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.

BACKGROUND:Degenerative scoliosis is defined as a condition that occurs in adulthood with a coronal cobb angle of the spine>10° accompanied by sagittal deformity and rotational subluxation,which often produces symptoms of spinal cord and nerve compression,such as lumbar pain,lower limb pain,numbness,weakness,and neurogenic claudication.The finite element method is a mechanical analysis technique for computer modelling,which can be used for spinal mechanics research by building digital models that can realistically restore the human spine model and design modifications. OBJECTIVE:To review the application of finite element method in the etiology and treatment of degenerative scoliosis. METHODS:The literature databases CNKI,PubMed,and Web of Science were searched for articles on the application of finite element method in degenerative scoliosis published before October 2023.Search terms were"finite element analysis,biomechanics,stress analysis,degenerative scoliosis,adult spinal deformity"in Chinese and English.Fifty-four papers were finally included. RESULTS AND CONCLUSION:(1)The biomechanical findings from the degenerative scoliosis model constructed using the finite element method were identical to those from the in vivo experimental studies,which proves that the finite element method has a high practical value in degenerative scoliosis.(2)The study of the etiology and treatment of degenerative scoliosis by the finite element method is conducive to the prevention of the occurrence of the scoliosis,slowing down the progress of the scoliosis,the development of a more appropriate treatment plan,the reduction of complications,and the promotion of the patients'surgical operation.(3)The finite element method has gradually evolved from a single bony structure to the inclusion of soft tissues such as muscle ligaments,and the small sample content is increasingly unable to meet the research needs.(4)The finite element method has much room for exploration in degenerative scoliosis.

Objective To establish an indirect enzyme-linked immunosorbent assay(ELISA)method for testing the concentration of a monoclonal antibody target tumor necrosis factor-α(TNF-α)in animal serum.Methods The critical parameters of the method including coating concentration of human TNF-α,source,concentration and stability of HRP-labeled goat anti-human immunoglobulin G(IgG)were investigated.The specificity,accuracy,precision,linearity and Limited of Determination of the method were investigated.Results The critical parameters of the method were confirmed as below:TNF-α was coated at 400 ng·mL-1;HRP labeled goat anti-human IgG antibody was diluted at 1:3.0 ×105;the diluted horseradish peroxidase labeled goat anti-human IgG antibody is well stored at 4 ℃ for 3 days.Meanwhile the method was confirmed to have good specificity,the recovery rate ranged from 84.00％to 106.82％,the coefficient of variation of different antibody concentration levels were no more than 10％;the method had a good linearity and the standard curve was y=(-8.37×103-2.37 × 106)/[1+(x/29.80)106]+2.37 × 106(R2=0.999);the limit of quantification was 1 ng·mL-1,all of which met the requirements.Conclusion A accurate and robust ELISA method was developed to test the concentration of anti-TNF-α monoclonal antibody in serum.

This study design of specific identification primers for the ITS2 sequence of F. ussuriensis. The reaction system and conditions were optimized, and PCR-nucleic acid test strips were constructed to realize the visual detection of F. ussuriensis Bark. Through molecular cloning and sequencing technology, we constructed a positive control for F. ussuriensis DNA and formulated quality standards. The established method was evaluated for sensitivity, specificity and reproducibility, and the authenticity of the commercially available samples was identified. Results demonstrated that based on the ITS2 sequences, F. ussuriensis and its mixed forgeries could be distinguished. The PCR products of the authentic F. ussuriensis on test strips showed two bands in the T and C lines, while the pseudo products and negative control showed only one band in the C line, which was consistent with the results of agarose gel electrophoresis. The specificity was 100%, and the sensitivity of the PCR-nucleic acid test strip was up to 0.1 ng·μL^-1, which was 10 times higher than that of the gel electrophoresis assay. 11 out of 16 commercially available samples of F. ussuriensis were qualified, and 5 were unqualified. Collectively, the PCR-nucleic acid test strip method established in this study is specific, rapid, accurate and visualized, which can provide a new technical idea for the detection of F. ussuriensis.

The paper is to establish an UPLC-MS/MS method for the simultaneous determination of 19 components in Microctis Folium from different production areas. The 50% methanol was used as extraction solvent. The Agilent ZORBAX SB C18 (150 mm × 2.1 mm, 1.8 μm) column was used; mobile phase was acetonitrile - 0.1% acetic acid with gradient elution, flow rate was 0.3 mL·min^-1, colume temperature was 30 ℃, and the injection volume was 2 μL; electrospray ionizaton source was used and detected in negative ion mode. The results showed that the established UPLC-MS/MS method could well separate the 19 components, and the methodological investigation results of 19 components were good. By means of orthogonal partial least squares discriminant analysis (OPLS-DA), 28 batches of Microctis Folium samples from different production areas can be divided into three categories, Guangdong, Guangxi and Hainan are each classified into one category, and 10 signature compounds which affecting the quality differences of different production areas were screened out. The established method is accurate, reliable, sensitive and reproducible. It can provide a basis for the establishment of the quality standard of Microctis Folium, as well as for safety and quality research.

Objective:To investigate the protective effect of naringenin on acute lung injury related with sepsis; To discuss its possible mechanism.Methods:Totally 30 male SD rats were randomly divided into sham-operation group, model group, naringin low-, medium- and high-dosage groups, with 6 rats in each group. The sepsis-related acute lung injury model was established by cecal ligation and puncture in all groups except the sham-operation group. After modeling, naringin low-, medium- and high-dosage groups were given naringin 20 mg/kg, 40 mg/kg and 80 mg/kg, respectively for gavage, while the sham-operation group and the model group were given the same volume of distilled water by gavage, once a day, for 2 days. Pathological changes in lung tissue were observed using HE staining. The levels of 1L-1, IL-6 and IL-18 in bronchoalveolar lavage fluid (BALF) were measured by ELISA; the expression of TNF-α in lung tissue was detected by immunofluorescence histopathology; the expressions of TGF-β1, TGF-βR1 and Smad2 were detected by Western Blot. An agonist group and a naringin plus agonist group were set up, with 6 mice in each group, and the expressions of TGF-β1 and Smad2 protein in the lung tissue of each group were detected by immunohistochemical staining to verify the effect of naringin on the expressions of TGF-β1 and Smad2 protein.Results:Compared with the model group, the pathological injury of lung tissue in naringin groups were obviously alleviated, and the levels of IL-1β, IL-6 and IL-18 in BALF decreased ( P<0.01), the protein expressions of TNF-α, TGF-β1, TGF-βR1 and Smad2 in lung tissue decreased ( P<0.01 or P<0.05). Further verification found that the expressions of TGF-β1 and Smad2 in the agonist group increased ( P<0.01), while the expressions of TGF-β1 and Smad2 in the naringin agonist group decreased ( P<0.01). Conclusion:Naringin can reduce the inflammatory response in the lung of the rats to protect against sepsis-related acute lung injury, and its protective effect could be related to the inhibition of the TGF-β1/Smad2 signaling pathway.

Objective:To explore the survival prognosis of hepatocellular carcinoma patients over 60 years old with comorbidities treated with microwave ablation.Methods:A retrospective analysis of 267 patients with hepatocellular carcinoma aged 60 years or older admitted to the PLA General Hospital from April 2012 to September 2022 were analyzed, including 179 patients with preoperative comorbidities and 88 patients without comorbidities. The overall survival (OS) and progression-free survival (PFS) of the two groups were compared by the Log-rank test, and the Cox proportional hazards regression model was used to evaluate ablation-related risk factors.Results:A total of 267 patients were included (comorbidity group, n=179; no comorbidity group, n=88). There were no statistical differences in OS and PFS between the two groups (all P>0.05). Multivariate Cox regression analysis showed that comorbidities were not risk factors that affected the survival prognosis (OS and PFS) of patients with hepatocellular carcinoma after microwave ablation ( P>0.05). Total bilirubin (hazard ratio 0.356, 95% CI=0.174-0.731, P=0.005) was a risk factor affecting OS; tumor number (hazard ratio 0.538, 95% CI=0.365-0.793, P=0.002) and international coagulation normalized ratio (hazard ratio 1.022, 95% CI=1.001-1.043, P=0.040) were risk factors affecting PFS. Subgroup analysis showed that patients with a maximum diameter of >3 cm and female patients, the OS of the comorbidity group was significantly lower than that of the non-comorbidity group( P<0.05). Conclusions:Microwave ablation therapy remains an effective treatment modality in hepatocellular carcinoma patients over 60 years of age with comorbidities, and its survival prognosis is not inferior to patients with hepatocellular carcinoma without comorbidities.

Objective China is among the 30 countries with a high burden of tuberculosis(TB)worldwide,and TB remains a public health concern.Kashgar Prefecture in the southern Xinjiang Autonomous Region is considered as one of the highest TB burden regions in China.However,molecular epidemiological studies of Kashgar are lacking. Methods A population-based retrospective study was conducted using whole-genome sequencing(WGS)to determine the characteristics of drug resistance and the transmission patterns. Results A total of 1,668 isolates collected in 2020 were classified into lineages 2(46.0%),3(27.5%),and 4(26.5%).The drug resistance rates revealed by WGS showed that the top three drugs in terms of the resistance rate were isoniazid(7.4%,124/1,668),streptomycin(6.0%,100/1,668),and rifampicin(3.3%,55/1,668).The rate of rifampicin resistance was 1.8%(23/1,290)in the new cases and 9.4%(32/340)in the previously treated cases.Known resistance mutations were detected more frequently in lineage 2 strains than in lineage 3 or 4 strains,respectively:18.6%vs.8.7 or 9%,P<0.001.The estimated proportion of recent transmissions was 25.9%(432/1,668).Multivariate logistic analyses indicated that sex,age,occupation,lineage,and drug resistance were the risk factors for recent transmission.Despite the low rate of drug resistance,drug-resistant strains had a higher risk of recent transmission than the susceptible strains(adjusted odds ratio,1.414;95%CI,1.023-1.954;P = 0.036).Among all patients with drug-resistant tuberculosis(DR-TB),78.4%(171/218)were attributed to the transmission of DR-TB strains. Conclusion Our results suggest that drug-resistant strains are more transmissible than susceptible strains and that transmission is the major driving force of the current DR-TB epidemic in Kashgar.

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.

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.