Objective To construct a recombinant poxvirus vector vaccine, rVTTδTK-RBD, and to evaluate its safety and immunogenicity. Methods The receptor-binding domain (RBD) gene was synthesized with reference to the gene sequence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and was inserted into the polyclonal site of the self-constructed recombinant plasmid pSTKE, to construct the recombinant poxvirus shuttle vector pSTKE-RBD. This was then transfected into BHK-21 cells pre-infected with the vaccinia virus Tiantan strain (VTT). The recombinant poxvirus rVTTδTK-RBD was successfully obtained after several rounds of fluorescence phage screening. The effect of rVTTδTK-RBD on the body mass of BALB/c mice was detected after immunizing mice by intra-nasal vaccination. The levels of specific and neutralizing antibodies produced by rVTTδTK-RBD on BALB/c mice were analyzed after immunizing mice intramuscularly. The effect of rVTTδTK-RBD on T cell subsets in BALB/c mice was detected by flow cytometry. Results Through homologous recombination, enhanced green fluorescent protein (EGFP) screening marker, and multiple rounds of fluorescent phosphorescence phage screening, a recombinant poxvirus rVTTδTK-RBD, expressing RBD with deletions in the thymidine kinase (TK) gene, was successfully obtained, which was validated by PCR. The in vivo experiments on BALB/c mice showed that rVTTδTK-RBD was highly immunogenic against SARS-CoV-2 and significantly reduced toxicity to the body compared to the parental strain VTT. Conclusion The recombinant poxvirus vaccine rVTTδTK-RBD against SARS-CoV-2 is successfully constructed and obtained, with its safety and immunogenicity confirmed through various experiments.
Animals ; Mice ; SARS-CoV-2/genetics* ; COVID-19 ; Vaccines, Synthetic/genetics* ; Genes, Reporter ; Bacteriophages ; Mice, Inbred BALB C

Pyran- and furanocoumarins are key representatives of tetrahydropyrans and tetrahydrofurans, respectively, exhibiting diverse physiological and medical bioactivities. However, the biosynthetic mechanisms for their core structures remain poorly understood. Here we combined multiomics analyses of biosynthetic enzymes in Peucedanum praeruptorum and in vitro functional verification and identified two types of key enzymes critical for pyran and furan ring biosynthesis in plants. These included three distinct P. praeruptorum prenyltransferases (PpPT1-3) responsible for the prenylation of the simple coumarin skeleton 7 into linear or angular precursors, and two novel CYP450 cyclases (PpDC and PpOC) crucial for the cyclization of the linear/angular precursors into either tetrahydropyran or tetrahydrofuran scaffolds. Biochemical analyses of cyclases indicated that acid/base-assisted epoxide ring opening contributed to the enzyme-catalyzed tetrahydropyran and tetrahydrofuran ring refactoring. The possible acid/base-assisted catalytic mechanisms of the identified cyclases were theoretically investigated and assessed using site-specific mutagenesis. We identified two possible acidic amino acids Glu303 in PpDC and Asp301 in PpOC as vital in the catalytic process. This study provides new enzymatic tools in the epoxide formation/epoxide-opening mediated cascade reaction and exemplifies how plants become chemically diverse in terms of enzyme function and catalytic process.

Objective:To explore the effects of the scaffolding-based flipped classroom approach in the teaching of Infectious Disease Nursing. Methods:We assigned 152 students of nursing and midwifery majors of grade 2018 (experimental group) to be taught using the scaffolding-based flipped classroom approach and 182 students of grade 2017 (control group) to be taught using the traditional lecture method. Teaching effects were evaluated through students' exam performance and a questionnaire survey. Numerical data were analyzed using the χ2 test and t test with the use of SPSS 18.0, and text data were processed using NVivo 11 for thematic analysis. Results:The experimental group and control group showed significant differences in the interim exam score (83.19±7.96 vs. 79.62±3.14, P<0.001) and final exam score (78.47±6.92 vs. 73.16±8.24, P<0.001). The students of grade 2018 had a high level of participation in online learning. The questionnaire results showed that the scaffolding-based flipped classroom was well recognized in terms of students' overall perception, perceived course quality, perceived value of learning, and satisfaction and the open-ended question, with low scores for learner complaints and loyalty. Conclusions:The scaffolding-based flipped classroom is feasible in the teaching of Infectious Disease Nursing, which can improve students' academic performance and overall competence.

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.

Objective The aim of this study is to explore the potential modulatory role of quercetin against Endotoxin or lipopolysaccharide (LPS) induced septic cardiac dysfunction.Methods Specific pathogen-free chicken embryos (n = 120) were allocated untreated control, phosphate buffer solution (PBS) vehicle, PBS with ethanol vehicle, LPS (500 ng/egg), LPS with quercetin treatment (10, 20, or 40 nmol/egg, respectively), Quercetin groups (10, 20, or 40 nmol/egg). Fifteen-day-old embryonated eggs were inoculated with abovementioned solutions via the allantoic cavity. At embryonic day 19, the hearts of the embryos were collected for histopathological examination, RNA extraction, real-time polymerase chain reaction, immunohistochemical investigations, and Western blotting.Results They demonstrated that the heart presented inflammatory responses after LPS induction. The LPS-induced higher mRNA expressions of inflammation-related factors (TLR4, TNFα, MYD88, NF-κB1, IFNγ, IL-1β, IL-8, IL-6, IL-10, p38, MMP3, and MMP9) were blocked by quercetin with three dosages. Quercetin significantly decreased immunopositivity to TLR4 and MMP9 in the treatment group when compared with the LPS group. Quercetin significantly decreased protein expressions of TLR4, IFNγ, MMP3, and MMP9 when compared with the LPS group. Quercetin treatment prevented LPS-induced increase in the mRNA expression of Claudin 1 and ZO-1, and significantly decreased protein expression of claudin 1 when compared with the LPS group. Quercetin significantly downregulated autophagy-related gene expressions (PPARα, SGLT1, APOA4, AMPKα1, AMPKα2, ATG5, ATG7, Beclin-1, and LC3B) and programmed cell death (Fas, Bcl-2, CASP1, CASP12, CASP3, and RIPK1) after LPS induction. Quercetin significantly decreased immunopositivity to APOA4, AMPKα2, and LC3-II/LC3-I in the treatment group when compared with the LPS group. Quercetin significantly decreased protein expressions of AMPKα1, LC3-I, and LC3-II. Quercetin significantly decreased the protein expression to CASP1 and CASP3 by immunohistochemical investigation or Western blotting in treatment group when compared with LPS group.Conclusion Quercetin alleviates cardiac inflammation induced by LPS through modulating autophagy, programmed cell death, and myocardiocytes permeability.

AIM To simultaneously determine the contents of neochlorogenic acid,caffeic acid,chlorogenic acid,cryptochlorogenic acid,hydroxysafflor yellow A,ferulic acid,senkyunolide I,senkyunolide H and senkyunolide A in Fuyang Granules,and to make chemical pattern recognition.METHODS The UHPLC was performed on a 35℃thermostatic Waters Acquity UPLC?BEH C18 column(150 mm×2.1 mm,1.7 μm),with the mobile phase comprising of acetonitrile-0.01%phosphoric acid flowing at 0.4 mL/min in a gradient elution manner,and the detection wavelengths were set at 278,322,325,390 nm.Then heatmap clustering analysis and principal component analysis were adopted.RESULTS Nine constituents showed good linear relationships within their own ranges(r>0.999 0),whose average recoveries were 93.89%-102.25%with the RSDs of 0.85%-2.88%.Different batches of samples from the same enterprises demonstrated consistent overall qualities,while the overall qualities of samples from different enterprises exhibited obvious differences.CONCLUSION This simple and accurate method can be used for the quality control of Fuyang Granules.

ObjectiveThe human angiotensin converting enzyme2 （hACE2） transgenic mouse model was used to clarify the antiviral efficacy of BD-77 against a novel coronavirus SARS-CoV-2 and explore the action mechanism of BD-77 against SARS-CoV-2. MethodSARS-CoV-2 Omicron and Delta variant strains-infected VeroE6 cell models were established and administered with BD-77 to observe the antiviral effect of BD-77 in vitro. A kit was used to detect the effect of BD-77 in vitro on the binding of spike S protein of SARS-CoV-2 virus （Delta/Omicron） to angiotensin converting enzyme2 （ACE2）. Chromatography was adopted to detect the binding of BD-77 to the S protein and N protein of the novel coronavirus. hACE2 transgenic C57BL/6 mice were divided into a blank control group， SARS-CoV-2 infection group， BD-77 administration groups of 37.5 mg·kg^-1 and 75 mg·kg^-1， with eight mice in each group. The pneumonia model of SARS-CoV-2-infected hACE2 transgenic mice was built to observe the survival of the mice， detect the virus titer of the lung tissue of the mice， and observe the lesions in the lung tissue. ResultBD-77 had a certain inhibitory effect on Omicron and Delta variant strains in vitro， with median inhibitory concentration （IC₅₀） of 526.3 mg·L^-1 and 653.0 mg·L^-1， respectively. BD-77 had no significant inhibitory effect on the binding of the S protein of WT， Omicron， and Delta variant strains of SARS-CoV-2 to ACE2 and had no binding effect with the S protein and N protein of the novel coronavirus. No mice in the blank group died， while the mortality rate of SARS-CoV-2-infected mice was 75%. There was a large amount of virus replication in the lung tissue of the mice and large areas of inflammatory infiltration in the lung tissue and interstitium. Compared with the model group， BD-77 administration groups of 37.5 mg·kg^-1 and 75 mg·kg^-1 could reduce the mortality of mice， significantly lower the virus titer in the lung tissue of mice （P<0.05）， and improve lung lesions. ConclusionBD-77 demonstrated significant inhibitory effects against SARS-CoV-2 virus in vitro and in vivo. However， its mechanism of action did not involve direct inhibition of the virus itself or intervention in the virus-host binding process. This finding suggests that the mechanism of action of BD-77 needs to be thoroughly investigated and elucidated by further experiments.

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.

We aimed to identify the infectious source of a case of melioidosis,to provide evidence for the prevention and control of melioidosis in Shanxi Province,China.The patient developed repeated fever,fatigue,diarrhea,and other symptoms after being caught in the rain while traveling in Hainan Province.The blood culture was positive,and the bacterial strain was i-dentified as Burkholderia thayensis and sent to the provincial Center for Disease Control and Prevention for further evaluation.MALDI-TOF MS and biochemical identification were used to identify the strain,whole genome sequencing was performed after nucleic acid extraction,MLST type and drug-resistance genes were analyzed,and a phylogenetic tree was constructed.The iso-lated strain was identified as Burkholderia pseudomallei by MALDI-TOF MS and biochemistry,and the MLST type was 366.The whole gene sequencing analysis indicated a close evolutionary relationship with the three isolates in Hainan Province,with high homology.This case of melioidosis was indeed imported from Hainan Province,according to molecular tracing analysis and epidemiological investigation,thus suggesting that medical institutions and disease control departments should strengthen understanding of melioidosis,and improve the diagnosis and treatment ability.

Objective To observe the clinical efficacy of thumb-tack needling for subcutaeous embedding combined with joint mobilization in the treatment of post-stroke shoulder-hand syndrome.Methods A total of 80 patients with post-stroke shoulder-hand syndrome were randomly divided into a treatment group and a control group,with 40 patients in each group.Both groups were given arthrocentesis,the control group was given ordinary acupuncture on the basis of arthrocentesis,and the treatment group was combined with thumb-tack needling for subcutaeous embedding.One course of treatment was 4 weeks and a total of 4 weeks of treatment was given.After 1 month of treatment,the clinical efficacy of the two groups was evaluated.The changes of Visual Analogue Scale(VAS)of pain scores and simplified Fugl-Meyer Assessment(FMA)scores,as well as the pain-free passive forward flexion and abduction of the shoulder joint of the affected limb were observed before and after treatment.The Simple Quality of Life Scale(SF-36)scores of the patients in the two groups were compared after treatment.The safety and the occurrence of adverse reactions in the two groups were also evaluated.Results(1)The total effective rate was 95.00%(38/40)in the treatment group and 80.00%(32/40)in the control group.The efficacy of the treatment group was superior to that of the control group,and the difference was statistically significant(P＜0.05).(2)After treatment,the VAS scores and upper extremity FMA scores of the patients in the two groups were significantly improved(P＜0.05),and the treatment group was significantly superior to the control group in improving the VAS scores and upper extremity FMA scores,and the differences were statistically significant(P＜0.05).(3)After treatment,the joint mobility of patients in the two groups were significantly improved(P＜0.05),and the improvement of shoulder joint movement in the treatment group was superior to that in the control group,and the difference was statistically significant(P＜0.05).(4)After treatment,the SF-36 Quality of Life Scale scores of the treatment group were significantly superior to those of the control group in terms of physical function,psychological function,emotional health,and social function levels,and the difference was statistically significant(P＜0.05).(5)There was no significant difference in the incidence of adverse reactions between the treatment group and the control group(P＞0.05).Conclusion Thumb-tack needling for subcutaeous embedding combined with joint mobilization exert certain effect in the treatment of post-stroke shoulder-hand syndrome.It can significantly improve the pain symptoms of patients,thus improving their quality of life,and the clinical effect is remarkable.