Determining the helical pitch and relative polarity of collagen using polarization-resolved SHG
Bibliographic record
Abstract
Collagen fibrils are nanoscale biological ropes which are the primary load bearing structures within the human body. Due to the non-centrosymmetric structure and high nonlinearity of the triple helical collagen molecule, collagen fibrils are able to produce significant second harmonic generation (SHG) when placed at the focus of an ultrafast laser. There have been many publications which have utilized polarization resolved SHG (PSHG) for investigating collagen organization in tissues, mainly for applications in disease diagnosis. However so far there has been little work on investigating individual isolated collagen fibrils using PSHG. This presents an exciting opportunity for research since PSHG imaging of individual fibrils can help us to gain a better understanding of PSHG images of collections of fibrils in tissues, and therefore improve the utility of PSHG as a potential diagnostic tool. Additionally, the high sensitivity of PSHG to changes in molecular structure can provide us with a better understanding of the nanoscale origins of injuries to tissues such as skin, tendons, and ligaments. Here we will review our recent work which has applied PSHG to study individual collagen fibrils, including investigation of how out of plane orientation affects PSHG images of collagen, and how differences in hydration alter collagen ultrastructure. We also present new data on the effect of applied tension on individual fibrils.
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) | 0.001 | 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 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".