Human exhaled breath has great application prospects,e.g.,monitoring pharmacokinetics,disease diagnosis,due to its advantages such as non-invasive and high-frequency sampling.Breath samples can be collected from the oral and nasal cavity.However,the oral and nasal environment affect the chemical composition of breath sample.Therefore,the investigation on the chemical composition of mouth-exhaled breath and nose-exhaled breath is crucial for selection of appropriate sampling strategy for individual studies.In this work,secondary electrospray ionization-high resolution mass spectrometry(SESI-HRMS)was applied to analysis of respiratory metabolomics in real time.A quantitative analysis approach was established for 9 kinds of volatile organic compounds(VOCs)e.g.2-butanone,2-pentanone,ethyl acetate,methyl methacrylate,toluene,styrene,mesitylene,isoprene and limonene.The limit of detection was 2.3?240.8 ng/m3.The intra-day(n=6)and inter-day(n=18)relative standard deviations were 0.6%?4.6%and 4.3%?12.2%,respectively.Nine healthy subjects were recruited to investigate the chemical composition of mouth-exhaled and nose-exhaled breath.The results showed the good performance in quantitative analysis of 9 VOCs in breath air.It was found that the number of unique component(m/z)detected in mouth-exhaled breath(167)was 2.2 times greater than that detected in nose-exhaled breath(76),which might result from the complex environment in oral cavity.The signal intensity of commun component(163)was significantly different between mouth-exhaled breath and nose-exhaled breath.Additionally,the elemental composition analysis showed that the proportion of polar compounds detected in nose-exhaled breath was higher than that in mouth-exhaled breath.This study demonstrated that there was significant differences in the chemical composition between mouth-exhaled and nose-exhaled breath,which provided a theoretical basis for selection of exhalation mode.

BACKGROUND:Trauma-induced coagulopathy(TIC)due to serious injuries significantly leads to increased mortality and morbidity among elderly patients.However,the risk factors of TIC are not well elucidated.This study aimed to explore the risk factors of TIC in elderly patients who have major trauma. METHODS:In this retrospective study,the risk factors for TIC in elderly trauma patients at a single trauma center were investigated between January 2015 and September 2020.The demographic information including gender,age,trauma parts,injury severity,use of blood products,use of vasopressors,need of emergency surgery,duration of mechanical ventilation,length of stay in the intensive care unit(ICU)and hospital,and clinical outcomes were extracted from electric medical records.Multivariate logistic regression analysis was performed to differentiate risk factors,and the performance of the model was evaluated using receiver operating characteristics(ROC)curves. RESULTS:Among the 371 elderly trauma patients,248(66.8%)were male,with the age of 72.5±6.8 years,median injury severity score(ISS)of 24(IQR:17-29),and Glasgow coma score(GCS)of 14(IQR:7-15).Of these patients,129(34.8%)were diagnosed with TIC,whereas 242(65.2%)were diagnosed with non-TIC.The severity scores such as ISS(25[20-34]vs.21[16-29],P<0.001)and shock index(SI),(0.90±0.66 vs.0.58±0.18,P<0.001)was significantly higher in the TIC group than in the non-TIC group.Serum calcium levels(1.97±0.19 mmol/L vs.2.15±0.16 mmol/L,P<0.001),fibrinogen levels(1.7±0.8 g/L vs.2.8±0.9 g/L,P<0.001),and base excess(BE,-4.9±4.6 mmol/L vs.-1.2±3.1 mmol/L,P<0.001)were significantly lower in the TIC group than in the non-TIC group.Multivariate logistic regression analysis revealed that ISS>16(OR:3.404,95%CI:1.471-7.880;P=0.004),SI>1(OR:5.641,95%CI:1.700-18.719;P=0.005),low BE(OR:0.868,95%CI:0.760-0.991;P=0.037),hypocalcemia(OR:0.060,95%CI:0.009-0.392;P=0.003),and hypofibrinogenemia(OR:0.266,95%CI:0.168-0.419;P<0.001)were independent risk factors for TIC in elderly trauma patients.The AUC of the prediction model included all these risk factors was 0.887(95%CI:0.851-0.923)with a sensitivity and specificity of 83.6%and 82.6%,respectively. CONCLUSION:Higher ISS(more than 16),higher SI(more than 1),acidosis,hypocalcemia,and hypofibrinogenemia emerged as independent risk factors for TIC in elderly trauma patients.

BACKGROUND:Trauma-induced coagulopathy(TIC)due to serious injuries significantly leads to increased mortality and morbidity among elderly patients.However,the risk factors of TIC are not well elucidated.This study aimed to explore the risk factors of TIC in elderly patients who have major trauma. METHODS:In this retrospective study,the risk factors for TIC in elderly trauma patients at a single trauma center were investigated between January 2015 and September 2020.The demographic information including gender,age,trauma parts,injury severity,use of blood products,use of vasopressors,need of emergency surgery,duration of mechanical ventilation,length of stay in the intensive care unit(ICU)and hospital,and clinical outcomes were extracted from electric medical records.Multivariate logistic regression analysis was performed to differentiate risk factors,and the performance of the model was evaluated using receiver operating characteristics(ROC)curves. RESULTS:Among the 371 elderly trauma patients,248(66.8%)were male,with the age of 72.5±6.8 years,median injury severity score(ISS)of 24(IQR:17-29),and Glasgow coma score(GCS)of 14(IQR:7-15).Of these patients,129(34.8%)were diagnosed with TIC,whereas 242(65.2%)were diagnosed with non-TIC.The severity scores such as ISS(25[20-34]vs.21[16-29],P<0.001)and shock index(SI),(0.90±0.66 vs.0.58±0.18,P<0.001)was significantly higher in the TIC group than in the non-TIC group.Serum calcium levels(1.97±0.19 mmol/L vs.2.15±0.16 mmol/L,P<0.001),fibrinogen levels(1.7±0.8 g/L vs.2.8±0.9 g/L,P<0.001),and base excess(BE,-4.9±4.6 mmol/L vs.-1.2±3.1 mmol/L,P<0.001)were significantly lower in the TIC group than in the non-TIC group.Multivariate logistic regression analysis revealed that ISS>16(OR:3.404,95%CI:1.471-7.880;P=0.004),SI>1(OR:5.641,95%CI:1.700-18.719;P=0.005),low BE(OR:0.868,95%CI:0.760-0.991;P=0.037),hypocalcemia(OR:0.060,95%CI:0.009-0.392;P=0.003),and hypofibrinogenemia(OR:0.266,95%CI:0.168-0.419;P<0.001)were independent risk factors for TIC in elderly trauma patients.The AUC of the prediction model included all these risk factors was 0.887(95%CI:0.851-0.923)with a sensitivity and specificity of 83.6%and 82.6%,respectively. CONCLUSION:Higher ISS(more than 16),higher SI(more than 1),acidosis,hypocalcemia,and hypofibrinogenemia emerged as independent risk factors for TIC in elderly trauma patients.

BACKGROUND:Trauma-induced coagulopathy(TIC)due to serious injuries significantly leads to increased mortality and morbidity among elderly patients.However,the risk factors of TIC are not well elucidated.This study aimed to explore the risk factors of TIC in elderly patients who have major trauma. METHODS:In this retrospective study,the risk factors for TIC in elderly trauma patients at a single trauma center were investigated between January 2015 and September 2020.The demographic information including gender,age,trauma parts,injury severity,use of blood products,use of vasopressors,need of emergency surgery,duration of mechanical ventilation,length of stay in the intensive care unit(ICU)and hospital,and clinical outcomes were extracted from electric medical records.Multivariate logistic regression analysis was performed to differentiate risk factors,and the performance of the model was evaluated using receiver operating characteristics(ROC)curves. RESULTS:Among the 371 elderly trauma patients,248(66.8%)were male,with the age of 72.5±6.8 years,median injury severity score(ISS)of 24(IQR:17-29),and Glasgow coma score(GCS)of 14(IQR:7-15).Of these patients,129(34.8%)were diagnosed with TIC,whereas 242(65.2%)were diagnosed with non-TIC.The severity scores such as ISS(25[20-34]vs.21[16-29],P<0.001)and shock index(SI),(0.90±0.66 vs.0.58±0.18,P<0.001)was significantly higher in the TIC group than in the non-TIC group.Serum calcium levels(1.97±0.19 mmol/L vs.2.15±0.16 mmol/L,P<0.001),fibrinogen levels(1.7±0.8 g/L vs.2.8±0.9 g/L,P<0.001),and base excess(BE,-4.9±4.6 mmol/L vs.-1.2±3.1 mmol/L,P<0.001)were significantly lower in the TIC group than in the non-TIC group.Multivariate logistic regression analysis revealed that ISS>16(OR:3.404,95%CI:1.471-7.880;P=0.004),SI>1(OR:5.641,95%CI:1.700-18.719;P=0.005),low BE(OR:0.868,95%CI:0.760-0.991;P=0.037),hypocalcemia(OR:0.060,95%CI:0.009-0.392;P=0.003),and hypofibrinogenemia(OR:0.266,95%CI:0.168-0.419;P<0.001)were independent risk factors for TIC in elderly trauma patients.The AUC of the prediction model included all these risk factors was 0.887(95%CI:0.851-0.923)with a sensitivity and specificity of 83.6%and 82.6%,respectively. CONCLUSION:Higher ISS(more than 16),higher SI(more than 1),acidosis,hypocalcemia,and hypofibrinogenemia emerged as independent risk factors for TIC in elderly trauma patients.

Objective To compare the effectiveness of TiRobot assisted F screw technique and inverted triangle parallel nail internal fixation in the treatment of unstable femoral neck fractures.Methods A retrospective analysis was conducted on 72 patients with unstable femoral neck fractures who were treated with percutaneous cannulated screw fixation assisted with TiRobot Orthopaedic robot from December 2019 to April 2021.Among them,37 patients were treated with F screw internal fixa-tion,including 16 males and 21 females,aged47 to 64years old with an average of(53.87±5.28)years old;According to Pauwels classification,there were 1 case of type Ⅰ,19 cases of type Ⅱ,17 cases of type Ⅲ;8 cases of combined medical diseases;17 cases of falling,8 cases of traffic accident and 12 cases of falling from height;The time from injury to operation was 29 to 49 hours with average of(35.00±7.34)hours.Another 35 cases used internal fixation with an inverted triangle parallel nail,including 13 males and 22 females with an average age of 46 to 63 years old(52.36±5.05)years old;According to the Pauwels injury classifi-cation:there were 2 cases of type Ⅰ,21 cases of type Ⅱ,12 cases of type Ⅲ;6 cases of medical diseases,15 cases of falling in-jury,9 cases of traffic accident,11 cases of falling injury;The time from injury to operation was 30 to 45 hours with an average of(33.00±6.83)h.The intraoperative blood loss,operation time,intraoperative fluoroscopy times,follow-up time,fracture healing time,postoperative complications were observed and compared between the two groups.The hip joint function was e-valuated by Harris score at 6 months and 12 months after operation.Results There was no significant difference in operation time,intraoperative blood loss,intraoperative fluoroscopy times and other intraoperative data between two groups(P＞0.05).Both groups were followed up regularly,and the follow-up time was 12 to 16 months.The fracture healing time and Harris score of the F screw internal fixation group were better than those of the inverted triangle parallel nail internal fixation group(P＜0.05).There was 1 case of femoral neck shortening in the F screw internal fixation group,1 case of nonunion,1 case of nail withdrawal,and 1 case of lower extremity deep vein thrombosis in the inverted triangle internal fixation group.The incidence of complications in the F screw internal fixation group was lower than that in the inverted triangle parallel nail internal fixation group(P＜0.05).Conclusion Percutaneous cannulated F screw technique using Tirobot navigation positioning system is a safe and effective treatment for patients with unstable femoral neck fractures.It can significantly shorten the fracture healing time,reduce the incidence of postoperative complications,significantly improve hip joint function,and improve the quality of life.

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.

Objective To understand the changing distribution and antimicrobial resistance profiles of Klebsiella strains in 52 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Antimicrobial susceptibility testing was carried out according to the unified CHINET protocol.The susceptibility results were interpreted according to the breakpoints in the Clinical & Laboratory Standards Institute(CLSI)M100 document.Results A total of 241,549 nonduplicate Klebsiella strains were isolated from 2015 to 2021,including Klebsiella pneumoniae(88.0％),Klebsiella aerogenes(5.8％),Klebsiella oxytoca(5.7％),and other Klebsiella species(0.6％).Klebsiella strains were mainly isolated from respiratory tract(48.49±5.32)％.Internal medicine(22.79±3.28)％,surgery(17.98±3.10)％,and ICU(14.03±1.39)％were the top 3 departments where Klebsiella strains were most frequently isolated.K.pneumoniae isolates showed higher resistance rate to most antimicrobial agents compared to other Klebsiella species.Klebsiella isolates maintained low resistance rates to tigecycline and polymyxin B.ESBLs-producing K.pneumoniae and K.oxytoca strains showed higher resistance rates to all the antimicrobial agents tested compared to the corresponding ESBLs-nonproducing strains.The K.pneumoniae and carbapenem-resistant K.pneumoniae(CRKP)strains isolated from ICU patients demonstrated higher resistance rates to majority of the antimicrobial agents tested than the strains isolated from non-ICU patients.The CRKP strains isolated from adult patients had higher resistance rates to most of the antimicrobial agents tested than the corresponding CRKP strains isolated from paediatric patients.Conclusions The prevalence of carbapenem-resistant strains in Klebsiella isolates increased greatly from 2015 to 2021.However,the Klebsiella isolates remained highly susceptible to tigecycline and polymyxin B.Antimicrobial resistance surveillance should still be strengthened for Klebsiella strains.