Synthesis of Building Blocks and Oligonucleotides with {T}N<sup>3</sup>‐Alkylene‐N<sup>3</sup>{T} Cross‐Links
Bibliographic record
Abstract
This unit describes two methods to directly prepare oligonucleotide duplexes containing an N3thymidine-alkylene-N3thymidine inter-strand cross-link. The inter-strand cross-link can be engineered into the duplex with a number of possible orientations. Both methods require the preparation of a protected thymidine dimer where the N3 atoms of the two nucleosides are covalently attached by an alkyl linker. This linker is prepared starting from a protected diol using two successive alkylation reactions under basic conditions to accomplish the alkylation selectively at the N3 atom of the nucleoside. The chain length of the cross-link can be varied based on the selection of the diol used in the dimer synthesis. The solid-phase mono-phosphoramidite approach involves oligonucleotide synthesis with 3'-O-phosphoramidites, on-column removal of a 3'-O-tert-butyldimethylsilyl protecting group, and continued oligonucleotide synthesis with 5'-O-phosphoramidites. The bis-phosphoramidite approach does not require synthesis with 5'-O-phosphoramidites. At the end of synthesis using either method, the N3thymidine-alkylene-N3thymidine inter-strand cross-linked oligonucleotides can be removed from the solid-support and purified using standard techniques (ion-exchange HPLC) in yields sufficient for various structural studies and repair assays.
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 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 | 0.000 |
| 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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.002 |
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".