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Uncertainty quantification of inverse analysis for geomaterials using probabilistic programming
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作者 Hongbo Zhao Shaojun Li +3 位作者 Xiaoyu Zang Xinyi Liu Lin Zhang Jiaolong Ren 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第3期895-908,共14页
Uncertainty is an essentially challenging for safe construction and long-term stability of geotechnical engineering.The inverse analysis is commonly utilized to determine the physico-mechanical parameters.However,conv... Uncertainty is an essentially challenging for safe construction and long-term stability of geotechnical engineering.The inverse analysis is commonly utilized to determine the physico-mechanical parameters.However,conventional inverse analysis cannot deal with uncertainty in geotechnical and geological systems.In this study,a framework was developed to evaluate and quantify uncertainty in inverse analysis based on the reduced-order model(ROM)and probabilistic programming.The ROM was utilized to capture the mechanical and deformation properties of surrounding rock mass in geomechanical problems.Probabilistic programming was employed to evaluate uncertainty during construction in geotechnical engineering.A circular tunnel was then used to illustrate the proposed framework using analytical and numerical solution.The results show that the geomechanical parameters and associated uncertainty can be properly obtained and the proposed framework can capture the mechanical behaviors under uncertainty.Then,a slope case was employed to demonstrate the performance of the developed framework.The results prove that the proposed framework provides a scientific,feasible,and effective tool to characterize the properties and physical mechanism of geomaterials under uncertainty in geotechnical engineering problems. 展开更多
关键词 Geological engineering Geotechnical engineering Inverse analysis Uncertainty quantification Probabilistic programming
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High-dimensional uncertainty quantification of projectile motion in the barrel of a truck-mounted howitzer based on probability density evolution method
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作者 Mingming Wang Linfang Qian +3 位作者 Guangsong Chen Tong Lin Junfei Shi Shijie Zhou 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期209-221,共13页
This paper proposed an efficient research method for high-dimensional uncertainty quantification of projectile motion in the barrel of a truck-mounted howitzer.Firstly,the dynamic model of projectile motion is establi... This paper proposed an efficient research method for high-dimensional uncertainty quantification of projectile motion in the barrel of a truck-mounted howitzer.Firstly,the dynamic model of projectile motion is established considering the flexible deformation of the barrel and the interaction between the projectile and the barrel.Subsequently,the accuracy of the dynamic model is verified based on the external ballistic projectile attitude test platform.Furthermore,the probability density evolution method(PDEM)is developed to high-dimensional uncertainty quantification of projectile motion.The engineering example highlights the results of the proposed method are consistent with the results obtained by the Monte Carlo Simulation(MCS).Finally,the influence of parameter uncertainty on the projectile disturbance at muzzle under different working conditions is analyzed.The results show that the disturbance of the pitch angular,pitch angular velocity and pitch angular of velocity decreases with the increase of launching angle,and the random parameter ranges of both the projectile and coupling model have similar influence on the disturbance of projectile angular motion at muzzle. 展开更多
关键词 Truck-mounted howitzer Projectile motion Uncertainty quantification Probability density evolution method
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Uncertainty quantification of mechanism motion based on coupled mechanism—motor dynamic model for ammunition delivery system
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作者 Jinsong Tang Linfang Qian +3 位作者 Longmiao Chen Guangsong Chen Mingming Wang Guangzu Zhou 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期125-133,共9页
In this paper,a dynamic modeling method of motor driven electromechanical system is presented,and the uncertainty quantification of mechanism motion is investigated based on this method.The main contribution is to pro... In this paper,a dynamic modeling method of motor driven electromechanical system is presented,and the uncertainty quantification of mechanism motion is investigated based on this method.The main contribution is to propose a novel mechanism-motor coupling dynamic modeling method,in which the relationship between mechanism motion and motor rotation is established according to the geometric coordination of the system.The advantages of this include establishing intuitive coupling between the mechanism and motor,facilitating the discussion for the influence of both mechanical and electrical parameters on the mechanism,and enabling dynamic simulation with controller to take the randomness of the electric load into account.Dynamic simulation considering feedback control of ammunition delivery system is carried out,and the feasibility of the model is verified experimentally.Based on probability density evolution theory,we comprehensively discuss the effects of system parameters on mechanism motion from the perspective of uncertainty quantization.Our work can not only provide guidance for engineering design of ammunition delivery mechanism,but also provide theoretical support for modeling and uncertainty quantification research of mechatronics system. 展开更多
关键词 Ammunition delivery system Electromechanical coupling dynamics Uncertainty quantification Generalized probability density evolution
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Quantification of the concrete freeze–thaw environment across the Qinghai–Tibet Plateau based on machine learning algorithms
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作者 QIN Yanhui MA Haoyuan +3 位作者 ZHANG Lele YIN Jinshuai ZHENG Xionghui LI Shuo 《Journal of Mountain Science》 SCIE CSCD 2024年第1期322-334,共13页
The reasonable quantification of the concrete freezing environment on the Qinghai–Tibet Plateau(QTP) is the primary issue in frost resistant concrete design, which is one of the challenges that the QTP engineering ma... The reasonable quantification of the concrete freezing environment on the Qinghai–Tibet Plateau(QTP) is the primary issue in frost resistant concrete design, which is one of the challenges that the QTP engineering managers should take into account. In this paper, we propose a more realistic method to calculate the number of concrete freeze–thaw cycles(NFTCs) on the QTP. The calculated results show that the NFTCs increase as the altitude of the meteorological station increases with the average NFTCs being 208.7. Four machine learning methods, i.e., the random forest(RF) model, generalized boosting method(GBM), generalized linear model(GLM), and generalized additive model(GAM), are used to fit the NFTCs. The root mean square error(RMSE) values of the RF, GBM, GLM, and GAM are 32.3, 4.3, 247.9, and 161.3, respectively. The R^(2) values of the RF, GBM, GLM, and GAM are 0.93, 0.99, 0.48, and 0.66, respectively. The GBM method performs the best compared to the other three methods, which was shown by the results of RMSE and R^(2) values. The quantitative results from the GBM method indicate that the lowest, medium, and highest NFTC values are distributed in the northern, central, and southern parts of the QTP, respectively. The annual NFTCs in the QTP region are mainly concentrated at 160 and above, and the average NFTCs is 200 across the QTP. Our results can provide scientific guidance and a theoretical basis for the freezing resistance design of concrete in various projects on the QTP. 展开更多
关键词 Freeze–thaw cycles quantification Machine learning algorithms Qinghai–Tibet Plateau CONCRETE
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Revolutionizing disease diagnosis and management:Open-access magnetic resonance imaging datasets a challenge for artificial intelligence driven liver iron quantification
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作者 Jaber H Jaradat Abdulqadir J Nashwan 《World Journal of Clinical Cases》 SCIE 2024年第17期2921-2924,共4页
Artificial intelligence(AI),particularly machine learning(ML)and deep learning(DL)techniques,such as convolutional neural networks(CNNs),have emerged as transformative technologies with vast potential in healthcare.Bo... Artificial intelligence(AI),particularly machine learning(ML)and deep learning(DL)techniques,such as convolutional neural networks(CNNs),have emerged as transformative technologies with vast potential in healthcare.Body iron load is usually assessed using slightly invasive blood tests(serum ferritin,serum iron,and serum transferrin).Serum ferritin is widely used to assess body iron and drive medical management;however,it is an acute phase reactant protein offering wrong interpretation in the setting of inflammation and distressed patients.Magnetic resonance imaging is a non-invasive technique that can be used to assess liver iron.The ML and DL algorithms can be used to enhance the detection of minor changes.However,a lack of open-access datasets may delay the advancement of medical research in this field.In this letter,we highlight the importance of standardized datasets for advancing AI and CNNs in medical imaging.Despite the current limitations,embracing AI and CNNs holds promise in revolutionizing disease diagnosis and treatment. 展开更多
关键词 Liver diseases Magnetic resonance imaging Iron quantification Machine learning Deep learning
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基于RNA-seq对复合益生菌作用于肉鸡回肠中新转录本预测及可变剪接、SNP分析
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作者 曹威荣 王燕飞 +3 位作者 张若男 贾浩 刘璇 张利环 《中国饲料》 北大核心 2024年第3期20-27,共8页
为分析复合益生菌饲喂肉鸡回肠转录组中的新转录本预测、可变剪接事件和SNP,选择200只1日龄黄麻肉鸡随机分为2组,每组5个重复,每个重复20只。对照组正常饮水,益生菌组饮用水中补充1%复合菌制剂,试验分为生长前期(1~21 d)、后期(22~42 d... 为分析复合益生菌饲喂肉鸡回肠转录组中的新转录本预测、可变剪接事件和SNP,选择200只1日龄黄麻肉鸡随机分为2组,每组5个重复,每个重复20只。对照组正常饮水,益生菌组饮用水中补充1%复合菌制剂,试验分为生长前期(1~21 d)、后期(22~42 d)两个阶段。42日龄时进行肉鸡屠宰试验,取对照组和益生菌组回肠各3个样本进行转录组测序。对测序数据进行分析,共发现1047个新基因,20176个新转录本,276个新基因在GO数据库中得到归类注释。对转录组数据进行可变剪接分析,外显子跳跃(SE)占可变剪接类型的比例最高,共筛选到1131个显著的差异剪接基因,在外显子跳跃(SE)、第一个外显子可变剪接(A5SS)、最后一个外显子可变剪接(A3SS)、外显子选择性跳跃(MXE)、内含子滞留(RI)事件中鉴定到的差异剪接基因数分别为588、139、176、136、92。对获得的差异剪接基因进行GO富集分析,主要富集在代谢和免疫GO term。KEGG富集到了胞吞作用、MAPK信号通路等。在各样品中大多数碱基取代均为转换大于颠换,其中转换单核苷酸多态性(SNP)所占百分比为73.53%~73.94%;颠换型SNP所占百分比为26.05%~26.47%。试验对对照组、益生菌组肉鸡的回肠进行了RNA-seq测序分析,为发掘复合益生菌作用于肉鸡回肠中的可变剪接事件提供基础,为进一步了解复合益生菌作用于肉鸡回肠中新转录本的发现和SNP位点提供了数据支撑。 展开更多
关键词 肉鸡 rna-seq 新转录本 SNP 可变剪接
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BSA-Seq结合RNA-Seq技术挖掘大豆叶片提前黄化衰老基因
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作者 李世宽 洪慧龙 +3 位作者 付佳祺 谷勇哲 孙如建 邱丽娟 《作物学报》 CAS CSCD 北大核心 2024年第2期294-309,共16页
大豆产量与其生殖生长的持续时间呈正相关,延缓其开花后叶片的衰老,提高其生理功能,有利于增加植物的粒重。叶片黄化是植物衰老的显著特征之一。关于在大豆鼓粒后期叶片黄化的研究鲜见报道。本研究对鼓粒后期叶片提前黄化突变体ly和野生... 大豆产量与其生殖生长的持续时间呈正相关,延缓其开花后叶片的衰老,提高其生理功能,有利于增加植物的粒重。叶片黄化是植物衰老的显著特征之一。关于在大豆鼓粒后期叶片黄化的研究鲜见报道。本研究对鼓粒后期叶片提前黄化突变体ly和野生型ofc杂交组合进行遗传分析,结果表明,大豆鼓粒后期叶片提前黄化性状受单隐性核基因控制。通过BSA-Seq在19号染色体得到一个2.23Mb的初定位区间,经开发标记图位克隆后将区间缩短至1.75 Mb,区间内有219个基因,再结合RNA-Seq分析,得到了区间内12个候选基因,其中有4个SNP变异基因和8个差异表达基因。本研究结果为大豆鼓粒后期叶片黄化衰老基因的克隆奠定了基础。 展开更多
关键词 大豆 突变体 BSA-Seq rna-seq 图位克隆
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基于RNA-Seq分析大白猪和巴马香猪背最长肌组织基因表达差异
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作者 韦茜尹 雷国凤 +8 位作者 陈奎蓉 黄志威 蒋昱雯 陈晓榕 容宁 陈钊 徐玉培 梁晶 兰干球 《中国畜牧杂志》 CAS CSCD 北大核心 2024年第2期208-214,共7页
以180日龄的大白猪(n=6)与巴马香猪(n=6)为研究对象,屠宰后测定肌内脂肪、肉色、嫩度、pH、滴水损失等肉质性状,采集背最长肌组织提取总RNA,利用RNA-Seq技术鉴定大白猪和巴马香猪背最长肌组织中的表达差异基因及其功能富集通路。结果发... 以180日龄的大白猪(n=6)与巴马香猪(n=6)为研究对象,屠宰后测定肌内脂肪、肉色、嫩度、pH、滴水损失等肉质性状,采集背最长肌组织提取总RNA,利用RNA-Seq技术鉴定大白猪和巴马香猪背最长肌组织中的表达差异基因及其功能富集通路。结果发现,以大白猪为对照组,在巴马香猪和大白猪背最长肌组织中共鉴定到5 037个差异表达基因,其中有3 326个上调表达基因,1 711个下调表达基因。经过KEGG富集通路分析,发现巴马香猪和大白猪一共有168条显著富集通路,其中上调DEGs有92条富集路径,下调DEGs有76条富集路径;GO功能分析中上调表达基因富集到BP有3 058条、CC有413条、MF有559条,下调表达基因富集到BP有3 050条、CC有415条、MF有557条。大白猪与巴马香猪肉色的亮度L在45min时呈极显著差异;大白猪与巴马香猪之间的肌内脂肪、水分均呈现显著差异。本文对大白猪与巴马香猪肌内脂肪含量进行转录组测序分析,初步认为CAPN3、MTM1、TMOD4等基因在巴马香猪肉质中发挥重要作用。 展开更多
关键词 巴马香猪 大白猪 rna-seq 肉质性状
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基于RNA-Seq探究蔗糖影响黑果枸杞枝刺发生的机理
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作者 乔杨 刘雯 +2 位作者 李璐佳 孙丽丽 王钦美 《经济林研究》 北大核心 2024年第1期126-139,共14页
【目的】黑果枸杞Lycium ruthenicum是集生态、经济和药用价值等为一体的灌木。然而,其密集的枝刺严重阻碍其作为经济林推广,本研究旨在探究蔗糖(Suc)促进黑果枸杞(黑杞)枝刺的发生机理,为培育其无刺优良品种提供依据。【方法】在证明Su... 【目的】黑果枸杞Lycium ruthenicum是集生态、经济和药用价值等为一体的灌木。然而,其密集的枝刺严重阻碍其作为经济林推广,本研究旨在探究蔗糖(Suc)促进黑果枸杞(黑杞)枝刺的发生机理,为培育其无刺优良品种提供依据。【方法】在证明Suc通过能量和信号路径促进黑杞枝刺发生的基础上,利用RNA-Seq对无刺茎顶芽(TleCK)、有刺茎顶芽(ThoCK)、黑暗处理的有刺茎顶芽(ThoDCK)、减少内源Suc处理后有刺变无刺茎顶芽(TleDPL)和喷施外源Suc后无刺变有刺茎顶芽(ThoSuc)5种样品的差异表达基因(DEG)和叶绿体差异基因(cpDEG)进行筛选和分析,并采用RT-qPCR验证了9个DEG的表达情况。【结果】5组有刺和无刺材料顶芽之间(ThoCK vs.TleCK、ThoCK vs.TleDPL、ThoDCK vs.TleDPL、TleCK vs.ThoSuc和TleDPL vs.ThoSuc)的DEG分别为5281、4363、3125、5226和3278个,这5组DEG共同显著富集在9个GO条目和4个KEGG通路(“类黄酮生物合成”“二萜生物合成”“苯丙烷生物合成”、“芪类、二芳基庚烷和姜辣素生物合成”)。韦恩图显示5组比较组共有的DEG是196个,其中33个被预测为转录因子基因,较多转录因子基因被预测为NAC和WRKY家族。5组比较组有3个共有DEG注释在植物激素信号转导KEGG通路,分别参与生长素、茉莉酸和水杨酸信号传导。3个关键有刺和无刺比较组(ThoCK vs.TleCK、ThoCK vs.TleDPL和TleCK vs.ThoSuc)中共有2个DEG被预测为TCP转录因子基因,这3个比较组均有cpDEG被注释到光合作用KEGG通路。9个DEG的RT-qPCR验证了RNA-Seq结果的可靠性。【结论】Suc可能通过影响生长素、茉莉酸和水杨酸信号传导以及赤霉素合成基因表达来促进黑杞枝刺发生,枝刺发生也可能与类黄酮积累和木质素减少有关,而且增施外源和减少内源Suc并非通过简单地逆转cpDEG的表达来影响枝刺发生。注释到WRKY、TCP和NAC转录因子家族的共有DEG可能是调控枝刺发生的关键基因。本研究建立了Suc影响黑杞枝刺发生的机理模型图。 展开更多
关键词 黑果枸杞 顶芽 枝刺 rna-seq 蔗糖
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Uncertainty quantification of predicting stable structures for high-entropy alloys using Bayesian neural networks
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作者 Yonghui Zhou Bo Yang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第6期118-124,I0005,共8页
High entropy alloys(HEAs)have excellent application prospects in catalysis because of their rich components and configuration space.In this work,we develop a Bayesian neural network(BNN)based on energies calculated wi... High entropy alloys(HEAs)have excellent application prospects in catalysis because of their rich components and configuration space.In this work,we develop a Bayesian neural network(BNN)based on energies calculated with density functional theory to search the configuration space of the CoNiRhRu HEA system.The BNN model was developed by considering six independent features of Co-Ni,Co-Rh,CoRu,Ni-Rh,Ni-Ru,and Rh-Ru in different shells and energies of structures as the labels.The root mean squared error of the energy predicted by BNN is 1.37 me V/atom.Moreover,the influence of feature periodicity on the energy of HEA in theoretical calculations is discussed.We found that when the neural network is optimized to a certain extent,only using the accuracy indicator of root mean square error to evaluate model performance is no longer accurate in some scenarios.More importantly,we reveal the importance of uncertainty quantification for neural networks to predict new structures of HEAs with proper confidence based on BNN. 展开更多
关键词 Uncertainty quantification High-entropy alloys Bayesian neural networks Energy prediction Structure screening
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Molecular diagnosis and direct quantification of cereal cyst nematode(Heterodera filipjevi) from field soil using TaqMan real-time PCR
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作者 JIAN Jin-zhuo HUANG Wen-kun +4 位作者 KONG Ling-an JIAN Heng Sulaiman ABDULSALAM PENG De-liang PENG Huan 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第8期2591-2601,共11页
Heterodera filipjevi continues to be a major threat to wheat production worldwide.Rapid detection and quantification of cyst nematodes are essential for more effective control against this nematode disease.In the pres... Heterodera filipjevi continues to be a major threat to wheat production worldwide.Rapid detection and quantification of cyst nematodes are essential for more effective control against this nematode disease.In the present study,a TaqManminor groove binder(TaqMan-MGB)probe-based fluorescence quantitative real-time PCR(qPCR)was successfully developed and used for quantifying H.filipjevi from DNA extracts of soil.The primers and probe designed from the obtained RAPD-SCAR marker fragments of H.filipjevi showed high specificity to H.filipjevi using DNA from isolatesconfirmed species of 23 Heterodera spp.,1 Globodera spp.and 3 Pratylenchus spp.The qPCR assay is highly sensitive and provides improved H.filipjevi detection sensitivity of as low as 4^(-3) single second-stage juvenile(J2)DNAs,10^(-3) female DNAs,and 0.01μgμL^(-1) genomic DNAs.A standard curve relating to the threshold cycle and log values of nematode numbers was generated and validated from artificially infested soils and was used to quantify H.filipjevi in naturally infested field soils.There was a high correlation between the H.filipjevi numbers estimated from 32 naturally infested field soils by both conventional methods and the numbers quantified using the qPCR assay.qPCR potentially provides a useful platform for the efficient detection and quantification of H.filipjevi directly from field soils and to quantify this species directly from DNA extracts of field soils. 展开更多
关键词 cereal cyst nematode Heterodera filipjevi molecular diagnosis quantification TaqMan real-time PCR
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Host cell protein quantification workflow using optimized standards combined with data-independent acquisition mass spectrometry
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作者 Steve Hessmann Cyrille Chery +2 位作者 Anne-Sophie Sikora Annick Gervais Christine Carapito 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2023年第5期494-502,共9页
Monitoring of host cell proteins(HCPs)during the manufacturing of monoclonal antibodies(mAb)has become a critical requirement to provide effective and safe drug products.Enzyme-linked immunosorbent assays are still th... Monitoring of host cell proteins(HCPs)during the manufacturing of monoclonal antibodies(mAb)has become a critical requirement to provide effective and safe drug products.Enzyme-linked immunosorbent assays are still the gold standard methods for the quantification of protein impurities.However,this technique has several limitations and does,among others,not enable the precise identification of proteins.In this context,mass spectrometry(MS)became an alternative and orthogonal method that delivers qualitative and quantitative information on all identified HCPs.However,in order to be routinely implemented in biopharmaceutical companies,liquid chromatography-MS based methods still need to be standardized to provide highest sensitivity and robust and accurate quantification.Here,we present a promising MS-based analytical workflow coupling the use of an innovative quantification standard,the HCP Profiler solution,with a spectral library-based data-independent acquisition(DIA)method and strict data validation criteria.The performances of the HCP Profiler solution were compared to more conventional standard protein spikes and the DIA approach was benchmarked against a classical datadependent acquisition on a series of samples produced at various stages of the manufacturing process.While we also explored spectral library-free DIA interpretation,the spectral library-based approach still showed highest accuracy and reproducibility(coefficients of variation<10%)with a sensitivity down to the sub-ng/mg mAb level.Thus,this workflow is today mature to be used as a robust and straightforward method to support mAb manufacturing process developments and drug products quality control. 展开更多
关键词 Host cell proteins Absolute quantification standards Data-independent acquisition
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Progress and prediction of multicomponent quantification in complex systems with practical LC-UV methods
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作者 Xi Chen Zhao Yang +4 位作者 Yang Xu Zhe Liu Yanfang Liu Yuntao Dai Shilin Chen 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2023年第2期142-155,共14页
Complex systems exist widely,including medicines from natural products,functional foods,and biological samples.The biological activity of complex systems is often the result of the synergistic effect of multiple compo... Complex systems exist widely,including medicines from natural products,functional foods,and biological samples.The biological activity of complex systems is often the result of the synergistic effect of multiple components.In the quality evaluation of complex samples,multicomponent quantitative analysis(MCQA)is usually needed.To overcome the difficulty in obtaining standard products,scholars have proposed achieving MCQA through the“single standard to determine multiple components(SSDMC)”approach.This method has been used in the determination of multicomponent content in natural source drugs and the analysis of impurities in chemical drugs and has been included in the Chinese Pharmacopoeia.Depending on a convenient(ultra)high-performance liquid chromatography method,how can the repeatability and robustness of the MCQA method be improved?How can the chromatography conditions be optimized to improve the number of quantitative components?How can computer software technology be introduced to improve the efficiency of multicomponent analysis(MCA)?These are the key problems that remain to be solved in practical MCQA.First,this review article summarizes the calculation methods of relative correction factors in the SSDMC approach in the past five years,as well as the method robustness and accuracy evaluation.Second,it also summarizes methods to improve peak capacity and quantitative accuracy in MCA,including column selection and twodimensional chromatographic analysis technology.Finally,computer software technologies for predicting chromatographic conditions and analytical parameters are introduced,which provides an idea for intelligent method development in MCA.This paper aims to provide methodological ideas for the improvement of complex system analysis,especially MCQA. 展开更多
关键词 Multicomponent quantification analysis Single standard to determine multiple components Predictive software
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Detection and quantification of Pb and Cr in oysters using laser-induced breakdown spectroscopy
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作者 闫清霞 田野 +7 位作者 李颖 林洪 贾自文 卢渊 俞进 孙琛 白雪石 Vincent DETALLE 《Plasma Science and Technology》 SCIE EI CAS CSCD 2023年第4期195-203,共9页
The quantitative determination of heavy metals in aquatic products is of great importance for food security issues.Laser-induced breakdown spectroscopy(LIBS)has been used in a variety of foodstuff analysis,but is stil... The quantitative determination of heavy metals in aquatic products is of great importance for food security issues.Laser-induced breakdown spectroscopy(LIBS)has been used in a variety of foodstuff analysis,but is still limited by its low sensitivity when targeting trace heavy metals.In this work,we compare three sample enrichment methods,namely drying,carbonization,and ashing,for increasing detection sensitivity by LIBS analysis for Pb and Cr in oyster samples.The results demonstrate that carbonization can remove a significant amount of the contributions of organic elements C,H,N and O;meanwhile,the signals of the metallic elements such as Cu,Pb,Sr,Ca,Cr and Mg are enhanced by3–6 times after carbonization,and further enhanced by 5–9 times after ashing.Such enhancement is not only due to the more concentrated metallic elements in the sample compared to the dried ones,but also the unifying of the matter in carbonized and ashed samples from which higher plasma temperature and electron density are observed.This condition favors the detection of trace elements.According to the calibration curves with univariate and multivariate analysis,the ashing method is considered to be the best choice.The limits of detection of the ashing method are 0.52 mg kg-1 for Pb and0.08 mg kg-1 for Cr,which can detect the presence of heavy metals in the oysters exceeding the maximum limits of Pb and Cr required by the Chinese national standard.This method provides a promising application for the heavy metal contamination monitoring in the aquatic product industry. 展开更多
关键词 laser-induced breakdown spectroscopy(LIBS) heavy metal detection signal enhancement sample preparation method quantification OYSTERS
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Two-point Dixon and six-point Dixon magnetic resonance techniques in the detection,quantification and grading of hepatic steatosis
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作者 Mohamed Elfaal Alanna Supersad +6 位作者 Craig Ferguson Stephanie Locas Florin Manolea Mitchell P Wilson Medica Sam Wendy Tu Gavin Low 《World Journal of Radiology》 2023年第10期293-303,共11页
BACKGROUND Hepatic steatosis is a very common problem worldwide.AIM To assess the performance of two-and six-point Dixon magnetic resonance(MR)techniques in the detection,quantification and grading of hepatic steatosi... BACKGROUND Hepatic steatosis is a very common problem worldwide.AIM To assess the performance of two-and six-point Dixon magnetic resonance(MR)techniques in the detection,quantification and grading of hepatic steatosis.METHODS A single-center retrospective study was performed in 62 patients with suspected parenchymal liver disease.MR sequences included two-point Dixon,six-point Dixon,MR spectroscopy(MRS)and MR elastography.Fat fraction(FF)estimates on the Dixon techniques were compared to the MRS-proton density FF(PDFF).Statistical tests used included Pearson’s correlation and receiver operating characteristic.RESULTS FF estimates on the Dixon techniques showed excellent correlation(≥0.95)with MRS-PDFF,and excellent accuracy[area under the receiver operating characteristic(AUROC)≥0.95]in:(1)Detecting steatosis;and(2)Grading severe steatosis,(P<0.001).In iron overload,two-point Dixon was not evaluable due to confounding T2*effects.FF estimates on six-point Dixon vs MRS-PDFF showed a moderate correlation(0.82)in iron overload vs an excellent correlation(0.97)without iron overload,(P<0.03).The accuracy of six-point Dixon in grading mild steatosis improved(AUROC:0.59 to 0.99)when iron overload cases were excluded.The excellent correlation(>0.9)between the Dixon techniques vs MRSPDFF did not change in the presence of liver fibrosis(P<0.01).CONCLUSION Dixon techniques performed satisfactorily for the evaluation of hepatic steatosis but with exceptions. 展开更多
关键词 Chemical shift encoded Dixon magnetic resonance techniques Hepatic steatosis Liver fat quantification Magnetic resonance spectroscopy Proton density fat fraction ULTRASOUND
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Hepatic MR imaging using IDEAL-IQ sequence:Will Gd-EOB-DTPA interfere with reproductivity of fat fraction quantification?
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作者 Yuan Tian Peng-Fei Liu +2 位作者 Jia-Yu Li Ya-Nan Li Peng Sun 《World Journal of Clinical Cases》 SCIE 2023年第25期5887-5896,共10页
BACKGROUND Iterative decomposition of water and fat with echo asymmetry and least squares estimation quantification sequence(IDEAL-IQ)is based on chemical shift-based water and fat separation technique to get proton d... BACKGROUND Iterative decomposition of water and fat with echo asymmetry and least squares estimation quantification sequence(IDEAL-IQ)is based on chemical shift-based water and fat separation technique to get proton density fat fraction.Multiple studies have shown that using IDEAL-IQ to test the stability and repeatability of liver fat is acceptable and has high accuracy.AIM To explore whether Gadoxetate Disodium(Gd-EOB-DTPA)interferes with the measurement of the hepatic fat content quantified with the IDEAL-IQ and to evaluate the robustness of this technique.METHODS IDEAL-IQ was used to quantify the liver fat content at 3.0T in 65 patients injected with Gd-EOB-DTPA contrast.After injection,IDEAL-IQ was estimated four times,and the fat fraction(FF)and R2* were measured at the following time points:Precontrast,between the portal phase(70 s)and the late phase(180 s),the delayed phase(5 min)and the hepatobiliary phase(20 min).One-way repeated-measures analysis was conducted to evaluate the difference in the FFs between the four time points.Bland-Altman plots were adopted to assess the FF changes before and after injection of the contrast agent.P<0.05 was considered statistically significant.RESULTS The assessment of the FF at the four time points in the liver,spleen and spine showed no significant differences,and the measurements of hepatic FF yielded good consistency between T1 and T2[95%confidence interval:-0.6768%,0.6658%],T1 and T3(-0.3900%,0.3178%),and T1 and T4(-0.3750%,0.2825%).R2* of the liver,spleen and spine increased significantly after injection(P<0.0001).CONCLUSION Using the IDEAL-IQ sequence to measure the FF,we can obtain results that will not be affected by Gd-EOB-DTPA.The high reproducibility of the IDEAL-IQ sequence makes it available in the scanning interval to save time during multiphase examinations. 展开更多
关键词 Gadoxetate Disodium Iterative decomposition of water and fat with echo asymmetry and least squares estimation quantification sequence Fat fraction Enhanced-Magnetic resonance imaging R2*
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RNA-seq技术在虾蟹研究中的应用
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作者 谢姝敏 张惠玲 +4 位作者 熊佳瑶 花松松 邢超凡 高焕 王攀攀 《水产学杂志》 CAS 2024年第2期116-125,共10页
基于高通量测序技术的RNA-seq技术已被广泛应用于较高经济价值的虾蟹类动物研究中,从分子水平剖析虾蟹类生命周期中相关基因的调控功能和遗传信息。本文综述了对虾蟹类动物转录组研究现状,包括虾蟹类的生长发育、生殖繁育、环境胁迫、... 基于高通量测序技术的RNA-seq技术已被广泛应用于较高经济价值的虾蟹类动物研究中,从分子水平剖析虾蟹类生命周期中相关基因的调控功能和遗传信息。本文综述了对虾蟹类动物转录组研究现状,包括虾蟹类的生长发育、生殖繁育、环境胁迫、免疫应答、营养代谢和分子标记开发等,分析了RNA-seq技术在虾蟹类研究中面临的局限与挑战,以期为更深入开展虾蟹类分子生物学研究提供参考。 展开更多
关键词 rna-seq 虾蟹类动物 生长繁育 环境胁迫
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Evaluation of RNA-Seq software in gene expression quantification
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作者 Yan Ji Ziliang Qian Jia Wei 《Journal of Biomedical Science and Engineering》 2013年第4期473-477,共5页
High-throughput RNA sequencing (RNA-Seq) promises a complete annotation and quantification of all genes and their isoforms across samples. Because sequencing reads from this new technology are shorter than transcripts... High-throughput RNA sequencing (RNA-Seq) promises a complete annotation and quantification of all genes and their isoforms across samples. Because sequencing reads from this new technology are shorter than transcripts from which they are derived, expression estimation with RNA-Seq requires increasingly complex computational methods. In recent years, a number of expression quantification methods have been published from both public and commercial sources. Here we presented an overview of these attempts on quantifying gene expression. We then defined a set of criteria and compared the performance of several programs based on these criteria, and we further provided advices on selecting suitable tools for different biological applications. 展开更多
关键词 rna-seq NEXT GENERATION SEQUENCING
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Identifying genetic susceptibility to Aspergillus fumigatus infection using collaborative cross mice and RNA-Seq approach
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作者 Roa'a H.S.Yosief Iqbal M.Lone +3 位作者 Aharon Nachshon Heinz Himmelbauer Irit Gat-Viks Fuad A.Iraqi 《Animal Models and Experimental Medicine》 CAS CSCD 2024年第1期36-47,共12页
Background:Aspergillus fumigatus(Af)is one of the most ubiquitous fungi and its infection potency is suggested to be strongly controlled by the host genetic back-ground.The aim of this study was to search for candidat... Background:Aspergillus fumigatus(Af)is one of the most ubiquitous fungi and its infection potency is suggested to be strongly controlled by the host genetic back-ground.The aim of this study was to search for candidate genes associated with host susceptibility to Aspergillus fumigatus(Af)using an RNAseq approach in CC lines and hepatic gene expression.Methods:We studied 31 male mice from 25 CC lines at 8 weeks old;the mice were infected with Af.Liver tissues were extracted from these mice 5 days post-infection,and next-generation RNA-sequencing(RNAseq)was performed.The GENE-E analysis platform was used to generate a clustered heat map matrix.Results:Significant variation in body weight changes between CC lines was ob-served.Hepatic gene expression revealed 12 top prioritized candidate genes differ-entially expressed in resistant versus susceptible mice based on body weight changes.Interestingly,three candidate genes are located within genomic intervals of the previ-ously mapped quantitative trait loci(QTL),including Gm16270 and Stox1 on chromo-some 10 and Gm11033 on chromosome 8.Conclusions:Our findings emphasize the CC mouse model's power in fine mapping the genetic components underlying susceptibility towards Af.As a next step,eQTL analysis will be performed for our RNA-Seq data.Suggested candidate genes from our study will be further assessed with a human cohort with aspergillosis. 展开更多
关键词 aspergillus fumigatus infection collaborative cross(CC)mice gene expression profile gene-network host susceptibility quantitative trait loci(QTL)mapping rna-seq
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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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