Chemical Composition and Antibacterial Activity of Angelica archangelica Root Essential Oil

Roots of wild growing Angelica archangelica L. from Mt. Ozren (Serbia) were subjected to hydrodistillation and GC-MS analysis. The roots contained 0.10% of essential oil with alpha-pinene (29.7%), delta-3-carene (14.2%), and a mixture of beta-phellandrene and limonene (13.2%) as main compounds. The modified resazurin microtiter-plate assay was used to evaluate the antibacterial activity of the essential oil against Staphylococcus aureus and Escherichia coli. The minimum inhibitory concentration (MIC) values were 14.2 mu L/mL for S. aureus and 28.4 mu L/mL for E. coli, while the minimum bactericidal concentrations (MBC) were 56.8 mu L/mL and 113.6 mu L/mL, respectively. According to the obtained results, the angelica root essential oil can be applied as a natural preservative in food and as a natural antibiotic for the treatment of several infectious diseases caused by these two bacteria

Copper Electrodeposition onto Palladium from a Deep Eutectic System Based on Choline Chloride

Recently, there has been an increasing interest in developing nonaqueous electrolytes which have been widely employed as an alternative media for a range of metals and metal alloys electrodepositions. A promising and new class of electrolytes among ionic liquids (Ils) are deep eutectic solvents (DESs)1 . The purpose of the copper deposition study from DESs is the application of copper coating and copper alloys in both, industry and fundamental research. In this work, the electrochemical deposition of copper onto palladium working substrate from ChCl/EG (1:2 ratio) DES electrolyte at 50°C was investigated. Additionally, the Cu(II) electroreduction process was studied by potentiodynamic measurements, cyclic voltammetry, chronoamperometry, in the electrolytes with different concentrations of Cu(II) ions ranging from 0.1 M to 0.5 M. The cyclic voltammetry results indicated that the bulk deposition of Cu(II) begins to occur at around –0.080 V vs. Cu. It was found that copper deposition onto the Pd cathode from ChCl:EG electrolyte under potentiostatic conditions is achievable. Data collected from X-ray diffraction (XRD) analysis proved that the cathodic deposits are composed of Cu and CuPd intermetallic. CuPd alloys with different Pd-Cu ratios were prepared by constant potential of –0.100 V vs. Cu from ChCl/EG containing 0.1 M and 0.5 M Cu(II). It is worth noting that the Xray data indicated that the composition of the produced Pd-Cu films could be varied by changing the concentration of Cu(II) ions in the electrolyte or changing the deposition mode

Chemical Characterization and Antibacterial Activity of Essential Oil of Medicinal Plants from Eastern Serbia

The objective of this study was to evaluate wild growing Satureja kitaibelii, Thymus serpyllum, Origanum vulgare, Achillea millefolium and Achillea clypeolata with respect to their essential oil (EO) content, composition and antimicrobial activity. The five species were collected at Mt. Rtanj and the village of Sesalac, Eastern Serbia. The main EO constituents of Lamiaceae plants were p-cymene (24.4%), geraniol (63.4%) and germacrene D (21.5%) in Satureja kitaibelii, Thymus serpyllum and Origanum vulgare ssp. vulgare, respectively. A. millefolium EO had multiple constituents with major ones being camphor (9.8%), caryophyllene oxide (6.5%), terpinen-4-ol (6.3%) and 1,8-cineole (5.6%), while the main EO constituents of A. clypeolata were 1,8-cineole (45.1%) and camphor (18.2%). Antimicrobial testing of the EO showed that Staphylococcus aureus (Gram-positive) was more sensitive to all of the tested EOs than Escherichia coli (Gram-negative). S. kitaibelii EO showed the highest antimicrobial activity against both tested bacterial strains. This is the first study to characterize the EO composition and antimicrobial activity of these five medicinal species from Eastern Serbia in comparison with comprehensive literature data. The results can be utilized by the perfumery, cosmetics, food and pharmaceutical industries, but also for healing purposes in self-medication

Relations between (κ, τ)-regular sets and star complements

Let G be a finite graph with an eigenvalue μ of multiplicity m. A set X of m vertices in G is called a star set for μ in G if μ is not an eigenvalue of the star complement G\X which is the subgraph of G induced by vertices not in X. A vertex subset of a graph is (k ,t)-regular if it induces a k -regular subgraph and every vertex not in the subset has t neighbors in it. We investigate the graphs having a (k,t)-regular set which induces a star complement for some eigenvalue. A survey of known results is provided and new properties for these graphs are deduced. Several particular graphs where these properties stand out are presented as examples

Copper Electrodeposition onto Palladium from a Deep Eutectic System Based on Choline Chloride

In this work, the electrochemical deposition of copper onto palladium working substrate from ChCl/EG (1:2 ratio) DES electrolyte at 50°C was investigated. Additionally, the Cu(II) electroreduction process was studied by potentiodynamic measurements, cyclic voltammetry, chronoamperometry, in the electrolytes with different concentrations of Cu(II) ions ranging from 0.1 M to 0.5 M

Actual contamination of the Danube and Sava Rivers at Belgrade (2013)

This study was focussed on a comprehensive investigation on the state of pollution of the Danube and Sava Rivers in the region of Belgrade. Different complementary analytical approaches were employed covering both i) organic contaminants in the river water by target analyses of hormones and neonicotinoids as well as non-target screening analyses and ii) heavy metals in the sediments. Finally, some common water quality parameters were analysed. The overall state of pollution is on a moderate level. Bulk parameters did not reveal any unusual observations. Moreover, quantification of preselected organic contaminants did not indicate to elevated pollution. More significant contaminations were registered for chromium, nickel, zinc and partially copper in sediments with values above the target values according to Serbian regulations. Lastly, non-target screening analysis revealed a wider spectrum of organic contaminants comprising pharmaceuticals, technical additives, personal care products and pesticides. The study presented a comprehensive view on the state of pollution of the Sava and Danube Rivers and is the base for setting up further monitoring programs. As a superior outcome, it was illustrated how different chemical analyses can result in different assessments of the river quality. A comparison of target and non-target analyses pointed to potential misinterpretation of the real state of pollution

Activity patterns and habitat preference of eastern Hermann’s tortoise(Testudo hermanni boettgeri) in Serbia

We analyzed variation in the distribution of eastern Hermann’s tortoise (Testudo hermanni boettgeri) in a complex landscape consisting of both natural and human-altered habitats in a temperate climate region in Serbia. Our results indicated nonrandom distribution of tortoises within different habitat types with large and medium effect size for year and activity pattern, respectively. Additionally, the tortoises expressed relatively weak preference for habitats modified by human activity (e.g., vineyards, orchards, or gardens). The results suggested that these tortoises preferred some particular habitats more than others when performing specific activities. They also did not exhibit the same distribution pattern among habitats over consequent years. In other words, they were not randomly distributed among habitat types with regard to specific activity or year. The information on preferences in complex habitat systems is important for the conservation management of eastern Hermann’s tortoise and should be considered when planning activities related to sustainable development within the region of study

Тransnational Project “Vox Mundi“ – Experience with Implementing Movement as a Pedagogical Tool in Working with Children’s Choirs

Starting from the fact that from the onset of formal education students encounter choral singing as an activity successively linked to general music education, the paper emphasizes the importance of using movement as a pedagogocal tool for the development of immanent rhythm, vocal technique, and intonation in working with children’s choirs. The main purpose of this research is to systematize the experience gained in the transnational project “Vox Mundi“ carried out in Temisoara, Romania in 2022 in order to point to potential choices and future approaches to movement at choral rehearsals at general mucis education level. In the course of a ten-day intensive youth exchange, five multiplicative events, and the elaboration of three intellectual outcomes, a survey was conducted, with the sample including 50 elementary school choir singers, members of choral organizations of five partner countries (Romania, Serbia, Poland, France and Hungary). By reviewing and unifying the exercises from different choral music activites, we modeled an approach to specific general music education resources with the aim of acquiring the skills and competencies necessary for using movement with polyphonic singing. A significant level of advantages of integrating movement and singing was identified, while the correlation between the delibarate use of movement and an increased engagement was also identified as a factor that was consistently present. In addition, it was discovered that movement and music can illustrate emotional meaning of music and improve relationships among choral singers. This article focuses on practical suggestions which can provide new points for discussion on the necessity of using movement in working with members of children’s choirs, children who are in the first or second cycle of elementary education

Bioactivity of blackberry (Rubus fruticosus L.) pomace: Polyphenol content, radical scavenging, antimicrobial and antitumor activity

A large volume of industrial waste of biological origin is produced annually worldwide, causing a serious disposal problem even though it is a huge source of beneficial compounds which may be used for their high nutritional and bioactive properties. The bio-potential of blackberry pomace (waste) obtained after juice separation from the Čačanska bestrna and Thornfree cultivars was evaluated. Higher amounts of total and monomeric anthocyanins, total phenolics, and total flavonoids were found in Thornfree pomace extract and demonstrated stronger 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (2.12 mmol TEAC g-1) than Čačanska bestrna pomace extract (1.03 mmol TEAC g-1). Both extracts highly increased apoptosis/necrosis ratios in all investigated cell lines. The highest cell growth inhibition effects (EC50=52.5 - 64.7 μg mL-1) and the highest increase of apoptosis (AI=12.2) were obtained in breast adenocarcinoma cell line. Both blackberry pomace extracts inhibited the growth of all tested microorganisms. In the reference and wild bacterial strains MIC and MBC/MFC were achieved in the 0.39-25 mg mL-1 and 0.78-25 mg mL-1 range, respectively. Blackberry cultivar pomaces are rich source of phytochemicals with significant health promoting properties that could be further utilized as beneficial food ingredients. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 31044