Antibacterial potential of electrochemically exfoliated graphene sheets

Electrochemically exfoliated graphene is functionalized graphene with potential application in biomedicine. Two most relevant biological features of this material are its electrical conductivity and excellent water dispersibility. In this study we have tried to establish the correlation between graphene structure and its antibacterial properties. The exfoliation process was performed in a two electrode-highly oriented pyrolytic graphite electrochemical cell. Solution of ammonium persulfate was used as an electrolyte. Exfoliated graphene sheets were dispersed in aqueous media and characterized by atomic force microscopy, scanning electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, X photoelectron spectroscopy, X-ray diffraction, electron paramagnetic resonance, zeta potential, contact angle measurements and surface energy. Antibacterial assays have shown lack of the significant antibacterial activity. Major effect on bacteria was slight change of bacteria morphology. Membrane remained intact despite significant change of chemical content of membrane components.This is the peer reviewed version of the paper: Marković, Z. M., Matijašević, D. M., Pavlović, V. B., Jovanović, S. P., Holclajtner-Antunović, I. D., Špitalský, Z., Mičušik, M., Dramićanin, M. D., Milivojević, D. D., Nikšić, M. P., & Todorović Marković, B. M. (2017). Antibacterial potential of electrochemically exfoliated graphene sheets. Journal of Colloid and Interface Science, 500, 30–43. [https://doi.org/10.1016/j.jcis.2017.03.110][https://www.sciencedirect.com/science/article/abs/pii/S0021979717303776?via%3Dihub

Multiple View Geometry of Omnidirectional Cameras - PhD Thesis Proposal.

The thesis proposal deals with multiple view geometry of central omnidirectional cameras. We aim at obtaining a full-calibrated camera from a plain images using point correspondences and epipolar constraint only. The full-calibrated omnidirectional camera obtained in such a way provides better ego-motion estimation, and more complete 3D reconstruction compared to standard directional cameras.Available from STL Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi

Estimation of Omnidirectional Camera Model from Epipolar Geometry.

Available from STL Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi

Magnetron Sputtered Non-Toxic and Precious Element-Free Ti-Zr-Ge Metallic Glass Nanofilms with Enhanced Biocorrosion Resistance

The chemical composition and structural state of advanced alloys are the decisive factors in optimum biomedical performance. This contribution presents unique Ti-Zr-Ge metallic glass thin-film compositions fabricated by magnetron sputter deposition targeted for nanocoatings for biofouling prevention. The amorphous nanofilms with nanoscale roughness exhibit a large relaxation and supercooled liquid regions as revealed by flash differential scanning calorimetry. Ti68Zr8Ge24 shows the lowest corrosion (0.17 µA cm−2) and passivation (1.22 µA cm−2) current densities, with the lowest corrosion potential of −0.648 V and long-range stability against pitting, corroborating its excellent performance in phosphate buffer solution at 37 °C. The oxide layer is comprised of TiO2, TiOx and ZrOx, as determined using X-ray photoelectron spectroscopy by short-term ion-etching of the surface layer. The two orders of magnitude increase in the oxide and interface resistance (from 14 to 1257 Ω cm2) along with an order of magnitude decrease in the capacitance parameter of the oxide interface (from 1.402 × 10−5 to 1.677 × 10−6 S sn cm−2) of the same composition is linked to the formation of carbonyl groups and reduction of the native oxide layer during linear sweep voltammetry