208 research outputs found

    Kinetics and optimization of process for isolation of plant extracts with antibacterial activity

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    Cilj ove doktorske disertacije bio je ispitivanje kinetike izolacije ekstrakata sa jakim antibakterijskim delovanjem iz biljnog materijala primenom različitih postupaka ekstrakcije. Za izolaciju bioaktivnih supstanci korišćena je natkritična ekstrakcija sa ugljenik(IV)-oksidom, hidrodestilacija i ekstrakcija etanolom sa i bez primene ultrazvuka. Predmetom istraživanja ove doktorske disertacije obuhvaćena je analiza i optimizacija različitih procesa izolacije, kao i ispitivanje sadržaja aktivnih komponenti i/ili antibakterijskog dejstva dobijenih ekstrakta za primenu u farmaceutskoj i/ili prehrambenoj industriji. U eksperimentima je, kao sirovina, korišćeno odabrano začinsko i lekovito bilje (Rosmarinus officinalis, Salvia officinalis, Thymus vulgaris, Origanum vulgare, Eugenia caryophyllata, Laurus nobilis, Angelica archangelica, Echinacea angustifolia, Verbascum thapsus, Calendula officinalis i Aloe barbadensis Miller), lišaj Usnea barbata i odabrane mešavine biljnog materijala (karanfilić/origano i karanfilić/timijan). U disertaciji je posebno ispitana i analizirana kinetika procesa natkritične ekstrakcije. S tim u vezi, ispitivan je uticaj operativnih parametara (pritiska i temperature) i odgovarajućeg predtretmana biljnog materijala sa natkritičnim ugljenik(IV)-oksidom na kinetiku natkritične ekstrakcije, kao i uticaj prisustva pojedinih biljnih sirovina u smeši (njihovih glavnih komponenata) na povećanje moći rastvaranja natkritičnog ugljenik(IV)- oksida (kosolventski efekat), pa samim tim i na povećanje brzine ekstrakcije i smanjenje potrošnje natkritičnog fluida. U disertaciji su, takođe, prikazani rezultati ispitivanja kinetike ekstrakcije etanolom sa i bez primene ultrazvuka. Za simulaciju procesa natkritične ekstrakcije iz pojedinačnih biljnih sirovina i izabranih mešavina biljnog materijala korišćeni su postojeći matematički modeli zasnovani na diferencijalnom bilansu mase (Stamenic i sar., 2008; Zizovic i sar., 2005; Sovova i sar., 1994a) i na analogiji sa prenosom toplote (Bartle i sar., 1990; Hong i sar., 1990; Reverchon i sar., 1994 i 1993). Odgovarajući parametri dobijeni primenom navedenih matematičkih modela, zajedno sa podacima o hemijskom sastavu, korišćeni su za interpretaciju fenomena prenosa mase u čvrstoj fazi i u filmu natkritičnog ugljenik(IV)-oksida do kojih dolazi tokom procesa natkritične ekstrakcije iz pojedinih biljnih sirovina i izabranih mešavina biljnog materijala. Za modelovanje procesa ekstrakcija sa etanolom korišćeni su postojeći modeli izvedeni iz drugog Fikovog zakona u cilju određivanja koeficijenata difuzije ekstraktivnih materija u čvrstoj fazi (Crank, 1975; Treybal, 1968). Za rešavanje jednačina navedenih matematičkih modela korišćen je softverski paket Microsoft Fortran PowerStation 4.0. Za ispitivanje antibakterijskog delovanja biljnih ekstrakata i etarskih ulja korišćenа је modifikovanа mikrodiluciona ili makrodiluciona metoda u bujonu opisana i preporučena od strane CLSI (Clinical Laboratory Standards Institute, 2008, SAD), koja se u rutinskoj laboratorijskoj praksi koristi za ispitivanje antibakterijskog delovanja antibiotika, tj. za određivanje vrednosti MIC (minimalne inhibitorne koncentracije) antibiotika. Antibakterijsko delovanje biljnih ekstrakata ispitivano је na sojevima: Staphylococcus vrsta, uključujući sojeve Staphylococcus aureus koji su rezistentni na meticilin (MRSA), Enterococcus vrsta (uključujući vankomicin rezistentne enterokoke, VRE), Streptococcus, Bacillus i Geobacillus vrsta. Ispitan je uticaj pojedinih ekstrakta i na sojeve Gram-negativnih bakterija, Е.coli, Enterobacter cloacae i Sallmonela Enteritidis...This study was aimed to investigate kinetics of isolation of the extracts with strong antibacterial activity from plant material by using different extraction processes. The bioactive substances from plant matrial were isolated by supercritical carbon dioxide extraction, hydrodistillation and ethanol extraction with and without ultrasound. The scope of the present study was kinetic analysis and optimization of different extraction processes as well as content of active substance and/or antibacterial activity of isolated supercritical extracts for application in pharmaceutical and/or food industry. Selected herbs and spices (Rosmarinus officinalis, Salvia officinalis, Thymus vulgaris, Origanum vulgare, Eugenia caryophyllata, Laurus nobilis, Angelica archangelic), Echinacea angustifolia, Verbascum thapsu, Calendula officinalis, Aloe barbadensis Miller), lichen Usnea barbata and selected mixtures of plant materials (clove/oregano and clove/thymus) were used as raw material for experiments. In this study, supercritical carbon dioxide extraction kinetics was particularly analyzed. Therewith, influence of operating parameters (pressure and temperature) and pretreatment of the plant material with supercritical carbon dioxide on the supercritical extraction kinetics, influence of presence of particular plant material in the mixtures of plants (their main components) on the solubility power of supercritical carbon dioxide (co-solvent effect) and subsquently on increase of extraction rate and reduction of supercritical fluid consumption was investigated in this work as well. The results of investigation of the kinetics of ethanol extractions are also presented here. Mathematical models based on differential mass balance (Stamenic et al., 2008; Zizovic et al., 2005; Sovova et al., 1994a,b) and heat transfer analogy (Bartle et al., 1990; Hong et al., 1990; Reverchon et al., 1994, 1993) were used for simulation of process of supercritical carbon dioxide extraction from pure plants and chosen mixture of plants for evaluation of parameters that can be used for interpretation of the mass transfer phenomena in the solid and supercritical carbon dioxide phase. Mathematical models based on the Second Fick’s Law were used for simulation of ethanol extractions in order to evaluate coefficients of diffusion of extractible substances in solid phase (Crank, 1975; Treybal, 1968). Solution of the equations of above metioned mathematical models were solved using Microsoft Fortran PowerStation 4.0. For antibacterial susceptibility testing, modified broth microdilution оr macrodilution method was applied in accordance with the prescription of CLSI (Clinical Laboratory Standards Institute, 2008, USA and corresponding MIC (minimal inhibitory concentration) values were determined. Antibacterial effect of plant extracts on Staphylococcus species including meticillin-resistant Staphylococcus aureus (MRSA) bacterial strains as well as Enterococcus (including vancomycin resistant strains–VRE), Streptococcus, Bacillus and Geobacillus species was investigated. Antibacterial activity of extracts on the Gram-negative bacteria such as Е.coli, Enterobacter cloacae and Sallmonela Enteritidis was investigated as well..

    Characterization of trypsin-like enzymes from the midgut of Morimus funereus (Coleoptera: Cerambycidae) larvae

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    The pH along the midgut of M. funereus larvae had different values, being acidic in the anterior section and basic in the middle and posterior sections. Elastase- and chymotrypsin-like activities were highest in the middle, low in the anterior, and negligible in the posterior section of the midgut. Trypsin-like activities were detected along the whole midgut, with more than 90% of activity in the anterior section. The level of elastase- and chymotrypsin-like activity was very low compared to trypsin-like activity. In the anterior section of the midgut, two isoforms of trypsin-like enzymes were found, both being basic and almost completely inhibited by benzamidine

    Relationships Between Bone Treatment Conditions and Co2+ Sorption Capacities

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    Co-60 is an important radionuclide in spent nuclear fuel and liquid radioactive wastes. For the purification of water containing Co2+, ions sorption on hydroxyapatite (Ca-10(PO4)(6)(OH)(2)) can be applied. The process is particularly cost-effective if biological apatite from animal bones is utilized. In this study, dependence between bovine bone treatment conditions and Co2+, sorption was investigated as a function of initial metal concentration. Eight sorbents were previously prepared using fractional factorial design, by simultaneous variations of five process variables between two levels: factor A-the type of the chemical reagent (H2O2 or NaOH), factor B-reagent concentration (0.1 mol/L or 2 mol/L), factor C-reaction temperature (20(o)C or 60(o)C), factor D-contact time (1h or 3h) and factor E-sample annealing (without or at 400(o)C). At this point, the effects of treatment factors on Co2+, sorption efficiency were evaluated using statistical analysis. Amounts of Co2+ sorbed, amounts of released Ca2+ ions and final pH values were considered as system responses. The results showed that the impact of various treatment factors was different for different starting concentrations of Co2+. Consequently, no statistically important relations could be established between treatment conditions and Co2+, sorption from 10(-4) and 5*10(-4) mol/L solutions, whereas thermal treatment at 400(o)C was the only statistically significant factor influencing sorption from the most concentrated solution (5*10(-3) mol/L). Depending on initial Co2+, concentration, various factors had statistically significant effect on equilibrium pH values, whereas no relation was found between bone treatment conditions and the amounts of Ca2+, released during the sorption.3rd International Conference on Radiation and Applications in Various Fields of Research (RAD), Jun 08-12, 2015, Budva, Montenegr

    Influence of nutrient substrates on the expression of cellulases in Cerambyx cerdo L. (Coleoptera: Cerambycidae) larvae

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    The expression and distribution of digestive cellulases along the midgut of Cerambyx cerdo larvae were analyzed for the first time and are presented in this article. Four groups of larvae were examined: larvae developed in the wild; larvae taken from the wild and successively reared on an artificial diet based on polenta; and larvae hatched in the laboratory and reared on two different artificial diets. Seven endocellulase and seven β-D-glucosidase isoforms were detected in all midgut extracts of C. cerdo with a zymogram after native PAGE. We observed that C. cerdo larvae are capable of producing cellulase isoforms with different PAGE mobilities depending on the nutrient substrate. From our findings it can be assumed that, depending on the distribution of endocellulase and β-D-glucosidase, cellulose molecules are first fragmented in the anterior and middle midgut by endo-β-1,4-glucanase; subsequently, the obtained fragments are broken down by β-D-glucosidase mostly in middle midgut

    Matične ćelije opredeljene za granulocitno-monocitnu lozu kostne srži i periferne krvi svinja

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    The pig is widely used as a large animal model for biomedical research and could be an interesting experimental model for studies of the hematopoietic system and its response in physiological and pathological conditions. With the intention of using the pig as a large animal model in hematopoietic research, a clonal assay in methylcellulose was developed and standardized for detection of committed progenitors of the granulocyte-macrophage lineage from adult pig bone marrow and peripheral blood. Progenitor cells were stimulated to proliferate and differentiate in vitro by adding pig leukocyte conditioned medium (LCM) as a source of homologous growth factors. The number of CFU-GM (Colony Forming Unit -Granulocyte-Macrophage) directly depended on the concentration of LCM. The proliferative rate of CFU-GM progenitor cells was determined by the cytosine arabinoside suicide technique. The percentage of bone marrow and peripheral blood CFU-GM cells in S phase of the cell cycle was 34.7% and 22.2%, respectively. The data obtained regarding the number and characteristics of pig bone marrow and peripheral blood CFU-GM confirmed that the organization of the pig CFU-GM progenitor cell compartment is similar and comparable to that in miniature swine, other animal species and humans.Svinja je životinja koja se koristi kao model u različitim biomedicinskim istraživanjima, a mogia bi biti i interesantan model u ispitivanju fiziologije i patolofizioloških promena hematopoetskog sistema. U cilju razvoja eksperimentalnog modela svinje u istraživanju hematopoeze, stanadardizovan je esej za odredivanje i karakterizaciju opredeljenih matičnih ćelija granulocitno-monocitne loze iz kostne srži i krvi odrasle svinje. Stimulacija proliferacije i diferencijacije ovih matičnih ćelija postignuta je dodavanjem medijuma kondicioniranog leukocitima (LCM - Leukocyte conditioned medium) bogatog faktorima rasta. Broj CFU-GM (Colony forming unit- granulocyte-macrophage) je direktno zavisio od koncentracije LCM-a. Procenat CFU-GM ćelija u S fazi ćelijskog cikiusa odredjivan je tehnikom 'suicida' korišćenjem citozin arabinozida (Ara-C) i iznosio je 34.7% za CFU-GM iz kostne srži i 22.2% za CFU-GM iz periferne krvi. Podaci dobijeni za broj i karakteristike CFU-GM iz kostne srži i periferne krvi potvrđuju da je ovaj odeljak matičnih ćelija kod odraslih svinja organizovan na isti način kao i kod minijaturnih svinja, drugih vrsta životinja i ljudi

    Leaching kinetics of Co(II) and Sr(II) contaminated soil via chemical extraction method

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    Artificially contaminated soil, with mixture of Co(II) and Sr(II) ions in different proportions, was tested. The main aim was to investigate the possibility of ethylenediamine-tetraacetic acid (EDTA) utilization in the chemical extraction process as a method for soil remediation in the case of mixed contamination. The efficiency of this process when EDTA of 10 -4 molL -1 was used was low, while the application of the EDTA solution of the initial concentration 5 · 10 -3 molL -1 or higher showed almost the same efficiency. This suggested that the application of the solution EDTA (5 · 10 -3 molL -1 ) is optimal from the aspect of cost and degradation of soil properties. Furthermore, process kinetic was fitted using one parameter shrinking core models. Kinetic data modeling showed that the process is complex, demanding multi resistance kinetic model. © 2018, Vinca Inst Nuclear Sci. All rights reserved

    Combined use of haemodialysis and haemoperfusion in the treatment of organophosphate poisoning

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    Prikazan je tijek bolesti trojice bolesnika otrovanih inhibitorima acetilkolinesteraze. Sva trojica bila su u stanju kome, a jedan je umjetno respiriran. Sva su trojica podvrgnuta postupku hemodijalize i hemoperfuzije jantarnom smolom istodobno i klinička se slika za kratko vrijeme poboljšala. Trombociti su nakon postupka iznosili prosječno 41% od ishodnih vrijednosti. Raspravlja se o nekim aspektima tih otrovanja.The paper deals with three cases of poisoning with cholinesterase inhibitors. All the three patients were in a comatous state. Simultaneous treatment with haemodialysis and XAD-4 haemoperfusion gave good results. The impairment of the coagulation mechanism poses the greatest disadvantage of this method which in some cases, however, is indispensable to save life

    Physico-chemical characterization and tritium activity determination in spring waters

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    The quality of drinking water should be monitored and analyzed with the aim of determination of water pollution and to minimize health hazards. From a radiological point of view, drinking water may contain natural and artificial radionuclides. One of the radionuclides that can occur in drinking water is tritium. Tritium, as the only radioactive isotope of hydrogen, occurs naturally as a cosmogenic radioisotope in the stratosphere but also has an anthropogenic origin. This study presents the results of some physico-chemical analysis and tritium activity determination carried out for natural water sources in the vicinity of Smederevska Palanka. Water samples from eleven natural water sources were analysed: (source “Veliki Sipovac” (Azanja), source “Pinosava” (Kusadak), source “Vrelo” (Glibovac), source “Vidovača” (Vodice), source “Mineral water” (Vodice), source “Mineral water” (Cerovac), source “Sveta Trojica” (Cerovac), source “Šiljakovac” (Ratari), source “Klis” (Golobok), source “Palanački Kiseljak” (Smederevska Palanka), source “Sveta Petka” (Smederevska Palanka)), in order to determine possible contamination, because the local population is supplied with drinking water from these springs. Physico-chemical characterization was performed measuring pH, total dissolved solids (TDS) and conductivity. The pH values were measured using InoLab pH meter WTW with glass electrode SenTix 81. The conductivity of the samples was measured using Conductometer InoLab WTW Cond7110 at 20°C. TDS measurement was based on the weight of the solid residue remained after evaporation of 40 ml of sample and subsequent drying at 105°C. For tritium activity determination samples were distilled and electrolytically enriched using direct current source SORENSEN DCR60-B30. After electrolytic enrichment samples were measured by Ultra Low Level Liquid Scintillation Spectrometer Quantulus 1220. Conductivity and pH were measured before and after distillation of water samples. Some of investigated waters are naturally acidic and measured values for pH and conductivity show different results for samples before and after distillation. TDS has a higher value for natural mineral waters. In accordance with the legislation in the Republic of Serbia elevated tritium levels in water samples may indicate the presence of other artificial radionuclides. If tritium concentration exceeds allowed value, additional analysis is required. In that case it is necessary to perform gamma spectrometric analysis of the content of artificial radionuclides or analysis of 90Sr. The permissible value of tritium in drinking water is 100 Bq/l. All analyzed waters in this study meet the legal regulations and from the radiation point of view can be used for drinking. The annual effective dose was calculated based on the tritium concentration in the investigated samples for different age groups. The obtained results are in accordance with legislation.X JUBILEE International Conference on Radiation in Various Fields of Research : RAD 2022 (Spring Edition) : book of abstracts; June 13-17, 2022; Herceg Novi, Montenegr

    Uticaj pentobarbitala i pentilenetetrazola na nivo azot oksida u frontalnom korteksu pacova

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    Levels of nitric oxide (NO) in the rats frontal cortex were continuously monitored before and after intraperitoneal administration of an antiepileptic drug-pentobarbital (20 and 40 mg/kg) or convulsant drug - pentylenetetrazol (50 mg/kg). Pentobarbital decreased the levels of NO in a dose dependent manner However, NO levels had a tendency to increase following the administration of pentylenetetrazol. It is suggested that central NO participates in the modulation of neuronal excitability, supporting the idea that NO is an important excitatory factor involved in the regulation of seizure susceptibility. Also, our results on anaesthetized rats suggests that endogenous NO may be involved in the mechanism of action of antiepileptic and analeptic drugs and this further suggest that NO levels in the human brain may decrease during antiepileptic therapy and increase during epileptic attacks or administration of excitatory drugs. The aim of the present study was to determine the possible role of NO levels in the brain during neuronal excitability and seizures.Nivo azot oksida (NO) u frontalnom korteksu pacova meren je kontinuirano kako pre, tako i nakon intraperitonealne primene antiepileptika pentobarbitala (u dozi od 20 i 40 mg/kg) ili konvulzivnog agensa pentilenetetrazola (u dozi od 50 mg/kg). Rezultati ovih eksperimenta su ukazali da pentobarbital smanjuje nivo NO u frontalnom korteksu pacova, dok koncentracija NO ima tendeciju rasta nakon primene pentilenetetrazola. Osim toga, dokazano je da endogeni NO ima važnu ekscitatornu ulogu u centralnim mehanizmima nastanka epilepsije. Takođe, naši rezultati su ukazali da kod anestetisanih životinja endogeni nivo NO ima uticaja na dejstvo kako antikonvulzivnih, tako i prokonvulzivnih lekova. Nivo NO u mozgu pacova je bio snižen tokom terapije antiepilepticima, a povišen tokom epileptičkih napada ili primene lekova iz grupe centralnih stimulansa

    Invariant information and quantum state estimation

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    The invariant information introduced by Brukner and Zeilinger, Phys. Rev. Lett. 83, 3354 (1999), is reconsidered from the point of view of quantum state estimation. We show that it is directly related to the mean error of the standard reconstruction from the measurement of a complete set of mutually complementary observables. We give its generalization in terms of the Fisher information. Provided that the optimum reconstruction is adopted, the corresponding quantity loses its invariant character.Comment: 4 pages, no figure
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