The influence of the radiofrequency excitation and conversion pulses on the lineshapes and intensities of the triple-quantum MAS NMR spectra of I = 3/2 nuclei.

Solid state nuclear magnetic resonance · 2000 · Benefit · Insufficient evidence

← Research stream

BenefitInsufficient evidencePaper 3961

Study snapshot

PublicationSolid state nuclear magnetic resonance · 2000

Study typeengineering

Reported directionBenefit

Evidence ratingInsufficient

Abstract

A rigorous examination of the various multiple-quantum magic angle spinning sequences is carried out with reference to sensitivity enhancement in the isotropic dimension and the lineshapes of the corresponding MAS peaks in the anisotropic dimension. An echo efficiency parameter is defined here, which is shown to be an indicator of the performance aspects of the various sequences. This can be used in the design of further new experiments in this field. A consequence of such a systematic analysis has been the combination of a spin-lock pulse for excitation of multiple-quantum coherences and an amplitude-modulated pulse for their conversion to observable single-quantum coherences. This approach has resulted in an improved performance over other sequences with respect to both the anisotropic lineshapes and the isotropic intensities.

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeengineering

Effect directionbenefit

PopulationNot supplied

Sample sizeNot supplied

ExposureNot supplied

Evidence strengthInsufficientConfidence: 74% · Peer reviewed: yes

Main findings

The paper reports a systematic analysis of multiple-quantum magic angle spinning (MAS) NMR sequences and defines an "echo efficiency" parameter as an indicator of sequence performance. It describes combining a spin-lock pulse for excitation with an amplitude-modulated pulse for conversion, which improved performance versus other sequences in terms of anisotropic lineshapes and isotropic intensities.

Outcomes measured

NMR spectral lineshapes (anisotropic dimension)
NMR peak intensities/sensitivity (isotropic dimension)
Echo efficiency parameter for multiple-quantum MAS sequences

View raw extracted JSON

{
  "study_type": "engineering",
  "exposure": {
    "band": null,
    "source": null,
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": null,
  "sample_size": null,
  "outcomes": [
    "NMR spectral lineshapes (anisotropic dimension)",
    "NMR peak intensities/sensitivity (isotropic dimension)",
    "Echo efficiency parameter for multiple-quantum MAS sequences"
  ],
  "main_findings": "The paper reports a systematic analysis of multiple-quantum magic angle spinning (MAS) NMR sequences and defines an \"echo efficiency\" parameter as an indicator of sequence performance. It describes combining a spin-lock pulse for excitation with an amplitude-modulated pulse for conversion, which improved performance versus other sequences in terms of anisotropic lineshapes and isotropic intensities.",
  "effect_direction": "benefit",
  "limitations": [],
  "evidence_strength": "insufficient",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "multiple-quantum MAS",
    "triple-quantum MAS",
    "NMR",
    "I=3/2 nuclei",
    "spin-lock pulse",
    "amplitude-modulated pulse",
    "echo efficiency",
    "lineshape",
    "sensitivity enhancement"
  ],
  "suggested_hubs": []
}

AI can be wrong. Always verify against the paper.

AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1006/snmr.2000.0007
PubMed: 11270738

Read the original paper →

Related papers

← Back to the Research Library