Estimating Time-Varying Effects of Prognostic Factors for Stomach Cancer Patients within a Dynamic Grouped Cox Model

We describe the identification of prognostic factors in the framework of a completely resected stomach cancer survival-study. For the analysis the dynamic grouped Cox-Model was used allowing for time-varying covariate effects. Therefore the hazard rate might be non-proportional. As estimation concept we applied the posterior mode, computed by iteratively weighted Kalman filtering and smoothing steps. The medical study and questions are described, the statistical method is illustrated, the results are given and interpreted and the method is discussed

Current and State of Charge Estimation of Lithium-Ion Battery Packs Using Distributed Fractional Extended Kalman Filters

In this paper, a method for current and state of charge estimation of lithium-ion battery packs is proposed. On the basis of a fractional 1-RQ equivalent circuit cell model, a string model containing cells in serial connection, and a pack model containing strings in parallel connection is built up. In order to reduce computational costs, the model is distributed string-wise into subsystems. An algorithm using distributed fractional extended Kalman filters is applied to estimate the state of charge of all cells of each string, locally. To avoid costly measurements of numerous currents, a model based calculation is proposed which describes how the total battery current is split up between the strings. The algorithm is tested and validated using measurement data

Retention force measurement of telescopic crowns

This study deals with the determination of the retentive force between primary and secondary telescopic crowns under clinical conditions. Forty-three combined fixed-removable prostheses with a total of 140 double crowns were used for retention force measurement of the telescopic crowns prior to cementation. The crowns had a preparation of 1-2°. A specifically designed measuring device was used. The retentive forces were measured with and without lubrication by a saliva substitute. The measured values were analyzed according to the type of tooth (incisors, canines, premolars, and molars). Additionally, a comparison between lubricated and unlubricated telescopic crowns was done. As maximum retention force value 29.98N was recorded with a telescopic crown on a molar, while the minimum of 0.08N was found with a specimen on a canine. The median value of retention force of all telescopic crowns reached 1.93N with an interquartile distance of 4.35N. No statistically significant difference between lubricated and unlubricated specimens was found. The results indicate that retention force values of telescopic crowns, measured in clinical practice, are often much lower than those cited in the literature. The measurements also show a wide range. Whether this proves to be a problem for the patient's quality of life or not can however only be established by a comparison of the presented results with a follow-up study involving measurement of intraoral retention and determination by e.g. oral health impact profil

Gain in Three-Dimensional Metamaterials utilizing Semiconductor Quantum Structures

We demonstrate gain in a three-dimensional metal/semiconductor metamaterial by the integration of optically active semiconductor quantum structures. The rolling-up of a metallic structure on top of strained semiconductor layers containing a quantum well allows us to achieve a three-dimensional superlattice consisting of alternating layers of lossy metallic and amplifying gain material. We show that the transmission through the superlattice can be enhanced by exciting the quantum well optically under both pulsed or continuous wave excitation. This points out that our structures can be used as a starting point for arbitrary three-dimensional metamaterials including gain

Clinical retention force development of double crowns

This study deals with the development of the retentive forces of double crowns intraorally measured. Twenty-five combined fixed-removable prostheses with a total of 84 double crowns were included in the study. The intraoral measurement was performed at 72 defined measuring points directly adjacent to the double crowns of the dentures. The measurement was performed 4-6weeks (baseline), 6months (recall 1), and 18months (recall 2) after the insertion of the restoration. A specifically designed measuring device was used. The median values for the single measuring points reached 4.705N at the baseline, 5.190N after 6months, and 3.740N after 18months. The measured values were analyzed according to differences between the median retention forces at the three defined points in time. The statistical analysis of the median values showed no statistical difference for the retention force change after 6months but for the decrease until the second recall (Mann-Whitney test). The retention force per denture was calculated by a summation of the single measuring points. At the baseline, 12.9N was reached. The forces did only decrease slightly and were not statistically significant. The results indicate that retention force values of double crowns, measured intraorally at the patient, do not relevantly change clinically within the first 1.5years. Within the limitations of this study, it can be stated that wear does not influence the retentive forces of double crowns within the first 18months. After this period the retention force should be still sufficient for denture retentio

Kreislaufanlagen - Positionen des Ökosektors

Geeignete Standorte für herkömmliche Formen der Aquakultur werden weltweit knapp, und eine Erhöhung der Produktion gerät zunehmend mit Zielen des Umwelt- und Naturschutzes in Konflikt. Der in Deutschland extrem geringe Selbstversorgungsgrad mit Fisch kann daher in erster Linie über eine Produktionssteigerung in Kreislaufanlagen (KLA), d.h. in geschlossenen, standortunabhängigen und entsprechend technisierten Systemen, erhöht werden. Im Nationalen Strategieplan Aquakultur für Deutschland wird insofern ein besonderer Fokus auf das Produktionspotential in KLA gelegt, bzw. ein deutliches Wachstum nur in diesem Bereich (Steigerung auf 20.000 t bis 2020) als möglich erachtet. Bei dem hier beantragten Vorhaben wird geklärt, wie relevante Interessensgruppen die Vereinbarkeit von Aquakultur in KLA mit der Ökologischen Lebensmittelwirtschaft bewerten. Die Frage stellt sich einerseits aus Sicht der Erzeuger, denn die Produktion in KLA ist durch hohe Umweltauflagen sowie komplexe Haltungssysteme aufwändig und benötigt daher Wege, ihre Alleinstellungsmerkmale (z.B. Transparenz, Regionalität, Verzicht auf Chemie und Tierarznei) auf glaubhaftem Weg an den Verbraucher zu kommunizieren. Andererseits aus Sicht der richtliniengebenden Ökoverbände und Institutionen, denn sie sind von Seiten des Marktes und der Gesellschaft aufgefordert, zu dieser immer wichtiger werdenden Zukunftstechnologie fundiert Stellung zu beziehen