Objective:To develop a rapid,cost effective RT-PCR method for the mass scale diagnosis of such diseases at the vireraia stage to find out the actual disease burden in that area.Methods:For this purpose,cases with the ...Objective:To develop a rapid,cost effective RT-PCR method for the mass scale diagnosis of such diseases at the vireraia stage to find out the actual disease burden in that area.Methods:For this purpose,cases with the history of only short febrile illness were considered.Thus 157 samples with the history of dengue/chikungunya like illness and only 58 samples with a history of acute encephalitis syndrome(AES)were selected.Results:Out of 157 samples,42 and 74 were detected as dengue and chikungunya,respectively and out of 58 AES cases only 23 could be detected as Japanese encephalitis by this RT-PCR method.Conclusions:This cost effective RT-PCR method can detect the total positive cases that remain undetected by EL1SA method.Moreover,this method is capable to detect the viral RNA from patients'sera even after the appearance of IgM antibody at one fifth costs as compared with the other commercially available kits.展开更多
In 2013, a human influenza outbreak caused by a novel H7N9 virus occurred in China. Recently, the H7N9 virus acquired multiple basic amino acids at its hemagglutinin（HA） cleavage site, leading to the emergence of a ...In 2013, a human influenza outbreak caused by a novel H7N9 virus occurred in China. Recently, the H7N9 virus acquired multiple basic amino acids at its hemagglutinin（HA） cleavage site, leading to the emergence of a highly pathogenic virus. The development of an effective diagnostic method is imperative for the prevention and control of highly pathogenic H7N9 influenza. Here, we designed and synthesized three pairs of primers based on the nucleotide sequence at the HA cleavage site of the newly emerged highly pathogenic H7N9 influenza virus. One of the primer pairs and the corresponding probe displayed a high level of amplification efficiency on which a real-time RT-PCR method was established. Amplification using this method resulted in a fluorescent signal for only the highly pathogenic H7N9 virus, and not for any of the H1–H15 subtype reference strains, thus demonstrating high specificity. The method detected as low as 39.1 copies of HA-positive plasmid and exhibited similar sensitivity to the virus isolation method using embryonated chicken eggs. Importantly, the real-time RT-PCR method exhibited 100% consistency with the virus isolation method in the diagnosis of field samples. Collectively, our data demonstrate that this real-time RT-PCR assay is a rapid, sensitive and specific method, and the application will greatly aid the surveillance, prevention, and control of highly pathogenic H7N9 influenza viruses.展开更多
Swine influenza A virus（swine IAV） circulates worldwide in pigs and poses a serious public health threat, as evidenced by the 2009 H1N1 influenza pandemic. Among multiple subtypes/lineages of swine influenza A virus...Swine influenza A virus（swine IAV） circulates worldwide in pigs and poses a serious public health threat, as evidenced by the 2009 H1N1 influenza pandemic. Among multiple subtypes/lineages of swine influenza A viruses, European avian-like（EA） H1N1 swine IAV has been dominant since 2005 in China and caused infections in humans in 2010. Highly sensitive and specific methods of detection are required to differentiate EA H1N1 swine IAVs from viruses belonging to other lineages and subtypes. In this study, a nested reverse transcription（RT）-PCR assay was developed to detect EA H1 swine IAVs. Two primer sets（outer and inner） were designed specifically to target the viral hemagglutinin genes. Specific PCR products were obtained from all tested EA H1N1 swine IAV isolates, but not from other lineages of H1 swine IAVs, other subtypes of swine IAVs, or other infectious swine viruses. The sensitivity of the nested RT-PCR was improved to 1 plaque forming unit（PFU） m L^（-1） which was over 10~4 PFU m L^（-1） for a previously established multiplex RT-PCR method. The nested RT-PCR results obtained from screening 365 clinical samples were consistent with those obtained using conventional virus isolation methods combined with sequencing. Thus, the nested RT-PCR assay reported herein is more sensitive and suitable for the diagnosis of clinical infections and surveillance of EA H1 swine IAVs in pigs and humans.展开更多
Objective: To establish a fluoregenic probe quantitative RT-PCR (FQ-RT-PCR) method for detection of the expression of MDR1 gene in tumor cells and to investigate the expression of MDR1 gene in patients with lung cance...Objective: To establish a fluoregenic probe quantitative RT-PCR (FQ-RT-PCR) method for detection of the expression of MDR1 gene in tumor cells and to investigate the expression of MDR1 gene in patients with lung cancer. Methods: The fluorogenic quantitative RT-PCR method for detection of the expression of MDR1 gene was established. K562/ADM and K562 cell lines or 45 tumor tissues from patients with lung cancer were examined on PE Applied Biosystems 7700 Sequence Detection machine. Results: the average levels of MDR1 gene expression in K562/ADM cells and K562 cells were (6.86±0.65)× 107 copies/μg RNA and (8.49±0.67)×105 copies/μg RNA, respectively. The former was 80.8 times greater than the latter. Each sample was measured 10 times and the coefficient variation (CV) was 9.5% and 7.9%, respectively. Various levels of MDR1 gene expression were detected in 12 of 45 patients with lung cancer. Conclusion: Quantitative detection of MDR1 gene expression in tumor cells was achieved by using FQ-RT-PCR. FQ-RT-PCR is an accurate, and sensitive method and easy to perform. Using this method, low levels of MDR1 gene expression could be detected in 24% of the patients with lung cancer.展开更多
In order to establish a rapid RT-PCR assay for detection of porcine epidemic diarrhea virus（PEDV）,a pair of special primers was designed based on S gene sequence of PEDV published in Gen Bank.After optimization of t...In order to establish a rapid RT-PCR assay for detection of porcine epidemic diarrhea virus（PEDV）,a pair of special primers was designed based on S gene sequence of PEDV published in Gen Bank.After optimization of the reaction system,a rapid RT-PCR method was established.Results showed that a fragment of 826 bp was successfully amplified only from the variant PEDV by RT-PCR,while the expected target fragment could not be amplified from TGEV,porcine rotavirus,porcine kobuvirus,PRRSV,PRV,CSFV,PPV.Sensitivity test of RT-PCR indicated that only 11.3 pg nuclear acids could be detected accurately and rapidly.A total of 123 samples collected from different farms in Guangxi Province were detected by the established RT-PCR,the positive rate of PEDV was 67.5%,and the positive rate of new PEDV was 86.7%（72/83）.Therefore,the RT-PCR could be used as an effective tool for differentiating diagnosis of the highly pathogenic PEDV in epidemiological investigations.展开更多
背景A群轮状病毒(group A rotavirus,RVA)是导致婴幼儿及幼龄动物发生腹泻的主要人兽共患病病原之一,具有较强的传染性。目的建立一种快速、特异检测猪、牛、羊、人等物种RVA的实时荧光定量RT-PCR检测方法。方法基于GenBank中的猪、牛...背景A群轮状病毒(group A rotavirus,RVA)是导致婴幼儿及幼龄动物发生腹泻的主要人兽共患病病原之一,具有较强的传染性。目的建立一种快速、特异检测猪、牛、羊、人等物种RVA的实时荧光定量RT-PCR检测方法。方法基于GenBank中的猪、牛、羊和人源RVA NSP5基因保守序列,设计1对特异性引物、1条探针,该探针带有TaqMan-MGB发光基团,优化最适退火温度(Tm)、最适引物和探针浓度,建立一种可以检测猪、牛、羊和人等物种RVA的实时荧光定量RT-PCR检测方法。结果建立的RVA荧光定量RT-PCR方法最佳退火温度为51℃;最适引物和探针浓度均为0.4μmol/L;敏感性高,最低检测限可达3.24 copies/μL;特异性强,与猪、牛、羊等常见病原无检测交叉反应;重复性好,其批内和批间试验变异系数分别为0.063%-0.812%和0.612%-1.016%,可以快速、特异检测猪、牛、羊样品和人轮状病毒,有很好的临床适用性。结论本实验建立了一种检测多物种RVA的实时荧光定量RT-PCR方法,为猪、牛、羊和人等多物种的RVA流行病学调查和早期诊断提供了良好的技术支撑。展开更多
为了实现对存在传入风险的南非2型(South African type 2, SAT2)口蹄疫病毒的早期发现、精准鉴定和有效预警,本研究基于SAT2型口蹄疫病毒毒株IRAN/2024和ETH/2022完整VP1基因序列,构建了pUC57-IRAN-VP1、pUC57-ETH-VP1质粒;参考SAT2型...为了实现对存在传入风险的南非2型(South African type 2, SAT2)口蹄疫病毒的早期发现、精准鉴定和有效预警,本研究基于SAT2型口蹄疫病毒毒株IRAN/2024和ETH/2022完整VP1基因序列,构建了pUC57-IRAN-VP1、pUC57-ETH-VP1质粒;参考SAT2型口蹄疫病毒VP1基因序列设计并筛选特异性引物,以所构建的质粒为模板,建立了SAT2型口蹄疫病毒特异性RT-PCR检测方法,并开展敏感性试验、特异性试验。敏感性试验结果显示,该方法可以检测质量浓度低至1 pg/mL的质粒DNA。特异性试验结果显示,该方法对伪狂犬病毒、猪繁殖与呼吸综合征病毒、乙型脑炎病毒、猪瘟病毒、1型蓝舌病病毒、牛病毒性腹泻病毒、山羊痘病毒、阿卡斑病毒、流行性出血热病毒等常见病毒的核酸,以及参试的O型和A型口蹄疫病毒(PanAsia、Cathay、Mya98、Ind2001-1、Ind2001-2、AKT-Ⅲ、Sea-97毒株)核酸均无交叉反应。应用该方法对2023年云南边境地区50份牛食道-咽部分泌物样品进行核酸检测,检测结果与RT-qPCR检测结果一致。本研究建立的SAT2型口蹄疫病毒特异性RT-PCR检测方法具有一定的实用性,为口蹄疫疫情防控提供技术支撑。展开更多
Nonlinear Rossby waves are used to describe typical wave phenomena in large-scale atmosphere andocean.Owing to the nonlinearity of the involved problems,the weakly nonlinear method,ie the derivative ex-pansion method,...Nonlinear Rossby waves are used to describe typical wave phenomena in large-scale atmosphere andocean.Owing to the nonlinearity of the involved problems,the weakly nonlinear method,ie the derivative ex-pansion method,was mainly used to investigate Rossby waves under the combined effects of the generalizedβ-effect and the basic flow effect.The derivative expansion method has the advantage of capturing the multi-scalecharacteristics of wave processes simultaneously.In the case where the perturbation expansion is independentof secular terms,the nonlinear equations describing the amplitude evolution of nonlinear waves were derived,such as the Korteweg-de Vries equation,the Boussinesq equation and Zakharov-Kuznetsov equation.Both quali-tative and quantitative analyses indicate that the generalizedβ-effect is the key factor inducing the evolution ofRossby solitary waves.展开更多
本研究以日本黄瓜绿斑驳花叶病毒(kyuri green mottle mosaic virus,KGMMV)为材料,设计1对常规RT-PCR检测引物KGCPN-F/KGCPN-R和1组引物/探针KGM-F/KGM-R/KGM-P,分析测试了2对已发表KGMMV常规RT-PCR检测引物KGCP-F/KGCP-R和KGMP-F/KGMP...本研究以日本黄瓜绿斑驳花叶病毒(kyuri green mottle mosaic virus,KGMMV)为材料,设计1对常规RT-PCR检测引物KGCPN-F/KGCPN-R和1组引物/探针KGM-F/KGM-R/KGM-P,分析测试了2对已发表KGMMV常规RT-PCR检测引物KGCP-F/KGCP-R和KGMP-F/KGMP-R,建立了KGMMV的常规和实时荧光RT-PCR检测方法。结果表明,引物KGCP-F/KGCP-R扩增KGMMV时出现预期大小的条带,扩增黄瓜绿斑驳花叶病毒(cucumber green mottle mosaic virus,CGMMV)时出现非常微弱的条带;引物KGCPN-F/KGCPN-R扩增KGMMV时出现预期大小的条带,扩增小西葫芦绿斑驳花叶病毒(zucchini green mottle mosaic virus,ZGMMV)时出现比预期稍大的条带,通过对PCR产物进行序列测定和分析比对可准确鉴定KGMMV。KGCP-F/KGCP-R和KGCPN-F/KGCPN-R的相对灵敏度分别为10^(-6)和10^(-5)稀释度,适用于KGMMV的常规RT-PCR检测。基于引物探针KGM-F/KGM-R/KGM-P建立的KGMMV实时荧光RT-PCR检测方法能特异性检出KGMMV,相对灵敏度达10^(-7)稀释度,分别比2对常规RT-PCR检测引物高10倍和100倍,适用于瓜类种子中KGMMV的快速检测。展开更多
SiC/Al-based composite foams were prepared by a two-step foaming method.The influence of the SiC content and its distribution uniformity on the foaming stability,cell structure,and mechanical properties of the aluminu...SiC/Al-based composite foams were prepared by a two-step foaming method.The influence of the SiC content and its distribution uniformity on the foaming stability,cell structure,and mechanical properties of the aluminum foams was investigated.The macro/micro-features of the aluminum foams were characterized and analyzed.Results demonstrate that an appropriate increase in SiC content and the uniform distribution of SiC can improve the foaming stability,optimize the cell diameter and cell wall thickness,ameliorate the cell distribution,and enhance the hardness and compressive strength of the aluminum foams.However,either insufficient or excessive SiC leads to uneven distribution of SiC particles,which is unfavorable to foaming stability and good cell structure formation.With 6wt%SiC,both the foaming stability and cell structure of the aluminum foam reach the optimal state,resulting in the highest compressive strength and optimal energy absorption capacity.展开更多
In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to ...In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to obtain the maximal positive definite solution of nonlinear matrix equation X+A^(*)X|^(-α)A=Q with the case 0<α≤1.Based on this method,a new iterative algorithm is developed,and its convergence proof is given.Finally,two numerical examples are provided to show the effectiveness of the proposed method.展开更多
This study presents an effective hybrid simulation approach for simulating broadband ground motion in complex near-fault locations.The approach utilizes a deterministic approach based on the spectral element method(SE...This study presents an effective hybrid simulation approach for simulating broadband ground motion in complex near-fault locations.The approach utilizes a deterministic approach based on the spectral element method(SEM),which is used to simulate low-frequency ground motion(f<1 Hz)by incorporating an innovative efficient discontinuous Galerkin(DG)method for grid division to accurately model basin sedimentary layers at reduced costs.It also introduces a comprehensive hybrid source model for high-frequency random scattering and a nonlinear analysis module for basin sedimentary layers.Deterministic outcomes are combined with modified three-dimensional stochastic finite fault method(3D-EXSIM)simulations of high-frequency ground motion(f>1 Hz).A fourth-order Butterworth filter with zero phase shift is employed for time-domain filtering of low-and high-frequency time series at a crossover frequency of 1 Hz,merging the low and high-frequency ground motions into a broadband time series.Taking an Ms 6.8 Luding earthquake,as an example,this hybrid method was used for a rapid and efficient simulation analysis of broadband ground motion in the region.The accuracy and efficiency of this hybrid method were verified through comparisons with actually observed station data and empirical attenuation curves.Deterministic method simulation results revealed the effects of mountainous topography,basin effects,nonlinear effects within the basin’s sedimentary layers,and a coupling interaction between the basin and the mountains.The findings are consistent with similar studies,showing that near-fault sedimentary basins significantly focus and amplify strong ground motion,and the soil’s nonlinear behavior in the basin influences ground motion to varying extents at different distances from the fault.The mountainous topography impacts the basin’s response to ground motion,leading to barrier effects.This research provides a scientific foundation for seismic zoning,urban planning,and seismic design in nearfault mountain basin regions.展开更多
This study systematically conducted preparation optimization and performance investigations on Co-modified Ce/TiO_(2) catalysts,with a focus on examining how preparation methods and Co loading regulate the catalyst’s...This study systematically conducted preparation optimization and performance investigations on Co-modified Ce/TiO_(2) catalysts,with a focus on examining how preparation methods and Co loading regulate the catalyst’s low-temperature denitrification activity.After identifying optimal preparation parameters via condition screening,multiple characterization techniques-including BET,XRD,XPS,H_(2)-TPR and in situ DRIFTS-were employed to deeply analyze the catalyst’s physicochemical properties and reaction mechanism.Results demonstrated that compared to the impregnation and co-precipitation methods,the Ce-Co_(0.025)/TiO_(2)-SG catalyst(prepared by the sol-gel method with a Co/Ti mass ratio of 0.025)exhibited significantly superior denitrification activity:NO conversion remained stably above 95%in the 225−350℃ temperature range,and it displayed high N_(2) selectivity.Characterization analysis revealed that abundant surface oxygen vacancies,a high proportion of Ce^(3+) species,and prominent acidic sites collectively contributed to enhancing its low-temperature denitrification performance.This work provides reference value for the development of highly efficient low-temperature denitrification catalysts.展开更多
[Objectives]This study was conducted to establish a quantitative assessment method for the textural quality of chieh-qua fruit.[Methods]Using two modes of a texture analyzer,namely TPA(texture profile analysis)and pun...[Objectives]This study was conducted to establish a quantitative assessment method for the textural quality of chieh-qua fruit.[Methods]Using two modes of a texture analyzer,namely TPA(texture profile analysis)and puncture,the index data of the fruit were obtained by setting different trigger forces,deformation levels,test speeds,as well as puncture speeds and puncture depths.The data included TPA hardness,adhesiveness,springiness,cohesiveness,gumminess,chewiness,resilience,as well as skin hardness,skin toughness,flesh hardness,fracturability,and compactness.[Results]Different deformation levels had a significant impact on all parameters.Hardness,adhesiveness,gumminess and chewiness showed a trend of first increasing and then decreasing with the deformation level increasing.When the deformation level was 30%,the adhesiveness,gumminess and chewiness reached their maximum values.When the deformation level was 50%,TPA hardness reached its maximum.When the compression speed was 3 mm/s,the measured values of TPA hardness,adhesiveness,chewiness,and resilience were at their maximums.The skin hardness varied significantly under different trigger forces.When the trigger force was 15 g,the skin hardness reached a maximum value of 944.63 g,and the skin toughness,flesh hardness,fracturability,and compactness also reach their maximum values respectively.When the puncture depth was 12 mm,the flesh hardness and skin toughness reached their maximums of 682.51 g and 1.82 mm,respectively.In the TPA mode,the flesh hardness of chieh-qua showed an extremely significant negative correlation with springiness,cohesiveness,and resilience(P<0.01).The fruit fracturability detected by puncture had an extremely significant positive correlation with compactness(P<0.01).[Conclusions]The evaluation method for measuring chieh-qua texture by combining TPA and the puncture mode could accurately and quantitatively reflect the differences in the flesh texture quality of chieh-qua.The optimal parameters for texture measurement of chieh-qua fruit were determined as a 15 g trigger force with 50%deformation and a 3 mm/s compression speed in TPA mode,and a 15 g trigger force with a 12 mm puncture depth in puncture mode.Puncture speed was found to have no significant effect on the texture indices of chieh-qua.展开更多
The testing of large structures is limited by high costs and long cycles, making scaling methods an attractive solution. However, the scaling process of elastic rings introduces complexities in multi-parameter geometr...The testing of large structures is limited by high costs and long cycles, making scaling methods an attractive solution. However, the scaling process of elastic rings introduces complexities in multi-parameter geometric distortions, leading to a diminution in the predictive accuracy of the distorted similitude. To address this challenge, this study formulates a novel set of scaling laws, tailored to account for the intricate geometric distortions associated with elastic rings. The proposed scaling laws are formulated based on the intrinsic deformation characteristics of elastic rings, rather than the traditional systemic governing equations. Numerical and experimental cases are conducted to assess the efficacy and precision of the proposed scaling laws, and the obtained results are compared with those achieved by traditional methods. The outcomes demonstrate that the scaling laws put forth by this study significantly enhance the predictive capabilities for deformations of elastic rings.展开更多
This study presents an implicit multiphysics coupling method integrating Computational Fluid Dynamics(CFD),the Multiphase Particle-in-Cell(MPPIC)model,and the Finite Element Method(FEM),implemented with OpenFOAM,Calcu...This study presents an implicit multiphysics coupling method integrating Computational Fluid Dynamics(CFD),the Multiphase Particle-in-Cell(MPPIC)model,and the Finite Element Method(FEM),implemented with OpenFOAM,CalculiX,and preCICE to simulate fluid-particle-structure interactions with large deformations.Mesh motion in the fluid field is handled using the radial basis function(RBF)method.The particle phase is modeled by MPPIC,where fluid-particle interaction is described through momentum exchange,and inter-particle collisions are characterized by collision stress.The structural field is solved by nonlinear FEM to capture large deformations induced by geometric nonlinearity.Coupling among fields is realized through a partitioned,parallel,and non-intrusive iterative strategy,ensuring stable transfer and convergence of interface forces and displacements.Notably,the influence of particles on the structure is not direct but mediated by the fluid,while structural motion directly affects particle dynamics.The results demonstrate that the proposed approach effectively captures multiphysics interaction processes and provides a valuable reference for numerical modeling of coupled fluid-particle-structure systems.展开更多
基金supported by the Department of Science and Technology,Goverment of West Bengal.India[grant No.705(Sanc.)ST/P/S&T/9G-27/2007]
文摘Objective:To develop a rapid,cost effective RT-PCR method for the mass scale diagnosis of such diseases at the vireraia stage to find out the actual disease burden in that area.Methods:For this purpose,cases with the history of only short febrile illness were considered.Thus 157 samples with the history of dengue/chikungunya like illness and only 58 samples with a history of acute encephalitis syndrome(AES)were selected.Results:Out of 157 samples,42 and 74 were detected as dengue and chikungunya,respectively and out of 58 AES cases only 23 could be detected as Japanese encephalitis by this RT-PCR method.Conclusions:This cost effective RT-PCR method can detect the total positive cases that remain undetected by EL1SA method.Moreover,this method is capable to detect the viral RNA from patients'sera even after the appearance of IgM antibody at one fifth costs as compared with the other commercially available kits.
基金supported by the National Key R&D Program of China(2016YFD0500800)the International Science&Technology Cooperation Program of China(2014DFR31260)
文摘In 2013, a human influenza outbreak caused by a novel H7N9 virus occurred in China. Recently, the H7N9 virus acquired multiple basic amino acids at its hemagglutinin（HA） cleavage site, leading to the emergence of a highly pathogenic virus. The development of an effective diagnostic method is imperative for the prevention and control of highly pathogenic H7N9 influenza. Here, we designed and synthesized three pairs of primers based on the nucleotide sequence at the HA cleavage site of the newly emerged highly pathogenic H7N9 influenza virus. One of the primer pairs and the corresponding probe displayed a high level of amplification efficiency on which a real-time RT-PCR method was established. Amplification using this method resulted in a fluorescent signal for only the highly pathogenic H7N9 virus, and not for any of the H1–H15 subtype reference strains, thus demonstrating high specificity. The method detected as low as 39.1 copies of HA-positive plasmid and exhibited similar sensitivity to the virus isolation method using embryonated chicken eggs. Importantly, the real-time RT-PCR method exhibited 100% consistency with the virus isolation method in the diagnosis of field samples. Collectively, our data demonstrate that this real-time RT-PCR assay is a rapid, sensitive and specific method, and the application will greatly aid the surveillance, prevention, and control of highly pathogenic H7N9 influenza viruses.
基金supported by the National High-Tech R&D Program of China (2012AA101303)
文摘Swine influenza A virus（swine IAV） circulates worldwide in pigs and poses a serious public health threat, as evidenced by the 2009 H1N1 influenza pandemic. Among multiple subtypes/lineages of swine influenza A viruses, European avian-like（EA） H1N1 swine IAV has been dominant since 2005 in China and caused infections in humans in 2010. Highly sensitive and specific methods of detection are required to differentiate EA H1N1 swine IAVs from viruses belonging to other lineages and subtypes. In this study, a nested reverse transcription（RT）-PCR assay was developed to detect EA H1 swine IAVs. Two primer sets（outer and inner） were designed specifically to target the viral hemagglutinin genes. Specific PCR products were obtained from all tested EA H1N1 swine IAV isolates, but not from other lineages of H1 swine IAVs, other subtypes of swine IAVs, or other infectious swine viruses. The sensitivity of the nested RT-PCR was improved to 1 plaque forming unit（PFU） m L^（-1） which was over 10~4 PFU m L^（-1） for a previously established multiplex RT-PCR method. The nested RT-PCR results obtained from screening 365 clinical samples were consistent with those obtained using conventional virus isolation methods combined with sequencing. Thus, the nested RT-PCR assay reported herein is more sensitive and suitable for the diagnosis of clinical infections and surveillance of EA H1 swine IAVs in pigs and humans.
基金a grant from the National New Technology Program (No. 1998-345).
文摘Objective: To establish a fluoregenic probe quantitative RT-PCR (FQ-RT-PCR) method for detection of the expression of MDR1 gene in tumor cells and to investigate the expression of MDR1 gene in patients with lung cancer. Methods: The fluorogenic quantitative RT-PCR method for detection of the expression of MDR1 gene was established. K562/ADM and K562 cell lines or 45 tumor tissues from patients with lung cancer were examined on PE Applied Biosystems 7700 Sequence Detection machine. Results: the average levels of MDR1 gene expression in K562/ADM cells and K562 cells were (6.86±0.65)× 107 copies/μg RNA and (8.49±0.67)×105 copies/μg RNA, respectively. The former was 80.8 times greater than the latter. Each sample was measured 10 times and the coefficient variation (CV) was 9.5% and 7.9%, respectively. Various levels of MDR1 gene expression were detected in 12 of 45 patients with lung cancer. Conclusion: Quantitative detection of MDR1 gene expression in tumor cells was achieved by using FQ-RT-PCR. FQ-RT-PCR is an accurate, and sensitive method and easy to perform. Using this method, low levels of MDR1 gene expression could be detected in 24% of the patients with lung cancer.
基金Supported by the Scientific Research Project of Guangxi Bureau of Livestock,Fisheries and Veterinary Services(12049031)the Systemic Research Project of Guangxi Key Laboratory of Animal Vaccines and New Technology(12-071-28-A-5)the Basal Research Fund of Guangxi(13-1)
文摘In order to establish a rapid RT-PCR assay for detection of porcine epidemic diarrhea virus（PEDV）,a pair of special primers was designed based on S gene sequence of PEDV published in Gen Bank.After optimization of the reaction system,a rapid RT-PCR method was established.Results showed that a fragment of 826 bp was successfully amplified only from the variant PEDV by RT-PCR,while the expected target fragment could not be amplified from TGEV,porcine rotavirus,porcine kobuvirus,PRRSV,PRV,CSFV,PPV.Sensitivity test of RT-PCR indicated that only 11.3 pg nuclear acids could be detected accurately and rapidly.A total of 123 samples collected from different farms in Guangxi Province were detected by the established RT-PCR,the positive rate of PEDV was 67.5%,and the positive rate of new PEDV was 86.7%（72/83）.Therefore,the RT-PCR could be used as an effective tool for differentiating diagnosis of the highly pathogenic PEDV in epidemiological investigations.
文摘背景A群轮状病毒(group A rotavirus,RVA)是导致婴幼儿及幼龄动物发生腹泻的主要人兽共患病病原之一,具有较强的传染性。目的建立一种快速、特异检测猪、牛、羊、人等物种RVA的实时荧光定量RT-PCR检测方法。方法基于GenBank中的猪、牛、羊和人源RVA NSP5基因保守序列,设计1对特异性引物、1条探针,该探针带有TaqMan-MGB发光基团,优化最适退火温度(Tm)、最适引物和探针浓度,建立一种可以检测猪、牛、羊和人等物种RVA的实时荧光定量RT-PCR检测方法。结果建立的RVA荧光定量RT-PCR方法最佳退火温度为51℃;最适引物和探针浓度均为0.4μmol/L;敏感性高,最低检测限可达3.24 copies/μL;特异性强,与猪、牛、羊等常见病原无检测交叉反应;重复性好,其批内和批间试验变异系数分别为0.063%-0.812%和0.612%-1.016%,可以快速、特异检测猪、牛、羊样品和人轮状病毒,有很好的临床适用性。结论本实验建立了一种检测多物种RVA的实时荧光定量RT-PCR方法,为猪、牛、羊和人等多物种的RVA流行病学调查和早期诊断提供了良好的技术支撑。
文摘Nonlinear Rossby waves are used to describe typical wave phenomena in large-scale atmosphere andocean.Owing to the nonlinearity of the involved problems,the weakly nonlinear method,ie the derivative ex-pansion method,was mainly used to investigate Rossby waves under the combined effects of the generalizedβ-effect and the basic flow effect.The derivative expansion method has the advantage of capturing the multi-scalecharacteristics of wave processes simultaneously.In the case where the perturbation expansion is independentof secular terms,the nonlinear equations describing the amplitude evolution of nonlinear waves were derived,such as the Korteweg-de Vries equation,the Boussinesq equation and Zakharov-Kuznetsov equation.Both quali-tative and quantitative analyses indicate that the generalizedβ-effect is the key factor inducing the evolution ofRossby solitary waves.
文摘本研究以日本黄瓜绿斑驳花叶病毒(kyuri green mottle mosaic virus,KGMMV)为材料,设计1对常规RT-PCR检测引物KGCPN-F/KGCPN-R和1组引物/探针KGM-F/KGM-R/KGM-P,分析测试了2对已发表KGMMV常规RT-PCR检测引物KGCP-F/KGCP-R和KGMP-F/KGMP-R,建立了KGMMV的常规和实时荧光RT-PCR检测方法。结果表明,引物KGCP-F/KGCP-R扩增KGMMV时出现预期大小的条带,扩增黄瓜绿斑驳花叶病毒(cucumber green mottle mosaic virus,CGMMV)时出现非常微弱的条带;引物KGCPN-F/KGCPN-R扩增KGMMV时出现预期大小的条带,扩增小西葫芦绿斑驳花叶病毒(zucchini green mottle mosaic virus,ZGMMV)时出现比预期稍大的条带,通过对PCR产物进行序列测定和分析比对可准确鉴定KGMMV。KGCP-F/KGCP-R和KGCPN-F/KGCPN-R的相对灵敏度分别为10^(-6)和10^(-5)稀释度,适用于KGMMV的常规RT-PCR检测。基于引物探针KGM-F/KGM-R/KGM-P建立的KGMMV实时荧光RT-PCR检测方法能特异性检出KGMMV,相对灵敏度达10^(-7)稀释度,分别比2对常规RT-PCR检测引物高10倍和100倍,适用于瓜类种子中KGMMV的快速检测。
基金Doctoral Startup Fund(20192066,20212028)Laijin Excellent Doctoral Fund(20202021)+1 种基金Scientific and Technological Innovation of Colleges and Universities in Shanxi Province(2020L0342)Fundamental Research Program of Shanxi Province(202303021222178)。
文摘SiC/Al-based composite foams were prepared by a two-step foaming method.The influence of the SiC content and its distribution uniformity on the foaming stability,cell structure,and mechanical properties of the aluminum foams was investigated.The macro/micro-features of the aluminum foams were characterized and analyzed.Results demonstrate that an appropriate increase in SiC content and the uniform distribution of SiC can improve the foaming stability,optimize the cell diameter and cell wall thickness,ameliorate the cell distribution,and enhance the hardness and compressive strength of the aluminum foams.However,either insufficient or excessive SiC leads to uneven distribution of SiC particles,which is unfavorable to foaming stability and good cell structure formation.With 6wt%SiC,both the foaming stability and cell structure of the aluminum foam reach the optimal state,resulting in the highest compressive strength and optimal energy absorption capacity.
基金Supported in part by Natural Science Foundation of Guangxi(2023GXNSFAA026246)in part by the Central Government's Guide to Local Science and Technology Development Fund(GuikeZY23055044)in part by the National Natural Science Foundation of China(62363003)。
文摘In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to obtain the maximal positive definite solution of nonlinear matrix equation X+A^(*)X|^(-α)A=Q with the case 0<α≤1.Based on this method,a new iterative algorithm is developed,and its convergence proof is given.Finally,two numerical examples are provided to show the effectiveness of the proposed method.
基金National Natural Science Foundation of China under Grant Nos.U2139208 and 52278516Key Laboratory of Earthquake Engineering and Engineering Vibration,China Earthquake Administration under Grant No.2024D15Key Laboratory of Soft Soil Characteristic and Engineering Environment,Tianjin Chengjian University under Grant No.2022SCEEKL003。
文摘This study presents an effective hybrid simulation approach for simulating broadband ground motion in complex near-fault locations.The approach utilizes a deterministic approach based on the spectral element method(SEM),which is used to simulate low-frequency ground motion(f<1 Hz)by incorporating an innovative efficient discontinuous Galerkin(DG)method for grid division to accurately model basin sedimentary layers at reduced costs.It also introduces a comprehensive hybrid source model for high-frequency random scattering and a nonlinear analysis module for basin sedimentary layers.Deterministic outcomes are combined with modified three-dimensional stochastic finite fault method(3D-EXSIM)simulations of high-frequency ground motion(f>1 Hz).A fourth-order Butterworth filter with zero phase shift is employed for time-domain filtering of low-and high-frequency time series at a crossover frequency of 1 Hz,merging the low and high-frequency ground motions into a broadband time series.Taking an Ms 6.8 Luding earthquake,as an example,this hybrid method was used for a rapid and efficient simulation analysis of broadband ground motion in the region.The accuracy and efficiency of this hybrid method were verified through comparisons with actually observed station data and empirical attenuation curves.Deterministic method simulation results revealed the effects of mountainous topography,basin effects,nonlinear effects within the basin’s sedimentary layers,and a coupling interaction between the basin and the mountains.The findings are consistent with similar studies,showing that near-fault sedimentary basins significantly focus and amplify strong ground motion,and the soil’s nonlinear behavior in the basin influences ground motion to varying extents at different distances from the fault.The mountainous topography impacts the basin’s response to ground motion,leading to barrier effects.This research provides a scientific foundation for seismic zoning,urban planning,and seismic design in nearfault mountain basin regions.
基金Supported by the National Key Research and Development Program of China (2023YFB4102903)。
文摘This study systematically conducted preparation optimization and performance investigations on Co-modified Ce/TiO_(2) catalysts,with a focus on examining how preparation methods and Co loading regulate the catalyst’s low-temperature denitrification activity.After identifying optimal preparation parameters via condition screening,multiple characterization techniques-including BET,XRD,XPS,H_(2)-TPR and in situ DRIFTS-were employed to deeply analyze the catalyst’s physicochemical properties and reaction mechanism.Results demonstrated that compared to the impregnation and co-precipitation methods,the Ce-Co_(0.025)/TiO_(2)-SG catalyst(prepared by the sol-gel method with a Co/Ti mass ratio of 0.025)exhibited significantly superior denitrification activity:NO conversion remained stably above 95%in the 225−350℃ temperature range,and it displayed high N_(2) selectivity.Characterization analysis revealed that abundant surface oxygen vacancies,a high proportion of Ce^(3+) species,and prominent acidic sites collectively contributed to enhancing its low-temperature denitrification performance.This work provides reference value for the development of highly efficient low-temperature denitrification catalysts.
基金Supported by Shanghai Agriculture Applied Technology Development Program (Grant No.T20220120).
文摘[Objectives]This study was conducted to establish a quantitative assessment method for the textural quality of chieh-qua fruit.[Methods]Using two modes of a texture analyzer,namely TPA(texture profile analysis)and puncture,the index data of the fruit were obtained by setting different trigger forces,deformation levels,test speeds,as well as puncture speeds and puncture depths.The data included TPA hardness,adhesiveness,springiness,cohesiveness,gumminess,chewiness,resilience,as well as skin hardness,skin toughness,flesh hardness,fracturability,and compactness.[Results]Different deformation levels had a significant impact on all parameters.Hardness,adhesiveness,gumminess and chewiness showed a trend of first increasing and then decreasing with the deformation level increasing.When the deformation level was 30%,the adhesiveness,gumminess and chewiness reached their maximum values.When the deformation level was 50%,TPA hardness reached its maximum.When the compression speed was 3 mm/s,the measured values of TPA hardness,adhesiveness,chewiness,and resilience were at their maximums.The skin hardness varied significantly under different trigger forces.When the trigger force was 15 g,the skin hardness reached a maximum value of 944.63 g,and the skin toughness,flesh hardness,fracturability,and compactness also reach their maximum values respectively.When the puncture depth was 12 mm,the flesh hardness and skin toughness reached their maximums of 682.51 g and 1.82 mm,respectively.In the TPA mode,the flesh hardness of chieh-qua showed an extremely significant negative correlation with springiness,cohesiveness,and resilience(P<0.01).The fruit fracturability detected by puncture had an extremely significant positive correlation with compactness(P<0.01).[Conclusions]The evaluation method for measuring chieh-qua texture by combining TPA and the puncture mode could accurately and quantitatively reflect the differences in the flesh texture quality of chieh-qua.The optimal parameters for texture measurement of chieh-qua fruit were determined as a 15 g trigger force with 50%deformation and a 3 mm/s compression speed in TPA mode,and a 15 g trigger force with a 12 mm puncture depth in puncture mode.Puncture speed was found to have no significant effect on the texture indices of chieh-qua.
基金Project supported by the National Natural Science Foundation of China(Nos.52405095,12272089,and 92360305)the Guangdong Basic and Applied Basic Research Foundation of China(No.2023A1515110557)+4 种基金the Natural Science Foundation of Liaoning Province of China(No.2023-BSBA-102)the Open Fund of National Key Laboratory of Particle Transport and Separation Technology of China(No.WZKF-2024-6)the Open Project of Guangxi Key Laboratory of Automobile Components and Vehicle Technology of China(Nos.2024GKLACVTKF07 and 2024GKLACVTKF06)the Basic Research Projects of Liaoning Provincial Department of Education of China(No.JYTQN2023162)the Fundamental Research Funds for the Central Universities of China(No.N2403022)。
文摘The testing of large structures is limited by high costs and long cycles, making scaling methods an attractive solution. However, the scaling process of elastic rings introduces complexities in multi-parameter geometric distortions, leading to a diminution in the predictive accuracy of the distorted similitude. To address this challenge, this study formulates a novel set of scaling laws, tailored to account for the intricate geometric distortions associated with elastic rings. The proposed scaling laws are formulated based on the intrinsic deformation characteristics of elastic rings, rather than the traditional systemic governing equations. Numerical and experimental cases are conducted to assess the efficacy and precision of the proposed scaling laws, and the obtained results are compared with those achieved by traditional methods. The outcomes demonstrate that the scaling laws put forth by this study significantly enhance the predictive capabilities for deformations of elastic rings.
基金supported in part by the Mining Hydraulic Technology and Equipment Engineering Research Center,Liaoning Technical University,Fuxin,China(Grant No.MHTE23-R04)the Fundamental Research Funds for the Central Universities(ID N25BSS068).
文摘This study presents an implicit multiphysics coupling method integrating Computational Fluid Dynamics(CFD),the Multiphase Particle-in-Cell(MPPIC)model,and the Finite Element Method(FEM),implemented with OpenFOAM,CalculiX,and preCICE to simulate fluid-particle-structure interactions with large deformations.Mesh motion in the fluid field is handled using the radial basis function(RBF)method.The particle phase is modeled by MPPIC,where fluid-particle interaction is described through momentum exchange,and inter-particle collisions are characterized by collision stress.The structural field is solved by nonlinear FEM to capture large deformations induced by geometric nonlinearity.Coupling among fields is realized through a partitioned,parallel,and non-intrusive iterative strategy,ensuring stable transfer and convergence of interface forces and displacements.Notably,the influence of particles on the structure is not direct but mediated by the fluid,while structural motion directly affects particle dynamics.The results demonstrate that the proposed approach effectively captures multiphysics interaction processes and provides a valuable reference for numerical modeling of coupled fluid-particle-structure systems.
