Induction of strand breaks by low-energy electrons (8–68eV) in a self-assembled monolayer of oligonucleotides: Effective cross sections and attenuation lengths
Bibliographic record
Abstract
Self-assembled monolayers of 5'-32P-labeled 3'-thiolated oligonucleotides chemisorbed on gold were bombarded by low-energy electrons (LEE) of 8-68 eV. Shorter 5'-32P-oligonucleotides produced by LEE-induced strand breaks were separated with denaturing polyacrylamide gel electrophoresis and quantified by phosphor imaging. The yields of short oligonucleotides (y) decrease exponentially with their length (n), following the equation y=ae-bn, where a and b are constants, which are related to the average effective cross section per nucleotide for DNA strand break (sigmaeff) and the attenuation length (AL=1b) of LEE, respectively. The AL decreases with LEE energies from 2.5+/-0.6 nm at 8 eV to 0.8+/-0.1 nm at 68 eV, whereas sigmaeff increases from (3+/-1)x10(-18) to (5.1+/-1.6)x10(-17) cm2 within the same energy range. The energy dependence of sigmaeff shows a resonance peak of (2.8+/-0.9)x10(-17) cm2 at 18 eV superimposed on a monotonically rising curve. Transient electron attachment to a sigma* anion state of the deoxyribose group, followed by dipolar dissociation into H- and the corresponding positive-ion radical, leading to C-O bond cleavage, is proposed to account for this maximum.
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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".