https://yingtongli.me/blog
2 posts
Science 50% · Tech 50%
Subscribe via RSS
PDFi is a simple tool for displaying the low-level structure of a PDF file in an interactive tree view. Arbitrary values can be modified or deleted. The motivation for PDFi is to allow modifying a PDF file in a precise, minimally invasive way; for example, to remove a portion of text or a watermark, without affecting the rest of the PDF file. Most naïve approaches to doing this involve converting the PDF file into a more editable file format, which introduces complexity and dependencies. For…
Warning! The intended audience of this article is medical professionals and students. I am not your doctor. This article is not medical advice. This article has not been subject to formal peer review. The model at https://yingtongli.me/blog/assets/posts/2026/vqmodel/ simulates a two-unit lung model where the two units may have different ventilation–perfusion (\(\dot{V}/\dot{Q}\)) ratios. The simulation demonstrates that, in the presence of \(\dot{V}/\dot{Q}\) mismatch, oxygenation is r...
