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.

ObjectiveThis study aimed to investigate the effects of 4-week high-intensity interval training (HIIT) on synaptic plasticity in the prefrontal cortex (PFC) of rats exposed to chronic unpredictable mild stress (CUMS), and to explore its potential mechanisms. MethodsA total of 48 male Sprague-Dawley rats were randomly divided into 4 groups: control (C), model (M), control plus HIIT (HC), and model plus HIIT (HM). Rats in groups M and HM underwent 8 weeks of CUMS to establish depression-like behaviors, while groups HC and HM received HIIT intervention beginning from the 5th week for 4 consecutive weeks. The HIIT protocol consisted of repeated intervals of 3 min at high speed (85%-90% maximal training speed, S_max) alternated with one minute at low speed (50%-55% S_max), with 3 to 5 sets per session, conducted 5 d per week. Behavioral assessments and tail-vein blood lactate levels were measured at the end of the 4th and 8th weeks. After the intervention, rat PFC tissues were collected for Golgi staining to analyze synaptic morphology. Enzyme-linked immunosorbent assays (ELISA) were employed to detect brain-derived neurotrophic factor (BDNF), monocarboxylate transporter 1 (MCT1), lactate, and glutamate levels in the PFC, as well as serotonin (5-HT) levels in serum. Additionally, Western blot analysis was conducted to quantify the expression of synaptic plasticity-related proteins, including c-Fos, activity-regulated cytoskeleton-associated protein (Arc), and N-methyl-D-aspartate receptor 1 (NMDAR1). ResultsCompared to the control group (C), the CUMS-exposed rats (group M) exhibited significant reductions in sucrose preference rates, number of grid crossings, frequency of upright postures, and entries into and duration spent in open arms of the elevated plus maze, indicating marked depressive-like behaviors. Additionally, the group M showed significantly reduced dendritic spine density in the PFC, along with elevated levels of c-Fos, Arc, NMDAR1 protein expression, and increased concentrations of lactate and glutamate. Conversely, BDNF and MCT1 contents in the PFC and 5-HT levels in serum were significantly decreased. Following HIIT intervention, rats in the group HM displayed considerable improvement in behavioral indicators compared with the group M, accompanied by significant elevations in PFC MCT1 and lactate concentrations. Furthermore, HIIT notably normalized the expression levels of c-Fos, Arc, NMDAR1, as well as glutamate and BDNF contents in the PFC. Synaptic spine density also exhibited significant recovery. ConclusionFour weeks of HIIT intervention may alleviate depressive-like behaviors in CUMS rats by increasing lactate levels and reducing glutamate concentration in the PFC, thereby downregulating the overexpression of NMDAR, attenuating excitotoxicity, and enhancing synaptic plasticity.

Objective To observe the therapeutic effect and mechanism of acupuncture at Zusanli-Zhongwan combined matching points on rats with exercise-induced stress gastric ulcer.Methods Forty male SD rats were randomly divided into blank group,model group,acupuncture group and Omeprazole group,with 10 rats in each group.Except for the blank group,the rats in the other groups were used to construct the model of exercise stress gastric ulcer by daily exhaustive swimming.After successful modeling,the acupuncture group was intervened by acupuncture at Zusanli(ST36)and Zhongwan(RN12),once a day,10 minutes each time.Rats in the Omeprazole group were given Omeprazole Enteric-Coated Tablets distilled water suspension by gavage two hours before daily swimming.After continuous 7-day intervention,the overall state and behavior of rats were observed,the gastric mucosal injury index was calculated by Guth method,the pathological morphology of gastric mucosa was observed by hematoxylin-eosin(HE)staining,the contents of superoxide dismutase(SOD),glutathione peroxidase(GSH-PX)and malondialdehyde(MDA)in serum were correspondingly determined by WST-1 method,colorimetry and TBA method,respectively,enzyme-linked immunosorbent assay(ELISA)was used to detect the contents of gastrin(GAS),somatostatin(SS),tumor necrosis factor-α(TNF-α),interleukin-1 β(IL-1β),interleukin-6(IL-6)and interleukin-10(IL-10)in serum,the expression levels of epidermal growth factor receptor(EGFR),matrix metalloproteinase 3(MMP3),nuclear factor erythroid-related factor 2(NRF2),heme oxygenase 1(HO-1)and mitochondrial SOD2,TNF-α,IL-1β,IL-6 and IL-10 mRNA in gastric mucosa were detected by real-time fluorescence quantitative polymerase chain reaction(qPCR).Results Compared with the blank group,the body mass of rats in the model group was increased slowly,the activity distance and activity in the open field test were decreased,the gastric mucosal ulcer index was increased significantly,the gastric mucosal function indexes involving GAS level was increased and SS level was decreased in serum,the mRNA expression level of EGFR in gastric mucosa was decreased and the mRNA expression level of MMP3 in gastric mucosa was increased.The serum levels of antioxidant substances SOD and GSH-PX were decreased significantly,and the serum level of oxidation product MDA was increased significantly.The mRNA expression levels of antioxidant genes NRF2,HO-1 and SOD2 in gastric mucosa were significantly decreased.The serum contents and the gastric mucosa mRNA levels of inflammatory factors TNF-α,IL-1α,IL-6 were significantly increased,while the serum content and the gastric mucosa mRNA level of IL-10 were significantly decreased.The differences were statistically significant(P＜0.05 or P＜0.01 or P＜0.001).HE staining showed obvious gastric mucosal injury.Compared with the model group,the above indexes in the acupuncture group and the Omeprazole group were significantly improved(P＜0.05 or P＜0.01 or P＜0.001).HE staining showed that the gastric mucosal injury was significantly reduced.Conclusion Acupuncture at Zusanli-Zhongwan combined matching points can reduce the local oxidative stress and inflammatory response in rats with exercise-induced stress gastric ulcer,reduce gastric mucosal injury,improve the emotional state of rats,and maintain the overall vitality of rats.

Objective:To investigate the status quo of training and domestic use of 707 clinical nutrition support specialty nurses from 21 provinces,cities,and autonomous regions in China. And to analyze their influencing factors and provide reference for improving the training system of clinical nutrition support specialty nurses,selection and development of specialist nurses in clinical nutrition support. Methods:From October to November 2023,a cross-sectional survey was conducted on 707 clinical nutrition support specialty nurses from 21 provinces,cities,and autonomous regions across China was conducted using a convenience sampling method based on a questionnaire about the training and home use of clinical nutrition support nurses. Univariate and multiple linear regression analysis was used to examine the use status and application of clinical nutrition support specialty nurses in five aspects:clinical nursing practice,nursing education,nursing management,coordination,nursing research and consultation. Results:The use of specialist clinical nutrition support nurses is not ideal,with 75.67％ of specialist nurses scoring less than 208 points (i.e. less than 80％ of the total score). Among the use of different dimensions,the clinical nursing practice dimension received the highest score (54.17±10.26),followed by the nursing education dimension (36.98±8.00). The results of multiple linear regression analysis show that hospital level and professional title are independent influencing factors influencing the use and development of specialist nurses. Conclusion:There is a need to further improve the utilisation of clinical nutrition support nurses. It is recommended that links and cooperation between hospitals at all levels,communities,and families be strengthened. For specialist nurses with higher professional titles,encourage them to fully play their roles,strengthen training in weak areas,continuously optimize the professional ability of clinical nutrition support nursing teams,comprehensively improve the quality of clinical nutrition support specialist nursing,and promote their high-level development.

To address the key challenges in multivariate statistical modeling,a higher-order derivative approach combined with vector space angle multiplicative error correction was proposed for establishing an acid value prediction ordinary least squares(OLS)regression model based on attenuated total reflectance-Fourier transform infrared(ATR-FTIR)spectroscopy.By using acid values measured by potentiometric titration as reference,ATR-FTIR spectroscopy was utilized for direct calibration and prediction of acid values on 96 kinds of lubricating oil samples from a wind turbine.Firstly,the simulated hyperbolic(SH)method was employed to obtain accurate fourth derivative spectrum,resolving overlapping bands and enhancing spectral selectivity.Then,from the calibration set(48 samples),informative spectral regions were identified based on correlation coefficients.Next,the sample with the highest acid value was selected as the reference and1/(1+tan(θ/2))was used as the metric relation of the spectrum to suppress the multiplicity error caused by factors such as the change of effective optical path in ATR-FTIR spectroscopy.After pretreatment of the spectrum by the method of fourth-order derivative combined with angular quantity,the number of variables decreased from 1737 to 8,and the matrix condition number decreased from 1.85×1015 to 56.34,which effectively eliminated the collinearity issue for OLS regression.Direct OLS modeling on spectral preprocessed data achieved a determination coefficient of 0.981 for 47 validation samples,with a relative error range of-8.38%-8.22%,outperforming the commonly used partial least squares(PLS)method(Determination coefficient of 0.865,relative error of-27.82%-22.38%).It was proved that effective data preprocessing significantly improved the prediction accuracy of the model.Furthermore,when the number of calibration set was compressed to 25 and the number of validation set was expanded to 70,the model retained 8 variables with a condition number of 42.60,the determination coefficient of validation set was 0.972,and the relative error ranged from-10.80%to 12.31%.Comparing with the PLS method(Determination coefficient of 0.724,relative error of-34.26%-53.84%),the improvement was more obvious,which showed that the method could still have high prediction accuracy even with fewer modeling samples as well as robustness against multiplicative error interference.

Objective To explore the potential mechanism of carvacrol on inhibiting the formation of biofilm of hy-pervirulent Klebsiella pneumoniae(hvKP).Methods The possible mechanisms of carvacrol were analyzed based on the detection of its effects on the formation and morphology of biofilms,changes in extracellular polysaccharide and capsule polysaccharide content,as well as changes in the expression levels of biofilm-related genes rmpA2,mag A,mrkA,mrkB,and treC of hvKP.Results The minimum inhibitory concentration of carvacrol on hvKP was 512 μg/mL,with an obvious inhibitory effect on the biofilm formation of hvKP,presenting a concentration-depen-dent effect.Under the scanning electron microscope,it was observed that the biofilm structure was loose and the in-tercellular connections were not dense under the intervention of carvacrol.The Congo Red adsorption test and m-hydroxybiphenyl colorimetric method showed that carvacrol could reduce the content of capsule polysaccharides of hvKP,but didn't affect the total extracellular polysaccharide content.Fluorescence quantitative polymerase chain reaction(PCR)showed that under the effect of carvacrol at sub-inhibitory concentration,the synthesis of capsule polysaccharide,expression levels of sugar transport system and pili adhesion-related genes all decreased by more than 50％.Conclusion Carvacrol has a significant inhibitory effect on the formation of biofilm in hvKP,and its mechanism may be related to the decrease of synthesis of capsule polysaccharide as well as expression of biofilm-re-lated genes,such as sugar transport system and pili adhesion.

Objective To compare screw versus Kirschner wire fixation in the treatment of lateral humeral condyle frac-tures in children.Methods A systematic search was conducted in PubMed,Embase,the Cochrane library,Web of Science,China National Knowledge Internet(CNKI),Wanfang Datebase from in ception to February 2022.Studies comparing screws and Kirschner wire fixation in the treatment of lateral humeral condyle fractures in children were included.Outcome measures included and excluded by a set of inclusion and exclusion criteria and evaluated for their quality,their excellent and good rate of fracture healing,malunion,delayed union or nonunion,infection,limitation of elbow flexion or extension(＞10°)were ex-tracted and analyzed using software Rev Man 5.3.Results A total of 9 retrospective studies involving 647 patients were includ-ed,with 255 patients in the screw fixation group(including screw combined with Kirschner wire)and 392 patients in the Kirschner wire fixation group.Meta analysis showed the following:infection rate in the screw group was significantly lower than that in the Kirschner wire group[OR=0.22,95％CI(0.09,0.56),P=0.001].There were no significant differences between the 2 groups in excellent and good rate of fracture healing,malunion rate(P＞0.05).Subgroup analysis showed that infection rate in the screw-only group was significantly lower than that in the Kirschner wire group[OR=0.18,95％CI(0.05,0.65),P=0.009].Conclusion For lateral humeral condyle fractures,Screw fixation alone had a lower infection rate than kirschner wire fixation and screw combined with Kirschner wire fixation.There were no significant differences in the excellent and good rate of fracture healing,malunion.In terms of postoperative efficacy and safety of internal fixation,orthopaedic surgeons are more like-ly to recommend screws for fixation of lateral humeral condyle fractures in children.

Objective:To investigate the effect of CD8+CD28-T cells on acute graft-versus-host disease(aGVHD)after haploidentical hematopoietic stem cell transplantation(haplo-HSCT).Methods:The relationship between absolute count of CD8+CD28-T cells and aGVHD in 60 patients with malignant hematological diseases was retrospectively analyzed after haplo-HSCT,and the differences in the incidence rate of chronic graft-versus host disease(cGVHD),infection and prognosis between different CD8+CD28-T absolute cells count groups were compared.Results:aGVHD occurred in 40 of 60 patients after haplo-HSCT,with an incidence rate of 66.67％.The median occurrence time of aGVHD was 32.5(20-100)days.At 30 days after the transplantation,the absolute count of CD8+CD28-T cells of aGVHD group was significantly lower than that of non-aGVHD group(P=0.03).Thus the absolute count of CD8+CD28-T cells at 30 days after transplantation can be used to predict the occurrence of aGVHD to some extent.At 30 days after transplantation,the incidence rate of aGVHD in the low cell count group(CD8+CD28-T cells absolute count＜0.06/μl)was significantly higher than that in the high cell count group(CD8+CD28-T cells absolute count ≥0.06/μl,P=0.011).Multivariate Cox regression analysis further confirmed that the absolute count of CD8+CD28-T cells at 30 days after transplantation was an independent risk factor for aGVHD,and the risk of aGVHD in the low cell count group was 2.222 times higher than that in the high cell count group(P=0.015).The incidence of cGVHD,fungal infection,EBV infection and CMV infection were not significantly different between the two groups with different CD8+CD28-T cells absolute count.The overall survival,non-recurrent mortality and relapse rates were not significantly different between different CD8+CD28-T cells absolute count groups.Conclusion:Patients with delayed CD8+CD28-T cells reconstitution after haplo-HSCT are more likely to develop aGVHD,and the absolute count of CD8+CD28-T cells can be used to predict the incidence of aGVHD to some extent.The absolute count of CD8+CD28-T cells after haplo-HSCT was not associated with cGVHD,fungal infection,EBV infection,and CMV infection,and was also not significantly associated with the prognosis after transplantation.

Methamphetamine abuse is a major public health problem in the world,and in recent years,methamphetamine is also the most abused synthetic drug in China.The neurotoxic or addiction mechanism of methamphetamine has not been fully clarified,and there is still a lack of specific withdrawal methods and drugs for methamphetamine abuse.Mitochondria are not on-ly the organelles to which methamphetamine directly produces toxic effects,but also participate in regulating the neurotoxic damage process of methamphetamine.Mitochondrial quality is the regulatory basis for maintaining mitochondrial homeostasis and is regulated by three main mechanisms,which are mitochon-drial biogenesis,mitochondrial dynamic,and mitophagy.This review summarizes the research progress of mitochondrial quality control in methamphetamine-induced neurotoxicity,which may provide theoretical support for further research on the mechanism of methamphetamine neurotoxicity and development the mito-chondria-targeting drugs.

Aim To investigate the effect of Dahuang Tangluo pills(DHTL)on NOD-like receptor protein 3(NLRP3)/cysteine aspartate proteolytic enzyme-1(caspase-1)/apodermic D(GSDMD)pathway-media-ted pyroptosis in db/db mice with diabetic kidney dis-ease(DKD)and the underlying mechanism.Methods Eight db/m mice were selected as control group,and forty db/db mice were randomly divided into mod-el group,low dose group,medium dose group,high dose group and dapagliflozin group,with eight mice in each group.The control group and model group were given equal volume normal saline intragastric adminis-tration,the low,medium and high dose groups were given DHTL solution of 0.9,1.8 and 3.6 mg·kg-1,respectively,and the dapagliflozin group was given dapagliflozin tablet solution of 1.5 mg·kg-1,and the six groups were given intragastric administration once a day for 10 weeks.The body weight of mice was meas-ured daily and the dose was adjusted during adminis-tration.Fasting blood glucose(FBG)and body weight were measured after administration.The levels of 24-hour urinary total protein(24h-UTP),blood creatinine(Scr)and urea nitrogen(BUN)were measured by au-tomatic biochemical analyzer.The levels of interleukin-1 β(IL-1β),interleukin-6(IL-6),interleukin-18(IL-18)and tumor necrosis factor-α(TNF-α)in re-nal tissue of mice were determined by enzyme-linked immunosorbent assay(ELISA).The pathological changes of renal tissue were observed by hematoxylin-eosin(HE)staining.The DNA damage in mouse kid-ney tissue was observed using in situ end labeling(TUNEL)staining.The mRNA and protein expres-sions of NLRP3,caspase-1 and GSDMD in mouse kid-ney tissues were detected by Real-time quantitative PCR and Western blot.Results Compared with the control group,FBG,body weight,IL-1β,IL-6,IL-18 and TNF-α in the model group significantly increased(P＜0.01).The mRNA and protein expressions of NLRP3,caspase-1 and GSDMD in mouse kidney tis-sues significantly increased(P＜0.01).Compared with the model group,the levels of FBG,body weight,IL-1β,IL-6,IL-18 and TNF-α in each administration group significantly decreased(P＜0.05).The patho-logical morphology of renal tissue was improved in dif-ferent degrees,and the number of positive cells in re-nal tissue was significantly reduced(P＜0.05).The mRNA and protein expressions of NLRP3,caspase-1 and GSDMD in renal tissue of mice in high and medi-um dose of DHTL and dapagliflozin group significantly decreased(P＜0.05).Conclusions DHTL can im-prove the renal injury of DKD,and its mechanism may be through the regulation of NLRP3/caspase-1/GSD-MD pathway to inhibit pyroptosis and relieve the in-flammatory response of DKD mice.