Spectroscopy

光谱学
  • 文章类型: Journal Article
    本研究使用密度泛函理论(DFT)在高斯09W软件上分析阿司匹林分子(C9H8O4)。首先,使用DFT方法以B3LYP功能和6-311G(d,P)基础设置。采用全球反应性研究来了解阿司匹林在气体和溶剂水中对阴离子和中性状态的反应性。为了了解轨道在化学稳定性和电子传导性中的参与,我们计算了HOMO-LUMO。使用热化学来理解分子的热力学功能。采用分子静电势(MEP)来了解阿司匹林的理化性质。我们观察了Mulliken原子电荷来计算阿司匹林的原子电荷。最后,标题分子的UV-Vis,FTIR,和拉曼光谱进行了分析,并与实验数据进行了比较。
    This study analyzed the aspirin molecule (C9H8O4) using Density Functional Theory (DFT) on Gaussian 09W software. First, the structure of aspirin was optimized using the DFT method with the B3LYP functional and the 6-311+G (d,p) basis set. A global reactivity study was employed to understand the reactivity of aspirin in gas and solvent water for both anion and neutral states. To understand the involvement of orbitals in chemical stability and electron conductivity, we calculated the HOMO-LUMO. The thermodynamic function of a molecule was understood using thermochemistry. Molecular Electrostatic Potential (MEP) was employed to understand the physiochemical properties of aspirin. We observed the Mulliken atomic charge to calculate the atomic charge of aspirin. Finally, the title molecule\'s UV-Vis, FTIR, and Raman spectra are analyzed and compared with the experimental data.
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  • 文章类型: Journal Article
    生物制造利用改良的微生物系统可持续地生产用于农业的商业上重要的生物分子,能源,食物,材料,和制药行业。然而,需要解决与无损和高通量代谢物筛选相关的技术挑战,以充分释放合成生物学和可持续生物制造的潜力。
    这个观点概述了工业细胞菌株开发计划中使用的当前分析筛选工具,并引入了无标签振动光谱显微镜作为替代对比机制。
    我们概述了当前在设计的“测试”部分中使用的分析仪器,build,test,学习合成生物学的周期。然后,我们重点介绍了拉曼散射和红外吸收成像技术的最新进展,这提高了分子特异性和灵敏度。
    高分辨率化学成像方法的最新发展允许更大的吞吐量,而不影响图像对比度。我们提供了支持与微流体集成以在单细胞水平进行快速筛查所需的未来工作的路线图。
    对代谢物的净表达进行定量,可以鉴定具有导致生物分子产生增加的代谢途径的细胞,这对于提高产量和降低工业生物制造成本至关重要。振动显微镜仪器的技术进步将极大地有利于生物材料作为非破坏性细胞筛选的补充方法。
    UNASSIGNED: Biomanufacturing utilizes modified microbial systems to sustainably produce commercially important biomolecules for use in agricultural, energy, food, material, and pharmaceutical industries. However, technological challenges related to non-destructive and high-throughput metabolite screening need to be addressed to fully unlock the potential of synthetic biology and sustainable biomanufacturing.
    UNASSIGNED: This perspective outlines current analytical screening tools used in industrial cell strain development programs and introduces label-free vibrational spectro-microscopy as an alternative contrast mechanism.
    UNASSIGNED: We provide an overview of the analytical instrumentation currently used in the \"test\" portion of the design, build, test, and learn cycle of synthetic biology. We then highlight recent progress in Raman scattering and infrared absorption imaging techniques, which have enabled improved molecular specificity and sensitivity.
    UNASSIGNED: Recent developments in high-resolution chemical imaging methods allow for greater throughput without compromising the image contrast. We provide a roadmap of future work needed to support integration with microfluidics for rapid screening at the single-cell level.
    UNASSIGNED: Quantifying the net expression of metabolites allows for the identification of cells with metabolic pathways that result in increased biomolecule production, which is essential for improving the yield and reducing the cost of industrial biomanufacturing. Technological advancements in vibrational microscopy instrumentation will greatly benefit biofoundries as a complementary approach for non-destructive cell screening.
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  • 文章类型: Journal Article
    在过去的20年里,胎儿脑MR成像分析方法有了显著的发展。本文深入研究了结构成像的细节,扩散成像,功能磁共振成像,和光谱学,强调运动矫正的最新进展,胎儿大脑发育图谱,挑战和创新。此外,本文探讨了这些先进的影像学技术在理解和诊断胎儿脑发育和异常中的临床应用。
    Over the last 20 years, there have been remarkable developments in fetal brain MR imaging analysis methods. This article delves into the specifics of structural imaging, diffusion imaging, functional MR imaging, and spectroscopy, highlighting the latest advancements in motion correction, fetal brain development atlases, and the challenges and innovations. Furthermore, this article explores the clinical applications of these advanced imaging techniques in comprehending and diagnosing fetal brain development and abnormalities.
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  • 文章类型: Journal Article
    在过去的几年里,细胞外囊泡(EV),由各种细胞和体液分泌的细胞在生物医学应用中显示出极大的潜力。越来越多的研究表明,蛋白质电晕可以粘附在电动汽车的表面,这可以对其功能产生根本影响。靶向和治疗功效。然而,移除和识别这些电晕成员目前是一项具有挑战性的任务。在这项研究中,我们采用了红细胞衍生的细胞外囊泡(REV)作为模型系统和三种膜活性抗菌肽(AMP),LL-37,FK-16和CM15,以测试它们是否可用于从囊泡表面去除蛋白质冠成员。据报道,这些AMP通过一种常见的螺旋表面覆盖模型优先发挥其膜相关活性,并且不会显着影响脂质双层体的内部。通过生物物理技术跟踪肽和REV之间的相互作用,例如流动-线性二色性光谱法,为蛋白质去除提供了有效的适用肽浓度。然后对REV样品进行随后的尺寸排阻色谱和蛋白质组学分析。基于对照REV与肽处理的样品的比较,17种蛋白质被鉴定为外部蛋白质电晕成员。从三个被调查的AMP中,FK-16可以被认为是进一步优化EV相关的AMP适用性的最佳候选。我们在REV模型系统上的结果设想,膜活性肽可能成为一组有用的工具,用于设计和修饰EV和其他基于脂质的天然颗粒的表面。
    In the last years, extracellular vesicles (EVs), secreted by various cells and body fluids have shown extreme potential in biomedical applications. Increasing number of studies suggest that a protein corona could adhere to the surface of EVs which can have a fundamental effect on their function, targeting and therapeutical efficacy. However, removing and identifying these corona members is currently a challenging task to achieve. In this study we have employed red blood cell-derived extracellular vesicles (REVs) as a model system and three membrane active antimicrobial peptides (AMPs), LL-37, FK-16 and CM15, to test whether they can be used to remove protein corona members from the surface of vesicles. These AMPs were reported to preferentially exert their membrane-related activity via one of the common helical surface-covering models and do not significantly affect the interior of lipid bilayer bodies. The interaction between the peptides and the REVs was followed by biophysical techniques, such as flow-linear dichroism spectroscopy which provided the effective applicable peptide concentration for protein removal. REV samples were then subjected to subsequent size exclusion chromatography and to proteomics analysis. Based on the comparison of control REVs with the peptide treated samples, seventeen proteins were identified as external protein corona members. From the three investigated AMPs, FK-16 can be considered as the best candidate to further optimize EV-related applicability of AMPs. Our results on the REV model system envisage that membrane active peptides may become a useful set of tools in engineering and modifying surfaces of EVs and other lipid-based natural particles.
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  • 文章类型: Journal Article
    许多主食来自硬粒小麦及其制粉产品;正因为如此,了解它们的特点是非常重要的。这项研究调查了这些产品中的元素含量以及有机农业是否存在差异。整个种子和碾磨产品中28种元素的浓度,也就是说,麸皮,粗面粉和面粉,硬粒小麦,通过ICP-OES测定。小麦在常规或有机农艺实践下种植,以验证区分的可能性,使用元素含量,来自一个或另一个实践的产品之间。这些元素在种子的外层更丰富,麸皮,但他们中的大多数也出现在其他人中。痕量Sb仅存在于3%的样品中,而在大约一半的种子和麸皮样品中检测到痕量Tl,但在其他样品中未检测到。缺乏元素是特定产品的更多特征,例如,大多数粗面粉和面粉缺乏Co,虽然其他元素显示有机和常规栽培产品之间或不同碾磨产品之间的差异很小,情况就是这样,例如,对于Ag的痕迹,B,和V。这些元素的浓度与多元判别分析相结合,特别是PLS-DA,以确定碾磨产品的种植来源。一些元素,虽然每个产品都不同,足以达到接近1的分类精度和准确度;不同产品存在微小差异。最糟糕的是面粉,其中预测的精度和准确度为0.92,尽管仅使用三个元素:B,K,还有Se。当还添加到前面的三个元素时,Semolina获得了完美的预测,Ag,Cd,和Cu。麸皮需要更多的元素,Fe和Mg代替K和Ag进行种子分类。总之,五个要素,B,Cd,Cu,K,Se,在区分有机农业和传统农业方面最重要;这些元素也允许产品之间的一些差异。该方法可以帮助预防欺诈。
    Many staple foods originate from durum wheat and its milling products; because of this, it is very important to know their characteristics. This study investigates elemental contents in these products and if differences exist because of organic farming. The concentrations of 28 elements in the whole seed and in milling products, that is, bran, semolina and flour, of durum wheat, were determined through ICP-OES. The wheats were grown under conventional or organic agronomic practices to verify the possibility of discriminating, using the elemental content, between products coming from one or the other practice. The elements were more abundant in the outer layer of the seed, the bran, but most of them were also present in the others. Traces of Sb were present only in 3% of the samples, while traces of Tl were detected in approximately half of the seed and bran samples but not in other samples. The absence of an element was more characteristic of specific products, e.g., most semolina and flour lacked Co, while other elements showed small differences between products from organic and conventional cultivation or between different milling products, which was the case, for example, for traces of Ag, B, and V. The concentrations of these elements were coupled with multivariate discriminant analysis, specifically PLS-DA, to identify the cultivation provenance of the milled products. A few elements, although different for each product, are sufficient to attain precision and accuracy of classification close to 1; small differences exist for different products. The worst is flour, where the predicted precision and accuracy are 0.92, although using only three elements: B, K, and Se. Semolina attains perfect prediction when also adding to the three previous elements, Ag, Cd, and Cu. Further elements are necessary for bran, while Fe and Mg replace K and Ag to classify seeds. In conclusion, five elements, B, Cd, Cu, K, and Se, are the most important in distinguishing between organic and conventional agriculture; these elements also permit some differentiation among products. The method could help in fraud prevention.
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  • 文章类型: Journal Article
    真核细胞已经开发了复杂的生物分子转运机制,特别是在紧张的条件下。这项跨学科研究深入研究了饥饿期间激活的非常规蛋白质分泌(UPS)途径,促进蛋白质的出口,绕过经典分泌机制的大多数组件。具体来说,我们专注于GRASP在UPS中的作用未得到充分开发的机制,特别是在UPS的囊泡状隔室的生物发生和货物募集中。我们的结果表明,液-液相分离(LLPS)在GRASP酵母同源物Grh1的凝聚中起着关键作用,在类似饥饿的条件下。这种关联似乎是非常规蛋白质分泌(CUPS)生物发生隔室的前兆。Grh1的自缔合是由静电调节的,疏水,和氢键相互作用。重要的是,我们的研究表明,在类似饥饿的情况下,Grh1的相分离状态可以招募UPS货物。此外,我们探讨了凝聚层液-固转变如何影响细胞恢复正常应激后状态的能力。我们的发现提供了对细胞内蛋白质动力学和细胞对压力的适应性反应的见解。
    Eukaryotic cells have developed intricate mechanisms for biomolecule transport, particularly in stressful conditions. This interdisciplinary study delves into unconventional protein secretion (UPS) pathways activated during starvation, facilitating the export of proteins bypassing most of the components of the classical secretory machinery. Specifically, we focus on the underexplored mechanisms of the GRASP\'s role in UPS, particularly in biogenesis and cargo recruitment for the vesicular-like compartment for UPS. Our results show that liquid-liquid phase separation (LLPS) plays a key role in the coacervation of Grh1, the GRASP yeast homologue, under starvation-like conditions. This association seems a precursor to the Compartment for Unconventional Protein Secretion (CUPS) biogenesis. Grh1\'s self-association is regulated by electrostatic, hydrophobic, and hydrogen-bonding interactions. Importantly, our study demonstrates that phase-separated states of Grh1 can recruit UPS cargo under starvation-like situations. Additionally, we explore how the coacervate liquid-to-solid transition could impact cells\' ability to return to normal post-stress states. Our findings offer insights into intracellular protein dynamics and cell adaptive responses to stress.
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    文章类型: Journal Article
    暂无摘要。
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  • 文章类型: Journal Article
    用平场掠入射光谱仪在约4nm-20nm的波长范围内观察了在国家标准技术研究院的电子束离子阱中产生的高电荷镱离子的极紫外光谱。通过非麦克斯韦EBIT等离子体的碰撞辐射建模,通过详细分析来解释测得的光谱。由于贝壳内(Δn=0,n=4)电偶极子,磁偶极子,并通过类NiYb42离子在类RbYb33中鉴定了电四极跃迁。在许多电离阶段,讨论了n=4络合物内强构型相互作用对测量光谱的影响。
    Extreme ultraviolet spectra of highly-charged ytterbium ions produced in an electron beam ion trap at the National Institute of Standards and Technology were observed with a flat-field grazing incidence spectrometer in the wavelength region of about 4 nm-20 nm. The measured spectra were interpreted through detailed analysis by collisional-radiative modeling of the non-Maxwellian EBIT plasma. Seventy-nine new spectral lines due to intrashell (Δn = 0, n = 4) electric-dipole, magnetic-dipole, and electric-quadrupole transitions were identified in Rb-like Yb33+ through Ni-like Yb42+ ions. The effects of strong configuration interaction within the n = 4 complex on the measured spectra are discussed for a number of ionization stages.
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  • 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
    无标记超分辨率(LFSR)成像依赖于纳米级物体中的光散射过程,而无需超分辨率FL显微镜中所需的荧光(FL)染色。本路线图的目标是提出对发展的全面愿景,这个领域最先进的,并讨论了打破LFSR成像的经典衍射极限需要克服的分辨率边界和障碍。本路线图的范围涵盖了先进的干扰检测技术,其中衍射限制的横向分辨率与无与伦比的轴向和时间分辨率相结合,基于将分辨率理解为信息科学问题的具有真正横向超分辨率能力的技术,在使用新颖的结构化照明时,近场扫描,和非线性光学方法,以及基于纳米等离子体的超透镜设计,超材料,变换光学,和微球辅助方法。为此,这个路线图带来了来自物理学和生物医学光学领域的研究人员,这些研究通常是分开发展的。本文的最终目的是基于其物理机制为LFSR成像的当前和未来发展创造一个愿景,并为该领域的系列文章创造一个巨大的开放。
    Label-free super-resolution (LFSR) imaging relies on light-scattering processes in nanoscale objects without a need for fluorescent (FL) staining required in super-resolved FL microscopy. The objectives of this Roadmap are to present a comprehensive vision of the developments, the state-of-the-art in this field, and to discuss the resolution boundaries and hurdles which need to be overcome to break the classical diffraction limit of the LFSR imaging. The scope of this Roadmap spans from the advanced interference detection techniques, where the diffraction-limited lateral resolution is combined with unsurpassed axial and temporal resolution, to techniques with true lateral super-resolution capability which are based on understanding resolution as an information science problem, on using novel structured illumination, near-field scanning, and nonlinear optics approaches, and on designing superlenses based on nanoplasmonics, metamaterials, transformation optics, and microsphere-assisted approaches. To this end, this Roadmap brings under the same umbrella researchers from the physics and biomedical optics communities in which such studies have often been developing separately. The ultimate intent of this paper is to create a vision for the current and future developments of LFSR imaging based on its physical mechanisms and to create a great opening for the series of articles in this field.
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