检索结果-南通市图书馆

Oligonucleotide chip, real-time PCR and sequencing for genotyping of hepatitis B virus

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2007年第31期13卷 4260-4263页

作者： Yong-Zhong Wang Guo-Xiang Wu li-Bo luo min Chen li-Hua Ruan Research Center for liver diseases The ThirdHospital of Changzhou Changzhou 213001 Jiangsu ProvinceChina

To compare the oligonucleotide chip, real-time PCR and sequencing for genotyping of hepatitis B virus in Chinese patients with chronic hepatitis B. METHODS： Mixture of samples with different genotypes and clinical serum samples from 126 chronic hepatitis B patients was tested for hepatitis B virus genotypes by oligonucleotide chip, real-time PCR and sequencing of PCR products, respectively. Clinical performances, time required and costs of the three assays were evaluated. RESULTS： Oligonucleotide chips and real-time PCR detected 1% and 0.1% genotypes, respectively, in mixed samples. Of the 126 clinical samples from patients with chronic hepatitis B, genotype B was detected in 41 （33%）, 41 （33%） and 45 （36%） samples, and genotype C in 76 （60%）, 76 （60%） and 81 （64%） samples, by oligonucleotide chip, real-time PCR and sequencing, respectively. Oligonucleotide chip and real-time PCR detected mixed genotypes B and C in 9 samples. Real- time PCR was the rapidest and cheapest among the three assays. CONCLUSION： Oligonucleotide chip and real-time PCR are able to detect mixed genotypes, while sequencing only detects the dominant genotype in clinical samples.

关键词： Hepatitis B virus Genotypes Oligonucleotidechips Real-time PCR Sequencing

Rollback reconstruction for TDC enhanced perfusion imaging

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2021年第8期32卷 23-33页

作者： Jia-Shun liu Yi-Kun Zhang Hui Tang li-Bo Zhang Ben-Qiang Yang Ying Yan li-min luo Yang Chen Laboratory of Image Science and Technology Southeast UniversityNanjing 210096China Department of Radiology General Hospital of the Northern Theater of the Chinese People’s Liberation ArmyShenyang 110016China Department of Radiotherapy General Hospital of the Northern Theater of the Chinese People’s Liberation ArmyShenyang 110016China Centre de Recherche en Information Biomedicale SinoFrancais(liA CRIBs) 35000 RennesFrance

Tomographic perfusion imaging is a significant imaging modality for stroke ***,the low rotational speed of the C-arm(6–8 s per circle)is a challenge for applying perfusion imaging in C-arm cone beam computed tomography(CBCT).Traditional reconstruction methods cannot remove the artifacts caused by the slow rotational speed or acquire enough sample points to restore the time density curve(TDC).This paper presents a dynamic rollback reconstruction method for *** proposed method can improve the temporal resolution by increasing the sample points used for calculating the *** with existing techniques,the algorithm allows slow-rotating scanners to be used for perfusion imaging *** the experiments,the proposed method was compared with other dynamic reconstruction algorithms based on standard reconstruction and the temporal interpolation *** presented algorithm could improve the temporal resolution without increasing the X-ray exposure time or contrast agent.

关键词： Rollback reconstruction CBCT Time resolution Time density curve

Synergistic effect of Co and Co_(6)Mo_(6)C for electroreduction of nitrate to ammonia on Co-MOF derived Co_(6)Mo_(6)C/Co/NC

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第7期17卷 5807-5816页

作者： Xinyan Wang Yue Cao Yan Hai Xiaoman li min luo State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering School of Chemistry and Chemical EngineeringNingxia UniversityYinchuan 750021China

Electrocatalytic nitrate reduction reaction(e-NO_(3)RR)offers a promising alternative method for nitrogen cycling and ammonia(NH3)production under ambient ***,the method is still in the dilemma of lowering the reaction overpotential and increasing the reaction *** successfully developed the composition-adjustable Co_(6)Mo_(6)C/Co/N-doped carbon(NC)catalysts by in situ carbonization of Co-based metal-organic framework(MOF)with the constrained phosphomolybdic *** adjusting the ratio of Co0 and Co_(6)Mo_(6)C,Co_(6)Mo_(6)C/Co/NC-3 could satisfy both NO_(3)−conversion at low potential and NH_(x)hydrogenation,and synthesize ammonia efficiently through the synergistic effect of Co0 and Co_(6)Mo_(6)*** achieved an ammonia yield rate as 1233.2μg·h^(−1)·mgcat^(−1)and Faradaic efficiency of NH4+93.6%at−0.33 V *** hydrogen electrode(RHE).Importantly,density functional theory(DFT)calculations and experimental results have demonstrated for the first time the excellent adsorption of nitrite(NO_(2)^(−))by the Mo sites of Co_(6)Mo_(6)C during e-NO_(3)RR,avoiding the undesirable accumulation of NO_(2)^(−).

关键词： synergistic effect nitrate electroreduction Co_(6)Mo_(6)C ammonia synthesis

Analysis of GC×GC fingerprints from medicinal materials using a novel contour detection algorithm:A case of Curcuma wenyujin

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Pharmaceutical Analysis 2024年第4期14卷 542-551页

作者： Xinyue Yang Yingyu Sima Xuhuai luo Yaping li min He Department of Pharmaceutical Engineering School of Chemical EngineeringXiangtan UniversityXiangtanHunan411105China Molecular Science and Biomedicine Laboratory(MBL) State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical EngineeringAptamer Engineering Center of Hunan ProvinceHunan UniversityChangsha410082China Department of Quality Control Xiangtan Central HospitalXiangtanHunan411100China

This study introduces an innovative contour detection algorithm,PeakCET,designed for rapid and efficient analysis of natural product image fingerprints using comprehensive two-dimensional gas chromatogram(GC×GC).This method innovatively combines contour edge tracking with affinity propagation(AP)clustering for peak detection in GC×GC fingerprints,the first in this *** edge tracking signif-icantly reduces false positives caused by“burr”signals,while AP clustering enhances detection accuracy in the face of false *** efficacy of this approach is demonstrated using three medicinal products derived from Curcuma *** not only performs contour detection but also employs inter-group peak matching and peak-volume percentage calculations to assess the compositional similarities and differences among various ***,this algorithm compares the GC×GC fingerprints of Radix/Rhizoma Curcumae Wenyujin with those of products from different botanical *** findings reveal that genetic and geographical factors influence the accumulation of secondary metabolites in various plant *** sample exhibits unique characteristic components alongside common ones,and vari-ations in content may influence their therapeutic *** research establishes a foundational data-set for the quality assessment of Curcuma products and paves the way for the application of computer vision techniques in two-dimensional(2D)fingerprint analysis of GC×GC data.

关键词： GC×GC Image fingerprints Contour detection Clustering of mass spectra Curcuma products

Reshaping force for deformed casing repairing with hydraulic rolling reshaper and its influencing factors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第4期21卷 2745-2757页

作者： Hong-Fei li min luo Ting-Ting Xu Qiao-Zhen li Cong-Jian Huang School of Mechanical Science and Engineering Northeast Petroleum University

Hydraulic rolling reshaper is an advanced reshaping tool to solve the problem of casing deformation,which has been widely used in recent years. When it is used for well repair operation, the reshaping force provided by ground devices is generally determined by experience. However, too large reshaping force may destroy the deformed casing, and too small reshaping force may also prolong the construction period and affect the repairing effect. In this paper, based on Hertz contact theory and elastic-plastic theory, combined with the process parameters of shaping, and considering the structural characteristics of the deformed casing and reshaper, we propose a mathematical model for calculating the reshaping force required for repairing deformed casing by hydraulic rolling reshaper. Meanwhile, the finite element model and numerical method of hydraulic rolling reshaper repairing deformed casing are established by using the finite element method, and the reliability of the mathematical model is verified by several examples. On this basis, the control variable method is used to investigate the influence of each parameter on the reshaping force, and the influence degree of each parameter is explored by orthogonal simulation test and Pearson correlation analysis. The research results not only provide an important theoretical basis for the prediction of reshaping force in on-site construction, but also provide a reference for the subsequent improvement of the shaping process.

关键词： Hydraulic rolling reshaper Reshaping force Deformed casing Casing reshaping Hertz contact theory

Construction of daily precipitation series and the observational characteristics of extreme precipitation in Tianjin,China during 1888-2022

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2024年第1期15卷 52-61页

作者： Peng SI Qing-Xiang li Xiao-Yang CHEN min WANG Chuan-Jun luo Tianjin Meteorological Information Center Tianjin Meteorological BureauTianjin 300074China Research Centerfor Ecology and Environment of Central Asia Chinese Academy of SciencesWulumuqi 830011China School of Atmospheric Sciences Sun Yat-sen UniversityZhuhai 528478China Key Laboratory of Tropical Amosphere-Ocean System Ministry of EducationZhuhai 528478China Shaoguan Meteorological Service Shaoguan 512028China

Given the difficulties in rescuing and ensuring the quality of long-term climate data,current studies on century-scale climate change are usually limited to annual and monthly data,resulting in the poor detection of extreme climate events and their changes before *** this study,we reconstructed a daily precipitation series for Tianjin from 15 September 1887 to 31 December 2022 on the basis of the most comprehensive daily precipitation records collected from the Tianjin Meteorological Archive,China,and in reference to the precipitation analysis results based on the datasets developed by the Climatic Research Unit Time-Series version 4.06,Global Precipitation Climatology Centre and University of Delaware along with the application of various homogenisation methods for climate *** approach provides a complete and reliable century-long daily precipitation series for the study of regional or local extreme weather and climate *** reconstructed daily dataset reveals that the annual precipitation amount and R95 intensity in Tianjin during 1888-2022 lack significant trends and have values of 0.74±6.99 and-1.84±3.22 mm per decade,*** the annual and seasonal scales,the precipitation amount and R95 intensity,particularly those in autumn,have increased since the latter half of the 20th century relative to those in ***,the increase in precipitation amount and R95 intensity is relatively limited compared with that in atmospheric water vapour content due to surface warming,indicating the highly sensitive response of extreme precipitation events to *** addition,the estimates for the return periods of 5,10,20,50 and 100 years covering 1888-2022,1888-1950 and 1951-2022 depict that the intensity of heavy rain and above magnitude was highest in 1888-1950 and decreased in 1951-2022.

关键词： Over a century-long timescale Daily precipitation series Extreme precipitation Return period

Monte Carlo method for evaluation of surface emission rate measurement uncertainty

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第7期35卷 126-136页

作者： Yuan-Qiao li min lin li-Jun Xu Rui luo Yu-He Zhang Qian-Xi Ni Yun-Tao liu China Institute of Atomic Energy Beijing102413China National Key Laboratory for Metrology and Calibration Techniques Beijing102413China Department of Radiation Oncology Hunan Cancer HospitalChangsha410031China The Affiliated Cancer Hospital of Xiangya School of Medicine Central South UniversityChangsha410031China

The aim of this study is to evaluate the uncertainty of 2πα and 2πβ surface emission rates using the windowless multiwire proportional counter *** study used the Monte Carlo method (MCM) to validate the conventional Guide to the Expression of Uncertainty in Measurement (GUM) method.A dead time measurement model for the two-source method was established based on the characteristics of a single-channel measurement system,and the voltage threshold correction factor measurement function was indirectly obtained by fitting the threshold correction *** uncertainty in the surface emission rate was calculated using the GUM method and the law of propagation of *** MCM provided clear definitions for each input quantity and its uncertainty distribution,and the simulation training was realized with a complete and complex mathematical *** results of the surface emission rate uncertainty evaluation for four radioactive plane sources using both methods showed the uncertainty’s consistency E_(n)lidation tool for GUM results.

关键词： Surface emission rate Monte Carlo method Metrology Probability distribution function Dead time Low-energy loss correction Least-squares method

Switching Behavior of Cascode GaN Under Influence of Gate Driver

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第4期10卷 1816-1833页

作者： Bin luo Guangzhao luo Sihai li School of Automation Northwestern Polytechnical UniversityXi’an 710072China

With high-frequency,low power dissipation and high-efficiency characteristics,Gallium nitride(GaN)power devices are of significant benefit in designing high-speed motor drives,as they improve performance and reduce ***,due to the cascode structure,coupling with the parasitics in gate driver and power circuits,power converters based on cascode GaN are prone to overshoot and oscillate on switching waveforms,which may lead to serious EMC problems,or even device *** complicated structure of cascode GaN device makes the gate driver design comparatively *** analytical model of the switching process considering gate driver parameters is proposed in this *** influence of gate driver parameters on switching behavior is investigated from the perspective of switching speed,waveform overshoot,and power ***-offs among overshoot,switching speed,and power loss are discussed;guidelines to design gate driver parameters are given.

关键词： Gallium nitride(GaN) gate driver oscillation and overshoot switching characteristics

Short-time maritime target detection based on polarization scattering characteristics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2024年第1期35卷 55-64页

作者： CHEN Shichao luo Feng TIAN min LYU Wanghan College of Computer and Information Engineering(College of Artificial Intelligence) Nanjing Tech UniversityNanjing 211816China Hangzhou Institute of Technology Xidian UniversityHangzhou 311200China

In this paper,a detection method combining Cameron decomposition based on polarization scattering characteristics in sea clutter background is ***,the Cameron decomposition is exploited to fuse the radar echoes of full polarization channels at the data *** to the artificial material structure on the surface of the target,it can be shown that the non-reciprocity of the target cell is stronger than that of the clutter ***,based on the analysis of the decomposition results,a new feature with scattering geometry characteristics in polarization domain,denoted as Cameron polarization decomposition scattering weight(CPD-SW),is extracted as the test statistic,which can achieve more detailed descriptions of the clutter scattering characteristics utilizing the difference between their scattering ***,the superiority of the proposed CPD-SW detector over traditional detectors in improving detection performance is verified by the IPIX measured dataset,which has strong stability under short-time observation in threshold detection and can also improve the separability of feature space zin anomaly detection.

关键词： sea clutter small target radar detection Cameron decomposition characteristics analysis