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.

Stromal interaction molecule 1 (STIM1) is a key component mediating store-operated calcium entry (SOCE), which controls the opening and closing of plasma membrane Ca 2+ channels by sensing the Ca 2+ content of endoplasmic reticulum luminal stores, and thus affects the processes of cell adhesion, migration, gene expression and proliferation. Studies have shown that STIM1 is abnormally expressed in a variety of cells such as neurons, endothelial cells and platelets during ischemic stroke (IS) development; it plays an important role in the pathological processes regulating hypertension, promoting thrombosis, activating cellular autophagy, mediating apoptosis and promoting neuroinflammation. This review summarizes the research progress of STIM1 in the development and prognostic assessment of IS, and seeks to provide theoretical references for potential therapeutic targets for IS.

Objective Viral encephalitis is an infectious disease severely affecting human health.It is caused by a wide variety of viral pathogens,including herpes viruses,flaviviruses,enteroviruses,and other viruses.The laboratory diagnosis of viral encephalitis is a worldwide challenge.Recently,high-throughput sequencing technology has provided new tools for diagnosing central nervous system infections.Thus,In this study,we established a multipathogen detection platform for viral encephalitis based on amplicon sequencing. Methods We designed nine pairs of specific polymerase chain reaction(PCR)primers for the 12 viruses by reviewing the relevant literature.The detection ability of the primers was verified by software simulation and the detection of known positive samples.Amplicon sequencing was used to validate the samples,and consistency was compared with Sanger sequencing. Results The results showed that the target sequences of various pathogens were obtained at a coverage depth level greater than 20×,and the sequence lengths were consistent with the sizes of the predicted amplicons.The sequences were verified using the National Center for Biotechnology Information BLAST,and all results were consistent with the results of Sanger sequencing. Conclusion Amplicon-based high-throughput sequencing technology is feasible as a supplementary method for the pathogenic detection of viral encephalitis.It is also a useful tool for the high-volume screening of clinical samples.

Objective To investigate changes in the urinary metabolite profiles of children exposed to polycyclic aromatic hydrocarbons(PAHs)during critical brain development and explore their potential link with the intestinal microbiota. Methods Liquid chromatography-tandem mass spectrometry was used to determine ten hydroxyl metabolites of PAHs(OH-PAHs)in 36-month-old children.Subsequently,37 children were categorized into low-and high-exposure groups based on the sum of the ten OH-PAHs.Ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry was used to identify non-targeted metabolites in the urine samples.Furthermore,fecal flora abundance was assessed by 16S rRNA gene sequencing using Illumina MiSeq. Results The concentrations of 21 metabolites were significantly higher in the high exposure group than in the low exposure group(variable importance for projection>1,P<0.05).Most of these metabolites were positively correlated with the hydroxyl metabolites of naphthalene,fluorine,and phenanthrene(r=0.336-0.531).The identified differential metabolites primarily belonged to pathways associated with inflammation or proinflammatory states,including amino acid,lipid,and nucleotide metabolism.Additionally,these distinct metabolites were significantly associated with specific intestinal flora abundances(r=0.34-0.55),which were mainly involved in neurodevelopment. Conclusion Higher PAH exposure in young children affected metabolic homeostasis,particularly that of certain gut microbiota-derived metabolites.Further investigation is needed to explore the potential influence of PAHs on the gut microbiota and their possible association with neurodevelopmental outcomes.

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 examine the application of a novel pedagogical approach multidimensional supportive psychological intervention(MSPI)in the clinical practice teaching of andrological nursing care.Methods:Using the Hamilton Depression Scale(HAMD),we assessed the psychology of 100 nursing interns about to enter clinical practice in the Department of Andrology from De-cember 2021 to December 2022.We equally randomized the subjects into an experimental and a control group,the former receiving MSPI and the latter trained on the conventional teaching model without any psychological support intervention.Results:Compared with the baseline,the HAMD scores were significantly decreased in the experimental group after intervention(12.4±2.1 vs 8.9±2.4,P＜0.01),but increased in the controls(13.1±1.8 vs 14.7±1.9,P＜0.01);the skill scores dramatically increased in the experimental group(82.6±4.7 vs 91.2±2.4,P＜0.01),but decreased in the control group after intervention(81.0±3.5 vs 80.4±2.7,P=0.28).Conclusion:MSPI can significantly enhance the learning enthusiasm of nursing students in a short period,re-duce their psychological stress and improve teaching outcomes.This approach,combining psychology with teaching,can also strength-en the mental resilience of nursing students and better confront them with future professional challenges.

Post-stroke cognitive impairment(PSCI)is a prevalent functional impairments following stroke that seriously affects patients'quality of life and daily activities.Studies indicate a close relationship between intestinal microflora dysbiosis and central nervous system diseases.Intestinal microflora profoundly impacts on human physiological health,contributing to the stability of nervous,metabolic and immune systems through regulation of the gut-brain axis.An increasing number of studies confirmed the important role of the gut microbiome-gut-brain axis in the occurrence and development of stroke and its associated PSCI,and regulation of microbiome-gut-brain could be potential target to treatment of PSCI.This review summarizes research progress on gut microbiome-gut-brain axis and PSCI to provide a reference for exploration of related mechanisms and clinical prevention and treatment strategies.

Objective:To analyze the correlation among human retinol binding protein 4(RBP4),miR-1-3p,re-combinant human vitamin D binding protein(VDBP)and severity of ST-segment elevation myocardial infarction(STEMI)based on SYNTAX score and their diagnostic value for it.Methods:A total of 162 STEMI patients admit-ted to our hospital for treatment from January 2020 to June 2021 were selected as STEMI group,and another 67 healthy subjects who received physical examination in our hospital simultaneously were selected as healthy control group.According to SYNTAX score,STEMI group was further divided into low risk group(n=68,＜22 points),medium risk group(n=53,23 points≤SYNTAX score≤32 points)and high risk group(n=41,＞33 points).Lev-els of RBP4,VDBP and miR-1-3p expression were compared among above groups.Diagnostic value of single and combined detection of above indexes for severity of STEMI were analyzed.Correlation between SYNTAX score and above indexes were analyzed in STEMI patients.Results:Compared with healthy control group,there were signifi-cant rise in levels of RBP4[(47.18±5.24)μg/L vs.(81.40±6.11)μg/L]and VDBP[(2.36±0.75)μg/ml vs.(3.55±1.04)μg/ml],and significant reduction in miR-1-3p expression[(1.18±0.13)vs.(0.72±0.07)]in STEMI group,P＜0.001 all.Compared with low risk group,there were significant rise in levels of RBP4[(69.97±2.98)μg/L vs.(85.23±3.76)μg/L vs.(95.41±3.16)μg/L]and VDBP[(3.19±0.50)μg/ml vs.(3.55±0.52)μg/ml vs.(4.16±0.64)μg/ml],and significant reduction in miR-1-3p expression[(0.80±0.05)vs.(0.70±0.04)vs.(0.61±0.03)]in medium risk group and high risk group,and levels of RBP4 and VDBP in high risk group were significantly higher than those of medium risk group,miR-1-3p expression in high risk group was significantly lower than that of medium risk group(P＜0.001 all).ROC analysis indicated that area under the curve(AUC)of combined detection of above indexes was 0.892,which was significantly higher than each single detection(Z=4.787,3.078,2.495,P＜0.05 or＜0.01).Spearman correlation analysis indicated that STEMI severity was significant positively correlated with levels of RBP4 and VDBP(r=0.849,0.776,P＜0.001 both),and significant inversely correla-ted with miR-1-3p expression(r=-0.790,P＜0.001).Conclusion:Levels of RBP4 and VDBP,and miR-1-3p ex-pression can reflect severity of STEMI patients.Triple combined detection possesses high diagnostic efficacy for disease se-verity,which can be used as clinical important indexes for assessing patient's condition.

Objective To design a novel oxygenator to solve the existing problems of extracorporeal membrane oxygenation(ECMO)machine in high transmembrane pressure difference,low efficiency of blood oxygen exchange and susceptibility to thrombosis.Methods The main body of the oxygenator vascular access flow field was gifted with a flat cylindrical shape.The topology of the vascular access was modeled in three dimensions,and the whole flow field was cut into a blood inlet section,an inlet buffer,a heat exchange zone,a blood oxygen exchange zone,an outlet buffer and a blood outlet section.The oxygenator was compared with Quadrox oxygenator by means of ANSYS FLUENT-based simulation and prototype experiments.Results Simulation calculations showed the oxygenator designed was comparable to the clinically used ones in general,and gained advantages in transmembrane pressure difference,blood oxygen exchange and flow uniformity.Experimental results indicated that the oxygenator behaved better than Quadrox oxygenator in transmembrane pressure difference and blood oxygen exchange.Conclusion The oxygenator has advantages in transmem-brane pressure difference,temperature change,blood oxygen ex-change and low probability of thrombosis.[Chinese Medical Equipment Journal,2024,45(3):23-28]

Objective To design a prescription statistics prevention system to enhance the audit ability of the hospital.Methods The prescription statistics prevention system was designed based on intelligent analysis technology and developed with B/S architecture and IntelliJ IDEA,which used JAVA language for front-end programming and C language for back-end programming and had the functions for suspicious event locating and data retrieving,retrieved data translating,access tool monitoring and risk treatment.Results The system with high stability could be used for operation data monitoring,analysis and on-demand alarm of 7 key operation systems and 13 servers of the hospital.Conclusion The system developed enhances the hospital for preventing prescription statistics,and provides an effective means of supervision for the operational and disciplinary authorities.[Chinese Medical Equipment Journal,2024,45(5):47-51]