Tetrodotoxin（TTX）is a potent neurotoxin known for its specific sodium channel blocking effects, widely used in biomedical research. While TTX has been identified in various marine organisms, its true origin remains unclear, and the specific biosynthetic pathways are yet to be elucidated. The reported sources of TTX and the progress in research on TTX biosynthesis were summarized, with a focus on potential microbial sources of TTX, which could provide scientific reference for the production and biosynthesis studies of TTX.

Objective: To analyze the mediating effect of self-efficacy on the relationship between social support and depression symptoms among elderly patients with type 2 diabetes mellitus (T2DM), so as to provide the evidence for improving mental health intervention strategies in this population. Methods: From June to July 2024, elderly patients aged ≥60 years with T2DM receiving basic public health management services were recruited from four community health service centers in Nanjing City using convenience sampling. Demographic and disease-related information were collected through questionnaire surveys. Depression symptoms, self-efficacy, and social support were assessed using the 9-item Patient Health Questionnaire, the Diabetes Self-Efficacy Scale, and the Social Support Rating Scale, respectively. A structural equation model was constructed using Mplus 8.3 to examine the mediating effect of self-efficacy on social support and depression symptoms. The significance of the mediating effect was tested using the Bootstrap method. Results: A total of 604 elderly patients with T2DM were surveyed. The median age was 72.00 (interquartile range, 9.00) years. There were 292 males (48.34%) and 312 females (51.66%). The median score of depression symptoms was 2.00 (interquartile range, 5.00) points. A total of 176 participants were identified as having depressive symptoms, with a detection rate of 29.10%. The median scores of self-efficacy and social support were 4.11 (interquartile range, 0.78) and 39.00 (interquartile range, 11.00) points, respectively. The mediation analysis showed that social support had a direct negative effect on depression symptoms among elderly patients with T2DM, with an effect value of -0.137 (95%CI: -0.226 to -0.043). Social support also indirectly affected depression symptoms through self-efficacy, with an effect value of -0.066 (95%CI: -0.099 to -0.037). The mediating effect accounted for 32.51% of the total effect. Conclusions Self-efficacy plays a partial mediating role between social support and depressive symptoms among elderly patients with T2DM. It is recommended to reduce the risk of depression symptoms in this population by improving social support levels and enhancing self-efficacy.

Objective: To analyze the healthcare-seeking delay and its influencing factors among pulmonary tuberculosis patients in Kaihua County, Zhejiang Province from 2016 to 2025, so as to provide a basis for identifying high-risk groups and optimizing comprehensive prevention and control measures for pulmonary tuberculosis. Methods: Data on pulmonary tuberculosis patients registered in Kaihua County from 2016 to 2025 were collected through the Tuberculosis Information Management System of Chinese Disease Prevention and Control Information System. The data included demographic information, disease and treatment information, and treatment policy phases. Factors affecting delay in healthcare-seeking among pulmonary tuberculosis patients were analyzed using a multivariable logistic regression model. Results: A total of 2 069 pulmonary tuberculosis patients were registered in Kaihua County from 2016 to 2025. There were 1 480 males (71.53%) and 589 females (28.47%). The median age was 64.00 (interquartile range, 20.00) years. There were 972 patients with healthcare-seeking delay, with a healthcare-seeking delay rate of 46.98%. The rates of healthcare-seeking delay were relatively high among tuberculosis patients aged >40-60 years, those seeking treatment due to symptoms, and those in the basic policy guarantee period, at 51.96%, 56.33%, and 49.25%, respectively. The rates of healthcare-seeking delay among tuberculosis patients from 2016 to 2025 were 55.81%, 44.25%, 50.00%, 47.27%, 42.98%, 51.64%, 50.79%, 44.38%, 43.13% and 38.67%, showing a downward trend (P<0.05). Multivariable logistic regression analysis show that, compared with pulmonary tuberculosis patients seeking medical consultation due to symptoms, those identified through physical examinations/active screening (OR=0.024, 95%CI: 0.011-0.047) and referrals/tracking/other sources (OR=0.781, 95%CI: 0.639-0.954) had a lower risk of healthcare-seeking delay. Conclusions From 2016 to 2025, the overall rate of healthcare-seeking delay among pulmonary tuberculosis patients in Kaihua County showed a downward trend from 2016 to 2025, but remained at a moderate level nationwide. The source of patients was an influencing factor for healthcare-seeking delay. Health examination/active screening and referral/tracing could effectively reduce the risk of healthcare-seeking delay.

Objective:To evaluate the long-term protective efficacy of the recombinant Chinese hamster ovary cell-derived hepatitis B vaccine（CHO-HepB）26 years post-vaccination in the rural China.Methods:Zhengding county，Hebei province was designated as a rural monitoring site for CHO-HepB efficacy. Study participants included individuals born between 1997 and 1999 who had completed the three-dose CHO-HepB primary series without booster doses. A cross-sectional survey was conducted in late 2024 using random sampling. Demographic and vaccination history data were collected via questionnaires，and hepatitis B virus（HBV）serological markers were detected using chemiluminescence. Historical surveillance data were integrated to infer infection statuses of HBsAg-positive individuals and evaluate longitudinal trends in anti-HBs seropositivity and antibody titers.Results:Among 178 participants（mean time since vaccination：26.2 years），the seroprevalence rates were 0.6% for HBsAg（95% CI：0.0%-1.6%），64.6% for anti-HBs（95% CI：57.6%-71.6%），and 1.1% for anti-HBc（95% CI：0.0%-2.7%）. Compared to the pre-vaccination baseline HBsAg positivity of 11.3% in children under 10 years of age，the estimated vaccine protection rate was 95%. Two notable cases were identified：one with concurrent HBsAg and anti-HBc positivity and one with anti-HBs and anti-HBc positivity，suggestive of transient HBV exposure（1999—2009）without chronicity. Natural immune boosting was inferred for the latter case based on anti-HBs titer dynamics. Longitudinal analysis of four prior cross-sectional surveys（2005，2009，2013，and 2017）revealed no significant upward trends in HBsAg and anti-HBc positivity（both P>0.05）over 26 years，while anti-HBs seropositivity declined significantly（ P<0.05）from 6 to 26 years post-vaccination. Conclusion:The CHO-HepB vaccine demonstrates sustained immunological persistence and robust long-term protection up to 26 years post-immunization. Continued emphasis on rigorous implementation of mother-to-child transmission prevention strategies is critical for future hepatitis B control.

OBJECTIVE To observe the effects of measures dominated by intensifying link quality on prevention and control of carbapenem-resistant Klebsiella pneumoniae(CRKP)among general ICU patients.METHODS The conventional intervention measures were taken from Jan.2016 to Oct.2020,which was assigned as the pre-inter-vention period;the intervention measures dominated by enhancement of link quality were taken for the general ICU patients(the study group)from Nov.2020 to Oct.2021,which was set as the intervention period,the inter-vention measures were taken for the neurosurgery ICU patients and the surgery ICU patients(the control group).A two-group interrupted time series of a quasi-experimental study was analyzed,and whether or not the intervention measures could reduce the incidence of CRKP hospital-associated infection among the general ICU patients was evaluated.RESULTS A total of 23 713 case-times of patients from three ICU wards were enrolled in the study.The incidence of CRKP hospital-associated infection among the general ICU patients was 4.49 cases per thousand patient-days during intervention period,3.71 cases per thousand patient-days during pre-intervention pe-riod,and there was no significant difference(u=-1.412,P=0.079);it was lower than 7.06 cases per thousand patient-days during nearly one year before the intervention period(from Nov.2019 to Oct.2020),and there was significant difference(u=3.128,P=0.002).The result of analysis of the interrupted time series showed that there was significant difference in the slope change between the study group and the control group after the inter-vention(P=0.035),indicating that the intervention measures could reduce the incidence of CRKP hospital-associ-ated infection in the study group,and there was significant difference in the changing trend between the study group and the control group.CONCLUSIONS The prevention and control measures for CRKP dominated by the link quality management can effectively reduce the incidence of CRKP hospital-associated infection among the gen-eral ICU patients.The prevention and control strategies may provide reference for prevention and control of CRKP in ICUs of other medical institutions.

Objective To investigate the cerebral protective role of Duzhi pills on ischemic stroke rats and its mechanisms.Methods The healthy male SD rats were assigned to 5 groups:sham group,model group,Duzhi pill low-dose group(1.0 g/kg a day),Duzhi pill high-dose group(2.0 g/kg a day),or argatroban group(positive control).The low-dose and high-dose groups of Duzhi pills were intragastrically administered once a day for 8 d,while the other groups were intragastrically administered with the same amount of normal saline.Except the sham group,the middle cerebral artery occlusion(MCAO)cerebral ischemia-reperfusion model was established by suture method at 0.5 h after intragastric administration on the 8th day in other groups,and the ischemia duration was 90 min.Argatroban group was given a single dose(3.0 mg/kg)of argatroban via caudal vein at the same time of reperfusion.After 24 h of cerebral ischemia,the area of cerebral infarction,degree of cerebral infarction and neurological function injury were evaluated by 2,3,5-triphenyltetrazolium chloride(TTC)staining,Nissl staining and neurobehavioral score,respectively.The levels of inflammatory factors(transforming growth factor-β1[TGF-β1]and interleukin-1β[IL-1β])in the brain after cerebral ischemia were detected by enzyme-linked immunosorbent assay(ELISA),and the coagulation indexes were detected by an automatic coagulation analyzer.The scavenging ability of Duzhi pills on free radicals was analyzed by 2,2-diphenyl-1-picrylhydrazyl(DPPH)scavenging experiment.Results High-dose Duzhi pills reduced the cerebral infarction area,decreased the deep Nissl staining score of neural cells,and improved the symptoms of neurobehavioral defects in MCAO rats(compared with the model group,all P＜0.01).The levels of IL-1β and TGF-β1 in the ischemic brain tissue of the model group were significantly increased(compared with the sham group,both P＜0.01),while the levels of IL-1β and TGF-β1 in the brain tissue of the rats treated with low-dose and high-dose Duzhi pills were significantly decreased(compared with the model group,all P＜0.01).The coagulation index fibrinogen level in the model group was significantly higher than that in the sham group(P＜0.01),and both low-dose and high-dose Duzhi pills could inhibit the production of fibrinogen(compared with the model group,both P＜0.01).DPPH scavenging test results showed that Duzhi pills could scavenge free radical,the half inhibitory concentration was(1.33±1.11)mg/mL,and the slope of the curve was 1.378±0.145.Conclusion Duzhi pills play a cerebral protective role in ischemic stroke rats.The mechanism may be related to the inhibition of fibrinogen production,the reduction of inflammatory factors(TGF-β1 and IL-1β),and the antioxidant effects.

Objective To screen for key genes and important pathways common for different etiologies of acute kidney injury(AKI)by pathway-associated deep neural network and multiple machine learning algorithms.Methods AKI microarray datasets GSE30718,GSE37838,GSE53769,GSE108113,GSE125779,GSE99325,and GSE174020 downloaded from the Gene Expression Omnibus(GEO)database were merged,including 60 kidney samples from AKI patients and 79 kidney samples from healthy controls.They were divided(8∶2)into training sets and test sets,and were used to train and evaluate pathway-associated deep neural network and 4 machine learning algorithms,including least absolute shrinkage and selection operator(LASSO),random forest(RF),support vector machine-recursive feature elimination(SVM-RFE),and extreme gradient boosting(XgBoost),to screen for common key genes and pathways of different etiologies of AKI.The downloaded datasets GSE99340 and GSE1563 were merged,including 43 kidney samples from AKI patients and 36 kidney samples from healthy controls,which were used as external validation sets for LASSO model and nomogram performance test based on the final screened genes.The pathway-associated deep neural network and machine learning algorithms were evaluated using receiver operating characteristic curves,precision,recall,accuracy,and F1-score.The immune cell infiltration characteristics were explored in AKI via cell-type identification by estimating relative subsets of RNA transcripts(CIBERSORT),and Pearson correlation coefficients were used to evaluate the correlation between the final screened common key genes and immune cell infiltration levels.Results The pathway-associated deep neural network trained by 5-fold cross validation produced an area under curve(AUC)of 0.914 5±0.007 0,a precision of 0.750 0±0.044 0,a recall of 0.923 1±0.048 0,an accuracy of 0.838 7±0.016 0,and an F1-score of 0.827 6±0.020 0 in the test set,yielding a robust and highly accurate classification performance for AKI,and identified key pathways and a subset of candidate genes.The 4 machine learning algorithms all achieved high discriminative performance for AKI in the test set with AUC≥0.860,precision≥0.750,recall≥0.800,and F1-score≥0.774,and screened 7 common key genes for AKI with different etiologies,including CD86,C-X-C motif chemokine ligand 10(CXCL10),dynamin 2(DNM2),proto-oncogene FOS,transcription factor 12(TCF12),VGF nerve growth factor inducible(VGF),and A kinase anchoring protein 5(AKAP5).Based on the final screened common key genes,the LASSO model had an AUC of 0.940 4 for the test set and an AUC of 0.944 4 for the external validation,and the model showed a very high discriminatory ability for the AKI,which demonstrated the overall regulatory performance of the genes.The nomogram constructed based on the screened 7 genes demonstrated the highest classification performance with an AUC of 0.928 9,validating the outstanding contribution and overall action performance of the screened individual genes.Immune cell infiltration analysis showed that there were significant differences in B cells na?ve,mast cells activated,monocytes,macrophages M1,B cells memory,and dendritic cells activated between AKI samples and healthy control samples(all P＜0.05).Macrophages M1 and monocytes were positively correlated with CD86 and CXCL10,mast cells activated were positively correlated with FOS,and B cells na?ve were negatively correlated with CD86 and CXCL10(all P＜0.01).Mast cells activated were positively correlated with VGF and negatively correlated with CD86 and TCF12,while memory B cells were positively correlated with CD86(all P＜0.05).Conclusion Strategy combining pathway-associated deep neural network and multiple machine learning classifiers can mine high-value key genes from high-dimensional,complex and heterogeneous transcriptomic data as potential targets for therapeutic interventions in AKI.

Objective To investigate the distribution and antibiotic resistance profiles of clinical isolates in Beijing Children's Hospital,Capital Medical University from 2016 to 2022.Methods All the strains isolated from inpatients in Beijing Children's Hospital during the period from 2016 to 2022 were analyzed.Antimicrobial susceptibility test was conducted by Kirby-Bauer method or automated system.Results were interpreted according to the breakpoints recommended in the CLSI Ml00 2022 edition.Results A total of 24 904 isolates were analyzed,including Gram-positive bacteria(49.4％)and Gram-negative bacteria(50.6％).The top three Gram-positive bacteria were Staphylococcus aureus(15.6％),coagulase-negative Staphylococcus(14.0％),and Streptococcus pneumoniae(8.9％).The top three Gram-negative bacteria were Klebsiella spp.(8.6％),Pseudomonas aeruginosa(8.6％),and Haemophilus influenzae(8.1％).The prevalence of methicillin-resistant strains was 30.9％in SS.aureus(MRSA)and 82.7％in coagulase-negative Staphylococcus(MRCNS).The prevalence of PRSP was 75.0％(24/32)in meningitis isolates and 2.6％(57/2 195)in non-meningitis isolates.Five strains of E.faecium and 10 strains of E.faecalis were found resistant to linezolid.Two strains of E.faecium were resistant to vancomycin.The prevalence of extended-spectrum beta-lactamases(ESBLs)and carbapenem-resistant strains(CREco)in E.coli isolates was 69.0％and 9.7％,respectively.The prevalence of ESBLs and carbapenem-resistant strains(CRKpn)in K.pneumoniae isolates was 73.7％,and 37.2％,respectively.The prevalence of carbapenem-resistant strains was 21.9％in P.aeruginosa isolates and 59.3％in A.baumannii isolates.β-lactamase was detected in 68.3％of the H.influenzae isolates.Conclusions Antimicrobial resistance is still serious in children.It is necessary to strength the surveillance of bacterial resistance and use antibiotics rationally in order to curb the spread of drug-resistant strains.

Objective To understand the changing composition and antibiotic resistance of bacterial species in the clinical isolates from outpatient and emergency department(hereinafter referred to as outpatients)and inpatient children over time in various hospitals,and to provide laboratory evidence for rational antibiotic use.Methods The data on clinically isolated pathogenic bacteria and antimicrobial susceptibility of isolates from outpatients and inpatient children in the CHINET program from 2015 to 2021 were collected and analyzed.Results A total of 278 471 isolates were isolated from pediatric patients in the CHINET program from 2015 to 2021.About 17.1％of the strains were isolated from outpatients,primarily group A β-hemolytic Streptococcus,Escherichia coli,and Staphylococcus aureus.Most of the strains(82.9％)were isolated from inpatients,mainly SS.aureus,E.coli,and H.influenzae.The prevalence of methicillin-resistant S.aureus(MRSA)in outpatients(24.5％)was lower than that in inpatient children(31.5％).The MRSA isolates from outpatients showed lower resistance rates to the antibiotics tested than the strains isolated from inpatient children.The prevalence of vancomycin-resistant Enterococcus faecalis or E.faecium and penicillin-resistant S.pneumoniae was low in either outpatients or inpatient children.S.pneumoniae,β-hemolytic Streptococcus and S.viridans showed high resistance rates to erythromycin.The prevalence of erythromycin-resistant group A β-hemolytic Streptococcus was higher in outpatients than that in inpatient children.The prevalence of β-lactamase-producing H.influenzae showed an overall upward trend in children,but lower in outpatients(45.1％)than in inpatient children(59.4％).The prevalence of carbapenem-resistant Klebsiella pneumoniae(CRKpn),carbapenem-resistant Pseudomonas aeruginosa(CRPae)and carbapenem-resistant Acinetobacter baumannii(CRAba)was 14％,11.7％,47.8％in outpatients,but 24.2％,20.6％,and 52.8％in inpatient children,respectively.The prevalence of multidrug-resistant E.coli,K.pneumoniae,Proteus mirabilis,P.aeruginosa and A.baumannii strains was lower in outpatients than in inpatient children.The prevalence of fluoroquinolone-resistant E.coli,ESBLs-producing K.pneumoniae,ESBLs-producing P.mirabilis,carbapenem-resistant E.coli(CREco),CRKpn,and CRPae was lower in children in outpatients than in inpatient children,but the prevalence of CRAba in 2021 was higher than in inpatient children.Conclusions The distribution of clinical isolates from children is different between outpatients and inpatients.The prevalence of MRSA,ESBL,and CRO was higher in inpatient children than in outpatients.Antibiotics should be used rationally in clinical practice based on etiological diagnosis and antimicrobial susceptibility test results.Ongoing antimicrobial resistance surveillance and prevention and control of hospital infections are crucial to curbing bacterial resistance.

Objective To investigate the changing antibiotic resistance profiles of E.coli isolated from patients in the 52 hospitals participating in the CHINET program from 2015 to 2021.Methods Antimicrobial susceptibility was tested for clinical isolates of E.coli according to the unified protocol of CHINET program.WHONET 5.6 and SPSS 20.0 software were used for data analysis.Results Atotal of 289 760 nonduplicate clinical strains ofE.coli were isolated from 2015 to 2021,mainly from urine samples(44.7±3.2)％.The proportion of E.coli strains isolated from urine samples was higher in females than in males(59.0％vs 29.5％).The proportion of E.coli strains isolated from respiratory tract and cerebrospinal fluid samples was significantly higher in children than in adults(16.7％vs 7.8％,0.8％vs 0.1％,both P＜0.05).The isolates from internal medicine department accounted for the largest proportion(28.9±2.8)％with an increasing trend over years.Overall,the prevalence of ESBLs-producing E.coli and carbapenem resistant E.coli(CREco)was 55.9％and 1.8％,respectively during the 7-year period.The prevalence of ESBLs-producing E.coli was the highest in tertiary hospitals each year from 2015 to 2021 compared to secondary hospitals.The prevalence of CREco was higher in children's hospitals compared to secondary and tertiary hospitals each year from 2015 to 2021.The prevalence of ESBLs-producing E.coli in tertiary hospitals and children's hospitals and the prevalence of CREco in children's hospitals showed a decreasing trend over the 7-year period.The prevalence of CREco in secondary and tertiary hospitals increased slowly.Antibiotic resistance rates changed slowly from 2015 to 2021.Carbapenem drugs(imipenem,meropenem)were the most active drugs amongβ-lactams against E.coli(resistance rate≤2.1％).The resistance rates of E.coli to β-lactam/β-lactam inhibitor combinations(piperacillin-tazobactam,cefoperazone-sulbactam),aminoglycosides(amikacin),nitrofurantoin and fosfomycin(for urinary isolates only)were all less than 10％.The resistance rate of E.coli strains to antibiotics varied with the level of hospitals and the departments where the strains were isolated,especially for cefazolin and ciprofloxacin,to which the resistance rate of E.coli strains from children in non-ICU departments was significantly lower than that of the strains isolated from other departments(P＜0.05).The E.coli isolates from ICU showed higher resistance rate to most antimicrobial agents tested(excluding tigecycline)than the strains isolated from other departments.The E.coli strains isolated from tertiary hospitals showed higher resistance rates to the antimicrobial agents tested(excluding tigecycline,polymyxin B,cefepime and carbapenems)than the strains from secondary hospitals and children's hospitals.Conclusions E.coli is an important pathogen causing clinical infection.More than half of the clinical isolates produced ESBL.The prevalence of CREco is increasing in secondary and tertiary hospitals over the 7-year period even though the overall prevalence is still low.This is an issue of concern.