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Sensitive detection of microRNAs using polyadenine-mediated fluorescent spherical nucleic acids and a microfluidic electrokinetic signal amplification chip

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Journal of Pharmaceutical Analysis 2022年第5期12卷 808-813页

作者： Jun Xu Qing Tang Runhui Zhang Haoyi Chen bee luan khoo Xinguo Zhang Yue Chen Hong Yan Jincheng Li Huaze Shao Lihong Liu NMPA Key Laboratory for Research and Evaluation of Drug Metabolism Guangdong Provincial Key Laboratory of New Drug ScreeningSchool of Pharmaceutical SciencesSouthern Medical UniversityGuangzhou510515China The Second Clinical Medical School Southern Medical UniversityGuangzhou510515China Department of Biomedical Engineering City University of Hong KongHong Kong999077China

The identification of tumor-related microRNAs(miRNAs)exhibits excellent promise for the early diagnosis of cancer and other bioanalytical applications.Therefore,we developed a sensitive and efficient biosensor using polyadenine(polyA)-mediated fluorescent spherical nucleic acid(FSNA)for miRNA analysis based on strand displacement reactions on gold nanoparticle(AuNP)surfaces and electrokinetic signal amplification(ESA)on a microfluidic chip.In this FSNA,polyA-DNA biosensor was anchored on AuNP surfaces via intrinsic affinity between adenine and Au.The upright conformational polyA-DNA recognition block hybridized with 6-carboxyfluorescein-labeled reporter-DNA,resulting in fluorescence quenching of FSNA probes induced by AuNP-based resonance energy transfer.Reporter DNA was replaced in the presence of target miRNA,leading to the recovery of reporter-DNA fluorescence.Subsequently,reporter-DNAs were accumulated and detected in the front of with Nafion membrane in the microchannel by ESA.Our method showed high selectivity and sensitivity with a limit of detection of 1.3 pM.This method could also be used to detect miRNA-21 in human serum and urine samples,with recoveries of 104.0%-113.3% and 104.9%-108.0%,respectively.Furthermore,we constructed a chip with three parallel channels for the simultaneous detection of multiple tumor-related miRNAs(miRNA-21,miRNA-141,and miRNA-375),which increased the detection efficiency.Our universal method can be applied to other DNA/RNA analyses by altering recognition sequences.

关键词： MicroRNAs Microfluidic chip Electrokinetic signal amplification Polyadenine-DNA Gold nanoparticle

A deformability-based biochip for precise label-free stratification of metastatic subtypes using deep learning

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Microsystems & Nanoengineering 2023年第5期9卷 161-176页

作者： Haojun Hua Shangjie Zou Zhiqiang Ma Wang Guo Ching Yin Fong bee luan khoo City University of Hong Kong 83 Tat Chee AvenueKowloonHong Kong 999077China Hong Kong Center for Cerebro-Cardiovascular Health Engineering(COCHE) Hong Kong 999077China City University of Hong Kong Futian-Shenzhen Research Institute Shenzhen 518057China

Cellular deformability is a promising biomarker for evaluating the physiological state of cells in medical applications.Microfluidics has emerged as a powerful technique for measuring cellular deformability.However,existing microfluidic-based assays for measuring cellular deformability rely heavily on image analysis,which can limit their scalability for high-throughput applications.Here,we develop a parallel constriction-based microfluidic flow cytometry device and an integrated computational framework(ATMQcD).The ATMQcD framework includes automatic training set generation,multiple object tracking,segmentation,and cellular deformability quantification.The system was validated using cancer cell lines of varying metastatic potential,achieving a classification accuracy of 92.4%for invasiveness assessment and stratifying cancer cells before and after hypoxia treatment.The ATMQcD system also demonstrated excellent performance in distinguishing cancer cells from leukocytes(accuracy=89.5%).We developed a mechanical model based on power-law rheology to quantify stiffness,which was fitted with measured data directly.The model evaluated metastatic potentials for multiple cancer types and mixed cell populations,even under realworld clinical conditions.Our study presents a highly robust and transferable computational framework for multiobject tracking and deformation measurement tasks in microfluidics.We believe that this platform has the potential to pave the way for high-throughput analysis in clinical applications,providing a powerful tool for evaluating cellular deformability and assessing the physiological state of cells.

关键词： deformability metastatic precise

Visualization of Methamphetamine-Contaminated Fingermarks on Glass Surfaces by Field Emission Scanning Electron Microscope for Forensic Investigation

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Journal of Forensic Science and Medicine 2023年第1期9卷 6-11页

作者： Sarah Aliah Amir Sarifudin Kah Haw Chang bee Ee khoo Ahmad Fahmi Lim Abdullah Forensic Science Program School of Health SciencesHealth CampusUniversiti Sains MalaysiaKelantanMalaysia Mechatronic Engineering Program School of Electrical and Electronic EngineeringEngineering CampusUniversiti Sains MalaysiaPenangMalaysia

Background:Fingermark is an individual’s primary identification source.It is helpful in determining individuals involved in illegal activities and is frequently encountered in clandestine laboratories.During forensic investigation,the critical question to be answered is whether a fingermark was left on a surface before or after the initiation of an unlawful activity.Aims and Objectives:This study aimed to investigate the visualization of methamphetamine-contaminated fingermarks on glass surfaces and estimate the immediacy of their depositions.Materials and Methods:In this study,the prior-deposition contaminated fingermarks,i.e.,fingermarks deposited a surface priorly contaminated by methamphetamine,and the postdeposition contaminated fingermarks,i.e.,fingermarks deposited on a clean surface but subsequently contaminated with methamphetamine were visualized and compared using Field Emission Scanning Electron Microscope(FESEM).Results:Under FESEM,the latent fingermarks and the crystalline structure of methamphetamine were clearly visualized.The postdeposition contaminated fingermarks appeared in smudge conditions in all the three replicate samples,where the ridge and nonridge areas could not be well-distinguished.On the contrary,the prior-deposition contaminated fingermark demonstrated distinct separations between ridges and nonridges.However,the application of fingerprint powders reduced the possibility to determine the immediacy of deposition.Conclusion:To conclude,both prior-deposition contaminated fingermarks and postdeposition contaminated fingermarks can be discriminated,providing information on the instance when a fingermark was left on a surface.

关键词： Fingermark methamphetamine scanning electron microscope visualization powder

Flexible Large-Area Graphene Films of 50-600 nm Thickness with High Carrier Mobility

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Nano-Micro Letters 2023年第5期15卷 1-14页

作者： Shiyu Luo Li Peng Yangsu Xie Xiaoxue Cao Xiao Wang Xiaoting Liu Tingting Chen Zhanpo Han Peidong Fan Haiyan Sun Ying Shen Fan Guo Yuxing Xia Kaiwen Li Xin Ming Chao Gao MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou 310027People’s Republic of China School of Micro-Nanoelectronics Zhejiang UniversityZJU-Hangzhou Global Scientific and Technological Innovation CenterHangzhou 311200People’s Republic of China College of Chemistry and Environmental Engineering Shenzhen UniversityShenzhen 518055GuangdongPeople’s Republic of China Shenzhen Key Laboratory of Nanobiomechanics Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055People’s Republic of China Hangzhou Gaoxi Technol Co Ltd Hangzhou 311113People’s Republic of China

Bulk graphene nanofilms feature fast electronic and phonon transport in combination with strong light-matter interaction and thus have great potential for versatile applications,spanning from photonic,electronic,and optoelectronic devices to charge-stripping and electromagnetic shielding,etc.However,large-area flexible close-stacked graphene nanofilms with a wide thickness range have yet to be reported.Here,we report a polyacrylonitrile-assisted’substrate replacement’strategy to fabricate large-area free-standing graphene oxide/polyacrylonitrile nanofilms(lateral size~20 cm).Linear polyacrylonitrile chains-derived nanochannels promote the escape of gases and enable macro-assembled graphene nanofilms(nMAGs)of 50-600 nm thickness following heat treatment at 3,000℃.The uniform nMAGs exhibit 802-1,540 cm^(2)V-1s-1carrier mobility,4.3-4.7 ps carrier lifetime,and>1,581 W m^(-1)K^(-1)thermal conductivity(n MAG-assembled 10μm-thick films,mMAGs).nMAGs are highly flexible and show no structure damage even after 1.0×10^(5)cycles of folding-unfolding.Furthermore,n MAGs broaden the detection region of graphene/silicon heterojunction from near-infrared to mid-infrared and demonstrate higher absolute electromagnetic interference(EMI)shielding effectiveness than state-of-the-art EMI materials of the same thickness.These results are expected to lead to the broad applications of such bulk nanofilms,especially as micro/nanoelectronic and optoelectronic platforms.

关键词： Flexible large-area graphene nanofilm High carrier mobility Mid-infrared detection Electromagnetic interference shielding Heat transfer

负载铁改性活性炭对城市污水厂二级出水中溶解性有机物的吸附性能

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环境工程 2024年第3期42卷 67-72页

作者：徐佳瑞刘浩栾维豪王超刘长青杨延栋青岛理工大学环境与市政工程学院山东青岛266033 青岛水务集团环境能源有限公司山东青岛266002

采用浸渍法对普通煤质活性炭(AC)进行负载铁改性,探究了负载铁改性活性炭(Fe-AC)对城市污水厂二级出水中溶解性有机物(DOM)的吸附性能。EDS、XRD和FTIR等分析表明,铁成功以Fe_(2)O_(3)形式负载在活性炭上。经改性,活性炭比表面积增大29... 详细信息

采用浸渍法对普通煤质活性炭(AC)进行负载铁改性,探究了负载铁改性活性炭(Fe-AC)对城市污水厂二级出水中溶解性有机物(DOM)的吸附性能。EDS、XRD和FTIR等分析表明,铁成功以Fe_(2)O_(3)形式负载在活性炭上。经改性,活性炭比表面积增大29.3%。Fe-AC对二级出水中的DOM有良好的吸附性能,DOC去除率为50.0%~63.5%,UV254去除率为71.3%~88.2%,均明显高于AC。Fe-AC对DOM的吸附可用修正的Freundlich等温线很好地描述。此外,Fe-AC对NO_(3)^(-)和PO_(4)^(3-)也具有良好的吸附效果,去除率分别为55.4%和76.5%。三维荧光光谱和紫外-可见吸收光谱表明,二级出水中的DOM主要为微生物代谢产生的腐植酸类物质,该有机组分可被Fe-AC很好地吸附去除。综上,Fe-AC吸附是一种有效的污水深度处理技术。

关键词：活性炭铁改性溶解性有机物吸附二级出水

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蜂产品中兽药残留限量标准的调整修订及现状

食品工业 2024年第2期45卷 200-203页

作者：陈明邵雪梅栾枫婷豆维胜农业农村部农产品质量安全风险评估实验室(南京) 江苏省食品质量安全重点实验室-省部共建国家重点实验室培育基地江苏省农业科学院农产品质量安全与营养研究所南京210014

中国是蜂蜜产品产销出口大国。文章梳理比较了国内外蜂产品兽药残留限量标准法规,分析了相关兽药使用政策的调整修订变化发展对蜂产品质量安全的影响,使养蜂业者知道可以做什么,监管者了解该做什么。这对提高我国蜂产品的质量安全标准... 详细信息

中国是蜂蜜产品产销出口大国。文章梳理比较了国内外蜂产品兽药残留限量标准法规,分析了相关兽药使用政策的调整修订变化发展对蜂产品质量安全的影响,使养蜂业者知道可以做什么,监管者了解该做什么。这对提高我国蜂产品的质量安全标准和顺畅出口贸易具有重大意义。

关键词：蜂产品兽药残留残留限量

Nitric oxide synthase and heme oxygenase expressions in human liver cirrhosis

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World Journal of Gastroenterology 2006年第4期12卷 588-594页

作者： Beatrice J Goh bee Tee Tan Wei Min Hon Kang Hoe Lee Hoon Eng khoo Department of Biochemistry Yong Loo Lin School of Medicine National University ofSingapore Department of Medicine Yong Loo Lin School of Medicine National University of Singapore Research Biolabs Pte Ltd

瞄准：门静脉高血压是肝肝硬化的普通复杂并发症。肝内压力能以几个方法被提高。从内脏的内脏影响脉管系统， vasoconstrictors 的增加和增加的循环进门静脉系统的反常建筑学都可以作出贡献。因而内长的血管扩张药也许能减轻高血压。我... 详细信息

瞄准：门静脉高血压是肝肝硬化的普通复杂并发症。肝内压力能以几个方法被提高。从内脏的内脏影响脉管系统， vasoconstrictors 的增加和增加的循环进门静脉系统的反常建筑学都可以作出贡献。因而内长的血管扩张药也许能减轻高血压。我们因此试图调查内长的血管扩张药的层次，氮的氧化物(没有) 并且通过氮的氧化物 synthase (NOS ) 的表示的一氧化碳(公司) 并且他我氧合酶(惊讶) 。方法：肝脏硬化症(n=20 ) 并且非肝脏硬化症(n=20 ) 肝从经历了外科的病人被获得。NOS 的各种各样的 isoforms 的 mRNA 和蛋白质表情并且惊讶用竞争 PCR，西方的污点和免疫组织化学被检验。结果：当内皮 NOS (eNOS ) 在硬变肝是起来调整的时，在可诱导的 NOS (i NOS ) 或神经元 NOS (nNOS ) 表情没有重要变化。附随地， caveolin-1， eNOS 的一个确定的下面管理者，是起来调整的。可诱导的 HO-1 和组成的 HO-2 被发现在不同本地化在硬变肝虽然显示出增加的表示。结论：NOS 表示力量的差别由于他们在在肝硬化的病理维持肝动态平衡或参与的不同角色。在高血压的肝以内的纯粹的应力可以导致 eNOS 的增加的表示。接着， caveolin-1 也被增加。这是否对进一步的肝硬化用作一个防御机理或是肝硬化的后果，是还未知的。HO-1 和 HO-2 的提高的表示建议公司可以微弱地作为血管扩张药虽然在它的角色补偿。它是可能的那个公司并且不在肝以内有平行或协调的功能并且可以在门静脉高血压的病理生理学反对地工作。

关键词：血红素肝硬化一氧化氮基因表达

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我国蜂产品相关兽药残留法规的变化与现状

中国蜂业 2024年第4期75卷 43-47页

作者：陈明邵雪梅栾枫婷龚兰豆维胜农业农村部农产品质量安全风险评估实验室(南京)江苏省食品质量安全重点实验室-省部共建国家重点实验室培育基地江苏省农业科学院农产品质量安全与营养研究所南京210014

随着我国食品中最大兽药残留限量国家标准的颁布更新,对蜂产品的质量安全监管提出了更高要求。本文汇总分析了当今中国蜂蜜主要出口国的蜂产品兽药残留限量标准政策和差异,梳理比较了我国历年发布的相关兽药法规政策,分析了相关兽药政... 详细信息

随着我国食品中最大兽药残留限量国家标准的颁布更新,对蜂产品的质量安全监管提出了更高要求。本文汇总分析了当今中国蜂蜜主要出口国的蜂产品兽药残留限量标准政策和差异,梳理比较了我国历年发布的相关兽药法规政策,分析了相关兽药政策的变化发展和对蜂产品质量安全的影响。使养蜂者清楚自己可以做什么,监管者了解自己该做什么。这对提高我国蜂产品的质量安全标准和顺畅出口贸易具有重大意义。

关键词：蜂蜜兽药残留残留限量

剪切载荷作用下岩体结构面动态接触特征数值模拟

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煤炭学报 2022年第1期47卷 233-245页

作者：蒋宇静张孙豪栾恒杰王长盛王冬韩伟山东科技大学能源与矿业工程学院山东青岛266590 山东科技大学矿山灾害预防控制省部共建国家重点实验室培育基地山东青岛266590 长崎大学工学研究科日本长崎852-8521

准确认识岩体结构面的动态接触特征是评价和预测结构面剪切行为的基础。首先,通过FISH语言修正了FLAC^(3D)软件自带的INTERFACE本构模型,使其能够准确表达粗糙结构面在剪切过程中的力学行为;然后,采用数值模拟和室内试验相结合的方法对... 详细信息

准确认识岩体结构面的动态接触特征是评价和预测结构面剪切行为的基础。首先,通过FISH语言修正了FLAC^(3D)软件自带的INTERFACE本构模型,使其能够准确表达粗糙结构面在剪切过程中的力学行为;然后,采用数值模拟和室内试验相结合的方法对剪切过程中结构面接触和受力的分布及其演化规律进行了研究,分析了法向应力和结构面粗糙度系数(JRC)对接触特征的影响规律;最后,研究了结构面表面形貌-接触特征-剪切应力3者间的关系,揭示了结构面剪切应力演化机理。结果表明:FLAC^(3D)自带INTERFACE模型无法很好地模拟结构面峰后剪切行为,是由于结构面凸起未啃断导致黏聚力和法向应力偏大,通过对INTERFACE破坏单元的黏聚力和法向刚度进行修正可很好地模拟结构面的损伤破坏行为。随着剪切位移增大,结构面的接触面积逐渐减小,但最大渗透深度却不断增加;随着法向应力的增大,结构面的接触面积和渗透深度都增大;随着JRC的增大,结构面的接触面积减小,最大渗透深度增大。剪切过程中结构面接触面积逐渐减小,结构面剪切应力集中现象越来越显著,当INTERFACE单元达到最大剪切应力后,最大剪应力分布范围增大;随着法向应力增大,结构面剪切应力分布范围和高剪切应力的分布范围都增大;随着JRC增大,结构面接触面积减小,但高剪切应力的分布范围显著增大。临界视倾角是判断结构面接触面积的重要参数,其随着结构面剪切位移的增大而增大,但增加速度逐渐变缓,呈幂函数关系;临界视倾角随着法向应力的增大而减小,随着JRC的增大而增大。结构面的剪切应力与接触面积有较强的相关性,不同剪切位移阶段的结构面接触面积比下降速率不同,弹性阶段下降最快,位移-软化阶段次之,残余阶段下降最慢。

关键词：岩石结构面剪切特性法向应力动态接触特征修正模型