Biological evidence is relatively common evidence in criminal cases,and it has strong pro-bative power because it carries DNA information for individual identification.At the scene of fire-related cases,the complex thermal environment,the escape of trapped people,the firefighting and res-cue operations,and the deliberate destruction of criminal suspects will all affect the biological evi-dence in the fire scene.Scholars at home and abroad have explored and studied the effectiveness of biological evidence identification in fire scenes,and found that the blood stains,semen stains,bones,etc.are the main biological evidence which can be easily recovered with DNA in fire scenes.In order to analyze the research status and development trend of biological evidence in fire scenes,this paper systematically sorts out the relevant research,mainly including the soot removal technology,appearance method of typical biological evidence,and possibility of identifying other biological evidence.This pa-per also prospects the next step of research direction,in order to provide reference for the identifica-tion of biological evidence and improve the value of biological evidence in fire scenes.

Objective:To observe the changes in the nutritional status of pediatric patients after allogeneic hematopoietic stem cell transplantation(allo-HSCT)for one year,and to analyze the risk factors.Methods:We collected data from 88 pediatric patients who underwent allo-HSCT at the Department of Hematology and Oncology in Children's Hospital of Nanjing Medical University between May 2018 and November 2022.All pediatric patients underwent nutritional status analysis before transplantation,at enrollment,3 months,6 months and 1 year after allo-HSCT.Linear regression model was used to analyze the risk factors for growth rate.Results:The body mass index Z score(BMI-Z)before allo-HSCT was(0.096±1.349),and decreased to(-0.258±1.438)、(-0.715±1.432)、(-0.584±1.444)at enrollment,3 months,6 months after allo-HSCT,and(-0.130±1.317)at 1 year after allo-HSCT(P<0.001).There was no significant change in BMI-Z between pre-transplantation and 1 year after transplantation(P=1.000).Height for age Z score(HAZ)before transplantation was(0.137±1.305)and decreased to(-0.083±1.267)、(-0.221±1.299)、(-0.269±1.282)in 3 months,6 months and 1 year after allo-HSCT(P<0.001).Multivariate linear regression showed that age≥10 years old(P=0.015)and chronic graft-versus-host disease(cGVHD)(P=0.005)were independent risk factors for change in HAZ.Conclusion:The BMI-Z of pediatric patients treated with allo-HSCT returned to the pre-transplantation level after one year,while HAZ continued to decrease.Allo-HSCT may cause impaired growth rate in pediatric patients.Attention should be paid to HAZ changes in pediatric patients before and after allo-HSCT,especially in pediatric patients≥10 years old of age and those with cGVHD.Effective nutritional intervention should be provided in time.

Objective To analyze the stress changes of thoracic vertebra(T)11-sacrum(S)titanium rods in patients with ankylosing spondylitis after vertebral column decancellation(VCD)osteotomy,and provide reference for the selection and improvement of titanium rods before surgery.Methods The original data of the continuous scanning tomographic images of patients with ankylosing spondylitis after VCD osteotomy were imported into Mimics 21.0 in DICOM format,and T11-S vertebrae,screws and titanium rods were respectively reconstructed.They were imported into 3-Matic to establish a preliminary geometric modeling,and then processed with noise removal,paving,smoothing,etc.The improved model was imported into Hypermesh 10 software for grid division,and the material was imported into ANSYS 19.2 to display the finite element model after attribute assignment,Set the boundary and load conditions,and measure the stress value at the connection between the screw and the titanium rod.Results Under neutral position,forward bending,lateral bending,and axial rotation conditions,the titanium rod had the highest stress at the upper vertebrae(T11)and the lowest stress at the top vertebrae(L3);Under the backward extension condition,the titanium rod has the highest stress at the lower end vertebra(L5).Conclusion In the upper and lower vertebrae,it is possible to consider increasing the diameter of the titanium rod,enhancing its hardness,or changing it to a double rod.

Objective:To explore the changes of serum levels of angiopoictin-1(Angpt1)and endothelin-1(ET-1)in patients with newly-onset atrial fibrillation(AF)after heart valve replacement,and analyze their clinical sig-nificance.Methods:A total of 130 patients who underwent heart valve replacement in our hospital from January 2020 to March 2022 were divided into no AF group(n=72)and AF group(n=58)according to presence of AF within 7d after surgery.Serum levels of Angpt1 and ET-1 were detected by ELISA in two groups;the correlation between serum Angptl and ET-1 was analyzed by Pearson method in AF patients;ROC curve analysis was used to analyze the predictive value of serum Angpt1 and ET-1 levels for postoperative AF in these patients;Logistic re-gression was used to analyze the influencing factors of postoperative AF in these patients.Results:The left atrial diameter(LAD),proportion of NYHA class Ⅳ and cardiopulmonary bypass time in AF group were significantly higher than those of no AF group(P＜0.05 or＜0.01).One day after surgery,compared with no AF group,serum Angpt1 level significantly reduced and ET-1 level significantly increased in AF group(P＜0.001 both).Pearson correlation analysis indicated that serum Angpt1 level was significant inversely correlated with ET-1 level in AF pa-tients(r=-0.366,P=0.005).ROC analysis indicated that area under the curve(AUC)of combined detection of serum Angpt1 and ET-1 in predicting AF after heart valve replacement was significantly higher than those of each single detection(Z=2.761,1.998,P=0.006,0.046).Multivariate Logistic regression analysis indicated that LAD,NYHA class Ⅳ,cardiopulmonary bypass time and postoperative ET-1 were independent risk factors for postoperative AF in these patients(OR=1.471～1.739,P＜0.05 or＜0.01),while postoperative Angpt1 was its independent protective factor(OR=0.634,P=0.004).Conclusion:Serum Angpt1 level significantly reduces and ET-1 level significantly increases in patients with newly-onset AF after heart valve replacement.Combined detec-tion of Angpt1 and ET-1 levels possesses high predictive value for postoperative AF.

Objective To investigate the incidence and risk factors for acute kidney injury(AKI)in children with primary nephrotic syndrome(PNS),as well as the role of neutrophil gelatinase-associated lipocalin(NGAL)and kidney injury molecule-1(KIM-1)in the early identification of AKI in these children.Methods A prospective collection of clinical data from children hospitalized with PNS at the Children's Hospital of the Capital Institute of Pediatrics from January 2021 to October 2022 was conducted.The children were divided into two groups based on the presence of AKI:the AKI group(47 cases)and the non-AKI group(169 cases).The risk factors for AKI in children with PNS were identified by multivariate logistic regression analysis.Urinary KIM-1 and NGAL levels were compared between the AKI and non-AKI groups,as well as among the different stages of AKI.Results The incidence of AKI in children with PNS was 21.8%.Multivariate logistic regression analysis revealed that steroid-resistant nephrotic syndrome,gastrointestinal infections,and heavy proteinuria were independent risk factors for AKI in these children with PNS(P<0.05).Urinary KIM-1 and NGAL levels were higher in the AKI group compared to the non-AKI group(P<0.05),and the urinary NGAL and KIM-1 levels in the AKI stage 2 and stage 3 subgroups were higher than those in the AKI stage 1 subgroup(P<0.017).Conclusions KIM-1 and NGAL can serve as biomarkers for the early diagnosis of AKI in children with PNS.Identifying high-risk populations for AKI in children with PNS and strengthening the monitoring of related risk factors is of significant importance.

Objective To investigate the factors influencing prognosis in patients with acute myocardial infarction complicated with cardiogenic shock undergoing primary percutaneous coronary intervention(PPCI).Methods Patients with acute myocardial infarction complicated with cardiogenic shock who underwent PPCI at our hospital between January 2015 and December 2019 were enrolled.Clinical baseline characteristics,coronary angiography and PCI-related parameters,and mechanical support information were collected.The patients were followed up for one year and divided into survival and death groups based on their survival status within one year.Differences in various factors between the two groups were compared.Results A total of 40 patients were enrolled,including 26 in the survival group and 14 in the death group.There were no differences in baseline data,diagnosis,risk factors,and comorbidities between the two groups.The survival group had a lower heart rate and higher blood pressure trend at admission compared to the death group.Myocardial enzymes were significantly lower in the survival group compared to the death group(median CK peak:496.00(198.25,2 830.00)U/L vs.3 040.00(405.75,5 626.53)U/L,P=0.003;median CK-MB peak:52.65(31.75,219.50)U/L vs.306.00(27.25,489.63)U/L,P=0.006).When comparing coronary angiography and PCI-related indicators between the two groups,the survival group had a higher rate of complete revascularization compared to the control group(53.85％vs.21.43％,P=0.048).The survival group had a higher proportion of extracorporeal membrane oxygenation(ECMO)combined with intra-aortic balloon pump(IABP)support compared to the control group[38.46％vs.7.14％,P=0.034].Conclusions Survival in patients with acute myocardial infarction complicated with cardiogenic shock undergoing PPCI is associated with lower level of myocardial enzymes,ECMO combined with IABP support and complete revascularization.

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.