Determination of sulpiride by capillary electrophoresis with end-column electrogenerated chemiluminescence detection

Background: Capillary electrophoresis (CE) with tris(2,2'-bipyridyl)ruthenium(II) [Ru(bpy)(3)(2+)]-electro-generated chemiluminescence (ECL) detection is a promising method for clinical analysis. In this study, a method combining CE with Ru(bpy)(3)(2+) ECL (CE-ECL) detection that can be applied to amine-containing clinical species was developed, and the performance of CE-ECL as a quantitative method for determination of sulpiride in human plasma or urine was evaluated. Methods: Sulpiride was separated by capillary zone electrophoresis in uncoated fused-silica capillaries [510 cm x 25 mum (i.d.)] filled with phosphate buffer (pH 8.0 and a driving voltage of +15 kV, with end-column Ru(bpy)(3)(2+) ECL detection. A platinum disc electrode was used as working electrode. Sulpiride in human plasma or urine samples (100 muL) was extracted by a double-step liquid-liquid extraction procedure, dried under nitrogen at 35 degreesC in a water bath, and reconstituted with 100 muL of filtered water. The extraction solvent was ethyl acetate-dichloromethane (5:1 by volume). Results: Under optimum conditions (pH 8.0 phosphate buffer, injection for 6 s at 10 kV, and +1.2 V as detection potential), separation of sulpiride was accomplished within 4 min. The calibration curve was linear over a concentration range of 0.05-25.0 mumol/L, and the limit of detection was 2.9 x 10(-8) mol/L for sulpiride. Intra- and interday CVs for ECL intensities were <6%. Extraction recoveries of sulpiride were 95.6-101% with CVs of 2.9-6.0%. The method was,clinically validated for patient plasma and urine samples. Conclusions: CE combined with Ru(bpy)(3)(2+) ECL is reproducible, precise, selective, and enables the analysis of sulpiride in human plasma and urine. It thus is of value for rapid and efficient analysis of amine-containing analytes of clinical interest.

Chemiluminescence determination of trace ascorbic acid with chromium (VI)-H2O2-luminol system

A new chemiluminescence(CL) system for the determination of ascorbic acid has been established. By the fast reduction reaction between chromium(VI) and ascorbic acid, chromium(M was generated to react with luminol and hydrogen peroxide in alkaline aqueous solution and hydrogen peroxide to produce CL. The CL emission intensity was correlated with ascorbic acid concentration in the range 8.0 x 10(-9) to 1.6 x 10(-4) mol/L, and the detection limit was 8.0 x 10(-9) mol/L ascorbic acid. The relative standard deviation (n = 11) for 1.0 x 10(-6) mol/L ascorbic acid is 0.9%. The method has been applied to the determination of ascorbic acid in vitamin C tablets with satisfactory results.

Evaluation of luminol-H2O2-KIO4 chemiluminescence system and its application to hydrogen peroxide, glucose and ascorbic acid assays

(A) novel chemiluminescence (CL) system was evaluated for the determination of hydrogen peroxide, glucose and ascorbic acid based on hydrogen peroxide, which has a catalytic-cooxidative effect on the oxidation of luminol by KIO4. Hydrogen peroxide can be directly determined by luminol-KIO4 -H2O2 CL system. The detection limit was 3.0 x 10(-8) mol l(-1) and the calibration graph was linear over the range of 2.0 x 10(-7)-6.0 x 10(-4) mol l(-1). The relative standard deviation of H2O2 was 1.1% for 2.0 x 10(-6) mol l(-1) (N = 11). Glucose was indirectly determined through measuring the H2O2 generated by the oxidation of glucose in the presence of glucose oxidase at pH 7.6. The present method provides a source for H2O2, which, in turn, coupled with the luminol-KIO4-H2O2 CL reaction system. The CL was linearly correlated with glucose concentration of 0.6-110 mu g ml(-1). The relative standard deviation was 2.1% for 10 mu g ml(-1) (N = 11). Detection limit of glucose was 0.08 mu g ml(-1). Ascorbic acid was also indirectly determined by the suppression of luminol-KIO4-H2O2 CL system. The calibration curve was linear over the range of 1.0 x 10(-7)-1.0 x 10(-5) mol l(-1) of ascorbic acid. The relative standard deviation was 1.0% for 8.0 x 10(-7) mol l(-1) (N = 11). Detection limit of ascorbic acid was 6.0 x 10(=8) mol l(-1). These proposed methods have been applied to determine glucose, ascorbic acid in tablets and injection. (C) 1999 Elsevier Science B.V. All rights reserved.

Automated, high performance, flow-through chemiluminescence microarray for the multiplexed detection of phycotoxins

A novel multiplexed immunoassay for the analysis of phycotoxins in shellfish samples has been developed. Therefore, a regenerable chemiluminescence (CL) microarray was established which is able to analyze automatically three different phycotoxins (domoic acid (DA), okadaic acid (OA) and saxitoxin (STX)) in parallel on the analysis platform MCR3. As a test format an indirect competitive immunoassay format was applied. These phycotoxins were directly immobilized on an epoxy-activated PEG chip surface. The parallel analysis was enabled by the simultaneous addition of all analytes and specific antibodies on one microarray chip. After the competitive reaction, the CL signal was recorded by a CCD camera. Due to the ability to regenerate the toxin microarray, internal calibrations of phycotoxins in parallel were performed using the same microarray chip, which was suitable for 25 consecutive measurements. For the three target phycotoxins multi-analyte calibration curves were generated. In extracted shellfish matrix, the determined LODs for DA, OA and STX with values of 0.5±0.3 µg L(-1), 1.0±0.6 µg L(-1), and 0.4±0.2 µg L(-1) were slightly lower than in PBS buffer. For determination of toxin recoveries, the observed signal loss in the regeneration was corrected. After applying mathematical corrections spiked shellfish samples were quantified with recoveries for DA, OA, and STX of 86.2%, 102.5%, and 61.6%, respectively, in 20 min. This is the first demonstration of an antibody based phycotoxin microarray.

The Scored Patient-Generated Subjective Global Assessment (PG-SGA) and its Association with Quality of Life in Ambulatory Patients Receiving Radiotherapy

OBJECTIVE: To evaluate the scored Patient-generated Subjective Global Assessment (PG-SGA) tool as an outcome measure in clinical nutrition practice and determine its association with quality of life (QoL). DESIGN: A prospective 4 week study assessing the nutritional status and QoL of ambulatory patients receiving radiation therapy to the head, neck, rectal or abdominal area. SETTING: Australian radiation oncology facilities. SUBJECTS: Sixty cancer patients aged 24-85 y. INTERVENTION: Scored PG-SGA questionnaire, subjective global assessment (SGA), QoL (EORTC QLQ-C30 version 3). RESULTS: According to SGA, 65.0% (39) of subjects were well-nourished, 28.3% (17) moderately or suspected of being malnourished and 6.7% (4) severely malnourished. PG-SGA score and global QoL were correlated (r=-0.66, P<0.001) at baseline. There was a decrease in nutritional status according to PG-SGA score (P<0.001) and SGA (P<0.001); and a decrease in global QoL (P<0.001) after 4 weeks of radiotherapy. There was a linear trend for change in PG-SGA score (P<0.001) and change in global QoL (P=0.003) between those patients who improved (5%) maintained (56.7%) or deteriorated (33.3%) in nutritional status according to SGA. There was a correlation between change in PG-SGA score and change in QoL after 4 weeks of radiotherapy (r=-0.55, P<0.001). Regression analysis determined that 26% of the variation of change in QoL was explained by change in PG-SGA (P=0.001). CONCLUSION: The scored PG-SGA is a nutrition assessment tool that identifies malnutrition in ambulatory oncology patients receiving radiotherapy and can be used to predict the magnitude of change in QoL.

User-Generated Content als Qualitätsmedium? Alternative Anreize für Qualitätscontent

Angetrieben und unterstützt durch Web-2.0-Technologien, gibt es heute einen Trend zur Verbindung der Nutzung und Produktion von Inhalten als Produtzung (engl. produsage ). Um dabei die Qualität der erstellten Inhalte und eine nachhaltige Teilnahme der Nutzer sicherzustellen, müsen vier grundlegende Prinzipien eingehalten werden: * Größtmögliche Offenheit. * Ankurbeln der Gemeinschaft durch Inhalte und Hilfsmittel. * Unterstützung der Gruppendynamik und Abtretung von Verantwortung. * Keine Ausbeutung der Gemeinschaft und ihrer Arbeit.

Vitreous cryopreservation of nanofibrous tissue-engineered constructs generated using mesenchymal stromal cells

Development of an effective preservation strategy to fulfill off-the-shelf availability of tissue-engineered constructs (TECs) is demanded for realizing their clinical potential. In this study, the feasibility of vitrification, ice-free cryopreservation, for precultured ready-to-use TECs was evaluated. To prepare the TECs, bone marrow-derived porcine mesenchymal stromal cells (MSCs) were seeded in polycaprolactone-gelatin nanofibrous scaffolds and cultured for 3 weeks before vitrification treatment. The vitrification strategy developed, which involved exposure of the TECs to low concentrations of cryoprotectants followed by a vitrification solution and sterile packaging in a pouch with its subsequent immersion directly into liquid nitrogen, was accomplished within 11min. Stepwise removal of cryoprotectants, after warming in a 38 degrees C water bath, enabled rapid restoration of the TECs. Vitrification did not impair microstructure of the scaffold or cell viability. No significant differences were found between the vitrified and control TECs in cellular metabolic activity and proliferation on matched days and in the trends during 5 weeks of continuous culture postvitrification. Osteogenic differentiation ability in vitrified and control groups was similar. In conclusion, we have developed a time- and cost-efficient cryopreservation method that maintains integrity of the TECs while preserving MSCs viability and metabolic activity, and their ability to differentiate.

Synthesis of 4-arm star poly(L-Lactide) oligomers using an in situ-generated calcium-based initiator

Using an in situ-generated calcium-based initiating species derived from pentaerythritol, the bulk synthesis of well-defined 4-arm star poly(L-lactide) oligomers has been studied in detail. The substitution of the traditional initiator, stannous octoate with calcium hydride allowed the synthesis of oligomers that had both low PDIs and a comparable number of polymeric arms (3.7 – 3.9) to oligomers of similar molecular weight. Investigations into the degree of control observed during the course of the polymerization found that the insolubility of pentaerythritol in molten L-lactide resulted in an uncontrolled polymerization only when the feed mole ratio of L-lactide to pentaerythritol was 13. At feed ratios of 40 and greater, a pseudo-living polymerization was observed. As part of this study, in situ FT-Raman spectroscopy was demonstrated to be a suitable method to monitor the kinetics of the ring-opening polymerization (ROP) of lactide. The advantages of using this technique rather than FT-IR-ATR and 1H NMR for monitoring L-lactide consumption during polymerization are discussed.

Cough-generated aerosols of Pseudomonas aeruginosa and other Gram Negative Bacteria from cystic fibrosis patients.

Background: Pseudomonas aeruginosa is the most common bacterial pathogen in cystic fibrosis (CF) patients. Current infection control guidelines aim to prevent transmission via contact and respiratory droplet routes and do not consider the possibility of airborne transmission. We hypothesized that with coughing, CF subjects produce viable, respirable bacterial aerosols. Methods: Cross-sectional study of 15 children and 13 adults with CF, 26 chronically infected with P. aeruginosa. A cough aerosol sampling system enabled fractioning of respiratory particles of different size, and culture of viable Gram negative non-fermentative bacteria. We collected cough aerosols during 5 minutes voluntary coughing and during a sputum induction procedure when tolerated. Standardized quantitative culture and genotyping techniques were used. Results: P. aeruginosa was isolated in cough aerosols of 25 (89%) subjects of whom 22 produced sputum samples. P. aeruginosa from sputum and paired cough aerosols were indistinguishable by molecular typing. In 4 cases the same genotype was isolated from ambient room air. Approximately 70% of viable aerosols collected during voluntary coughing were of particles ≤ 3.3 microns aerodynamic diameter. P. aeruginosa, Burkholderia cenocepacia Stenotrophomonas maltophilia and Achromobacter xylosoxidans were cultivated from respiratory particles in this size range. Positive room air samples were associated with high total counts in cough aerosols (P=0.003). The magnitude of cough aerosols were associated with higher FEV1 (r=0.45, P=0.02) and higher quantitative sputum culture results (r=0.58, P=0.008). Conclusion: During coughing, CF patients produce viable aerosols of P. aeruginosa and other Gram negative bacteria of respirable size range, suggesting the potential for airborne transmission.

User-generated content and the future of public broadcasting : a case study of the special broadcasting service

This thesis presents a case study of the Special Broadcasting Service documenting the broadcasting challenges posed by user-generated content initiatives and the work-place approach to strategies for participation. Using the action research method, the project findings reveal that limitations to resources and funding determined the scope for innovation and that the practice of executive editorial control over content was considered fundamental to fulfilling the responsibilities of the public service mandate. Media workers were overwhelmingly positive about the enhanced productive capabilities of the audience and willing to facilitate moderated interactions, however the effectiveness of these initiatives differed according to the level of skills required. This thesis demonstrates how participatory initiatives can enhance aspects of the public service remit relating to cultural diversity, the servicing of niche interests, and broader social representation, and help reinvigorate the relevance of public service broadcasting in the digitalised media sphere.

An optimising compiler for generated tiny virtual machines

VMSCRIPT is a scripting language designed to allow small programs to be compiled for a range of generated tiny virtual machines, suitable for sensor network devices. The VMSCRIPT compiler is an optimising compiler designed to allow quick re-targeting, based on a template, code rewriting model. A compiler backend can be specified at the same time as a virtual machine, with the compiler reading the specification and using it as a code generator.