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Christoph Hollnagel Heike Vallery Rainer Schädler Isaac Gómez-Lor López Lukas Jaeger Peter Wolf Robert Riener Laura Marchal-Crespo 《Medical & biological engineering & computing》2013,51(7):799-809
Pneumatics is one of the few actuation principles that can be used in an MR environment, since it can produce high forces without affecting imaging quality. However, pneumatic control is challenging, due to the air high compliance and cylinders non-linearities. Furthermore, the system’s properties may change for each subject. Here, we present novel control strategies that adapt to the subject’s individual anatomy and needs while performing accurate periodic gait-like movements with an MRI compatible pneumatically driven robot. In subject-passive mode, an iterative learning controller (ILC) was implemented to reduce the system’s periodic disturbances. To allow the subjects to intend the task by themselves, a zero-force controller minimized the interaction forces between subject and robot. To assist patients who may be too weak, an assist-as-needed controller that adapts the assistance based on online measurement of the subject’s performance was designed. The controllers were experimentally tested. The ILC successfully learned to reduce the variability and tracking errors. The zero-force controller allowed subjects to step in a transparent environment. The assist-as-needed controller adapted the assistance based on individual needs, while still challenged the subjects to perform the task. The presented controllers can provide accurate pneumatic control in MR environments to allow assessments of brain activation. 相似文献
73.
Bassem R. Haddad Lei Gu Tuomas Mirtti Ayush Dagvadorj Paraskevi Vogiatzi David T. Hoang Renu Bajaj Benjamin Leiby Elyse Ellsworth Shauna Blackmon Christian Ruiz Mark Curtis Paolo Fortina Adam Ertel Chengbao Liu Hallgeir Rui Tapio Visakorpi Lukas Bubendorf Marja T. Nevalainen 《The American journal of pathology》2013,182(6):2264-2275
74.
Lukas Meyer Michael Schnfeld Matthias Bechstein Uta Hanning Bastian Cheng Gtz Thomalla Gerhard Schn Andre Kemmling Jens Fiehler Gabriel Broocks 《Journal of cerebral blood flow and metabolism》2021,41(1):45
The effect of age on lesion pathophysiology in the context of thrombectomy has been poorly investigated. We aimed to investigate the impact of age on ischemic lesion water homeostasis measured with net water uptake (NWU) within a multicenter cohort of patients receiving thrombectomy for anterior circulation large vessel occlusion (LVO) stroke. Lesion-NWU was quantified in multimodal CT on admission and 24 h for calculating Δ-NWU as their difference. The impact of age and procedural parameters on Δ-NWU was analyzed. Multivariable regression analysis was performed to identify significant predictors for Δ-NWU. Two hundred and four patients with anterior circulation stroke were included in the retrospective analysis. Comparison of younger and elderly patients showed no significant differences in NWU on admission but significantly higher Δ-NWU (p = 0.005) on follow-up CT in younger patients. In multivariable regression analysis, higher age was independently associated with lowered Δ-NWU (95% confidence interval: −0.59 to −0.16, p < 0.001). Although successful recanalization (TICI ≥ 2b) significantly reduced Δ-NWU progression by 6.4% (p < 0.001), younger age was still independently associated with higher Δ-NWU (p < 0.001). Younger age is significantly associated with increased brain edema formation after thrombectomy for LVO stroke. Younger patients might be particularly receptive targets for future adjuvant neuroprotective drugs that influence ischemic edema formation. 相似文献
75.
Juncal Fernández-Orth Leoni Rolfes Lukas Gola Stefan Bittner Joseph Andronic Vladimir L. Sukhorukov Dmitri Sisario Peter Landgraf Daniela C. Dieterich Manuela Cerina Karl-Heinz Smalla Thilo Kähne Thomas Budde Stjepana Kovac Tobias Ruck Markus Sauer Sven G. Meuth 《European journal of immunology》2021,51(2):342-353
The immunological synapse is a transient junction that occurs when the plasma membrane of a T cell comes in close contact with an APC after recognizing a peptide from the antigen-MHC. The interaction starts when CRAC channels embedded in the T cell membrane open, flowing calcium ions into the cell. To counterbalance the ion influx and subsequent depolarization, Kv1.3 and KCa3.1 channels are recruited to the immunological synapse, increasing the extracellular K+ concentration. These processes are crucial as they initiate gene expression that drives T cell activation and proliferation. The T cell-specific function of the K2P channel family member TASK2 channels and their role in autoimmune processes remains unclear. Using mass spectrometry analysis together with epifluorescence and super-resolution single-molecule localization microscopy, we identified TASK2 channels as novel players recruited to the immunological synapse upon stimulation. TASK2 localizes at the immunological synapse, upon stimulation with CD3 antibodies, likely interacting with these molecules. Our findings suggest that, together with Kv1.3 and KCa3.1 channels, TASK2 channels contribute to the proper functioning of the immunological synapse, and represent an interesting treatment target for T cell-mediated autoimmune disorders. 相似文献
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77.
Ondrej Kyselak Vladimir Soska Jan Kovar Lukas Tichy Hana Grombirikova Jaroslav A. Hubacek Tomas Freiberger 《Journal of clinical lipidology》2021,15(3):435-440
We describe the casuistry of a homozygous familial hypercholesterolemia female patient with a biallelic missense variant (NM_000527.4:c.1775G>A, p.Gly592Glu) in the LDLR gene, severe hypertriglyceridemia and late manifestation of coronary heart disease not earlier than at the age of 45 years. An atypical phenotype led to a delayed diagnosis. 相似文献
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79.
Lars Donath Lukas Zahner Ralf Roth Livia Fricker Mareike Cordes Henner Hanssen Arno Schmidt-Trucksäss Oliver Faude 《European journal of applied physiology》2013,113(3):661-669
Impaired balance and gait performance increase fall-risk in seniors. Acute effects of different exercise bouts on gait and balance were not yet addressed. Therefore, 19 healthy seniors (10 women, 9 men, age: 64.6 ± 3.2 years) were examined on 3 days. After exhaustive treadmill testing, participants randomly completed a 2-km treadmill walking test (76 ± 8 % VO2max) and a resting control condition. Standing balance performance (SBALP) was assessed by single limb-eyes opened (SLEO) and double limb-eyes closed (DLEC) stance. Gait parameters were collected at comfortable walking velocity. A condition × time interaction of center of pressure path length (COPpath) was observed for both balance tasks (p < 0.001). Small (Cohen’s d = 0.42, p = 0.05) and large (d = 1.04, p < 0.001) COPpath increases were found after 2-km and maximal exercise during DLEC. Regarding SLEO, slightly increased COPpath occurred after 2-km walking (d = 0.29, p = 0.65) and large increases after exhaustive exercise (d = 1.24, p < 0.001). No significant differences were found for gait parameters. Alterations of SBALP after exhaustive exercise might lead to higher fall-risk in seniors. Balance changes upon 2-km testing might be of minor relevance. Gait is not affected during single task walking at given velocities. 相似文献
80.