Supporting wound infection diagnosis: advancements and challenges with electronic noses

Wound infections are a major problem worldwide, both for the healthcare system and for patients affected. Currently available diagnostic methods to determine the responsible germs are time-consuming and costly. Wound infections are mostly caused by various bacteria, which in turn produce volatile organic compounds. From clinical experience, we know that depending on the bacteria involved, a specific odor impression can be expected. For this reason, we hypothesized that electronic noses, i.e., non-invasive electronic sensors for the detection of volatile organic compounds, are applicable for diagnostic purposes. By providing a comprehensive overview of the state-of-research, we tested our hypothesis. In particular, we addressed three overarching questions: 1) which sensor technologies are suitable for the diagnosis of wound infections and why? 2) how must the (biological) sample be prepared and presented to the measurement system? 3) which machine learning methods and algorithms have already proven successful for the classification of microorganisms? The corresponding articles have critically been reviewed and are discussed particularly in the context of their potential for clinical diagnostics. In summary, it can already be stated today that the use of electronic noses for the detection of bacteria in wound infections is a very interesting, fast and non-invasive method. However, reliable clinical studies are still missing and further research is necessary

Independent comparison study of six different electronic tongues applied for pharmaceutical analysis

Electronic tongue technology based on arrays of cross-sensitive chemical sensors and chemometric data processing has attracted a lot of researchers' attention through the last years. Several so far reported applications dealing with pharmaceutical related tasks employed different e-tongue systems to address different objectives. In this situation, it is hard to judge on the benefits and drawbacks of particular e-tongue implementations for R&D in pharmaceutics. The objective of this study was to compare the performance of six different e-tongues applied to the same set of pharmaceutical samples. For this purpose, two commercially available systems (from Insent and AlphaMOS) and four laboratory prototype systems (two potentiometric systems from Warsaw operating in flow and static modes, one potentiometric system from St. Petersburg, one voltammetric system from Barcelona) were employed. The sample set addressed in the study comprised nine different formulations based on caffeine citrate, lactose monohydrate, maltodextrine, saccharin sodium and citric acid in various combinations. To provide for the fair and unbiased comparison, samples were evaluated under blind conditions and data processing from all the systems was performed in a uniform way. Different mathematical methods were applied to judge on similarity of the e-tongues response from the samples. These were principal component analysis (PCA), RV' matrix correlation coefficients and Tuckeŕs congruency coefficients

First principles investigation of exchange interactions in quasi-one-dimensional antiferromagnet CaV2O4

The effect of orbital degrees of freedom on the exchange interactions in the spin-1 quasi-one-dimensional antiferromagnet CaV2O4 is systematically studied. For this purpose a realistic low-energy model with the parameters derived from the first-principles calculations is constructed. The exchange interactions are calculated using both the theory of infinitesimal spin rotations near the mean-field ground state and the superexchange model, which provide a consistent description. The obtained behaviour of exchange interactions substantially differs from the previously proposed phenomenological picture based on the magnetic measurements and structural considerations, namely: (i) Despite quasi-one-dimensional character of the crystal structure, consisting of the zigzag chains of edge-sharing VO6 octahedra, the electronic structure is essentially three-dimensional, that leads to finite interactions between the chains; (ii) The exchange interactions along the legs of the chains appear to dominate; and (iii) There is a substantial difference of exchange interactions in two crystallographically inequivalent chains. The combination of these three factors successfully reproduces the behaviour of experimental magnetic susceptibility.Comment: 15 pages, 6 figures, supplementary materia

Hands-on-Project: Wissen und Können – greifbar gemacht an einem Wasch- oder Reinigungsmittelprodukt

Das im Bachelor-Studiengang „Technologie der Kosmetika und Waschmittel“ angebotene Wahlpflichtfach „Wasch- und Reinigungsmitteltechnologie“ (WRT) vereint didaktische Aspekte des problembasierten Lernens und des forschenden Lernens, indem eine sinnvolle Aufgabenstellung mit Projektcharakter durchgeführt wird. Die einzelnen Phasen des forschenden Lernens (Entwicklung der Fragen und Hypothesen, Selbstständige Arbeit, Aktive Mitarbeit; (mit)gestalten, erfahren und reflektieren, Wahl und Ausführung der Methoden, Entwicklung der Fragen und Hypothesen, Aktive Mitarbeit, Wahl und Ausführung der Methoden, Wahl und Ausführung der Methoden, Prüfung der Ergebnisse, Darstellung der Ergebnisse) werden im WRT-Modul in die Entwicklung eines Wasch- und/oder Reinigungsmittelprodukts übersetzt. Die praxisnahe Aufgabenstellung, die bedingungslose Unterstellung der fachlichen Kompetenz der Studierenden durch die Lehrpersonen und die selbstbestimmten Gestaltungsmöglichkeiten stärken das fachliche Selbstbewusstsein der Studierenden, resultieren in einer großen Motivation für das Projekt und ermöglichen einen deutlichen Wissenszuwachs. (DIPF/Orig.

Development of a taste-masked orodispersible film containing dimenhydrinate

Orodispersible dosage forms are promising new approaches for drug delivery. They enable an easy application, as there is no need to drink high amounts of liquids or swallow large solid dosage forms. The aim of the study was to develop an orodispersible film (ODF) as an alternative to tablets, syrups or suppositories for the treatment of vomiting and nausea, especially for the pediatric population. Formulations were investigated by X-ray diffraction, scanning electron and polarized light microscopy. Additionally, two commercially available electronic taste sensing systems were used to investigate the applied taste-masking strategies. Results obtained from X-ray-diffraction and polarized light microscopy showed no recrystallization of dimenhydrinate in the formulation when cyclodextrin or maltodextrin were used as solubilizing and complexing agent. All ODFs showed fast disintegration depending on the characterization method. In order to get taste information, the dimenhydrinate formulations were analytically compared to pure drug and drug-free formulations by electronic tongues. Results obtained from both systems are comparable and were used together for the first time. It was possible to develop an ODF of dimenhydrinate that is fast disintegrating even in small volumes of liquid. Furthermore, in vitro taste assessment by two electronic tongues revealed taste-masking effects by the excipients

Key Indicators for the Discrimination of Wines by Electronic Noses

In the food industry, and especially in wines as products thereof, ethanol and sulfur dioxide play an equally important role. Both substances are important wine quality characteristics as they influence the taste and odor. As both substances comprise volatile matter, electronic noses should be applicable to discriminate the different qualities of wines. Our study investigates the influence of alcohol and sulfur dioxide on the discrimination ability of wines (especially those of the same grape variety) using two different electronic nose systems. One system is equipped with metal oxide sensors and the other with quartz crystal microbalance sensors. Contrary to indications in literature, where the alcohol content is discussed to have a large influence on e-nose results, it was shown that a difference of 1 % ethanol was not sufficient to allow accurate discrimination using Linear Discriminant Analysis by any system. On the positive side, the analyzed concentrations of ethanol (about 12 %) did not superimpose other volatile information. So difference in sulfur dioxide content gave an accuracy for sample discrimination of up to 90.6 % with MOS nose. Thus, we are so far partially able to discriminate wines with electronic noses based on their volatile imprint

Data for a pre-performance test of self-developed electronic tongue sensors

This article presents data, which can be applied for a pre-performance test of self-developed electronic tongue sensors. Contained data is related to the research article “Impact of Sodium Lauryl Sulfate in oral liquids on E-Tongue Measurements” (http://dx.doi.org/10.1016/j.ijpharm.2016.10.045; (L.I. Immohr, R. Turner, M. Pein-Hackelbusch, 2016) [1]). Sensor responses were obtained from 10 subsequent measurements and four different concentrations of quinine hydrochloride by electronic tongue (TS-5000Z, Insent Inc., Atsugi-Shi, Japan) measurements. Based on the data for the pre-performance testing, which were calculated based on the fluctuation range of the sensor responses around the median, stability criteria and required preconditions cycles were defined