Performance Evaluation of Open Channel Buhlmann Fecal Calprotectin Turbo Assay on Abbott Alinity C Analyzer.

Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the gastrointestinal (GI) tract. Fecal calprotectin (fCAL) is a noninvasive laboratory test used in the diagnosis and monitoring of IBDs such as Crohn's disease and ulcerative colitis. The fCAL send-out test that our facility has been offering so far uses an ELISA-based method.

Recent Recall of Iron Reagent-Investigation of Potential Reagent Contamination and Assay Improvement Strategy.

Background: Recently, a major manufacturer recalled several lots of iron assay reagent due to positive bias of roughly 15%-30% and the cause remains unknown. This study investigated the root cause of this positive bias and evaluated a simple practical approach to improve the assay.

Methods: Performance comparison of recalled and unimpacted iron assay kits was done utilizing calibrators, quality control (QC) materials, and 42 remnant patient samples.

An improved rhythmicity analysis method using Gaussian Processes detects cell-density dependent circadian oscillations in stem cells.

Motivation: Detecting oscillations in time series remains a challenging problem even after decades of research. In chronobiology, rhythms (for instance in gene expression, eclosion, egg-laying, and feeding) tend to be low amplitude, display large variations amongst replicates, and often exhibit varying peak-to-peak distances (non-stationarity). Most currently available rhythm detection methods are not specifically designed to handle such datasets, and are also limited by their use of P-values in detecting oscillations.

An improved rhythmicity analysis method using Gaussian Processes detects cell-density dependent circadian oscillations in stem cells.

Detecting oscillations in time series remains a challenging problem even after decades of research. In chronobiology, rhythms in time series (for instance gene expression, eclosion, egg-laying and feeding) datasets tend to be low amplitude, display large variations amongst replicates, and often exhibit varying peak-to-peak distances (non-stationarity). Most currently available rhythm detection methods are not specifically designed to handle such datasets.

Unraveling the mechanism of the cadherin-catenin-actin catch bond.

The adherens junctions between epithelial cells involve a protein complex formed by E-cadherin, β-catenin, α-catenin and F-actin. The stability of this complex was a puzzle for many years, since in vitro studies could reconstitute various stable subsets of the individual proteins, but never the entirety. The missing ingredient turned out to be mechanical tension: a recent experiment that applied physiological forces to the complex with an optical tweezer dramatically increased its lifetime, a phenomenon known as catch bonding.

Conformation of a flexible polymer in explicit solvent: Accurate solvation potentials for Lennard-Jones chains.

The conformation of a polymer chain in solution is coupled to the local structure of the surrounding solvent and can undergo large changes in response to variations in solvent density and temperature. The many-body effects of solvent on the structure of an n-mer polymer chain can be formally mapped to an exact n-body solvation potential. Here, we use a pair decomposition of this n-body potential to construct a set of two-body potentials for a Lennard-Jones (LJ) polymer chain in explicit LJ solvent.

Conformation of a flexible chain in explicit solvent: exact solvation potentials for short Lennard-Jones chains.

The average conformation of a flexible chain molecule in solution is coupled to the local solvent structure. In a dense solvent, local chain structure often mirrors the pure solvent structure, whereas, in a dilute solvent, the chain can strongly perturb the solvent structure which, in turn, can lead to either chain expansion or compression. Here we use Monte Carlo (MC) simulation to study such solvent effects for a short Lennard-Lones (LJ) chain in monomeric LJ solvent.