Spectroscopy

光谱学
  • 文章类型: Journal Article
    近年来观察到的石油衍生产品的生产和运输呈指数级增长,这是由对能源的需求不断增长所推动的,纺织品,塑料基材料,和其他源自石油的货物。因此,这些石油衍生物的泄漏量相应增加,特别是在用于运输或的水源中,偶尔,非法用于储罐清洗或工业设备维护。许多研究人员提出了检测这些产品的高效技术,旨在促进它们的清理或遏制,从而最大限度地减少环境污染。然而,许多这些技术依赖于单个化合物的识别,这带来了显著的缺点,包括处理的复杂性,主体性,漫长的分析时间,原位分析不可行,和高成本。作为回应,传感器或广义轮廓分析技术的使用显着激增,用作传感器来生成这些产品的特征指纹,从而避免了上述缺点。这篇评论全面审查了用于检测水样中石油衍生产品的技术的演变,以及它们相关的优点和缺点。此外,审查审查了从水源中去除和/或限制这些产品的方法的当前观点,尽量减少它们对环境的影响以及对生物体和生态系统的相关健康影响。
    The exponential increase in the production and transportation of petroleum-derived products observed in recent years has been driven by the escalating demand for energy, textiles, plastic-based materials, and other goods derived from petroleum. Consequently, there has been a corresponding rise in spills of these petroleum derivatives, particularly in water sources utilized for transportation or, occasionally, illegally utilized for tank cleaning or industrial equipment maintenance. Numerous researchers have proposed highly effective techniques for detecting these products, aiming to facilitate their cleanup or containment and thereby minimize environmental pollution. However, many of these techniques rely on the identification of individual compounds, which presents significant drawbacks, including complexity of handling, subjectivity, lengthy analysis times, infeasibility for in situ analysis, and high costs. In response, there has been a notable surge in the utilization of sensors or generalized profiling techniques serving as sensors to generate characteristic fingerprints of these products, thereby circumventing the aforementioned disadvantages. This review comprehensively examines the evolution of techniques employed for detecting petroleum-derived products in water samples, along with their associated advantages and disadvantages. Furthermore, the review examines current perspectives on methods for the removal and/or containment of these products from water sources, to minimize their environmental impact and the associated health repercussions on living organisms and ecosystems.
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  • 文章类型: Journal Article
    微塑料在水生环境中无处不在,由于它们对人类健康和生态系统的潜在影响,已经成为一个重要的环境问题。当前基于实验室的微塑料检测方法存在各种缺点,包括缺乏标准化,有限的空间和时间覆盖范围,高成本,和耗时的程序。因此,需要开发原位技术来检测和监测微塑料,以有效地识别和了解其来源,通路,和行为。在这里,我们采用了系统的文献综述方法来评估为原位检测和监测水生微塑料而设计的实验和现场技术的开发和应用,不需要样品制备。2023年3月搜索了四个科学数据库,审查了62项相关研究。这些研究分为七个传感器类别,并讨论了它们的工作原理。传感器类包括光学设备,数字全息,拉曼光谱,其他光谱学,高光谱成像,遥感,和其他方法。我们还研究了来自这些技术的数据如何与机器学习模型集成,以开发能够准确表征微塑料的物理和化学性质并将其与其他颗粒区分开来的分类器。这篇综述得出结论,水生环境中微塑料的原位检测是可行的,可以高精度地实现,尽管这些方法仍处于发展的早期阶段。尽管如此,仍需要进一步的研究来加强微塑料的原位检测。这包括探索结合各种检测方法和开发健壮的机器学习分类器的可能性。此外,建议在现场实施已审查的方法,以评估其在检测微塑料方面的有效性并确定其局限性。
    Microplastics are ubiquitous in the aquatic environment and have emerged as a significant environmental issue due to their potential impacts on human health and the ecosystem. Current laboratory-based microplastic detection methods suffer from various drawbacks, including a lack of standardisation, limited spatial and temporal coverage, high costs, and time-consuming procedures. Consequently, there is a need for the development of in-situ techniques to detect and monitor microplastics to effectively identify and understand their sources, pathways, and behaviours. Herein, we adopt a systematic literature review method to assess the development and application of experimental and field technologies designed for the in-situ detection and monitoring of aquatic microplastics, without the need for sample preparation. Four scientific databases were searched in March 2023, resulting in a review of 62 relevant studies. These studies were classified into seven sensor categories and their working principles were discussed. The sensor classes include optical devices, digital holography, Raman spectroscopy, other spectroscopy, hyperspectral imaging, remote sensing, and other methods. We also looked at how data from these technologies are integrated with machine learning models to develop classifiers capable of accurately characterising the physical and chemical properties of microplastics and discriminating them from other particles. This review concluded that in-situ detection of microplastics in aquatic environments is feasible and can be achieved with high accuracy, even though the methods are still in the early stages of development. Nonetheless, further research is still needed to enhance the in-situ detection of microplastics. This includes exploring the possibility of combining various detection methods and developing robust machine-learning classifiers. Additionally, there is a recommendation for in-situ implementation of the reviewed methods to assess their effectiveness in detecting microplastics and identify their limitations.
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  • 文章类型: Journal Article
    背景:使用指纹技术对中药材(CHMs)进行质量控制是当前的研究热点,为建立符合CHMs特点的全面质量控制提供了科学依据。研究领域涵盖了许多学科,如分析化学,药理学,药剂学,生物化学,和分子生物学。
    目的:为了有效地了解有关CHMs的指纹和掺假的关键领域和未来研究方向。
    结果:本文分析了2000年至2023年在WebofScienceCoreCollection中使用CiteSpace和VOSviewer发表的879篇文章,并系统地评估了研究过程,热点,学科之间的主题分布,等。CHMs指纹图谱和掺假研究的最突出贡献者主要来自中国,印度,美国,英格兰,和巴西。CHMs的指纹和掺假研究的知识领域主要集中在分子认证的主题上,DNA条形码,HPLC,近红外光谱,管理数据,化学计量学,和电化学指纹。大多数国家已经认识到天然产物的制药潜力,在过去的十年中,人们越来越关注CHMs的指纹和掺假问题。未来的研究将更多地集中在分子鉴定和认证上,
    结论:本研究为相关领域的学者分析现有研究成果提供了有价值的参考。了解发展趋势,探索新的研究方向。
    BACKGROUND: It has been a current research hospots using fingerprinting technology for quality control of Chinese herbal medicines (CHMs), which provides a scientific basis for establishment of overall quality control in accordance with the characteristics of CHMs. The fingerprinting technology for CHMs is diverse, and the research field covers many disciplines, such as analytical chemistry, pharmacology, pharmaceutics, biochemistry, and molecular biology.
    OBJECTIVE: To effectively understand the key areas and future directions of research regarding the fingerprint and adulteration of CHMs.
    RESULTS: this paper analyzed 879 articles in this field in the Web of Science Core Collection from 2000 to 2023 with CiteSpace and VOSviewer, and systematically assessed the research process, hotspots, topic distribution among disciplines, etc. The most prominent contributors of fingerprint and adulteration of CHMs research are mainly from China, India, the United States, England, and Brazil. The knowledge domains of fingerprint and adulteration of CHMs research focus mainly on the topics of molecular authentication, DNA barcoding, HPLC, near-infrared spectroscopy, manage data, chemometrics, and electrochemical fingerprinting. Most countries have recognized the pharmaceutical potential of natural products, and have paid more attention to the fingerprint and adulteration of CHMs in the past decade. Future the research tends to focus more on molecular identification and authentication, and electrochemical and chromatographic fingerprinting in controlling the adulteration of CHMs.
    CONCLUSIONS: This research provides a valuable reference for scholars in related fields to analyze existing research results, understand the development trend, and explore new research directions.
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  • 文章类型: Journal Article
    磁共振成像(MRI)在兽医实践中广泛用于颅内肿瘤的死前诊断。这里,我们提供了已发表的狗和猫的原发性和继发性颅内肿瘤的MRI特征的说明摘要,遵循PRISMA范围审查指南。搜索了PubMed和WebofScience数据库的相关记录,并征求利益相关者的意见,以选择数据进行提取。67项中等至低水平证据质量的研究,描述了经病理证实的犬和猫脑肿瘤的MRI特征,符合纳入标准。数据包含和报告的差异很大,以及低案件数量,禁止比较数据分析。现有数据支持结合病变数量的整体MRI方法,在大脑中的位置,形状,多参数序列上的固有信号出现,对比度增强的模式,以及相关的继发性大脑变化,以优先考虑鉴别成像诊断,并且通常可以对常见的颅内肿瘤进行准确的推定诊断。定量MRI技术有望改善肿瘤与非肿瘤性脑部病变的区分,以及区分脑肿瘤类型和等级,但是样本量的限制可能仍然是设计强大动力的放射学研究的重大实际障碍。对于许多脑肿瘤变种来说,特别是在猫中,仍然需要将临床病理和神经影像学数据相关联的标准化研究.
    Magnetic resonance imaging (MRI) is used pervasively in veterinary practice for the antemortem diagnosis of intracranial tumors. Here, we provide an illustrated summary of the published MRI features of primary and secondary intracranial tumors of dogs and cats, following PRISMA scoping review guidelines. The PubMed and Web of Science databases were searched for relevant records, and input from stakeholders was solicited to select data for extraction. Sixty-seven studies of moderate to low-level evidence quality describing the MRI features of pathologically confirmed canine and feline brain tumors met inclusion criteria. Considerable variability in data inclusion and reporting, as well as low case numbers, prohibited comparative data analyses. Available data support a holistic MRI approach incorporating lesion number, location within the brain, shape, intrinsic signal appearances on multiparametric sequences, patterns of contrast enhancement, and associated secondary changes in the brain to prioritize differential imaging diagnoses, and often allows for accurate presumptive diagnosis of common intracranial tumors. Quantitative MRI techniques show promise for improving discrimination of neoplastic from non-neoplastic brain lesions, as well as differentiating brain tumor types and grades, but sample size limitations will likely remain a significant practical obstacle to the design of robustly powered radiomic studies. For many brain tumor variants, particularly in cats, there remains a need for standardized studies that correlate clinicopathologic and neuroimaging data.
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  • 文章类型: Journal Article
    二维聚合物包含一类新的具有有希望的机械和化学性质的大分子,其最近在温和的合成条件下变得可获得。由于纳米大小的孔和缺陷可能会影响这些材料的性能,需要分析方法来对它们进行空间和化学表征,直至纳米级。在这篇文章中,我们将尖端增强拉曼光谱与纳米分析中的常用方法进行了比较,以研究分子薄2D聚合物片材中的缺陷位点,并简要介绍了应对尖端诱导降解过程带来的挑战的措施。
    Two-dimensional polymers comprise a novel class of macromolecules with promising mechanical and chemical properties that have recently become accessible under mild synthetic conditions. As nanometer-sized holes and defects are likely to influence these materials\' properties, there is a need for analytical methods to spatially and chemically characterize them down to the nanoscale. In this article, we compare tip-enhanced Raman spectroscopy to common methods in nanoanalysis for the investigation of defect sites in molecularly thin 2D-polymer sheets and briefly present measures to meet the challenges arising from tip-induced degradation processes.
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  • 文章类型: Journal Article
    本教程将激光器的设计和操作的基础知识与它们在与保护和文化遗产(CH)科学相关的应用中的使用相结合-作为材料化学成分研究的分析设备的组成部分。激光仪器的发展及其基本物理背景,包括对它们的属性和参数的简短解释,简要总结,并概述了不同的基于激光的分析技术。本教程中涵盖的分析技术根据其技术方面和特性分为三组:(1)振动光谱学,(2)元素分析,和(3)不同的分子质谱技术。
    This tutorial review combines the fundamentals of the design and operation of lasers with their usage in applications related to conservation and cultural heritage (CH) science - as components of analytical devices for the study of the chemical composition of materials. The development of laser instruments and their fundamental physical background, including a short explanation of their properties and parameters, are briefly summarised, and an overview of different laser-based analytical techniques is given. The analytical techniques covered in this tutorial are divided into three groups based on their technical aspects and properties: (1) vibrational spectroscopy, (2) elemental analysis, and (3) different molecular mass spectrometric techniques.
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  • 文章类型: Journal Article
    作为制茶的原料,茶叶的质量直接影响成品茶的质量。新鲜茶叶的品质主要通过人工判断或理化检测内部成分的含量来评定。物理化学方法比较成熟,测试结果更加准确和客观,但传统的化学方法测定茶叶的生化指标耗时,劳动力成本高,复杂,和破坏性的。随着成像和光谱技术的飞速发展,光谱技术作为一种新兴的技术已经广泛应用于农产品质量安全的快速无损检测。由于存在低信噪比的光谱信息,高信息冗余,和强的自相关性,对光谱数据预处理进行了一系列研究。通过平滑降噪提高光谱数据与目标数据的相关性,更正,提取特征带,等等,建造一个稳定的,具有较强泛化能力的高精度估计或判别模型。已经发表了更多关于光谱技术的研究论文,以检测茶鲜叶的质量。本研究总结了原则,分析方法,以及高光谱成像技术(HSI)在茶叶鲜叶质量安全无损检测中的应用,旨在跟踪国内外最新研究进展。同时,包括近红外光谱(NIRS)在内的其他光谱技术的原理和应用,中红外光谱(MIRS),拉曼光谱(RS),还简要介绍了用于新鲜茶叶质量和安全性无损检测的光谱技术。最后,在技术障碍和实际应用方面,研究了光谱分析技术在茶叶品质无损评价中的挑战和发展趋势。
    As the raw material for tea making, the quality of tea leaves directly affects the quality of finished tea. The quality of fresh tea leaves is mainly assessed by manual judgment or physical and chemical testing of the content of internal components. Physical and chemical methods are more mature, and the test results are more accurate and objective, but traditional chemical methods for measuring the biochemical indexes of tea leaves are time-consuming, labor-costly, complicated, and destructive. With the rapid development of imaging and spectroscopic technology, spectroscopic technology as an emerging technology has been widely used in rapid non-destructive testing of the quality and safety of agricultural products. Due to the existence of spectral information with a low signal-to-noise ratio, high information redundancy, and strong autocorrelation, scholars have conducted a series of studies on spectral data preprocessing. The correlation between spectral data and target data is improved by smoothing noise reduction, correction, extraction of feature bands, and so on, to construct a stable, highly accurate estimation or discrimination model with strong generalization ability. There have been more research papers published on spectroscopic techniques to detect the quality of tea fresh leaves. This study summarizes the principles, analytical methods, and applications of Hyperspectral imaging (HSI) in the nondestructive testing of the quality and safety of fresh tea leaves for the purpose of tracking the latest research advances at home and abroad. At the same time, the principles and applications of other spectroscopic techniques including Near-infrared spectroscopy (NIRS), Mid-infrared spectroscopy (MIRS), Raman spectroscopy (RS), and other spectroscopic techniques for non-destructive testing of quality and safety of fresh tea leaves are also briefly introduced. Finally, in terms of technical obstacles and practical applications, the challenges and development trends of spectral analysis technology in the nondestructive assessment of tea leaf quality are examined.
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  • 文章类型: Journal Article
    在全球范围内,食品安全和保障方面需要在整个农场到餐桌的连续过程中加以考虑,考虑食品的供应链。一般来说,农业食品系统是一个相互连接的特征和过程的多重网络,很难预测的速度,维护食品安全是不可或缺的要素,也是可持续发展目标(SDGs)的一部分。带动科学界发展先进的应用分析方法,例如用于评估食源性疾病的机器学习(ML)和深度学习(DL)技术。本文的主要目的是从分析的角度为正在进行的有关人工智能(AI)工具在粮食作物安全领域应用的研究的共识版本的开发做出贡献。为更具体的主题撰写全面的评论也可能具有挑战性,尤其是在文献中搜索时。据我们所知,这次审查是第一次解决这个问题。这项工作包括对文献进行独特而详尽的研究,使用我们的基于TriScope关键词的综合方法。根据我们的纳入和排除标准,对与我们的主题相关的所有可用文献进行了调查。数据论文的最终计数经过深入阅读和分析,以提取必要的信息来回答我们的研究问题。尽管已经进行了许多研究,对人工智能工具与基于作物的食品安全分析策略相结合的应用的关注有限。
    On a global scale, food safety and security aspects entail consideration throughout the farm-to-fork continuum, considering food\'s supply chain. Generally, the agrifood system is a multiplex network of interconnected features and processes, with a hard predictive rate, where maintaining the food\'s safety is an indispensable element and is part of the Sustainable Development Goals (SDGs). It has led the scientific community to develop advanced applied analytical methods, such as machine learning (ML) and deep learning (DL) techniques applied for assessing foodborne diseases. The main objective of this paper is to contribute to the development of the consensus version of ongoing research about the application of Artificial Intelligence (AI) tools in the domain of food-crop safety from an analytical point of view. Writing a comprehensive review for a more specific topic can also be challenging, especially when searching within the literature. To our knowledge, this review is the first to address this issue. This work consisted of conducting a unique and exhaustive study of the literature, using our TriScope Keywords-based Synthesis methodology. All available literature related to our topic was investigated according to our criteria of inclusion and exclusion. The final count of data papers was subject to deep reading and analysis to extract the necessary information to answer our research questions. Although many studies have been conducted, limited attention has been paid to outlining the applications of AI tools combined with analytical strategies for crop-based food safety specifically.
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  • 文章类型: Journal Article
    The present review places emphasis on a comprehensive survey of experimental techniques to probe the structural and morphological features at the nanoscale range in thin magnetic films, incorporating those available at in-house laboratories as well as those at state-of-the-art synchrotron radiation facilities. This elucidating the range of available techniques, and the information they can yield represents a step for advancing the understanding of and for unlocking new possibilities in the design and optimization of thin magnetic films across a wide range of applications.
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  • 文章类型: Journal Article
    身体活动(PA)在包括认知在内的各个领域促进大脑健康,心情,和神经可塑性。在神经化学层面,这些影响在大脑中的潜在机制尚未完全了解。用质子磁共振波谱(1H-MRS),可以对代谢物浓度进行非侵入性量化,使研究能够获得运动引起的神经化学变化的措施。本系统综述旨在通过1H-MRS测量PA对脑代谢物的急性影响的现有文献。四个数据库(Cochrane中央对照试验登记册,PubMed,Embase,和PsycINFO)进行了搜索,确定2965项研究,其中9人符合纳入标准。在整个研究中,运动后,γ-氨基丁酸(GABA)和乳酸趋于增加,而胆碱没有显著变化的报道。对于谷氨酰胺/谷氨酸(Glx),研究没有定论。结论受到对1H-MRS数据处理和锻炼方案缺乏共识的限制。为了减少研究之间的差异,未来的研究建议(1):应用标准化运动指数(2),考虑MRS扫描的开始时间,(3)遵循标准化的MRS定量方法。
    Physical activity (PA) promotes brain health in a variety of domains including cognition, mood, and neuroplasticity. At the neurochemical level, the mechanisms underlying these effects in the brain are not fully understood. With proton Magnetic Resonance Spectroscopy (1H-MRS), it is possible to non-invasively quantify metabolite concentrations, enabling studies to obtain measures of exercise-induced neurochemical changes. This systematic review aimed to examine the existing literature on acute effects of PA on brain metabolites as measured by 1H-MRS. Four databases (Cochrane Central Register of Controlled Trials, PubMed, Embase, and PsycINFO) were searched, identifying 2965 studies, of which 9 met the inclusion criteria. Across studies, Gamma-AminoButyric Acid (GABA) and lactate tended to increase after exercise, while no significant changes in choline were reported. For glutamine/glutamate (Glx), studies were inconclusive. Conclusions were limited by the lack of consensus on 1H-MRS data processing and exercise protocols. To reduce inter-study differences, future studies are recommended to (1): apply a standardized exercise index (2), consider the onset time of MRS scans, and (3) follow standardized MRS quantification methods.
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