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.

ObjectiveTo investigate the efficacy of Xingpi capsules （XPC） in treating diarrhea-predominant irritable bowel syndrome （IBS-D） with spleen deficiency and elucidate its potential molecular mechanisms. MethodsA rat model of IBS-D with spleen deficiency was established by administering senna leaf in combination with restrained stress and swimming fatigue for 14 d. Ten specific pathogen free （SPF）-grade healthy rats were used as the normal control group. After successful modeling， SPF-grade rats were randomly divided into a model group， a pinaverium bromide group （1.5 mg·kg^-1）， and low- and high-dose XPC groups （0.135 and 0.54 g·kg^-1）， with 10 rats in each group. Rats in the normal control group and the model group were given distilled water by gavage， while the remaining groups were administered corresponding drug solutions by gavage once a day for 14 consecutive days. The rat body weights and fecal condition were observed every day， and the Bristol score was recorded. Enzyme-linked immunosorbent assay （ELISA） was used to determine the levels of 5-hydroxytryptamine （5-HT） in serum and colon tissue. Transmission electron microscopy was used to observe the microvilli and tight junctions in the colon. The integrity of the colonic barrier， intestinal motility， and expression of related pathway proteins were evaluated by hematoxylin-eosin （HE） staining， immunohistochemistry， and Western blot. ResultsCompared with those in the normal control group， rats in the model group showed a significantly decreased body weight and increased diarrhea rate， diarrhea grade， and Bristol score （P<0.01）. HE staining revealed incomplete colonic mucosa in the model group， with evident congestion and edema observed. Electron microscopy results indicated decreased density and integrity of the colonic barrier， shedding and disappearance of microvilli， and significant widening of tight junctions. The expression levels of colonic tight junction proteins Occludin and Claudin-5 were downregulated （P<0.01）， and the levels of 5-HT in serum and colon tissue were elevated （P<0.01）. The small intestine propulsion rate significantly increased （P<0.01）， and the expression of contractile proteins Ras homolog family member A （RhoA） and Rho-associated coiled-coil containing protein kinase 2 （ROCK2） in colon and phosphorylation of myosin light chain （MLC₂₀） were upregulated （P<0.01）. Compared with the model group， the treatment groups showed alleviated diarrhea， diarrhea-associated symptoms， and pathological manifestations of colon tissue to varying degrees. Specifically， high-dose XPC exhibited effectively relieved diarrhea， promoted recovery of colonic mucosal structure， significantly reduced congestion and edema， upregulated expression of Occludin and Claudin-5 （P<0.01）， decreased levels of 5-HT in serum and colon tissue （P<0.05，P<0.01）， significantly slowed small intestine propulsion rate （P<0.01）， and significantly downregulated expression of contractile proteins RhoA and ROCK2 in colon and phosphorylation of MLC₂₀ （P<0.05，P<0.01）. ConclusionXPC effectively alleviates symptoms of spleen deficiency and diarrhea and regulates the secretion of brain-gut peptide. The characteristics of XPC are mainly manifested in alleviating IBS-D with spleen deficiency from the aspects of protecting intestinal mucosa and inhibiting smooth muscle contraction， and the mechanism is closely related to the regulation of the 5-HT-RhoA/ROCK2 pathway expression.

Electroencephalogram (EEG) is a non-invasive, high temporal-resolution technique for monitoring brain activity. However, affected by the volume conduction effect, EEG has a low spatial resolution and is difficult to locate brain neuronal activity precisely. The surface Laplacian (SL) technique obtains the Laplacian EEG (LEEG) by estimating the second-order spatial derivative of the scalp potential. LEEG can reflect the radial current activity under the scalp, with positive values indicating current flow from the brain to the scalp (“source”) and negative values indicating current flow from the scalp to the brain (“sink”). It attenuates signals from volume conduction, effectively improving the spatial resolution of EEG, and is expected to contribute to breakthroughs in neural engineering. This paper provides a systematic overview of the principles and development of SL technology. Currently, there are two implementation paths for SL technology: current source density algorithms (CSD) and concentric ring electrodes (CRE). CSD performs the Laplace transform of the EEG signals acquired by conventional disc electrodes to indirectly estimate the LEEG. It can be mainly classified into local methods, global methods, and realistic Laplacian methods. The global method is the most commonly used approach in CSD, which can achieve more accurate estimation compared with the local method, and it does not require additional imaging equipment compared with the realistic Laplacian method. CRE employs new concentric ring electrodes instead of the traditional disc electrodes, and measures the LEEG directly by differential acquisition of the multi-ring signals. Depending on the structure, it can be divided into bipolar CRE, quasi-bipolar CRE, tripolar CRE, and multi-pole CRE. The tripolar CRE is widely used due to its optimal detection performance. While ensuring the quality of signal acquisition, the complexity of its preamplifier is relatively acceptable. Here, this paper introduces the study of the SL technique in resting rhythms, visual-related potentials, movement-related potentials, and sensorimotor rhythms. These studies demonstrate that SL technology can improve signal quality and enhance signal characteristics, confirming its potential applications in neuroscientific research, disease diagnosis, visual pathway detection, and brain-computer interfaces. CSD is frequently utilized in applications such as neuroscientific research and disease detection, where high-precision estimation of LEEG is required. And CRE tends to be used in brain-computer interfaces, that have stringent requirements for real-time data processing. Finally, this paper summarizes the strengths and weaknesses of SL technology and envisages its future development. SL technology boasts advantages such as reference independence, high spatial resolution, high temporal resolution, enhanced source connectivity analysis, and noise suppression. However, it also has shortcomings that can be further improved. Theoretically, simulation experiments should be conducted to investigate the theoretical characteristics of SL technology. For CSD methods, the algorithm needs to be optimized to improve the precision of LEEG estimation, reduce dependence on the number of channels, and decrease computational complexity and time consumption. For CRE methods, the electrodes need to be designed with appropriate structures and sizes, and the low-noise, high common-mode rejection ratio preamplifier should be developed. We hope that this paper can promote the in-depth research and wide application of SL technology.

Objective:To discuss the role of M2 macrophages in epithelial-mesenchymal transition(EMT)and cisplatin(DDP)resistance in the non-small cell lung cancer(NSCLC),and to clarify the regulatory mechanism of nuclear factor κB(NF-κB)signaling pathway.Methods:The human monocytic leukemia THP-1 cells were selected and differentiated into M0 macrophages by phorbol myristate acetate(PMA)induction,followed by M2 macrophage polarization through interleukin(IL)-4 and IL-13 stimulation.Western blotting and immunofluorescence methods were used to detect the protein expression levels of CD163,CD86,and arginase-1(Arg-1)in M0 and M2 macrophages.The human NSCLC A549 cells were co-cultured non-contactly with M0 or M2 macrophages in Transwell chambers,and the cells were divided into A549+M0 group(A549 cells co-cultured with M0 macrophages),A549+M2 group(A549 cells co-cultured with M2 macrophages),and A549+M2+BAY11-7082 group(A549 cells co-cultured with M2 macrophages and treated with 10 mmol·L-1 NF-κB inhibitor BAY11-7082).Wound healing assay was used to detect the wound healing rate of the A549 cells in various groups;Transwell assay was used to detect the number of invasion A549 cells in various groups;cell counting kit-8(CCK-8)assay was used to detect the inhibitory rate of proliferation and half maximal inhibitory concentration(IC50)value of the A549 cells after treated with DDP in the co-culture system;Western blotting method was used to detect the expression levels of vimentin,E-cadherin,N-cadherin,transcription factor Snail,phosphorylated P65(p-P65),P-glycoprotein(P-gp),and programmed death-ligand 1(PD-L1)proteins in the A549 cells in various groups.Results:The Western blotting results showed that compared with M0 group,the expression levels of CD163 and Arg-1 proteins in the macrophages in M2 group were significantly increased(P<0.05),while the expression level of CD86 protein was significantly decreased(P<0.05).The immunofluorescence results showed that compared with M0 group,the expression of CD163 protein in the macrophages in M2 group was enhanced and the expression of CD86 protein was weakened.The wound healing assay results showed that at 24 and 48 h of culture,compared with A549+M0 group,the wound healing rate of the A549 cells in A549+M2 group was significantly increased(P<0.05);in the co-culture system,compared with A549+M0 group,the wound healing rate of the A549 cells in A549+M2 group was significantly increased(P<0.05);compared with A549+M2 group,the wound healing rate of the A549 cells in A549+M2+BAY11-7082 group was significantly decreased(P<0.05).The Transwell assay results showed that compared with A549+M0 group,the number of invasion A549 cells in A549+M2 group was significantly increased(P<0.05);compared with A549+M2 group,the number of invasion A549 cells in A549+M2+BAY11-7082 group was significantly decreased(P<0.05);in the co-culture system,compared with A549+M0 group,the number of invasion A549 cells in A549+M2 group was significantly increased(P<0.05).The CCK-8 assay results showed that after treated with 2.50,5.00,10.00,20.00,and 40.00 mg·L-1 DDP,compared with A549+M0 group,the inhibitory rate of proliferation of the A549 cells in A549+M2 group was significantly decreased(P<0.05 or P<0.01),and the IC50 value was significantly increased(P<0.01);in the co-culture system,compared with A549+M0 group,the inhibitory rate of proliferation of the A549 cells in A549+M2 group was significantly decreased(P<0.05 or P<0.01),and the IC50 value was significantly increased(P<0.01);compared with A549+M2 group,the inhibitory rate of proliferation of the A549 cells in A549+M2+BAY11-7082 group was significantly increased(P<0.05),and the IC50 value was significantly decreased(P<0.05).The Western blotting results showed that compared with A549+M0 group,the expression level of E-cadherin proteins in the A549 cells in A549+M2 group was significantly decreased(P<0.05),while the expression levels of N-cadherin,vimentin,and Snail proteins were significantly increased(P<0.05);in the co-culture system,compared with A549+M0 group,the expression levels of vimentin,Snail,N-cadherin,and p-P65 proteins in the A549 cells in A549+M2 group were significantly increased(P<0.05),while the expression level of E-cadherin proteins was significantly decreased(P<0.05);compared with A549+M2 group,the expression levels of vimentin,N-cadherin,and p-P65 proteins in the A549 cells in A549+M2+BAY11-7082 group were significantly decreased(P<0.05),while the expression level of E-cadherin proteins was significantly increased(P<0.05);compared with A549+M0 group,the expression levels of P-gp and PD-L1 proteins in the A549 cells in A549+M2 group were significantly increased(P<0.05);in the co-culture system,compared with A549+M0 group,the expression levels of P-gp and PD-L1 proteins in the A549 cells in A549+M2 group were significantly increased(P<0.05);compared with A549+M2 group,the expression levels of P-gp and PD-L1 proteins in the A549 cells in A549+M2+BAY11-7082 group were significantly decreased(P<0.05).Conclusion:The M2 macrophages can regulate EMT in the NSCLC cells to promote the invasion and metastasis of tumor,and modulate the expressions of P-gp and PD-L1 to enhance DDP resistance,which is associated with the NF-κB signaling pathway.

Arsenic is a semi-metal,and lipid-soluble arsenic compounds are one of the widespread forms in the environment and food chain,but there is a lack of standards for lipid-soluble arsenic compounds,which is one of the bottlenecks in the current analytical detection and toxicological studies of organic arsenic.In this study,four saturated arsenic-containing hydrocarbons,AsHC 318,AsHC 332,AsHC 346,and AsHC 374(The number is relative molecular mass),were successfully synthesized in three steps by using dimethylarsinic acid,potassium iodide,sodium hydroxide,and four brominated alkanes(1-Bromotetradecane,1-bromopentadecane,1-bromohexadecane,and 1-bromooctadecane)as raw materials.The structures of these four saturated arsenic-containing hydrocarbons were characterized by proton nuclear magnetic resonance(1H NMR)spectroscopy,13C nuclear magnetic resonance(13C NMR)spectroscopy,and high-resolution mass spectrometry(HR-MS).The yields of the method were 8%-10%,and the synthesized compounds could be used in subsequent toxicity evaluation experiments to assess the toxic effects and mechanisms of action of arsenic-containing hydrocarbons.This study provided an effective method for synthesis of arsenic-containing hydrocarbons,enriching the synthesis methods of arsenic-containing hydrocarbons,and provided raw materials for the subsequent toxicological studies of arsenic-containing hydrocarbons.

Ribonucleic acid(RNA)molecules with repeat expansion sequences can liquid-liquid phase separate into droplet-like condensates,which usually have good fluidity and can dynamically exchange matter and energy with the outside world,so as to play physiological functions.However,when the conditions are changed,the droplets will undergo a phase transition,forming gel-like or solid-like condensates.The change in the morphology of the condensates is closely related to many diseases.In this work,the effects of the RNA repeat length,concentration,cation and pH value on the liquid-liquid phase separation(LLPS)of RNA with CAG repeats were systematically studied,and the molecular structure of the condensates formed by LLPS was analyzed by Raman spectroscopy.This study revealed the molecular basis of the formation of different condensates from the perspective of structural biology,and provided new insights for in-depth understanding of the molecular assembly of RNA phase separation and phase transition.

Objective To establish and evaluate a nomogram prediction model for spontaneous peritonitis in HBV-related primary liver cancer.Methods A retrospective study was conducted on 1298 patients with HBV-related primary liver cancer hospitalized in the Kunming Third People's Hospital from January 2012 to December 2022.General data and serological indicators were collected,and patients were divided into infection group(n=262)and control group(n=1036)based on the occurrence of spontaneous peritonitis.Univariate and LASSO regression analyses were used to screen variables,followed by binary logistic regression to analyze the influencing factors of spontaneous peritonitis in HBV-related primary liver cancer patients,leading to the establishment of a nomogram prediction model.Finally,the Hosmer-lemeshow(H-L)goodness of fit test,receiver operating characteristic(ROC)curve,calibration curve,decision curve analysis(DCA)and clinical impact curve(CIC)were utilized to evaluate the fit degree,accuracy,calibration,and clinical practicability of the nomogram prediction model.Results Single factor analysis revealed significant differences between infection group and control group in portal vein cancer thrombus(PVTT),Child-Pugh grade,China Liver Cancer Staging(CNLC)stage,alcohol consumption history,smoking history,white blood cell count(WBC),neutrophil count(NE),hemoglobin(Hb),fibrinogen(FIB),abnormal prothrombin(PIVKA-Ⅱ),aspartate aminotransferase(AST),alanine aminotransferase(ALT),total protein(TP),prealbumin(PA),γ-glutamyltransferase(GGT),alkaline phosphatase(ALP),cholinesterase(CHE),total bile acid(TBA),total cholesterol(TC),low density lipoprotein(LDL),creatinine(Cr),HBV DNA,CD3+T cells count,CD4+T cells count,CD8+T cells count,CD4+T cells/CD8+T cells ratio,procalcitonin(PCT),serum amyloid A(SAA),interleukin-6(IL-6),high-sensitivity C-reactive protein(hs-CRP),alpha-fetoprotein(AFP),and IL-4(P＜0.05).LASSO regression analysis identified 5 variables:Child-Pugh grade,PVTT,WBC,CHE and hs-CRP.Binary logistic regression analysis indicated that Child-Pugh grade(Grade B:OR=5.780,95％CI 3.271-10.213,P＜0.001;Grade C:OR=14.818,95％CI 7.697-28.526,P＜0.001),PVTT(OR=2.893,95％CI 2.037-4.108,P＜0.001),WBC(OR=1.088,95％CI 1.031-1.148,P=0.002),and hs-CRP(OR=1.005,95％CI 1.001-1.010,P=0.026)were the independent risk factors of spontaneous peritonitis in HBV-related primary liver cancer patients.Using these 4 variables,a nomogram prediction model was constructed and evaluated.The P-value of the H-L goodness of fit test was 0.760.Moreover,the area under ROC curve(AUC)was 0.866,with a sensitivity of 0.870 and a specificity of 0.716.The average absolute error of the calibration curve is 0.022.DCA and CIC analyses demonstrated that the nomogram prediction model possessed some clinical utility.Conclusion The nomogram prediction model for spontaneous peritonitis in HBV-related primary liver cancer patients,constructed using Child-Pugh grade,PVTT,WBC and hs-CRP,exhibits a high fitting degree and accuracy,with the prediction probability highly consistent with the actual occurrence probability,and possesses certain clinical practicability.

Objective To investigate gender differences and age-related changes in body composition(BC)among Miao adults in Rongshui,Guangxi Province,and to provide the basis for assessing nutritional status and health.Methods With informed consent,630 Miao adults(218 males,412 females)were randomly selected for this study.Body composition was assessed using bioelectrical impedance analysis(BIA).Results Weight,fat-free mass,muscle mass,trunk muscle mass,limb muscle mass,waist-to-hip ratio(WHR),body water,presumtion of bone mass and protein were significantly higher in males than in females.And the fat mass,trunk fat mass,limb fat mass,visceral fat content,subcutaneous fat content and percentage of body fat were significantly higher in females than in males.According to the evaluation of body mass index(BMI)and WHR,the proportion of overweight and obesity of Miao adults was higher than the average level of Miao residents,and their obesity was characterized by central obesity.With age,weight,fat mass,muscle mass,fat-free mass,limb muscle mass,limb fat mass,subcutaneous fat content,percentage of body fat,body water,presumtion of bone mass,and protein of Rongshui Miao adults showed a gradual decreasing trend,while visceral fat content and WHR increased progressively.BMI in male Miao adults,along with BMI,fat mass,trunk fat mass,subcutaneous fat content,percentage of body fat,and body water in female Miao adults,showed a trend of increasing followed by decreasing,peaking at the age of 40-49 years.Conclusion The body composition of Miao adults in Rongshui,Guangxi,exhibits significant gender differences and age-related variation change patterns,which may increase the risk of sarcopenia and metabolic diseases with aging.

AIM To evaluate the quality of benchmark sample of Zexie Decoction.METHODS HPLC fingerprints were established,after which the content determination of epoxy alisma ene,23-acetyl alisol B,23-acetyl alisol C,alisol A,alisol B,atractylenolide Ⅰ,atractylenolide Ⅱ and atractylenolide Ⅲ was performed,and the transfer rate and paste yield were calculated.RESULTS There were 20 common peaks in the fingerprints for 15 batches of benchmark samples with the similarities of more than 0.95.The average contents of various effective constituents were 180.86 μg/g for alisol B 23-acetate,18.65 μg/g for alisol C 23-acetate,34.74 μg/g for alismoxide,17.65 μg/g for alisol A,238.19 μg/g for alisol B,2.85 μg/g for atractylenolide Ⅰ,6.38 μg/g for atractylenolide Ⅱ,and 15.42 μg/g for atractylenolide Ⅲ,respectively.In the decoction piece-benchmark sample,alisol B 23-acetate,alisol C 23-acetate,atractylenolide Ⅰ,atractylenolide Ⅱ and atractylenolide Ⅲ demonstrated the average transfer rates of 12.09％,16.45％,3.93％,12.17％and 34.37％respectively.The paste yields in various batches of benchmark samples were 15.2％-20.2％.CONCLUSION HPLC fingerprints combined with content determination can be used for the quality control of benchmark sample of Zexie Decoction,thus provides a reference for the development of its compound preparations.

AIM To investigate the effects of Qifu Yixin Granules on cardiac inflammation in a rat model of heart failure.METHODS The rats were induced into chronic heart failure(CHF)models by 6-week intraperitoneal injection of doxorubicin followed by the random assignment of the successful rat models into the model group,the captopril group(22.5 mg/kg),and the low-dose,medium-dose,and high-dose Qifu Yixin Granules groups(2.84,5.67,11.34 g/kg),in contrast to the normal rats of the blank group.The rats had their body weight monitored;their cardiac function assessed by echocardiography;their serum levels of NT-proBNP,TNF-α,IL-6,IL-1 and CRP measured by ELISA;their cardiac morphological alterations observed by HE and Masson staining;their cardiac protein expressions of TLR4,MyD88 and NF-κB detected by immunohistochemistry and Western blot;and their cardiac mRNA expressions of TLR4,MyD88 and NF-κB measured by RT-qPCR.RESULTS Compared to the blank group,the model group exhibited significantly reduced body weight,LVEF and LVFS(P＜0.01),alongside significantly elevated LVEDD,LVESD,and serum concentrations of NT-proBNP,TNF-α,IL-6,IL-1 and CRP(P＜0.01).Additionally,the model group displayed greater myocardial inflammatory cell aggregation,increased collagen deposition(P＜0.01);and upregulated myocardial protein and mRNA expressions of TLR4,MyD88 and NF-κB(P＜0.01).Compared to the model group,the groups intervened with captopril or medium/high dose Qifu Yixin Granules demonstrated significantly increased body weight,LVEF and LVFS(P＜0.05,P＜0.01);significantly reduced LVEDD,LVESD,and serum levels of the aforementioned indicators(P＜0.05,P＜0.01);mitigated inflammation and collagen deposition(P＜0.05,P＜0.01);and downregulated myocardial protein and mRNA expressions of TLR4,MyD88 and NF-κB(P＜0.05,P＜0.01).CONCLUSION Qifu Yixin Granules attenuate cardiac inflammation and improve cardiac function in doxorubicin-induced CHF rats;this therapeutic effect is mediated by inhibiting the activation of the TLR4/MyD88/NF-κB signaling pathway.