288 research outputs found
Preparation of biologically active polyphenols by utilising the primrose (Primula veris), the horsetail (Equisetum arvense) and the yarrow (Achillea millefolium) processing waste.
Predmet ove disertacije je iskoriÅ”Äenje otpadnih sirovina koje su dobijene u procesu prerade jagorÄevine (Primula veris), rastaviÄa (Equisetum arvense) i hajduÄke trave (Achillea millefolium) za dobijanje bioloÅ”ki aktivnih ekstrakata bogatih polifenolima...The subject of this dissertation is the utilization of waste materials from the processing of primrose (Primula veris), horsetail (Equisetum arvense) and yarrow (Achillea millefolium) for obtaining biologically active and polyphenol-rich extracts..
The role of central vasopressin V2 receptors in cardiovascular homeostasis
Poznato je da vazopresin modulira nervnu regulaciju kardiovaskularnog sistema centralno i periferno, ali taÄan mehanizam joÅ” uvek je nepoznat. Da bi ispitali da li centralni V2 receptori vazopresina modifikuju nervnu regulaciju kardiovaskularnog sistema ispitivali smo efekte centralno ubrizganog selektivnog antagoniste V2 receptora na hemodinamske parametre: krvni pritisak, srÄanu frekvenciju i njihov varijabilitet, pod bazalnim fizioloÅ”kim uslovima i u stresu. Pored toga, pod bazalnim fizioloÅ”kim uslovima ispitali smo efekat hiperekspresije V2 receptora u paraventrikularnom jedru hipotalamusa na hemodinamske parametre neanestetisanog pacova. Krvni pritisak i srÄana frekvencija registrovani su direktnom metodom preko katetera postavljenog u femoralnu arteriju ili radiotelemetrijskog transmitera u aortu. Nervna regulacija krvnog pritiska i srÄane frekevencije evaluirana je spektralnom metodom. Pod bazalnim fizioloÅ”kim uslovima antagonist V2 vazopresinskih receptora nije modifikovao krvni pritisak i srÄanu frekvenciju, ali je izazvao porast oscilacija veoma niskih frekvencija krvnog pritiska. Hiperekspresija V2 receptora u paraventrikularnom jedru hipotalamusa pacova izazvala je porast niskofrekventnog varijabiliteta simpatiÄkog porekla kako u krvnom pritisku, tako i u srÄanoj frekvenciji. Stres izazvan mlazom vazduha pod pritiskom usmeren u potiljak pacova prouzrokovao je istovremeni porast krvnog pritiska i srÄane frekvencije, kao i njihovog niskofrekventnog varijabiliteta simpatiÄkog porekla i visokofrekventnog varijabiliteta respiratornog porekla. Pacovi pretretirani antagonistom V2 receptora i potom izlagani stresu ispoljili su manji skok krvnog pritiska i varijabiliteta simpatiÄkog i respiratornog porekla, kao i kraÄi oporavak. Rezultati pokazuju da vazopresin putem stimulacije centralnih V2 receptora utiÄe na kardiorespiratorni odgovor na stres.It is well established that vasopressin modulates neurogenic control of the circulation both centrally and peripherally. However the exact mechanism is still unexplored. To investigate whether central V2 receptors modulate the neurogenic control of the circulation, we studied the effects of centrally injected selective V2 antagonist on hemodynamic parameters: blood pressure (BP), heart rate (HR) and their variability, under baseline physiological conditions and during stress. We also investigated the effects of over-expression of V2 receptors in the paraventricular nucelus of the hypothalamus on cardiovascular hemodynamic under baseline conditions. BP and HR were assessed by direct recording via indwelling catheter in femoral artery or by radiotelemetric probe inserted in abdominal aorta. Neurogenic control of the circulation was assessed by spectral methodology. Under baseline physiological conditons V2 antagonist didn't modify the level of BP and HR and increased the very low frequency variability of BP. Over-expression of V2 receptors in the paraventricular nucleus increased sympathetically mediated, low-frequency oscillation of BP and HR. Exposure of rats to air-jet stress increased BP, HR and their sympahtetically mediated low-frequency variability and respiration-induced high-frequency variability. Rats pre-treated with the V2 antagonist and exposed to stress exhibited lower BP increase and lower increase od BP variability, as well as shorter recovery time. It follows that vasopressin by the stimulation of central V2 receptors influence the cardiorespiratory response to stress
Characterization of nanostructured spinel NiFe2O4 obtained by soft mechanochemical synthesis
Powdery nickel ferrite, NiFe2O4 has been obtained by soft mechanochemical synthesis in a planetary ball mill. Ni(OH)2 and Fe(OH)3 are used as initial compounds. This mixture was mechanically activated for 25h, uniaxial pressed and sintered at 1100Ā°C for 2h. The phase composition of the sintered sample was analyzed by X-ray diffraction (XRD), energy dispersive spectrometer (EDS) and Raman spectroscopy. Morphologies were examined by scanning electron microscopy (SEM). The electrical DC/resistivity/conductivity at different temperatures was measured using a Source Meter Keithley 2410. An Impedance/Gain-Phase Analyzer (HP-4194) was used to measure the impedance spectra (100Hz - 10MHz) at different temperatures. [Projekat Ministarstva nauke Republike Srbije, br. III 45003 i br. III 45015
Development of a sampling plan for Myzus persicae (Hemiptera : Aphidoidea) and its predator Macrolophus costalis (Hemiptera : Miridae) on tobacco
A tobacco field in Greece was sampled during the 2001 and 2002 growing seasons to assess the seasonal trends in densities and spatial distributions of the aphid Myzus persicae (Sulzer) and its predatory mirid Macrolophus costalis (Fieber). On repeated occasions between June Oust after the transplantation) and September Oust before harvest), 20 tobacco leaves (10 from the upper and 10 from the lower plant part) were taken from randomly chosen plants. These leaves were sampled for aphids and mirids. In both years, the highest aphid densities were recorded during July and August, while aphid numbers were low in September. In contrast, the majority of M costalis individuals were found during September when aphid numbers were low. Significantly more M persieae individuals were found in the upper part of the plants, whereas significantly more M costalis individuals were found in the lower part of the plants. As indicated by Taylor's Power Law estimates, both species were aggregated in their spatial distributions among sampling units (leaves). Wilson and Room's model, based on the Taylor's estimates, was used to calculate the mean number of aphids and mirids, from the proportion of sampling units (leaves) that had gt 0 individuals of each species. This model provided a satisfactory fit of the data for both the aphid and the mirid. In addition, Wilson and Room's model was successfully used to predict the mean number of aphids and mirids in a series of samples that were carried out in the same area between June and September 2003 for model validation. Finally, equations are given for the calculation of precision in estimating the mean number of aphids or mirids per sampling unit, and the required sample size for a given level of precision
Measurement of the Ļ x BR(HāZZ*) at 350 GeV and 3 TeV center-of-mass energies CLIC
In this paper we present results of the determination of the statistical precision of the branching fraction measurement, for Higgs decaying to ā pairs at 3 TeV and 350 GeV CLIC. Measurements are simulated with the CLIC_ILD detector model, taking into consideration all relevant physics and beam-induced background processes. It is shown that the product of the branching fraction ( ā ā ) and the Higgs production cross-section can be measured with a relative statistical uncertainty of 3% (20%) at 3 TeV (350 GeV) center-of-mass energy, using semileptonic final states and assuming an integrated luminosity of 5 (1) abā1 .BPU11 : 11th International Conference of the Balkan Physical Union : Proceedings book; Aug 11 - Sep 1, 2022S05-HEP High Energy Physics (Particles and Fields
Third mission of the university ā basic differences in approaches
Tradicionalne i osnovne misije sveuÄiliÅ”ta, nastava i istraživanje sve se viÅ”e proÅ”iruju. TreÄa misija sveuÄiliÅ”ta je viÅ”edimenzionalan koncept koji poprima Å”iroke razmjere na svjetskom nivou. Kao cilj rada postavlja se prouÄavanje osnovnih sliÄnosti i razlika u pristupima treÄoj misiji sveuÄiliÅ”ta kada je rijeÄ o ameriÄkim u odnosu na europska sveuÄiliÅ”ta. Kao polazna osnova za usporedbu uzima se Äinjenica da treÄa misija sveuÄiliÅ”ta svoje porijeklo ima na ameriÄkom kontinentu dok se nastanak sveuÄiliÅ”ta vezuje za Europu. Cilj rada je konkretiziran na sljedeÄe zadatke: ispitati utjecaj globalnih obrazovnih politika na pristupe treÄoj misiji sveuÄiliÅ”ta; ispitati razlike u naÄinu funkcioniranja europskih u odnosu na ameriÄka sveuÄiliÅ”ta; objasniti obrazovne implikacije provedbe treÄe misije na europskim sveuÄiliÅ”tima. Kao zakljuÄak rada istiÄe se da je neophodno razumijevanje globalnih druÅ”tveno-ekonomskih utjecaja na proces visokog obrazovanja kako bi se sveobuhvatnije pristupilo obrazovnim reformama i naÄinima njihovog sprovoÄenja. TakoÄer, s obzirom na sudjelovanje sve brojnijih interesnih grupa u okviru realizacije treÄe misije sveuÄiliÅ”ta, neminovno je razvijanje stavova o vrijednostima i naÄelima treÄe misije kod svih onih koji su ukljuÄeni u proces visokog obrazovanja.The traditional and basic missions of the university, teaching and research are expanding. Terminology on the third mission of the university is gaining wide scope at the global level. The aim of this paper is to study basic similarities and differences in approach to the third mission of the university by comparing American to European universities. The starting point for comparing these approaches is the fact that the third mission of the university has its origins in the American continent, while the creation of the university is linked to Europe. The aim of this paper is to specify the following tasks: to examine the impact of global education policies on approaches to the third mission of the university; to examine the differences in the way European universities operate in relation to American universities; to explain the educational implications of the implementation of the universityās third mission at European universities. In conclusion, it is necessary to understand the global socioeconomic impacts on the process of higher education in order to approach educational reforms and ways of implementing them more comprehensively. Also, given the growing number of the participating interest groups in the implementation of the third mission of the university, it is inevitable to develop attitudes about the values and principles of the third mission among all those who are involved in the process of higher education
Primena metode informacionih spektara u ispitivanju enzimatskih razliÄitih alfa amilaza
A series of eight alpha amylases (EC 3.2.1.1) of known primary structure were investigated using the Informational Spectrum Method (ISM) for the purpose of predicting new enzymes with increased efficiency.Niz od 8 Ī±-amilaza (1,4-Ī±-D-glukan-glukano -hidrolaze, EC 3.2.1.1) poznate primarne strukture ispitivano je metodom informacionih spektara (ISM) , s ciljem da se predlože novi enzimi veÄe efikasnosti. PomoÄu ISM-a transformisana je primarna struktura enzima u niz brojeva, a zatim je bilo moguÄe dobiti i uporediti originalne spektre. KoriÅ”Äenjem multi-spektralne funkcije utvrÄen je samo jedan zajedniÄki, dobro definisan pik. Frekvenca ovog pika predstavlja karakteristiÄnu frekvencu svih ispitivanih amilaza. Postoji zavisnost izmeÄu vrednosti amplitude na karakteristiÄnoj frekvenciji i aktivnosti biomolekula. Daljom matematiÄkom obradom, metoda je dala predlog za minimalne promene u strukturi prirodnog proizvoda kojima se omoguÄava poveÄana efikasnost enzima. Ove minimalne promene moguÄe je izvesti najjednostavnijom metodom genetskog inženjerstva - metodom taÄkaste mutacije. Mutacije su predložene za Ī±-amilaze iz sledeÄih izvora: Aspergillus oryzae, Bacillus arnyloliquefaciens i jeÄam
Kinematika kompleksne viŔeosne i viŔevretene maŔine alatke namenjene za proces obrade glodanjem
U okviru ovog rada je prikazana analiza jedne viŔeosne i viŔevretene maŔine alatke namenjene za proces obrade glodanjem. Prema svojoj konfiguraciji, razmatrana maŔina alatka se može okarakterisati kao glodalica horizontalno-vertikalnog tipa Ŕto je svrstava u grupu multifunkcionalnih maŔina alatki. MaŔina alatka se prema viŔe kriterijuma može okarakterisati kao maŔina alatka rekonfigurabilnog tipa i u zavisnosti od potreba se može konfigurisati za 3-osnu, 4-osnu ili 5-osnu obradu glodanjem. Konfiguracija maŔine alatke poseduje dva nezavisna dvoosna rekonfigurabilna paralelna mehanizma Ŕto samu maŔinu alatku svrstava u grupu kompleksnih maŔina alatki
Oksidacioni procesi pri zagrevanju praha intermetalnog jedinjenja SmCo5
Understanding of the thermal stability of intermetallic SmCo5 powder is essential for designing the working atmosphere in all phases of the technological procedure in the production of sintered SmCo5 magnets to obtain maximal magnetic properties. The thermal stability of the SmCo5 powder with defined chemical composition and particle size was investigated in the interval from 20 to 900*C. It was found by thermogravimetic analysis (TGA) that up to 240*C, the oxidation of SmCo5 does not occur. X-Ray diffraction of the thermogravimetric experimental residue of the SmCo5 powder, heated at 240*C, yielded only the presence of the SmCo5 phase. By X-ray diffraction analysis different crystal forms were identified depending on the maximal heating temperature. The following phases were identified: Sm2O3, Co, CoO, Co3O4 and SmCoO3. According to TG and X-ray results, for each of the investigated temperatures, the corresponding chemical reactions were established. The experimental data from both the thermal and X-ray investigations confirm that the phases of pressing and aligning the SmCo5 powder, in the process of producing sintered SmCo5 magnets, may be performed without a protective atmosphere
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