Usability and Feasibility of PmEB: A Mobile Phone Application for Monitoring Real Time Caloric Balance

Obesity is a major public health challenge with over 65% of US adults either overweight or obese. Estimated annual costs of obesity are $78.5 billion. Self-monitoring is a critical skill for successful weight management. However, self-monitoring is labor-intensive, and compliance is often difficult. In this paper, the authors describe the Patient-Centered Assessment and Counseling Mobile Energy Balance (PmEB) mobile phone application that allows users to self-monitor caloric balance in real time. The application was developed and applied in a four-phase iterative research and development methodology. A usability study and a preliminary feasibility study were conducted. The 1 month feasibility study measured compliance and satisfaction among a sample of 15 participants randomized to one of three groups: (1) a paper diary group, (2) a PmEB group with one daily prompt, and (3) a PmEB group with three daily prompts. PmEB scored highly on usability, compliance, and satisfaction. In addition, mobile phone group users scored PmEB the same as or better than Paper Group members scored the paper diary in nearly all categories. Thematic analysis of comments revealed very positive reviews of PmEB as well as areas for improvement. PmEB is both usable and feasible for weight management self-monitoring, and the iterative pilot study methodology was effective in improving its usability.     

Epitaxial growth of zinc-blende AIN on Si(100) substrates by plasma source molecular beam epitaxy

Epitaxial zinc-blende AlN films were deposited on Si(100) substrates by plasma source molecular beam epitaxy (PSMBE). The lattice parameter of the zinc-blende AlN was determined to be 4.373Å. The epitaxial relationship between film and substrate was (100)AlN‖(100)Si and [011]AlN‖[011]Si. The zinc-blende AlN films were formed using a hollow cathode source with a pulse d.c. power supply in the PSMBE system. The high energy and large density of the Al⁺ and N⁺ species emerging from the hollow cathode and the presence of a substrate surface with cubic symmetry are probably the main factors for the formation of the metastable zinc-blende phase of AlN.     

Channel estimation in narrowband wireless communication systems

Channel estimation is an integral part of standard adaptive receiver designs used in narrowband, digital wireless communication systems. In this tutorial paper, commonly used approaches to channel estimation are reviewed. Both time‐invariant and time‐varying channels are considered. For time‐varying channels, both pilot symbol interpolation and data‐directed channel tracking are considered. Applications include the Global System for Mobile communications, the Enhanced Data rates for Global Evolution system, and another Time‐Division Multiple‐Access system known as Telecommunications Industry Association/Electronics Industry Association/Interim Standard—136 (TIA/EIA/IS‐136 or IS‐136). Copyright © 2001 John Wiley & Sons, Ltd.     

Cyclometalated iridium-coumarin ratiometric oxygen sensors: improved signal resolution and tunable dynamic ranges

In this work we introduce a new series of ratiometric oxygen sensors based on phosphorescent cyclometalated iridium centers partnered with organic coumarin fluorophores. Three different cyclometalating ligands and two different pyridyl-containing coumarin types were used to prepare six target complexes with tunable excited-state energies. Three of the complexes display dual emission, with fluorescence arising from the coumarin ligand, and phosphorescence from either the cyclometalated iridium center or the coumarin. These dual-emitting complexes function as ratiometric oxygen sensors, with the phosphorescence quenched under O₂ while fluorescence is unaffected. The use of blue-fluorescent coumarins results in good signal resolution between fluorescence and phosphorescence. Moreover, the sensitivity and dynamic range, measured with Stern–Volmer analysis, can be tuned two orders of magnitude by virtue of our ability to synthetically control the triplet excited-state ordering. The complex with cyclometalated iridium ³MLCT phosphorescence operates under hyperoxic conditions, whereas the two complexes with coumarin-centered phosphorescence are sensitive to very low levels of O₂ and function as hypoxic sensors.

Cyclometalated iridium(iii) coumarin complexes with improved signal resolution for ratiometric oxygen sensing are described. Dynamic ranges are tunable over >2 orders of magnitude.     

Pro-Inflammatory Interactions of Dolutegravir with Human Neutrophils in an In Vitro Study

There is increasing awareness of an association between the uptake of the HIV integrase inhibitor, dolutegravir, in first-line antiretroviral regimens with unusual weight gain and development of the metabolic syndrome, particularly in African women. Although seemingly unexplored, the development of systemic inflammation linked to the putative pro-inflammatory activity of dolutegravir represents a plausible pathophysiological mechanism of this unusual weight gain. This possibility was explored in the current study undertaken to investigate the effects of dolutegravir (2.5–20 μg/mL) on several pro-inflammatory activities of neutrophils isolated from the blood of healthy, adult humans. These activities included the generation of reactive oxygen species (ROS), degranulation (elastase release) and alterations in the concentrations of cytosolic Ca²⁺ using chemiluminescence, spectrophotometric and fluorimetric procedures, respectively. Exposure of neutrophils to dolutegravir alone resulted in the abrupt, dose-related, and significant (p < 0.0039–p < 0.0022) generation of ROS that was attenuated by the inclusion of the Ca²⁺-chelating agent, EGTA, or inhibitors of NADPH oxidase (diphenyleneiodonium chloride, DPI), phospholipase C (U733122), myeloperoxidase (sodium azide) and phosphoinositol-3-kinase (wortmannin). In addition, exposure to dolutegravir augmented the release of elastase by stimulus-activated neutrophils. These pro-inflammatory effects of dolutegravir on neutrophils were associated with significant, rapid, and sustained increases in the concentrations of cytosolic Ca²⁺ that appeared to originate from the extracellular compartment, seemingly consistent with an ionophore-like property of dolutegravir. These findings are preliminary and necessitate verification in the clinical setting of HIV infection. Nevertheless, given the complex link between inflammation and obesity, these pro-inflammatory interactions of dolutegravir with neutrophils may contribute to unexplained weight gain, possibly via the development of insulin resistance.     

Activity-based protein profiling in vivo using a copper(i)-catalyzed azide-alkyne [3 + 2] cycloaddition

Toward the goal of assigning function to the tens of thousands of protein products encoded by eukaryotic and prokaryotic genomes, the field of proteomics requires new technologies that can functionally characterize proteins within the dynamic environment of the cell, where these biomolecules are subject to myriad posttranslational modifications and the actions of endogenous activators and inhibitors. Here, we report an advanced strategy for activity-based protein profiling (ABPP) that addresses this important need. We show that several enzymes can be labeled in an activity-based manner both in vitro and in vivo by an azido-sulfonate ester probe and that these labeling events can be detected in whole proteomes by copper-catalyzed ligation with a rhodamine-alkyne reagent. This click chemistry-based strategy for ABPP represents a unique and versatile method for functional proteome analysis.     

Zum Nachweis und zur kolorimetrischen Bestimmung kleiner Eisenmengen

Ohne Zusammenfassung     

MASSPEC: a graphics-based data system for correlating a mass spectrum with a proposed structure

A graphics-based user-friendly data system called MASSPEC was developed to aid in the analysis of a mass spectrum when a proposed structure is provided. The proposed chemical structure is drawn and combinatorial algorithms correlate the masses of the substructures with the masses of the fragment ions observed in the mass spectrum. These substructures are subsequently drawn on the terminal screen. The commands and algorithms for operating MASSPEC are described. The MASSPEC data system can be used to interpret either nominal or exact mass data generated from relatively large molecules in any ionization mode. Illustrations utilizing MASSPEC include the interpretation of mass spectra generated on tandem mass spectrometers in the thermospray and fast atom bombardment (FAB) modes and the analysis of a FAB mass spectrum of a digested polypeptide to reveal post-translational modifications.