@article{AlbrachtArampatzis2013, author = {Albracht, Kirsten and Arampatzis, Adamantios}, title = {Exercise-induced changes in triceps surae tendon stiffness and muscle strength affect running economy in humans}, series = {European Journal of Applied Physiology}, volume = {113}, journal = {European Journal of Applied Physiology}, number = {6}, publisher = {Springer}, address = {Berlin}, issn = {1439-6327}, doi = {10.1007/s00421-012-2585-4}, pages = {1605 -- 1615}, year = {2013}, language = {en} } @article{KaramanidisAlbrachtBraunsteinetal.2011, author = {Karamanidis, Kiros and Albracht, Kirsten and Braunstein, Bjoern and Catala, Maria Moreno and Goldmann, Jan-Peter and Br{\"u}ggemann, Gert-Peter}, title = {Lower leg musculoskeletal geometry and sprint performance}, series = {Gait and Posture}, volume = {34}, journal = {Gait and Posture}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0966-6362}, doi = {10.1016/j.gaitpost.2011.03.009}, pages = {138 -- 141}, year = {2011}, abstract = {The purpose of this study was to investigate whether sprint performance is related to lower leg musculoskeletal geometry within a homogeneous group of highly trained 100-m sprinters. Using a cluster analysis, eighteen male sprinters were divided into two groups based on their personal best (fast: N = 11, 10.30 ± 0.07 s; slow: N = 7, 10.70 ± 0.08 s). Calf muscular fascicle arrangement and Achilles tendon moment arms (calculated by the gradient of tendon excursion versus ankle joint angle) were analyzed for each athlete using ultrasonography. Achilles tendon moment arm, foot and ankle skeletal geometry, fascicle arrangement as well as the ratio of fascicle length to Achilles tendon moment arm showed no significant (p > 0.05) correlation with sprint performance, nor were there any differences in the analyzed musculoskeletal parameters between the fast and slow sprinter group. Our findings provide evidence that differences in sprint ability in world-class athletes are not a result of differences in the geometrical design of the lower leg even when considering both skeletal and muscular components.}, language = {en} } @article{ArampatzisPeperBierbaumetal.2010, author = {Arampatzis, Adamantios and Peper, Andreas and Bierbaum, Stefanie and Albracht, Kirsten}, title = {Plasticity of human Achilles tendon mechanical and morphological properties in response to cyclic strain}, series = {Journal of Biomechanics}, volume = {43}, journal = {Journal of Biomechanics}, number = {16}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0021-9290}, doi = {10.1016/j.jbiomech.2010.08.014}, pages = {3073 -- 3079}, year = {2010}, abstract = {The purpose of the current study in combination with our previous published data (Arampatzis et al., 2007) was to examine the effects of a controlled modulation of strain magnitude and strain frequency applied to the Achilles tendon on the plasticity of tendon mechanical and morphological properties. Eleven male adults (23.9±2.2 yr) participated in the study. The participants exercised one leg at low magnitude tendon strain (2.97±0.47\%), and the other leg at high tendon strain magnitude (4.72±1.08\%) of similar frequency (0.5 Hz, 1 s loading, 1 s relaxation) and exercise volume (integral of the plantar flexion moment over time) for 14 weeks, 4 days per week, 5 sets per session. The exercise volume was similar to the intervention of our earlier study (0.17 Hz frequency; 3 s loading, 3 s relaxation) allowing a direct comparison of the results. Before and after the intervention ankle joint moment has been measured by a dynamometer, tendon-aponeurosis elongation by ultrasound and cross-sectional area of the Achilles tendon by magnet resonance images (MRI). We found a decrease in strain at a given tendon force, an increase in tendon-aponeurosis stiffness and tendon elastic modulus of the Achilles tendon only in the leg exercised at high strain magnitude. The cross-sectional area (CSA) of the Achilles tendon did not show any statistically significant (P>0.05) differences to the pre-exercise values in both legs. The results indicate a superior improvement in tendon properties (stiffness, elastic modulus and CSA) at the low frequency (0.17 Hz) compared to the high strain frequency (0.5 Hz) protocol. These findings provide evidence that the strain magnitude applied to the Achilles tendon should exceed the value, which occurs during habitual activities to trigger adaptational effects and that higher tendon strain duration per contraction leads to superior tendon adaptational responses.}, language = {en} } @article{AggeloussisGiannakouAlbrachtetal.2010, author = {Aggeloussis, Nickos and Giannakou, Erasmia and Albracht, Kirsten and Arampatzis, Adamantios}, title = {Reproducibility of fascicle length and pennation angle of gastrocnemius medialis in human gait in vivo}, series = {Gait and Posture}, volume = {31}, journal = {Gait and Posture}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0966-6362}, doi = {10.1016/j.gaitpost.2009.08.249}, pages = {73 -- 77}, year = {2010}, abstract = {The purpose of the current study was to examine the reproducibility of fascicle length and pennation angle of gastrocnemius medialis while human walking. To the best of our knowledge, this is the first study of the reproducibility of fascicle length and pennation angle of gastrocnemius medialis in vivo during human gait. Twelve males performed 10 gait trials on a treadmill, in 2 separate days. B-mode ultrasonography, with the ultrasound probe firmly adjusted in the transverse and frontal planes using a special cast, was used to measure the fascicle length and the pennation angle of the gastrocnemius medialis (GM). A Vicon 624 system with three cameras operating at 120 Hz was also used to record the ankle and knee joint angles. The results showed that measurements of fascicle length and pennation angle showed high reproducibility during the gait cycle, both within the same day and between different days. Moreover, the root mean square differences between the repeated waveforms of both variables were very small, compared with their ranges (fascicle length: RMS = ∼3 mm, range: 38-63 mm; pennation angle: RMS = ∼1.5°, range: 22-32°). However, their reproducibility was lower compared to the joint angles. It was found that representative data have to be derived by a wide number of gait trials (fascicle length ∼six trials, pennation angle more than 10 trials), to assure the reliability of the fascicle length and pennation angle in human gait.}, language = {en} } @article{ArampatzisKaramanidisMademlietal.2009, author = {Arampatzis, Adamantios and Karamanidis, Kiros and Mademli, Lida and Albracht, Kirsten}, title = {Plasticity of the human tendon to short and long-term mechanical loading}, series = {Exercise and Sport Sciences Reviews}, volume = {37}, journal = {Exercise and Sport Sciences Reviews}, number = {2}, issn = {1538-3008}, doi = {10.1097/JES.0b013e31819c2e1d}, pages = {66 -- 72}, year = {2009}, language = {en} } @article{AlbrachtArampatzisBaltzopoulos2008, author = {Albracht, Kirsten and Arampatzis, A. and Baltzopoulos, V.}, title = {Assessment of muscle volume and physiological cross-sectional area of the human triceps surae muscle in vivo}, series = {Journal of Biomechanics}, volume = {41}, journal = {Journal of Biomechanics}, issn = {0021-9290}, doi = {10.1016/j.jbiomech.2008.04.020}, pages = {2211 -- 2218}, year = {2008}, language = {en} } @inproceedings{KesslerBalcGebhardt2016, author = {Kessler, Julia and Balc, Nicolae and Gebhardt, Andreas}, title = {Basic research on lattice structures focused on the strut shape and welding beads}, series = {Physics Procedia}, volume = {Vol. 83}, booktitle = {Physics Procedia}, issn = {1875-3884}, doi = {10.1016/j.phpro.2016.08.086}, pages = {833 -- 838}, year = {2016}, language = {en} } @article{MiyamotoSatoAbeetal.2016, author = {Miyamoto, Ko-Ichiro and Sato, Takuya and Abe, Minami and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {Light-addressable potentiometric sensor as a sensing element in plug-based microfluidic devices}, series = {Micromachines}, volume = {7}, journal = {Micromachines}, number = {7}, publisher = {MDPI}, address = {Basel}, issn = {2072-666X}, doi = {10.3390/mi7070111}, pages = {111}, year = {2016}, abstract = {A plug-based microfluidic system based on the principle of the light-addressable potentiometric sensor (LAPS) is proposed. The LAPS is a semiconductor-based chemical sensor, which has a free addressability of the measurement point on the sensing surface. By combining a microfluidic device and LAPS, ion sensing can be performed anywhere inside the microfluidic channel. In this study, the sample solution to be measured was introduced into the channel in a form of a plug with a volume in the range of microliters. Taking advantage of the light-addressability, the position of the plug could be monitored and pneumatically controlled. With the developed system, the pH value of a plug with a volume down to 400 nL could be measured. As an example of plug-based operation, two plugs were merged in the channel, and the pH change was detected by differential measurement.}, language = {en} } @article{MahmoudiFleischhakerSahraietal.2008, author = {Mahmoudi, Mohammad and Fleischhaker, Robert and Sahrai, Mostafa and Evers, J{\"o}rg}, title = {Group velocity control in the ultraviolet domain via interacting dark-state resonances}, series = {Journal of physics B: Atomic, molecular and optical physics}, volume = {41}, journal = {Journal of physics B: Atomic, molecular and optical physics}, number = {2}, issn = {0953-4075}, doi = {10.1088/0953-4075/41/2/025504}, pages = {25504 -- 25600}, year = {2008}, language = {en} } @inproceedings{PrickingGebsFleischhakeretal.2015, author = {Pricking, Sebastian and Gebs, Raphael and Fleischhaker, Robert and Kleinbauer, Jochen and Budnicki, Aleksander and Sutter, Dirk and Killi, Alexander and Weiler, Sascha and Mielke, M. and Beaudou, B. and Debord, B. and Gerome, F. and Benabid, F.}, title = {Hollow core fiber delivery of sub-ps pulses from a TruMicro 5000 Femto edition thin disk amplifier}, series = {High-power laser materials processing: Lasers, beam delivery, diagnostics, and applications IV : 7 Februar 2015, San Francisco, USA. - (SPIE proceedings series ; 9356)}, booktitle = {High-power laser materials processing: Lasers, beam delivery, diagnostics, and applications IV : 7 Februar 2015, San Francisco, USA. - (SPIE proceedings series ; 9356)}, editor = {Dorsch, Friedhelm}, publisher = {SPIE, International Society for Optical Engineering}, organization = {The international society for optical engineering, SPIE <2, 2015, San Francisco, CA>}, isbn = {978-162841446-2}, issn = {0277-786X}, doi = {10.1117/12.2079289}, pages = {935602}, year = {2015}, language = {en} }