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 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 systematically review and evaluate the effect of intraoperative regional cerebral oxygen saturation (rSO 2) monitoring on perioperative neurocognitive disorders (PNDs) in elderly patients undergoing non-cardiac surgery. Methods:China National Knowledge Infrastructure, Wanfang Database, China Biomedical Literature Database, China Science and Technology Journal Database, PubMed, Cochrane Library, Embase and Web of Science databases were searched from inception to October 2022 for randomized controlled trials involving the effects of intraoperative rSO 2 monitoring on PND in elderly patients underwent non-cardiac surgery. The primary outcome measure was the incidence of PND (1-7 days after surgery), and secondary outcome measures were intraoperative minimum rSO 2 (rSO 2min), intraoperative mean rSO 2 (rSO 2mean), maximum percentage of decrease (rSO 2% max) in rSO 2 from baseline (rSO 2baseline), and the Montreal Cognitive Assessment Scale was used to evaluate the quality of references that met the inclusion criteria, and data were extracted for meta-analysis using RevMan5.4 software. Results:Thirteen randomized controlled trials were enrolled, involving 1 134 patients with 557 patients in experimental group (anesthesia under rSO 2 monitoring) and 577 patients in control group. The results of meta-analysis showed that the incidence of PND was significantly lower in experimental group than in control group ( RR=0.32, 95% confidence interval [ CI] 0.25-0.41, P<0.001), the intraoperative rSO 2min was significantly higher in experimental group than in control group ( MD=7.46, 95% CI 5.05-9.86, P<0.001), and the intraoperative rSO 2mean was significantly higher in experimental group than in control group ( MD=5.49, 95% CI 3.97-7.02, P<0.001), the intraoperative rSO 2% max was significantly lower in experimental group than in control group ( MD=-6.55, 95% CI-9.03--4.07, P<0.001), and the postoperative Montreal Cognitive Assessment Scale score was significantly higher in experimental group than in control group ( MD=1.37, 95% CI 0.74-1.99, P<0.001). Conclusions:Intraoperative application of rSO 2 monitoring can reduce the occurrence of PND in elderly patients undergoing non-cardiac surgery.

Osteoporosis is a common metabolic bone disease, which is involved in disrupted normal bone remodeling process and bone resorption exceeding bone formation. Osteoblasts and osteoclasts play critical roles in maintaining bone homeostasis. In recent years, more and more studies have found that immune cells are involved in the regulation of osteoblast and osteoclast activity via releasing various chemokines and cytokines, and the concept of immunoporosis has been proposed accordingly. This article summarizes the current state of knowledge on the immune system in the pathophysiology of osteoporosis, so as to study and prevent osteoporosis from the perspective of immunology.

Objective:To investigate the clinical characteristics of vasa previa (VP) with low-lying placenta (LP).Methods:A retrospective case-control study was conducted on pregnant women with VP who delivered at Guangzhou Women and Children's Medical Center from January 2015 to August 2021. According to the status of LP, these cases were classified into VP with LP (VP+LP) and VP without LP (VP-LP) group. The cases diagnosed with placenta previa (PP, n=128) during the same period were collected as control. Maternal-fetal clinical characteristics and outcomes were compared among the three groups using t-test, Mann-Whitney U test, and Chi-square test (or Fisher's exact test). Results:During the study period, 116 VP cases were diagnosed, accounting for 0.085% (116/136 450) of all deliveries. Apart from one case of intrauterine death caused by non-VP reasons in the third trimester, there were 64 in the VP+LP group and 51 in the VP-LP group. VP+LP cases accounted for about 2.9% (64/2 219) of all the cases with PP or LP. The proportions of multiparae and women with a history of cesarean section were significantly higher in the VP+LP group than in the VP-LP group [62.5% (40/64) vs 39.2% (20/51), χ 2= 6.17, P=0.013; 31.3% (20/64) vs 13.7% (7/51), χ 2= 4.85, P=0.028]. Besides, a rare type of VP (type Ⅲ) was only found in the VP+LP group (9.4%, 6/64). The median gestational age at first diagnosis by prenatal ultrasound was significantly larger in the VP+LP group than in the VP-LP group [28.3 (23.6-31.7) vs 23.9 (23.3-25.9) weeks, Z=2.61, P=0.007]. There was no significant difference in the incidence of antepartum hemorrhage between the two groups. In contrast, the amount of postpartum hemorrhage was significantly increased in the VP+LP group [550 (436-732) vs 420 (300-540) ml, Z=3.37, P=0.001]. Compared with the VP-LP group, the VP+LP group showed a lower incidence of lower neonatal Apgar score (<7 at 5 min) and hypoxic-ischemic encephalopathy [0.0%(0/64) vs 6.9%(4/58), 0.0%(0/64) vs 8.6% (5/58), Fisher's exact test, both P<0.05]. No neonatal death was reported in the VP+LP and VP-LP groups. No significant difference in the incidence of antepartum hemorrhage was found between the VP+LP group and the PP group. Still, the median time at delivery was earlier [36.0 (34.3-36.9) vs 37.0 (35.7-37.3) weeks, Z=3.79, P<0.001], and the incidence of abnormal fetal heart rate was higher [10.9% (7/64) vs 3.1% (4/128), Fisher's exact test , P=0.044] in the VP+LP group. Furthermore, the neonatal NICU admission rate and the incidence of respiratory distress syndrome were significantly higher in the VP+LP group than in the PP group [36.4% (24/66) vs 12.1% (16/132), χ 2= 16.04, P<0.001; 25.8% (17/66) vs 12.1% (16/132), χ 2= 5.89, P=0.015]. Conclusions:For VP+LP cases, there might be an additional type (type Ⅲ VP). Patients with VP+LP would have more blood loss within 24 h after delivery and a higher risk of adverse neonatal outcomes. Intensive attention should be paid to those diagnosed with LP during the third trimester to identify any VP.

Objective: To verify the applicability of the theory of planned behavior(TPB) in the physical exercise behaviors of rural adolescents in Sichuan Province, and to explore the possible influencing factors of physical exercise behaviors, and to provide a theoretical basis for further effective intervention measures. Methods: A total of 2 302 students were selected from grade seven and grade ten of two rural middle schools in Zizhong, Sichuan Province. The survey was conducted with a structured questionnaire. Using TPB as the research framework and basis, the structural equation model was constructed for analysis. Results: Lack of physical exercise was 1 527(66.3%).Physical exercise behavior was statistically different among schools, grades(t=-7.40，-2.90，10.90,P<0.05)， and genders. Based on TPB, the structural equation model was established and corrected to obtain the revised model, and the fitting index GFI=0.93, CFI=0.94, NFI=0.94, TLI=0.93, IFI=0.94,RMSEA=0.07, indicating the model fitted good. Exercise intention directly affected exercise behaviors. The standardized effect was 0.45(95%CI=0.39-0.52). Subjective norms and perceived power were the main two mediators of the relationship between value evaluation and exercise intention. The standardized effect values were 0.66(95%CI=0.57-0.73), 0.23(95%CI=0.16-0.93)(P<0.01). Conclusion There is serious lack of physical exercise in rural adolescents in Sichuan Province. TPB has a good applicability for physical exercise in rural adolescents in Sichuan Province. Subjective norm is the most important factors to promote exercise intentions.

Objective:To investigate the distribution and antimicrobial resistance profile of clinical bacteria isolated from blood culture in China.Methods:The clinical bacterial strains isolated from blood culture from member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS) were collected during January 2018 to December 2019. Antibiotic susceptibility tests were conducted with agar dilution or broth dilution methods recommended by US Clinical and Laboratory Standards Institute (CLSI). WHONET 5.6 was used to analyze data.Results:During the study period, 14 778 bacterial strains were collected from 50 hospitals, of which 4 117 (27.9%) were Gram-positive bacteria and 10 661(72.1%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (37.2%), Klebsiella pneumoniae (17.0%), Staphylococcus aureus (9.7%), coagulase-negative Staphylococci (8.7%), Pseudomonas aeruginosa (3.7%), Enterococcus faecium (3.4%), Acinetobacter baumannii(3.4%), Enterobacter cloacae (2.9%), Streptococci(2.8%) and Enterococcus faecalis (2.3%). The the prevalence of methicillin-resistant S. aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus were 27.4% (394/1 438) and 70.4% (905/1 285), respectively. No glycopeptide-resistant Staphylococcus was detected. More than 95% of S. aureus were sensitive to amikacin, rifampicin and SMZco. The resistance rate of E. faecium to vancomycin was 0.4% (2/504), and no vancomycin-resistant E. faecalis was detected. The ESBLs-producing rates in no carbapenem-resistance E. coli, carbapenem sensitive K. pneumoniae and Proteus were 50.4% (2 731/5 415), 24.6% (493/2001) and 35.2% (31/88), respectively. The prevalence of carbapenem-resistance in E. coli and K. pneumoniae were 1.5% (85/5 500), 20.6% (518/2 519), respectively. 8.3% (27/325) of carbapenem-resistance K. pneumoniae was resistant to ceftazidime/avibactam combination. The resistance rates of A. baumannii to polymyxin and tigecycline were 2.8% (14/501) and 3.4% (17/501) respectively, and that of P. aeruginosa to carbapenem were 18.9% (103/546). Conclusions:The surveillance results from 2018 to 2019 showed that the main pathogens of bloodstream infection in China were gram-negative bacteria, while E. coli was the most common pathogen, and ESBLs-producing strains were in majority; the MRSA incidence is getting lower in China; carbapenem-resistant E. coli keeps at a low level, while carbapenem-resistant K. pneumoniae is on the rise obviously.

Objective:To investigate the bacterial composition and antimicrobial resistance profile of clinical isolates from bloodstream infections in China.Methods:The clinical bacterial strains isolated from blood culture were collected during January 2020 to December 2020 in member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS). Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical Laboratory Standards Institute(CLSI, USA). WHONET 5.6 was used to analyze data.Results:During the study period, 10 043 bacterial strains were collected from 54 hospitals, of which 2 664 (26.5%) were Gram-positive bacteria and 7 379 (73.5%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (38.6%), Klebsiella pneumoniae (18.4%), Staphylococcus aureus (9.9%), coagulase-negative Staphylococci (7.5%), Pseudomonas aeruginosa (3.9%), Enterococcus faecium (3.3%), Enterobacter cloacae (2.8%), Enterococcus faecalis (2.6%), Acinetobacter baumannii (2.4%) and Klebsiella spp (1.8%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus aureus were 27.6% and 74.4%, respectively. No glycopeptide- and daptomycin-resistant Staphylococci were detected. More than 95% of Staphylococcus aureus were sensitive to rifampicin and SMZco. No vancomycin-resistant Enterococci strains were detected. Extended spectrum β-lactamase (ESBL) producing Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were 48.4%, 23.6% and 36.1%, respectively. The prevalence rates of carbapenem-resistance in Escherichia coli and Klebsiella pneumoniae were 2.3% and 16.1%, respectively; 9.6% of carbapenem-resistant Klebsiella pneumoniae strains were resistant to ceftazidime/avibactam combination. The prevalence rate of carbapenem-resistance in Acinetobacter baumannii was 60.0%, while polymyxin and tigecycline showed good activity against Acinetobacter baumannii. The prevalence rate of carbapenem-resistance of Pseudomonas aeruginosa was 23.2%. Conclusions:The surveillance results in 2020 showed that the main pathogens of bloodstream infection in China were gram-negative bacteria, while Escherichia coli was the most common pathogen, and ESBL-producing strains declined while carbapenem-resistant Klebsiella pneumoniae kept on high level. The proportion and the prevalence of carbapenem-resistant Pseudomonas aeruginosa were on the rise slowly. On the other side, the MRSA incidence got lower in China, while the overall prevalence of vancomycin-resistant Enterococci was low.

The adverse health effects of air pollution remains a daunting public health problem globally. The research of the health effects of air pollution provides important evidence for ambient air quality standard establishments and air pollution interventions. In recent years, causal inference has been gradually introduced into the observational study of environmental epidemiology, which provides more statistical method options for the study of causal relationships between air pollution and population health effects. Controlling confounders in observational studies is a major challenge for causal inference. This study introduces the causal inference methods for the identification and control of confounding factors currently used in the study of air pollution and population health effects, in order to provide methodological reference and basis for the causal inference study of air pollution and population health effects in China.