OBJECTIVE To explore the effect and mechanism of Zexie tang （ZXT） on reducing lipid accumulation through network pharmacology， and compare the difference of traditional decoction versus formula granules. METHODS The active components and targets of ZXT were identified using TCMSP and SwissTargetPrediction databases. GeneCards， OMIM， DisGeNET and TTD databases were used to analyze the related targets of non-alcoholic fatty liver disease （NAFLD）； protein-protein interaction network model was constructed by String database；“ ZXT-NAFLD target-pathway” network diagram was constructed by using CytoScape software； target enrichment analysis was performed by using Metascape platform. Fat accumulation model of human hepatocellular carcinoma HepG2 cells was established to observe the effects of traditional decoction and formula granules of ZXT on lipid accumulation of cells. RESULTS Alisol B， alisol C， 1-monolinolein and alisol B monoacetate were the key active components of ZXT in the treatment of NAFLD. The core targets included MDM2， MAPK1， PIK3CB， PRKCQ and MAPK14， etc. The core signaling pathways included endocrine resistance， insulin resistance and Th17 cell differentiation. Compared with model group， except for the Zexie formula granules group and Baizhu formula granules group， the absorbance values in all other administration groups were significantly decreased （P＜0.01）； the absorbance value of Baizhu traditional decoction group was significantly higher than that of ZXT traditional decoction group （P＜0.01）； the absorbance values of Zexie formula granule group and Baizhu formula granule group were significantly higher than that of ZXT formula granule group （P＜0.01）； the absorbance value of Zexie formula granule group was significantly higher than that of Zexie traditional decoction group （P＜0.01）； the absorbance value of Baizhu formula granule group was significantly higher than that of Baizhu traditional decoction group （P＜0.01）. CONCLUSIONS ZXT reduces lipid accumulation of human hepatocellular carcinoma cells through multiple components， multiple target and multiple pathways， and its traditional decoction and formula granules exhibit slightly different lipid-lowering effects.

Objective:To evaluate the clinical outcomes of combined complete preservation of chordal structure mitral valve replacement (C-MVR) with total anatomical arterial myocardial revascularization (TACR) in coronary patients with moderate-to-severe or severe ischemic mitral regurgitation (IMR).Methods:This is a retrospective multi-center case series study. Data were retrospectively collected from 127 patients with coronary artery disease with moderate to severe or severe IMR who received TACR with C-MVR from July 2015 to April 2024 in 13 hospitals in China. There were 90 males and 37 females, aged (56.5±10.7) years (range: 33 to 74 years). Perioperative data and follow-up data including left ventricular ejection fraction, left ventricular end-diastolic diameter, and patency rate of arterial grafts of patients were collected. Comparisons were made using paired sample t-test or χ2 test. Results:In this cohort of 127 patients, 67 underwent concurrent tricuspid valve repair. During surgery, 113 grafts of the left internal mammary artery (LIMA), 127 grafts of the left radial artery, 80 grafts of the right radial artery, and 110 grafts of the right internal mammary artery (RIMA) were harvested. The number of the distal anastomosis was 4.2±0.4 (range: 3 to 5). The aortic cross-clamp time and cardiopulmonary bypass time were (97.5±23.4) minutes (range: 90 to 161 minutes) and (145.4±19.2) minutes (range: 101 to 210 minutes), respectively. There was one operative death. Intraoperative placement of an intra-aortic balloon pump was performed in 21 patients to improve the left ventricular ejection. No sternal ischemic occurred. All patients completed follow-up, with a mean follow-up period of (64.3±7.5) months (range: 4 to 110 months). No major cerebrovascular events occurred during the follow-up period, and all patients survived. Left ventricular ejection fraction improved postoperatively (55.0%±5.3% vs. 41.0%±15.3%, t=17.23, P<0.01). The proportion of patients with New York Heart Association functional class ≤2 increased postoperatively (23.6% (30/127) vs. 87.3% (110/126), χ2=103.77, P<0.01). The proportion of patients with Canadian Cardiovascular Society Angina Classification ≤3 decreased postoperatively (4.8% (6/126) vs. 78.7% (100/127), χ2=142.19, P<0.01). The left ventricular end-diastolic diameter decreased postoperatively ((5.70±4.50) cm vs. (6.10±0.23) cm, t=12.15, P<0.01). Coronary multi-detector computed tomography angiography (MDCTA) follow-up was conducted for (60.5±11.7) months (range: 6 to 109 months) postoperatively. MDCTA confirmed the patency rates of the grafts: 96.4% (108/112) for the LIMA grafts, 88.9% (112/126) for the left radial artery grafts, 93.7% (74/79) for the right radial artery grafts, and 90.9% (100/110) for the free RIMA grafts. No significant differences in graft patency rates were observed between the arterial grafts ( χ2=5.24, P=0.155). Conclusion:The results of this multi-centre study demonstrate satisfactory mid-term results of C-MVR with TACR for the treatment of coronary artery disease with moderate to severe or severe IMR.

Objective:To evaluate the clinical outcomes of combined complete preservation of chordal structure mitral valve replacement (C-MVR) with total anatomical arterial myocardial revascularization (TACR) in coronary patients with moderate-to-severe or severe ischemic mitral regurgitation (IMR).Methods:This is a retrospective multi-center case series study. Data were retrospectively collected from 127 patients with coronary artery disease with moderate to severe or severe IMR who received TACR with C-MVR from July 2015 to April 2024 in 13 hospitals in China. There were 90 males and 37 females, aged (56.5±10.7) years (range: 33 to 74 years). Perioperative data and follow-up data including left ventricular ejection fraction, left ventricular end-diastolic diameter, and patency rate of arterial grafts of patients were collected. Comparisons were made using paired sample t-test or χ2 test. Results:In this cohort of 127 patients, 67 underwent concurrent tricuspid valve repair. During surgery, 113 grafts of the left internal mammary artery (LIMA), 127 grafts of the left radial artery, 80 grafts of the right radial artery, and 110 grafts of the right internal mammary artery (RIMA) were harvested. The number of the distal anastomosis was 4.2±0.4 (range: 3 to 5). The aortic cross-clamp time and cardiopulmonary bypass time were (97.5±23.4) minutes (range: 90 to 161 minutes) and (145.4±19.2) minutes (range: 101 to 210 minutes), respectively. There was one operative death. Intraoperative placement of an intra-aortic balloon pump was performed in 21 patients to improve the left ventricular ejection. No sternal ischemic occurred. All patients completed follow-up, with a mean follow-up period of (64.3±7.5) months (range: 4 to 110 months). No major cerebrovascular events occurred during the follow-up period, and all patients survived. Left ventricular ejection fraction improved postoperatively (55.0%±5.3% vs. 41.0%±15.3%, t=17.23, P<0.01). The proportion of patients with New York Heart Association functional class ≤2 increased postoperatively (23.6% (30/127) vs. 87.3% (110/126), χ2=103.77, P<0.01). The proportion of patients with Canadian Cardiovascular Society Angina Classification ≤3 decreased postoperatively (4.8% (6/126) vs. 78.7% (100/127), χ2=142.19, P<0.01). The left ventricular end-diastolic diameter decreased postoperatively ((5.70±4.50) cm vs. (6.10±0.23) cm, t=12.15, P<0.01). Coronary multi-detector computed tomography angiography (MDCTA) follow-up was conducted for (60.5±11.7) months (range: 6 to 109 months) postoperatively. MDCTA confirmed the patency rates of the grafts: 96.4% (108/112) for the LIMA grafts, 88.9% (112/126) for the left radial artery grafts, 93.7% (74/79) for the right radial artery grafts, and 90.9% (100/110) for the free RIMA grafts. No significant differences in graft patency rates were observed between the arterial grafts ( χ2=5.24, P=0.155). Conclusion:The results of this multi-centre study demonstrate satisfactory mid-term results of C-MVR with TACR for the treatment of coronary artery disease with moderate to severe or severe IMR.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-positive bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-positive bacteria from blood cultures in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:A total of 3 163 strains of Gram-positive pathogens were collected from 51 member units，and the top five bacteria were Staphylococcus aureus（ n=1 147，36.3%），coagulase-negative Staphylococci（ n=928，29.3%）， Enterococcus faecalis（ n=369，11.7%）， Enterococcus faecium（ n=296，9.4%）and alpha-hemolyticus Streptococci（ n=192，6.1%）. The detection rates of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）were 26.4%（303/1 147）and 66.7%（619/928），respectively. No glycopeptide and daptomycin-resistant Staphylococci were detected. The sensitivity rates of Staphylococcus aureus to cefpirome，rifampin，compound sulfamethoxazole，linezolid，minocycline and tigecycline were all >95.0%. Enterococcus faecium was more prevalent than Enterococcus faecalis. The resistance rates of Enterococcus faecium to vancomycin and teicoplanin were both 0.5%（2/369），and no vancomycin-resistant Enterococcus faecium was detected. The detection rate of MRSA in southern China was significantly lower than that in other regions（ χ2=14.578， P=0.002），while the detection rate of MRCNS in northern China was significantly higher than that in other regions（ χ2=15.195， P=0.002）. The detection rates of MRSA and MRCNS in provincial hospitals were higher than those in municipal hospitals（ χ2=13.519 and 12.136， P<0.001）. The detection rates of MRSA and MRCNS in economically more advanced regions（per capita GDP≥92 059 Yuan in 2022）were higher than those in economically less advanced regions（per capita GDP<92 059 Yuan）（ χ2=9.969 and 7.606， P=0.002和0.006）. Conclusions:Among the Gram-positive pathogens causing bloodstream infections in China， Staphylococci is the most common while the MRSA incidence decreases continuously with time；the detection rate of Enterococcus faecium exceeds that of Enterococcus faecalis. The overall prevalence of vancomycin-resistant Enterococci is still at a low level. The composition ratio of Gram-positive pathogens and resistant profiles varies slightly across regions of China，with the prevalence of MRSA and MRCNS being more pronounced in provincial hospitals and areas with a per capita GDP≥92 059 yuan.

Objective:To explore chromosomal copy number variations (CNVs) and pregnancy outcomes in fetuses with mild to moderate isolated ventriculomegaly (IVM), but without other indications for invasive prenatal diagnosis.Methods:A retrospective analysis was conducted on clinical data of 215 singleton pregnancies with mild to moderate IVM (lateral ventricular width≥10-<15 mm) who underwent chromosomal microarray analysis (CMA), not indicated by advanced age, high risk in serum screening or abnormal history of pregnancy, at the Fujian Maternity and Child Health Hospital between June 2016 and March 2023. The 215 fetuses were grouped into mild ( n=167) and moderate ( n=48) IVM;unilateral ( n=142) and bilateral ( n=73) IVM; first diagnosis of IVM before 28 weeks ( n=138) and thereafter ( n=77). Anomalies other than IVM were excluded via three-dimensional color Doppler ultrasound examination between 22 and 26 weeks of gestation. Out of these cases, 129 were confirmed by fetal cranial MRI, 191 underwent chromosomal karyotype analysis, and 202 cases received cytomegalovirus DNA quantification test for amniotic fluid. The detection rates of pathogenic CNVs in various groups were compared using Fisher's exact test. Results:Among the 215 fetuses, 11 cases (5.1%) of chromosomal abnormalities were detected through CMA, including one trisomy 21, five pathogenic CNVs, and five CNVs of uncertain clinical significance. Within the pathogenic CNVs, there were two de novo mutations with 16p11.2 microdeletion and one de novo mutation with 16p11.2 microduplication, while one 16p11.2 microduplication and one Xp22.31 microdeletion were inherited maternally. Of the CNVs of uncertain significance, there were two 16p13.11 microduplications, each inherited from a different parent, one paternally and one maternally; meanwhile, family validation was refused in the other three cases with 3p22.1 microdeletion, 3p26.3 microdeletion, and 9q21.33q22.31 microduplication. The detection rate of pathogenic CNVs in the moderate IVM group was higher than that in the mild IVM group [6.3% (3/48) vs. 1.2% (2/167)], but the difference was not statistically significant ( P=0.083). Similarly, no significant difference was found in the detection rate of pathogenic CNVs when comparing the unilateral IVM group [2.1% (3/142)] with the bilateral IVM group [2.7% (2/73)], nor between the group diagnosed with VM before 28 weeks gestation [2.2% (3/138)] and that diagnosed ≥28 weeks [2.6% (2/77)] (both P>0.05). After the exclusion of fetuses with chromosomal pathogenic abnormalities ( n=11), cytomegalovirus infection( n=1), and additional ultrasound anomalies ( n=7), and several cases with missing data intrauterine outcomes were followed up in 169 IVM fetuses, including 104 (61.5%) improved, 60 (35.5%) unchanged, and five (3.0%) progressed. Follow-ups were successful for 194 women, of which eight pregnancies were terminated (including one trisomy 21, four pathogenic CNVs, one fetal cytomegalovirus infection, and two progressed to severe IVM). Among the 186 newborns, one was diagnosed with X-linked ichthyosis, and one child who progressed to severe IVM before born was followed until 20 months of age without notable phenotypic abnormalities. The rest 184 babies, including those with CNVs of uncertain clinical significance, exhibited no developmental abnormalities during follow-up between the ages of three months and six years. Conclusions:For those fetuses with isolated mild to moderate IVM, but without indications for prenatal diagnosis such as advanced maternal age, high risk in serum screening or abnormal history of pregnancy, remain having the risk for chromosomal aberrations, and 16p11.2 microdeletion/microduplication might be a frequent CNV associated with this condition. Aside from those with pathogenic chromosomal aberrations, fetal cytomegalovirus infection, or progressive enlargement of the lateral ventricles, most fetuses with isolated mild to moderate IVM have a good prognosis.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

To promote the development of extracellular vesicles of herbal medicine especially the establishment of standardization, led by the National Expert Committee on Research and Application of Chinese Herbal Vesicles, research experts in the field of herbal medicine and extracellular vesicles were invited nationwide with the support of the Expert Committee on Research and Application of Chinese Herbal Vesicles, Professional Committee on Extracellular Vesicle Research and Application, Chinese Society of Research Hospitals and the Guangdong Engineering Research Center of Chinese Herbal Vesicles. Based on the collation of relevant literature, we have adopted the Delphi method, the consensus meeting method combined with the nominal group method to form a discussion draft of "Consensus statement on research and application of Chinese herbal medicine derived extracellular vesicles-like particles (2023)". The first draft was discussed in online and offline meetings on October 12, 14, November 2, 2022 and April and May 2023 on the current status of research, nomenclature, isolation methods, quality standards and research applications of extracellular vesicles of Chinese herbal medicines, and 13 consensus opinions were finally formed. At the Third Academic Conference on Research and Application of Chinese Herbal Vesicles, held on May 26, 2023, Kewei Zhao, convenor of the consensus, presented and read the consensus to the experts of the Expert Committee on Research and Application of Chinese Herbal Vesicles. The consensus highlights the characteristics and advantages of Chinese medicine, inherits the essence, and keeps the righteousness and innovation, aiming to provide a reference for colleagues engaged in research and application of Chinese herbal vesicles at home and abroad, decode the mystery behind Chinese herbal vesicles together, establish a safe, effective and controllable accurate Chinese herbal vesicle prevention and treatment system, and build a bridge for Chinese medicine to the world.

BACKGROUND:Swimming is an important non-pharmacological treatment for knee osteoarthritis,which can effectively alleviate the disease.However,the effect and mechanism of swimming on senile knee osteoarthritis are still unclear. OBJECTIVE:To investigate the effect of swimming exercise on the articular cartilage of aged mice with knee osteoarthritis. METHODS:Six 3-month-old male C57BL/6 mice were selected as the young group,and twelve 18-month-old male C57BL/6 mice were randomized into the aged group and the swimming group,with six mice in each group.Mice in the swimming group received adaptive swimming for 1 week and formal swimming for 8 weeks.After the intervention,stride length analysis and sampling were performed in each group.The total number of leukocytes and lymphocytes in peripheral blood was detected by blood routine examinations.The morphology of the articular cartilage was observed by hematoxylin-eosin and safranin O-fast green staining.Chondrocyte counts and the modified Mankin's score were used to evaluate the degree of articular cartilage damage.The protein and mRNA expressions of type Ⅱ collagen,aggrecan and matrix metalloproteinase 13 in articular cartilage were detected by immunohistochemical staining and RT-qPCR. RESULTS AND CONCLUSION:Compared with the young group,the mice in the aged group showed significantly decreased stride length(P＜0.05),significantly increased numbers of peripheral leukocytes and lymphocytes(P＜0.05),significantly decreased count of chondrocytes(P＜0.05),significantly increased modified Mankin's score(P＜0.05),significantly decreased protein and mRNA expression of type Ⅱ collagen and aggreca(P＜0.05),and significantly increased matrix metalloproteinase 13 expression(P＜0.05).Moreover,hematoxylin-eosin and safranin O-fast green staining showed the uneven surface of the articular cartilage,abnormal chondrocytes,and proteoglycan loss in the aged group.Compared with the aged group,swimming exercise significantly improved the stride length of mice(P＜0.05),decreased the count of peripheral blood lymphocytes(P＜0.05),increased the count of chondrocytes(P＜0.05),decreased the modified Mankin's score(P＜0.05),increased the protein and mRNA expression of type Ⅱ collagen and aggrecan(P＜0.05),and decreased the expression of matrix metalloproteinase 13(P＜0.05).Hematoxylin-eosin and safranin O-fast green staining showed that the articular surface of mice in the swimming group was smooth,chondrocytes were normal,and proteoglycan loss was less.All these findings indicate that swimming exercise can reduce the number of inflammatory cells in the blood of aged mice,improve articular chondrocytes,matrix composition and cartilage tissue morphology;thus,it has a protective effect on the cartilage of aged mice with knee osteoarthritis.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.

The breakage pattern of unit particles during the production of oral solid dosage forms (OSD) is closely related to the quality of intermediate or final products. To accurately characterize the particles and study the evolution law of particle breakage, the Bonding model of the discrete element method (DEM) was used to investigate the breakage patterns of model parameters, particle shape and process conditions (loading mode and loading rate) on the dynamic breakage, force-time curve, breakage rate, maximum breakage size ratio and fracture strength of particles. The results showed that the particle breakage force was positively correlated with normal strength and bonded disk scale, negatively correlated with normal stiffness per unit area and tangential stiffness per unit area, and weakly correlated with tangential strength. The particle breakage rate was negatively correlated with the aspect ratio of the particles, and the maximum breakage size ratio was positively correlated with the aspect ratio of the particles; among the three loading modes, the breakage rate of compression breakage model was the largest, the breakage rate of shear breakage model was the second largest, and the breakage rate of wear breakage model was the smallest; the maximum breakage size ratio was positively correlated with the loading rate, the loading mode and the loading rate had no mutual influence on particle breakage rate, but had mutual influence on the maximum breakage size ratio. The research results will provide a theoretical basis for the shift of OSD from batch manufacturing to advanced manufacturing.