Background Air pollution exposure has a significant impact on maternal and child health. However, the research on the association between ambient ozone (O₃) exposure during pregnancy and the risk of premature birth in newborns is limited, and the conclusions are inconsistent. Objective To investigate the association of ambient O₃ exposure during pregnancy with the risk of preterm birth in Guangdong Province. Methods Data of pregnant women in Guangzhou from 2013 to 2019 and Foshan from 2018 to 2023 were collected, and O₃ concentrations during different trimesters were assessed according to maternal residential addresses. Bilinear interpolation was used to evaluate the concentrations of air pollution. A cohort study design was adopted in our study. Restricted cubic spline curves were used to evaluate the exposure-response relationship between O₃ exposure and preterm birth risk and explore potential exposure threshold of O₃. Logistic regression models were used to evaluate the association of O₃ exposure with preterm birth. Results A total of 702 924 pregnant women were included in this study, of whom 43 051 (6.12%) were preterm. The average O₃ exposure concentrations of pregnant women during the first, second, third, and whole trimesters were 95.51, 97.51, 100.60, and 97.87 μg·m⁻³, respectively. We observed J-shaped associations between O₃ exposure and preterm birth risk during the second, third, and whole trimesters of pregnancy using restricted cubic spline curves. This study found that there were threshold concentrations between O₃ exposure and preterm birth risk during different gestational periods, and the threshold concentrations in the first, second, third, and whole trimesters were 112.32, 99.83, 111.74, and 112.46 μg·m⁻³, respectively. During the second, third, and whole trimesters of pregnancy, after adjusting for maternal age, baby sex, pre-pregnancy body mass index, mode of delivery, baby birth weight, gestational diabetes, and gestational hypertension, the odds ratios (OR) of preterm birth were 1.02 (95%CI: 1.01, 1.04), 1.02 (95%CI: 1.00, 1.03), and 1.17 (95%CI: 1.13, 1.21) for each 10 μg·m⁻³ increase in O₃ concentration above the O₃ threshold. No significant association was found between O₃ exposure and the risk of preterm birth during the first trimester. Conclusion There is a nonlinear association between the risk of preterm birth and O₃ exposure during pregnancy, and higher concentrations of O₃ exposure during pregnancy are associated with the risk of preterm birth. Above the O₃ threshold concentration during pregnancy, especially during the second, third, and whole trimesters, the risk of preterm birth elevates with the increase of O₃ exposure concentrations.

ObjectiveTo establish a method for the identification of Haliotidis Concha and its counterfeits， and to improve its quality evaluation method. MethodsA total of 17 batches of Haliotis discus hannai， 4 batches of H. ruber， 3 batches of H. laevigata， 3 batches of H. ovina， 3 batches of H. diversicolor， 3 batches of H. asinina， 3 batches of H. iris were collected. Ultra-high performance liquid chromatography-quadrupole/electrostatic field orbitrap high-resolution mass spectrometry（UPLC-Q-Exactive-Orbitrap-MS/MS） was used to analyze the hydrolysates of different original Haliotidis Concha and its counterfeits， and the potential characteristic ions of each species were screened by Venn diagram. UPLC-triple quadrupole tandem mass spectrometry（UPLC-QqQ-MS/MS） was used to validate the characteristic ions， and the specific detection method of the characteristic ions was established. ResultsA total of 1 182， 167， 47， 89， 104， 203， 424 potential characteristic ions were screened from H. discus hannai， H. ruber， H. laevigata， H. ovina， H. diversicolor， H. asinina and H. iris， respectively. And 9 characteristic ions were selected. The precision， stability and repeatability of the 9 characteristic ions in the established identification method met the requirements. Different original Haliotidis Concha and its counterfeits could detect their own characteristic ions， including m/z 631.83-886.48（double charge） and m/z 631.83-443.74（double charge） of H. discus hannai， m/z 699.28-232.11（double charge） and m/z 699.28-544.27（double charge） of H. ruber， m/z 535.76-752.37（double charge） and m/z 535.76-548.28（double charge） of H. laevigata， m/z 708.35-442.28（double charge） and m/z 708.35-215.14（double charge） of H. ovina， m/z 561.33-614.86（triple charge）， m/z 561.33-468.28（triple charge）， m/z 608.29-618.32（double charge） and m/z 608.29-390.21（double charge） of H. diversicolor， m/z 769.85-274.10（double charge）， m/z 769.85-532.75（double charge）， m/z 827.43-646.36（single charge）， m/z 827.43-257.12（single charge） of H. asinina， and m/z 468.24-576.29（double charge） and m/z 468.24-505.26（double charge） of H. iris. ConclusionIn this study， a total of 9 characteristic ions are screened from 6 kinds of original Haliotidis Concha and its counterfeits， and a specific identification method is established， which is helpful to solve the limitations of the existing quality evaluation methods of Haliotidis Concha， and provide a basis for the production， circulation and medication quality.

ObjectiveTo establish a method for the identification of Haliotidis Concha and its counterfeits， and to improve its quality evaluation method. MethodsA total of 17 batches of Haliotis discus hannai， 4 batches of H. ruber， 3 batches of H. laevigata， 3 batches of H. ovina， 3 batches of H. diversicolor， 3 batches of H. asinina， 3 batches of H. iris were collected. Ultra-high performance liquid chromatography-quadrupole/electrostatic field orbitrap high-resolution mass spectrometry（UPLC-Q-Exactive-Orbitrap-MS/MS） was used to analyze the hydrolysates of different original Haliotidis Concha and its counterfeits， and the potential characteristic ions of each species were screened by Venn diagram. UPLC-triple quadrupole tandem mass spectrometry（UPLC-QqQ-MS/MS） was used to validate the characteristic ions， and the specific detection method of the characteristic ions was established. ResultsA total of 1 182， 167， 47， 89， 104， 203， 424 potential characteristic ions were screened from H. discus hannai， H. ruber， H. laevigata， H. ovina， H. diversicolor， H. asinina and H. iris， respectively. And 9 characteristic ions were selected. The precision， stability and repeatability of the 9 characteristic ions in the established identification method met the requirements. Different original Haliotidis Concha and its counterfeits could detect their own characteristic ions， including m/z 631.83-886.48（double charge） and m/z 631.83-443.74（double charge） of H. discus hannai， m/z 699.28-232.11（double charge） and m/z 699.28-544.27（double charge） of H. ruber， m/z 535.76-752.37（double charge） and m/z 535.76-548.28（double charge） of H. laevigata， m/z 708.35-442.28（double charge） and m/z 708.35-215.14（double charge） of H. ovina， m/z 561.33-614.86（triple charge）， m/z 561.33-468.28（triple charge）， m/z 608.29-618.32（double charge） and m/z 608.29-390.21（double charge） of H. diversicolor， m/z 769.85-274.10（double charge）， m/z 769.85-532.75（double charge）， m/z 827.43-646.36（single charge）， m/z 827.43-257.12（single charge） of H. asinina， and m/z 468.24-576.29（double charge） and m/z 468.24-505.26（double charge） of H. iris. ConclusionIn this study， a total of 9 characteristic ions are screened from 6 kinds of original Haliotidis Concha and its counterfeits， and a specific identification method is established， which is helpful to solve the limitations of the existing quality evaluation methods of Haliotidis Concha， and provide a basis for the production， circulation and medication quality.

Objective: To explore the effect of YTH domain family protein 1(YTHDF1) on the activation, proliferation and migration of hepatic stellate cells(HSCs) by regulating mitochondrial fission mediated by mitochondrial fission protein 1(Fis1). Methods: The mouse hepatic stellate cell line JS-1 was treated with 5 ng/ml TGF-β1 for 24 h to induce its activation and proliferation, andYTHDF1-siRNA was used to construct aYTHDF1silencing model.The experiment was divided into Control group, TGF-β1 group, TGF-β1+si-NC group and TGF-β1+si-YTHDF1 group.Expression changes ofYTHDF1,Fis1and key indicators of fibrosis, type Ⅰ collagen(CollagenⅠ) and α-smooth muscle actin(α-SMA) were detected through reverse transcription quantitative polymerase chain reaction(RT-qPCR) and Western blot; CCK-8 was used to detect cell proliferation ability; Transwell migration assay and cell scratch assay were used to detect cell migration ability; immunofluorescence staining experiment was used to detect the effect ofYTHDF1onFis1-mediated mitochondrial fission; finally, JC-1 staining was used to experimentally detect the effect ofYTHDF1on mitochondrial membrane potential. Results: Compared with the Control group, RT-qPCR and Western blot experimental results showed that the expression ofYTHDF1andFis1increased in the TGF-β1 group(P<0.05,P<0.01;P<0.000 1), as well as the fibrosis markersCollagenⅠand the expression level of α-SMA increased(P<0.01;P<0.001,P<0.000 1); while adding CCK-8, the experimental results showed that the proliferation ability of HSCs in the TGF-β1 group was enhanced(P<0.000 1); Transwell experimental results showed that the migration ability of HSCs in the TGF-β1 group was enhanced(P<0.01); the cell scratch experiment results showed that the migration ability of HSCs in the TGF-β1 group was enhanced(P<0.000 1); the immunofluorescence experiment results showed that the TGF-β1 group Mito-Tracker Red staining andFis1co-localization signal increased(P<0.05); JC-1 staining experiment results showed that the mitochondrial membrane potential increased in the TGF-β1 group(P<0.01). Compared with the TGF-β1+si-NC group, RT-qPCR and Western blot experimental results showed that the expression ofYTHDF1andFis1in the TGF-β1+si-YTHDF1 group was reduced(P<0.01;P<0.001), and fibrosis markers the levels ofCollagenⅠandα-SMAwere reduced(P<0.01;P<0.001,P<0.01).CCK-8 experimental results showed that the proliferation ability of HSCs in the TGF-β1+si-YTHDF1 group was weakened(P<0.000 1); Transwell experiment results showed that the migration ability of HSCs in the TGF-β1+si-YTHDF1 group was weakened(P<0.001); cell scratch experiment results showed that the migration ability of HSCs in the TGF-β1+si-YTHDF1 group was weakened(P<0.000 1); immunofluorescence experiment results showed that the Mito-Tracker Red staining andFis1co-localization signal decreased in the TGF-β1+si-YTHDF1 group(P<0.01); JC-1 staining experiment results showed that mitochondrial membrane potential decreased in the TGF-β1+si-YTHDF1 group(P<0.05). Conclusion YTHDF1promotes the activation, proliferation and migration capabilities of HSCs by positively regulatingFis1-mediated mitochondrial fission. This suggests thatYTHDF1may be a key gene involved in regulating the activation, proliferation and migration of HSCs.

Objective To explore clinical effect of allogeneic peroneal bone marrow support combined with plate internal fixation in treating Neer type Ⅳ proximal humeral fractures.Methods From December 2017 to December 2020,12 patients with Neer type Ⅳ proximal humeral fractures were treated with allogeneic peroneal bone marrow support combined with plate internal fixation,including 7 males and 5 females,aged from 56 to 78 years old;the time from injury to operation ranged from 1 to7 days.Operative time,fracture healing time and complications during follow-up were observed,and clinical efficacy was e-valuated by Constant-Murley score at the latest follow-up.Results All patients were obtained follow up for 20 to 29 months.All patients got bone healing and incisicons were healed at stage Ⅰ,operative time ranged from 95 to 138 min,blood loss ranged from 210 to 275 ml,fracture healing time ranged from 14 to 18 weeks.Two patients occurred postoperative shoulder stiffness and recovered after 2 weeks of passive exercise.There were no complications such as infection,poor wound healing,and fail-ure(fracture and loosening)of internal fixators occurred.Constant-Murley shoulder function score ranged from 69 to 89 at the latest follow up,2 patients got excellent results,9 good and 1 fair.Conclusion The application of allogeneic fibular bone mar-row placement could provide effective support for medial humerus,which is conducive to assisting reduction of fracture end,re-ducing occurrence of internal fixation failure caused by collapse of humerus head and screw perforation,and significantly im-proving function of shoulder joint.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

Objective To investigate the distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.

Objective To examine the changing antimicrobial resistance profile of Enterobacter spp.isolates in 53 hospitals across China from 2015 t0 2021.Methods The clinical isolates of Enterobacter spp.were collected from 53 hospitals across China during 2015-2021 and tested for antimicrobial susceptibility using Kirby-Bauer method or automated testing systems according to the CHINET unified protocol.The results were interpreted according to the breakpoints issued by the Clinical & Laboratory Standards Institute(CLSI)in 2021(M100 31st edition)and analyzed with WHONET 5.6 software.Results A total of 37 966 Enterobacter strains were isolated from 2015 to 2021.The proportion of Enterobacter isolates among all clinical isolates showed a fluctuating trend over the 7-year period,overall 2.5％in all clinical isolates amd 5.7％in Enterobacterale strains.The most frequently isolated Enterobacter species was Enterobacter cloacae,accounting for 93.7％(35 571/37 966).The strains were mainly isolated from respiratory specimens(44.4±4.6)％,followed by secretions/pus(16.4±2.3)％and urine(16.0±0.9)％.The strains from respiratory samples decreased slightly,while those from sterile body fluids increased over the 7-year period.The Enterobacter strains were mainly isolated from inpatients(92.9％),and only(7.1±0.8)％of the strains were isolated from outpatients and emergency patients.The patients in surgical wards contributed the highest number of isolates(24.4±2.9)％compared to the inpatients in any other departement.Overall,≤ 7.9％of the E.cloacae strains were resistant to amikacin,tigecycline,polymyxin B,imipenem or meropenem,while ≤5.6％of the Enterobacter asburiae strains were resistant to these antimicrobial agents.E.asburiae showed higher resistance rate to polymyxin B than E.cloacae(19.7％vs 3.9％).Overall,≤8.1％of the Enterobacter gergoviae strains were resistant to tigecycline,amikacin,meropenem,or imipenem,while 10.5％of these strains were resistant to polycolistin B.The overall prevalence of carbapenem-resistant Enterobacter was 10.0％over the 7-year period,but showing an upward trend.The resistance profiles of Enterobacter isolates varied with the department from which they were isolated and whether the patient is an adult or a child.The prevalence of carbapenem-resistant E.cloacae was the highest in the E.cloacae isolates from ICU patients.Conclusions The results of the CHINET Antimicrobial Resistance Surveillance Program indicate that the proportion of Enterobacter strains in all clinical isolates fluctuates slightly over the 7-year period from 2015 to 2021.The Enterobacter strains showed increasing resistance to multiple antimicrobial drugs,especially carbapenems over the 7-year period.

Objective To understand the changing distribution and antimicrobial resistance profiles of Proteus,Morganella and Providencia in hospitals across China from January 1,2015 to December 31,2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods Antimicrobial susceptibility testing was carried out following the unified CHINET protocol.The results were interpreted in accordance with the breakpoints in the 2021 Clinical & Laboratory Standards Institute(CLSI)M100(31 st Edition).Results A total of 32 433 Enterobacterales strains were isolated during the 7-year period,including 24 160 strains of Proteus,6 704 strains of Morganella,and 1 569 strains of Providencia.The overall number of these Enterobacterales isolates increased significantly over the 7-year period.The top 3 specimen source of these strains were urine,lower respiratory tract specimens,and wound secretions.Proteus,Morganella,and Providencia isolates showed lower resistance rates to amikacin,meropenem,cefoxitin,cefepime,cefoperazone-sulbactam,and piperacillin-tazobactam.For most of the antibiotics tested,less than 10％of the Proteus and Morganella strains were resistant,while less than 20％of the Providencia strains were resistant.The prevalence of carbapenem-resistant Enterobacterales(CRE)was 1.4％in Proteus isolates,1.9％in Morganella isolates,and 15.6％in Providencia isolates.Conclusions The overall number of clinical isolates of Proteus,Morganella and Providencia increased significantly in the 7-year period from 2015 to 2021.The prevalence of CRE strains also increased.More attention should be paid to antimicrobial resistance surveillance and rational antibiotic use so as to prevent the emergence and increase of antimicrobial resistance.