ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.

AIM To investigate the variation rules of main secondary metabolites in Hedysari Radix before and after rubbing strip.METHODS UPLC-MS/MS was adopted in the content determination of formononetin,ononin,calycosin,calycosin-7-glucoside,medicarpin,genistein,luteolin,liquiritigenin,isoliquiritigenin,vanillic acid,ferulic acid,γ-aminobutyric acid,adenosine and betaine,after which cluster analysis,principal component analysis and orthogonal partial least squares discriminant analysis were used for chemical pattern recognition to explore differential components.RESULTS After rubbing strip,formononetin,calycosin,liquiritigenin and γ-aminobutynic acid demonstrated increased contents,along with decreased contents of ononin,calycosin-7-glucoside and vanillic acid.The samples with and without rubbing strip were clustered into two types,calycosin-7-glucoside,formononetin,γ-aminobutynic acid,vanillic acid,calycosin-7-glucoside and formononetin were differential components.CONCLUSION This experiment clarifies the differences of chemical constituents in Hedysari Radix before and after rubbing strip,which can provide a reference for the research on rubbing strip mechanism of other medicinal materials.

Objective:To explore the clinical application of Hisense Computer-Assisted Sur-gery System(CAS)in the perioperative period of hepatectomy for liver cancer.Methods:Clinical data of patients undergoing laparoscopic hepatectomy(LH)for liver cancer from January 2021 to December 2022 were collected.Patients were divided into three groups based on surgical difficulty(low,medium,high)and further stratified into CAS-assisted subgroup and control subgroup ac-cording to whether the CAS system was used.Demographic and perioperative data were com-pared among different groups.Results:A total of 317 patients'clinical data were collected,in-cluding 31 cases in the low difficulty group,132 cases in th medium difficulty group,and 154 cases in the high difficulty group,with 108 cases(34.1％)in the CAS-assisted subgroup and 209 cases(65.9％)in the control group.In the medium difficulty group,the CAS-assisted subgroup had shorter operation time,drainage tube duration,and postoperative hospital stay compared to the control group(P＜0.001),and the AFP levels at 1 month postoperatively in the CAS-assisted sub-group were lower than those in the control group(P＜0.001).In the high difficulty group,the CAS-assisted subgroup showed shorter operation time,drainage tube duration,and postoperative hospi-tal stay,less intraoperative blood loss,and lower AFP levels 1 month post-operation compared to the control group(P＜0.001 for all).Conclusion:Preoperative CAS in medium and high difficulty laparoscopic liver resections improves perioperative outcomes.Hisense CAS effectively assists general surgeons in accurately identifying the anatomical site of liver tumors,providing precise pre-operative simulation and intraoperative navigation,thereby optimizing surgical strategies for pa-tients.

Bacterial biofilms gave rise to persistent infections and multi-organ failure, thereby posing a serious threat to human health. Biofilms were formed by cross-linking of hydrophobic extracellular polymeric substances (EPS), such as proteins, polysaccharides, and eDNA, which were synthesized by bacteria themselves after adhesion and colonization on biological surfaces. They had the characteristics of dense structure, high adhesiveness and low drug permeability, and had been found in many human organs or tissues, such as the brain, heart, liver, spleen, lungs, kidneys, gastrointestinal tract, and skeleton. By releasing pro-inflammatory bacterial metabolites including endotoxins, exotoxins and interleukin, biofilms stimulated the body’s immune system to secrete inflammatory factors. These factors triggered local inflammation and chronic infections. Those were the key reason for the failure of traditional clinical drug therapy for infectious diseases.In order to cope with the increasingly severe drug-resistant infections, it was urgent to develop new therapeutic strategies for bacterial-biofilm eradication and anti-bacterial infections. Based on the nanoscale structure and biocompatible activity, nanobiomaterials had the advantages of specific targeting, intelligent delivery, high drug loading and low toxicity, which could realize efficient intervention and precise treatment of drug-resistant bacterial biofilms. This paper highlighted multiple strategies of biofilms eradication based on nanobiomaterials. For example, nanobiomaterials combined with EPS degrading enzymes could be used for targeted hydrolysis of bacterial biofilms, and effectively increased the drug enrichment within biofilms. By loading quorum sensing inhibitors, nanotechnology was also an effective strategy for eradicating bacterial biofilms and recovering the infectious symptoms. Nanobiomaterials could intervene the bacterial metabolism and break the bacterial survival homeostasis by blocking the uptake of nutrients. Moreover, energy-driven micro-nano robotics had shown excellent performance in active delivery and biofilm eradication. Micro-nano robots could penetrate physiological barriers by exogenous or endogenous driving modes such as by biological or chemical methods, ultrasound, and magnetic field, and deliver drugs to the infection sites accurately. Achieving this using conventional drugs was difficult. Overall, the paper described the biological properties and drug-resistant molecular mechanisms of bacterial biofilms, and highlighted therapeutic strategies from different perspectives by nanobiomaterials, such as dispersing bacterial mature biofilms, blocking quorum sensing, inhibiting bacterial metabolism, and energy driving penetration. In addition, we presented the key challenges still faced by nanobiomaterials in combating bacterial biofilm infections. Firstly, the dense structure of EPS caused biofilms spatial heterogeneity and metabolic heterogeneity, which created exacting requirements for the design, construction and preparation process of nanobiomaterials. Secondly, biofilm disruption carried the risk of spread and infection the pathogenic bacteria, which might lead to other infections. Finally, we emphasized the role of nanobiomaterials in the development trends and translational prospects in biofilm treatment.

In this study,the immunological characteristics of the PhoP protein were explored with a two-component system of Mycobacterium tuberculosis(Mtb).Bioinformatics was used to predict the B and T cell epitopes of the PhoP protein.A re-combinant expression plasmid was constructed by PCR analysis of the phoP sequence and cloning into the prokaryotic expres-sion vector pET-28a(+).Competent Escherichia coli BL21 cells were transformed with the recombinant plasmid and expres-sion was induced with IPTG.The recombinant PhoP protein was purified by affinity chromatography.Serum levels of PhoP-specific antibodies in Mtb-infected mice and tuberculosis(TB)patients were analyzed with an ELISA.BALB/c mice were im-munized with the PhoP recombinant protein by intramuscular injection.Sera of mice were collected and antibody titers were detected with an ELISA and specificity was assessed by West-ern blot analysis.Mouse splenocytes were isolated and the pro-portions of IFN-y-positive cells and cytokine levels were detec-ted with an ELISpot and ELISA,respectively.Bioinformatics i-dentified 24 B cell and 11 T cell epitopes of the PhoP protein.A prokaryotic recombinant vector of PhoP was successfully con-structed and the recombinant PhoP protein was obtained by purification.Specific antibody levels to PhoP in sera of Mtb in-fected mice and TB patients increased significantly,with preci-sion of 99.9％and 82.5％,and specificity of 100％,respectively.PhoP protein immunization successfully induced production of specific antibodies in mice.Stimulated by antigens in vitro,IL-2 and IFN-γ levels were significantly increased in the splenocytes of immunized mice.Immunization with the PhoP protein induce a humoral immune response and Thl-dominated cellular immu-nity,indicating that the PhoP protein was immunogenic with diagnostic efficacy for TB.These results lay a foundation to clari-fy the role of PhoP in Mtb infection and application for diagnosis and prevention of TB.

Objective:To screen interleukin(IL)-1β secretion-related membrane transporters by macrophage experiment in vitro and conventional knockout mice.Methods:THP-1 cell line was differentiated to obtain human THP-1-derived macrophages,and the primary macrophages were obtained from human peripheral blood.FVB wild-type mice with the same sex and age were used as the controls of MRP1 knockout mice.The macrophages in abdominal cavity and bone marrow of mice were cultivated.The cells were treated with ABCC1/MRP1,ABCG2/BCRP,ABCB1/P-gp,OATP1B1,and MATE transporter inhibitors,then stimulated by lipopolysaccharide and adenosine triphosphate.The secretion level of IL-iβ was detected by ELISA,Western blot,and immunofluorescence.Results:After inhibiting ABCC1/MRP1 transporter,the secretion of IL-1β decreased significantly,while inhibition of the other 4 transporters had no effect.In animal experiment,the level of IL-1 β secreted by macrophages in bone marrow of MRP1 knockout mice was significantly lower than control group(P＜0.05).Conclusion:ABCC1/MRP1 transporter is a newly discovered IL-1β secretion pathway,which is expected to become a new target for solving clinical problems such as cytokine release syndrome.

Fluorescent carbon dots(CDs)were synthesized via a solvothermal method with citric acid and urea as raw materials,and ethylene glycol as reaction solvent.The micromorphology,crystal structure,elemental composition,surface functional group,and optical property of as-synthesized CDs were characterized.The excitation-dependent fluorescence property of CDs was investigated,and the effects of synthesis conditions including reaction temperature,reaction time and raw materials on excitation and emission wavelengths of the CDs were also discussed.Then,a series of CDs-based fluorescent composites were prepared by combining CDs with starch,nano-silica,montmorillonite,kaoline,kieselguhr and magnesium oxide,respectively.Finally,the CDs-starch composites were used for latent fingerprint development on smooth substrates,and the qualitative as well as quantitative evaluation of the contrast,sensitivity and selectivity in fingerprint development were also made.Enhanced development of latent fingerprints was thus achieved by the aid of the excitation-dependent fluorescence property of CDs-starch composite combined with the optical filtering technique,which could decrease the background noise interference to a great extent.Experimental results showed that,the contrast between fingerprint(developing signal)and substrate(background noise)was obvious,exhibiting a strong contrast;the minutiae of papillary ridges were clear,indicating a high sensitivity;the adsorption between CDs-starch composites and fingerprint residues was specific,showing a good selectivity.

A serious of rare earth luminescent micro/nano-materials with various properties were synthesized via chemical method for fluorescent development of latent fingerprints(LFPs).Three evaluation indexes namely contrast,sensitivity and selectivity were introduced to evaluate the effects of LFP development.Quantitative formulas for calculating the contrast,sensitivity and selectivity were further put forward,and a quality evaluation system based on Python was thus established.In addition,the objective evaluation value was finally confirmed to be consistent with the subjective visual judgment.The reproducibility of this evaluation method was finally confirmed.The effects of luminescence intensity and color of developing materials on the contrast,particle size of developing materials on the sensitivity,and micromorphology and surface property of developing materials on the selectivity were discussed in detail.Five effective ways were also proposed to promote the quality of LFP development,such as increasing the luminescence intensity,tuning the luminescence color,decreasing the particle size,adjusting the micromorphology,and modifying the surface property.This quality evaluation system based on Python could evaluate the effects of LFP development objectively,accurately and comprehensively,exhibiting easy operability,high efficiency,sensitive response,accurate and reliable results,and wide applicability,which would provide beneficial references for the reasonable selection of LFP development methods as well as objective evaluation of evidence value.

Objective To compare the application value of three image post-processing techniques volume rendering(VR),multiplanar reformation(MPR)and curved planar reformation(CPR)in the identifi-cation of rib fracture malunion.Methods The types and numbers of rib fracture malunion in 75 pa-tients were recorded,and the sensitivity,specificity,accuracy and Youden index of VR,MPR and CPR in the diagnosis of rib fracture malunion were compared.Receiver operator characteristic(ROC)curve was drawn and area under the curve(AUC)was calculated,and the detection rates of three image post-processing techniques for different types of rib fracture malunion were compared.Results A total of 243 rib fractures were malunion in 75 patients.The diagnostic sensitivity of VR,MPR and CPR for rib fracture malunion was 52.67%,79.84%and 91.36%,the specificity was 99.58%,97.89%and 99.15%,the accuracy was 83.66%,91.76%and 96.51%,the Youden index was 0.52,0.78 and 0.91,the AUC was 0.761,0.889 and 0.953,respectively.Compared with VR,there were statistically signifi-cant differences in the number of broken rib end misalignment over 1/3,broken rib end overlap,bro-ken rib end angulation and intercostal bridge detected in MPR(P<0.05).Compared with VR,there was a statistically significant difference in the number of different types of rib fracture malunion de-tected by CPR(P<0.05).Compared with MPR,there were statistically significant differences in the number of broken rib end misalignment over 1/3,broken rib end separation and intercostal bridge de-tected in CPR(P<0.05).Conclusion The three image post-processing techniques are of great signifi-cance for the identification of rib fracture malunion.Especially CPR is highly effective in the diagno-sis of rib fracture malunion,and can be used as the main post-processing technique for forensic clini-cal identification of rib fracture malunion.

Further evidence is needed to explore the impact of high-altitude environments on the neurologic function of neonates.Non-invasive techniques such as cerebral near-infrared spectroscopy and amplitude-integrated electroencephalography can provide data on cerebral oxygenation and brain electrical activity.This study will conduct multiple cerebral near-infrared spectroscopy and amplitude-integrated electroencephalography monitoring sessions at various time points within the first 3 days postpartum for healthy full-term neonates at different altitudes.The obtained data on cerebral oxygenation and brain electrical activity will be compared between different altitudes,and corresponding reference ranges will be established.The study involves 6 participating centers in the Chinese High Altitude Neonatal Medicine Alliance,with altitude gradients divided into 4 categories:800 m,1 900 m,2 400 m,and 3 500 m,with an anticipated sample size of 170 neonates per altitude gradient.This multicenter prospective cohort study aims to provide evidence supporting the impact of high-altitude environments on early brain function and metabolism in neonates.[Chinese Journal of Contemporary Pediatrics,2024,26(4):403-409]