E Actitrode: The new selective stimulation interface for functional movements in hemiplegics patients

We describe the new multi-contact electrode-array for surface electrical stimulation, and the corresponding interface device that allows on-line selection of the conductive fields during the application of the system. This new device has a specific value for therapeutic applications of electrical stimulation since it allows effective generation of desired functional movements. The user-friendly interface also allows patients at home to select the optimal electrode array; thereby, to receive therapies out of the clinical environment. The electrode was tested in three post-stroke hemiplegics patients. The pilot experiments showed that system works sufficiently good for control of fingers during grasp and release functions without the interference of the wrist movement. The use of electrode is also envisioned for many other applications (foot-drop fitness, shoulder subluxation, etc)

EMG Map for Designing the Electrode Shape for Functional Electrical Therapy of Upper Extremities

Achieving the functional grasp by electrical stimulation using surface electrodes is a demanding task. The innervations of muscles come via ulnar, radial and median nerves. The anatomy of nerve branches connecting various muscles in the forearm differs significantly between individuals. We hypothesize that the anatomical differences between the paretic and nonparetic arms are minimal. Based on this assumption we developed a method where the differences of muscle activities (EMG) between the healthy and paretic arms recorded by the 24-contact electrode within an array define the target zones to be stimulated on the affected forearm. We used special electrode where magnetic contacts allow simple change of the stimulation pads. The examiner positions the magnetic contact on the pads where the EMG differences are maximal. The stimulator delivers asynchronous stimulation to the selected pads. We proved that the method is working in stroke patients by measuring joint angles and the grasping force. © 2019, Springer Nature Switzerland AG.Biosystems and Biorobotics, Vol. 21This is the peer-reviewed version of the following article: Popović-Maneski, L., Topalović, I., 2019. EMG Map for Designing the Electrode Shape for Functional Electrical Therapy of Upper Extremities, in: Masia, L., Micera, S., Akay, M., Pons, J.L. (Eds.), Converging Clinical and Engineering Research on Neurorehabilitation III, Biosystems & Biorobotics. Springer International Publishing, pp. 1003–1007, http://dx.doi.org/10.1007/978-3-030-01845-0_20

Biomineralization in the Sea Hare Aplysia punctata Initiated by Nano-Dolomite

X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), high resolution transmission electron microscopy (HRTEM), environmental scanning electron microscopy (ESEM) and energy dispersive X-ray analysis (EDS) were used in study of starting biomineralization processes in embryos of the sea hare species Aplysia punctata. 10 days old embryos appeared amorphous according to XRD patterns. TEM of the same sample showed that first grains of nanocrystalline dolomite began to form in the amorphous area. The identification of dolomite was confirmed according to TEM dark field images and SAED, as well as by HRTEM. In further development stages of the embryos very faint aragonite rings became visible by SAED. It was shown that the biomineralization process in A. punctata started by formation of the dolomite nanograins which served as centres of crystallization for further aragonite deposition in the larval shell. The creation of unusual intermediate crystalline phase of nano-dolomite in A. punctata embryos is of equal interest for biologist and ecologist as an evolutionary ancestral trait of molluskan biomineralization, as well as for materials scientists, as a promising template in potential bioengineering application and design of appropriate biomimetic routes that could lead to the development of new implantable biomaterials. The discussion of the present results is based on recent knowledge on general biomineralization in mollusks

Supplementary data for article: Božić, B.; Korać, J.; Stanković, D. M.; Stanić, M.; Popović-Bijelić, A.; Bogdanović Pristov, J.; Spasojević, I.; Bajčetić, M. Mechanisms of Redox Interactions of Bilirubin with Copper and the Effects of Penicillamine. Chemico-Biological Interactions 2017, 278, 129–134. https://doi.org/10.1016/j.cbi.2017.10.022

Supplementary material for: [https://doi.org/10.1016/j.cbi.2017.10.022]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2570]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3105

Glucosomes: Magnetically induced controlled release of glucose modified liposomes

Novel methods of cancer therapy are constantly being investigated since the current approach heavily relies on the use of non-specific and toxic chemotherapy agents. Ideally, a drug used for cancer therapy would specifically target tumor sites or rather bind specifically with cancer cells. The way to achieve this is by targeting cancer cell specific receptors or receptors present in abnormally high counts at the surface. Rapid proliferation of cancer cells is fueled by large amounts of energy that is in turn produced by abnormal glucose uptake. Because of this high energy/glucose demand, cancer cells exhibit an abnormally high glucose receptor (GLUTs) count on their surface, compared to normal, healthy cells. We have utilized this glucose dependency to create glucose modified liposomes (Glucosomes) that are specifically bound by cancer cells. Glucosomes can be used to transport different substances, either hydrophilic or hydrophobic, and can therefore deliver any type of drug to cancer cells, increasing its efficiency. Another important aspect to consider is the controlled release of the drug being transported in order to maximize therapeutic efficiency. Controlled release can be achieved by utilizing different internal or external influences. In our study, we have used standard Fe3O4 magnetic nanoparticles to load glucosomes and induce their controlled opening via an external magnetic field. By applying an external magnetic field, the magnetic nanoparticles start heating up and transferring this thermal energy to the surrounding lipid bilayer, causing its perturbation and opening of the glucosome. Our study has found that controlled release can be achieved with high efficiency while the chemical stability of the Fe3O4 nanoparticles stays practically intact. Using EPR spectroscopy, we have shown that Fe3O4 nanoparticles remain trapped within the lipid bilayer and are essentially protected from oxidation that would diminish their magnetic properties. Since magnetic Fe3O4 nanoparticles are lodged well within the lipid bilayer no thermal damage can be caused to the drug being transported within the glucosome bilayer, making this a viable controlled release cancer targeting drug delivery system.Twentieth Young Researchers’ Conference - Materials Science and Engineering: Program and the Book of Abstracts; November 30 – December 2, 2022, Belgrade, Serbi

Long cycle life of CoMn2O4 lithium ion battery anodes with high crystallinity

CoMn2O4 nanomaterials are prepared by a low temperature precipitation route employing metal acetates and NaOH. Structural changes, induced by different annealing temperatures, are comprehensively analyzed by X-ray powder diffraction and Raman spectroscopy. With rising annealing temperature the crystal lattice of CoMn2O4 undergoes changes ; AO4 tetrahedra expand due to thermally induced substitution of Co2+ by larger Mn2+ metal ions on the A-site of the spinel structure, while in contrast, BO6 octahedra shrink since the B-site becomes partially occupied by smaller Co3+ metal ions on account of the migrated Mn ions. CoMn2O4 particle sizes are easily fine-tuned by applying different annealing temperatures ; the particle size increases with increasing annealing temperature. During the battery operation, pulverization and reduction of particle sizes occurs regardless of the initial size of the particles, but the degree of division of the particles during the operation is dependent on the initial particle properties. Thus, contrary to the common assumption that nanostructuring of the anode material improves the battery performance, samples with the largest particle sizes exhibit excellent performance with a capacity retention of 104% after 1000 cycles (compared to the 2nd cycle)

Supplementary data for the article: Božić, B.; Korać, J.; Stanković, D. M.; Stanić, M.; Romanović, M.; Pristov, J. B.; Spasić, S.; Popović-Bijelić, A.; Spasojević, I.; Bajčetić, M. Coordination and Redox Interactions of β-Lactam Antibiotics with Cu2+ in Physiological Settings and the Impact on Antibacterial Activity. Free Radical Biology and Medicine 2018, 129, 279–285. https://doi.org/10.1016/j.freeradbiomed.2018.09.038

Supplementary material for: [https://doi.org/10.1016/j.freeradbiomed.2018.09.038]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/349]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/2940