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.

Aim To explore whether platelet-derived growth factor C(PDGFC)derived from cancer-associat-ed fibroblasts(CAFs)can promote resistance of breast cancer cells to doxorubicin(DOX)and the underlying mechanisms.Methods CAFs and normal fibroblasts(NFs)were extracted from freshly resected breast cancer tissue and adjacent normal breast tissue respec-tively.Conditioned medium(CM)from CAFs and NFs was collected and co-cultured with breast cancer cells.Cell proliferation and toxicity were assessed using a Cell Counting Kit-8(CCK-8).The expression of PDG-FC in CAFs,NFs and corresponding CM was detected by Western blot and ELISA respectively.The influence of CAFs-CM on intracellular doxorubicin content in breast cancer cells was observed by fluorescence mi-croscopy.The impact of CAFs-CM on apoptosis-related proteins BAX and BCL2 was predicted and valifated u-sing the Starbase database and Western blot.The changes in ROS levels,mitochondrial membrane po-tential,and mitochondrial membrane proteins TOM20 and COX Ⅳ in breast cancer cells were measured using DCFH-DA fluorescence staining,JC-1 assay,and Western blot.Results CAFs-CM decreased the intra-cellular doxorubicin content and inhibited the sensitivi-ty of breast cancer cells to doxorubicin.Additionally,the expression of apoptosis protein BAX decreased while the anti-apoptotic protein BCL2 increased in breast cancer cells cultured with CAFs-CM.Further-more,CAFs-CM led to decreased ROS levels and in-creased mitochondrial membrane potential in breast cancer cells accompanied with elevated expression of mitochondrial membrane proteins TOM20 and COX Ⅳ.Further study found that PDGEF was highly expressed in CAFs and CAFs-CM,recombinant human PDGFC produced resistance of breast cancer cells to DOX simi-lar to CAFs-CM,and the specific inhibitors of PDGFRα significantly inhibited CAFs-CM.Further mechanistic studies revealed that PDGFC in CAFs-CM induced chemoresistance by activating PI3K-mTOR signaling pathway.Conclusion PDGFC secreted by CAFs promotes doxorubicin resistance in breast cancer cells through PI3K-mTOR signaling pathway,which provides a new perspective for the development of anti-cancer drugs targeting CAFs.

Objective:To establish a general method for the simultaneous determination of hydroxyphenyl esters and quaternary ammonium bacteriostatic agents in eye drops.Methods:The chromatographic analysis was per-formed on an Agilent C18 column(4.6 mm ×250 mm,5 μm)with 1％triethylamine solution(pH adjusted to 5.0 with phosphoric acid)as mobile phase A and methanol as mobile phase B.Gradient elution was performed at col-umn temperature of 40 ℃.The detection wavelength was 214 nm,the flow rate was 1 mL·min-1,and the injec-tion volume was 20 μL.Results:Methylparaben,ethylparaben,propylparaben,butylparaben,benzalkonium chlo-ride and benzalkonium bromide were 0.11-559.0,0.10-513.0,0.10-258.8,0.11-270.5,1.07-537.0 and 1.03-512.8 μg·mL-1,respectively.The linear range was good(r＞0.999).The average recoveries of meth-ylparaben,benzalkonium bromide and benzalkonium chloride were 104.7％(RSD=1.3％),102.6％(RSD=1.1％)and 100.9％(RSD=1.1％),respectively.The contents of bacteriostatic agent in 100 batches of eye drops from 36 varieties of 12 enterprises were determined,and the accurate results were obtained.Conclusion:This meth-od provides a reference for the content quality control and safety evaluation of bacteriostatic agents in eye drops.

Objective To explore the clinical efficacy of double beam double tunnel enhanced reconstruction technique in the treatment of knee anterior cruciate ligament(ACL)training injuries.Methods Twenty-nine cases of ACL injury of knee joint from January 2021 to December 2021 were retrospectively analyzed.All the cases were underwent ligament reconstruc-tion surgery.Cases were grouped by surgical technique:there were 14 patients in conventional reconstruction group,including 13 males and 1 female,aged from 22 to 31 years old with an average of(27.07±7.28)years old,autogenous hamstring tendon was used for ligament reconstruction.There were 15 patients in the enhanced reconstruction group,including 13 males and 2 females,aged from 25 to 34 years old with an average of(29.06±4.23)years old,double tunnel ligament reconstruction,the autogenous hamstring muscle was used as the anteromedial bundle,and the posterolateral bundle was replaced by a high-strength line.The difference between knee tibial anterior distance,Lysholm score,International Knee Literature Committee(IKDC)subjective score,Tegner motor level score and visual analog scale(VAS)at 6th and 12th months after the surgery,limb symmetry index(LSI)were recorded at the last follow-up and surgery-related adverse effects during follow-up.Results All patients were followed up,ranged from 13 to 15 months with an average of(13.7±0.8)months.There were no serious adverse reactions related to surgery during the period.There was no statistical difference between the preoperative general data and the observation index of the two groups(P＞0.05).The difference in tibial anterior distance at 6 and 12 months in the enhanced re-construction group(1.45±0.62)mm and(1.74±0.78)mm which were lower those that in the conventional reconstruction group(2.42±0.60)mm and(2.51±0.63)mm(P＜0.05).There was no significant difference in postoperative Lysholm score,Tegner motor level score,IKDC score,VAS,and limb symmetry index at the last follow-up(P＞0.05).Conclusion The enhanced recon-struction technique can more effectively maintain the stability of the knee joint and has no significant effect on the postoperative knee joint function compared with the traditional ligament reconstruction technique.The short-term curative effect is satisfac-tory,and it is suitable for the group with high sports demand.

Objective:To understand the whole genome and genetic evolution characteristics of the first epidemic influenza A (H3N2) viruses in Wuxi from 2022-2023.Methods:Real time fluorescence quantitative RT-PCR method was used to perform typing on respiratory samples of influenza cases. Virus isolation was performed on samples with positive nucleic acid of subtype A H3N2 influenza virus detected. After cell culture, nucleic acid was extracted from strains with red blood cell agglutination test (HA) ≥ 1∶8, whole genome sequence was amplified, library was constructed, and computer sequencing was performed using MiSeq sequencer. Using NC_007366.1 as reference strain, the data were analyzed using CLC Genomics Workbench (Version 23) software. The phylogenetic tree was constructed using MEGA 7.0 software, and the N-glycosylation sites were predicted by NetNGlyc 1.0 Server software.Results:The nucleotide homology and amino acid homology among 35 strains of influenza A H3N2 virus from 2022 to 2023 were 96.4%-100% and 95.2%-100%, respectively. The 16 epidemic strains in 2022 belong to the 3C.2a1b.2a.1a evolutionary branch, while the 19 epidemic strains in 2023 belong to the 3C.2a1b.2a.2a.3a.1 evolutionary branch. There are 7 differences in the nucleotide sequence of the HA gene between the 2022 epidemic strain and the corresponding vaccine strain, sharing 15 mutation sites; There are 28 differences in the nucleotide sequence of the HA gene between the 2023 epidemic strain and the corresponding vaccine strain, sharing 17 mutation sites. The HA genes of 35 epidemic strains all lack N-glycosylation site 61: NSS, while in 2023, the HA genes of 19 epidemic strains added N-glycosylation site 110: NSS.Conclusions:The HA and NA genes of influenza A H3N2 virus in 2022 and 2023 belong to two evolutionary branches, respectively, and both show specific amino acid site changes compared to the corresponding vaccine strains. The antigen matching between the 2022 epidemic strain and the vaccine strain is relatively good, while there is a risk of low antigen matching between the 2023 epidemic strain and the vaccine strain.

Objective To explore the effectiveness and safety of percutaneous coronary artery shock wave balloon angioplasty(IVL)under the guidance of intravascular ultrasound(IVUS)for the treatment of severe calcification lesions in the left main artery(LM).Methods A total of 26 patients with severe LM(mouth,body,bifurcation)calcification admitted to Jiangnan University Affiliated Hospital from October 2022 to April 2024 were included,with an average age of 72.0(61.8,75.4)years.Under the guidance of IVUS,IVL was used for pre-treatment of calcified lesions,followed by percutaneous coronary intervention(PCI)with stent/drug balloon implantation.All patients were evaluated using IVUS before and after the use of IVL and after PCI.And compare the IVUS intracavity related data before and after treatment[plaque burden(PB)、minimum lumen area(MLA)、minimum lumen diameter(MLD)]and calcification fracture number,minimum stent area(MSA),stent expansion coefficient(expansion,EXP),etc.Results There were 26 patients(2 with opening lesions,7 with body lesions,and 17 with bifurcation lesions at the end of the main trunk),including 7 with stable angina pectoris(SAP),10 with unstable angina(UA),4 with acute ST-segment elevation myocardial infarction(STEMI),and 5 with non ST-segment elevation myocardial infarction(NSTEMI).The PB at the most severe site of calcification decreased by 79.50(76.00,83.75)％compared to 80.00(76.00,83.75)％after IVL(P=0.001),MLA increased by 3.39(3.14,3.68)mm2 compared to 3.38(3.14,3.67)mm2 after IVL(P=0.039),MLD increased by 3.21(3.07,3.30)mm compared to 3.20(3.07,3.30)mm after IVL(P=0.024),and there was 100％calcification rupture(1/2 cases,2/9 cases,≥3/15 cases).The stent/drug ball was successfully implanted 100％,with EXP of(89.15±4.42)％and an MSA of 7.20(6.46,7.45)mm2.No adverse events such as death,angina or recurrent myocardial infarction occurred during the 3 months follow-up after surgery.Conclusions After evaluation by IVUS and pre-treatment with IVL,PCI was successfully completed for severe calcification lesions in LM,and IVL can be used as an option for the treatment of severe calcification in LM.

Here,5 important pathogens carried by ticks in Maanshan City,Anhui Province,China were identified.In to-tal,642 ticks were collected from 13 villages around Maanshan City and identified by morphological and mitochondrial COI genes.The 16S rRNA gene of Francisella tularensis,ssrA gene of Bartonella,16S rRNA,ompA and ompB genes of Rickett-sia,16S rRNA and gltA genes of Anaplasma,and groEL and rpoB genes of Coxiella were sequenced.Reference sequences were retrieved from a public database.Phylogenetic trees were constructed with MEG A1 1.0 software.In total,36 Rickettsiae isolates were detected in 640 Haemaphysalis longicornis ticks,which included 20 isolates of Rickettsia heilongjian-gensis,16 of Candidatus Rickettsia jingxinensis,2 of Ana-plasma bovis,and 186 of Coxiella-like endosymbiont.R.hei-longjiangensis HY2 detected in this study and Anhui B8 strain,Ca.R.jingxinensis QL3 and those from Shanxi Prov-ince and Jiangsu Province,A.bovis JX4 and those from Shanxi Province were clustered on the same branch.Overall,17 ticks had combined infections and none of the 5 bacteria were detected in two Amblyomma testudinarium ticks.This is the first report of Ca.R.jingxinensis detected in H.longicornis ticks from Anhui Province.It is recommended that the two types of Rickettsia that cause spotted fever and A.bovis should be reported to local health authorities to initiate appropriate prevention and control measures.

Objective:To optimize the technical parameters related to the preparation of novel frozen human platelets and formulate corresponding protocol for its preparation.Methods:Novel frozen human platelets were prepared with O-type bagged platelet-rich plasma(PRP),the key technical parameters(DMSO addition,incubation time,centrifugation conditions,etc.)of the preparation process were optimized,and the quality of the frozen platelets was evaluated by routine blood tests,apoptosis rate,platelet activation rate and surface protein expression level.Results:In the preparation protocol of novel frozen human platelets,the operation of centrifugation to remove supernatant was adjusted to before the procedure of platelets freezing,and the effect of centrifugation on platelets was minimal when the centrifugation condition was 800 xg for 8 min.In addition,platelets incubated with DMSO for 30 min before centrifugation exhibited better quality after freezing and thawing.The indexes of novel frozen human platelets prepared with this protocol remained stable after long-term cryopreservation.Conclusion:The preparation technique of novel frozen human platelets was established and the protocol was formulated.It was also confirmed that the quality of frozen platelets could be improved by incubating platelets with DMSO for 30 min and then centrifuging them at 800 ×g for 8 min in the preparation of novel frozen human platelets.

Objective To explore the influencing factors of home pulmonary rehabilitation for lung transplant re-cipients,so as to provide a basis for the construction of targeted intervention for home rehabilitation.Methods From August to November 2023,the purposive sampling was used to select 20 cases of lung transplant recipients for semi-structured interviews.Data was analyzed by traditional content analysis method based on capability,opportunity,and motivation-behavior model.Results Facilitators of rehabilitation behavior included opportunity factors(rehabilitation management of transplant center,multiple social support),motivational factors(perceived benefits,high self-efficacy,strong motivation,strong sense of responsibility,and good exercise habits).Barriers of rehabilitation behavior included ability factors(physical dysfunction,lack of knowledge),opportunity factors(poor rehabilitation environment,heavy eco-nomic burden),motivational factors(fear of exercise,uncomfortable activity experience,and lack of rehabilitation self-discipline).Conclusion The influencing factors of home pulmonary rehabilitation in lung transplant recipients are complex.Medical staff should take targeted measures to promote home rehabilitation to improve the exercise ability,quality of life,and clinical outcomes.

Objective:To establish a rapid quantitative PCR (qPCR) technique for Mycobacterium marinum skin infections, and to analyze its clinical diagnostic efficiency. Methods:DNA was extracted from Mycobacterium marinum colonies and serially diluted (10 -1 to 10 -8). Twelve pairs of previously reported primers and probes, as well as 6 pairs of newly designed primers and probes in this study, were used for qPCR amplification to identify the most sensitive primers and probes for the detection of Mycobacterium marinum. Skin lesion tissues were collected from 72 patients with confirmed Mycobacterium marinum infections (experimental group) and 68 with other mycobacterial infections (control group) at Shandong Provincial Hospital for Skin Diseases & Shandong Provincial Institute of Dermatology and Venereology, Shandong First Medical University & Shandong Academy of Medical Sciences in 2021. These skin tissues were subjected to qPCR amplification, interferon-gamma release assay (IGRA), acid-fast staining, and tissue culture to evaluate the diagnostic efficacy. Results:The newly designed primers and probes targeting the mycobacterial enhanced infection locus 2 (Mel2) demonstrated the highest sensitivity, with a detection limit of 0.86 copies/μl (cycle threshold value = 37) ; the qPCR amplification with the Mel2 primers/probes did not yield positive results when used for the detection of other mycobacteria (including Mycobacterium leprae and Staphylococcus spp) . Among the 72 patients in the experimental group, 44 were positive for qPCR with a sensitivity of 61.1% (95% CI: 49.6% - 71.5%), and 47 were positive for culture with a sensitivity of 65.2% (95% CI: 53.8% - 75.3%) ; all the 68 controls were negative for both qPCR and culture, with their specificities both being 100%. Among 65 patients subjected to IGRA, 31 were positive with a sensitivity of 47.7% (95% CI: 36.0% - 59.6%), while 16 out of 25 controls were negative for IGRA with a specificity of 64.0% (95% CI: 44.5% - 79.8%). Among 58 patients subjected to acid-fast staining, 37 were positive with a sensitivity of 63.8% (95% CI: 50.9% - 74.9%), and 52 out of 66 controls were negative for acid-fast staining with a specificity of 78.8% (95% CI: 67.5% - 86.9%). The combination of qPCR and culture resulted in a sensitivity of 93% and a specificity of 100% for the detection of Mycobacterium marinum. Conclusion:In this study, a highly sensitive qPCR assay was developed for the detection of Mycobacterium marinum, and its combination with culture could further improve the detection sensitivity.