations of patients, treatment modalities included radical surgery combined with systemic treatment, palliative surgery combined with systemic treatment, and systemic treatment alone. Observation indicators: (1) clinical characteristics of patients who were treated by different modalities; (2) prognostic outcomes of patients who were treated by different modalities; (3) analysis of influencing factors for prognosis of patients with initially resectable GCLM; (4) screening of potential beneficiaries in patients who were treated by radical surgery plus systemic treatment and patients who were treated by palliative surgery plus systemic treatment. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the independent sample t test. Measurement data with skewed distribution were represented as M( Q1, Q3), and comparison between groups was conducted using the rank sum test. Count data were described as absolute numbers or percentages, and comparison between groups was conducted using the chi-square test. The Kaplan-Meier method was used to calculate survival rate and draw survival curve, and Log-Rank test was used for survival analysis. Univariate and multivariate analyses were conducted using the COX proportional hazard regression model. The propensity score matching was employed by the 1:1 nearest neighbor matching method with a caliper value of 0.1. The forest plots were utilized to evaluate potential benefits of diverse surgical combined with systemic treatments within the population. Results:(1) Clinical characteristics of patients who were treated by different modalities. Of 327 patients, there were 118 cases undergoing radical surgery plus systemic treatment, 164 cases undergoing palliative surgery plus systemic treatment, and 45 cases undergoing systemic treatment alone. There were significant differences in smoking, drinking, site of primary gastric tumor, diameter of primary gastric tumor, site of liver metastasis, and metastatic interval among the three groups of patients ( P<0.05). (2) Prognostic outcomes of patients who were treated by different modalities. The median overall survival time of the 327 pati-ents was 19.9 months (95% confidence interval as 14.9-24.9 months), with 1-, 3-year overall survival rate of 61.3%, 32.7%, respectively. The 1-year overall survival rates of patients undergoing radical surgery plus systemic treatment, palliative surgery plus systemic treatment and systemic treatment alone were 68.3%, 63.1%, 30.6%, and the 3-year overall survival rates were 41.1%, 29.9%, 11.9%, showing a significant difference in overall survival rate among the three groups of patients ( χ2=19.46, P<0.05). Results of further analysis showed that there was a significant difference in overall survival rate between patients undergoing radical surgery plus systemic treatment and patients undergoing systemic treatment alone ( hazard ratio=0.40, 95% confidence interval as 0.26-0.61, P<0.05), between patients undergoing palliative surgery plus systemic treatment and patients under-going systemic treatment alone ( hazard ratio=0.47, 95% confidence interval as 0.32-0.71, P<0.05). (3) Analysis of influencing factors for prognosis of patients with initially resectable GCLM. Results of multivariate analysis showed that the larger primary gastric tumor, poorly differentiated tumor, larger liver metastasis, multiple hepatic metastases were independent risk factors for prognosis of patients with initially resectable GCLM ( hazard ratio=1.20, 1.70, 1.20, 2.06, 95% confidence interval as 1.14-1.27, 1.25-2.31, 1.04-1.42, 1.45-2.92, P<0.05) and immunotherapy or targeted therapy, the treatment modality of radical or palliative surgery plus systemic therapy were independent protective factors for prognosis of patients with initially resectable GCLM ( hazard ratio=0.60, 0.39, 0.46, 95% confidence interval as 0.42-0.87, 0.25-0.60, 0.30-0.70, P<0.05). (4) Screening of potentinal beneficiaries in patients who were treated by radical surgery plus systemic treatment and patients who were treated by palliative surgery plus systemic treatment. Results of forest plots analysis showed that for patients with high-moderate differentiated GCLM and patients with liver metastasis located in the left liver, the overall survival rate of patients undergoing radical surgery plus systemic treatment was better than patients undergoing palliative surgery plus systemic treatment ( hazard ratio=0.21, 0.42, 95% confidence interval as 0.09-0.48, 0.23-0.78, P<0.05). Conclusions:Compared to systemic therapy alone, both radical and palliative surgery plus systemic therapy can improve the pro-gnosis of patients with initially resectable GCLM. The larger primary gastric tumor, poorly differen-tiated tumor, larger liver metastasis, multiple hepatic metastases are independent risk factors for prognosis of patients with initial resectable GCLM and immunotherapy or targeted therapy, the treatment modality of radical or palliative surgery plus systemic therapy are independent protective factors for prognosis of patients with initially resectable GCLM.

This paper discussed the current education status on medical ethics and styles and the assessment condition in the examination of doctors' qualification， as well as the existing problems and potential solutions by reviewing domestic and foreign literature and summarizing the practice experience. Traditionally， medical ethics and styles have always been integrated into clinical medical practice in China. However， under the modern medical education system， it is challenged to integrate traditional education on medical ethics and styles with the rules of modern medical knowledge. By summarizing the education and assessment status of medical ethics and styles in the examination of doctors' qualification， it is found that the current examination is relatively poor in the evaluation content， and the way of evaluation is not diverse， with lack of curriculum of medical humanities. The solutions suggested are enriching relevant examination content， introducing more and comprehensive evaluation method， and establishing more medical humanities-related courses.

Objective:To investigate the incidence of postoperative complications in Chinese patients with gastric or colorectal cancer, and to evaluate the risk factors for postoperative complications.Methods:This was a national, multicenter, prospective, registry-based, cohort study of data obtained from the database of the Prevalence of Abdominal Complications After Gastro- enterological Surgery (PACAGE) study sponsored by the China Gastrointestinal Cancer Surgical Union. The PACAGE database prospectively collected general demographic characteristics, protocols for perioperative treatment, and variables associated with postoperative complications in patients treated for gastric or colorectal cancer in 20 medical centers from December 2018 to December 2020. The patients were grouped according to the presence or absence of postoperative complications. Postoperative complications were categorized and graded in accordance with the expert consensus on postoperative complications in gastrointestinal oncology surgery and Clavien-Dindo grading criteria. The incidence of postoperative complications of different grades are presented as bar charts. Independent risk factors for occurrence of postoperative complications were identified by multifactorial unconditional logistic regression.Results:The study cohort comprised 3926 patients with gastric or colorectal cancer, 657 (16.7%) of whom had a total of 876 postoperative complications. Serious complications (Grade III and above) occurred in 4.0% of patients (156/3926). The rate of Grade V complications was 0.2% (7/3926). The cohort included 2271 patients with gastric cancer with a postoperative complication rate of 18.1% (412/2271) and serious complication rate of 4.7% (106/2271); and 1655 with colorectal cancer, with a postoperative complication rate of 14.8% (245/1655) and serious complication rate of 3.0% (50/1655). The incidences of anastomotic leakage in patients with gastric and colorectal cancer were 3.3% (74/2271) and 3.4% (56/1655), respectively. Abdominal infection was the most frequently occurring complication, accounting for 28.7% (164/572) and 39.5% (120/304) of postoperative complications in patients with gastric and colorectal cancer, respectively. The most frequently occurring grade of postoperative complication was Grade II, accounting for 65.4% (374/572) and 56.6% (172/304) of complications in patients with gastric and colorectal cancers, respectively. Multifactorial analysis identified (1) the following independent risk factors for postoperative complications in patients in the gastric cancer group: preoperative comorbidities (OR=2.54, 95%CI: 1.51-4.28, P<0.001), neoadjuvant therapy (OR=1.42, 95%CI:1.06-1.89, P=0.020), high American Society of Anesthesiologists (ASA) scores (ASA score 2 points:OR=1.60, 95% CI: 1.23-2.07, P<0.001, ASA score ≥3 points:OR=0.43, 95% CI: 0.25-0.73, P=0.002), operative time >180 minutes (OR=1.81, 95% CI: 1.42-2.31, P<0.001), intraoperative bleeding >50 mL (OR=1.29,95%CI: 1.01-1.63, P=0.038), and distal gastrectomy compared with total gastrectomy (OR=0.65,95%CI: 0.51-0.83, P<0.001); and (2) the following independent risk factors for postoperative complications in patients in the colorectal cancer group: female (OR=0.60, 95%CI: 0.44-0.80, P<0.001), preoperative comorbidities (OR=2.73, 95%CI: 1.25-5.99, P=0.030), neoadjuvant therapy (OR=1.83, 95%CI:1.23-2.72, P=0.008), laparoscopic surgery (OR=0.47, 95%CI: 0.30-0.72, P=0.022), and abdominoperineal resection compared with low anterior resection (OR=2.74, 95%CI: 1.71-4.41, P<0.001). Conclusion:Postoperative complications associated with various types of infection were the most frequent complications in patients with gastric or colorectal cancer. Although the risk factors for postoperative complications differed between patients with gastric cancer and those with colorectal cancer, the presence of preoperative comorbidities, administration of neoadjuvant therapy, and extent of surgical resection, were the commonest factors associated with postoperative complications in patients of both categories.

Objective:To examine the impact of varied surgical treatment strategies on the prognosis of patients with initial resectable gastric cancer liver metastases (IR-GCLM).Methods:This is a retrospective cohort study. Employing a retrospective cohort design, the study selected clinicopathological data from the national multi-center retrospective cohort study database, focusing on 282 patients with IR-GCLM who underwent surgical intervention between January 2010 and December 2019. There were 231 males and 51 males, aging ( M(IQR)) 61 (14) years (range: 27 to 80 years). These patients were stratified into radical and palliative treatment groups based on treatment decisions. Survival curves were generated using the Kaplan-Meier method and distinctions in survival rates were assessed using the Log-rank test. The Cox risk regression model evaluated HR for various factors, controlling for confounders through multivariate analysis to comprehensively evaluate the influence of surgery on the prognosis of IR-GCLM patients. A restricted cubic spline Cox proportional hazard model assessed and delineated intricate associations between measured variables and prognosis. At the same time, the X-tile served as an auxiliary tool to identify critical thresholds in the survival analysis for IR-GCLM patients. Subgroup analysis was then conducted to identify potential beneficiary populations in different surgical treatments. Results:(1) The radical group comprised 118 patients, all undergoing R0 resection or local physical therapy of primary and metastatic lesions. The palliative group comprised 164 patients, with 52 cases undergoing palliative resections for gastric primary tumors and liver metastases, 56 cases undergoing radical resections for gastric primary tumors only, 45 cases undergoing palliative resections for gastric primary tumors, and 11 cases receiving palliative treatments for liver metastases. A statistically significant distinction was observed between the groups regarding the site and the number of liver metastases (both P<0.05). (2) The median overall survival (OS) of the 282 patients was 22.7 months (95% CI: 17.8 to 27.6 months), with 1-year and 3-year OS rates were 65.4% and 35.6%, respectively. The 1-year OS rates for patients in the radical surgical group and palliative surgical group were 68.3% and 63.1%, while the corresponding 3-year OS rates were 42.2% and 29.9%, respectively. A comparison of OS between the two groups showed no statistically significant difference ( P=0.254). Further analysis indicated that patients undergoing palliative gastric cancer resection alone had a significantly worse prognosis compared to other surgical options ( HR=1.98, 95% CI: 1.21 to 3.24, P=0.006). (3) The size of the primary gastric tumor significantly influenced the patients′ prognosis ( HR=2.01, 95% CI: 1.45 to 2.79, P<0.01), with HR showing a progressively increasing trend as tumor size increased. (4) Subgroup analysis indicates that radical treatment may be more effective compared to palliative treatment in the following specific cases: well/moderately differentiated tumors ( HR=2.84, 95% CI 1.49 to 5.41, P=0.001), and patients with liver metastases located in the left lobe of the liver ( HR=2.06, 95% CI 1.19 to 3.57, P=0.010). Conclusions:In patients with IR-GCLM, radical surgery did not produce a significant improvement in the overall prognosis compared to palliative surgery. However, within specific patient subgroups (well/moderately differentiated tumors, and patients with liver metastases located in the left lobe of the liver), radical treatment can significantly improve prognosis compared to palliative approaches.

Objectives:To investigate the effect of the expression of low-density lipoprotein receptor associated protein (LDLR) on the vascular abnormalities in hepatocellular carcinoma (HCC) and its mechanisms.Methods:Based on the information of Oncomine Cancer GeneChip database, we analyzed the correlation between the expression level of LDLR and the expression level of carcinoembryonic antigen (CEA) and CD31 in hepatocellular carcinoma tissues. Lentiviral transfection of short hairpin RNA target genes was used to construct LDLR-knockdown MHCC-97H and HLE hepatocellular carcinoma cells. The differential genes and their expression level changes in LDLR-knockdown hepatocellular carcinoma cells were detected by transcriptome sequencing, real-time fluorescence quantitative polymerase chain reaction, and protein immunoblotting. The gene-related signaling pathways that involve LDLR were clarified by enrichment analysis. The effect of LDLR on CEA was assessed by the detection of CEA content in conditioned medium of hepatocellular carcinoma cells. Angiogenesis assay was used to detect the effect of LDLR on the angiogenic capacity of human umbilical vein endothelial cells, as well as the role of CEA in the regulation of angiogenesis by LDLR. Immunohistochemical staining was used to detect the expression levels of LDLR in 176 hepatocellular carcinoma tissues, and CEA and CD31 in 146 hepatocellular carcinoma tissues, and analyze the correlations between the expression levels of LDLR, CEA, and CD31 in the tissues, serum CEA, and alanine transaminase (ALT).Results:Oncomine database analysis showed that the expressions of LDLR and CEA in the tissues of hepatocellular carcinoma patients with portal vein metastasis were negatively correlated ( r=-0.64, P=0.001), whereas the expressions of CEA and CD31 in these tissues were positively correlated ( r=0.46, P=0.010). The transcriptome sequencing results showed that there were a total of 1 032 differentially expressed genes in the LDLR-knockdown group and the control group of MHCC-97H cells, of which 517 genes were up-regulated and 515 genes were down-regulated. The transcript expression level of CEACAM5 was significantly up-regulated in the cells of the LDLR-knockdown group. The Gene Ontology (GO) function enrichment analysis showed that the differential genes were most obviously enriched in the angiogenesis function. The Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway enrichment analysis showed that the relevant pathways involved mainly included the cellular adhesion patch, the extracellular matrix receptor interactions, and the interactions with the extracellular matrix receptors. The CEA content in the conditioned medium of the LDLR-knockdown group was 43.75±8.43, which was higher than that of the control group (1.15±0.14, P＜0.001). The results of angiogenesis experiments showed that at 5 h, the number of main junctions, the number of main segments, and the total area of the lattice formed by HUVEC cells cultured with the conditioned medium of MHCC-97H cells in the LDLR-knockdown group were 295.3±26.4, 552.5±63.8, and 2 239 781.0±13 8211.9 square pixels, which were higher than those of the control group (113.3±23.5, 194.8±36.5, and 660 621.0±280 328.3 square pixels, respectively, all P＜0.01).The number of vascular major junctions, the number of major segments, and the total area of the lattice formed by HUVEC cells cultured in conditioned medium with HLE cells in the LDLR-knockdown group were 245.3±42.4, 257.5±20.4, and 2 535 754.5±249 094.2 square pixels, respectively, which were all higher than those of the control group (113.3±23.5, 114.3±12.2, and 1 565 456.5±219 259.7 square pixels, respectively, all P＜0.01). In the conditioned medium for the control group of MHCC-97H cells,the number of main junctions, the number of main segments, and the total area of the lattice formed by the addition of CEA to cultured HUVEC cells were 178.9±12.0, 286.9±12.3, and 1 966 990.0±126 249.5 spixels, which were higher than those in the control group (119.7±22.1, 202.7±33.7, and 1 421 191.0±189 837.8 square pixels, respectively). The expression of LDLR in hepatocellular carcinoma tissues was not correlated with the expression of CEA, but was negatively correlated with the expression of CD31 ( r=-0.167, P=0.044), the level of serum CEA ( r=-0.061, P=0.032), and the level of serum ALT (r=-0.147, P=0.05). The expression of CEA in hepatocellular carcinoma tissues was positively correlated with the expression of CD31 ( r=0.192, P=0.020). The level of serum CEA was positively correlated with the level of serum ALT ( r=0.164, P=0.029). Conclusion:Knocking down LDLR can promote vascular abnormalities in HCC by releasing CEA.

Objective To understand the respiratory protection competency of staff in hospitals.Methods Staff from six hospitals of different levels and characteristics in Beijing were selected,including doctors,nurses,medical technicians,and servicers,to conduct knowledge assessment on respiratory protection competency.According to exposure risks of respiratory infectious diseases,based on actual cases and daily work scenarios,content of respira-tory protection competency assessment was designed from three aspects:identification of respiratory infectious di-seases,transmission routes and corresponding protection requirements,as well as correct selection and use of masks.The assessment included 6,6,and 8 knowledge points respectively,with 20 knowledge points in total,all of which were choice questions.For multiple-choice questions,full marks,partial marks,and no mark were given respective-ly if all options were correct,partial options were correct and without incorrect options,and partial options were correct but with incorrect options.Difficulty and discrimination analyses on question of each knowledge point was conducted based on classical test theory.Results The respiratory protection competency knowledge assessment for 326 staff members at different risk levels in 6 hospitals showed that concerning the 20 knowledge points,more than 60％participants got full marks for 6 points,while the proportion of full marks for other questions was relatively low.Less than 10％participants got full marks for the following 5 knowledge points:types of airborne diseases,types of droplet-borne diseases,conventional measures for the prevention and control of healthcare-associated infec-tion with respiratory infectious diseases,indications for wearing respirators,and indications for wearing medical protective masks.Among the 20 knowledge questions,5,1,and 14 questions were relatively easy,medium,and difficult,respectively;6,1,4,and 9 questions were with discrimination levels of ≥0.4,0.30-0.39,0.20-0.29,and ≤0.19,respectively.Conclusion There is still much room for hospital staff to improve their respiratory protection competency,especially in the recognition of diseases with different transmission routes and the indications for wearing different types of masks.

Objective To analyze the atrioventricular synchronization rate after implantation of Micra AV leadless pacemaker,and the impact of postoperative programming optimization on atrioventricular synchronization rate.Methods A prospective cohort study was conducted to select patients with complete atrioventricular block who underwent Micra AV leadless pacemaker implantation at Beijing Anzhen Hospital from August 2022 to June 2023.Programming optimization were performed at 1 week,1 month,and 3 months postoperatively,and atrioventricular synchronization rate,electrical parameters,and echocardiography were recorded.Results A total of 68 patients with complete atrioventricular block implanted with Micra AV were selected,with an average age of(68.2±9.7)years,including 47 males(69.1％).All patients were successfully implanted with Micra AV,and there were no serious postoperative complications;The average threshold,sense,and impedance parameters were stable during 1 week,1 month,and 3 months after the procedure;There was no significant difference in the EF value of postoperative echocardiography(P=0.162);The average atrioventricular synchronization rates at 1 week,1 month,and 3 months postoperatively were(75.2％vs.83.8％vs.91.6％,P=0.001).Conclusions As an mechanical atrial sensing,Micra AV requires personalized adjustment of relevant parameters;Postoperative follow-up programming optimization plays an important role in the atrioventricular synchronization and comfort level in patients with complete atrioventricular block after implantation of Micra AV leadless pacemaker.