Immobilized enzyme-based enzyme electrode biosensors, characterized by high sensitivity and efficiency, strong specificity, and compact size, demonstrate broad application prospects in life science research, disease diagnosis and monitoring, etc. Immobilization of enzyme is a critical step in determining the performance (stability, sensitivity, and reproducibility) of the biosensors. Random immobilization (physical adsorption, covalent cross-linking, etc.) can easily bring about problems, such as decreased enzyme activity and relatively unstable immobilization. Whereas, directional immobilization utilizing amino acid residue mutation, affinity peptide fusion, or nucleotide-specific binding to restrict the orientation of the enzymes provides new possibilities to solve the problems caused by random immobilization. In this paper, the principles, advantages and disadvantages and the application progress of enzyme electrode biosensors of different directional immobilization strategies for enzyme molecular sensing elements by specific amino acids (lysine, histidine, cysteine, unnatural amino acid) with functional groups introduced based on site-specific mutation, affinity peptides (gold binding peptides, carbon binding peptides, carbohydrate binding domains) fused through genetic engineering, and specific binding between nucleotides and target enzymes (proteins) were reviewed, and the application fields, advantages and limitations of various immobilized enzyme interface characterization techniques were discussed, hoping to provide theoretical and technical guidance for the creation of high-performance enzyme sensing elements and the manufacture of enzyme electrode sensors.

Objective To understand the surveillance situation of poliovirus in Guangzhou from 2011 to 2024, and to further strengthen polio surveillance and ensure the continued maintenance of a polio-free status. Methods An analysis was conducted on the discovery and investigation results of six cases of vaccine-derived poliovirus (VDPV) detected in Guangzhou. Results A total of 6 VDPV incidents were reported in Guangzhou from 2011 to June 2024, among which 5 incidents were from sewage sample testing in the Liede Sewage Treatment Plant in Guangzhou, all of which were confirmed as VDPV, with 1 for type I, 1 for type II, and 3 for type III. In addition, one confirmed HFMD case was identified as a type VDPV II carrier. No presence of any wild poliovirus (WPV), VDPV cases, or circulating VDPV (cVDPV) was reported. Conclusion Guangzhou City has maintained a high level of vigilance and effectiveness in the monitoring and prevention of polio. Continuously strengthening the construction of the polio monitoring network, optimizing vaccination strategies, and comprehensively improving public health awareness are still the focus of the prevention and control work in the future.

Pulmonary electrical impedance tomography (EIT), a noninvasive, continuous, dynamic, and radiation-free bedside imaging technique for monitoring pulmonary ventilation, is now widely utilized in the diagnosis and management of critically ill patients. Beyond ventilation monitoring, hypertonic saline contrast-enhanced EIT for bedside pulmonary perfusion assessment has recently garnered significant attention. This article describes the application of hypertonic saline contrast-enhanced EIT to evaluate pulmonary perfusion in two patients following pulmonary endarterectomy, providing a reference for its perioperative application in such patients.

Task performance is an important concern in ergonomics. Task performance is often affected by adverse ergonomic factors, resulting in health and economic losses. How to utilize effective indicators to evaluate the degree of impact of adverse ergonomic factors on workers' task performance is particularly important. In this paper, we conducted a literature review and analysis on the impact of adverse ergonomic factors on workers' task performance, focusing on summarizing available physiological, psychological, and neurocognitive behavioral function test indicators for evaluating workers' task performance. This summary of existing evaluation indicators provided reference and guidance for future evaluations of the impact of adverse ergonomic factors on workers' task performance.

Background Diesel engines are widely used in transportation, agriculture, construction, industry, and other fields. Diesel exhaust, classified as a Group 1 carcinogen, emits particles (DEP) that can penetrate deep into the respiratory tract, posing significant health risks. DEP pollution is particularly severe in confined environments, necessitating effective control measures. Objective Under laboratory simulation conditions, to explore the spatiotemporal distribution characteristics of the mass and number concentrations of DEP as it diffuses indoors and to reveal the effects of ventilation and additional airflow on indoor DEP pollution levels. Methods A diesel engine was placed in a laboratory (length 3.39 m × width 2.85 m × height 2.4 m) with its exhaust emitted from east to west. An air purifier was installed 1 m south of the engine. Eight measurement points (1 m horizontal distance from the exhaust outlet, height: 1 m/1.5 m) were setup to monitor DEP concentrations using portable laser particle sizers. The effects of engine power (4.05 kW vs. 5.15 kW), ventilation (maximum airflow: 600 m³·h⁻¹), additional airflow intensity (low and high), and direction (forward/reverse) on DEP pollution were analyzed. DEP levels of 5 diesel vehicle models were also compared. Results The mass and number concentrations of DEP indoors increased immediately after the diesel engine started. The peak mass concentration time at the eastern measurement point (−1, 0) m opposite to the exhaust direction (17.70 min) was significantly longer than that at the western (1, 0) m (16.20 min), southern (0, -1) m (14.45 min), and northern (0, 1) m (12.70 min) points (P<0.05), with no significant differences between the other points (western, southern, and northern) (P>0.05). The northern point (0, 1) m exhibited the highest DEP mass and number concentration peaks (174.62 μg·m⁻³, 1319.85 p·cm⁻³), significantly exceeding those at the southern (0, −1) m (129.89 μg·m⁻³, 1175.24 p·cm⁻³), eastern (−1, 0) m (140.12 μg·m⁻³, 1120.53 p·cm⁻³), and western (1, 0) m (147.60 μg·m⁻³, 818.62 p·cm⁻³) points (P<0.05), and no significant differences were observed among other points (P>0.05). There were no significant differences in peak DEP mass and number concentrations by measurement heights (P>0.05). Diesel engine power, ventilation, airflow intensity, and airflow direction had no significant effect on the time of peak DEP concentration (P>0.05). However, higher engine power (5.15 kW) produced greater DEP peaks [(186.66±19.29) μg·m⁻³, (1382.79±122.56) p·cm⁻³] than the 4.05 kW engine power [(168.41±12.65) μg·m⁻³, (1284.45±71.30) p·cm⁻³] (P<0.05). The peak mass concentration [(342.04±35.03) μg·m⁻³] and number concentration [(1886.87±57.91) p·cm⁻³] of DEP in the non-ventilated group were significantly higher than those in the ventilated group [(186.66±19.29) μg·m⁻³, (1382.79±122.56) p·cm⁻³] (P<0.001). Forward airflow elevated DEP mass concentrations compared to reverse airflow (287.71 μg·m⁻³ vs. 243.74 μg·m⁻³, t=−2.592, P=0.009), but no effects on DEP number concentration (P>0.05). Significant differences in mass concentration were observed among selected 5 vehicle models (Z=38.109, P<0.001). Conclusion The operation of diesel engines will emit a large amount of particulate matter, causing pollution in enclosed spaces. Diesel engines with greater power have higher levels of DEP pollution emissions. Based on the spatiotemporal distribution characteristics, it is recommended to set the operation position in the reverse direction of exhaust emissions and close to air purifiers, while avoiding the use of additional air flow equipment.

Hereditary angioedema (HAE) is a rare autosomal dominant genetic disorder characterized by recurrent episodes of subcutaneous and submucosal edema, which can be life-threatening in severe cases. Lanadelumab, a recombinant human monoclonal antibody against kallikrein, has been recommended as a first-line option for long-term prophylaxis of HAE. This paper analyzed the clinical data of four patients with HAE diagnosed and treated with lanadelumab for long-term prophylaxis in our department since 2020. It also reviewed relevant literature, summarizing the clinical manifestations of HAE, as well as the efficacy and safety of lanadelumab in treating HAE, to provide therapeutic references for clinicians.

Umbilical cord mesenchymal stem cells (UC-MSCs) have been widely used in regenerative medicine, but there is limited research on the stability of UC-MSCs formulation during production. This study aims to assess the stability of the cell stock solution and intermediate product throughout the production process, as well as the final product following reconstitution, in order to offer guidance for the manufacturing process and serve as a reference for formulation reconstitution methods. Three batches of cell formulation were produced and stored under low temperature (2-8 ℃) and room temperature (20-26 ℃) during cell stock solution and intermediate product stages. The storage time intervals for cell stock solution were 0, 2, 4, and 6 h, while for intermediate products, the intervals were 0, 1, 2, and 3 h. The evaluation items included visual inspection, viable cell concentration, cell viability, cell surface markers, lymphocyte proliferation inhibition rate, and sterility. Additionally, dilution and culture stability studies were performed after reconstitution of the cell product. The reconstitution diluents included 0.9% sodium chloride injection, 0.9% sodium chloride injection + 1% human serum albumin, and 0.9% sodium chloride injection + 2% human serum albumin, with dilution ratios of 10-fold and 40-fold. The storage time intervals after dilution were 0, 1, 2, 3, and 4 h. The reconstitution culture media included DMEM medium, DMEM + 2% platelet lysate, 0.9% sodium chloride injection, and 0.9% sodium chloride injection + 1% human serum albumin, and the culture duration was 24 h. The evaluation items were viable cell concentration and cell viability. The results showed that the cell stock solution remained stable for up to 6 h under both low temperature (2-8 ℃) and room temperature (20-26 ℃) conditions, while the intermediate product remained stable for up to 3 h under the same conditions. After formulation reconstitution, using sodium chloride injection diluted with 1% or 2% human serum albumin maintained a viability of over 80% within 4 h. It was observed that different dilution factors had an impact on cell viability. After formulation reconstitution, cultivation in medium with 2% platelet lysate resulted in a cell viability of over 80% after 24 h. In conclusion, the stability of cell stock solution within 6 h and intermediate product within 3 h meets the requirements. The addition of 1% or 2% human serum albumin in the reconstitution diluent can better protect the post-reconstitution cell viability.

Objective To study the application of CE-Chirp in the evaluation of hearing impairment in forensic medicine by testing the auditory brainstem response(ABR)in adults using CE-Chirp to ana-lyze the relationship between the V-wave response threshold of CE-Chirp ABR test and the pure tone hearing threshold.Methods Subjects(aged 20-77 with a total of 100 ears)who underwent CE-Chirp ABR test in Changzhou De'an Hospital from January 2018 to June 2019 were selected to obtain the V-wave response threshold,and pure tone air conduction hearing threshold tests were conducted at 0.5,1.0,2.0 and 4.0 kHz,respectively,to obtain pure tone listening threshold.The differences and statistical differences between the average pure tone hearing threshold and V-wave response threshold were compared in different hearing levels and different age groups.The correlation,differences and statistical differences between the two tests at each frequency were analyzed for all subjects.The lin-ear regression equation for estimating pure tone hearing threshold for all subjects CE-Chirp ABR V-wave response threshold was established,and the feasibility of the equation was tested.Results There was no statistical significance in the CE-Chirp ABR response threshold and pure tone hearing threshold dif-ference between different hearing level groups and different age groups(P>0.05).There was a good correlation between adult CE-Chirp ABR V-wave response threshold and pure tone hearing threshold with statistical significance(P<0.05),and linear regression analysis showed a significant linear correla-tion between the two(P<0.05).Conclusion The use of CE-Chirp ABR V-wave response threshold can be used to evaluate subjects'pure tone hearing threshold under certain conditions,and can be used as an audiological test method for forensic hearing impairment assessment.

Objective To investigate the toxicokinetic differences of 3,4-methylenedioxy-N-methylamphetamine(MDMA)and its metabolite 4,5-methylene dioxy amphetamine(MDA)in rats af-ter single and continuous administration of MDMA,providing reference data for the forensic identifica-tion of MDMA.Methods A total of 24 rats in the single administration group were randomly divided into 5,10 and 20 mg/kg experimental groups and the control group,with 6 rats in each group.The ex-perimental group was given intraperitoneal injection of MDMA,and the control group was given intraperi-toneal injection of the same volume of normal saline as the experimental group.The amount of 0.5 mL blood was collected from the medial canthus 5 min,30 min,1 h,1.5 h,2 h,4 h,6 h,8 h,10 h,12 h after administration.In the continuous administration group,24 rats were randomly divided into the experi-mental group(18 rats)and the control group(6 rats).The experimental group was given MDMA 7 d by continuous intraperitoneal injection in increments of 5,7,9,11,13,15,17 mg/kg per day,respectively,while the control group was given the same volume of normal saline as the experimental group by in-traperitoneal injection.On the eighth day,the experimental rats were randomly divided into 5,10 and 20 mg/kg dose groups,with 6 rats in each group.MDMA was injected intraperitoneally,and the con-trol group was injected intraperitoneally with the same volume of normal saline as the experimental group.On the eighth day,0.5 mL of blood was taken from the medial canthus 5 min,30 min,1 h,1.5 h,2 h,4 h,6 h,8 h,10 h,12 h after administration.Liquid chromatography-triple quadrupole tandem mass spectrometry was used to detect MDMA and MDA levels,and statistical software was employed for data analysis.Results In the single-administration group,peak concentrations of MDMA and MDA were reached at 5 min and 1 h after administration,respectively,with the largest detection time limit of 12 h.In the continuous administration group,peak concentrations were reached at 30 min and 1.5 h af-ter administration,respectively,with the largest detection time limit of 10 h.Nonlinear fitting equations for the concentration ratio of MDMA and MDA in plasma and administration time in the single-administration group and continuous administration group were as follows:T=10.362C-1.183,R2=0.974 6;T=7.397 3C-0.694,R2=0.961 5(T:injection time;C:concentration ratio of MDMA to MDA in plasma).Conclusions The toxicokinetic data of MDMA and its metabolite MDA in rats,obtained through single and continuous administration,including peak concentration,peak time,detection time limit,and the relationship between concentration ratio and administration time,provide a theoretical and data foundation for relevant forensic identification.

Objective This study aimed to compare the current Essen rabies post-exposure immunization schedule(0-3-7-14-28)in China and the simple 4-dose schedule(0-3-7-14)newly recommended by the World Health Organization in terms of their safety,efficacy,and protection. Methods Mice were vaccinated according to different immunization schedules,and blood was collected for detection of rabies virus neutralizing antibodies(RVNAs)on days 14,21,28,35,and 120 after the first immunization.Additionally,different groups of mice were injected with lethal doses of the CVS-11 virus on day 0,subjected to different rabies immunization schedules,and assessed for morbidity and death status.In a clinical trial,185 rabies-exposed individuals were selected for post-exposure vaccination according to the Essen schedule,and blood was collected for RVNAs detection on days 28 and 42 after the first immunization. Results A statistically significant difference in RVNAs between mice in the Essen and 0-3-7-14 schedule groups was observed on the 35th day(P<0.05).The groups 0-3-7-14,0-3-7-21,and 0-3-7-28 showed no statistically significant difference(P>0.05)in RVNAs levels at any time point.The post-exposure immune protective test showed that the survival rate of mice in the control group was 20%,whereas that in the immunization groups was 40%.In the clinical trial,the RVNAs positive conversion rates on days 28(14 days after 4 doses)and 42(14 days after 5 doses)were both 100%,and no significant difference in RVNAs levels was observed(P>0.05). Conclusion The simple 4-dose schedule can produce sufficient RVNAs levels,with no significant effect of a delayed fourth vaccine dose(14-28 d)on the immunization potential.