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 study the neuroprotective effects of Herba siegesbeckiae extract on cerebral ischemia/ reperfusion rats and its mechanism. Methods Sixty SD rats were randomly divided into model group, low, middle and high dose groups of Herba siegesbeckiae, and Sham operation group, and the drug was given continuously for seven days. The degree of neurologic impairment was evaluated by mNSS, and the infarct volume was measured by MRI. The number of Nissl-posi- tive cells was detected by Nissl staining, and the apop- tosis was accessed by Tunel staining. Furthermore, the expression of Bax, Bcl-2 and NeuN was observed by Western blot, and the expression of NeuN was detected by immunofluorescence staining. The expression of IL- 1β, TNF-α and IL-6 mRNA was performed by RT- qPCR. Results The mNSS score and the volume of ischemic cerebral infarction in the model group were significantly increased, and Herba siegesbeckiae extract treatment significantly decreased the mNSS score and infarct volume (P<0.05, P<0.01). Herba siegesbeckiae extract could increase the number of Nissl-pos- itive cells and the expression of NeuN (P<0.01), and reduce the number of Tunel-positive cells (P<0.01). Western blot showed that Herba siegesbeckiae extract inhibited the expression of Bax, increased Bcl-2 and NeuN in ischemic brain tissue (P<0.01). RT-qPCR showed that Herba siegesbeckiae extract inhibited the expression of IL-1 β, TNF-α and IL-6 mRNA in the is-chemic brain tissue (P<0.01). Conclusions Herba siegesbeckiae extract can reduce the cerebral infarction volume, improve the neurological function damage, inhibit the apoptosis of nerve cells and the expression of inflammatory factors and promote the expression of NeuN, there by exerting protective effects on MCAO rats.

Objective To investigate the predictive value of new simplified insulin resistance(IR)assessment indexes in identifying subclinical left ventricular systolic function impairment in patients with type 2 diabetes mellitus(T2DM).Methods A total of 150 T2DM patients with preserved left ventricular ejection fraction(LVEF≥50%)who were admitted to Department of Endocrinology of the First Affiliated Hospital of Air Force Medical University from June 2021 to December 2021 were retrospectively analyzed.All patients underwent two-dimensional speckle tracking echocardiography to measure left ventricular global longitudinal strain(GLS).According to GLS value,the subjects were divided into the normal group(GLS≥18%group,n=80)and the impaired group(GLS<18%group,n=70).Some new simplified IR assessment indicators were calculated and compared between the two groups,including body mass index(BMI),TG/HDL-C ratio,triglyceride-glucose(TyG)index,TyG-BMI index,TyG-WHR and metabolic score for IR(METS-IR).Correlation between the GLS and the new simplified IR assessment indexes was analyzed.The receiver operating characteristic(ROC)curve was used to analyze the diagnostic efficacy of different simplified IR assessment indexes,with the area under the curve(AUC)calculated.Furthermore,according to whether the subjects were complicated with hypertension,binary logistics regression analysis was performed to explore the independent correlation between the simplified IR assessment index and GLS<18%.Results Total 150 were included with aged(54.5±13.7)years with 96(64.0%)men and 54(36.0%)women.Compared with the GLS≥18%group,the TG/HDL-C ratio,TyG index,TyG-BMI,and METS-IR of subjects in the GLS<18%group were significantly increased(P<0.05).Pearson correlation analysis showed that TG/HDL-C ratio,TyG index,TyG-BMI,TyG-WHR,and METS-IR were negatively correlated with GLS(P<0.05).ROC analysis showed that TyG index had a certain predictive value for the evaluation of GLS<18%(AUC=0.678,95%CI 0.591-0.765,P<0.001).Stratification based on hypertension and further adjusting for confounding factors,TyG index remains significantly associated with GLS<18%(OR=3.249,95%CI 1.045-10.103,P=0.042).Conclusions The novel simplified insulin resistance evaluation indexes are closely associated with left ventricular subclinical systolic dysfunction in T2DM patients with preserved ejection fraction.TyG index is an effective index to identify left ventricular subclinical dysfunction in these populations.

Objective To investigate the attributable risk(AR)of Acinetobacter baumannii(AB)infection in criti-cally ill patients.Methods A multicenter retrospective cohort study was conducted among adult patients in inten-sive care unit(ICU).Patients with AB isolated from sterile body fluid and confirmed with AB infection in each cen-ter were selected as the infected group.According to the matching criteria that patients should be from the same pe-riod,in the same ICU,as well as with similar APACHE Ⅱ score(±5 points)and primary diagnosis,patients who did not infect with AB were selected as the non-infected group in a 1:2 ratio.The AR was calculated.Results The in-hospital mortality of patients with AB infection in sterile body fluid was 33.3％,and that of non-infected group was 23.1％,with no statistically significant difference between the two groups(P=0.069).The AR was 10.2％(95％CI:-2.3％-22.8％).There is no statistically significant difference in mortality between non-infected pa-tients and infected patients from whose blood,cerebrospinal fluid and other specimen sources AB were isolated(P＞0.05).After infected with AB,critically ill patients with the major diagnosis of pulmonary infection had the high-est AR.There was no statistically significant difference in mortality between patients in the infected and non-infec-ted groups(P＞0.05),or between other diagnostic classifications.Conclusion The prognosis of AB infection in critically ill patients is highly overestimated,but active healthcare-associated infection control for AB in the ICU should still be carried out.

Objective To explore the relevant factors of new-onset conduction disturbance(NOCD)after transcatheter aortic valve replacement(TAVR),such as anatomical structure,device type,surgical strategies,etc.,discover relevant predictive factors,and establish a predictive model to assess the risk of conduction blockages.Methods From January 2016 to March 2022,clinical data of symptomatic patients with severe aortic valve stenosis or severe regurgitation who underwent TAVR at Xiangya Second Hospital of Central South University were collected through the hospital information system and imaging database.ECG,echocardiography,CTA,surgical materials,etc.,were extracted and analyzed by specialists.SPSS software was used for statistical analysis,and a multi-factor regression prediction model for NOCDwas built.Results A total of 184 patients were included,the occurrence rate of NOCD after TAVR was 31.0%,pure regurgitation patients'NOCD occurrence rate was 63.6%(7/11).The NOCD group had a larger aortic angles[(57.7±10.3)°vs.(52.0±9.0)°,P＜0.001],larger Oversizing[(129±28)%vs.(120±21)%,P=0.018],deeper implantation depth[(7.2±5.1)mm vs.(4.8±4.2)mm,P=0.001],and higher pure regurgitation patients'proportion[12.3%vs.3.1%,P=0.037]than the non-NOCD group.Multifactorial Logistic regression analysis indicated that an aorta angle＞54.5°(OR 3.78,95%CI 1.86-7.63,P＜0.001)or implantation depth＞5.7 mm(OR 3.39,95%CI 1.68-6.85,P＜0.001)are independent risk factors for new onset conduction disturbances after TAVR,and a predictive model was established with aortic angle,implantation depth,and Oversizing ratio as variables.The receiver operating characteristics curve showed area under ROC curve 0.709,95%CI 0.623-0.795,predicting NOCD after TAVR.Conclusions A retrospective analysis carried out at a single center discovered that the aortic angle in the NOCD group was larger than that in the non-NOCD group,the Oversizing ratio was higher,the implantation location was deeper,and there was a higher proportion of patients with pure regurgitation lesions.An aortic angle greater than 54.5°or an implantation depth more than 5.7 mm were identified as independent risk factors for NOCD after TAVR.

Transmission electron microscopy(TEM)is considered as an important characterization tool for revealing morphology of materials and an indispensable strategy for studying the mechanisms of charge-discharge process in battery.TEM samples needs be less than 0.1 μm thick,which means electrodeposited materials must undergo pre-treatment processes such as focusing ion beam etching,ultra-thin slicing,or ultrasonic dispersion before they can be observed via TEM.However,such treatments cause structure changes,and what real formed in electrodes is hard to estimate.In this work,a self-interlacing film layer composed of carbon nanotubes(CNTs)was fabricated on a copper grid through blade coating.A novel TEM grid was produced by optimizing the interlacing film's thickness and covering area through adjusting the interlacing state of various concentrations of CNTs.Utilizing the novel TEM grid as the battery's positive electrode,electrode deposits were acquired and subjected to TEM analysis to generate high-definition microstructure images of the electrode surface.This process provided new insights into sample preparation for investigating the deposition/stripping mechanism in high-energy-density metal anodes.

The aim of this study was to investigate the prevalence of spotted fever group rickettsia(SFGR)in wild rodents collected from Fengshan County in the Guangxi Zhuang Autonomous Region,and to determine their species.Wild rodents were captured in cages in Fengshan County,Hechi City,Guangxi Zhuang Autonomous Region.The rodents were identified according to morphological characteristics,and the findings were confirmed through molecular biology methods.Subsequently,spleen samples were collected,and DNA was extracted.The outer membrane protein A(ompA)gene was amplified with semi-nested PCR to determine the species of SFGR in captured wild rodents.After sequencing of the PCR products,homology and phylogenetic analyses of ompA gene sequences were performed.A total of 105 wild rodents belonging to seven species were captured.FGR was detected in six rodent species(Bandicota indica,Leopoldamys edwardsi,Mus caroli,Mus Pahari,Rat-tus andamanensis,and Rattus losea,but not Berylmys bower si),and the total positivity rate was 23.8％.Three Rickettsia species,Candidatus Rickettsia jingxinensis,Rickettsia raoultii,and Rickettsia sibirica,were identified from analysis of the ompA gene sequence.This study revealed the presence of three species of SFGR infecting wild rodents from Fengshan County,Guangxi Zhuang Autonomous Region,thus suggesting that Fengshan County is a natural focus of tick-borne spotted fever.This study highlights the need to strengthen monitoring and prevention measures for rickettsiosis.

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.

Objective:The main purpose of this study is to analyse the current situation and inequity status of children's medical security in China from the vision of children first.Methods:Using data from the China Family Panel Studies 2020 and based on the framework of universal health coverage cube,multivariate regression is used to analyse the differences in medical security between children and adults and among groups of children.Results:The participation rate of children in China is 80.96%,out-of-pocket ratios are 64.71%and 90.09%for inpatient and outpatient groups respectively.In terms of participation rate,insured children are less than that of adults(OR=0.434,P＜0.01);within children's groups,attending school(OR=2.075,P＜0.01)significantly increases children's participation rate,while left-behind by parent(s)(OR=0.791,P＜0.05)significantly decrease children's participation rate.With respect to service and cost coverage,children have higher out-of-pocket ratios compared to adults(β=0.066,P＜0.01);within children's groups,children eged 6 years and older have lower out-of-pocket medical expenses(β＜-0.316,P＜0.01),children with higher family income(β＜-0.022,P＜0.05),participated(β=-0.033,P＜0.01),and hospitalized(β=-0.270,P＜0.01)have lower out-of-pocket ratios.Conclusion:Double in equality exists in children's medical security in China.The level of children's health security in China is significantly lower than that of adults;within children's groups,children aged 0～5 years,not in school,left-behind by parent(s),and from lower-income families are more vulnerable.It is proposed to focus on increasing the participation rate of children through measures such as optimizing the contribution for children and launching family joint insurance.Policy design should also consider the needs of children and raise the level of children's benefits.Meanwhile,the focus should be on helping vulnerable groups in children,so as to ultimately achieve"children first"in health security.

AIM:To investigate the mechanism of curcumin inhibiting the choroidal neovascularization(CNV)of brown Norway(BN)rats.METHODS: CNV model of 36 BN rats was established through laser photocoagulation induction, and they were divided into 6 groups with 6 rats in each group. Normal group was fed normally with no intervention, while 532nm laser photocoagulation was used to establish a experimental CNV model in BN rats. Rats after modeling were respectively intervened for 14d and divided into model group, ranibizumab group, curcumin low [100mg/(kg·d)], medium [200mg/(kg·d)], and high [400mg/(kg·d)] dose group. The model group was given intragastric administration of saline for 14d, ranibizumab(10mg/mL, 0.2mL/dose)was injected at 2d after photocoagulation with 5μL once for rats in ranibizumab group, and different concentrations of curcumin were intragastrically administrated to the rats in low, medium and high groups for 14d. Fundus photography, fundus fluorescein angiography(FFA)and indocyanine green angiography(ICGA)examination were performed at 14d after photocoagulation. Ocular histopathological specimens of rats with CNV were made, and the central thickness of CNV were observed by HE staining. Ocular histopathological specimens were made, and the expressions of AKT/p-AKT/HIF-1α/VEGF signaling pathway-related proteins were observed by immunohistochemistry. The mRNA relative expressions of AKT/HIF-1α/VEGF factor in CNV tissues were detected by RT-qPCR, and the protein expressions of AKT/p-AKT/HIF-1α/VEGF factor in CNV tissues were detected by Western-blot.RESULTS: CNV generation rates in the model group, the ranibizumab group, and the low, medium and high-dose curcumin groups were 78.18%, 73.21%, 77.19%, 75.86%, 74.55%, respectively, which were higher than 70%. The average absorbance were 182.12±6.59, 119.22±8.03, 166.45±8.33, 164.34±5.69, 149.22±6.45, respectively; the ranibizumab group was significantly lower than the model group(P<0.05); the low-dose, medium-dose and high-dose groups were significantly higher than the ranibizumab group(P<0.05), and the curcumin high-dose group was significantly lower than the model group(P<0.05). HE staining showed that the retinal tissue structure of BN rats in normal group was clear and neatly arranged. The central thickness of CNV in the ranibizumab group was significantly reduced at 14d after photocoagulation compared with the model group(P<0.05); While the curcumin high-dose group was significantly reduced compared with the model group(P<0.05), but increased when compared with ranibizumab group(P<0.05). Immunohistochemistry results showed that AKT, p-AKT, HIF-1α, and VEGF factors were negatively expressed in the retinal tissue structure of BN rats in the normal group, and no brown-yellow reactants were found. The expression of AKT, p-AKT, HIF-1α, and VEGF factors in the model group were higher than that in the normal group at 14d after photocoagulation(P<0.05); the ranibizumab group was lower than the model group(P<0.05). While the expression of the curcumin high-dose group was significantly decreased compared with the model group(P<0.05), but significantly increased when compared with ranibizumab group(P<0.05). The mRNA results showed that the relative expression levels of AKT, HIF-1α and VEGF mRNA in the model group at 14d after photocoagulation were higher than those of the normal group(P<0.05); the ranibizumab group was lower than the model group(P<0.05). While curcumin high-dose group was significantly decreased compared with the model group(P<0.05), but significantly increased when compared with ranibizumab group(P<0.05). Western-blot results showed that there was no significant difference in the relative expression of AKT protein among each experimental groups at 14d after photocoagulation. The relative expression of p-AKT protein in the model group was significantly higher than that in the normal group(P<0.05); the ranibizumab group was significantly lower than the model group(P<0.05); the curcumin high-dose group was significantly lower than the model group(P<0.05). The relative expression levels of HIF-1α protein were significantly higher in the model group than in the normal group(P<0.05), and the ranibizumab group was lower than in the model group(P<0.05). The relative expression levels of HIF-1α protein was lower in the curcumin high-dose group than in the model group(P<0.05)but higher than ranibizumab group(P<0.05). The relative expression level of VEGF protein was significantly lower in the curcumin medium/high-dose group than in the model group(P<0.05).CONCLUSION: Curcumin at 400mg/(kg·d)has an inhibitory effect on CNV in BN rats. The mechanism may be closely related to inhibiting the activation of AKT/p-AKT/HIF-1α/VEGF signaling pathways.