Objective:To report the nationwide surveillance results of pathogenic profiles and antimicrobial resistance patterns of Gram-positive bloodstream infections in China in 2023.Methods:The clinical isolates of Gram-posttive bacteria from blood cultures were collected in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）during January to December 2023. Antimicrobial susceptibility testing was performed using the dilution method recommended by the Clinical and Laboratory Standards Institute（CLSI）. Statistical analyses were conducted using WHONET 5.6 and SPSS 25.0 software.Results:A total of 4 385 Gram-positive bacterial isolates were obtained from 60 participating center. The top five pathogens were Staphylococcus aureus（ n=1 544，35.2%），coagulase-negative Staphylococci（ n=1 441，32.9%）， Enterococcus faecium（ n=574，13.1%）， Enterococcus faecalis（ n=385，8.8%），and α-hemolytic Streptococci（ n=187，4.3%）. The prevalence of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）was 26.2%（405/1 544）and 69.8%（1 006/1 441），respectively. Notably，all Staphylococci remained susceptible to glycopeptide or daptomycin. Staphylococcus aureus demonstrated excellent susceptibility（>97.0%）to cephalobiol，rifampicin，trimethoprim-sulfamethoxazole，linezolid，minocycline，tigecycline，and eravacycline. No Enterococcus exhibiting resistance to linezolid were detected. Glycopeptide resistance was uncommon but more frequent in Enterococcus faecium（resistance to vancomycin and teicoplanin：both 1.7%）compared to Enterococcus faecalis（both 0.3%）. The detection rates of MRSA and MRCNS exhibited significant regional variations across the country（ χ2=17.674 and 148.650，respectively，both P<0.001）. No vancomycin-resistant Enterococci were detected in central China. Institutional comparison demonstrated higher prevalence of MRSA（ χ2=14.111， P<0.001）and MRCNS（ χ2=4.828， P=0.028）in provincial hospitals than that in municipal hospitals. Socioeconomic analysis identified elevated detection rates of both MRSA（ χ2=18.986， P<0.001）and MRCNS（ χ2=4.477， P=0.034）in less developed regions（per capita GDP

Objective:To report the results of bacterial resistant investigation collaborative system（BRICS）on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2023，and provide reference for clinical tretment of bloodstream infections and prevention and control of bacterial resistance.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of BRICS were collected during January 2023 to December 2023. 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 were used to analyze the data.Results:During the study period，11 492 strains of Gram-negative bacteria were collected from 60 hospitals，of which 10 098（87.9%）were Enterobacterales and 1 394（12.1%）were non-fermentative bacteria. The top 5 bacterial species were Escherichia coli（50.0%）， Klebsiella pneumoniae（26.1%）， Pseudomonas aeruginosa（5.1%）， Acinetobacter baumannii complex（5.0%）and Enterobacter cloacae complex（4.1%）. The ESBL-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus mirablilis were 46.8%（2 685/5 741），18.3%（549/2 999）and 44.0%（77/175），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（76/5 741）and 15.0%（450/2 999）；32.9%（25/76）and 78.0%（351/450）of CREC and CRKP were sensitive to ceftazidime/avibactam combination，respectively. 94.7%（72/76）and 90.2%（406/450）of CREC and CRKP were sensitive to aztreonam/avibactam combination. Furthermore，57.9%（44/76）and 79.1%（356/450）were sensitive to imipenem/relebactam combination. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 64.6%（370/573），while more than 80.0% of CRAB complex was sensitive to tigecycline，eravacycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 17.0%（99/581）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of important Gram-negative bacteria resistance among different regions in China，with statistically significant differences in the prevalence of CREC，CRKP，CRPA and CRAB complex（ χ2=10.6，28.6，10.8 and 19.3， P<0.05）. The prevalence of ESBL-producing Escherichia coli， CREC，CRAB complex and CRKP were higher in provincial hospitals than those in municipal hospitals（ χ2=12.5，9.8，12.7 and 57.8，all P<0.01）. Conclusions:Gram-negative bacteria are the main pathogens causing bloodstream infections in China，and Escherichia coli is ranked in the top，while the trend of Klebsiella pneumoniae increases continuously with time. CRKP infection shows a slow upward trend，CREC infecton maintains a low prevalence level，and CRAB complex infection continues to exhibit a high prevalence rate. The composition and resistance patterns of pathogens causing bloodstream infections vary to some extent across different regions and levels of hospitals in China.

Objective:To report the nationwide surveillance results of pathogenic profiles and antimicrobial resistance patterns of Gram-positive bloodstream infections in China in 2023.Methods:The clinical isolates of Gram-posttive bacteria from blood cultures were collected in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）during January to December 2023. Antimicrobial susceptibility testing was performed using the dilution method recommended by the Clinical and Laboratory Standards Institute（CLSI）. Statistical analyses were conducted using WHONET 5.6 and SPSS 25.0 software.Results:A total of 4 385 Gram-positive bacterial isolates were obtained from 60 participating center. The top five pathogens were Staphylococcus aureus（ n=1 544，35.2%），coagulase-negative Staphylococci（ n=1 441，32.9%）， Enterococcus faecium（ n=574，13.1%）， Enterococcus faecalis（ n=385，8.8%），and α-hemolytic Streptococci（ n=187，4.3%）. The prevalence of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）was 26.2%（405/1 544）and 69.8%（1 006/1 441），respectively. Notably，all Staphylococci remained susceptible to glycopeptide or daptomycin. Staphylococcus aureus demonstrated excellent susceptibility（>97.0%）to cephalobiol，rifampicin，trimethoprim-sulfamethoxazole，linezolid，minocycline，tigecycline，and eravacycline. No Enterococcus exhibiting resistance to linezolid were detected. Glycopeptide resistance was uncommon but more frequent in Enterococcus faecium（resistance to vancomycin and teicoplanin：both 1.7%）compared to Enterococcus faecalis（both 0.3%）. The detection rates of MRSA and MRCNS exhibited significant regional variations across the country（ χ2=17.674 and 148.650，respectively，both P<0.001）. No vancomycin-resistant Enterococci were detected in central China. Institutional comparison demonstrated higher prevalence of MRSA（ χ2=14.111， P<0.001）and MRCNS（ χ2=4.828， P=0.028）in provincial hospitals than that in municipal hospitals. Socioeconomic analysis identified elevated detection rates of both MRSA（ χ2=18.986， P<0.001）and MRCNS（ χ2=4.477， P=0.034）in less developed regions（per capita GDP

Objective:To report the results of bacterial resistant investigation collaborative system（BRICS）on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2023，and provide reference for clinical tretment of bloodstream infections and prevention and control of bacterial resistance.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of BRICS were collected during January 2023 to December 2023. 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 were used to analyze the data.Results:During the study period，11 492 strains of Gram-negative bacteria were collected from 60 hospitals，of which 10 098（87.9%）were Enterobacterales and 1 394（12.1%）were non-fermentative bacteria. The top 5 bacterial species were Escherichia coli（50.0%）， Klebsiella pneumoniae（26.1%）， Pseudomonas aeruginosa（5.1%）， Acinetobacter baumannii complex（5.0%）and Enterobacter cloacae complex（4.1%）. The ESBL-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus mirablilis were 46.8%（2 685/5 741），18.3%（549/2 999）and 44.0%（77/175），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（76/5 741）and 15.0%（450/2 999）；32.9%（25/76）and 78.0%（351/450）of CREC and CRKP were sensitive to ceftazidime/avibactam combination，respectively. 94.7%（72/76）and 90.2%（406/450）of CREC and CRKP were sensitive to aztreonam/avibactam combination. Furthermore，57.9%（44/76）and 79.1%（356/450）were sensitive to imipenem/relebactam combination. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 64.6%（370/573），while more than 80.0% of CRAB complex was sensitive to tigecycline，eravacycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 17.0%（99/581）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of important Gram-negative bacteria resistance among different regions in China，with statistically significant differences in the prevalence of CREC，CRKP，CRPA and CRAB complex（ χ2=10.6，28.6，10.8 and 19.3， P<0.05）. The prevalence of ESBL-producing Escherichia coli， CREC，CRAB complex and CRKP were higher in provincial hospitals than those in municipal hospitals（ χ2=12.5，9.8，12.7 and 57.8，all P<0.01）. Conclusions:Gram-negative bacteria are the main pathogens causing bloodstream infections in China，and Escherichia coli is ranked in the top，while the trend of Klebsiella pneumoniae increases continuously with time. CRKP infection shows a slow upward trend，CREC infecton maintains a low prevalence level，and CRAB complex infection continues to exhibit a high prevalence rate. The composition and resistance patterns of pathogens causing bloodstream infections vary to some extent across different regions and levels of hospitals in China.

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.

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 investigate whether propofol can cause injury to hippocampal mitochondria in neonatal rats and the regulation of excitatory amino acid receptor AMPA receptor.Methods:Forty-eight Sprague-Dawley (SD) rats aged 7 days were randomly divided into control group, propofol group, propofol+AMPA receptor agonist AMPA group (propofol+AMPA group) and propofol+AMPA receptor inhibitor CNQX group (propofol+CNQX group), with 12 rats in each group. The rats in the propofol groups were intraperitoneally injected with 30 mg/kg propofol, while in control group with 3 mg/kg normal saline. Each group was given 1/2 of the first dose every 20 minutes after the first administration, three times a day, for three consecutive days. The rats in the propofol+AMPA group and the propofol+CNQX group were injected with 1 g/L AMPA or CNQX 5 μL through left ventricle after the first administration. Three days after administration, the rats were sacrificed to obtain brain tissue. Western blotting was used to determine the expression of AMPA receptor glutamate receptors (GluR1, GluR2) subunit totally (T) and on membrane (M) in hippocampus. The expression of dynamin-related protein-1 (DRP-1) and phosphorylated-DRP-1 (p-DRP-1) and mitofusin 2 (Mfn2) related to mitochondrial fission and fusion were determined. The adenosine triphosphate (ATP) content and ATPase activity were determined.Results:Compared with the control group, GluR1 expression and its M/T ratio were significantly increased after treatment of propofol, GluR2 expression and its M/T ratio were significantly decreased, the ATP content and ATP-related enzyme activity were decreased significantly, while the expression of DRP-1 and its phosphorylation was significantly increased, and the expression of Mfn2 was significantly decreased. The changes indicated that repeated intraperitoneal injection of 30 mg/kg propofol leading to the injury of mitochondria in neural cells. Compared with the propofol group, the GluR1 expression and its M/T ratio further increased after AMPA agonist administration [T-GluR1 protein (T-GluR1/β-actin): 2.41±0.29 vs. 1.72±0.11, M-GluR1 protein (M-GluR1/β-actin): 1.18±0.15 vs. 0.79±0.09, M/T ratio: 0.78±0.12 vs. 0.46±0.08, all P < 0.01], GluR2 expression was significantly increased [T-GluR2 protein (T-GluR2/β-actin): 0.65±0.13 vs. 0.30±0.14, P < 0.01; M-GluR2 protein (M-GluR2/β-actin): 0.17±0.05 vs. 0.13±0.07, P > 0.05], but its M/T ratio was further decreased (0.27±0.10 vs. 0.41±0.08, P < 0.05). The ATP-related enzyme activity was further decreased, and the ATP content was further decreased (μmol/g: 0.32±0.07 vs. 0.70±0.10, P < 0.01). Mitochondria DRP-1 expression and its phosphorylation were further increased [DRP-1 protein (DRP-1/GAPDH): 2.75±0.36 vs. 1.70±0.19, p-DRP-1 protein (p-DRP-1/GAPDH): 0.99±0.14 vs. 0.76±0.15, both P < 0.05], and Mfn2 expression was further decreased (Mfn2/GAPDH: 0.23±0.12 vs. 0.54±0.12, P < 0.05). This indicated that the AMPA agonist increased the expression of the AMPA receptor GluR1 subunit on the cell membrane and shifted the GluR2 into the cell, thus increasing the mitochondrial injury caused by propofol. Compared with the propofol group, the GluR1 expression and its M/T ratio decreased significantly after AMPA inhibitor administration [T-GluR1 protein (T-GluR1/β-actin): 0.99±0.14 vs. 1.72±0.11, M-GluR1 protein (M-GluR1/β-actin): 0.21±0.07 vs. 0.79±0.09, M/T ratio: 0.21±0.07 vs. 0.46±0.08, all P < 0.01], the change of GluR2 expression was not significant, but its M/T ratio was significantly increased (0.59±0.09 vs. 0.41±0.08, P < 0.05). The ATP-related enzyme activity was increased significantly, and the ATP content was increased significantly (μmol/g: 0.87±0.12 vs. 0.70±0.10, P < 0.05). Mitochondria DRP-1 expression and its phosphorylation were significantly decreased [DRP-1 protein (DRP-1/GAPDH): 1.18±0.17 vs. 1.70±0.19, p-DRP-1 protein (p-DRP-1/GAPDH): 0.37±0.10 vs. 0.76±0.10, both P < 0.05], and Mfn2 expression was significantly increased (Mfn2/GAPDH: 0.78±0.10 vs. 0.54±0.12, P < 0.05). This indicated that AMPA inhibitor promoted the movement to the cell membrane of GluR2 subunits meanwhile inhibited the expression of GluR1 subunits, thus alleviating the injury of mitochondrial caused by propofol in the brain. Conclusions:Repeated intraperitoneal injection of 30 mg/kg propofol for 3 days can increase the expression of GluR1 subunits of AMPA receptor in 7-day neonatal rats hippocampus mainly distributing in the cell membrane, decrease the expression of GluR2 subunits moving into the cell, thus causing injury of mitochondrial function and dynamics, which can be aggravated by AMPA receptor agonist and alleviated by AMPA receptor inhibitors.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical bacterial isolates from bloodstream infections in China in 2021.Methods:The clinical bacterial strains isolated from blood culture from member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS) were collected during January 2021 to December 2021. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical Laboratory Standards Institute (CLSI). WHONET 5.6 was used to analyze data.Results:During the study period, 11 013 bacterial strains were collected from 51 hospitals, of which 2 782 (25.3%) were Gram-positive bacteria and 8 231 (74.7%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (37.6%), Klebsiella pneumoniae (18.9%), Staphylococcus aureus (9.8%), coagulase-negative Staphylococci (6.3%), Pseudomonas aeruginosa (3.6%), Enterococcus faecium (3.6%), Acinetobacter baumannii (2.8%), Enterococcus faecalis (2.7%), Enterobacter cloacae (2.5%) and Klebsiella spp (2.1%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus aureus were 25.3% and 76.8%, respectively. No glycopeptide- and daptomycin-resistant Staphylococci was detected; more than 95.0% of Staphylococcus aureus were sensitive to ceftobiprole. No vancomycin-resistant Enterococci strains were detected. The rates of extended spectrum B-lactamase (ESBL)-producing isolated in Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were 49.6%, 25.5% and 39.0%, respectively. The prevalence rates of carbapenem-resistance in Escherichia coli and Klebsiella pneumoniae were 2.2% and 15.8%, respectively; 7.9% of carbapenem-resistant Klebsiella pneumoniae was resistant to ceftazidime/avibactam combination. Ceftobiprole demonstrated excellent activity against non-ESBL-producing Escherichia coli and Klebsiella pneumoniae. Aztreonam/avibactam was highly active against carbapenem-resistant Escherichia coli and Klebsiella pneumoniae. The prevalence rate of carbapenem-resistance in Acinetobacter baumannii was 60.0%, while polymyxin and tigecycline showed good activity against Acinetobacter baumannii (5.5% and 4.5%). The prevalence of carbapenem-resistance in Pseudomonas aeruginosa was 18.9%. Conclusions:The BRICS surveillance results in 2021 shows that the main pathogens of blood stream infection in China are gram-negative bacteria, in which Escherichia coli is the most common. The MRSA incidence shows a further decreasing trend in China and the overall prevalence of vancomycin-resistant Enterococci is low. The prevalence of Carbapenem-resistant Klebsiella pneumoniae is still on a high level, but the trend is downwards.

Objective: To investigate the preliminary screening results of Alzheimer's disease (AD) among the elderly in Ningbo City, Zhejiang Province and analyze the influencing factors, so as to provide insights into prevention and control of AD in the elderly. Methods: A multi-stage stratified proportional sampling method was used to select the registered residents aged 60 years and older in Ningbo City as subjects. Demographic characteristics, lifestyle factors, physical conditions and social activities of the subjects was evaluated with questionnaires. AD was screened using the Mini-Mental State Examination (MMSE), and factors affecting the positive rate of AD preliminary screening were identified using a multivariable logistic regression model. Results: A total of 34 027 elderly residents were investigated, with an mean age of (71.71±6.89) years. There were 15 115 males (44.42%) and 18 912 females (55.58%), 16 146 residents living in rural areas (47.45%) and 17 881 residents living in urban areas (52.55%). The positive rate of AD preliminary screening was 7.28% (2 476 cases). Multivariable logistic regression analysis showed that age (70 to 74 years, OR=1.357; 75 to 79 years, OR=1.807; 80 to 84 years, OR=2.782; 85 years and older, OR=4.907), gender (female, OR=1.118), residence (urban areas, OR=0.713), marital status (unmarried, OR=3.078; widowed/separated/divorced, OR=1.301), educational level (primary school, OR=0.629; junior high school and above, OR=0.609), occupation before retirement (others, OR=0.741), family genetic history (no, OR=0.651), household disposable monthly income (1 000 to 1 999 Yuan, OR=0.636; 2 000 to 2 999 Yuan, OR=0.569; 3 000 Yuan and above, OR=0.448), exercise (seldom, OR=0.855; regular, OR=0.780), number of chronic diseases (2~5, OR=1.328), hearing loss (no, OR=0.764), smell loss (no, OR=0.615), chronic constipation (no, OR=0.696), major negative life events (no, OR=0.804), subjective memory loss (no, OR=0.583), sleep quality (general, OR=0.640; good, OR=0.616), living style (living with spouse, OR=0.300; living alone, OR=0.315; living with children, OR=0.350) and social activities (2-3 times/week, OR=0.584; 4 times/week and more, OR=0.409) were factors affecting the positive rate of AD preliminary screening. Conclusions The positive rate of AD preliminary screening among the elderly in Ningbo City is relatively high. Age, gender, economic conditions, exercise, social activities and physical conditions were factors affecting the positive rate of AD preliminary screening.

Objective:To compare oxytocin combined with ergometrine with oxytocin alone in terms of primary prophylaxis for postpartum hemorrhage (PPH) at the time of cesarean section (CS).Methods:This was a multicenter double-blind randomized controlled interventional study comparing ergometrine combined with oxytocin and oxytocin alone administered at CS. From December 2018 to November 2019, a total of 298 parturients were enrolled in 16 hospitals nationwide. They were randomly divided into experimental group (ergometrine intra-myometrial injection following oxytocin intravenously; 148 cases) and control group (oxytocin intra-myometrial injection following oxytocin intravenously; 150 cases) according to 1∶1 random allocation. The following indexes were compared between the two groups: (1) main index: blood loss 2 hours (h) after delivery; (2) secondary indicators: postpartum blood loss at 6 h and 24 h, placental retention time, incidence of PPH, the proportion of additional use of uterine contraction drugs, hemostatic drugs or other hemostatic measures at 2 h and 24 h after delivery, the proportion requiring blood transfusion, and the proportion of prolonged hospital stay due to poor uterine involution; (3) safety indicators: nausea, vomiting, dizziness and other adverse reactions, and blood pressure at each time point of administration.Results:(1) The blood loss at 2 h after delivery in the experimental group [(402±18) ml] was less than that in the control group [(505±18) ml], and the difference was statistically significant ( P<0.05). (2) The blood loss at 6 h and 24 h after delivery in the experimental group were less than those in the control group, and the differences were statistically significant (all P<0.05). There were no significant differences between the two groups in the incidence of PPH, the proportion of additional use of uterine contraction drugs, hemostatic drugs or other hemostatic measures at 2 h and 24 h after delivery, the proportion requiring blood transfusion, and the proportion of prolonged hospital stay due to poor uterine involution (all P>0.05). (3) Adverse reactions occurred in 2 cases (1.4%, 2/148) in the experimental group and 1 case (0.7%, 1/150) in the control group. There was no significant difference between the two groups ( P>0.05). The systolic blood pressure within 2.0 h and diastolic blood pressure within 1.5 h of drug administration in the experimental group were higher than those in the control group, and the differences were statistically significant ( P<0.05), but the blood pressure of the two groups were in the normal range. Conclusion:The use of ergometrine injection in CS could reduce the amount of PPH, which is safe and feasible.