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 investigate the completion rate of tumor evaluation at initial assessment and after neoadjuvant therapy for mid and low rectal cancer patients in the national multicenter real-world database.Methods:The prospective real-world study was conducted. The clinicopathological data of 1 074 patients who underwent surgical treatment for mid and low rectal cancer in 47 national medical institutions, including Peking Union Medical College Hospital et al, from May 12,2023 to May 11,2024 were collected. Observation indicators: (1) clinical characteristics of patients with mid and low rectal cancer; (2) initial colonoscopy and pathologic evaluation of tumors in patients with mid and low rectal cancer; (3) initial imaging evaluation of patients with mid and low rectal cancer; (4) imaging evaluation after neoadjuvant therapy for patients with mid and low rectal cancer. Measurement data with normal distribution were represented as Mean± SD, and measurement data with skewed distribution were represented as M( Q1, Q3). Count data were described as absoluter numbers and/or percentages. Results:(1) Clinical characteristics of patients with mid and low rectal cancer. Of the 1 074 patients, there were 713 males and 361 females, aged 63(56,70)years. The body mass index of 1 074 patients was 24(21,26)kg/m 2.For American Society of Anesthesiologists classification, there were 147 cases of stage Ⅰ, 641 cases of stage Ⅱ, 157 cases of stage Ⅲ, 2 cases of stage Ⅳ, and there were 127 cases missing data. (2) Initial colonoscopy and pathologic evaluation of tumors in patients with mid and low rectal cancer. Of the 1 074 patients, there were 787 cases (73.28%) undergoing complete colonoscopy, and there were only 197 cases (18.34%) undergoing immunohistochemical evaluation of all four mismatch repair proteins. (3) Initial imaging evaluation of patients with mid and low rectal cancer. Of the 1 074 patients, there were 842(78.40%) patients completing magnetic resonance imaging (MRI) or ultrasound evaluation, and there were 914(85.10%) patients completing chest, abdomen, and pelvis enhanced computed tomography (CT) evaluation. In the 149 patients completing rectal ultrasound evaluation, there were 122 cases (81.88%) comple-ting T staging evaluation, and there were 81 cases (54.36%) completing N staging evaluation. In the 808 patients completing rectal MRI evaluation, there were 708 cases (87.62%) completing T staging evaluation, and there were 590 cases (73.02%) completing N staging evaluation. (4) Imaging evalua-tion after neoadjuvant therapy for patients with mid and low rectal cancer. Of the 388 patients with neoadjuvant therapy, there were 332 patients (85.57%) completing MRI or ultrasound evaluation, and there were 327 patients (84.28%) completing chest, abdomen, and pelvis enhanced CT evalua-tion. In the 70 patients completing rectal ultrasound evaluation, there were 65 cases (92.86%) com-pleting T staging evaluation, and there were 49 cases (70.00%) completing N staging evaluation. In the 327 patients completing rectal MRI evaluation, there were 246 cases (75.23%) completing T staging, and there were 228 cases (69.72%) completing N staging evaluation. Conclusion:The com-pletion rate of tumor imaging evaluation at initial assessment and after neoadjuvant therapy for mid and low rectal cancer patients on a national scale is relatively good.

Objective To explore the protective effect and related mechanism of Compound Baimai Powder(CBMP,a compound description of Mongolian medicine)on astrocytes after oxygen glu-cose deprivation and reoxygenation(OGD/R)injury.Methods Astrocyte model of OGD/R injury was subjected to simulate in vitro cerebral ischemia/reperfusion injury.Cultured astrocytes were randomly divided into normal group,OGD/R group,OGD/R+nimodipine group(10 μmol/L),OGD/R+low-and high-dose CBMP groups(25,50 μmol/L).Cell viability and apoptosis were de-tected with CCK-8 assay and flow cytometry,respectively.Western blotting was used to measure the expression levels of the proteins related to the nuclear factor erythroid-2-related factor-2(NRF2)/antioxidant response element and Janus kinase(J AK)/signal transducer and activator of transcription(STAT)signaling pathways.ELISA was employed to examine the levels of inflam-matory factors IL-1β,IL-6,and TNF-α,as well as oxidative stress molecules ROS,GSH,MDA and SOD.Results Compared to the normal group,the OGD/R group showed significant decreases in cell viability,NRF2 protein level,and SOD and GSH activities(P＜0.05,P＜0.01),and obvious increases in p-JAK and p-STAT proteins levels,contents of IL-1β,IL-6 and TNF-α,and ROS and MDA levels(P＜0.05,P＜0.01).High-dose CBMP treatment resulted in notably elevated cell via-bility and NRF2 protein level,while reduced levels of p-JAK[(1.20±0.20)vs(2.50±0.26)]and p-STAT[(1.15±0.25)vs(2.10±0.21)]proteins,IL-6[(30.33±5.20)vs(180.35±18.50)]and TNF-α[(50.12±8.24)vs(160.45±15.20)]when compared to the OGD/R group(P＜0.05,P＜0.01).Conclusion CBMP exerts protective effect on astrocytes against OGD/R injury.

Objective:To investigate, for multi-sensitized allergic rhinitis (AR) patients allergic to dust mites combined with other allergens (pollen, mold, animal dander, etc.), whether the single dust mite subcutaneous immunotherapy (SCIT) can improve the specific symptoms caused by other allergens in the patients, and to analyze the relationship between the effectiveness of symptom improvement in these patients and the type, quantity and severity of the allergens.Methods:A multicenter retrospective study was conducted to collect mul-sensitized AR patients from allergy or respiratory departments of 5 hospitals who received house dust mite allergen preparation SCIT for 12 to 36 months and met other inclusion and exclusion criteria from February to July 2024. General clinical data were collected and the perennial or seasonal symptoms before and after treatment were evaluated with visual analogue scale (VAS) to assess whether there was an perennial or allergen-specific symptom improvement (VAS score decrease ≥30%), by which the patients were divided into effective group and ineffective. R software was used to analyze the differences between groups by using Fisher′s exact test and Mann-Whitney U test. Results:A total of 62 patients were enrolled, and the treatment were effective in 39 of them, with an effective rate of 62.9%. For allergen-specific symptoms, the median age of the effective group was higher than that of the ineffective group (12 years old vs. 8 years old, P=0.039), and the effective rate in dust mite specific immunoglobin E (sIgE) grade ≤5 group was higher than that in sIgE grade >5 group (81.6% vs. 45.5%, P=0.008), and the effective rate of mold sIgE grade ≤2 group was higher than that of sIgE grade >2 group (83.3% vs. 28.6%, P=0.045), and there was no statistically significant correlation between the other allergen grades and the effective rate ( P>0.05). For perennial symptoms, the effective rate in the mold grade ≤2 group was higher than that in the sIgE grade >2 group (91.3% vs. 28.6%, P=0.010), and there was no statistically significant correlation between the other allergen grades and the effective rate ( P>0.05). There was no significant correlation between the treatment effectiveness of perennial or allergen-specific symptoms and the number of combined allergens, the grade of skin test, and the difference between the grade of combined allergens and that of dust mites ( P>0.05). Conclusion:Among the patients with multi-sensitized AR allergic to dust mites included in this study, single dust mite SCIT is effective in some of them, and for allergen-specific symptoms, the effective group was elder, and dust mite sIgE grade 6 and mold sIgE grade ≥2 was related to the low effective rate of SCIT. The present results are insufficient for selecting single or multiple AIT in any type of multi-sensitized patients.

Objective:To analyze the correlation between serum uric acid-to-high-density lipoprotein cholesterol ratio (UHR) and risk of all-cause death or cardiovascular disease (CVD) death among urban and rural elderly in Beijing.Methods:Based on the Beijing Healthy Aging Cohort Study, 9 022 participants with complete baseline data were enrolled, and their survival and death outcomes were followed up. Multivariable Cox proportional hazard regression model were used to analyze the associations between the UHR level and the risks of all-cause mortality and CVD mortality.Results:As of March 31, 2021, the median follow-up time M( Q1, Q3) was 6.18 (5.36, 6.75) years. There were 1 166 all-deaths, with a death density of 19.26 per 1 000 person-years, and 562 CVD deaths, with a death density of 9.28 per 1 000 person-years. After adjusting sociodemographic characteristics and lifestyle factors, multivariable Cox proportional hazard regression model showed that the risk of all-cause mortality increased by 3% ( HR=1.03, 95% CI: 1.02-1.04) and the risk of CVD mortality increased by 4% ( HR=1.04, 95% CI: 1.02-1.06) for every 1% increase in UHR. Compared with the T1 group of UHR tertiles, the T3 group had a 42% increase in the risk of all-cause death ( HR=1.42, 95% CI: 1.22-1.66) and a 53% increase in the risk of CVD death ( HR=1.53, 95% CI: 1.21-1.94). Conclusions:The UHR level is significantly associated with the risks of all-cause mortality and CVD mortality among urban and rural older adults in Beijing. The UHR level may be one of the potential predictors of death risk in community-dwelling older adults.

In order to investigate the mitigating effect of Yin Chen aqueous extract on liver injury induced by LPS combined with D-GalN in mice,a mouse liver injury model was established by in-traperitoneal injection of LPS and D-GalN,and the mice were group-fed by instillation of saline,bi-phenyl dibenzyl ester,and Yin Chen aqueous extract with different concentrations of LPS and D-GalN.The liver index of mice was calculated,pathological tissue sections were observed,and the expression of ALT,AST,inflammatory cytokines,oxidative stress,hepatic enzymes,and IL-17/TNF pathway were detected in serum to investigate the effects and mechanisms of the aqueous ex-tracts of Yin Chen in alleviating the liver injury in mice.The results showed that the liver index of mice in the model group was significantly elevated,the serum levels of ALT and AST were signifi-cantly elevated,the levels of IL-iβ,IL-8 and TNF-α in liver tissue were significantly elevated,the levels of IL-4 were significantly reduced,the levels of GSH-Px,CAT and SOD were significantly reduced,the levels of ROS and MDA were significantly elevated,CYP2E1 and CYP1A2 protein content and mRNA expression were significantly up-regulated,and the expression levels of TNF,TNFR1,IL-17A,ACT1 and IL-6 mRNA were significantly up-regulated.The study showed that the aqueous extract of Yin Chen had a certain alleviating effect on the liver injury caused by LPS combined with D-GalN in mice.The mechanism of action includes decreasing the metabolic level of hepatic drug enzymes,alleviating oxidative stress,inhibiting the expression of IL-17/TNF pathway and down-regulating the level of inflammatory factors in mice.

Poly(lactic-co-glycolide)(PLGA)is a key excipient in long-acting sustained-release preparations,and its degradation properties directly affect the drug release behavior.In this study,PLGA microspheres were prepared by microfluidic techniques,and the morphology changes of the microspheres were observed by scanning electron microscopy(SEM).In alkaline environment,due to the accelerated hydrolysis of ester bonds,the surface of the microspheres was rapidly dissolved and eroded,and the degradation rate was significantly higher than that in acidic environment.High temperature accelerated the degradation of PLGA microspheres.Under neutral and alkaline conditions,the microspheres showed aggregation and adhesion.Under acidic conditions,the microspheres gradually decomposed into irregular fragments.The high ionic strength further promoted the surface corrosion of the microspheres,especially under extreme pH conditions.Simultaneously,PLGA microspheres encapsulating coumarin were prepared to simulate the microsphere formulation.The release rate of coumarin after degradation of the microspheres under different conditions was observed by measuring the absorbance with ultraviolet-visible spectrophotometry.The results were consistent with those of the blank microspheres.This study revealed that the degradation of PLGA microspheres was significantly pH-dependent,temperature sensitive and ion strength responsive.These findings not only helped to understand and optimize the long-term stability and controlled release performance of drug-carrying microspheres,but also provided a theoretical basis for further improvement of PLGA-based drug carrier design.

Objective To construct a competency evaluation model for forensic practitioners,providing a reference for their training and assessment.Methods Based on the iceberg and onion models of com-petency,and with reference to Spencer's Competency Dictionary,literature research was conducted and focus group interviews were employed to preliminarily construct core indices and measurement items for evaluating the competency of forensic practitioners.The Delphi method was applied for two rounds of expert consultation to further refine the competency evaluation index system.The analytic hierarchy process(AHP)was used to calculate the weights of the indices.Results A competency evaluation model for forensic practitioners was constructed,consisting of 7 core indices,encompassing forensic skills,identification service capabilities,and the ability to apply relevant legal knowledge and 49 mea-surement items.The weights of the core indices and measurement items were determined.Conclusion The constructed competency evaluation model for forensic practitioners is scientifically sound and inno-vative,and has unique characteristics of forensic medicine compared with other medical models.

Objective To explore the protective effect and related mechanism of Compound Baimai Powder(CBMP,a compound description of Mongolian medicine)on astrocytes after oxygen glu-cose deprivation and reoxygenation(OGD/R)injury.Methods Astrocyte model of OGD/R injury was subjected to simulate in vitro cerebral ischemia/reperfusion injury.Cultured astrocytes were randomly divided into normal group,OGD/R group,OGD/R+nimodipine group(10 μmol/L),OGD/R+low-and high-dose CBMP groups(25,50 μmol/L).Cell viability and apoptosis were de-tected with CCK-8 assay and flow cytometry,respectively.Western blotting was used to measure the expression levels of the proteins related to the nuclear factor erythroid-2-related factor-2(NRF2)/antioxidant response element and Janus kinase(J AK)/signal transducer and activator of transcription(STAT)signaling pathways.ELISA was employed to examine the levels of inflam-matory factors IL-1β,IL-6,and TNF-α,as well as oxidative stress molecules ROS,GSH,MDA and SOD.Results Compared to the normal group,the OGD/R group showed significant decreases in cell viability,NRF2 protein level,and SOD and GSH activities(P＜0.05,P＜0.01),and obvious increases in p-JAK and p-STAT proteins levels,contents of IL-1β,IL-6 and TNF-α,and ROS and MDA levels(P＜0.05,P＜0.01).High-dose CBMP treatment resulted in notably elevated cell via-bility and NRF2 protein level,while reduced levels of p-JAK[(1.20±0.20)vs(2.50±0.26)]and p-STAT[(1.15±0.25)vs(2.10±0.21)]proteins,IL-6[(30.33±5.20)vs(180.35±18.50)]and TNF-α[(50.12±8.24)vs(160.45±15.20)]when compared to the OGD/R group(P＜0.05,P＜0.01).Conclusion CBMP exerts protective effect on astrocytes against OGD/R injury.

Objective:To investigate, for multi-sensitized allergic rhinitis (AR) patients allergic to dust mites combined with other allergens (pollen, mold, animal dander, etc.), whether the single dust mite subcutaneous immunotherapy (SCIT) can improve the specific symptoms caused by other allergens in the patients, and to analyze the relationship between the effectiveness of symptom improvement in these patients and the type, quantity and severity of the allergens.Methods:A multicenter retrospective study was conducted to collect mul-sensitized AR patients from allergy or respiratory departments of 5 hospitals who received house dust mite allergen preparation SCIT for 12 to 36 months and met other inclusion and exclusion criteria from February to July 2024. General clinical data were collected and the perennial or seasonal symptoms before and after treatment were evaluated with visual analogue scale (VAS) to assess whether there was an perennial or allergen-specific symptom improvement (VAS score decrease ≥30%), by which the patients were divided into effective group and ineffective. R software was used to analyze the differences between groups by using Fisher′s exact test and Mann-Whitney U test. Results:A total of 62 patients were enrolled, and the treatment were effective in 39 of them, with an effective rate of 62.9%. For allergen-specific symptoms, the median age of the effective group was higher than that of the ineffective group (12 years old vs. 8 years old, P=0.039), and the effective rate in dust mite specific immunoglobin E (sIgE) grade ≤5 group was higher than that in sIgE grade >5 group (81.6% vs. 45.5%, P=0.008), and the effective rate of mold sIgE grade ≤2 group was higher than that of sIgE grade >2 group (83.3% vs. 28.6%, P=0.045), and there was no statistically significant correlation between the other allergen grades and the effective rate ( P>0.05). For perennial symptoms, the effective rate in the mold grade ≤2 group was higher than that in the sIgE grade >2 group (91.3% vs. 28.6%, P=0.010), and there was no statistically significant correlation between the other allergen grades and the effective rate ( P>0.05). There was no significant correlation between the treatment effectiveness of perennial or allergen-specific symptoms and the number of combined allergens, the grade of skin test, and the difference between the grade of combined allergens and that of dust mites ( P>0.05). Conclusion:Among the patients with multi-sensitized AR allergic to dust mites included in this study, single dust mite SCIT is effective in some of them, and for allergen-specific symptoms, the effective group was elder, and dust mite sIgE grade 6 and mold sIgE grade ≥2 was related to the low effective rate of SCIT. The present results are insufficient for selecting single or multiple AIT in any type of multi-sensitized patients.