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.

ObjectiveBody fluid stains left at crime scenes are frequently trace amounts, while the identification of body fluids through real time fluorogenic quantitative technique often necessitates the repeated detection within the limited sample, as multiple miRNA markers are the basis for the identification. Based on the goal of both the throughput and efficiency improvement of miRNA analysis in trace samples, a duplex real time fluorogenic quantitative PCR assay system was designed to accurately quantify two miRNAs simultaneously, and the system should be further verified by actual sample for the body fluid identification. MethodsThe duplex real time fluorogenic quantitative PCR system of miR-451a to miR-21-5p was established with specially designed primers and probes, and the concentrations of the primers and probes were both optimized. The specificity, sensitivity and reproducibility of the system were validated, while its capability for body fluid identification was assessed using the miR-451a to miR-21-5p ratio. ResultsThe optimized assay system exhibited excellent specificity and repeatability, with coefficients of variation consistently below 8% for both intra- and inter-batch variability. The amplification efficiency of miR-451a and miR-21-5p reached 71.77% and 74.81%, respectively, with high and relatively consistent results. By utilizing this duplex real time fluorogenic quantitative PCR assay system, a total of 58 body fluid samples were analyzed, exhibiting a discrimination rate of 100% between blood and non-blood samples, as well as between peripheral blood and menstrual blood samples. Moreover, the results, obtained from single real time fluorogenic quantitative PCR assay system and duplex real time fluorogenic quantitative PCR assay system, showed no statistically significant difference with randomly selected blood samples (n=20). Compared to previous single real time fluorogenic quantitative PCR assay system, the sensitivity of duplex real time fluorogenic quantitative PCR assay system exhibited remarkable improvement. A minimum input of only 0.1 ng total RNA was sufficient for accurate detection of peripheral blood and menstrual blood samples, while saliva, semen, and vaginal secretion required only 1 ng total RNA for precise identification purposes. Additionally, the duplex real time fluorogenic quantitative PCR assay system successfully differentiated between different types of body fluids in simulated samples under natural outdoor conditions. ConclusionThe duplex real time fluorogenic quantitative PCR assay system effectively reduced both the time and material costs by half compared to the single system, especially suitable for the examination of body fluid stains left at crime scenes, solving the contradiction between the trace amount and the multiple sample volumes demand of repeated real time fluorogenic quantitative PCR. The duplex real time fluorogenic quantitative PCR assay successfully distinguished blood and other body fluid, as well as peripheral blood and menstrual blood samples, which maintains an equivalent capability for body fluid identification with half sample, time and reagent consumption. This system provides an efficient tool for identifying suspicious body fluids, as well as a foundation for more multiplexed real time fluorogenic quantitative PCR assay system research.

Currently,human health due to corona virus disease 2019(COVID-19)pandemic has been seriously threatened.The coronavirus severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)spike(S)protein plays a crucial role in virus transmission and several S-based therapeutic approaches have been approved for the treatment of COVID-19.However,the efficacy is compromised by the SARS-CoV-2 evolvement and mutation.Here we report the SARS-CoV-2 S protein receptor-binding domain(RBD)inhibitor licorice-saponin A3(A3)could widely inhibit RBD of SARS-CoV-2 variants,including Beta,Delta,and Omicron BA.1,XBB and BQ1.1.Furthermore,A3 could potently inhibit SARS-CoV-2 Omicron virus in Vero E6 cells,with EC50 of 1.016 pM.The mechanism was related to binding with Y453 of RBD deter-mined by hydrogen-deuterium exchange mass spectrometry(HDX-MS)analysis combined with quan-tum mechanics/molecular mechanics(QM/MM)simulations.Interestingly,phosphoproteomics analysis and multi fluorescent immunohistochemistry(mIHC)respectively indicated that A3 also inhibits host inflammation by directly modulating the JNK and p38 mitogen-activated protein kinase(MAPK)path-ways and rebalancing the corresponding immune dysregulation.This work supports A3 as a promising broad-spectrum small molecule drug candidate for COVID-19.

Objective To explore the efficacy and safety of recombinant human anti-severe acute respiratory syn-drome coronavirus 2(anti-SARS-CoV-2)monoclonal antibody injection(F61 injection)in the treatment of patients with coronavirus disease 2019(COVID-19)combined with renal damage.Methods Patients with COVID-19 and renal damage who visited the PLA General Hospital from January to February 2023 were selected.Subjects were randomly divided into two groups.Control group was treated with conventional anti-COVID-19 therapy,while trial group was treated with conventional anti-COVID-19 therapy combined with F61 injection.A 15-day follow-up was conducted after drug administration.Clinical symptoms,laboratory tests,electrocardiogram,and chest CT of pa-tients were performed to analyze the efficacy and safety of F61 injection.Results Twelve subjects(7 in trial group and 5 in control group)were included in study.Neither group had any clinical progression or death cases.The ave-rage time for negative conversion of nucleic acid of SARS-CoV-2 in control group and trial group were 3.2 days and 1.57 days(P=0.046),respectively.The scores of COVID-19 related target symptom in the trial group on the 3rd and 5th day after medication were both lower than those of the control group(both P＜0.05).According to the clinical staging and World Health Organization 10-point graded disease progression scale,both groups of subjects improved but didn't show statistical differences(P＞0.05).For safety,trial group didn't present any infusion-re-lated adverse event.Subjects in both groups demonstrated varying degrees of elevated blood glucose,elevated urine glucose,elevated urobilinogen,positive urine casts,and cardiac arrhythmia,but the differences were not statistica-lly significant(all P＞0.05).Conclusion F61 injection has initially demonstrated safety and clinical benefit in trea-ting patients with COVID-19 combined with renal damage.As the domestically produced drug,it has good clinical accessibility and may provide more options for clinical practice.

Isocitrate dehydrogenase 1 (IDH1) R132H is the most common mutated gene in grade II-III gliomas and oligodendrogliomas. Instead of activating telomerase (a reverse transcriptase which using RNA as a template to extend telomere length), the majority of IDH1^R132H mutant glioma maintain telomere length through an alternative mechanism that relies on homologous recombination (HR), which is known as alterative lengthening of telomere (ALT).The phenotype of ALT mechanism include: ALT associated promyelocytic leukemia protein (PML) bodies (APBs); extrachromosomal telomeric DNA repeats such as C- and T-loops; telomeric sister chromatid exchange (T-SCE), etc. The mechanism of ALT activation is not fully understood. Recent studies have shown that mutation IDH1 contributes to ALT phenotype in glioma cells in at least three key ways. Firstly, the IDH1^R132H mutation mediates RAP1 down-regulation leading to telomere dysfunction, thus ensuring persistent endogenous telomeric DNA damage, which is important for ALT activation. Spontaneous DNA damage at telomeres may provide a substrate for mutation break-induced replication (BIR)‑mediated ALT telomere lengthening, and it has been demonstrated that RAP1 inhibits telomeric repeat-containing RNA, transcribed from telomeric DNA repeat sequences (TERRA) transcription to down-regulate ALT telomere DNA replication stress and telomeric DNA damage, thereby inhibiting ALT telomere synthesis. Similarly, in ALT cells, knockdown of telomere-specific RNaseH1 nuclease triggers TERRA accumulation, which leads to increased replication pressure. Overexpression of RNaseH1, on the other hand, attenuates the recombination capacity of ALT telomeres, leading to telomere depletion, suggesting that RAP1 can regulate the level of replication pressure and thus ALT activity by controlling TERRA expression. Secondly, the IDH1^R132H also alters the preference of the telomere damage repair pathway by down-regulating XRCC1, which inhibits the alternative non-homologous end joining (A-NHEJ) pathway at telomeres and alters cellular preference for the HR pathway to promote ALT. Finally, the IDH1^R132H has a decreased affinity for isocitric acid and NADP+ and an increased affinity for α ketoglutarate (α‑KG) and NADPH, so that the mutant IDH1^R132H catalyzes the hydrogenation of α‑KG to produce 2-hydroxyglutarate (2-HG)in a NADPH-dependent manner. Because 2-HG is structurally similar to α‑KG, which maintains the trimethylation level of H3k9me3 by competitively inhibiting the activity of the α‑KG-dependent histone demethylase KDM4B, and recruits heterochromatin protein HP1α to heterochromatinize telomeres, and promote ALT phenotypes in cooperation with the inactivating of ATRX. In addition, it has been shown that APBs contain telomeric chromatin, which is essentially heterochromatin, and HP1α is directly involved in the formation of APBs. Based on these studies, this article reviews the mechanism of IDH1^R132H mediated telomere dysfunction and the preference of DNA repair pathway at telomeres in cooperate with ATRX loss to promote ALT, which may provide references for clinical targeted therapy of IDH1^R132H mutant glioma.

Extracting extracts of secondary metabolites from the karst cave fungus Metarhizium anisopliae NHC-M3-2 from the Yilingyan Scenic Area in Guangxi. Ten compounds were isolated and purified from fungal secondary metabolites using thin-layer chromatography and high-performance liquid chromatography. 7-Hydroxy-3-hydroxypropyl-5,6-dimethylisochrome-1-one (1) and 7-hydroxy-3,5,6-trimethyl-isochromen-1-one (2) were new isocoumarin compounds, N-acetyl phenylalanine (3), chaetosumin J (4), 2-one-13-hydroxy-3,5,8,7(11)-eudesmatetraen-12,8-olide (5), 1H-indole-3-carboxaldehyde (6), irpexolaceus B (7), irlactin L (8), cytochalasin K (9), and helvolic acid (10), a total of 8 known compounds. The structure of the compound was determined using methods such as NMR and mass spectrometry. The tumor cytotoxicity of the compound was evaluated using the CCK-8 method. The results showed that the IC₅₀ of compound 2 on HepG2 cells was 29.83 µmol·L^-1, and compound 9 on HCT116 cells was 27.44 µmol·L^-1.

Elemental imaging analysis based on laser induced-breakdown spectroscopy(LIBS)can provide significant reference value for oil and gas exploration activities.Improving the scanning speed and spatial resolution of LIBS elemental imaging analysis instruments contributes to enhancing the efficiency of mineral surface elemental analysis,which is crucial for achieving in-situ,real-time,and rapid LIBS analysis.In this study,a high-speed scanning LIBS elemental imaging analysis instrument was developed based on a scanning mirror device,achieving a scanning speed of 100 Hz and a spatial resolution of 50 μm.The stability of spectral data collected by this instrument was validated using aluminum alloy standard samples with uniform elemental distribution.The experimental results showed that the relative standard deviations(RSD)of the spectral data collected at different locations were 2.76％,2.79％,2.35％and 2.55％,respectively,demonstrating that the instrument's performance met analysis requirements.Analysis of spectral acquisition channels led to the selection of the 337-595 nm spectral range.Imaging analysis of major elements on the surface of meteorite mineral samples with complex matrices was conducted using this instrument,coupled with a multi-element imaging algorithm enabling visualization analysis of four major elements on the same image.The results revealed a higher level of detail and complexity in element distribution.The study demonstrated that this instrument,combined with multi-element imaging analysis algorithms,could provide crucial technical support for rapid imaging of element distribution in minerals at a microscopic scale during geological research.

Objective:This study aims to explore the synergistic effects of DIP and other medical insurance supply-side policies.Method:City A that has piloted DIP reform was set as the treatment group,and City B without reform was set as the control group.A total of 1 120 public medical institution samples from 2019 to 2022 were collected.The total medical expenses during hospitalization and some structural expenses were analyzed using DID method.Result:DIP had a significant inhibitory effect on the medical expenses,and the expenses of checkups and examinations during hospitalization in city A,but had no impact on the drug and the material expenses during hospitalization.Conclusion:DIP played a significant cost control role and effectively controlled the total medical expenses during hospitalization.The synergistic effects of price adjustment of medical services policy and national centralized drug/material procurement policy on cost control were insufficient.DIP synergized with other supply-side policies to promote rational medical cost structure.It is suggested that medical insurance departments should focus on the synergistic effects of medical insurance supply-side policies to jointly improve the efficiency of medical insurance fund utilization.

Objective:Analyze the medical reimbursement rate and influencing factors under the DIP payment method to refine the DIP payment policy,promote the optimization of internal operations in medical institutions,and ensure reasonable compensation.Methods:Based on the 2022 DIP fund settlement data from 196 medical institutions in City A,the study used multiple linear regression to analyze the factors affecting medical reimbursement rate and conducted a heterogeneity analysis for medical institutions of different levels.Results:The medical reimbursement rate for medical institutions in City A in 2022 was 103.32%.Medical institutions with lower CMI standardized inpatient costs,lower rates of deviation cases,tertiary care institutions,lower proportion of level-four surgeries,and lower ratios of resident to employee medical insurance cases have higher medical reimbursement rate(P<0.05).Heterogeneity analysis reveals that therates of deviation cases,the proportion of primary care diseases,the ratio of resident to employee medical insurance cases,and the low-standard admission rate have different impacts on medical institutions of different levels.Conclusion:Medical insurance departments should improve policies for primary care diseases,dynamically adjust disease catalogs and payment standards,optimize funding levels and institutional coefficients,and increase penalties for violations to ensure effective use of funds.Medical institutions need to strengthen their understanding of policies,focus on refined internal management,promote standardized and rational diagnosis and treatment through performance assessment transformation,and leverage their own advantages in medical services to reasonably increase the medical reimbursement rate.

Objective:To investigate the effect of selenium on cyclophosphamide(CTX)-induced spermatogenic impairment(SI)in mice and its underlying mechanism.Methods:We equally randomized 36 male KM mice into 3 SI model and 3 control groups,the first 3 treated by intraperitoneal injection of CTX at 100 mg/kg(the SI model control group),CTX plus SI model control group,selenium deficient model group(-Se SI),selenium supplemented model group(+Se SI),while latter 3 by intraperitoneal injection of normal saline(the normal control),selenium deficiency control group(-Se control),selenium addition control group(+Se control),respectively,all once a week for 6 successive weeks.Then we observed the histopathological changes in the testes of all the mice by HE staining,obtained the sperm count in the epididymides,determined the expressions of glutathione peroxidase 4(GPx4)and SLC7A11 proteins by Western blot and ferroptosis-related genes by RT-qPCR,and examined the changes in the expres-sions of ferroptosis-related proteins and genes in the GC2-spd cells treated with ferroptosis inhibitors and inducers in combination with different concentrations of inorganic sodium selenite(SeS)and organic selenomethionine(SeM).Results:Compared with the nor-mal controls,the SI model mice showed significantly decreased testicular and prostatic organ coefficients,reduced spermatogenic lay-ers,increased voids,decreased serum ferritin concentration(P<0.05),and elevated transferrin concentration(P<0.05).The or-gan coefficients were significantly higher in the+Se SI and+Se control than in the-Se SI and-Se control groups(P<0.05,P<0.01),with evident pathological improvement of the testis tissue in the+Se controls.The expressions of the GPx4 and solute carrier family 7 members 11(SLC7A11)genes in the testis were dramatically down-regulated in the SI model controls(P<0.01),but up-reg-ulated in the+Se SI and+Se control compared with those in the-Se SI and-Se control group(P<0.01 and P<0.05),but there were no statistically significant differences between their protein expressions.The results of in vitro GC2 spd cell experiments indicated that the GPx4 gene and GPx4 protein levels in the-Se group were significantly lower than those in the normal control group(P<0.05),while the SLC7A11 gene level decreased(P<0.01).Different doses of SeS and SeM significantly increased the GPx4 protein expression compared to the average Se group.Low doses of SeM promoted a significant increase in GPx4 gene levels,while high doses of SeS increased the expression levels of SLC7A11 gene and SLC7A11 protein(P<0.05,P<0.01).The Se group showed a signifi-cant decrease in the levels of acsl4 and ptgs2 genes compared to the normal control group.SeM promoted the expression of acsl4,while SeS promoted the expression of ptgs2 and fth1(P<0.01,P<0.05).The intervention results of GC2 spd showed that the Erastin group had a decrease in ptgs2 compared to the normal control group,while the SeS+Erastin and SeM+Erastin groups had an increase in ptgs2 gene expression compared to the Erastin group.However,the ptgs2 expression of Fer-1 was lower than that of the normal con-trol group,and the ptgs2 gene level of SeS+Fer-1 and SeM+Fer-1 groups was lower than that of Fer-1 group(P<0.05);The gene quantity of GPx4 in the SeM+Erastin and SeM+Fer-1 groups increased compared to the Erastin and Fer-1 groups(P<0.01,P<0.05);SeM+Erastin and SeS+Erastin showed a decrease in SLC7A11 compared to the Erastin group,as well as SeM+Fer-1 and SeS+Fer-1 groups compared to the Fer-1 group,accompanied by an increase in acsl4 and fth1(P<0.01).Conclusion:Selenium deficiency causes the reduction of the SLC7A11 and GPx4 gene levels,disorder of ferroptosis-related genes and down-regulation of the GPx4 protein expression in the mouse testis and spermatocytes.Selenium can promote the expression of GPx4,up-regulate the level of SLC7A11,and improve spermatogenesis in the testis of the mouse with SI.There are differences between organic SeM and inorganic SeS in regulating the ferroptosis pathway-related genes.