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.

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 Little is known about the association between whole-blood nicotinamide adenine dinucleotide(NAD+)levels and nabothian cysts.This study aimed to assess the association between NAD+levels and nabothian cysts in healthy Chinese women. Methods Multivariate logistic regression analysis was performed to analyze the association between NAD+levels and nabothian cysts. Results The mean age was 43.0±11.5 years,and the mean level of NAD+was 31.3±5.3 μmol/L.Nabothian cysts occurred in 184(27.7%)participants,with single and multiple cysts in 100(15.0%)and 84(12.6%)participants,respectively.The total nabothian cyst prevalence gradually decreased from 37.4%to 21.6%from Q1 to Q4 of NAD+and the prevalence of single and multiple nabothian cysts also decreased across the NAD+quartiles.As compared with the highest NAD+quartile(≥34.4 μmol/L),the adjusted odds ratios with 95%confidence interval of the NAD+Q1 was 1.89(1.14-3.14)for total nabothian cysts.The risk of total and single nabothian cysts linearly decreased with increasing NAD+levels,while the risk of multiple nabothian cysts decreased more rapidly at NAD+levels of 28.0 to 35.0 μmol/L. Conclusion:Low NAD+levels were associated with an increased risk of total and multiple nabothian cysts.

Tuberculosis （TB） and human immunodeficiency virus infection / acquired immune deficiency syndrome （HIV/AIDS） are both serious global public health threats. Early detection of infected persons and/or patients through TB/HIV bi-directional screening is crucial for prevention and control strategy in China and globally. In recent years， with the promotion and application of new TB and HIV detection technologies worldwide， TB/HIV bi-directional screening technologies and strategies have made remarkable changes. This expert consensus introduces the significance and challenges of TB/HIV bi-directional screening， summarizes important progress of research and applications， and makes recommendations on screening measures and procedures to further strengthen TB/HIV bi-directional screening in China.

Background::Clinical opportunistic screening is a cost-effective cancer screening modality. This study aimed to establish an easy-to-use diagnostic model serving as a risk stratification tool for identification of individuals with malignant gastric lesions for opportunistic screening.Methods::We developed a questionnaire-based diagnostic model using a joint dataset including two clinical cohorts from northern and southern China. The cohorts consisted of 17,360 outpatients who had undergone upper gastrointestinal endoscopic examination in endoscopic clinics. The final model was derived based on unconditional logistic regression, and predictors were selected according to the Akaike information criterion. External validation was carried out with 32,614 participants from a community-based randomized controlled trial.Results::This questionnaire-based diagnostic model for malignant gastric lesions had eight predictors, including advanced age, male gender, family history of gastric cancer, low body mass index, unexplained weight loss, consumption of leftover food, consumption of preserved food, and epigastric pain. This model showed high discriminative power in the development set with an area under the receiver operating characteristic curve (AUC) of 0.791 (95% confidence interval [CI]: 0.750–0.831). External validation of the model in the general population generated an AUC of 0.696 (95% CI: 0.570–0.822). This model showed an ideal ability for enriching prevalent malignant gastric lesions when applied to various scenarios.Conclusion::This easy-to-use questionnaire-based model for diagnosis of prevalent malignant gastric lesions may serve as an effective prescreening tool in clinical opportunistic screening for gastric cancer.

Objective To investigate the clinical efficacy and safety of Yiqi Huatan Tongluo Prescription(mainly composed of Fici Simplicissimae Radix,Notoginseng Radix et Rhizoma,Pinelliae Rhizoma Praeparatum,Poria,Nelumbinis Folium,and Glycyrrhizae Radix et Rhizoma,etc.)combined with drug-coated balloon(DCB)in the treatment of coronary heart disease(CHD)and to observe its effect on low-shear related serological indicators.Methods A total of 106 patients with CHD of qi deficiency and phlegm stasis obstructing collateral type who were scheduled to undergo percutaneous coronary intervention were randomly divided into a treatment group and a control group,with 53 cases in each group.The control group was treated with drug-eluting stent implantation,and the treatment group was treated with DCB.After the operation,the control group was given conventional antiplatelet aggregation drugs,and the treatment group was given oral administration of Yiqi Huatan Tongluo Prescription.The medication for the two groups lasted for 12 weeks.The changes in the serum levels of monocyte chemoattractant protein 1(MCP-1),interleukin 1 β(IL-1β)and vascular endothelial growth factor(VEGF)in the two groups were observed before and after treatment.Moreover,the traditional Chinese medicine(TCM)syndrome efficacy after treatment and the incidence of adverse events one year after operation were compared between the two groups.Results(1)After 12 weeks of treatment,the total effective rate for TCM syndrome efficacy of the treatment group was 88.68％(47/53),and that of the control group was 75.47％(40/53).The intergroup comparison(tested by chi-square test)showed that the TCM syndrome efficacy in the treatment group was significantly superior to that in the control group(P＜0.05).(2)The analysis of indicators related to endothelial dysfunction in the blood flow with low shear stress showed that after treatment,the levels of serum MCP-1,IL-1βand VEGF in the control group presented no obvious changes(P＞0.05),but the serum levels of MCP-1 and IL-1β in the treatment group were significantly lowered compared with those before treatment(P＜0.05).The intergroup comparison showed that the decrease of serum MCP-1,IL-1β and VEGF levels in the treatment group was significantly superior to that in the control group(P＜0.05).(3)The one-year follow-up after the operation showed that the total incidence of adverse events in the treatment group was 18.87％(10/53),and that in the control group was 20.75％(11/53).There was no significant difference between the two groups(P＞0.05).Conclusion Yiqi Huatan Tongluo Prescription combined with DCB has definite action on the targets related to endothelial dysfunction in coronary blood flow with low shear stress,which is conducive to reducing inflammatory response,improving the symptoms of angina pectoris and enhancing clinical efficacy.The incidence of adverse events did not increase one year after operation,indicating good safety and effectiveness.

Objective To investigate the short-term efficacy and safety of chemotherapy induced by nimotuzumab(NTZ)combined with TP regimen and sequential concurrent chemoradiotherapy in patients with epidermal growth factor receptor positive(EGFR-positive)locally advanced nasopharyngeal carcinoma.Methods A total of 48 patients with stage Ⅲ to Ⅳ A nasopharyngeal carcinoma in Guizhou Provincial People's Hospital from January 2020 to December 2022 were prospectively enrolled,and were randomized into two groups:NTP(NTZ+docetaxel/albumin-paclitaxel+cisplatin)group and TP(Docetaxel/albumin-paclitaxel+cisplatin)group(24 cases per group)by random number table method.After 2 or 3 cycles of induction chemotherapy in NTP group,NTZ was sequentially used in combination with cisplatin for concurrent chemoradiotherapy.Immunohistochemistry was used to detect the EGFR expression level,exploring EGFR expression intensity and the therapeutic effect of NTZ in NTP group patients.Meanwhile,short-term efficacy,withdrawal rate and toxic side effects were compared between the two groups after induction chemotherapy.Results In NTP group,the positive expression rate of EGFR was 100％,and EGFR expression intensity significantly correlated with the efficacy of NTZ-combined induction therapy(P<0.05).After induction chemotherapy,the objective response rate(ORR)of cervical lymph nodes in NTP group was significantly higher than that in TP group(75％vs.45.8％,P=0.039).The primary lesion ORR and overall(primary lesion and cervical lymph node)ORR showed no significant difference between the two groups(P>0.05).Comparison of adverse reactions between the two groups during induction therapy:leukopenia and gastrointestinal reaction in NTP group were lower than those in TP group(P<0.05),but rash was higher than those in TP group(P<0.05).There was no significant difference in liver function,hemoglobin and thrombocytopenia between two groups(P>0.05).Conclusions EGFR expression intensity varies in nasopharyngeal carcinoma tissues,with higher levels indicating greater clinical benefit of combined induction therapy with NTZ.NTZ combined with TP induction regimen demonstrates good short-term efficacy and safety for cervical lymph nodes in patients with locally advanced nasopharyngeal carcinoma.

Mitral valve prolapse is one of the common causes of mitral regurgitation.Mitral valve prolapse complicated with leaflet cleft is rare in clinical practice,which most often undergo surgical mitral valve repair or mitral valve replacement.We report a case of mitral valve prolapse with posterior leaflet cleft treated by transcatheter edge-to-edge mitral valve repair,in order to provide a model for similar cases.

Objective This study aimed to explore the diagnostic concordance of fractional flow reserve(FFR)and quantitative flow ratio(QFR)and the characteristics affecting this concordance.Methods Patients with non-acute myocardial infarction admitted to the Department of Cardiology,Peking University Third Hospital between January 2019 and December 2021 were enrolled.The patients were divided into four groups:FFR+/QFR+and FFR-/QFR-,FFR+/QFR-and FFR-/QFR+with FFR or QFR≤0.80 as positive and＞0.80 as negative.Using FFR as the gold standard,the diagnostic value of QFR was analyzed,and differences in clinical features and pathological characteristics among the groups were compared.Results A total of 236 patients were included.The mean age was(64.48±9.63)years,and 67.8％were male.All patients had 30％-70％coronary stenosis.The consistency rate of QFR and FFR was 78.0％(n=184),and the Person correlation coefficient was 0.557(P＜0.001).Among FFR+patients,the minimum lumen diameter was larger[(1.56±0.34)mm vs.(1.39±0.31)mm,P=0.019],lesion length was shorter[(21.37±11.73)mm vs.(36.86±18.09)mm,P＜0.001],and coronary angiography-based index of microcirculartory resistance(AMR)was higher[(277.50±28.87)mmHg·s/m vs.(178.02±49.13)mmHg·s/m,P＜0.001]in the disconcordance group.Multivariate regression analysis suggested that AMR[OR 0.93,95％CI 0.88-0.99,P=0.030]and lesion length[OR 1.27,95％CI 1.01-1.60,P=0.045]were independent predictors of disconcordance.In the FFR-group,the lesion length was longer[(33.08±16.05)mm vs.(21.40±13.36)mm,P=0.020],and AMR[(169.66±24.01)mmHg·s/m vs.(265.95±44.78)mmHg·s/m,P＜0.001]and low-density lipoprotein-C[1.57(1.10,1.97)mmol/L vs.2.15(1.79,2.74)mmol/L,P=0.031]were lower in the disconcordance group.No statistically significant variables were identified by multivariate regression.Conclusions QFR had high diagnostic value compared with FFR.In the FFR+group,AMR and lesion length may have affected the diagnostic consistency of QFR and FFR.The study provided more evidence for the clinical application of QFR.

Objective:To explore the levels of regulatory T cells(Tregs)and cytokines IL-35,TGF-β and IL-10 in peripheral blood of hemophilia A(HA)patients with F Ⅷ inhibitor and their clinical significance.Methods:43 HA patients admitted to the Hematology Department of the Affiliated Hospital of North China University of Science and Technology from October 2019 to December 2020 were selected,including 6 cases with F Ⅷ inhibitor and 37 cases without FⅧ inhibitor.In addition,20 healthy males who underwent physical examinations were selected as healthy controls.Flow cytometry was used to detect the levels of CD4+CD25+CD127-Tregs in peripheral blood of the HA patients and healthy controls,and ELISA assay was used to detect the expression levels of IL-35,TGF-β and IL-10 in serum,and their differences between different groups were compared.Results:Compared with the healthy control group,the level of Tregs in HA patients was decreased,and the level of Tregs in the FⅧ inhibitor positive group was the lowest,the difference was statistically significant(P＜0.05).There was no significant difference in the expression level of Tregs in HA patients of different severity levels.The serum IL-35,TGF-β,and IL-10 levels in both FⅧ inhibitor negative and positive groups were significantly lower than those in healthy control group,and those in FⅧ inhibitor positive group were significantly lower than those in FⅧ inhibitor negative group(all P＜0.05).Conclusion:The decrease of Tregs,IL-35,TGF-β,and IL-10 levels in HA patients may be related to the formation of FⅧ inhibitors.