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.

Lipid turbidity disease is a metabolic disease featuring lipid metabolism disorders caused by many factors such as social environment， diet， and lifestyle， which is closely related to many diseases in modern medicine， such as hyperlipidemia， obesity， fatty liver， atherosclerosis， metabolic syndrome， and cardiovascular and cerebrovascular diseases， with a wide range of influence and far-reaching harm. According to the Huangdi Neijing， lipid turbidity disease reflects the pathological change of the body's physiologic grease. Grease is the thick part of body fluids， which has the function of nourishing， and it is the initial state and source of important substances in the human body such as brain， marrow， essence， and blood. Once the grease of the human body is abnormal， it can lead to lipid turbidity disease. The Huangdi Neijing also points out the physiological relationship between the transportation and transformation of body fluids and the rise and fall of the spleen and stomach， which can deduce the pathological relationship between the occurrence of lipid turbidity disease and the abnormal rise and fall of the spleen and stomach functions. Lipid turbidity disease is caused by overconsumption of fatty and sweet foods or insufficient spleen and stomach endowments， leading to disorders of the function of promoting clear and reducing turbidity in the spleen and stomach. This leads to the transformation of thick grease in body fluids into lipid turbidity， which accumulates in the body's meridians， blood vessels， skin pores， and organs， forming various forms of metabolic diseases. The research team believed that the pathological basis of lipid turbidity disease was the abnormal rise and fall of the spleen and stomach and the obstruction of the transfer of grease. According to the different locations where lipid turbidity stays， it was divided into four common pathogenesis types： ''inability to distinguish between the clear and turbid， turbid stagnation in the Ying blood''， ''spleen not rising clear， turbid accumulation in the vessels''， ''spleen dysfunction， lipid retention in the pores''， ''spleen failure to transportation and transformation， and grease accumulation in the liver''. According to the pathogenesis， it could be divided into four common syndromes， namely， turbid stagnation in the Ying blood， turbid accumulation in the vessels， lipid retention in the pores， and grease accumulation in the liver， and the corresponding prescriptions were given for syndrome differentiation and treatment， so as to guide clinical differentiation and treatment of the lipid turbidity disease.

Houpo Sanwutang， included in the Catalogue of Ancient Classical Prescriptions （Second Batch）， was first recorded in the Synopsis of Golden Chamber written by ZHANG Zhongjing from the Eastern Han dynasty and was modified by successive generations of medical experts. A total of 37 pieces of effective data involving 37 ancient Chinese medical books were retrieved from different databases. Through literature mining， statistical analysis， and data processing， combined with modern articles， this study employed bibliometrics to investigate the historical origin， composition， decoction methods， clinical application， and other key information. The results showed that the medicinal origin of Houpo Sanwutang was clearly documented in classic books. Based on the conversion of the measurements from the Han Dynasty， it is recommended that 110.4 g Magnolia Officinalis Cortex， 55.2 g Rhei Radix et Rhizoma， and 72 g Aurantii Fructus Immaturus should be taken. Magnolia Officinalis Cortex and Aurantii Fructus Immaturus should be decocted with 2 400 mL water first， and 1 000 mL should be taken from the decocted liquid. Following this， Rhei Radix et Rhizoma should be added for further decoction， and then 600 mL should be taken from the decocted liquid. A single dose of administration is 200 mL， and the medication can be stopped when patients restore smooth bowel movement. Houpo Sanwutang has the effect of moving Qi， relieving stuffiness and fullness， removing food stagnation， and regulating bowels. It can be used in treating abdominal distending pain， guarding， constipation， and other diseases with the pathogenesis of stagnated heat and stagnated Qi in the stomach. The above results provide reference for the future development and research of Houpo Sanwutang.

Amantadine(AMD)residue can accumulate in organisms through the food chain and cause serious harm to human body.AMD can specifically bind to AMD specific aptamer and cause its conformation to change from a random single strand to a stem-loop structure.To avoid the influence of excess nucleotides on binding of aptamer to AMD,the truncation of the AMD original aptamer J was optimized by retaining an appropriate stem-loop structure,and a new type of truncation aptamers was developed in this work.By comparing the truncated aptamer with the original aptamer,it was found that the truncated aptamer J-7 had better affinity and specificity with AMD.The detection limit of AMD was 0.11 ng/mL by using J-7 as specific recognition element and molybdenum disulfide nanosheet(MoS2Ns)as signal amplification element.The developed method base on truncated aptamer J-7 was used for detection of AMD in milk,yogurt and SD rat serum samples for the first time with recoveries of 86.6%-108.2%.This study provided a reference for truncating other long sequence aptamers and provided a more sensitive detection method for monitoring AMD residues in food.

"MS/MS spectrum to structure"plays a critical role in the confirmative identification of complicated matrices and is currently regarded as an extremely challenging endeavor.MS/MS information provides vital clues to structural identification.In this study,a strategy was proposed to facilitate unambiguous identification through matching MS3 with MS2 spectra.Initially,MS3 spectra of the featured ions(c-and y-type ions)generated by the decomposition of ester functional group in esters and the MS2 spectrum of the structural unit([M-H]-)were all captured on the Qtrap-MS platform equipped with two tandem-in-space collision cells,including the second quadrupole cell(q2)and linear ion trap(LIT)chambers(actually the third quadrupole unit).Subsequently,the MS/MS spectrum matching between MS3 spectra of the ester compound and MS2 spectra of the structural unit(s)were achieved.As a result,the findings corresponding to MS3 and MS2 spectra matching were summarized.Finally,based on HR-MS/MS information of total salvianolic acid derivatives(TSA),36 kinds of compounds were preliminarily identified through matching with literature information and database retrieval.The applicability of MS3 and MS2 spectra matching strategy was further justified by the confirmative identification of phenolic acid compounds(Rosmarinic acid and salvianolic acid B)in TSA.Above all,MS3 and MS2 spectra matching strategy was quite meaningful towards advancing"MS/MS spectrum to structure"analysis through recognizing and identifying featured fragment ions,and also provided inspiration and new insights for the structural characterization.

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 To establish the method for content determination of three lignans of Dendrobium Fimbriatum Hook..Methods The lignans in Dendrobium tasselii were identified by high-performance liquid chromatography/multi-stage mass spectrometry(HPLC-ESI/MSn)coupled with ultraviolet absorption spectrometry(UV)coupled with retention time localization of high-performance liquid chromatography(HPLC).The separation was carried out on a Kromasil 100-5 C18 column(4.6 mm×250 mm,5 μm)using a gradient elution of acetonitrile-0.1%formic acid solution as the mobile phase,the volume flow rate was 0.8 mL·min-1 and the column temperature was 35℃,and the mass spectrometry was performed using an ESI ion source with the data collected in the negative ion mode.The HPLC content was determined on the same column as that of MS analysis,with the mobile phase methanol + acetonitrile(V/V=1∶1)-0.01 mol/L ammonium acetate solution,gradient elution,flow rate of 0.8 mL·min-1,column temperature of 40℃,and detection wavelength of 215 nm.Results Syringaresinol di-O-glucoside and(-)-Syringaresinol 4-O-β-D-glucopyranoside and DL-Syringaresinol were identified from Dendrobium fimbriatum Hook.,and the results of content determination showed that the linear ranges of above three components were respectively 0.1701-3.4020,0.1020-2.0400,0.0403-0.8060 μg(r≥0.9995),the average recoveries were in the range of 97.71%-101.67%,and the relative standard deviations(RSDs)were all less than 3.0%.The contents of Syringaresinol di-O-glucoside and(-)-Syringaresinol 4-O-β-D-glucopyranoside and DL-Syringaresinol in the 10 batches of samples were 0.7779-1.3852,0.0734-0.1966,0.0295-0.1882 mg·g-1.Conclusion This research method can provide a reference basis for the quality evaluation method of Dendrobium fimbriatum Hook..

Objective To retrospectively investigate the efficacy of pelvic floor muscle training(PFMT)using APP-based home device in the real-world scenario.Methods A retrospective survey was conducted among 171 000 Chinese female users over 18 years old who freely registered APP and performed PFMT using a domestic manufactured home device from Oct 1,2019 to Mar 31,2021.The Patient Global Impression of Improvement(PGI-I)questionnaires concerning pelvic floor general condition,sexual satisfaction and other three major symptoms related to pelvic floor muscle laxity such as stress urinary incontinence(SUI),pelvic organ prolapse(POP),and vaginal laxity(VL)were broadcast public online for users to self-assess the improvement.The vaginal muscle strength values prior and post training recorded by APP were also reported.All data were collected anonymously for further stratified analysis.Results A total of 984 valid questionnaires were collected by systematic sampling.The PGI-I scores of pelvic floor general condition(P=0.000 1),sexual satisfaction(P=0.009),SUI(P=0.000 1),POP(P=0.044)and VL(P=0.034)were statistically significant in users who reported to use the device for 3 months or more compared with those less than 3 months.In addition,the increase of vaginal muscle strength was related to the improvement of PGI-I scores in SUI and POP with statistical significance.There were no significant difference in subgroups such as age,education,parity,and delivery mode.Conclusion The subjective benefit of pelvic floor function-related symptoms and the improvement of vaginal muscle strength could be observed after PFMT for three months or more using APP-based home device in Chinese women in the real-world scenario.