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.

Reproductive system diseases are among the primary contributors to the decline in social fertility rates and the intensification of aging, posing significant threats to both physical and mental health, as well as quality of life. Recent research has revealed the substantial potential of the gut microbiota in improving reproductive system diseases. Under healthy conditions, the gut microbiota maintains a dynamic balance, whereas dysfunction can trigger immune-inflammatory responses, metabolic disorders, and other issues, subsequently leading to reproductive system diseases through the gut-gonadal axis. Reproductive diseases, in turn, can exacerbate gut microbiota imbalance. This article reviews the impact of the gut microbiota and its metabolites on both male and female reproductive systems, analyzing changes in typical gut microorganisms and their metabolites related to reproductive function. The composition, diversity, and metabolites of gut bacteria, such as Bacteroides, Prevotella, and Firmicutes, including short-chain fatty acids, 5-hydroxytryptamine, γ-aminobutyric acid, and bile acids, are closely linked to reproductive function. As reproductive diseases develop, intestinal immune function typically undergoes changes, and the expression levels of immune-related factors, such as Toll-like receptors and inflammatory cytokines (including IL-6, TNF-α, and TGF-β), also vary. The gut microbiota and its metabolites influence reproductive hormones such as estrogen, luteinizing hormone, and testosterone, thereby affecting folliculogenesis and spermatogenesis. Additionally, the metabolism and absorption of vitamins can also impact spermatogenesis through the gut-testis axis. As the relationship between the gut microbiota and reproductive diseases becomes clearer, targeted regulation of the gut microbiota can be employed to address reproductive system issues in both humans and animals. This article discusses the regulation of the gut microbiota and intestinal immune function through microecological preparations, fecal microbiota transplantation, and drug therapy to treat reproductive diseases. Microbial preparations and drug therapy can help maintain the intestinal barrier and reduce chronic inflammation. Fecal microbiota transplantation involves transferring feces from healthy individuals into the recipient’s intestine, enhancing mucosal integrity and increasing microbial diversity. This article also delves into the underlying mechanisms by which the gut microbiota influences reproductive capacity through the gut-gonadal axis and explores the latest research in diagnosing and treating reproductive diseases using gut microbiota. The goal is to restore reproductive capacity by targeting the regulation of the gut microbiota. While the gut microbiota holds promise as a therapeutic target for reproductive diseases, several challenges remain. First, research on the association between gut microbiota and reproductive diseases is insufficient to establish a clear causal relationship, which is essential for proposing effective therapeutic methods targeting the gut microbiota. Second, although gut microbiota metabolites can influence lipid, glucose, and hormone synthesis and metabolism via various signaling pathways—thereby indirectly affecting ovarian and testicular function—more in-depth research is required to understand the direct effects of these metabolites on germ cells or granulosa cells. Lastly, the specific efficacy of gut microbiota in treating reproductive diseases is influenced by multiple factors, necessitating further mechanistic research and clinical studies to validate and optimize treatment regimens.

Aim To establish a stable hepatic stellate cell ( HSC ) -specific G protein-coupled receptor kinase 2 ( GRK2 ) knockout mice and provide the important animal model for further studying the biological function of GRK2 in HSC. Methods The loxP-labeled Grk2 gene mouse (Grk2

In recent years,with the continuous progress of DNA extraction and detection technology,cell-free DNA(cfDNA)has been widely used in the life science field,and its potential application value in forensic identification is becoming more and more obvious.This paper reviews the concept,formation mechanism,and classification of cfDNA,etc.,and describes the latest research progress of cfDNA in personal identification of crime scene touch DNA samples and non-invasive prenatal pater-nity testing(NIPPT).Meanwhile,this paper summarizes the potential application of cfDNA in injury inference,and discusses the advantages and disadvantages of common cfDNA analysis methods and techniques,and its application prospects,to provide a new idea for the wide application of cfDNA in the field of forensic science.

Neoantigen pulsed dendritic cell vaccine(Neo-DCVac)is a new type of tumor immunotherapy.Neoantigen is strong immunologic and tumor-specific mutated peptides expressed in a tumor.Neo-DCVac is a therapeutic modality based on the uptake and processing of neoantigens by dendritic cells and their delivery and activation of T cells to trigger the body's immune response for anti-tumor effects.The development of individualized Neo-DCVac based on high-throughput sequencing is expected to be a new direction for precision immunotherapy of tumors.In this review,we discuss construction of individualized Neo-DCVac,clinical application of combination therapy in solid tumors,suitable population for vaccination and the current limitations of Neo-DCVac,aiming to provide a theoretical reference for research on tumor immunotherapy.

Objective: To investigate the association between early life adversity(ELA) and the triglycerideglucose (TyG) index for an indicator of insulin resistance among girls with precocious puberty, so as to provide scientific basis for effective prevention and intervention measures. Methods: From July 2020 to September 2021, girls with precocious puberty were recruited from the childrens health clinic of Anhui Provincial Childrens Hospital. Among them, 150 girls with complete blood indicators and questionnaire information were included. Both parental reports and child selfreports were combined to assess ELA exposure. Fasting blood samples were collected to evaluate thetyg index. According to the ELA score classification, girls were classified into 3 groups for 0, 1 and >2, multiple linear regression analysis were conducted to examine the association between ELA exposure and TyG index in girls with precocious puberty. Results: Precocious pubertal girls subjectively reported high rates of ELA exposure, with an average ELA score of (1.07±1.17) and an average TyG level of (7.99±0.49). A single adverse association was found that the exposure of girls with precocious puberty to a lack of warm nurturing was significantly positively correlated with the TyG index (β=0.26, 95%CI=0.03-0.50, P<0.05). Multiple linear regression analysis showed that girls in the ELA≥2 group had a 0.24 increase in TyG levels compared to girls who did not experience ELA (β=0.24, 95%CI=0.04-0.43). After controlling for covariates such as child age, mothers age, fathers age, physical activity, screen time, birth weight, birth method (including natural and cesarean sections), perceived stress, BMI standardized Zscore, and parental assessment SDQ score, The association remained significant after controlling for covariates and was independent of BMI (β=0.25, 95%CI=0.04-0.46)(P<0.05). Conclusions Cumulative early life adversity in girls with precocious puberty is significantly positively correlated with the TyG index. It should early identify the girls exposed to high ELA for precocious puberty and timely intervent to improve their glucose metabolism function.

ObjectiveTo simulate the microstructure and mechanical properties of tendon tissue and promote its regeneration and repair, electrospinning technology was used to prepare L-polylactic acid (PLLA) fiber membranes loaded with different nano zinc oxide contents and with oriented structures. Physical and chemical characterization and biological performance evaluation were carried out to explore their effects on tendon cell proliferation and differentiation. MethodsPreparation of PLLA fiber scaffolds and PLLA/ZnO fiber scaffolds containing different mass fractions of nano ZnO was performed using electrospinning technology. The physicochemical properties of the scaffold were characterized by scanning electron microscopy, mechanical stretching, and EDS spectroscopy. The scaffold was co-cultured with mouse tendon cells to detect its biocompatibility and regulatory effects on cell differentiation behavior. ResultsThe fiber scaffolds were arranged in an oriented manner, and zinc elements were uniformly distributed in the fibers. The tensile strength and Young’s modulus of PLLA/0.1%ZnO fiber scaffolds were significantly higher than PLLA fiber scaffolds. The number of cells on the surface of PLLA/0.1%ZnO fiber scaffold was significantly higher than that of the PLLA group, and the activity was better; mouse tendon cells exhibit directional adhesion and growth along the fiber arrangement direction. ConclusionThe oriented PLLA/0.1%ZnO fiber scaffold had excellent physicochemical properties, which can significantly promote the oriented growth, proliferation and differentiation of tendon cells. It is expected to be used for tendon tissue regeneration and repair in the future.

Celastrol and wilforlide A are the main active triterpenoids of the traditional Chinese medicine Lei Gong Teng, which have anti-tumour, anti-inflammatory and immunosuppressive activities, and are the material basis for the clinical efficacy of Lei Gong Teng-related Chinese medicinal preparations. By analysing the biosynthetic pathway of active ingredients, optimizing genetic elements and utilizing "cell factory" to produce triterpenoids heterologously will be an effective way to obtain from Tripterygium wilfordii in the future in a "low-cost and high-efficient" manner. CYP712Ks are the first cytochrome P450s involved in the skeleton modification of friedelane-type and oleanane-type triterpenoids in T. wilfordii, and they can catalyse the generation of polpunonic acid from friedelin and 3-epi-katonic acid from β-amyrin by carboxylation at C-29 position. In this study, four multifunctional TwCYP712K1/2/3/5 were used to clarify the catalytic function and substrate selection preference using in vivo functional characterization in Saccharomyces cerevisiae. The spatial structure of the protein-substrate binding was clarified through homology modeling and molecular docking, and then the differential amino acids in the active pocket of the protein were mutated to clarify the crucial amino acids determining the catalytic function and the selection of substrate structure. A total of 63 mutant elements were constructed, and the amino acid sites affecting the carboxylation function of TwCYP712Ks were analyzed. In particular, the key amino acids affecting the substrate selectivity of TwCYP712K2 towards oleanane-type and friedelane-type triterpenoids were revealed and the TwCYP712K2^F127I and TwCYP712K2^A227T mutants would result in a reversal of the product ratio. In conclusion, four proteins of TwCYP712Ks were semi-rationally designed by homologous protein alignment and mutual mutation to elucidate multiple amino acid sites determining the catalytic function of the proteins, and a series of activity-enhancing or altering mutants were obtained, which provide abundant catalytic elements for the biosynthesis of active triterpenoids from T. wilfordii, and the mechanism of carboxylation in the C-29 position was initially elucidated.

Objective To observe the effectiveness of fluorescence labeling-based assay bundle intervention in the prevention and control of multidrug-resistant organism(MDRO)infection.Methods Patients who were detected MDRO in a hospital from January to December 2022 were selected as the research subjects.MDRO monitoring data and implementation status of prevention and control measures were collected.Fluorescence labeling assay was adopted to monitor the cleaning and disinfection effectiveness of the surrounding object surface of the bed units.Based on the bundled prevention and control measures as well as management mode of the pre-intervention group,the post-intervention group implemented enhanced rectification measures for the problems found by the pre-interven-tion group.Changes in relevant indicators between January-June 2022(before intervention)and July-December 2022(after intervention)were compared.Results There were 136 MDRO-infected patients in the pre-intervention group,208 MDRO strains were detected and 10 healthcare-associated infection(HAI)occurred.There were 128 MDRO-infected patients in the post-intervention group,198 MDRO strains were detected and 9 HAI occurred.Af-ter intervention,the total detection rates of methicillin-resistant Staphylococcus aureus(MRSA),carbapenem-re-sistant Acinetobacter baumannii(CRAB),and total MDRO from patients decreased significantly compared to before intervention(all P＜0.05).After intervention,the detection rates of MRSA,carbapenem-resistant Pseudomonas aeruginosa(CRPA),CRAB,and total MDRO from the surrounding object surface were all lower than those before intervention(all P＜0.05).The detection rate of MDRO from surrounding object surface before intervention was 34.52％,which showed a decreased trend after intervention(P＜0.05).The clearance rate of fluorescent labeled markers before intervention was 41.84％,which showed an upward trend after implementing intervention measures(from July to December),and increased to 85.00％at the end of intervention(November-December).The comp-liance rates of issuing isolation medical orders,placing isolation labels,using medical supplies exclusively,and cor-rectly handling medical waste after intervention have all increased compared to before intervention(all P＜0.05).Conclusion Adopting fluorescence labeling-based assay bundle intervention can effectively improve the effectiveness of MDRO infection prevention and control.

Objective To investigate the current situation and influencing factors of latent tuberculosis infection(LTBI)among close contacts of positive etiology pulmonary tuberculosis(PTB)patients,provide basis for formula-ting intervention measures for LTBI.Methods A multi-stage stratified cluster random sampling method was used to select close contacts of positive etiology PTB patients from 39 districts and counties in Chongqing City as the study objects.Demographic information was collected by questionnaire survey and the infection of Mycobacterium tuberculosis was detected by interferon gamma release assay(IGRA).The influencing factors of LTBI were analyzed by x2 test and binary logistic regression model.Results A total of 2 591 close contacts were included,the male to female ratio was 0.69∶1,with the mean age of(35.72±16.64)years.1 058 cases of LTBI were detected,Myco-bacterium tuberculosis latent infection rate was 40.83％.Univariate analysis showed that the infection rate was dif-ferent among peoples of different age,body mass index(BMI),occupation,education level,marital status,wheth-er they had chronic disease or major surgery history,whether they lived together with the indicator case,and whether the cumulative contact time with the indicator case ≥250 hours,difference were all statistically significant(all P＜0.05);infection rate presented increased trend with the increase of age and BMI(both P＜0.001),and decreased trend with the increase of education(P＜0.05).Logistic regression analysis showed that age 45-54 years old(OR=1.951,95％CI:1.031-3.693),age 55-64 years old(OR=2.473,95％CI:1.279-4.781),other occupations(OR=0.530,95％CI:0.292-0.964),teachers(OR=0.439,95％CI:0.242-0.794),students(OR=0.445,95％CI:0.233-0.851),junior high school education or below(OR=1.412,95％CI:1.025-1.944),BMI＜18.5 kg/m2(OR=0.762,95％CI:0.586-0.991),co-living with indicator cases(OR=1.621,95％CI1.316-1.997)and cumu-lative contact time with indicator cases ≥250 hours(OR=1.292,95％CI:1.083-1.540)were the influential fac-tors for LTBI(all P＜0.05).Conclusion The close contacts with positive etiology PTB have a high latent infection rate of Mycobacterium tuberculosis,and it is necessary to pay attention to close contacts of high age,farmers,and frequent contact with patients,and take timely targeted interventions to reduce the risk of occurrence of disease.