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Search Results: 1 - 10 of 201535 matches for " Stanojevi? Ljiljana P. "
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Antioxidant activity of Galium mollugo L. extracts obtained by different recovery techniques
Mili? Petar S.,StanojeviLjiljana P.,Rajkovi? Katarina M.,Mili? Slavica M.
Hemijska Industrija , 2013, DOI: 10.2298/hemind120314042m
Abstract: The yield of extractive substances, antioxidant activity, as well as total phenolic and total flavonoid contents of aqueous-ethanolic extracts obtained from aerial parts of Galium mollugo L. by different extraction techniques (maceration, reflux and ultrasonic extraction) were reported. The antioxidant activity of extracts was tested by measuring their ability to scavenge a stable DPPH free radical, while the total phenolic and total flavonoid contents were determined according to the Folin-Ciocalteu procedure and a colorimetric method, respectively. The Duncan’s multiple range tests were used to evaluate if there were significant differences among yields of extractive substances, total phenolics, total flavonoids and EC50 values for the extracts obtained by different extraction techniques. The extracts obtained by the reflux extraction contained higher amounts of extractive substances, as well as phenolic and flavonoid compounds, and showed a better antioxidant activity than those obtained by the two other recovering techniques.
The effect of the operation conditions and the extraction techniques on the yield, kinetics and composition of methanol extracts of Hieracium pilosella L.
StanojeviLjiljana P.,Stankovi? Mihajlo Z.,Caki? Milorad D.,Nikoli? Vesna D.
Hemijska Industrija , 2009, DOI: 10.2298/hemind0902079s
Abstract: The optimal operational extraction conditions were determined by investigating the influence of the methanol concentration, solvomodule and temperature of the maceration extraction on the yield and kinetics of total extractive matter, chlorogenic acid, umbelliferone and apigenin-7-O-glucoside from Hieracium pilosella L. Based on the results of Soxhlet and Tillepape extraction kinetics investigations of the total extractive matter and the components under the optimal maceration operation conditions it was found that the highest yields of the extractive matter and investigated bioactive components extracted from the dry plant material were obtained by using the Soxhlet extraction method. The contents of chlorogenic acid, umbelliferone and apigenin-7-O-glucoside in the extracts were determined by HPLC method. Chlorogenic acid is the component with the highest share in all the extracts.
Climate change and river discharge: case study Kolubara River, Beli brod hydrological gauge
Buri? Dragan,Stanojevi? Gorica,Lukovi? Jelena,Gavrilovi? Ljiljana
Glasnik Srpskog Geografskog Dru?tva , 2012, DOI: 10.2298/gsgd1201123b
Abstract: This paper analyzes climate change and its impact on river discharge. This issue is very well studied worldwide, but in Serbia so far has been poorly studied. The first part of the paper presents the views of two different opinions, those who favored anthropogenic impact on the increasing greenhouse effect, and those who say that this is due to natural factors. Most attention is paid to changes in temperature and precipitation patterns. Classification by the group of those who favor the promotion of natural phenomena is demonstrated through the analysis of river flow fluctuations in the hydrological gauge Beli brod located on Kolubara River.
The effect of hydrodistillation techniques on yield, kinetics, composition and antimicrobial activity of essential oils from flowers of Lavandula officinalis L.
StanojeviLjiljana,Stankovi? Mihajlo,Caki? Milorad,Nikoli? Vesna
Hemijska Industrija , 2011, DOI: 10.2298/hemind110129047s
Abstract: The essential oils from flowers of Lavandula officinalis L. (L. officinalis L. = L. angustifolia Mill.) were obtained by two hydrodistillation techniques: standard (technique I) and modified (technique II) Clevenger hydrodistillation. The yield, hydrodistillation kinetics, composition and antimicrobial activity of essential oils were investigated. The higher yield of oil was obtained by hydrodistillation technique II. The new analytical hydrodistillation kinetics model of essential oil from Lavandulae flowers was defined. The essential oil composition was analyzed by gas chromatography-mass spectroscopy (GC-MS). There are differences in chemical compositions of the oils obtained by different techniques. Antimicrobial activity of essential oil obtained by technique I and II against Salmonella enteritidis, Klebsiella pneumoniae, Staphylococcus aureus, Enterococcus faecalis, Candida albicans and Aspergillus niger is the same, while the activity against Escherichia coli and Pseudomonas aeruginosa is slightly different.
The effect of hydrodistillation technique on the yield and composition of essential oil from the seed of petroselinum crispum (mill.) Nym. Ex. A.W. Hill
Stankovi? Mihajlo Z.,Nikoli? Nada ?.,StanojeviLjiljana,Caki? Milorad D.
Hemijska Industrija , 2004, DOI: 10.2298/hemind0409409s
Abstract: The essential oil was isolated from the seed of Petroselinum crispum (Mill.) Nym. ex. A.W. Hill by using different techniques of Clevenger-type hydrodistillation. The highest yield of oil, after five consecutive hydrodistillation runs (3.9 mL/100 g of plant material), was obtained by the technique in which water from the still flask was separated by filtration and used together with fresh water for immersing the plant material in a subsequent distillation. Regardless of the technique used, the oil contained different amounts of α-pinene, -p/nene, limonene, 2,3,4,5-tetramethoxy-1-allylbenzene, apiole and 1,2-benzenedicarbonic acid.
In vitro synergistic antibacterial activity of Salvia officinalis L. and some preservatives
Stanojevi? Dragana,?omi? Ljiljana,Stefanovi? Olgica,Soluji?-Sukdolak Slavica
Archives of Biological Sciences , 2010, DOI: 10.2298/abs1001167s
Abstract: The aim of this work was to investigate the antibacterial activity of aqueous extracts of the species Salvia officinalis L. and its synergistic action with the preservatives sodium nitrite, sodium benzoate and potassium sorbate in vitro against selected food spoiling bacteria. Synergism was assessed by the checkerboard assay method and quantitatively represented by the FIC index. Synergistic action was established for aqueous extract/sodium benzoate, aqueous extract/potassium sorbate, aqueous extract/sodium nitrite combinations. Synergism was detected in relation to: Agrobacterium tumefaciens, Bacillus subtilis and Proteus sp. Synergism was established at plant extract and preservative concentrations corresponding up to 1/8 MIC values.
The influence of the operation conditions and the extraction techniques on the yield, kinetics and the composition of ethanol extracts of Hieracium pilosella l.
Ljiljana Stanojevi,Mihajlo Stankovi?,Ljubi?a Nikoli?,Vesna Nikoli?
Chemical Industry and Chemical Engineering Quarterly , 2007,
Abstract: N/A
Code of ethics in science and research good scientific practice
Vu?kovi?-Deki? Ljiljana,Radulovi? Sini?a,Stanojevi?-Brki? Nevenka,Jeli? Svetislav
Stomatolo?ki Glasnik Srbije , 2007, DOI: 10.2298/sgs0702132v
Abstract:
Use of linear radiofrequency device in liver resection
Stojanovi? Miroslav P.,Radojkovi? Milan,Stanojevi? Goran
Vojnosanitetski Pregled , 2010, DOI: 10.2298/vsp1011910s
Abstract: Background/Aim. Linear radiofrequency device (LRFD) is disposable tool designed for liver parenchyma transection using controlled radiofrequency to 'seal' blood vessels and bile ducts, making liver resection easier and safer compared to classical resectional techniques. The aim of this study was to determine real value of the LRFD compared to the standard 'keliclasia' technique. Methods. This prospective study analyzed the significant intraoperative parameters and postoperative results of the 200 patients who underwent surgery at the Surgery Clinic of Clinical Centre in Ni , between January 1, 2001, and January 1, 2009. The patients were divided into two groups: the control Keli group (144 patients) with the 'keliclasia' resection technique and the control RF group (with resection performed using LRFD - Tissue Link / Dissection Sealer (DS - 3.0) (56 patients). The following parameters were analyzed: duration of liver ischemia, liver parenchyma transection time, intraoperative blood loss, significant intraoperative and postoperative complication rate, duration of hospitalization and mortality. Results. LRFD was used in 56 liver resections. The average duration of liver ischemia in the RF group was shorter than in the Keli group (7 versus 22 minutes). Parenchymal liver transection was significantly slower in the RF group than in the Keli group (2.05 versus 4.34 cm2/minutes, respectively). There was less intraoperative bleeding using LRFD 'Keliclasia' tehniquethan in the control group (390 mL compared to 420 mL, respectively). After the use of LRFD two cases of biliary leak and 4 pleural effusions were registered. Conclusion. LRFD is simple device for safe liver transection with decreased need for liver ischemia and singificant reducing of the intraoperative blood loss. High price for disposable device and slow parenchyma transection are disadvantages of this device.
Antioxidant Activity and Total Phenolic and Flavonoid Contents of Hieracium pilosella L. Extracts
Ljiljana Stanojevi,Mihajlo Stankovi?,Vesna Nikoli?,Ljubi?a Nikoli?,Du?ica Risti?,Jasna ?anadanovic-Brunet,Vesna Tumbas
Sensors , 2009, DOI: 10.3390/s90705702
Abstract: The antioxidant activity ofwater, ethanol and methanol Hieracium pilosella L.extracts is reported. The antioxidative activity was tested by spectrophotometrically measuring their ability to scavenge a stable DPPH· free radical and a reactive hydroxyl radical trapped by DMPO during the Fenton reaction, using the ESR spectroscopy. Total phenolic content and total flavonoid content were evaluated according to the Folin-Ciocalteu procedure, and a colorimetric method, respectively. A HPLC method was used for identification of some phenolic compounds (chlorogenic acid, apigenin-7-O-glucoside and umbelliferone). The antioxidant activity of the investigated extracts slightly differs depending on the solvent used. The concentration of 0.30 mg/mL of water, ethanol and methanol extract is less effective in scavenging hydroxyl radicals (56.35, 58.73 and 54.35%, respectively) in comparison with the DPPH· radical scavenging activity (around 95% for all extracts). The high contents of total phenolic compounds (239.59–244.16 mg GAE/g of dry extract) and total flavonoids (79.13–82.18 mg RE/g of dry extract) indicated that these compounds contribute to the antioxidative activity.
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