TY  - JOUR
A1  - Ngamga, Eulalie Joelle
A1  - Bialonski, Stephan
A1  - Marwan, Norbert
A1  - Kurths, Jürgen
A1  - Geier, Christian
A1  - Lehnertz, Klaus
T1  - Evaluation of selected recurrence measures in discriminating pre-ictal and inter-ictal periods from epileptic EEG data
JF  - Physics Letters A
N2  - We investigate the suitability of selected measures of complexity based on recurrence quantification analysis and recurrence networks for an identification of pre-seizure states in multi-day, multi-channel, invasive electroencephalographic recordings from five epilepsy patients. We employ several statistical techniques to avoid spurious findings due to various influencing factors and due to multiple comparisons and observe precursory structures in three patients. Our findings indicate a high congruence among measures in identifying seizure precursors and emphasize the current notion of seizure generation in large-scale epileptic networks. A final judgment of the suitability for field studies, however, requires evaluation on a larger database.
Y1  - 2016
U6  - https://doi.org/10.1016/j.physleta.2016.02.024
SN  - 0375-9601
VL  - 380
IS  - 16
SP  - 1419
EP  - 1425
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Nguyen, N.-H.
A1  - Raatschen, Hans-Jürgen
A1  - Staat, Manfred
T1  - A hyperelastic model of biological tissue materials in tubular organs
Y1  - 2010
N1  - ECCM 2010, IV European Conference on Computational Mechanics, Paris, France, May 16-21, 2010.
SP  - 1
EP  - 12
ER  - 
TY  - JOUR
A1  - Nguyen, Nhu Huynh
A1  - Duong, Minh Tuan
A1  - Tran, Thanh Ngoc
A1  - Pham, Phu Tinh
A1  - Grottke, O.
A1  - Tolba, R.
A1  - Staat, Manfred
T1  - Influence of a freeze–thaw cycle on the stress–stretch curves of tissues of porcine abdominal organs
JF  - Journal of Biomechanics
N2  - The paper investigates both fresh porcine spleen and liver and the possible decomposition of these organs under a freeze–thaw cycle. The effect of tissue preservation condition is an important factor which should be taken into account for protracted biomechanical tests. In this work, tension tests were conducted for a large number of tissue specimens from twenty pigs divided into two groups of 10. Concretely, the first group was tested in fresh state; the other one was tested after a freeze-thaw cycle which simulates the conservation conditions before biomechanical experiments. A modified Fung model for isotropic behavior was adopted for the curve fitting of each kind of tissues. Experimental results show strong effects of the realistic freeze–thaw cycle on the capsule of elastin-rich spleen but negligible effects on the liver which virtually contains no elastin. This different behavior could be explained by the autolysis of elastin by elastolytic enzymes during the warmer period after thawing. Realistic biomechanical properties of elastin-rich organs can only be expected if really fresh tissue is tested. The observations are supported by tests of intestines.
KW  - Autolysis
KW  - Decomposition
KW  - Freeze–thaw process
KW  - Spleen
KW  - Liver
Y1  - 2012
U6  - https://doi.org/10.1016/j.jbiomech.2012.07.008
SN  - 1873-2380
VL  - 45
IS  - 14
SP  - 2382
EP  - 2386
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Nguyen-Xuan, H.
A1  - Rabczuk, T.
A1  - Nguyen-Thoi, T.
A1  - Tran, Thanh Ngoc
A1  - Nguyen-Thanh, N.
T1  - Computation of limit and shakedown loads using a node-based smoothed finite element method
JF  - International Journal for Numerical Methods in Engineering
N2  - This paper presents a novel numerical procedure for computing limit and shakedown loads of structures using a node-based smoothed FEM in combination with a primal–dual algorithm. An associated primal–dual form based on the von Mises yield criterion is adopted. The primal-dual algorithm together with a Newton-like iteration are then used to solve this associated primal–dual form to determine simultaneously both approximate upper and quasi-lower bounds of the plastic collapse limit and the shakedown limit. The present formulation uses only linear approximations and its implementation into finite element programs is quite simple. Several numerical examples are given to show the reliability, accuracy, and generality of the present formulation compared with other available methods.
Y1  - 2011
U6  - https://doi.org/10.1002/nme.3317
SN  - 1097-0207
VL  - 90
IS  - 3
SP  - 287
EP  - 310
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Nomdedeu, Mar Monsonis
A1  - Willen, Christine
A1  - Schieffer, Andre
A1  - Arndt, Hartmut
T1  - Temperature-dependent ranges of coexistence in a model of a two-prey-one-predator microbial food web
JF  - Marine Biology
N2  - The objective of our study was to analyze the effects of temperature on the population dynamics of a three-species food web consisting of two prey bacteria (Pedobacter sp. and Acinetobacter johnsonii) and a protozoan predator (Tetrahymena pyriformis) as model organisms. We assessed the effects of temperature on the growth rates of all three species with the objective of developing a model with four differential equations based on the experimental data. The following hypotheses were tested at a theoretical level: Firstly, temperature changes can affect the dynamic behavior of a system by temperature-dependent parameters and interactions and secondly, food web response to temperature cannot be derived from the single species temperature response. The main outcome of the study is that temperature changes affect the parameter range where coexistence is possible within all three species. This has significant consequences on our ideas regarding the evaluation of effects of global warming.
Y1  - 2012
U6  - https://doi.org/10.1007/s00227-012-1966-x
SN  - 1432-1793
VL  - 159
IS  - 11
SP  - 2423
EP  - 2430
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Novacek, V.
A1  - Tran, Thanh Ngoc
A1  - Klinge, U.
A1  - Tolba, R. H.
A1  - Staat, Manfred
A1  - Bronson, D. G.
A1  - Miesse, A. M.
A1  - Whiffen, J.
A1  - Turquier, F.
T1  - Finite element modelling of stapled colorectal end-to-end anastomosis : Advantages of variable height stapler design
JF  - Journal of Biomechanics
N2  - The impact of surgical staplers on tissues has been studied mostly in an empirical manner. In this paper, finite element method was used to clarify the mechanics of tissue stapling and associated phenomena. Various stapling modalities and several designs of circular staplers were investigated to evaluate the impact of the device on tissues and mechanical performance of the end-to-end colorectal anastomosis. Numerical simulations demonstrated that a single row of staples is not adequate to resist leakage due to non-linear buckling and opening of the tissue layers between two adjacent staples. Compared to the single staple row configuration, significant increase in stress experienced by the tissue at the inner staple rows was observed in two and three rows designs. On the other hand, adding second and/or third staple row had no effect on strain in the tissue inside the staples. Variable height design with higher staples in outer rows significantly reduced the stresses and strains in outer rows when compared to the same configuration with flat cartridge.
KW  - Variable height stapler design
KW  - Anastomotic leakage
KW  - Finite element modelling
KW  - End-to-end colorectal anastomosis
KW  - Surgical staplers
Y1  - 2012
U6  - https://doi.org/10.1016/j.jbiomech.2012.07.021
SN  - 1873-2380
VL  - 45
IS  - 115
SP  - 2693
EP  - 2697
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Nurispahic, A.
A1  - Kotliar, Konstantin
A1  - Lanzl, I.
T1  - Messung der Akkommodation mittels optischer Biometrie
JF  - Der Ophthalmologe
Y1  - 2008
SN  - 1433-0423
VL  - 105
IS  - 4
SP  - 369
EP  - 375
PB  - -
ER  - 
TY  - JOUR
A1  - Näther, Niko
A1  - Auger, V.
A1  - Poghossian, Arshak
A1  - Koudelka-Hep, M.
A1  - Schöning, Michael Josef
T1  - A miniaturized flow-through cell in SU-8 technique for EIS sensors
JF  - Biomedizinische Technik. 49 (2004), H. 2
Y1  - 2004
SN  - 0932-4666
SP  - 994
EP  - 995
ER  - 
TY  - JOUR
A1  - Näther, Niko
A1  - Berger, Jörg
A1  - Emmerich, Rüdiger
A1  - Friedrich, P.
A1  - Henkel, H.
A1  - Schöning, Michael Josef
T1  - H2O2-Konzentrationsbestimmung für die Prozessgasanalytik mittels eines kalorimetrischen Sensoraufbaus
JF  - Sensoren und Messsysteme 2008 : 14. Fachtagung Ludwigsburg, 11. und 12. März 2008 / VDI/VDE-Gesellschaft Mess- und Automatisierungstechnik
Y1  - 2008
SN  - 978-3-18-092011-5
N1  - VDI-Berichte ; 2011 ; Sensoren und Messsysteme 2008, 14. GMA/ITG-Fachtagung, VDI/VDE- Gesellschaft Mess- und Automatisierungstechnik, + CD-ROM, Ludwigsburg, DE, 11.-12. Mar, 2008
SP  - 783
EP  - 792
PB  - VDI-Verl.
CY  - Düsseldorf
ER  - 
TY  - JOUR
A1  - Näther, Niko
A1  - Berger, Jörg
A1  - Emmerich, Rüdiger
A1  - Friedrich, Peter
A1  - Henkel, Hartmut
A1  - Schneider, Andreas
A1  - Schöning, Michael Josef
T1  - Entwicklung einer kalorimetrischen H2O2-Gassensoranordnung für die Prozessgaskontrolle
JF  - 8. Dresdner Sensor-Symposium : Sensoren für Umwelt, Klima und Sicherheit, Biosensoren und Biosysteme, Sensoren und Sensorsysteme für die Prozesstechnik, Trends in der Sensortechnik, Materialentwicklung für die Sensorik; 8. Dresdner Sensor-Symposium, 10. - 12. Dezember 2007, Dresden / Gerald Gerlach ... (Hg.)
Y1  - 2007
SN  - 978-3-940046-45-1
N1  - Dresdner Beiträge zur Sensorik ; 29
SP  - 261
EP  - 264
PB  - TUDpress, Verl. der Wissenschaften
CY  - Dresden
ER  -