Equilibria and microorganism studies with analytical separation technique

The applications of analytical techniques to evaluate solute-ligand interactions and to analyze microbiological samples are discussed in this work. The dissertation is organized into two sections based on the natural division of studies done in the past several years. Part I includes studies involving the estimation of binding constants and partition coefficients and the modeling of pseudophase gas-liquid chromatography. The binding of solutes to pseudophases, such as micelles and cyclodextrins, is an important phenomenon in numerous areas of chemistry. Here, the ability of various native and derivatized cyclodextrins to sequester oral malodorous compounds and other volatile solutes was examined by measuring their association constants. Numerous techniques were utilized to determine the solute-cyclodextrin affinities. The results of this study indicate that cyclodextrins are capable of binding with a wide variety of oral malodorous compounds to varying degrees. The equations used in this study were then developed further and applied to the separation of several enantiomers using a methylated-cyclodextrin/polysiloxane stationary phase. These calculations allow the contributions from all three solute equilibria to retention and selectivity to be measured. This work was then extended to micellar/ionic liquid gas-liquid chromatography stationary phases, and the Abraham solvation parameter model was used in order to deconvolute the types of interactions responsible for analyte partitioning to these two phases. Part II of this dissertation focuses on the work done on the development of a rapid capillary electrophoretic sterility test. This technique coalesces all cells in a sample into a single peak and removes them from potential interferences in the sample matrix. Cationic surfactants were used in the run buffer to impart charge onto the microorganisms and sweep them out of the sample zone, while a plug of blocking agent induced cellular aggregation and negated the cells\u27 electrophoretic mobility. A wide variety of bacteria are compatible with this method, and analysis times are typically less than 10 minutes. Single cell detection was accomplished via laser-induced fluorescence detection and fluorescent cell staining. By coupling this capillary electrophoresis method with fluorescence in situ hybridization, a method that utilizes fluorescently tagged nucleic acid probes to selectively stain specific microorganism species or classes, identification of microbial contaminants was achieved

Capillary Electrophoresis Based Microbial Detection and Separation

Capillary Electrophoresis (CE) represents a significant tool for the separation of microorganisms as well as the detection and isolation of Candida albicans (CA) fungus in human blood. There currently exists few rapid means by which biological pathogens can be tested, at low concentration, in blood, and other organic matrices. Other common chromatographic techniques, such as GC, HPLC, IR and MS do not have the capability of analyzing living microorganisms, nor the ability to separate them with any precision. CE offers the rare opportunity to separate individual cells by the charge to size ratio as well as their isoelectric focusing point (pI). Candida albicans fungi was successfully focused and detected in prepared blood samples using surfactant buffer additives to control the cells’ surface charge. A second method was developed using capillary isoelectric focusing to separate bacteria species, namely Bacillus subtilis, Pseudomonas fluorescens, and Escherichia coli. The method with which fungus and many other pathogens can be isolated, developed through this study, shows the potential for complete separation cell types within the capillary. These methods will be carried on through further studies of microbial separation using CE and refined

Socioeconomic indicators that matter for population health

Increasing research and policy attention is being given to how the socioeconomic environment influences health. This article discusses potential indicators or metrics regarding the socioeconomic environment that could play a role in an incentive-based system for population health. Given the state of the research regarding the influence of socioeconomic contextual variables on health outcomes, the state of data and metrics for these variables at the local level, and the potential for program and policy intervention, we recommend a set of metrics related to the socioeconomic composition of a community (including poverty, unemployment, and public assistance rates); educational attainment and achievement; racial segregation; and social-capital indicators such as density of voluntary organizations and voter turnout. These indicators reflect the evidence that population health gains depend on improvements in many of the fundamental social determinants of health, including meaningful employment, income security, educational opportunities, and engaged, active communities

Renewable Acrylic Acid

Acrylic acid is an important industrial chemical, used as a raw material in a wide variety of consumer end products. The present predominant source of acrylic acid is from the partial oxygenation of propene, produced as a by-product in the industrial production of ethylene and gasoline. Both processes depend heavily on the processing of petrochemicals as the base raw material. The purpose of this process is to produce acrylic acid from renewable carbon sources (such as corn or sugarcane) in an economically preferential manner. Our process has used genetically recombinant Escherichia coli (E. coli) to ferment the carbohydrate content of the proposed feedstock to 3-hydroxypropionic acid (3-HP) which is then dehydrated in the presence of strong acid catalyst (phosphoric acid) to form acrylic acid. The acrylic acid is then purified to the standard required for use as a polymer raw material (99.98% by mass) with total capacity of 160,000 MT/year of product. This design analyzes two proposed locations, the US Midwest or Brazil, and their associated renewable feedstocks, corn or sugarcane juice, respectively. This report investigates the relative economic attractiveness of each option. The US case requires location near an existing industrial ethanol fermentation plant to give easy access to dry-ground corn as a carbohydrate source. This case yields an IRR of 17.56% and an overall NPV of $35.2 million at a 15% discount rate. The Brazil case has comparatively cheaper feedstock, however because of seasonality and total usable carbohydrate content, it requires a greater mass of feedstock and increased capital investment relative to the US case. The NPV difference of the two cases is extremely sensitive to the assumed price of sugarcane juice which has recently shown extraordinary volatility. Based on this analysis, the US location seems most promising; however, detailed laboratory level studies are needed to confirm the profitability and assumptions made

Theory and Use of the Pseudophase Model in Gas−Liquid Chromatographic Enantiomeric Separations

The theory and use of the “three-phase” model in enantioselective gas−liquid chromatography utilizing a methylated cyclodextrin/polysiloxane stationary phase is presented for the first time. Equations are derived that account for all three partition equilibria in the system, including partitioning between the gas mobile phase and both stationary-phase components and the analyte equilibrium between the polysiloxane and cyclodextrin pseudophase. The separation of the retention contributions from the achiral and chiral parts of the stationary phase can be easily accomplished. Also, it allows the direct examination of the two contributions to enantioselctivity, i.e., that which occurs completely in the liquid stationary phase versus the direct transfer of the chiral analyte in the gas phase to the dissolved chiral selector. Six compounds were studied to verify the model:  1-phenylethanol, α-ionone, 3-methyl-1-indanone, o-(chloromethyl)phenyl sulfoxide, o-(bromomethyl)phenyl sulfoxide, and ethyl p-tolylsulfonate. Generally, the cyclodextrin component of the stationary phase contributes to retention more than the bulk liquid polysiloxane. This may be an important requirement for effective GC chiral stationary phases. In addition, the roles of enthalpy and entropy toward enantiorecognition by this stationary phase were examined. While enantiomeric differences in both enthalpy and entropy provide chiral discrimination, the contribution of entropy appears to be more significant in this regard. The three-phase model may be applied to any gas−liquid chromatography stationary phase involving a pseudophase

Koinonia

Spotlight FeaturesSovereign Stumbling: My Life Journey to Date, Larry Crabb Conversations About Racism, Jessie Brown Anxiety: A Growing Problem in College Students, Steven M. Conn Thinking TheologicallyTeaching the Truth, Michael and Stephanie Santarosa Book ReviewsKingdom Triangle: Recover the Christian Mind, Renovate the Soul, Restore the Spirit\u27s Power (by J.P. Moreland), reviewed by Steve Ivester The Soul of a Christian University: A Field Guide for Educators (edited by Stephen T. Beers), reviewed by Kyle Lantz The Outrageous Idea of Academic Faithfullness (by Donald Opitz and Derek Melleby), reviewed by Nathan Geer I Once Was Lost: What Postmodern Skeptics Taught Us About Their Path to Jesus (by Don Everts and Doug Schaupp), reviewed by Andrew D. Rowell FeaturesThe President\u27s Corner Editor\u27s Deskhttps://pillars.taylor.edu/acsd_koinonia/1012/thumbnail.jp

Erythropoietin Does Not Enhance Skeletal Muscle Protein Synthesis Following Exercise in Young and Older Adults

PURPOSE: Erythropoietin (EPO) is a renal cytokine that is primarily involved in hematopoiesis while also playing a role in non-hematopoietic tissues expressing the EPO-receptor (EPOR). The EPOR is present in human skeletal muscle. In mouse skeletal muscle, EPO stimulation can activate the AKT serine/threonine kinase 1 (AKT) signaling pathway, the main positive regulator of muscle protein synthesis. We hypothesized that a single intravenous EPO injection combined with acute resistance exercise would have a synergistic effect on skeletal muscle protein synthesis via activation of the AKT pathway. METHODS: Ten young (24.2 ± 0.9 years) and 10 older (66.6 ± 1.1 years) healthy subjects received a primed, constant infusion of [ring-13C(6)] L-phenylalanine and a single injection of 10,000 IU epoetin-beta or placebo in a double-blind randomized, cross-over design. 2 h after the injection, the subjects completed an acute bout of leg extension resistance exercise to stimulate skeletal muscle protein synthesis. RESULTS: Significant interaction effects in the phosphorylation levels of the members of the AKT signaling pathway indicated a differential activation of protein synthesis signaling in older subjects when compared to young subjects. However, EPO offered no synergistic effect on vastus lateralis mixed muscle protein synthesis rate in young or older subjects. CONCLUSIONS: Despite its ability to activate the AKT pathway in skeletal muscle, an acute EPO injection had no additive or synergistic effect on the exercise-induced activation of muscle protein synthesis or muscle protein synthesis signaling pathways

The effect of acute sleep deprivation on skeletal muscle protein synthesis and the hormonal environment

Chronic sleep loss is a potent catabolic stressor, increasing the risk of metabolic dysfunction and loss of muscle mass and function. To provide mechanistic insight into these clinical outcomes, we sought to determine if acute sleep deprivation blunts skeletal muscle protein synthesis and promotes a catabolic environment. Healthy young adults (N = 13; seven male, six female) were subjected to one night of total sleep deprivation (DEP) and normal sleep (CON) in a randomized cross-over design. Anabolic and catabolic hormonal profiles were assessed across the following day. Postprandial muscle protein fractional synthesis rate (FSR) was assessed between 13:00 and 15:00 and gene markers of muscle protein degradation were assessed at 13:00. Acute sleep deprivation reduced muscle protein synthesis by 18% (CON: 0.072 ± 0.015% vs. DEP: 0.059 ± 0.014%·h-1, p =.040). In addition, sleep deprivation increased plasma cortisol by 21% (p =.030) and decreased plasma testosterone by 24% (p =.029). No difference was found in the markers of protein degradation. A single night of total sleep deprivation is sufficient to induce anabolic resistance and a procatabolic environment. These acute changes may represent mechanistic precursors driving the metabolic dysfunction and body composition changes associated with chronic sleep deprivation

Recipient mucosal-associated invariant T cells control GVHD within the colon

Mucosal-associated invariant T (MAIT) cells are a unique innate-like T cell subset that responds to a wide array of bacteria and yeast through recognition of riboflavin metabolites presented by the MHC class I–like molecule MR1. Here, we demonstrate using MR1 tetramers that recipient MAIT cells are present in small but definable numbers in graft-versus-host disease (GVHD) target organs and protect from acute GVHD in the colon following bone marrow transplantation (BMT). Consistent with their preferential juxtaposition to microbial signals in the colon, recipient MAIT cells generate large amounts of IL-17A, promote gastrointestinal tract integrity, and limit the donor alloantigen presentation that in turn drives donor Th1 and Th17 expansion specifically in the colon after BMT. Allogeneic BMT recipients deficient in IL-17A also develop accelerated GVHD, suggesting MAIT cells likely regulate GVHD, at least in part, by the generation of this cytokine. Indeed, analysis of stool microbiota and colon tissue from IL-17A–/– and MR1–/– mice identified analogous shifts in microbiome operational taxonomic units (OTU) and mediators of barrier integrity that appear to represent pathways controlled by similar, IL-17A–dependent mechanisms. Thus, MAIT cells act to control barrier function to attenuate pathogenic T cell responses in the colon and, given their very high frequency in humans, likely represent an important population in clinical BMT

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes