Structural features and kinetic characterization of alanine racemase from Staphylococcus aureus (Mu50)

The tertiary structure and kinetic properties of alanine racemase from Staphylococcus aureus are described and compared to other related alanine racemase structures

Meta-Analysis—Correlation between Spiral Ganglion Cell Counts and Speech Perception with a Cochlear Implant

The presence of spiral ganglion cells (SGCs) is widely accepted to be a prerequisite for successful speech perception with a cochlear implant (CI), because SGCs provide the only known conduit between the implant electrode and the central auditory system. By extension, it has been hypothesized that the number of SGCs might be an important factor in CI outcomes. An impressive body of work has been published on findings from the laborious process of collecting temporal bones from CI users and counting the number of SGCs to correlate those numbers with speech perception scores, but the findings thus far have been conflicting. We performed a meta-analysis of all published studies with the hope that combining existing data may help us reach a more definitive conclusion about the relationship between SGC count and speech perception scores in adults

Quantification of transient absorption in photo-reactive monolayers using reflectometry in the vicinity of Brewster angle

A method is presented that enables the determination of transient absorption in Langmuir films made from a monolayer of spiropyran on water. This is achievable even though the optical pathlength of such a monolayer is <10−9 m. The approach is to monitor reflectivity changes close to the Brewster angle, where the background of reflected light is minimized. This is the key to the sensitivity of the method. Relatively speaking the small changes in reflectivity due to changes in both real and imaginary parts of the refractive index are easier to observe with the intrinsically low backgrounds at the Brewster angle. Notably using Fresnel equations we can show that the real and imaginary parts of the refractive index can be independently assessed for ultrathin films and monolayers using the approach presented

Low-cost vector network analyzer for communication devices testing - brief review

A low-cost and portable one-port vector network analyzer (VNA) which covered operating frequency between 50 MHz to 1 GHz is developed for vector reflection coefficient measurement of the communication devices. A four-port reflectometry technique is implemented in the VNA module design. To collect and analyze data from the VNA, graphical user interface (GUI) is designed using LABVIEW software. In addition, open-short-load calibration technique was programmed in GUI to counterbalance systematic errors of the VNA. The performance of this designed VNA is approximately equivalent to the available commercial VNA

Surface analysis of lipids by mass spectrometry: More than just imaging

Mass spectrometry is now an indispensable tool for lipid analysis and is arguably the driving force in the renaissance of lipid research. In its various forms, mass spectrometry is uniquely capable of resolving the extensive compositional and structural diversity of lipids in biological systems. Furthermore, it provides the ability to accurately quantify molecular-level changes in lipid populations associated with changes in metabolism and environment; bringing lipid science to the "omics" age. The recent explosion of mass spectrometry-based surface analysis techniques is fuelling further expansion of the lipidomics field. This is evidenced by the numerous papers published on the subject of mass spectrometric imaging of lipids in recent years. While imaging mass spectrometry provides new and exciting possibilities, it is but one of the many opportunities direct surface analysis offers the lipid researcher. In this review we describe the current state-of-the-art in the direct surface analysis of lipids with a focus on tissue sections, intact cells and thin-layer chromatography substrates. The suitability of these different approaches towards analysis of the major lipid classes along with their current and potential applications in the field of lipid analysis are evaluated. © 2013 Elsevier Ltd. All rights reserved