42 research outputs found
The content of heavy metals in the leaves of Hypericum perforatum L. on serpentinite soils in Serbia
St John's wort is one of the best known and used medicinal plants. The demands for St John's wort in Serbia is still supplied by the collection of native plants. Therefore it was necessary to examine the concentration of heavy metals in the soil and in plant material on serpentinites and to assess the potential safe harvesting and further utilisation of this plant species. The research was performed on three serpentinite sites in Serbia: Zlatibor, Divčibare and Goč. The main soil types were determined and the contents of 7 chemical elements were analyzed in the soil and in the plant material. It was determined that the soils of all three localities had increased concentrations of nickel, chromium and manganese. The St John's wort plant material (leaves) showed the increased concentrations of iron, nickel and chromium. It was concluded that St John's wort was a tolerant species regarding the heavy metal content, and it was recommended to avoid its harvesting on the investigated localities
Experimental determination of double vibe function parameters in diesel engines with biodiesel
A zero-dimensional, one zone model of engine cycle for steady-state regimes of engines and a simplified procedure for indicator diagrams analysis have been developed at the Laboratory for internal combustion engines, fuels and lubricants of the Faculty of Mechanical Engineering in Kragujevac. In addition to experimental research, thermodynamic modeling of working process of diesel engine with direct injection has been presented in this paper. The simplified procedure for indicator diagrams analysis has been applied, also. The basic problem, a selection of shape parameters of double Vibe function used for modeling the engine operation process, has been solved. The influence of biodiesel fuel and engine working regimes on the start of combustion, combustion duration and shape parameter of double Vibe was determined by a leastsquare fit of experimental heat release curve
Distribution of the genus Galanthus L. (Amaryllidaceae) in Serbia
The distribution of species from the genus Galanthus in Serbia is presented, and notes on their taxonomy and ecology are given in the paper. To date, only two species from the genus are known to be present, namely G. nivalis and G. elwesii. Further research on delimitation of the taxa occurring in Serbia is needed
Physico-chemical and mechanical properties of geopolymer/zircon composites
The effect of zircon (ZrSiO4) on the physico-chemical and mechanical properties of geopolymer/zircon composites was examined in this study. Four geopolymer/zircon composites containing 10, 20, 30 and 40 wt.% zircon were prepared from metakaolin with alkali activators. Characterization of the obtained geopolymers was performed by X-ray diffraction (XRD), Scanning electron microscope (SEM-EDS), Fourier transform infrared spectroscopy (FTIR) and Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF). XRD results did not confirmed the formation of interconnected phases between added zircon, starting aluminum silicates and alkali activators. Compressive strength of prepared geopolymer was examined. The maximum obtained compressive strength of 70.15 MPa was measured in sample containing the smallest fraction of zircon, i.e., 10 wt.%. Addition of larger amount of zircon (20 wt.%) hinders the progress of geopolymerization reaction and consequently decreases compressive strength
Synthesis and cytotoxic activity of selected dual COX-2 and 5-LOX inhibitors in HeLa and MIA PaCa-2 human cancer cell lines
Among novel cancer chemotherapy approaches, the use of cyclooxygenases (COXs) and lipoxygenases (LOXs) inhibitors represents a promising mean for cancer treatment showing lesser toxicity comparing to the currently used cytotoxic drugs. This study detailed the synthesis of three novel compounds: 1ME, BHTK-AA, and IBU-Ac, each with the capability to concurrently inhibit both COX-2 and 5-LOX. Subsequently, we assessed their effectiveness in inhibiting the proliferation of HeLa cervical and MIA PaCa-2 pancreatic cancer cells. The IC50 values for both examined cell lines were approximately 40 μM, indicating the promising inhibitory potential of the IBU-Ac compound in both types of cancer cells. This finding is positioned to stimulate further investigation into the potential application of IBU-Ac against these particular types of cancers, while also advocating its use in combination with standard anti-cancer protocols, i.e., chemoterapeutics or radiation therapy. The results of this work are also advocating the development and refinement of dual COX-2 and 5-LOX inhibitors, thus improving their efficacy and safety.ICCBIKG 2023 : 2nd International Conference on Chemo and Bioinformatics, September 28-29, 2023; Kragujeva
Physicochemical/structural investigation of lipid nanoparticles with high lecithin amounts loaded with patent protected pyrazoloquinolinone ligand DK-I-60-3
Molim vas da ovaj unos mapirate i u podgrupu NanoCellEmoCo
Dijabetesna nefropatija u tipu 2 dijabetesa: učestalost i faktori rizika
Uvod. Ciljevi rada su bili da se utvrdi učestalost i faktori rizika za dijabetesnunefropatiju (DN) kod bolesnika sa tipom 2 dijabetesa i faktori povezanisa pogoršanjem funkcije bubrega tokom trogodišnjeg perioda.Metode. Studija je obuhvatila 81 bolesnika sa tipom 2 dijabetesa kojisu na početku studije svrstani u dvije grupe: prva, 41 bolesnik sa DN (27muškaraca, 62,03 ± 7,73 godina) i druga, 40 bolesnika bez DN (17 muškogpola, 61,73 ± 11,55 godina). Svim bolesnicima je uzeta anamneza, urađenobjektivni pregled i laboratorijska ispitivanja. Na osnovu rezultata ispitivanja,poslije tri godine bolesnici obje grupe su podijeljeni u podgrupe sanepromjenjenom funkcijom bubrega i podgrupe sa pogoršanjem funkcijedefinisanim kao povećanje proteinurija i/ili smanjenje jačine glomerulskefiltracije (JGF) za više od 25%.Rezultati. Na početku ispitivanja zabilježena je visoka učestalost poznatihfaktora rizika za dijabetes i DN kod obje grupe. Multivarijantna logističkaanaliza izdvojila je ženski pol i trajanje dijabetesa kao značajne prediktoreDN. Nakon tri godine funkcija bubrega se pogoršala kod oko 50% bolesnikasa i bez DN, a u podgrupama sa pogoršanjem funkcije bubrega glikemijanašte i HbA1c su bili statistički značajno veći nego u podgrupama sastabilnom funkcijom bubrega. Linearna regresiona analiza je pokazala daje promjena JGF u trogodišnjem periodu značajno povezana sa starošćubolesnika, trajanjem dijabetesa, sistolnim krvnim pritiskom, razlikom u dijastolnomkrvnom pritisku i proteinuriji. Promjena u proteinuriji značajnoje povezana sa sistolnim krvnim pritiskom, razlikom u dijastolnom krvnompritisku, kao i HbA1c i JGF na kraju studije.Zaključak. Kod bolesnika sa tipom 2 dijabetesa ženski pol i duže trajanjedijabetesa izdvojeni su kao značajni faktori rizika za DN, a starost bolesnika,trajanje dijabetesa, povišen krvni pritisak, loša glikoregulacija kao faktoririzika za pogoršanje funkcije bubrega
Physicochemical/structural investigation of lipid nanoparticles with high lecithin amounts loaded with patent protected pyrazoloquinolinone ligand DK-I-60-3
Poster presented at 13th World meeting on pharmaceutics, biopharmaceutics and pharmaceutical technology, 28-31 March 2022, Rotterdam, Netherland
In vitro biological effects of clonal red wines
This study aimed to determine the phenolic compound content, in vitro antioxidative potential, and cytotoxic effects of four red wine samples: a commercial (V) and three clonal wines (V1, V2, and V3). LC/MS-MS, cyclic voltammetry, and MTT assay techniques were employed for this purpose. Results revealed that all wines were rich in phenolic compounds. Clonal wines outperformed the commercial ones in most phenolic compounds (except myricetin). Notably, V2 and V3 showed the highest levels of gallic acid, catechin, and epicatechin. Among them, V3 exhibited superior antioxidative activity. The MTT assay demonstrated stronger cytotoxic effects of the wine samples on pancreas (Bx-PC3) and colon (HT29) carcinoma cells (47% to 16% and 27% to 7% compared to control, respectively) than on the normal lung fibroblasts (MRC-5) cell line (106% to 77%). It can be concluded that HT29 cells were more sensitive than Bx-PC3 cells. Finally, both clonal and commercial wines serve as valuable sources of polyphenolic compounds, which could have a significant role in preventing cancer and diseases related to oxidative stress.ICCBIKG 2023 : 2nd International Conference on Chemo and Bioinformatics, 28-29 September 2023, Kragujevac, Serbi
A posteriori error bound methods for the inclusion of polynomial zeros
AbstractUsing Carstensen's results from 1991 we state a theorem concerning the localization of polynomial zeros and derive two a posteriori error bound methods with the convergence order 3 and 4. These methods possess useful property of inclusion methods to produce disks containing all simple zeros of a polynomial. We establish computationally verifiable initial conditions that guarantee the convergence of these methods. Some computational aspects and the possibility of implementation on parallel computers are considered, including two numerical examples. A comparison of a posteriori error bound methods with the corresponding circular interval methods, regarding the computational costs and sizes of produced inclusion disks, were given