Establishment of an indirect immunofluorescence assay for the detection of African swine fever virus antibodies

African swine fever(ASF)continues to cause enormous economic loss to the global pig industry.Since there is no safe and effective vaccine,accurate and timely diagnosis of ASF is essential to implement control measures.Indirect immunofluorescence assay(IFA)is a gold standard serological method recommended by the World Organization for Animal Health(WOAH).In this study,we used primary fetal kidney cells to establish a wild boar cell line(BK2258)that supported the efficient replication of ASF virus(ASFV)SD/DY-I/21 and showed visible cytopathic effect(CPE).Moreover,using BK2258,we established a sensitive and specific IFA for ASFV antibody detection.To standardize and evaluate the performance of this assay,we used serum samples from pigs infected with the low virulent genotype I SD/DY-I/21 and genotype II HLJ/HRB1/20,and immunized with the vaccine candidate HLJ/18-7GD,field samples,and negative serum samples.The IFA reacted with the ASFV-positive sera and displayed bright fluorescence foci.There was no non-specific green fluorescence due to cellular senescence or other cell damage-causing factors.Compared to a commercial indirect enzyme-linked immunosorbent assay(iELISA),ASFV antibodies were detected 1–4 days earlier using our IFA.The detection limits of the IFA and iELISA for the same ASFV-antibody positive serum samples were 1:25,600 and 1:6,400,respectively,indicating that the IFA is more sensitive than iELISA.The newly established IFA was highly specific and did not cross-react with sera positive for six other important porcine pathogens(i.e.,Classical swine fever virus(CSFV),Porcine reproductive and respiratory syndrome virus(PRRSV),Porcme circovirus type 2(PCV2),Pseudorabies virus(PRV),Foot-and-Mouth disease virus type O(FMDV/O),and Porcine epidemic diarrhea virus(PEDV)).This study thus provides a sensitive,specific,and reliable detection method that is suitable for the serological diagnosis of ASF.

Satellite-Air-Terrestrial Cloud Edge Collaborative Networks:Architecture,Multi-Node Task Processing and Computation

Integrated satellite-terrestrial network(ISTN)has been considered a novel network architecture to achieve global three-dimensional coverage and ultra-wide area broadband access anytime and anywhere.Being a promising paradigm,cloud computing and mobile edge computing(MEC)have been identified as key technology enablers for ISTN to further improve quality of service and business continuity.However,most of the existing ISTN studies based on cloud computing and MEC regard satellite networks as relay networks,ignoring the feasibility of directly deploying cloud computing nodes and edge computing nodes on satellites.In addition,most computing tasks are transferred to cloud servers or offloaded to nearby edge servers,the layered design of integrated satellite-air-terrestrial architecture and the cloud-edge-device cooperative processing problems have not been fully considered.Therefore,different from previous works,this paper proposed a novel satellite-air-terrestrial layered architecture for cloud-edge-device collaboration,named SATCECN.Then this paper analyzes the appropriate deployment locations of cloud servers and edge servers in ISTN,and describes the processing flow of typical satellite computing tasks.For computing resource allocation problems,this paper proposed a device-edge-cloud Multi-node Cross-layer Collaboration Computing(MCCC)method to find the optimal task allo-cation strategy that minimizes the task completion delay and the weighted system energy consumption.Furthermore,the approximate optimal solutions of the optimization model are obtained by using successive convex approxi-mation algorithm,and the outstanding advantages of the proposed method in reducing system energy consumption and task execution delay are verified through experiments.Finally,some potential issues and directions for future research are highlighted.

The predictive value of vascular endothelial growth factor and Ki-67 expression on neoadjuvant therapy in rectal cancer

调查脉管的内皮生长因素(VEGF ) 和增殖的房间的表情的目的在有直肠的腺癌的病人和他们有 neoadjuvant 的协会的原子抗原(Ki-67 ) 治疗。方法包括两预告的处理肿瘤活体检视和手术后的标本，在直肠的腺癌的 32 种情况中的 Ki-67 和 VEGF 的表情被免疫组织化学用特定的抗体检测，并且与 clinicopathological 因素被相关。结果染色的 VEGF 的紧张显著地与淋巴被相关节的转移( P = 0.033 )，肿瘤侵略的深度( P = 0.007 )并且肿瘤舞台( P = 0.016 )，然而并非与组织学的类型，肿瘤尺寸，病人的年龄和性( P 】 0.05 )。VEGF 表示的底层与对 neoadjuvant 治疗的反应的高敏感有重要关联(P = 0.016 ) 。VEGF 表示的短暂增加能在 neoadjuvant 治疗以后被看见(P = 0.035 ) 。把索引(Ki-67-LI ) 标记的 Ki-67 显著地与淋巴节点转移被相关(P = 0.028 ) ，然而并非相关到肿瘤尺寸，病人的年龄和性(P 】 0.05 ) 。有更低的 Ki-67-LI 的肿瘤对 neoadjuvant 治疗更敏感(P = 0.032 ) 。Ki-67 水平在 neoadjuvant 治疗以后减少了，但是没有统计意义被发现 P 】 0.05 ) 。我们的结果表明的结论在预告的处理的 VEGF 和 Ki-67 的表示直肠的腺癌活体检视可能对 neoadjuvant 的肿瘤反应是预兆的治疗。

ASFV transcription reporter screening system identifies ailanthone as a broad antiviral compound

African swine fever(ASF)is an acute,highly contagious and deadly viral disease in swine that jeopardizes the worldwide pig industry.Unfortunately,there are no authoritative vaccine and antiviral drug available for ASF control.African swine fever virus(ASFV)is the etiological agent of ASF.Among the ASFV proteins,p72 is the most abundant component in the virions and thus a potential target for anti-ASFV drug design.Here,we con-structed a luciferase reporter system driven by the promoter of p72,which is transcribed by the co-transfected ASFV RNA polymerase complex.Using this system,we screened over 3200 natural product compounds and obtained three potent candidates against ASFV.We further evaluated the anti-ASFV effects and proved that among the three candidates,ailanthone(AIL)inhibits the replication of ASFV at the nanomolar concentration(IC_(50)=15 nmol/L).Our in vitro experiments indicated that the antiviral effect of AIL is associated with its inhibition of the HSP90-p23 cochaperone.Finally,we showed the antiviral activity of AIL on Zika virus and hepatitis B virus(HBV),which supports that AIL is a potential broad-spectrum antiviral agent.

Emergence and prevalence of naturally occurring lower virulent African swine fever viruses in domestic pigs in China in 2020

African swine fever virus(ASFV)has been circulating in China for more than two years,and it is not clear whether the biological properties of the virus have changed.Here,we report on our surveillance of ASFVs in seven provinces of China,from June to December,2020.A total of 22 viruses were isolated and characterized as genotype II ASFVs,with mutations,deletions,insertions,or short-fragment replacement occurring in all isolates compared with Pig/HLJ/2018(HLJ/18),the earliest isolate in China.Eleven isolates had four different types of natural mutations or deletion in the EP402R gene and displayed a nonhemadsorbing(non-HAD)phenotype.Four isolates were tested for virulence in pigs;two were found to be as highly lethal as HLJ/18.However,two non-HAD isolates showed lower virulence but were highly transmissible;infection with 106 TCID50 dose was partially lethal and caused acute or sub-acute disease,whereas 103 TCID50 dose caused non-lethal,sub-acute or chronic disease,and persistent infection.The emergence of lower virulent natural mutants brings greater difficulty to the early diagnosis of ASF and creates new challenges for ASFV control.

Novel P22-monoclonal antibody based blocking ELISA for the detection of African swine fever virus antibodies in serum

African swine fever(ASF)is a highly infectious,transboundary viral disease of domestic and wild pigs,and is currently the most serious threat to world swine production,resulting in significant economic loss.In the absence of vaccines and treatments,the control of the disease entirely depends on accurate and early diagnosis accompanied by the culling of infected pigs.Thus,a highly specific and sensitive diagnostic assay is required during an outbreak and surveillance of the disease.In this study,a highly sensitive,specific,rapid and repeatable P22-monoclonal antibody-based blocking enzyme-linked immunosorbent assay(bELISA)assay was developed for the detection of antibodies against genotype I and II African swine fever viruses(ASFVs).A total of 806 pig serum samples were tested to evaluate the performance of the diagnostic assay.To determine the PI(percent Inhibition)cut-off value,receiver-operating characteristic(ROC)analysis was applied.According to the ROC analysis of the data,98.10%specificity and 100%sensitivity were recorded when the threshold cut-off value of PI was established at 47%.In addition,the assay was able to detect ASFV antibodies as early as 9 days post-infection when serum samples from experimentally infected pigs were used.Taking all together,the results of the present study indicated that the P22-mAb based bELISA assay can be used for rapid and accurate detection of antibodies against ASFV,which could play a valuable role in the containment and prevention of ASFV as an alternative to other serological diagnostic methods.Also,this study will assist researchers to further investigate the immunogenic importance of P22 protein in ASFV infection.

智利华侨华人的源流变迁和历史贡献——《智利智京中华会馆120年简史》述评

《智利智京中华会馆120年简史》是智利侨胞自发编写的第一部关于智利华侨华人历史的著述,史料意义十分重要。本文以该书为主要资料,分五个阶段考察了智利华侨华人的历史源流和时代变迁,评价了智利侨胞的历史贡献。170余年来,智利华侨华人心系祖籍国,是中国海外软实力的重要资源。旅智侨胞为中智建交和两国关系的繁荣发展作出了重要贡献。