Identification of Constriction in Large versus Small Vessels using the Arterial-Venous and the Double-Occlusion Techniques in Isolated Canine Lungs
Bibliographic record
Abstract
By applying the arterial and venous occlusion technique and the double-occlusion technique in the isolated perfused dog left lower lobe, the total pressure gradient across the pulmonary vasculature can be partitioned into four segments: upstream arterial (delta Pa), precapillary (delta Pa'), postcapillary (delta Pv') and downstream venous (delta Pv). Changes in delta Pa and in delta Pv would result from constriction of the large arteries and veins, respectively, while changes in delta Pa' and delta Pv' would result from constriction of the smallest muscular arteries and veins. The results revealed that at the dosages used, serotonin and angiotensin II constricted the large arteries only. Histamine constricted the large and small veins, whereas norepinephrine constricted the large arteries and large veins. Hypoxia constricted primarily the precapillary vessels, and slightly the postcapillary vessels. Elevation of alveolar pressure relative to vascular pressure increased primarily the pressure gradient across the postcapillary vessels (delta Pv'), and to some extent, increased the pressure gradient across the precapillary vessels (delta Pa'). Thus the two techniques when applied together in the isolated lung can differentiate between constriction in large versus small vessels. Caution is recommended when extrapolating these results to other animal species, because the site of vasoconstriction may be different for a given substance.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".