Directed assembly of optically bound matter

We present a study of optically bound matter formation in a counter-propagating evanescent field, exploiting total internal reflection on a prism surface. Small ensembles of silica microspheres are assembled in a controlled manner using optical tweezers. The structures and dynamics of the resulting optically bound chains are interpreted using a simulation implementing generalized Lorentz-Mie theory. In particular, we observe enhancement of the scattering force along the propagation direction of the optically bound colloidal chains leading to a microscopic analogue of a driven pendulum which, at least superficially, resembles Newton’s cradle

Supplementary data for article: Mišić, D.; Šiler, B.; Gašić, U.; Avramov, S.; Živković, S.; Živković, J. N.; Milutinović, M.; Tešić, Ž. Simultaneous UHPLC/DAD/(+/-)HESI-MS/MS Analysis of Phenolic Acids and Nepetalactones in Methanol Extracts of Nepeta Species: A Possible Application in Chemotaxonomic Studies. Phytochemical Analysis 2015, 26 (1), 72–85. https://doi.org/10.1002/pca.2538

Supporting information for: [https://doi.org/10.1002/pca.2538]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1663

Supplementary data for article: Banjanac, T.; Dragićević, M.; Šiler, B.; Gašić, U.; Bohanec, B.; Nestorović Živković, J.; Trifunović, S.; Mišić, D. Chemodiversity of Two Closely Related Tetraploid Centaurium Species and Their Hexaploid Hybrid: Metabolomic Search for High-Resolution Taxonomic Classifiers. Phytochemistry 2017, 140, 27–44. https://doi.org/10.1016/j.phytochem.2017.04.005

Supplementary material for: [https://doi.org/10.1016/j.phytochem.2017.04.005]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2477

Supplementary data for article: Banjanac, T.; Dragićević, M.; Šiler, B.; Gašić, U.; Bohanec, B.; Nestorović Živković, J.; Trifunović, S.; Mišić, D. Chemodiversity of Two Closely Related Tetraploid Centaurium Species and Their Hexaploid Hybrid: Metabolomic Search for High-Resolution Taxonomic Classifiers. Phytochemistry 2017, 140, 27–44. https://doi.org/10.1016/j.phytochem.2017.04.005

Supplementary material for: [https://doi.org/10.1016/j.phytochem.2017.04.005]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2477

Supplementary data for article: Mišić, D.; Šiler, B.; Gašić, U.; Avramov, S.; Živković, S.; Živković, J. N.; Milutinović, M.; Tešić, Ž. Simultaneous UHPLC/DAD/(+/-)HESI-MS/MS Analysis of Phenolic Acids and Nepetalactones in Methanol Extracts of Nepeta Species: A Possible Application in Chemotaxonomic Studies. Phytochemical Analysis 2015, 26 (1), 72–85. https://doi.org/10.1002/pca.2538

Supporting information for: [https://doi.org/10.1002/pca.2538]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1663

Three-dimensional holographic optical manipulation through a high-numerical-aperture soft-glass multimode fibre

Holographic optical tweezers (HOT) hold great promise for many applications in biophotonics, allowing the creation and measurement of minuscule forces on biomolecules, molecular motors and cells. Geometries used in HOT currently rely on bulk optics, and their exploitation in vivo is compromised by the optically turbid nature of tissues. We present an alternative HOT approach in which multiple three-dimensional (3D) traps are introduced through a high-numerical-aperture multimode optical fibre, thus enabling an equally versatile means of manipulation through channels having cross-section comparable to the size of a single cell. Our work demonstrates real-time manipulation of 3D arrangements of micro-objects, as well as manipulation inside otherwise inaccessible cavities. We show that the traps can be formed over fibre lengths exceeding 100 mm and positioned with nanometric resolution. The results provide the basis for holographic manipulation and other high-numerical-aperture techniques, including advanced microscopy, through single-core-fibre endoscopes deep inside living tissues and other complex environments

Bioactive characterization of Persea americana Mill. by-products: A rich source of inherent antioxidants

[EN] Avocado (Persea americana Mill.) is a worldwide consumed fruit, with great interest for cosmetic and pharmaceutical industries; however, 30% of avocado fruits are bio-wastes (peels and kernels), converting them into a potential source of bioactive compounds, such as phenolic compounds. Therefore, the hydroethanolic extracts of peels and kernels of Persea america Mill. var. Hass were analysed regarding their individual phenolic profile by HPLC-DAD/ESI-MS and correlated with their antioxidant, antimicrobial and cytotoxic activities. Avocado by-products presented a very distinct phenolic profile, presenting higher concentration in peels (227.9 mg/g of extract for total phenolic content), mainly in (epi)catechin derivatives (175 mg/g of extract), followed by chlorogenic derivatives (42.9 mg/g of extract). In this study hydrophilic and lipophilic antioxidant assays were performed together for the first time in P. americana by-products, and although kernels showed a great antioxidant potential (EC50 values ranging from 18.1 to 276 mu g/mL), peels presented the highest potential (EC50 ranging from 11.7 to 152 mu g/mL), mainly due to the presence of phenolic compounds, and an overall better performance in the antibacterial assays. Further studies needs to be conducted to better understand the correlation between the presence of phenolic compounds and bioactivities, however, the main objective is to implement these biocompounds in different products and industries, due to results obtained, P. americana peels could be a great alternative in the substitution of synthetic antioxidants.The authors are grateful to the Foundation for Science and Technology(FCT, Portugal) and FEDER under Program PT2020 for financial support to CIMO (UID/AGR/00690/2013) and L. Barros contract. The authors would like to thank the Interreg Espana-Portugal for financial support through the project 0377_Iberphenol_6_E. B. Melgar thanks CONACyT for his grant (No. 329930). The authors are also grateful to the Serbian Ministry of Education, Science and Technological Development, grant number 173032 for financial support.Melgar-Castañeda, B.; Dias, MI.; Ciric, A.; Sokovic, M.; Garcia-Castello, EM.; Rodríguez López, AD.; Barros, L.... (2018). Bioactive characterization of Persea americana Mill. by-products: A rich source of inherent antioxidants. Industrial Crops and Products. 111:212-218. https://doi.org/10.1016/j.indcrop.2017.10.024S21221811

Effect of fermentation on antioxidant properties of some cereals and pseudo cereals

The influence of fermentation by two types of microorganisms (lactic acid bacteria Lactobacillus rhamnosus, and yeast Saccharomyces cerevisiae) on antioxidant activities and total phenolics of 4 cereals, namely buckwheat, wheat germ, barley and rye, was determined and compared with those of their unfermented counterparts. The total phenolic content (TPC), determined by the Folin-Ciocalteu method, increased upon fermentation. Antioxidant activities (AOA) were assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity, ferric ion-reducing antioxidant power (FRAP) and thiobarbituric acid (TBA) methods. The presence of those microorganisms was more or less important for enhanced levels of antioxidant activity. Thus fermentation offers a tool to further increase the bioactive potential of cereal products

Antioksidativna aktivnost različitih morfoloških frakcija zrna nekih cerealija

The purpose of this study was to examine the antioxidant properties of 70% ethanolic extracts of cereal grains and their different morphological fractions. Wheat (Triticum durum L.), barley (Hordeum vulgare L.), rye (Secale cereale L.), and buckwheat (Fagopyrum esculentum) were used. The total phenolic content (TPC), determined by the Folin-Ciocalteu method and antioxidant activities (AOA) were assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity, ferric ion-reducing antioxidant power (FRAP) and thiobarbituric acid (TBA) methods. The following hierarchy of antioxidant activity was provided for 70% ethanolic extracts originated from whole grain: buckwheat gt barley gt wheat gt rye. In respect to hulls, the antioxidant hierarchy was the same. The outer layers of grains had higher amount of phenolic compounds and subsequently higher antioxidant activity. Buckwheat had the highest amount of total phenolics, with the highest DPPH radical scavenging activity and capacity for Fe3+ reduction, but it had the lowest lipid peroxidation inhibition ability.Cilj rada je bio da se ispita antioksidativna aktivnost etanolnog ekstrakta zrna cerealija i njihovih morfoloških frakcija. Ispitivani se : pšenica (Triticum durum L.), ječam (Hordeum vulgare L.), raž (Secale cereale L.) i heljda (Fagopyrum esculentum). Određivan je sadržaj ukupnih fenola (TPC) metodom po Folin-Ciocalteu i antioksidativna aktivnost (AOA) po tri najčešće korišćene metode: DPPH (sposobnost neutralizacije 2,2-difenil-1-pikrilhidrazil radikala), FRAP (antioksidativna sposobnost redukcije Fe III jona) i TBA ( metoda sa tiobarbiturnom kiselinom). Antioksidativna aktivnost etanolnog ekstrakta celog zrna opada u sledećem nizu: heljda gt ječam gt pšenica gt raž. Isti odnos je dobijen i za mekinje. Spoljni slojevi zrna imaju veći sadržaj polifenola, pa sledstveno tome i veću antioksidativnu aktivnost. Heljda sadrži najviše polifenola i ima najveću antioksidativnu aktivnost određenu DPPH i FRAP metodom, ali ima najmanju sposobnost inhibicije lipidne peroksidacije