GUIDELINES FOR THE USE OF OVERSAMPLING IN PROTEIN NMR
GUIDELINES FOR THE USE OF OVERSAMPLING IN PROTEIN NMR
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DOI：
10.1006/jmra.1995.1083
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发表时间：
1995-04-01
期刊：
影响因子：
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通讯作者：
ZUIDERWEG, ERP
中科院分区：
文献类型：
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作者：
BECKMAN, RA;ZUIDERWEG, ERP
随着对越来越大的蛋白质进行详细的NMR研究，出现了一个问题，即典型的16位模数转换器（ADC）是否具有足够的动态范围来消除信号之和以及感兴趣的小信号，即使在存在出色的溶剂抑制的情况下。过采样有时可以用来缓解这个问题。NMR谱中的噪声包括模拟接收器噪声、来自模数转换器组件的模拟噪声以及由于垂直数字化的有限精度而产生的“量化噪声”。过采样（即，比采样定理所要求的采样更快）可以减小后两个噪声分量的影响，后两个噪声分量都具有高频分量并且不受音频滤波器的影响。此外，在某些条件下，间接时域中的过采样可能是有价值的。信噪比进行了评估掺杂和未掺杂的H2O/D2 O混合物的接收器增益范围内的1D和2D质子NOESY与或没有过采样，在直接和间接的时域。结果表明，一般建议使用过采样。这些一般原则使光谱学家能够快速确定在特定的实验条件下，直接或间接维度的过采样是否有用。(C)北京：科学出版社. Inc.
With detailed NMR studies being pursued on ever larger proteins, the question arises as to whether the typical 16-bit analog-to-digital converter (ADC) has sufficient dynamic range to digitize the sum of signals as well as a small signal of interest, even in the presence of excellent solvent suppression. Oversampling may sometimes be indicated to alleviate this problem. The noise in an NMR spectrum consists of analog receiver noise, analog noise from the analog-to-digital converter components, and ''quantization noise'' due to the limited precision of vertical digitization. Oversampling (i.e., sampling faster than required by the sampling theorem) may decrease the influence of the latter two noise components, both of which have high-frequency components and are not influenced by audio filters. In addition, oversampling in the indirect time domain may be of value under certain conditions. Signal-to-noise ratios were evaluated for doped and undoped H2O/D2O mixtures over a range of receiver gains for 1D and 2D proton NOESYs with or without oversampling in direct and indirect time domains. The results suggest general recommendations concerning the use of oversampling. These general principles allow spectroscopists to rapidly determine whether oversampling in direct or indirect dimensions will be useful under their particular experimental conditions. (C) 1995 Academic Press. Inc.