Pore geometry of ceramic device: The key factor of drug release kinetics

Release kinetics of tigecycline, a potential antibiotic in treatment of osteomyelitis, from calcium hydroxyapatite (CHA), as one of the most important ceramic materials in bone tissue engineering, was investigated in this study. Tigecycline, in solid state, was mixed with CHA powder and the obtained mixture was compressed into tablets using two different pressures. These tablets were immersed in a phosphate-buffered saline solution and tigecycline release was measured by a UV-VIS spectrophotometer. The total release time was 5 or 28 days, depending on the pressure applied during compression. It was shown that there is a close relationship between pore sizes and drug release rate. The drug release kinetics was interpreted on the base of pore sizes and pore size distribution. [Projekat Ministarstva nauke Republike Srbije, br. 172026

enzimska lipofilizacija vitamina C linolnom kiselinom - određivanje antioksidativnih i difuzionih svojstava L-askorbil-linolata

Lipophilic derivatives of vitamin C are additives with antioxidant properties, attractive for application in food, cosmetics and pharmaceutics. They could be synthesized in lipase-catalyzed processes by using various acyl donors. Hereby, we present application of linoleic acid, which is polyunsaturated fatty acid essential in human nutrition, for esterification of vitamin C catalyzed by immobilized enzyme preparation Novozym® 435 in acetone. Highest specific ester yield, 9.7 mmol/g of immobilized lipase, was accomplished with 0.15 M of vitamin C, 0.6 M of linoleic acid, 3 g/l of enzyme and 0.07% (v/v) of water, at 60°C. NMR analyses of purified product proved that synthesized molecule was identical to 6-O-ascorbyl linoleate. Capacity of ester for scavenging 2,2-diphenyl-1-picrylhydrazyl radicals was two times higher comparing to parent molecule, vitamin C. Its diffusion coefficient, determined using Franz cell and cellulose acetate membrane, was 40% higher than palmitate and 62% higher than oleate. Obtained results showed that L-ascorbyl linoleate could be successfully synthesized in biocatalyzed processes. Furthermore, it was demonstrated that it possess high potential for application in different lipophilic products due to its liposolubility, high antioxidant efficiency and good diffusion properties.Lipofilni derivati vitamina C su aditivi sa antioksidativnim dejstvom pogodni za primenu u prehrambenim, kozmetičkim i farmaceutskim proizvodima. Mogu biti sintetisani u procesima katalizovanim lipazama korišćenjem različitih acil-donora. U ovom radu, opisana je primena linolne kiseline, polinezasićene masne kiseline esencijalne u ljudskoj ishrani, u esterifikaciji vitamina C katalizovanoj imobilisanim enzimskim preparatom Novozym® 435 u acetonu. Najviši specifični prinos estra od 9,7 mmol/g imobilisane lipaze, ostvaren je sa 0,15 M vitamina C, 0,6 M linolne kiseline, 3 g/l enzima i 0,07 zapr. % vode, na 60°C. NMR analize prečišćenog proizvoda dokazale su da je sintetisani molekul identičan 6-O-askorbil-linolatu. Kapacitet estra za vezivanje 2,2- difenil-1-pikrilhidrazil radikala bio je dva puta viši u odnosu na sam vitamin C. Njegov koeficijent difuzije, određen korišćenjem Franz-ove ćelije i celuloza-acetatne membrane, bio je za 40% viši u odnosu na palmitat i za 62% u odnosu na oleat. Ostvareni rezultati pokazali su da L-askorbil-linolat može uspešno biti sintetisan u biokatalizovanom procesu. Pored toga, dokazano je da ovaj estar poseduje značajan potencijal za primenu u različitim lipofilnim proizvodima zbog svoje liposolubilnosti, snažnog antioksidativnog dejstva i pogodnih difuzionih karakteristika

Uticaj genotipa i uzrasta na proizvodne osobine lakih linijskih hibrida kokoši

The aim of this work was parallel investigation of the producing characteristics of light line hen hybrids. Investigation enclosed two hen proveniences: Hisex Brown and Shawer 579. Within the period of 19 up to 63 weeks we followed next parameters: egg-laying hen body mass, mortality, food consumption and egg-laying capacity. Hens body mass on the beginning of the examination, within the 19 weeks of growth was, for Hisex Brown provenience 1607g, and for Shawer 579 provenience 1563g. Hisex Brown provenience achieved about 250 g higher body mass on the end of investigation. During the experiment, mortality at Hisex Brown egg-laying hen was a little bit smaller (5,40%), while the Shawer 579 had 5,56% of dead hens. Globally, the mortality at both hen hybrids was in the range of technological normative. The average consumption of the food at Hisex Brown provenience was higher and it was 127,28g, and at Shawer 579 provenience 125,14g. The average consumption of the nutrition for egg production at both provenience was the same (150g).Cilj ovog rada bio je da se izvrši uporedno ispitivanje proizvodnih sposobnosti lakih linijskih hibrida kokoši. Ispitivanjima su obuhvaćene dve provenijence kokoši: Hisex Brown i Shawer 579. U periodu od 19. do 63. nedelje starosti praćeni su sledeći parametri: telesna masa nosilja, mortalitet, utrošak hrane i nosivost. Telesna masa kokoši na početku ispitivanja, sa 19 nedelja uzrasta, za provenijencu Hisex Brown, iznosila je 1607 g, a za provenijencu Shawer 579-1563 g. Veću telesnu masu na kraju eksperimenta, za oko 250 g postigle su nosilje provenijence Hisex Brown. U toku ispitivanja, mortalitet kod Hisex Brown nosilja je bio nešto manji (5,40%), dok je Shawer 579 imao 5,56% uginulih nosilja. Posmatrano u celini, mortalitet nosilja kod oba hibrida, bio je u granicama tehnoloških normativa. Prosečna dnevna potrošnja hrane kod provenijence Hisex Brown je veća i iznosila je 127,28 g, a kod Shawer 579-125,14 g. Prosečna potrošnja hrane za proizvodnju jajeta kod obe provenijence je bila ista (150 g)

Zinc(II) Complexes with Dimethyl 2,2 '-Bipyridine-4,5-dicarboxylate: Structure, Antimicrobial Activity and DNA/BSA Binding Study

Two zinc(II) complexes with dimethyl 2,2 '-bipyridine-4,5-dicarboxylate (py-2py) of the general formula [Zn(py-2py)X-2], X = Cl- (1) and Br- (2) were synthesized and characterized by NMR, IR and UV-Vis spectroscopy and single-crystal X-ray diffraction analysis. Complexes 1 and 2 are isostructural and adopt a slightly distorted tetrahedral geometry with values of tetrahedral indices tau(4) and tau'(4) in the range of 0.80-0.85. The complexes were evaluated for their in vitro antimicrobial activity against two bacterial (Pseudomonas aeruginosa and Staphylococcus aureus) and two fungal strains (Candida albicans and Candida parapsilosis), while their cytotoxicity was tested on the normal human lung fibroblast cell line (MRC-5) and the model organism Caenorhabditis elegans. Complex 1 showed moderate activity against both Candida strains. However, this complex was twofold more cytotoxic compared to complex 2. The complexes tested had no effect on the survival rate of C. elegans. Complex 2 showed the ability to inhibit filamentation of C. albicans, while complex 1 was more effective than complex 2 in inhibiting biofilm formation. The interactions of complexes 1 and 2 with calf thymus DNA (ct-DNA) and bovine serum albumin (BSA) were studied to evaluate their binding affinity toward these biomolecules

High Dynamic Range Mapping for Synthetic Aperture Radar Images

Luminance compression is often performed for high dynamic range images (still images and videos). A nonlinear tone mapping is applied for the compression in order to reproduce high dynamic range images using devices with a more limited (low) dynamic range. The images obtained after mapping may provide significant content differences in comparison to original data. This can be found for both optical and non-optical images. In this paper, we consider non-optical high dynamic range images, such as synthetic aperture radar images. Particularly, luminance compression may produce unwanted effects. Artificial objects found in an image and speckle noise may significantly affect the quality after tone mapping. In this paper, we consider several examples related to synthetic aperture radar images, as well as several global and a local luminance reduction method. The experimental analysis includes a comparison of several quality assessment methods

Poređenje dve procedure hladnog testa za ispitivanje vigora semena samooplodnih linija kukuruza

Cold test (CT) is a valuable method of assessing maize seed vigour. Although widely used CT is not standardized because of variations in CT procedures. The objective of this study was to evaluate seed vigour of 15 maize inbred lines developed at the Maize Research Institute Zemun Polje, using two different substrates (soil and sand) in a severe CT (7.5°C for 10 days followed by 7 days at 20/30 °C). Statistical analysis showed that inbred lines differ significantly in seed vigour, and no difference between two applied substrates in CT. Coefficients of variation were lower in CT with sand (6.05 %), compared to the CT with soil (6.74%) due to variation in soil quality and presence of soil-borne pathogens. Both CT procedures were highly correlated with field emergence. Results of this research indicate that CT with sand is appropriate for testing maize seed vigour, with the potential for standardization.Vigor semena je veoma važan parametar kvaliteta, jer ukazuje na sposobnost semena da klija u suboptimalnim uslovima (niska temperatura, visoka vlažnost zemljišta itd.). Hladni test je važan metod za utvrđivanje vigora semena kukuruza. Iako je dobar pokazatelj nicanja u polju, i koristi se širom sveta, hladni test nije standardizovan zbog razlika u proceduri (temperatura, vrsta i vlažnost supstrata). Cilj ovog rada bio je ispitivanje vigora semena samooplodnih linija kukuruza primenom dva različita supstrata (zemlja i pesak) u hladnom testu. Za ispitivanje je odabrano 15 samooplodnih linija kukuruza stvorenih u Institutu za kukuruz 'Zemun Polje'. Primenjeni su izrazito stresni uslovi ispitivanja u hladnom testu (10 dana na 7,5°C, a zatim 7 dana na 20/30°C). Statističkom obradom podataka utvrđeno je da su se samooplodne linije značajno razlikovale po vigoru semena tj. tolerantnosti na niske temperature u periodu klijanja i početnog porasta. Sa druge strane nije utvrđena značajna razlika između dva primenjena supstrata u hladnom testu. Prosečna klijavost 15 samooplodnih linija u hladnom testu sa peskom iznosila je 82,2%, a u hladnom testu sa zemljom 80,1%. Koeficijent varijacije je bio niži u hladnom testu sa peskom (6,05%), nego u hladnom testu sa zemljom (6,74%), što se objašnjava variranjem u kvalitetu zemlje i prisustvu zemljišnih patogena. Obe ispitivane procedure su postigle visoku korelaciju sa nicanjem u polju. Rezultati ovih istraživanja ukazuju na mogućnost korišćenja peska kao supstrata u hladnom testu, čime bi se ispitivanje vigora semena kukuruza znatno olakšalo, a ujedno bi se stekli uslovi za standardizaciju hladnog testa

Eksperimentalna procena organskih podloga za ispitivanje klijavosti semena soje

High germination of seeds and seedling establishment are critical for soybean production since it determines crop density and eventually affects the yield. Accurate evaluation of the ger mination potential of sowing material is valuable, as well as initial quality assessment of newly harvested seed. ISTA Rules prescribe alternative methods for soybean seed germination: sand, between paper, top of paper covered with sand and since 2020 organic growing media. In the Seed Testing Laboratory at the Maize Research Institute soybean germination is conducted in the sand at 2030°C. The objective of this study was to evaluate several available organic growing media and compare results obtained with the standard laboratory method. Five soybean seed lots of different quality were tested in four germination growing media (3 organic and sand), at two temperature regimes (25 °C and 2030°C). Statistical analyses showed that all types of organic growing media were of the same quality. Slightly higher germination in organic growing media was obtained in the experiment at 2030°C compared to sand, but those differences were not statistically significant. When testing was done in germinator with 25°C positive effects of organic growing media were identified and this impact was significant, especially for low-quality seed lots. The experimental outcome was to continue with routine practice and use organic growing media for retesting of seed lots with lower germination as an alternative substrate. Key words: germination, organic substrate, sand, soybean, temperatureVisoka klijavost semena i uniforman rast klijanaca su presudni za proizvodnju soje, jer od toga zavisi gustina useva i na kraju, prinos. Precizna procena potencijala klijavosti setvenog ma terijala je izuzetno važna, kao i početna procena kvaliteta tek požnjevenog semena. Međunarod na pravila za ispitivanje semena propisuju alternativne metode za klijanje semena soje: pesak, između filter papira, na filter papiru uz prekrivanje peskom, i od 2020. godine organski supstrat. U Laboratoriji za ispitivanje semena, Instituta za kukuruz “Zemun Polje”, naklijavanje soje se vrši u pesku, na temperaturi 2030°C. Cilj ove studije bio je proceniti nekoliko dostupnih organskih supstrata i uporediti dobijene rezultate sa dosadašnjom laboratorijskom metodom. Pet partija soje različitog kvaliteta testirano je u četiri podloge za naklijavanje (3 organske i pe sak), pri dva temperaturna režima (25°C i 2030°C). Statistička analiza pokazala je da su sve organske podloge istog kvaliteta. Nešto veća klijavost u organskom supstratu u poređenju sa pes kom je ostvarena u eksperimentu na 2030°C, ali te razlike nisu bile statistički značajne. Pri likom ispitivanja u klijalištu sa 25°C pokazali su se pozitivni efekti organske podloge i ovaj uticaj je bio značajan, posebno za partije slabijeg kvaliteta. Nakon analize eksperimentalnih rezultata odlučeno je da se nastavi sa dosadašnjom laboratorijskom praksom naklijavanja u pesku i da se organska podloga koristi kao alternativni supstrat za ponovno ispitivanje partija semena sa nižim procentom klijavosti

Supplementary data for article: Milivojević, A.; Ćorović, M.; Carevic, M.; Banjanac, K.; Vujisić, L. V.; Velickovic, D.; Bezbradica, D. Highly Efficient Enzymatic Acetylation of Flavonoids: Development of Solvent-Free Process and Kinetic Evaluation. Biochemical Engineering Journal 2017, 128, 106–115. https://doi.org/10.1016/j.bej.2017.09.018.

Supplementary material for: [https://doi.org/10.1016/j.bej.2017.09.018]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2558

Increasing the pepper seed quality using mycorrhizal fungi

The purpose of this paper is to evaluate the effect of the year of cultivation, seed population and mycorrhizal seed treatment on two most important indicators of the pepper seed quality, namely germination energy and total germination. The pepper seed quality parameters, i.e. the first count and the total germination rate, were examined in the period 2017-2018. The results obtained show significant differences (p < 0.01) between the parameter values under consideration relative to the year of cultivation (Factor A), seed population (Factor B) and mycorrhizal sees treatment (Factor C). In the first experimental year, there was an increase in the first count and total germination of 4 to 6 % compared to the control when pepper seeds were treated with the mycorrhizal formulation. In the second experimental year, an increase in the first count was in the range of 3 to 16 %, whereas an increase in the total germination was 3 to 4 %, compared to the control. The effect of mycorrhizal pepper seed treatment proved beneficial especially to aged seeds that were slow to germinate.Cilj istraživanja je bio da se izvrši ocena uticaja godine, populacije semena i tretmana semana formulacijom mikorize na dva najznačajnija pokazatelja kvaliteta semena paprike. Kao materijal u istraživanjima korišćene su tri domaće populacije začinske paprike poreklom sa dva lokaliteta iz Srbije: istočna - Negotin (dve populacije slatka i ljuta) i zapadna - Badovinci (ljuta). Seme populacija paprika proizvedeno je u organskom sistemu gajenja 2017. godine. Utvrđivanje vrednosti pokazatelja kvaliteta (energije klijanja i ukupne klijavosti) semena paprika izvedeno je 2017. i 2018. godine u Laboratoriji za ispitivanje kvaliteta semena poljoprivrednog bilja Instituta za zaštitu bilja i životnu sredinu u Beogradu. Analiza energije klijanja i klijavosti semena paprika pokazala je visoko značajne razlike (r <0,01) pod uticajem svih pojedinačnih faktora godine (faktor A), populacije semena (faktor B) i tretmana (faktor C). Veoma značajne interakcije ispitivanih faktora u pogledu energije klijanja i ukupne klijavosti semena paprika dobijene su i kod inetrakcije faktora A × B. Tretman semena populacija paprika izveden je komercijalnom formulacijom biostimulatora (Coveron) koji u sastavu sadrži Glomus mosseae, Glomus intraradices i Trihoderma atroviride. Tretmanom semena biostimulatorom u prvoj godini zabeleženo je povećanje energije klijanja i ukupne klijavosti od 4 do 6%, u odnosu na kontrolu. U drugoj godini povećanje energije klijanja kretalo se u interval od 3 do 16%, dok je efekat povećanja ukupne klijavosti bio od 3 do 4%, u odnosu na kontrolu. Porastom starosti semena opada energija klijanja i ukupna klijavost. U tim slučajevima efekat tretmana semena paprika biostimulatorima posebno dobija na značaju, jer utičena poboljšanje parametara kvalieteta semena

Ambient light induced antibacterial action of curcumin/graphene nanomesh hybrids

Curcumin and its derivates are well-known for their different biological activities including antibacterial. On the other hand there are controversial reports concerning the antibacterial potential of graphene and, in particular, graphene oxide. In this study we have reported for the first time the antibacterial activity of curcumin/graphene nanomesh hybrids under ambient light conditions. The graphene nanomesh was synthesized by electrochemical exfoliation of highly oriented pyrolytic graphite in 1 M solution of ammonium persulfate and further functionalized by curcumin. Identical values of minimum inhibitory concentration (1 mg mL(-1)) were determined for pure curcumin and curcumin/graphene nanomesh hybrids toward Staphylococcus aureus. All tested samples had more pronounced antibacterial activity against Gram positive bacteria, Staphylococcus aureus compared to Escherichia coli as a representative of Gram negative strains. The poor antibacterial potential of exfoliated graphene improves significantly by the functionalization with curcumin, which allows for its usage as a antibacterial coating