ObjectiveTo prepare a recombinant PETase with a dual-catalytic-triad and to evaluate its efficiency in the biodegradation of polyethylene terephthalate （PET）. MethodsBased on the crystal structure of wild-type PETase， point mutations （T88H/L117D） were introduced via site-directed mutagenesis. The recombinant protein was prepared using prokaryotic expression and chromatography purification techniques. The enzymatic hydrolysis of the mutant PETase was assessed by relatively quantifying the products mono （2-hydroxyethyl） terephthalate （MHET） and terephthalic acid （TPA）. ResultsBoth wild-type and mutant PETases accumulated as inclusion bodies， accounting for approximately 20% of the total bacterial protein. After solubilization in urea， the proteins were eluted at 300 mmol/L imidazole during affinity chromatography purification， with concentrations of 1.824 and 1.833 mg/mL and purities of 83.11% and 84.32%， respectively. Subsequent anion-exchange chromatography yielded highly pure enzymes in the 200 mmol/L NaCl fraction： 2.776 mg/mL （96.86% purity） for the wild type and 1.967 mg/mL （95.13% purity） for the mutant. Following refolding， the final concentrations were 0.484 mg/mL for the wild type and 0.991 mg/mL for the mutant. Hydrolysis assays revealed that the mutant released MHET and TPA at （237.67±17.00）% and （197.33±12.01）% of the wild-type levels， respectively. ConclusionThe T88H/L117D dual-catalytic-triad PETase is successfully prepared and it significantly enhanced PET-degrading activity， thus， it′s a promising biocatalyst for PET bioremediation.

Objective To study the five-year survival status and influencing factors of elderly patients with lung cancer complicated with chronic obstructive pulmonary disease (COPD). Methods A cohort study was conducted to follow up 450 patients with lung cancer and chronic obstructive pulmonary disease who were hospitalized in our hospital from January 2018 to December 2023. The endpoint of the follow-up was the end of a five-year period or death. The Life Tables method was used to calculate survival rates and plot survival curves. The Cox proportional hazards model was used to analyze the influencing factors of five-year survival. Results The results indicated that the overall five-year survival rate of patients was 4.89%, and it decreased year by year. Cox regression analysis showed that age, gender, family functioning, and psychological status significantly influenced patient survival rate (all P<0.05). Stratified analysis found that the smoking status, family functioning, and psychological status of male patients all had an impact on survival rate (all P<0.05), while the psychological status of female patients had a more significant impact on survival (P=0.008). Conclusion This study provides a scientific basis for comprehensive intervention of elderly lung cancer patients with COPD. It is recommended that clinical attention should be paid to psychological and family factors to improve patient prognosis.

Electronic cigarettes are a new type of tobacco products, the harm and addiction of which cannot be ignored. The comprehensive smoking history taking, including electronic cigarette use, is a primary evaluation skill for the clinical encounter and is conducive to developing a precise smoking quiting plan. This article expounds the prevalence of electronic cigarette use, the status quo on methods of history taking and dependence assessment for electronic cigarette use; and put forward suggestions of comprehensive history taking in the context of domestic market environment, including electronic cigarette parameters, avoiding information missing, adopting comprehensive methods and targeted counseling, in order to provide a reference for clinical smoking history taking.

Objective To explore the objective characteristics of tongue in primary immune thrombocytopenia(ITP);To provide references for accurate syndrome differentiation.Methods Totally 112 patients with ITP were divided into groups according to their platelet count,TCM symptoms and drug treatment lines.Infrared thermal imager,hygrometer,colorimetry and image analysis software were used to detect the temperature,humidity,colorimetry and morphology of tongue body(TB),tongue coating(TC)and sublingual vessel(SV),and analyze their characteristics.The tongue was divided into five areas:tip of tongue(T),middle of tongue(M),behind of tongue(B),middle left of tongue(ML)and middle right of tongue(MR),and its temperature was measured.Humility(H)of tongue and tongue coating were measured by hygrometer.The images of tongue body,tongue coating and sublingual collaterals were taken,and the chromaticity indexes of R,G,B,L,a,b were analyzed by Adobe Photoshop 2023.The width,length and tortuosity of sublingual collaterals were under morphological analysis.Results ① Comparison of platelet count groups:compared with 30-50 platelet count group and more than 100 platelet count group,the TB-R of 51-100 platelet count group decreased(P<0.05,P<0.01),and compared with 30-50 platelet count group,the TB-a of 51-100 platelet count group decreased(P<0.01);compared with platelet<30 group and platelet 30-50 group,the TC-H of platelet>100 group increased(P<0.05,P<0.01);compared with platelet>100 group,the length of sublingual collaterals in platelet<30 group was longer(P<0.05).② Comparison of different TCM symptom groups:compared with the bleeding group and asymptomatic group,the M and SV-B in the fatigue group decreased(P<0.05,P<0.01);compared with the asymptomatic group,the TC-b in the anxious group was significantly higher(P<0.05).③ Comparison of administration groups:compared with the Danazol group and Chinese materia medica group,the TC-H in the glucocorticoid group was significantly higher(P<0.05,P<0.01).Conclusion There are differences in tongue characteristic indexes among ITP patients with different platelet counts,TCM symptoms and drug treatment lines,which can measure of tongue indexes to provide references for accurate syndrome differentiation of ITP.

Objective To investigate the imaging features of post-transplant lymphoproliferative disorder(PTLD)after allogeneic hematopoietic stem cell transplantation(allo-HSCT).Methods The imaging findings of EB virus-associated PTLD(EBV-PTLD)after allo-HSCT in 8 patients with hematological diseases were retrospectively analyzed,including 1 case with acute lymphoblastic leukemia(ALL),3 cases with acute myeloid leukemia(AML),1 case with myelodysplastic syndrome(MDS)and 3 cases with aplas-tic anemia(AA).All patients were positive for EB virus(EBV)after transplantation.MRI,CT plain scan and enhanced scan were performed to analyze the imaging features of all lesions.Results Central nervous system(CNS)was involved in 5 cases,pharyngeal lymphatic ring and left lacrimal sac was involved in 1 case,liver was involved in 1 case,intraperitoneal and retroperitoneal lymph nodes was involved in 1 case.All patients were pathologically confirmed with PTLD.Conclusion PTLD may involve multiple organs and tissues after hematopoietic stem cell transplantation with different onset time.Timely MRI and CT examination,combined with PTLD screening and EBV detection,can detect and diagnose PTLD lesions in early stage,providing important clinical value.

Objective:To explore the characteristics of social skills and problem behaviors of children and adolescents with autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD), as well as the association with core symptoms.Methods:A total of 409 patients aged 5-18 years old with ASD or ADHD in the outpatient department of Nanjing Brain Hospital from 2023 to 2024, and 344 children and adolescents with typical development(TD) were recruited.All participants were matched in a ratio of 1∶1∶1 (ASD∶ADHD∶TD) according to gender and age, and 97 participants were included in each group for analysis.The Chinese version of the social skills improvement system rating scales(SSIS-RS-C) was used to evaluate social skills and problem behaviors, and autistic child behavior checklist(ABC), childhood autism rating scale(CARS), the Chinese version of the social communication questionnaire(SCQ) and the Chinese version of Swanson, Nolan, and Pelham, version Ⅳ scale-parent form(SNAP-Ⅳ) were used to evaluate the core symptoms of ASD and ADHD, respectively. SPSS 26.0 software was used to perform variance, Chi-square test, Spearman correlation analysis and multivariate Logistic regression analysis.Results:The social skills score of ASD group was lower than ADHD group ((61.53±24.26) vs (80.89±15.19), P<0.05), while the problem behavior score of ASD group was higher than ADHD group ((38.82±11.92) vs (34.00±12.45), P<0.05). In ASD group, the scores of ABC, CARS and SCQ were negatively correlated with the score of social skills ( r=-0.26--0.55, P<0.05). In ADHD group, the total score and each subscale of SNAP-Ⅳ were positively correlated with the score of problem behavior ( r=0.25-0.65, P<0.05). Multivariate Logistic regression analysis showed that empathy was a negative influencing factor of ASD ( B=-0.246, OR=0.782, P<0.05), and hyperactivity/inattention was a positive influencing factor of ASD ( B=0.589, OR=1.802, P<0.01), while only hyperactivity/inattention was a positive influencing factor of ADHD( B=0.779, OR=2.180, P<0.01). Conclusion:Children and adolescents with ASD and ADHD both have defects in social skills and problem behaviors, and these defects are associated with the core characteristics of their respective diseases.

Objective To investigate the impact of risk prevention and control on the quality efficiency of medical equipment procurement.Methods The medical equipment procurement projects with enhanced risk prevention measures during 2023(119 items)were assigned to an observation group,while those without strengthened risk control during 2022(118 items)were enrolled into a control group.The two groups were compared in terms of bid failure/rejection rates,procurement completion cycles(including procurement execution cycle and total procurement cycle)and procurement satisfaction.Statistical analysis was performed using SPSS 20.0 software.Results The observation group demonstrated significantly lower bid failure/rejection rates when compared with the control group(≥2 occurrences:5.88％vs.15.25％,P＜0.05).The procurement execution cycle was notably shorter in the observation group((69.16±78.65)d vs.(97.67±49.84)d,P＜0.05),though no significant difference was observed in total procurement cycle(P＞0.05).The observation group behaved better significantly than the control group in procurement efficiency,equipment performance,procedural compliance and post-purchase service satisfaction(all P＜0.05).Conclusion Risk prevention and control measures in medical equipment procurement effectively reduce bid failure/rejection risks while enhancing procurement quality efficiency.[Chinese Medical Equipment Journal,2025,46(3):81-85]

Objective To explore the relationship between overactive bladder(OAB)and neuropsychological characteristics in patients with cerebral small-vessel disease(CSVD).Methods A total of 208 patients with CSVD admitted to the First Affiliated Hospital of Shihezi University from December 2023 to November 2024 were selected as research subjects.They were divided into OAB group(44 cases)and non-OAB group(164 cases)according to overactive bladder symptom score.The general information and imaging data of two groups of patients were compared.The cognitive function,anxiety and depression of patients were evaluated by using Montreal cognitive assessment(MoCA),digit span test(DST),auditory verbal learning test(AVLT),verbal fluency test(VFT),clock drawing test(CDT),Hamilton anxiety scale(HAMA)and Hamilton depression scale(HAMD).Logistic regression analysis was used to analyze the influencing factors of OAB in patients with CSVD.Pearson correlation analysis was used to analyze the correlation between imaging indicators and anxiety symptoms of patients in OAB group.Results The HAMA and HAMD scores of patients in OAB group were higher than those in non-OAB group(P＜0.05),but there were no statistically significant differences in MoCA,DST,AVLT,VFT,and CDT scores between two groups(P＞0.05).There was a statistically significant difference in the incidence of anxiety among patients with different degrees of OAB(P＜0.05).Multivariate Logistic regression analysis after adjusting for confounding factors showed that anxiety was an independent influencing factor for OAB in patients with CSVD(P＜0.05).The periventricular white matter hyperintensity of patients in OAB group was negatively correlated with the HAMA score(P＜0.05),while basal ganglia lacunar infarction,centrum semiovale lacunar infarction,basal ganglia enlarged perivascular space and centrum semiovale enlarged perivascular space were all positively correlated with the HAMA score(P＜0.05).Conclusion The anxiety and depression symptoms of patients with CSVD accompanied by OAB were more severe than those of non-OAB patients.Anxiety may be an independent influencing factor for the occurrence of OAB in patients with CSVD.

Objective:Based on the theoretical framework of policy innovation diffusion,it systematically explores the diffusion mechanism and core influencing factors of national regional medical centers,and reveals their internal diffusion laws and key driving factors,so as to provide theoretical basis and practical guidance for the rational expansion,precise sinking and scientific layout of high-quality medical resources.Methods:Based on the panel data related to the construction of national medical centers in 31 provincial-level administrative regions of China from 2019 to 2023,the random effect and fixed effect models were used for benchmark regression analysis,and the spatial Durbin model was innovatively introduced to explore the influencing factors and internal mechanisms of the expansion of high-quality medical resources.Results:The degree of population aging,the level of regional education development and the intensity of medical financial expenditure showed a significant positive correlation with the layout of national regional medical centers,which has become the key strategic fulcrum driving the construction of national regional medical centers.Conclusion:In order to improve the efficiency of medical resource allocation and promote the expansion and balanced distribution of high-quality resources,it is necessary to accurately meet the demand for health services brought about by the evolution of population structure,systematically promote the upgrading of national education quality,and continue to increase the allocation of financial resources in the field of medical and health care,and establish a multi-institutional collaboration mechanism to promote the integration and sharing of resources to ensure the accessibility and equitable development of medical resources.

Electronic cigarettes are a new type of tobacco products, the harm and addiction of which cannot be ignored. The comprehensive smoking history taking, including electronic cigarette use, is a primary evaluation skill for the clinical encounter and is conducive to developing a precise smoking quiting plan. This article expounds the prevalence of electronic cigarette use, the status quo on methods of history taking and dependence assessment for electronic cigarette use; and put forward suggestions of comprehensive history taking in the context of domestic market environment, including electronic cigarette parameters, avoiding information missing, adopting comprehensive methods and targeted counseling, in order to provide a reference for clinical smoking history taking.