7 research outputs found
The impact of size and position of reference electrode on the localization of biphasic electrotactile stimulation on the fingertips
Development of haptic interfaces to enrich augmented and virtual reality with the sense of touch is the next frontier for technological advancement of these systems. Among available technologies, electrotactile stimulation enables design of high-density interfaces that can provide natural-like sensation of touch in interaction with virtual objects. The present study investigates the human perception of electrotactile sensations on fingertips, focusing on the sensation localization in function of the size and position of reference electrode. Ten healthy subjects participated in the study, with the task to mark the sensations elicited by stimulating the index fingertip using an 8-pad electrode. The test systematically explored several configurations of the active (position) and reference (position and size) electrode pads. The results indicated that there was a spreading of perceived sensations across the fingertip, but that they were mostly localized below the active pad. The position and size of the reference electrode were shown to affect the location of the perceived sensations, which can potentially be exploited as an additional parameter to modulate the feedback. The present study demonstrates that the fingertip is a promising target for the delivery of high-resolution feedback.The work in this study was performed within the TACTILITY project, which has received funding by European Union’s Horizon 2020 framework programme for research and innovation H2020-ICT-2018-2020/H2020-ICT 2018-3 under grant agreement no. 85671
A compact system for simultaneous stimulation and recording for closed-loop myoelectric control
Background.Despite important advancements in control and mechatronics of myoelectric prostheses, the communication between the user and his/her bionic limb is still unidirectional, as these systems do not provide somatosensory feedback. Electrotactile stimulation is an attractive technology to close the control loop since it allows flexible modulation of multiple parameters and compact interface design via multi-pad electrodes. However, the stimulation interferes with the recording of myoelectric signals and this can be detrimental to control.The work in this study was supported by the project ROBIN (8022-00243A and 8022-00226B) funded by the Independent Research Fund Denmark
Development of resistance to antiglioma agents in rat C6 cells caused collateral sensitivity to doxorubicin
Chemoresistance is a severe limitation to glioblastoma (GBM) therapy and
there is a strong need to understand the underlying mechanisms that
determine its response to different chemotherapeutics. Therefore, we
induced resistance in C6 rat glioma cell line, which considerably
resembles the characteristics of human GBM. The resistant phenotype was
developed by 3-bis (2-chloroethyl)-1-nitrosourea (BCNU), one of the most
commonly used therapeutic drug in the course of GBM treatment. After
confirmation of the cross-resistance to cisplatin (CPt) and temozolomide
(TMZ) in newly established RC6 cell line, we examined cell death
induction and DNA damage by these drugs. Resistance to apoptosis and
deficiency in forming DNA double-strand breaks was followed by
significant decrease in the mRNA expression of pro-apoptotic and
anti-apoptotic genes. The development of drug resistance was associated
with significant increase in reactive oxygen species (ROS) and decrease
in oxidized to reduced gluthatione ratio in RC6 cell line indicating a
reduced level of oxidative stress. The mRNA expression levels of
manganese superoxid dismutase (MnSOD), inducible nitric oxide synthase
(iNOS) and gluthatione peroxidase (GPx) were increased while
hypoxia-inducible factor 1-alpha (HIF-1 alpha) was decreased in RC6
compared to C6 cells. This was in line with obtained changes in ROS
content and increased antioxidative capacity of RC6 cells. Importantly,
RC6 cells demonstrated collateral sensitivity to doxorubicin (DOX). The
analysis of this phenomenon revealed increased accumulation of DOX in
RC6 cells due to their adaptation to high ROS content and acidification
of cytoplasm. In conclusion, newly established RC6 rat glioma cell line
could be used as a starting material for the development of allogenic
animal model and preclinical evaluation of new antiglioma agents.
Collateral sensitivity to DOX obtained after BCNU treatment may prompt
new studies aimed to find efficient delivery of DOX to the glioma site
in brain. (C) 2015 Elsevier Inc. All rights reserved.Ministry of Education, Science and Technological Development of Serbia
{[}III 41031, III 41025
Role of gonadal hormones in programming developmental changes in thymopoietic efficiency and sexual diergism in thymopoiesis
There is a growing body of evidence indicating the important role of the neonatal steroid milieu in programming sexually diergic changes in thymopoietic efficiency, which in rodents occur around puberty and lead to a substantial phenotypic and functional remodeling of the peripheral T-cell compartment. This in turn leads to an alteration in the susceptibility to infection and various immunologically mediated pathologies. Our laboratory has explored interdependence in the programming and development of the hypothalamo-pituitary-gonadal axis and thymus using experimental model of neonatal androgenization. We have outlined critical points in the complex process of T-cell development depending on neonatal androgen imprinting and the peripheral outcome of these changes and have pointed to underlying mechanisms. Our research has particularly contributed to an understanding of the putative role of changes in catecholamine-mediated communications in the thymopoietic alterations in adult neonatally androgenized rats