Real-time analysis of liquid jet sample delivery stability for an X-ray free-electron laser using machine vision.

Automated evaluation of optical microscopy images of liquid jets, commonly used for sample delivery at X-ray free-electron lasers (XFELs), enables real-time tracking of the jet position and liquid jet hit rates, defined here as the proportion of XFEL pulses intersecting with the liquid jet. This method utilizes machine vision for preprocessing, feature extraction, segmentation and jet detection as well as tracking to extract key physical characteristics (such as the jet angle) from optical microscopy images captured during experiments. To determine the effectiveness of these tools in monitoring jet stability and enhancing sample delivery efficiency, we conducted XFEL experiments with various sample compositions (pure water, buffer and buffer with crystals), nozzle designs and jetting conditions.

Genetic diversity and antibiotic resistance patterns of Escherichia coli isolates causing septicemia: A phylogenetic typing and PFGE analysis.

Introduction: This study aims to analyze clinical isolates of E. coli causing septicemia across various phylogroups utilizing the PFGE method.

Materials And Methods: A total of 100 clinical isolates were collected.

Crystal structure of a bacterial photoactivated adenylate cyclase determined by serial femtosecond and serial synchrotron crystallography.

OaPAC is a recently discovered blue-light-using flavin adenosine dinucleotide (BLUF) photoactivated adenylate cyclase from the cyanobacterium Oscillatoria acuminata that uses adenosine triphosphate and translates the light signal into the production of cyclic adenosine monophosphate. Here, we report crystal structures of the enzyme in the absence of its natural substrate determined from room-temperature serial crystallography data collected at both an X-ray free-electron laser and a synchrotron, and we compare these structures with cryo-macromolecular crystallography structures obtained at a synchrotron by us and others. These results reveal slight differences in the structure of the enzyme due to data collection at different temperatures and X-ray sources.

Hepatitis B vaccine responders show higher frequencies of CD8 effector memory and central memory T cells compared to non-responders.

Hepatitis B (HB) infection is a major global health problem. There is limited knowledge about HB vaccination-induced immune memory responses. We compared the frequency of CD8 memory T cell subsets between responders (RSs) and non-responders (NRs) to HB vaccination.