An open-source pipeline for multivariate evaluation of ternary solvent system composition on HPTLC chromatograms

Fungi of the genus Ganoderma have been in the zeitgeist of medicinal fungi research and natural product chemistry for more than 20 years [1], yet this model system still presents challenges in obtaining the highest product yield while preserving good quality. A lot of work has gone into learning the relationships between solvent systems used for extraction and large spectra of compounds within this genus of fungi. The High-Performance Thin Layer Chromatography is a cheap and reliable method for qualitative and quantitative studies in mushrooms using chemometrics [2]. When using HPTLC, preprocessing of chromatograms, such as spectral warping, can give variable results based on the algorithm used and its parameters [3]. Here, we present an open-source pipeline for optimizing chromatogram warping algorithms and building multivariate models using Orange Data Mining [4] software as well as R and Python programming languages. Orange Data Mining is used as a quick and visual way to inspect how changes in the dataset impact the models, while R and Python fill the void of using more specialized tools, not yet implemented in software. Using this pipeline, it is possible to pinpoint pre-processing methods in order to obtain the best supervised and unsupervised models, as well as to elucidate the most important factors and their impacts on composition within Box-Behnken design. Open-source models also allow better verifiability and reproducibility of methods across the scientific community.Poster: [https://cherry.chem.bg.ac.rs/handle/123456789/7721

Synthesis, characterization and antimicrobial activity of novel Pd(II) complexes with athracenyl-based Schiff bases

Four new Schiff bases, one well-known Schiff base, and five new Pd(II) complexes were synthesized, characterized, and evaluated in their antimicrobial activities. New ligands were synthesized in the reaction of 9-anthracenecarboxaldehyde and phenylenediamines (4-methyl-1,2-phenylenediamine, 4-chloro-1,2-phenylenediamine, 4,5-dimethyl-1,2-phenylenediamine, and methyl 3,4-diaminobenzoate). The chemical structures of all synthesized compounds were confirmed using standard NMR and IR spectroscopy, and MS spectrometry, as well as molar conductivity measurements, while their purity was evaluated by elemental analysis. The antimicrobial activities of these novel compounds were assessed in vitro against a representative panel of microbial strains. The test organisms included three Gram-positive bacteria (Staphylococcus aureus, Bacillus cereus, and Enterococcus faecalis), four Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis, and Enterobacter aerogenes), and a single yeast strain (Candida albicans ATCC 10231), selected to assess antifungal activity. The assay included two commercial antibiotics, streptomycin and chloramphenicol, as positive controls to ensure assay validity and enable comparative analysis of antimicrobial activity. The free ligands exhibited limited antimicrobial activity, while the metal complexes demonstrated significantly enhanced, broader-spectrum activity. Complex C2 (with N,N’-(4-methyl-1,2-phenylene)bis(1-(anthracen-9- yl)methanimine)) showed the best activity, surpassing the standard antibiotics streptomycin and chloramphenicol in several cases

Uticaj Wilsonove bolesti na status esencijalnih elemenata u tragu: analiza uzoraka pune krvi i urina

U ovom radu ispituje se koncentracija elemenata u tragu (Cu, Zn, Fe, Mn i Se) u biološkim uzorcima primenom ICP-MS metode. Posebna pažnja posvećena je bakru kao ključnom elementu u patogenezi Wilsonove bolesti. Cilj rada je da se na osnovu analize dostupnih eksperimentalnih podataka sagledaju promene u koncentracijama ovih elemenata i njihov značaj u kontekstu Wilsonove bolesti

Mentha piperita Essential Oil in Olive Oil: Extending Erythrocyte Viability and Limiting Bacterial Growth Under Serum-Free Conditions

Background: Serum-free culture of red blood cells (RBCs) typically leads to rapid loss of viability, limiting experimental and translational applications. Lipid-rich formulations and essential oils may provide biocompatible support for RBC integrity while limiting microbial overgrowth. Methods: RBCs from nine healthy adult donors were cultured in serum-free RPMI under four conditions: control, vehicle (olive oil, 1:100 v/v), genuine adenosine triphosphate (ATP)-oil® (1:100 v/v), and laboratory oil, “mimicking” ATP-oil®. Cultures were maintained for 18 days. Viability was assessed by light microscopy and trypan blue exclusion; bacterial contamination was qualitatively observed on day 18. Results: Genuine ATP-oil® maintained 35–45% RBC viability at day 18, whereas control and vehicle cultures declined rapidly. The mimicking preparation did not reproduce these effects. ATP-oil® immersion was associated with a qualitative reduction in bacterial contamination versus control, consistent with a dual action on RBC preservation and microbial suppression under serum-free conditions. Conclusions: Supplementation with ATP-oil® substantially prolongs RBC survival and limits bacterial overgrowth in vitro, outperforming commonly used serum or plasma supplements on a per-volume basis. These findings suggest potential applications for improving ex vivo handling or storage of blood components and for reducing background contamination in diagnostic microbiology. Further studies with larger cohorts are warranted to reveal underlying mechanisms and to define active constituents in order to standardize production

Elementarni status malignih tkiva pluća

Cilj ovog rada je ispitivanje elementarnog statusa malignog plućnog tkiva i poređenje dobijenih rezultata sa koncentracijama elemenata u zdravom plućnom tkivu. Dodatni cilj istraživanja je poređenje dobijenih rezultata sa podacima iz naučne literature kako bi se utvrdile eventualne sličnosti i razlike u koncentracijama analiziranih elemenata

Промене епикутикуларног воска код листова Chenopodium album L. и Abutilon theophrasti Medik. различите старости

Epicuticular wax comprises a complex mixture of diverse organic compounds. The predominant class of compounds consists of long-chain n-alkanes. Chenopodium album and Abutilon theophrasti are cosmopolitan weed species, both of economic importance due to difficulties in control, and both species produce wax on the leaf surface. This study shows that in C. album, the proportion of epicuticular waxes has higher values in the oldest leaves and lower in the youngest leaves. Conversely, in A. theophrasti, the mean wax content tended to be slightly higher in the younger upper leaves compared to the lower leaves. The proportion of waxes in leaves does not reflect the stage of development in either species. In the epicuticular wax composition of C. album leaves, alkanes and alcohols are the most abundant compounds. Conversely, in A. theophrasti leaves, alkanes, alcohols, and triterpenes dominate. Quantitative variations in leaf epicuticular waxes are influenced by leaf age.Епикутикуларни воскови се састоје од комплексне мешавине различитих органскихједињења. Преовлађујућа класа једињења се састоји од n-алкана. Chenopodium album иAbutilon theophrasti су космополитске коровске врсте, обе од економског значаја због потешкоћа у сузбијању и обе врсте синтетишу восак на површини листова.Ово истраживање је показало да је код C. аlbum садржај воскова највећи код најстаријих листова, анајмањи код најмлађих листова. Насупрот томе, код A. theophrasti је садржај восковаконстантан код млађих листова као и код старијих. Удео воскова у листовима не зависиод старости листова код обе врсте. У садржају епикутикалних воскова листова C. аlbumдоминирају алкани и алкохоли. Док код листова A. theophrasti доминирају алкани, алкохоли и тритерпени. Квантитативне варијабилности епикутикуларних воскова зависе од старости листова

Insights into adaptation mechanisms and survival strategies of Pseudomonas chlororaphis subsp. aurantiaca: A comparative proteomic study under PFOA exposure

Perfluorooctanoic acid (PFOA), increasingly detected at extreme concentrations in industrial hotspots, caused a reduction in growth and a prolonged lag phase in Pseudomonas chlororaphis subsp. aurantiaca. In order to reveal microbial adaptation mechanisms and survival strategies under exposure to PFOA, a comparative proteomic analysis was undertaken. The up-regulation of phosphoglycerol transferase, lipoproteins, and long-chain fatty acid synthesis, together with the down regulation of cis unsaturation of fatty acids and changes in specific membrane-embedded porins, indicate alterations in membrane structure, fluidity, and permeability. The up-regulation of the divalent cation–regulated outer membrane protein H1, accompanied by the down-regulation of zinc and other metal transporters, reflect changes in metal ion homeostasis. In particular, altered iron homeostasis and expression of iron-, Fe-S clusters-, and heme-containing proteins were detected, along with the reduced activity of some iron-containing enzymes, as a result of inhibition by PFOA. Up-regulated enzymes of the methylcitrate and the glyoxylate cycles indicate alterations in central metabolic pathways associated with lipid metabolism in PFOA-treated cells. Changes in the respiratory chain may influence enhanced superoxide radical formation, triggering increased ROS production and the up-regulation of antioxidant enzymes, except those involved in thiol-based redox processes. In addition, PFOA alters the regulation of virulence-associated proteins

Efficient Schweizer’s reagent-based protocol for microplastic extraction from fecal samples: Toward standardized human biomonitoring

Reliable methods for the isolation of microplastics (MPs) from human feces are essential for advancing exposure and health risk assessment. However, the cellulose-rich fecal matrix is analytically very challenging. This study evaluated two different pre-treatments in protocols for MPs isolation from fecal samples. Protocol A, involved pre-treatment with a urea/thiourea/KOH (UTS) solution, followed by a comprehensive four-step digestion process (acidic, enzymatic, alkaline, and oxidative digestion) and Protocol B, involved Schweizer’s reagent (copper(II) hydroxide in ammonium hydroxide, SR) for pre-treatment, followed by the same four digestion steps. The protocol based on SR pre-treatment was further optimized. The developed protocol achieved >99.8% removal of biological matrix and a 98 ± 3% recovery rate across five polymer standards, without interfering with polymer identification by µ-FTIR. The method was successfully applied to children’s stool samples, detecting MPs in 7 of 14 cases with concentrations ranging from 1.18 to 7.25 items g−¹ feces. The size of the detected MPs ranged from 40 to 300 μm. Polyethylene was the dominant polymer (56%), and fragments represented the main morphology (69%). Compared to conventional digestion workflows, the SR-based approach offers clear advantages in efficiency, reproducibility, and cost, making it well-suited for routine application in clinical and environmental health laboratories. By facilitating standardization in fecal MP analysis, this method may provide a practical tool for large-scale biomonitoring studies. Building on its established use in ASTM D8333 for water and wastewater, this is the first application of SR to cellulose-rich biological matrices

Proizvodnja rekombinantnog alergena PR-10 iz graška (Pisum sativum) i ispitivanje njegovog efekta na THP-1 makrofage

PR-10 proteini su superfamilija proteina koji učestvuju u imunološkoj odbrani biljaka od stresa. Oni takođe predstavljaju alergene, koji mogu izazivati nepovoljne simptome i reakcije kod ljudi. Alergije su jako učestale u proslednjih nekoliko decenija, posebno u razvijenim zemljama, i zbog toga je potrebno identifikovati i okarakterisati sve alergene iz hrane koja se koristi u ljudskoj ishrani. PR-10 alergen iz graška (Pisum sativum) predstavlja jedan od takvih alergena, a usled velike upotrebe graška u ishrani i nedovoljne istraženosti njegovih alergenih svojstava, potrebno je uraditi dodatna ispitivanja. Cilj ovog master rada je bila heterologa proizvodnja PR-10 proteina iz graška u E. coli i ispitivanje efekata njegovog dejstva na THP-1 ćelijsku liniju diferenciranih makrofaga

Виртуелне лабораторије као средство за унапређивање разумевања фундаменталних хемијских концепата код ученика основних школа

Previous research indicates that laboratory experimentation is considerably more effective than traditional receptive teaching in promoting the development of elementary school pupils’ understanding of fundamental chemistry concepts. Thus, for elementary schools that do not have a chemical laboratory, the use of virtual laboratories that are freely available from numerous educational websites was recommended. To compare the impact of virtual laboratory experimentation and traditional receptive teaching on the development of elementary school pupils’ understanding of fundamental chemistry concepts, a pedagogical experiment with parallel groups was conducted. The experiment was organized within the elaboration of the teaching topic Solutions, and it included 137 seventh-grade pupils (70 pupils in the experimental and 67 pupils in the control group). To assess the pupils’ understanding of the composition and preparation of solutions, a test comprised of six open-ended questions was used. The pre-testing showed that none of the pupils had previous knowledge related to this content. However, on the posttest, the experimental group archived a significantly higher overall percentage of correct answers (t (135) = 2.105, p = 0.037), which implies that virtual laboratories are highly effective in enhancing elementary school pupils’ understanding of fundamental chemistry concepts.Претходна истраживања указују да je експериментални лаборато- ријски рад далеко ефективнији од традиционалне рецептивне наставе у погледу подстицања развоја разумевања фундаменталних хемијских конце- пата код ученика основних школа. Последично, основним школама које не- мају хемијску лабораторију препоручено је коришћење виртуелних лабора- торија, које су бесплатно доступне на бројним образовним веб-сајтовима. Ради поређења утицаја експерименталног рада у виртуелним лабораторијама и традиционалне рецептивне наставе на развој разумевања фундаменталних хемијских концепата код ученика основних школа, спроведен је педагошки експеримент са паралелним групама. Експеримент је организован у оквиру обраде наставне теме Раствори и у њему је учествовало 137 ученика седмог разреда (70 ученика у експерименталној и 67 ученика у контролној групи). За проверу ученичког разумевања састава и припреме раствора коришћен је тест који се састојао из шест питања отвореног типа. Иницијално тестирање је показало да нико од ученика није поседовао предзнања везана за помену- те наставне садржаје. Међутим, на завршном тесту, ученици из експеримен- талне групе остварили су статистички значајно већи укупан проценат тачних одговора (t (135) = 2,105, p = 0,037), што указује да су виртуелне лабораторије веома ефективне у погледу унапређивања разумевања фундаменталних хе- мијских концепата код ученика основних школа