Kinetic principles of chemical cross-link formation for protein-protein interactions.

Proteins play a central role in most biological processes within the cell, and deciphering how they interact is key to understand their function. Cross-linking coupled with mass spectrometry is an essential tool for elucidating protein-protein interactions (PPIs). Despite its importance, we still know surprisingly little about the principles that underlie the process of chemical cross-link formation itself and how it is influenced by different physicochemical factors.

Cell-Permeable Nicotinamide Adenine Dinucleotides for Exploration of Cellular Protein ADP-Ribosylation.

Posttranslational modifications (PTMs) greatly enhance the functional diversity of proteins, surpassing the number of gene-encoded variations. One intriguing PTM is ADP-ribosylation, which utilizes nicotinamide adenine dinucleotide (NAD) as a substrate and is essential in cell signaling pathways regulating cellular responses. Here, we report the first cell-permeable NAD analogs and demonstrate their utility for investigating cellular ADP-ribosylation.

A link between the steepest descent method and fixed-point iterations.

We will make a link between the steepest descent method for an unconstrained minimisation problem and fixed-point iterations for its Euler-Lagrange equation. In this context, we shall rediscover the preconditioned algebraic conjugate gradient method for the discretised problem. The benefit of the connection of those concepts will be illustrated by a numerical experiment.

[Second reading in breast cancer screening program: State of knowledge and future].

Second reading is an important part of breast cancer organized screening program. Image quality control and detection of non-diagnosed cancer by first reader are the two goals of this process. In France, 6 % of all screening cancer are diagnosed by second reading, actually done on screen film.