Construction and Software Design for a Microcomputer Controlled pH/Ion Titrator

The construction of an automated titration device is described. The major components include an Apple II+ Microcomputer and 8-bit parallel interface. Fisher Accumet, Model 520 Digital pH/lon Meter, Gilmont Micrometer Buret of 2.5 mL capacity, Sigma stepper motor, power supply and driver to operate the buret, and a constant temperature bath of ± 0.005 °C stability. The limitations of the system are 0.001 pH/0.1 mv for the pH/ion sensing system, and 0.125 μL per step for the buret. The system as described is designed to determine equilibrium constants for metal ion-amino acid complexes. By changing the software a variety of different pH and redox titration experiments may be performed. A computer program used to operate the stepper motor driven syringe buret and record the pH from a digital pH meter is described. The program uses both Apple BASIC and assembly language. This is a closed loop operation in which the data from the pH meter is used to control the amount of reagent delivered by the buret. The results are displayed graphically as the titration proceeds. The variance of the pH readings are calculated using an assembly language subroutine and the calculations are done with zero round-off error

Controlled release of microencapsulated docosahexaenoic acid (DHA) by spray–drying processing

The omega-3-fatty acid, docosahexaenoic acid (DHA) 22:6 n-3, is an important food component for the visual and brain development of infants. In this study two approaches have been explored for the encapsulation of DHA in the pH dependant polymer hydroxyl-propyl-methyl-cellulose-acetate-succinate (HPMCAS). In the first approach Direct Spray Drying (DSD) was implemented for the microencapsulation of DHA/HPMCAS organic solutions, whilst in the second approach solid lipid nanoparticle (SLN) dispersions of DHA, were first produced by high-pressure homogenization, prior to being spray dried in HPMCAS aqueous solutions. The DSD approach resulted in significantly higher quantities of DHA being encapsulated, at 2.09 g/100 g compared to 0.60 g/100 g in the spray-dried SLNs. The DHA stability increased with the direct spray-drying approach. Release studies of DHA in the direct sprayed dried samples revealed a lag time for 2 h in acidic media followed by rapid release in phosphate buffer (pH 6.8)

The Magellanic Clouds Photometric Survey: The Large Magellanic Cloud Stellar Catalog and Extinction Map

We present our catalog of U, B, V, and I stellar photometry of the central 64 sq. deg. area of the Large Magellanic Cloud. Internal and external astrometric and photometric tests using existing optical photometry (U, B, and V from Massey's bright star catalog and I from the near-infrared sky survey DENIS) are used to confirm our observational uncertainty estimates. We fit stellar atmosphere models to the optical data to check the consistency of the photometry for individual stars across the passbands and to estimate the line-of-sight extinction. Finally, we use the estimated line-of-sight extinctions to produce an extinction map across the Large Magellanic Cloud, confirm the variation of extinction as a function of stellar population, and produce a simple geometrical model for the extinction as a function of stellar population.Comment: 7 pages (emulateapj), accepted for publication in the Astronomical Journa

The Impact of Urinary Urgency and Frequency on Health-Related Quality of Life in Overactive Bladder: Results from a National Community Survey

AbstractObjectivesOveractive bladder (OAB) is described as urinary urgency, with and without urge incontinence and usually with frequency and nocturia. Most attention to OAB's impact on health-related quality of life (HRQL), however, has focused on urge incontinence. The objective of this study was to evaluate the burden of OAB, specifically urinary urgency and frequency on HRQL.MethodsIn the National Overactive Bladder Evaluation Program (NOBLE), a computer-assisted telephone interview survey was conducted to assess the prevalence of OAB in the United States. Based on interview responses, respondents were classified into three groups: continent OAB, incontinent OAB, and controls. To evaluate the HRQL impact of OAB, HRQL questionnaires were mailed to all respondents with OAB and age- and sex-matched controls as a performed nested case–control study. Continuous data were compared using Student's t tests and analysis of variance with post hoc pairwise comparisons; results were adjusted for age, sex, and comorbid conditions. Multivariable regressions were performed to assess the impact of each urinary variable on symptom bother and HRQL.ResultsA total of 919 participants responded to the questionnaires (52% response rate) with a mean age of 54.2 years (SD 16.4 years); 70.4% were female and 85% were white. Continent OAB participants comprised 24.8% of the sample, incontinent OAB 18.3%, and controls 56.9%. In each regression analysis, urinary urge intensity accounted for the greatest variance for increases in symptom bother and decreases in HRQL.ConclusionsThe experience of urinary urgency has a significant negative effect on HRQL and increases symptom bother, an effect that, in this community sample, is greater than that of incontinence, frequency, or nocturia