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.

Type 1 diabetes mellitus is a chronic autoimmune disease caused by the destruction of pancreatic islet β cells. Pancreatic islet transplantation provides a treatment method for patients with type 1 diabetes mellitus to restore endogenous insulin secretion. However, some problems limit the widespread application of islet transplantation, such as the shortage of donors and post-transplantation rejection damage. Mesenchymal stem cell-derived exosome (MSC-Exo) has become a potential tool for islet transplantation therapy due to their immunomodulatory and tissue repair capabilities. MSC-Exo shows great promise for application, because of low immunogenicity, easily being stored and transported, and the potential as drug delivery vehicles. However, challenges such as preparation, purification, standardization and safety verification need to be overcome before converting MSC-Exo into clinical practice. Therefore, this article reviews the application and potential advantages of MSC-Exo in islet transplantation, aiming to providing more effective and safer treatment options for patients with type 1 diabetes mellitus.

Objective Personalized calculation of contrast agent dose based on body surface area(BSA)was conducted to explore the feasibility of obtaining virtual single energy or reconstruction fusion through dual-energy CT without affecting the enhancement effect of portal vein trunk under the condition of reducing the contrast agent dose.Methods A total of 60 patients who received enhanced upper abdominal CT examination in the First Affiliated Hospital of Army Medical University were selected and divided into the normal dose group and the reduced dose group.The normal dose group used the BSA estimated value as the contrast agent dose,and the reduced dose group used the BSA estimated value reduced by 20%as the contrast agent dose.Both groups of patients were treated with dual-energy CT scanning in portal vein stage,and the scanning parameters were the same.After scanning,Syngo dual-energy post-processing software of Siemens multi-mode image workstation was used to reconstruct and fuse the 5 mm layer thickness image of the portal vein stage in the reduced dose group by two methods:"optimum contrast(OC)"and"monoenergetic(Mono)".The CT value and SD value of the portal vein trunk and the normal liver parenchyma of images in each group were measured.The contrast to noise ratio(CNR)of theportal vein and the liver parenchyma and portal vein signal to ratio(SNR)were calculated.Results Compared with the normal dose group,there was no statistically significant difference in the subjective score in the reduced dose OC group(P>0.05),but the CNR and SNR of the portal vein trunk in the images were significantly improved(P<0.05).The portal vein CT value and the difference between portal vein and liver parenchyma in the reduced dose Mono group were significantly lower than those in the normal dose group,and the subjective score was the lowest,with statistical differences(P<0.05).Conclusion In the case of reducing the contrast agent dose by 20%,the dual-energy CT reconstruction fusion method can not only reduce the damage of contrast agent to patients,but also significantly improve the lesion display,and improve the consistency of liver enhancement image quality.

Objective:To investigate the effects of Ziyin Liangxue formula combined with prednisone on immune function and the ST2/IL-33 pathway in mice with immune thrombocytopenia.Methods:In 40 BALB/c mice,32 were constructed as immune thrombocytopenia mouse models by antiplatelet serum injection.After successful modeling,the mice were randomly divided into model group,Ziyin Liangxue formula group(0.2 ml/10 g),prednisone group(0.2 ml/10 g),and Ziyin Liangxue formula+prednisone group(0.2 ml/10 g),8 mice in each group,and the other 8 mice were set as control group.The drugs were administered by gavage at the dose,and the model group and control group were given equal amounts of saline by gavage once a day for 2 weeks of continuous intervention.Blood samples and spleen tissues were collected,the peripheral platelet count was measured by automatic hematology analyzer,the pathological changes in spleen tissue was observed by HE staining,the levels of serum transforming growth factor(TGF)-β,interleukin(IL)-17,and peripheral blood thrombopoietin(TPO)were detected by enzyme-linked immunosorbent assay(ELISA),the expression of IL-33,sST2,and ST2 in spleen tissue was detected by Western blot,and the cell counts of peripheral blood Th17 and Treg were detected by flow cytometry.Results:Compared with the control group,the number of platelets,the level of TPO,TGF-β,and Treg cells were significantly decreased(P＜().05),while the level of IL-17,Thl7 cells,and the expression of IL-33,sST2,and ST2 protein were significantly increased in the model group(P＜0.01).Compared with the model group,the number of platelets,the level of TPO,TGF-β,and Treg cells were significantly increased(P＜0.05),while the level of IL-17,Th17 cells,and the expression of IL-33,sST2,and ST2 protein were significantly decreased in the Ziyin Liangxue formula+prednisone group(P＜0.01).Conclusion:Ziyin Liangxue formula+prednisone can effectively regulate Th17/Treg balance,thus effectively improve immune thrombocytopenia,and the mechanism may be related to the regulation of ST2/IL-33 signaling pathway.

Objective To understand the respiratory protection competency of staff in hospitals.Methods Staff from six hospitals of different levels and characteristics in Beijing were selected,including doctors,nurses,medical technicians,and servicers,to conduct knowledge assessment on respiratory protection competency.According to exposure risks of respiratory infectious diseases,based on actual cases and daily work scenarios,content of respira-tory protection competency assessment was designed from three aspects:identification of respiratory infectious di-seases,transmission routes and corresponding protection requirements,as well as correct selection and use of masks.The assessment included 6,6,and 8 knowledge points respectively,with 20 knowledge points in total,all of which were choice questions.For multiple-choice questions,full marks,partial marks,and no mark were given respective-ly if all options were correct,partial options were correct and without incorrect options,and partial options were correct but with incorrect options.Difficulty and discrimination analyses on question of each knowledge point was conducted based on classical test theory.Results The respiratory protection competency knowledge assessment for 326 staff members at different risk levels in 6 hospitals showed that concerning the 20 knowledge points,more than 60％participants got full marks for 6 points,while the proportion of full marks for other questions was relatively low.Less than 10％participants got full marks for the following 5 knowledge points:types of airborne diseases,types of droplet-borne diseases,conventional measures for the prevention and control of healthcare-associated infec-tion with respiratory infectious diseases,indications for wearing respirators,and indications for wearing medical protective masks.Among the 20 knowledge questions,5,1,and 14 questions were relatively easy,medium,and difficult,respectively;6,1,4,and 9 questions were with discrimination levels of ≥0.4,0.30-0.39,0.20-0.29,and ≤0.19,respectively.Conclusion There is still much room for hospital staff to improve their respiratory protection competency,especially in the recognition of diseases with different transmission routes and the indications for wearing different types of masks.

Objective To investigate the implementation of surveillance,prevention and control measures for healthcare-associated infection(HAI)in maternal and child healthcare(MCH)institutions,and provide policy evi-dence for optimizing HAI prevention and control in MCH institutions.Methods Stratified sampling was conducted among the MCH institutions at provincial,municipal and county levels in 8 provinces/autonomous regions.A uni-fied questionnaire was designed and the online survey was conducted through"Questionnaire Star".Results The data from 123 MCH institutions were included in the analysis.90.24％of the MCH institutions carried out compre-hensive surveillance on HAI.The ratios of MCH institutions which implemented targeted surveillance on HAI in neonatal intensive care unit(NICU),surgical site infection,multidrug-resistant organisms(MDROs)and HAI in intensive care units(non-NICU excluded)were 89.66％,85.96％,80.77％,and 74.19％,respectively.51.22％MCH institutions adopted information surveillance system on HAI cases.94.31％MCH institutions carried out surveillance on hand hygiene compliance.Over 90％MCH institutions carried out surveillance on environment hy-giene in high-risk departments.71.54％MCH institutions conducted centralized cleaning,disinfection,sterilization and supply for reusable medical instruments in the central sterile supply department(CSSD).Over 90％MCH insti-tutions established three-level pre-examination triage systems.86.18％set up transitional wards.MCH institutions generally adopted a management model with established effective communication,full appointment visits,and sepa-rate visits for special medical groups,such as registered pregnant women,high-risk newborns,healthcare groups,and long-term rehabilitation patients.However,the ratio of institutions conducting on-line follow-up visits was less than 50％.Conclusion MCH institutions have generally carried out comprehensive and targeted surveillance on HAI.Information surveillance need to be facilitated.Hand hygiene and environmental hygiene surveillance has been popularized to a certain extent at all levels of MCH institutions.The cleaning,disinfection,sterilization,and supply processes of reusable medical devices in a few MCH institutions are not standardized.Special medical populations get effective management.On-line healthcare is to be further promoted.

Objective To study the mechanism of polyene phosphatidylcholine in improving metabolic disorders and fatty liver induced by high fat diet.Methods Thirty-two C57BL/6 mice were randomly divided into blank group,control group,model group and experimental group.The blank group was fed with low-fat diet and intraperitoneal injection of 10％glucose 200 μL twice a week.Control group was fed with low-fat diet twice a week and intraperitoneally injected 10％glucose solution 200 μL containing polyene phosphatidylcholine(PPC)20 μg.Model group was fed with high-fat diet and intraperitoneal injection of 10％glucose 200 μL twice a week.Experimental group was fed with high-fat diet twice a week and intraperitoneally injected 10％glucose solution 200 μL containing PPC 20 μg.The body weight of the mice was measured,blood glucose test strips and insulin resistance was analyzed.The levels of triglyceride(TG),high density lipoprotein(HDL),low density lipoprotein(LDL),glutamic oxalic aminotransferase(GOT)and glutamic pyruvic aminotransferase(GPT)in serum and liver were analyzed by biochemical method.The levels of tumor necrosis factor-α(TNF-α),interleukin-6 and IL-8 were detected by enzyme-linked immunosorbent assay(ELISA).Results The serum TG levels of blank group,control group,model group and experimental group were(0.15±0.01),(0.11±0.01),(0.21±0.01)and(0.12±0.01)mmol·L-1;LDL levels were(0.41±0.01),(0.25±0.01),(0.71±0.02)and(0.49±0.01)mmol·L-1;GOT levels were(30.30±0.89),(31.39±1.18),(43.04±2.82)and(25.64±0.72)mmol·L-1;GPT levels were(9.15±0.45),(7.39±1.88),(12.87±1.81)and(7.96±1.64)mmol·L-1;fasting blood glucose levels were(4.97±0.08),(6.08±0.18),(8.12±0.20)and(7.29±0.02)mmol·L-1;fasting insulin levels were(6.52±1.11),(5.45±0.28),(54.83±4.32)and(30.55±2.73)mU·L-1;the levels of TNF-α in liver tissues were(3.98±0.63),(3.95±0.98),(20.55±4.71)and(15.28±1.73)pg·g-1;IL-6 levels were(18.93±8.56),(17.64±3.29),(59.40±4.63)and(37.54±7.33)pg·g-1;IL-8 levels were(67.16±12.37),(59.44±3.58),(198.40±9.27)and(132.10±7.04)pg·g-1.The difference of above indicatory between experimental group and model group was statistically significant(all P＜0.05).Conclusion Polyene phosphatidylcholine may inhibit the expression of TNF-α,IL-6 and IL-8 inflammatory factors by mediating the inhibition of inflammation on liver tissue and then improve metabolic disorders.

ObjectiveCellular temperature imaging can assist scientists in studying and comprehending the temperature distribution within cells, revealing critical information about cellular metabolism and biochemical processes. Currently, cell temperature imaging techniques based on fluorescent temperature probes suffer from limitations such as low temperature resolution and a limited measurement range. This paper aims to develop a single-cell temperature imaging and real-time monitoring technique by leveraging the temperature-dependent properties of single-molecule quantum coherence processes. MethodsUsing femtosecond pulse lasers, we prepare delayed and phase-adjustable pairs of femtosecond pulses. These modulated pulse pairs excite fluorescent single molecules labeled within cells through a microscopic system, followed by the collection and recording of the arrival time of each fluorescent photon. By defining the quantum coherence visibility (V) of single molecules in relation to the surrounding environmental temperature, a correspondence between V and environmental temperature is established. By modulating and demodulating the arrival times of fluorescent photons, we obtain the local temperature of single molecules. Combined with scanning imaging, we finally achieve temperature imaging and real-time detection of cells. ResultsThis method achieves high precision (temperature resolution<0.1°C) and a wide temperature range (10-50°C) for temperature imaging and measurement, and it enables the observation of temperature changes related to individual cell metabolism. ConclusionThis research contributes to a deeper understanding of cellular metabolism, protein function, and disease mechanisms, providing a valuable tool for biomedical research.

ObjectiveTemporal heterogeneity in lung cancer presents as fluctuations in the biological characteristics, genomic mutations, proliferation rates, and chemotherapeutic responses of tumor cells over time, posing a significant barrier to effective treatment. The complexity of this temporal variance, coupled with the spatial diversity of lung cancer, presents formidable challenges for research. This article will pave the way for new avenues in lung cancer research, aiding in a deeper understanding of the temporal heterogeneity of lung cancer, thereby enhancing the cure rate for lung cancer. MethodsRaman spectroscopy emerges as a powerful tool for real-time surveillance of biomolecular composition changes in lung cancer at the cellular scale, thus shedding light on the disease’s temporal heterogeneity. In our investigation, we harnessed Raman spectroscopic microscopy alongside multivariate statistical analysis to scrutinize the biomolecular alterations in human lung epithelial cells across various timeframes after benzo(a)pyrene exposure. ResultsOur findings indicated a temporal reduction in nucleic acids, lipids, proteins, and carotenoids, coinciding with a rise in glucose concentration. These patterns suggest that benzo(a)pyrene induces structural damage to the genetic material, accelerates lipid peroxidation, disrupts protein metabolism, curtails carotenoid production, and alters glucose metabolic pathways. Employing Raman spectroscopy enabled us to monitor the biomolecular dynamics within lung cancer cells in a real-time, non-invasive, and non-destructive manner, facilitating the elucidation of pivotal molecular features. ConclusionThis research enhances the comprehension of lung cancer progression and supports the development of personalized therapeutic approaches, which may improve the clinical outcomes for patients.

Intracranial seminoma is a rare malignant tumor originating from the germ cells,usually occurring in the pineal gland or pituitary gland.In June 2020,the Department of Endocrinology at the First Affiliated Hospital of Army Military Medical University admitted a 20-year-old male patient with an intracranial germ cell tumor and spinal metastases.The patient presented with headache,dizziness,and visual impairment.Enhanced magnetic resonance imaging(MRI)of the head indicated thickening of the pituitary stalk.After multidisciplinary consultation,the patient underwent endonasal transsphenoidal resection of the tumor,with the pathological diagnosis confirming germ cell tumor.The patient received regular radiotherapy postoperatively.One year later,the tumor recurred and metastasized,leading to a second surgery for tumor resection in the thoracic spinal canal,followed by continued chemotherapy.The patient's clinical symptoms,such as headache and visual disturbances,improved,but he continued to experience panhypopituitarism and required long-term hormone replacement therapy.Early diagnosis of intracranial germ cell tumors is challenging,and they are prone to metastasis and highly sensitive to radiotherapy and chemotherapy.Early diagnosis and multidisciplinary comprehensive treatment can help improve the quality of life and prognosis for patients.