Chromatographic analysis of immobilized cefotaxime

The aim of the present work was to widen the application of an in-house developed fast, flexible and sensitive high performance liquid chromatography (HPLC) method to the assessment of cefotaxime sodium from aqueous samples. The method was applied to establish the release profile of cefotaxime sodium immobilised in MCM-41 nanoparticles using pH controlled release in aqueous medium. The analytical method proved to be sensible, repeatable (RSD < 1.5 %) and reproducible (RSD < 1 %) in the concentration range studied (0.01-10 μg•mL-1), limit of detection and limit of quantification were 0.036 and 0.12 μg•mL-1 respectively, suitable for the analysis of release of a single active ingredient, having a short analysis time (10 minutes)

Biosensors Applications on Assessment of Reactive Oxygen Species and Antioxidants

Computer networking & communication

Fourier Transform Infrared Spectroscopy - Useful Analytical Tool for Non-Destructive Analysis

Email: consumer/user guide

Information Dynamics in Transportation Systems with Traffic Lights Control

Due to recent advanced communication possibilities between traffic infrastructure, vehicles and drivers, the optimization of traffic lights control can be approached in novel ways. At the same time, this may introduce new unexpected dynamics in transportation systems. The authors' research aims to determine how drivers and traffic lights systems interact and influence each other when they are informed one about another's behaviour. In order to study this, the authors developed an agent based model to simulate transportation systems with static and dynamic traffic lights and drivers using information about the traffic lights behaviour. Experiments reveal that the system's performance improves when a bigger share of drivers receive information for both static and dynamic traffic lights systems. This performance improvement is due to drivers managing to avoid stopping at red light rather them adapting their speed to different distances to the traffic lights systems. Additionally, it is demonstrated that the duration of the fixed phases also influences the performance when drivers use speed recommendations. Moreover, the results show that dynamic traffic lights can produce positive effects for roads with high speed limits and high traffic intensity, while in the rest of the cases static control is better. The findings can be used for building more efficient traffic lights systems. Document type: Articl

Information impact on transportation systems

AbstractWith a broader distribution of personal smart devices and with an increasing availability of advanced navigation tools, more drivers can have access to real time information regarding the traffic situation. Our research focuses on determining how using the real time information about a transportation system could influence the system itself. We developed an agent based model to simulate the effect of drivers using real time information to avoid traffic congestion. Experiments reveal that the system's performance is influenced by the number of participants that have access to real time information. We also discover that, in certain circumstances, the system performance when all participants have information is no different from, and perhaps even worse than, when no participant has access to information

Electrochemical determination of minocycline in pharmaceutical preparations

The possibility of electrochemical determination of minocycline on mercury and solid electrodes by various voltammetric and polarographic techniques has been undertaken. The influence of some chemical (ionic strength and pH) and instrumental parameters on the main reduction signal of minocycline was investigated. The alternating current polarographic (ACP) technique was applied to the minocycline determination either in pure form or in a commercial pharmaceutical preparation. The common excipients did not interfere. The antibiotic could be detected in the concentration range $1\ 10^{-3} - 5\ 10^{-6}$ mol L$^{-1}$. The detection limit for the quantitative determination by ACP was 1 10$^{-6}$ mol L$^{-1}$ minocycline in aqueous medium of 0.1 M NaCl. The mean recovery was 99.2% with a relative standard deviation (RSD) of 2.93% ($n = 8$)

Laccase-Nafion biosensor for polyphenolic secondary metabolites determination

A laccase-based biosensor was developed by specific enzyme adsorption on screen-printed working electrodes of DROPSENS cells, and stabilized with Nafion 0.1% membrane. The electrode was characterized with respect to response time, sensitivity, linear range, detection limit, pH dependence, interferences, and long-term stability. The tested substrates were catechol, rosmarinic acid, caffeic acid, chlorogenic acid, and gallic acid. The optimized biosensor proved the following characteristic performances: the apparent Michaelis Menten calcd. considering rosmarinic acid substrate 8.3 × 10-6 mol L-1 (r = 0.995, n = 6); the dynamic range of biosensor response for rosmarinic acid 7 × 10-7 - 1.5 × 10-6 mol L-1; the detection limit for rosmarinic acid 1.19 × 10-7 mol L-1 (RSD = 1.08%, n = 3). It was noticed that the biosensor reaches systematically 90% to 94.3% from the response obtained by LC-DAD-ESI-MS for real samples

Laccase-Nafion Based Biosensor for the Determination of Polyphenolic Secondary Metabolites

A laccase-based biosensor was developed by specific enzyme adsorption on screen-printed working electrodes of DROPSENS cells, and stabilized with Nafion 0.1% membrane. The electrode was characterized with respect to response time, sensitivity, linear range, detection limit, pH dependence, interferences, and long-term stability. The tested substrates were catechol, rosmarinic acid, caffeic acid, chlorogenic acid, and gallic acid. The optimized biosensor proved the following characteristic performances: the apparent Michaelis Menten calculated considering rosmarinic acid substrate 8.3 × 10-6 mol L-1 (r = 0.995, n = 6); the dynamic range of biosensor response for rosmarinic acid 7 × 10-7 - 1.5 × 10-6 mol L-1; the detection limit for rosmarinic acid 1.19 × 10-7 mol L-1 (RSD = 1.08%, n = 3). It was noticed that the biosensor reaches systematically 90% to 94.3% from the response obtained by LC-DAD-ESI-MS for real samples