Polar organic chemical integrative sampler (POCIS) is a passive sampling device that offers many advantages over traditional discrete sampling methods, but quantitative time-weighted average (TWA) ...concentrations rely heavily on the robustness of sampling rates. The effects of changing chemical concentration exposures on POCIS sampling rates and its ability to operate in an integrative regime were investigated for 12 pesticides across a range of environmentally relevant concentrations. In five independent 21-day experiments, POCIS devices were exposed to these compounds at constant concentrations ranging from 3 to 60 μg/L and multiple pulsed concentrations with maximum peaks ranging from 5 to 150 μg/L (TWA concentrations = 3 to 92 μg/L). For the 21-day exposures to constant and pulsed concentrations, there were no significant differences in the POCIS sampling rates between corresponding TWA concentrations. Similarly, there was no significant effect on POCIS ability to operate in an integrative regime. However, loss of linearity was visible for some replicates when exposed to higher pulsed concentrations over an extended period. Modeling and Freundlich isotherms did not predict sorbent saturation, but the extraction and reconstitution protocol likely contributed to atrazine dissolution and subsequent underestimation of sorbed chemical mass when HLB adsorption exceeded 400 μg.
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IJS, KILJ, NUK, PNG, UL, UM
Concept maps are graphical representations of how various concepts relate to one another. Assessment of concept maps developed by students in the pharmacy curriculum helps to evaluate student ...understanding of course material. However, providing feedback on concept maps can be time-consuming and often requires the grader to be a content expert. The purpose of this study was to develop and validate a software program to provide students with feedback on their concept map performance. Student maps for four different disease states were compared against expert concept maps. The analysis of the program compared favorably to a manual assessment of student maps for the maps' complexity and content but did not correlate for their organization. The value of using a software program to quickly and efficiently analyze concept maps is discussed.
► Recognition mechanism of zwitterionic chiral selectors elaborated for peptides. ► Electrospray MS data complements prior HPLC work and adds new insight. ► Significant diastereoselective binding and ...discrimination for biorelevant peptides. ► Systematic variation of binding increments to elucidate binding mechanisms.
Electrospray ionization-mass spectrometry (ESI-MS) was used to investigate stereoselective interactions between seven zwitterionic alkylsulfonate-modified cinchona alkaloid chiral selectors and biologically relevant lysine–alanine–alanine tripeptide and alanine–alanine dipeptide selectands in modified methanolic solutions. Ion intensities from full scan mass spectra were used to assess degrees of association, the ratios of which were used to calculate selectivities for different selector–selectand pairs. The results support prior work on similar systems using HPLC, in that binding is mediated in these systems primarily through the quinuclidine amine on the selector and the C-terminal carboxylate of the peptide. Nα- and Nα, Nɛ-acetylated forms of the tripeptide were used to study the relative contribution to binding imparted by the presence of multiple basic amines on the tripeptide with the selectors; this was not previously investigated by HPLC. The ability of the sulfonate group on the selector to reach and preferentially interact with the Nɛ-amine on the side chain of lysine was revealed. Overall, in acidic methanol conditions (0.5% acetic acid), degrees of association ranged from 1.5% to 17%, and selectivities ranged from non-selective to a 5.5:1 preference for binding one peptide stereoisomer over another with a given chiral selector. In sodium acetate (100μM)-modified methanol solutions, significant changes in degrees of association (ranging from 4% to 25%) and selectivities (ranging from non-selective to 4.2:1 preference) were observed. These mass spectrometry experiments help to clarify the chiral recognition mechanism for these selectors and suggest that retention and selectivity could be further modulated in HPLC experiments through the utilization of alkali salt-containing mobile phases.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The efficacy and tolerability of alosetron in women with diarrhea-predominant irritable bowel syndrome (IBS) have been established in double-blind, placebo-controlled trials. However, the degree to ...which alosetron fulfills the needs of those suffering from IBS has not been thoroughly examined from the patient's perspective. This randomized, double-blind, placebo-controlled study conducted in women with diarrhea-predominant IBS evaluated patients' overall satisfaction with treatment as well as their satisfaction with respect to several specific medication attributes.
Patients randomized to receive either alosetron 1 mg b.id. (n = 532) or placebo (n = 269) were administered a questionnaire on which they rated on 7-point Likert scales their prestudy IBS treatment (at the screening visit) or study medication (on wk 12 or final study visit) with respect to overall satisfaction and 11 specific medication attributes.
Whereas approximately 10% of patients were satisfied or very satisfied overall with prestudy IBS medication, 69% of patients were satisfied or very satisfied overall with alosetron and 46% with placebo (p < 0.001) at the end of 12 wk of therapy. The majority of alosetron-treated patients (61-87%) were satisfied or very satisfied with each of 11 specific medication attributes (p < 0.001 vs placebo for each attribute). Favorable satisfaction ratings for alosetron were assigned to the five medication attributes that patients considered to be most important, including relief of urgency (68% alosetron vs 41% placebo), speed of relief (71% vs 40%), time to return to normal activities (75% vs 49%), relief of abdominal pain (62% vs 44%), and prevention of return of urgency (68% vs 42%).
Women with diarrhea-predominant IBS are satisfied with alosetron 1 mg b.i.d. treatment overall and also with respect to specific attributes of IBS medication they consider most important.
We determined effective concentration ranges for carbonic acid as an anesthetic for rainbow trout Oncorhynchus mykiss across a wide range of water temperatures and alkalinities. Effective ...concentrations were based on criteria for induction time (<3 min), recovery time (<10 min), and 72‐h survival (100%). Induction time decreased and recovery time increased with increasing concentration. Mortalities were associated with high concentrations of carbonic acid, and all occurred during exposure to anesthetic (no delayed mortality was observed within 72 h). Although the effective concentration range was roughly equal in width across temperatures, the limits of the effective concentration range decreased as temperature increased. We found no difference in effective concentration ranges for high‐ and low‐alkalinity waters at similar temperatures. Recovery times were longer in low‐alkalinity water but met our efficacy criteria. The results can be used to estimate effective carbonic acid concentrations for anesthetizing rainbow trout, to minimize induction and recovery times, and to prevent mortality.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
77.
Sonic Boom: Six Decades of Research Maglieri, Domenic J; Bobbitt, Percy J; Plotkin, Kenneth J ...
NASA Center for AeroSpace Information (CASI). Reports,
12/2014
Report
Sonic booms generated by aircraft traveling at supersonic speeds have been the subject of extensive aeronautics research for over 60 years. Hundreds of papers have been published that document the ...experimental and analytical research conducted during this time period. The purpose of this publication is to assess and summarize this work and establish the state-of-the-art for researchers just entering the field, or for those interested in a particular aspect of the subject. This publication consists of ten chapters that cover the experimental and analytical aspects of sonic boom generation, propagation and prediction with summary remarks provided at the end of each chapter. Aircraft maneuvers, sonic boom minimization, simulation techniques and devices as well as human, structural, and other responses to sonic booms are also discussed. The geometry and boom characteristics of various low-boom concepts, both large civil transports and smaller business-jet concepts, are included. The final chapter presents an assessment of civilian supersonic overland flight and highlights the need for continued research and a low-boom demonstrator vehicle. Summary remarks are provided at the end of each chapter. The studies referenced in this publication have been drawn from over 500 references.
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