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 levels of radionuclides in food in Beijing, China, and assess the committed effective dose to local residents from food intake. Methods From 2021 to 2022, a total of 65 food samples across 7 categories were collected in Beijing. The activity concentrations of radionuclides, including ¹³⁷Cs, ²¹⁰Pb, ²³⁸U, ²²⁸Ra, ²²⁶Ra, ⁴⁰K, ⁹⁰Sr, ²¹⁰Po, ³H and ¹⁴C, were measured using gamma spectrometry and radiochemical methods. By combining the monitoring results with dietary consumption data of Beijing residents and the internal dose coefficients for Chinese reference adult phantom, the committed effective dose was estimated. Results The levels of radionuclides in food in Beijing were within the normal background range, consistent with related surveys in China and abroad, with activity concentrations below national standard limits. No significant differences were found in the activity concentrations of ¹³⁷Cs, ²³⁸U, ²²⁸Ra, ²²⁶Ra and ⁴⁰K between food samples collected from key areas and those from control areas (P > 0.05). The committed effective doses calculated according to internal dose coefficients for Chinese reference adult male phantom and GB 18871-2002 were 0.26 mSv and 0.19 mSv, respectively. Based on the Chinese reference adult male phantom, the majority of the committed effective dose was attributed to ²¹⁰Pb (45.1%), ²²⁸Ra (37.1%), ²¹⁰Po (12.3%), and ²²⁶Ra (4.7%). Conclusion The levels of radionuclides in food in Beijing fluctuated within the background range, resulting in a low radiation dose burden to the population.

Aim To investigate the effect of homocys-teine(Hcy)on the permeability of pulmonary micro-vascular endothelial cells(PMVECs)and the role and mechanism of RASAL1.Methods CBS+/-mice were fed a high methionine diet(HMD)for 16 weeks to replicate an animal model of hyperhomocysteinemia(HHcy).HE staining was used to observe the changes in lung tissue structure.qRT-PCR was used to detect the levels of RASAL1 and DNMT1 mRNA in lung tis-sue.Western blot was used to detect the expression of RASAL1,DNMT1,ZO-1,and VE cadherin proteins.Methylation specific PCR was used to detect methyla-tion in the RASAL1 promoter region.PMVECs were transfected with Ad-RASAL1 to detect the expression of ZO-1 and VE cadherin.The si-DNMT1 interference fragment was transfected into PMVECs,and the ex-pression of the RASAL1 was detected by qRT-PCR and Western blot.Results Serum Hcy level of HMD mice was significantly raised,and HE staining showed severe structural disorder in lung tissue.The expres-sion of RASAL1,ZO-1,and VE cadherin was de-creased,while the expression of DNMT1 was in-creased.The degree of methylation in the RASAL1 promoter region was raised.The expression of ZO-1 and VE cadherin increased after PMVECs were trans-fected with Ad-RASAL1.After knocking down DN-MT1,RASAL1 expression was increased.Conclusion Hcy can increase the permeability of PMVECs,and its mechanism is related to the upregulation of RASAL1 methylation level.

Objective To investigate the risk factors for gastrointestinal fistula after esophageal cancer surgery.Methods The clinical data of 437 patients who underwent esophagectomy in our hospital were retrospectively analyzed.According to whether gastrointestinal fistula occurred after operation,they were divided into the study group(n=157)and the control group(n=280).The related risk factors of the ocurrence of postoperative gastrointestinal fistula were screened by univariate and multivariate analyses.Results The results of the univariate analysis showed that there were statistically significant differences of patients between the two groups in terms of operation time,anastomotic site,tumor location,tumor infiltration depth,surgical method,pleural adhesion,reinforcement suture of anastomotic stoma,post-operative pulmonary infection,and postoperative incision infection(P<0.05).Multivariate Logistic regression analysis showed that pleural adhesion,operation time≥4.5 hours,postoperative pulmonary infection,and postoperative incision infection were independent risk factors for the occurence of postoperative gastrointestinal fistula(P<0.05).The reinforcement suture of anastomotic stoma and the increase of the first postoperative hemoglobin level were independent protective factors for the occurrence of postoperative gastrointestinal fistula(P<0.05).Conclusion Controlling operation time,applying active anti-infection measures,implementing dressing changes,taking reinforcement suture of anastomotic stoma,and correcting of anemia may help to reduce the occurrence of gastrointestinal fistulas after esophagectomy.

Objective:To investigate the effect of deacylase Sirtuin 5 in the recovery of hematopoietic stem cells(HSCs)after treated by 5-FU in mouse.Methods:Flow cytometry was used to analyze the effect of SIRT5 deletion on the proportion of hematopoietic stem/progenitor cells(HSPCs)in bone marrow(BM),the proportion of T cells,B cells and myeloid cells(TBM)in peripheral blood(PB)and spleen,and the development of T cells in thymus.Mouse were treated with 5-FU to study the effect of SIRT5 deletion on the cell cycle,apoptosis and the proportion of HSPCs in BM.The effect of SIRT5 deletion on the proliferation of HSCs was analyzed by flow sorting in vitro.Results:SIRT5 deletion did not affect the development of T cells in thymus and the proportion of TBM cells in PB and spleen compared with wild type mice.SIRT5 deletion increased proportion of HSPCs in BM.After 5-FU treatment,the proportion of HSCs in SIRT5 deletion mice was significant decreased(P＜0.05),the HSPC in SIRT5 deletion mice was activated from G0 to G1 phase(P＜0.05),and the proportion of early apoptosis increased(P＜0.05).By monoclonal culture in vitro,the ability of HSCs to form clones in SIRT5 deletion mice was decreased significantly(P＜0.05).Conclusion:SIRT5 deletion lead to a decreased the ability of HSCs to clone in vitro.SIRT5 deletion is not conducive to the recovery of HSPCs injury in mice under hematopoietic stress.

Objective To develop a medical positive pressure protective suit for long-voyage aeromedical evacuation to realize protective isolation and drinking water and energy supply for medical personnel during long-voyage aeromedical evacuation of respiratory infectious disease patients.Methods The medical positive pressure protective suit had a one-piece structure,with its main part made of hydroentangled non-woven fabric,head and forebreast parts made of amorphous polyethylene terephthalate anti-fog material and wearing-and taking-off parts sealed with zipper and autohesion,which was equipped with a portable positive pressure air supply device,an airborne centralized positive pressure air supply device and a monitoring and warning device.The portable positive pressure air supply device was fixed in the back of the suit at the waist,the airborne device was made by modifying the commercially available positive pressure air supply fan,and the monitoring and warning device monitored the air supply volume of the fan,the battery power and the pressure inside the suit.Results The suit behaved well in protection,clean fresh air supply without time limitation and facilitating hydration and energy replenishment of medical personnel by forming three activity spaces.Conclusion The suit developed can continuously provide a clean and comfortable microenvironment,meeting the requirements of medical personnel for protection and hydration and energy replenishment during long-voyage aeromedical evacuation.[Chinese Medical Equipment Journal,2024,45(11):113-116]

Objective To investigate whether the mechanism of action of electro-acupuncture in MPTP-induced Parkinson's disease(PD)model mice is related to neuroinflammation mediated by the forkhead box protein O1(FoXO1)/NOD-like receptor heat protein structural domain-related protein 3(NLRP3)signaling pathway.Methods Thirty mice were randomly divided into control(Ctrl),model(MPTP),and electro-acupuncture(EA)groups,with 10 mice in each group.PD mouse model was prepared by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)30 mg/(kg·d)for 7 d consecutively.Behavioral changes of mice were observed by open field and pole-climbing experiments;α-synuclein(α-syn)expression in the substantia nigra of the midbrain was observed by immunohistochemistry;FoXO1,NLRP3,ASC,and Caspase-1 were deter-mined by Western blot;and the expression of inflammatory factors such as tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β)was detected by ELISA in the substantia nigra of the midbrain.Results Mice in the MPTP group showed significant behavioral deficits,with a significant increase in midbrain substantia nigra α-syn(P＜0.01),elevated levels of Iba-1,FoXO1,NLRP3,ASC,and Caspase-1 proteins(P＜0.05 and P＜0.01,respectively),and a significant increase in the levels of TNF-α,and IL-1β(P＜0.01).The treatment of EA was effective in improve the dyskinesia of PD mice,improve motor balance and coordination(P＜0.01),reduce the abnormal aggregation of α-syn(P＜0.01),reduce the abnormal activation of microglia,and alleviate neuroinflammation(P＜0.05).Conclusion Electro-acupuncture may play a protective role in PD by modulating FoXO1/NLRP3 pathway-mediated neuroinflammation.

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.

Objective:To investigate the regulatory effect of transient receptor potential cation channel subfamily C member 3 (TRPC3) on the retina in oxygen-induced retinopathy (OIR) mice and biological behavior of human retinal vascular endothelial cells (HREC).Methods:A total of 32 healthy SPF grade 7-day-old C57BL/6 mice were selected and randomly divided into a control group and an OIR group by the random number table method, with 16 mice in each group.The control group received no special treatment, and the OIR model was established in the OIR group.On postnatal day 17 (PN17), the success of the model establishment was verified by immunofluorescence staining of the retinal patch.The in vitro cultured HREC were divided into a normal control group, a transfection reagent group, and a si-TRPC3 group.The normal control group received no special treatment, while the transfection reagent group and the si-TRPC3 group were transfected with transfection reagent or transfection reagent + si-TRPC3.The relative expression of TRPC3 mRNA was detected by real-time quantitative fluorescence PCR.The relative expressions of TRPC3, transcription factor NF-E2 related factor (Nrf2), and superoxide dismutase (SOD) proteins were determined by Western blot.HREC were further divided into a normal control group, a vascular endothelial growth factor (VEGF) group, a si-TRPC3 group, and a Pyr3 (TRPC3 channel inhibitor) group, which were cultured in complete medium, medium containing 20 ng/ml VEGF recombinant protein, medium containing 20 ng/ml VEGF recombinant protein (si-TRPC3 transfection for 72 hours), and medium containing 20 ng/ml VEGF recombinant protein+ 1 μmol/L Pyr3 for 48 hours, respectively.The proliferation ability of HREC was detected using cell counting kit 8 (CCK-8). The horizontal and vertical migration ability of cells were detected by cell scratch assay and transwell assay, respectively.This study followed the 3R principles of animal welfare and was approved by the Ethics Committee of Hebei Eye Hospital (No.2023LW04). Results:Pathological neovascular clusters with strong fluorescent staining appeared in the retina of OIR mice on PN17.The relative expressions of TRPC3 mRNA and protein in the retina of OIR mice were 2.057±0.244 and 1.517±0.290, respectively, significantly higher than 0.983±0.033 and 0.874±0.052 of control group ( t=6.165, 3.094; both at P<0.05). The relative expression levels of TRPC3 mRNA and protein were significantly lower, and the relative expression levels of Nrf2 and SOD proteins were higher in the si-TRPC3 group than in the normal control and transfection reagent groups, and the differences were statistically significant (all at P<0.05). The CCK-8 experiment results showed that the cell absorbance value was higher in the VEGF group than in the normal control group, and lower in the si-TRPC3 and Pyr3 groups than in the VEGF group, with statistically significant differences (all at P<0.05). The results of the cell scratch experiment showed that the lateral migration rate of VEGF group cells was higher than that of normal control group, while the lateral migration rate of si-TRPC3 group and Pyr3 group cells was lower than that of VEGF group, and the differences were statistically significant (all at P<0.05). The transwell experiment results showed that the number of stained cells in the VEGF group was higher than that in the normal control group, and the number of stained cells in the si-TRPC3 group and Pyr3 group was lower than that in the VEGF group, with statistically significant differences (all at P<0.05). Conclusions:Hypoxia induces increased TRPC3 expression in OIR mouse retina, and downregulation of TRPC3 inhibits HREC proliferation and migration.The mechanism is related to the activation of the Nrf2-related oxidative stress pathway.

ObjectiveThe absorption of substances into blood is mainly dependent on the mesenteric lymphatic pathway and the portal venous pathway. The substances transported via the portal venous pathway can be metabolized by the biotransformation in the liver. On the contrary, the substances in the mesenteric lymph fluid enter the blood circulation without biotransformation and can affect the body directly. Alcohol consumption is strongly linked to global health risk. Previous reports have analyzed the changes of metabolites in plasma, serum, urine, liver and feces after alcohol consumption. Whether alcohol consumption affects the metabolites in lymph fluid is still unknown. Therefore, it is particularly important to explore the changes of substances transported via the mesenteric lymphatic pathway and analyze their harmfulness after alcohol drinking. MethodsIn this study, male Wistar rats were divided into high, medium, and low-dosage alcohol groups (receiving Chinese Baijiu at 56%, 28% and 5.6% ABV, respectively) and water groups. The experiment was conducted by alcohol gavage lasting 10 d, 10 ml·kg^-1·d^-1. Then mesenteric lymph fluid was collected for non-targeted metabolomic analysis by using liquid chromatography-mass spectrometry (LC-MS) and bioinformatic analysis. Principal component analysis and hierarchical clustering were performed by using Biodeep. Meanwhile, KEGG enrichment analysis of the differential metabolites was also performed by Biodeep. MetaboAnalyst was used to analyze the relationship between the differential metabolites and diseases. ResultsThe metabolites in the mesenteric lymph fluid of the high-dosage alcohol group change the most. Based on the KEGG enrichment analysis, the pathways of differential metabolites between the high-dosage alcohol group and the control group are mainly enriched in the central carbon metabolism in cancer, bile secretion, linoleic acid metabolism, biosynthesis of unsaturated fatty acids, etc. Interestingly, in the biosynthesis of unsaturated fatty acids category, the content of arachidonic acid is increased by 7.25 times, whereas the contents of palmitic acid, oleic acid, stearic acid, arachidic acid and erucic acid all decrease, indicating lipid substances in lymph fluid are absorbed selectively after alcohol intake. It’s worth noting that arachidonic acid is closely related to inflammatory response. Furthermore, the differential metabolites are mainly related with schizophrenia, Alzheimer’s disease and lung cancer. The differential metabolites between the medium-dosage alcohol and the control group were mainly enriched in phenylalanine metabolism, valine, leucine and isoleucine biosynthesis, linoleic acid metabolism and cholesterol metabolism. The differential metabolites are mainly related to schizophrenia, Alzheimer’s disease, lung cancer and Parkinson’s disease. As the dose of alcohol increases, the contents of some metabolites in lymph fluid increase, including cholesterol, L-leucine, fumaric acid and mannitol, and the number of metabolites related to schizophrenia also tends to increase, indicatingthat some metabolites absorbed by the intestine-lymphatic pathway are dose-dependent on alcohol intake. ConclusionAfter alcohol intake, the metabolites transported via the intestinal-lymphatic pathway are significantly changed, especially in the high-dosage group. Some metabolites absorbed via the intestinal-lymphatic pathway are dose-dependent on alcohol intake. Most importantly, alcohol intake may cause inflammatory response and the occurrence of neurological diseases, psychiatric diseases and cancer diseases. High-dosage drinking may aggravate or accelerate the occurrence of related diseases. These results provide new insights into the pathogenesis of alcohol-related diseases based on the intestinal-lymphatic pathway.