A Reference-Free Calibration for Ultrafast Spatiotemporally Encoded 2-D NMR Spectroscopy
A Reference-Free Calibration for Ultrafast Spatiotemporally Encoded 2-D NMR Spectroscopy
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DOI：
10.1109/tim.2023.3234082
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发表时间：
2023
影响因子：
5.6
通讯作者：
Hong Li;Yu Yang;L. Frydman;Zhong Chen;Yulan Lin
中科院分区：
文献类型：
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作者：
Hong Li;Yu Yang;L. Frydman;Zhong Chen;Yulan Lin
时空编码 (SPEN) 是一种最先进的核磁共振 (NMR) 技术，用于在单次（或几次）扫描中获取二维甚至多维 ($n$ -D) NMR 谱和/或图像。受益于特殊的编码和解码方案，SPEN 可以将经典的 2-D NMR 实验加速几个数量级。 SPEN的解码尤其是在振荡磁场梯度的影响下执行的；不可避免的硬件缺陷可能会导致奇数和偶数 SPEN 数据线之间的不一致，从而仅使所采集数据的一半（奇数或偶数）可用于处理。这使得直接维度上可用的光谱带宽减半，并降低了光谱灵敏度，导致峰值折叠伪影的出现和/或光谱质量的下降。过去的研究已经进行以纠正由梯度缺陷引起的这些失真，但需要在相同的实验条件下收集额外的参考扫描。这项工作对各种缺陷对二维 SPEN NMR 谱的影响进行了详细的理论分析，并根据理论分析提出了三步无参考校准算法。对使用 SPEN 收集的单次二维相关光谱 (COSY) 和异核单量子相关 (HSQC) NMR 光谱的实验数据进行了处理和处理，证明了所提出的无参考算法的可行性和适用性。
Spatiotemporal encoding (SPEN) is a state-of-the-art nuclear magnetic resonance (NMR) technique, utilized to acquire 2-D or even multidimensional ( $n$ -D) NMR spectra and/or images in a single (or a few) scans. Benefitting from special encoding and decoding schemes, SPEN can thus accelerate the classical 2-D NMR experiment by orders of magnitude. SPEN’s decoding in particular is executed under the effects of oscillating magnetic field gradients; inevitable hardware imperfections may then give rise to inconsistencies between odd and even SPEN data lines, making only half (odd or even) of the acquired data available for processing. This halves the spectral bandwidth available in the direct dimension and decreases the spectral sensitivity, leading to the emergence of peak folding artifacts and/or a decline of the spectral quality. Past research has been carried out to correct these distortions induced by gradient imperfections, but requires an extra reference scan collected under identical experimental conditions. This work presents a detailed theoretical analysis of the impacts of various imperfections on the 2-D SPEN NMR spectrum and proposes a three-step reference-free calibration algorithm in accordance with theoretical analysis. Experimental data on single-shot 2-D correlation spectroscopy (COSY) and heteronuclear single-quantum correlation (HSQC) NMR spectra collected using SPEN were performed and processed, which demonstrate the feasibility and applicability of the proposed reference-free algorithm.