34 research outputs found

    Fulleropyrrolidine dyads and triads: synthesis, investigation of electrochemical properties and hierarchical self-organization

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    Polimerne solarne ćelije, kao izvor električne energije, poslednjih godina privlače mnogo pažnje zbog svoje ekoloÅ”ke prihvatljivosti, niske cene i fleksibilnosti. Novi organski prekursori, iskoriŔćeni za njihovu konstrukciju, značajno su poboljÅ”ali stepen efikasnosti konverzije sunčeve energije. Zbog visokog afiniteta prema elektronima, fulerenski derivati su postali neophodna i gotovo nezamenljiva komponenta u aktivnom sloju organskih solarnih ćelija. Pomenuti derivati koriste se kao elektron-akceptorska jedinica, koja prihvata elektrone od donorske komponente i tako osigurava razdvajanje Å”arži. Značajni nedostaci su im slaba rastvorljivost u organskim rastvaračima i slaba apsorpcija vidljive svetlosti. Veliki broj istraživanja odnosi se upravo na pokuÅ”aje da se elektronske i morfoloÅ”ke osobine fulerenskih derivata poboljÅ”aju...Lately polymer solar cells have attracted much attention, as renewable energy resourse due to being environmentally friendly, low cost and flexible. New organic precursors used in the solar cells construction have greatly enhanced energy power conversion efficiency. Because of its high electron affinity, fullerene derivatives become almost irreplaceable component in the active layer of the organic solar cells. These derivatives are used as an electron-accepting unit, which accepts electrons from the donor and ensures charge-separated states. The biggest drawbacks of C60 derivatives are still poor solubility in typical organic solvents and low absorption in the red part of the visible spectrum. To this day, a considerable amount of research has been devoted to improving electronic and morphological characteristics of these derivatives..

    Early flowering species - model plants for studies of ontogenesis in vitro

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    Chenopodium rubrum L. and Chenopodium murale L. are two annual weed species with different photoperiodic demands. The use of species from the same genus, with a similar type of morphogenesis but with different photoperiodic demands, is valuable for comparative studies of flowering. In addition, being classified as early flowering species, these two species represent model plants suitable for studies of ontogenesis in vitro. This review describes part of our results obtained on these two model plants under the guidance of Professor Ljubinka Ćulafić, starting with early development, such as somatic embryogenesis, followed by photoperiodic and hormonal regulation of flowering, to the photoperiodic control of different stages of ontogenesis

    Study of the optical power of nanophotonic soft contact lenses based on poly (2-hydroxyethyl methacrylate) and fullerene

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    U radu su predstavljeni rezultati komparativnih istraživanja optičke snage mekih kontaktnih sočiva (MKS) sa različitim tehnikama mjerenja koje se koriste pri finalnoj obradi kontaktnih sočiva. Tri vrste nanofotoničnih mekih kontaktnih sočiva su napravljene od standardnog polimacon materijala (Soleko SP38TM) sa inkorporiranim fulerenom C60, fulerolom C60(OH)24 i fuleren-metformin-hidroksilatom C60(OH)12(OC4N5H10)12. Za potrebe karakterizacije materijala za potencijalnu primjenu kod mekih kontaktnih sočiva, mjerena su optička svojstva mekih kontaktnih sočiva Rotleks i Nidek uređajem. Sa Rotleks uređajem dobijeni su sledeći optički rezultati: optička snaga i mapa defekata, a sa Nidek uređajem: optička snaga, snaga cilindra i ugao cilindra. Dobijene vrijednosti optičke snage i mape defekata pokazali su da optička snaga sintetisanih nanofotoničnih mekih kontaktnih sočiva je identična nominalnoj vrijednosti, dok to nije bio slučaj za standardna meka kontaktna sočiva. Takođe, kvalitet nanofotoničnih mekih kontaktnih sočiva je bolji nego kod standardnih mekih kontaktnih sočiva. Iz prikazanog se može zaključiti da je moguće sintetisati nova nanofotonična meka kontaktna sočiva željenih optičkih karakteristika, Å”to otvara mogućnosti za njihovu primjenu u ovoj oblasti.In this paper results of comparative study of the optical power of soft contact lenses (SCL) made of standard material for SCL and nanophotonic materials with different measurement techniques used for the final contact lens controllers are presented. Three types of nanophotonic soft contact lenses were made of standard polymacon material (Soleko SP38 TM) incorporated with fullerene C 60 , fullerol C 60 (OH) 24 and fullerene metformin hydroxylate C 60 (OH) 12 (OC 4 N 5 H 10) 12. For the purposes of material characterization for potential application as soft contact lenses, the optical properties of the soft contact lenses were measured by Rotlex and Nidek device. With Rotlex device the following optical results were obtained: optical power and map of defects, while with the Nidek device: optical power, cylinder power and cylinder axis. The obtained values of optical power and map of defects showed that the optical power of synthesized nanophotonic soft contact lens is same to the nominal value, while this was not the case for the standard soft contact lens. Also, the quality of the nanophotonic soft contact lens is better than the standard one. Hence, it is possible to synthesize new nanophotonic soft contact lenses of desired optical characteristics, implying possibilities for their application in this field

    Enzimi zaÅ”tite od oksidacionih oÅ”tećenja u toku klijanja dve linije omorike [Picea omorika (Panč.) Purkyně]

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    dTwo lines of Picea omorika (Pane.) Purkyne were compared with respect to germination percentage as well as specific activity and isoenzyme pattern of catalase, superoxide dismutase, and peroxidase (POD) during germination. Line A had a higher gennination percentage and higher enzyme activities in dry seeds and seedlings compared to line C. Peroxidase activity was not detected in dry seeds, but measured up to 10 U/g and 28 U/g on the 7(th) day of germination in lines C and A, respectively. The most abundant POD basic isoform in seedlings of both lines (pl 8.2) was not found previously in needles of adult Serbian spruce trees of the same lines.Poređeni su procenat klijanja, specifična aktivnost i izoenzimski profil katalaze, superoksid dismutaze i peroksidaze u dve linije omorike [Picea omorika (Panč.) Purkyně] u toku klijanja. Linija A je imala veći procenat klijanja i veće enzimske aktivnosti u suvom semenu i klijancima, u poređenju sa linijom C. Peroksidazna aktivnost nije nađena u suvim semenima, a povećavala se do 10 U/g i 28 U/g sed- mog dana klijanja u linijama C i A, respektivno. Najzastupljenija bazna izoforma peroksidaze u klijancima obe linije (pI 8.2) nije nađena ranije u četinama odraslih jedinki istih linija.

    Vascularisation of the geniculate ganglion

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    Background: Lack of the relevant data in the literature and possible clinical significance of the geniculate ganglion vasculature inspired us to examine the vessels of this ganglion. Materials and methods: Twelve temporal bones were taken during autopsy and microdissected. Four geniculate ganglions were taken as well, serially sectioned and used for haematoxylin-eosin and trichrome staining, and for CD34 immunostaining. Results: The geniculate ganglion was supplied by the petrosal artery, which averaged 1.1 in number, 0.44 mm in the outer diameter, 0.24 mm in the luminal diameter, and 17.1 mm in length. The artery approached the greater petrosal nerve, giving off 1-3 twigs to it with a mean diameter of 24 mu m, and entered the nerve hiatus or a small bone opening close to the ganglion. Before the artery continued to the tympanic segment of the facial nerve, it gave rise to 1 (8.33%), 2 (75.00%) or 3 (16.67%) branches to the geniculate ganglion, which ranged in diameter between 18 mu m and 56 mu m (mean 29 mu m). From the formed superficial network, several twigs penetrated the ganglion and built an intraganglionic plexus. The counting, performed in microscopic fields, each measuring 341.7 mu m x 250.0 mu m in size, contained between 20 and 38 (mean 28.1) ganglion cells, as well as from 87 to 143 microvessels (mean 99.8), so that the neuron/vessel ratio was 1:3.6. Conclusions: This is the first detailed examination of the geniculate ganglion vasculature. The obtained data could be of clinical importance, especially in relation to the Bell's palsy, ganglionitis, geniculate neuralgia, petrous bone imaging, and operations in the same region
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