141 research outputs found
Variability of pomological characteristics of the Šumatovka apple
Variability refers to a process by which differences occur among individuals of the same plant species. However, some characteristics change very little while others, especially quantative ones, change rather quickly and readily even when environmental conditions change slightly. This fact has prompted an investigation aimed to establish the variability of pomological characteristics of the Šumatovka cv. apple tree, a rather old and autochthonous cultivar grown widely throughout Eastern Serbia. Its special characteristic is an ability to grow and bear fruit without any particular care and cultivation, and in conditions of especially severe water deficiency and drought. Šumatovka cv. fruits are small- or medium-sized on the average, the length Measuring 51.3 ± 6.62 mm (CV 12.9%), width 55.5 ± 6.35 mm (CV 11.4%), pedicel lenght 19.5 ± 3.2 mm (CV 16.4%) and fruit mass 66.0 ±20.6 g (CV 31.3%). Total soluble dry matter content of the mesocarp varies between 15.6 and 1.92% (CV 12.31%), total sugars 14.3 ± 4.7% (CV 32.8%) and total sour substances 0.95 ± 0.11% (CV 18.6%). Especially examined were the large-sized Šumatovka fruits measuring 72.0 mm in lenght and width, and 169.4 g in mass
One Review on Solid Oxide Fuel Cell Applications
The fuel cell is a highly efficient electrochemical clean energy conversion device that converts chemical energy into electrical energy by reacting gaseous fuel (H+) with oxidizing gas (O2-) though a solid ion conducting electrolyte with reduced greenhouse gas emission and reduced oil consumption. FC generates high alteration efficiencies as compared to the other available conventional combustion engine mechanical approaches. The working principle of batteries and fuel cell are analogues to each other for the production of electricity. Oxygen pass through the cathode and hydrogen or hydrocarbon fuels supply through the anode, and then the electrochemical reaction takes place at the electrode/electrolyte interface due to the active charge carrier passing through the electrolyte, thereby releasing the electrons into external circuit to generate electricity without pollution. There is no need to store energy as it is a continuous reforming process as long as both fuel and oxidant are provided in the fuel cell continuously. Thus, the main characteristic of a fuel cell is the production of highly efficient energy with negligible pollution. Thus, in the 21st century, energy technology such as fuel cell becomes a key determinant factor of economic development and is essential to raising the living standards in the form of the most influencing and challenging alternating source of generation of electricity
Sinteza i kristalna struktura 1,2,3,4-tetrahidro-9-aminoakridin-tetrahlorocinkata(II) monohidrata
In the reaction of ZnCl(2) with tacrine hydrochloride in water novel tetracoordinated (C(13)H(15)N(2))(2)[ZnCl(4)]-H(2)O complex was obtained and characterized by elemental analysis, molar conductivity and X-ray analysis. The complex crystallizes in the space group P-1 of the triclinic crystal system. The structure contains two crystallographically different molecules of protonated tacrine present as counter cations, the [ZnCl(4)](2-) complex anion and one water solvent molecule. The counter cations slightly differ in the puckering of the cyclohexene ring. The molecules of protonated tacrine are involved in different intermolecular hydrogen bonds. In the crystal, the hydrogen bonding generates a 3D assembly. In the crystal, pi center dot center dot center dot pi stacking interactions between the rings of protonated tacrine were evidenced. The [ZnCl(4)](2-) complex anion has a distorted tetrahedral geometry. Three out of the four Cl atoms are involved in intermolecular hydrogen bonding. The intermolecular H-bond interactions involving the Cl atoms affect the Zn-CI bond lengths.U reakciji ZnCl2 sa takrin-hidrohloridom u vodi, dobijen je novi tetrakoordinovani (C13H15N2)2[ZnCl4]?H2O kompleks koji je okarakterisan pomoću elementalne analize, molarne provodljivosti i rendgenske strukturne analize. Kompleks kristališe u prostornoj grupi P?1 trikliničnog kristalnog sistema. Struktura sadrži dva kristalografski različita molekula protonovanog takrina koji su prisutni kao kontra-katjoni, [ZnCl4]2 kompleksni anjon i molekul kristalne vode. Molekuli katjona se neznatno razlikuju u stepenu nabiranja cikloheksenovog prstena. Molekuli protonovanog takrina su uključeni u različite intermolekulske vodonične veze. Intermolekulsko vodonično vezivanje u kristalu generiše 3D molekulski skup pi...pi interakcije između prstenova protonovanog takrina su primećene u kristalu. [ZnCl4]2- ima distorgovanu tetraedarsku geometriju. Tri od četiri Cl atoma su uključena u intermolekulske vodonične veze. Intermolekulske vodonične interakcije koje uključuju Cl atome utiču na dužinu Zn-Cl veza
Visoki antioksidativni potencijal i mali toksični efekat selenosemikarbazonskih kompleksa
Novel metal-based compounds with therapeutic potential have become the subject of intense investigations in inorganic chemistry and biomedical science. Recently, strong dose-dependent cytotoxic activities of selenosemicarbazone metal complexes against several human cancer cell lines were demonstrated. The aim of the present study was to investigate in vitro antioxidative potential of Ni(II), Cd(II) and Zn(II) selenosemicarbazone complexes. All three investigated complexes exhibited high 2,2'-azinobis(3-ethyl-benzothiazoline-6-sulphonic acid) radical cation (ABTS(center dot+)) scavenging capacity, comparable with ascorbic acid. In an acute toxicity study, administration of the compounds was performed orally to mice at single doses. The mice were observed for clinical signs, body weight effects and mortality for 14 days, after which they were sacrificed for gross organ necropsy. The body weight did not vary after administration, and the autoptic analysis failed to show appreciable macroscopic alterations of internal organs. Generally, the compounds exhibited low toxic effects as required for further in vivo therapeutic studies.Nova jedinjenja na bazi metala sa terapeutskim dejstvom postala su predmet istraživanja u neorganskoj hemiji i biomedicinskim naukama. Pokazana je jaka dozno-zavisna citotoksična aktivnost kompleksa selenosemikarbazona na većem broju ćelijskih linija humanih ćelija kancera. Cilj rada je ispitivanje in vitro antioksidativnog dejstva selenosemikarbazonskih kompleksa nikla, cinka i kadmijuma. Sva tri ispitivana kompleksa pokazala su jaku antioksidativnu aktivnost prema ABTS radikalu, uporedivu sa aktivnošću askorbinske kiseline. Tokom ispitivanja akutne toksičnosti, jedinjenja su oralno davana miševima u pojedinačnim dozama i praćeni su klinički znaci, težina tela i mortalitet nakon 14 dana, a potom su životinje žrtvovane radi autopsije organa. Težina tela nije varirala nakon aplikacije. Generalno, jedinjenja su pokazala mali toksični efekat što i zahteva buduće in vivo terapeutsko ispitivanje
2,2 '-{1,1 '-[2,2 '-Oxalylbis(hydrazin-2-yl-1-ylidene)]diethylidyne}dipyridinium bis(perchlorate) dihydrate
The title salt, C(16)H(18)N(6)O(2)(2+)center dot 2ClO(4)(-)center dot 2H(2)O, was obtained unintentionally as a major product in the reaction of Zn(ClO(4))(2)center dot 6H(2)O with the N',N'(2)-bis[(1E)-1-(2-pyridyl)ethylidene]ethanedihydrazide (H(2)L) ligand. The (H(4)L)(2+) cation lies across a centre of inversion. The pyridiniumimine fragments of (H(4)L)(2+) adopt syn orientations. Intramolecular N-H center dot center dot center dot N and N-H center dot center dot center dot O hydrogen bonds lead to the formation of S(5) motifs. In the crystal, neighbouring cations are connected by pi-pi interactions between pyridinium units with a centroid-centroid distance of 3.600 (1) angstrom. Moreover, the crystal components are assembled into two-dimensional layers via N-H center dot center dot center dot O and O-H center dot center dot center dot O hydrogen bonds, with no direct hydrogen-bonding interactions between cations
Nicotiana glauca Graham (Solanaceae), a new invasive plant in Croatia
The South American species Nicotiana glauca Graham (Solanaceae) is invasive in the western Mediterranean and has been found for the first time at four localities in Croatia. The first locality was discovered in 1977 on the island of Lokrum, but has previously been neglected, the second in Komi`a on the island of Vis, the third in the city of Split and the fourth in the city of Dubrovnik. The newly discovered N. glauca is a woody perennial species, while two other Nicotiana species occurring in Croatian, N. tabacum L. and N. rustica L., are annual herbs. An identification key for these three species and their morphological
comparison is presented. The further spreading of N. glauca in Croatian littoral can be expected, and should be prevented
Sodium-alginate biopolymer as a template for the synthesis of nontoxic red emitting Mn2+-doped CdS nanoparticles
Manganese-doped cadmium sulfide (CdS:Mn) nanoparticles were prepared by chemical synthesis using sodium-alginate as template. The preparation of the nanocomposites involved ionic crosslinking of the biopolymer by dimerization of its alpha-L-guluronic monomers with Cd2+ and subsequent formation of the semiconductor nanoparticles upon addition of sulfide ions in the presence of Mn2+. The crystalline phase of CdS in the material was confirmed by XRD. The surface morphology of the nanocomposites was investigated by SEM. The observation by TEM showed that the CdS:Mn particles were spherical in shape with diameters of approximately 4 nm. EPR measurements of the CdS:Mn-alginate nanocomposite showed that the Mn2+ ions were incorporated in cationic sites of CdS with lower symmetry. Due to a distorted crystal field induced by the Mn2+ ions, photoluminescence spectra of the CdS:Mn-alginate showed red fluorescence between 650 nm and 750 nm falling into the optical window for bioimaging in which the light has its maximum tissue penetration depth. It was demonstrated that the interaction between the nanoparticles and the matrix prevents release of CdS into the environment, leading to low acute toxicity of the nanocomposites
Supplementary data for the article: Filipović, N. R.; Marković, I.; Mitić, D.; Polović, N.; Milčić, M.; Dulović, M.; Jovanović, M.; Savić, M.; Nikšić, M.; Andelković, K.; et al. A Comparative Study of In Vitro Cytotoxic, Antioxidant, and Antimicrobial Activity of Pt(II), Zn(II), Cu(II), and Co(III) Complexes with N-Heteroaromatic Schiff Base (E)-2-[N’-(1-Pyridin-2-Yl-Ethylidene)Hydrazino]Acetate. Journal of Biochemical and Molecular Toxicology 2014, 28 (3), 99–110. https://doi.org/10.1002/jbt.21541
Supplementary material for: [https://doi.org/10.1002/jbt.21541]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1509
Sinteza, NMR i DFT proračunavanja i ispitivanje antimikrobne aktivnosti Zn(II) kompleksa sa N-benziloksikarbonil-S-alaninom
In this study, the first complexes of Zn(II) with the N-benzyloxycarbonyl-S-alaninato ligand (N-Boc-S-ala) were synthesized. The new complexes were characterized by elemental analysis, conductometric measurements, IR. (1)H-NMR, (13)C-NMR and 2D-NMR spectroscopy. On the basis of the experimental data, tetrahedral geometry of the Zn(II) complexes was proposed. A very good agreement between the NMR and DFT calculated data was obtained. Investigation of antimicrobial activity of the newly synthesized complexes was also performed. It was established that [Zn(N-Boc-S-ala)(2)] was selective and acts only on Candida aibicans.U ovom radu su sintetizovani prvi kompleksi Zn(II) sa N-benziloksikarbonil-S-alaninato ligandom (N-Boc-S-ala). Kompleksi su okarakterisani elementalnom analizom, konduktometrijskim merenjem, IR, 1H-NMR, 13C-NMR i 2D-NMR spektroskopijom. Tetraedarska geometrija Zn(II) kompleksa pretpostavljena je na osnovu eksperimentalnih podataka. Dobijeno je veoma dobro slaganje između NMR i DFT podataka. Ispitivana je antimikrobna aktivnost novosintetizovanih kompleksa. Ustanovljeno je da je [Zn(N-Boc-S-ala)2] kompleks selektivan i da deluje samo na gljivu Candida albicans
- …