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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Automatizovano izdvajanje semantike iz naučnih članaka u oblasti informatike / A scientific-research activities information system

Kovačević Aleksandar 14 September 2011 (has links)
<p style="text-align: justify; ">Cilj - Cilj istraživanja je razvoj modela, implementacija prototipa i verifikacija sistema za ekstrakciju metodologija iz naučnih članaka iz oblasti Informatike. Da bi se, pomoću tog sistema, naučnicima mogao obezbediti bolji uvid u metodologije u svojim oblastima potrebno je ekstrahovane metodolgije povezati sa metapodacima vezanim za publikaciju iz koje su ekstrahovani. Iz tih razloga istraživanje tako&ntilde;e za cilj ima i razvoj modela sistema za automatsku ekstrakciju metapodataka iz naučnih članaka. Metodologija - Ekstrahovane metodologije se kategorizuju u četiri kategorije: kategorizuju se u četiri semantičke kategorije: zadatak (Task), metoda (Method), resurs/osobina (Resource/Feature) i implementacija (Implementation). Sistem se sastoji od dva nivoa: prvi je automatska identifikacija metodolo&scaron;kih rečenica; drugi nivo vr&scaron;i prepoznavanje metodolo&scaron;kih fraza (segmenata). Zadatak ekstrakcije i<br />kategorizacije formalizovan je kao problem označavanja sekvenci i upotrebljena su četiri zasebna Conditional Random Fields modela koji su zasnovani na sintaktičkim frazama. Sistem je evaluiran na ručno anotiranom korpusu iz oblasti Automatske Ekstrakcije Termina koji se sastoji od 45 naučnih članaka. Sistem za automatsku ekstrakciju metapodataka zasnovan je na klasifikaciji. Klasifikacija metapodataka vr&scaron;i se u osam unapred definisanih sematičkih kategorija: Naslov, Autori, Pripadnost, Adresa, Email, Apstrakt, Ključne reči i Mesto publikacije. Izvr&scaron;eni su eksperimenti sa<br />svim standardnim modelima za klasifikaciju: naivni bayes, stablo odlučivanja, k-najbližih suseda i ma&scaron;ine potpornih vektora. Rezultati - Sistem za ekstrakciju<br />metodologija postigao je sledeće rezultate: F-mera od 53% za identifikaciju Task i Method kategorija (sa precizno&scaron;ću od 70%) dok su vrednosti za F-mere za Resource/Feature i Implementation kategorije bile 60% (sa precizno&scaron;ću od 67%) i 75% (sa precizno&scaron;ću od 85%) respektivno. Nakon izvr&scaron;enih klasifikacionih eksperimenata, za sistem za ekstrakciju metapodataka, utvr&ntilde;eno je da ma&scaron;ine potpornih vektora (SVM) pružaju najbolje performanse. Dobijeni rezultati SVM modela su generalno dobri, F-mera preko 85% kod skoro svih kategorija, a preko 90% kod većine. Ograničenja istraživanja/implikacije - Sistem za ekstrakciju metodologija, kao i sistem za esktrakciju metapodataka primenljivi su samo na naučne članke na<br />engleskom jeziku. Praktične implikacije - Predloženi modeli mogu se, pre svega, koristiti za analizu i pregled razvoja naučnih oblasti kao i za kreiranje sematički bogatijih informacionih sistema naučno-istraživačke delatnosti.<br />Originalnost/vrednost - Originalni doprinosi su sledeći: razvijen je model za ekstrakciju i semantičku kategorijzaciju metodologija iz naučnih članaka iz oblasti<br />Informatike, koji nije opisan u postojećoj literaturi. Izvr&scaron;ena je analiza uticaja različitih vrsta osobina na ekstrakciju metodolo&scaron;kih fraza. Razvijen je u potpunosti automatizovan sistem za ekstrakciju metapodataka u informacionim sistemima naučno-istraživačke delatnosti.</p> / <p style="text-align: justify; "> Purpose - The purpose of this research&nbsp;is model development, software&nbsp;prototype implementation and&nbsp;verification of the system for the&nbsp;identification of methodology mentions&nbsp;in scientific publications in a subdomain&nbsp;of automatic terminology&nbsp;extraction. In order to provide a better&nbsp;insight for scientists into the<br /> methodologies in their fields extracted&nbsp;methodologies should be connected&nbsp;with the metadata associated with the&nbsp;publication from which they are&nbsp;extracted. For this reason the purpose&nbsp;of this research was also a development&nbsp;of a system for the automatic extraction&nbsp;of metadata from scientific&nbsp;publications.&nbsp;Design/methodology/approach -&nbsp;Methodology mentions are categorized&nbsp;in four semantic categories: Task,&nbsp;Method, Resource/Feature and&nbsp;Implementation. The system comprises&nbsp;two major layers: the first layer is an&nbsp;automatic identification of&nbsp;methodological sentences; the second&nbsp;layer highlights methodological phrases&nbsp;(segments). Extraction and&nbsp;classification of the segments was&nbsp;171&nbsp;formalized as a sequence tagging&nbsp;problem and four separate phrase-based&nbsp;Conditional Random Fields were used&nbsp;to accomplish the task. The system has&nbsp;been evaluated on a manually&nbsp;annotated corpus comprising 45 full&nbsp;text articles. The system for the&nbsp;automatic extraction of metadata from&nbsp;scientific publications is based on&nbsp;classification. The metadata are&nbsp;classified eight pre-defined categories:<br /> Title, Authors, Affiliation, Address,&nbsp;Email, Abstract, Keywords and&nbsp;Publication Note. Experiments were&nbsp;performed with standard classification&nbsp;models: Decision Tree, Naive Bayes,&nbsp;K-nearest Neighbours and Support&nbsp;Vector Machines.&nbsp;Findings - The results of the system for&nbsp;methodology extraction show an Fmeasure&nbsp;of 53% for identification of&nbsp;both Task and Method mentions (with&nbsp;70% precision), whereas the Fmeasures&nbsp;for Resource/Feature and&nbsp;Implementation identification was 60%&nbsp;(with 67% precision) and 75% (with&nbsp;85% precision) respectively. As for the&nbsp;system for the automatic extraction of&nbsp;metadata Support Vector Machines&nbsp;provided the best performance. The Fmeasure&nbsp;was over 85% for almost all of&nbsp;the categories and over 90% for the&nbsp;most of them.&nbsp;Research limitations/implications -&nbsp;Both the system for the extractions of&nbsp;methodologies and the system for the&nbsp;extraction of metadata are only&nbsp;applicable to the scientific papers in&nbsp;English language.&nbsp;172&nbsp;Practical implications - The proposed&nbsp;models can be used in order to gain&nbsp;insight into a development of a&nbsp;scientific discipline and also to create&nbsp;semantically rich research activity<br /> information systems.&nbsp;Originality/Value - The main original&nbsp;contributions are: a novel model for the&nbsp;extraction of methodology mentions&nbsp;from scientific publications. The&nbsp;impact of the various types of features&nbsp;on the performance of the system was&nbsp;determined and presented. A fully&nbsp;automated system for the extraction of&nbsp;metadata for the rich research activity<br /> information systems was developed.</p>
2

Potencijal cijanobakterija u formulaciji prehrambenih proizvoda sa dodatom vrednošću / Potential of cyanobacteria in formulation ofvalue-added food products

Milovanović Ivan 18 May 2016 (has links)
<p>U okviru disertacije je ispitan hemijski sastav odabranih cijanobakterijskih sojeva roda Anabaena, Nostoc i Spirulina, kao i uticaj azota na sastav rodova Anabaena i Nostoc. U ispitivanim sojevima određen je sadržaj lipida, proteina, mineralnih materija, sastav i sadržaj lakoisparljivih jedinjenja, aminokiselina i masnih kiselina. U heksanskim i metanolno/vodenim ekstraktima sojeva određen je sadržaj ukupnih fenola, sastav i sadržaj<br />karotenoida i proteinskih pigmenata, kao i antioksidativni potencijal ekstrakata prema DPPH radikalu. Takođe, ispitan je antihiperlipidemijski potencijal roda Spirulina S2 u biolo&scaron;kom ogledu, pri čemu je određen nivo ukupnog holesterola, LDL i HDL čestica, izračunati su relevantni biohemijski markeri hiperlipidemije, kao i koncentracija ALS i AST u plazmi eksperimentalnih životinja. Određen je hemijski sastav fecesa eksperimentalnih životinja, kao i sadržaj holesterola i sastav i sadržaj žučnih kiselina u fecesu. Na bazi<br />hemijskog sastava ispitivanih sojeva cijanobakterija: visokog sadržaja proteina, izbalansiranog aminokiselinskog i masnokiselinskog sastava i visokog sadržaja karotenoida, može se zaključiti da oni imaju potencijal kao sirovine za unapređenje nutritivnog sastava prehrambenih proizvoda. Dokazana antihiperlipidemijska aktivnost soja S2 dodatno ga čini atraktivnim za razvoj proizvoda sa dodatom vredno&scaron;ću namenjenih osobama sa poremećajem u metabolizmu lipida. Rezultati na&scaron;ih ispitivanja su pokazali i da se na hemijskih sastav pojedinih sojeva može uticati putem promene sastave hranljive podloge &scaron;to svakako ostavlja prostora za buduća istraživanja.</p> / <p>In this thesis, the chemical composition of the selected strains of cyanobacteria belonging to Anabaena, Nostoc and Spirulina genus was determined. Influence of nitrogen addition on the chemical composition of Anabaena and Nostoc strains has also been investigated. Content of lipids, crude protein, and minerals, as well as composition and content of volatile organic compounds, amino acids, fatty acids was determined in the investigated strains. Total phenolic content and composition and content of carotenoids, protein pigments and antioxidative action toward DPPH radical was determined in the hexane and methanol/water extracts of the investigated strains. Antihyperlipidemic potential of the Spirulina S2 strain was investigated in a biological<br />assay, and content of total cholesterol, LDL and HDL was determined in plasma of the experimental animals, which allowed calculation of relevant biochemical parameters for hyperlipidemia. ALT and AST concentrations were also determined in the plasma of the experimental animals. Chemical composition, as well as content of cholesterol and composition and content of bile acids in the feces of the experimental animals was also<br />determined. Based on the determined chemical composition of the investigated cyanobacterial strains: high protein and carotenoid content, balanced amino acid and fatty acid profiles, it can be concluded that these strains have a potential as ingredients for improving nutritional characteristics of food products. Antihyperlipidemic activity shown by the tested strain S2 makes it attractive for creation of value-added food products intended for people with lipid disorders. The results of this research also show that manipulation of composition of the growing medium can influence the chemical composition of certain investigated strains, which makes it viable to conduct further research on this topic.</p>
3

Antihistamininių vaistų (klemastino fumarato, loratadino, desloratadino) mišinio išskyrimas iš kraujo plazmos ir identifikavimas efektyviosios skysčių chromatografijos metodu / Antihistamines (clemastine fumarate, loratadine, desloratadine) extraction from human plasma and identification using high performance liquid chromatography

Zdanytė, Birutė 30 June 2014 (has links)
Darbo tikslas: optimizuoti metodiką, kuria būtų galima atlikti antihistamininių vaistų mišinio, sudaryto iš klemastino fumarato, loratadino ir desloratadino, ekstrakciją iš kraujo plazmos ir kokybinį nustatymą efektyviosios skysčių chromatografijos metodu. Darbo uždaviniai: Atlikti mokslinės literatūros analizę siekiant įvertinti antihistamininių vaistų savybes ir pasirinktų junginių ekstrakcijos iš kraujo plazmos ir tapatybės nusatymo metodikas. Optimizuoti ir validuoti ESC metodiką kokybiniam pasirinktų preparatų mišinio nustatymui iš kraujo plazmos. Parinkti klemastino fumarato, loratadino ir desloratadino skysčių – skysčių ekstrakcijos iš kraujo plazmos sąlygas. Apibendrinti gautus ekstrakcijos ir ESC rezultatus. Metodai: skysčių – skysčių ekstrakcija ir ESC. Tyrimo objektas: kraujo plazma, į kurią įterpti antihistamininiai vaistai klemastino fumaratas, loratadinas, desloratadinas ir jų mišinys. Rezultatai: tiriamųjų medžiagų sulaikymo laikai: desloratatadino apie – 5,9 min, loratadino – apie 11,4 min, klemastino fumarato – apie 13,2 min. Validuota ESC atlikimo metodika. Atliekant ekstrakciją su trichlormetanu neišsiekstrahavo nei vienas tiriamasis junginys, su dichlormetanu – loratadinas, su dietileteriu ir cikloheksanu – visi trys tiriamieji junginiai. Išvados: 1. Atlikta mokslinės literatūros analizė, apžvelgiant antihistamininių vaistų savybes, ekstrakcijos iš kraujo plazmos būdus bei identifikavimo metodus, didžiausią dėmesį skiriant efektyviajai skysčių... [toliau žr. visą tekstą] / Aim: to optimise a method, by which mixture of antihistamines containing clemastine fumarate, loratadine and desloratadine could be extracted from human plasma and qualitative determination using high performance liquid chromatogrophy could be made. Tasks: to carry out analysis of scientific literature and evaluate characteristics of antihistamines and methods of chosen compounds extraction from human plasma and identity determination. Optimise and validate HPLC method for qualitative determination of chosen medicines. Select conditions suitable for chosen antihistamines liquid – liquid extraction from human plasma. Carry out qualitative determination of clemastine fumarate, loratadine and desloratadine in human plasma using validated HPLC method. Summarize results of extraction and HPLC. Methods: liquid – liquid extraction and HPLC. Object: human plasma with embedded antihistamines: clemastine fumarate, loratadine, deloratadine and their mixture. Results: retention times of test substances: desloratadine – 5,9 min, loratadine – 11,4 min, clemastine fumarate – 13,2 min. HPLC method was validated. None of the compounds were extracted using trichlormethan. Only loratadine was extracted using dichlormethan. All three compounds were extracted using diethyl ether and cyclohexane. Conclusions: 1. Analysis of scientific literature was caried out, characteristics of antihistamines, methods of extraction from human plasma and identity determination of chosen compounds were overviewed... [to full text]
4

Ekstrakcija, sastav, delovanje i moguće primene odabranih vrsta pečuraka / Extraction, content, activity and possible applications of selected mushroom species

Vidović Senka 30 May 2011 (has links)
<p>Upotrebom 50% etanola i superkritičnog ugljendioksida kao ekstragensa izvr&scaron;ena je ekstrakcija različitih vrsta pečuraka. Nakon određivanja prinosa suvih ekstrakata, u njima su određeni: sadržaj ukupnih fenola i ukupnih flavonoida, sadržaj makro- i mikro-elemenata, sadržaj adenozina, kao i sadržaj karakterističnih komponenata pistilarina i variegetične kiseline. Najveći sadržaj ukupnih fenolnih jedinjenja određen je u suvom ekstraktu pečurke <em>C. pistillaris</em>, najveći sadržaj ukupnih flavonoida u ekstraktu <em>D. confragosa</em>, a najvi&scaron;e esencijalnog cinka i selena sadrži suvi ekstrakt pečurke <em>B. edulis</em>. U odnosu na ostale suve ekstrakte ekstrakt pečurke <em>L. saccatum</em> sadrži nekoliko puta veću količinu adenozina. Antioksidativno delovanje suvih ekstrakata analizirano je primenom spektrofotometrijskih i EPR metode. Ekstrakti <em>C. pistillaris, B. edulis </em>i <em>A. mellea</em> pokazali su se kao najefikasniji skevindžeri najopasnije slobodnoradikalske vrste hidroksil radikala, dok se efikasnim u prevenciji lipidne peroksidacije mogu smatrati ekstrakti <em>B. edulis, A. mellea </em>i<em> L. saccatum</em>. Nakon određivanja prinosa supekritičnih ekstrakata ispitivanih pečuraka, u njima je analiziran sastav masnih kiselina i detektovana jedinjenja sterolnog tipa. U ispitivanim ekstraktima dominantna je nezasićena linoleinska kiselina, a značajan je udeo i oleinske nezasićene masne kiseline. Dominantno jedinjenje sterolne strukture u gotovo svim ekstraktima je ergosterol. Ispitan je uticaj superkritičnih ekstrakata pečuraka na fluidnost membrane eritrocita i na osnovu dobijenih rezultata zaključeno da bi značajnu ulogu u antihipertenzivnoj ishrani mogle imati pečurke <em>A. mellea </em>i<em> M. procera</em>.</p> / <p>Using 50% ethanol and supercritical carbon dioxide different mushroom extracts were prepared. After analysis of extraction yield, content of total phenols and total flavonoids, content of macro-elements and micro-elements, as well as content of adenosine and characteristic compounds (pistilarin and variegatic acid) were determined. Highest content od total phenols was determined in <em>C. pistillaris</em> extract, highest content of total flavonoids in<em> D. confragosa</em> and highest content of essential zinc and selenium in B. edulis dry extract. In comparsion to other extracts <em>L. saccatum</em> posses few time higher content of adenosine. Antioxidat activity was analysed by spectrophotometric and EPR methods. Extracts of <em>C. pistillaris</em>,<em> B. edulis</em> and <em>A. mellea</em> have been showed as a most efficient in scavenging of dangerous OH˙ radical. In lipid peroxidation prevention significant were mushrooms extracts of<em> B. edulis</em>, <em>A. mellea</em> and<em> L. saccatum</em>.<br />After determination of mushrooms supercritical extraction yield, fatty acid composition and sterol components were analysed. Dominant unsaturated fatty acid in investigated mushroom extracts was linoleic acid. Content of oleic fatty acid was also significant. Dominant compound of sterol structure, in almost all supercritical extracts, was ergosterole. Influence of supercritical mushroom extracts on eritrocite membrane fluidity was investigated. Acording to obtained results, mushrooms <em>A. mellea</em> and <em>M. procera</em> could have significant role in antihypertensive diet.</p>
5

Antidepresantų amitriptilino ir venlafaksino mišinio išskyrimo iš kraujo plazmos optimalių sąlygų nustatymas / The determination of optimal conditions of isolation antidepressant amitriptyline and venlafaxine mixture from human plasma

Guokaitė, Gabrielė 18 June 2014 (has links)
Atlikta mokslinių literatūros šaltinių apžvalga. Tiriamųjų medžiagų identifikavimui ir kiekybinei analizei pritaikyta ir validuota efektyvioji skysčių chromatografija. Antidepresantų mišinys išskirtas iš kraujo plazmos kietos fazės ekstrakcijos metodu. KFE metodas optimizuotas keičiant eliuentą ir eliuento pH. Atliktas optimizacijos sąlygų palyginimas. Nustatyti 3 organiniai tirpikliai, kuriais efektyviausiai eliuuojamos sorbente sulaikytos tiriamosios medžiagos bei gauti statistiškai patikimi rezultatai (p>0,05) : 2 proc. etano rūgšties tirpalas 100 proc. metanolyje, 2 proc. etano rūgšties tirpalas 80 proc. metanolyje ir 2 proc. metano rūgšties tirpalas 100 proc. metanolyje. / In this thesis was performed research of scientific literature. Applied and validated high performance liquid chromatography for identification and quantification of target compounds. Antidepressant mixture extracted from blood plasma samples using LLE and SPE methods. SPE method was optimized by changing the elutor and its pH. Three organic solvents were determined, which best elute target compounds from sorbent and show statistical confidence (p>0,05): 2 proc. acetic acid in 100 proc. methanol solution, 2 proc. acetic acid in 80 proc. methanol solution and 2 proc. formic acid in 100 proc. methanol solution.
6

Praćenje ostataka sulfonilurea u zemljištu u realnim uslovima primenom visoko-pritisne tečne hromatografije / Monitoring of residues of sulfonylurea in soil under real conditions by using high pressure liquid chromatography

Grahovac Nada 26 December 2016 (has links)
<p>U okviru doktorske disertacije razvijena je brza i selektivna metoda za<br />određivanje i praćenje ostataka herbicida na bazi sulfonilurea (nikosulfuron,<br />oksasulfuron, tribenuron metil, tritosulfuron, triasulfuron, rimsulfuron i<br />prosulfuron) u zemlji&scaron;tu primenom visoko pritisne tečne hromatografije sa<br />UV detektor sa nizom fotoosetljivih dioda (HPLC-UV-DAD). Razdvajanje<br />sulfonilurea je izvedeno uz primenu Zorbax Eclipse XDB-C18 kolone. U cilju<br />definisanja odgovarajućih uslova analize, ispitan je i definisan uticaj<br />najznačajnijih eksperimentalnih faktora. Usvojeni su sledeći optimalni uslovi<br />gradijentne elucije: mobilna faza acetonitril (A) i 0,1% sirćetna kiselina (B) t<br />= 0 min, 52% A; t = 2-2,5 min, 47% A; t = 2,5-5 min, 52% A, pri konstatnom<br />protoku od 1 mL min-1 i temperaturi kolone od 250C. Na osnovu odziva<br />analitičkog signala, njegove reproduktivnosti i linearnosti, talasna dužina od<br />240 nm je usvojena kao odgovarajuća. Utvrđeno je da je uticaj matriksa bio<br />izražen te je stoga za kvantitativno određivanje sadržaja SU u uzorcima<br />zemlji&scaron;ta primenom HPLC-UV-DAD metode kori&scaron;ćena MMC kalibraciona<br />kriva. Pri analizi ekstrakata nekontaminiranog zemlji&scaron;ta ostvarena je granica<br />kvantitativnog određivanja za nikosulfuron, oksasulfuron, tribenuron metil,<br />tritosulfuron, triasulfuron, rimsulfuron i prosulfuron od 3,16 &mu;g kg-1, 3,40 &mu;g<br />kg-1, 3,76 &mu;g kg-1, 4,13 &mu;g kg-1, 3,60 &mu;g kg-1, 3,04 &mu;g kg-1 i 2,97 &mu;g kg-1,<br />redom. Za potrebe osetljivijih, selektivnijih i tačnijih određivanja SU u<br />zemlji&scaron;tu, definisana je metoda uz primenu tečne hromatografije sa<br />tandemskom masenom spektrometrijom (HPLC-MS-MS). HPLC-MS-MS je<br />kori&scaron;ćena kao referntna tehnika za proveru rezultata koji su dobijeni<br />primenom HPLC uz UV-DAD detektor. Definisan je efikasan postupak za<br />pripremu uzoraka zemlji&scaron;ta u cilju hromatografskog određivanja SU.<br />Najefikasnija ekstrakcija ostvarena je primenom sme&scaron;e dihlormetanacetonitril<br />(2:1, v/v), zaki&scaron;eljene sirćetnom kiselinom (0,8%, v/v), uz dodatak<br />uree (0,3 g/ 10g zemlji&scaron;ta). Postupak mikrotalasne estrakcije u zatvorenom<br />sistemu omogućio je najbolje uslove za ekstrakciju SU. U cilju izdvajanja SU,<br />iz matriksa ekstrakata zemlji&scaron;ta, primenjena je ekstrakcija na čvrstoj fazi (SPE) sa silika gelom kao adsorbensom. Definisana metoda za određivanje<br />ispitivanih SU, kao i razvijeni postupak pripreme uzoraka, uspe&scaron;no je<br />primenjen u analizi realnih uzoraka zemlji&scaron;ta. Veoma dobre vrednosti testa<br />povrata ostvarene pri analizi primenom HPLC-UV-DAD metode, potvrdile su<br />pre svega ispravnost postupka pripreme uzoraka, a delom i kompletne<br />metode. Tačnost razvijene metode za određivanje SU u zemlji&scaron;tu potvrđena je<br />paralelnim analizama uzoraka zemlji&scaron;ta kori&scaron;ćenjem HPLC-MS-MS.<br />Primenom Studentovog t-testa (upareni), utvrđeno je da se rezultati paralelnih<br />analiza statistički značajno ne razlikuju (P=95%). Istraživanja u okviru<br />disertacije obuhvatila su i praćenje disipacije nikosulfurona, rimsulfurona,<br />oksasulfurona i prosufurona u različitim komercijalnim dozama primene<br />tokom 50 dana u polju na tri različite dubine (0-15 cm, 15-30 cm i 30-45 cm),<br />kao i laboratorijskim uslovima na dve temperature (250C i 300C). Vreme<br />polurazgradnje (DT50) ispitivanih SU (nikosulfuron, oksasulfuron i<br />prosulfuron) definisano Mitttag-Lefler-ovom funkcijom u ogledima u<br />laboratorijskim uslovima na 250C iznosilo je 0,65 dana (50 g ha-1 a.k.), 0,64<br />dana (160 g ha-1 a.k.) i 0,66 dana (30 g ha-1 a.k.), redom, a na 300C za<br />nikosulfuron 0,20 dana (50 g ha-1 a.k.) i prosulfuron 0,49 dana (50 g ha-1 a.k.).<br />DT50 za ispitivane SU u polju, takođe definisano Mitttag-Lefler-ovom<br />funkcijom, iznosilo je 72 minuta (0,05 dana), 0,23 dana, 0,12 dana i 0,15<br />dana, za nikosulfuron, rimsulfuron, oksasulfuron i prosulfuron, redom.<br />Značajno veća disipacija koja je utvrđena istraživanjima u okviru ove<br />disertacije najverovatnije je uzrokovana uticajem abiotičkih i biotičkih<br />procesa, kao i faktora spolja&scaron;nje sredine.</p> / <p>In this thesis a fast and selective method for determination and monitoring<br />of residues sulfonylurea herbicides (SU) (nicosulfuron, oxasulfuron,<br />tribenuron methyl, tritosulfuron, triasulfuron, rimsulfuron and prosulfuron)<br />in soil, by applying high-performance liquid chromatography with UV<br />detector with diode array diodes (HPLC-UV-DAD) was developed. The<br />separation of the sulfonylurea was performed by use of a Zorbax Eclipse<br />XDB-C18 column. In order to define appropriate conditions of analysis,<br />the influence of the most significant the experimental factors was<br />investigated and defined. The following optimal conditions for gradient<br />elution: mobile phase acetonitrile (A) and 0.1% acetic acid (B) t = 0 min,<br />52% A; t = 2-2.5 min, 47% A; t = 2.5-5 min, 52% A were adopted at a<br />constant flow rate of 1 mL min-1 and column temperature of 250C. On<br />basis of the response of the analytical signal, its reproducibility and<br />linearity, the wavelength of 240 nm was adopted as an appropriate. The<br />influence of the matrix was expressed and therefore for the quantitative<br />determination of investigated SU in soil samples application of HPLCUV-<br />DAD methods was used MMC calibration curve. In the analysis of<br />extracts of nocontaminated soil limits of quantitation for nicosulfuron,<br />oxasulfuron, tribenuron methyl, tritosulfuron, triasulfuron, rimsulfuron and<br />prosulfuron was achieved 3.16 &mu;g kg-1, 3.40 &mu;g kg-1, 3.76 &mu;g kg-1, 4.13 &mu;g<br />kg-1, 3.60 &mu;g kg-1, 3.04 &mu;g kg-1 and 2.97 &mu;g kg-1, respectively. The method<br />by using liquid chromatography-tandem mass spectrometry (HPLC-MSMS)<br />was defined in order to find more sensitive, more selective and more<br />accurate way to determine concentration SU in soil. HPLC-MS-MS was<br />used as the reference technique for checking results that have been<br />obtained by HPLC with UV-DAD detector. An efficient procedure<br />preparation of soil samples for the purpose chromatographic determination<br />of SU was defined. Using a mixture of dichloromethane-acetonitrile (2: 1,<br />v / v), acidified with acetic acid (0.8%, v / v), with the addition of urea (0.3<br />g / 10 g soil) was applied as the most effective way for extraction SU.<br />Microwave extraction process in a closed system allowed the best<br />conditions for the extraction of SU. In order to extract SU from matrix<br />exctracts soil the solid phase the extraction (SPE) with silica gel as an<br />adsorbent was used. The defined method for determination of investigated SU, as well as the developed procedure of sample preparation, was<br />successfully applied in the analysis of real samples of soil. The correctness<br />of procedure of sample preparation was confirmed with very good values<br />of recovery test which was applied in the analysis by using HPLC-UVDAD.<br />The accuracy of the developed method for determination of SU was<br />confirmed by coupled analysis soil samples using HPLC-MS-MS. The<br />results of parallel analysis does not differ significantly at 95% confidence<br />level. It was obtained using Student t-test (paired). The method developed<br />in this thesis was used for monitoring the dissipation of nicosulfuron,<br />rimsulfuron, oxasulfuron prosufuron, in different commercial doses of<br />application during 50 days in field at three different depths (0-15 cm, 15-<br />30 cm and 30-45 cm) and for laboratory conditions at two temperatures<br />(25&ordm;C and 30&ordm;C). The half-life time (DT50) of investigated SU were<br />calculated by use of Mitttag-Lefler function in experiments under<br />laboratory conditions at 25&ordm;C. The values of DT50 for nicosulfuron,<br />prosufuron and oxasulfuron read: 0.65 days (50 g ha-1 a.k.), 0.64 days (160<br />g ha-1 a.k.) and 0.66 days (30 g ha-1 a.k.), respectively. In the same type of<br />experiments at 30&ordm;C we get DT50 for nicosulfuron equals 0.20 days (50 g<br />ha-1 a.k.) and for prosulfuron equals 0.49 days (50 g ha-1 a.k.). The values<br />of DT50 on experiments in field were obtain also by use of Mitttag-Lefler&#39;s<br />function, and half-life times for nicosulfuron, rimsulfuron, oxasulfuron and<br />prosufuron from the commercially recommended doses, equal 72 minutes<br />(0.05 days), 0.23 days, 0.12 days and 0.15 days, respectively. Significantly<br />greater dissipation which was determined in this thesis was probably<br />caused by the influence of abiotic and biotic processes as well as<br />environmental factors.</p>
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Rausvažiedės ežiuolės (Echinacea Purpurea (L.) Moench) ekstraktų, gautų skirtingais metodais, palyginimas / Comparison of purple coneflower (Echinacea purpurea (L.) Moench) extracts obtained by different extraction methods

Maleckienė, Rūta 26 June 2008 (has links)
Rausvažiedė ežiuolė (Echinacea purpurea (L.) Moench) apibūdinama kaip priemonė skatinanti medžiagų apykaitą; stimuliuojanti metabolizmo pakitimus ir ląstelių natūralią gynybą esant lėtinėms ir ūmioms ligoms; antiseptikas; dezinfekuojantis žaizdas agentas; vaistas. Darbo tikslas buvo atlikti fenolinių junginių analizę rausvažiedės ežiuolės (Echinacea purpurea (L.) Moench) ekstraktuose, gautuose skirtingais metodais, naudojant spektrofotometrinį metodą ir efektyviąją skysčių chromatografiją. Darbo uždaviniai buvo optimizuoti ekstrakcijos sąlygas (maceracijos metodu) įvertinant skirtingas metanolio koncentracijas ir ekstrakcijos trukmės įtaką fenolinių junginių kiekybinei sudėčiai ekstraktuose; paruošti ekstraktus maceracijos, soksleto ir ekstrakcijos superkritiniais skysčiais metodais; optimizuoti efektyviosios skysčių chromatografijos sąlygas; atlikti kokybinę ir kiekybinę fenolinių junginių analizę Rausvažiedės ežiuolės ekstraktuose, įvertinant a) skirtingas ekstraktų paruošimo metodikas; b) skirtingas augalo dalis. Tyrimo metu optimizuotos ekstrakcijos sąlygos (maceracijos metodu); nustatyta, kad daugiausiai fenolinių junginių išekstrahuota naudojant 70 % metanolį per pirmas 4 ekstrakcijos valandas. Paruošti ekstraktai maceracijos, soksleto ir ekstrakcijos superkritiniais skysčiais metodais. Spektrofotometru nustatyta, kad daugiausiai fenolinių junginių išekstrahuojama maceracijos metodu — 3 kartus daugiau nei soksleto metodu ir 14 kartų daugiau nei ekstrakcija... [toliau žr. visą tekstą] / Echinacea purpurea (L.) Moench (family Asteraceae) herbal medicines and dietary supplements are traditionally used as immunostimulants in the treatment of inflammatory and viral diseases. Employed are roots and aerial parts. The main active compounds of Echinacea purpurea (L.) Moench are alkamides and polyacetylenes, caffeic acid derivatives, polysaccharides and glycoproteins. With regard to caffeic acid derivatives, several compounds have been identified from the hydrophilic fractions of Echinacea extracts, such as caftaric acid, chlorogenic acid, caffeic acid and cichoric acid. Cichoric acid is found to be the main phenolic compound in E. purpurea. From the caffeic acid derivatives, only cichoric acid has shown immunostimulatory properties, promoting phagocyte activity in vitro and in vivo. In addition, cichoric acid has antihyaluronidase activity, and has a protective effect on the free-radical-induced degradation of collagen. Cichoric acid has also shown antiviral activity and has recently been found to inhibit HIV-1 integrase and replication. Tasks of investigation: to prepare samples for phenolic acids analysis by supercritical fluid, soxhlet extractions and maceration methods and optimize SPE parameters. Evaluate amount of cichoric acid and compare it in different parts of plant by spectrophotometric method. Optimize HPLC analysis conditions and identify the main phenolic acids by HPLC. Compare amounts of phenolic acids between plant parts and extraction methods... [to full text]
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Vitamino E preparatų analizė efektyviosios skysčių chromatografijos metodu / The analysis of food supplements containing vitamin E using high performance liquid chromatography

Kirjanovas, Mindaugas 18 June 2014 (has links)
Nuolatos plečiantis maisto papildų rinkai ir augant naujai sukuriamų papildų kiekiui būtina sukurti greitas, tikslias ir efektyvias papildų analizės metodikas, norint užtikrinti į rinką tiekiamų farmacinių prepartų kokybę. Vitamino E nustatymui efektyviosios skysčių chromatografijos būdu yra sukurta nemažai įvairių metodikų, tačiau svarbu žinoti, kuri metodika yra efektyviausia būtent vitamino E preparatams. Tyrimo tikslas - atlikti kokybinį ir kiekybinį tokoferolio acetato nustatymą pritaikant efektyviosios skysčių chromatografijos metodą bei surasti efektyviausią tokoferolio acetato ekstrakcijos metodiką vaistinių preparatų analizei. Tyrimo uždaviniai - surinkti ir apibendrinti informaciją apie vitaminą E, jo poveikį organizmui, maisto papildus su tokoferolio acetatu bei jų analizę; optimizuoti metodiką tokoferolio acetato preparatų analizei efektyviosios skysčių chromatografijos būdu ir ją validuoti; atlikti tokoferolio acetato preparatų (maisto papildo ir vaistinio preparato) paruošimą analizei įvairiomis ekstrakcijos metodikomis; išanalizuoti gautus duomenis ir padaryti išvadas apie efektyviausias ekstrakcijos metodikas bandinių paruošimui bei skirtumus tarp vaistinio preparato ir maisto papildo analizės. Metodas – tyrimas atliktas chromatografine sistema su fotodiodų matricos detektoriumi. Mobilioji fazė – metanolis:distiliuotas vanduo (95:5), tekėjimo greitis – 1.2 ml/min, bandinio tūris – 10 µl, trukmė – 14 min, bangos ilgis – 282 nm. Išbandytos preparatų... [toliau žr. visą tekstą] / The food supplements market is constantly growing and new products are entering it everyday. In order to assure the quality of these pharmaceuticals it is important to develop methods of analysis which are fast, precise and effective. There are many methods created for the analysis of vitamin E using high-performance liquid chromatography so it is important to know which of them are the most effective for vitamin E food supplements. The aim – to perform a qualitative and a quantitive assey of tochopherol acetate using high performance liquid chromatography and to find the most effective method of extracting tocopherol acetate from food suplements. The tasks – to collect and to summarize the data on vitamin E, its effects on human body, on the supplements containing tocopherol acetate and their analysis; to develop a high-performance liquid chromatography method of analysis suitable for the pharmaceuticals containing tocopherol acetate ant to validate it; to perform a tocopherol acetate (a food supplement and a drug) samples preparation using different techniques chosen; to analyze the data collected and to make conclusions about the most effective way of preparing samples for the analysis and about the differences between a drug and a food supplement analysis. The method – the study was conducted by high-performance liquid chromatography using a photodiode matrix detector. Mobile phase – methanol:purified water (95:5), flow-rate – 1.2 ml/min, injection volume – 10 µl... [to full text]
9

Mėginio ruošimo metodikų lyginimas toksikologinėje analizinėje / Comparison of sample preparation methods in toxicological analysis

Dulius, Aurimas 18 June 2014 (has links)
Šiame darbe nagrinėjami kietazės ekstrakcijos ir skysčių – skysčių ekstrakcijos metodai, bei lyginami jų efektyvumai ekstrahuojant kodeiną iš kraujo plazmos ir šlapimo. Ekstrakcijų efektyvumai buvo nustatinėjami UV spektrometrijos būdu. Darbo tikslas – nustatyti optimalias mėginio ruošimo toksikologinėje analizėje metodikas, tinkamas kodeino išskyrimui iš biologinių terpių – kraujo plazmos, šlapimo, bei palyginti šių metodikų efektyvumą. įvertinus gautus duomenis, galima teigti, kad ekstrahuojant kodeiną iš šlapimo, skysčių – skysčių ekstrakcijos ir kietafazės ekstrakcijos efektyvumai buvo panašūs. Ekstrahuojant kodeiną iš kraujo plazmos – efektyvesnė pasirodė kietafzė ekstrkcija. / In this master’s thesis are examined solid phase extraction and liquid - liquid extraction methods. Codeine has been extracted by using these methotds, efficiencies of extraction methods were determined by UV spectrophotometry. The aim of this this master’s thesis is to determine the optimal sample preparation methodologies for toxicological analysis, codeine proper isolation of biological media - plasma, urine, and to compare the effectiveness of these methods. After assessment of the data, it can be said that the extraction of codeine from urine, efficiencies were similar extracting by using liquid - liquid extraction and solid phase extraction. Codeine is more efficiently extracted from blood plasma by solid phase extraction method than liquid - liquid extraction method.
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Dobijanje ekstrakta nevena (Calendula officinalis L.) ugljen dioksidom pod pritiskom i njegovo mikrokapsuliranje u sistemu polimer-površinski aktivna materija / Preparation of marigold (Calendula officinalis L.) extract using carbon dioxide under pressure and its microencapsulation in the polymer–surfactant system

Petrović Lidija 01 July 2010 (has links)
<p>Savremene svetske tendencije upućuju na sve &scaron;iru primenu<br />ekstrakata lekovitog i aromatičnog bilja, kako u prehrambenim<br />proizvodima&ndash; funkcionalna hrana, tako i u proizvodima<br />farmaceutske i kozmetičke industrije. Ekstrakti biljnog<br />materijala, dobijeni primenom ugljendioksida pod pritiskom,<br />sadrže termički nepromenjene aktivne komponente, te se<br />poslednjih godina sve vi&scaron;e primenjuju u farmaceutskoj i<br />prehrambenoj industriji.<br />Cilj ove doktorske disertacije je da se ispita mogućnost<br />inkorporiranja ekstrakta nevena (<em>Calendula officinalis</em> L.), kao<br />farmakolo&scaron;ki aktivne materije, u mikrokapsule sa ciljem za&scaron;tite<br />od spolja&scaron;njih uticaja, produžetka njegovog delovanja i<br />pro&scaron;irenja mogućnosti primene.<br />Za dobijanje ekstrakata nevena primenjeni su postupci<br />ekstrakcije ugljendioksidom u tečnom i superkritičnom stanju.<br />Definisani su uslovi pri kojima je moguće dobiti ekstrakat sa<br />visokim sadržajem etarskog ulja, nosiocem gastro-intestinalnog<br />delovanja (200 bar, 40<sup>o</sup>C). Totalni ekstrakt dobijen pod ovim<br />uslovima ekstrakcije je odabran za dobijanje mikrokapsula.<br />Ispitivana je mogućnosti primene polimer&ndash;PAM interakcije<br />nejonskih derivata celuloze- hidroksipropilmetil celuloze<br />(HPMC) i anjonske PAM- natrijum dodecilsulfata (SDS), za<br />formiranje omotača mikrokapsula. Primenom konduktometrijske<br />i viskozimetrijske metode, određene su karakteristične<br />koncentracije pri kojima HPMC&ndash;SDS interakcija započinje i<br />zavr&scaron;ava se. Definisan je uticaj osobina molekula HPMC<br />(molekulska masa, stepen supstitucije, vrsta supstituenta) i<br />temperature na &scaron;irinu intervala interakcije i obja&scaron;njeni<br />mehanizmi njihovog povezivanja, sa osvrtom na strukturu i<br />osobine formiranih HPMC/SDS komleksa. Reolo&scaron;kim<br />ispitivanjima pri različitim uslovima definisane su promene u<br />pona&scaron;anju sistema u zavisnosti od HPMC&ndash;SDS interakcije.<br />Ispitivan je uticaj interakcije na osobine 20% emulzija<br />suncokretovog ulja u vodi određivanjem njihovih reolo&scaron;kih<br />osobina, veličina i raspodela veličina kapi i praćenjem<br />stabilnosti. Utvrđeno je da se u oblasti najizraženije HPMC&ndash;SDS interakcije, odnosno kada se na granici faza ulje-voda<br />nalazi umrežen HPMC/SDS kompleks, dobijaju emulzije<br />najveće stabilnosti, sa njajmanjim srednjim prečnikom kapi.<br />Su&scaron;enjem emulzija, primenom spray drying postupka,<br />dobijene su mikrokapsule uljnog sadržaja, stabilizovane<br />kompleksom HPMC/SDS. Najbolje karakteristike mikrokapsula<br />(mehanička otpornost, morfolo&scaron;ke karakteristike, sposobnost<br />redispergovanja, veličina i raspodela veličina čestica i količina<br />inkapsuliranog ulja), dobijene u oblasti najizraženije interakcije.<br />Dodatak odabranog CO<sub>2</sub> ekstrakta nevena u uljnu fazu<br />emulzija ne menja značajno njihove osobine, kao ni osobine iz<br />njih dobijenih mikrokapsula.<br />Ispitivanja sprovedena u ovoj doktorskoj disertaciji<br />pokazala su da se osobine kompleksa polimer/PAM mogu<br />iskoristiti za mikrokapsulaciju ulja kao nosača farmakolo&scaron;ki<br />aktivnih materija.</p> / <p>Contemporary global trends in food- functional food,<br />pharmaceutical and cosmetic industry as well have been<br />focused on a wider medical plants extracts application during<br />the recent decade. Plant extracts obtained by means of carbon<br />dioxide under high pressure contained all unchanged active<br />compounds from plant, so that they have became more<br />popular for application in food and pharmaceuticals recently.<br />The aim of this thesis was to investigate the possibility to<br />incorporate marigold extract (<em>Calendula officinalis</em> L.), as a<br />pharmacologicaly active compound, into microcapsules in<br />order to protect them from surrounding medium, improve<br />their activity and enlarge application.<br />Marigold extracts were obtained by means of carbon<br />dioxide- CO2 under subcritical and supercritical conditions.<br />Extraction conditions under which obtained extract has high<br />content of essential oil, responsible for gastrointestinal<br />activity, were determined (200bar and 40<sup>o</sup>C). Total extract<br />obtained under such conditions, was chosen for microcapsule<br />preparation. Application possibility of polymer&ndash;surfactant<br />interaction between non-ionic cellulose derivativehydroxypropylmethyl<br />cellulose (HPMC) and anionic<br />surfactant- sodium dodecylsulfate (SDS) to microcapsule<br />wall formation was investigated. Characteristic<br />concentrations at which interaction starts and ends were<br />determined by means of conductometric and viscometric<br />measurements. The influence of HPMC molecular<br />characteristics (molecular weight, degree of substitution and<br />substituents kind) and temperature on interaction were<br />determined and, considering the structure and characteristics<br />of HPMC/SDS complexes, binding mechanism was<br />explained. The changes in HPMC-SDS system caused by<br />their interaction were defined by rheological investigations<br />that took place under various conditions.<br />The influence of interaction on the properties of 20%<br />sunflower oil/water emulsion was investigated by rheology<br />measurement, particle size and particle size distribution<br />determination and stability testing. It was provided that<br />emulsions prepared in the region of pronounced HPMC&ndash;SDS<br />interaction, where HPMC/SDS complex is adsorbed at the</p><p>o/w interface, have highest stability and smallest particle<br />mean diameter.<br />Microcapsules were obtained by spray drying of<br />emulsions stabilized with HPMC/SDS complex. The best<br />characteristics (mechanical resistance, morphological<br />characteristics, redispersing ability, particle size and particle<br />size distribution and amount of encapsulated oil) have<br />microcapsules obtained in the region of most pronounced<br />interaction.<br />Addition of marigold CO<sub>2</sub> extract in to the oil phase of<br />emulsions has no significant influence neither on their, nor on<br />corresponding microcapsules characteristics<br />Investigations conducted in this thesis showed that<br />characteristics of polymer/surfactant complexes can be used<br />in microencapsulation of oil as carrier of pharmacologically<br />active compounds</p>

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