【背景】猪圆环病毒2型(porcine circovirus type 2,PCV2)是引发猪群多种临床表现疾病的重要病原,对养猪业造成了重大经济损失。【目的】建立更适合PCV2感染的动物模型,分析一株PCV2d型毒株对C57BL/6小鼠的致病性。【方法】腹腔注射PCV...【背景】猪圆环病毒2型(porcine circovirus type 2,PCV2)是引发猪群多种临床表现疾病的重要病原,对养猪业造成了重大经济损失。【目的】建立更适合PCV2感染的动物模型,分析一株PCV2d型毒株对C57BL/6小鼠的致病性。【方法】腹腔注射PCV2感染C57BL/6小鼠,观察小鼠的临床症状及组织病理变化;qPCR测定组织中的病毒载量;血常规分析外周血中白细胞、红细胞和血小板的变化,流式细胞术分析外周血淋巴细胞的变化;RT-qPCR测定脾脏中IL-10、IL-6、TNF-α和IFN-αmRNA的表达。【结果】PCV2感染导致小鼠精神萎靡、体重下降,所有小鼠脾脏均出现肿大、坏死,部分肝脏色泽变浅、肺脏有出血;组织病理切片显示,脾脏均出现多核巨细胞浸润,感染第14天后含铁血黄素明显增多;脾脏中病毒载量约为(2.19±0.93)×10^(2)copies/mg;PCV2感染诱导小鼠外周血中红细胞、血小板数量显著减少,流式细胞术分析表明,在感染后第3、7、14天,小鼠外周血均出现淋巴细胞数量减少,主要涉及CD_(8)^(+)T细胞和CD_(4)^(+)T细胞。PCV2感染促进了小鼠脾脏中IL-10、IL-6、TNF-αmRNA的表达,而IFN-αmRNA的表达只在感染后第3天和第21天显著降低。【结论】本研究鉴定了一株PCV2d型毒株对C57BL/6小鼠的致病性,为PCV2小鼠模型建立及其致病性研究提供了参考。展开更多
With the rapid expansion of the Internet of Things(IoT),user data has experienced exponential growth,leading to increasing concerns about the security and integrity of data stored in the cloud.Traditional schemes rely...With the rapid expansion of the Internet of Things(IoT),user data has experienced exponential growth,leading to increasing concerns about the security and integrity of data stored in the cloud.Traditional schemes relying on untrusted third-party auditors suffer from both security and efficiency issues,while existing decentralized blockchain-based auditing solutions still face shortcomings in correctness and security.This paper proposes an improved blockchain-based cloud auditing scheme,with the following core contributions:Identifying critical logical contradictions in the original scheme,thereby establishing the foundation for the correctness of cloud auditing;Designing an enhanced mechanism that integrates multiple hashing with dynamic aggregate signatures,binding encrypted blocks through bilinear pairings and BLS signatures,and improving the scheme by setting parameters based on the Computational Diffie-Hellman(CDH)problem,significantly strengthening data integrity protection and anti-forgery capabilities;Introducing a random challenge mechanism and dynamic parameter adjustment strategy,effectively resisting various attacks such as forgery,tampering,and deletion,significantly improving the detection probability of malicious Cloud Service Providers(CSPs),and significantly reducing the proof generation overhead for CSPswhilemaintaining the same computational cost forDataOwners.Theoretical analysis and performance evaluation experiments demonstrate that the proposed scheme achieves significant improvements in both security and efficiency.Finally,the paper explores potential applications of the Enhanced Security Scheme in fields such as healthcare,drone swarms,and government office attendance systems,providing an effective approach for building secure,efficient,and decentralized cloud auditing systems.展开更多
We present the results of the γ-ray flux distribution study on the brightest blazars which were observed by Fermi-LAT. We selected 50 of the brightest blazars based on the maximum number of detections reported in the...We present the results of the γ-ray flux distribution study on the brightest blazars which were observed by Fermi-LAT. We selected 50 of the brightest blazars based on the maximum number of detections reported in the Third LAT AGN Catalog. We performed standard unbinned maximum likelihood analysis on the LAT data during the period between August 2008 and December 2016, in order to obtain the average monthly flux. After quality cuts, blazars for which at least 90% of the total flux had survived were selected for further study, and this included 19 FSRQs and 19 BL Lacs. The Anderson-Darling and χ2 tests suggest that the integrated monthly flux follows a log-normal distribution for all sources, except for three FSRQs for which neither a normal nor a log-normal distribution was preferred. A double log-normal flux distribution tendency was observed in these sources, though this has to be confirmed with improved statistics. We also found that the standard deviation of the log-normal flux distribution increases with the mean spectral index of the blazar, and can be fitted with a line of slope 0.24±0.04. We repeat our study on three additional brightest unclassified blazars to identify their flux distribution properties. Based on the features of their log-normal flux distribution, we infer these unclassified blazars may be closely associated with FSRQs. We also highlight that considering the lognormal behavior of the flux distribution of blazars, averaging their long term flux on a linear scale can largely underestimate the nominal flux and this discrepancy can propagate down to the estimation of source parameters through spectral modeling.展开更多
文摘【背景】猪圆环病毒2型(porcine circovirus type 2,PCV2)是引发猪群多种临床表现疾病的重要病原,对养猪业造成了重大经济损失。【目的】建立更适合PCV2感染的动物模型,分析一株PCV2d型毒株对C57BL/6小鼠的致病性。【方法】腹腔注射PCV2感染C57BL/6小鼠,观察小鼠的临床症状及组织病理变化;qPCR测定组织中的病毒载量;血常规分析外周血中白细胞、红细胞和血小板的变化,流式细胞术分析外周血淋巴细胞的变化;RT-qPCR测定脾脏中IL-10、IL-6、TNF-α和IFN-αmRNA的表达。【结果】PCV2感染导致小鼠精神萎靡、体重下降,所有小鼠脾脏均出现肿大、坏死,部分肝脏色泽变浅、肺脏有出血;组织病理切片显示,脾脏均出现多核巨细胞浸润,感染第14天后含铁血黄素明显增多;脾脏中病毒载量约为(2.19±0.93)×10^(2)copies/mg;PCV2感染诱导小鼠外周血中红细胞、血小板数量显著减少,流式细胞术分析表明,在感染后第3、7、14天,小鼠外周血均出现淋巴细胞数量减少,主要涉及CD_(8)^(+)T细胞和CD_(4)^(+)T细胞。PCV2感染促进了小鼠脾脏中IL-10、IL-6、TNF-αmRNA的表达,而IFN-αmRNA的表达只在感染后第3天和第21天显著降低。【结论】本研究鉴定了一株PCV2d型毒株对C57BL/6小鼠的致病性,为PCV2小鼠模型建立及其致病性研究提供了参考。
基金funded by the National Natural Science Foundation of China(New Design and Analysis of Fully Homomorphic Signatures,Grant No.62172436).
文摘With the rapid expansion of the Internet of Things(IoT),user data has experienced exponential growth,leading to increasing concerns about the security and integrity of data stored in the cloud.Traditional schemes relying on untrusted third-party auditors suffer from both security and efficiency issues,while existing decentralized blockchain-based auditing solutions still face shortcomings in correctness and security.This paper proposes an improved blockchain-based cloud auditing scheme,with the following core contributions:Identifying critical logical contradictions in the original scheme,thereby establishing the foundation for the correctness of cloud auditing;Designing an enhanced mechanism that integrates multiple hashing with dynamic aggregate signatures,binding encrypted blocks through bilinear pairings and BLS signatures,and improving the scheme by setting parameters based on the Computational Diffie-Hellman(CDH)problem,significantly strengthening data integrity protection and anti-forgery capabilities;Introducing a random challenge mechanism and dynamic parameter adjustment strategy,effectively resisting various attacks such as forgery,tampering,and deletion,significantly improving the detection probability of malicious Cloud Service Providers(CSPs),and significantly reducing the proof generation overhead for CSPswhilemaintaining the same computational cost forDataOwners.Theoretical analysis and performance evaluation experiments demonstrate that the proposed scheme achieves significant improvements in both security and efficiency.Finally,the paper explores potential applications of the Enhanced Security Scheme in fields such as healthcare,drone swarms,and government office attendance systems,providing an effective approach for building secure,efficient,and decentralized cloud auditing systems.
基金the Indian Space Research Organization program(ISRO-RESPOND)for the financial support(Grant No.ISRO/RES/2/396)
文摘We present the results of the γ-ray flux distribution study on the brightest blazars which were observed by Fermi-LAT. We selected 50 of the brightest blazars based on the maximum number of detections reported in the Third LAT AGN Catalog. We performed standard unbinned maximum likelihood analysis on the LAT data during the period between August 2008 and December 2016, in order to obtain the average monthly flux. After quality cuts, blazars for which at least 90% of the total flux had survived were selected for further study, and this included 19 FSRQs and 19 BL Lacs. The Anderson-Darling and χ2 tests suggest that the integrated monthly flux follows a log-normal distribution for all sources, except for three FSRQs for which neither a normal nor a log-normal distribution was preferred. A double log-normal flux distribution tendency was observed in these sources, though this has to be confirmed with improved statistics. We also found that the standard deviation of the log-normal flux distribution increases with the mean spectral index of the blazar, and can be fitted with a line of slope 0.24±0.04. We repeat our study on three additional brightest unclassified blazars to identify their flux distribution properties. Based on the features of their log-normal flux distribution, we infer these unclassified blazars may be closely associated with FSRQs. We also highlight that considering the lognormal behavior of the flux distribution of blazars, averaging their long term flux on a linear scale can largely underestimate the nominal flux and this discrepancy can propagate down to the estimation of source parameters through spectral modeling.
