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Preliminary study on a quantification method and standardization for aquatic microbial loads based on microbial diversity absolute quantitative sequencing
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作者 Wen Li Jing Libin +4 位作者 Li Xiawei Lu Jing Jin Haowei Yang Yongqi Li Xueling 《China Standardization》 2026年第1期68-73,共6页
This study establishes and validates a method for the precise quantification of aquatic microbial loads using microbial diversity absolute quantitative sequencing.By adding synthetic spike-in DNA to water samples from... This study establishes and validates a method for the precise quantification of aquatic microbial loads using microbial diversity absolute quantitative sequencing.By adding synthetic spike-in DNA to water samples from the Dahei River prior to DNA extraction and 16S rRNA gene sequencing,it generates standard curves to convert sequencing data into absolute microbial copy numbers.The method,which is proved highly accurate(R^(2)>0.99),reveals a clear contrast between the river sites:the upstream community has not only a significantly higher total microbial load but also a completely different makeup of species compared to the downstream site.This approach effectively overcomes the limitations of relative abundance analysis,providing a powerful tool for environmental monitoring,and proposes key steps for future standardization to ensure data comparability and integration. 展开更多
关键词 absolute quantification microbial load 16S rRNA sequencing spike-in STANDARDIZATION aquatic microbes
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Sequential search-based Latin hypercube sampling scheme for digital twin uncertainty quantification with application in EHA 被引量:1
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作者 Dong LIU Shaoping WANG +1 位作者 Jian SHI Di LIU 《Chinese Journal of Aeronautics》 2025年第4期176-192,共17页
For uncertainty quantification of complex models with high-dimensional,nonlinear,multi-component coupling like digital twins,traditional statistical sampling methods,such as random sampling and Latin hypercube samplin... For uncertainty quantification of complex models with high-dimensional,nonlinear,multi-component coupling like digital twins,traditional statistical sampling methods,such as random sampling and Latin hypercube sampling,require a large number of samples,which entails huge computational costs.Therefore,how to construct a small-size sample space has been a hot issue of interest for researchers.To this end,this paper proposes a sequential search-based Latin hypercube sampling scheme to generate efficient and accurate samples for uncertainty quantification.First,the sampling range of the samples is formed by carving the polymorphic uncertainty based on theoretical analysis.Then,the optimal Latin hypercube design is selected using the Latin hypercube sampling method combined with the"space filling"criterion.Finally,the sample selection function is established,and the next most informative sample is optimally selected to obtain the sequential test sample.Compared with the classical sampling method,the generated samples can retain more information on the basis of sparsity.A series of numerical experiments are conducted to demonstrate the superiority of the proposed sequential search-based Latin hypercube sampling scheme,which is a way to provide reliable uncertainty quantification results with small sample sizes. 展开更多
关键词 Digital Twin(DT) Genetic algorithms(GA) Optimal Latin Hypercube Design(Opt LHD) Sequential test Uncertainty quantification(UQ) EHA
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A Gel-Free Budget-Friendly Approach to GFP-Tagged Viruses Quantification in Plant Samples
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作者 Rohith Grandhi Mélodie B.Plourde +1 位作者 Aditi Balasubramani Hugo Germain 《Phyton-International Journal of Experimental Botany》 2025年第5期1497-1504,共8页
Viral diseases are an important threat to crop yield,as they are responsible for losses greater than US$30 billion annually.Thus,understanding the dynamics of virus propagation within plant cells is essential for devi... Viral diseases are an important threat to crop yield,as they are responsible for losses greater than US$30 billion annually.Thus,understanding the dynamics of virus propagation within plant cells is essential for devising effective control strategies.However,viruses are complex to propagate and quantify.Existing methodologies for viral quantification tend to be expensive and time-consuming.Here,we present a rapid cost-effective approach to quantify viral propagation using an engineered virus expressing a fluorescent reporter.Using a microplate reader,we measured viral protein levels and we validated our findings through comparison by western blot analysis of viral coat protein,the most common approach to quantify viral titer.Our proposed methodology provides a practical and accessible approach to studying virus-host interactions and could contribute to enhancing our understanding of plant virology. 展开更多
关键词 Microplate reader CP-PlAMV viruses plant viral quantification green fluorescent protein western blot quantification Nicotiana benthamiana Arabidopsis thaliana Pearson’s correlation
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Uncertainty Quantification of Dynamic Stall Aerodynamics for Large Mach Number Flow around Pitching Airfoils
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作者 Yizhe Han Guangjing Huang +2 位作者 Fei Xiao Zhiyin Huang Yuting Dai 《Fluid Dynamics & Materials Processing》 2025年第7期1657-1671,共15页
During high-speed forward flight,helicopter rotor blades operate across a wide range of Reynolds and Mach numbers.Under such conditions,their aerodynamic performance is significantly influenced by dynamic stall—a com... During high-speed forward flight,helicopter rotor blades operate across a wide range of Reynolds and Mach numbers.Under such conditions,their aerodynamic performance is significantly influenced by dynamic stall—a complex,unsteady flow phenomenon highly sensitive to inlet conditions such asMach and Reynolds numbers.The key features of three-dimensional blade stall can be effectively represented by the dynamic stall behavior of a pitching airfoil.In this study,we conduct an uncertainty quantification analysis of dynamic stall aerodynamics in high-Mach-number flows over pitching airfoils,accounting for uncertainties in inlet parameters.A computational fluid dynamics(CFD)model based on the compressible unsteady Reynolds-averagedNavier–Stokes(URANS)equations,coupledwith sliding mesh techniques,is developed to simulate the unsteady aerodynamic behavior and associated flow fields.To efficiently capture the aerodynamic responses while maintaining high accuracy,a multi-fidelity Co-Kriging surrogate model is constructed.This model integrates the precision of high-fidelity wind tunnel experiments with the computational efficiency of lower-fidelity URANS simulations.Its accuracy is validated through direct comparison with experimental data.Building upon this surrogate model,we employ interval analysis and the Sobol sensitivity method to quantify the uncertainty and parameter sensitivity of the unsteady aerodynamic forces resulting frominlet condition variability.Both the inlet Mach number and Reynolds number are treated as uncertain inputs,modeled using interval representations.Our results demonstrate that variations inMach number contribute far more significantly to aerodynamic uncertainty than those in Reynolds number.Moreover,the presence of dynamic stall vortices markedly amplifies the aerodynamic sensitivity to Mach number fluctuations. 展开更多
关键词 Dynamic stall uncertainty quantification multi-fidelity surrogate modeling sensitivity analysis
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Quantification of Streptococcus salivarius using the digital polymerase chain reaction as a liver fibrosis marker
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作者 Shuichiro Iwasaki Akira Také +8 位作者 Haruki Uojima Kazue Horio Yoshihiko Sakaguchi Kazuyoshi Gotoh Takashi Satoh Hisashi Hidaka Yasuhito Tanaka Shunji Hayashi Chika Kusano 《World Journal of Hepatology》 2025年第4期53-66,共14页
BACKGROUND The Streptococcus salivarius(S.salivarius)group,which produces the enzyme urease has been identified as a potential contributor to ammonia production in the gut.Researchers have reported that patients with ... BACKGROUND The Streptococcus salivarius(S.salivarius)group,which produces the enzyme urease has been identified as a potential contributor to ammonia production in the gut.Researchers have reported that patients with minimal HE had an increased abundance of the S.salivarius group,which is a specific change in the gut microbiota that distinguishes them from healthy individuals.The correlation between the aggregation of specific bacterial species and fibrosis progression in chronic liver disease(CLD)is yet to be fully elucidated.AIM To quantify S.salivarius using digital PCR(dPCR)as a liver fibrosis marker of CLD.METHODS This study retrospectively analysed 52 patients with CLD.To quantify S.salivarius in patients with CLD using dPCR,we evaluated the specificity and sensitivity of S.salivarius bacterial load using dPCR for a type strain.Next,we evaluated the clinical usefulness of dPCR for S.salivarius load quantification for detecting liver fibrosis in patients with CLD.The liver fibrosis stage was categorized into mild and advanced fibrosis based on pathological findings.RESULTS The dPCR assay revealed that S.salivarius was highly positive for the tnpA gene.The lower limit of quantification for dPCR using the tnpA gene with a 1μL template comprising 1.28×102 CFU/mL was 4.3 copies.After considering the detection range in dPCR,we adjusted the extracted DNA concentration to 5.0×10-4 ng/μL from 200 mg stool samples.The median bacterial loads of S.salivarius in stool sample from patients with mild and advanced fibrosis were 1.9 and 7.4 copies/μL,respectively.The quantification of S.salivarius load was observed more frequently in patients with advanced fibrosis than in those with mild fibrosis(P=0.032).CONCLUSION Quantifying of S.salivarius load using digital PCR is a useful biomarker for liver fibrosis in patients with CLD. 展开更多
关键词 Chronic liver disease Streptococcus salivarius Digital PCR Liver fibrosis Liver cirrhosis quantification
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Research on Quantification Mechanism of Data Source Reliability Based on Trust Evaluation
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作者 Gaoshang Lu Fa Fu Zixiang Tang 《Computers, Materials & Continua》 2025年第6期4239-4256,共18页
In the data transaction process within a data asset trading platform,quantifying the trustworthiness of data source nodes is challenging due to their numerous attributes and complex structures.To address this issue,a ... In the data transaction process within a data asset trading platform,quantifying the trustworthiness of data source nodes is challenging due to their numerous attributes and complex structures.To address this issue,a distributed data source trust assessment management framework,a trust quantification model,and a dynamic adjustment mechanism are proposed.Themodel integrates the Analytic Hierarchy Process(AHP)and Dempster-Shafer(D-S)evidence theory to determine attribute weights and calculate direct trust values,while the PageRank algorithm is employed to derive indirect trust values.Thedirect and indirect trust values are then combined to compute the comprehensive trust value of the data source.Furthermore,a dynamic adjustment mechanism is introduced to continuously update the comprehensive trust value based on historical assessment data.By leveraging the collaborative efforts of multiple nodes in the distributed network,the proposed framework enables a comprehensive,dynamic,and objective evaluation of data source trustworthiness.Extensive experimental analyses demonstrate that the trust quantification model effectively handles large-scale data source trust assessments,exhibiting both strong trust differentiation capability and high robustness. 展开更多
关键词 Trust evaluation data source reliability distributed network quantification mechanism
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Fe^(3+) ion quantification with reusable bioinspired nanopores
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作者 Yanqiong Wang Yaqi Hou +1 位作者 Fengwei Huo Xu Hou 《Chinese Chemical Letters》 2025年第2期179-184,共6页
Excessive Fe^(3+) ion concentrations in wastewater pose a long-standing threat to human health.Achieving low-cost,high-efficiency quantification of Fe^(3+) ion concentration in unknown solutions can guide environmenta... Excessive Fe^(3+) ion concentrations in wastewater pose a long-standing threat to human health.Achieving low-cost,high-efficiency quantification of Fe^(3+) ion concentration in unknown solutions can guide environmental management decisions and optimize water treatment processes.In this study,by leveraging the rapid,real-time detection capabilities of nanopores and the specific chemical binding affinity of tannic acid to Fe^(3+),a linear relationship between the ion current and Fe^(3+) ion concentration was established.Utilizing this linear relationship,quantification of Fe^(3+) ion concentration in unknown solutions was achieved.Furthermore,ethylenediaminetetraacetic acid disodium salt was employed to displace Fe^(3+) from the nanopores,allowing them to be restored to their initial conditions and reused for Fe^(3+) ion quantification.The reusable bioinspired nanopores remain functional over 330 days of storage.This recycling capability and the long-term stability of the nanopores contribute to a significant reduction in costs.This study provides a strategy for the quantification of unknown Fe^(3+) concentration using nanopores,with potential applications in environmental assessment,health monitoring,and so forth. 展开更多
关键词 Bioinspired nanopores Fe^(3+)ion quantification Chemical binding affinity Tannic acid REUSABILITY
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MultiJSQ:Direct joint segmentation and quantification of left ventricle with deep multitask-derived regression network
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作者 Xiuquan Du Zheng Pei +3 位作者 Ying Liu Xinzhi Cao Lei Li Shuo Li 《CAAI Transactions on Intelligence Technology》 2025年第1期175-192,共18页
Quantitative analysis of clinical function parameters from MRI images is crucial for diagnosing and assessing cardiovascular disease.However,the manual calculation of these parameters is challenging due to the high va... Quantitative analysis of clinical function parameters from MRI images is crucial for diagnosing and assessing cardiovascular disease.However,the manual calculation of these parameters is challenging due to the high variability among patients and the time-consuming nature of the process.In this study,the authors introduce a framework named MultiJSQ,comprising the feature presentation network(FRN)and the indicator prediction network(IEN),which is designed for simultaneous joint segmentation and quantification.The FRN is tailored for representing global image features,facilitating the direct acquisition of left ventricle(LV)contour images through pixel classification.Additionally,the IEN incorporates specifically designed modules to extract relevant clinical indices.The authors’method considers the interdependence of different tasks,demonstrating the validity of these relationships and yielding favourable results.Through extensive experiments on cardiac MR images from 145 patients,MultiJSQ achieves impressive outcomes,with low mean absolute errors of 124 mm^(2),1.72 mm,and 1.21 mm for areas,dimensions,and regional wall thicknesses,respectively,along with a Dice metric score of 0.908.The experimental findings underscore the excellent performance of our framework in LV segmentation and quantification,highlighting its promising clinical application prospects. 展开更多
关键词 global image features joint segmentation and quantification left ventricle(LV) multitask-derived regression network
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A rapid tool for quantification of latent infection of wheat leaves by powdery mildew
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作者 Aolin Wang Ru Jiang +9 位作者 Meihui Zhang Hudie Shao Fei Xu Kouhan Liu Haifeng Gao Jieru Fan Wei Liu Xiaoping Hu Yilin Zhou Xiangming Xu 《Journal of Integrative Agriculture》 2025年第12期4690-4702,共13页
Wheat powdery mildew caused by Blumeria graminis f.sp.tritici(Bgt)is an important disease worldwide.Detection of latent infection of leaves by the pathogen in late autumn is valuable for estimating the inoculum potent... Wheat powdery mildew caused by Blumeria graminis f.sp.tritici(Bgt)is an important disease worldwide.Detection of latent infection of leaves by the pathogen in late autumn is valuable for estimating the inoculum potential to assess disease risks in the spring.We developed a new tool for rapid detection and quantification of latent infection of seedlings by the pathogen.The method was based on recombinase polymerase amplification(RPA)coupled with an end-point detection via lateral flow device(LFD).The limit of detection is 100 agμL^(-1)of Bgt DNA,without noticeable interference from either other common wheat pathogens or wheat material(Triticum aestivum).It was evaluated on wheat seedlings for this accuracy and sensitivity in detecting latent infection of Bgt.We further extended this RPALFD assay to estimate the level of latent infection by Bgt based on imaging analysis.There was a strong correlation between the image-based and real-time PCR assay estimates of Bgt DNA.The present results suggested that this new tool can provide rapid and accurate quantification of Bgt in latently infected leaves and can be further development as an on-site monitoring tool. 展开更多
关键词 Blumeria graminis f.sp.tritici(Bgt) recombinase polymerase amplification(RPA) lateral flow device(LFD) image-based quantification disease monitoring
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一种基于HAZOP-LOPA的碱回收燃烧工段安全仪表系统设计方法
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作者 汤伟 郑晓虎 +1 位作者 王孟效 王其林 《中国造纸》 北大核心 2026年第1期149-156,共8页
针对当前造纸工业安全仪表系统(SIS)设计方法存在的风险分析碎片化、定量评估不足等问题,本研究以碱回收燃烧工段汽包控制部分SIS设计为例,提出一种基于危险与可操作性分析-保护层分析(HAZOP-LOPA)的SIS定级及设计方法。首先对碱回收燃... 针对当前造纸工业安全仪表系统(SIS)设计方法存在的风险分析碎片化、定量评估不足等问题,本研究以碱回收燃烧工段汽包控制部分SIS设计为例,提出一种基于危险与可操作性分析-保护层分析(HAZOP-LOPA)的SIS定级及设计方法。首先对碱回收燃烧工段进行工艺流程节点划分,并设计对应的风险概率-后果二维风险矩阵,通过HAZOP方法系统识别该工段的潜在偏差与风险场景,结合LOPA分析构建独立保护层量化模型;然后基于风险传导特性建立保护层分析-安全完整性等级(LOPA-SIL)动态映射关系,对SIS等级进行合理定级,最后根据定级结果进行SIS的设计,并通过系统失效概率、剩余风险值等指标验证系统的有效性。结果表明,该方法可成功识别2项高风险场景并判定需增设SIL2级SIS,改进后将风险概率成功降至企业可接受水平(<1.0×10-6/年)。 展开更多
关键词 碱回收燃烧工段 HAZOP-LOPA 安全完整性等级 安全仪表系统 风险量化
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运用Real-time quantification PCR方法建立副溶血性弧菌在即食虾中的生长预测模型 被引量:5
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作者 彭织云 王敬敬 +2 位作者 唐晓阳 潘迎捷 赵勇 《食品工业科技》 CAS CSCD 北大核心 2013年第8期108-110,共3页
运用Real-time quantification PCR(real-time qPCR)方法建立副溶血性弧菌在即食虾中生长预测模型。首先构建质粒标准品,梯度稀释后建立标准曲线,然后用Real-time qPCR方法检测虾中副溶血性弧菌的数量,最后建立37℃下即食虾中副溶血性... 运用Real-time quantification PCR(real-time qPCR)方法建立副溶血性弧菌在即食虾中生长预测模型。首先构建质粒标准品,梯度稀释后建立标准曲线,然后用Real-time qPCR方法检测虾中副溶血性弧菌的数量,最后建立37℃下即食虾中副溶血性弧菌生长预测模型,并与传统涂布计数方法进行比较。结果表明,Real-time qPCR方法和传统计数方法均可建立Gmopertz模型、Logistic模型和Richards模型,模型拟合的相关系数R2均在0.9以上。基于Real-timeqPCR方法省时省力、特异性好等优点,用Real-time qPCR方法建立微生物预测模型是未来预测微生物学领域的一种发展趋势。 展开更多
关键词 REAL-TIME quantification PCR 副溶血性弧菌 生长预测模型
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Simultaneous quantification of flavonol glycosides, terpene lactones, polyphenols and carboxylic acids in Ginkgo biloba leaf extract by UPLC-QTOF-MS^E based metabolomic approach 被引量:10
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作者 赵一懿 郭洪祝 +1 位作者 陈有根 傅欣彤 《Journal of Chinese Pharmaceutical Sciences》 CAS CSCD 2017年第11期789-804,共16页
Abstract: In the present study, we established an ultra performance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC-QTOF-MSE) method to simultaneously quantify 33 components in Ginkgo bilo... Abstract: In the present study, we established an ultra performance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC-QTOF-MSE) method to simultaneously quantify 33 components in Ginkgo biloba leaf extracts (GBEs), including 17 flavonol glycosides, five terpene trilactones (TTLs), four polyphenols and seven carboxylic acids. This optimized method was successfully applied to analyze the explicit compositions of GBE samples collected from different places. Furthermore, the data were processed through unsupervised principal component analysis (PCA) and supervised orthogonal partial least squared discrimination analysis (OPLS-DA) to evaluate the quality and compare the differences between the samples according to the contents of the 33 chemical constituents. Bilobalide, protocatechuic acid, shikimic acid, quinic acid, ginkgolide B, ginkgolide J, kaempferol-3-O-rutinoside, isorhamnetin-3-O-rutinoside, quercetin-3-O-ct-L-rhamnopyranocyl-2"-(6'"-p-coumaroyl)-β-D-glucoside and rutin were recognized as characteristic chemical markers that contributed most to control the quality of GBEs. Based on the fact that GBEs should be standardized with the characteristic components as quality control chemical markers, it is most important to maintain the quality of GBEs stable and reliable, and this method also provided a good strategy to further rectify and standardize the GBEs market. 展开更多
关键词 Ginkgo biloba L. leaf extract UPLC-QTOF-MS^E PCA Multi-components quantification Genuine flavonol glycoside
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Quantification of seven phenylpropanoid compounds in Chinese Cinnamomi Cortex and Ramulus by HPLC 被引量:3
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作者 袁鹏飞 马雅静 +7 位作者 苏丹 尚明英 徐风 刘广学 Niloufar Iranmanesh 李兰芳 姜廷良 蔡少青 《Journal of Chinese Pharmaceutical Sciences》 CAS CSCD 2015年第9期591-599,共9页
In the present study, we developed and validated a high-performance liquid chromatography method for the simultaneous determination of seven phenylpropanoid compounds (2-hydroxyl cinnamaldehyde, coumarin, cinnamyl al... In the present study, we developed and validated a high-performance liquid chromatography method for the simultaneous determination of seven phenylpropanoid compounds (2-hydroxyl cinnamaldehyde, coumarin, cinnamyl alcohol, cinnamic acid, 2-methoxy cinnamic acid, cinnamaldehyde and 2-methoxy cinnamaldehyde) in Cinnamomi Cortex and Cinnamomi Ramulus. The levels of seven phenylpropanoid compounds in Cinnamomi Cortex and Cinnamomi Ramulus were compared using this method. A total of 48 samples (27 Cinnamomi Cortex and 21 Cinnamomi Ramulus) were purchased in China and analyzed. Quantities of seven phenylpropanoid compounds ranged from 17.5 to 61.6 mg/g in Cinnamomi Cortex and ranged from 9.91 to 23.4 mg/g in Ciunamomi Ramulus. The level of 2-methoxy cinnamic acid in the Cinnamomi Cortex samples was below the LOD, whereas it ranged from 0 to 0.119 mg/g in the Cinnamomi Ramulus samples. The (cinnamyl alcohol+cinnamic acid)/cinnamaldehyde ratios (R346) of Ciunamomi Cortex and Cinnamomi Ramulus ranged from 0.0121 to 0.0467 and 0.0598 to 0.182, respectively. This ratio could be used to discriminate Cinnamomi Cortex (〈0.05) and Cinnamomi Ramulus (〉0.05). The extraction rates (Dn) of seven compounds in boiling water were different, with the lowest dissolution for cinnamaldehyde (〈3%) and the highest for cinnamic acid (about 60%). 展开更多
关键词 quantification Phenylpropanoid compounds Cinnamomi Cortex Cinnamomi Ramulus High-performance liquid chromatography
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Quantification of eugenol and bancroftione in Caryophylli Fructus using high-performance liquid chromatography 被引量:1
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作者 刘淑娟 林宗涛 +1 位作者 王弘 陈世忠 《Journal of Chinese Pharmaceutical Sciences》 CAS 2010年第6期459-463,共5页
For the first time, we have utilized high-performance liquid chromatography (HPLC) to simultaneously quantify the eugenol and bancroffione in Caryophylli Fructus. The optimized parameters included: Inertsil ODS-4 c... For the first time, we have utilized high-performance liquid chromatography (HPLC) to simultaneously quantify the eugenol and bancroffione in Caryophylli Fructus. The optimized parameters included: Inertsil ODS-4 column (150 mm×4.6 mm, 5 μm); column temperature: 35 ℃; mobile phase: methanol water (65:35, v/v); flow rate: 1.0 mL/min; detection wavelength: 280 nm. Eugenol and bancroftione showed good linear relationships with peak areas within the range of (0.0998 0.8982) mg/mL (r = 0.9999) and (0.1474-1.3266) mg/mL (r = 0.9999), respectively. The average recoveries were 102.52% and 100.96% for eugenol and bancroftione, respectively. Our results showed that the established method is simple, rapid, and accurate with good reproducibility to evaluate the quality of Caryophylli Fructus. 展开更多
关键词 Caryophylli Fructus EUGENOL Bancroftione quantification HPLC
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Quantification of the active ingredient quercetin of “Guangdong Wang-bu-liu-xing” by high-performance liquid chromatography with UV detection 被引量:1
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作者 曾颂 韩秀奇 李书渊 《Journal of Chinese Pharmaceutical Sciences》 CAS CSCD 2013年第1期101-105,共5页
High-performance liquid chromatography with UV detection was used for the quantification of the flavonoid quercetin, the active compound found in "Guangdong Wang-bu-liu-xing". The method was developed and demonstrat... High-performance liquid chromatography with UV detection was used for the quantification of the flavonoid quercetin, the active compound found in "Guangdong Wang-bu-liu-xing". The method was developed and demonstrated to provide superior performance over other commonly documented methods. This HPLC assay achieved high specificity through the use of a reversed-phase C18 column eluted with a mobile phase of methanol-0.4% (v/v) phosphoric acid (50:50, v/v) over the course of 30 min. UV detection at 360 nm was used. This analytical method provided excellent precision and a mean recovery of 99%, demonstrated by repeated analysis of 11 sample groups. Because of its high performance and simplicity, this HPLC assay can be readily utilized as a practical method for the quality control of active compounds extracted from Guangdong Wang-bu-liu-xing. 展开更多
关键词 Guangdong Wang-bu-liu-xing quantification HPLC QUERCETIN
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基于化学衍生和质谱技术的苹婆酸定量方法研究
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作者 王芙蓉 冯潇慧 +4 位作者 冯胜楠 张正杰 王玉娇 孟庆石 张春香 《中国畜牧兽医》 北大核心 2026年第1期266-275,共10页
【目的】试验旨在建立准确测定棉粕和饲料中苹婆酸含量的检测方法,以合理利用棉粕蛋白资源。【方法】通过优化2-吡啶甲酰肼与苹婆酸的反应条件、苹婆酸提取流程和质谱检测参数,建立采用外标法的液相色谱-串联质谱(LC-MS/MS)定量苹婆酸... 【目的】试验旨在建立准确测定棉粕和饲料中苹婆酸含量的检测方法,以合理利用棉粕蛋白资源。【方法】通过优化2-吡啶甲酰肼与苹婆酸的反应条件、苹婆酸提取流程和质谱检测参数,建立采用外标法的液相色谱-串联质谱(LC-MS/MS)定量苹婆酸的方法,并考察该检测方法的线性范围、检测限、定量限、回收率、批内与批间精密度和准确度,使用该方法进行实际样品检测。【结果】优化后2-吡啶甲酰肼与苹婆酸的最佳反应溶液组成为500 mmol/L EDC、15 mmol/L HOAt和40 mmol/L 2-吡啶甲酰肼,最佳反应温度为20℃,最佳反应时间为60 min。游离态苹婆酸的最佳提取液为甲醇,结合态苹婆酸最佳水解条件为50℃水解12 h。苹婆酸在1~1 000 ng/mL范围内线性关系良好,相关系数(r)均>0.99,检测限为5μg/kg,定量限为12.5μg/kg。游离态苹婆酸的回收率为80.13%~95.30%,批内变异系数为1.01%~2.21%,批间变异系数为1.61%~2.38%;结合态苹婆酸的回收率为85.46%~105.20%,批内变异系数为0.79%~2.01%,批间变异系数为3.40%~6.22%。经实际样品验证,建立方法可以精确测定棉油、棉粕、脱酚棉粕和棉籽蛋白原料中的苹婆酸,检测范围在0.09~1 812.76 mg/kg之间。【结论】本研究建立的LC-MS/MS检测方法具有高灵敏度、高准确度和高精密度等优点,适用于饲料中游离态和结合态苹婆酸的检测,可为合理利用棉粕提供技术支撑。 展开更多
关键词 苹婆酸 棉粕 衍生化 定量
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Real-Time PCR Technique and Its Application in Quantification of Plant Nucleic Acid Molecules 被引量:8
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作者 刘进元 《Acta Botanica Sinica》 CSCD 2003年第6期631-637,共7页
Real-time PCR is a closed DNA amplification system that skillfully integrates biochemical, photoelectric and computer techniques. Fluorescence data acquired once per cycle provides rapid absolute quantification of ini... Real-time PCR is a closed DNA amplification system that skillfully integrates biochemical, photoelectric and computer techniques. Fluorescence data acquired once per cycle provides rapid absolute quantification of initial template copy numbers as PCR products are generated. This technique significantly simplifies and accelerates the process of producing reproducible quantification of nucleic acid molecules. It not only is a sensitive, accurate and rapid quantitative method, but it also provides an easier way to calculate the absolute starting copy number of nucleic acid molecules to be tested. Together with molecular bio-techniques, like microarray, real-time PCR will play a very important role in many aspects of molecular life science such as functional gene analysis and disease molecular diagnostics. This review introduces the detailed principles and application of the real-time PCR technique, describes a recently developed system for exact quantification of AUX/IAA genes In Arabidopsis, and discusses the problems with the real-time PCR process. 展开更多
关键词 real-time PCR technique quantification of plant nucleic acid molecules gene expression molecular medicine
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氧化镁和铼压标不确定度量化研究:基于贝叶斯统计方法
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作者 戴飞凡 向士凯 +5 位作者 李威威 张睿智 张建 罗国强 武润 咸蕴庭 《高压物理学报》 北大核心 2026年第1期134-146,共13页
静高压实验中精确的压力测量依赖于标准材料的物态方程,而物态方程参数的不确定度会显著影响压力预测的准确性。以氧化镁(MgO,B1相)和铼(Re,密排六方相)为研究对象,采用贝叶斯统计方法与马尔可夫链蒙特卡罗模拟技术,系统量化了其在金刚... 静高压实验中精确的压力测量依赖于标准材料的物态方程,而物态方程参数的不确定度会显著影响压力预测的准确性。以氧化镁(MgO,B1相)和铼(Re,密排六方相)为研究对象,采用贝叶斯统计方法与马尔可夫链蒙特卡罗模拟技术,系统量化了其在金刚石对顶砧实验中的压力预测不确定度。通过均匀分布先验和正态似然函数构建贝叶斯框架,整合了多组实验数据进行参数校准。结果表明,贝叶斯统计方法成功量化了物态方程参数的后验分布,并揭示了参数间的强相关性,如MgO的Grüneisen参数与初始体积呈负相关,Re的体模量与Grüneisen参数呈正相关。MgO和Re的压力预测不确定度随着压力升高而显著增大;Re的压力预测不确定度随温度升高而显著增大,MgO则没有明显规律。研究结果为提升高压实验压力测量精度提供了具有不确定度的压标,可为提升材料科学和地球物理研究中的实验数据可靠性提供重要参考。 展开更多
关键词 贝叶斯统计方法 马尔科夫链蒙特卡罗 物态方程 不确定度量化
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基于深度神经网络的南极洲大地热流预测
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作者 初东方 范晓鹏 +3 位作者 李静 白利舸 王卓 郭井学 《地球与行星物理论评(中英文)》 2026年第2期177-190,共14页
南极冰盖对全球气候系统的调控作用愈发显著,其中大地热流(GHF)作为基底热状态的关键指标,了解其分布特征对研究动力学演化具有重要意义.南极洲GHF测量受限于极寒地质条件与高昂钻孔成本,已知的热流点仅有52个.基于地质与地球物理数据... 南极冰盖对全球气候系统的调控作用愈发显著,其中大地热流(GHF)作为基底热状态的关键指标,了解其分布特征对研究动力学演化具有重要意义.南极洲GHF测量受限于极寒地质条件与高昂钻孔成本,已知的热流点仅有52个.基于地质与地球物理数据估计的热流分布存在较大不确定性,无法解释基底的非线性传热过程.深度学习算法可以捕捉热流与不同数据特征的耦合关系,对稀疏数据的插值重构具有较高的预测精度.本研究构建了一种深度神经网络(DNN)与高维不确定性量化框架,用于预测南极洲GHF分布.通过将4000多个全球热流观测点及22类地质与地球物理特征参数(地壳厚度、重磁异常、莫霍面等)作为训练数据,对澳大利亚与南极已知热流点进行了测试对比.不确定性量化方法通过相关性、灵敏度和主成分分析重组训练集,结合DNN模型评估南极洲最佳热流分布.预测结果显示南极洲热流范围为24~103mW/m^(2),平均值为60.1mW/m^(2),与已知热流误差为10.05%,其中甘布尔采夫冰下山脉表现出显著高热流异常(50~74mW/m^(2)).通过不确定量化结果证实甘布尔采夫冰下山脉的高预测热流具有较高置信度.该模型解译了南极地壳热结构的空间异质性特征,预测结果可用于南极尺度的冰盖动力学或热力学模拟,为冰盖运动、冰下湖分布等研究提供了可靠的数据支持. 展开更多
关键词 深度神经网络 大地热流 南极洲 不确定性量化
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基于TCN-MDN和概率潮流的电力系统灵活性量化分析方法
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作者 高天宇 徐天奇 李琰 《现代电子技术》 北大核心 2026年第2期133-141,共9页
高比例可再生能源的接入使电力系统的潮流具有波动性和随机性,也为电力系统的灵活运行带来了挑战。为了应对挑战,首要策略是建立一种灵活性量化和分析方法,用来表征灵活性资源供需平衡与系统运行之间的关系,为此,提出一种基于神经网络... 高比例可再生能源的接入使电力系统的潮流具有波动性和随机性,也为电力系统的灵活运行带来了挑战。为了应对挑战,首要策略是建立一种灵活性量化和分析方法,用来表征灵活性资源供需平衡与系统运行之间的关系,为此,提出一种基于神经网络和概率潮流的电力系统灵活性量化和分析方法。首先,构建神经网络对可再生能源的出力进行多时间尺度的概率预测;其次,引入考虑静态特性的潮流模型,通过系统频率来反映电力系统有功灵活性的供需平衡;然后,改进半不变量法,结合Gram-Charlier级数展开得到系统频率和线路潮流的概率密度函数,以此量化电力系统灵活性;最后,基于修改后的IEEE-30节点系统,通过与蒙特卡洛法对比来验证所提方法的准确性。实验结果表明,所提方法能够在概率框架下量化电力系统的灵活性,具有较高的运算精度和较快的速度。 展开更多
关键词 时序混合密度网络 TCN 概率预测 线性潮流模型 半不变量法 灵活性量化 Gram-Charlier级数
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