神经网络用于将模拟的NMR光谱从低场转换为高场,用于定量代谢学
Hayden Johnson1, Aaryani Tipirneni-Sajja1,2
1Department of Biomedical Engineering, The University of Memphis, Memphis, TN 38152, USA.
Metabolites
|December 27, 2024
概括
一个变压器网络有效地将低场NMR光谱转换为高场,增强了对代谢物量化的数据. 对低场光谱的直接分析显示了可比的准确性,这表明需要进一步研究以获得最佳的定量NMR光谱.
科学领域:
- 核磁共振 (NMR) 光谱学 核磁共振 (NMR) 光谱学
- 计算化学的计算化学
- 代谢学 代谢学 代谢学
背景情况:
- 基板NMR仪器为研究和工业提供可访问和负担得起的NMR光谱.
- 低磁场NMR光谱仪在光谱分辨率和信号噪声比 (SNR) 中存在挑战,使定量分析复杂化.
- 提高低场NMR光谱的质量对于准确的分析物量化至关重要.
研究的目的:
- 评估神经网络架构,用于将低场 (100 MHz) NMR频谱转换为高场 (400 MHz) 频谱.
- 提高光谱质量,以改善代谢物的定量分析.
- 为了比较使用低场和高场转换光谱的直接代谢物量化性能.
主要方法:
- 模拟的100MHz的NMR光谱使用各种神经网络架构进行处理,包括变压器和多层感知子 (MLP).
- 主要任务是将低场光谱转换为高场光谱.
- 此外,MLP还用于从模拟的低场 (100 MHz) 和高场 (400 MHz) 频谱中直接量化代谢物.
主要成果:
- 变压器网络展示了可靠地将低场NMR光谱转换为高场光谱的能力,即使在复杂的混合物 (21和87代谢物) 中也是如此.
- 使用MLP对低场光谱进行直接代谢物量化,比使用转换为高场光谱的光谱获得略高的准确性.
- 这些发现表明,从低场光谱直接量化可能是足够的,尽管需要进一步验证.
结论:
- 基于变压器的方法有效地将低场NMR光谱转换为高场光谱在代谢应用中.
- 这种方法有可能在各种NMR光谱学领域实现数据处理的自动化.
- 需要进一步的研究和实验验证,才能充分确定低场与高场光谱转换在量化方面的好处.
相关概念视频
01:02¹H NMR: Interpreting Distorted and Overlapping Signals
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Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
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01:14NMR Spectrometers: Resolution and Error Correction
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When magnetic nuclei in a sample achieve resonance and undergo relaxation, the signal detected in NMR is an approximately exponential free induction decay. Fourier transform of an exponential decay yields a Lorentzian peak in the frequency domain. Lorentzian peaks in an NMR spectrum are defined by their amplitude, full width at half maximum, and position, where the peak width is governed by the spin-spin relaxation time alone. In real experiments, however, the applied magnetic field is rendered...
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01:20NMR Spectrometers: Overview
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NMR spectrometers consist of a strong magnet, a radiofrequency transmitter, and a detector attached to a computer console for recording spectra of samples containing NMR-active nuclei. In first-generation NMR instruments called continuous-wave spectrometers, the resonance frequencies of the nuclei are determined by frequency-sweep or field-sweep methods. The magnetic field strength is fixed and the rf signal is swept in the former, while the radiofrequency signal is fixed and the magnetic field...
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01:182D NMR: Overview of Heteronuclear Correlation Techniques
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Heteronuclear correlation spectroscopy is an analytical technique that investigates the coupling between different types of nuclei, often a proton and an X-nucleus, such as carbon-13 or nitrogen-15. This method is commonly used in nuclear magnetic resonance (NMR) spectroscopy to gain insights into complex chemical compounds' structural and compositional aspects. A typical heteronuclear correlation spectrum displays X-nucleus chemical shifts on one axis and a proton spectrum on the other...
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01:12Two-Dimensional (2D) NMR: Overview
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The 1D NMR spectrum of large and complex molecules like natural products has complicated splitting patterns and overlapping signals, which can be easily interpreted using 2-dimensional (2D) NMR. Unlike 1D NMR, 2D NMR has two frequency axes that provide the coupling information between the nucleus A and nucleus B in a molecule. The process from which 2D spectra are obtained has four steps.
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse....
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse....
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01:192D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)
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Heteronuclear single-quantum correlation spectroscopy (HSQC) is a 2D NMR technique that reveals one-bond correlations between hydrogen and a heteronucleus. The HSQC experiment is similar to the heteronuclear correlation experiment (HETCOR) but is more sensitive. In the HSQC spectrum, the proton chemical shift is plotted on the horizontal F2 axis, while the 13C chemical shift is plotted on the vertical F1 axis. The corresponding proton and 13C spectra are also shown. The HSQC contour plot does...
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