Measurement of brain glutamate and glutamine by spectrally‐selective refocusing at 3 tesla
Bibliographic record
Abstract
A new single-voxel proton NMR spectrally-selective refocusing method for measuring glutamate (Glu) and glutamine (Gln) in the human brain in vivo at 3T is reported. Triple-resonance selective 180 degrees RF pulses with a bandwidth of 12 Hz were implemented within point-resolved spectroscopy (PRESS) for selective detection of Glu or Gln, and simultaneous acquisition of creatine singlets for use as a reference in phase correction. The carriers of the spectrally-selective 180 degrees pulses and the echo times (TEs) were optimized with both numerical and experimental analyses of the filtering performance, which enabled measurements of the target metabolites with negligible contamination from N-acetylaspartate and glutathione. The concentrations of Glu and Gln in the prefrontal cortex were estimated to be 9.7+/-0.5 and 3.0+/-0.7 mM (mean+/-SD, N=7), with reference to Cr at 8 mM.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".