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Search Results: 1 - 10 of 263647 matches for " Dra?i? Gordana D. "
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Potential uses of biomass from fast-growing crop miscanthus×giganteus
Babovi? Nada V.,DraiGordana D.,?or?evi? Ana M.
Hemijska Industrija , 2012, DOI: 10.2298/hemind110711082b
Abstract: There is an increasing interest in perennial grasses as a renewable source of bioenergy and feedstock for second-generation cellulosic biofuels. Switchgrass (Panicum virgatum) and miscanthus (Miscanthus×giganteus), belonging to the parennial grasses group, are the major lignocellulosic materials being studied today as sources for direct energy production, biofuels, bioremediation and other. They have the ability to grow at low cost on marginal land where they will not compete with the traditional food crops. Miscanthus×giganteus possesses a number of advantages in comparison with the other potential energy crops such as are: high yields, low moisture content at harvest, high water and nitrogen use efficiencies, low need for annual agronomic inputs such as fertilizers and pesticides, high cellulose content, non-invasive character, low susceptibility to pests and diseases and broad adaptation to temperate growing environments. The main problems are low rate of survival during the first winter after the creation of plantation and the relatively high establishment costs. Miscanthus×giganteus is grown primarily for heat and electricity generation but can also be used to produce transport fuels. Miscanthus biomass has a very good combustion quality due to its low water concentration as well as its low Cl, K, N, S and ash concentrations compared to other lignocellulose plants. It is expected that miscanthus will provide cheaper and more sustainable source of cellulose for production of bioethanol than annual crops such as corn. Miscanthus has great promise as a renewable energy source, but it can only be realised when the grass production has been optimised for large-scale commercial cultivation. However, further research is still needed to optimise agronomy of miscanthus, to develop the production chain and pre-treatment as well as to optimise energy conversation route to produce heat, electricity, and/or fuels from biomass, if miscanthus is to compete with fossil fuel use and be widely produced.
Effects of somatostatin-14 on active avoidance behavior in female rats
Ma?irevi?-Dra?kovi? Gordana,Terzi? Milica,Ne?iD.,Stevanovi? D.
Archives of Biological Sciences , 2007, DOI: 10.2298/abs0704055m
Salicylic acid modulates accumulation of Cd in seedlings of Cd-tolerant and Cd-susceptible soybean genotypes
DraiGordana,Mihailovi? Nevena
Archives of Biological Sciences , 2009, DOI: 10.2298/abs0903431d
Abstract: The seedlings of Cd-tolerant (Balkan) and Cd-susceptible (L 608) soybean genotypes were used to investigate the effect of salicylic acid pretreatment (10-5 M) on Cd toxic action. Cadmium-induced leaf desiccation, chlorophyll degradation, and increase of membrane impairment were more pronounced and partially ameliorated by SA treatment in the Cd-susceptible genotype. Root Cd accumulation was similar in the two genotypes, but SA stimulated Cd accumulation in the tolerant genotype, while in the susceptible genotype this accumulation was inhibited by SA. The Cd-tolerant Balkan genotype was apparently characterized by more efficient control of the oxidative stress induced by Cd, so it did not trigger mechanisms preventing further uptake of this heavy metal. It appears that differences between the genotypes with respect to Cd-tolerance occurred due to different degrees of efficiency of nonspecific defense mechanisms involving salicylic acid as a signal molecule.
Determination of heavy metal deposition in the county of Obrenovac (Serbia) using mosses as bioindicators: I. Aluminum (Al), arsenic (As), and boron (B)
Sabovljevi? M.,Vukojevi? V.,Mihajlovi? Nevena,DraiGordana
Archives of Biological Sciences , 2005, DOI: 10.2298/abs0503205s
Abstract: In the present study, the deposition of three heavy metals (Al, As and B) in the county of Obrenovac (Serbia) is determined using four moss taxa (Bryum argenteum, Bryum capillare, Brachythecium sp., and Hypnum cupressiforme) as bioindicators. Distribution of average heavy metal content in all mosses in the county of Obrenovac is presented in maps, while long-term atmospheric deposition (in the mosses Bryum argenteum and B. capillare) and short-term atmospheric deposition (in the mosses Brachythecium sp. and Hypnum cupressiforme) are discussed and given in tables. Areas of the highest contaminations are highlighted.
Acid–base equilibria of the Zn(II) and Fe(III) complexes with condensation products of 2-acetylpyridine and the dihydrazide of oxalic and malonic acid
Journal of the Serbian Chemical Society , 2009,
Abstract: Acid–base equilibria of Zn(II) and Fe(III) complexes with N',N'2-bis[(1E)-1-(2-pyridyl)ethylidene]ethanedihydrazide (ligand L1) and N',N'2-bis[(1E)-1-(2-pyridyl)ethylidene]propanedihydrazide (ligand L2), i.e., [Fe(L1)Cl2(H2O)], [Fe(L2)Cl(H2O)]2+, [Zn(L1)(H2O)3]+ and [Zn(L2)(H2O)2]2+, which expressed cytotoxic activity, were investigated in aqueous media. The equilibrium constants were determined potentiometrically at 25 °C at a constant ionic strength of 0.10 mol/dm3 (Na2SO4). The results showed that at pH < 8 both the Fe(III) complexes studied here have three, while [Zn(L1)(H2O)3]+ and [Zn(L2)(H2O)2]2+ have one and two titratable protons, respectively. Based on the obtained values for the equilibrium constants, protonation schemes of the examined complexes are proposed.
Fistulas in gynecologic and obstetric surgical procedures
?etkovi? Nenad,Dra?a Tatjana P.,Dra?a Petar D.,Radeka Gordana
Medicinski Pregled , 2004, DOI: 10.2298/mpns0406258c
Abstract: Introduction The study pointed to the significance and most frequent causes of development of fistula following gynecologic and obstetric surgical procedures. Prevention and management of fistulas Some possibilities of prevention, i.e. the necessity of correct administration of surgical procedures have been described. The authors pointed to the imperative of knowing the structure of vesicovaginal region and administration of adequate surgical technique. They described surgical procedures in most frequent gynecologic operations in prevention of ureteral injuries. They have presented 25-year result of operative treatment of these patients and treatment of postoperative fistulas at the Department of Obstetrics and Gynecology in Novi Sad. In regard to the number of gynecologic operations in that period (23067), the incidence of fistulas was not high (43). Conclusion During the last years, the incidence is constantly decreasing, due to application of appropriate surgical techniques, careful manipulation, and administration of up-to-date surgical materials.
Successful production of recombinant buckwheat cysteine-rich aspartic protease in Escherichia coli
Journal of the Serbian Chemical Society , 2009,
Abstract: Herein, the expression of recombinant cysteine-rich atypical buckwheat (Fagopyrum esculentum) aspartic protease (FeAPL1) in five Escherichia coli strains differing in their expression capabilities is presented. It was shown that the expression success depended highly on the choice of FeAPL1 fusion partner. His6-FeAPL1 was produced in large quantities as an insoluble protein localized in inclusion bodies. On the other hand, MBP-FeAPL1 was localized in both the cytoplasm and inclusion bodies in BL21 and Rosetta-gami strains. Only purified soluble MBP-FeAPL1 from Rosetta-gami cells showed proteolytic activity at pH 3.0 with BSA as the substrate. The results also indicated that FeAPL1 contained a PRO segment that had to be removed for the enzyme activity to appear. The activity of FeAPL1 produced in the Rosetta-gami strain, which enables disulfide bond formation indicated the importance of the twelve cysteine residues for correct folding and functionality.
The influence of the grain-size distribution and soil structure on the unsaturated shear strength of loess sediments in Belgrade, Central Serbia
Had?i-Nikovi? Gordana D.
Geolo?ki Anali Balkanskog Poluostrva , 2009, DOI: 10.2298/gabp0970083h
Abstract: There is a negative pore water pressure or matric suction in the zone above the ground water level in silty loess soil, which can be as deep as 5-10 m in the Belgrade area. This primary characteristic of unsaturated soil, i.e., matric suction, should be included in laboratory testing and geotechnical analyses. Direct shear or triaxial testing of unsaturated soil are very expensive and time-consuming and require specially modified equipment. Instead, the prediction of unsaturated shear strength using the soil water characteristic curve, SWCC, and the effective shear strength parameters c' and φ' is a widely accepted practice. In this study, constitutive soil-water characteristic curves were obtained from the results of experimental testing by draining saturated soil samples under different pressures. This testing was performed for the first time in Serbia in a 15 bar pressure plate extractor according to ASTM standards. The laboratory testing included natural samples of loess sediments with the original macroporous structure and loess sediments with a destroyed soil structure. The influence of the grain-size distribution and natural soil structure on the unsaturated shear strength of Belgrade loess sediments above the ground water level was also evaluated. The obtained results are in accordance with the results from other investigations.
Journal of Central European Agriculture , 2002,
Abstract: Varroa destructor is a parasitic mite of the honeybee, Apis mellifera, responsible for reduced honey and brood production, higher bee mortality in winter. Because the resistance to the acaricides and they residues to bee products, alternative products and methods have been used against Varroa. One of this methods is treatment with formic acid. Formic acid induce to Varroa mite in brood and do not leave any residues in products. Concentric formic acid (60-85%) is very effective, but at higher air temperature, it has influence on bee. In the last few years, except concentric formic acid, 15 % formic acid was recommended as control of varroosis. Diluted formic acid (15%) reduced the bee response to treatment. In treatment with 15% formic acid, higher air temperature and different forms of application have positive influence to they function (65 – 95%).
Propylene glycol energy supplementation during peripartal period in dairy cows and reproduction efficiency parameters
Vakanjac Slobodanka,Drai? M.,Pavlovi? V.,Gvozdi? D.
Acta Veterinaria , 2012, DOI: 10.2298/avb1203249v
Abstract: The aim of this work was to investigate the impact of two energy supplements based on propylene glycol in dairy cows diet on ovarian and follicular morphology, conception, insemination index and length of service period. A total number of 60 Holstein Friesian dairy cows, parity between 2-8, with an average milk production of 7000 kg/305 days of lactation were divided into three experimental groups (20 dairy cows per group). The first group of dairy cows was supplemented daily with "Energy-plus" (O1 group; 200 mL propylene-glycol supplement) and the second group was supplemented with "Ketal" (O2 group; 160 mL propylene-glycol supplement), two weeks before partus until 30 days post partum. The third experimental group were non supplemented dairy cows (O3, control group). Ultrasound examination of the reproductive system using real time echo camera Falco VET 100 (ESAOTE PieMedical, Holland, B-shaped scan with linear-array endorectal 5-8 MHz probe) was conducted on every animal starting from day 40 postpartum. The diameters of the ovaries (left and right) and of the dominant follicle(s) were recorded. Ultrasound testing was repeated on day 50 and 60 postpartum only in cows which in the meantime were not inseminated. Reproduction efficiency parameters (conception rate, number of inseminations and length of service period) were recorded individually. The statistical significance of the differences between groups was tested using ANOVA with LSD test at the level of significance p<0.05, chi-square test and Kaplan-Meier survival analysis (the length of service period). There was no significant impact of the propylene glycol supplementation on the ovarian and follicular morphology at the first ultrasound examination. At the second ultrasound examination there was a significant difference between left ovarian dominant follicle diameter in the control and supplemented dairy cows (1.67±0.53 vs 1.12±0.29 and 1.11±0.35 cm, p<0.05, O3 vs O1 and O2, respectively). The cumulative percentage of conception after the first and second insemination was 60%, 81% and 25% in groups O1, O2 and O3, respectively (p<0.05, chi-square test). The insemination index was lowest in group O2 and statistically significant differences were found between groups O2 and O3 (1.69±0.79 : 3.38±1.36, respectively, p<0,05). The length of the service period was significantly (p<0.05, LSD test) shorter in the O2 group (100±35 days) compared to groups O1 and O3 (168±59 and 157±52 days, respectively), that was confirmed by the Kaplan-Meier survival analysis of days open periods. The use of propylene gly
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