TY  - JOUR
A1  - Brendtke, Rico
A1  - Wiehl, Michael
A1  - Groeber, Florian
A1  - Schwarz, Thomas
A1  - Walles, Heike
A1  - Hansmann, Jan
T1  - Feasibility Study on a Microwave-Based Sensor for Measuring Hydration Level Using Human Skin Models
JF  - PLoS ONE
N2  - Tissue dehydration results in three major types of exsiccosis—hyper-, hypo-, or isonatraemia. All three types entail alterations of salt concentrations leading to impaired biochemical processes, and can finally cause severe morbidity. The aim of our study was to demonstrate the feasibility of a microwave-based sensor technology for the non-invasive measurement of the hydration status. Electromagnetic waves at high frequencies interact with molecules, especially water. Hence, if a sample contains free water molecules, this can be detected in a reflected microwave signal. To develop the sensor system, human three-dimensional skin equivalents were instituted as a standardized test platform mimicking reproducible exsiccosis scenarios. Therefore, skin equivalents with a specific hydration and density of matrix components were generated and microwave measurements were performed. Hydration-specific spectra allowed deriving the hydration state of the skin models. A further advantage of the skin equivalents was the characterization of the impact of distinct skin components on the measured signals to investigate mechanisms of signal generation. The results demonstrate the feasibility of a non-invasive microwave-based hydration sensor technology. The sensor bears potential to be integrated in a wearable medical device for personal health monitoring.
KW  - gels
KW  - microwave radiation
KW  - collagens
KW  - skin physiology
KW  - reflection
KW  - skin anatomy
KW  - epidermis
KW  - antennas
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-179934
VL  - 11
IS  - 4
ER  - 
TY  - JOUR
A1  - Jockel-Schneider, Yvonne
A1  - Harks, Inga
A1  - Haubitz, Imme
A1  - Fickl, Stefan
A1  - Eigenthaler, Martin
A1  - Schlagenhauf, Ulrich
A1  - Baulmann, Johannes
T1  - Arterial Stiffness and Pulse Wave Reflection Are Increased in Patients Suffering from Severe Periodontitis
JF  - PLOS ONE
N2  - Aim: This single blind cross-sectional study compared the vascular health of subjects suffering from severe chronic periodontitis, severe aggressive periodontitis and periodontal healthy controls by evaluating pulse wave velocity (PWV), augmentation index (AIx) and pulse pressure amplification (PPA).
Material and Methods: In a total of 158 subjects, 92 suffering from severe periodontitis and 66 matched periodontal healthy controls, PWV, AIx, central and peripheral blood pressure were recorded using an oscillometric device (Arteriograph).
Results: Subjects suffering from severe chronic or aggressive periodontitis exhibited significantly higher PWV (p = 0.00004), higher AIx (p = 0.0049) and lower PPA (p = 0.028) than matched periodontal healthy controls.
Conclusions: The results of this study confirm the association between periodontal inflammation and increased cardiovascular risk shown by impaired vascular health in case of severe periodontitis. As impaired vascular health is a common finding in patients suffering from severe periodontal disease a concomitant routine cardiovascular evaluation may be advised.
KW  - periodontal diseases
KW  - diagnostic medicine
KW  - teeth
KW  - stiffness
KW  - reflection
KW  - periodontitis
KW  - blood pressure
KW  - hypertension
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-119459
SN  - 1932-6203
VL  - 9
IS  - 8
ER  - 
TY  - JOUR
A1  - Karagiannakis, Evangelia
T1  - Autonomes Lernen durch Beobachtung, Reflexion und Evaluation des eigenen Lernprozesses – Punktuelle und kontinuierliche Verfahren
N2  - "Autonomes Lernen ist das Übernehmen von Verantwortung für das eigene Lernen." (Rieder, o. J.) Bedeutend für den Lernprozess ist weiterhin die Fähigkeit, diesen selbst zu organisieren. Damit Eigenverantwortung und Selbstorganisation gelingen können, müssen Lernende ihren Lernprozess regelmäßig reflektieren sowie Ergebnisse selbstständig evaluieren und bewerten. (vgl. Wolff, 1997:3) Von Zeit zu Zeit sollte die gesamte Lerngruppe am Reflexions- und Evaluationsprozess beteiligt werden. Im vorliegenden Beitrag werden Methoden vorgestellt, mit denen teils in Einzelarbeit, teils in der Gruppe schnelle Zwischenevaluationen oder kontinuierlich begleitende Reflexionen realisiert werden können.
N2  - Learner autonomy means to be responsible for one's own process of learning as well as to organise it oneself. In order to do so, learners should regularly reflect on and evaluate what and how they learn, which aims they have already reached and what they are going to do next. The following chapters aim to introduce a variety of methods and tools which may be used for fast or continuing, individual or peer evaluations and reflections.
KW  - Fremdsprachenlernen
KW  - Fremdsprachenunterricht
KW  - Evaluation
KW  - Lernautonomie
KW  - Reflexion
KW  - Learning autonomy
KW  - reflection
KW  - evaluation
Y1  - 2010
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-49879
ER  -