Structure and Magnetic Properties of L-α-Alanine Radicals in Radiation Dosimetry Applications: An Ab Initio Molecular Dynamics Simulation
Bibliographic record
Abstract
Alanine is a transfer standard dosimeter using in gamma-ray and electron beam calibration. One of the important factor affecting its dosimetric response is amount of humidity which can deviate the dosimetry expert from the exact value of absorbed doses. Ab initio molecular dynamics calculations were performed to determine the environmental effects on the EPR parameters of L-α-Alanine radicals in acidic and alkaline solutions. Similar to the closed-shell amino acid molecule alanine, the zwitterionic form of alanine radical is the stable form in the gas phase while the non-zwitterionic neutral alanine radical is not a stable structure. Geometric and EPR parameters of radicals in both gas and solution phases are found to be dependent on hydrogen bonding of water molecules with the polar groups and by dynamic solvation. Calculations on the optimized free radicals in the gas phase revealed that for neutral radical, hydrogen bonding to water molecules drives a decrease in the magnitudes of g-tensor components gxx and gyy without affecting neither gzz component nor the HFCCs. For the transfer from the gas to solution phase of the alanine radical anion is accompanied with an increase in the spin density on the carboxylic group’s oxygen atoms. However, for the neutral radical, this transfer from gas to solution phase is accompanied with the decrease in the spin density on oxygen atoms. Calculated isotropic HFCCs and g-tensor of all radicals were in good agreement with their experimental counterparts in both acidic and alkaline solutions, which enhances the confidence in our calculated results.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 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 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".