Papers by Anka TRAJKOVSKA PETKOSKA
Soft lithography encompasses a collection of inexpensive low-expertise methods to fabricate compl... more Soft lithography encompasses a collection of inexpensive low-expertise methods to fabricate complex microand nano-structured topographies. The most forms of soft lithography use a patterned elastomeric stamp bearing inverse relief features, which can transfer the desired patterns on almost any, flat or curved, surface. The short "turn-around" time from an idea to prototype, coupled with its suitability for a broad range of soft materials and a good control over surface chemistries, has made soft lithography one of the top most versatile fabrication tool in many research laboratories. In this work, soft lithographic replica molding method was used to fabricate anti-fouling and self-cleaning engineered topographies. Anti-fouling patterned surfaces developed have shown increased inhibition toward bacterial attachment and biofilm formation compared to control surfaces, all made of the same material. The fabrication of self-cleaning hydrophobic topographies, is further proof of the capability and versatility of soft lithography. When these topographies were assessed for their non-wetting and self-cleaning character, most of them have shown the "Lotus-leaf-effect", i.e. water contact angles above 140 o and sliding angles between 3-8 o. In both types of topographies fabricated in this work, the surface features' size and periodicity seem to play the major role in the surface final performance.
Starch - Stärke, 2014
To characterize the flour and starch from peach palm fruit, a non-conventional raw material, thes... more To characterize the flour and starch from peach palm fruit, a non-conventional raw material, these powders were studied by means of chemical composition, SEM, particle size analyzer, XRD, FTIR, and differential scanning calorimeter, with different water contents. The rheological properties of the solutions and suspensions also were evaluated. Results showed that flour and starch powders have high starch contents (between 73.0 and 84.5%) with average particle size between 9.8 mm (flour) and 8.4 mm (starch). Thermograms revealed endothermic peaks that were affected by hydration conditions between 70-72°C for flour and 61-62°C for starch. Solutions of peach palm fruit flour and starch had a pseudoplastic behavior at 30°C that can be fit well to the power-law model. Peach palm fruit is a non-conventional source of flour and starch, but the results proved that these powders could have promising industrial applications, due to their physicochemical properties being similar to those reported for other starches.
OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information), May 11, 2010
CINECA IRIS Institutial research information system (University of Pisa), Sep 8, 2015
P separated from natural sources have been regarded as important immune stimulant candidates due ... more P separated from natural sources have been regarded as important immune stimulant candidates due to their broad spectrum of immune stimulatory activities. In a previous study, we isolated and characterized polysaccharides from the leaves of Diospyros kaki (PLE0) prepared by pectinase digestion. PLE0 exhibited immune stimulatory effects through enhanced lymphocyte proliferation, natural killer (NK) cell cytotoxicity against tumor cells, and anti-complementary activity. To obtain safety information for PLE0, its acute oral toxicity and genotoxicity were evaluated in this study. Acute oral toxicity test of PLE0 was performed in Sprague-Dawley rats. In acute oral toxicity test, PLE0 exhibited no mortality, body weight and behavioral changes and adverse effects in male and female rats up to 5,000 mg/kg dose. To evaluate genotoxicity of PLE0, we tested bacterial reverse mutation test, comet assay, and chromosomal aberration test. PLE0 did not significantly increase the number of the bacterial revertant colonies in bacterial reverse mutation test. Moreover, PLE0 related DNA damage and chromosomal aberration was not observed in CHO-k1 cells. These results suggested that the approximate lethal dose of PLE0 is considered to be higher than 5,000 mg/kg, and PLE0 does not act as a mutagenic or genotoxic material at the concentrations evaluated.
Metal ..., 2021
The microstructure, hardness, and corrosion behavior of Cu-modified austenitic stainless steels (... more The microstructure, hardness, and corrosion behavior of Cu-modified austenitic stainless steels (SS) were investigated in the present work. The materials were prepared by controlled melting of SS (chemical composition Cr 22 wt. %, Ni 9 %, Mo 2 %, Mn 2 %, Si 1%, P 0.045%, S 0.03%, C 0.03%, Fe bal.) with 1, 2 and 5 wt. % Cu. The ingots were thermo-mechanically processed and annealed at 1100 °C for 30 min. The materials were metallographically prepared by grounding and polishing for microscopy observation. The steels were found to consist of austenite matrix. A small amount of δ-ferrite precipitated in the matrix during solidification. The microhardness of the materials was measured by Vickers method. The hardness of Cumodified SS was slightly reduced compared to the parent material due to Cu dissolution in austenite. The corrosion behavior of the steels was studied in physiological solution (0.9 wt. % NaCl) by electrode polarization. A three-electrode cell controlled by potentiostat was used to monitor the progress of the reaction. Corrosion potentials were shifted to more noble values with increasing Cu concentration. The corrosion rate of SS alloyed with 2 wt. % Cu was significantly reduced compared to the parent material. The results can be used as a guideline for an efficient design of Cu-modified SS for biomedical applications.
Optics & Photonics News, Dec 1, 2004
Food bioscience, Jun 1, 2022
Springer eBooks, 2011
ABSTRACT In this paper polymer cholesteric liquid crystal (PCLC) flakes will be introduced as a n... more ABSTRACT In this paper polymer cholesteric liquid crystal (PCLC) flakes will be introduced as a novel form of particles for active applications, like electronic paper displays, as well as for sensors. The concept of electro-optic applications based on PCLC flakes is very attractive, because it offers a possibility for thin, reflective, lightweight, flexible devices that use little power. The uniqueness of PCLC flakes lies in their bright, saturated and full color capability, as well as their circular polarization effects, without the need of additional color filters and polarizers.
Sustainability, Oct 31, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Proceedings, Jan 29, 2021
The 44th Annual Scientific Meeting of the Nutrition Society of Australia was held virtually from ... more The 44th Annual Scientific Meeting of the Nutrition Society of Australia was held virtually from 3 to 4 December 2020. The theme of the meeting was Nutrition: Adapting to a New World. Abstracts were submitted from 27 countries. In total, 305 registrants attended the conference and 128 papers were presented consisting of 6 plenary, 54 oral and 68 poster presentations. This issue presents the proceedings of this meeting in the form of abstracts for papers presented at the conference.
Advanced Materials Letters, May 1, 2020
The author sincerely acknowledges the contributions of the co-authors and their institutions and ... more The author sincerely acknowledges the contributions of the co-authors and their institutions and delegates their selfless efforts. Conflicts of interest There are no conflicts to declare.
ABSTRACT Polymer cholesteric liquid crystal (PCLC) flake/fluid host suspensions are a new and pro... more ABSTRACT Polymer cholesteric liquid crystal (PCLC) flake/fluid host suspensions are a new and promising particle display technology for both full-color flexible display applications and electronic paper. Devices containing these "polarizing pigments" switch rapidly at very low voltages and produce highly saturated, circularly polarized reflectance colors without requiring polarizers or color filters.
Materials, Jun 15, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Food Science and Nutrition, May 15, 2023
Nowadays, natural foods that can provide positive health effects are gaining more and more popula... more Nowadays, natural foods that can provide positive health effects are gaining more and more popularity. Bees and the products they produce are our common natural heritage that should be developed. In the article, we presented the characteristics of bee products and their use in industry. We described the development and importance of beekeeping in the modern world. Due to their high nutritional value and therapeutic properties, bee products are of great interest and their consumption is constantly growing. The basis for the use of bee products in human nutrition is their properties and unique chemical composition. The conducted research and opinions confirm the beneficial effect of bee products on health. The current consumer awareness of the positive impact of food having a pro‐health effect on health and well‐being affects the increase in interest and demand for this type of food among various social groups. Enriching the daily diet with bee products may support the functioning of the organism. New technologies have appeared on the market to improve the process of obtaining bee products. The use of bee products plays a large role in many industries; moreover, the consumption of bee products and promotion of their medicinal properties are very important in shaping proper eating habits.
Advanced Functional Materials, Feb 1, 2005
The cover shows a variety of shaped flakes fabricated from polymer cholesteric liquid-crystal mat... more The cover shows a variety of shaped flakes fabricated from polymer cholesteric liquid-crystal material using soft lithography. In work reported by Jacobs and co-workers on p. 217, the micrometer-sized flakes exhibit brilliant circularly polarized selective reflection colors without polarizers or color filters when placed in a fluid-filled electro-optic cell. With the application of a low-magnitude alternating current field, the flakes reorient in hundreds of milliseconds and the colors disappear. Polymer cholesteric liquid-crystal (PCLC) flakes were investigated for their electro-optical behavior under an applied alternating-current field. Shaped flakes, fabricated using soft lithography and suspended in dielectric-fluid-filled cells, reoriented more uniformly than randomly shaped flakes made by fracturing of PCLC films. Extensive characterization found shaped flakes to be smooth and uniform in size, shape, and thickness. Reorientation in applied fields as low as tens of mVrms μm–1 was fastest for flakes with lateral aspect ratios greater than 1:1, confirming theoretical predictions based on Maxwell–Wagner polarization. Brilliant reflective colors and inherent polarization make shaped PCLC flakes of interest for particle displays.
Uploads
Papers by Anka TRAJKOVSKA PETKOSKA