Prilog flori otoka Malog Drvenika

Since there has been to date no account of the flora of the island of Mali Drvenik, we have begun floristic research that is still in progress. We have found 100 taxa of vascular plants (36 families), recorded for this island for the first time.Prigodom florističkih istraživanja na otoku Malom Drveniku pronašli smo 100 svojti vaskularnih biljaka (svrstanih u 36 porodice) koje dosad nisu bile zabilježene na ovom otoku. Floristička istraživanja se nastavljaju

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

Kinetic Determination of Arsenic(III) as Inhibitor of Victoria Blue 4R Oxidation in Strong Acid Solution

A new selective, sensitive and simple kinetic method was developed for the determination of As3+ traces in solution on the basis of their inhibiting effect on Victoria blue 4R (VB) oxidation by KBrO3 in the presence of HCl. The reaction was followed spectrophotometrically at 596.3 nm. The detection limit was 50.00 ng cm–3. The relative error vas 4.2 % to 1.5 % for As3+ in the concentration range from 80.00 to 350.00 ng cm–3. Also, appropriate kinetic equations were formulated and the influence of different ions upon the reaction rate was studied. The developed procedure was successfully applied to the determination of As3+ in various model and real samples

Biological Activity of Some Cobalt(II) and Molybdenum(VI) Complexes: in vitro Cytotoxicity

Cytotoxicity and cell growth inhibition studies were performed for five distinct cobalt(ll) [Co2(acac)tpmc](ClO4)3, [Co2(dibzac)tpmc](ClO4)3, [Co2(hfac)tpmc](CIO4)2, [Co2(tmhd)tpmc](CIO4)3 and [Co2(ox)tpmc](CIO4)2.3H20 and five molybdenum(Vl) complexes, [MoO2(pipdtc)2], [MoO2(morphdtc)], [MoO2(timdtc)2], [MoO2(pzdtc)2] and [MoO2(N-Mepzdtc)2]. The former were tested in two leukemia cell lines: chronic myelogenic leukemia (K562) and human promyelocytic cell line (U937). They showed to have relatively high toxicity in K562 cells and a relatively low cytotoxicity in U937 cells, as assessed by both MTT and Trypan Blue assays. The five molybdenum complexes were tested in human promyelotic U937 cell line and they showed to have high toxicity

A new endemic representative of the genus Rascioduvalius S. B. Ćurčić, Brajković, Mitić & B. P. M. Ćurčić from Mt. Zlatibor, Western Serbia (Trechini, Carabidae, Coleoptera)

A new species of cavernicolous and endemic trechine ground beetles Rascioduvalis zlatiborensis n. sp., is described and diagnosed in the present paper. Also, all important taxonomic features are considered and illustrated. The type specimens of the new species were collected from the Markova (= Ršumska) Pećina Cave, village of Gornji Ljubiš, Mt. Zlatibor, Western Serbia. The new species and its congeners belong to a separate phyletic lineage of Tertiary age. All members of Rascioduvalius S. B. Ćurčić, Brajković, Mitić & B. P. M. Ćurčić are distributed in Western Serbia only, where they have gone through intense differentiation and radiation due to evolution of the karstic relief

Flora Stupnika i okolice (sjeverozapadna Hrvatska)

Stupnik is located in northwest Croatia, 10 km southwest of the city of Zagreb, and the researched area includes villages of Gornji Stupnik and Donji Stupnik, as well as smaller parts of the villages Kalinovica and Lučko. The area was floristically researched in the period from 2002 to 2005 during vegetation seasons. A total of 454 taxa of vascular plants from 81 families were found. Of the identified taxa, the most belonged to Poaceae (8.4%), Asteraceae (7.5%), Fabaceae (5.9%), Lamiaceae (5.8%) and Rosaceae (4.7%). In the life form spectrum hemicryptophytes were dominant (225 taxa; 49.6%), therophytes were also numerous (109 taxa; 24.0%), followed by phanerophytes (50 taxa; 10.9%), geophytes (45 taxa; 10.0%), chamaephytes (14 taxa; 3.1%), and hydrophytes (11 taxa; 2.4%). Phytogeographical analysis showed that Euro-Asiatic geoelement (148 taxa; 32.5%) was predominant, followed by cosmopolites (126 taxa; 27.7%), the European (52 taxa; 11.5%), South-European (41 taxa; 9.0%), Circum-Holartic geoelement (33 taxa; 7.3%) and Central-European geoelement (19 taxa; 4.2%). The Mediterranean geoelement encompassed 9 taxa (2.0%), the East European-Pontic four taxa (0.9%), the Atlantic two taxa (0.4%), as well as the Southeast European (0.4%) geoelement. The Illyrian-Balkan geoelement was represented by only one species (0.2%). Neophytes were represented with 17 taxa (3.7%) and most of them are invasive alien species. Four species (Lilium martagon, Alopecurus geniculatus, Carex vesicaria and Glyceria fluitans) belong to VU category according to the Red Book.Stupnik se nalazi u sjeverozapadnoj Hrvatskoj, 10 km jugozapadno od Zagreba. Istraživano područje obuhvaća sela Gornji i Donji Stupnik, te manje dijelove sela Kalinovica i Lučko. Područje smo floristički istraživali tijekom vegetacijske sezone u periodu od 2002. do 2005. godine. Zabilježili smo 454 svojti vaskularnih biljaka koje pripadaju u 81 porodicu. Najbrojnije porodice su Poaceae (8.4%), Asteraceae (7.5%), Fabaceae (5.9%), Lamiaceae (5.8%) i Rosaceae (4.7%). U spektru životnih oblika dominiraju hemikriptofiti (225 svojti; 49.6%), brojni su terofiti (109 svojti; 24.0%), slijede fanerofiti (50 svojti; 10.9%), geofiti (45 svojti; 10.0%), hamefiti (14 svojti; 3.1%) i hidrofiti (11 svojti; 2.4%). Fitogeografska analiza pokazala je da dominira euroazijski florni element sa 148 svojti (32.5%), slijede široko rasprostranjene biljke (126 svojti; 27.7%), europski florni element (52 svojte; 11.5%) te južnoeuropski (41 svojta; 9.0%) i cirkumholarktički florni element (33 svojte; 7.3%). Srednjeeuropski florni element zastupljen je s 19 svojti (4.2%), mediteranski s 9 svojti (2.0%), istočnoeuropskopontski s četiri svojte (0.9%), atlantski s dvije svojte (0.4%), isto kao i jugoistočnoeuropski (dvije svojte; 0.4%). Ilirsko-balkanski florni element je zastupljen sa samo jednom vrstom (0.2%). Na istraživanom području zabilježili smo 17 (3.7%) neofita, koji su većinom i invazivne vrste. Prema Crvenoj knjizi, četiri vrste (Lilium martagon, Alopecurus geniculatus, Carex vesicaria i Glyceria fluitans) pripadaju kategoriji osjetljiva vrsta (VU)

Enzimska kinetička metoda za određivanje propranolol-hidrohlorida u farmaceutskim preparatima zasnovana na njegovom inhibitorskom delovanju na holinesterazu

Propranolol, a widely used beta-blocker, inhibits the hydrolysis reaction of enzyme cholinesterase. Measurements of the difference in rate of hydrolysis rate between uninhibited and inhibited reactions allow the development of a kinetic method for its determination. Both systems, enzyme-substrate-chromogen and enzyme-substrate-chromogen-inhibitor, were characterized through biochemical kinetic parameters (K-M, 0.326-0.330 mmol/L; V-max, 40.0-43.0 mu mol/Lmin). The inhibition type was recognized as competitive and the inhibition constant, Ki, was determined to be 22.60 mu mol/L. The detection and quantification limits were calculated as 0.004 and 0.0136 mu mol/L, respectively. Accuracy and precision of proposed methods were tested. The proposed method showed good sensitivity, selectivity, simplicity and rapidity, thus it is convenient for clinical applications.Za propranolol, često propisivani neselektivni beta blokator, utvrđeno je da inhibira reakciju enzimske hidrolize butiriltioholin-jodida, koja je katalizovana serumskom holinesterazom. Merenjem razlike u brzini osnovne i inhibitorske reakcije hidrolize u prisustvu propranolola kao inhibitora, moguće je razviti kinetičku metodu za određivanje propranolola. Oba sistema, enzim-supstrat-hromogen kao i enzim-supstrat-hromogen-inhibitor, okarakterisani su biohemijskim kinetičkim parametrima (KM, 0,326-0,330 mmol/L; Vmax, 40-42,99 μmol/L min), inhibicija je definisana kao kompetitivna i određena je konstanta inhibicije 22,60 μmol/L. Da bi se u potpunosti iskoristile sve mogućnosti predložene metode u pogledu osetljivosti, tačnosti, preciznosti i selektivnosti, optimizovani su reakcioni uslovi. Konstruisana je kalibraciona prava, izračunata odgovarajuća jednačina i određeni granica detekcije i kvantifikacije i to 0,004 i 0,0136 μmol/L, redom. Tačnost i preciznost predložene metode su ispitane za tri koncentracije propranolola u oblasti kalibracione prave (0,082-21,120 μmol/L) u pet ponavljanja. Takođe, ispitan je uticaj većeg broja supstanci koje se mogu naći u uzorku na brzinu reakcije. Optimizovana metoda je primenjena za određivanje propranolola u farmaceutskim preparatima. Tačnost predložene metode je ispitana primenom metode standardnog dodatka. Predložena metoda ima dobru osetljivost, selektivnost, jednostavna je i brza, i nadasve lako dostupna, i na taj način primenljiva u velikom broju laboratorija

Spektroskopska svojstva i antimikrobna aktivnost dioksomolibden(VI) kompleksa sa heterocikličnim S,S'-ligandima

Five new dioxomolybdenum(VI) complexes of the general formula [MoO2(Rdtc)2], 1-5, where Rdtc- refer to piperidine (Pipdtc), 4-morpholine (Morphdtc), 4-thiomorpholine (Timdtc), piperazine (Pzdtc) or N-methylpiperazine (N-Mepzdtc) dithiocarbamates, respectively, have been prepared. The complexes were characterized by elemental analysis, conductometric measurements, electronic, IR and NMR spectroscopy. The complexes 1-5 contain a cis-MoO2 group and have an octahedral geometry. Two dithiocarbamato ions join as bidentates with both the sulfur atoms to the molybdenum atom. The presence of different heteroatoms in the piperidino moiety influences the v(C=N) and v(C=S) vibrations, which wavelengths decrease in the order: Pipdtc > N-Mepzdtc > Morphdtc > Pzdtc > Timdtc ligands. Based on their spectral data, the molecular structures of complexes 1-5 were optimized at the semi-empirical molecular-orbital level, and the geometries, as obtained from calculations, are described. The antimicrobial activities of the complexes were tested against nine different laboratory control strains of bacteria and two strains of the yeast Candida albicans. All the tested strains were sensitive. Complexes bearing heteroatom in position 4 of piperidine moiety were significantly more potent against the tested bacteria compared to the corresponding ligands.Sintetisano je pet novih dioksomolibden(VI) kompleksa, opšte formule [MoO2(Rdtc-)2], sa Rdtc- ligandima: piperidin- (Pipdtc), 4-morfolin- (Morphdtc), 4-tiomorfolin- (Timdtc), piperazin- (Pzdtc) i N-metilpiperazin- (N-Mepzdtc) ditiokarbamatima. Kompleksi su okarakterisani elementalnom analizom, IR i NMR spektroskopijom kao i merenjem molarne provodljivosti. Pretpostavljena geometrija svih kompleksa je oktaedarska. Rdtc- ligandi su bidentatno koordinovani preko oba atoma sumpora za atom molibdena. Prisustvo različitih heteroatoma utiče na promenu položaja v(C=N) i v(C=S) vibracija, čiji opada sledećim redom liganada: Pipdtc > N-Mepzdtc > Morphdt > Pzdtc > Timdtc. Na osnovu spektralnih podataka, strukture svih kompleksa su optimizovane na semiempirijskom molekulsko-orbitalnom nivou upotrebom PM6 metoda. Antimikrobna aktivnost ispitivana je na jedanaest različitih patogena. Uočeno je da kompleksi koji imaju heteroatom u položaju 4 piperidinskog prstena ispoljavaju značajno veću jačinu antimikrobnog dejstva prema bakterijama, u poređenju sa odgovarajućim ligandima